eventbarrier.cc

linux的例子,就是下载后到自己的机子上去运行

#include"EventBarrier.h"

EventBarrier::EventBarrier(char* debugname)
{
	name = debugname;
	state = UNSIGNALED;
	num = 0;
	signum = 0;
	lock = new Lock("lock");
	sigcond = new Condition("signal");
	complete = new Condition("complete");
}

EventBarrier::~EventBarrier()
{
	delete lock;
	delete sigcond;
	delete complete;
}

void
EventBarrier::Wait()
{
	lock->Acquire();
	if(state == UNSIGNALED){
		++num;
		sigcond->Wait(lock);
		Complete();
	}		
	lock->Release();
}

void
EventBarrier::Signal()
{
	lock->Acquire();
	state = SIGNALED;
	if(num != 0){
		sigcond->Broadcast(lock);
		complete->Wait(lock);
	}
	else
		++signum;
	state = UNSIGNALED;
	lock->Release();
}

void
EventBarrier::Complete()
{
	--num;
	if(num == 0)
		complete->Broadcast(lock);
	else
		complete->Wait(lock);
}

int
EventBarrier::Waiters()
{
	return num;
}