/*
* Copyright 2008 Free Software Foundation, Inc.
*
* This software is distributed under the terms of the GNU Public License.
* See the COPYING 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 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 General Public License for more details.

    You should have received a copy of the GNU 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"

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); }

	void unlock() { pthread_mutex_unlock(&mMutex); }

	friend class Signal;

};



/** A C++ interthread signal based on pthread condition variables. */
class Signal {

	private:

	mutable pthread_cond_t mSignal;

	public:

	Signal() { assert(!pthread_cond_init(&mSignal,NULL)); }

	~Signal() { pthread_cond_destroy(&mSignal); }

	/** Block for the signal up to the cancellation timeout. */
	void wait(Mutex& wMutex, unsigned timeout=1000000000) const;

	void signal() { pthread_cond_signal(&mSignal); }

	void broadcast() { pthread_cond_broadcast(&mSignal); }

};



#define START_THREAD(thread,function,argument) \
	thread.start((void *(*)(void*))function, (void*)argument);

/** A C++ wrapper for pthread threads.  */
class Thread {

	private:

	pthread_t mThread;
	pthread_attr_t mAttrib;
	const static size_t mStackSize=4*65536;
	

	public:

	/** Create a thread in a non-running state. */
	Thread():mThread((pthread_t)0) { }

	/**
		Destroy the Thread.
		It should be stopped and joined.
	*/
	~Thread() { assert(!pthread_attr_destroy(&mAttrib)); }


	/** Start the thread on a task. */
	void start(void *(*task)(void*), void *arg);

	/** Join a thread that will stop on its own. */
	void join() { assert(!pthread_join(mThread,NULL)); }

};




#endif
// vim: ts=4 sw=4