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/*
* Copyright 2008, 2011 Free Software Foundation, Inc.
* Copyright 2013 Alexander Chemeris <Alexander.Chemeris@fairwaves.ru>
*
* This software is distributed under the terms of the GNU Affero Public License.
* See the COPYING file in the main directory for details.
*
* This use of this software may be subject to additional restrictions.
* See the LEGAL file in the main directory for details.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef THREADS_H
#define THREADS_H
#include <pthread.h>
#include <iostream>
#include <assert.h>
#include <unistd.h>
class Mutex;
/**@name Multithreaded access for standard streams. */
//@{
/**@name Functions for gStreamLock. */
//@{
extern Mutex gStreamLock; ///< global lock for cout and cerr
void lockCerr(); ///< call prior to writing cerr
void unlockCerr(); ///< call after writing cerr
void lockCout(); ///< call prior to writing cout
void unlockCout(); ///< call after writing cout
//@}
/**@name Macros for standard messages. */
//@{
#define COUT(text) { lockCout(); std::cout << text; unlockCout(); }
#define CERR(text) { lockCerr(); std::cerr << __FILE__ << ":" << __LINE__ << ": " << text; unlockCerr(); }
#ifdef NDEBUG
#define DCOUT(text) {}
#define OBJDCOUT(text) {}
#else
#define DCOUT(text) { COUT(__FILE__ << ":" << __LINE__ << " " << text); }
#define OBJDCOUT(text) { DCOUT(this << " " << text); }
#endif
//@}
//@}
/**@defgroup C++ wrappers for pthread mechanisms. */
//@{
/** A class for recursive mutexes based on pthread_mutex. */
class Mutex {
private:
pthread_mutex_t mMutex;
pthread_mutexattr_t mAttribs;
public:
Mutex();
~Mutex();
void lock() { pthread_mutex_lock(&mMutex); }
bool trylock() { return pthread_mutex_trylock(&mMutex)==0; }
void unlock() { pthread_mutex_unlock(&mMutex); }
friend class Signal;
};
class ScopedLock {
private:
Mutex& mMutex;
public:
ScopedLock(Mutex& wMutex) :mMutex(wMutex) { mMutex.lock(); }
~ScopedLock() { mMutex.unlock(); }
};
/** A C++ interthread signal based on pthread condition variables. */
class Signal {
private:
mutable pthread_cond_t mSignal;
public:
Signal() { int s = pthread_cond_init(&mSignal,NULL); assert(!s); }
~Signal() { pthread_cond_destroy(&mSignal); }
/**
Block for the signal up to the cancellation timeout.
Under Linux, spurious returns are possible.
*/
int wait(Mutex& wMutex, unsigned timeout) const;
/**
Block for the signal.
Under Linux, spurious returns are possible.
*/
int wait(Mutex& wMutex) const
{ return pthread_cond_wait(&mSignal,&wMutex.mMutex); }
void signal() { pthread_cond_signal(&mSignal); }
void broadcast() { pthread_cond_broadcast(&mSignal); }
};
/** A C++ wrapper for pthread threads. */
class Thread {
public:
typedef void *(*Adaptor)(void*);
enum ReturnStatus {
RETURN_OK = 0,
ALREADY_STARTED,
ALREADY_IDLE,
PTHREAD_ERROR,
WRONG_STATE,
RETURN_TIMEOUT
};
enum ThreadState {
THREAD_STATE_IDLE, ///< Thread is not started. On start() => STARTING
THREAD_STATE_STARTING, ///< Thread is about to start. When actually started => RUNNING
THREAD_STATE_RUNNING, ///< Thread is active. On stop() => STOPPING
THREAD_STATE_STOPPING ///< Thread is about to stop. When actually stopped => IDLE
};
enum {
THREAD_STARTUP_TIMEOUT=5, ///< Time to wait for thread startup (in seconds).
THREAD_STOP_TIMEOUT=5 ///< Time to wait for thread stop (in seconds).
};
/** Create a thread in a non-running state. */
Thread(const std::string &name, size_t stackSize = (65536*4));
/** Destroy the Thread. */
virtual ~Thread();
/** Start the thread. */
ReturnStatus startThread(void *data=NULL);
/** Stop the thread. */
ReturnStatus stopThread();
ThreadState getThreadState() const
{
ScopedLock lock(mThreadStateMutex);
return mThreadState;
}
bool isThreadRunning() const
{
ScopedLock lock(mThreadStateMutex);
return mThreadState == THREAD_STATE_RUNNING;
}
void requestThreadStop()
{
ScopedLock lock(mThreadStateMutex);
if (mThreadState == THREAD_STATE_RUNNING)
mThreadState = THREAD_STATE_STOPPING;
}
bool isThreadStopping() const
{
ScopedLock lock(mThreadStateMutex);
return mThreadState == THREAD_STATE_STOPPING;
}
const std::string &getThreadName() const {return mThreadName;}
protected:
pthread_t mThreadId; ///< OS id of the thread.
const std::string mThreadName; ///< Name of the thread.
size_t mStackSize; ///< Requested stack size for the thread.
ThreadState mThreadState; ///< The current state of the thread.
mutable Mutex mThreadStateMutex; ///< Mutex to protect ThreadState variable
void *mThreadData; ///< Data to be passed to the thread loop.
Mutex mThreadStartupMutex; ///< Mutex, used with the next two conditional
///< variables to synchronize thread startup.
Signal mThreadInitializedEvent; ///< Conditional variable, signaling
///< that this thread object initialization is completed
///< and the thread could go on.
Signal mThreadStartStopEvent; ///< Conditional variable, signaling
///< that the thread is started and start() method could
///< return to caller.
/** Function with the actual thread loop.
* Override this function in child classes to do real work.
*/
virtual void runThread() =0;
// Static funciton which actually starts the run() method.
static void *threadAdaptor(void *data);
void ackThreadStart() {
ScopedLock lock(mThreadStateMutex);
assert(mThreadState == THREAD_STATE_STARTING);
mThreadState = THREAD_STATE_RUNNING;
}
void ackThreadStop() {
ScopedLock lock(mThreadStateMutex);
assert(mThreadState == THREAD_STATE_STOPPING);
mThreadState = THREAD_STATE_IDLE;
}
};
#endif
// vim: ts=4 sw=4
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