freebsd-dev/lib/libthr/thread/thr_kern.c
Mike Makonnen 2b33fc6470 Make it possible for the library to specify a timeout value when
waiting on a locked mutex. This involves passing a struct timespec
from the pthread mutex locking interfaces all the way down to the
function that suspends the thread until the mutex is released.
The timeout is assumed to be an absolute time (i.e. not relative to
the current time).

Also, in _thread_suspend() make the passed in timespec const.
2003-12-30 08:34:57 +00:00

147 lines
4.0 KiB
C

/*
* Copyright (c) 2003 Jeffrey Roberson <jeff@freebsd.org>
* 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 unmodified, 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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 <sys/cdefs.h>
#include <sys/types.h>
#include <sys/signalvar.h>
#include <sys/time.h>
#include <sys/timespec.h>
#include <pthread.h>
#include <signal.h>
#include <stdlib.h>
#include <errno.h>
#include <unistd.h>
#include "thr_private.h"
/* XXX Why can't I get this from time.h? :-( */
#define timespecsub(vvp, uvp) \
do { \
(vvp)->tv_sec -= (uvp)->tv_sec; \
(vvp)->tv_nsec -= (uvp)->tv_nsec; \
if ((vvp)->tv_nsec < 0) { \
(vvp)->tv_sec--; \
(vvp)->tv_nsec += 1000000000; \
} \
} while (0)
void
_thread_critical_enter(pthread_t pthread)
{
_thread_sigblock();
UMTX_LOCK(&pthread->lock);
}
void
_thread_critical_exit(pthread_t pthread)
{
UMTX_UNLOCK(&pthread->lock);
_thread_sigunblock();
}
void
_thread_sigblock()
{
sigset_t set;
sigset_t sav;
/*
* Block all signals.
*/
SIGFILLSET(set);
SIGADDSET(set, SIGTHR);
#ifdef _PTHREADS_INVARIANTS
SIGDELSET(set, SIGABRT);
#endif
SIGDELSET(set, SIGTRAP);
/* If we have already blocked signals, just up the refcount */
if (++curthread->signest > 1)
return;
PTHREAD_ASSERT(curthread->signest == 1,
("Blocked signal nesting level must be 1!"));
if (__sys_sigprocmask(SIG_SETMASK, &set, &sav)) {
_thread_printf(STDERR_FILENO, "Critical Enter: sig err %d\n",
errno);
abort();
}
curthread->savedsig = sav;
}
void
_thread_sigunblock()
{
sigset_t set;
/* We might be in a nested 'blocked signal' section */
if (--curthread->signest > 0)
return;
PTHREAD_ASSERT(curthread->signest == 0,
("Non-Zero blocked signal nesting level."));
/*
* Restore signals.
*/
set = curthread->savedsig;
if (__sys_sigprocmask(SIG_SETMASK, &set, NULL)) {
_thread_printf(STDERR_FILENO, "Critical Exit: sig err %d\n",
errno);
abort();
}
}
int
_thread_suspend(pthread_t pthread, const struct timespec *abstime)
{
struct timespec remaining;
struct timespec *ts;
siginfo_t info;
int error;
/*
* Compute the remainder of the run time.
*/
if (abstime) {
struct timespec now;
struct timeval tv;
GET_CURRENT_TOD(tv);
TIMEVAL_TO_TIMESPEC(&tv, &now);
remaining = *abstime;
timespecsub(&remaining, &now);
ts = &remaining;
} else
ts = NULL;
error = sigtimedwait(&_thread_suspend_sigset, &info, ts);
error = (error == -1) ? errno : 0;
return (error);
}