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Diffstat (limited to 'ACE/ace/Condition_T.h')
-rw-r--r-- | ACE/ace/Condition_T.h | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/ACE/ace/Condition_T.h b/ACE/ace/Condition_T.h new file mode 100644 index 00000000000..535642a77e8 --- /dev/null +++ b/ACE/ace/Condition_T.h @@ -0,0 +1,167 @@ +// -*- C++ -*- + +//========================================================================== +/** + * @file Condition_T.h + * + * $Id$ + * + * Moved from Synch.h. + * + * @author Douglas C. Schmidt <schmidt@cs.wustl.edu> + */ +//========================================================================== + +#ifndef ACE_CONDITION_T_H +#define ACE_CONDITION_T_H + +#include /**/ "ace/pre.h" + +#include "ace/OS_NS_Thread.h" +#include "ace/Lock.h" + +#if !defined (ACE_LACKS_PRAGMA_ONCE) +# pragma once +#endif /* ACE_LACKS_PRAGMA_ONCE */ + +#if defined (ACE_HAS_THREADS) /* ACE platform supports some form of threading. */ + +ACE_BEGIN_VERSIONED_NAMESPACE_DECL + +class ACE_Time_Value; + +/** + * @class ACE_Condition + * + * @brief ACE_Condition variable wrapper, which allows threads to block + * until shared data changes state. + * + * A condition variable enables threads to atomically block and + * test the condition under the protection of a mutual exclu- + * sion lock (mutex) until the condition is satisfied. That is, + * the mutex must have been held by the thread before calling + * wait or signal on the condition. If the condition is false, + * a thread blocks on a condition variable and atomically + * releases the mutex that is waiting for the condition to + * change. If another thread changes the condition, it may wake + * up waiting threads by signaling the associated condition + * variable. The waiting threads, upon awakening, reacquire the + * mutex and re-evaluate the condition. + * Note, you can only parameterize <ACE_Condition> with + * @a ACE_Thread_Mutex, @a ACE_Recursive_Thread_Mutex, or @a ACE_Null_Mutex. + */ +template <class MUTEX> +class ACE_Condition +{ +public: + // = Initialiation and termination methods. + /// Initialize the condition variable. + ACE_Condition (MUTEX &m, int type = USYNC_THREAD, + const ACE_TCHAR *name = 0, void *arg = 0); + + /// Implicitly destroy the condition variable. + ~ACE_Condition (void); + + // = Lock accessors. + /** + * Block on condition, or until absolute time-of-day has passed. If + * abstime == 0 use "blocking" <wait> semantics. Else, if <abstime> + * != 0 and the call times out before the condition is signaled + * <wait> returns -1 and sets errno to ETIME. + */ + int wait (const ACE_Time_Value *abstime); + + /// Block on condition. + int wait (void); + + /** + * Block on condition or until absolute time-of-day has passed. If + * abstime == 0 use "blocking" wait() semantics on the <mutex> + * passed as a parameter (this is useful if you need to store the + * <Condition> in shared memory). Else, if <abstime> != 0 and the + * call times out before the condition is signaled <wait> returns -1 + * and sets errno to ETIME. + */ + int wait (MUTEX &mutex, const ACE_Time_Value *abstime = 0); + + /// Signal one waiting thread. + int signal (void); + + /// Signal *all* waiting threads. + int broadcast (void); + + // = Utility methods. + /// Explicitly destroy the condition variable. + int remove (void); + + /// Returns a reference to the underlying mutex_; + MUTEX &mutex (void); + + /// Dump the state of an object. + void dump (void) const; + + // ACE_ALLOC_HOOK_DECLARE; + // Declare the dynamic allocation hooks. + +protected: + /// Condition variable. + ACE_cond_t cond_; + + /// Reference to mutex lock. + MUTEX &mutex_; + +private: + // = Prevent assignment and initialization. + ACE_UNIMPLEMENTED_FUNC (void operator= (const ACE_Condition<MUTEX> &)) + ACE_UNIMPLEMENTED_FUNC (ACE_Condition (const ACE_Condition<MUTEX> &)) +}; + +/** + * @class ACE_Thread_Condition + * + * @brief ACE_Condition variable wrapper that works within processes. + * + * A condition variable enables threads to atomically block and + * test the condition under the protection of a mutual exclu- + * sion lock (mutex) until the condition is satisfied. That is, + * the mutex must have been held by the thread before calling + * wait or signal on the condition. If the condition is false, + * a thread blocks on a condition variable and atomically + * releases the mutex that is waiting for the condition to + * change. If another thread changes the condition, it may wake + * up waiting threads by signaling the associated condition + * variable. The waiting threads, upon awakening, reacquire the + * mutex and re-evaluate the condition. + */ +template <class MUTEX> +class ACE_Thread_Condition : public ACE_Condition<MUTEX> +{ +public: + // = Initialization method. + ACE_Thread_Condition (MUTEX &m, const ACE_TCHAR *name = 0, void *arg = 0); + + /// Dump the state of an object. + void dump (void) const; + + // ACE_ALLOC_HOOK_DECLARE; + // Declare the dynamic allocation hooks. +}; + +ACE_END_VERSIONED_NAMESPACE_DECL + +#if defined (__ACE_INLINE__) +#include "ace/Condition_T.inl" +#endif /* __ACE_INLINE__ */ + +#if defined (ACE_TEMPLATES_REQUIRE_SOURCE) +#include "ace/Condition_T.cpp" +#endif /* ACE_TEMPLATES_REQUIRE_SOURCE */ + +#if defined (ACE_TEMPLATES_REQUIRE_PRAGMA) +#pragma implementation ("Condition_T.cpp") +#endif /* ACE_TEMPLATES_REQUIRE_PRAGMA */ + +#endif /* ACE_HAS_THREADS */ + +#include /**/ "ace/post.h" +#endif /* ACE_CONDITION_T_H */ |