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/*
* Copyright (c) 2005 David Xu <davidxu@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 <time.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/signalvar.h>
#include "thr_private.h"
struct timer {
int signo;
union sigval value;
void (*function)(union sigval *);
int exit;
int timerid;
umtx_t lock;
};
extern int __sys_timer_create(clockid_t clockid, struct sigevent *evp,
timer_t *timerid);
static void *timer_loop(void *arg);
__weak_reference(__timer_create, timer_create);
__weak_reference(__timer_create, _timer_create);
#define SIGTIMER SIGCANCEL /* Reuse SIGCANCEL */
/*
* Purpose of the function is to implement POSIX timer's
* SEGEV_THREAD notification mechanism.
*/
int
__timer_create(clockid_t clockid, struct sigevent *evp, timer_t *timerid)
{
struct pthread *curthread = _get_curthread();
pthread_attr_t attr;
struct sigevent ev;
struct timer *tmr;
pthread_t newtd;
sigset_t set, oset;
int ret;
/* Call syscall directly if it is not SIGEV_THREAD */
if (evp == NULL || evp->sigev_notify != SIGEV_THREAD)
return (__sys_timer_create(clockid, evp, timerid));
/* Otherwise, do all magical things. */
tmr = malloc(sizeof(*tmr));
if (__predict_false(tmr == NULL)) {
errno = EAGAIN;
return (-1);
}
tmr->signo = SIGTIMER;
tmr->value = evp->sigev_value;
tmr->function = evp->sigev_notify_function;
tmr->exit = 0;
tmr->timerid = -1;
_thr_umtx_init(&tmr->lock);
pthread_attr_init(&attr);
if (evp->sigev_notify_attributes != NULL) {
*attr = **(pthread_attr_t *)(evp->sigev_notify_attributes);
pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
}
/*
* Lock the mutex, so new thread can not continue until
* we have fully setup it.
*/
THR_UMTX_LOCK(curthread, &tmr->lock);
/*
* Block signal the timer will fire for new thread, new thread
* will use sigwaitinfo, signal action should not be invoked.
*
* Application user: if you want set signal mask for the
* background thread, please call sigprocmask for current before
* calling timer_create, this way, the signal mask will be inherited
* by new thread.
*/
SIGEMPTYSET(set);
SIGADDSET(set, tmr->signo);
__sys_sigprocmask(SIG_BLOCK, &set, &oset);
ret = pthread_create(&newtd, &attr, timer_loop, tmr);
__sys_sigprocmask(SIG_SETMASK, &oset, NULL);
pthread_attr_destroy(&attr);
if (__predict_false(ret != 0)) {
THR_UMTX_UNLOCK(curthread, &tmr->lock);
free(tmr);
errno = ret;
return (-1);
}
/*
* Build a new sigevent, and tell kernel to deliver
* SIGTIMER signal to the new thread.
*/
ev.sigev_notify = SIGEV_THREAD_ID;
ev.sigev_signo = tmr->signo;
ev.sigev_notify_thread_id = (int)newtd->tid;
ev.sigev_value.sigval_ptr = tmr;
ret = __sys_timer_create(clockid, &ev, timerid);
if (ret != 0) {
ret = errno;
tmr->exit = 1;
THR_UMTX_UNLOCK(curthread, &tmr->lock);
pthread_join(newtd, NULL);
errno = ret;
return (-1);
}
tmr->timerid = *timerid;
/*
* As specification says, the service thread should run in
* detached state, so you lose control of the thread!
*/
pthread_detach(newtd);
THR_UMTX_UNLOCK(curthread, &tmr->lock);
return (0);
}
/* Thread function to serve SEGEV_THREAD notifcation. */
static void *
timer_loop(void *arg)
{
struct pthread *curthread = _get_curthread();
struct timer *tmr = arg;
siginfo_t si;
sigset_t set;
THR_UMTX_LOCK(curthread, &tmr->lock);
THR_UMTX_UNLOCK(curthread, &tmr->lock);
SIGEMPTYSET(set);
SIGADDSET(set, tmr->signo);
while (tmr->exit == 0) {
if (__sys_sigwaitinfo(&set, &si) != -1) {
if (si.si_code == SI_TIMER &&
si.si_timerid == tmr->timerid)
tmr->function(&tmr->value);
}
}
free(tmr);
return (0);
}
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