Error RWLockWindows::write_try_lock() {
if (TryAcquireSRWLockExclusive(&lock) == 0) {
return ERR_BUSY;
} else {
return OK;
}
}
BOOL CRWLockSlim::AcquireWriterLock( DWORD dwTimeout )
{
BOOL bRet = FALSE;
#if ( _WIN32_WINNT_WIN7 <= _WIN32_WINNT )
if ( INFINITE == dwTimeout || FALSE == m_bWin7AndLater )
{
AcquireSRWLockExclusive( &m_srwLock );
bRet = TRUE;
}
else
{
LARGE_INTEGER lnCurr , lnEnd;
QueryPerformanceCounter( &lnCurr );
lnEnd.QuadPart = lnCurr.QuadPart + dwTimeout * ( m_lnFreq.QuadPart / 1000 );
do
{
QueryPerformanceCounter( &lnCurr );
bRet = (BOOL)TryAcquireSRWLockExclusive( &m_srwLock );
} while ( lnCurr.QuadPart < lnEnd.QuadPart );
}
#else
AcquireSRWLockExclusive( &m_srwLock );
bRet = TRUE;
#endif
return bRet;
}
/// <summary>
/// Tries to acquire write lock (now). Returns true if succeeded, false if failed.
/// </summary>
/// <returns></returns>
bool RWLock::TryLockWrite()
{
#ifdef PLATFORM_WIN
return (TryAcquireSRWLockExclusive( &mRwlock ) > 0);
#else
return (pthread_rwlock_trywrlock( &mRwlock ) == 0);
#endif
}
int
pthread_rwlock_trywrlock(pthread_rwlock_t *rwlock)
{
if (TryAcquireSRWLockExclusive(&rwlock->rwlock)) {
rwlock->exclusive_locked = GetCurrentThreadId();
return (0);
}
return (EBUSY);
}
bool TRI_TryWriteLockReadWriteLock (TRI_read_write_lock_t* lock) {
#if TRI_WINDOWS_VISTA_LOCKS
BOOL result;
// ...........................................................................
// Here we use TryEnterCriticalSection instead of EnterCriticalSection
// There could already be a write lock - which will actuall block from this
// point on.
// ...........................................................................
result = TryEnterCriticalSection(&lock->_lockWriter);
if (result == 0) {
// appears some other writer is writing
return false;
}
// ...........................................................................
// Wait until the lock->_writerEvent is in a 'signalled' state
// This might fail because a reader is just about to read
// ...........................................................................
if (WaitForSingleObject(lock->_writerEvent, 0) != WAIT_OBJECT_0) {
LeaveCriticalSection(&lock->_lockWriter);
return false;
}
// ...........................................................................
// Set _writeEvent as nonsignalled -- this will block other read/write
// lockers
// ...........................................................................
ResetEvent(lock->_writerEvent);
// ...........................................................................
// If there are ANY read locks outstanding, leave
// ...........................................................................
if (WaitForSingleObject(lock->_readersEvent, 0) != WAIT_OBJECT_0) {
LeaveCriticalSection(&lock->_lockWriter);
SetEvent(lock->_writerEvent);
return false;
}
// ...........................................................................
// Allow other threads to access this function
// ...........................................................................
LeaveCriticalSection(&lock->_lockWriter);
return true;
#else
return (TryAcquireSRWLockExclusive(&lock->_lock) != 0);
#endif
}
int qemu_mutex_trylock_impl(QemuMutex *mutex, const char *file, const int line)
{
int owned;
assert(mutex->initialized);
owned = TryAcquireSRWLockExclusive(&mutex->lock);
if (owned) {
trace_qemu_mutex_locked(mutex, file, line);
return 0;
}
return -EBUSY;
}
bool ReadWriteLock::TryBeginWrite()
{
return TryAcquireSRWLockExclusive(&mLock) == TRUE;
}
bool tryLockWrite()
{
return TryAcquireSRWLockExclusive(&this->_rwlock) != 0;
}
bool TRI_TryWriteLockReadWriteLock (TRI_read_write_lock_t* lock) {
return (TryAcquireSRWLockExclusive(&lock->_lock) != 0);
}
bool RWMutex::tryWriteLock()
{
return TryAcquireSRWLockExclusive(&_mutex);
}
bool trywrlock()
{
return TryAcquireSRWLockExclusive(&rwlock_);
}
BOOLEAN try_lock ()
{
return TryAcquireSRWLockExclusive ( &_lock ) ;
}
bool WinReadWriteLock::tryLockForWrite()
{
return TryAcquireSRWLockExclusive(&m_lock);
}
bool SlimReaderWriterLock::try_lock()
{
return TryAcquireSRWLockExclusive( &mSrwlock ) != 0;
}
