ppapi/proxy/ppb_message_loop_proxy.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef PPAPI_PROXY_PPB_MESSAGE_LOOP_PROXY_H_
   6 #define PPAPI_PROXY_PPB_MESSAGE_LOOP_PROXY_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/bind.h"
  10 #include "base/memory/ref_counted.h"
  11 #include "base/memory/scoped_ptr.h"
  12 #include "base/message_loop/message_loop.h"
  13 #include "base/single_thread_task_runner.h"
  14 #include "ppapi/proxy/interface_proxy.h"
  15 #include "ppapi/proxy/ppapi_proxy_export.h"
  16 #include "ppapi/shared_impl/ppb_message_loop_shared.h"
  17 #include "ppapi/thunk/ppb_message_loop_api.h"
  18
  19 struct PPB_MessageLoop_1_0;
  20
  21 namespace ppapi {
  22 namespace proxy {
  23
  24 class PPAPI_PROXY_EXPORT MessageLoopResource : public MessageLoopShared {
  25  public:
  26   explicit MessageLoopResource(PP_Instance instance);
  27   // Construct the one MessageLoopResource for the main thread. This must be
  28   // invoked on the main thread.
  29   explicit MessageLoopResource(ForMainThread);
  30   ~MessageLoopResource() override;
  31
  32   // Resource overrides.
  33   thunk::PPB_MessageLoop_API* AsPPB_MessageLoop_API() override;
  34
  35   // PPB_MessageLoop_API implementation.
  36   int32_t AttachToCurrentThread() override;
  37   int32_t Run() override;
  38   int32_t PostWork(PP_CompletionCallback callback, int64_t delay_ms) override;
  39   int32_t PostQuit(PP_Bool should_destroy) override;
  40
  41   static MessageLoopResource* GetCurrent();
  42   void DetachFromThread();
  43   bool is_main_thread_loop() const {
  44     return is_main_thread_loop_;
  45   }
  46
  47   const scoped_refptr<base::SingleThreadTaskRunner>& task_runner() {
  48     return task_runner_;
  49   }
  50
  51   void set_currently_handling_blocking_message(bool handling_blocking_message) {
  52     currently_handling_blocking_message_ = handling_blocking_message;
  53   }
  54
  55  private:
  56   struct TaskInfo {
  57     tracked_objects::Location from_here;
  58     base::Closure closure;
  59     int64 delay_ms;
  60   };
  61
  62   // Returns true if the object is associated with the current thread.
  63   bool IsCurrent() const;
  64
  65   // MessageLoopShared implementation.
  66   //
  67   // Handles posting to the message loop if there is one, or the pending queue
  68   // if there isn't.
  69   // NOTE: The given closure will be run *WITHOUT* acquiring the Proxy lock.
  70   //       This only makes sense for user code and completely thread-safe
  71   //       proxy operations (e.g., MessageLoop::QuitClosure).
  72   void PostClosure(const tracked_objects::Location& from_here,
  73                    const base::Closure& closure,
  74                    int64 delay_ms) override;
  75   base::SingleThreadTaskRunner* GetTaskRunner() override;
  76   bool CurrentlyHandlingBlockingMessage() override;
  77
  78   // TLS destructor function.
  79   static void ReleaseMessageLoop(void* value);
  80
  81   // Created when we attach to the current thread, since MessageLoop assumes
  82   // that it's created on the thread it will run on. NULL for the main thread
  83   // loop, since that's owned by somebody else. This is needed for Run and Quit.
  84   // Any time we post tasks, we should post them using task_runner_.
  85   scoped_ptr<base::MessageLoop> loop_;
  86   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
  87
  88   // Number of invocations of Run currently on the stack.
  89   int nested_invocations_;
  90
  91   // Set to true when the message loop is destroyed to prevent forther
  92   // posting of work.
  93   bool destroyed_;
  94
  95   // Set to true if all message loop invocations should exit and that the
  96   // loop should be destroyed once it reaches the outermost Run invocation.
  97   bool should_destroy_;
  98
  99   bool is_main_thread_loop_;
 100
 101   bool currently_handling_blocking_message_;
 102
 103   // Since we allow tasks to be posted before the message loop is actually
 104   // created (when it's associated with a thread), we keep tasks posted here
 105   // until that happens. Once the loop_ is created, this is unused.
 106   std::vector<TaskInfo> pending_tasks_;
 107
 108   DISALLOW_COPY_AND_ASSIGN(MessageLoopResource);
 109 };
 110
 111 class PPB_MessageLoop_Proxy : public InterfaceProxy {
 112  public:
 113   explicit PPB_MessageLoop_Proxy(Dispatcher* dispatcher);
 114   virtual ~PPB_MessageLoop_Proxy();
 115
 116   static const PPB_MessageLoop_1_0* GetInterface();
 117
 118  private:
 119   DISALLOW_COPY_AND_ASSIGN(PPB_MessageLoop_Proxy);
 120 };
 121
 122 }  // namespace proxy
 123 }  // namespace ppapi
 124
 125 #endif  // PPAPI_PROXY_PPB_MESSAGE_LOOP_PROXY_H_