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author | Neo2003 <none@none> | 2008-10-02 16:23:55 -0500 |
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committer | Neo2003 <none@none> | 2008-10-02 16:23:55 -0500 |
commit | 9b1c0e006f20091f28f3f468cfcab1feb51286bd (patch) | |
tree | b5d1ba94a656e6679f8737f9ea6bed1239b73b14 /dep/include/zthread/Condition.h |
[svn] * Proper SVN structureinit
--HG--
branch : trunk
Diffstat (limited to 'dep/include/zthread/Condition.h')
-rw-r--r-- | dep/include/zthread/Condition.h | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/dep/include/zthread/Condition.h b/dep/include/zthread/Condition.h new file mode 100644 index 00000000000..eba93619bfe --- /dev/null +++ b/dep/include/zthread/Condition.h @@ -0,0 +1,154 @@ +/* + * 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. + * + */ + +#ifndef __ZTCONDITION_H__ +#define __ZTCONDITION_H__ + +#include "zthread/Lockable.h" +#include "zthread/NonCopyable.h" +#include "zthread/Waitable.h" + +namespace ZThread { + + class FifoConditionImpl; + + /** + * @class Condition + * @author Eric Crahen <http://www.code-foo.com> + * @date <2003-07-16T14:38:59-0400> + * @version 2.2.1 + * + * A Condition is a Waitable object used to block a thread until a particular + * condition is met. A Condition object is always used in conjunction with Lockable + * object. This object should be a FastMutex, Mutex, PriorityMutex or PriorityInheritanceMutex. + * + * Condition objects are reminiscent of POSIX condition variables in several ways but + * are slightly different. + * + * A Condition is <i>not</i> subject to spurious wakeup. + * + * Like all Waitable objects, Conditions are sensitive to Thread::interupt() which can + * be used to prematurely end a wait(). + * + * @see Thread::interupt() + * + * Before a wait() is performed on a Condition, the associated Lockable object should + * have been acquire()ed. When the wait() begins, that Lockable object is release()d + * (wait() will atomically begin the wait and unlock the Lockable). + * + * A thread blocked by wait() will remain so until an exception occurs, or until + * the thread awakened by a signal() or broadcast(). When the thread resumes execution, + * the associated Lockable is acquire()d before wait() returns. + * + * <b>Scheduling</b> + * + * Threads blocked on a Condition are resumed in FIFO order. + */ + class ZTHREAD_API Condition : public Waitable, private NonCopyable { + + FifoConditionImpl* _impl; + + public: + + /** + * Create a Condition associated with the given Lockable object. + * + * @param l Lockable object to associate with this Condition object. + */ + Condition(Lockable& l); + + //! Destroy Condition object + virtual ~Condition(); + + /** + * Wake <em>one</em> thread waiting on this Condition. + * + * The associated Lockable need not have been acquire when this function is + * invoked. + * + * @post a waiting thread, if any exists, will be awakened. + */ + void signal(); + + /** + * Wake <em>all</em> threads wait()ing on this Condition. + * + * The associated Lockable need not have been acquire when this function is + * invoked. + * + * @post all wait()ing threads, if any exist, will be awakened. + */ + void broadcast(); + + /** + * Wait for this Condition, blocking the calling thread until a signal or broadcast + * is received. + * + * This operation atomically releases the associated Lockable and blocks the calling thread. + * + * @exception Interrupted_Exception thrown when the calling thread is interrupted. + * A thread may be interrupted at any time, prematurely ending any wait. + * + * @pre The thread calling this method must have first acquired the associated + * Lockable object. + * + * @post A thread that has resumed execution without exception (because of a signal(), + * broadcast() or exception) will have acquire()d the associated Lockable object + * before returning from a wait(). + * + * @see Waitable::wait() + */ + virtual void wait(); + + /** + * Wait for this Condition, blocking the calling thread until a signal or broadcast + * is received. + * + * This operation atomically releases the associated Lockable and blocks the calling thread. + * + * @param timeout maximum amount of time (milliseconds) this method could block + * + * @return + * - <em>true</em> if the Condition receives a signal or broadcast before + * <i>timeout</i> milliseconds elapse. + * - <em>false</em> otherwise. + * + * @exception Interrupted_Exception thrown when the calling thread is interrupted. + * A thread may be interrupted at any time, prematurely ending any wait. + * + * @pre The thread calling this method must have first acquired the associated + * Lockable object. + * + * @post A thread that has resumed execution without exception (because of a signal(), + * broadcast() or exception) will have acquire()d the associated Lockable object + * before returning from a wait(). + * + * @see Waitable::wait(unsigned long timeout) + */ + virtual bool wait(unsigned long timeout); + + + }; + +} // namespace ZThread + +#endif // __ZTCONDITION_H__ |