diff options
Diffstat (limited to 'sysdeps/htl/pt-mutex-unlock.c')
-rw-r--r-- | sysdeps/htl/pt-mutex-unlock.c | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/sysdeps/htl/pt-mutex-unlock.c b/sysdeps/htl/pt-mutex-unlock.c new file mode 100644 index 0000000..e46a913 --- /dev/null +++ b/sysdeps/htl/pt-mutex-unlock.c @@ -0,0 +1,107 @@ +/* Unlock a mutex. Generic version. + Copyright (C) 2000-2018 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If + not, see <http://www.gnu.org/licenses/>. */ + +#include <pthread.h> + +#include <pt-internal.h> + +#define LOSE do { * (int *) 0 = 0; } while (1) + +/* Unlock MUTEX, rescheduling a waiting thread. */ +int +__pthread_mutex_unlock (pthread_mutex_t *mutex) +{ + struct __pthread *wakeup; + const struct __pthread_mutexattr *attr = mutex->__attr; + + if (attr == __PTHREAD_ERRORCHECK_MUTEXATTR) + attr = &__pthread_errorcheck_mutexattr; + if (attr == __PTHREAD_RECURSIVE_MUTEXATTR) + attr = &__pthread_recursive_mutexattr; + + __pthread_spin_lock (&mutex->__lock); + + if (attr == NULL || attr->__mutex_type == PTHREAD_MUTEX_NORMAL) + { +#if defined(ALWAYS_TRACK_MUTEX_OWNER) +# ifndef NDEBUG + if (_pthread_self ()) + { + assert (mutex->__owner); + assert (mutex->__owner == _pthread_self ()); + mutex->__owner = NULL; + } +# endif +#endif + } + else + switch (attr->__mutex_type) + { + case PTHREAD_MUTEX_ERRORCHECK: + case PTHREAD_MUTEX_RECURSIVE: + if (mutex->__owner != _pthread_self ()) + { + __pthread_spin_unlock (&mutex->__lock); + return EPERM; + } + + if (attr->__mutex_type == PTHREAD_MUTEX_RECURSIVE) + if (--mutex->__locks > 0) + { + __pthread_spin_unlock (&mutex->__lock); + return 0; + } + + mutex->__owner = 0; + break; + + default: + LOSE; + } + + + if (mutex->__queue == NULL) + { + __pthread_spin_unlock (&mutex->__held); + __pthread_spin_unlock (&mutex->__lock); + return 0; + } + + wakeup = mutex->__queue; + __pthread_dequeue (wakeup); + +#ifndef NDEBUG +# if !defined (ALWAYS_TRACK_MUTEX_OWNER) + if (attr != NULL && attr->__mutex_type != PTHREAD_MUTEX_NORMAL) +# endif + { + mutex->__owner = wakeup; + } +#endif + + /* We do not unlock MUTEX->held: we are transferring the ownership + to the thread that we are waking up. */ + + __pthread_spin_unlock (&mutex->__lock); + __pthread_wakeup (wakeup); + + return 0; +} + +strong_alias (__pthread_mutex_unlock, _pthread_mutex_unlock); +strong_alias (__pthread_mutex_unlock, pthread_mutex_unlock); |