1 /*
2  *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 #ifndef WEBRTC_MODULES_UTILITY_SOURCE_PROCESS_THREAD_IMPL_H_
12 #define WEBRTC_MODULES_UTILITY_SOURCE_PROCESS_THREAD_IMPL_H_
13 
14 #include <list>
15 #include <queue>
16 
17 #include "webrtc/base/criticalsection.h"
18 #include "webrtc/base/platform_thread.h"
19 #include "webrtc/base/thread_checker.h"
20 #include "webrtc/modules/utility/include/process_thread.h"
21 #include "webrtc/system_wrappers/include/event_wrapper.h"
22 #include "webrtc/typedefs.h"
23 
24 namespace webrtc {
25 
26 class ProcessThreadImpl : public ProcessThread {
27  public:
28   explicit ProcessThreadImpl(const char* thread_name);
29   ~ProcessThreadImpl() override;
30 
31   void Start() override;
32   void Stop() override;
33 
34   void WakeUp(Module* module) override;
35   void PostTask(rtc::scoped_ptr<ProcessTask> task) override;
36 
37   void RegisterModule(Module* module) override;
38   void DeRegisterModule(Module* module) override;
39 
40  protected:
41   static bool Run(void* obj);
42   bool Process();
43 
44  private:
45   struct ModuleCallback {
ModuleCallbackModuleCallback46     ModuleCallback() : module(nullptr), next_callback(0) {}
ModuleCallbackModuleCallback47     ModuleCallback(const ModuleCallback& cb)
48         : module(cb.module), next_callback(cb.next_callback) {}
ModuleCallbackModuleCallback49     ModuleCallback(Module* module) : module(module), next_callback(0) {}
50     bool operator==(const ModuleCallback& cb) const {
51       return cb.module == module;
52     }
53 
54     Module* const module;
55     int64_t next_callback;  // Absolute timestamp.
56 
57    private:
58     ModuleCallback& operator=(ModuleCallback&);
59   };
60 
61   typedef std::list<ModuleCallback> ModuleList;
62 
63   // Warning: For some reason, if |lock_| comes immediately before |modules_|
64   // with the current class layout, we will  start to have mysterious crashes
65   // on Mac 10.9 debug.  I (Tommi) suspect we're hitting some obscure alignemnt
66   // issues, but I haven't figured out what they are, if there are alignment
67   // requirements for mutexes on Mac or if there's something else to it.
68   // So be careful with changing the layout.
69   rtc::CriticalSection lock_;  // Used to guard modules_, tasks_ and stop_.
70 
71   rtc::ThreadChecker thread_checker_;
72   const rtc::scoped_ptr<EventWrapper> wake_up_;
73   // TODO(pbos): Remove scoped_ptr and stop recreating the thread.
74   rtc::scoped_ptr<rtc::PlatformThread> thread_;
75 
76   ModuleList modules_;
77   // TODO(tommi): Support delayed tasks.
78   std::queue<ProcessTask*> queue_;
79   bool stop_;
80   const char* thread_name_;
81 };
82 
83 }  // namespace webrtc
84 
85 #endif // WEBRTC_MODULES_UTILITY_SOURCE_PROCESS_THREAD_IMPL_H_
86