sysdeps/unix/sysv/linux/sysdep-cancel.h

   1 /* Single-thread optimization definitions.  Linux version.
   2    Copyright (C) 2017-2019 Free Software Foundation, Inc.
   3
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <https://www.gnu.org/licenses/>.  */
  19
  20 #ifndef _SYSDEP_CANCEL_H
  21 #define _SYSDEP_CANCEL_H
  22
  23 #include <sysdep.h>
  24 #include <tls.h>
  25 #include <errno.h>
  26
  27 /* The two functions are in libc.so and not exported.  */
  28 extern int __libc_enable_asynccancel (void) attribute_hidden;
  29 extern void __libc_disable_asynccancel (int oldtype) attribute_hidden;
  30
  31 /* The two functions are in librt.so and not exported.  */
  32 extern int __librt_enable_asynccancel (void) attribute_hidden;
  33 extern void __librt_disable_asynccancel (int oldtype) attribute_hidden;
  34
  35 /* The two functions are in libpthread.so and not exported.  */
  36 extern int __pthread_enable_asynccancel (void) attribute_hidden;
  37 extern void __pthread_disable_asynccancel (int oldtype) attribute_hidden;
  38
  39 /* Set cancellation mode to asynchronous.  */
  40 #define CANCEL_ASYNC() \
  41   __pthread_enable_asynccancel ()
  42 /* Reset to previous cancellation mode.  */
  43 #define CANCEL_RESET(oldtype) \
  44   __pthread_disable_asynccancel (oldtype)
  45
  46 #if IS_IN (libc)
  47 /* Same as CANCEL_ASYNC, but for use in libc.so.  */
  48 # define LIBC_CANCEL_ASYNC() \
  49   __libc_enable_asynccancel ()
  50 /* Same as CANCEL_RESET, but for use in libc.so.  */
  51 # define LIBC_CANCEL_RESET(oldtype) \
  52   __libc_disable_asynccancel (oldtype)
  53 #elif IS_IN (libpthread)
  54 # define LIBC_CANCEL_ASYNC() CANCEL_ASYNC ()
  55 # define LIBC_CANCEL_RESET(val) CANCEL_RESET (val)
  56 #elif IS_IN (librt)
  57 # define LIBC_CANCEL_ASYNC() \
  58   __librt_enable_asynccancel ()
  59 # define LIBC_CANCEL_RESET(val) \
  60   __librt_disable_asynccancel (val)
  61 #else
  62 # define LIBC_CANCEL_ASYNC()    0 /* Just a dummy value.  */
  63 # define LIBC_CANCEL_RESET(val) ((void)(val)) /* Nothing, but evaluate it.  */
  64 #endif
  65
  66
  67 #endif