[WIP] Add DCHECK for mojo::edk::Init().

mojo/edk/embedder/embedder.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "mojo/edk/embedder/embedder.h"
 
 #include <stdint.h>
 #include <utility>
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/rand_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "mojo/edk/embedder/embedder_internal.h"
 #include "mojo/edk/embedder/entrypoints.h"
 #include "mojo/edk/embedder/platform_channel_pair.h"
 #include "mojo/edk/embedder/process_delegate.h"
 #include "mojo/edk/system/core.h"
 
 #if !defined(OS_NACL)
+#include "base/debug/stack_trace.h"
 #include "crypto/random.h"
 #endif
 
 namespace mojo {
 namespace edk {
-
-class Core;
-class PlatformSupport;
-
 namespace internal {
 
-Core* g_core;
-ProcessDelegate* g_process_delegate;
-
-Core* GetCore() { return g_core; }
+Core* g_core = nullptr;
+ProcessDelegate* g_process_delegate = nullptr;
 
 }  // namespace internal
 
 void SetMaxMessageSize(size_t bytes) {
 }
 
 void ChildProcessLaunched(base::ProcessHandle child_process,
                           ScopedPlatformHandle server_pipe,
                           const std::string& child_token) {
   ChildProcessLaunched(child_process, std::move(server_pipe),
@@ skipping 41 matching lines @@
 
 void ClosePeerConnection(const std::string& peer_token) {
   CHECK(internal::g_process_delegate);
   return internal::g_core->ClosePeerConnection(peer_token);
 }
 
 void Init() {
   MojoSystemThunks thunks = MakeSystemThunks();
   size_t expected_size = MojoEmbedderSetSystemThunks(&thunks);
   DCHECK_EQ(expected_size, sizeof(thunks));
-
+#if defined(OS_NACL) || 1
+  DCHECK(!internal::g_core) << "No nacl stack trace.";
+#else
+  static std::string prev_stack;
+  DCHECK(!internal::g_core) << prev_stack << "\nEndOfPrevStack";
+  prev_stack = base::debug::StackTrace().ToString();
+#endif
   internal::g_core = new Core();
 }
 
 void SetDefaultProcessErrorCallback(const ProcessErrorCallback& callback) {
   internal::g_core->SetDefaultProcessErrorCallback(callback);
 }
 
 MojoResult CreatePlatformHandleWrapper(
     ScopedPlatformHandle platform_handle,
     MojoHandle* platform_handle_wrapper_handle) {
@@ skipping 21 matching lines @@
     base::SharedMemoryHandle* shared_memory_handle,
     size_t* num_bytes,
     bool* read_only) {
   return internal::g_core->PassSharedMemoryHandle(
       mojo_handle, shared_memory_handle, num_bytes, read_only);
 }
 
 void InitIPCSupport(ProcessDelegate* process_delegate,
                     scoped_refptr<base::TaskRunner> io_thread_task_runner) {
   CHECK(internal::g_core);
+#if defined(OS_NACL) || 1
+  DCHECK(!internal::g_process_delegate) << "No stack trace on NaCl";
+#else
+  static std::string prev_stack;
+  DCHECK(!internal::g_process_delegate) << prev_stack << "\nEndOfPrevStack";
+  prev_stack = base::debug::StackTrace().ToString();
+#endif
   internal::g_core->SetIOTaskRunner(io_thread_task_runner);
   internal::g_process_delegate = process_delegate;
 }
 
 void ShutdownIPCSupport() {
   CHECK(internal::g_process_delegate);
   CHECK(internal::g_core);
   internal::g_core->RequestShutdown(
       base::Bind(&ProcessDelegate::OnShutdownComplete,
                  base::Unretained(internal::g_process_delegate)));
+  internal::g_process_delegate = nullptr;
 }
 
 #if defined(OS_MACOSX) && !defined(OS_IOS)
 void SetMachPortProvider(base::PortProvider* port_provider) {
   DCHECK(port_provider);
   internal::g_core->SetMachPortProvider(port_provider);
 }
 #endif
 
 ScopedMessagePipeHandle CreateMessagePipe(
     ScopedPlatformHandle platform_handle) {
-  CHECK(internal::g_process_delegate);
+  CHECK(internal::g_core);
   return internal::g_core->CreateMessagePipe(std::move(platform_handle));
 }
 
 ScopedMessagePipeHandle CreateParentMessagePipe(
     const std::string& token, const std::string& child_token) {
-  CHECK(internal::g_process_delegate);
+  CHECK(internal::g_core);
   return internal::g_core->CreateParentMessagePipe(token, child_token);
 }
 
 ScopedMessagePipeHandle CreateChildMessagePipe(const std::string& token) {
-  CHECK(internal::g_process_delegate);
+  CHECK(internal::g_core);
   return internal::g_core->CreateChildMessagePipe(token);
 }
 
 std::string GenerateRandomToken() {
   char random_bytes[16];
 #if defined(OS_NACL)
   // Not secure. For NaCl only!
   base::RandBytes(random_bytes, 16);
 #else
   crypto::RandBytes(random_bytes, 16);
 #endif
   return base::HexEncode(random_bytes, 16);
 }
 
 MojoResult SetProperty(MojoPropertyType type, const void* value) {
   CHECK(internal::g_core);
   return internal::g_core->SetProperty(type, value);
 }
 
 }  // namespace edk
 }  // namespace mojo