Change single-interface mojo bindings to use SequencedTaskRunner.

mojo/public/cpp/bindings/connector.h

 // Copyright 2013 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.
 
 #ifndef MOJO_PUBLIC_CPP_BINDINGS_CONNECTOR_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_CONNECTOR_H_
 
 #include <memory>
 
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
-#include "base/single_thread_task_runner.h"
-#include "base/threading/thread_checker.h"
+#include "base/sequence_checker.h"
+#include "base/sequenced_task_runner.h"
 #include "mojo/public/cpp/bindings/bindings_export.h"
 #include "mojo/public/cpp/bindings/message.h"
 #include "mojo/public/cpp/bindings/sync_handle_watcher.h"
 #include "mojo/public/cpp/system/core.h"
 #include "mojo/public/cpp/system/watcher.h"
 
 namespace base {
 class Lock;
 }
 
@@ skipping 15 matching lines @@
   enum ConnectorConfig {
     // Connector::Accept() is only called from a single thread.
     SINGLE_THREADED_SEND,
     // Connector::Accept() is allowed to be called from multiple threads.
     MULTI_THREADED_SEND
   };
 
   // The Connector takes ownership of |message_pipe|.
   Connector(ScopedMessagePipeHandle message_pipe,
             ConnectorConfig config,
-            scoped_refptr<base::SingleThreadTaskRunner> runner);
+            scoped_refptr<base::SequencedTaskRunner> runner);
   ~Connector() override;
 
   // Sets the receiver to handle messages read from the message pipe.  The
   // Connector will read messages from the pipe regardless of whether or not an
   // incoming receiver has been set.
   void set_incoming_receiver(MessageReceiver* receiver) {
-    DCHECK(thread_checker_.CalledOnValidThread());
+    DCHECK(sequence_checker_.CalledOnValidSequence());
     incoming_receiver_ = receiver;
   }
 
   // Errors from incoming receivers will force the connector into an error
   // state, where no more messages will be processed. This method is used
   // during testing to prevent that from happening.
   void set_enforce_errors_from_incoming_receiver(bool enforce) {
-    DCHECK(thread_checker_.CalledOnValidThread());
+    DCHECK(sequence_checker_.CalledOnValidSequence());
     enforce_errors_from_incoming_receiver_ = enforce;
   }
 
   // Sets the error handler to receive notifications when an error is
   // encountered while reading from the pipe or waiting to read from the pipe.
   void set_connection_error_handler(const base::Closure& error_handler) {
-    DCHECK(thread_checker_.CalledOnValidThread());
+    DCHECK(sequence_checker_.CalledOnValidSequence());
     connection_error_handler_ = error_handler;
   }
 
   // Returns true if an error was encountered while reading from the pipe or
   // waiting to read from the pipe.
   bool encountered_error() const {
-    DCHECK(thread_checker_.CalledOnValidThread());
+    DCHECK(sequence_checker_.CalledOnValidSequence());
     return error_;
   }
 
   // Closes the pipe. The connector is put into a quiescent state.
   //
   // Please note that this method shouldn't be called unless it results from an
   // explicit request of the user of bindings (e.g., the user sets an
   // InterfacePtr to null or closes a Binding).
   void CloseMessagePipe();
 
   // Releases the pipe. Connector is put into a quiescent state.
   ScopedMessagePipeHandle PassMessagePipe();
 
   // Enters the error state. The upper layer may do this for unrecoverable
   // issues such as invalid messages are received. If a connection error handler
   // has been set, it will be called asynchronously.
   //
   // It is a no-op if the connector is already in the error state or there isn't
   // a bound message pipe. Otherwise, it closes the message pipe, which notifies
   // the other end and also prevents potential danger (say, the caller raises
   // an error because it believes the other end is malicious). In order to
   // appear to the user that the connector still binds to a message pipe, it
   // creates a new message pipe, closes one end and binds to the other.
   void RaiseError();
 
   // Is the connector bound to a MessagePipe handle?
   bool is_valid() const {
-    DCHECK(thread_checker_.CalledOnValidThread());
+    DCHECK(sequence_checker_.CalledOnValidSequence());
     return message_pipe_.is_valid();
   }
 
   // Waits for the next message on the pipe, blocking until one arrives,
   // |deadline| elapses, or an error happens. Returns |true| if a message has
   // been delivered, |false| otherwise.
   bool WaitForIncomingMessage(MojoDeadline deadline);
 
   // See Binding for details of pause/resume.
   void PauseIncomingMethodCallProcessing();
   void ResumeIncomingMethodCallProcessing();
 
   // MessageReceiver implementation:
   bool Accept(Message* message) override;
 
   MessagePipeHandle handle() const {
-    DCHECK(thread_checker_.CalledOnValidThread());
+    DCHECK(sequence_checker_.CalledOnValidSequence());
     return message_pipe_.get();
   }
 
   // Allows |message_pipe_| to be watched while others perform sync handle
   // watching on the same thread. Please see comments of
   // SyncHandleWatcher::AllowWokenUpBySyncWatchOnSameThread().
   void AllowWokenUpBySyncWatchOnSameThread();
 
   // Watches |message_pipe_| (as well as other handles registered to be watched
   // together) synchronously.
   // This method:
   //   - returns true when |should_stop| is set to true;
   //   - return false when any error occurs, including |message_pipe_| being
   //     closed.
   bool SyncWatch(const bool* should_stop);
 
   // Whether currently the control flow is inside the sync handle watcher
   // callback.
   // It always returns false after CloseMessagePipe()/PassMessagePipe().
   bool during_sync_handle_watcher_callback() const {
     return sync_handle_watcher_callback_count_ > 0;
   }
 
-  base::SingleThreadTaskRunner* task_runner() const {
-    return task_runner_.get();
-  }
+  base::SequencedTaskRunner* task_runner() const { return task_runner_.get(); }
 
   // Sets the tag used by the heap profiler.
   // |tag| must be a const string literal.
   void SetWatcherHeapProfilerTag(const char* tag);
 
  private:
   // Callback of mojo::Watcher.
   void OnWatcherHandleReady(MojoResult result);
   // Callback of SyncHandleWatcher.
   void OnSyncHandleWatcherHandleReady(MojoResult result);
@@ skipping 17 matching lines @@
   // Cancels any calls made to |waiter_|.
   void CancelWait();
 
   void EnsureSyncWatcherExists();
 
   base::Closure connection_error_handler_;
 
   ScopedMessagePipeHandle message_pipe_;
   MessageReceiver* incoming_receiver_ = nullptr;
 
-  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
+  scoped_refptr<base::SequencedTaskRunner> task_runner_;
   std::unique_ptr<Watcher> handle_watcher_;
 
   bool error_ = false;
   bool drop_writes_ = false;
   bool enforce_errors_from_incoming_receiver_ = true;
 
   bool paused_ = false;
 
   // If sending messages is allowed from multiple threads, |lock_| is used to
   // protect modifications to |message_pipe_| and |drop_writes_|.
   std::unique_ptr<base::Lock> lock_;
 
   std::unique_ptr<SyncHandleWatcher> sync_watcher_;
   bool allow_woken_up_by_others_ = false;
   // If non-zero, currently the control flow is inside the sync handle watcher
   // callback.
   size_t sync_handle_watcher_callback_count_ = 0;
 
-  base::ThreadChecker thread_checker_;
+  base::SequenceChecker sequence_checker_;
 
   base::Lock connected_lock_;
   bool connected_ = true;
 
   // The tag used to track heap allocations that originated from a Watcher
   // notification.
   const char* heap_profiler_tag_ = nullptr;
 
   // Create a single weak ptr and use it everywhere, to avoid the malloc/free
   // cost of creating a new weak ptr whenever it is needed.
   // NOTE: This weak pointer is invalidated when the message pipe is closed or
   // transferred (i.e., when |connected_| is set to false).
   base::WeakPtr<Connector> weak_self_;
   base::WeakPtrFactory<Connector> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(Connector);
 };
 
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_CONNECTOR_H_