Wefts::OSConditionBase Class Reference
[OS Threading Level Abstraction.]

#include <wefts_os_base.h>

Inheritance diagram for Wefts::OSConditionBase:

[legend]List of all members.

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Detailed Description

This class implement an os-dependant condition.

Supposition about OS condition that must be respected by implementations:

• condition signaling is made rising a flag that wakes all the threads that are currently waiting; threads trying to wait after a cond singal are safely blocked (even if some unsignaled thread must still be awaken).
• To enter the wait, the waiter must give off a mutex that is used to check if a predicate has become true.
• Timed wait is expressed in seconds and nanoseconds.
• Upon cancellation the mutex used in signaling is locked before cancellation sequence is called.

  Note:

  All OS dependant classes should be completely inline.

  See also:

  OS Threading Abstraction (and Independence) Layer

Public Member Functions
virtual void	signal ()=0
	Signal a condition variable on ALL waiting threads.
virtual void	signalOne ()=0
	Signal a condition variable on ONE waiting thread.
virtual bool	wait (OSMutexBase &mtx, CleanupItem &guard)=0
	Waiting for a condition (giving off an already held mutex).
virtual bool	timedWait (OSMutexBase &mtx, long seconds, long nanoseconds, CleanupItem &guard)=0
	Timed wait.
Protected Member Functions
	OSConditionBase ()
	Intializes pthread condition.

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Constructor & Destructor Documentation

Wefts::OSConditionBase::OSConditionBase (   )  [inline, protected]

Intializes pthread condition.

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Member Function Documentation

virtual void Wefts::OSConditionBase::signal (   )  [pure virtual]

Signal a condition variable on ALL waiting threads. This correspond roughly to pthread_cond_broadcast. Implemented in Wefts::OSConditionPthread, and Wefts::OSConditionWindows.

virtual void Wefts::OSConditionBase::signalOne (   )  [pure virtual]

Signal a condition variable on ONE waiting thread. This correspond roughly to pthread_cond_signal. Implemented in Wefts::OSConditionPthread, and Wefts::OSConditionWindows.

virtual bool Wefts::OSConditionBase::timedWait (  OSMutexBase &  mtx, long  seconds, long  nanoseconds, CleanupItem &  guard )  [pure virtual]

Timed wait. Parameters: mtx  the mutex to be used with this condition guard  a cleanup item (pair of cleanup object pointer plus integer parameter seconds  count of second nanoseconds  count of nanoseconds Returns: true on condition signaled, false on timeout or interrupted wait. Implemented in Wefts::OSConditionPthread, and Wefts::OSConditionWindows.

virtual bool Wefts::OSConditionBase::wait (  OSMutexBase &  mtx, CleanupItem &  guard )  [pure virtual]

Waiting for a condition (giving off an already held mutex). The mutex must be held on entrance. Also notice that the guard parameter is passed by value to make a copy of it in the thread stack, so that, after return of the function (and subquesent unlocking of the mutex), another thread can change safely the guard object, and still the cleanup function for this thread will refer to the desired one. Parameters: mtx  the mutex to be used with this condition guard  a cleanup item (pair of cleanup object pointer plus integer parameter Returns: true on condition signaled, false on timeout or interrupted wait. Implemented in Wefts::OSConditionPthread, and Wefts::OSConditionWindows.

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The documentation for this class was generated from the following file:

• wefts_os_base.h

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