sysdeps/hppa/nptl/bits/struct_rwlock.h

   1 /* HPPA  internal rwlock struct definitions.
   2    Copyright (C) 2019-2021 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    <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef _RWLOCK_INTERNAL_H
  21 #define _RWLOCK_INTERNAL_H
  22
  23 struct __pthread_rwlock_arch_t
  24 {
  25   /* In the old Linuxthreads pthread_rwlock_t, this is the
  26      start of the 4-word 16-byte aligned lock structure. The
  27      next four words are all set to 1 by the Linuxthreads
  28      PTHREAD_RWLOCK_INITIALIZER. We ignore them in NPTL.  */
  29   int __compat_padding[4] __attribute__ ((__aligned__(16)));
  30   unsigned int __readers;
  31   unsigned int __writers;
  32   unsigned int __wrphase_futex;
  33   unsigned int __writers_futex;
  34   unsigned int __pad3;
  35   unsigned int __pad4;
  36   int __cur_writer;
  37   /* An unused word, reserved for future use. It was added
  38      to maintain the location of the flags from the Linuxthreads
  39      layout of this structure.  */
  40   int __reserved1;
  41   /* FLAGS must stay at this position in the structure to maintain
  42      binary compatibility.  */
  43   unsigned char __pad2;
  44   unsigned char __pad1;
  45   unsigned char __shared;
  46   unsigned char __flags;
  47   /* The NPTL pthread_rwlock_t is 4 words smaller than the
  48      Linuxthreads version. One word is in the middle of the
  49      structure, the other three are at the end.  */
  50   int __reserved2;
  51   int __reserved3;
  52   int __reserved4;
  53 };
  54
  55 #define __PTHREAD_RWLOCK_INITIALIZER(__flags) \
  56   { 0, 0, 0, 0 }, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, __flags, 0, 0, 0
  57
  58 #endif