@@ -408,6 +408,9 @@ struct pthread
/* rseq area registered with the kernel. */
struct rseq rseq_area;
+ /* POSIX per-process timer. */
+ int timerid;
+
/* This member must be last. */
char end_padding[];
@@ -99,6 +99,7 @@ include ../Rules
CFLAGS-aio_suspend.c += -fexceptions
CFLAGS-mq_timedreceive.c += -fexceptions -fasynchronous-unwind-tables
CFLAGS-mq_timedsend.c += -fexceptions -fasynchronous-unwind-tables
+CFLAGS-timer_create.c += -fexceptions -fasynchronous-unwind-tables
LDFLAGS-rt.so = -Wl,--enable-new-dtags,-z,nodelete
@@ -29,29 +29,43 @@
static pthread_barrier_t barrier;
+static void
+__attribute_used__
+cl (void *arg)
+{
+ xpthread_barrier_wait (&barrier);
+}
+
static void
thread_handler (union sigval sv)
{
- sigset_t ss;
- sigprocmask (SIG_BLOCK, NULL, &ss);
- if (test_verbose > 0)
- printf ("%s: blocked signal mask = { ", __func__);
- for (int sig = 1; sig < NSIG; sig++)
- {
- /* POSIX timers threads created to handle SIGEV_THREAD block all
- signals except SIGKILL, SIGSTOP and glibc internals ones. */
- if (sigismember (&ss, sig))
- {
- TEST_VERIFY (sig != SIGKILL && sig != SIGSTOP);
- TEST_VERIFY (!is_internal_signal (sig));
- }
- if (test_verbose && sigismember (&ss, sig))
- printf ("%d, ", sig);
- }
- if (test_verbose > 0)
- printf ("}\n");
+ /* POSIX timers threads created to handle SIGEV_THREAD block all
+ signals except SIGKILL, SIGSTOP, and SIGSETXID. */
+ sigset_t expected_set = {
+ .__val = {[0 ... __NSIG_WORDS-1 ] = -1 }
+ };
+ __sigdelset (&expected_set, SIGSETXID);
+ __sigdelset (&expected_set, SIGKILL);
+ __sigdelset (&expected_set, SIGSTOP);
- xpthread_barrier_wait (&barrier);
+ sigset_t ss;
+ sigprocmask (SIG_SETMASK, NULL, &ss);
+
+ TEST_COMPARE_BLOB (&ss.__val, __NSIG_BYTES, &expected_set, __NSIG_BYTES);
+
+ /* Unblock some signals, the signal mask should be reset by the timer_create
+ helper thread. */
+ {
+ sigset_t toset;
+ sigemptyset (&toset);
+ sigaddset (&toset, SIGHUP);
+ sigaddset (&toset, SIGILL);
+ sigprocmask (SIG_UNBLOCK, &toset, NULL);
+ }
+
+ pthread_cleanup_push (cl, NULL);
+ pthread_exit (NULL);
+ pthread_cleanup_pop (0);
}
static int
@@ -66,11 +80,12 @@ do_test (void)
xpthread_barrier_init (&barrier, NULL, 2);
- struct itimerspec trigger = { 0 };
- trigger.it_value.tv_nsec = 1000000;
+ struct itimerspec trigger = { { 0, 1000000 }, { 0, 1000000 } };
TEST_COMPARE (timer_settime (timerid, 0, &trigger, NULL), 0);
- xpthread_barrier_wait (&barrier);
+ enum { TIMERS_TO_CHECK = 2 };
+ for (int i = 0; i < TIMERS_TO_CHECK; i++)
+ xpthread_barrier_wait (&barrier);
return 0;
}
@@ -20,7 +20,6 @@
#define _FORK_H
#include <assert.h>
-#include <kernel-posix-timers.h>
#include <ldsodefs.h>
#include <list.h>
#include <mqueue.h>
@@ -45,7 +44,6 @@ fork_system_setup_after_fork (void)
__default_pthread_attr_lock = LLL_LOCK_INITIALIZER;
call_function_static_weak (__mq_notify_fork_subprocess);
- call_function_static_weak (__timer_fork_subprocess);
}
/* In case of a fork() call the memory allocation in the child will be
@@ -28,48 +28,64 @@
#include <support/xthread.h>
static pthread_barrier_t barrier;
-static pthread_t timer_thread;
+
+#define VALUE1_INITIAL 0
+static __thread unsigned int value1 = VALUE1_INITIAL;
+#define VALUE2_INITIAL 0xdeadbeef
+static __thread unsigned int value2 = VALUE2_INITIAL;
+
+static int cl_called = 0;
static void
cl (void *arg)
{
- xpthread_barrier_wait (&barrier);
+ cl_called++;
+ xpthread_barrier_wait (&barrier); /* 1 */
}
static void
thread_handler (union sigval sv)
{
- timer_thread = pthread_self ();
+ /* Check if thread state is correctly reset after a pthread_exit. */
+ TEST_COMPARE (value1, VALUE1_INITIAL);
+ TEST_COMPARE (value2, VALUE2_INITIAL);
+
+ value1 = VALUE2_INITIAL;
+ value2 = VALUE1_INITIAL;
- xpthread_barrier_wait (&barrier);
+ xpthread_barrier_wait (&barrier); /* 0 */
pthread_cleanup_push (cl, NULL);
- while (1)
- clock_nanosleep (CLOCK_REALTIME, 0, &(struct timespec) { 1, 0 }, NULL);
+ pthread_exit (NULL);
pthread_cleanup_pop (0);
}
static int
do_test (void)
{
- struct sigevent sev = { 0 };
- sev.sigev_notify = SIGEV_THREAD;
- sev.sigev_notify_function = &thread_handler;
+ struct sigevent sev = {
+ .sigev_notify = SIGEV_THREAD,
+ .sigev_notify_function = &thread_handler,
+ };
timer_t timerid;
TEST_COMPARE (timer_create (CLOCK_REALTIME, &sev, &timerid), 0);
xpthread_barrier_init (&barrier, NULL, 2);
- struct itimerspec trigger = { 0 };
- trigger.it_value.tv_nsec = 1000000;
+ struct itimerspec trigger = { { 0, 1000000 }, { 0, 1000000 } };
TEST_COMPARE (timer_settime (timerid, 0, &trigger, NULL), 0);
- xpthread_barrier_wait (&barrier);
+ enum { TIMERS_TO_CHECK = 4 };
+ for (int i = 0; i < TIMERS_TO_CHECK; i++)
+ {
+ /* Check the thread local values. */
+ xpthread_barrier_wait (&barrier); /* 0 */
- xpthread_cancel (timer_thread);
+ xpthread_barrier_wait (&barrier); /* 1 */
+ }
- xpthread_barrier_wait (&barrier);
+ TEST_COMPARE (cl_called, TIMERS_TO_CHECK);
return 0;
}
@@ -99,12 +99,4 @@ static const sigset_t sigtimer_set = {
}
};
-/* Unblock only SIGTIMER. */
-static inline void
-signal_unblock_sigtimer (void)
-{
- INTERNAL_SYSCALL_CALL (rt_sigprocmask, SIG_UNBLOCK, &sigtimer_set, NULL,
- __NSIG_BYTES);
-}
-
#endif
@@ -8,6 +8,8 @@
- A clockid is invalid if bits 2, 1, and 0 are all set.
*/
+#include <time.h>
+
#define CPUCLOCK_PID(clock) ((pid_t) ~((clock) >> 3))
#define CPUCLOCK_PERTHREAD(clock) \
(((clock) & (clockid_t) CPUCLOCK_PERTHREAD_MASK) != 0)
@@ -19,29 +19,7 @@
#include <setjmp.h>
#include <signal.h>
#include <sys/types.h>
-
-
-/* Nonzero if the system calls are not available. */
-extern int __no_posix_timers attribute_hidden;
-
-/* Callback to start helper thread. */
-extern void __timer_start_helper_thread (void) attribute_hidden;
-
-/* Control variable for helper thread creation. */
-extern pthread_once_t __timer_helper_once attribute_hidden;
-
-/* Called from fork so that the new subprocess re-creates the
- notification thread if necessary. */
-void __timer_fork_subprocess (void) attribute_hidden;
-
-/* TID of the helper thread. */
-extern pid_t __timer_helper_tid attribute_hidden;
-
-/* List of active SIGEV_THREAD timers. */
-extern struct timer *__timer_active_sigev_thread attribute_hidden;
-
-/* Lock for __timer_active_sigev_thread. */
-extern pthread_mutex_t __timer_active_sigev_thread_lock attribute_hidden;
+#include <nptl/descr.h>
extern __typeof (timer_create) __timer_create;
libc_hidden_proto (__timer_create)
@@ -53,25 +31,9 @@ libc_hidden_proto (__timer_getoverrun)
/* Type of timers in the kernel. */
typedef int kernel_timer_t;
-/* Internal representation of SIGEV_THREAD timer. */
-struct timer
-{
- kernel_timer_t ktimerid;
-
- void (*thrfunc) (sigval_t);
- sigval_t sival;
- pthread_attr_t attr;
-
- /* Next element in list of active SIGEV_THREAD timers. */
- struct timer *next;
-};
-
-
/* For !SIGEV_THREAD, the resulting 'timer_t' is the returned kernel timer
- identifier (kernel_timer_t), while for SIGEV_THREAD it uses the fact malloc
- returns at least _Alignof (max_align_t) pointers plus that valid
- kernel_timer_t are always positive to set the MSB bit of the returned
- 'timer_t' to indicate the timer handles a SIGEV_THREAD. */
+ identifier (kernel_timer_t), while for SIGEV_THREAD it assumes the
+ pthread_t is always 8-byte aligned. */
static inline timer_t
kernel_timer_to_timerid (kernel_timer_t ktimerid)
@@ -80,7 +42,7 @@ kernel_timer_to_timerid (kernel_timer_t ktimerid)
}
static inline timer_t
-timer_to_timerid (struct timer *ptr)
+pthread_to_timerid (pthread_t ptr)
{
return (timer_t) (INTPTR_MIN | (uintptr_t) ptr >> 1);
}
@@ -91,17 +53,17 @@ timer_is_sigev_thread (timer_t timerid)
return (intptr_t) timerid < 0;
}
-static inline struct timer *
-timerid_to_timer (timer_t timerid)
+static inline struct pthread *
+timerid_to_pthread (timer_t timerid)
{
- return (struct timer *)((uintptr_t) timerid << 1);
+ return (struct pthread *)((uintptr_t) timerid << 1);
}
static inline kernel_timer_t
timerid_to_kernel_timer (timer_t timerid)
{
if (timer_is_sigev_thread (timerid))
- return timerid_to_timer (timerid)->ktimerid;
+ return timerid_to_pthread (timerid)->timerid;
else
return (kernel_timer_t) ((uintptr_t) timerid);
}
@@ -15,46 +15,200 @@
License along with the GNU C Library; see the file COPYING.LIB. If
not, see <https://www.gnu.org/licenses/>. */
-#include <errno.h>
-#include <pthread.h>
-#include <signal.h>
-#include <stdlib.h>
-#include <string.h>
-#include <time.h>
-#include <sysdep.h>
-#include <internaltypes.h>
+#include <jmpbuf-unwind.h>
+#include <kernel-posix-cpu-timers.h>
+#include <kernel-posix-timers.h>
+#include <ldsodefs.h>
+#include <libc-internal.h>
+#include <libc-lock.h>
#include <pthreadP.h>
-#include "kernel-posix-timers.h"
-#include "kernel-posix-cpu-timers.h"
#include <shlib-compat.h>
+struct timer_helper_thread_args_t
+{
+ /* The barrier is used to synchronize the arguments copy from timer_create
+ and the SIGEV_THREAD thread and to instruct the thread to exit if the
+ timer_create syscall fails. */
+ pthread_barrier_t b;
+ struct sigevent *evp;
+};
+
+struct cleanup_args_t
+{
+ struct pthread_unwind_buf *cleanup_jmp_buf;
+ jmp_buf jb;
+};
+
+/* Reset internal thread state if the callback issues pthread_exit. It avoids
+ recreating the thread and having possible unreported missed events due
+ thread creation failure. */
+static void
+timer_helper_thread_cleanup (void *arg)
+{
+ struct pthread *self = THREAD_SELF;
+
+ /* Call destructors for the thread_local TLS variables. */
+#ifndef SHARED
+ if (&__call_tls_dtors != NULL)
+#endif
+ __call_tls_dtors ();
+
+ /* Run the destructor for the thread-local data. */
+ __nptl_deallocate_tsd ();
+
+ /* Clean up any state libc stored in thread-local variables. */
+ __libc_thread_freeres ();
+
+ /* Reset internal TCB state. */
+ struct cleanup_args_t *args = arg;
+ self->cleanup_jmp_buf = args->cleanup_jmp_buf;
+ self->cleanup_jmp_buf->priv.data.prev = NULL;
+ self->cleanup_jmp_buf->priv.data.cleanup = NULL;
+ self->cleanup_jmp_buf->priv.data.canceltype = 0;
+ self->cleanup = NULL;
+ self->exc = (struct _Unwind_Exception) { 0 };
+ self->cancelhandling = 0;
+ self->nextevent = NULL;
+
+ /* Re-initialize the TLS. */
+ _dl_allocate_tls_init (TLS_TPADJ (self), true);
+
+ /* Reset to the expected initial signal mask. */
+ internal_sigset_t ss;
+ internal_sigfillset (&ss);
+ internal_sigdelset (&ss, SIGSETXID);
+ internal_sigprocmask (SIG_SETMASK, &ss, NULL);
+
+ /* There is no need to perform any additional cleanup by the frames. */
+ struct __jmp_buf_tag *env = args->jb;
+ __longjmp (env[0].__jmpbuf, 1);
+}
+
+static void *
+timer_helper_thread (void *arg)
+{
+ struct pthread *self = THREAD_SELF;
+
+ struct timer_helper_thread_args_t *args = arg;
+
+ void (*thrfunc) (sigval_t) = args->evp->sigev_notify_function;
+ sigval_t sival = args->evp->sigev_value;
+ __pthread_barrier_wait (&args->b);
+
+ /* timer_create syscall failed. */
+ if (self->timerid < 0)
+ return 0;
+
+ struct cleanup_args_t clargs = {
+ .cleanup_jmp_buf = self->cleanup_jmp_buf
+ };
+
+ while (1)
+ {
+ siginfo_t si;
+ while (__sigwaitinfo (&sigtimer_set, &si) < 0) {};
+
+ if (si.si_code == SI_TIMER && !setjmp (clargs.jb))
+ {
+ pthread_cleanup_push (timer_helper_thread_cleanup, &clargs);
+ thrfunc (sival);
+ pthread_cleanup_pop (0);
+ }
+
+ /* timer_delete will set the MSB and signal the thread. */
+ if (atomic_load_relaxed (&self->timerid) < 0)
+ break;
+ }
+
+ /* Clear the MSB bit set by timer_delete. */
+ INTERNAL_SYSCALL_CALL (timer_delete, self->timerid & INT_MAX);
+
+ return NULL;
+}
+
+static int
+timer_create_sigev_thread (clockid_t syscall_clockid, struct sigevent *evp,
+ timer_t *timerid)
+{
+ int ret = -1;
+
+ pthread_attr_t attr;
+ if (evp->sigev_notify_attributes != NULL)
+ __pthread_attr_copy (&attr, evp->sigev_notify_attributes);
+ else
+ __pthread_attr_init (&attr);
+ __pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
+
+ /* Block all signals in the helper thread but SIGSETXID. */
+ sigset_t ss;
+ __sigfillset (&ss);
+ __sigdelset (&ss, SIGSETXID);
+ ret = __pthread_attr_setsigmask_internal (&attr, &ss);
+ if (ret != 0)
+ goto out;
+
+ struct timer_helper_thread_args_t args;
+ __pthread_barrier_init (&args.b, NULL, 2);
+ args.evp = evp;
+
+ pthread_t th;
+ ret = __pthread_create (&th, &attr, timer_helper_thread, &args);
+ if (ret != 0)
+ {
+ __set_errno (ret);
+ goto out;
+ }
+
+ struct sigevent kevp = {
+ .sigev_value.sival_ptr = NULL,
+ .sigev_signo = SIGTIMER,
+ .sigev_notify = SIGEV_THREAD_ID,
+ ._sigev_un = { ._pad = { [0] = ((struct pthread *)th)->tid } }
+ };
+
+ struct pthread *pthr = (struct pthread *)th;
+
+ kernel_timer_t ktimerid;
+ if (INLINE_SYSCALL_CALL (timer_create, syscall_clockid, &kevp, &ktimerid) < 0)
+ pthr->timerid = -1;
+ pthr->timerid = ktimerid;
+ /* Signal the thread to continue execution after it copies the arguments
+ or exit if the timer can not be created. */
+ __pthread_barrier_wait (&args.b);
+
+ if (timerid >= 0)
+ *timerid = pthread_to_timerid (th);
+
+ ret = 0;
+out:
+ if (&attr != evp->sigev_notify_attributes)
+ __pthread_attr_destroy (&attr);
+
+ return ret;
+}
+
int
___timer_create (clockid_t clock_id, struct sigevent *evp, timer_t *timerid)
{
- {
- clockid_t syscall_clockid = (clock_id == CLOCK_PROCESS_CPUTIME_ID
- ? PROCESS_CLOCK
- : clock_id == CLOCK_THREAD_CPUTIME_ID
- ? THREAD_CLOCK
- : clock_id);
-
- /* If the user wants notification via a thread we need to handle
- this special. */
- if (evp == NULL
- || __builtin_expect (evp->sigev_notify != SIGEV_THREAD, 1))
- {
- struct sigevent local_evp;
+ clockid_t syscall_clockid = (clock_id == CLOCK_PROCESS_CPUTIME_ID
+ ? PROCESS_CLOCK
+ : clock_id == CLOCK_THREAD_CPUTIME_ID
+ ? THREAD_CLOCK
+ : clock_id);
+ switch (evp != NULL ? evp->sigev_notify : SIGEV_SIGNAL)
+ {
+ case SIGEV_NONE:
+ case SIGEV_SIGNAL:
+ case SIGEV_THREAD_ID:
+ {
+ struct sigevent kevp;
if (evp == NULL)
{
- /* The kernel has to pass up the timer ID which is a
- userlevel object. Therefore we cannot leave it up to
- the kernel to determine it. */
- local_evp.sigev_notify = SIGEV_SIGNAL;
- local_evp.sigev_signo = SIGALRM;
- local_evp.sigev_value.sival_ptr = NULL;
-
- evp = &local_evp;
+ kevp.sigev_notify = SIGEV_SIGNAL;
+ kevp.sigev_signo = SIGALRM;
+ kevp.sigev_value.sival_ptr = NULL;
+ evp = &kevp;
}
kernel_timer_t ktimerid;
@@ -64,75 +218,15 @@ ___timer_create (clockid_t clock_id, struct sigevent *evp, timer_t *timerid)
*timerid = kernel_timer_to_timerid (ktimerid);
}
- else
- {
- /* Create the helper thread. */
- __pthread_once (&__timer_helper_once, __timer_start_helper_thread);
- if (__timer_helper_tid == 0)
- {
- /* No resources to start the helper thread. */
- __set_errno (EAGAIN);
- return -1;
- }
-
- struct timer *newp = malloc (sizeof (struct timer));
- if (newp == NULL)
- return -1;
-
- /* Copy the thread parameters the user provided. */
- newp->sival = evp->sigev_value;
- newp->thrfunc = evp->sigev_notify_function;
-
- /* We cannot simply copy the thread attributes since the
- implementation might keep internal information for
- each instance. */
- __pthread_attr_init (&newp->attr);
- if (evp->sigev_notify_attributes != NULL)
- {
- struct pthread_attr *nattr;
- struct pthread_attr *oattr;
-
- nattr = (struct pthread_attr *) &newp->attr;
- oattr = (struct pthread_attr *) evp->sigev_notify_attributes;
-
- nattr->schedparam = oattr->schedparam;
- nattr->schedpolicy = oattr->schedpolicy;
- nattr->flags = oattr->flags;
- nattr->guardsize = oattr->guardsize;
- nattr->stackaddr = oattr->stackaddr;
- nattr->stacksize = oattr->stacksize;
- }
-
- /* In any case set the detach flag. */
- __pthread_attr_setdetachstate (&newp->attr, PTHREAD_CREATE_DETACHED);
-
- /* Create the event structure for the kernel timer. */
- struct sigevent sev =
- { .sigev_value.sival_ptr = newp,
- .sigev_signo = SIGTIMER,
- .sigev_notify = SIGEV_SIGNAL | SIGEV_THREAD_ID,
- ._sigev_un = { ._pad = { [0] = __timer_helper_tid } } };
-
- /* Create the timer. */
- int res;
- res = INTERNAL_SYSCALL_CALL (timer_create, syscall_clockid, &sev,
- &newp->ktimerid);
- if (INTERNAL_SYSCALL_ERROR_P (res))
- {
- free (newp);
- __set_errno (INTERNAL_SYSCALL_ERRNO (res));
- return -1;
- }
-
- /* Add to the queue of active timers with thread delivery. */
- __pthread_mutex_lock (&__timer_active_sigev_thread_lock);
- newp->next = __timer_active_sigev_thread;
- __timer_active_sigev_thread = newp;
- __pthread_mutex_unlock (&__timer_active_sigev_thread_lock);
-
- *timerid = timer_to_timerid (newp);
- }
- }
+ break;
+ case SIGEV_THREAD:
+ if (timer_create_sigev_thread (syscall_clockid, evp, timerid) < 0)
+ return -1;
+ break;
+ default:
+ __set_errno (EINVAL);
+ return -1;
+ }
return 0;
}
@@ -26,42 +26,17 @@
int
___timer_delete (timer_t timerid)
{
- kernel_timer_t ktimerid = timerid_to_kernel_timer (timerid);
- int res = INLINE_SYSCALL_CALL (timer_delete, ktimerid);
-
- if (res == 0)
+ if (timer_is_sigev_thread (timerid))
{
- if (timer_is_sigev_thread (timerid))
- {
- struct timer *kt = timerid_to_timer (timerid);
-
- /* Remove the timer from the list. */
- __pthread_mutex_lock (&__timer_active_sigev_thread_lock);
- if (__timer_active_sigev_thread == kt)
- __timer_active_sigev_thread = kt->next;
- else
- {
- struct timer *prevp = __timer_active_sigev_thread;
- while (prevp->next != NULL)
- if (prevp->next == kt)
- {
- prevp->next = kt->next;
- break;
- }
- else
- prevp = prevp->next;
- }
- __pthread_mutex_unlock (&__timer_active_sigev_thread_lock);
-
- free (kt);
- }
+ struct pthread *th = timerid_to_pthread (timerid);
+ /* The helper thread itself will be responsible to call the
+ timer_delete syscall. */
+ atomic_fetch_or_relaxed (&th->timerid, INT_MIN);
+ __pthread_kill_internal ((pthread_t) th, SIGTIMER);
return 0;
}
-
- /* The kernel timer is not known or something else bad happened.
- Return the error. */
- return -1;
+ return INLINE_SYSCALL_CALL (timer_delete, timerid);
}
versioned_symbol (libc, ___timer_delete, timer_delete, GLIBC_2_34);
libc_hidden_ver (___timer_delete, __timer_delete)
@@ -1,154 +1 @@
-/* Copyright (C) 2003-2023 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
-
- 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, see <https://www.gnu.org/licenses/>. */
-
-#include <errno.h>
-#include <setjmp.h>
-#include <signal.h>
-#include <stdbool.h>
-#include <sysdep-cancel.h>
-#include <pthreadP.h>
-#include "kernel-posix-timers.h"
-
-
-/* List of active SIGEV_THREAD timers. */
-struct timer *__timer_active_sigev_thread;
-
-/* Lock for _timer_active_sigev_thread. */
-pthread_mutex_t __timer_active_sigev_thread_lock = PTHREAD_MUTEX_INITIALIZER;
-
-struct thread_start_data
-{
- void (*thrfunc) (sigval_t);
- sigval_t sival;
-};
-
-
-/* Helper thread to call the user-provided function. */
-static void *
-timer_sigev_thread (void *arg)
-{
- signal_unblock_sigtimer ();
-
- struct thread_start_data *td = (struct thread_start_data *) arg;
- void (*thrfunc) (sigval_t) = td->thrfunc;
- sigval_t sival = td->sival;
-
- /* The TD object was allocated in timer_helper_thread. */
- free (td);
-
- /* Call the user-provided function. */
- thrfunc (sival);
-
- return NULL;
-}
-
-
-/* Helper function to support starting threads for SIGEV_THREAD. */
-static _Noreturn void *
-timer_helper_thread (void *arg)
-{
- /* Endless loop of waiting for signals. The loop is only ended when
- the thread is canceled. */
- while (1)
- {
- siginfo_t si;
-
- while (__sigwaitinfo (&sigtimer_set, &si) < 0);
- if (si.si_code == SI_TIMER)
- {
- struct timer *tk = (struct timer *) si.si_ptr;
-
- /* Check the timer is still used and will not go away
- while we are reading the values here. */
- __pthread_mutex_lock (&__timer_active_sigev_thread_lock);
-
- struct timer *runp = __timer_active_sigev_thread;
- while (runp != NULL)
- if (runp == tk)
- break;
- else
- runp = runp->next;
-
- if (runp != NULL)
- {
- struct thread_start_data *td = malloc (sizeof (*td));
-
- /* There is not much we can do if the allocation fails. */
- if (td != NULL)
- {
- /* This is the signal we are waiting for. */
- td->thrfunc = tk->thrfunc;
- td->sival = tk->sival;
-
- pthread_t th;
- __pthread_create (&th, &tk->attr, timer_sigev_thread, td);
- }
- }
-
- __pthread_mutex_unlock (&__timer_active_sigev_thread_lock);
- }
- }
-}
-
-
-/* Control variable for helper thread creation. */
-pthread_once_t __timer_helper_once = PTHREAD_ONCE_INIT;
-
-
-/* TID of the helper thread. */
-pid_t __timer_helper_tid;
-
-
-/* Reset variables so that after a fork a new helper thread gets started. */
-void
-__timer_fork_subprocess (void)
-{
- __timer_helper_once = PTHREAD_ONCE_INIT;
- __timer_helper_tid = 0;
-}
-
-
-void
-__timer_start_helper_thread (void)
-{
- /* The helper thread needs only very little resources
- and should go away automatically when canceled. */
- pthread_attr_t attr;
- __pthread_attr_init (&attr);
- __pthread_attr_setstacksize (&attr, __pthread_get_minstack (&attr));
-
- /* Block all signals in the helper thread but SIGSETXID. */
- sigset_t ss;
- __sigfillset (&ss);
- __sigdelset (&ss, SIGSETXID);
- int res = __pthread_attr_setsigmask_internal (&attr, &ss);
- if (res != 0)
- {
- __pthread_attr_destroy (&attr);
- return;
- }
-
- /* Create the helper thread for this timer. */
- pthread_t th;
- res = __pthread_create (&th, &attr, timer_helper_thread, NULL);
- if (res == 0)
- /* We managed to start the helper thread. */
- __timer_helper_tid = ((struct pthread *) th)->tid;
-
- /* No need for the attribute anymore. */
- __pthread_attr_destroy (&attr);
-}
+/* Empty. */