sysdeps/htl/pt-mutex-transfer-np.c

   1 /* Transfer ownership of a mutex.  Generic version.
   2    Copyright (C) 2008-2020 Free Software Foundation, Inc.
   3    Written by Neal H. Walfield <neal@gnu.org>.
   4
   5    This file is part of the GNU Hurd.
   6
   7    The GNU Hurd is free software; you can redistribute it and/or
   8    modify it under the terms of the GNU Lesser General Public License
   9    as published by the Free Software Foundation; either version 3 of
  10    the License, or (at your option) any later version.
  11
  12    The GNU Hurd is distributed in the hope that it will be useful, but
  13    WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15    Lesser General Public License for more details.
  16
  17    You should have received a copy of the GNU Lesser General Public
  18    License along with this program.  If not, see
  19    <https://www.gnu.org/licenses/>.  */
  20
  21 #include <pthread.h>
  22 #include <assert.h>
  23
  24 #include <pt-internal.h>
  25
  26 int
  27 __pthread_mutex_transfer_np (struct __pthread_mutex *mutex, pthread_t tid)
  28 {
  29   assert (mutex->__owner == _pthread_self ());
  30
  31   struct __pthread *thread = __pthread_getid (tid);
  32   const struct __pthread_mutexattr *attr = mutex->__attr;
  33
  34   if (thread == NULL)
  35     return ESRCH;
  36
  37   if (thread == _pthread_self ())
  38     return 0;
  39
  40   if (attr == __PTHREAD_ERRORCHECK_MUTEXATTR)
  41     attr = &__pthread_errorcheck_mutexattr;
  42   if (attr == __PTHREAD_RECURSIVE_MUTEXATTR)
  43     attr = &__pthread_recursive_mutexattr;
  44
  45   if (attr != NULL && attr->__mutex_type == PTHREAD_MUTEX_ERRORCHECK)
  46     {
  47
  48       if (mutex->__owner != _pthread_self ())
  49         return EPERM;
  50
  51       mutex->__owner = thread;
  52     }
  53
  54 #ifndef NDEBUG
  55 # if !defined(ALWAYS_TRACK_MUTEX_OWNER)
  56   if (attr != NULL && attr->__mutex_type != PTHREAD_MUTEX_NORMAL)
  57 # endif
  58     {
  59       mutex->__owner = thread;
  60     }
  61 #endif
  62
  63   return 0;
  64 }
  65
  66 strong_alias (__pthread_mutex_transfer_np, pthread_mutex_transfer_np)