webrtc/system_wrappers/interface/thread_wrapper.h

87 lines
3.4 KiB
C++

/*
* Copyright (c) 2011 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.
*/
// System independant wrapper for spawning threads
// Note: the spawned thread will loop over the callback function until stopped.
// Note: The callback function is expected to return every 2 seconds or more
// often.
#ifndef WEBRTC_SYSTEM_WRAPPERS_INTERFACE_THREAD_WRAPPER_H_
#define WEBRTC_SYSTEM_WRAPPERS_INTERFACE_THREAD_WRAPPER_H_
namespace webrtc {
// Object that will be passed by the spawned thread when it enters the callback
// function.
#define ThreadObj void*
// Callback function that the spawned thread will enter once spawned
typedef bool(*ThreadRunFunction)(ThreadObj);
enum ThreadPriority
{
kLowPriority = 1,
kNormalPriority = 2,
kHighPriority = 3,
kHighestPriority = 4,
kRealtimePriority = 5
};
class ThreadWrapper
{
public:
enum {kThreadMaxNameLength = 64};
virtual ~ThreadWrapper() {};
// 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.
// threadName NULL terminated thread name, will be visable in the Windows
// debugger.
static ThreadWrapper* CreateThread(ThreadRunFunction func = 0,
ThreadObj obj= 0,
ThreadPriority prio = kNormalPriority,
const char* threadName = 0);
// Non blocking termination of the spawned thread. Note that it is not safe
// to delete this class until the spawned thread has been reclaimed.
virtual void SetNotAlive() = 0;
// Spawns the thread. This will start the triggering of the callback
// function.
virtual bool Start(unsigned int& id) = 0;
// Sets the threads CPU affinity. CPUs are listed 0 - (number of CPUs - 1).
// The numbers in processorNumbers specify which CPUs are allowed to run the
// thread. processorNumbers should not contain any duplicates and elements
// should be lower than (number of CPUs - 1). amountOfProcessors should be
// equal to the number of processors listed in processorNumbers
virtual bool SetAffinity(const int* /*processorNumbers*/,
const unsigned int /*amountOfProcessors*/)
{return false;}
// 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.
virtual bool Stop() = 0;
// Stops the spawned thread dead in its tracks. Will likely result in a
// corrupt state. There should be an extremely good reason for even looking
// at this function. Can cause many problems deadlock being one of them.
virtual bool Shutdown() {return false;}
};
} // namespace webrtc
#endif // WEBRTC_SYSTEM_WRAPPERS_INTERFACE_THREAD_WRAPPER_H_