kits/shared/RWLockManager.cpp

36 RWLockManager::ReadLock(RWLockable* lockable)
40 	if (lockable->fWaiters.IsEmpty()) {
41 		lockable->fReaderCount++;
45 	return _Wait(lockable, false, B_INFINITE_TIMEOUT) == B_OK;
50 RWLockManager::TryReadLock(RWLockable* lockable)
54 	if (lockable->fWaiters.IsEmpty()) {
55 		lockable->fReaderCount++;
64 RWLockManager::ReadLockWithTimeout(RWLockable* lockable, bigtime_t timeout)
68 	if (lockable->fWaiters.IsEmpty()) {
69 		lockable->fReaderCount++;
73 	return _Wait(lockable, false, timeout);
78 RWLockManager::ReadUnlock(RWLockable* lockable)
82 	if (lockable->fReaderCount <= 0) {
87 	if (--lockable->fReaderCount == 0)
88 		_Unblock(lockable);
93 RWLockManager::WriteLock(RWLockable* lockable)
99 	if (lockable->fOwner == thread) {
100 		lockable->fOwnerCount++;
104 	if (lockable->fReaderCount == 0 && lockable->fWaiters.IsEmpty()) {
105 		lockable->fOwnerCount = 1;
106 		lockable->fOwner = find_thread(NULL);
110 	return _Wait(lockable, true, B_INFINITE_TIMEOUT) == B_OK;
115 RWLockManager::TryWriteLock(RWLockable* lockable)
121 	if (lockable->fOwner == thread) {
122 		lockable->fOwnerCount++;
126 	if (lockable->fReaderCount == 0 && lockable->fWaiters.IsEmpty()) {
127 		lockable->fOwnerCount++;
128 		lockable->fOwner = thread;
137 RWLockManager::WriteLockWithTimeout(RWLockable* lockable, bigtime_t timeout)
143 	if (lockable->fOwner == thread) {
144 		lockable->fOwnerCount++;
148 	if (lockable->fReaderCount == 0 && lockable->fWaiters.IsEmpty()) {
149 		lockable->fOwnerCount++;
150 		lockable->fOwner = thread;
154 	return _Wait(lockable, true, timeout);
159 RWLockManager::WriteUnlock(RWLockable* lockable)
163 	if (find_thread(NULL) != lockable->fOwner) {
169 	if (--lockable->fOwnerCount == 0) {
170 		lockable->fOwner = -1;
171 		_Unblock(lockable);
177 RWLockManager::_Wait(RWLockable* lockable, bool writer, bigtime_t timeout)
184 	lockable->fWaiters.Add(&waiter);
206 	lockable->fWaiters.Remove(&waiter);
208 	_Unblock(lockable);
215 RWLockManager::_Unblock(RWLockable* lockable)
219 	RWLockable::Waiter* waiter = lockable->fWaiters.Head();
220 	if (waiter == NULL || lockable->fOwner >= 0)
225 		if (lockable->fReaderCount == 0) {
228 			lockable->fWaiters.Remove(waiter);
229 			lockable->fOwner = waiter->thread;
230 			lockable->fOwnerCount = 1;
239 	while (!lockable->fWaiters.IsEmpty()
240 			&& !lockable->fWaiters.Head()->writer) {
246 				&& (waiter = lockable->fWaiters.Head()) != NULL
250 			lockable->fWaiters.Remove(waiter);
253 			lockable->fReaderCount++;