PPAPI: Make PPB_MessageLoop_Dev::GetForMainThread work

ppapi/proxy/ppb_message_loop_proxy.h

 // Copyright (c) 2012 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 PPAPI_PROXY_PPB_MESSAGE_LOOP_PROXY_H_
 #define PPAPI_PROXY_PPB_MESSAGE_LOOP_PROXY_H_
 
 #include "base/basictypes.h"
+#include "base/bind.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/message_loop.h"
 #include "ppapi/proxy/interface_proxy.h"
+#include "ppapi/shared_impl/resource.h"
+#include "ppapi/thunk/ppb_message_loop_api.h"
 
 struct PPB_MessageLoop_Dev_0_1;
 
 namespace ppapi {
 namespace proxy {
 
+class MessageLoopResource : public Resource, public thunk::PPB_MessageLoop_API {
+ public:
+  explicit MessageLoopResource(PP_Instance instance);
+  // Construct the one MessageLoopResource for the main thread. This must be
+  // invoked on the main thread.
+  struct ForMainThread {};
+  MessageLoopResource(ForMainThread);
+  virtual ~MessageLoopResource();
+
+  // Resource overrides.
+  virtual thunk::PPB_MessageLoop_API* AsPPB_MessageLoop_API() OVERRIDE;
+
+  // PPB_MessageLoop_API implementation.
+  virtual int32_t AttachToCurrentThread() OVERRIDE;
+  virtual int32_t Run() OVERRIDE;
+  virtual int32_t PostWork(PP_CompletionCallback callback,
+                           int64_t delay_ms) OVERRIDE;
+  virtual int32_t PostQuit(PP_Bool should_destroy) OVERRIDE;
+
+  void DetachFromThread();
+  bool is_main_thread_loop() const {
+    return is_main_thread_loop_;
+  }
+
+ private:
+  struct TaskInfo {
+    tracked_objects::Location from_here;
+    base::Closure closure;
+    int64 delay_ms;
+  };
+
+  // Returns true if the object is associated with the current thread.
+  bool IsCurrent() const;
+
+  // Handles posting to the message loop if there is one, or the pending queue
+  // if there isn't.
+  // NOTE: The given closure will be run *WITHOUT* acquiring the Proxy lock.
+  //       This only makes sense for user code and completely thread-safe
+  //       proxy operations (e.g., MessageLoop::QuitClosure).
+  void PostClosure(const tracked_objects::Location& from_here,
+                   const base::Closure& closure,
+                   int64 delay_ms);
+
+  // TLS destructor function.
+  static void ReleaseMessageLoop(void* value);
+
+  // Created when we attach to the current thread, since MessageLoop assumes
+  // that it's created on the thread it will run on. NULL for the main thread
+  // loop, since that's owned by somebody else. This is needed for Run and Quit.
+  // Any time we post tasks, we should post them using loop_proxy_.
+  scoped_ptr<MessageLoop> loop_;
+  scoped_refptr<base::MessageLoopProxy> loop_proxy_;
+
+  // Number of invocations of Run currently on the stack.
+  int nested_invocations_;
+
+  // Set to true when the message loop is destroyed to prevent forther
+  // posting of work.
+  bool destroyed_;
+
+  // Set to true if all message loop invocations should exit and that the
+  // loop should be destroyed once it reaches the outermost Run invocation.
+  bool should_destroy_;
+
+  bool is_main_thread_loop_;
+
+  // Since we allow tasks to be posted before the message loop is actually
+  // created (when it's associated with a thread), we keep tasks posted here
+  // until that happens. Once the loop_ is created, this is unused.
+  std::vector<TaskInfo> pending_tasks_;
+
+  DISALLOW_COPY_AND_ASSIGN(MessageLoopResource);
+};
+
 class PPB_MessageLoop_Proxy : public InterfaceProxy {
  public:
-  PPB_MessageLoop_Proxy(Dispatcher* dispatcher);
+  explicit PPB_MessageLoop_Proxy(Dispatcher* dispatcher);
   virtual ~PPB_MessageLoop_Proxy();
 
   static const PPB_MessageLoop_Dev_0_1* GetInterface();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(PPB_MessageLoop_Proxy);
 };
 
 }  // namespace proxy
 }  // namespace ppapi
 
 #endif  // PPAPI_PROXY_PPB_MESSAGE_LOOP_PROXY_H_