Stage #1 of core breakup: move everything under lib

1 files changed, 0 insertions, 1491 deletions

diff --git a/src/core/surface/call.c b/src/core/surface/call.c
deleted file mode 100644
index 6f1cd1df10..0000000000
--- a/src/core/surface/call.c
+++ /dev/null
@@ -1,1491 +0,0 @@
-/*
- *
- * 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/channel/channel_stack.h"
-#include "src/core/compression/algorithm_metadata.h"
-#include "src/core/iomgr/timer.h"
-#include "src/core/profiling/timers.h"
-#include "src/core/support/string.h"
-#include "src/core/surface/api_trace.h"
-#include "src/core/surface/call.h"
-#include "src/core/surface/channel.h"
-#include "src/core/surface/completion_queue.h"
-#include "src/core/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);
-}