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/* ====================================================================
* Copyright (c) 2003-2006, The Subcommander Crew
* http://subcommander.tigris.org
*
* Subcommander is licensed as described in the file doc/COPYING, which
* you should have received as part of this distribution.
* ====================================================================
*/
// sc
#include "Condition.h"
#include "Guard.h"
// apr
#include <apr_thread_cond.h>
namespace sc
{
/**
* Create a condition variable.
*/
Condition::Condition() : _c(false)
{
apr_thread_cond_create( &_condition, _pool );
}
/**
* Clean up.
*/
Condition::~Condition()
{
apr_thread_cond_destroy(_condition);
}
/**
* Wake up a single waiting thread.
* \sa wakeAll()
*/
void Condition::wakeOne()
{
Guard<Mutex> guard(_mutex);
_c = true;
apr_thread_cond_signal(_condition);
}
/**
* Wake up all waiting threads.
* \sa wait()
*/
void Condition::wakeAll()
{
Guard<Mutex> guard(_mutex);
_c = true;
apr_thread_cond_broadcast(_condition);
}
/**
* Wait for the condition. This call blocks until the condition is set.
*/
void Condition::wait()
{
Guard<Mutex> guard(_mutex);
// the loop handles 2 special cases:
// 1. don't block the calling thread if the condition is already set.
// 2. only return if the condition is set. The condition may be reset
// before the waking thread reaquires the mutex. (is that correct?)
while( ! _c )
{
apr_thread_cond_wait( _condition, _mutex._mutex );
}
}
/**
* Wait for the condition. This call blocks until the condition is set
* (returns true) or a time span of microsec has elapsed (returns false).
*/
bool Condition::wait( unsigned long millies )
{
Guard<Mutex> guard(_mutex);
while( ! _c )
{
apr_status_t status =
apr_thread_cond_timedwait( _condition, _mutex._mutex, millies*1000 );
if( status == APR_TIMEUP )
{
return false;
}
}
return true;
}
/**
* Reset the condition.
*/
void Condition::reset()
{
Guard<Mutex> guard(_mutex);
_c = false;
}
} // namespace
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