diff options
Diffstat (limited to 'dep/src/zthread/MutexImpl.h')
| -rw-r--r-- | dep/src/zthread/MutexImpl.h | 378 |
1 files changed, 0 insertions, 378 deletions
diff --git a/dep/src/zthread/MutexImpl.h b/dep/src/zthread/MutexImpl.h deleted file mode 100644 index 83b32d47a98..00000000000 --- a/dep/src/zthread/MutexImpl.h +++ /dev/null @@ -1,378 +0,0 @@ -/* - * Copyright (c) 2005, Eric Crahen - * - * 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 PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE - * AUTHORS OR COPYRIGHT 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 "zthread/Exceptions.h" -#include "zthread/Guard.h" - -#include "Debug.h" -#include "FastLock.h" -#include "Scheduling.h" - -#include <assert.h> -#include <errno.h> - -namespace ZThread { - - -/** - * @author Eric Crahen <http://www.code-foo.com> - * @date <2003-07-16T19:52:12-0400> - * @version 2.2.11 - * @class NullBehavior - */ -class NullBehavior { -protected: - - inline void waiterArrived(ThreadImpl*) { } - - inline void waiterDeparted(ThreadImpl*) { } - - inline void ownerAcquired(ThreadImpl*) { } - - inline void ownerReleased(ThreadImpl*) { } - -}; - -/** - * @author Eric Crahen <http://www.code-foo.com> - * @date <2003-07-16T19:52:12-0400> - * @version 2.2.11 - * @class MutexImpl - * - * The MutexImpl template allows how waiter lists are sorted, and - * what actions are taken when a thread interacts with the mutex - * to be parametized. - */ -template <typename List, typename Behavior> -class MutexImpl : Behavior { - - //! List of Events that are waiting for notification - List _waiters; - - //! Serialize access to this Mutex - FastLock _lock; - - //! Current owner - volatile ThreadImpl* _owner; - - public: - - - /** - * Create a new MutexImpl - * - * @exception Initialization_Exception thrown if resources could not be - * properly allocated - */ - MutexImpl() : _owner(0) { } - - ~MutexImpl(); - - void acquire(); - - void release(); - - bool tryAcquire(unsigned long timeout); - -}; - - /** - * Destroy this MutexImpl and release its resources - */ -template<typename List, typename Behavior> -MutexImpl<List, Behavior>::~MutexImpl() { - -#ifndef NDEBUG - - // It is an error to destroy a mutex that has not been released - if(_owner != 0) { - - ZTDEBUG("** You are destroying a mutex which was never released. **\n"); - assert(0); // Destroyed mutex while in use - - } - - if(!_waiters.empty()) { - - ZTDEBUG("** You are destroying a mutex which is blocking %d threads. **\n", _waiters.size()); - assert(0); // Destroyed mutex while in use - - } - -#endif - - } - - - /** - * Acquire a lock on the mutex. If this operation succeeds the calling - * thread holds an exclusive lock on this mutex, otherwise it is blocked - * until the lock can be acquired. - * - * @exception Deadlock_Exception thrown when the caller attempts to acquire() more - * than once, If the checking flag is set. - * @exception Interrupted_Exception thrown when the caller status is interrupted - * @exception Synchronization_Exception thrown if there is some other error. - */ -template<typename List, typename Behavior> -void MutexImpl<List, Behavior>::acquire() { - - ThreadImpl* self = ThreadImpl::current(); - Monitor& m = self->getMonitor(); - - Monitor::STATE state; - - Guard<FastLock> g1(_lock); - - // Deadlock will occur if the current thread is the owner - // and there is no entry count. - if(_owner == self) - throw Deadlock_Exception(); - - // Acquire the lock if it is free and there are no waiting threads - if(_owner == 0 && _waiters.empty()) { - - _owner = self; - - this->ownerAcquired(self); - - } - - // Otherwise, wait for a signal from a thread releasing its - // ownership of the lock - else { - - _waiters.insert(self); - m.acquire(); - - this->waiterArrived(self); - - { - - Guard<FastLock, UnlockedScope> g2(g1); - state = m.wait(); - - } - - this->waiterDeparted(self); - - m.release(); - - // Remove from waiter list, regardless of wether release() is called or - // not. The monitor is sticky, so its possible a state 'stuck' from a - // previous operation and will leave the wait() w/o release() having - // been called (e.g. interrupted) - typename List::iterator i = std::find(_waiters.begin(), _waiters.end(), self); - if(i != _waiters.end()) - _waiters.erase(i); - - // If awoke due to a notify(), take ownership. - switch(state) { - case Monitor::SIGNALED: - - assert(_owner == 0); - _owner = self; - - this->ownerAcquired(self); - - break; - - case Monitor::INTERRUPTED: - throw Interrupted_Exception(); - - default: - throw Synchronization_Exception(); - } - - } - - } - - - /** - * Acquire a lock on the mutex. If this operation succeeds the calling - * thread holds an exclusive lock on this mutex. If the lock cannot be - * obtained before the timeout expires, the caller returns false. - * - * @exception Deadlock_Exception thrown when the caller attempts to acquire() more - * than once, If the checking flag is set. - * @exception Interrupted_Exception thrown when the caller status is interrupted - * @exception Synchronization_Exception thrown if there is some other error. - */ -template<typename List, typename Behavior> -bool MutexImpl<List, Behavior>::tryAcquire(unsigned long timeout) { - - ThreadImpl* self = ThreadImpl::current(); - Monitor& m = self->getMonitor(); - - Guard<FastLock> g1(_lock); - - // Deadlock will occur if the current thread is the owner - // and there is no entry count. - if(_owner == self) - throw Deadlock_Exception(); - - // Acquire the lock if it is free and there are no waiting threads - if(_owner == 0 && _waiters.empty()) { - - _owner = self; - - this->ownerAcquired(self); - - } - - // Otherwise, wait for a signal from a thread releasing its - // ownership of the lock - else { - - _waiters.insert(self); - - Monitor::STATE state = Monitor::TIMEDOUT; - - // Don't bother waiting if the timeout is 0 - if(timeout) { - - m.acquire(); - - this->waiterArrived(self); - - { - - Guard<FastLock, UnlockedScope> g2(g1); - state = m.wait(timeout); - - } - - this->waiterDeparted(self); - - m.release(); - - } - - - // Remove from waiter list, regarless of weather release() is called or - // not. The monitor is sticky, so its possible a state 'stuck' from a - // previous operation and will leave the wait() w/o release() having - // been called. - typename List::iterator i = std::find(_waiters.begin(), _waiters.end(), self); - if(i != _waiters.end()) - _waiters.erase(i); - - // If awoke due to a notify(), take ownership. - switch(state) { - case Monitor::SIGNALED: - - assert(0 == _owner); - _owner = self; - - this->ownerAcquired(self); - - break; - - case Monitor::INTERRUPTED: - throw Interrupted_Exception(); - - case Monitor::TIMEDOUT: - return false; - - default: - throw Synchronization_Exception(); - } - - } - - return true; - - } - - /** - * Release a lock on the mutex. If this operation succeeds the calling - * thread no longer holds an exclusive lock on this mutex. If there are - * waiting threads, one will be selected, assigned ownership and specifically - * awakened. - * - * @exception InvalidOp_Exception - thrown if an attempt is made to - * release a mutex not owned by the calling thread. - */ -template<typename List, typename Behavior> -void MutexImpl<List, Behavior>::release() { - - ThreadImpl* impl = ThreadImpl::current(); - - Guard<FastLock> g1(_lock); - - // Make sure the operation is valid - if(_owner != impl) - throw InvalidOp_Exception(); - - _owner = 0; - - this->ownerReleased(impl); - - // Try to find a waiter with a backoff & retry scheme - for(;;) { - - // Go through the list, attempt to notify() a waiter. - for(typename List::iterator i = _waiters.begin(); i != _waiters.end();) { - - // Try the monitor lock, if it cant be locked skip to the next waiter - impl = *i; - Monitor& m = impl->getMonitor(); - - if(m.tryAcquire()) { - - // If notify() is not sucessful, it is because the wait() has already - // been ended (killed/interrupted/notify'd) - bool woke = m.notify(); - - m.release(); - - // Once notify() succeeds, return - if(woke) - return; - - } else ++i; - - } - - if(_waiters.empty()) - return; - - { // Backoff and try again - - Guard<FastLock, UnlockedScope> g2(g1); - ThreadImpl::yield(); - - } - - } - - } - -} // namespace ZThread - - - - - - - |