event.c

xenomai 很好的linux实时补丁

/*
 * Copyright (C) 2001,2002,2003 Philippe Gerum <[e-mail]>.
 *
 * Xenomai is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published
 * by the Free Software Foundation; either version 2 of the License,
 * or (at your option) any later version.
 *
 * Xenomai is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Xenomai; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 */

#include "psos+/task.h"

void ev_init (psosevent_t *evgroup)

{
    xnsynch_init(&evgroup->synchbase,XNSYNCH_FIFO);
    evgroup->events = 0;
}

void ev_destroy (psosevent_t *evgroup)

{
    if (xnsynch_destroy(&evgroup->synchbase) == XNSYNCH_RESCHED)
	xnpod_schedule();
}

u_long ev_receive (u_long events,
		   u_long flags,
		   u_long timeout,
		   u_long *events_r)
{
    psosevent_t *evgroup;
    u_long err = SUCCESS;
    spl_t s;

    xnpod_check_context(XNPOD_THREAD_CONTEXT);

    xnlock_get_irqsave(&nklock,s);

    evgroup = &psos_current_task()->evgroup;

    if (!events)
	{
	*events_r = evgroup->events;
	goto unlock_and_exit;
	}
	    
    if (flags & EV_NOWAIT)
	{
	u_long bits = (evgroup->events & events);
	evgroup->events &= ~events;
	*events_r = bits;

	if (flags & EV_ANY)
	    {
	    if (!bits)
		err = ERR_NOEVS;
	    }
	else if (bits != events)
	    err =  ERR_NOEVS;

	goto unlock_and_exit;
	}
    
    if (((flags & EV_ANY) && (events & evgroup->events) != 0) ||
	(!(flags & EV_ANY) && ((events & evgroup->events) == events)))
	{
	*events_r = (evgroup->events & events);
	evgroup->events &= ~events;
	goto unlock_and_exit;
	}

    psos_current_task()->waitargs.evgroup.flags = flags;
    psos_current_task()->waitargs.evgroup.events = events;
    xnsynch_sleep_on(&evgroup->synchbase,timeout);

    if (xnthread_test_flags(&psos_current_task()->threadbase,XNTIMEO))
	{
	*events_r = psos_current_task()->waitargs.evgroup.events;
	err = ERR_TIMEOUT;
	}
    else
	*events_r = psos_current_task()->waitargs.evgroup.events;

 unlock_and_exit:

    xnlock_put_irqrestore(&nklock,s);

    return err;
}

u_long ev_send (u_long tid,
		u_long events)
{
    u_long err = SUCCESS;
    psosevent_t *evgroup;
    psostask_t *task;
    spl_t s;

    xnlock_get_irqsave(&nklock,s);

    task = psos_h2obj_active(tid,PSOS_TASK_MAGIC,psostask_t);

    if (!task)
	{
	err = psos_handle_error(tid,PSOS_TASK_MAGIC,psostask_t);
	goto unlock_and_exit;
	}

    evgroup = &task->evgroup;
    evgroup->events |= events;

    /* Only the task to which the event group pertains can
       pend on it. */

    if (countpq(xnsynch_wait_queue(&evgroup->synchbase)) > 0)
	{
	u_long flags = task->waitargs.evgroup.flags;
	u_long bits = task->waitargs.evgroup.events;

	if (((flags & EV_ANY) && (bits & evgroup->events) != 0) ||
	    (!(flags & EV_ANY) && ((bits & evgroup->events) == bits)))
	    {
	    xnsynch_wakeup_one_sleeper(&evgroup->synchbase);
	    task->waitargs.evgroup.events = (bits & evgroup->events);
	    evgroup->events &= ~bits;
	    xnpod_schedule();
	    }
	}

 unlock_and_exit:

    xnlock_put_irqrestore(&nklock,s);

    return err;
}