Merge branch 'master' into make_unix_sockets_great_again

37 files changed, 6880 insertions, 0 deletions

diff --git a/src/core/lib/surface/alarm.c b/src/core/lib/surface/alarm.c
new file mode 100644
index 0000000000..368683378e
--- /dev/null
+++ b/src/core/lib/surface/alarm.c
@@ -0,0 +1,84 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <grpc/grpc.h>
+#include <grpc/support/alloc.h>
+#include "src/core/lib/iomgr/timer.h"
+#include "src/core/lib/surface/completion_queue.h"
+
+struct grpc_alarm {
+  grpc_timer alarm;
+  grpc_cq_completion completion;
+  /** completion queue where events about this alarm will be posted */
+  grpc_completion_queue *cq;
+  /** user supplied tag */
+  void *tag;
+};
+
+static void do_nothing_end_completion(grpc_exec_ctx *exec_ctx, void *arg,
+                                      grpc_cq_completion *c) {}
+
+static void alarm_cb(grpc_exec_ctx *exec_ctx, void *arg, bool success) {
+  grpc_alarm *alarm = arg;
+  grpc_cq_end_op(exec_ctx, alarm->cq, alarm->tag, success,
+                 do_nothing_end_completion, NULL, &alarm->completion);
+}
+
+grpc_alarm *grpc_alarm_create(grpc_completion_queue *cq, gpr_timespec deadline,
+                              void *tag) {
+  grpc_alarm *alarm = gpr_malloc(sizeof(grpc_alarm));
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+
+  GRPC_CQ_INTERNAL_REF(cq, "alarm");
+  alarm->cq = cq;
+  alarm->tag = tag;
+
+  grpc_cq_begin_op(cq, tag);
+  grpc_timer_init(&exec_ctx, &alarm->alarm,
+                  gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC),
+                  alarm_cb, alarm, gpr_now(GPR_CLOCK_MONOTONIC));
+  grpc_exec_ctx_finish(&exec_ctx);
+  return alarm;
+}
+
+void grpc_alarm_cancel(grpc_alarm *alarm) {
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  grpc_timer_cancel(&exec_ctx, &alarm->alarm);
+  grpc_exec_ctx_finish(&exec_ctx);
+}
+
+void grpc_alarm_destroy(grpc_alarm *alarm) {
+  grpc_alarm_cancel(alarm);
+  GRPC_CQ_INTERNAL_UNREF(alarm->cq, "alarm");
+  gpr_free(alarm);
+}
diff --git a/src/core/lib/surface/api_trace.c b/src/core/lib/surface/api_trace.c
new file mode 100644
index 0000000000..3702c024db
--- /dev/null
+++ b/src/core/lib/surface/api_trace.c
@@ -0,0 +1,36 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/surface/api_trace.h"
+
+int grpc_api_trace = 0;
diff --git a/src/core/lib/surface/api_trace.h b/src/core/lib/surface/api_trace.h
new file mode 100644
index 0000000000..b50011c9e5
--- /dev/null
+++ b/src/core/lib/surface/api_trace.h
@@ -0,0 +1,65 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_SURFACE_API_TRACE_H
+#define GRPC_CORE_LIB_SURFACE_API_TRACE_H
+
+#include <grpc/support/log.h>
+#include "src/core/lib/debug/trace.h"
+
+extern int grpc_api_trace;
+
+/* Provide unwrapping macros because we're in C89 and variadic macros weren't
+   introduced until C99... */
+#define GRPC_API_TRACE_UNWRAP0()
+#define GRPC_API_TRACE_UNWRAP1(a) , a
+#define GRPC_API_TRACE_UNWRAP2(a, b) , a, b
+#define GRPC_API_TRACE_UNWRAP3(a, b, c) , a, b, c
+#define GRPC_API_TRACE_UNWRAP4(a, b, c, d) , a, b, c, d
+#define GRPC_API_TRACE_UNWRAP5(a, b, c, d, e) , a, b, c, d, e
+#define GRPC_API_TRACE_UNWRAP6(a, b, c, d, e, f) , a, b, c, d, e, f
+#define GRPC_API_TRACE_UNWRAP7(a, b, c, d, e, f, g) , a, b, c, d, e, f, g
+#define GRPC_API_TRACE_UNWRAP8(a, b, c, d, e, f, g, h) , a, b, c, d, e, f, g, h
+#define GRPC_API_TRACE_UNWRAP9(a, b, c, d, e, f, g, h, i) \
+  , a, b, c, d, e, f, g, h, i
+#define GRPC_API_TRACE_UNWRAP10(a, b, c, d, e, f, g, h, i, j) \
+  , a, b, c, d, e, f, g, h, i, j
+
+/* Due to the limitations of C89's preprocessor, the arity of the var-arg list
+   'nargs' must be specified. */
+#define GRPC_API_TRACE(fmt, nargs, args)                      \
+  if (grpc_api_trace) {                                       \
+    gpr_log(GPR_INFO, fmt GRPC_API_TRACE_UNWRAP##nargs args); \
+  }
+
+#endif /* GRPC_CORE_LIB_SURFACE_API_TRACE_H */
diff --git a/src/core/lib/surface/byte_buffer.c b/src/core/lib/surface/byte_buffer.c
new file mode 100644
index 0000000000..03071ef92c
--- /dev/null
+++ b/src/core/lib/surface/byte_buffer.c
@@ -0,0 +1,97 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <grpc/byte_buffer.h>
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+
+grpc_byte_buffer *grpc_raw_byte_buffer_create(gpr_slice *slices,
+                                              size_t nslices) {
+  return grpc_raw_compressed_byte_buffer_create(slices, nslices,
+                                                GRPC_COMPRESS_NONE);
+}
+
+grpc_byte_buffer *grpc_raw_compressed_byte_buffer_create(
+    gpr_slice *slices, size_t nslices, grpc_compression_algorithm compression) {
+  size_t i;
+  grpc_byte_buffer *bb = malloc(sizeof(grpc_byte_buffer));
+  bb->type = GRPC_BB_RAW;
+  bb->data.raw.compression = compression;
+  gpr_slice_buffer_init(&bb->data.raw.slice_buffer);
+  for (i = 0; i < nslices; i++) {
+    gpr_slice_ref(slices[i]);
+    gpr_slice_buffer_add(&bb->data.raw.slice_buffer, slices[i]);
+  }
+  return bb;
+}
+
+grpc_byte_buffer *grpc_raw_byte_buffer_from_reader(
+    grpc_byte_buffer_reader *reader) {
+  grpc_byte_buffer *bb = malloc(sizeof(grpc_byte_buffer));
+  gpr_slice slice;
+  bb->type = GRPC_BB_RAW;
+  bb->data.raw.compression = GRPC_COMPRESS_NONE;
+  gpr_slice_buffer_init(&bb->data.raw.slice_buffer);
+
+  while (grpc_byte_buffer_reader_next(reader, &slice)) {
+    gpr_slice_buffer_add(&bb->data.raw.slice_buffer, slice);
+  }
+  return bb;
+}
+
+grpc_byte_buffer *grpc_byte_buffer_copy(grpc_byte_buffer *bb) {
+  switch (bb->type) {
+    case GRPC_BB_RAW:
+      return grpc_raw_byte_buffer_create(bb->data.raw.slice_buffer.slices,
+                                         bb->data.raw.slice_buffer.count);
+  }
+  GPR_UNREACHABLE_CODE(return NULL);
+}
+
+void grpc_byte_buffer_destroy(grpc_byte_buffer *bb) {
+  if (!bb) return;
+  switch (bb->type) {
+    case GRPC_BB_RAW:
+      gpr_slice_buffer_destroy(&bb->data.raw.slice_buffer);
+      break;
+  }
+  free(bb);
+}
+
+size_t grpc_byte_buffer_length(grpc_byte_buffer *bb) {
+  switch (bb->type) {
+    case GRPC_BB_RAW:
+      return bb->data.raw.slice_buffer.length;
+  }
+  GPR_UNREACHABLE_CODE(return 0);
+}
diff --git a/src/core/lib/surface/byte_buffer_reader.c b/src/core/lib/surface/byte_buffer_reader.c
new file mode 100644
index 0000000000..7248f5fe71
--- /dev/null
+++ b/src/core/lib/surface/byte_buffer_reader.c
@@ -0,0 +1,123 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <grpc/byte_buffer_reader.h>
+#include <string.h>
+
+#include <grpc/byte_buffer.h>
+#include <grpc/compression.h>
+#include <grpc/grpc.h>
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/slice_buffer.h>
+
+#include "src/core/lib/compression/message_compress.h"
+
+static int is_compressed(grpc_byte_buffer *buffer) {
+  switch (buffer->type) {
+    case GRPC_BB_RAW:
+      if (buffer->data.raw.compression == GRPC_COMPRESS_NONE) {
+        return 0 /* GPR_FALSE */;
+      }
+      break;
+  }
+  return 1 /* GPR_TRUE */;
+}
+
+void grpc_byte_buffer_reader_init(grpc_byte_buffer_reader *reader,
+                                  grpc_byte_buffer *buffer) {
+  gpr_slice_buffer decompressed_slices_buffer;
+  reader->buffer_in = buffer;
+  switch (reader->buffer_in->type) {
+    case GRPC_BB_RAW:
+      gpr_slice_buffer_init(&decompressed_slices_buffer);
+      if (is_compressed(reader->buffer_in)) {
+        grpc_msg_decompress(reader->buffer_in->data.raw.compression,
+                            &reader->buffer_in->data.raw.slice_buffer,
+                            &decompressed_slices_buffer);
+        reader->buffer_out =
+            grpc_raw_byte_buffer_create(decompressed_slices_buffer.slices,
+                                        decompressed_slices_buffer.count);
+        gpr_slice_buffer_destroy(&decompressed_slices_buffer);
+      } else { /* not compressed, use the input buffer as output */
+        reader->buffer_out = reader->buffer_in;
+      }
+      reader->current.index = 0;
+      break;
+  }
+}
+
+void grpc_byte_buffer_reader_destroy(grpc_byte_buffer_reader *reader) {
+  switch (reader->buffer_in->type) {
+    case GRPC_BB_RAW:
+      /* keeping the same if-else structure as in the init function */
+      if (is_compressed(reader->buffer_in)) {
+        grpc_byte_buffer_destroy(reader->buffer_out);
+      }
+      break;
+  }
+}
+
+int grpc_byte_buffer_reader_next(grpc_byte_buffer_reader *reader,
+                                 gpr_slice *slice) {
+  switch (reader->buffer_in->type) {
+    case GRPC_BB_RAW: {
+      gpr_slice_buffer *slice_buffer;
+      slice_buffer = &reader->buffer_out->data.raw.slice_buffer;
+      if (reader->current.index < slice_buffer->count) {
+        *slice = gpr_slice_ref(slice_buffer->slices[reader->current.index]);
+        reader->current.index += 1;
+        return 1;
+      }
+      break;
+    }
+  }
+  return 0;
+}
+
+gpr_slice grpc_byte_buffer_reader_readall(grpc_byte_buffer_reader *reader) {
+  gpr_slice in_slice;
+  size_t bytes_read = 0;
+  const size_t input_size = grpc_byte_buffer_length(reader->buffer_out);
+  gpr_slice out_slice = gpr_slice_malloc(input_size);
+  uint8_t *const outbuf = GPR_SLICE_START_PTR(out_slice); /* just an alias */
+
+  while (grpc_byte_buffer_reader_next(reader, &in_slice) != 0) {
+    const size_t slice_length = GPR_SLICE_LENGTH(in_slice);
+    memcpy(&(outbuf[bytes_read]), GPR_SLICE_START_PTR(in_slice), slice_length);
+    bytes_read += slice_length;
+    gpr_slice_unref(in_slice);
+    GPR_ASSERT(bytes_read <= input_size);
+  }
+  return out_slice;
+}
diff --git a/src/core/lib/surface/call.c b/src/core/lib/surface/call.c
new file mode 100644
index 0000000000..d63a4a7401
--- /dev/null
+++ b/src/core/lib/surface/call.c
@@ -0,0 +1,1491 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+#include <assert.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <grpc/compression.h>
+#include <grpc/grpc.h>
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+#include <grpc/support/useful.h>
+
+#include "src/core/lib/channel/channel_stack.h"
+#include "src/core/lib/compression/algorithm_metadata.h"
+#include "src/core/lib/iomgr/timer.h"
+#include "src/core/lib/profiling/timers.h"
+#include "src/core/lib/support/string.h"
+#include "src/core/lib/surface/api_trace.h"
+#include "src/core/lib/surface/call.h"
+#include "src/core/lib/surface/channel.h"
+#include "src/core/lib/surface/completion_queue.h"
+#include "src/core/lib/transport/static_metadata.h"
+
+/** The maximum number of concurrent batches possible.
+    Based upon the maximum number of individually queueable ops in the batch
+   api:
+      - initial metadata send
+      - message send
+      - status/close send (depending on client/server)
+      - initial metadata recv
+      - message recv
+      - status/close recv (depending on client/server) */
+#define MAX_CONCURRENT_BATCHES 6
+
+typedef struct {
+  grpc_ioreq_completion_func on_complete;
+  void *user_data;
+  int success;
+} completed_request;
+
+#define MAX_SEND_EXTRA_METADATA_COUNT 3
+
+/* Status data for a request can come from several sources; this
+   enumerates them all, and acts as a priority sorting for which
+   status to return to the application - earlier entries override
+   later ones */
+typedef enum {
+  /* Status came from the application layer overriding whatever
+     the wire says */
+  STATUS_FROM_API_OVERRIDE = 0,
+  /* Status was created by some internal channel stack operation */
+  STATUS_FROM_CORE,
+  /* Status came from 'the wire' - or somewhere below the surface
+     layer */
+  STATUS_FROM_WIRE,
+  /* Status came from the server sending status */
+  STATUS_FROM_SERVER_STATUS,
+  STATUS_SOURCE_COUNT
+} status_source;
+
+typedef struct {
+  uint8_t is_set;
+  grpc_status_code code;
+  grpc_mdstr *details;
+} received_status;
+
+/* How far through the GRPC stream have we read? */
+typedef enum {
+  /* We are still waiting for initial metadata to complete */
+  READ_STATE_INITIAL = 0,
+  /* We have gotten initial metadata, and are reading either
+     messages or trailing metadata */
+  READ_STATE_GOT_INITIAL_METADATA,
+  /* The stream is closed for reading */
+  READ_STATE_READ_CLOSED,
+  /* The stream is closed for reading & writing */
+  READ_STATE_STREAM_CLOSED
+} read_state;
+
+typedef enum {
+  WRITE_STATE_INITIAL = 0,
+  WRITE_STATE_STARTED,
+  WRITE_STATE_WRITE_CLOSED
+} write_state;
+
+typedef struct batch_control {
+  grpc_call *call;
+  grpc_cq_completion cq_completion;
+  grpc_closure finish_batch;
+  void *notify_tag;
+  gpr_refcount steps_to_complete;
+
+  uint8_t send_initial_metadata;
+  uint8_t send_message;
+  uint8_t send_final_op;
+  uint8_t recv_initial_metadata;
+  uint8_t recv_message;
+  uint8_t recv_final_op;
+  uint8_t is_notify_tag_closure;
+  uint8_t success;
+} batch_control;
+
+struct grpc_call {
+  grpc_completion_queue *cq;
+  grpc_channel *channel;
+  grpc_call *parent;
+  grpc_call *first_child;
+  /* TODO(ctiller): share with cq if possible? */
+  gpr_mu mu;
+
+  /* client or server call */
+  uint8_t is_client;
+  /* is the alarm set */
+  uint8_t have_alarm;
+  /** has grpc_call_destroy been called */
+  uint8_t destroy_called;
+  /** flag indicating that cancellation is inherited */
+  uint8_t cancellation_is_inherited;
+  /** bitmask of live batches */
+  uint8_t used_batches;
+  /** which ops are in-flight */
+  uint8_t sent_initial_metadata;
+  uint8_t sending_message;
+  uint8_t sent_final_op;
+  uint8_t received_initial_metadata;
+  uint8_t receiving_message;
+  uint8_t received_final_op;
+
+  /* have we received initial metadata */
+  bool has_initial_md_been_received;
+
+  batch_control active_batches[MAX_CONCURRENT_BATCHES];
+
+  /* first idx: is_receiving, second idx: is_trailing */
+  grpc_metadata_batch metadata_batch[2][2];
+
+  /* Buffered read metadata waiting to be returned to the application.
+     Element 0 is initial metadata, element 1 is trailing metadata. */
+  grpc_metadata_array *buffered_metadata[2];
+
+  /* Received call statuses from various sources */
+  received_status status[STATUS_SOURCE_COUNT];
+
+  /* Compression algorithm for the call */
+  grpc_compression_algorithm compression_algorithm;
+  /* Supported encodings (compression algorithms), a bitset */
+  uint32_t encodings_accepted_by_peer;
+
+  /* Contexts for various subsystems (security, tracing, ...). */
+  grpc_call_context_element context[GRPC_CONTEXT_COUNT];
+
+  /* Deadline alarm - if have_alarm is non-zero */
+  grpc_timer alarm;
+
+  /* for the client, extra metadata is initial metadata; for the
+     server, it's trailing metadata */
+  grpc_linked_mdelem send_extra_metadata[MAX_SEND_EXTRA_METADATA_COUNT];
+  int send_extra_metadata_count;
+  gpr_timespec send_deadline;
+
+  /** siblings: children of the same parent form a list, and this list is
+     protected under
+      parent->mu */
+  grpc_call *sibling_next;
+  grpc_call *sibling_prev;
+
+  grpc_slice_buffer_stream sending_stream;
+  grpc_byte_stream *receiving_stream;
+  grpc_byte_buffer **receiving_buffer;
+  gpr_slice receiving_slice;
+  grpc_closure receiving_slice_ready;
+  grpc_closure receiving_stream_ready;
+  grpc_closure receiving_initial_metadata_ready;
+  uint32_t test_only_last_message_flags;
+
+  union {
+    struct {
+      grpc_status_code *status;
+      char **status_details;
+      size_t *status_details_capacity;
+    } client;
+    struct {
+      int *cancelled;
+    } server;
+  } final_op;
+
+  struct {
+    void *bctlp;
+    bool success;
+  } saved_receiving_stream_ready_ctx;
+};
+
+#define CALL_STACK_FROM_CALL(call) ((grpc_call_stack *)((call) + 1))
+#define CALL_FROM_CALL_STACK(call_stack) (((grpc_call *)(call_stack)) - 1)
+#define CALL_ELEM_FROM_CALL(call, idx) \
+  grpc_call_stack_element(CALL_STACK_FROM_CALL(call), idx)
+#define CALL_FROM_TOP_ELEM(top_elem) \
+  CALL_FROM_CALL_STACK(grpc_call_stack_from_top_element(top_elem))
+
+static void set_deadline_alarm(grpc_exec_ctx *exec_ctx, grpc_call *call,
+                               gpr_timespec deadline);
+static void execute_op(grpc_exec_ctx *exec_ctx, grpc_call *call,
+                       grpc_transport_stream_op *op);
+static grpc_call_error cancel_with_status(grpc_exec_ctx *exec_ctx, grpc_call *c,
+                                          grpc_status_code status,
+                                          const char *description);
+static void destroy_call(grpc_exec_ctx *exec_ctx, void *call_stack,
+                         bool success);
+static void receiving_slice_ready(grpc_exec_ctx *exec_ctx, void *bctlp,
+                                  bool success);
+
+grpc_call *grpc_call_create(grpc_channel *channel, grpc_call *parent_call,
+                            uint32_t propagation_mask,
+                            grpc_completion_queue *cq,
+                            const void *server_transport_data,
+                            grpc_mdelem **add_initial_metadata,
+                            size_t add_initial_metadata_count,
+                            gpr_timespec send_deadline) {
+  size_t i, j;
+  grpc_channel_stack *channel_stack = grpc_channel_get_channel_stack(channel);
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  grpc_call *call;
+  GPR_TIMER_BEGIN("grpc_call_create", 0);
+  call = gpr_malloc(sizeof(grpc_call) + channel_stack->call_stack_size);
+  memset(call, 0, sizeof(grpc_call));
+  gpr_mu_init(&call->mu);
+  call->channel = channel;
+  call->cq = cq;
+  call->parent = parent_call;
+  call->is_client = server_transport_data == NULL;
+  if (call->is_client) {
+    GPR_ASSERT(add_initial_metadata_count < MAX_SEND_EXTRA_METADATA_COUNT);
+    for (i = 0; i < add_initial_metadata_count; i++) {
+      call->send_extra_metadata[i].md = add_initial_metadata[i];
+    }
+    call->send_extra_metadata_count = (int)add_initial_metadata_count;
+  } else {
+    GPR_ASSERT(add_initial_metadata_count == 0);
+    call->send_extra_metadata_count = 0;
+  }
+  for (i = 0; i < 2; i++) {
+    for (j = 0; j < 2; j++) {
+      call->metadata_batch[i][j].deadline = gpr_inf_future(GPR_CLOCK_MONOTONIC);
+    }
+  }
+  call->send_deadline = send_deadline;
+  GRPC_CHANNEL_INTERNAL_REF(channel, "call");
+  /* initial refcount dropped by grpc_call_destroy */
+  grpc_call_stack_init(&exec_ctx, channel_stack, 1, destroy_call, call,
+                       call->context, server_transport_data,
+                       CALL_STACK_FROM_CALL(call));
+  if (cq != NULL) {
+    GRPC_CQ_INTERNAL_REF(cq, "bind");
+    grpc_call_stack_set_pollset(&exec_ctx, CALL_STACK_FROM_CALL(call),
+                                grpc_cq_pollset(cq));
+  }
+  if (parent_call != NULL) {
+    GRPC_CALL_INTERNAL_REF(parent_call, "child");
+    GPR_ASSERT(call->is_client);
+    GPR_ASSERT(!parent_call->is_client);
+
+    gpr_mu_lock(&parent_call->mu);
+
+    if (propagation_mask & GRPC_PROPAGATE_DEADLINE) {
+      send_deadline = gpr_time_min(
+          gpr_convert_clock_type(send_deadline,
+                                 parent_call->send_deadline.clock_type),
+          parent_call->send_deadline);
+    }
+    /* for now GRPC_PROPAGATE_TRACING_CONTEXT *MUST* be passed with
+     * GRPC_PROPAGATE_STATS_CONTEXT */
+    /* TODO(ctiller): This should change to use the appropriate census start_op
+     * call. */
+    if (propagation_mask & GRPC_PROPAGATE_CENSUS_TRACING_CONTEXT) {
+      GPR_ASSERT(propagation_mask & GRPC_PROPAGATE_CENSUS_STATS_CONTEXT);
+      grpc_call_context_set(call, GRPC_CONTEXT_TRACING,
+                            parent_call->context[GRPC_CONTEXT_TRACING].value,
+                            NULL);
+    } else {
+      GPR_ASSERT(propagation_mask & GRPC_PROPAGATE_CENSUS_STATS_CONTEXT);
+    }
+    if (propagation_mask & GRPC_PROPAGATE_CANCELLATION) {
+      call->cancellation_is_inherited = 1;
+    }
+
+    if (parent_call->first_child == NULL) {
+      parent_call->first_child = call;
+      call->sibling_next = call->sibling_prev = call;
+    } else {
+      call->sibling_next = parent_call->first_child;
+      call->sibling_prev = parent_call->first_child->sibling_prev;
+      call->sibling_next->sibling_prev = call->sibling_prev->sibling_next =
+          call;
+    }
+
+    gpr_mu_unlock(&parent_call->mu);
+  }
+  if (gpr_time_cmp(send_deadline, gpr_inf_future(send_deadline.clock_type)) !=
+      0) {
+    set_deadline_alarm(&exec_ctx, call, send_deadline);
+  }
+  grpc_exec_ctx_finish(&exec_ctx);
+  GPR_TIMER_END("grpc_call_create", 0);
+  return call;
+}
+
+void grpc_call_set_completion_queue(grpc_exec_ctx *exec_ctx, grpc_call *call,
+                                    grpc_completion_queue *cq) {
+  GPR_ASSERT(cq);
+  call->cq = cq;
+  GRPC_CQ_INTERNAL_REF(cq, "bind");
+  grpc_call_stack_set_pollset(exec_ctx, CALL_STACK_FROM_CALL(call),
+                              grpc_cq_pollset(cq));
+}
+
+#ifdef GRPC_STREAM_REFCOUNT_DEBUG
+#define REF_REASON reason
+#define REF_ARG , const char *reason
+#else
+#define REF_REASON ""
+#define REF_ARG
+#endif
+void grpc_call_internal_ref(grpc_call *c REF_ARG) {
+  GRPC_CALL_STACK_REF(CALL_STACK_FROM_CALL(c), REF_REASON);
+}
+void grpc_call_internal_unref(grpc_exec_ctx *exec_ctx, grpc_call *c REF_ARG) {
+  GRPC_CALL_STACK_UNREF(exec_ctx, CALL_STACK_FROM_CALL(c), REF_REASON);
+}
+
+static void destroy_call(grpc_exec_ctx *exec_ctx, void *call, bool success) {
+  size_t i;
+  int ii;
+  grpc_call *c = call;
+  GPR_TIMER_BEGIN("destroy_call", 0);
+  for (i = 0; i < 2; i++) {
+    grpc_metadata_batch_destroy(
+        &c->metadata_batch[1 /* is_receiving */][i /* is_initial */]);
+  }
+  if (c->receiving_stream != NULL) {
+    grpc_byte_stream_destroy(exec_ctx, c->receiving_stream);
+  }
+  grpc_call_stack_destroy(exec_ctx, CALL_STACK_FROM_CALL(c));
+  GRPC_CHANNEL_INTERNAL_UNREF(exec_ctx, c->channel, "call");
+  gpr_mu_destroy(&c->mu);
+  for (i = 0; i < STATUS_SOURCE_COUNT; i++) {
+    if (c->status[i].details) {
+      GRPC_MDSTR_UNREF(c->status[i].details);
+    }
+  }
+  for (ii = 0; ii < c->send_extra_metadata_count; ii++) {
+    GRPC_MDELEM_UNREF(c->send_extra_metadata[ii].md);
+  }
+  for (i = 0; i < GRPC_CONTEXT_COUNT; i++) {
+    if (c->context[i].destroy) {
+      c->context[i].destroy(c->context[i].value);
+    }
+  }
+  if (c->cq) {
+    GRPC_CQ_INTERNAL_UNREF(c->cq, "bind");
+  }
+  gpr_free(c);
+  GPR_TIMER_END("destroy_call", 0);
+}
+
+static void set_status_code(grpc_call *call, status_source source,
+                            uint32_t status) {
+  if (call->status[source].is_set) return;
+
+  call->status[source].is_set = 1;
+  call->status[source].code = (grpc_status_code)status;
+
+  /* TODO(ctiller): what to do about the flush that was previously here */
+}
+
+static void set_compression_algorithm(grpc_call *call,
+                                      grpc_compression_algorithm algo) {
+  call->compression_algorithm = algo;
+}
+
+grpc_compression_algorithm grpc_call_test_only_get_compression_algorithm(
+    grpc_call *call) {
+  grpc_compression_algorithm algorithm;
+  gpr_mu_lock(&call->mu);
+  algorithm = call->compression_algorithm;
+  gpr_mu_unlock(&call->mu);
+  return algorithm;
+}
+
+uint32_t grpc_call_test_only_get_message_flags(grpc_call *call) {
+  uint32_t flags;
+  gpr_mu_lock(&call->mu);
+  flags = call->test_only_last_message_flags;
+  gpr_mu_unlock(&call->mu);
+  return flags;
+}
+
+static void destroy_encodings_accepted_by_peer(void *p) { return; }
+
+static void set_encodings_accepted_by_peer(grpc_call *call, grpc_mdelem *mdel) {
+  size_t i;
+  grpc_compression_algorithm algorithm;
+  gpr_slice_buffer accept_encoding_parts;
+  gpr_slice accept_encoding_slice;
+  void *accepted_user_data;
+
+  accepted_user_data =
+      grpc_mdelem_get_user_data(mdel, destroy_encodings_accepted_by_peer);
+  if (accepted_user_data != NULL) {
+    call->encodings_accepted_by_peer =
+        (uint32_t)(((uintptr_t)accepted_user_data) - 1);
+    return;
+  }
+
+  accept_encoding_slice = mdel->value->slice;
+  gpr_slice_buffer_init(&accept_encoding_parts);
+  gpr_slice_split(accept_encoding_slice, ",", &accept_encoding_parts);
+
+  /* No need to zero call->encodings_accepted_by_peer: grpc_call_create already
+   * zeroes the whole grpc_call */
+  /* Always support no compression */
+  GPR_BITSET(&call->encodings_accepted_by_peer, GRPC_COMPRESS_NONE);
+  for (i = 0; i < accept_encoding_parts.count; i++) {
+    const gpr_slice *accept_encoding_entry_slice =
+        &accept_encoding_parts.slices[i];
+    if (grpc_compression_algorithm_parse(
+            (const char *)GPR_SLICE_START_PTR(*accept_encoding_entry_slice),
+            GPR_SLICE_LENGTH(*accept_encoding_entry_slice), &algorithm)) {
+      GPR_BITSET(&call->encodings_accepted_by_peer, algorithm);
+    } else {
+      char *accept_encoding_entry_str =
+          gpr_dump_slice(*accept_encoding_entry_slice, GPR_DUMP_ASCII);
+      gpr_log(GPR_ERROR,
+              "Invalid entry in accept encoding metadata: '%s'. Ignoring.",
+              accept_encoding_entry_str);
+      gpr_free(accept_encoding_entry_str);
+    }
+  }
+
+  gpr_slice_buffer_destroy(&accept_encoding_parts);
+
+  grpc_mdelem_set_user_data(
+      mdel, destroy_encodings_accepted_by_peer,
+      (void *)(((uintptr_t)call->encodings_accepted_by_peer) + 1));
+}
+
+uint32_t grpc_call_test_only_get_encodings_accepted_by_peer(grpc_call *call) {
+  uint32_t encodings_accepted_by_peer;
+  gpr_mu_lock(&call->mu);
+  encodings_accepted_by_peer = call->encodings_accepted_by_peer;
+  gpr_mu_unlock(&call->mu);
+  return encodings_accepted_by_peer;
+}
+
+static void set_status_details(grpc_call *call, status_source source,
+                               grpc_mdstr *status) {
+  if (call->status[source].details != NULL) {
+    GRPC_MDSTR_UNREF(call->status[source].details);
+  }
+  call->status[source].details = status;
+}
+
+static void get_final_status(grpc_call *call,
+                             void (*set_value)(grpc_status_code code,
+                                               void *user_data),
+                             void *set_value_user_data) {
+  int i;
+  for (i = 0; i < STATUS_SOURCE_COUNT; i++) {
+    if (call->status[i].is_set) {
+      set_value(call->status[i].code, set_value_user_data);
+      return;
+    }
+  }
+  if (call->is_client) {
+    set_value(GRPC_STATUS_UNKNOWN, set_value_user_data);
+  } else {
+    set_value(GRPC_STATUS_OK, set_value_user_data);
+  }
+}
+
+static void get_final_details(grpc_call *call, char **out_details,
+                              size_t *out_details_capacity) {
+  int i;
+  for (i = 0; i < STATUS_SOURCE_COUNT; i++) {
+    if (call->status[i].is_set) {
+      if (call->status[i].details) {
+        gpr_slice details = call->status[i].details->slice;
+        size_t len = GPR_SLICE_LENGTH(details);
+        if (len + 1 > *out_details_capacity) {
+          *out_details_capacity =
+              GPR_MAX(len + 1, *out_details_capacity * 3 / 2);
+          *out_details = gpr_realloc(*out_details, *out_details_capacity);
+        }
+        memcpy(*out_details, GPR_SLICE_START_PTR(details), len);
+        (*out_details)[len] = 0;
+      } else {
+        goto no_details;
+      }
+      return;
+    }
+  }
+
+no_details:
+  if (0 == *out_details_capacity) {
+    *out_details_capacity = 8;
+    *out_details = gpr_malloc(*out_details_capacity);
+  }
+  **out_details = 0;
+}
+
+static grpc_linked_mdelem *linked_from_md(grpc_metadata *md) {
+  return (grpc_linked_mdelem *)&md->internal_data;
+}
+
+static int prepare_application_metadata(grpc_call *call, int count,
+                                        grpc_metadata *metadata,
+                                        int is_trailing,
+                                        int prepend_extra_metadata) {
+  int i;
+  grpc_metadata_batch *batch =
+      &call->metadata_batch[0 /* is_receiving */][is_trailing];
+  if (prepend_extra_metadata) {
+    if (call->send_extra_metadata_count == 0) {
+      prepend_extra_metadata = 0;
+    } else {
+      for (i = 0; i < call->send_extra_metadata_count; i++) {
+        GRPC_MDELEM_REF(call->send_extra_metadata[i].md);
+      }
+      for (i = 1; i < call->send_extra_metadata_count; i++) {
+        call->send_extra_metadata[i].prev = &call->send_extra_metadata[i - 1];
+      }
+      for (i = 0; i < call->send_extra_metadata_count - 1; i++) {
+        call->send_extra_metadata[i].next = &call->send_extra_metadata[i + 1];
+      }
+    }
+  }
+  for (i = 0; i < count; i++) {
+    grpc_metadata *md = &metadata[i];
+    grpc_linked_mdelem *l = (grpc_linked_mdelem *)&md->internal_data;
+    GPR_ASSERT(sizeof(grpc_linked_mdelem) == sizeof(md->internal_data));
+    l->md = grpc_mdelem_from_string_and_buffer(
+        md->key, (const uint8_t *)md->value, md->value_length);
+    if (!grpc_header_key_is_legal(grpc_mdstr_as_c_string(l->md->key),
+                                  GRPC_MDSTR_LENGTH(l->md->key))) {
+      gpr_log(GPR_ERROR, "attempt to send invalid metadata key: %s",
+              grpc_mdstr_as_c_string(l->md->key));
+      return 0;
+    } else if (!grpc_is_binary_header(grpc_mdstr_as_c_string(l->md->key),
+                                      GRPC_MDSTR_LENGTH(l->md->key)) &&
+               !grpc_header_nonbin_value_is_legal(
+                   grpc_mdstr_as_c_string(l->md->value),
+                   GRPC_MDSTR_LENGTH(l->md->value))) {
+      gpr_log(GPR_ERROR, "attempt to send invalid metadata value");
+      return 0;
+    }
+  }
+  for (i = 1; i < count; i++) {
+    linked_from_md(&metadata[i])->prev = linked_from_md(&metadata[i - 1]);
+  }
+  for (i = 0; i < count - 1; i++) {
+    linked_from_md(&metadata[i])->next = linked_from_md(&metadata[i + 1]);
+  }
+  switch (prepend_extra_metadata * 2 + (count != 0)) {
+    case 0:
+      /* no prepend, no metadata => nothing to do */
+      batch->list.head = batch->list.tail = NULL;
+      break;
+    case 1:
+      /* metadata, but no prepend */
+      batch->list.head = linked_from_md(&metadata[0]);
+      batch->list.tail = linked_from_md(&metadata[count - 1]);
+      batch->list.head->prev = NULL;
+      batch->list.tail->next = NULL;
+      break;
+    case 2:
+      /* prepend, but no md */
+      batch->list.head = &call->send_extra_metadata[0];
+      batch->list.tail =
+          &call->send_extra_metadata[call->send_extra_metadata_count - 1];
+      batch->list.head->prev = NULL;
+      batch->list.tail->next = NULL;
+      break;
+    case 3:
+      /* prepend AND md */
+      batch->list.head = &call->send_extra_metadata[0];
+      call->send_extra_metadata[call->send_extra_metadata_count - 1].next =
+          linked_from_md(&metadata[0]);
+      linked_from_md(&metadata[0])->prev =
+          &call->send_extra_metadata[call->send_extra_metadata_count - 1];
+      batch->list.tail = linked_from_md(&metadata[count - 1]);
+      batch->list.head->prev = NULL;
+      batch->list.tail->next = NULL;
+      break;
+    default:
+      GPR_UNREACHABLE_CODE(return 0);
+  }
+
+  return 1;
+}
+
+void grpc_call_destroy(grpc_call *c) {
+  int cancel;
+  grpc_call *parent = c->parent;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+
+  GPR_TIMER_BEGIN("grpc_call_destroy", 0);
+  GRPC_API_TRACE("grpc_call_destroy(c=%p)", 1, (c));
+
+  if (parent) {
+    gpr_mu_lock(&parent->mu);
+    if (c == parent->first_child) {
+      parent->first_child = c->sibling_next;
+      if (c == parent->first_child) {
+        parent->first_child = NULL;
+      }
+      c->sibling_prev->sibling_next = c->sibling_next;
+      c->sibling_next->sibling_prev = c->sibling_prev;
+    }
+    gpr_mu_unlock(&parent->mu);
+    GRPC_CALL_INTERNAL_UNREF(&exec_ctx, parent, "child");
+  }
+
+  gpr_mu_lock(&c->mu);
+  GPR_ASSERT(!c->destroy_called);
+  c->destroy_called = 1;
+  if (c->have_alarm) {
+    grpc_timer_cancel(&exec_ctx, &c->alarm);
+  }
+  cancel = !c->received_final_op;
+  gpr_mu_unlock(&c->mu);
+  if (cancel) grpc_call_cancel(c, NULL);
+  GRPC_CALL_INTERNAL_UNREF(&exec_ctx, c, "destroy");
+  grpc_exec_ctx_finish(&exec_ctx);
+  GPR_TIMER_END("grpc_call_destroy", 0);
+}
+
+grpc_call_error grpc_call_cancel(grpc_call *call, void *reserved) {
+  GRPC_API_TRACE("grpc_call_cancel(call=%p, reserved=%p)", 2, (call, reserved));
+  GPR_ASSERT(!reserved);
+  return grpc_call_cancel_with_status(call, GRPC_STATUS_CANCELLED, "Cancelled",
+                                      NULL);
+}
+
+grpc_call_error grpc_call_cancel_with_status(grpc_call *c,
+                                             grpc_status_code status,
+                                             const char *description,
+                                             void *reserved) {
+  grpc_call_error r;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  GRPC_API_TRACE(
+      "grpc_call_cancel_with_status("
+      "c=%p, status=%d, description=%s, reserved=%p)",
+      4, (c, (int)status, description, reserved));
+  GPR_ASSERT(reserved == NULL);
+  gpr_mu_lock(&c->mu);
+  r = cancel_with_status(&exec_ctx, c, status, description);
+  gpr_mu_unlock(&c->mu);
+  grpc_exec_ctx_finish(&exec_ctx);
+  return r;
+}
+
+typedef struct cancel_closure {
+  grpc_closure closure;
+  grpc_call *call;
+  grpc_status_code status;
+} cancel_closure;
+
+static void done_cancel(grpc_exec_ctx *exec_ctx, void *ccp, bool success) {
+  cancel_closure *cc = ccp;
+  GRPC_CALL_INTERNAL_UNREF(exec_ctx, cc->call, "cancel");
+  gpr_free(cc);
+}
+
+static void send_cancel(grpc_exec_ctx *exec_ctx, void *ccp, bool success) {
+  grpc_transport_stream_op op;
+  cancel_closure *cc = ccp;
+  memset(&op, 0, sizeof(op));
+  op.cancel_with_status = cc->status;
+  /* reuse closure to catch completion */
+  grpc_closure_init(&cc->closure, done_cancel, cc);
+  op.on_complete = &cc->closure;
+  execute_op(exec_ctx, cc->call, &op);
+}
+
+static grpc_call_error cancel_with_status(grpc_exec_ctx *exec_ctx, grpc_call *c,
+                                          grpc_status_code status,
+                                          const char *description) {
+  grpc_mdstr *details =
+      description ? grpc_mdstr_from_string(description) : NULL;
+  cancel_closure *cc = gpr_malloc(sizeof(*cc));
+
+  GPR_ASSERT(status != GRPC_STATUS_OK);
+
+  set_status_code(c, STATUS_FROM_API_OVERRIDE, (uint32_t)status);
+  set_status_details(c, STATUS_FROM_API_OVERRIDE, details);
+
+  grpc_closure_init(&cc->closure, send_cancel, cc);
+  cc->call = c;
+  cc->status = status;
+  GRPC_CALL_INTERNAL_REF(c, "cancel");
+  grpc_exec_ctx_enqueue(exec_ctx, &cc->closure, true, NULL);
+
+  return GRPC_CALL_OK;
+}
+
+static void execute_op(grpc_exec_ctx *exec_ctx, grpc_call *call,
+                       grpc_transport_stream_op *op) {
+  grpc_call_element *elem;
+
+  GPR_TIMER_BEGIN("execute_op", 0);
+  elem = CALL_ELEM_FROM_CALL(call, 0);
+  op->context = call->context;
+  elem->filter->start_transport_stream_op(exec_ctx, elem, op);
+  GPR_TIMER_END("execute_op", 0);
+}
+
+char *grpc_call_get_peer(grpc_call *call) {
+  grpc_call_element *elem = CALL_ELEM_FROM_CALL(call, 0);
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  char *result;
+  GRPC_API_TRACE("grpc_call_get_peer(%p)", 1, (call));
+  result = elem->filter->get_peer(&exec_ctx, elem);
+  if (result == NULL) {
+    result = grpc_channel_get_target(call->channel);
+  }
+  if (result == NULL) {
+    result = gpr_strdup("unknown");
+  }
+  grpc_exec_ctx_finish(&exec_ctx);
+  return result;
+}
+
+grpc_call *grpc_call_from_top_element(grpc_call_element *elem) {
+  return CALL_FROM_TOP_ELEM(elem);
+}
+
+static void call_alarm(grpc_exec_ctx *exec_ctx, void *arg, bool success) {
+  grpc_call *call = arg;
+  gpr_mu_lock(&call->mu);
+  call->have_alarm = 0;
+  if (success) {
+    cancel_with_status(exec_ctx, call, GRPC_STATUS_DEADLINE_EXCEEDED,
+                       "Deadline Exceeded");
+  }
+  gpr_mu_unlock(&call->mu);
+  GRPC_CALL_INTERNAL_UNREF(exec_ctx, call, "alarm");
+}
+
+static void set_deadline_alarm(grpc_exec_ctx *exec_ctx, grpc_call *call,
+                               gpr_timespec deadline) {
+  if (call->have_alarm) {
+    gpr_log(GPR_ERROR, "Attempt to set deadline alarm twice");
+    assert(0);
+    return;
+  }
+  GRPC_CALL_INTERNAL_REF(call, "alarm");
+  call->have_alarm = 1;
+  call->send_deadline = gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC);
+  grpc_timer_init(exec_ctx, &call->alarm, call->send_deadline, call_alarm, call,
+                  gpr_now(GPR_CLOCK_MONOTONIC));
+}
+
+/* we offset status by a small amount when storing it into transport metadata
+   as metadata cannot store a 0 value (which is used as OK for grpc_status_codes
+   */
+#define STATUS_OFFSET 1
+static void destroy_status(void *ignored) {}
+
+static uint32_t decode_status(grpc_mdelem *md) {
+  uint32_t status;
+  void *user_data;
+  if (md == GRPC_MDELEM_GRPC_STATUS_0) return 0;
+  if (md == GRPC_MDELEM_GRPC_STATUS_1) return 1;
+  if (md == GRPC_MDELEM_GRPC_STATUS_2) return 2;
+  user_data = grpc_mdelem_get_user_data(md, destroy_status);
+  if (user_data != NULL) {
+    status = ((uint32_t)(intptr_t)user_data) - STATUS_OFFSET;
+  } else {
+    if (!gpr_parse_bytes_to_uint32(grpc_mdstr_as_c_string(md->value),
+                                   GPR_SLICE_LENGTH(md->value->slice),
+                                   &status)) {
+      status = GRPC_STATUS_UNKNOWN; /* could not parse status code */
+    }
+    grpc_mdelem_set_user_data(md, destroy_status,
+                              (void *)(intptr_t)(status + STATUS_OFFSET));
+  }
+  return status;
+}
+
+static uint32_t decode_compression(grpc_mdelem *md) {
+  grpc_compression_algorithm algorithm =
+      grpc_compression_algorithm_from_mdstr(md->value);
+  if (algorithm == GRPC_COMPRESS_ALGORITHMS_COUNT) {
+    const char *md_c_str = grpc_mdstr_as_c_string(md->value);
+    gpr_log(GPR_ERROR, "Invalid compression algorithm: '%s'", md_c_str);
+  }
+  return algorithm;
+}
+
+static grpc_mdelem *recv_common_filter(grpc_call *call, grpc_mdelem *elem) {
+  if (elem->key == GRPC_MDSTR_GRPC_STATUS) {
+    GPR_TIMER_BEGIN("status", 0);
+    set_status_code(call, STATUS_FROM_WIRE, decode_status(elem));
+    GPR_TIMER_END("status", 0);
+    return NULL;
+  } else if (elem->key == GRPC_MDSTR_GRPC_MESSAGE) {
+    GPR_TIMER_BEGIN("status-details", 0);
+    set_status_details(call, STATUS_FROM_WIRE, GRPC_MDSTR_REF(elem->value));
+    GPR_TIMER_END("status-details", 0);
+    return NULL;
+  }
+  return elem;
+}
+
+static grpc_mdelem *publish_app_metadata(grpc_call *call, grpc_mdelem *elem,
+                                         int is_trailing) {
+  grpc_metadata_array *dest;
+  grpc_metadata *mdusr;
+  GPR_TIMER_BEGIN("publish_app_metadata", 0);
+  dest = call->buffered_metadata[is_trailing];
+  if (dest->count == dest->capacity) {
+    dest->capacity = GPR_MAX(dest->capacity + 8, dest->capacity * 2);
+    dest->metadata =
+        gpr_realloc(dest->metadata, sizeof(grpc_metadata) * dest->capacity);
+  }
+  mdusr = &dest->metadata[dest->count++];
+  mdusr->key = grpc_mdstr_as_c_string(elem->key);
+  mdusr->value = grpc_mdstr_as_c_string(elem->value);
+  mdusr->value_length = GPR_SLICE_LENGTH(elem->value->slice);
+  GPR_TIMER_END("publish_app_metadata", 0);
+  return elem;
+}
+
+static grpc_mdelem *recv_initial_filter(void *callp, grpc_mdelem *elem) {
+  grpc_call *call = callp;
+  elem = recv_common_filter(call, elem);
+  if (elem == NULL) {
+    return NULL;
+  } else if (elem->key == GRPC_MDSTR_GRPC_ENCODING) {
+    GPR_TIMER_BEGIN("compression_algorithm", 0);
+    set_compression_algorithm(call, decode_compression(elem));
+    GPR_TIMER_END("compression_algorithm", 0);
+    return NULL;
+  } else if (elem->key == GRPC_MDSTR_GRPC_ACCEPT_ENCODING) {
+    GPR_TIMER_BEGIN("encodings_accepted_by_peer", 0);
+    set_encodings_accepted_by_peer(call, elem);
+    GPR_TIMER_END("encodings_accepted_by_peer", 0);
+    return NULL;
+  } else {
+    return publish_app_metadata(call, elem, 0);
+  }
+}
+
+static grpc_mdelem *recv_trailing_filter(void *callp, grpc_mdelem *elem) {
+  grpc_call *call = callp;
+  elem = recv_common_filter(call, elem);
+  if (elem == NULL) {
+    return NULL;
+  } else {
+    return publish_app_metadata(call, elem, 1);
+  }
+}
+
+grpc_call_stack *grpc_call_get_call_stack(grpc_call *call) {
+  return CALL_STACK_FROM_CALL(call);
+}
+
+/*
+ * BATCH API IMPLEMENTATION
+ */
+
+static void set_status_value_directly(grpc_status_code status, void *dest) {
+  *(grpc_status_code *)dest = status;
+}
+
+static void set_cancelled_value(grpc_status_code status, void *dest) {
+  *(int *)dest = (status != GRPC_STATUS_OK);
+}
+
+static int are_write_flags_valid(uint32_t flags) {
+  /* check that only bits in GRPC_WRITE_(INTERNAL?)_USED_MASK are set */
+  const uint32_t allowed_write_positions =
+      (GRPC_WRITE_USED_MASK | GRPC_WRITE_INTERNAL_USED_MASK);
+  const uint32_t invalid_positions = ~allowed_write_positions;
+  return !(flags & invalid_positions);
+}
+
+static batch_control *allocate_batch_control(grpc_call *call) {
+  size_t i;
+  for (i = 0; i < MAX_CONCURRENT_BATCHES; i++) {
+    if ((call->used_batches & (1 << i)) == 0) {
+      call->used_batches = (uint8_t)(call->used_batches | (uint8_t)(1 << i));
+      return &call->active_batches[i];
+    }
+  }
+  return NULL;
+}
+
+static void finish_batch_completion(grpc_exec_ctx *exec_ctx, void *user_data,
+                                    grpc_cq_completion *storage) {
+  batch_control *bctl = user_data;
+  grpc_call *call = bctl->call;
+  gpr_mu_lock(&call->mu);
+  call->used_batches = (uint8_t)(
+      call->used_batches & ~(uint8_t)(1 << (bctl - call->active_batches)));
+  gpr_mu_unlock(&call->mu);
+  GRPC_CALL_INTERNAL_UNREF(exec_ctx, call, "completion");
+}
+
+static void post_batch_completion(grpc_exec_ctx *exec_ctx,
+                                  batch_control *bctl) {
+  grpc_call *call = bctl->call;
+  if (bctl->is_notify_tag_closure) {
+    grpc_exec_ctx_enqueue(exec_ctx, bctl->notify_tag, bctl->success, NULL);
+    gpr_mu_lock(&call->mu);
+    bctl->call->used_batches =
+        (uint8_t)(bctl->call->used_batches &
+                  ~(uint8_t)(1 << (bctl - bctl->call->active_batches)));
+    gpr_mu_unlock(&call->mu);
+    GRPC_CALL_INTERNAL_UNREF(exec_ctx, call, "completion");
+  } else {
+    grpc_cq_end_op(exec_ctx, bctl->call->cq, bctl->notify_tag, bctl->success,
+                   finish_batch_completion, bctl, &bctl->cq_completion);
+  }
+}
+
+static void continue_receiving_slices(grpc_exec_ctx *exec_ctx,
+                                      batch_control *bctl) {
+  grpc_call *call = bctl->call;
+  for (;;) {
+    size_t remaining = call->receiving_stream->length -
+                       (*call->receiving_buffer)->data.raw.slice_buffer.length;
+    if (remaining == 0) {
+      call->receiving_message = 0;
+      grpc_byte_stream_destroy(exec_ctx, call->receiving_stream);
+      call->receiving_stream = NULL;
+      if (gpr_unref(&bctl->steps_to_complete)) {
+        post_batch_completion(exec_ctx, bctl);
+      }
+      return;
+    }
+    if (grpc_byte_stream_next(exec_ctx, call->receiving_stream,
+                              &call->receiving_slice, remaining,
+                              &call->receiving_slice_ready)) {
+      gpr_slice_buffer_add(&(*call->receiving_buffer)->data.raw.slice_buffer,
+                           call->receiving_slice);
+    } else {
+      return;
+    }
+  }
+}
+
+static void receiving_slice_ready(grpc_exec_ctx *exec_ctx, void *bctlp,
+                                  bool success) {
+  batch_control *bctl = bctlp;
+  grpc_call *call = bctl->call;
+
+  if (success) {
+    gpr_slice_buffer_add(&(*call->receiving_buffer)->data.raw.slice_buffer,
+                         call->receiving_slice);
+    continue_receiving_slices(exec_ctx, bctl);
+  } else {
+    grpc_byte_stream_destroy(exec_ctx, call->receiving_stream);
+    call->receiving_stream = NULL;
+    grpc_byte_buffer_destroy(*call->receiving_buffer);
+    *call->receiving_buffer = NULL;
+    if (gpr_unref(&bctl->steps_to_complete)) {
+      post_batch_completion(exec_ctx, bctl);
+    }
+  }
+}
+
+static void process_data_after_md(grpc_exec_ctx *exec_ctx, batch_control *bctl,
+                                  bool success) {
+  grpc_call *call = bctl->call;
+  if (call->receiving_stream == NULL) {
+    *call->receiving_buffer = NULL;
+    call->receiving_message = 0;
+    if (gpr_unref(&bctl->steps_to_complete)) {
+      post_batch_completion(exec_ctx, bctl);
+    }
+  } else if (call->receiving_stream->length >
+             grpc_channel_get_max_message_length(call->channel)) {
+    cancel_with_status(exec_ctx, call, GRPC_STATUS_INTERNAL,
+                       "Max message size exceeded");
+    grpc_byte_stream_destroy(exec_ctx, call->receiving_stream);
+    call->receiving_stream = NULL;
+    *call->receiving_buffer = NULL;
+    call->receiving_message = 0;
+    if (gpr_unref(&bctl->steps_to_complete)) {
+      post_batch_completion(exec_ctx, bctl);
+    }
+  } else {
+    call->test_only_last_message_flags = call->receiving_stream->flags;
+    if ((call->receiving_stream->flags & GRPC_WRITE_INTERNAL_COMPRESS) &&
+        (call->compression_algorithm > GRPC_COMPRESS_NONE)) {
+      *call->receiving_buffer = grpc_raw_compressed_byte_buffer_create(
+          NULL, 0, call->compression_algorithm);
+    } else {
+      *call->receiving_buffer = grpc_raw_byte_buffer_create(NULL, 0);
+    }
+    grpc_closure_init(&call->receiving_slice_ready, receiving_slice_ready,
+                      bctl);
+    continue_receiving_slices(exec_ctx, bctl);
+    /* early out */
+    return;
+  }
+}
+
+static void receiving_stream_ready(grpc_exec_ctx *exec_ctx, void *bctlp,
+                                   bool success) {
+  batch_control *bctl = bctlp;
+  grpc_call *call = bctl->call;
+
+  gpr_mu_lock(&bctl->call->mu);
+  if (bctl->call->has_initial_md_been_received) {
+    gpr_mu_unlock(&bctl->call->mu);
+    process_data_after_md(exec_ctx, bctlp, success);
+  } else {
+    call->saved_receiving_stream_ready_ctx.bctlp = bctlp;
+    call->saved_receiving_stream_ready_ctx.success = success;
+    gpr_mu_unlock(&bctl->call->mu);
+  }
+}
+
+static void receiving_initial_metadata_ready(grpc_exec_ctx *exec_ctx,
+                                             void *bctlp, bool success) {
+  batch_control *bctl = bctlp;
+  grpc_call *call = bctl->call;
+
+  gpr_mu_lock(&call->mu);
+
+  grpc_metadata_batch *md =
+      &call->metadata_batch[1 /* is_receiving */][0 /* is_trailing */];
+  grpc_metadata_batch_filter(md, recv_initial_filter, call);
+  call->has_initial_md_been_received = true;
+
+  if (gpr_time_cmp(md->deadline, gpr_inf_future(md->deadline.clock_type)) !=
+          0 &&
+      !call->is_client) {
+    GPR_TIMER_BEGIN("set_deadline_alarm", 0);
+    set_deadline_alarm(exec_ctx, call, md->deadline);
+    GPR_TIMER_END("set_deadline_alarm", 0);
+  }
+
+  if (call->saved_receiving_stream_ready_ctx.bctlp != NULL) {
+    grpc_closure *saved_rsr_closure = grpc_closure_create(
+        receiving_stream_ready, call->saved_receiving_stream_ready_ctx.bctlp);
+    grpc_exec_ctx_enqueue(exec_ctx, saved_rsr_closure,
+                          call->saved_receiving_stream_ready_ctx.success, NULL);
+    call->saved_receiving_stream_ready_ctx.bctlp = NULL;
+  }
+
+  gpr_mu_unlock(&call->mu);
+
+  if (gpr_unref(&bctl->steps_to_complete)) {
+    post_batch_completion(exec_ctx, bctl);
+  }
+}
+
+static void finish_batch(grpc_exec_ctx *exec_ctx, void *bctlp, bool success) {
+  batch_control *bctl = bctlp;
+  grpc_call *call = bctl->call;
+  grpc_call *child_call;
+  grpc_call *next_child_call;
+
+  gpr_mu_lock(&call->mu);
+  if (bctl->send_initial_metadata) {
+    grpc_metadata_batch_destroy(
+        &call->metadata_batch[0 /* is_receiving */][0 /* is_trailing */]);
+  }
+  if (bctl->send_message) {
+    call->sending_message = 0;
+  }
+  if (bctl->send_final_op) {
+    grpc_metadata_batch_destroy(
+        &call->metadata_batch[0 /* is_receiving */][1 /* is_trailing */]);
+  }
+  if (bctl->recv_final_op) {
+    grpc_metadata_batch *md =
+        &call->metadata_batch[1 /* is_receiving */][1 /* is_trailing */];
+    grpc_metadata_batch_filter(md, recv_trailing_filter, call);
+
+    if (call->have_alarm) {
+      grpc_timer_cancel(exec_ctx, &call->alarm);
+    }
+    /* propagate cancellation to any interested children */
+    child_call = call->first_child;
+    if (child_call != NULL) {
+      do {
+        next_child_call = child_call->sibling_next;
+        if (child_call->cancellation_is_inherited) {
+          GRPC_CALL_INTERNAL_REF(child_call, "propagate_cancel");
+          grpc_call_cancel(child_call, NULL);
+          GRPC_CALL_INTERNAL_UNREF(exec_ctx, child_call, "propagate_cancel");
+        }
+        child_call = next_child_call;
+      } while (child_call != call->first_child);
+    }
+
+    if (call->is_client) {
+      get_final_status(call, set_status_value_directly,
+                       call->final_op.client.status);
+      get_final_details(call, call->final_op.client.status_details,
+                        call->final_op.client.status_details_capacity);
+    } else {
+      get_final_status(call, set_cancelled_value,
+                       call->final_op.server.cancelled);
+    }
+
+    success = 1;
+  }
+  bctl->success = success != 0;
+  gpr_mu_unlock(&call->mu);
+  if (gpr_unref(&bctl->steps_to_complete)) {
+    post_batch_completion(exec_ctx, bctl);
+  }
+}
+
+static grpc_call_error call_start_batch(grpc_exec_ctx *exec_ctx,
+                                        grpc_call *call, const grpc_op *ops,
+                                        size_t nops, void *notify_tag,
+                                        int is_notify_tag_closure) {
+  grpc_transport_stream_op stream_op;
+  size_t i;
+  const grpc_op *op;
+  batch_control *bctl;
+  int num_completion_callbacks_needed = 1;
+  grpc_call_error error = GRPC_CALL_OK;
+
+  GPR_TIMER_BEGIN("grpc_call_start_batch", 0);
+
+  GRPC_CALL_LOG_BATCH(GPR_INFO, call, ops, nops, notify_tag);
+
+  memset(&stream_op, 0, sizeof(stream_op));
+
+  /* TODO(ctiller): this feels like it could be made lock-free */
+  gpr_mu_lock(&call->mu);
+  bctl = allocate_batch_control(call);
+  memset(bctl, 0, sizeof(*bctl));
+  bctl->call = call;
+  bctl->notify_tag = notify_tag;
+  bctl->is_notify_tag_closure = (uint8_t)(is_notify_tag_closure != 0);
+
+  if (nops == 0) {
+    GRPC_CALL_INTERNAL_REF(call, "completion");
+    bctl->success = 1;
+    if (!is_notify_tag_closure) {
+      grpc_cq_begin_op(call->cq, notify_tag);
+    }
+    gpr_mu_unlock(&call->mu);
+    post_batch_completion(exec_ctx, bctl);
+    error = GRPC_CALL_OK;
+    goto done;
+  }
+
+  /* rewrite batch ops into a transport op */
+  for (i = 0; i < nops; i++) {
+    op = &ops[i];
+    if (op->reserved != NULL) {
+      error = GRPC_CALL_ERROR;
+      goto done_with_error;
+    }
+    switch (op->op) {
+      case GRPC_OP_SEND_INITIAL_METADATA:
+        /* Flag validation: currently allow no flags */
+        if (op->flags != 0) {
+          error = GRPC_CALL_ERROR_INVALID_FLAGS;
+          goto done_with_error;
+        }
+        if (call->sent_initial_metadata) {
+          error = GRPC_CALL_ERROR_TOO_MANY_OPERATIONS;
+          goto done_with_error;
+        }
+        if (op->data.send_initial_metadata.count > INT_MAX) {
+          error = GRPC_CALL_ERROR_INVALID_METADATA;
+          goto done_with_error;
+        }
+        bctl->send_initial_metadata = 1;
+        call->sent_initial_metadata = 1;
+        if (!prepare_application_metadata(
+                call, (int)op->data.send_initial_metadata.count,
+                op->data.send_initial_metadata.metadata, 0, call->is_client)) {
+          error = GRPC_CALL_ERROR_INVALID_METADATA;
+          goto done_with_error;
+        }
+        /* TODO(ctiller): just make these the same variable? */
+        call->metadata_batch[0][0].deadline = call->send_deadline;
+        stream_op.send_initial_metadata =
+            &call->metadata_batch[0 /* is_receiving */][0 /* is_trailing */];
+        break;
+      case GRPC_OP_SEND_MESSAGE:
+        if (!are_write_flags_valid(op->flags)) {
+          error = GRPC_CALL_ERROR_INVALID_FLAGS;
+          goto done_with_error;
+        }
+        if (op->data.send_message == NULL) {
+          error = GRPC_CALL_ERROR_INVALID_MESSAGE;
+          goto done_with_error;
+        }
+        if (call->sending_message) {
+          error = GRPC_CALL_ERROR_TOO_MANY_OPERATIONS;
+          goto done_with_error;
+        }
+        bctl->send_message = 1;
+        call->sending_message = 1;
+        grpc_slice_buffer_stream_init(
+            &call->sending_stream,
+            &op->data.send_message->data.raw.slice_buffer, op->flags);
+        stream_op.send_message = &call->sending_stream.base;
+        break;
+      case GRPC_OP_SEND_CLOSE_FROM_CLIENT:
+        /* Flag validation: currently allow no flags */
+        if (op->flags != 0) {
+          error = GRPC_CALL_ERROR_INVALID_FLAGS;
+          goto done_with_error;
+        }
+        if (!call->is_client) {
+          error = GRPC_CALL_ERROR_NOT_ON_SERVER;
+          goto done_with_error;
+        }
+        if (call->sent_final_op) {
+          error = GRPC_CALL_ERROR_TOO_MANY_OPERATIONS;
+          goto done_with_error;
+        }
+        bctl->send_final_op = 1;
+        call->sent_final_op = 1;
+        stream_op.send_trailing_metadata =
+            &call->metadata_batch[0 /* is_receiving */][1 /* is_trailing */];
+        break;
+      case GRPC_OP_SEND_STATUS_FROM_SERVER:
+        /* Flag validation: currently allow no flags */
+        if (op->flags != 0) {
+          error = GRPC_CALL_ERROR_INVALID_FLAGS;
+          goto done_with_error;
+        }
+        if (call->is_client) {
+          error = GRPC_CALL_ERROR_NOT_ON_CLIENT;
+          goto done_with_error;
+        }
+        if (call->sent_final_op) {
+          error = GRPC_CALL_ERROR_TOO_MANY_OPERATIONS;
+          goto done_with_error;
+        }
+        if (op->data.send_status_from_server.trailing_metadata_count >
+            INT_MAX) {
+          error = GRPC_CALL_ERROR_INVALID_METADATA;
+          goto done_with_error;
+        }
+        bctl->send_final_op = 1;
+        call->sent_final_op = 1;
+        call->send_extra_metadata_count = 1;
+        call->send_extra_metadata[0].md = grpc_channel_get_reffed_status_elem(
+            call->channel, op->data.send_status_from_server.status);
+        if (op->data.send_status_from_server.status_details != NULL) {
+          call->send_extra_metadata[1].md = grpc_mdelem_from_metadata_strings(
+              GRPC_MDSTR_GRPC_MESSAGE,
+              grpc_mdstr_from_string(
+                  op->data.send_status_from_server.status_details));
+          call->send_extra_metadata_count++;
+          set_status_details(
+              call, STATUS_FROM_API_OVERRIDE,
+              GRPC_MDSTR_REF(call->send_extra_metadata[1].md->value));
+        }
+        set_status_code(call, STATUS_FROM_API_OVERRIDE,
+                        (uint32_t)op->data.send_status_from_server.status);
+        if (!prepare_application_metadata(
+                call,
+                (int)op->data.send_status_from_server.trailing_metadata_count,
+                op->data.send_status_from_server.trailing_metadata, 1, 1)) {
+          error = GRPC_CALL_ERROR_INVALID_METADATA;
+          goto done_with_error;
+        }
+        stream_op.send_trailing_metadata =
+            &call->metadata_batch[0 /* is_receiving */][1 /* is_trailing */];
+        break;
+      case GRPC_OP_RECV_INITIAL_METADATA:
+        /* Flag validation: currently allow no flags */
+        if (op->flags != 0) {
+          error = GRPC_CALL_ERROR_INVALID_FLAGS;
+          goto done_with_error;
+        }
+        if (call->received_initial_metadata) {
+          error = GRPC_CALL_ERROR_TOO_MANY_OPERATIONS;
+          goto done_with_error;
+        }
+        call->received_initial_metadata = 1;
+        call->buffered_metadata[0] = op->data.recv_initial_metadata;
+        grpc_closure_init(&call->receiving_initial_metadata_ready,
+                          receiving_initial_metadata_ready, bctl);
+        bctl->recv_initial_metadata = 1;
+        stream_op.recv_initial_metadata =
+            &call->metadata_batch[1 /* is_receiving */][0 /* is_trailing */];
+        stream_op.recv_initial_metadata_ready =
+            &call->receiving_initial_metadata_ready;
+        num_completion_callbacks_needed++;
+        break;
+      case GRPC_OP_RECV_MESSAGE:
+        /* Flag validation: currently allow no flags */
+        if (op->flags != 0) {
+          error = GRPC_CALL_ERROR_INVALID_FLAGS;
+          goto done_with_error;
+        }
+        if (call->receiving_message) {
+          error = GRPC_CALL_ERROR_TOO_MANY_OPERATIONS;
+          goto done_with_error;
+        }
+        call->receiving_message = 1;
+        bctl->recv_message = 1;
+        call->receiving_buffer = op->data.recv_message;
+        stream_op.recv_message = &call->receiving_stream;
+        grpc_closure_init(&call->receiving_stream_ready, receiving_stream_ready,
+                          bctl);
+        stream_op.recv_message_ready = &call->receiving_stream_ready;
+        num_completion_callbacks_needed++;
+        break;
+      case GRPC_OP_RECV_STATUS_ON_CLIENT:
+        /* Flag validation: currently allow no flags */
+        if (op->flags != 0) {
+          error = GRPC_CALL_ERROR_INVALID_FLAGS;
+          goto done_with_error;
+        }
+        if (!call->is_client) {
+          error = GRPC_CALL_ERROR_NOT_ON_SERVER;
+          goto done_with_error;
+        }
+        if (call->received_final_op) {
+          error = GRPC_CALL_ERROR_TOO_MANY_OPERATIONS;
+          goto done_with_error;
+        }
+        call->received_final_op = 1;
+        call->buffered_metadata[1] =
+            op->data.recv_status_on_client.trailing_metadata;
+        call->final_op.client.status = op->data.recv_status_on_client.status;
+        call->final_op.client.status_details =
+            op->data.recv_status_on_client.status_details;
+        call->final_op.client.status_details_capacity =
+            op->data.recv_status_on_client.status_details_capacity;
+        bctl->recv_final_op = 1;
+        stream_op.recv_trailing_metadata =
+            &call->metadata_batch[1 /* is_receiving */][1 /* is_trailing */];
+        break;
+      case GRPC_OP_RECV_CLOSE_ON_SERVER:
+        /* Flag validation: currently allow no flags */
+        if (op->flags != 0) {
+          error = GRPC_CALL_ERROR_INVALID_FLAGS;
+          goto done_with_error;
+        }
+        if (call->is_client) {
+          error = GRPC_CALL_ERROR_NOT_ON_CLIENT;
+          goto done_with_error;
+        }
+        if (call->received_final_op) {
+          error = GRPC_CALL_ERROR_TOO_MANY_OPERATIONS;
+          goto done_with_error;
+        }
+        call->received_final_op = 1;
+        call->final_op.server.cancelled =
+            op->data.recv_close_on_server.cancelled;
+        bctl->recv_final_op = 1;
+        stream_op.recv_trailing_metadata =
+            &call->metadata_batch[1 /* is_receiving */][1 /* is_trailing */];
+        break;
+    }
+  }
+
+  GRPC_CALL_INTERNAL_REF(call, "completion");
+  if (!is_notify_tag_closure) {
+    grpc_cq_begin_op(call->cq, notify_tag);
+  }
+  gpr_ref_init(&bctl->steps_to_complete, num_completion_callbacks_needed);
+
+  stream_op.context = call->context;
+  grpc_closure_init(&bctl->finish_batch, finish_batch, bctl);
+  stream_op.on_complete = &bctl->finish_batch;
+  gpr_mu_unlock(&call->mu);
+
+  execute_op(exec_ctx, call, &stream_op);
+
+done:
+  GPR_TIMER_END("grpc_call_start_batch", 0);
+  return error;
+
+done_with_error:
+  /* reverse any mutations that occured */
+  if (bctl->send_initial_metadata) {
+    call->sent_initial_metadata = 0;
+    grpc_metadata_batch_clear(&call->metadata_batch[0][0]);
+  }
+  if (bctl->send_message) {
+    call->sending_message = 0;
+    grpc_byte_stream_destroy(exec_ctx, &call->sending_stream.base);
+  }
+  if (bctl->send_final_op) {
+    call->sent_final_op = 0;
+    grpc_metadata_batch_clear(&call->metadata_batch[0][1]);
+  }
+  if (bctl->recv_initial_metadata) {
+    call->received_initial_metadata = 0;
+  }
+  if (bctl->recv_message) {
+    call->receiving_message = 0;
+  }
+  if (bctl->recv_final_op) {
+    call->received_final_op = 0;
+  }
+  gpr_mu_unlock(&call->mu);
+  goto done;
+}
+
+grpc_call_error grpc_call_start_batch(grpc_call *call, const grpc_op *ops,
+                                      size_t nops, void *tag, void *reserved) {
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  grpc_call_error err;
+
+  GRPC_API_TRACE(
+      "grpc_call_start_batch(call=%p, ops=%p, nops=%lu, tag=%p, reserved=%p)",
+      5, (call, ops, (unsigned long)nops, tag, reserved));
+
+  if (reserved != NULL) {
+    err = GRPC_CALL_ERROR;
+  } else {
+    err = call_start_batch(&exec_ctx, call, ops, nops, tag, 0);
+  }
+
+  grpc_exec_ctx_finish(&exec_ctx);
+  return err;
+}
+
+grpc_call_error grpc_call_start_batch_and_execute(grpc_exec_ctx *exec_ctx,
+                                                  grpc_call *call,
+                                                  const grpc_op *ops,
+                                                  size_t nops,
+                                                  grpc_closure *closure) {
+  return call_start_batch(exec_ctx, call, ops, nops, closure, 1);
+}
+
+void grpc_call_context_set(grpc_call *call, grpc_context_index elem,
+                           void *value, void (*destroy)(void *value)) {
+  if (call->context[elem].destroy) {
+    call->context[elem].destroy(call->context[elem].value);
+  }
+  call->context[elem].value = value;
+  call->context[elem].destroy = destroy;
+}
+
+void *grpc_call_context_get(grpc_call *call, grpc_context_index elem) {
+  return call->context[elem].value;
+}
+
+uint8_t grpc_call_is_client(grpc_call *call) { return call->is_client; }
+
+grpc_compression_algorithm grpc_call_compression_for_level(
+    grpc_call *call, grpc_compression_level level) {
+  gpr_mu_lock(&call->mu);
+  const uint32_t accepted_encodings = call->encodings_accepted_by_peer;
+  gpr_mu_unlock(&call->mu);
+  return grpc_compression_algorithm_for_level(level, accepted_encodings);
+}
diff --git a/src/core/lib/surface/call.h b/src/core/lib/surface/call.h
new file mode 100644
index 0000000000..e2e75865be
--- /dev/null
+++ b/src/core/lib/surface/call.h
@@ -0,0 +1,116 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_SURFACE_CALL_H
+#define GRPC_CORE_LIB_SURFACE_CALL_H
+
+#include "src/core/lib/channel/channel_stack.h"
+#include "src/core/lib/channel/context.h"
+#include "src/core/lib/surface/api_trace.h"
+#include "src/core/lib/surface/surface_trace.h"
+
+#include <grpc/grpc.h>
+#include <grpc/impl/codegen/compression_types.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef void (*grpc_ioreq_completion_func)(grpc_exec_ctx *exec_ctx,
+                                           grpc_call *call, int success,
+                                           void *user_data);
+
+grpc_call *grpc_call_create(grpc_channel *channel, grpc_call *parent_call,
+                            uint32_t propagation_mask,
+                            grpc_completion_queue *cq,
+                            const void *server_transport_data,
+                            grpc_mdelem **add_initial_metadata,
+                            size_t add_initial_metadata_count,
+                            gpr_timespec send_deadline);
+
+void grpc_call_set_completion_queue(grpc_exec_ctx *exec_ctx, grpc_call *call,
+                                    grpc_completion_queue *cq);
+
+#ifdef GRPC_STREAM_REFCOUNT_DEBUG
+void grpc_call_internal_ref(grpc_call *call, const char *reason);
+void grpc_call_internal_unref(grpc_exec_ctx *exec_ctx, grpc_call *call,
+                              const char *reason);
+#define GRPC_CALL_INTERNAL_REF(call, reason) \
+  grpc_call_internal_ref(call, reason)
+#define GRPC_CALL_INTERNAL_UNREF(exec_ctx, call, reason) \
+  grpc_call_internal_unref(exec_ctx, call, reason)
+#else
+void grpc_call_internal_ref(grpc_call *call);
+void grpc_call_internal_unref(grpc_exec_ctx *exec_ctx, grpc_call *call);
+#define GRPC_CALL_INTERNAL_REF(call, reason) grpc_call_internal_ref(call)
+#define GRPC_CALL_INTERNAL_UNREF(exec_ctx, call, reason) \
+  grpc_call_internal_unref(exec_ctx, call)
+#endif
+
+grpc_call_stack *grpc_call_get_call_stack(grpc_call *call);
+
+grpc_call_error grpc_call_start_batch_and_execute(grpc_exec_ctx *exec_ctx,
+                                                  grpc_call *call,
+                                                  const grpc_op *ops,
+                                                  size_t nops,
+                                                  grpc_closure *closure);
+
+/* Given the top call_element, get the call object. */
+grpc_call *grpc_call_from_top_element(grpc_call_element *surface_element);
+
+void grpc_call_log_batch(char *file, int line, gpr_log_severity severity,
+                         grpc_call *call, const grpc_op *ops, size_t nops,
+                         void *tag);
+
+/* Set a context pointer.
+   No thread safety guarantees are made wrt this value. */
+void grpc_call_context_set(grpc_call *call, grpc_context_index elem,
+                           void *value, void (*destroy)(void *value));
+/* Get a context pointer. */
+void *grpc_call_context_get(grpc_call *call, grpc_context_index elem);
+
+#define GRPC_CALL_LOG_BATCH(sev, call, ops, nops, tag) \
+  if (grpc_api_trace) grpc_call_log_batch(sev, call, ops, nops, tag)
+
+uint8_t grpc_call_is_client(grpc_call *call);
+
+/* Return an appropriate compression algorithm for the requested compression \a
+ * level in the context of \a call. */
+grpc_compression_algorithm grpc_call_compression_for_level(
+    grpc_call *call, grpc_compression_level level);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_LIB_SURFACE_CALL_H */
diff --git a/src/core/lib/surface/call_details.c b/src/core/lib/surface/call_details.c
new file mode 100644
index 0000000000..08f606d84a
--- /dev/null
+++ b/src/core/lib/surface/call_details.c
@@ -0,0 +1,50 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <grpc/grpc.h>
+#include <grpc/support/alloc.h>
+
+#include <string.h>
+
+#include "src/core/lib/surface/api_trace.h"
+
+void grpc_call_details_init(grpc_call_details* cd) {
+  GRPC_API_TRACE("grpc_call_details_init(cd=%p)", 1, (cd));
+  memset(cd, 0, sizeof(*cd));
+}
+
+void grpc_call_details_destroy(grpc_call_details* cd) {
+  GRPC_API_TRACE("grpc_call_details_destroy(cd=%p)", 1, (cd));
+  gpr_free(cd->method);
+  gpr_free(cd->host);
+}
diff --git a/src/core/lib/surface/call_log_batch.c b/src/core/lib/surface/call_log_batch.c
new file mode 100644
index 0000000000..bc5a2ffb65
--- /dev/null
+++ b/src/core/lib/surface/call_log_batch.c
@@ -0,0 +1,118 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/surface/call.h"
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/string_util.h>
+#include "src/core/lib/support/string.h"
+
+static void add_metadata(gpr_strvec *b, const grpc_metadata *md, size_t count) {
+  size_t i;
+  for (i = 0; i < count; i++) {
+    gpr_strvec_add(b, gpr_strdup("\nkey="));
+    gpr_strvec_add(b, gpr_strdup(md[i].key));
+
+    gpr_strvec_add(b, gpr_strdup(" value="));
+    gpr_strvec_add(b, gpr_dump(md[i].value, md[i].value_length,
+                               GPR_DUMP_HEX | GPR_DUMP_ASCII));
+  }
+}
+
+char *grpc_op_string(const grpc_op *op) {
+  char *tmp;
+  char *out;
+
+  gpr_strvec b;
+  gpr_strvec_init(&b);
+
+  switch (op->op) {
+    case GRPC_OP_SEND_INITIAL_METADATA:
+      gpr_strvec_add(&b, gpr_strdup("SEND_INITIAL_METADATA"));
+      add_metadata(&b, op->data.send_initial_metadata.metadata,
+                   op->data.send_initial_metadata.count);
+      break;
+    case GRPC_OP_SEND_MESSAGE:
+      gpr_asprintf(&tmp, "SEND_MESSAGE ptr=%p", op->data.send_message);
+      gpr_strvec_add(&b, tmp);
+      break;
+    case GRPC_OP_SEND_CLOSE_FROM_CLIENT:
+      gpr_strvec_add(&b, gpr_strdup("SEND_CLOSE_FROM_CLIENT"));
+      break;
+    case GRPC_OP_SEND_STATUS_FROM_SERVER:
+      gpr_asprintf(&tmp, "SEND_STATUS_FROM_SERVER status=%d details=%s",
+                   op->data.send_status_from_server.status,
+                   op->data.send_status_from_server.status_details);
+      gpr_strvec_add(&b, tmp);
+      add_metadata(&b, op->data.send_status_from_server.trailing_metadata,
+                   op->data.send_status_from_server.trailing_metadata_count);
+      break;
+    case GRPC_OP_RECV_INITIAL_METADATA:
+      gpr_asprintf(&tmp, "RECV_INITIAL_METADATA ptr=%p",
+                   op->data.recv_initial_metadata);
+      gpr_strvec_add(&b, tmp);
+      break;
+    case GRPC_OP_RECV_MESSAGE:
+      gpr_asprintf(&tmp, "RECV_MESSAGE ptr=%p", op->data.recv_message);
+      gpr_strvec_add(&b, tmp);
+      break;
+    case GRPC_OP_RECV_STATUS_ON_CLIENT:
+      gpr_asprintf(&tmp,
+                   "RECV_STATUS_ON_CLIENT metadata=%p status=%p details=%p",
+                   op->data.recv_status_on_client.trailing_metadata,
+                   op->data.recv_status_on_client.status,
+                   op->data.recv_status_on_client.status_details);
+      gpr_strvec_add(&b, tmp);
+      break;
+    case GRPC_OP_RECV_CLOSE_ON_SERVER:
+      gpr_asprintf(&tmp, "RECV_CLOSE_ON_SERVER cancelled=%p",
+                   op->data.recv_close_on_server.cancelled);
+      gpr_strvec_add(&b, tmp);
+  }
+  out = gpr_strvec_flatten(&b, NULL);
+  gpr_strvec_destroy(&b);
+
+  return out;
+}
+
+void grpc_call_log_batch(char *file, int line, gpr_log_severity severity,
+                         grpc_call *call, const grpc_op *ops, size_t nops,
+                         void *tag) {
+  char *tmp;
+  size_t i;
+  for (i = 0; i < nops; i++) {
+    tmp = grpc_op_string(&ops[i]);
+    gpr_log(file, line, severity, "ops[%d]: %s", i, tmp);
+    gpr_free(tmp);
+  }
+}
diff --git a/src/core/lib/surface/call_test_only.h b/src/core/lib/surface/call_test_only.h
new file mode 100644
index 0000000000..400214189e
--- /dev/null
+++ b/src/core/lib/surface/call_test_only.h
@@ -0,0 +1,64 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_SURFACE_CALL_TEST_ONLY_H
+#define GRPC_CORE_LIB_SURFACE_CALL_TEST_ONLY_H
+
+#include <grpc/grpc.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Return the compression algorithm from \a call.
+ *
+ * \warning This function should \b only be used in test code. */
+grpc_compression_algorithm grpc_call_test_only_get_compression_algorithm(
+    grpc_call *call);
+
+/** Return the message flags from \a call.
+ *
+ * \warning This function should \b only be used in test code. */
+uint32_t grpc_call_test_only_get_message_flags(grpc_call *call);
+
+/** Returns a bitset for the encodings (compression algorithms) supported by \a
+ * call's peer.
+ *
+ * To be indexed by grpc_compression_algorithm enum values. */
+uint32_t grpc_call_test_only_get_encodings_accepted_by_peer(grpc_call *call);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_LIB_SURFACE_CALL_TEST_ONLY_H */
diff --git a/src/core/lib/surface/channel.c b/src/core/lib/surface/channel.c
new file mode 100644
index 0000000000..d815daa70c
--- /dev/null
+++ b/src/core/lib/surface/channel.c
@@ -0,0 +1,324 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/surface/channel.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+
+#include "src/core/lib/client_config/resolver_registry.h"
+#include "src/core/lib/iomgr/iomgr.h"
+#include "src/core/lib/support/string.h"
+#include "src/core/lib/surface/api_trace.h"
+#include "src/core/lib/surface/call.h"
+#include "src/core/lib/surface/channel_init.h"
+#include "src/core/lib/surface/init.h"
+#include "src/core/lib/transport/static_metadata.h"
+
+/** Cache grpc-status: X mdelems for X = 0..NUM_CACHED_STATUS_ELEMS.
+ *  Avoids needing to take a metadata context lock for sending status
+ *  if the status code is <= NUM_CACHED_STATUS_ELEMS.
+ *  Sized to allow the most commonly used codes to fit in
+ *  (OK, Cancelled, Unknown). */
+#define NUM_CACHED_STATUS_ELEMS 3
+
+typedef struct registered_call {
+  grpc_mdelem *path;
+  grpc_mdelem *authority;
+  struct registered_call *next;
+} registered_call;
+
+struct grpc_channel {
+  int is_client;
+  uint32_t max_message_length;
+  grpc_mdelem *default_authority;
+
+  gpr_mu registered_call_mu;
+  registered_call *registered_calls;
+  char *target;
+};
+
+#define CHANNEL_STACK_FROM_CHANNEL(c) ((grpc_channel_stack *)((c) + 1))
+#define CHANNEL_FROM_CHANNEL_STACK(channel_stack) \
+  (((grpc_channel *)(channel_stack)) - 1)
+#define CHANNEL_FROM_TOP_ELEM(top_elem) \
+  CHANNEL_FROM_CHANNEL_STACK(grpc_channel_stack_from_top_element(top_elem))
+
+/* the protobuf library will (by default) start warning at 100megs */
+#define DEFAULT_MAX_MESSAGE_LENGTH (100 * 1024 * 1024)
+
+static void destroy_channel(grpc_exec_ctx *exec_ctx, void *arg, bool success);
+
+grpc_channel *grpc_channel_create(grpc_exec_ctx *exec_ctx, const char *target,
+                                  const grpc_channel_args *args,
+                                  grpc_channel_stack_type channel_stack_type,
+                                  grpc_transport *optional_transport) {
+  bool is_client = grpc_channel_stack_type_is_client(channel_stack_type);
+
+  grpc_channel *channel = grpc_channel_init_create_stack(
+      exec_ctx, channel_stack_type, sizeof(grpc_channel), args, 1,
+      destroy_channel, NULL, optional_transport);
+
+  memset(channel, 0, sizeof(*channel));
+  channel->target = gpr_strdup(target);
+  channel->is_client = is_client;
+  gpr_mu_init(&channel->registered_call_mu);
+  channel->registered_calls = NULL;
+
+  channel->max_message_length = DEFAULT_MAX_MESSAGE_LENGTH;
+  if (args) {
+    for (size_t i = 0; i < args->num_args; i++) {
+      if (0 == strcmp(args->args[i].key, GRPC_ARG_MAX_MESSAGE_LENGTH)) {
+        if (args->args[i].type != GRPC_ARG_INTEGER) {
+          gpr_log(GPR_ERROR, "%s ignored: it must be an integer",
+                  GRPC_ARG_MAX_MESSAGE_LENGTH);
+        } else if (args->args[i].value.integer < 0) {
+          gpr_log(GPR_ERROR, "%s ignored: it must be >= 0",
+                  GRPC_ARG_MAX_MESSAGE_LENGTH);
+        } else {
+          channel->max_message_length = (uint32_t)args->args[i].value.integer;
+        }
+      } else if (0 == strcmp(args->args[i].key, GRPC_ARG_DEFAULT_AUTHORITY)) {
+        if (args->args[i].type != GRPC_ARG_STRING) {
+          gpr_log(GPR_ERROR, "%s ignored: it must be a string",
+                  GRPC_ARG_DEFAULT_AUTHORITY);
+        } else {
+          if (channel->default_authority) {
+            /* setting this takes precedence over anything else */
+            GRPC_MDELEM_UNREF(channel->default_authority);
+          }
+          channel->default_authority = grpc_mdelem_from_strings(
+              ":authority", args->args[i].value.string);
+        }
+      } else if (0 ==
+                 strcmp(args->args[i].key, GRPC_SSL_TARGET_NAME_OVERRIDE_ARG)) {
+        if (args->args[i].type != GRPC_ARG_STRING) {
+          gpr_log(GPR_ERROR, "%s ignored: it must be a string",
+                  GRPC_SSL_TARGET_NAME_OVERRIDE_ARG);
+        } else {
+          if (channel->default_authority) {
+            /* other ways of setting this (notably ssl) take precedence */
+            gpr_log(GPR_ERROR,
+                    "%s ignored: default host already set some other way",
+                    GRPC_SSL_TARGET_NAME_OVERRIDE_ARG);
+          } else {
+            channel->default_authority = grpc_mdelem_from_strings(
+                ":authority", args->args[i].value.string);
+          }
+        }
+      }
+    }
+  }
+
+  if (channel->is_client && channel->default_authority == NULL &&
+      target != NULL) {
+    char *default_authority = grpc_get_default_authority(target);
+    if (default_authority) {
+      channel->default_authority =
+          grpc_mdelem_from_strings(":authority", default_authority);
+    }
+    gpr_free(default_authority);
+  }
+
+  return channel;
+}
+
+char *grpc_channel_get_target(grpc_channel *channel) {
+  GRPC_API_TRACE("grpc_channel_get_target(channel=%p)", 1, (channel));
+  return gpr_strdup(channel->target);
+}
+
+static grpc_call *grpc_channel_create_call_internal(
+    grpc_channel *channel, grpc_call *parent_call, uint32_t propagation_mask,
+    grpc_completion_queue *cq, grpc_mdelem *path_mdelem,
+    grpc_mdelem *authority_mdelem, gpr_timespec deadline) {
+  grpc_mdelem *send_metadata[2];
+  size_t num_metadata = 0;
+
+  GPR_ASSERT(channel->is_client);
+
+  send_metadata[num_metadata++] = path_mdelem;
+  if (authority_mdelem != NULL) {
+    send_metadata[num_metadata++] = authority_mdelem;
+  } else if (channel->default_authority != NULL) {
+    send_metadata[num_metadata++] = GRPC_MDELEM_REF(channel->default_authority);
+  }
+
+  return grpc_call_create(channel, parent_call, propagation_mask, cq, NULL,
+                          send_metadata, num_metadata, deadline);
+}
+
+grpc_call *grpc_channel_create_call(grpc_channel *channel,
+                                    grpc_call *parent_call,
+                                    uint32_t propagation_mask,
+                                    grpc_completion_queue *cq,
+                                    const char *method, const char *host,
+                                    gpr_timespec deadline, void *reserved) {
+  GRPC_API_TRACE(
+      "grpc_channel_create_call("
+      "channel=%p, parent_call=%p, propagation_mask=%x, cq=%p, method=%s, "
+      "host=%s, "
+      "deadline=gpr_timespec { tv_sec: %lld, tv_nsec: %d, clock_type: %d }, "
+      "reserved=%p)",
+      10, (channel, parent_call, (unsigned)propagation_mask, cq, method, host,
+           (long long)deadline.tv_sec, (int)deadline.tv_nsec,
+           (int)deadline.clock_type, reserved));
+  GPR_ASSERT(!reserved);
+  return grpc_channel_create_call_internal(
+      channel, parent_call, propagation_mask, cq,
+      grpc_mdelem_from_metadata_strings(GRPC_MDSTR_PATH,
+                                        grpc_mdstr_from_string(method)),
+      host ? grpc_mdelem_from_metadata_strings(GRPC_MDSTR_AUTHORITY,
+                                               grpc_mdstr_from_string(host))
+           : NULL,
+      deadline);
+}
+
+void *grpc_channel_register_call(grpc_channel *channel, const char *method,
+                                 const char *host, void *reserved) {
+  registered_call *rc = gpr_malloc(sizeof(registered_call));
+  GRPC_API_TRACE(
+      "grpc_channel_register_call(channel=%p, method=%s, host=%s, reserved=%p)",
+      4, (channel, method, host, reserved));
+  GPR_ASSERT(!reserved);
+  rc->path = grpc_mdelem_from_metadata_strings(GRPC_MDSTR_PATH,
+                                               grpc_mdstr_from_string(method));
+  rc->authority = host ? grpc_mdelem_from_metadata_strings(
+                             GRPC_MDSTR_AUTHORITY, grpc_mdstr_from_string(host))
+                       : NULL;
+  gpr_mu_lock(&channel->registered_call_mu);
+  rc->next = channel->registered_calls;
+  channel->registered_calls = rc;
+  gpr_mu_unlock(&channel->registered_call_mu);
+  return rc;
+}
+
+grpc_call *grpc_channel_create_registered_call(
+    grpc_channel *channel, grpc_call *parent_call, uint32_t propagation_mask,
+    grpc_completion_queue *completion_queue, void *registered_call_handle,
+    gpr_timespec deadline, void *reserved) {
+  registered_call *rc = registered_call_handle;
+  GRPC_API_TRACE(
+      "grpc_channel_create_registered_call("
+      "channel=%p, parent_call=%p, propagation_mask=%x, completion_queue=%p, "
+      "registered_call_handle=%p, "
+      "deadline=gpr_timespec { tv_sec: %lld, tv_nsec: %d, clock_type: %d }, "
+      "reserved=%p)",
+      9, (channel, parent_call, (unsigned)propagation_mask, completion_queue,
+          registered_call_handle, (long long)deadline.tv_sec,
+          (int)deadline.tv_nsec, (int)deadline.clock_type, reserved));
+  GPR_ASSERT(!reserved);
+  return grpc_channel_create_call_internal(
+      channel, parent_call, propagation_mask, completion_queue,
+      GRPC_MDELEM_REF(rc->path),
+      rc->authority ? GRPC_MDELEM_REF(rc->authority) : NULL, deadline);
+}
+
+#ifdef GRPC_STREAM_REFCOUNT_DEBUG
+#define REF_REASON reason
+#define REF_ARG , const char *reason
+#else
+#define REF_REASON ""
+#define REF_ARG
+#endif
+void grpc_channel_internal_ref(grpc_channel *c REF_ARG) {
+  GRPC_CHANNEL_STACK_REF(CHANNEL_STACK_FROM_CHANNEL(c), REF_REASON);
+}
+
+void grpc_channel_internal_unref(grpc_exec_ctx *exec_ctx,
+                                 grpc_channel *c REF_ARG) {
+  GRPC_CHANNEL_STACK_UNREF(exec_ctx, CHANNEL_STACK_FROM_CHANNEL(c), REF_REASON);
+}
+
+static void destroy_channel(grpc_exec_ctx *exec_ctx, void *arg,
+                            bool iomgr_success) {
+  grpc_channel *channel = arg;
+  grpc_channel_stack_destroy(exec_ctx, CHANNEL_STACK_FROM_CHANNEL(channel));
+  while (channel->registered_calls) {
+    registered_call *rc = channel->registered_calls;
+    channel->registered_calls = rc->next;
+    GRPC_MDELEM_UNREF(rc->path);
+    if (rc->authority) {
+      GRPC_MDELEM_UNREF(rc->authority);
+    }
+    gpr_free(rc);
+  }
+  if (channel->default_authority != NULL) {
+    GRPC_MDELEM_UNREF(channel->default_authority);
+  }
+  gpr_mu_destroy(&channel->registered_call_mu);
+  gpr_free(channel->target);
+  gpr_free(channel);
+}
+
+void grpc_channel_destroy(grpc_channel *channel) {
+  grpc_transport_op op;
+  grpc_channel_element *elem;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  GRPC_API_TRACE("grpc_channel_destroy(channel=%p)", 1, (channel));
+  memset(&op, 0, sizeof(op));
+  op.disconnect = 1;
+  elem = grpc_channel_stack_element(CHANNEL_STACK_FROM_CHANNEL(channel), 0);
+  elem->filter->start_transport_op(&exec_ctx, elem, &op);
+
+  GRPC_CHANNEL_INTERNAL_UNREF(&exec_ctx, channel, "channel");
+
+  grpc_exec_ctx_finish(&exec_ctx);
+}
+
+grpc_channel_stack *grpc_channel_get_channel_stack(grpc_channel *channel) {
+  return CHANNEL_STACK_FROM_CHANNEL(channel);
+}
+
+grpc_mdelem *grpc_channel_get_reffed_status_elem(grpc_channel *channel, int i) {
+  char tmp[GPR_LTOA_MIN_BUFSIZE];
+  switch (i) {
+    case 0:
+      return GRPC_MDELEM_GRPC_STATUS_0;
+    case 1:
+      return GRPC_MDELEM_GRPC_STATUS_1;
+    case 2:
+      return GRPC_MDELEM_GRPC_STATUS_2;
+  }
+  gpr_ltoa(i, tmp);
+  return grpc_mdelem_from_metadata_strings(GRPC_MDSTR_GRPC_STATUS,
+                                           grpc_mdstr_from_string(tmp));
+}
+
+uint32_t grpc_channel_get_max_message_length(grpc_channel *channel) {
+  return channel->max_message_length;
+}
diff --git a/src/core/lib/surface/channel.h b/src/core/lib/surface/channel.h
new file mode 100644
index 0000000000..09de0fccc9
--- /dev/null
+++ b/src/core/lib/surface/channel.h
@@ -0,0 +1,75 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_SURFACE_CHANNEL_H
+#define GRPC_CORE_LIB_SURFACE_CHANNEL_H
+
+#include "src/core/lib/channel/channel_stack.h"
+#include "src/core/lib/client_config/subchannel_factory.h"
+#include "src/core/lib/surface/channel_stack_type.h"
+
+grpc_channel *grpc_channel_create(grpc_exec_ctx *exec_ctx, const char *target,
+                                  const grpc_channel_args *args,
+                                  grpc_channel_stack_type channel_stack_type,
+                                  grpc_transport *optional_transport);
+
+/** Get a (borrowed) pointer to this channels underlying channel stack */
+grpc_channel_stack *grpc_channel_get_channel_stack(grpc_channel *channel);
+
+/** Get a grpc_mdelem of grpc-status: X where X is the numeric value of
+    status_code.
+
+    The returned elem is owned by the caller. */
+grpc_mdelem *grpc_channel_get_reffed_status_elem(grpc_channel *channel,
+                                                 int status_code);
+uint32_t grpc_channel_get_max_message_length(grpc_channel *channel);
+
+#ifdef GRPC_STREAM_REFCOUNT_DEBUG
+void grpc_channel_internal_ref(grpc_channel *channel, const char *reason);
+void grpc_channel_internal_unref(grpc_exec_ctx *exec_ctx, grpc_channel *channel,
+                                 const char *reason);
+#define GRPC_CHANNEL_INTERNAL_REF(channel, reason) \
+  grpc_channel_internal_ref(channel, reason)
+#define GRPC_CHANNEL_INTERNAL_UNREF(exec_ctx, channel, reason) \
+  grpc_channel_internal_unref(exec_ctx, channel, reason)
+#else
+void grpc_channel_internal_ref(grpc_channel *channel);
+void grpc_channel_internal_unref(grpc_exec_ctx *exec_ctx,
+                                 grpc_channel *channel);
+#define GRPC_CHANNEL_INTERNAL_REF(channel, reason) \
+  grpc_channel_internal_ref(channel)
+#define GRPC_CHANNEL_INTERNAL_UNREF(exec_ctx, channel, reason) \
+  grpc_channel_internal_unref(exec_ctx, channel)
+#endif
+
+#endif /* GRPC_CORE_LIB_SURFACE_CHANNEL_H */
diff --git a/src/core/lib/surface/channel_connectivity.c b/src/core/lib/surface/channel_connectivity.c
new file mode 100644
index 0000000000..2f5d763e70
--- /dev/null
+++ b/src/core/lib/surface/channel_connectivity.c
@@ -0,0 +1,207 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/surface/channel.h"
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+
+#include "src/core/lib/channel/client_channel.h"
+#include "src/core/lib/iomgr/timer.h"
+#include "src/core/lib/surface/api_trace.h"
+#include "src/core/lib/surface/completion_queue.h"
+
+grpc_connectivity_state grpc_channel_check_connectivity_state(
+    grpc_channel *channel, int try_to_connect) {
+  /* forward through to the underlying client channel */
+  grpc_channel_element *client_channel_elem =
+      grpc_channel_stack_last_element(grpc_channel_get_channel_stack(channel));
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  grpc_connectivity_state state;
+  GRPC_API_TRACE(
+      "grpc_channel_check_connectivity_state(channel=%p, try_to_connect=%d)", 2,
+      (channel, try_to_connect));
+  if (client_channel_elem->filter == &grpc_client_channel_filter) {
+    state = grpc_client_channel_check_connectivity_state(
+        &exec_ctx, client_channel_elem, try_to_connect);
+    grpc_exec_ctx_finish(&exec_ctx);
+    return state;
+  }
+  gpr_log(GPR_ERROR,
+          "grpc_channel_check_connectivity_state called on something that is "
+          "not a (u)client channel, but '%s'",
+          client_channel_elem->filter->name);
+  grpc_exec_ctx_finish(&exec_ctx);
+  return GRPC_CHANNEL_FATAL_FAILURE;
+}
+
+typedef enum {
+  WAITING,
+  CALLING_BACK,
+  CALLING_BACK_AND_FINISHED,
+  CALLED_BACK
+} callback_phase;
+
+typedef struct {
+  gpr_mu mu;
+  callback_phase phase;
+  int success;
+  grpc_closure on_complete;
+  grpc_timer alarm;
+  grpc_connectivity_state state;
+  grpc_completion_queue *cq;
+  grpc_cq_completion completion_storage;
+  grpc_channel *channel;
+  void *tag;
+} state_watcher;
+
+static void delete_state_watcher(grpc_exec_ctx *exec_ctx, state_watcher *w) {
+  grpc_channel_element *client_channel_elem = grpc_channel_stack_last_element(
+      grpc_channel_get_channel_stack(w->channel));
+  if (client_channel_elem->filter == &grpc_client_channel_filter) {
+    GRPC_CHANNEL_INTERNAL_UNREF(exec_ctx, w->channel,
+                                "watch_channel_connectivity");
+  } else {
+    abort();
+  }
+  gpr_mu_destroy(&w->mu);
+  gpr_free(w);
+}
+
+static void finished_completion(grpc_exec_ctx *exec_ctx, void *pw,
+                                grpc_cq_completion *ignored) {
+  int delete = 0;
+  state_watcher *w = pw;
+  gpr_mu_lock(&w->mu);
+  switch (w->phase) {
+    case WAITING:
+    case CALLED_BACK:
+      GPR_UNREACHABLE_CODE(return );
+    case CALLING_BACK:
+      w->phase = CALLED_BACK;
+      break;
+    case CALLING_BACK_AND_FINISHED:
+      delete = 1;
+      break;
+  }
+  gpr_mu_unlock(&w->mu);
+
+  if (delete) {
+    delete_state_watcher(exec_ctx, w);
+  }
+}
+
+static void partly_done(grpc_exec_ctx *exec_ctx, state_watcher *w,
+                        int due_to_completion) {
+  int delete = 0;
+
+  if (due_to_completion) {
+    grpc_timer_cancel(exec_ctx, &w->alarm);
+  }
+
+  gpr_mu_lock(&w->mu);
+  if (due_to_completion) {
+    w->success = 1;
+  }
+  switch (w->phase) {
+    case WAITING:
+      w->phase = CALLING_BACK;
+      grpc_cq_end_op(exec_ctx, w->cq, w->tag, w->success, finished_completion,
+                     w, &w->completion_storage);
+      break;
+    case CALLING_BACK:
+      w->phase = CALLING_BACK_AND_FINISHED;
+      break;
+    case CALLING_BACK_AND_FINISHED:
+      GPR_UNREACHABLE_CODE(return );
+    case CALLED_BACK:
+      delete = 1;
+      break;
+  }
+  gpr_mu_unlock(&w->mu);
+
+  if (delete) {
+    delete_state_watcher(exec_ctx, w);
+  }
+}
+
+static void watch_complete(grpc_exec_ctx *exec_ctx, void *pw, bool success) {
+  partly_done(exec_ctx, pw, 1);
+}
+
+static void timeout_complete(grpc_exec_ctx *exec_ctx, void *pw, bool success) {
+  partly_done(exec_ctx, pw, 0);
+}
+
+void grpc_channel_watch_connectivity_state(
+    grpc_channel *channel, grpc_connectivity_state last_observed_state,
+    gpr_timespec deadline, grpc_completion_queue *cq, void *tag) {
+  grpc_channel_element *client_channel_elem =
+      grpc_channel_stack_last_element(grpc_channel_get_channel_stack(channel));
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  state_watcher *w = gpr_malloc(sizeof(*w));
+
+  GRPC_API_TRACE(
+      "grpc_channel_watch_connectivity_state("
+      "channel=%p, last_observed_state=%d, "
+      "deadline=gpr_timespec { tv_sec: %lld, tv_nsec: %d, clock_type: %d }, "
+      "cq=%p, tag=%p)",
+      7, (channel, (int)last_observed_state, (long long)deadline.tv_sec,
+          (int)deadline.tv_nsec, (int)deadline.clock_type, cq, tag));
+
+  grpc_cq_begin_op(cq, tag);
+
+  gpr_mu_init(&w->mu);
+  grpc_closure_init(&w->on_complete, watch_complete, w);
+  w->phase = WAITING;
+  w->state = last_observed_state;
+  w->success = 0;
+  w->cq = cq;
+  w->tag = tag;
+  w->channel = channel;
+
+  grpc_timer_init(&exec_ctx, &w->alarm,
+                  gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC),
+                  timeout_complete, w, gpr_now(GPR_CLOCK_MONOTONIC));
+
+  if (client_channel_elem->filter == &grpc_client_channel_filter) {
+    GRPC_CHANNEL_INTERNAL_REF(channel, "watch_channel_connectivity");
+    grpc_client_channel_watch_connectivity_state(&exec_ctx, client_channel_elem,
+                                                 grpc_cq_pollset(cq), &w->state,
+                                                 &w->on_complete);
+  } else {
+    abort();
+  }
+
+  grpc_exec_ctx_finish(&exec_ctx);
+}
diff --git a/src/core/lib/surface/channel_create.c b/src/core/lib/surface/channel_create.c
new file mode 100644
index 0000000000..e8777ce816
--- /dev/null
+++ b/src/core/lib/surface/channel_create.c
@@ -0,0 +1,223 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <grpc/grpc.h>
+
+#include <stdlib.h>
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/slice.h>
+#include <grpc/support/slice_buffer.h>
+
+#include "src/core/lib/census/grpc_filter.h"
+#include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/channel/client_channel.h"
+#include "src/core/lib/channel/compress_filter.h"
+#include "src/core/lib/channel/http_client_filter.h"
+#include "src/core/lib/client_config/resolver_registry.h"
+#include "src/core/lib/iomgr/tcp_client.h"
+#include "src/core/lib/surface/api_trace.h"
+#include "src/core/lib/surface/channel.h"
+#include "src/core/lib/transport/chttp2_transport.h"
+
+typedef struct {
+  grpc_connector base;
+  gpr_refcount refs;
+
+  grpc_closure *notify;
+  grpc_connect_in_args args;
+  grpc_connect_out_args *result;
+  grpc_closure initial_string_sent;
+  gpr_slice_buffer initial_string_buffer;
+
+  grpc_endpoint *tcp;
+
+  grpc_closure connected;
+} connector;
+
+static void connector_ref(grpc_connector *con) {
+  connector *c = (connector *)con;
+  gpr_ref(&c->refs);
+}
+
+static void connector_unref(grpc_exec_ctx *exec_ctx, grpc_connector *con) {
+  connector *c = (connector *)con;
+  if (gpr_unref(&c->refs)) {
+    /* c->initial_string_buffer does not need to be destroyed */
+    gpr_free(c);
+  }
+}
+
+static void on_initial_connect_string_sent(grpc_exec_ctx *exec_ctx, void *arg,
+                                           bool success) {
+  connector_unref(exec_ctx, arg);
+}
+
+static void connected(grpc_exec_ctx *exec_ctx, void *arg, bool success) {
+  connector *c = arg;
+  grpc_closure *notify;
+  grpc_endpoint *tcp = c->tcp;
+  if (tcp != NULL) {
+    if (!GPR_SLICE_IS_EMPTY(c->args.initial_connect_string)) {
+      grpc_closure_init(&c->initial_string_sent, on_initial_connect_string_sent,
+                        c);
+      gpr_slice_buffer_init(&c->initial_string_buffer);
+      gpr_slice_buffer_add(&c->initial_string_buffer,
+                           c->args.initial_connect_string);
+      connector_ref(arg);
+      grpc_endpoint_write(exec_ctx, tcp, &c->initial_string_buffer,
+                          &c->initial_string_sent);
+    }
+    c->result->transport =
+        grpc_create_chttp2_transport(exec_ctx, c->args.channel_args, tcp, 1);
+    grpc_chttp2_transport_start_reading(exec_ctx, c->result->transport, NULL,
+                                        0);
+    GPR_ASSERT(c->result->transport);
+    c->result->channel_args = c->args.channel_args;
+  } else {
+    memset(c->result, 0, sizeof(*c->result));
+  }
+  notify = c->notify;
+  c->notify = NULL;
+  notify->cb(exec_ctx, notify->cb_arg, 1);
+}
+
+static void connector_shutdown(grpc_exec_ctx *exec_ctx, grpc_connector *con) {}
+
+static void connector_connect(grpc_exec_ctx *exec_ctx, grpc_connector *con,
+                              const grpc_connect_in_args *args,
+                              grpc_connect_out_args *result,
+                              grpc_closure *notify) {
+  connector *c = (connector *)con;
+  GPR_ASSERT(c->notify == NULL);
+  GPR_ASSERT(notify->cb);
+  c->notify = notify;
+  c->args = *args;
+  c->result = result;
+  c->tcp = NULL;
+  grpc_closure_init(&c->connected, connected, c);
+  grpc_tcp_client_connect(exec_ctx, &c->connected, &c->tcp,
+                          args->interested_parties, args->addr, args->addr_len,
+                          args->deadline);
+}
+
+static const grpc_connector_vtable connector_vtable = {
+    connector_ref, connector_unref, connector_shutdown, connector_connect};
+
+typedef struct {
+  grpc_subchannel_factory base;
+  gpr_refcount refs;
+  grpc_channel_args *merge_args;
+  grpc_channel *master;
+} subchannel_factory;
+
+static void subchannel_factory_ref(grpc_subchannel_factory *scf) {
+  subchannel_factory *f = (subchannel_factory *)scf;
+  gpr_ref(&f->refs);
+}
+
+static void subchannel_factory_unref(grpc_exec_ctx *exec_ctx,
+                                     grpc_subchannel_factory *scf) {
+  subchannel_factory *f = (subchannel_factory *)scf;
+  if (gpr_unref(&f->refs)) {
+    GRPC_CHANNEL_INTERNAL_UNREF(exec_ctx, f->master, "subchannel_factory");
+    grpc_channel_args_destroy(f->merge_args);
+    gpr_free(f);
+  }
+}
+
+static grpc_subchannel *subchannel_factory_create_subchannel(
+    grpc_exec_ctx *exec_ctx, grpc_subchannel_factory *scf,
+    grpc_subchannel_args *args) {
+  subchannel_factory *f = (subchannel_factory *)scf;
+  connector *c = gpr_malloc(sizeof(*c));
+  grpc_channel_args *final_args =
+      grpc_channel_args_merge(args->args, f->merge_args);
+  grpc_subchannel *s;
+  memset(c, 0, sizeof(*c));
+  c->base.vtable = &connector_vtable;
+  gpr_ref_init(&c->refs, 1);
+  args->args = final_args;
+  s = grpc_subchannel_create(exec_ctx, &c->base, args);
+  grpc_connector_unref(exec_ctx, &c->base);
+  grpc_channel_args_destroy(final_args);
+  return s;
+}
+
+static const grpc_subchannel_factory_vtable subchannel_factory_vtable = {
+    subchannel_factory_ref, subchannel_factory_unref,
+    subchannel_factory_create_subchannel};
+
+/* Create a client channel:
+   Asynchronously: - resolve target
+                   - connect to it (trying alternatives as presented)
+                   - perform handshakes */
+grpc_channel *grpc_insecure_channel_create(const char *target,
+                                           const grpc_channel_args *args,
+                                           void *reserved) {
+  grpc_channel *channel = NULL;
+  grpc_resolver *resolver;
+  subchannel_factory *f;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  GRPC_API_TRACE(
+      "grpc_insecure_channel_create(target=%p, args=%p, reserved=%p)", 3,
+      (target, args, reserved));
+  GPR_ASSERT(!reserved);
+
+  channel =
+      grpc_channel_create(&exec_ctx, target, args, GRPC_CLIENT_CHANNEL, NULL);
+
+  f = gpr_malloc(sizeof(*f));
+  f->base.vtable = &subchannel_factory_vtable;
+  gpr_ref_init(&f->refs, 1);
+  f->merge_args = grpc_channel_args_copy(args);
+  f->master = channel;
+  GRPC_CHANNEL_INTERNAL_REF(f->master, "subchannel_factory");
+  resolver = grpc_resolver_create(target, &f->base);
+  if (!resolver) {
+    GRPC_CHANNEL_INTERNAL_UNREF(&exec_ctx, f->master, "subchannel_factory");
+    grpc_subchannel_factory_unref(&exec_ctx, &f->base);
+    grpc_exec_ctx_finish(&exec_ctx);
+    return NULL;
+  }
+
+  grpc_client_channel_set_resolver(
+      &exec_ctx, grpc_channel_get_channel_stack(channel), resolver);
+  GRPC_RESOLVER_UNREF(&exec_ctx, resolver, "create");
+  grpc_subchannel_factory_unref(&exec_ctx, &f->base);
+
+  grpc_exec_ctx_finish(&exec_ctx);
+
+  return channel;
+}
diff --git a/src/core/lib/surface/channel_init.c b/src/core/lib/surface/channel_init.c
new file mode 100644
index 0000000000..fc69f61f77
--- /dev/null
+++ b/src/core/lib/surface/channel_init.c
@@ -0,0 +1,146 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/surface/channel_init.h"
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/useful.h>
+
+typedef struct stage_slot {
+  grpc_channel_init_stage fn;
+  void *arg;
+  int priority;
+  size_t insertion_order;
+} stage_slot;
+
+typedef struct stage_slots {
+  stage_slot *slots;
+  size_t num_slots;
+  size_t cap_slots;
+} stage_slots;
+
+static stage_slots g_slots[GRPC_NUM_CHANNEL_STACK_TYPES];
+static bool g_finalized;
+
+void grpc_channel_init_init(void) {
+  for (int i = 0; i < GRPC_NUM_CHANNEL_STACK_TYPES; i++) {
+    g_slots[i].slots = NULL;
+    g_slots[i].num_slots = 0;
+    g_slots[i].cap_slots = 0;
+  }
+  g_finalized = false;
+}
+
+void grpc_channel_init_register_stage(grpc_channel_stack_type type,
+                                      int priority,
+                                      grpc_channel_init_stage stage,
+                                      void *stage_arg) {
+  GPR_ASSERT(!g_finalized);
+  if (g_slots[type].cap_slots == g_slots[type].num_slots) {
+    g_slots[type].cap_slots = GPR_MAX(8, 3 * g_slots[type].cap_slots / 2);
+    g_slots[type].slots =
+        gpr_realloc(g_slots[type].slots,
+                    g_slots[type].cap_slots * sizeof(*g_slots[type].slots));
+  }
+  stage_slot *s = &g_slots[type].slots[g_slots[type].num_slots++];
+  s->insertion_order = g_slots[type].num_slots;
+  s->priority = priority;
+  s->fn = stage;
+  s->arg = stage_arg;
+}
+
+static int compare_slots(const void *a, const void *b) {
+  const stage_slot *sa = a;
+  const stage_slot *sb = b;
+
+  int c = GPR_ICMP(sa->priority, sb->priority);
+  if (c != 0) return c;
+  return GPR_ICMP(sa->insertion_order, sb->insertion_order);
+}
+
+void grpc_channel_init_finalize(void) {
+  GPR_ASSERT(!g_finalized);
+  for (int i = 0; i < GRPC_NUM_CHANNEL_STACK_TYPES; i++) {
+    qsort(g_slots[i].slots, g_slots[i].num_slots, sizeof(*g_slots[i].slots),
+          compare_slots);
+  }
+  g_finalized = true;
+}
+
+void grpc_channel_init_shutdown(void) {
+  for (int i = 0; i < GRPC_NUM_CHANNEL_STACK_TYPES; i++) {
+    gpr_free(g_slots[i].slots);
+    g_slots[i].slots = (void *)(uintptr_t)0xdeadbeef;
+  }
+}
+
+static const char *name_for_type(grpc_channel_stack_type type) {
+  switch (type) {
+    case GRPC_CLIENT_CHANNEL:
+      return "CLIENT_CHANNEL";
+    case GRPC_CLIENT_SUBCHANNEL:
+      return "CLIENT_SUBCHANNEL";
+    case GRPC_SERVER_CHANNEL:
+      return "SERVER_CHANNEL";
+    case GRPC_CLIENT_LAME_CHANNEL:
+      return "CLIENT_LAME_CHANNEL";
+    case GRPC_CLIENT_DIRECT_CHANNEL:
+      return "CLIENT_DIRECT_CHANNEL";
+    case GRPC_NUM_CHANNEL_STACK_TYPES:
+      break;
+  }
+  GPR_UNREACHABLE_CODE(return "UNKNOWN");
+}
+
+void *grpc_channel_init_create_stack(
+    grpc_exec_ctx *exec_ctx, grpc_channel_stack_type type, size_t prefix_bytes,
+    const grpc_channel_args *args, int initial_refs, grpc_iomgr_cb_func destroy,
+    void *destroy_arg, grpc_transport *transport) {
+  GPR_ASSERT(g_finalized);
+
+  grpc_channel_stack_builder *builder = grpc_channel_stack_builder_create();
+  grpc_channel_stack_builder_set_name(builder, name_for_type(type));
+  grpc_channel_stack_builder_set_channel_arguments(builder, args);
+  grpc_channel_stack_builder_set_transport(builder, transport);
+
+  for (size_t i = 0; i < g_slots[type].num_slots; i++) {
+    const stage_slot *slot = &g_slots[type].slots[i];
+    if (!slot->fn(builder, slot->arg)) {
+      grpc_channel_stack_builder_destroy(builder);
+      return NULL;
+    }
+  }
+
+  return grpc_channel_stack_builder_finish(exec_ctx, builder, prefix_bytes,
+                                           initial_refs, destroy, destroy_arg);
+}
diff --git a/src/core/lib/surface/channel_init.h b/src/core/lib/surface/channel_init.h
new file mode 100644
index 0000000000..a4d8271ca6
--- /dev/null
+++ b/src/core/lib/surface/channel_init.h
@@ -0,0 +1,86 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_SURFACE_CHANNEL_INIT_H
+#define GRPC_CORE_LIB_SURFACE_CHANNEL_INIT_H
+
+#include "src/core/lib/channel/channel_stack_builder.h"
+#include "src/core/lib/surface/channel_stack_type.h"
+#include "src/core/lib/transport/transport.h"
+
+/// This module provides a way for plugins (and the grpc core library itself)
+/// to register mutators for channel stacks.
+/// It also provides a universal entry path to run those mutators to build
+/// a channel stack for various subsystems.
+
+/// One stage of mutation: call functions against \a builder to influence the
+/// finally constructed channel stack
+typedef bool (*grpc_channel_init_stage)(grpc_channel_stack_builder *builder,
+                                        void *arg);
+
+/// Global initialization of the system
+void grpc_channel_init_init(void);
+
+/// Register one stage of mutators.
+/// Stages are run in priority order (lowest to highest), and then in
+/// registration order (in the case of a tie).
+/// Stages are registered against one of the pre-determined channel stack
+/// types.
+void grpc_channel_init_register_stage(grpc_channel_stack_type type,
+                                      int priority,
+                                      grpc_channel_init_stage stage_fn,
+                                      void *stage_arg);
+
+/// Finalize registration. No more calls to grpc_channel_init_register_stage are
+/// allowed.
+void grpc_channel_init_finalize(void);
+/// Shutdown the channel init system
+void grpc_channel_init_shutdown(void);
+
+/// Construct a channel stack of some sort: see channel_stack.h for details
+/// \a type is the type of channel stack to create
+/// \a prefix_bytes is the number of bytes before the channel stack to allocate
+/// \a args are configuration arguments for the channel stack
+/// \a initial_refs is the initial refcount to give the channel stack
+/// \a destroy and \a destroy_arg specify how to destroy the channel stack
+///    if destroy_arg is NULL, the returned value from this function will be
+///    substituted
+/// \a optional_transport is either NULL or a constructed transport object
+/// Returns a pointer to the base of the memory allocated (the actual channel
+/// stack object will be prefix_bytes past that pointer)
+void *grpc_channel_init_create_stack(
+    grpc_exec_ctx *exec_ctx, grpc_channel_stack_type type, size_t prefix_bytes,
+    const grpc_channel_args *args, int initial_refs, grpc_iomgr_cb_func destroy,
+    void *destroy_arg, grpc_transport *optional_transport);
+
+#endif /* GRPC_CORE_LIB_SURFACE_CHANNEL_INIT_H */
diff --git a/src/core/lib/surface/channel_ping.c b/src/core/lib/surface/channel_ping.c
new file mode 100644
index 0000000000..dd862cdadd
--- /dev/null
+++ b/src/core/lib/surface/channel_ping.c
@@ -0,0 +1,79 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/surface/channel.h"
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+
+#include "src/core/lib/surface/api_trace.h"
+#include "src/core/lib/surface/completion_queue.h"
+
+typedef struct {
+  grpc_closure closure;
+  void *tag;
+  grpc_completion_queue *cq;
+  grpc_cq_completion completion_storage;
+} ping_result;
+
+static void ping_destroy(grpc_exec_ctx *exec_ctx, void *arg,
+                         grpc_cq_completion *storage) {
+  gpr_free(arg);
+}
+
+static void ping_done(grpc_exec_ctx *exec_ctx, void *arg, bool success) {
+  ping_result *pr = arg;
+  grpc_cq_end_op(exec_ctx, pr->cq, pr->tag, success, ping_destroy, pr,
+                 &pr->completion_storage);
+}
+
+void grpc_channel_ping(grpc_channel *channel, grpc_completion_queue *cq,
+                       void *tag, void *reserved) {
+  grpc_transport_op op;
+  ping_result *pr = gpr_malloc(sizeof(*pr));
+  grpc_channel_element *top_elem =
+      grpc_channel_stack_element(grpc_channel_get_channel_stack(channel), 0);
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  GPR_ASSERT(reserved == NULL);
+  memset(&op, 0, sizeof(op));
+  pr->tag = tag;
+  pr->cq = cq;
+  grpc_closure_init(&pr->closure, ping_done, pr);
+  op.send_ping = &pr->closure;
+  op.bind_pollset = grpc_cq_pollset(cq);
+  grpc_cq_begin_op(cq, tag);
+  top_elem->filter->start_transport_op(&exec_ctx, top_elem, &op);
+  grpc_exec_ctx_finish(&exec_ctx);
+}
diff --git a/src/core/lib/surface/channel_stack_type.c b/src/core/lib/surface/channel_stack_type.c
new file mode 100644
index 0000000000..c35d603ca3
--- /dev/null
+++ b/src/core/lib/surface/channel_stack_type.c
@@ -0,0 +1,54 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/surface/channel_stack_type.h"
+#include <grpc/support/log.h>
+#include <grpc/support/port_platform.h>
+
+bool grpc_channel_stack_type_is_client(grpc_channel_stack_type type) {
+  switch (type) {
+    case GRPC_CLIENT_CHANNEL:
+      return true;
+    case GRPC_CLIENT_SUBCHANNEL:
+      return true;
+    case GRPC_CLIENT_LAME_CHANNEL:
+      return true;
+    case GRPC_CLIENT_DIRECT_CHANNEL:
+      return true;
+    case GRPC_SERVER_CHANNEL:
+      return false;
+    case GRPC_NUM_CHANNEL_STACK_TYPES:
+      break;
+  }
+  GPR_UNREACHABLE_CODE(return true;);
+}
diff --git a/src/core/lib/surface/channel_stack_type.h b/src/core/lib/surface/channel_stack_type.h
new file mode 100644
index 0000000000..16608fa386
--- /dev/null
+++ b/src/core/lib/surface/channel_stack_type.h
@@ -0,0 +1,58 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_SURFACE_CHANNEL_STACK_TYPE_H
+#define GRPC_CORE_LIB_SURFACE_CHANNEL_STACK_TYPE_H
+
+#include <stdbool.h>
+
+typedef enum {
+  // normal top-half client channel with load-balancing, connection management
+  GRPC_CLIENT_CHANNEL,
+  // bottom-half of a client channel: everything that happens post-load
+  // balancing (bound to a specific transport)
+  GRPC_CLIENT_SUBCHANNEL,
+  // a permanently broken client channel
+  GRPC_CLIENT_LAME_CHANNEL,
+  // a directly connected client channel (without load-balancing, directly talks
+  // to a transport)
+  GRPC_CLIENT_DIRECT_CHANNEL,
+  // server side channel
+  GRPC_SERVER_CHANNEL,
+  // must be last
+  GRPC_NUM_CHANNEL_STACK_TYPES
+} grpc_channel_stack_type;
+
+bool grpc_channel_stack_type_is_client(grpc_channel_stack_type type);
+
+#endif /* GRPC_CORE_LIB_SURFACE_CHANNEL_STACK_TYPE_H */
diff --git a/src/core/lib/surface/completion_queue.c b/src/core/lib/surface/completion_queue.c
new file mode 100644
index 0000000000..a0d7002053
--- /dev/null
+++ b/src/core/lib/surface/completion_queue.c
@@ -0,0 +1,512 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/surface/completion_queue.h"
+
+#include <stdio.h>
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/atm.h>
+#include <grpc/support/log.h>
+#include <grpc/support/time.h>
+
+#include "src/core/lib/iomgr/pollset.h"
+#include "src/core/lib/iomgr/timer.h"
+#include "src/core/lib/profiling/timers.h"
+#include "src/core/lib/support/string.h"
+#include "src/core/lib/surface/api_trace.h"
+#include "src/core/lib/surface/call.h"
+#include "src/core/lib/surface/event_string.h"
+#include "src/core/lib/surface/surface_trace.h"
+
+typedef struct {
+  grpc_pollset_worker **worker;
+  void *tag;
+} plucker;
+
+/* Completion queue structure */
+struct grpc_completion_queue {
+  /** owned by pollset */
+  gpr_mu *mu;
+  /** completed events */
+  grpc_cq_completion completed_head;
+  grpc_cq_completion *completed_tail;
+  /** Number of pending events (+1 if we're not shutdown) */
+  gpr_refcount pending_events;
+  /** Once owning_refs drops to zero, we will destroy the cq */
+  gpr_refcount owning_refs;
+  /** 0 initially, 1 once we've begun shutting down */
+  int shutdown;
+  int shutdown_called;
+  int is_server_cq;
+  int num_pluckers;
+  plucker pluckers[GRPC_MAX_COMPLETION_QUEUE_PLUCKERS];
+  grpc_closure pollset_shutdown_done;
+
+#ifndef NDEBUG
+  void **outstanding_tags;
+  size_t outstanding_tag_count;
+  size_t outstanding_tag_capacity;
+#endif
+
+  grpc_completion_queue *next_free;
+};
+
+#define POLLSET_FROM_CQ(cq) ((grpc_pollset *)(cq + 1))
+
+static gpr_mu g_freelist_mu;
+static grpc_completion_queue *g_freelist;
+
+static void on_pollset_shutdown_done(grpc_exec_ctx *exec_ctx, void *cc,
+                                     bool success);
+
+void grpc_cq_global_init(void) { gpr_mu_init(&g_freelist_mu); }
+
+void grpc_cq_global_shutdown(void) {
+  gpr_mu_destroy(&g_freelist_mu);
+  while (g_freelist) {
+    grpc_completion_queue *next = g_freelist->next_free;
+    grpc_pollset_destroy(POLLSET_FROM_CQ(g_freelist));
+#ifndef NDEBUG
+    gpr_free(g_freelist->outstanding_tags);
+#endif
+    gpr_free(g_freelist);
+    g_freelist = next;
+  }
+}
+
+struct grpc_cq_alarm {
+  grpc_timer alarm;
+  grpc_cq_completion completion;
+  /** completion queue where events about this alarm will be posted */
+  grpc_completion_queue *cq;
+  /** user supplied tag */
+  void *tag;
+};
+
+grpc_completion_queue *grpc_completion_queue_create(void *reserved) {
+  grpc_completion_queue *cc;
+  GPR_ASSERT(!reserved);
+
+  GPR_TIMER_BEGIN("grpc_completion_queue_create", 0);
+
+  GRPC_API_TRACE("grpc_completion_queue_create(reserved=%p)", 1, (reserved));
+
+  gpr_mu_lock(&g_freelist_mu);
+  if (g_freelist == NULL) {
+    gpr_mu_unlock(&g_freelist_mu);
+
+    cc = gpr_malloc(sizeof(grpc_completion_queue) + grpc_pollset_size());
+    grpc_pollset_init(POLLSET_FROM_CQ(cc), &cc->mu);
+#ifndef NDEBUG
+    cc->outstanding_tags = NULL;
+    cc->outstanding_tag_capacity = 0;
+#endif
+  } else {
+    cc = g_freelist;
+    g_freelist = g_freelist->next_free;
+    gpr_mu_unlock(&g_freelist_mu);
+    /* pollset already initialized */
+  }
+
+  /* Initial ref is dropped by grpc_completion_queue_shutdown */
+  gpr_ref_init(&cc->pending_events, 1);
+  /* One for destroy(), one for pollset_shutdown */
+  gpr_ref_init(&cc->owning_refs, 2);
+  cc->completed_tail = &cc->completed_head;
+  cc->completed_head.next = (uintptr_t)cc->completed_tail;
+  cc->shutdown = 0;
+  cc->shutdown_called = 0;
+  cc->is_server_cq = 0;
+  cc->num_pluckers = 0;
+#ifndef NDEBUG
+  cc->outstanding_tag_count = 0;
+#endif
+  grpc_closure_init(&cc->pollset_shutdown_done, on_pollset_shutdown_done, cc);
+
+  GPR_TIMER_END("grpc_completion_queue_create", 0);
+
+  return cc;
+}
+
+#ifdef GRPC_CQ_REF_COUNT_DEBUG
+void grpc_cq_internal_ref(grpc_completion_queue *cc, const char *reason,
+                          const char *file, int line) {
+  gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "CQ:%p   ref %d -> %d %s", cc,
+          (int)cc->owning_refs.count, (int)cc->owning_refs.count + 1, reason);
+#else
+void grpc_cq_internal_ref(grpc_completion_queue *cc) {
+#endif
+  gpr_ref(&cc->owning_refs);
+}
+
+static void on_pollset_shutdown_done(grpc_exec_ctx *exec_ctx, void *arg,
+                                     bool success) {
+  grpc_completion_queue *cc = arg;
+  GRPC_CQ_INTERNAL_UNREF(cc, "pollset_destroy");
+}
+
+#ifdef GRPC_CQ_REF_COUNT_DEBUG
+void grpc_cq_internal_unref(grpc_completion_queue *cc, const char *reason,
+                            const char *file, int line) {
+  gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "CQ:%p unref %d -> %d %s", cc,
+          (int)cc->owning_refs.count, (int)cc->owning_refs.count - 1, reason);
+#else
+void grpc_cq_internal_unref(grpc_completion_queue *cc) {
+#endif
+  if (gpr_unref(&cc->owning_refs)) {
+    GPR_ASSERT(cc->completed_head.next == (uintptr_t)&cc->completed_head);
+    grpc_pollset_reset(POLLSET_FROM_CQ(cc));
+    gpr_mu_lock(&g_freelist_mu);
+    cc->next_free = g_freelist;
+    g_freelist = cc;
+    gpr_mu_unlock(&g_freelist_mu);
+  }
+}
+
+void grpc_cq_begin_op(grpc_completion_queue *cc, void *tag) {
+#ifndef NDEBUG
+  gpr_mu_lock(cc->mu);
+  GPR_ASSERT(!cc->shutdown_called);
+  if (cc->outstanding_tag_count == cc->outstanding_tag_capacity) {
+    cc->outstanding_tag_capacity = GPR_MAX(4, 2 * cc->outstanding_tag_capacity);
+    cc->outstanding_tags =
+        gpr_realloc(cc->outstanding_tags, sizeof(*cc->outstanding_tags) *
+                                              cc->outstanding_tag_capacity);
+  }
+  cc->outstanding_tags[cc->outstanding_tag_count++] = tag;
+  gpr_mu_unlock(cc->mu);
+#endif
+  gpr_ref(&cc->pending_events);
+}
+
+/* Signal the end of an operation - if this is the last waiting-to-be-queued
+   event, then enter shutdown mode */
+/* Queue a GRPC_OP_COMPLETED operation */
+void grpc_cq_end_op(grpc_exec_ctx *exec_ctx, grpc_completion_queue *cc,
+                    void *tag, int success,
+                    void (*done)(grpc_exec_ctx *exec_ctx, void *done_arg,
+                                 grpc_cq_completion *storage),
+                    void *done_arg, grpc_cq_completion *storage) {
+  int shutdown;
+  int i;
+  grpc_pollset_worker *pluck_worker;
+#ifndef NDEBUG
+  int found = 0;
+#endif
+
+  GPR_TIMER_BEGIN("grpc_cq_end_op", 0);
+
+  storage->tag = tag;
+  storage->done = done;
+  storage->done_arg = done_arg;
+  storage->next =
+      ((uintptr_t)&cc->completed_head) | ((uintptr_t)(success != 0));
+
+  gpr_mu_lock(cc->mu);
+#ifndef NDEBUG
+  for (i = 0; i < (int)cc->outstanding_tag_count; i++) {
+    if (cc->outstanding_tags[i] == tag) {
+      cc->outstanding_tag_count--;
+      GPR_SWAP(void *, cc->outstanding_tags[i],
+               cc->outstanding_tags[cc->outstanding_tag_count]);
+      found = 1;
+      break;
+    }
+  }
+  GPR_ASSERT(found);
+#endif
+  shutdown = gpr_unref(&cc->pending_events);
+  if (!shutdown) {
+    cc->completed_tail->next =
+        ((uintptr_t)storage) | (1u & (uintptr_t)cc->completed_tail->next);
+    cc->completed_tail = storage;
+    pluck_worker = NULL;
+    for (i = 0; i < cc->num_pluckers; i++) {
+      if (cc->pluckers[i].tag == tag) {
+        pluck_worker = *cc->pluckers[i].worker;
+        break;
+      }
+    }
+    grpc_pollset_kick(POLLSET_FROM_CQ(cc), pluck_worker);
+    gpr_mu_unlock(cc->mu);
+  } else {
+    cc->completed_tail->next =
+        ((uintptr_t)storage) | (1u & (uintptr_t)cc->completed_tail->next);
+    cc->completed_tail = storage;
+    GPR_ASSERT(!cc->shutdown);
+    GPR_ASSERT(cc->shutdown_called);
+    cc->shutdown = 1;
+    grpc_pollset_shutdown(exec_ctx, POLLSET_FROM_CQ(cc),
+                          &cc->pollset_shutdown_done);
+    gpr_mu_unlock(cc->mu);
+  }
+
+  GPR_TIMER_END("grpc_cq_end_op", 0);
+}
+
+grpc_event grpc_completion_queue_next(grpc_completion_queue *cc,
+                                      gpr_timespec deadline, void *reserved) {
+  grpc_event ret;
+  grpc_pollset_worker *worker = NULL;
+  int first_loop = 1;
+  gpr_timespec now;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+
+  GPR_TIMER_BEGIN("grpc_completion_queue_next", 0);
+
+  GRPC_API_TRACE(
+      "grpc_completion_queue_next("
+      "cc=%p, "
+      "deadline=gpr_timespec { tv_sec: %lld, tv_nsec: %d, clock_type: %d }, "
+      "reserved=%p)",
+      5, (cc, (long long)deadline.tv_sec, (int)deadline.tv_nsec,
+          (int)deadline.clock_type, reserved));
+  GPR_ASSERT(!reserved);
+
+  deadline = gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC);
+
+  GRPC_CQ_INTERNAL_REF(cc, "next");
+  gpr_mu_lock(cc->mu);
+  for (;;) {
+    if (cc->completed_tail != &cc->completed_head) {
+      grpc_cq_completion *c = (grpc_cq_completion *)cc->completed_head.next;
+      cc->completed_head.next = c->next & ~(uintptr_t)1;
+      if (c == cc->completed_tail) {
+        cc->completed_tail = &cc->completed_head;
+      }
+      gpr_mu_unlock(cc->mu);
+      ret.type = GRPC_OP_COMPLETE;
+      ret.success = c->next & 1u;
+      ret.tag = c->tag;
+      c->done(&exec_ctx, c->done_arg, c);
+      break;
+    }
+    if (cc->shutdown) {
+      gpr_mu_unlock(cc->mu);
+      memset(&ret, 0, sizeof(ret));
+      ret.type = GRPC_QUEUE_SHUTDOWN;
+      break;
+    }
+    now = gpr_now(GPR_CLOCK_MONOTONIC);
+    if (!first_loop && gpr_time_cmp(now, deadline) >= 0) {
+      gpr_mu_unlock(cc->mu);
+      memset(&ret, 0, sizeof(ret));
+      ret.type = GRPC_QUEUE_TIMEOUT;
+      break;
+    }
+    first_loop = 0;
+    /* Check alarms - these are a global resource so we just ping
+       each time through on every pollset.
+       May update deadline to ensure timely wakeups.
+       TODO(ctiller): can this work be localized? */
+    gpr_timespec iteration_deadline = deadline;
+    if (grpc_timer_check(&exec_ctx, now, &iteration_deadline)) {
+      GPR_TIMER_MARK("alarm_triggered", 0);
+      gpr_mu_unlock(cc->mu);
+      grpc_exec_ctx_flush(&exec_ctx);
+      gpr_mu_lock(cc->mu);
+      continue;
+    } else {
+      grpc_pollset_work(&exec_ctx, POLLSET_FROM_CQ(cc), &worker, now,
+                        iteration_deadline);
+    }
+  }
+  GRPC_SURFACE_TRACE_RETURNED_EVENT(cc, &ret);
+  GRPC_CQ_INTERNAL_UNREF(cc, "next");
+  grpc_exec_ctx_finish(&exec_ctx);
+
+  GPR_TIMER_END("grpc_completion_queue_next", 0);
+
+  return ret;
+}
+
+static int add_plucker(grpc_completion_queue *cc, void *tag,
+                       grpc_pollset_worker **worker) {
+  if (cc->num_pluckers == GRPC_MAX_COMPLETION_QUEUE_PLUCKERS) {
+    return 0;
+  }
+  cc->pluckers[cc->num_pluckers].tag = tag;
+  cc->pluckers[cc->num_pluckers].worker = worker;
+  cc->num_pluckers++;
+  return 1;
+}
+
+static void del_plucker(grpc_completion_queue *cc, void *tag,
+                        grpc_pollset_worker **worker) {
+  int i;
+  for (i = 0; i < cc->num_pluckers; i++) {
+    if (cc->pluckers[i].tag == tag && cc->pluckers[i].worker == worker) {
+      cc->num_pluckers--;
+      GPR_SWAP(plucker, cc->pluckers[i], cc->pluckers[cc->num_pluckers]);
+      return;
+    }
+  }
+  GPR_UNREACHABLE_CODE(return );
+}
+
+grpc_event grpc_completion_queue_pluck(grpc_completion_queue *cc, void *tag,
+                                       gpr_timespec deadline, void *reserved) {
+  grpc_event ret;
+  grpc_cq_completion *c;
+  grpc_cq_completion *prev;
+  grpc_pollset_worker *worker = NULL;
+  gpr_timespec now;
+  int first_loop = 1;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+
+  GPR_TIMER_BEGIN("grpc_completion_queue_pluck", 0);
+
+  GRPC_API_TRACE(
+      "grpc_completion_queue_pluck("
+      "cc=%p, tag=%p, "
+      "deadline=gpr_timespec { tv_sec: %lld, tv_nsec: %d, clock_type: %d }, "
+      "reserved=%p)",
+      6, (cc, tag, (long long)deadline.tv_sec, (int)deadline.tv_nsec,
+          (int)deadline.clock_type, reserved));
+  GPR_ASSERT(!reserved);
+
+  deadline = gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC);
+
+  GRPC_CQ_INTERNAL_REF(cc, "pluck");
+  gpr_mu_lock(cc->mu);
+  for (;;) {
+    prev = &cc->completed_head;
+    while ((c = (grpc_cq_completion *)(prev->next & ~(uintptr_t)1)) !=
+           &cc->completed_head) {
+      if (c->tag == tag) {
+        prev->next = (prev->next & (uintptr_t)1) | (c->next & ~(uintptr_t)1);
+        if (c == cc->completed_tail) {
+          cc->completed_tail = prev;
+        }
+        gpr_mu_unlock(cc->mu);
+        ret.type = GRPC_OP_COMPLETE;
+        ret.success = c->next & 1u;
+        ret.tag = c->tag;
+        c->done(&exec_ctx, c->done_arg, c);
+        goto done;
+      }
+      prev = c;
+    }
+    if (cc->shutdown) {
+      gpr_mu_unlock(cc->mu);
+      memset(&ret, 0, sizeof(ret));
+      ret.type = GRPC_QUEUE_SHUTDOWN;
+      break;
+    }
+    if (!add_plucker(cc, tag, &worker)) {
+      gpr_log(GPR_DEBUG,
+              "Too many outstanding grpc_completion_queue_pluck calls: maximum "
+              "is %d",
+              GRPC_MAX_COMPLETION_QUEUE_PLUCKERS);
+      gpr_mu_unlock(cc->mu);
+      memset(&ret, 0, sizeof(ret));
+      /* TODO(ctiller): should we use a different result here */
+      ret.type = GRPC_QUEUE_TIMEOUT;
+      break;
+    }
+    now = gpr_now(GPR_CLOCK_MONOTONIC);
+    if (!first_loop && gpr_time_cmp(now, deadline) >= 0) {
+      del_plucker(cc, tag, &worker);
+      gpr_mu_unlock(cc->mu);
+      memset(&ret, 0, sizeof(ret));
+      ret.type = GRPC_QUEUE_TIMEOUT;
+      break;
+    }
+    first_loop = 0;
+    /* Check alarms - these are a global resource so we just ping
+       each time through on every pollset.
+       May update deadline to ensure timely wakeups.
+       TODO(ctiller): can this work be localized? */
+    gpr_timespec iteration_deadline = deadline;
+    if (grpc_timer_check(&exec_ctx, now, &iteration_deadline)) {
+      GPR_TIMER_MARK("alarm_triggered", 0);
+      gpr_mu_unlock(cc->mu);
+      grpc_exec_ctx_flush(&exec_ctx);
+      gpr_mu_lock(cc->mu);
+    } else {
+      grpc_pollset_work(&exec_ctx, POLLSET_FROM_CQ(cc), &worker, now,
+                        iteration_deadline);
+    }
+    del_plucker(cc, tag, &worker);
+  }
+done:
+  GRPC_SURFACE_TRACE_RETURNED_EVENT(cc, &ret);
+  GRPC_CQ_INTERNAL_UNREF(cc, "pluck");
+  grpc_exec_ctx_finish(&exec_ctx);
+
+  GPR_TIMER_END("grpc_completion_queue_pluck", 0);
+
+  return ret;
+}
+
+/* Shutdown simply drops a ref that we reserved at creation time; if we drop
+   to zero here, then enter shutdown mode and wake up any waiters */
+void grpc_completion_queue_shutdown(grpc_completion_queue *cc) {
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  GPR_TIMER_BEGIN("grpc_completion_queue_shutdown", 0);
+  GRPC_API_TRACE("grpc_completion_queue_shutdown(cc=%p)", 1, (cc));
+  gpr_mu_lock(cc->mu);
+  if (cc->shutdown_called) {
+    gpr_mu_unlock(cc->mu);
+    GPR_TIMER_END("grpc_completion_queue_shutdown", 0);
+    return;
+  }
+  cc->shutdown_called = 1;
+  if (gpr_unref(&cc->pending_events)) {
+    GPR_ASSERT(!cc->shutdown);
+    cc->shutdown = 1;
+    grpc_pollset_shutdown(&exec_ctx, POLLSET_FROM_CQ(cc),
+                          &cc->pollset_shutdown_done);
+  }
+  gpr_mu_unlock(cc->mu);
+  grpc_exec_ctx_finish(&exec_ctx);
+  GPR_TIMER_END("grpc_completion_queue_shutdown", 0);
+}
+
+void grpc_completion_queue_destroy(grpc_completion_queue *cc) {
+  GRPC_API_TRACE("grpc_completion_queue_destroy(cc=%p)", 1, (cc));
+  GPR_TIMER_BEGIN("grpc_completion_queue_destroy", 0);
+  grpc_completion_queue_shutdown(cc);
+  GRPC_CQ_INTERNAL_UNREF(cc, "destroy");
+  GPR_TIMER_END("grpc_completion_queue_destroy", 0);
+}
+
+grpc_pollset *grpc_cq_pollset(grpc_completion_queue *cc) {
+  return POLLSET_FROM_CQ(cc);
+}
+
+void grpc_cq_mark_server_cq(grpc_completion_queue *cc) { cc->is_server_cq = 1; }
+
+int grpc_cq_is_server_cq(grpc_completion_queue *cc) { return cc->is_server_cq; }
diff --git a/src/core/lib/surface/completion_queue.h b/src/core/lib/surface/completion_queue.h
new file mode 100644
index 0000000000..35591cb6f4
--- /dev/null
+++ b/src/core/lib/surface/completion_queue.h
@@ -0,0 +1,91 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_SURFACE_COMPLETION_QUEUE_H
+#define GRPC_CORE_LIB_SURFACE_COMPLETION_QUEUE_H
+
+/* Internal API for completion queues */
+
+#include <grpc/grpc.h>
+#include "src/core/lib/iomgr/pollset.h"
+
+typedef struct grpc_cq_completion {
+  /** user supplied tag */
+  void *tag;
+  /** done callback - called when this queue element is no longer
+      needed by the completion queue */
+  void (*done)(grpc_exec_ctx *exec_ctx, void *done_arg,
+               struct grpc_cq_completion *c);
+  void *done_arg;
+  /** next pointer; low bit is used to indicate success or not */
+  uintptr_t next;
+} grpc_cq_completion;
+
+#ifdef GRPC_CQ_REF_COUNT_DEBUG
+void grpc_cq_internal_ref(grpc_completion_queue *cc, const char *reason,
+                          const char *file, int line);
+void grpc_cq_internal_unref(grpc_completion_queue *cc, const char *reason,
+                            const char *file, int line);
+#define GRPC_CQ_INTERNAL_REF(cc, reason) \
+  grpc_cq_internal_ref(cc, reason, __FILE__, __LINE__)
+#define GRPC_CQ_INTERNAL_UNREF(cc, reason) \
+  grpc_cq_internal_unref(cc, reason, __FILE__, __LINE__)
+#else
+void grpc_cq_internal_ref(grpc_completion_queue *cc);
+void grpc_cq_internal_unref(grpc_completion_queue *cc);
+#define GRPC_CQ_INTERNAL_REF(cc, reason) grpc_cq_internal_ref(cc)
+#define GRPC_CQ_INTERNAL_UNREF(cc, reason) grpc_cq_internal_unref(cc)
+#endif
+
+/* Flag that an operation is beginning: the completion channel will not finish
+   shutdown until a corrensponding grpc_cq_end_* call is made.
+   \a tag is currently used only in debug builds. */
+void grpc_cq_begin_op(grpc_completion_queue *cc, void *tag);
+
+/* Queue a GRPC_OP_COMPLETED operation; tag must correspond to the tag passed to
+   grpc_cq_begin_op */
+void grpc_cq_end_op(grpc_exec_ctx *exec_ctx, grpc_completion_queue *cc,
+                    void *tag, int success,
+                    void (*done)(grpc_exec_ctx *exec_ctx, void *done_arg,
+                                 grpc_cq_completion *storage),
+                    void *done_arg, grpc_cq_completion *storage);
+
+grpc_pollset *grpc_cq_pollset(grpc_completion_queue *cc);
+
+void grpc_cq_mark_server_cq(grpc_completion_queue *cc);
+int grpc_cq_is_server_cq(grpc_completion_queue *cc);
+
+void grpc_cq_global_init(void);
+void grpc_cq_global_shutdown(void);
+
+#endif /* GRPC_CORE_LIB_SURFACE_COMPLETION_QUEUE_H */
diff --git a/src/core/lib/surface/event_string.c b/src/core/lib/surface/event_string.c
new file mode 100644
index 0000000000..360c718a17
--- /dev/null
+++ b/src/core/lib/surface/event_string.c
@@ -0,0 +1,81 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/surface/event_string.h"
+
+#include <stdio.h>
+
+#include <grpc/byte_buffer.h>
+#include <grpc/support/string_util.h>
+#include "src/core/lib/support/string.h"
+
+static void addhdr(gpr_strvec *buf, grpc_event *ev) {
+  char *tmp;
+  gpr_asprintf(&tmp, "tag:%p", ev->tag);
+  gpr_strvec_add(buf, tmp);
+}
+
+static const char *errstr(int success) { return success ? "OK" : "ERROR"; }
+
+static void adderr(gpr_strvec *buf, int success) {
+  char *tmp;
+  gpr_asprintf(&tmp, " %s", errstr(success));
+  gpr_strvec_add(buf, tmp);
+}
+
+char *grpc_event_string(grpc_event *ev) {
+  char *out;
+  gpr_strvec buf;
+
+  if (ev == NULL) return gpr_strdup("null");
+
+  gpr_strvec_init(&buf);
+
+  switch (ev->type) {
+    case GRPC_QUEUE_TIMEOUT:
+      gpr_strvec_add(&buf, gpr_strdup("QUEUE_TIMEOUT"));
+      break;
+    case GRPC_QUEUE_SHUTDOWN:
+      gpr_strvec_add(&buf, gpr_strdup("QUEUE_SHUTDOWN"));
+      break;
+    case GRPC_OP_COMPLETE:
+      gpr_strvec_add(&buf, gpr_strdup("OP_COMPLETE: "));
+      addhdr(&buf, ev);
+      adderr(&buf, ev->success);
+      break;
+  }
+
+  out = gpr_strvec_flatten(&buf, NULL);
+  gpr_strvec_destroy(&buf);
+  return out;
+}
diff --git a/src/core/lib/surface/event_string.h b/src/core/lib/surface/event_string.h
new file mode 100644
index 0000000000..577e9c718f
--- /dev/null
+++ b/src/core/lib/surface/event_string.h
@@ -0,0 +1,42 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_SURFACE_EVENT_STRING_H
+#define GRPC_CORE_LIB_SURFACE_EVENT_STRING_H
+
+#include <grpc/grpc.h>
+
+/* Returns a string describing an event. Must be later freed with gpr_free() */
+char *grpc_event_string(grpc_event *ev);
+
+#endif /* GRPC_CORE_LIB_SURFACE_EVENT_STRING_H */
diff --git a/src/core/lib/surface/init.c b/src/core/lib/surface/init.c
new file mode 100644
index 0000000000..b5546fb44a
--- /dev/null
+++ b/src/core/lib/surface/init.c
@@ -0,0 +1,239 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <grpc/support/port_platform.h>
+
+#include <limits.h>
+#include <memory.h>
+
+#include <grpc/grpc.h>
+#include <grpc/support/alloc.h>
+#include <grpc/support/time.h>
+/* TODO(ctiller): find another way? - better not to include census here */
+#include "src/core/lib/census/grpc_plugin.h"
+#include "src/core/lib/channel/channel_stack.h"
+#include "src/core/lib/channel/client_channel.h"
+#include "src/core/lib/channel/compress_filter.h"
+#include "src/core/lib/channel/connected_channel.h"
+#include "src/core/lib/channel/http_client_filter.h"
+#include "src/core/lib/channel/http_server_filter.h"
+#include "src/core/lib/client_config/lb_policies/pick_first.h"
+#include "src/core/lib/client_config/lb_policies/round_robin.h"
+#include "src/core/lib/client_config/lb_policy_registry.h"
+#include "src/core/lib/client_config/resolver_registry.h"
+#include "src/core/lib/client_config/resolvers/dns_resolver.h"
+#include "src/core/lib/client_config/resolvers/sockaddr_resolver.h"
+#include "src/core/lib/client_config/subchannel.h"
+#include "src/core/lib/client_config/subchannel_index.h"
+#include "src/core/lib/debug/trace.h"
+#include "src/core/lib/iomgr/executor.h"
+#include "src/core/lib/iomgr/iomgr.h"
+#include "src/core/lib/profiling/timers.h"
+#include "src/core/lib/surface/api_trace.h"
+#include "src/core/lib/surface/call.h"
+#include "src/core/lib/surface/channel_init.h"
+#include "src/core/lib/surface/completion_queue.h"
+#include "src/core/lib/surface/init.h"
+#include "src/core/lib/surface/lame_client.h"
+#include "src/core/lib/surface/server.h"
+#include "src/core/lib/surface/surface_trace.h"
+#include "src/core/lib/transport/chttp2_transport.h"
+#include "src/core/lib/transport/connectivity_state.h"
+#include "src/core/lib/transport/transport_impl.h"
+
+#ifndef GRPC_DEFAULT_NAME_PREFIX
+#define GRPC_DEFAULT_NAME_PREFIX "dns:///"
+#endif
+
+#define MAX_PLUGINS 128
+
+static gpr_once g_basic_init = GPR_ONCE_INIT;
+static gpr_mu g_init_mu;
+static int g_initializations;
+
+static void do_basic_init(void) {
+  gpr_mu_init(&g_init_mu);
+  /* TODO(ctiller): ideally remove this strict linkage */
+  grpc_register_plugin(census_grpc_plugin_init, census_grpc_plugin_destroy);
+  g_initializations = 0;
+}
+
+static bool append_filter(grpc_channel_stack_builder *builder, void *arg) {
+  return grpc_channel_stack_builder_append_filter(
+      builder, (const grpc_channel_filter *)arg, NULL, NULL);
+}
+
+static bool prepend_filter(grpc_channel_stack_builder *builder, void *arg) {
+  return grpc_channel_stack_builder_prepend_filter(
+      builder, (const grpc_channel_filter *)arg, NULL, NULL);
+}
+
+static bool maybe_add_http_filter(grpc_channel_stack_builder *builder,
+                                  void *arg) {
+  grpc_transport *t = grpc_channel_stack_builder_get_transport(builder);
+  if (t && strstr(t->vtable->name, "http")) {
+    return grpc_channel_stack_builder_prepend_filter(
+        builder, (const grpc_channel_filter *)arg, NULL, NULL);
+  }
+  return true;
+}
+
+static void register_builtin_channel_init() {
+  grpc_channel_init_register_stage(GRPC_CLIENT_CHANNEL, INT_MAX, prepend_filter,
+                                   (void *)&grpc_compress_filter);
+  grpc_channel_init_register_stage(GRPC_CLIENT_DIRECT_CHANNEL, INT_MAX,
+                                   prepend_filter,
+                                   (void *)&grpc_compress_filter);
+  grpc_channel_init_register_stage(GRPC_SERVER_CHANNEL, INT_MAX, prepend_filter,
+                                   (void *)&grpc_compress_filter);
+  grpc_channel_init_register_stage(GRPC_CLIENT_SUBCHANNEL, INT_MAX,
+                                   maybe_add_http_filter,
+                                   (void *)&grpc_http_client_filter);
+  grpc_channel_init_register_stage(GRPC_CLIENT_SUBCHANNEL, INT_MAX,
+                                   grpc_add_connected_filter, NULL);
+  grpc_channel_init_register_stage(GRPC_CLIENT_DIRECT_CHANNEL, INT_MAX,
+                                   maybe_add_http_filter,
+                                   (void *)&grpc_http_client_filter);
+  grpc_channel_init_register_stage(GRPC_CLIENT_DIRECT_CHANNEL, INT_MAX,
+                                   grpc_add_connected_filter, NULL);
+  grpc_channel_init_register_stage(GRPC_SERVER_CHANNEL, INT_MAX,
+                                   maybe_add_http_filter,
+                                   (void *)&grpc_http_server_filter);
+  grpc_channel_init_register_stage(GRPC_SERVER_CHANNEL, INT_MAX,
+                                   grpc_add_connected_filter, NULL);
+  grpc_channel_init_register_stage(GRPC_CLIENT_CHANNEL, INT_MAX, append_filter,
+                                   (void *)&grpc_client_channel_filter);
+  grpc_channel_init_register_stage(GRPC_CLIENT_LAME_CHANNEL, INT_MAX,
+                                   append_filter, (void *)&grpc_lame_filter);
+  grpc_channel_init_register_stage(GRPC_SERVER_CHANNEL, INT_MAX, prepend_filter,
+                                   (void *)&grpc_server_top_filter);
+}
+
+typedef struct grpc_plugin {
+  void (*init)();
+  void (*destroy)();
+} grpc_plugin;
+
+static grpc_plugin g_all_of_the_plugins[MAX_PLUGINS];
+static int g_number_of_plugins = 0;
+
+void grpc_register_plugin(void (*init)(void), void (*destroy)(void)) {
+  GRPC_API_TRACE("grpc_register_plugin(init=%p, destroy=%p)", 2,
+                 ((void *)(intptr_t)init, (void *)(intptr_t)destroy));
+  GPR_ASSERT(g_number_of_plugins != MAX_PLUGINS);
+  g_all_of_the_plugins[g_number_of_plugins].init = init;
+  g_all_of_the_plugins[g_number_of_plugins].destroy = destroy;
+  g_number_of_plugins++;
+}
+
+void grpc_init(void) {
+  int i;
+  gpr_once_init(&g_basic_init, do_basic_init);
+
+  gpr_mu_lock(&g_init_mu);
+  if (++g_initializations == 1) {
+    gpr_time_init();
+    grpc_mdctx_global_init();
+    grpc_channel_init_init();
+    grpc_lb_policy_registry_init(grpc_pick_first_lb_factory_create());
+    grpc_register_lb_policy(grpc_pick_first_lb_factory_create());
+    grpc_register_lb_policy(grpc_round_robin_lb_factory_create());
+    grpc_resolver_registry_init(GRPC_DEFAULT_NAME_PREFIX);
+    grpc_register_resolver_type(grpc_dns_resolver_factory_create());
+    grpc_register_resolver_type(grpc_ipv4_resolver_factory_create());
+    grpc_register_resolver_type(grpc_ipv6_resolver_factory_create());
+#ifdef GPR_HAVE_UNIX_SOCKET
+    grpc_register_resolver_type(grpc_unix_resolver_factory_create());
+#endif
+    grpc_register_tracer("api", &grpc_api_trace);
+    grpc_register_tracer("channel", &grpc_trace_channel);
+    grpc_register_tracer("http", &grpc_http_trace);
+    grpc_register_tracer("flowctl", &grpc_flowctl_trace);
+    grpc_register_tracer("connectivity_state", &grpc_connectivity_state_trace);
+    grpc_register_tracer("channel_stack_builder",
+                         &grpc_trace_channel_stack_builder);
+    grpc_security_pre_init();
+    grpc_iomgr_init();
+    grpc_executor_init();
+    grpc_tracer_init("GRPC_TRACE");
+    gpr_timers_global_init();
+    grpc_cq_global_init();
+    grpc_subchannel_index_init();
+    for (i = 0; i < g_number_of_plugins; i++) {
+      if (g_all_of_the_plugins[i].init != NULL) {
+        g_all_of_the_plugins[i].init();
+      }
+    }
+    /* register channel finalization AFTER all plugins, to ensure that it's run
+     * at the appropriate time */
+    grpc_register_security_filters();
+    register_builtin_channel_init();
+    /* no more changes to channel init pipelines */
+    grpc_channel_init_finalize();
+  }
+  gpr_mu_unlock(&g_init_mu);
+  GRPC_API_TRACE("grpc_init(void)", 0, ());
+}
+
+void grpc_shutdown(void) {
+  int i;
+  GRPC_API_TRACE("grpc_shutdown(void)", 0, ());
+  gpr_mu_lock(&g_init_mu);
+  if (--g_initializations == 0) {
+    grpc_executor_shutdown();
+    grpc_cq_global_shutdown();
+    grpc_iomgr_shutdown();
+    grpc_subchannel_index_shutdown();
+    gpr_timers_global_destroy();
+    grpc_tracer_shutdown();
+    grpc_resolver_registry_shutdown();
+    grpc_lb_policy_registry_shutdown();
+    for (i = 0; i < g_number_of_plugins; i++) {
+      if (g_all_of_the_plugins[i].destroy != NULL) {
+        g_all_of_the_plugins[i].destroy();
+      }
+    }
+    grpc_channel_init_shutdown();
+    grpc_mdctx_global_shutdown();
+  }
+  gpr_mu_unlock(&g_init_mu);
+}
+
+int grpc_is_initialized(void) {
+  int r;
+  gpr_once_init(&g_basic_init, do_basic_init);
+  gpr_mu_lock(&g_init_mu);
+  r = g_initializations > 0;
+  gpr_mu_unlock(&g_init_mu);
+  return r;
+}
diff --git a/src/core/lib/surface/init.h b/src/core/lib/surface/init.h
new file mode 100644
index 0000000000..10e2a5896e
--- /dev/null
+++ b/src/core/lib/surface/init.h
@@ -0,0 +1,41 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_SURFACE_INIT_H
+#define GRPC_CORE_LIB_SURFACE_INIT_H
+
+void grpc_register_security_filters(void);
+void grpc_security_pre_init(void);
+int grpc_is_initialized(void);
+
+#endif /* GRPC_CORE_LIB_SURFACE_INIT_H */
diff --git a/src/core/lib/surface/init_secure.c b/src/core/lib/surface/init_secure.c
new file mode 100644
index 0000000000..d3c2f645a7
--- /dev/null
+++ b/src/core/lib/surface/init_secure.c
@@ -0,0 +1,89 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/surface/init.h"
+
+#include <limits.h>
+#include <string.h>
+
+#include "src/core/lib/debug/trace.h"
+#include "src/core/lib/security/auth_filters.h"
+#include "src/core/lib/security/credentials.h"
+#include "src/core/lib/security/secure_endpoint.h"
+#include "src/core/lib/security/security_connector.h"
+#include "src/core/lib/surface/channel_init.h"
+#include "src/core/lib/tsi/transport_security_interface.h"
+
+void grpc_security_pre_init(void) {
+  grpc_register_tracer("secure_endpoint", &grpc_trace_secure_endpoint);
+  grpc_register_tracer("transport_security", &tsi_tracing_enabled);
+}
+
+static bool maybe_prepend_client_auth_filter(
+    grpc_channel_stack_builder *builder, void *arg) {
+  const grpc_channel_args *args =
+      grpc_channel_stack_builder_get_channel_arguments(builder);
+  if (args) {
+    for (size_t i = 0; i < args->num_args; i++) {
+      if (0 == strcmp(GRPC_SECURITY_CONNECTOR_ARG, args->args[i].key)) {
+        return grpc_channel_stack_builder_prepend_filter(
+            builder, &grpc_client_auth_filter, NULL, NULL);
+      }
+    }
+  }
+  return true;
+}
+
+static bool maybe_prepend_server_auth_filter(
+    grpc_channel_stack_builder *builder, void *arg) {
+  const grpc_channel_args *args =
+      grpc_channel_stack_builder_get_channel_arguments(builder);
+  if (args) {
+    for (size_t i = 0; i < args->num_args; i++) {
+      if (0 == strcmp(GRPC_SERVER_CREDENTIALS_ARG, args->args[i].key)) {
+        return grpc_channel_stack_builder_prepend_filter(
+            builder, &grpc_server_auth_filter, NULL, NULL);
+      }
+    }
+  }
+  return true;
+}
+
+void grpc_register_security_filters(void) {
+  grpc_channel_init_register_stage(GRPC_CLIENT_SUBCHANNEL, INT_MAX,
+                                   maybe_prepend_client_auth_filter, NULL);
+  grpc_channel_init_register_stage(GRPC_CLIENT_DIRECT_CHANNEL, INT_MAX,
+                                   maybe_prepend_client_auth_filter, NULL);
+  grpc_channel_init_register_stage(GRPC_SERVER_CHANNEL, INT_MAX,
+                                   maybe_prepend_server_auth_filter, NULL);
+}
diff --git a/src/core/lib/surface/init_unsecure.c b/src/core/lib/surface/init_unsecure.c
new file mode 100644
index 0000000000..243c005d86
--- /dev/null
+++ b/src/core/lib/surface/init_unsecure.c
@@ -0,0 +1,38 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/surface/init.h"
+
+void grpc_security_pre_init(void) {}
+
+void grpc_register_security_filters(void) {}
diff --git a/src/core/lib/surface/lame_client.c b/src/core/lib/surface/lame_client.c
new file mode 100644
index 0000000000..95ec4b06c3
--- /dev/null
+++ b/src/core/lib/surface/lame_client.c
@@ -0,0 +1,155 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/surface/lame_client.h"
+
+#include <grpc/grpc.h>
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include "src/core/lib/channel/channel_stack.h"
+#include "src/core/lib/support/string.h"
+#include "src/core/lib/surface/api_trace.h"
+#include "src/core/lib/surface/call.h"
+#include "src/core/lib/surface/channel.h"
+
+typedef struct {
+  grpc_linked_mdelem status;
+  grpc_linked_mdelem details;
+} call_data;
+
+typedef struct {
+  grpc_status_code error_code;
+  const char *error_message;
+} channel_data;
+
+static void fill_metadata(grpc_call_element *elem, grpc_metadata_batch *mdb) {
+  call_data *calld = elem->call_data;
+  channel_data *chand = elem->channel_data;
+  char tmp[GPR_LTOA_MIN_BUFSIZE];
+  gpr_ltoa(chand->error_code, tmp);
+  calld->status.md = grpc_mdelem_from_strings("grpc-status", tmp);
+  calld->details.md =
+      grpc_mdelem_from_strings("grpc-message", chand->error_message);
+  calld->status.prev = calld->details.next = NULL;
+  calld->status.next = &calld->details;
+  calld->details.prev = &calld->status;
+  mdb->list.head = &calld->status;
+  mdb->list.tail = &calld->details;
+  mdb->deadline = gpr_inf_future(GPR_CLOCK_REALTIME);
+}
+
+static void lame_start_transport_stream_op(grpc_exec_ctx *exec_ctx,
+                                           grpc_call_element *elem,
+                                           grpc_transport_stream_op *op) {
+  GRPC_CALL_LOG_OP(GPR_INFO, elem, op);
+  if (op->recv_initial_metadata != NULL) {
+    fill_metadata(elem, op->recv_initial_metadata);
+  } else if (op->recv_trailing_metadata != NULL) {
+    fill_metadata(elem, op->recv_trailing_metadata);
+  }
+  grpc_transport_stream_op_finish_with_failure(exec_ctx, op);
+}
+
+static char *lame_get_peer(grpc_exec_ctx *exec_ctx, grpc_call_element *elem) {
+  return NULL;
+}
+
+static void lame_start_transport_op(grpc_exec_ctx *exec_ctx,
+                                    grpc_channel_element *elem,
+                                    grpc_transport_op *op) {
+  if (op->on_connectivity_state_change) {
+    GPR_ASSERT(*op->connectivity_state != GRPC_CHANNEL_FATAL_FAILURE);
+    *op->connectivity_state = GRPC_CHANNEL_FATAL_FAILURE;
+    op->on_connectivity_state_change->cb(
+        exec_ctx, op->on_connectivity_state_change->cb_arg, 1);
+  }
+  if (op->on_consumed != NULL) {
+    op->on_consumed->cb(exec_ctx, op->on_consumed->cb_arg, 1);
+  }
+}
+
+static void init_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
+                           grpc_call_element_args *args) {}
+
+static void destroy_call_elem(grpc_exec_ctx *exec_ctx,
+                              grpc_call_element *elem) {}
+
+static void init_channel_elem(grpc_exec_ctx *exec_ctx,
+                              grpc_channel_element *elem,
+                              grpc_channel_element_args *args) {
+  GPR_ASSERT(args->is_first);
+  GPR_ASSERT(args->is_last);
+}
+
+static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
+                                 grpc_channel_element *elem) {}
+
+const grpc_channel_filter grpc_lame_filter = {
+    lame_start_transport_stream_op,
+    lame_start_transport_op,
+    sizeof(call_data),
+    init_call_elem,
+    grpc_call_stack_ignore_set_pollset,
+    destroy_call_elem,
+    sizeof(channel_data),
+    init_channel_elem,
+    destroy_channel_elem,
+    lame_get_peer,
+    "lame-client",
+};
+
+#define CHANNEL_STACK_FROM_CHANNEL(c) ((grpc_channel_stack *)((c) + 1))
+
+grpc_channel *grpc_lame_client_channel_create(const char *target,
+                                              grpc_status_code error_code,
+                                              const char *error_message) {
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  grpc_channel_element *elem;
+  channel_data *chand;
+  grpc_channel *channel = grpc_channel_create(&exec_ctx, target, NULL,
+                                              GRPC_CLIENT_LAME_CHANNEL, NULL);
+  elem = grpc_channel_stack_element(grpc_channel_get_channel_stack(channel), 0);
+  GRPC_API_TRACE(
+      "grpc_lame_client_channel_create(target=%s, error_code=%d, "
+      "error_message=%s)",
+      3, (target, (int)error_code, error_message));
+  GPR_ASSERT(elem->filter == &grpc_lame_filter);
+  chand = (channel_data *)elem->channel_data;
+  chand->error_code = error_code;
+  chand->error_message = error_message;
+  grpc_exec_ctx_finish(&exec_ctx);
+  return channel;
+}
diff --git a/src/core/lib/surface/lame_client.h b/src/core/lib/surface/lame_client.h
new file mode 100644
index 0000000000..5f6ea34d4b
--- /dev/null
+++ b/src/core/lib/surface/lame_client.h
@@ -0,0 +1,41 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_SURFACE_LAME_CLIENT_H
+#define GRPC_CORE_LIB_SURFACE_LAME_CLIENT_H
+
+#include "src/core/lib/channel/channel_stack.h"
+
+extern const grpc_channel_filter grpc_lame_filter;
+
+#endif /* GRPC_CORE_LIB_SURFACE_LAME_CLIENT_H */
diff --git a/src/core/lib/surface/metadata_array.c b/src/core/lib/surface/metadata_array.c
new file mode 100644
index 0000000000..4436f2da87
--- /dev/null
+++ b/src/core/lib/surface/metadata_array.c
@@ -0,0 +1,49 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <grpc/grpc.h>
+#include <grpc/support/alloc.h>
+
+#include <string.h>
+
+#include "src/core/lib/surface/api_trace.h"
+
+void grpc_metadata_array_init(grpc_metadata_array* array) {
+  GRPC_API_TRACE("grpc_metadata_array_init(array=%p)", 1, (array));
+  memset(array, 0, sizeof(*array));
+}
+
+void grpc_metadata_array_destroy(grpc_metadata_array* array) {
+  GRPC_API_TRACE("grpc_metadata_array_destroy(array=%p)", 1, (array));
+  gpr_free(array->metadata);
+}
diff --git a/src/core/lib/surface/secure_channel_create.c b/src/core/lib/surface/secure_channel_create.c
new file mode 100644
index 0000000000..dcb367023e
--- /dev/null
+++ b/src/core/lib/surface/secure_channel_create.c
@@ -0,0 +1,319 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <grpc/grpc.h>
+
+#include <stdlib.h>
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/slice.h>
+#include <grpc/support/slice_buffer.h>
+
+#include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/channel/client_channel.h"
+#include "src/core/lib/client_config/resolver_registry.h"
+#include "src/core/lib/iomgr/tcp_client.h"
+#include "src/core/lib/security/auth_filters.h"
+#include "src/core/lib/security/credentials.h"
+#include "src/core/lib/security/security_context.h"
+#include "src/core/lib/surface/api_trace.h"
+#include "src/core/lib/surface/channel.h"
+#include "src/core/lib/transport/chttp2_transport.h"
+#include "src/core/lib/tsi/transport_security_interface.h"
+
+typedef struct {
+  grpc_connector base;
+  gpr_refcount refs;
+
+  grpc_channel_security_connector *security_connector;
+
+  grpc_closure *notify;
+  grpc_connect_in_args args;
+  grpc_connect_out_args *result;
+  grpc_closure initial_string_sent;
+  gpr_slice_buffer initial_string_buffer;
+
+  gpr_mu mu;
+  grpc_endpoint *connecting_endpoint;
+  grpc_endpoint *newly_connecting_endpoint;
+
+  grpc_closure connected_closure;
+} connector;
+
+static void connector_ref(grpc_connector *con) {
+  connector *c = (connector *)con;
+  gpr_ref(&c->refs);
+}
+
+static void connector_unref(grpc_exec_ctx *exec_ctx, grpc_connector *con) {
+  connector *c = (connector *)con;
+  if (gpr_unref(&c->refs)) {
+    /* c->initial_string_buffer does not need to be destroyed */
+    gpr_free(c);
+  }
+}
+
+static void on_secure_handshake_done(grpc_exec_ctx *exec_ctx, void *arg,
+                                     grpc_security_status status,
+                                     grpc_endpoint *secure_endpoint,
+                                     grpc_auth_context *auth_context) {
+  connector *c = arg;
+  grpc_closure *notify;
+  grpc_channel_args *args_copy = NULL;
+  gpr_mu_lock(&c->mu);
+  if (c->connecting_endpoint == NULL) {
+    memset(c->result, 0, sizeof(*c->result));
+    gpr_mu_unlock(&c->mu);
+  } else if (status != GRPC_SECURITY_OK) {
+    gpr_log(GPR_ERROR, "Secure handshake failed with error %d.", status);
+    memset(c->result, 0, sizeof(*c->result));
+    c->connecting_endpoint = NULL;
+    gpr_mu_unlock(&c->mu);
+  } else {
+    grpc_arg auth_context_arg;
+    c->connecting_endpoint = NULL;
+    gpr_mu_unlock(&c->mu);
+    c->result->transport = grpc_create_chttp2_transport(
+        exec_ctx, c->args.channel_args, secure_endpoint, 1);
+    grpc_chttp2_transport_start_reading(exec_ctx, c->result->transport, NULL,
+                                        0);
+    auth_context_arg = grpc_auth_context_to_arg(auth_context);
+    args_copy = grpc_channel_args_copy_and_add(c->args.channel_args,
+                                               &auth_context_arg, 1);
+    c->result->channel_args = args_copy;
+  }
+  notify = c->notify;
+  c->notify = NULL;
+  /* look at c->args which are connector args. */
+  notify->cb(exec_ctx, notify->cb_arg, 1);
+  if (args_copy != NULL) grpc_channel_args_destroy(args_copy);
+}
+
+static void on_initial_connect_string_sent(grpc_exec_ctx *exec_ctx, void *arg,
+                                           bool success) {
+  connector *c = arg;
+  grpc_channel_security_connector_do_handshake(exec_ctx, c->security_connector,
+                                               c->connecting_endpoint,
+                                               on_secure_handshake_done, c);
+}
+
+static void connected(grpc_exec_ctx *exec_ctx, void *arg, bool success) {
+  connector *c = arg;
+  grpc_closure *notify;
+  grpc_endpoint *tcp = c->newly_connecting_endpoint;
+  if (tcp != NULL) {
+    gpr_mu_lock(&c->mu);
+    GPR_ASSERT(c->connecting_endpoint == NULL);
+    c->connecting_endpoint = tcp;
+    gpr_mu_unlock(&c->mu);
+    if (!GPR_SLICE_IS_EMPTY(c->args.initial_connect_string)) {
+      grpc_closure_init(&c->initial_string_sent, on_initial_connect_string_sent,
+                        c);
+      gpr_slice_buffer_init(&c->initial_string_buffer);
+      gpr_slice_buffer_add(&c->initial_string_buffer,
+                           c->args.initial_connect_string);
+      grpc_endpoint_write(exec_ctx, tcp, &c->initial_string_buffer,
+                          &c->initial_string_sent);
+    } else {
+      grpc_channel_security_connector_do_handshake(
+          exec_ctx, c->security_connector, tcp, on_secure_handshake_done, c);
+    }
+  } else {
+    memset(c->result, 0, sizeof(*c->result));
+    notify = c->notify;
+    c->notify = NULL;
+    notify->cb(exec_ctx, notify->cb_arg, 1);
+  }
+}
+
+static void connector_shutdown(grpc_exec_ctx *exec_ctx, grpc_connector *con) {
+  connector *c = (connector *)con;
+  grpc_endpoint *ep;
+  gpr_mu_lock(&c->mu);
+  ep = c->connecting_endpoint;
+  c->connecting_endpoint = NULL;
+  gpr_mu_unlock(&c->mu);
+  if (ep) {
+    grpc_endpoint_shutdown(exec_ctx, ep);
+  }
+}
+
+static void connector_connect(grpc_exec_ctx *exec_ctx, grpc_connector *con,
+                              const grpc_connect_in_args *args,
+                              grpc_connect_out_args *result,
+                              grpc_closure *notify) {
+  connector *c = (connector *)con;
+  GPR_ASSERT(c->notify == NULL);
+  GPR_ASSERT(notify->cb);
+  c->notify = notify;
+  c->args = *args;
+  c->result = result;
+  gpr_mu_lock(&c->mu);
+  GPR_ASSERT(c->connecting_endpoint == NULL);
+  gpr_mu_unlock(&c->mu);
+  grpc_closure_init(&c->connected_closure, connected, c);
+  grpc_tcp_client_connect(
+      exec_ctx, &c->connected_closure, &c->newly_connecting_endpoint,
+      args->interested_parties, args->addr, args->addr_len, args->deadline);
+}
+
+static const grpc_connector_vtable connector_vtable = {
+    connector_ref, connector_unref, connector_shutdown, connector_connect};
+
+typedef struct {
+  grpc_subchannel_factory base;
+  gpr_refcount refs;
+  grpc_channel_args *merge_args;
+  grpc_channel_security_connector *security_connector;
+  grpc_channel *master;
+} subchannel_factory;
+
+static void subchannel_factory_ref(grpc_subchannel_factory *scf) {
+  subchannel_factory *f = (subchannel_factory *)scf;
+  gpr_ref(&f->refs);
+}
+
+static void subchannel_factory_unref(grpc_exec_ctx *exec_ctx,
+                                     grpc_subchannel_factory *scf) {
+  subchannel_factory *f = (subchannel_factory *)scf;
+  if (gpr_unref(&f->refs)) {
+    GRPC_SECURITY_CONNECTOR_UNREF(&f->security_connector->base,
+                                  "subchannel_factory");
+    GRPC_CHANNEL_INTERNAL_UNREF(exec_ctx, f->master, "subchannel_factory");
+    grpc_channel_args_destroy(f->merge_args);
+    gpr_free(f);
+  }
+}
+
+static grpc_subchannel *subchannel_factory_create_subchannel(
+    grpc_exec_ctx *exec_ctx, grpc_subchannel_factory *scf,
+    grpc_subchannel_args *args) {
+  subchannel_factory *f = (subchannel_factory *)scf;
+  connector *c = gpr_malloc(sizeof(*c));
+  grpc_channel_args *final_args =
+      grpc_channel_args_merge(args->args, f->merge_args);
+  grpc_subchannel *s;
+  memset(c, 0, sizeof(*c));
+  c->base.vtable = &connector_vtable;
+  c->security_connector = f->security_connector;
+  gpr_mu_init(&c->mu);
+  gpr_ref_init(&c->refs, 1);
+  args->args = final_args;
+  s = grpc_subchannel_create(exec_ctx, &c->base, args);
+  grpc_connector_unref(exec_ctx, &c->base);
+  grpc_channel_args_destroy(final_args);
+  return s;
+}
+
+static const grpc_subchannel_factory_vtable subchannel_factory_vtable = {
+    subchannel_factory_ref, subchannel_factory_unref,
+    subchannel_factory_create_subchannel};
+
+/* Create a secure client channel:
+   Asynchronously: - resolve target
+                   - connect to it (trying alternatives as presented)
+                   - perform handshakes */
+grpc_channel *grpc_secure_channel_create(grpc_channel_credentials *creds,
+                                         const char *target,
+                                         const grpc_channel_args *args,
+                                         void *reserved) {
+  grpc_channel *channel;
+  grpc_arg connector_arg;
+  grpc_channel_args *args_copy;
+  grpc_channel_args *new_args_from_connector;
+  grpc_channel_security_connector *security_connector;
+  grpc_resolver *resolver;
+  subchannel_factory *f;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+
+  GRPC_API_TRACE(
+      "grpc_secure_channel_create(creds=%p, target=%s, args=%p, "
+      "reserved=%p)",
+      4, (creds, target, args, reserved));
+  GPR_ASSERT(reserved == NULL);
+
+  if (grpc_find_security_connector_in_args(args) != NULL) {
+    gpr_log(GPR_ERROR, "Cannot set security context in channel args.");
+    grpc_exec_ctx_finish(&exec_ctx);
+    return grpc_lame_client_channel_create(
+        target, GRPC_STATUS_INVALID_ARGUMENT,
+        "Security connector exists in channel args.");
+  }
+
+  if (grpc_channel_credentials_create_security_connector(
+          creds, target, args, &security_connector, &new_args_from_connector) !=
+      GRPC_SECURITY_OK) {
+    grpc_exec_ctx_finish(&exec_ctx);
+    return grpc_lame_client_channel_create(
+        target, GRPC_STATUS_INVALID_ARGUMENT,
+        "Failed to create security connector.");
+  }
+
+  connector_arg = grpc_security_connector_to_arg(&security_connector->base);
+  args_copy = grpc_channel_args_copy_and_add(
+      new_args_from_connector != NULL ? new_args_from_connector : args,
+      &connector_arg, 1);
+
+  channel = grpc_channel_create(&exec_ctx, target, args_copy,
+                                GRPC_CLIENT_CHANNEL, NULL);
+
+  f = gpr_malloc(sizeof(*f));
+  f->base.vtable = &subchannel_factory_vtable;
+  gpr_ref_init(&f->refs, 1);
+  GRPC_SECURITY_CONNECTOR_REF(&security_connector->base, "subchannel_factory");
+  f->security_connector = security_connector;
+  f->merge_args = grpc_channel_args_copy(args_copy);
+  f->master = channel;
+  GRPC_CHANNEL_INTERNAL_REF(channel, "subchannel_factory");
+  resolver = grpc_resolver_create(target, &f->base);
+  if (resolver) {
+    grpc_client_channel_set_resolver(
+        &exec_ctx, grpc_channel_get_channel_stack(channel), resolver);
+    GRPC_RESOLVER_UNREF(&exec_ctx, resolver, "create");
+  }
+  grpc_subchannel_factory_unref(&exec_ctx, &f->base);
+  GRPC_SECURITY_CONNECTOR_UNREF(&security_connector->base, "channel_create");
+  grpc_channel_args_destroy(args_copy);
+  if (new_args_from_connector != NULL) {
+    grpc_channel_args_destroy(new_args_from_connector);
+  }
+
+  if (!resolver) {
+    GRPC_CHANNEL_INTERNAL_UNREF(&exec_ctx, channel, "subchannel_factory");
+    channel = NULL;
+  }
+  grpc_exec_ctx_finish(&exec_ctx);
+
+  return channel;
+}
diff --git a/src/core/lib/surface/server.c b/src/core/lib/surface/server.c
new file mode 100644
index 0000000000..080734e9d5
--- /dev/null
+++ b/src/core/lib/surface/server.c
@@ -0,0 +1,1319 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/surface/server.h"
+
+#include <limits.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+#include <grpc/support/useful.h>
+
+#include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/channel/connected_channel.h"
+#include "src/core/lib/iomgr/iomgr.h"
+#include "src/core/lib/support/stack_lockfree.h"
+#include "src/core/lib/support/string.h"
+#include "src/core/lib/surface/api_trace.h"
+#include "src/core/lib/surface/call.h"
+#include "src/core/lib/surface/channel.h"
+#include "src/core/lib/surface/completion_queue.h"
+#include "src/core/lib/surface/init.h"
+#include "src/core/lib/transport/metadata.h"
+#include "src/core/lib/transport/static_metadata.h"
+
+typedef struct listener {
+  void *arg;
+  void (*start)(grpc_exec_ctx *exec_ctx, grpc_server *server, void *arg,
+                grpc_pollset **pollsets, size_t pollset_count);
+  void (*destroy)(grpc_exec_ctx *exec_ctx, grpc_server *server, void *arg,
+                  grpc_closure *closure);
+  struct listener *next;
+  grpc_closure destroy_done;
+} listener;
+
+typedef struct call_data call_data;
+typedef struct channel_data channel_data;
+typedef struct registered_method registered_method;
+
+typedef struct {
+  call_data *next;
+  call_data *prev;
+} call_link;
+
+typedef enum { BATCH_CALL, REGISTERED_CALL } requested_call_type;
+
+typedef struct requested_call {
+  requested_call_type type;
+  void *tag;
+  grpc_server *server;
+  grpc_completion_queue *cq_bound_to_call;
+  grpc_completion_queue *cq_for_notification;
+  grpc_call **call;
+  grpc_cq_completion completion;
+  grpc_metadata_array *initial_metadata;
+  union {
+    struct {
+      grpc_call_details *details;
+    } batch;
+    struct {
+      registered_method *registered_method;
+      gpr_timespec *deadline;
+      grpc_byte_buffer **optional_payload;
+    } registered;
+  } data;
+  grpc_closure publish;
+} requested_call;
+
+typedef struct channel_registered_method {
+  registered_method *server_registered_method;
+  grpc_mdstr *method;
+  grpc_mdstr *host;
+} channel_registered_method;
+
+struct channel_data {
+  grpc_server *server;
+  grpc_connectivity_state connectivity_state;
+  grpc_channel *channel;
+  /* linked list of all channels on a server */
+  channel_data *next;
+  channel_data *prev;
+  channel_registered_method *registered_methods;
+  uint32_t registered_method_slots;
+  uint32_t registered_method_max_probes;
+  grpc_closure finish_destroy_channel_closure;
+  grpc_closure channel_connectivity_changed;
+};
+
+typedef struct shutdown_tag {
+  void *tag;
+  grpc_completion_queue *cq;
+  grpc_cq_completion completion;
+} shutdown_tag;
+
+typedef enum {
+  /* waiting for metadata */
+  NOT_STARTED,
+  /* inital metadata read, not flow controlled in yet */
+  PENDING,
+  /* flow controlled in, on completion queue */
+  ACTIVATED,
+  /* cancelled before being queued */
+  ZOMBIED
+} call_state;
+
+typedef struct request_matcher request_matcher;
+
+struct call_data {
+  grpc_call *call;
+
+  /** protects state */
+  gpr_mu mu_state;
+  /** the current state of a call - see call_state */
+  call_state state;
+
+  grpc_mdstr *path;
+  grpc_mdstr *host;
+  gpr_timespec deadline;
+
+  grpc_completion_queue *cq_new;
+
+  grpc_metadata_batch *recv_initial_metadata;
+  grpc_metadata_array initial_metadata;
+
+  grpc_closure got_initial_metadata;
+  grpc_closure server_on_recv_initial_metadata;
+  grpc_closure kill_zombie_closure;
+  grpc_closure *on_done_recv_initial_metadata;
+
+  call_data *pending_next;
+};
+
+struct request_matcher {
+  call_data *pending_head;
+  call_data *pending_tail;
+  gpr_stack_lockfree *requests;
+};
+
+struct registered_method {
+  char *method;
+  char *host;
+  request_matcher request_matcher;
+  registered_method *next;
+};
+
+typedef struct {
+  grpc_channel **channels;
+  size_t num_channels;
+} channel_broadcaster;
+
+struct grpc_server {
+  grpc_channel_args *channel_args;
+
+  grpc_completion_queue **cqs;
+  grpc_pollset **pollsets;
+  size_t cq_count;
+
+  /* The two following mutexes control access to server-state
+     mu_global controls access to non-call-related state (e.g., channel state)
+     mu_call controls access to call-related state (e.g., the call lists)
+
+     If they are ever required to be nested, you must lock mu_global
+     before mu_call. This is currently used in shutdown processing
+     (grpc_server_shutdown_and_notify and maybe_finish_shutdown) */
+  gpr_mu mu_global; /* mutex for server and channel state */
+  gpr_mu mu_call;   /* mutex for call-specific state */
+
+  registered_method *registered_methods;
+  request_matcher unregistered_request_matcher;
+  /** free list of available requested_calls indices */
+  gpr_stack_lockfree *request_freelist;
+  /** requested call backing data */
+  requested_call *requested_calls;
+  size_t max_requested_calls;
+
+  gpr_atm shutdown_flag;
+  uint8_t shutdown_published;
+  size_t num_shutdown_tags;
+  shutdown_tag *shutdown_tags;
+
+  channel_data root_channel_data;
+
+  listener *listeners;
+  int listeners_destroyed;
+  gpr_refcount internal_refcount;
+
+  /** when did we print the last shutdown progress message */
+  gpr_timespec last_shutdown_message_time;
+};
+
+#define SERVER_FROM_CALL_ELEM(elem) \
+  (((channel_data *)(elem)->channel_data)->server)
+
+static void begin_call(grpc_exec_ctx *exec_ctx, grpc_server *server,
+                       call_data *calld, requested_call *rc);
+static void fail_call(grpc_exec_ctx *exec_ctx, grpc_server *server,
+                      requested_call *rc);
+/* Before calling maybe_finish_shutdown, we must hold mu_global and not
+   hold mu_call */
+static void maybe_finish_shutdown(grpc_exec_ctx *exec_ctx, grpc_server *server);
+
+/*
+ * channel broadcaster
+ */
+
+/* assumes server locked */
+static void channel_broadcaster_init(grpc_server *s, channel_broadcaster *cb) {
+  channel_data *c;
+  size_t count = 0;
+  for (c = s->root_channel_data.next; c != &s->root_channel_data; c = c->next) {
+    count++;
+  }
+  cb->num_channels = count;
+  cb->channels = gpr_malloc(sizeof(*cb->channels) * cb->num_channels);
+  count = 0;
+  for (c = s->root_channel_data.next; c != &s->root_channel_data; c = c->next) {
+    cb->channels[count++] = c->channel;
+    GRPC_CHANNEL_INTERNAL_REF(c->channel, "broadcast");
+  }
+}
+
+struct shutdown_cleanup_args {
+  grpc_closure closure;
+  gpr_slice slice;
+};
+
+static void shutdown_cleanup(grpc_exec_ctx *exec_ctx, void *arg,
+                             bool iomgr_status_ignored) {
+  struct shutdown_cleanup_args *a = arg;
+  gpr_slice_unref(a->slice);
+  gpr_free(a);
+}
+
+static void send_shutdown(grpc_exec_ctx *exec_ctx, grpc_channel *channel,
+                          int send_goaway, int send_disconnect) {
+  grpc_transport_op op;
+  struct shutdown_cleanup_args *sc;
+  grpc_channel_element *elem;
+
+  memset(&op, 0, sizeof(op));
+  op.send_goaway = send_goaway;
+  sc = gpr_malloc(sizeof(*sc));
+  sc->slice = gpr_slice_from_copied_string("Server shutdown");
+  op.goaway_message = &sc->slice;
+  op.goaway_status = GRPC_STATUS_OK;
+  op.disconnect = send_disconnect;
+  grpc_closure_init(&sc->closure, shutdown_cleanup, sc);
+  op.on_consumed = &sc->closure;
+
+  elem = grpc_channel_stack_element(grpc_channel_get_channel_stack(channel), 0);
+  elem->filter->start_transport_op(exec_ctx, elem, &op);
+}
+
+static void channel_broadcaster_shutdown(grpc_exec_ctx *exec_ctx,
+                                         channel_broadcaster *cb,
+                                         int send_goaway,
+                                         int force_disconnect) {
+  size_t i;
+
+  for (i = 0; i < cb->num_channels; i++) {
+    send_shutdown(exec_ctx, cb->channels[i], send_goaway, force_disconnect);
+    GRPC_CHANNEL_INTERNAL_UNREF(exec_ctx, cb->channels[i], "broadcast");
+  }
+  gpr_free(cb->channels);
+}
+
+/*
+ * request_matcher
+ */
+
+static void request_matcher_init(request_matcher *rm, size_t entries) {
+  memset(rm, 0, sizeof(*rm));
+  rm->requests = gpr_stack_lockfree_create(entries);
+}
+
+static void request_matcher_destroy(request_matcher *rm) {
+  GPR_ASSERT(gpr_stack_lockfree_pop(rm->requests) == -1);
+  gpr_stack_lockfree_destroy(rm->requests);
+}
+
+static void kill_zombie(grpc_exec_ctx *exec_ctx, void *elem, bool success) {
+  grpc_call_destroy(grpc_call_from_top_element(elem));
+}
+
+static void request_matcher_zombify_all_pending_calls(grpc_exec_ctx *exec_ctx,
+                                                      request_matcher *rm) {
+  while (rm->pending_head) {
+    call_data *calld = rm->pending_head;
+    rm->pending_head = calld->pending_next;
+    gpr_mu_lock(&calld->mu_state);
+    calld->state = ZOMBIED;
+    gpr_mu_unlock(&calld->mu_state);
+    grpc_closure_init(
+        &calld->kill_zombie_closure, kill_zombie,
+        grpc_call_stack_element(grpc_call_get_call_stack(calld->call), 0));
+    grpc_exec_ctx_enqueue(exec_ctx, &calld->kill_zombie_closure, true, NULL);
+  }
+}
+
+static void request_matcher_kill_requests(grpc_exec_ctx *exec_ctx,
+                                          grpc_server *server,
+                                          request_matcher *rm) {
+  int request_id;
+  while ((request_id = gpr_stack_lockfree_pop(rm->requests)) != -1) {
+    fail_call(exec_ctx, server, &server->requested_calls[request_id]);
+  }
+}
+
+/*
+ * server proper
+ */
+
+static void server_ref(grpc_server *server) {
+  gpr_ref(&server->internal_refcount);
+}
+
+static void server_delete(grpc_exec_ctx *exec_ctx, grpc_server *server) {
+  registered_method *rm;
+  size_t i;
+  grpc_channel_args_destroy(server->channel_args);
+  gpr_mu_destroy(&server->mu_global);
+  gpr_mu_destroy(&server->mu_call);
+  while ((rm = server->registered_methods) != NULL) {
+    server->registered_methods = rm->next;
+    request_matcher_destroy(&rm->request_matcher);
+    gpr_free(rm->method);
+    gpr_free(rm->host);
+    gpr_free(rm);
+  }
+  for (i = 0; i < server->cq_count; i++) {
+    GRPC_CQ_INTERNAL_UNREF(server->cqs[i], "server");
+  }
+  request_matcher_destroy(&server->unregistered_request_matcher);
+  gpr_stack_lockfree_destroy(server->request_freelist);
+  gpr_free(server->cqs);
+  gpr_free(server->pollsets);
+  gpr_free(server->shutdown_tags);
+  gpr_free(server->requested_calls);
+  gpr_free(server);
+}
+
+static void server_unref(grpc_exec_ctx *exec_ctx, grpc_server *server) {
+  if (gpr_unref(&server->internal_refcount)) {
+    server_delete(exec_ctx, server);
+  }
+}
+
+static int is_channel_orphaned(channel_data *chand) {
+  return chand->next == chand;
+}
+
+static void orphan_channel(channel_data *chand) {
+  chand->next->prev = chand->prev;
+  chand->prev->next = chand->next;
+  chand->next = chand->prev = chand;
+}
+
+static void finish_destroy_channel(grpc_exec_ctx *exec_ctx, void *cd,
+                                   bool success) {
+  channel_data *chand = cd;
+  grpc_server *server = chand->server;
+  GRPC_CHANNEL_INTERNAL_UNREF(exec_ctx, chand->channel, "server");
+  server_unref(exec_ctx, server);
+}
+
+static void destroy_channel(grpc_exec_ctx *exec_ctx, channel_data *chand) {
+  if (is_channel_orphaned(chand)) return;
+  GPR_ASSERT(chand->server != NULL);
+  orphan_channel(chand);
+  server_ref(chand->server);
+  maybe_finish_shutdown(exec_ctx, chand->server);
+  chand->finish_destroy_channel_closure.cb = finish_destroy_channel;
+  chand->finish_destroy_channel_closure.cb_arg = chand;
+
+  grpc_transport_op op;
+  memset(&op, 0, sizeof(op));
+  op.set_accept_stream = true;
+  op.on_consumed = &chand->finish_destroy_channel_closure;
+  grpc_channel_next_op(exec_ctx,
+                       grpc_channel_stack_element(
+                           grpc_channel_get_channel_stack(chand->channel), 0),
+                       &op);
+}
+
+static void finish_start_new_rpc(grpc_exec_ctx *exec_ctx, grpc_server *server,
+                                 grpc_call_element *elem, request_matcher *rm) {
+  call_data *calld = elem->call_data;
+  int request_id;
+
+  if (gpr_atm_acq_load(&server->shutdown_flag)) {
+    gpr_mu_lock(&calld->mu_state);
+    calld->state = ZOMBIED;
+    gpr_mu_unlock(&calld->mu_state);
+    grpc_closure_init(&calld->kill_zombie_closure, kill_zombie, elem);
+    grpc_exec_ctx_enqueue(exec_ctx, &calld->kill_zombie_closure, true, NULL);
+    return;
+  }
+
+  request_id = gpr_stack_lockfree_pop(rm->requests);
+  if (request_id == -1) {
+    gpr_mu_lock(&server->mu_call);
+    gpr_mu_lock(&calld->mu_state);
+    calld->state = PENDING;
+    gpr_mu_unlock(&calld->mu_state);
+    if (rm->pending_head == NULL) {
+      rm->pending_tail = rm->pending_head = calld;
+    } else {
+      rm->pending_tail->pending_next = calld;
+      rm->pending_tail = calld;
+    }
+    calld->pending_next = NULL;
+    gpr_mu_unlock(&server->mu_call);
+  } else {
+    gpr_mu_lock(&calld->mu_state);
+    calld->state = ACTIVATED;
+    gpr_mu_unlock(&calld->mu_state);
+    begin_call(exec_ctx, server, calld, &server->requested_calls[request_id]);
+  }
+}
+
+static void start_new_rpc(grpc_exec_ctx *exec_ctx, grpc_call_element *elem) {
+  channel_data *chand = elem->channel_data;
+  call_data *calld = elem->call_data;
+  grpc_server *server = chand->server;
+  uint32_t i;
+  uint32_t hash;
+  channel_registered_method *rm;
+
+  if (chand->registered_methods && calld->path && calld->host) {
+    /* TODO(ctiller): unify these two searches */
+    /* check for an exact match with host */
+    hash = GRPC_MDSTR_KV_HASH(calld->host->hash, calld->path->hash);
+    for (i = 0; i <= chand->registered_method_max_probes; i++) {
+      rm = &chand->registered_methods[(hash + i) %
+                                      chand->registered_method_slots];
+      if (!rm) break;
+      if (rm->host != calld->host) continue;
+      if (rm->method != calld->path) continue;
+      finish_start_new_rpc(exec_ctx, server, elem,
+                           &rm->server_registered_method->request_matcher);
+      return;
+    }
+    /* check for a wildcard method definition (no host set) */
+    hash = GRPC_MDSTR_KV_HASH(0, calld->path->hash);
+    for (i = 0; i <= chand->registered_method_max_probes; i++) {
+      rm = &chand->registered_methods[(hash + i) %
+                                      chand->registered_method_slots];
+      if (!rm) break;
+      if (rm->host != NULL) continue;
+      if (rm->method != calld->path) continue;
+      finish_start_new_rpc(exec_ctx, server, elem,
+                           &rm->server_registered_method->request_matcher);
+      return;
+    }
+  }
+  finish_start_new_rpc(exec_ctx, server, elem,
+                       &server->unregistered_request_matcher);
+}
+
+static int num_listeners(grpc_server *server) {
+  listener *l;
+  int n = 0;
+  for (l = server->listeners; l; l = l->next) {
+    n++;
+  }
+  return n;
+}
+
+static void done_shutdown_event(grpc_exec_ctx *exec_ctx, void *server,
+                                grpc_cq_completion *completion) {
+  server_unref(exec_ctx, server);
+}
+
+static int num_channels(grpc_server *server) {
+  channel_data *chand;
+  int n = 0;
+  for (chand = server->root_channel_data.next;
+       chand != &server->root_channel_data; chand = chand->next) {
+    n++;
+  }
+  return n;
+}
+
+static void kill_pending_work_locked(grpc_exec_ctx *exec_ctx,
+                                     grpc_server *server) {
+  registered_method *rm;
+  request_matcher_kill_requests(exec_ctx, server,
+                                &server->unregistered_request_matcher);
+  request_matcher_zombify_all_pending_calls(
+      exec_ctx, &server->unregistered_request_matcher);
+  for (rm = server->registered_methods; rm; rm = rm->next) {
+    request_matcher_kill_requests(exec_ctx, server, &rm->request_matcher);
+    request_matcher_zombify_all_pending_calls(exec_ctx, &rm->request_matcher);
+  }
+}
+
+static void maybe_finish_shutdown(grpc_exec_ctx *exec_ctx,
+                                  grpc_server *server) {
+  size_t i;
+  if (!gpr_atm_acq_load(&server->shutdown_flag) || server->shutdown_published) {
+    return;
+  }
+
+  kill_pending_work_locked(exec_ctx, server);
+
+  if (server->root_channel_data.next != &server->root_channel_data ||
+      server->listeners_destroyed < num_listeners(server)) {
+    if (gpr_time_cmp(gpr_time_sub(gpr_now(GPR_CLOCK_REALTIME),
+                                  server->last_shutdown_message_time),
+                     gpr_time_from_seconds(1, GPR_TIMESPAN)) >= 0) {
+      server->last_shutdown_message_time = gpr_now(GPR_CLOCK_REALTIME);
+      gpr_log(GPR_DEBUG,
+              "Waiting for %d channels and %d/%d listeners to be destroyed"
+              " before shutting down server",
+              num_channels(server),
+              num_listeners(server) - server->listeners_destroyed,
+              num_listeners(server));
+    }
+    return;
+  }
+  server->shutdown_published = 1;
+  for (i = 0; i < server->num_shutdown_tags; i++) {
+    server_ref(server);
+    grpc_cq_end_op(exec_ctx, server->shutdown_tags[i].cq,
+                   server->shutdown_tags[i].tag, 1, done_shutdown_event, server,
+                   &server->shutdown_tags[i].completion);
+  }
+}
+
+static grpc_mdelem *server_filter(void *user_data, grpc_mdelem *md) {
+  grpc_call_element *elem = user_data;
+  call_data *calld = elem->call_data;
+  if (md->key == GRPC_MDSTR_PATH) {
+    calld->path = GRPC_MDSTR_REF(md->value);
+    return NULL;
+  } else if (md->key == GRPC_MDSTR_AUTHORITY) {
+    calld->host = GRPC_MDSTR_REF(md->value);
+    return NULL;
+  }
+  return md;
+}
+
+static void server_on_recv_initial_metadata(grpc_exec_ctx *exec_ctx, void *ptr,
+                                            bool success) {
+  grpc_call_element *elem = ptr;
+  call_data *calld = elem->call_data;
+  gpr_timespec op_deadline;
+
+  grpc_metadata_batch_filter(calld->recv_initial_metadata, server_filter, elem);
+  op_deadline = calld->recv_initial_metadata->deadline;
+  if (0 != gpr_time_cmp(op_deadline, gpr_inf_future(op_deadline.clock_type))) {
+    calld->deadline = op_deadline;
+  }
+  if (calld->host && calld->path) {
+    /* do nothing */
+  } else {
+    success = 0;
+  }
+
+  calld->on_done_recv_initial_metadata->cb(
+      exec_ctx, calld->on_done_recv_initial_metadata->cb_arg, success);
+}
+
+static void server_mutate_op(grpc_call_element *elem,
+                             grpc_transport_stream_op *op) {
+  call_data *calld = elem->call_data;
+
+  if (op->recv_initial_metadata != NULL) {
+    calld->recv_initial_metadata = op->recv_initial_metadata;
+    calld->on_done_recv_initial_metadata = op->recv_initial_metadata_ready;
+    op->recv_initial_metadata_ready = &calld->server_on_recv_initial_metadata;
+  }
+}
+
+static void server_start_transport_stream_op(grpc_exec_ctx *exec_ctx,
+                                             grpc_call_element *elem,
+                                             grpc_transport_stream_op *op) {
+  GRPC_CALL_LOG_OP(GPR_INFO, elem, op);
+  server_mutate_op(elem, op);
+  grpc_call_next_op(exec_ctx, elem, op);
+}
+
+static void got_initial_metadata(grpc_exec_ctx *exec_ctx, void *ptr,
+                                 bool success) {
+  grpc_call_element *elem = ptr;
+  call_data *calld = elem->call_data;
+  if (success) {
+    start_new_rpc(exec_ctx, elem);
+  } else {
+    gpr_mu_lock(&calld->mu_state);
+    if (calld->state == NOT_STARTED) {
+      calld->state = ZOMBIED;
+      gpr_mu_unlock(&calld->mu_state);
+      grpc_closure_init(&calld->kill_zombie_closure, kill_zombie, elem);
+      grpc_exec_ctx_enqueue(exec_ctx, &calld->kill_zombie_closure, true, NULL);
+    } else if (calld->state == PENDING) {
+      calld->state = ZOMBIED;
+      gpr_mu_unlock(&calld->mu_state);
+      /* zombied call will be destroyed when it's removed from the pending
+         queue... later */
+    } else {
+      gpr_mu_unlock(&calld->mu_state);
+    }
+  }
+}
+
+static void accept_stream(grpc_exec_ctx *exec_ctx, void *cd,
+                          grpc_transport *transport,
+                          const void *transport_server_data) {
+  channel_data *chand = cd;
+  /* create a call */
+  grpc_call *call =
+      grpc_call_create(chand->channel, NULL, 0, NULL, transport_server_data,
+                       NULL, 0, gpr_inf_future(GPR_CLOCK_MONOTONIC));
+  grpc_call_element *elem =
+      grpc_call_stack_element(grpc_call_get_call_stack(call), 0);
+  call_data *calld = elem->call_data;
+  grpc_op op;
+  memset(&op, 0, sizeof(op));
+  op.op = GRPC_OP_RECV_INITIAL_METADATA;
+  op.data.recv_initial_metadata = &calld->initial_metadata;
+  grpc_closure_init(&calld->got_initial_metadata, got_initial_metadata, elem);
+  grpc_call_start_batch_and_execute(exec_ctx, call, &op, 1,
+                                    &calld->got_initial_metadata);
+}
+
+static void channel_connectivity_changed(grpc_exec_ctx *exec_ctx, void *cd,
+                                         bool iomgr_status_ignored) {
+  channel_data *chand = cd;
+  grpc_server *server = chand->server;
+  if (chand->connectivity_state != GRPC_CHANNEL_FATAL_FAILURE) {
+    grpc_transport_op op;
+    memset(&op, 0, sizeof(op));
+    op.on_connectivity_state_change = &chand->channel_connectivity_changed,
+    op.connectivity_state = &chand->connectivity_state;
+    grpc_channel_next_op(exec_ctx,
+                         grpc_channel_stack_element(
+                             grpc_channel_get_channel_stack(chand->channel), 0),
+                         &op);
+  } else {
+    gpr_mu_lock(&server->mu_global);
+    destroy_channel(exec_ctx, chand);
+    gpr_mu_unlock(&server->mu_global);
+    GRPC_CHANNEL_INTERNAL_UNREF(exec_ctx, chand->channel, "connectivity");
+  }
+}
+
+static void init_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
+                           grpc_call_element_args *args) {
+  call_data *calld = elem->call_data;
+  channel_data *chand = elem->channel_data;
+  memset(calld, 0, sizeof(call_data));
+  calld->deadline = gpr_inf_future(GPR_CLOCK_REALTIME);
+  calld->call = grpc_call_from_top_element(elem);
+  gpr_mu_init(&calld->mu_state);
+
+  grpc_closure_init(&calld->server_on_recv_initial_metadata,
+                    server_on_recv_initial_metadata, elem);
+
+  server_ref(chand->server);
+}
+
+static void destroy_call_elem(grpc_exec_ctx *exec_ctx,
+                              grpc_call_element *elem) {
+  channel_data *chand = elem->channel_data;
+  call_data *calld = elem->call_data;
+
+  GPR_ASSERT(calld->state != PENDING);
+
+  if (calld->host) {
+    GRPC_MDSTR_UNREF(calld->host);
+  }
+  if (calld->path) {
+    GRPC_MDSTR_UNREF(calld->path);
+  }
+  grpc_metadata_array_destroy(&calld->initial_metadata);
+
+  gpr_mu_destroy(&calld->mu_state);
+
+  server_unref(exec_ctx, chand->server);
+}
+
+static void init_channel_elem(grpc_exec_ctx *exec_ctx,
+                              grpc_channel_element *elem,
+                              grpc_channel_element_args *args) {
+  channel_data *chand = elem->channel_data;
+  GPR_ASSERT(args->is_first);
+  GPR_ASSERT(!args->is_last);
+  chand->server = NULL;
+  chand->channel = NULL;
+  chand->next = chand->prev = chand;
+  chand->registered_methods = NULL;
+  chand->connectivity_state = GRPC_CHANNEL_IDLE;
+  grpc_closure_init(&chand->channel_connectivity_changed,
+                    channel_connectivity_changed, chand);
+}
+
+static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
+                                 grpc_channel_element *elem) {
+  size_t i;
+  channel_data *chand = elem->channel_data;
+  if (chand->registered_methods) {
+    for (i = 0; i < chand->registered_method_slots; i++) {
+      if (chand->registered_methods[i].method) {
+        GRPC_MDSTR_UNREF(chand->registered_methods[i].method);
+      }
+      if (chand->registered_methods[i].host) {
+        GRPC_MDSTR_UNREF(chand->registered_methods[i].host);
+      }
+    }
+    gpr_free(chand->registered_methods);
+  }
+  if (chand->server) {
+    gpr_mu_lock(&chand->server->mu_global);
+    chand->next->prev = chand->prev;
+    chand->prev->next = chand->next;
+    chand->next = chand->prev = chand;
+    maybe_finish_shutdown(exec_ctx, chand->server);
+    gpr_mu_unlock(&chand->server->mu_global);
+    server_unref(exec_ctx, chand->server);
+  }
+}
+
+const grpc_channel_filter grpc_server_top_filter = {
+    server_start_transport_stream_op,
+    grpc_channel_next_op,
+    sizeof(call_data),
+    init_call_elem,
+    grpc_call_stack_ignore_set_pollset,
+    destroy_call_elem,
+    sizeof(channel_data),
+    init_channel_elem,
+    destroy_channel_elem,
+    grpc_call_next_get_peer,
+    "server",
+};
+
+void grpc_server_register_completion_queue(grpc_server *server,
+                                           grpc_completion_queue *cq,
+                                           void *reserved) {
+  size_t i, n;
+  GRPC_API_TRACE(
+      "grpc_server_register_completion_queue(server=%p, cq=%p, reserved=%p)", 3,
+      (server, cq, reserved));
+  GPR_ASSERT(!reserved);
+  for (i = 0; i < server->cq_count; i++) {
+    if (server->cqs[i] == cq) return;
+  }
+  GRPC_CQ_INTERNAL_REF(cq, "server");
+  grpc_cq_mark_server_cq(cq);
+  n = server->cq_count++;
+  server->cqs = gpr_realloc(server->cqs,
+                            server->cq_count * sizeof(grpc_completion_queue *));
+  server->cqs[n] = cq;
+}
+
+grpc_server *grpc_server_create(const grpc_channel_args *args, void *reserved) {
+  size_t i;
+
+  GRPC_API_TRACE("grpc_server_create(%p, %p)", 2, (args, reserved));
+
+  grpc_server *server = gpr_malloc(sizeof(grpc_server));
+
+  GPR_ASSERT(grpc_is_initialized() && "call grpc_init()");
+
+  memset(server, 0, sizeof(grpc_server));
+
+  gpr_mu_init(&server->mu_global);
+  gpr_mu_init(&server->mu_call);
+
+  /* decremented by grpc_server_destroy */
+  gpr_ref_init(&server->internal_refcount, 1);
+  server->root_channel_data.next = server->root_channel_data.prev =
+      &server->root_channel_data;
+
+  /* TODO(ctiller): expose a channel_arg for this */
+  server->max_requested_calls = 32768;
+  server->request_freelist =
+      gpr_stack_lockfree_create(server->max_requested_calls);
+  for (i = 0; i < (size_t)server->max_requested_calls; i++) {
+    gpr_stack_lockfree_push(server->request_freelist, (int)i);
+  }
+  request_matcher_init(&server->unregistered_request_matcher,
+                       server->max_requested_calls);
+  server->requested_calls = gpr_malloc(server->max_requested_calls *
+                                       sizeof(*server->requested_calls));
+
+  server->channel_args = grpc_channel_args_copy(args);
+
+  return server;
+}
+
+static int streq(const char *a, const char *b) {
+  if (a == NULL && b == NULL) return 1;
+  if (a == NULL) return 0;
+  if (b == NULL) return 0;
+  return 0 == strcmp(a, b);
+}
+
+void *grpc_server_register_method(grpc_server *server, const char *method,
+                                  const char *host) {
+  registered_method *m;
+  GRPC_API_TRACE("grpc_server_register_method(server=%p, method=%s, host=%s)",
+                 3, (server, method, host));
+  if (!method) {
+    gpr_log(GPR_ERROR,
+            "grpc_server_register_method method string cannot be NULL");
+    return NULL;
+  }
+  for (m = server->registered_methods; m; m = m->next) {
+    if (streq(m->method, method) && streq(m->host, host)) {
+      gpr_log(GPR_ERROR, "duplicate registration for %s@%s", method,
+              host ? host : "*");
+      return NULL;
+    }
+  }
+  m = gpr_malloc(sizeof(registered_method));
+  memset(m, 0, sizeof(*m));
+  request_matcher_init(&m->request_matcher, server->max_requested_calls);
+  m->method = gpr_strdup(method);
+  m->host = gpr_strdup(host);
+  m->next = server->registered_methods;
+  server->registered_methods = m;
+  return m;
+}
+
+void grpc_server_start(grpc_server *server) {
+  listener *l;
+  size_t i;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+
+  GRPC_API_TRACE("grpc_server_start(server=%p)", 1, (server));
+
+  server->pollsets = gpr_malloc(sizeof(grpc_pollset *) * server->cq_count);
+  for (i = 0; i < server->cq_count; i++) {
+    server->pollsets[i] = grpc_cq_pollset(server->cqs[i]);
+  }
+
+  for (l = server->listeners; l; l = l->next) {
+    l->start(&exec_ctx, server, l->arg, server->pollsets, server->cq_count);
+  }
+
+  grpc_exec_ctx_finish(&exec_ctx);
+}
+
+void grpc_server_setup_transport(grpc_exec_ctx *exec_ctx, grpc_server *s,
+                                 grpc_transport *transport,
+                                 const grpc_channel_args *args) {
+  size_t i;
+  size_t num_registered_methods;
+  size_t alloc;
+  registered_method *rm;
+  channel_registered_method *crm;
+  grpc_channel *channel;
+  channel_data *chand;
+  grpc_mdstr *host;
+  grpc_mdstr *method;
+  uint32_t hash;
+  size_t slots;
+  uint32_t probes;
+  uint32_t max_probes = 0;
+  grpc_transport_op op;
+
+  for (i = 0; i < s->cq_count; i++) {
+    memset(&op, 0, sizeof(op));
+    op.bind_pollset = grpc_cq_pollset(s->cqs[i]);
+    grpc_transport_perform_op(exec_ctx, transport, &op);
+  }
+
+  channel =
+      grpc_channel_create(exec_ctx, NULL, args, GRPC_SERVER_CHANNEL, transport);
+  chand = (channel_data *)grpc_channel_stack_element(
+              grpc_channel_get_channel_stack(channel), 0)
+              ->channel_data;
+  chand->server = s;
+  server_ref(s);
+  chand->channel = channel;
+
+  num_registered_methods = 0;
+  for (rm = s->registered_methods; rm; rm = rm->next) {
+    num_registered_methods++;
+  }
+  /* build a lookup table phrased in terms of mdstr's in this channels context
+     to quickly find registered methods */
+  if (num_registered_methods > 0) {
+    slots = 2 * num_registered_methods;
+    alloc = sizeof(channel_registered_method) * slots;
+    chand->registered_methods = gpr_malloc(alloc);
+    memset(chand->registered_methods, 0, alloc);
+    for (rm = s->registered_methods; rm; rm = rm->next) {
+      host = rm->host ? grpc_mdstr_from_string(rm->host) : NULL;
+      method = grpc_mdstr_from_string(rm->method);
+      hash = GRPC_MDSTR_KV_HASH(host ? host->hash : 0, method->hash);
+      for (probes = 0; chand->registered_methods[(hash + probes) % slots]
+                           .server_registered_method != NULL;
+           probes++)
+        ;
+      if (probes > max_probes) max_probes = probes;
+      crm = &chand->registered_methods[(hash + probes) % slots];
+      crm->server_registered_method = rm;
+      crm->host = host;
+      crm->method = method;
+    }
+    GPR_ASSERT(slots <= UINT32_MAX);
+    chand->registered_method_slots = (uint32_t)slots;
+    chand->registered_method_max_probes = max_probes;
+  }
+
+  gpr_mu_lock(&s->mu_global);
+  chand->next = &s->root_channel_data;
+  chand->prev = chand->next->prev;
+  chand->next->prev = chand->prev->next = chand;
+  gpr_mu_unlock(&s->mu_global);
+
+  GRPC_CHANNEL_INTERNAL_REF(channel, "connectivity");
+  memset(&op, 0, sizeof(op));
+  op.set_accept_stream = true;
+  op.set_accept_stream_fn = accept_stream;
+  op.set_accept_stream_user_data = chand;
+  op.on_connectivity_state_change = &chand->channel_connectivity_changed;
+  op.connectivity_state = &chand->connectivity_state;
+  op.disconnect = gpr_atm_acq_load(&s->shutdown_flag) != 0;
+  grpc_transport_perform_op(exec_ctx, transport, &op);
+}
+
+void done_published_shutdown(grpc_exec_ctx *exec_ctx, void *done_arg,
+                             grpc_cq_completion *storage) {
+  (void)done_arg;
+  gpr_free(storage);
+}
+
+static void listener_destroy_done(grpc_exec_ctx *exec_ctx, void *s,
+                                  bool success) {
+  grpc_server *server = s;
+  gpr_mu_lock(&server->mu_global);
+  server->listeners_destroyed++;
+  maybe_finish_shutdown(exec_ctx, server);
+  gpr_mu_unlock(&server->mu_global);
+}
+
+void grpc_server_shutdown_and_notify(grpc_server *server,
+                                     grpc_completion_queue *cq, void *tag) {
+  listener *l;
+  shutdown_tag *sdt;
+  channel_broadcaster broadcaster;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+
+  GRPC_API_TRACE("grpc_server_shutdown_and_notify(server=%p, cq=%p, tag=%p)", 3,
+                 (server, cq, tag));
+
+  /* lock, and gather up some stuff to do */
+  gpr_mu_lock(&server->mu_global);
+  grpc_cq_begin_op(cq, tag);
+  if (server->shutdown_published) {
+    grpc_cq_end_op(&exec_ctx, cq, tag, 1, done_published_shutdown, NULL,
+                   gpr_malloc(sizeof(grpc_cq_completion)));
+    gpr_mu_unlock(&server->mu_global);
+    goto done;
+  }
+  server->shutdown_tags =
+      gpr_realloc(server->shutdown_tags,
+                  sizeof(shutdown_tag) * (server->num_shutdown_tags + 1));
+  sdt = &server->shutdown_tags[server->num_shutdown_tags++];
+  sdt->tag = tag;
+  sdt->cq = cq;
+  if (gpr_atm_acq_load(&server->shutdown_flag)) {
+    gpr_mu_unlock(&server->mu_global);
+    goto done;
+  }
+
+  server->last_shutdown_message_time = gpr_now(GPR_CLOCK_REALTIME);
+
+  channel_broadcaster_init(server, &broadcaster);
+
+  gpr_atm_rel_store(&server->shutdown_flag, 1);
+
+  /* collect all unregistered then registered calls */
+  gpr_mu_lock(&server->mu_call);
+  kill_pending_work_locked(&exec_ctx, server);
+  gpr_mu_unlock(&server->mu_call);
+
+  maybe_finish_shutdown(&exec_ctx, server);
+  gpr_mu_unlock(&server->mu_global);
+
+  /* Shutdown listeners */
+  for (l = server->listeners; l; l = l->next) {
+    grpc_closure_init(&l->destroy_done, listener_destroy_done, server);
+    l->destroy(&exec_ctx, server, l->arg, &l->destroy_done);
+  }
+
+  channel_broadcaster_shutdown(&exec_ctx, &broadcaster, 1, 0);
+
+done:
+  grpc_exec_ctx_finish(&exec_ctx);
+}
+
+void grpc_server_cancel_all_calls(grpc_server *server) {
+  channel_broadcaster broadcaster;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+
+  GRPC_API_TRACE("grpc_server_cancel_all_calls(server=%p)", 1, (server));
+
+  gpr_mu_lock(&server->mu_global);
+  channel_broadcaster_init(server, &broadcaster);
+  gpr_mu_unlock(&server->mu_global);
+
+  channel_broadcaster_shutdown(&exec_ctx, &broadcaster, 0, 1);
+  grpc_exec_ctx_finish(&exec_ctx);
+}
+
+void grpc_server_destroy(grpc_server *server) {
+  listener *l;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+
+  GRPC_API_TRACE("grpc_server_destroy(server=%p)", 1, (server));
+
+  gpr_mu_lock(&server->mu_global);
+  GPR_ASSERT(gpr_atm_acq_load(&server->shutdown_flag) || !server->listeners);
+  GPR_ASSERT(server->listeners_destroyed == num_listeners(server));
+
+  while (server->listeners) {
+    l = server->listeners;
+    server->listeners = l->next;
+    gpr_free(l);
+  }
+
+  gpr_mu_unlock(&server->mu_global);
+
+  server_unref(&exec_ctx, server);
+  grpc_exec_ctx_finish(&exec_ctx);
+}
+
+void grpc_server_add_listener(
+    grpc_exec_ctx *exec_ctx, grpc_server *server, void *arg,
+    void (*start)(grpc_exec_ctx *exec_ctx, grpc_server *server, void *arg,
+                  grpc_pollset **pollsets, size_t pollset_count),
+    void (*destroy)(grpc_exec_ctx *exec_ctx, grpc_server *server, void *arg,
+                    grpc_closure *on_done)) {
+  listener *l = gpr_malloc(sizeof(listener));
+  l->arg = arg;
+  l->start = start;
+  l->destroy = destroy;
+  l->next = server->listeners;
+  server->listeners = l;
+}
+
+static grpc_call_error queue_call_request(grpc_exec_ctx *exec_ctx,
+                                          grpc_server *server,
+                                          requested_call *rc) {
+  call_data *calld = NULL;
+  request_matcher *rm = NULL;
+  int request_id;
+  if (gpr_atm_acq_load(&server->shutdown_flag)) {
+    fail_call(exec_ctx, server, rc);
+    return GRPC_CALL_OK;
+  }
+  request_id = gpr_stack_lockfree_pop(server->request_freelist);
+  if (request_id == -1) {
+    /* out of request ids: just fail this one */
+    fail_call(exec_ctx, server, rc);
+    return GRPC_CALL_OK;
+  }
+  switch (rc->type) {
+    case BATCH_CALL:
+      rm = &server->unregistered_request_matcher;
+      break;
+    case REGISTERED_CALL:
+      rm = &rc->data.registered.registered_method->request_matcher;
+      break;
+  }
+  server->requested_calls[request_id] = *rc;
+  gpr_free(rc);
+  if (gpr_stack_lockfree_push(rm->requests, request_id)) {
+    /* this was the first queued request: we need to lock and start
+       matching calls */
+    gpr_mu_lock(&server->mu_call);
+    while ((calld = rm->pending_head) != NULL) {
+      request_id = gpr_stack_lockfree_pop(rm->requests);
+      if (request_id == -1) break;
+      rm->pending_head = calld->pending_next;
+      gpr_mu_unlock(&server->mu_call);
+      gpr_mu_lock(&calld->mu_state);
+      if (calld->state == ZOMBIED) {
+        gpr_mu_unlock(&calld->mu_state);
+        grpc_closure_init(
+            &calld->kill_zombie_closure, kill_zombie,
+            grpc_call_stack_element(grpc_call_get_call_stack(calld->call), 0));
+        grpc_exec_ctx_enqueue(exec_ctx, &calld->kill_zombie_closure, true,
+                              NULL);
+      } else {
+        GPR_ASSERT(calld->state == PENDING);
+        calld->state = ACTIVATED;
+        gpr_mu_unlock(&calld->mu_state);
+        begin_call(exec_ctx, server, calld,
+                   &server->requested_calls[request_id]);
+      }
+      gpr_mu_lock(&server->mu_call);
+    }
+    gpr_mu_unlock(&server->mu_call);
+  }
+  return GRPC_CALL_OK;
+}
+
+grpc_call_error grpc_server_request_call(
+    grpc_server *server, grpc_call **call, grpc_call_details *details,
+    grpc_metadata_array *initial_metadata,
+    grpc_completion_queue *cq_bound_to_call,
+    grpc_completion_queue *cq_for_notification, void *tag) {
+  grpc_call_error error;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  requested_call *rc = gpr_malloc(sizeof(*rc));
+  GRPC_API_TRACE(
+      "grpc_server_request_call("
+      "server=%p, call=%p, details=%p, initial_metadata=%p, "
+      "cq_bound_to_call=%p, cq_for_notification=%p, tag=%p)",
+      7, (server, call, details, initial_metadata, cq_bound_to_call,
+          cq_for_notification, tag));
+  if (!grpc_cq_is_server_cq(cq_for_notification)) {
+    gpr_free(rc);
+    error = GRPC_CALL_ERROR_NOT_SERVER_COMPLETION_QUEUE;
+    goto done;
+  }
+  grpc_cq_begin_op(cq_for_notification, tag);
+  details->reserved = NULL;
+  rc->type = BATCH_CALL;
+  rc->server = server;
+  rc->tag = tag;
+  rc->cq_bound_to_call = cq_bound_to_call;
+  rc->cq_for_notification = cq_for_notification;
+  rc->call = call;
+  rc->data.batch.details = details;
+  rc->initial_metadata = initial_metadata;
+  error = queue_call_request(&exec_ctx, server, rc);
+done:
+  grpc_exec_ctx_finish(&exec_ctx);
+  return error;
+}
+
+grpc_call_error grpc_server_request_registered_call(
+    grpc_server *server, void *rmp, grpc_call **call, gpr_timespec *deadline,
+    grpc_metadata_array *initial_metadata, grpc_byte_buffer **optional_payload,
+    grpc_completion_queue *cq_bound_to_call,
+    grpc_completion_queue *cq_for_notification, void *tag) {
+  grpc_call_error error;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  requested_call *rc = gpr_malloc(sizeof(*rc));
+  registered_method *rm = rmp;
+  GRPC_API_TRACE(
+      "grpc_server_request_registered_call("
+      "server=%p, rmp=%p, call=%p, deadline=%p, initial_metadata=%p, "
+      "optional_payload=%p, cq_bound_to_call=%p, cq_for_notification=%p, "
+      "tag=%p)",
+      9, (server, rmp, call, deadline, initial_metadata, optional_payload,
+          cq_bound_to_call, cq_for_notification, tag));
+  if (!grpc_cq_is_server_cq(cq_for_notification)) {
+    gpr_free(rc);
+    error = GRPC_CALL_ERROR_NOT_SERVER_COMPLETION_QUEUE;
+    goto done;
+  }
+  grpc_cq_begin_op(cq_for_notification, tag);
+  rc->type = REGISTERED_CALL;
+  rc->server = server;
+  rc->tag = tag;
+  rc->cq_bound_to_call = cq_bound_to_call;
+  rc->cq_for_notification = cq_for_notification;
+  rc->call = call;
+  rc->data.registered.registered_method = rm;
+  rc->data.registered.deadline = deadline;
+  rc->initial_metadata = initial_metadata;
+  rc->data.registered.optional_payload = optional_payload;
+  error = queue_call_request(&exec_ctx, server, rc);
+done:
+  grpc_exec_ctx_finish(&exec_ctx);
+  return error;
+}
+
+static void publish_registered_or_batch(grpc_exec_ctx *exec_ctx,
+                                        void *user_data, bool success);
+
+static void cpstr(char **dest, size_t *capacity, grpc_mdstr *value) {
+  gpr_slice slice = value->slice;
+  size_t len = GPR_SLICE_LENGTH(slice);
+
+  if (len + 1 > *capacity) {
+    *capacity = GPR_MAX(len + 1, *capacity * 2);
+    *dest = gpr_realloc(*dest, *capacity);
+  }
+  memcpy(*dest, grpc_mdstr_as_c_string(value), len + 1);
+}
+
+static void begin_call(grpc_exec_ctx *exec_ctx, grpc_server *server,
+                       call_data *calld, requested_call *rc) {
+  grpc_op ops[1];
+  grpc_op *op = ops;
+
+  memset(ops, 0, sizeof(ops));
+
+  /* called once initial metadata has been read by the call, but BEFORE
+     the ioreq to fetch it out of the call has been executed.
+     This means metadata related fields can be relied on in calld, but to
+     fill in the metadata array passed by the client, we need to perform
+     an ioreq op, that should complete immediately. */
+
+  grpc_call_set_completion_queue(exec_ctx, calld->call, rc->cq_bound_to_call);
+  grpc_closure_init(&rc->publish, publish_registered_or_batch, rc);
+  *rc->call = calld->call;
+  calld->cq_new = rc->cq_for_notification;
+  GPR_SWAP(grpc_metadata_array, *rc->initial_metadata, calld->initial_metadata);
+  switch (rc->type) {
+    case BATCH_CALL:
+      GPR_ASSERT(calld->host != NULL);
+      GPR_ASSERT(calld->path != NULL);
+      cpstr(&rc->data.batch.details->host,
+            &rc->data.batch.details->host_capacity, calld->host);
+      cpstr(&rc->data.batch.details->method,
+            &rc->data.batch.details->method_capacity, calld->path);
+      rc->data.batch.details->deadline = calld->deadline;
+      break;
+    case REGISTERED_CALL:
+      *rc->data.registered.deadline = calld->deadline;
+      if (rc->data.registered.optional_payload) {
+        op->op = GRPC_OP_RECV_MESSAGE;
+        op->data.recv_message = rc->data.registered.optional_payload;
+        op++;
+      }
+      break;
+    default:
+      GPR_UNREACHABLE_CODE(return );
+  }
+
+  GRPC_CALL_INTERNAL_REF(calld->call, "server");
+  grpc_call_start_batch_and_execute(exec_ctx, calld->call, ops,
+                                    (size_t)(op - ops), &rc->publish);
+}
+
+static void done_request_event(grpc_exec_ctx *exec_ctx, void *req,
+                               grpc_cq_completion *c) {
+  requested_call *rc = req;
+  grpc_server *server = rc->server;
+
+  if (rc >= server->requested_calls &&
+      rc < server->requested_calls + server->max_requested_calls) {
+    GPR_ASSERT(rc - server->requested_calls <= INT_MAX);
+    gpr_stack_lockfree_push(server->request_freelist,
+                            (int)(rc - server->requested_calls));
+  } else {
+    gpr_free(req);
+  }
+
+  server_unref(exec_ctx, server);
+}
+
+static void fail_call(grpc_exec_ctx *exec_ctx, grpc_server *server,
+                      requested_call *rc) {
+  *rc->call = NULL;
+  rc->initial_metadata->count = 0;
+
+  server_ref(server);
+  grpc_cq_end_op(exec_ctx, rc->cq_for_notification, rc->tag, 0,
+                 done_request_event, rc, &rc->completion);
+}
+
+static void publish_registered_or_batch(grpc_exec_ctx *exec_ctx, void *prc,
+                                        bool success) {
+  requested_call *rc = prc;
+  grpc_call *call = *rc->call;
+  grpc_call_element *elem =
+      grpc_call_stack_element(grpc_call_get_call_stack(call), 0);
+  call_data *calld = elem->call_data;
+  channel_data *chand = elem->channel_data;
+  server_ref(chand->server);
+  grpc_cq_end_op(exec_ctx, calld->cq_new, rc->tag, success, done_request_event,
+                 rc, &rc->completion);
+  GRPC_CALL_INTERNAL_UNREF(exec_ctx, call, "server");
+}
+
+const grpc_channel_args *grpc_server_get_channel_args(grpc_server *server) {
+  return server->channel_args;
+}
+
+int grpc_server_has_open_connections(grpc_server *server) {
+  int r;
+  gpr_mu_lock(&server->mu_global);
+  r = server->root_channel_data.next != &server->root_channel_data;
+  gpr_mu_unlock(&server->mu_global);
+  return r;
+}
diff --git a/src/core/lib/surface/server.h b/src/core/lib/surface/server.h
new file mode 100644
index 0000000000..3845eb2981
--- /dev/null
+++ b/src/core/lib/surface/server.h
@@ -0,0 +1,62 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_SURFACE_SERVER_H
+#define GRPC_CORE_LIB_SURFACE_SERVER_H
+
+#include <grpc/grpc.h>
+#include "src/core/lib/channel/channel_stack.h"
+#include "src/core/lib/transport/transport.h"
+
+extern const grpc_channel_filter grpc_server_top_filter;
+
+/* Add a listener to the server: when the server starts, it will call start,
+   and when it shuts down, it will call destroy */
+void grpc_server_add_listener(
+    grpc_exec_ctx *exec_ctx, grpc_server *server, void *listener,
+    void (*start)(grpc_exec_ctx *exec_ctx, grpc_server *server, void *arg,
+                  grpc_pollset **pollsets, size_t npollsets),
+    void (*destroy)(grpc_exec_ctx *exec_ctx, grpc_server *server, void *arg,
+                    grpc_closure *on_done));
+
+/* Setup a transport - creates a channel stack, binds the transport to the
+   server */
+void grpc_server_setup_transport(grpc_exec_ctx *exec_ctx, grpc_server *server,
+                                 grpc_transport *transport,
+                                 const grpc_channel_args *args);
+
+const grpc_channel_args *grpc_server_get_channel_args(grpc_server *server);
+
+int grpc_server_has_open_connections(grpc_server *server);
+
+#endif /* GRPC_CORE_LIB_SURFACE_SERVER_H */
diff --git a/src/core/lib/surface/server_chttp2.c b/src/core/lib/surface/server_chttp2.c
new file mode 100644
index 0000000000..f0c2ee5153
--- /dev/null
+++ b/src/core/lib/surface/server_chttp2.c
@@ -0,0 +1,146 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <grpc/grpc.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/useful.h>
+#include "src/core/lib/channel/http_server_filter.h"
+#include "src/core/lib/iomgr/resolve_address.h"
+#include "src/core/lib/iomgr/tcp_server.h"
+#include "src/core/lib/surface/api_trace.h"
+#include "src/core/lib/surface/server.h"
+#include "src/core/lib/transport/chttp2_transport.h"
+
+static void setup_transport(grpc_exec_ctx *exec_ctx, void *server,
+                            grpc_transport *transport) {
+  grpc_server_setup_transport(exec_ctx, server, transport,
+                              grpc_server_get_channel_args(server));
+}
+
+static void new_transport(grpc_exec_ctx *exec_ctx, void *server,
+                          grpc_endpoint *tcp,
+                          grpc_tcp_server_acceptor *acceptor) {
+  /*
+   * Beware that the call to grpc_create_chttp2_transport() has to happen before
+   * grpc_tcp_server_destroy(). This is fine here, but similar code
+   * asynchronously doing a handshake instead of calling grpc_tcp_server_start()
+   * (as in server_secure_chttp2.c) needs to add synchronization to avoid this
+   * case.
+   */
+  grpc_transport *transport = grpc_create_chttp2_transport(
+      exec_ctx, grpc_server_get_channel_args(server), tcp, 0);
+  setup_transport(exec_ctx, server, transport);
+  grpc_chttp2_transport_start_reading(exec_ctx, transport, NULL, 0);
+}
+
+/* Server callback: start listening on our ports */
+static void start(grpc_exec_ctx *exec_ctx, grpc_server *server, void *tcpp,
+                  grpc_pollset **pollsets, size_t pollset_count) {
+  grpc_tcp_server *tcp = tcpp;
+  grpc_tcp_server_start(exec_ctx, tcp, pollsets, pollset_count, new_transport,
+                        server);
+}
+
+/* Server callback: destroy the tcp listener (so we don't generate further
+   callbacks) */
+static void destroy(grpc_exec_ctx *exec_ctx, grpc_server *server, void *tcpp,
+                    grpc_closure *destroy_done) {
+  grpc_tcp_server *tcp = tcpp;
+  grpc_tcp_server_unref(exec_ctx, tcp);
+  grpc_exec_ctx_enqueue(exec_ctx, destroy_done, true, NULL);
+}
+
+int grpc_server_add_insecure_http2_port(grpc_server *server, const char *addr) {
+  grpc_resolved_addresses *resolved = NULL;
+  grpc_tcp_server *tcp = NULL;
+  size_t i;
+  unsigned count = 0;
+  int port_num = -1;
+  int port_temp;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+
+  GRPC_API_TRACE("grpc_server_add_insecure_http2_port(server=%p, addr=%s)", 2,
+                 (server, addr));
+
+  resolved = grpc_blocking_resolve_address(addr, "http");
+  if (!resolved) {
+    goto error;
+  }
+
+  tcp = grpc_tcp_server_create(NULL);
+  GPR_ASSERT(tcp);
+
+  for (i = 0; i < resolved->naddrs; i++) {
+    port_temp = grpc_tcp_server_add_port(
+        tcp, (struct sockaddr *)&resolved->addrs[i].addr,
+        resolved->addrs[i].len);
+    if (port_temp > 0) {
+      if (port_num == -1) {
+        port_num = port_temp;
+      } else {
+        GPR_ASSERT(port_num == port_temp);
+      }
+      count++;
+    }
+  }
+  if (count == 0) {
+    gpr_log(GPR_ERROR, "No address added out of total %d resolved",
+            resolved->naddrs);
+    goto error;
+  }
+  if (count != resolved->naddrs) {
+    gpr_log(GPR_ERROR, "Only %d addresses added out of total %d resolved",
+            count, resolved->naddrs);
+  }
+  grpc_resolved_addresses_destroy(resolved);
+
+  /* Register with the server only upon success */
+  grpc_server_add_listener(&exec_ctx, server, tcp, start, destroy);
+  goto done;
+
+/* Error path: cleanup and return */
+error:
+  if (resolved) {
+    grpc_resolved_addresses_destroy(resolved);
+  }
+  if (tcp) {
+    grpc_tcp_server_unref(&exec_ctx, tcp);
+  }
+  port_num = 0;
+
+done:
+  grpc_exec_ctx_finish(&exec_ctx);
+  return port_num;
+}
diff --git a/src/core/lib/surface/surface_trace.h b/src/core/lib/surface/surface_trace.h
new file mode 100644
index 0000000000..6b3f673924
--- /dev/null
+++ b/src/core/lib/surface/surface_trace.h
@@ -0,0 +1,48 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_SURFACE_SURFACE_TRACE_H
+#define GRPC_CORE_LIB_SURFACE_SURFACE_TRACE_H
+
+#include <grpc/support/log.h>
+#include "src/core/lib/debug/trace.h"
+#include "src/core/lib/surface/api_trace.h"
+
+#define GRPC_SURFACE_TRACE_RETURNED_EVENT(cq, event)    \
+  if (grpc_api_trace) {                                 \
+    char *_ev = grpc_event_string(event);               \
+    gpr_log(GPR_INFO, "RETURN_EVENT[%p]: %s", cq, _ev); \
+    gpr_free(_ev);                                      \
+  }
+
+#endif /* GRPC_CORE_LIB_SURFACE_SURFACE_TRACE_H */
diff --git a/src/core/lib/surface/validate_metadata.c b/src/core/lib/surface/validate_metadata.c
new file mode 100644
index 0000000000..bf4126867f
--- /dev/null
+++ b/src/core/lib/surface/validate_metadata.c
@@ -0,0 +1,73 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <stdlib.h>
+#include <string.h>
+
+#include <grpc/support/port_platform.h>
+
+static int conforms_to(const char *s, size_t len, const uint8_t *legal_bits) {
+  const char *p = s;
+  const char *e = s + len;
+  for (; p != e; p++) {
+    int idx = *p;
+    int byte = idx / 8;
+    int bit = idx % 8;
+    if ((legal_bits[byte] & (1 << bit)) == 0) return 0;
+  }
+  return 1;
+}
+
+int grpc_header_key_is_legal(const char *key, size_t length) {
+  static const uint8_t legal_header_bits[256 / 8] = {
+      0x00, 0x00, 0x00, 0x00, 0x00, 0x60, 0xff, 0x03, 0x00, 0x00, 0x00,
+      0x80, 0xfe, 0xff, 0xff, 0x07, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
+  if (length == 0) {
+    return 0;
+  }
+  return conforms_to(key, length, legal_header_bits);
+}
+
+int grpc_header_nonbin_value_is_legal(const char *value, size_t length) {
+  static const uint8_t legal_header_bits[256 / 8] = {
+      0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+      0xff, 0xff, 0xff, 0xff, 0x7f, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
+  return conforms_to(value, length, legal_header_bits);
+}
+
+int grpc_is_binary_header(const char *key, size_t length) {
+  if (length < 5) return 0;
+  return 0 == memcmp(key + length - 4, "-bin", 4);
+}
diff --git a/src/core/lib/surface/version.c b/src/core/lib/surface/version.c
new file mode 100644
index 0000000000..7723f39401
--- /dev/null
+++ b/src/core/lib/surface/version.c
@@ -0,0 +1,39 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+/* This file is autogenerated from:
+   templates/src/core/surface/version.c.template */
+
+#include <grpc/grpc.h>
+
+const char *grpc_version_string(void) { return "0.14.0-dev"; }