nptl/pthread_rwlock_init.c

   1 /* Copyright (C) 2002-2022 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    <https://www.gnu.org/licenses/>.  */
  17
  18 #include "pthreadP.h"
  19 #include <string.h>
  20 #include <pthread-offsets.h>
  21 #include <shlib-compat.h>
  22
  23 static const struct pthread_rwlockattr default_rwlockattr =
  24   {
  25     .lockkind = PTHREAD_RWLOCK_DEFAULT_NP,
  26     .pshared = PTHREAD_PROCESS_PRIVATE
  27   };
  28
  29
  30 /* See pthread_rwlock_common.c.  */
  31 int
  32 ___pthread_rwlock_init (pthread_rwlock_t *rwlock,
  33                        const pthread_rwlockattr_t *attr)
  34 {
  35   ASSERT_TYPE_SIZE (pthread_rwlock_t, __SIZEOF_PTHREAD_RWLOCK_T);
  36
  37   /* The __flags is the only field where its offset should be checked to
  38      avoid ABI breakage with static initializers.  */
  39   ASSERT_PTHREAD_INTERNAL_OFFSET (pthread_rwlock_t, __data.__flags,
  40                                   __PTHREAD_RWLOCK_FLAGS_OFFSET);
  41   ASSERT_PTHREAD_INTERNAL_MEMBER_SIZE (pthread_rwlock_t, __data.__flags,
  42                                        int);
  43
  44   const struct pthread_rwlockattr *iattr;
  45
  46   iattr = ((const struct pthread_rwlockattr *) attr) ?: &default_rwlockattr;
  47
  48   memset (rwlock, '\0', sizeof (*rwlock));
  49
  50   rwlock->__data.__flags = iattr->lockkind;
  51
  52   /* The value of __SHARED in a private rwlock must be zero.  */
  53   rwlock->__data.__shared = (iattr->pshared != PTHREAD_PROCESS_PRIVATE);
  54
  55   return 0;
  56 }
  57 versioned_symbol (libc, ___pthread_rwlock_init, pthread_rwlock_init,
  58                   GLIBC_2_34);
  59 libc_hidden_ver (___pthread_rwlock_init, __pthread_rwlock_init)
  60 #ifndef SHARED
  61 strong_alias (___pthread_rwlock_init, __pthread_rwlock_init)
  62 #endif
  63
  64 #if OTHER_SHLIB_COMPAT (libpthread, GLIBC_2_1, GLIBC_2_34)
  65 compat_symbol (libpthread, ___pthread_rwlock_init, pthread_rwlock_init,
  66                GLIBC_2_1);
  67 #endif
  68 #if OTHER_SHLIB_COMPAT (libpthread, GLIBC_2_2, GLIBC_2_34)
  69 compat_symbol (libpthread, ___pthread_rwlock_init, __pthread_rwlock_init,
  70                GLIBC_2_2);
  71 #endif