Support early associated interface binding on ChannelMojo

ipc/ipc_message_pipe_reader.h

 // Copyright 2014 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 IPC_IPC_MESSAGE_PIPE_READER_H_
 #define IPC_IPC_MESSAGE_PIPE_READER_H_
 
 #include <stdint.h>
 
 #include <memory>
 #include <vector>
 
 #include "base/atomicops.h"
 #include "base/compiler_specific.h"
 #include "base/macros.h"
+#include "base/process/process_handle.h"
 #include "base/threading/thread_checker.h"
 #include "ipc/ipc.mojom.h"
 #include "ipc/ipc_export.h"
 #include "ipc/ipc_message.h"
 #include "mojo/public/cpp/bindings/associated_binding.h"
 #include "mojo/public/cpp/bindings/scoped_interface_endpoint_handle.h"
 #include "mojo/public/cpp/system/core.h"
 #include "mojo/public/cpp/system/message_pipe.h"
 
 namespace IPC {
@@ skipping 14 matching lines @@
 //    The constructor automatically start listening on the pipe.
 //
 // All functions must be called on the IO thread, except for Send(), which can
 // be called on any thread. All |Delegate| functions will be called on the IO
 // thread.
 //
 class IPC_EXPORT MessagePipeReader : public NON_EXPORTED_BASE(mojom::Channel) {
  public:
   class Delegate {
    public:
+    virtual void OnPeerPidReceived() = 0;
     virtual void OnMessageReceived(const Message& message) = 0;
     virtual void OnPipeError() = 0;
     virtual void OnAssociatedInterfaceRequest(
         const std::string& name,
         mojo::ScopedInterfaceEndpointHandle handle) = 0;
   };
 
-  // Delay the object deletion using the current message loop.
-  // This is intended to used by MessagePipeReader owners.
-  class DelayedDeleter {
-   public:
-    typedef std::default_delete<MessagePipeReader> DefaultType;
-
-    static void DeleteNow(MessagePipeReader* ptr) { delete ptr; }
-
-    DelayedDeleter() {}
-    explicit DelayedDeleter(const DefaultType&) {}
-    DelayedDeleter& operator=(const DefaultType&) { return *this; }
-
-    void operator()(MessagePipeReader* ptr) const;
-  };
-
   // Builds a reader that reads messages from |receive_handle| and lets
   // |delegate| know.
   //
   // |pipe| is the message pipe handle corresponding to the channel's master
   // interface. This is the message pipe underlying both |sender| and
   // |receiver|.
   //
   // Both |sender| and |receiver| must be non-null.
   //
   // Note that MessagePipeReader doesn't delete |delegate|.
   MessagePipeReader(mojo::MessagePipeHandle pipe,
                     mojom::ChannelAssociatedPtr sender,
                     mojo::AssociatedInterfaceRequest<mojom::Channel> receiver,
-                    base::ProcessId peer_pid,
                     Delegate* delegate);
   ~MessagePipeReader() override;
 
   // Close and destroy the MessagePipe.
   void Close();
 
   // Return true if the MessagePipe is alive.
   bool IsValid() { return sender_; }
 
   // Sends an IPC::Message to the other end of the pipe. Safe to call from any
   // thread.
   bool Send(std::unique_ptr<Message> message);
 
   // Requests an associated interface from the other end of the pipe.
   void GetRemoteInterface(const std::string& name,
                           mojo::ScopedInterfaceEndpointHandle handle);
 
   base::ProcessId GetPeerPid() const { return peer_pid_; }
 
  protected:
   void OnPipeClosed();
   void OnPipeError(MojoResult error);
 
  private:
   // mojom::Channel:
+  void SetPeerPid(int32_t peer_pid) override;
   void Receive(mojo::Array<uint8_t> data,
                mojo::Array<mojom::SerializedHandlePtr> handles) override;
   void GetAssociatedInterface(
       const mojo::String& name,
       mojom::GenericInterfaceAssociatedRequest request) override;
 
   // |delegate_| is null once the message pipe is closed.
   Delegate* delegate_;
-  base::ProcessId peer_pid_;
+  base::ProcessId peer_pid_ = base::kNullProcessId;
   mojom::ChannelAssociatedPtr sender_;
   mojo::AssociatedBinding<mojom::Channel> binding_;
 
   // Raw message pipe handle and interface ID we use to send legacy IPC messages
   // over the associated pipe.
   const uint32_t sender_interface_id_;
   const mojo::MessagePipeHandle sender_pipe_;
 
   base::ThreadChecker thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(MessagePipeReader);
 };
 
 }  // namespace internal
 }  // namespace IPC
 
 #endif  // IPC_IPC_MESSAGE_PIPE_READER_H_