freebsd-nq/lib/libkse/thread/thr_yield.c
David Xu e81bbed597 Treat initial thread as scope system thread when KSE mode is not activated
yet, so we can protect some locking code from being interrupted by signal
handling. When KSE mode is turned on, reset the thread flag to scope process
except we are running in 1:1 mode which we needn't turn it off.
Also remove some unused member variables in structure kse.

Tested by: deischen
2003-08-18 03:58:29 +00:00

74 lines
2.6 KiB
C

/*
* Copyright (c) 1995 John Birrell <jb@cimlogic.com.au>.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by John Birrell.
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <pthread.h>
#include "thr_private.h"
__weak_reference(_sched_yield, sched_yield);
__weak_reference(_pthread_yield, pthread_yield);
int
_sched_yield(void)
{
struct pthread *curthread = _get_curthread();
if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM)
return (__sys_sched_yield());
/* Reset the accumulated time slice value for the current thread: */
curthread->slice_usec = -1;
/* Schedule the next thread: */
_thr_sched_switch(curthread);
/* Always return no error. */
return(0);
}
/* Draft 4 yield */
void
_pthread_yield(void)
{
struct pthread *curthread = _get_curthread();
if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM) {
__sys_sched_yield();
return;
}
/* Reset the accumulated time slice value for the current thread: */
curthread->slice_usec = -1;
/* Schedule the next thread: */
_thr_sched_switch(curthread);
}