ucc::barrier Class Reference

A portable implimentation of "barrier" thread sychronization. More...

#include <thread.h>

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Public Member Functions

 barrier (unsigned count)
 Construct a barrier with an initial size.
 ~barrier ()
 Destroy barrier and release pending threads.
void set (unsigned count)
 Dynamically alter the number of threads required.
void wait (void)
 Wait at the barrier until the count of threads waiting is reached.
bool wait (timeout_t timeout)
 Wait at the barrier until either the count of threads waiting is reached or a timeout has occurred.

Static Public Member Functions

static void wait (barrier &sync)
 Convenience function to wait at a barrier.
static bool wait (barrier &sync, timeout_t timeout)
 Convenience function to wait at a barrier with a timeout.
static void set (barrier &sync, unsigned count)
 Convenience function to set a barrier count.

Detailed Description

A portable implimentation of "barrier" thread sychronization.

A barrier waits until a specified number of threads have all reached the barrier, and then releases all the threads together. This implimentation works regardless of whether the thread library supports barriers since it is built from conditional. It also differs in that the number of threads required can be changed dynamically at runtime, unlike pthread barriers which, when supported, have a fixed limit defined at creation time. Since we use conditionals, another feature we can add is optional support for a wait with timeout.

Author:
David Sugar <dyfet@gnutelephony.org>

Definition at line 903 of file thread.h.


Constructor & Destructor Documentation

ucc::barrier::barrier ( unsigned  count  ) 

Construct a barrier with an initial size.

Parameters:
count of threads required.

Member Function Documentation

static void ucc::barrier::set ( barrier sync,
unsigned  count 
) [inline, static]

Convenience function to set a barrier count.

Parameters:
sync object to set.
count of threads to set.

Definition at line 963 of file thread.h.

void ucc::barrier::set ( unsigned  count  ) 

Dynamically alter the number of threads required.

If the size is set below the currently waiting threads, then the barrier releases.

Parameters:
count of threads required.
static bool ucc::barrier::wait ( barrier sync,
timeout_t  timeout 
) [inline, static]

Convenience function to wait at a barrier with a timeout.

Parameters:
sync object to wait at.
timeout to wait in milliseconds.
Returns:
false if timer expired.

Definition at line 954 of file thread.h.

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static void ucc::barrier::wait ( barrier sync  )  [inline, static]

Convenience function to wait at a barrier.

Parameters:
sync object to wait at.

Definition at line 945 of file thread.h.

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bool ucc::barrier::wait ( timeout_t  timeout  ) 

Wait at the barrier until either the count of threads waiting is reached or a timeout has occurred.

Parameters:
timeout to wait in milliseconds.
Returns:
true if barrier reached, false if timer expired.

Reimplemented from ucc::Conditional.


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

Generated on 18 Dec 2009 for UCommon by  doxygen 1.6.1