Initial refactoring and context API changes

11 files changed, 341 insertions, 24 deletions

diff --git a/src/core/census/README.md b/src/core/census/README.md
new file mode 100644
index 0000000000..fb615a2194
--- /dev/null
+++ b/src/core/census/README.md
@@ -0,0 +1,76 @@
+<!---
+ * Copyright 2015, 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.
+-->
+
+# Census - a resource measurement and tracing system
+
+This directory contains code for Census, which will ultimately provide the
+following features for any gRPC-using system:
+* A [dapper](http://research.google.com/pubs/pub36356.html)-like tracing
+  system, enabling tracing across a distributed infrastructure.
+* RPC statistics and measurements for key metrics, such as latency, bytes
+  transferred, number of errors etc.
+* Resource measurement framework which can be used for measuring custom
+  metrics. Through the use of [tags](#Tags), these can be broken down across
+  the entire distributed stack.
+* Easy integration of the above with
+  [Google Cloud Trace](https://cloud.google.com/tools/cloud-trace) and
+  [Google Cloud Monitoring](https://cloud.google.com/monitoring/).
+
+## Concepts
+
+### Context
+
+### Operations
+
+### Tags
+
+### Metrics
+
+## API
+
+### Internal/RPC API
+
+### External/Client API
+
+### RPC API
+
+## Files in this directory
+
+Note that files and functions in this directory can be split into two
+categories:
+* Files that define core census library functions. Functions etc. in these
+  files are named census\_\*, and constitute the core census library
+  functionality. At some time in the future, these will become a standalone
+  library.
+* Files that define functions etc. that provide a convenient interface between
+  grpc and the core census functionality. These files are all named
+  grpc\_\*.{c,h}, and define function names beginning with grpc\_census\_\*.
+
diff --git a/src/core/census/context.c b/src/core/census/context.c
new file mode 100644
index 0000000000..a940e96ec0
--- /dev/null
+++ b/src/core/census/context.c
@@ -0,0 +1,59 @@
+/*
+ *
+ * Copyright 2015, 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 "context.h"
+
+#include <string.h>
+#include <grpc/census.h>
+#include <grpc/support/alloc.h>
+
+/* Placeholder implementation only. */
+
+size_t census_context_serialize(const census_context *context, char *buffer,
+                                size_t buf_size) {
+  /* TODO(aveitch): implement serialization */
+  return 0;
+}
+
+census_context *census_context_deserialize(char *buffer) {
+  census_context *ret;
+  if (buffer != NULL) {
+    /* TODO(aveitch): implement deserialization */
+    return NULL;
+  }
+  ret = gpr_malloc(sizeof(census_context));
+  memset(ret, 0, sizeof(census_context));
+  return ret;
+}
+
+void census_context_destroy(census_context *context) { gpr_free(context); }
diff --git a/src/core/census/context.h b/src/core/census/context.h
new file mode 100644
index 0000000000..d43a69f7e5
--- /dev/null
+++ b/src/core/census/context.h
@@ -0,0 +1,49 @@
+/*
+ *
+ * Copyright 2015, 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_INTERNAL_CORE_CENSUS_CONTEXT_H
+#define GRPC_INTERNAL_CORE_CENSUS_CONTEXT_H
+
+#include <grpc/census.h>
+
+/* census_context is the in-memory representation of information needed to
+ * maintain tracing, RPC statistics and resource usage information. */
+struct census_context {
+  gpr_uint64 op_id;    /* Operation identifier - unique per-context */
+  gpr_uint64 trace_id; /* Globally unique trace identifier */
+  /* TODO(aveitch) Add census tags:
+  const census_tag_set *tags;
+  */
+};
+
+#endif /* GRPC_INTERNAL_CORE_CENSUS_CONTEXT_H */
diff --git a/src/core/census/grpc_context.c b/src/core/census/grpc_context.c
new file mode 100644
index 0000000000..4b1ba49e70
--- /dev/null
+++ b/src/core/census/grpc_context.c
@@ -0,0 +1,41 @@
+/*
+ *
+ * Copyright 2015, 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/census.h>
+#include "src/core/census/grpc_context.h"
+
+void *grpc_census_context_create() { return census_context_deserialize(NULL); }
+
+void grpc_census_context_destroy(void *context) {
+  census_context_destroy((census_context *)context);
+}
diff --git a/src/core/census/grpc_context.h b/src/core/census/grpc_context.h
new file mode 100644
index 0000000000..f610f6ce21
--- /dev/null
+++ b/src/core/census/grpc_context.h
@@ -0,0 +1,42 @@
+/*
+ *
+ * Copyright 2015, 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.
+ *
+ */
+
+/* GRPC <--> CENSUS context interface */
+
+#ifndef CENSUS_GRPC_CONTEXT_H
+#define CENSUS_GRPC_CONTEXT_H
+
+void *grpc_census_context_create();
+void grpc_census_context_destroy(void *context);
+
+#endif /* CENSUS_GRPC_CONTEXT_H */
diff --git a/src/core/census/initialize.c b/src/core/census/initialize.c
new file mode 100644
index 0000000000..d72c08b91c
--- /dev/null
+++ b/src/core/census/initialize.c
@@ -0,0 +1,38 @@
+/*
+ *
+ * Copyright 2015, 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/census.h>
+
+int census_initialize(int functions) { return 0; }
+
+void census_shutdown() {}
diff --git a/src/core/surface/call.c b/src/core/surface/call.c
index 50df36cae9..b0b922b642 100644
--- a/src/core/surface/call.c
+++ b/src/core/surface/call.c
@@ -31,6 +31,7 @@
  *
  */
 
+#include "src/core/census/grpc_context.h"
 #include "src/core/surface/call.h"
 #include "src/core/channel/channel_stack.h"
 #include "src/core/iomgr/alarm.h"
@@ -242,9 +243,9 @@ static int fill_send_ops(grpc_call *call, grpc_transport_op *op);
 static void execute_op(grpc_call *call, grpc_transport_op *op);
 static void recv_metadata(grpc_call *call, grpc_metadata_batch *metadata);
 static void finish_read_ops(grpc_call *call);
-static grpc_call_error cancel_with_status(
-    grpc_call *c, grpc_status_code status, const char *description,
-    gpr_uint8 locked);
+static grpc_call_error cancel_with_status(grpc_call *c, grpc_status_code status,
+                                          const char *description,
+                                          gpr_uint8 locked);
 
 grpc_call *grpc_call_create(grpc_channel *channel, grpc_completion_queue *cq,
                             const void *server_transport_data,
@@ -268,6 +269,8 @@ grpc_call *grpc_call_create(grpc_channel *channel, grpc_completion_queue *cq,
   if (call->is_client) {
     call->request_set[GRPC_IOREQ_SEND_TRAILING_METADATA] = REQSET_DONE;
     call->request_set[GRPC_IOREQ_SEND_STATUS] = REQSET_DONE;
+    call->context[GRPC_CONTEXT_TRACING] = grpc_census_context_create();
+    call->destroy_context[GRPC_CONTEXT_TRACING] = grpc_census_context_destroy;
   }
   GPR_ASSERT(add_initial_metadata_count < MAX_SEND_INITIAL_METADATA_COUNT);
   for (i = 0; i < add_initial_metadata_count; i++) {
@@ -402,7 +405,8 @@ static void lock(grpc_call *call) { gpr_mu_lock(&call->mu); }
 
 static int need_more_data(grpc_call *call) {
   return is_op_live(call, GRPC_IOREQ_RECV_INITIAL_METADATA) ||
-         (is_op_live(call, GRPC_IOREQ_RECV_MESSAGE) && grpc_bbq_empty(&call->incoming_queue)) ||
+         (is_op_live(call, GRPC_IOREQ_RECV_MESSAGE) &&
+          grpc_bbq_empty(&call->incoming_queue)) ||
          is_op_live(call, GRPC_IOREQ_RECV_TRAILING_METADATA) ||
          is_op_live(call, GRPC_IOREQ_RECV_STATUS) ||
          is_op_live(call, GRPC_IOREQ_RECV_STATUS_DETAILS) ||
@@ -557,13 +561,13 @@ static void finish_live_ioreq_op(grpc_call *call, grpc_ioreq_op op,
           break;
         case GRPC_IOREQ_RECV_INITIAL_METADATA:
           GPR_SWAP(grpc_metadata_array, call->buffered_metadata[0],
-               *call->request_data[GRPC_IOREQ_RECV_INITIAL_METADATA]
-                    .recv_metadata);
+                   *call->request_data[GRPC_IOREQ_RECV_INITIAL_METADATA]
+                        .recv_metadata);
           break;
         case GRPC_IOREQ_RECV_TRAILING_METADATA:
           GPR_SWAP(grpc_metadata_array, call->buffered_metadata[1],
-               *call->request_data[GRPC_IOREQ_RECV_TRAILING_METADATA]
-                    .recv_metadata);
+                   *call->request_data[GRPC_IOREQ_RECV_TRAILING_METADATA]
+                        .recv_metadata);
           break;
         case GRPC_IOREQ_OP_COUNT:
           abort();
@@ -653,9 +657,8 @@ static int add_slice_to_message(grpc_call *call, gpr_slice slice) {
   }
   /* we have to be reading a message to know what to do here */
   if (!call->reading_message) {
-    cancel_with_status(
-        call, GRPC_STATUS_INVALID_ARGUMENT,
-        "Received payload data while not reading a message", 1);
+    cancel_with_status(call, GRPC_STATUS_INVALID_ARGUMENT,
+                       "Received payload data while not reading a message", 1);
     return 0;
   }
   /* append the slice to the incoming buffer */
@@ -1021,9 +1024,9 @@ grpc_call_error grpc_call_cancel_with_status(grpc_call *c,
   return cancel_with_status(c, status, description, 0);
 }
 
-static grpc_call_error cancel_with_status(
-    grpc_call *c, grpc_status_code status, const char *description,
-    gpr_uint8 locked) {
+static grpc_call_error cancel_with_status(grpc_call *c, grpc_status_code status,
+                                          const char *description,
+                                          gpr_uint8 locked) {
   grpc_transport_op op;
   grpc_mdstr *details =
       description ? grpc_mdstr_from_string(c->metadata_context, description)
@@ -1287,8 +1290,8 @@ grpc_call_error grpc_call_start_batch(grpc_call *call, const grpc_op *ops,
                                              tag);
 }
 
-void grpc_call_context_set(grpc_call *call, grpc_context_index elem, void *value,
-                           void (*destroy)(void *value)) {
+void grpc_call_context_set(grpc_call *call, grpc_context_index elem,
+                           void *value, void (*destroy)(void *value)) {
   if (call->destroy_context[elem]) {
     call->destroy_context[elem](value);
   }
diff --git a/src/core/surface/channel_create.c b/src/core/surface/channel_create.c
index daa8d3a7c6..9fa6696bf6 100644
--- a/src/core/surface/channel_create.c
+++ b/src/core/surface/channel_create.c
@@ -195,9 +195,10 @@ grpc_channel *grpc_channel_create(const char *target,
   const grpc_channel_filter *filters[MAX_FILTERS];
   int n = 0;
   filters[n++] = &grpc_client_surface_filter;
+  /* TODO(census)
   if (grpc_channel_args_is_census_enabled(args)) {
     filters[n++] = &grpc_client_census_filter;
-  }
+    } */
   filters[n++] = &grpc_client_channel_filter;
   GPR_ASSERT(n <= MAX_FILTERS);
   channel = grpc_channel_create_from_filters(filters, n, args, mdctx, 1);
diff --git a/src/core/surface/init.c b/src/core/surface/init.c
index d6eb9b2c24..5cd5d9197f 100644
--- a/src/core/surface/init.c
+++ b/src/core/surface/init.c
@@ -31,11 +31,11 @@
  *
  */
 
+#include <grpc/census.h>
 #include <grpc/grpc.h>
 #include "src/core/channel/channel_stack.h"
 #include "src/core/debug/trace.h"
 #include "src/core/iomgr/iomgr.h"
-#include "src/core/statistics/census_interface.h"
 #include "src/core/profiling/timers.h"
 #include "src/core/surface/call.h"
 #include "src/core/surface/init.h"
@@ -64,7 +64,7 @@ void grpc_init(void) {
     grpc_security_pre_init();
     grpc_iomgr_init();
     grpc_tracer_init("GRPC_TRACE");
-    census_init();
+    census_initialize(CENSUS_NONE);
     grpc_timers_global_init();
   }
   gpr_mu_unlock(&g_init_mu);
diff --git a/src/core/surface/secure_channel_create.c b/src/core/surface/secure_channel_create.c
index 3e331293b5..23156c981e 100644
--- a/src/core/surface/secure_channel_create.c
+++ b/src/core/surface/secure_channel_create.c
@@ -234,9 +234,10 @@ grpc_channel *grpc_secure_channel_create(grpc_credentials *creds,
       new_args_from_connector != NULL ? new_args_from_connector : args,
       &connector_arg);
   filters[n++] = &grpc_client_surface_filter;
+  /* TODO(census)
   if (grpc_channel_args_is_census_enabled(args)) {
     filters[n++] = &grpc_client_census_filter;
-  }
+    } */
   filters[n++] = &grpc_client_channel_filter;
   GPR_ASSERT(n <= MAX_FILTERS);
   channel = grpc_channel_create_from_filters(filters, n, args_copy, mdctx, 1);
diff --git a/src/core/surface/server.c b/src/core/surface/server.c
index 351ed5b758..b8ac410687 100644
--- a/src/core/surface/server.c
+++ b/src/core/surface/server.c
@@ -592,9 +592,15 @@ static void destroy_channel_elem(grpc_channel_element *elem) {
 }
 
 static const grpc_channel_filter server_surface_filter = {
-    server_start_transport_op, channel_op, sizeof(call_data), init_call_elem,
-    destroy_call_elem, sizeof(channel_data), init_channel_elem,
-    destroy_channel_elem, "server",
+    server_start_transport_op,
+    channel_op,
+    sizeof(call_data),
+    init_call_elem,
+    destroy_call_elem,
+    sizeof(channel_data),
+    init_channel_elem,
+    destroy_channel_elem,
+    "server",
 };
 
 void grpc_server_register_completion_queue(grpc_server *server,
@@ -640,9 +646,10 @@ grpc_server *grpc_server_create_from_filters(grpc_channel_filter **filters,
   server->channel_filters =
       gpr_malloc(server->channel_filter_count * sizeof(grpc_channel_filter *));
   server->channel_filters[0] = &server_surface_filter;
+  /* TODO(census)
   if (census_enabled) {
     server->channel_filters[1] = &grpc_server_census_filter;
-  }
+    } */
   for (i = 0; i < filter_count; i++) {
     server->channel_filters[i + 1 + census_enabled] = filters[i];
   }