sysdeps/i386/nptl/pthread_spin_lock.S

   1 /* Copyright (C) 2012-2018 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
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the 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; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <lowlevellock.h>
  19
  20         .globl  pthread_spin_lock
  21         .type   pthread_spin_lock,@function
  22         .align  16
  23 pthread_spin_lock:
  24         mov     4(%esp), %eax
  25 1:      LOCK
  26         decl    0(%eax)
  27         jne     2f
  28         xor     %eax, %eax
  29         ret
  30
  31         .align  16
  32 2:      rep
  33         nop
  34         cmpl    $0, 0(%eax)
  35         jg      1b
  36         jmp     2b
  37         .size   pthread_spin_lock,.-pthread_spin_lock