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/* Copyright (C) 2003 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2003.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2.1 of the
License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <setjmp.h>
#include <signal.h>
#include <stdbool.h>
#include <sysdep.h>
#include <kernel-features.h>
#include <nptl/pthreadP.h>
#include "kernel-posix-timers.h"
#ifdef __NR_timer_create
/* Helper thread to call the user-provided function. */
static void *
timer_sigev_thread (void *arg)
{
struct timer *tk = (struct timer *) arg;
/* Call the user-provided function. */
tk->thrfunc (tk->sival);
return NULL;
}
/* Helper function to support starting threads for SIGEV_THREAD. */
static void *
timer_helper_thread (void *arg)
{
/* Block all signals. We will only wait for the signal the kernel
will send. */
sigset_t ss;
sigemptyset (&ss);
sigaddset (&ss, SIGTIMER);
/* SIGTIMER is the same signal as SIGCANCEL and it is therefore
unblocked so far. Block it for this thread, we handle
cancellation explicitly. */
INTERNAL_SYSCALL_DECL (err);
INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_BLOCK, &ss, NULL, _NSIG / 8);
/* Endless loop of waiting for signals. The loop is only ended when
the thread is canceled. */
while (1)
{
siginfo_t si;
if (sigwaitinfo (&ss, &si) > 0)
{
if (si.si_code == SI_TIMER)
{
struct timer *tk = (struct timer *) si.si_ptr;
/* That the signal we are waiting for. */
pthread_t th;
(void) pthread_create (&th, &tk->attr, timer_sigev_thread, tk);
}
else if (si.si_code == SI_TKILL)
/* The thread is canceled. */
pthread_exit (NULL);
}
}
}
/* Control variable for helper thread creation. */
pthread_once_t __helper_once attribute_hidden;
/* TID of the helper thread. */
pid_t __helper_tid attribute_hidden;
/* Reset variables so that after a fork a new helper thread gets started. */
static void
reset_helper_control (void)
{
__helper_once = PTHREAD_ONCE_INIT;
__helper_tid = 0;
}
void
attribute_hidden
__start_helper_thread (void)
{
/* The helper thread needs only very little resources
and should go away automatically when canceled. */
pthread_attr_t attr;
(void) pthread_attr_init (&attr);
(void) pthread_attr_setstacksize (&attr, PTHREAD_STACK_MIN);
/* Create the helper thread for this timer. */
pthread_t th;
int res = pthread_create (&th, &attr, timer_helper_thread, NULL);
if (res == 0)
/* We managed to start the helper thread. */
__helper_tid = ((struct pthread *) th)->tid;
/* No need for the attribute anymore. */
(void) pthread_attr_destroy (&attr);
/* We have to make sure that after fork()ing a new helper thread can
be created. */
pthread_atfork (NULL, NULL, reset_helper_control);
}
#endif
#ifndef __ASSUME_POSIX_TIMERS
# include <nptl/sysdeps/pthread/timer_routines.c>
#endif
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