1  /* Copyright (C) 2020-2023 Free Software Foundation, Inc.
       2  
       3     This file is part of the GNU Atomic Library (libatomic).
       4  
       5     Libatomic is free software; you can redistribute it and/or modify it
       6     under the terms of the GNU General Public License as published by
       7     the Free Software Foundation; either version 3 of the License, or
       8     (at your option) any later version.
       9  
      10     Libatomic is distributed in the hope that it will be useful, but WITHOUT ANY
      11     WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
      12     FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
      13     more details.
      14  
      15     Under Section 7 of GPL version 3, you are granted additional
      16     permissions described in the GCC Runtime Library Exception, version
      17     3.1, as published by the Free Software Foundation.
      18  
      19     You should have received a copy of the GNU General Public License and
      20     a copy of the GCC Runtime Library Exception along with this program;
      21     see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
      22     <http://www.gnu.org/licenses/>.  */
      23  
      24  /* Functions libat_lock_n/libat_unlock_n based on GOMP_atomic_start/end in
      25     libgomp/atomic.c.  */
      26  
      27  #include "libatomic_i.h"
      28  
      29  static int atomic_lock;
      30  
      31  void
      32  libat_lock_n (void *ptr __attribute__((unused)),
      33  	      size_t n __attribute__((unused)))
      34  {
      35    while (__sync_lock_test_and_set (&atomic_lock, 1))
      36      ;  /* Spin.  */
      37  }
      38  
      39  void
      40  libat_unlock_n (void *ptr __attribute__((unused)),
      41  		size_t n __attribute__((unused)))
      42  {
      43    __sync_lock_release (&atomic_lock);
      44  }
      45  
      46  void
      47  libat_lock_1 (void *ptr)
      48  {
      49    libat_lock_n (ptr, 1);
      50  }
      51  
      52  void
      53  libat_unlock_1 (void *ptr)
      54  {
      55    libat_unlock_n (ptr, 1);
      56  }