sysdeps/i386/pthread_spin_trylock.S

   1 /* Copyright (C) 2002-2020 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <pthread-errnos.h>
  20
  21
  22 #ifdef UP
  23 # define LOCK
  24 #else
  25 # define LOCK lock
  26 #endif
  27
  28         .globl  pthread_spin_trylock
  29         .type   pthread_spin_trylock,@function
  30         .align  16
  31 pthread_spin_trylock:
  32         movl    4(%esp), %edx
  33         movl    $1, %eax
  34         xorl    %ecx, %ecx
  35         LOCK
  36         cmpxchgl %ecx, (%edx)
  37         movl    $EBUSY, %eax
  38 #ifdef HAVE_CMOV
  39         cmovel  %ecx, %eax
  40 #else
  41         jne     0f
  42         movl    %ecx, %eax
  43 0:
  44 #endif
  45         ret
  46         .size   pthread_spin_trylock,.-pthread_spin_trylock