/* xpevent.c */

/* *nix emulation of Win32 *Event API */

/* $Id: xpevent.c,v 1.9 2005/10/21 21:49:48 deuce Exp $ */

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 * Copyright 2005 Rob Swindell - http://www.synchro.net/copyright.html		*
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 * This library is free software; you can redistribute it and/or			*
 * modify it under the terms of the GNU Lesser General Public License		*
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#include <stdio.h>		/* NULL */
#include <stdlib.h>		/* malloc() */
#include "xpevent.h"
#include "genwrap.h"

xpevent_t
CreateEvent(void *sec, BOOL bManualReset, BOOL bInitialState, void *name)
{
	xpevent_t	event;

	event = (xpevent_t)malloc(sizeof(struct xpevent));
	if (event == NULL) {
		errno = ENOSPC;
		return(NULL);
	}

	/*
	 * Initialize
	 */
	if (pthread_mutex_init(&event->lock, NULL) != 0) {
		free(event);
		errno = ENOSPC;
		return(NULL);
	}

	if (pthread_cond_init(&event->gtzero, NULL) != 0) {
		while(pthread_mutex_destroy(&event->lock)==EBUSY)
			SLEEP(1);
		free(event);
		errno = ENOSPC;
		return(NULL);
	}

	event->mreset=bManualReset;
	event->value=bInitialState;
	event->nwaiters = 0;
	event->magic=EVENT_MAGIC;

	return(event);
}

BOOL
SetEvent(xpevent_t event)
{
	if (event==NULL || (event->magic != EVENT_MAGIC)) {
		errno = EINVAL;
		return(FALSE);
	}

	pthread_mutex_lock(&event->lock);

	event->value=TRUE;
	if (event->nwaiters > 0) {
		/*
		 * We must use pthread_cond_broadcast() rather than
		 * pthread_cond_signal() in order to assure that the highest
		 * priority thread is run by the scheduler, since
		 * pthread_cond_signal() signals waiting threads in FIFO order.
		 */
		pthread_cond_broadcast(&event->gtzero);
	}

	pthread_mutex_unlock(&event->lock);

	return(TRUE);
}

BOOL
ResetEvent(xpevent_t event)
{
	if (event==NULL || (event->magic != EVENT_MAGIC)) {
		errno = EINVAL;
		return(FALSE);
	}

	pthread_mutex_lock(&event->lock);

	event->value=FALSE;

	pthread_mutex_unlock(&event->lock);

	return(TRUE);
}

BOOL
CloseEvent(xpevent_t event)
{
	if (event==NULL || (event->magic != EVENT_MAGIC)) {
		errno = EINVAL;
		return(FALSE);
	}

	/* Make sure there are no waiters. */
	pthread_mutex_lock(&event->lock);
	if (event->nwaiters > 0) {
		pthread_mutex_unlock(&event->lock);
		errno = EBUSY;
		return(FALSE);
	}

	pthread_mutex_unlock(&event->lock);

	while(pthread_mutex_destroy(&event->lock)==EBUSY)
		SLEEP(1);
	while(pthread_cond_destroy(&event->gtzero)==EBUSY)
		SLEEP(1);
	event->magic = 0;

	free(event);

	return(TRUE);
}

DWORD
WaitForEvent(xpevent_t event, DWORD ms)
{
	DWORD	retval=WAIT_FAILED;
	struct timespec abstime;
	struct timeval currtime;

	if (event==NULL || (event->magic != EVENT_MAGIC)) {
		errno = EINVAL;
		return(WAIT_FAILED);
	}

	if(ms && ms!=INFINITE) {
		gettimeofday(&currtime,NULL);
		abstime.tv_sec=currtime.tv_sec + (currtime.tv_usec/1000 + ms)/1000;
		abstime.tv_nsec=(currtime.tv_usec*1000 + ms*1000000)%1000000000;
	}
	
	pthread_mutex_lock(&event->lock);

	while (!(event->value)) {
		event->nwaiters++;
		switch(ms) {
			case 0:
				if(event->value)
					retval=0;
				else
					retval=WAIT_TIMEOUT;
				goto DONE;
				break;
			case INFINITE:
				retval=pthread_cond_wait(&event->gtzero, &event->lock);
				break;
			default:
				retval=pthread_cond_timedwait(&event->gtzero, &event->lock, &abstime);
				if(retval)  {
					if(retval==ETIMEDOUT)
						retval=WAIT_TIMEOUT;
					else {
						errno=retval;
						retval=WAIT_FAILED;
					}
					goto DONE;
				}
		}
		event->nwaiters--;
	}

  DONE:

	if(retval==0) {
		retval=WAIT_OBJECT_0;
		if(!event->mreset)
			event->value=FALSE;
	}

	pthread_mutex_unlock(&event->lock);

	return retval;
}
