Make DataPipe own an impl.

mojo/edk/system/local_data_pipe_impl.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_LOCAL_DATA_PIPE_IMPL_H_
 #define MOJO_EDK_SYSTEM_LOCAL_DATA_PIPE_IMPL_H_
 
 #include "base/macros.h"
 #include "base/memory/aligned_memory.h"
-#include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
-#include "mojo/edk/system/data_pipe.h"
+#include "mojo/edk/system/data_pipe_impl.h"
 #include "mojo/edk/system/system_impl_export.h"
 
 namespace mojo {
 namespace system {
 
+class DataPipe;
+
 // |LocalDataPipeImpl| is a subclass that "implements" |DataPipe| for data pipes
-// whose producer and consumer are both local. This class is thread-safe (with
-// protection provided by |DataPipe|'s |lock_|.
-class MOJO_SYSTEM_IMPL_EXPORT LocalDataPipeImpl : public DataPipe {
+// whose producer and consumer are both local. This class's methods, other than
+// the constructor and destructor, are always protected by |DataPipe|'s |lock_|.
+class MOJO_SYSTEM_IMPL_EXPORT LocalDataPipeImpl : public DataPipeImpl {
  public:
   // |validated_options| should be the output of |DataPipe::ValidateOptions()|.

[viettrungluu, 2015/02/19 19:08:46]

Oops, this comment was stale too.

   // In particular: |struct_size| is ignored (so |validated_options| must be the
   // current version of the struct) and |capacity_num_bytes| must be nonzero.
-  explicit LocalDataPipeImpl(
-      const MojoCreateDataPipeOptions& validated_options);
+  LocalDataPipeImpl();
+  ~LocalDataPipeImpl() override;
+
+  static DataPipe* Create(const MojoCreateDataPipeOptions& validated_options);

[yzshen1, 2015/02/19 18:27:11]

nit: It seems a little bit unusual for a static Create() method to create an
object of a different type (and not its base class).

 
  private:
-  friend class base::RefCountedThreadSafe<LocalDataPipeImpl>;
-  ~LocalDataPipeImpl() override;
-
-  // |DataPipe| implementation:
-  void ProducerCloseImplNoLock() override;
-  MojoResult ProducerWriteDataImplNoLock(
-      UserPointer<const void> elements,
-      UserPointer<uint32_t> num_bytes,
-      uint32_t max_num_bytes_to_write,
-      uint32_t min_num_bytes_to_write) override;
-  MojoResult ProducerBeginWriteDataImplNoLock(
-      UserPointer<void*> buffer,
-      UserPointer<uint32_t> buffer_num_bytes,
-      uint32_t min_num_bytes_to_write) override;
-  MojoResult ProducerEndWriteDataImplNoLock(
-      uint32_t num_bytes_written) override;
-  HandleSignalsState ProducerGetHandleSignalsStateImplNoLock() const override;
-  void ProducerStartSerializeImplNoLock(Channel* channel,
-                                        size_t* max_size,
-                                        size_t* max_platform_handles) override;
-  bool ProducerEndSerializeImplNoLock(
+  // |DataPipeImpl| implementation:
+  void ProducerClose() override;
+  MojoResult ProducerWriteData(UserPointer<const void> elements,
+                               UserPointer<uint32_t> num_bytes,
+                               uint32_t max_num_bytes_to_write,
+                               uint32_t min_num_bytes_to_write) override;
+  MojoResult ProducerBeginWriteData(UserPointer<void*> buffer,
+                                    UserPointer<uint32_t> buffer_num_bytes,
+                                    uint32_t min_num_bytes_to_write) override;
+  MojoResult ProducerEndWriteData(uint32_t num_bytes_written) override;
+  HandleSignalsState ProducerGetHandleSignalsState() const override;
+  void ProducerStartSerialize(Channel* channel,
+                              size_t* max_size,
+                              size_t* max_platform_handles) override;
+  bool ProducerEndSerialize(
       Channel* channel,
       void* destination,
       size_t* actual_size,
       embedder::PlatformHandleVector* platform_handles) override;
-  void ConsumerCloseImplNoLock() override;
-  MojoResult ConsumerReadDataImplNoLock(UserPointer<void> elements,
-                                        UserPointer<uint32_t> num_bytes,
-                                        uint32_t max_num_bytes_to_read,
-                                        uint32_t min_num_bytes_to_read,
-                                        bool peek) override;
-  MojoResult ConsumerDiscardDataImplNoLock(
-      UserPointer<uint32_t> num_bytes,
-      uint32_t max_num_bytes_to_discard,
-      uint32_t min_num_bytes_to_discard) override;
-  MojoResult ConsumerQueryDataImplNoLock(
-      UserPointer<uint32_t> num_bytes) override;
-  MojoResult ConsumerBeginReadDataImplNoLock(
-      UserPointer<const void*> buffer,
-      UserPointer<uint32_t> buffer_num_bytes,
-      uint32_t min_num_bytes_to_read) override;
-  MojoResult ConsumerEndReadDataImplNoLock(uint32_t num_bytes_read) override;
-  HandleSignalsState ConsumerGetHandleSignalsStateImplNoLock() const override;
-  void ConsumerStartSerializeImplNoLock(Channel* channel,
-                                        size_t* max_size,
-                                        size_t* max_platform_handles) override;
-  bool ConsumerEndSerializeImplNoLock(
+  void ConsumerClose() override;
+  MojoResult ConsumerReadData(UserPointer<void> elements,
+                              UserPointer<uint32_t> num_bytes,
+                              uint32_t max_num_bytes_to_read,
+                              uint32_t min_num_bytes_to_read,
+                              bool peek) override;
+  MojoResult ConsumerDiscardData(UserPointer<uint32_t> num_bytes,
+                                 uint32_t max_num_bytes_to_discard,
+                                 uint32_t min_num_bytes_to_discard) override;
+  MojoResult ConsumerQueryData(UserPointer<uint32_t> num_bytes) override;
+  MojoResult ConsumerBeginReadData(UserPointer<const void*> buffer,
+                                   UserPointer<uint32_t> buffer_num_bytes,
+                                   uint32_t min_num_bytes_to_read) override;
+  MojoResult ConsumerEndReadData(uint32_t num_bytes_read) override;
+  HandleSignalsState ConsumerGetHandleSignalsState() const override;
+  void ConsumerStartSerialize(Channel* channel,
+                              size_t* max_size,
+                              size_t* max_platform_handles) override;
+  bool ConsumerEndSerialize(
       Channel* channel,
       void* destination,
       size_t* actual_size,
       embedder::PlatformHandleVector* platform_handles) override;
 
-  void EnsureBufferNoLock();
-  void DestroyBufferNoLock();
+  void EnsureBuffer();
+  void DestroyBuffer();
 
   // Get the maximum (single) write/read size right now (in number of elements);
   // result fits in a |uint32_t|.
-  size_t GetMaxNumBytesToWriteNoLock();
-  size_t GetMaxNumBytesToReadNoLock();
+  size_t GetMaxNumBytesToWrite();
+  size_t GetMaxNumBytesToRead();
 
   // Marks the given number of bytes as consumed/discarded. |num_bytes| must be
   // greater than |current_num_bytes_|.
-  void MarkDataAsConsumedNoLock(size_t num_bytes);
+  void MarkDataAsConsumed(size_t num_bytes);
 
-  // The members below are protected by |DataPipe|'s |lock_|:
   scoped_ptr<char, base::AlignedFreeDeleter> buffer_;
   // Circular buffer.
   size_t start_index_;
   size_t current_num_bytes_;
 
   DISALLOW_COPY_AND_ASSIGN(LocalDataPipeImpl);
 };
 
 }  // namespace system
 }  // namespace mojo
 
 #endif  // MOJO_EDK_SYSTEM_LOCAL_DATA_PIPE_IMPL_H_