Mojo: Armed Watchers

content/common/message_port.h

 // Copyright 2017 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 CONTENT_COMMON_MESSAGE_PORT_H_
 #define CONTENT_COMMON_MESSAGE_PORT_H_
 
 #include <vector>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/strings/string16.h"
 #include "content/common/content_export.h"
 #include "mojo/public/cpp/system/message_pipe.h"
+#include "mojo/public/cpp/system/watcher.h"
 
 namespace content {
 
 // MessagePort corresponds to a HTML MessagePort. It is a thin wrapper around a
 // Mojo MessagePipeHandle and provides methods for reading and writing messages.
 //
 // A MessagePort is only actively listening for incoming messages once
 // SetCallback has been called with a valid callback. If ClearCallback is
 // called (or if SetCallback is called with a null callback), then the
 // MessagePort will stop listening for incoming messages. The callback runs on
@@ skipping 49 matching lines @@
   void ClearCallback();
 
  private:
   class State : public base::RefCountedThreadSafe<State> {
    public:
     State();
     State(mojo::ScopedMessagePipeHandle handle);
 
     void AddWatch();
     void CancelWatch();
-    static void OnHandleReady(uintptr_t context,
-                              MojoResult result,
-                              MojoHandleSignalsState signals_state,
-                              MojoWatchNotificationFlags flags);
 
+    mojo::ScopedWatcherHandle watcher_handle_;
     mojo::ScopedMessagePipeHandle handle_;
     base::Closure callback_;
 
    private:
     friend class base::RefCountedThreadSafe<State>;
+
     ~State();
+
+    void ArmWatcher();
+    void OnHandleReady(MojoResult result);
+
+    static void CallOnHandleReady(uintptr_t context,
+                                  MojoResult result,
+                                  MojoHandleSignalsState signals_state,
+                                  MojoWatcherNotificationFlags flags);
+
+    uintptr_t context_;
   };
   mutable scoped_refptr<State> state_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_COMMON_MESSAGE_PORT_H_