sysdeps/unix/sysv/linux/aio_misc.h

   1 /* Copyright (C) 2004-2024 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public License as
   6    published by the Free Software Foundation; either version 2.1 of the
   7    License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If
  16    not, see <https://www.gnu.org/licenses/>.  */
  17
  18 #ifndef _AIO_MISC_H
  19 # include_next <aio_misc.h>
  20 # include <limits.h>
  21 # include <pthread.h>
  22 # include <signal.h>
  23 # include <sysdep.h>
  24
  25 # define aio_start_notify_thread __aio_start_notify_thread
  26 # define aio_create_helper_thread __aio_create_helper_thread
  27
  28 extern inline void
  29 __aio_start_notify_thread (void)
  30 {
  31   sigset_t ss;
  32   sigemptyset (&ss);
  33   INTERNAL_SYSCALL_CALL (rt_sigprocmask, SIG_SETMASK, &ss, NULL,
  34                          __NSIG_BYTES);
  35 }
  36
  37 extern inline int
  38 __aio_create_helper_thread (pthread_t *threadp, void *(*tf) (void *),
  39                             void *arg)
  40 {
  41   pthread_attr_t attr;
  42
  43   /* Make sure the thread is created detached.  */
  44   __pthread_attr_init (&attr);
  45   __pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
  46
  47   /* The helper thread needs only very little resources.  */
  48   __pthread_attr_setstacksize (&attr, __pthread_get_minstack (&attr));
  49
  50   /* Block all signals in the helper thread.  To do this thoroughly we
  51      temporarily have to block all signals here.  */
  52   sigset_t ss;
  53   sigset_t oss;
  54   sigfillset (&ss);
  55   INTERNAL_SYSCALL_CALL (rt_sigprocmask, SIG_SETMASK, &ss, &oss,
  56                          __NSIG_BYTES);
  57
  58   int ret = __pthread_create (threadp, &attr, tf, arg);
  59
  60   /* Restore the signal mask.  */
  61   INTERNAL_SYSCALL_CALL (rt_sigprocmask, SIG_SETMASK, &oss, NULL,
  62                          __NSIG_BYTES);
  63
  64   __pthread_attr_destroy (&attr);
  65   return ret;
  66 }
  67 #endif