Move ThreadWrapper to ProcessThread in base.

webrtc/base/platform_thread.h

 /*
  *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #ifndef WEBRTC_BASE_PLATFORM_THREAD_H_
 #define WEBRTC_BASE_PLATFORM_THREAD_H_
 
-#if defined(WEBRTC_WIN)
-#include <winsock2.h>
-#include <windows.h>
-#elif defined(WEBRTC_POSIX)
-#include <pthread.h>
-#include <unistd.h>
-#endif
+#include <string>
+
+#include "webrtc/base/constructormagic.h"
+#include "webrtc/base/event.h"
+#include "webrtc/base/platform_thread_types.h"
+#include "webrtc/base/scoped_ptr.h"
+#include "webrtc/base/thread_checker.h"
 
 namespace rtc {
 
-#if defined(WEBRTC_WIN)
-typedef DWORD PlatformThreadId;
-typedef DWORD PlatformThreadRef;
-#elif defined(WEBRTC_POSIX)
-typedef pid_t PlatformThreadId;
-typedef pthread_t PlatformThreadRef;
-#endif
-
 PlatformThreadId CurrentThreadId();
 PlatformThreadRef CurrentThreadRef();
 
 // Compares two thread identifiers for equality.
 bool IsThreadRefEqual(const PlatformThreadRef& a, const PlatformThreadRef& b);
 
 // Sets the current thread name.
 void SetCurrentThreadName(const char* name);
 
 }  // namespace rtc
 
+// TODO(pbos): Merge with namespace rtc.
+namespace webrtc {
+
+// Callback function that the spawned thread will enter once spawned.
+// A return value of false is interpreted as that the function has no
+// more work to do and that the thread can be released.
+typedef bool (*ThreadRunFunction)(void*);
+
+enum ThreadPriority {
+#ifdef WEBRTC_WIN
+  kLowPriority = THREAD_PRIORITY_BELOW_NORMAL,
+  kNormalPriority = THREAD_PRIORITY_NORMAL,
+  kHighPriority = THREAD_PRIORITY_ABOVE_NORMAL,
+  kHighestPriority = THREAD_PRIORITY_HIGHEST,
+  kRealtimePriority = THREAD_PRIORITY_TIME_CRITICAL
+#else
+  kLowPriority = 1,
+  kNormalPriority = 2,
+  kHighPriority = 3,
+  kHighestPriority = 4,
+  kRealtimePriority = 5
+#endif
+};
+
+// Represents a simple worker thread.  The implementation must be assumed
+// to be single threaded, meaning that all methods of the class, must be
+// called from the same thread, including instantiation.
+// TODO(tommi): There's no need for this to be a virtual interface since there's
+// only ever a single implementation of it.
+class PlatformThread {
+ public:
+  PlatformThread(ThreadRunFunction func, void* obj, const char* thread_name);
+  virtual ~PlatformThread();
+
+  // Factory method. Constructor disabled.
+  //
+  // func        Pointer to a, by user, specified callback function.
+  // obj         Object associated with the thread. Passed in the callback
+  //             function.
+  // prio        Thread priority. May require root/admin rights.
+  // thread_name  NULL terminated thread name, will be visable in the Windows
+  //             debugger.
+  // TODO(pbos): Move users onto explicit initialization/member ownership
+  // instead of additional heap allocation due to CreateThread.
+  static rtc::scoped_ptr<PlatformThread> CreateThread(ThreadRunFunction func,
+                                                      void* obj,
+                                                      const char* thread_name);
+
+  // Tries to spawns a thread and returns true if that was successful.
+  // Additionally, it tries to set thread priority according to the priority
+  // from when CreateThread was called. However, failure to set priority will
+  // not result in a false return value.
+  // TODO(pbos): Make void not war.
+  bool Start();
+
+  // Stops the spawned thread and waits for it to be reclaimed with a timeout
+  // of two seconds. Will return false if the thread was not reclaimed.
+  // Multiple tries to Stop are allowed (e.g. to wait longer than 2 seconds).
+  // It's ok to call Stop() even if the spawned thread has been reclaimed.
+  // TODO(pbos): Make void not war.
+  bool Stop();
+
+  // Set the priority of the worker thread.  Must be called when thread
+  // is running.
+  bool SetPriority(ThreadPriority priority);
+
+ private:
+  void Run();
+
+  ThreadRunFunction const run_function_;
+  void* const obj_;
+  // TODO(pbos): Make sure call sites use string literals and update to a const
+  // char* instead of a std::string.
+  const std::string name_;
+  rtc::ThreadChecker thread_checker_;
+#if defined(WEBRTC_WIN)
+  static DWORD WINAPI StartThread(void* param);
+
+  bool stop_;
+  HANDLE thread_;
+#else
+  static void* StartThread(void* param);
+
+  rtc::Event stop_event_;
+
+  pthread_t thread_;
+#endif  // defined(WEBRTC_WIN)
+  RTC_DISALLOW_COPY_AND_ASSIGN(PlatformThread);
+};
+
+}  // namespace webrtc
+
 #endif  // WEBRTC_BASE_PLATFORM_THREAD_H_