Add API tracing to gRPC core

src/core/census/grpc_context.c

@@ -33,9 +33,12 @@
 
 #include <grpc/census.h>
 #include <grpc/grpc.h>
+#include "src/core/surface/api_trace.h"
 #include "src/core/surface/call.h"
 
 void grpc_census_call_set_context(grpc_call *call, census_context *context) {
+  GRPC_API_TRACE("grpc_census_call_set_context(call=%p, census_context=%p)", 2,
+                 (call, context));
   if (census_enabled() == CENSUS_FEATURE_NONE) {
     return;
   }
@@ -45,5 +48,6 @@ void grpc_census_call_set_context(grpc_call *call, census_context *context) {
 }
 
 census_context *grpc_census_call_get_context(grpc_call *call) {
+  GRPC_API_TRACE("grpc_census_call_get_context(call=%p)", 1, (call));
   return (census_context *)grpc_call_context_get(call, GRPC_CONTEXT_TRACING);
 }

src/core/client_config/resolvers/zookeeper_resolver.c

@@ -45,6 +45,7 @@
 #include "src/core/client_config/resolver_registry.h"
 #include "src/core/iomgr/resolve_address.h"
 #include "src/core/support/string.h"
+#include "src/core/surface/api_trace.h"
 #include "src/core/json/json.h"
 
 /** Zookeeper session expiration time in milliseconds */
@@ -487,6 +488,7 @@ static void zookeeper_plugin_init() {
 }
 
 void grpc_zookeeper_register() {
+  GRPC_API_TRACE("grpc_zookeeper_register(void)", 0, ());
   grpc_register_plugin(zookeeper_plugin_init, NULL);
 }
 

src/core/compression/algorithm.c

@@ -37,12 +37,19 @@
 #include <grpc/compression.h>
 #include <grpc/support/useful.h>
 
+#include "src/core/surface/api_trace.h"
+
 int grpc_compression_algorithm_parse(const char *name, size_t name_length,
                                      grpc_compression_algorithm *algorithm) {
   /* we use strncmp not only because it's safer (even though in this case it
    * doesn't matter, given that we are comparing against string literals, but
    * because this way we needn't have "name" nil-terminated (useful for slice
    * data, for example) */
+  GRPC_API_TRACE(
+      "grpc_compression_algorithm_parse("
+        "name=%*.*s, name_length=%lu, algorithm=%p)", 5,
+        ((int)name_length, (int)name_length, name,
+         (unsigned long)name_length, algorithm));
   if (name_length == 0) {
     return 0;
   }
@@ -60,6 +67,8 @@ int grpc_compression_algorithm_parse(const char *name, size_t name_length,
 
 int grpc_compression_algorithm_name(grpc_compression_algorithm algorithm,
                                     char **name) {
+  GRPC_API_TRACE("grpc_compression_algorithm_parse(algorithm=%d, name=%p)", 2,
+                 ((int)algorithm, name));
   switch (algorithm) {
     case GRPC_COMPRESS_NONE:
       *name = "identity";
@@ -80,6 +89,8 @@ int grpc_compression_algorithm_name(grpc_compression_algorithm algorithm,
  * compression algorithms */
 grpc_compression_algorithm grpc_compression_algorithm_for_level(
     grpc_compression_level level) {
+  GRPC_API_TRACE("grpc_compression_algorithm_for_level(level=%d)", 1,
+                 ((int)level));
   switch (level) {
     case GRPC_COMPRESS_LEVEL_NONE:
       return GRPC_COMPRESS_NONE;
@@ -96,6 +107,8 @@ grpc_compression_algorithm grpc_compression_algorithm_for_level(
 grpc_compression_level grpc_compression_level_for_algorithm(
     grpc_compression_algorithm algorithm) {
   grpc_compression_level clevel;
+  GRPC_API_TRACE("grpc_compression_level_for_algorithm(algorithm=%d)", 1,
+                 ((int)algorithm));
   for (clevel = GRPC_COMPRESS_LEVEL_NONE; clevel < GRPC_COMPRESS_LEVEL_COUNT;
        ++clevel) {
     if (grpc_compression_algorithm_for_level(clevel) == algorithm) {

src/core/security/credentials.c

@@ -41,6 +41,7 @@
 #include "src/core/json/json.h"
 #include "src/core/httpcli/httpcli.h"
 #include "src/core/iomgr/iomgr.h"
+#include "src/core/surface/api_trace.h"
 #include "src/core/support/string.h"
 
 #include <grpc/support/alloc.h>
@@ -91,6 +92,7 @@ void grpc_credentials_unref(grpc_credentials *creds) {
 }
 
 void grpc_credentials_release(grpc_credentials *creds) {
+  GRPC_API_TRACE("grpc_credentials_release(creds=%p)", 1, (creds));
   grpc_credentials_unref(creds);
 }
 
@@ -152,6 +154,7 @@ void grpc_server_credentials_unref(grpc_server_credentials *creds) {
 }
 
 void grpc_server_credentials_release(grpc_server_credentials *creds) {
+  GRPC_API_TRACE("grpc_server_credentials_release(creds=%p)", 1, (creds));
   grpc_server_credentials_unref(creds);
 }
 
@@ -166,6 +169,11 @@ grpc_security_status grpc_server_credentials_create_security_connector(
 
 void grpc_server_credentials_set_auth_metadata_processor(
     grpc_server_credentials *creds, grpc_auth_metadata_processor processor) {
+  GRPC_API_TRACE(
+      "grpc_server_credentials_set_auth_metadata_processor("
+        "creds=%p, "
+        "processor=grpc_auth_metadata_processor { process: %lx, state: %p })",
+      3, (creds, (unsigned long)processor.process, processor.state));
   if (creds == NULL) return;
   if (creds->processor.destroy != NULL && creds->processor.state != NULL) {
     creds->processor.destroy(creds->processor.state);
@@ -317,6 +325,10 @@ grpc_credentials *grpc_ssl_credentials_create(
     const char *pem_root_certs, grpc_ssl_pem_key_cert_pair *pem_key_cert_pair,
     void *reserved) {
   grpc_ssl_credentials *c = gpr_malloc(sizeof(grpc_ssl_credentials));
+  GRPC_API_TRACE("grpc_ssl_credentials_create(pem_root_certs=%s, "
+                                             "pem_key_cert_pair=%p, "
+                                             "reserved=%p)",
+                 3, (pem_root_certs, pem_key_cert_pair, reserved));
   GPR_ASSERT(reserved == NULL);
   memset(c, 0, sizeof(grpc_ssl_credentials));
   c->base.type = GRPC_CREDENTIALS_TYPE_SSL;
@@ -331,6 +343,12 @@ grpc_server_credentials *grpc_ssl_server_credentials_create(
     size_t num_key_cert_pairs, int force_client_auth, void *reserved) {
   grpc_ssl_server_credentials *c =
       gpr_malloc(sizeof(grpc_ssl_server_credentials));
+  GRPC_API_TRACE(
+      "grpc_ssl_server_credentials_create("
+        "pem_root_certs=%s, pem_key_cert_pairs=%p, num_key_cert_pairs=%lu, "
+        "force_client_auth=%d, reserved=%p)", 5,
+      (pem_root_certs, pem_key_cert_pairs, (unsigned long)num_key_cert_pairs,
+       force_client_auth, reserved));
   GPR_ASSERT(reserved == NULL);
   memset(c, 0, sizeof(grpc_ssl_server_credentials));
   c->base.type = GRPC_CREDENTIALS_TYPE_SSL;
@@ -449,6 +467,14 @@ grpc_service_account_jwt_access_credentials_create_from_auth_json_key(
 
 grpc_credentials *grpc_service_account_jwt_access_credentials_create(
     const char *json_key, gpr_timespec token_lifetime, void *reserved) {
+  GRPC_API_TRACE(
+      "grpc_service_account_jwt_access_credentials_create("
+        "json_key=%s, "
+        "token_lifetime="
+          "gpr_timespec { tv_sec: %ld, tv_nsec: %d, clock_type: %d }, "
+          "reserved=%p)",
+      5, (json_key, (long)token_lifetime.tv_sec,
+          token_lifetime.tv_nsec, (int)token_lifetime.clock_type, reserved));
   GPR_ASSERT(reserved == NULL);
   return grpc_service_account_jwt_access_credentials_create_from_auth_json_key(
       grpc_auth_json_key_create_from_string(json_key), token_lifetime);
@@ -659,6 +685,8 @@ grpc_credentials *grpc_google_compute_engine_credentials_create(
     void *reserved) {
   grpc_oauth2_token_fetcher_credentials *c =
       gpr_malloc(sizeof(grpc_oauth2_token_fetcher_credentials));
+  GRPC_API_TRACE("grpc_compute_engine_credentials_create(reserved=%p)", 1,
+                 (reserved));
   GPR_ASSERT(reserved == NULL);
   init_oauth2_token_fetcher(c, compute_engine_fetch_oauth2);
   c->base.vtable = &compute_engine_vtable;
@@ -720,6 +748,9 @@ grpc_credentials *grpc_refresh_token_credentials_create_from_auth_refresh_token(
 
 grpc_credentials *grpc_google_refresh_token_credentials_create(
     const char *json_refresh_token, void *reserved) {
+  GRPC_API_TRACE("grpc_refresh_token_credentials_create(json_refresh_token=%s, "
+                 "reserved=%p)",
+                 2, (json_refresh_token, reserved));
   GPR_ASSERT(reserved == NULL);
   return grpc_refresh_token_credentials_create_from_auth_refresh_token(
       grpc_auth_refresh_token_create_from_string(json_refresh_token));
@@ -820,6 +851,9 @@ grpc_credentials *grpc_access_token_credentials_create(const char *access_token,
   grpc_access_token_credentials *c =
       gpr_malloc(sizeof(grpc_access_token_credentials));
   char *token_md_value;
+  GRPC_API_TRACE("grpc_access_token_credentials_create(access_token=%s, "
+                                                       "reserved=%p)", 2,
+                 (access_token, reserved));
   GPR_ASSERT(reserved == NULL);
   memset(c, 0, sizeof(grpc_access_token_credentials));
   c->base.type = GRPC_CREDENTIALS_TYPE_OAUTH2;
@@ -1056,6 +1090,9 @@ grpc_credentials *grpc_composite_credentials_create(grpc_credentials *creds1,
   grpc_credentials_array creds1_array;
   grpc_credentials_array creds2_array;
   grpc_composite_credentials *c;
+  GRPC_API_TRACE("grpc_composite_credentials_create(creds1=%p, creds2=%p, "
+                                                   "reserved=%p)", 3,
+                 (creds1, creds2, reserved));
   GPR_ASSERT(reserved == NULL);
   GPR_ASSERT(creds1 != NULL);
   GPR_ASSERT(creds2 != NULL);
@@ -1158,6 +1195,9 @@ static grpc_credentials_vtable iam_vtable = {
 grpc_credentials *grpc_google_iam_credentials_create(
     const char *token, const char *authority_selector, void *reserved) {
   grpc_google_iam_credentials *c;
+  GRPC_API_TRACE("grpc_iam_credentials_create(token=%s, authority_selector=%s, "
+                                             "reserved=%p)",
+                 3, (token, authority_selector, reserved));
   GPR_ASSERT(reserved == NULL);
   GPR_ASSERT(token != NULL);
   GPR_ASSERT(authority_selector != NULL);

src/core/security/google_default_credentials.c

@@ -42,6 +42,7 @@
 #include "src/core/httpcli/httpcli.h"
 #include "src/core/support/env.h"
 #include "src/core/support/file.h"
+#include "src/core/surface/api_trace.h"
 
 /* -- Constants. -- */
 
@@ -178,6 +179,9 @@ end:
 grpc_credentials *grpc_google_default_credentials_create(void) {
   grpc_credentials *result = NULL;
   int serving_cached_credentials = 0;
+
+  GRPC_API_TRACE("grpc_google_default_credentials_create(void)", 0, ());
+
   gpr_once_init(&g_once, init_default_credentials);
 
   gpr_mu_lock(&g_mu);

src/core/security/security_context.c

@@ -34,6 +34,7 @@
 #include <string.h>
 
 #include "src/core/security/security_context.h"
+#include "src/core/surface/api_trace.h"
 #include "src/core/surface/call.h"
 #include "src/core/support/string.h"
 
@@ -47,6 +48,8 @@
 grpc_call_error grpc_call_set_credentials(grpc_call *call,
                                           grpc_credentials *creds) {
   grpc_client_security_context *ctx = NULL;
+  GRPC_API_TRACE("grpc_call_set_credentials(call=%p, creds=%p)", 2,
+                 (call, creds));
   if (!grpc_call_is_client(call)) {
     gpr_log(GPR_ERROR, "Method is client-side only.");
     return GRPC_CALL_ERROR_NOT_ON_SERVER;
@@ -71,6 +74,7 @@ grpc_call_error grpc_call_set_credentials(grpc_call *call,
 
 grpc_auth_context *grpc_call_auth_context(grpc_call *call) {
   void *sec_ctx = grpc_call_context_get(call, GRPC_CONTEXT_SECURITY);
+  GRPC_API_TRACE("grpc_call_auth_context(call=%p)", 1, (call));
   if (sec_ctx == NULL) return NULL;
   return grpc_call_is_client(call)
              ? GRPC_AUTH_CONTEXT_REF(
@@ -82,6 +86,7 @@ grpc_auth_context *grpc_call_auth_context(grpc_call *call) {
 }
 
 void grpc_auth_context_release(grpc_auth_context *context) {
+  GRPC_API_TRACE("grpc_auth_context_release(context=%p)", 1, (context));
   GRPC_AUTH_CONTEXT_UNREF(context, "grpc_auth_context_unref");
 }
 
@@ -174,6 +179,8 @@ void grpc_auth_context_unref(grpc_auth_context *ctx) {
 
 const char *grpc_auth_context_peer_identity_property_name(
     const grpc_auth_context *ctx) {
+  GRPC_API_TRACE("grpc_auth_context_peer_identity_property_name(ctx=%p)", 1,
+                 (ctx));
   return ctx->peer_identity_property_name;
 }
 
@@ -182,6 +189,9 @@ int grpc_auth_context_set_peer_identity_property_name(grpc_auth_context *ctx,
   grpc_auth_property_iterator it =
       grpc_auth_context_find_properties_by_name(ctx, name);
   const grpc_auth_property *prop = grpc_auth_property_iterator_next(&it);
+  GRPC_API_TRACE(
+      "grpc_auth_context_set_peer_identity_property_name(ctx=%p, name=%s)", 2,
+      (ctx, name));
   if (prop == NULL) {
     gpr_log(GPR_ERROR, "Property name %s not found in auth context.",
             name != NULL ? name : "NULL");
@@ -192,12 +202,14 @@ int grpc_auth_context_set_peer_identity_property_name(grpc_auth_context *ctx,
 }
 
 int grpc_auth_context_peer_is_authenticated(const grpc_auth_context *ctx) {
+  GRPC_API_TRACE("grpc_auth_context_peer_is_authenticated(ctx=%p)", 1, (ctx));
   return ctx->peer_identity_property_name == NULL ? 0 : 1;
 }
 
 grpc_auth_property_iterator grpc_auth_context_property_iterator(
     const grpc_auth_context *ctx) {
   grpc_auth_property_iterator it = empty_iterator;
+  GRPC_API_TRACE("grpc_auth_context_property_iterator(ctx=%p)", 1, (ctx));
   if (ctx == NULL) return it;
   it.ctx = ctx;
   return it;
@@ -205,6 +217,7 @@ grpc_auth_property_iterator grpc_auth_context_property_iterator(
 
 const grpc_auth_property *grpc_auth_property_iterator_next(
     grpc_auth_property_iterator *it) {
+  GRPC_API_TRACE("grpc_auth_property_iterator_next(it=%p)", 1, (it));
   if (it == NULL || it->ctx == NULL) return NULL;
   while (it->index == it->ctx->properties.count) {
     if (it->ctx->chained == NULL) return NULL;
@@ -229,6 +242,8 @@ const grpc_auth_property *grpc_auth_property_iterator_next(
 grpc_auth_property_iterator grpc_auth_context_find_properties_by_name(
     const grpc_auth_context *ctx, const char *name) {
   grpc_auth_property_iterator it = empty_iterator;
+  GRPC_API_TRACE("grpc_auth_context_find_properties_by_name(ctx=%p, name=%s)",
+                 2, (ctx, name));
   if (ctx == NULL || name == NULL) return empty_iterator;
   it.ctx = ctx;
   it.name = name;
@@ -237,6 +252,7 @@ grpc_auth_property_iterator grpc_auth_context_find_properties_by_name(
 
 grpc_auth_property_iterator grpc_auth_context_peer_identity(
     const grpc_auth_context *ctx) {
+  GRPC_API_TRACE("grpc_auth_context_peer_identity(ctx=%p)", 1, (ctx));
   if (ctx == NULL) return empty_iterator;
   return grpc_auth_context_find_properties_by_name(
       ctx, ctx->peer_identity_property_name);
@@ -255,6 +271,11 @@ static void ensure_auth_context_capacity(grpc_auth_context *ctx) {
 void grpc_auth_context_add_property(grpc_auth_context *ctx, const char *name,
                                     const char *value, size_t value_length) {
   grpc_auth_property *prop;
+  GRPC_API_TRACE(
+      "grpc_auth_context_add_property(ctx=%p, name=%s, value=%*.*s, "
+                                     "value_length=%lu)",
+      6, (ctx, name, (int)value_length, (int)value_length, value,
+          (unsigned long)value_length));
   ensure_auth_context_capacity(ctx);
   prop = &ctx->properties.array[ctx->properties.count++];
   prop->name = gpr_strdup(name);
@@ -268,6 +289,9 @@ void grpc_auth_context_add_cstring_property(grpc_auth_context *ctx,
                                             const char *name,
                                             const char *value) {
   grpc_auth_property *prop;
+  GRPC_API_TRACE(
+      "grpc_auth_context_add_cstring_property(ctx=%p, name=%s, value=%s)", 3,
+      (ctx, name, value));
   ensure_auth_context_capacity(ctx);
   prop = &ctx->properties.array[ctx->properties.count++];
   prop->name = gpr_strdup(name);

src/core/security/server_secure_chttp2.c

@@ -44,6 +44,7 @@
 #include "src/core/security/credentials.h"
 #include "src/core/security/security_connector.h"
 #include "src/core/security/security_context.h"
+#include "src/core/surface/api_trace.h"
 #include "src/core/surface/server.h"
 #include "src/core/transport/chttp2_transport.h"
 #include <grpc/support/alloc.h>
@@ -222,6 +223,10 @@ int grpc_server_add_secure_http2_port(grpc_server *server, const char *addr,
   grpc_security_connector *sc = NULL;
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
 
+  GRPC_API_TRACE("grpc_server_add_secure_http2_port("
+                    "server=%p, addr=%s, creds=%p)",
+                 3, (server, addr, creds));
+
   /* create security context */
   if (creds == NULL) goto error;
   status = grpc_server_credentials_create_security_connector(creds, &sc);

src/core/surface/api_trace.c

@@ -0,0 +1,36 @@
+/*
+ *
+ * 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 "src/core/surface/api_trace.h"
+
+int grpc_api_trace = 0;

src/core/surface/api_trace.h

@@ -0,0 +1,65 @@
+/*
+ *
+ * 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_SURFACE_API_TRACE_H
+#define GRPC_INTERNAL_CORE_SURFACE_API_TRACE_H
+
+#include "src/core/debug/trace.h"
+#include <grpc/support/log.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_INTERNAL_CORE_SURFACE_API_TRACE_H */

src/core/surface/call.c

@@ -45,6 +45,7 @@
 #include "src/core/iomgr/alarm.h"
 #include "src/core/profiling/timers.h"
 #include "src/core/support/string.h"
+#include "src/core/surface/api_trace.h"
 #include "src/core/surface/byte_buffer_queue.h"
 #include "src/core/surface/call.h"
 #include "src/core/surface/channel.h"
@@ -1280,6 +1281,8 @@ void grpc_call_destroy(grpc_call *c) {
   grpc_call *parent = c->parent;
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
 
+  GRPC_API_TRACE("grpc_call_destroy(c=%p)", 1, (c));
+
   if (parent) {
     gpr_mu_lock(&parent->mu);
     if (c == parent->first_child) {
@@ -1308,6 +1311,7 @@ void grpc_call_destroy(grpc_call *c) {
 }
 
 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);
@@ -1319,6 +1323,10 @@ grpc_call_error grpc_call_cancel_with_status(grpc_call *c,
                                              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);
   lock(c);
   r = cancel_with_status(c, status, description);
@@ -1386,6 +1394,7 @@ 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 = elem->filter->get_peer(&exec_ctx, elem);
+  GRPC_API_TRACE("grpc_call_get_peer(%p)", 1, (call));
   grpc_exec_ctx_finish(&exec_ctx);
   return result;
 }
@@ -1580,6 +1589,10 @@ grpc_call_error grpc_call_start_batch(grpc_call *call, const grpc_op *ops,
   grpc_call_error error;
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
 
+  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) {
     error = GRPC_CALL_ERROR;
     goto done;

src/core/surface/call_details.c

@@ -36,11 +36,15 @@
 
 #include <string.h>
 
+#include "src/core/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);
 }

src/core/surface/channel.c

@@ -43,6 +43,7 @@
 #include "src/core/client_config/resolver_registry.h"
 #include "src/core/iomgr/iomgr.h"
 #include "src/core/support/string.h"
+#include "src/core/surface/api_trace.h"
 #include "src/core/surface/call.h"
 #include "src/core/surface/init.h"
 
@@ -184,6 +185,7 @@ grpc_channel *grpc_channel_create_from_filters(
 }
 
 char *grpc_channel_get_target(grpc_channel *channel) {
+  GRPC_API_TRACE("grpc_channel_get_target(channel=%p)", 1, (channel));
   return gpr_strdup(channel->target);
 }
 
@@ -213,6 +215,15 @@ grpc_call *grpc_channel_create_call(grpc_channel *channel,
                                     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: %ld, tv_nsec: %d, clock_type: %d }, "
+        "reserved=%p)",
+      10, (channel, parent_call, (unsigned)propagation_mask, cq, method,
+           host, (long)deadline.tv_sec, deadline.tv_nsec,
+           (int)deadline.clock_type, reserved));
   GPR_ASSERT(!reserved);
   return grpc_channel_create_call_internal(
       channel, parent_call, propagation_mask, cq,
@@ -230,6 +241,9 @@ grpc_call *grpc_channel_create_call(grpc_channel *channel,
 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(
       channel->metadata_context, GRPC_MDSTR_REF(channel->path_string),
@@ -252,6 +266,15 @@ grpc_call *grpc_channel_create_registered_call(
     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: %ld, tv_nsec: %d, clock_type: %d }, "
+        "reserved=%p)",
+      9, (channel, parent_call, (unsigned)propagation_mask, completion_queue,
+          registered_call_handle, (long)deadline.tv_sec, deadline.tv_nsec,
+          (int)deadline.clock_type, reserved));
   GPR_ASSERT(!reserved);
   return grpc_channel_create_call_internal(
       channel, parent_call, propagation_mask, completion_queue,
@@ -317,6 +340,7 @@ 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);

src/core/surface/channel_connectivity.c

@@ -38,6 +38,7 @@
 
 #include "src/core/channel/client_channel.h"
 #include "src/core/iomgr/alarm.h"
+#include "src/core/surface/api_trace.h"
 #include "src/core/surface/completion_queue.h"
 
 grpc_connectivity_state grpc_channel_check_connectivity_state(
@@ -47,6 +48,9 @@ grpc_connectivity_state grpc_channel_check_connectivity_state(
       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) {
     gpr_log(GPR_ERROR,
             "grpc_channel_check_connectivity_state called on something that is "
@@ -175,6 +179,14 @@ void grpc_channel_watch_connectivity_state(
   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: %ld, tv_nsec: %d, clock_type: %d }, "
+        "cq=%p, tag=%p)",
+      7, (channel, (int)last_observed_state, (long)deadline.tv_sec,
+          deadline.tv_nsec, (int)deadline.clock_type, cq, tag));
+
   grpc_cq_begin_op(cq);
 
   gpr_mu_init(&w->mu);

src/core/surface/channel_create.c

@@ -45,6 +45,7 @@
 #include "src/core/channel/http_client_filter.h"
 #include "src/core/client_config/resolver_registry.h"
 #include "src/core/iomgr/tcp_client.h"
+#include "src/core/surface/api_trace.h"
 #include "src/core/surface/channel.h"
 #include "src/core/transport/chttp2_transport.h"
 
@@ -184,6 +185,9 @@ grpc_channel *grpc_insecure_channel_create(const char *target,
   grpc_mdctx *mdctx = grpc_mdctx_create();
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   size_t n = 0;
+  GRPC_API_TRACE(
+      "grpc_insecure_channel_create(target=%p, args=%p, reserved=%p)", 3,
+      (target, args, reserved));
   GPR_ASSERT(!reserved);
   if (grpc_channel_args_is_census_enabled(args)) {
     filters[n++] = &grpc_client_census_filter;

src/core/surface/completion_queue.c

@@ -38,6 +38,7 @@
 
 #include "src/core/iomgr/pollset.h"
 #include "src/core/support/string.h"
+#include "src/core/surface/api_trace.h"
 #include "src/core/surface/call.h"
 #include "src/core/surface/event_string.h"
 #include "src/core/surface/surface_trace.h"
@@ -75,6 +76,7 @@ static void on_pollset_destroy_done(grpc_exec_ctx *exec_ctx, void *cc,
 
 grpc_completion_queue *grpc_completion_queue_create(void *reserved) {
   grpc_completion_queue *cc = gpr_malloc(sizeof(grpc_completion_queue));
+  GRPC_API_TRACE("grpc_completion_queue_create(reserved=%p)", 1, (reserved));
   GPR_ASSERT(!reserved);
   memset(cc, 0, sizeof(*cc));
   /* Initial ref is dropped by grpc_completion_queue_shutdown */
@@ -182,6 +184,13 @@ grpc_event grpc_completion_queue_next(grpc_completion_queue *cc,
   gpr_timespec now;
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
 
+  GRPC_API_TRACE(
+      "grpc_completion_queue_next("
+        "cc=%p, "
+        "deadline=gpr_timespec { tv_sec: %ld, tv_nsec: %d, clock_type: %d }, "
+        "reserved=%p)",
+      5, (cc, (long)deadline.tv_sec, deadline.tv_nsec,
+          (int)deadline.clock_type, reserved));
   GPR_ASSERT(!reserved);
 
   deadline = gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC);
@@ -259,6 +268,13 @@ grpc_event grpc_completion_queue_pluck(grpc_completion_queue *cc, void *tag,
   int first_loop = 1;
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
 
+  GRPC_API_TRACE(
+      "grpc_completion_queue_pluck("
+        "cc=%p, tag=%p, "
+        "deadline=gpr_timespec { tv_sec: %ld, tv_nsec: %d, clock_type: %d }, "
+        "reserved=%p)",
+      6, (cc, tag, (long)deadline.tv_sec, deadline.tv_nsec,
+          (int)deadline.clock_type, reserved));
   GPR_ASSERT(!reserved);
 
   deadline = gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC);
@@ -324,6 +340,7 @@ done:
    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;
+  GRPC_API_TRACE("grpc_completion_queue_shutdown(cc=%p)", 1, (cc));
   gpr_mu_lock(GRPC_POLLSET_MU(&cc->pollset));
   if (cc->shutdown_called) {
     gpr_mu_unlock(GRPC_POLLSET_MU(&cc->pollset));
@@ -343,6 +360,7 @@ void grpc_completion_queue_shutdown(grpc_completion_queue *cc) {
 }
 
 void grpc_completion_queue_destroy(grpc_completion_queue *cc) {
+  GRPC_API_TRACE("grpc_completion_queue_destroy(cc=%p)", 1, (cc));
   grpc_completion_queue_shutdown(cc);
   GRPC_CQ_INTERNAL_UNREF(cc, "destroy");
 }

src/core/surface/init.c

@@ -49,6 +49,7 @@
 #include "src/core/debug/trace.h"
 #include "src/core/iomgr/iomgr.h"
 #include "src/core/profiling/timers.h"
+#include "src/core/surface/api_trace.h"
 #include "src/core/surface/call.h"
 #include "src/core/surface/init.h"
 #include "src/core/surface/surface_trace.h"
@@ -75,6 +76,8 @@ 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=%lx, destroy=%lx)", 2,
+                 ((unsigned long)init, (unsigned long)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;
@@ -98,6 +101,7 @@ void grpc_init(void) {
 #ifdef GPR_POSIX_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("surface", &grpc_surface_trace);
     grpc_register_tracer("http", &grpc_http_trace);
@@ -120,10 +124,12 @@ void grpc_init(void) {
     }
   }
   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_iomgr_shutdown();

src/core/surface/lame_client.c

@@ -37,6 +37,7 @@
 
 #include "src/core/channel/channel_stack.h"
 #include "src/core/support/string.h"
+#include "src/core/surface/api_trace.h"
 #include "src/core/surface/channel.h"
 #include "src/core/surface/call.h"
 #include <grpc/support/alloc.h>
@@ -151,6 +152,10 @@ grpc_channel *grpc_lame_client_channel_create(const char *target,
   channel = grpc_channel_create_from_filters(&exec_ctx, target, filters, 1,
                                              NULL, grpc_mdctx_create(), 1);
   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 == &lame_filter);
   chand = (channel_data *)elem->channel_data;
   chand->error_code = error_code;

src/core/surface/metadata_array.c

@@ -36,10 +36,14 @@
 
 #include <string.h>
 
+#include "src/core/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);
 }

src/core/surface/secure_channel_create.c

@@ -47,6 +47,7 @@
 #include "src/core/iomgr/tcp_client.h"
 #include "src/core/security/auth_filters.h"
 #include "src/core/security/credentials.h"
+#include "src/core/surface/api_trace.h"
 #include "src/core/surface/channel.h"
 #include "src/core/transport/chttp2_transport.h"
 #include "src/core/tsi/transport_security_interface.h"
@@ -246,7 +247,11 @@ grpc_channel *grpc_secure_channel_create(grpc_credentials *creds,
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   size_t n = 0;
 
+  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);

src/core/surface/server.c

@@ -48,6 +48,7 @@
 #include "src/core/iomgr/iomgr.h"
 #include "src/core/support/stack_lockfree.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"
@@ -776,6 +777,9 @@ 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;
@@ -854,6 +858,8 @@ static int streq(const char *a, const char *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");
@@ -881,6 +887,8 @@ void grpc_server_start(grpc_server *server) {
   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]);
@@ -1011,6 +1019,9 @@ void grpc_server_shutdown_and_notify(grpc_server *server,
   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));
+
   GRPC_SERVER_LOG_SHUTDOWN(GPR_INFO, server, cq, tag);
 
   /* lock, and gather up some stuff to do */
@@ -1063,6 +1074,8 @@ 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);
@@ -1075,6 +1088,8 @@ 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));
@@ -1169,6 +1184,12 @@ grpc_call_error grpc_server_request_call(
   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));
   GRPC_SERVER_LOG_REQUEST_CALL(GPR_INFO, server, call, details,
                                initial_metadata, cq_bound_to_call,
                                cq_for_notification, tag);
@@ -1202,6 +1223,13 @@ grpc_call_error grpc_server_request_registered_call(
   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;

src/core/surface/server_chttp2.c

@@ -36,6 +36,7 @@
 #include "src/core/channel/http_server_filter.h"
 #include "src/core/iomgr/resolve_address.h"
 #include "src/core/iomgr/tcp_server.h"
+#include "src/core/surface/api_trace.h"
 #include "src/core/surface/server.h"
 #include "src/core/transport/chttp2_transport.h"
 #include <grpc/support/alloc.h>
@@ -92,6 +93,9 @@ int grpc_server_add_insecure_http2_port(grpc_server *server, const char *addr) {
   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;

src/core/surface/server_create.c

@@ -32,13 +32,14 @@
  */
 
 #include <grpc/grpc.h>
+#include "src/core/surface/api_trace.h"
 #include "src/core/surface/completion_queue.h"
 #include "src/core/surface/server.h"
 #include "src/core/channel/compress_filter.h"
 
 grpc_server *grpc_server_create(const grpc_channel_args *args, void *reserved) {
   const grpc_channel_filter *filters[] = {&grpc_compress_filter};
-  (void)reserved;
+  GRPC_API_TRACE("grpc_server_create(%p, %p)", 2, (args, reserved));
   return grpc_server_create_from_filters(filters, GPR_ARRAY_SIZE(filters),
                                          args);
 }

src/core/surface/version.c

@@ -36,4 +36,10 @@
 
 #include <grpc/grpc.h>
 
-const char *grpc_version_string(void) { return "0.11.0.0"; }
+#include "src/core/surface/api_trace.h"
+
+const char *grpc_version_string(void) {
+  GRPC_API_TRACE("grpc_version_string(void)", 0, ());
+  return "0.11.0.0";
+}
+