Mojo: Add a RawChannel::EnqueueMessage() that can be overridden by subclasses.

mojo/system/raw_channel.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_SYSTEM_RAW_CHANNEL_H_
 #define MOJO_SYSTEM_RAW_CHANNEL_H_
 
 #include <deque>
 #include <vector>
 
@@ skipping 167 matching lines @@
     // The first message's data may have been partially sent. |data_offset_|
     // indicates the position in the first message's data to start the next
     // write.
     size_t data_offset_;
 
     DISALLOW_COPY_AND_ASSIGN(WriteBuffer);
   };
 
   RawChannel();
 
+  // Must be called on the I/O thread WITHOUT |write_lock_| held.
+  void OnReadCompleted(bool result, size_t bytes_read);
+  // Must be called on the I/O thread WITHOUT |write_lock_| held.
+  void OnWriteCompleted(bool result,
+                        size_t platform_handles_written,
+                        size_t bytes_written);
+
   base::MessageLoopForIO* message_loop_for_io() { return message_loop_for_io_; }
   base::Lock& write_lock() { return write_lock_; }
 
-  // Only accessed on the I/O thread.
-  ReadBuffer* read_buffer();
+  // Should only be called on the I/O thread.
+  ReadBuffer* read_buffer() { return read_buffer_.get(); }
 
-  // Only accessed under |write_lock_|.
-  WriteBuffer* write_buffer_no_lock();
+  // Only called under |write_lock_|.
+  WriteBuffer* write_buffer_no_lock() {
+    write_lock_.AssertAcquired();
+    return write_buffer_.get();
+  }
+
+  // Adds |message| to the write message queue. Implementation subclasses may
+  // override this to add any additional "control" messages needed. This is
+  // called (on any thread) with |write_lock_| held.
+  virtual void EnqueueMessageNoLock(scoped_ptr<MessageInTransit> message);
 
   // Reads into |read_buffer()|.
   // This class guarantees that:
   // - the area indicated by |GetBuffer()| will stay valid until read completion
   //   (but please also see the comments for |OnShutdownNoLock()|);
   // - a second read is not started if there is a pending read;
   // - the method is called on the I/O thread WITHOUT |write_lock_| held.
   //
   // The implementing subclass must guarantee that:
   // - |bytes_read| is untouched unless |Read()| returns |IO_SUCCEEDED|;
@@ skipping 36 matching lines @@
 
   // Must be called on the I/O thread WITHOUT |write_lock_| held.
   virtual bool OnInit() = 0;
   // On shutdown, passes the ownership of the buffers to subclasses, which may
   // want to preserve them if there are pending read/write. Must be called on
   // the I/O thread under |write_lock_|.
   virtual void OnShutdownNoLock(
       scoped_ptr<ReadBuffer> read_buffer,
       scoped_ptr<WriteBuffer> write_buffer) = 0;
 
-  // Must be called on the I/O thread WITHOUT |write_lock_| held.
-  void OnReadCompleted(bool result, size_t bytes_read);
-  // Must be called on the I/O thread WITHOUT |write_lock_| held.
-  void OnWriteCompleted(bool result,
-                        size_t platform_handles_written,
-                        size_t bytes_written);
-
  private:
   // Calls |delegate_->OnFatalError(fatal_error)|. Must be called on the I/O
   // thread WITHOUT |write_lock_| held.
   void CallOnFatalError(Delegate::FatalError fatal_error);
 
   // If |result| is true, updates the write buffer and schedules a write
   // operation to run later if there are more contents to write. If |result| is
   // false or any error occurs during the method execution, cancels pending
   // writes and returns false.
   // Must be called only if |write_stopped_| is false and under |write_lock_|.
@@ skipping 19 matching lines @@
   // are only used/invalidated on the I/O thread.
   base::WeakPtrFactory<RawChannel> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RawChannel);
 };
 
 }  // namespace system
 }  // namespace mojo
 
 #endif  // MOJO_SYSTEM_RAW_CHANNEL_H_