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BUG#: 5919
TITLE: Condition variable broken in Windows release mode

DESCRIPTION:

Modify Windows Mutex implementation to always keep track of the mutex lock count. This is needed by the Windows Condition variable implementation, which uses the count to unlock and lock the mutex in the Condition::wait() method.

//%2006////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2000, 2001, 2002 BMC Software; Hewlett-Packard Development
// Company, L.P.; IBM Corp.; The Open Group; Tivoli Systems.
// Copyright (c) 2003 BMC Software; Hewlett-Packard Development Company, L.P.;
// IBM Corp.; EMC Corporation, The Open Group.
// Copyright (c) 2004 BMC Software; Hewlett-Packard Development Company, L.P.;
// IBM Corp.; EMC Corporation; VERITAS Software Corporation; The Open Group.
// Copyright (c) 2005 Hewlett-Packard Development Company, L.P.; IBM Corp.;
// EMC Corporation; VERITAS Software Corporation; The Open Group.
// Copyright (c) 2006 Hewlett-Packard Development Company, L.P.; IBM Corp.;
// EMC Corporation; Symantec Corporation; The Open Group.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// THE ABOVE COPYRIGHT NOTICE AND THIS PERMISSION NOTICE SHALL BE INCLUDED IN
// ALL COPIES OR SUBSTANTIAL PORTIONS OF THE SOFTWARE. THE SOFTWARE IS PROVIDED
// "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
// LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
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// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
// ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
//==============================================================================
//
//%/////////////////////////////////////////////////////////////////////////////

#include "Mutex.h"
#include "Time.h"
#include "PegasusAssert.h"
#include "Once.h"

PEGASUS_NAMESPACE_BEGIN

//==============================================================================
//
// PEGASUS_HAVE_PTHREADS
//
//==============================================================================

#if defined(PEGASUS_HAVE_PTHREADS)

static Once _once = PEGASUS_ONCE_INITIALIZER;
static pthread_mutexattr_t _attr;

static void _init_attr()
{
    pthread_mutexattr_init(&_attr);
    pthread_mutexattr_settype(&_attr, PTHREAD_MUTEX_RECURSIVE);
}

Mutex::Mutex()
{
    once(&_once, _init_attr);
    pthread_mutex_init(&_rep.mutex, &_attr);
#if defined(PEGASUS_DEBUG)
    _rep.count = 0;
#endif
}

Mutex::Mutex(RecursiveTag)
{
    once(&_once, _init_attr);
    pthread_mutex_init(&_rep.mutex, &_attr);
#if defined(PEGASUS_DEBUG)
    _rep.count = 0;
#endif
}

Mutex::Mutex(NonRecursiveTag)
{
    pthread_mutex_init(&_rep.mutex, NULL);
#if defined(PEGASUS_DEBUG)
    _rep.count = 0;
#endif
}

Mutex::~Mutex()
{
    PEGASUS_DEBUG_ASSERT(_magic);
    pthread_mutex_destroy(&_rep.mutex);
}

void Mutex::lock()
{
    PEGASUS_DEBUG_ASSERT(_magic);

    switch (pthread_mutex_lock(&_rep.mutex))
    {
        case 0:
#if defined(PEGASUS_DEBUG)
            _rep.count++;
#endif
            break;

        default:
            throw WaitFailed(Threads::self());
    }
}

void Mutex::try_lock()
{
    PEGASUS_DEBUG_ASSERT(_magic);

    int r = pthread_mutex_trylock(&_rep.mutex);
    if (r == -1)
        r=errno;
    switch (r)
    {
        case 0:
#if defined(PEGASUS_DEBUG)
            _rep.count++;
#endif
            break;

        case EBUSY:
            throw AlreadyLocked(Threads::self());

        default:
            throw WaitFailed(Threads::self());
    }
}

void Mutex::timed_lock(Uint32 milliseconds)
{
    PEGASUS_DEBUG_ASSERT(_magic);

    struct timeval now;
    struct timeval finish;
    struct timeval remaining;
    {
        Uint32 usec;
        gettimeofday(&finish, NULL);
        finish.tv_sec += (milliseconds / 1000 );
        milliseconds %= 1000;
        usec = finish.tv_usec + ( milliseconds * 1000 );
        finish.tv_sec += (usec / 1000000);
        finish.tv_usec = usec % 1000000;
    }

    for (;;)
    {
        int r=pthread_mutex_trylock(&_rep.mutex);
        if (r == -1)
            r = errno;
        switch (r)
        {
            case 0:
#if defined(PEGASUS_DEBUG)
                _rep.count++;
#endif
                return;

            case EBUSY:
            {
                gettimeofday(&now, NULL);

                if (Time::subtract(&remaining, &finish, &now))
                    throw TimeOut(Threads::self());

                Threads::yield();
                break;
            }

            default:
                throw WaitFailed(Threads::self());
        }
    }
}

void Mutex::unlock()
{
    PEGASUS_DEBUG_ASSERT(_magic);
    PEGASUS_DEBUG_ASSERT(_rep.count > 0);

#if defined(PEGASUS_DEBUG)
    _rep.count--;
#endif

    if (pthread_mutex_unlock(&_rep.mutex) != 0)
        throw Permission(Threads::self());
}

#if defined(PEGASUS_OS_LINUX)
void Mutex::reinitialize()
{
    pthread_mutex_init(&_rep.mutex, &_attr);
#if defined(PEGASUS_DEBUG)
    _rep.count = 0;
#endif
}
#endif

#endif /* PEGASUS_HAVE_PTHREADS */

//==============================================================================
//
// PEGASUS_HAVE_WINDOWS_THREADS
//
//==============================================================================

#if defined(PEGASUS_HAVE_WINDOWS_THREADS)

static inline void _initialize(MutexRep& rep)
{
    rep.handle = CreateMutex(NULL, FALSE, NULL);
    rep.count = 0;
}

Mutex::Mutex()
{
    _initialize(_rep);
}

Mutex::Mutex(RecursiveTag)
{
    _initialize(_rep);
}

Mutex::Mutex(NonRecursiveTag)
{
    _initialize(_rep);
}

Mutex::~Mutex()
{
    PEGASUS_DEBUG_ASSERT(_magic);

    WaitForSingleObject(_rep.handle, INFINITE);
    CloseHandle(_rep.handle);
}

void Mutex::lock()
{
    PEGASUS_DEBUG_ASSERT(_magic);

    DWORD rc = WaitForSingleObject(_rep.handle, INFINITE);

    if (rc == WAIT_FAILED)
        throw WaitFailed(Threads::self());

    _rep.count++;
}

void Mutex::try_lock()
{
    PEGASUS_DEBUG_ASSERT(_magic);

    DWORD rc = WaitForSingleObject(_rep.handle, 0);

    if (rc == WAIT_TIMEOUT)
        throw AlreadyLocked(Threads::self());

    if (rc == WAIT_FAILED)
        throw WaitFailed(Threads::self());

    _rep.count++;
}

void Mutex::timed_lock(Uint32 milliseconds)
{
    PEGASUS_DEBUG_ASSERT(_magic);

    DWORD rc = WaitForSingleObject(_rep.handle, milliseconds);

    if (rc == WAIT_TIMEOUT)
        throw TimeOut(Threads::self());

    if (rc == WAIT_FAILED)
        throw WaitFailed(Threads::self());

    _rep.count++;
}

void Mutex::unlock()
{
    PEGASUS_DEBUG_ASSERT(_magic);
    PEGASUS_DEBUG_ASSERT(_rep.count > 0);

    _rep.count--;
    ReleaseMutex(_rep.handle);
}

#endif /* PEGASUS_HAVE_WINDOWS_THREADS */

PEGASUS_NAMESPACE_END