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PrioritySemaphore Class Reference

#include <PrioritySemaphore.h>

Inheritance diagram for PrioritySemaphore:

List of all members.

Public Methods
	PrioritySemaphore (int count=1, unsigned int maxCount=1)
virtual	~PrioritySemaphore () throw ()
	Destroy the PrioritySemaphore.
void	wait ()
bool	tryWait (unsigned long)
void	post ()
virtual int	count () throw ()
virtual bool	tryAcquire (unsigned long timeout)
virtual void	acquire ()
virtual void	release ()

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Detailed Description

Author:

Eric Crahen <crahen@cse.buffalo.edu>

Date:

<2002-06-02T08:11:08-0400>

Version:

2.2.1

A PrioritySemaphore operates in the same way as a Semaphore. Its an ownerless Lockable object that is sensative to priority.

Scheduling

Threads blocked on a PrioritySemaphore are resumed in priority order, highest priority first.

Error Checking

An attempt to increase a PrioritySemaphore beyond its maximum value will result in an InvalidOp_Exception.

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Constructor & Destructor Documentation

PrioritySemaphore (  int    count = 1, unsigned int    maxCount = 1 )

Create a new PrioritySemaphore. Parameters: count  - initial count maxCount  - upper bound Exceptions: Synchronization_Exception  thrown if the PrioritySemaphore could not be created

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Member Function Documentation

virtual void acquire (    )  [virtual]

Decrement the count, blocking that calling thread if the count becomes 0 or less than 0. The calling thread will remain blocked until the count is raised above 0 or if an exception is thrown. Exceptions: Interrupted_Exception  thrown when the calling thread is interupt()ed. A thread may be interrupted at any time, prematurely ending any wait. Synchronization_Exception  thrown if there is some other error. See also: Lockable::acquire() Implements Lockable.

virtual int count (    )  throw () [virtual]

Get the current count of the semaphore. This value may change immediately after this function returns to the calling thread. Returns : int - count

void post (    )

Increment the count. See also: release() - provided to reflect the traditional PrioritySemaphore semantics

virtual void release (    )  [virtual]

Increment the count, unblocking one thread if count is posative. Exceptions: InvalidOp_Exception  thrown if this operation would increase the count beyond the maximum Synchronization_Exception  thrown if there is some other error. See also: Lockable::release() Implements Lockable.

virtual bool tryAcquire (  unsigned long    timeout )  [virtual]

Decrement the count, blocking that calling thread if the count becomes 0 or less than 0. The calling thread will remain blocked until the count is raised above 0, an exception is thrown or the given amount of time expires. Parameters: timeout  - maximum amount of time (milliseconds) this method could block Returns : bool true if the PrioritySemaphore was acquire()ed before the timeout expired, otherwise false Exceptions: Interrupted_Exception  thrown when the calling thread is interupt()ed. A thread may be interrupted at any time, prematurely ending any wait. Synchronization_Exception  thrown if there is some other error. See also: Lockable::tryAcquire(unsigned long) Implements Lockable.

bool tryWait (  unsigned    long )

Decrement the count. See also: tryAcquire() - provided to reflect the traditional PrioritySemaphore semantics

void wait (    )

Decrement the count. See also: acquire() - provided to reflect the traditional PrioritySemaphore semantics

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

• PrioritySemaphore.h

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