Barrier Class Template Reference

#include <Barrier.h>

Inheritance diagram for Barrier:


Public Member Functions
	Barrier ()
	Create a Barrier.
	Barrier (const Task &task)
virtual	~Barrier ()
	Destroy this Barrier.
virtual void	wait ()
virtual bool	wait (unsigned long timeout)
void	shatter ()
void	reset ()

Detailed Description

template<unsigned int Count, class LockType>
class ZThread::Barrier< Count, LockType >

Author:: Eric Crahen <http://www.code-foo.com>

Date:: <2003-07-16T09:54:01-0400>

Version:: 2.2.1

A Barrier is a Waitable object that serves as synchronization points for a set of threads. A Barrier is constructed for a fixed number (N) of threads. Threads attempting to wait() on a Barrier ( 1 - N) will block until the Nth thread arrives. The Nth thread will awaken all the the others.

An optional Runnable command may be associated with the Barrier. This will be run() when the Nth thread arrives and Barrier is not broken.

Error Checking

A Barrier uses an all-or-nothing. All threads involved must successfully meet at Barrier. If any one of those threads leaves before all the threads have (as the result of an error or exception) then all threads present at the Barrier will throw BrokenBarrier_Exception.

A broken Barrier will cause all threads attempting to wait() on it to throw a BrokenBarrier_Exception.

A Barrier will remain 'broken', until it is manually reset().

Constructor & Destructor Documentation

Barrier ( const Task & task ) [inline]

Create a Barrier that executes the given task when all threads arrive without error

Parameters:

task

Task to associate with this Barrier

Member Function Documentation

void reset ( ) [inline]

Reset the Barrier.

Postcondition:: the Barrier is no longer Broken and can be used again.

void shatter ( ) [inline]

Break the Barrier ending the wait for any threads that were waiting on the barrier.

Postcondition:: the Barrier is broken, all waiting threads will throw the BrokenBarrier_Exception

virtual bool wait ( unsigned long timeout ) [inline, virtual]

Enter barrier and wait for the other threads to arrive. This can block up to the amount of time specified with the timeout parameter. The barrier will not break if a thread leaves this function due to a timeout.

Parameters:

timeout

maximum amount of time, in milliseconds, to wait before

Returns:

true if the set of tasks being wait for complete before timeout milliseconds elapse.
false otherwise.

Exceptions:

	BrokenBarrier_Exception	thrown when any thread has left a wait on this Barrier as a result of an error.
	Interrupted_Exception	thrown when the calling thread is interrupted. A thread may be interrupted at any time, prematurely ending a wait for one thread and breaking the barrier for all threads

See also:: Waitable::wait(unsigned long timeout)

Postcondition:: If no exception was thrown, all threads have successfully arrived
If an exception was thrown, the barrier is broken

Implements Waitable.

virtual void wait ( ) [inline, virtual]

Enter barrier and wait for the other threads to arrive. This can block for an indefinite amount of time.