text: /*
   *
   * Copyright 2015 gRPC authors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   *
   */
  
  #include <grpc/support/port_platform.h>
  
  #include <limits.h>
  #include <memory.h>
  
  #include <grpc/grpc.h>
  #include <grpc/support/alloc.h>
  #include <grpc/support/log.h>
  #include <grpc/support/time.h>
  #include "src/core/lib/channel/channel_stack.h"
  #include "src/core/lib/channel/connected_channel.h"
  #include "src/core/lib/channel/handshaker_registry.h"
  #include "src/core/lib/debug/trace.h"
  #include "src/core/lib/http/parser.h"
  #include "src/core/lib/iomgr/combiner.h"
  #include "src/core/lib/iomgr/executor.h"
  #include "src/core/lib/iomgr/iomgr.h"
  #include "src/core/lib/iomgr/resource_quota.h"
  #include "src/core/lib/profiling/timers.h"
  #include "src/core/lib/slice/slice_internal.h"
  #include "src/core/lib/surface/alarm_internal.h"
  #include "src/core/lib/surface/api_trace.h"
  #include "src/core/lib/surface/call.h"
  #include "src/core/lib/surface/channel_init.h"
  #include "src/core/lib/surface/completion_queue.h"
  #include "src/core/lib/surface/init.h"
  #include "src/core/lib/surface/lame_client.h"
  #include "src/core/lib/surface/server.h"
  #include "src/core/lib/transport/bdp_estimator.h"
  #include "src/core/lib/transport/connectivity_state.h"
  #include "src/core/lib/transport/transport_impl.h"
  
  /* (generated) built in registry of plugins */
  extern void grpc_register_built_in_plugins(void);
  
  #define MAX_PLUGINS 128
  
  static gpr_once g_basic_init = GPR_ONCE_INIT;
  static gpr_mu g_init_mu;
  static int g_initializations;
  
  static void do_basic_init(void) {
    gpr_log_verbosity_init();
    gpr_mu_init(&g_init_mu);
    grpc_register_built_in_plugins();
    g_initializations = 0;
  }
  
  static bool append_filter(grpc_exec_ctx *exec_ctx,
                            grpc_channel_stack_builder *builder, void *arg) {
    return grpc_channel_stack_builder_append_filter(
        builder, (const grpc_channel_filter *)arg, NULL, NULL);
  }
  
  static bool prepend_filter(grpc_exec_ctx *exec_ctx,
                             grpc_channel_stack_builder *builder, void *arg) {
    return grpc_channel_stack_builder_prepend_filter(
        builder, (const grpc_channel_filter *)arg, NULL, NULL);
  }
  
  static void register_builtin_channel_init() {
    grpc_channel_init_register_stage(GRPC_CLIENT_SUBCHANNEL,
                                     GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
                                     grpc_add_connected_filter, NULL);
    grpc_channel_init_register_stage(GRPC_CLIENT_DIRECT_CHANNEL,
                                     GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
                                     grpc_add_connected_filter, NULL);
    grpc_channel_init_register_stage(GRPC_SERVER_CHANNEL,
                                     GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
                                     grpc_add_connected_filter, NULL);
    grpc_channel_init_register_stage(GRPC_CLIENT_LAME_CHANNEL,
                                     GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
                                     append_filter, (void *)&grpc_lame_filter);
    grpc_channel_init_register_stage(GRPC_SERVER_CHANNEL, INT_MAX, prepend_filter,
                                     (void *)&grpc_server_top_filter);
  }
  
  typedef struct grpc_plugin {
    void (*init)();
    void (*destroy)();
  } grpc_plugin;
  
  static grpc_plugin g_all_of_the_plugins[MAX_PLUGINS];
  static int g_number_of_plugins = 0;
  
  void grpc_register_plugin(void (*init)(void), void (*destroy)(void)) {
    GRPC_API_TRACE("grpc_register_plugin(init=%p, destroy=%p)", 2,
                   ((void *)(intptr_t)init, (void *)(intptr_t)destroy));
    GPR_ASSERT(g_number_of_plugins != MAX_PLUGINS);
    g_all_of_the_plugins[g_number_of_plugins].init = init;
    g_all_of_the_plugins[g_number_of_plugins].destroy = destroy;
    g_number_of_plugins++;
  }
  
  void grpc_init(void) {
    int i;
    gpr_once_init(&g_basic_init, do_basic_init);
  
    grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
    gpr_mu_lock(&g_init_mu);
    if (++g_initializations == 1) {
      gpr_time_init();
      grpc_slice_intern_init();
      grpc_mdctx_global_init();
      grpc_channel_init_init();
      grpc_register_tracer(&grpc_api_trace);
      grpc_register_tracer(&grpc_trace_channel);
      grpc_register_tracer(&grpc_connectivity_state_trace);
      grpc_register_tracer(&grpc_trace_channel_stack_builder);
      grpc_register_tracer(&grpc_http1_trace);
      grpc_register_tracer(&grpc_cq_pluck_trace);  // default on
      grpc_register_tracer(&grpc_combiner_trace);
      grpc_register_tracer(&grpc_server_channel_trace);
      grpc_register_tracer(&grpc_bdp_estimator_trace);
      grpc_register_tracer(&grpc_cq_event_timeout_trace);  // default on
      grpc_register_tracer(&grpc_trace_operation_failures);
      grpc_register_tracer(&grpc_resource_quota_trace);
      grpc_register_tracer(&grpc_call_error_trace);
  #ifndef NDEBUG
      grpc_register_tracer(&grpc_trace_pending_tags);
      grpc_register_tracer(&grpc_trace_alarm_refcount);
      grpc_register_tracer(&grpc_trace_cq_refcount);
      grpc_register_tracer(&grpc_trace_closure);
      grpc_register_tracer(&grpc_trace_error_refcount);
      grpc_register_tracer(&grpc_trace_stream_refcount);
      grpc_register_tracer(&grpc_trace_fd_refcount);
      grpc_register_tracer(&grpc_trace_metadata);
  #endif
      grpc_security_pre_init();
      grpc_iomgr_init(&exec_ctx);
      gpr_timers_global_init();
      grpc_handshaker_factory_registry_init();
      grpc_security_init();
      for (i = 0; i < g_number_of_plugins; i++) {
        if (g_all_of_the_plugins[i].init != NULL) {
          g_all_of_the_plugins[i].init();
        }
      }
      /* register channel finalization AFTER all plugins, to ensure that it's run
       * at the appropriate time */
      grpc_register_security_filters();
      register_builtin_channel_init();
      grpc_tracer_init("GRPC_TRACE");
      /* no more changes to channel init pipelines */
      grpc_channel_init_finalize();
      grpc_iomgr_start(&exec_ctx);
    }
    gpr_mu_unlock(&g_init_mu);
    grpc_exec_ctx_finish(&exec_ctx);
    GRPC_API_TRACE("grpc_init(void)", 0, ());
  }
  
  void grpc_shutdown(void) {
    int i;
    GRPC_API_TRACE("grpc_shutdown(void)", 0, ());
    grpc_exec_ctx exec_ctx =
        GRPC_EXEC_CTX_INITIALIZER(0, grpc_never_ready_to_finish, NULL);
    gpr_mu_lock(&g_init_mu);
    if (--g_initializations == 0) {
      grpc_iomgr_shutdown(&exec_ctx);
      gpr_timers_global_destroy();
      grpc_tracer_shutdown();
      for (i = g_number_of_plugins; i >= 0; i--) {
        if (g_all_of_the_plugins[i].destroy != NULL) {
          g_all_of_the_plugins[i].destroy();
        }
      }
      grpc_mdctx_global_shutdown(&exec_ctx);
      grpc_handshaker_factory_registry_shutdown(&exec_ctx);
      grpc_slice_intern_shutdown();
    }
    gpr_mu_unlock(&g_init_mu);
    grpc_exec_ctx_finish(&exec_ctx);
  }
  
  int grpc_is_initialized(void) {
    int r;
    gpr_once_init(&g_basic_init, do_basic_init);
    gpr_mu_lock(&g_init_mu);
    r = g_initializations > 0;
    gpr_mu_unlock(&g_init_mu);
    return r;
  }
  