Mojo: Make Core own a PlatformSupport, and plumb it through to Channel.

mojo/system/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_CHANNEL_H_
 #define MOJO_SYSTEM_CHANNEL_H_
 
 #include <stdint.h>
 
 #include "base/compiler_specific.h"
 #include "base/containers/hash_tables.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/string_piece.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/thread_checker.h"
 #include "mojo/embedder/scoped_platform_handle.h"
 #include "mojo/public/c/system/types.h"
 #include "mojo/system/message_in_transit.h"
 #include "mojo/system/message_pipe.h"
 #include "mojo/system/raw_channel.h"
 #include "mojo/system/system_impl_export.h"
 
 namespace mojo {
+
+namespace embedder {
+class PlatformSupport;
+}
+
 namespace system {
 
 // This class is mostly thread-safe. It must be created on an I/O thread.
 // |Init()| must be called on that same thread before it becomes thread-safe (in
 // particular, before references are given to any other thread) and |Shutdown()|
 // must be called on that same thread before destruction. Its public methods are
 // otherwise thread-safe. It may be destroyed on any thread, in the sense that
 // the last reference to it may be released on any thread, with the proviso that
 // |Shutdown()| must have been called first (so the pattern is that a "main"
 // reference is kept on its creation thread and is released after |Shutdown()|
@@ skipping 12 matching lines @@
 // by |Channel| must be removed by calling |DetachMessagePipeEndpoint()| (which
 // is done by |MessagePipe|/|ProxyMessagePipeEndpoint|, which simultaneously
 // removes its reference to |Channel|).
 class MOJO_SYSTEM_IMPL_EXPORT Channel
     : public base::RefCountedThreadSafe<Channel>,
       public RawChannel::Delegate {
  public:
   // The first message pipe endpoint attached will have this as its local ID.
   static const MessageInTransit::EndpointId kBootstrapEndpointId = 1;
 
-  Channel();
+  // |platform_support| (typically owned by |Core|) must remain alive until
+  // after |Shutdown()| is called.
+  explicit Channel(embedder::PlatformSupport* platform_support);
 
   // This must be called on the creation thread before any other methods are
   // called, and before references to this object are given to any other
   // threads. |raw_channel| should be uninitialized. Returns true on success. On
   // failure, no other methods should be called (including |Shutdown()|).
   bool Init(scoped_ptr<RawChannel> raw_channel);
 
   // This must be called on the creation thread before destruction (which can
   // happen on any thread).
   void Shutdown();
@@ skipping 44 matching lines @@
   // This removes the message pipe/port's endpoint (with the given local ID and
   // given remote ID, which should be |kInvalidEndpointId| if not yet running),
   // returned by |AttachMessagePipeEndpoint()| from this channel. After this is
   // called, |local_id| may be reused for another message pipe.
   void DetachMessagePipeEndpoint(MessageInTransit::EndpointId local_id,
                                  MessageInTransit::EndpointId remote_id);
 
   // See |RawChannel::GetSerializedPlatformHandleSize()|.
   size_t GetSerializedPlatformHandleSize() const;
 
+  embedder::PlatformSupport* platform_support() const {
+    return platform_support_;
+  }
+
  private:
   struct EndpointInfo {
     enum State {
       // Attached, possibly running or not.
       STATE_NORMAL,
       // "Zombie" states:
       // Waiting for |DetachMessagePipeEndpoint()| before removing.
       STATE_WAIT_LOCAL_DETACH,
       // Waiting for a |kSubtypeChannelRemoveMessagePipeEndpointAck| before
       // removing.
@@ skipping 40 matching lines @@
   void HandleLocalError(const base::StringPiece& error_message);
 
   // Helper to send channel control messages. Returns true on success. Should be
   // called *without* |lock_| held.
   bool SendControlMessage(MessageInTransit::Subtype subtype,
                           MessageInTransit::EndpointId source_id,
                           MessageInTransit::EndpointId destination_id);
 
   base::ThreadChecker creation_thread_checker_;
 
+  embedder::PlatformSupport* const platform_support_;
+
   // Note: |MessagePipe|s MUST NOT be used under |lock_|. I.e., |lock_| can only
   // be acquired after |MessagePipe::lock_|, never before. Thus to call into a
   // |MessagePipe|, a reference should be acquired from
   // |local_id_to_endpoint_info_map_| under |lock_| (e.g., by copying the
   // |EndpointInfo|) and then the lock released.
   base::Lock lock_;  // Protects the members below.
 
   scoped_ptr<RawChannel> raw_channel_;
   bool is_running_;
   // Set when |WillShutdownSoon()| is called.
   bool is_shutting_down_;
 
   typedef base::hash_map<MessageInTransit::EndpointId, EndpointInfo>
       IdToEndpointInfoMap;
   IdToEndpointInfoMap local_id_to_endpoint_info_map_;
   // The next local ID to try (when allocating new local IDs). Note: It should
   // be checked for existence before use.
   MessageInTransit::EndpointId next_local_id_;
 
   DISALLOW_COPY_AND_ASSIGN(Channel);
 };
 
 }  // namespace system
 }  // namespace mojo
 
 #endif  // MOJO_SYSTEM_CHANNEL_H_