Don't leak the WatcherThreadManager background thread.

mojo/edk/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_EDK_SYSTEM_RAW_CHANNEL_H_
 #define MOJO_EDK_SYSTEM_RAW_CHANNEL_H_
 
 #include <vector>
 
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
+#include "base/message_loop/message_loop.h"
 #include "base/synchronization/lock.h"
 #include "mojo/edk/embedder/platform_handle_vector.h"
 #include "mojo/edk/embedder/scoped_platform_handle.h"
 #include "mojo/edk/system/message_in_transit.h"
 #include "mojo/edk/system/message_in_transit_queue.h"
 #include "mojo/edk/system/system_impl_export.h"
 #include "mojo/public/cpp/system/macros.h"
 
 namespace mojo {
 namespace edk {
 
 // |RawChannel| is an interface and base class for objects that wrap an OS
 // "pipe". It presents the following interface to users:
 //  - Receives and dispatches messages on an I/O thread (running a
 //    |MessageLoopForIO|.
 //  - Provides a thread-safe way of writing messages (|WriteMessage()|);
 //    writing/queueing messages will not block and is atomic from the point of
 //    view of the caller. If necessary, messages are queued (to be written on
 //    the aforementioned thread).
 //
 // OS-specific implementation subclasses are to be instantiated using the
 // |Create()| static factory method.
 //
 // With the exception of |WriteMessage()|, this class is thread-unsafe (and in
 // general its methods should only be used on the I/O thread, i.e., the thread
 // on which |Init()| is called).
-class MOJO_SYSTEM_IMPL_EXPORT RawChannel {
+class MOJO_SYSTEM_IMPL_EXPORT RawChannel :
+    public base::MessageLoop::DestructionObserver {
  public:
 
   // The |Delegate| is only accessed on the same thread as the message loop
   // (passed in on creation).
   class MOJO_SYSTEM_IMPL_EXPORT Delegate {
    public:
     enum Error {
       // Failed read due to raw channel shutdown (e.g., on the other side).
       ERROR_READ_SHUTDOWN,
       // Failed read due to raw channel being broken (e.g., if the other side
@@ skipping 183 matching lines @@
     size_t data_offset_;
 
     MOJO_DISALLOW_COPY_AND_ASSIGN(WriteBuffer);
   };
 
   RawChannel();
 
   // Shutdown must be called on the IO thread. This object deletes itself once
   // it's flushed all pending writes and insured that the other side of the pipe
   // read them.
-  virtual ~RawChannel();
+  ~RawChannel() override;
 
   // |result| must not be |IO_PENDING|. Must be called on the I/O thread WITHOUT
   // |write_lock_| held. This object may be destroyed by this call. This
-  // acquires |read_lock_| inside of it. The caller needs to acquire read_lock_
+  // acquires |write_lock_| inside of it. The caller needs to acquire read_lock_
   // first.
   void OnReadCompletedNoLock(IOResult io_result, size_t bytes_read);
   // |result| must not be |IO_PENDING|. Must be called on the I/O thread WITHOUT
   // |write_lock_| held. This object may be destroyed by this call. The caller
   // needs to acquire write_lock_ first.
   void OnWriteCompletedNoLock(IOResult io_result,
                               size_t platform_handles_written,
                               size_t bytes_written);
 
   // Serialize the read buffer into the given array so that it can be sent to
@@ skipping 150 matching lines @@
 
   // Acquires read_lock_ and calls OnReadCompletedNoLock.
   void CallOnReadCompleted(IOResult io_result, size_t bytes_read);
 
   // Used with PostTask to acquire both locks and call LazyInitialize.
   void LockAndCallLazyInitialize();
 
   // Connects to the OS pipe.
   void LazyInitialize();
 
+  // base::MessageLoop::DestructionObserver:
+  void WillDestroyCurrentMessageLoop() override;
+
 
 
 
 
   // TODO(jam): one lock only... but profile first to ensure it doesn't slow
   // things down compared to fine grained locks.
 
 
 
 
@@ skipping 26 matching lines @@
   // are only used/invalidated on the I/O thread.
   base::WeakPtrFactory<RawChannel> weak_ptr_factory_;
 
   MOJO_DISALLOW_COPY_AND_ASSIGN(RawChannel);
 };
 
 }  // namespace edk
 }  // namespace mojo
 
 #endif  // MOJO_EDK_SYSTEM_RAW_CHANNEL_H_