// NeL - MMORPG Framework <http://dev.ryzom.com/projects/nel/>
// Copyright (C) 2010  Winch Gate Property Limited
//
// 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/>.


#include "stdmisc.h"

#ifdef NL_OS_UNIX

#include "nel/misc/p_thread.h"

#include <sched.h>
#include <pwd.h>

namespace NLMISC {

/* Key for thread specific storage holding IThread pointer. */
static pthread_key_t threadSpecificKey;

/* Special thread type representing the main thread. */
struct CPMainThread : public CPThread
{
	CPMainThread() : CPThread(NULL, 0)
	{
		if(pthread_key_create(&threadSpecificKey, NULL) != 0) 
			throw EThread("cannot create thread specific storage key.");

		if(pthread_setspecific(threadSpecificKey, this) != 0)
			throw EThread("cannot set main thread ptr in thread specific storage.");
	}

	~CPMainThread() 
	{
		if(pthread_key_delete(threadSpecificKey) != 0) 
			throw EThread("cannot delete thread specific storage key.");
	}
};

/* Holds the thread instance representing the main thread. */
static CPMainThread mainThread = CPMainThread();

/*
 * The IThread static creator
 */
IThread *IThread::create( IRunnable *runnable, uint32 stackSize)
{
	return new CPThread( runnable, stackSize );
}

/*
 * Get the current thread
 */
IThread *IThread::getCurrentThread ()
{
	return (IThread *)pthread_getspecific(threadSpecificKey);
}

/*
 * Thread beginning
 */
static void *ProxyFunc( void *arg )
{
	CPThread *parent = (CPThread*)arg;

	// Set this thread's thread specific storage to IThread instance pointer
	if(pthread_setspecific(threadSpecificKey, parent) != 0)
		throw EThread("cannot set thread ptr in thread specific storage.");

	// Allow to terminate the thread without cancellation point
	pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, 0);

	// Run the code of the thread
	parent->Runnable->run();

	// Allow some clean
//	pthread_exit(0);
	return NULL;
}



/*
 * Constructor
 */
CPThread::CPThread(IRunnable *runnable, uint32 stackSize)
	:	Runnable(runnable),
		_State(0),
		_StackSize(stackSize)
{}


/*
 * Destructor
 */
CPThread::~CPThread()
{
	if(_State == 1)
		terminate(); // force the end of the thread if not already ended

	if(_State > 0)
		pthread_detach(_ThreadHandle); // free allocated resources only if it was created
}

/*
 * start
 */
void CPThread::start()
{
	pthread_attr_t tattr;
	pthread_t tid;
	int ret;

	/* initialized with default attributes */
	ret = pthread_attr_init(&tattr);

	/* setting the size of the stack also */
	ret = pthread_attr_setstacksize(&tattr, _StackSize);

	if(pthread_create(&_ThreadHandle, _StackSize != 0 ? &tattr : 0, ProxyFunc, this) != 0)
	{
		throw EThread("Cannot start new thread");
	}
	_State = 1;
}

bool CPThread::isRunning()
{
	// TODO : need a real implementation here that check thread status
	return _State == 1;
}

/*
 * terminate
 */
void CPThread::terminate()
{
	if(_State == 1)
	{
		// cancel only if started
		pthread_cancel(_ThreadHandle);
		_State = 2;	// set to finished
	}
}

/*
 * wait
 */
void CPThread::wait ()
{
	if(_State == 1)
	{
		if(pthread_join(_ThreadHandle, 0) != 0)
		{
			throw EThread( "Cannot join with thread" );
		}
		_State = 2;	// set to finished
	}
}

/*
 * setCPUMask
 */
bool CPThread::setCPUMask(uint64 cpuMask)
{
#ifdef __USE_GNU
	sint res = pthread_setaffinity_np(_ThreadHandle, sizeof(uint64), (const cpu_set_t*)&cpuMask);

	if (res)
	{
		nlwarning("pthread_setaffinity_np() returned %d", res);
		return false;
	}
#endif // __USE_GNU

	return true;
}

/*
 * getCPUMask
 */
uint64 CPThread::getCPUMask()
{
	uint64 cpuMask = 1;

#ifdef __USE_GNU
	sint res = pthread_getaffinity_np(_ThreadHandle, sizeof(uint64), (cpu_set_t*)&cpuMask);

	if (res)
	{
		nlwarning("pthread_getaffinity_np() returned %d", res);
		return 0;
	}
#endif // __USE_GNU

	return cpuMask;
}

/*
 * getUserName
 */
std::string CPThread::getUserName()
{
	struct passwd *pw = getpwuid(getuid());

	if (!pw)
		return "";

	return pw->pw_name;
}


// **** Process

// The current process
CPProcess CurrentProcess;

// Get the current process
IProcess *IProcess::getCurrentProcess ()
{
	return &CurrentProcess;
}

/*
 * getCPUMask
 */
uint64 CPProcess::getCPUMask()
{
	uint64 cpuMask = 1;

#ifdef __USE_GNU
	sint res = sched_getaffinity(getpid(), sizeof(uint64), (cpu_set_t*)&cpuMask);

	if (res)
	{
		nlwarning("sched_getaffinity() returned %d, errno = %d: %s", res, errno, strerror(errno));
		return 0;
	}
#endif // __USE_GNU

	return cpuMask;
}

/// set the CPU mask
bool CPProcess::setCPUMask(uint64 cpuMask)
{
#ifdef __USE_GNU
	sint res = sched_setaffinity(getpid(), sizeof(uint64), (const cpu_set_t*)&cpuMask);

	if (res)
	{
		nlwarning("sched_setaffinity() returned %d, errno = %d: %s", res, errno, strerror(errno));
		return false;
	}
#endif // __USE_GNU

	return true;
}


} // NLMISC

#else // NL_OS_UNIX

// remove stupid VC6 warnings
void foo_p_thread_cpp() {}

#endif // NL_OS_UNIX