ipc_sync_message_filter.cc 6.2 KB

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  1. // Copyright (c) 2012 The Chromium Authors. All rights reserved.
  2. // Use of this source code is governed by a BSD-style license that can be
  3. // found in the LICENSE file.
  4. #include "ipc/ipc_sync_message_filter.h"
  5. #include "base/bind.h"
  6. #include "base/check.h"
  7. #include "base/location.h"
  8. #include "base/memory/ptr_util.h"
  9. #include "base/memory/ref_counted.h"
  10. #include "base/synchronization/waitable_event.h"
  11. #include "base/threading/thread_task_runner_handle.h"
  12. #include "base/trace_event/trace_event.h"
  13. #include "ipc/ipc_channel.h"
  14. #include "ipc/ipc_sync_message.h"
  15. #include "mojo/public/cpp/bindings/associated_receiver.h"
  16. #include "mojo/public/cpp/bindings/sync_handle_registry.h"
  17. namespace IPC {
  18. namespace {
  19. // A generic callback used when watching handles synchronously. Sets |*signal|
  20. // to true.
  21. void OnEventReady(bool* signal) {
  22. *signal = true;
  23. }
  24. } // namespace
  25. bool SyncMessageFilter::Send(Message* message) {
  26. if (!message->is_sync()) {
  27. {
  28. base::AutoLock auto_lock(lock_);
  29. if (!io_task_runner_.get()) {
  30. pending_messages_.emplace_back(base::WrapUnique(message));
  31. return true;
  32. }
  33. }
  34. io_task_runner_->PostTask(
  35. FROM_HERE,
  36. base::BindOnce(&SyncMessageFilter::SendOnIOThread, this, message));
  37. return true;
  38. }
  39. base::WaitableEvent done_event(
  40. base::WaitableEvent::ResetPolicy::MANUAL,
  41. base::WaitableEvent::InitialState::NOT_SIGNALED);
  42. PendingSyncMsg pending_message(
  43. SyncMessage::GetMessageId(*message),
  44. static_cast<SyncMessage*>(message)->GetReplyDeserializer(),
  45. &done_event);
  46. {
  47. base::AutoLock auto_lock(lock_);
  48. // Can't use this class on the main thread or else it can lead to deadlocks.
  49. // Also by definition, can't use this on IO thread since we're blocking it.
  50. if (base::ThreadTaskRunnerHandle::IsSet()) {
  51. DCHECK(base::ThreadTaskRunnerHandle::Get() != listener_task_runner_);
  52. DCHECK(base::ThreadTaskRunnerHandle::Get() != io_task_runner_);
  53. }
  54. pending_sync_messages_.insert(&pending_message);
  55. if (io_task_runner_.get()) {
  56. io_task_runner_->PostTask(
  57. FROM_HERE,
  58. base::BindOnce(&SyncMessageFilter::SendOnIOThread, this, message));
  59. } else {
  60. pending_messages_.emplace_back(base::WrapUnique(message));
  61. }
  62. }
  63. {
  64. bool done = false;
  65. bool shutdown = false;
  66. scoped_refptr<mojo::SyncHandleRegistry> registry =
  67. mojo::SyncHandleRegistry::current();
  68. mojo::SyncHandleRegistry::EventCallbackSubscription shutdown_subscription =
  69. registry->RegisterEvent(shutdown_event_,
  70. base::BindRepeating(&OnEventReady, &shutdown));
  71. mojo::SyncHandleRegistry::EventCallbackSubscription done_subscription =
  72. registry->RegisterEvent(&done_event,
  73. base::BindRepeating(&OnEventReady, &done));
  74. const bool* stop_flags[] = {&done, &shutdown};
  75. registry->Wait(stop_flags, 2);
  76. if (done) {
  77. TRACE_EVENT_WITH_FLOW0("toplevel.flow", "SyncMessageFilter::Send",
  78. &done_event, TRACE_EVENT_FLAG_FLOW_IN);
  79. }
  80. }
  81. {
  82. base::AutoLock auto_lock(lock_);
  83. delete pending_message.deserializer;
  84. pending_sync_messages_.erase(&pending_message);
  85. }
  86. return pending_message.send_result;
  87. }
  88. void SyncMessageFilter::OnFilterAdded(Channel* channel) {
  89. std::vector<std::unique_ptr<Message>> pending_messages;
  90. {
  91. base::AutoLock auto_lock(lock_);
  92. channel_ = channel;
  93. io_task_runner_ = base::ThreadTaskRunnerHandle::Get();
  94. std::swap(pending_messages_, pending_messages);
  95. }
  96. for (auto& msg : pending_messages)
  97. SendOnIOThread(msg.release());
  98. }
  99. void SyncMessageFilter::OnChannelError() {
  100. base::AutoLock auto_lock(lock_);
  101. channel_ = nullptr;
  102. SignalAllEvents();
  103. }
  104. void SyncMessageFilter::OnChannelClosing() {
  105. base::AutoLock auto_lock(lock_);
  106. channel_ = nullptr;
  107. SignalAllEvents();
  108. }
  109. bool SyncMessageFilter::OnMessageReceived(const Message& message) {
  110. base::AutoLock auto_lock(lock_);
  111. for (PendingSyncMessages::iterator iter = pending_sync_messages_.begin();
  112. iter != pending_sync_messages_.end(); ++iter) {
  113. if (SyncMessage::IsMessageReplyTo(message, (*iter)->id)) {
  114. if (!message.is_reply_error()) {
  115. (*iter)->send_result =
  116. (*iter)->deserializer->SerializeOutputParameters(message);
  117. }
  118. TRACE_EVENT_WITH_FLOW0("toplevel.flow",
  119. "SyncMessageFilter::OnMessageReceived",
  120. (*iter)->done_event, TRACE_EVENT_FLAG_FLOW_OUT);
  121. (*iter)->done_event->Signal();
  122. return true;
  123. }
  124. }
  125. return false;
  126. }
  127. SyncMessageFilter::SyncMessageFilter(base::WaitableEvent* shutdown_event)
  128. : channel_(nullptr),
  129. listener_task_runner_(base::ThreadTaskRunnerHandle::Get()),
  130. shutdown_event_(shutdown_event) {}
  131. SyncMessageFilter::~SyncMessageFilter() = default;
  132. void SyncMessageFilter::SendOnIOThread(Message* message) {
  133. if (channel_) {
  134. channel_->Send(message);
  135. return;
  136. }
  137. if (message->is_sync()) {
  138. // We don't know which thread sent it, but it doesn't matter, just signal
  139. // them all.
  140. base::AutoLock auto_lock(lock_);
  141. SignalAllEvents();
  142. }
  143. delete message;
  144. }
  145. void SyncMessageFilter::SignalAllEvents() {
  146. lock_.AssertAcquired();
  147. for (PendingSyncMessages::iterator iter = pending_sync_messages_.begin();
  148. iter != pending_sync_messages_.end(); ++iter) {
  149. TRACE_EVENT_WITH_FLOW0("toplevel.flow",
  150. "SyncMessageFilter::SignalAllEvents",
  151. (*iter)->done_event, TRACE_EVENT_FLAG_FLOW_OUT);
  152. (*iter)->done_event->Signal();
  153. }
  154. }
  155. void SyncMessageFilter::GetRemoteAssociatedInterface(
  156. mojo::GenericPendingAssociatedReceiver receiver) {
  157. base::AutoLock auto_lock(lock_);
  158. DCHECK(io_task_runner_ && io_task_runner_->BelongsToCurrentThread());
  159. if (!channel_) {
  160. // Attach the associated interface to a disconnected pipe, so that the
  161. // associated interface pointer can be used to make calls (which are
  162. // dropped).
  163. mojo::AssociateWithDisconnectedPipe(receiver.PassHandle());
  164. return;
  165. }
  166. Channel::AssociatedInterfaceSupport* support =
  167. channel_->GetAssociatedInterfaceSupport();
  168. support->GetRemoteAssociatedInterface(std::move(receiver));
  169. }
  170. } // namespace IPC