mutex.cpp

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/*
**  ClanLib SDK
**  Copyright (c) 1997-2005 The ClanLib Team
**
**  This software is provided 'as-is', without any express or implied
**  warranty.  In no event will the authors be held liable for any damages
**  arising from the use of this software.
**
**  Permission is granted to anyone to use this software for any purpose,
**  including commercial applications, and to alter it and redistribute it
**  freely, subject to the following restrictions:
**
**  1. The origin of this software must not be misrepresented; you must not
**     claim that you wrote the original software. If you use this software
**     in a product, an acknowledgment in the product documentation would be
**     appreciated but is not required.
**  2. Altered source versions must be plainly marked as such, and must not be
**     misrepresented as being the original software.
**  3. This notice may not be removed or altered from any source distribution.
**
**  Note: Some of the libraries ClanLib link to may have additional
**  requirements or restrictions.
**
**  File Author(s):
**
**    Magnus Norddahl
*/

#include "precomp.h"
#include "mutex.h"
#include "exception.h"

#ifndef WIN32
// We need to do this because the posix threads library under linux obviously
// suck:
extern "C"
{
#ifdef __FreeBSD__
        int pthread_mutexattr_settype(pthread_mutexattr_t *attr, int kind);
#else
        int pthread_mutexattr_setkind_np(pthread_mutexattr_t *attr, int kind);
#endif
}
#endif

// CL_Mutex Construction:

CL_Mutex::CL_Mutex()
{
#ifdef WIN32
        InitializeCriticalSection(&critical_section);
#else
        pthread_mutexattr_t attr;
        pthread_mutexattr_init(&attr);
        #ifdef __FreeBSD__
        pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
        #else
        #if PTHREAD_MUTEX_RECURSIVE_NP
        pthread_mutexattr_setkind_np(&attr, PTHREAD_MUTEX_RECURSIVE);
        #else
        pthread_mutexattr_setkind_np(&attr, PTHREAD_MUTEX_RECURSIVE_NP);
        #endif
        #endif
        pthread_mutex_init(&handle, &attr);
        pthread_mutexattr_destroy(&attr);
#endif
}

CL_Mutex::~CL_Mutex()
{
#ifdef WIN32
        DeleteCriticalSection(&critical_section);
#else
        pthread_mutex_destroy(&handle);
#endif
}

// CL_Mutex Attributes:


// CL_Mutex Operations:

void CL_Mutex::lock()
{
#ifdef WIN32
        EnterCriticalSection(&critical_section);
#else
        pthread_mutex_lock(&handle);
#endif
}

bool CL_Mutex::try_lock()
{
#ifdef WIN32
        BOOL result = TryEnterCriticalSection(&critical_section);
        return (result != FALSE);
#else
        throw CL_Exception(TEXT("Congratulations, you just got the task of implementing CL_Mutex::try_lock() for unix!"));
        return false;
#endif
}

void CL_Mutex::unlock()
{
#ifdef WIN32
        LeaveCriticalSection(&critical_section);
#else
        pthread_mutex_unlock(&handle);
#endif
}

// CL_Mutex Implementation:


// CL_MutexSection Construction:

CL_MutexSection::CL_MutexSection(CL_Mutex *mutex, bool lock_mutex) : mutex(mutex), lock_count(0)
{
        if (lock_mutex)
                lock();
}

CL_MutexSection::~CL_MutexSection()
{
        while (lock_count > 0)
                unlock();
}

// CL_MutexSection Attributes:

int CL_MutexSection::get_lock_count() const
{
        return lock_count;
}

// CL_MutexSection Operations:

void CL_MutexSection::lock()
{
        if (mutex)
                mutex->lock();
        lock_count++;
}

bool CL_MutexSection::try_lock()
{
        if (mutex == 0 || mutex->try_lock())
        {
                lock_count++;
                return true;
        }
        return false;
}

void CL_MutexSection::unlock()
{
        if (lock_count <= 0)
                return;

        if (mutex)
                mutex->unlock();
        lock_count--;
}

// CL_MutexSection Implementation:

---