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/* Copyright (C) 2002, 2003, 2005, 2006 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <errno.h>
#include <stdlib.h>
#include "pthreadP.h"
#include <lowlevellock.h>
int
internal_function attribute_hidden
__pthread_mutex_unlock_usercnt (mutex, decr)
pthread_mutex_t *mutex;
int decr;
{
int newowner = 0;
switch (__builtin_expect (mutex->__data.__kind, PTHREAD_MUTEX_TIMED_NP))
{
case PTHREAD_MUTEX_RECURSIVE_NP:
/* Recursive mutex. */
if (mutex->__data.__owner != THREAD_GETMEM (THREAD_SELF, tid))
return EPERM;
if (--mutex->__data.__count != 0)
/* We still hold the mutex. */
return 0;
goto normal;
case PTHREAD_MUTEX_ERRORCHECK_NP:
/* Error checking mutex. */
if (mutex->__data.__owner != THREAD_GETMEM (THREAD_SELF, tid)
|| ! lll_mutex_islocked (mutex->__data.__lock))
return EPERM;
/* FALLTHROUGH */
case PTHREAD_MUTEX_TIMED_NP:
case PTHREAD_MUTEX_ADAPTIVE_NP:
/* Always reset the owner field. */
normal:
mutex->__data.__owner = 0;
if (decr)
/* One less user. */
--mutex->__data.__nusers;
/* Unlock. */
lll_mutex_unlock (mutex->__data.__lock);
break;
case PTHREAD_MUTEX_ROBUST_RECURSIVE_NP:
/* Recursive mutex. */
if ((mutex->__data.__lock & FUTEX_TID_MASK)
== THREAD_GETMEM (THREAD_SELF, tid)
&& __builtin_expect (mutex->__data.__owner
== PTHREAD_MUTEX_INCONSISTENT, 0))
{
if (--mutex->__data.__count != 0)
/* We still hold the mutex. */
return ENOTRECOVERABLE;
goto notrecoverable;
}
if (mutex->__data.__owner != THREAD_GETMEM (THREAD_SELF, tid))
return EPERM;
if (--mutex->__data.__count != 0)
/* We still hold the mutex. */
return 0;
goto robust;
case PTHREAD_MUTEX_ROBUST_ERRORCHECK_NP:
case PTHREAD_MUTEX_ROBUST_NORMAL_NP:
case PTHREAD_MUTEX_ROBUST_ADAPTIVE_NP:
if ((mutex->__data.__lock & FUTEX_TID_MASK)
!= THREAD_GETMEM (THREAD_SELF, tid)
|| ! lll_mutex_islocked (mutex->__data.__lock))
return EPERM;
/* If the previous owner died and the caller did not succeed in
making the state consistent, mark the mutex as unrecoverable
and make all waiters. */
if (__builtin_expect (mutex->__data.__owner
== PTHREAD_MUTEX_INCONSISTENT, 0))
notrecoverable:
newowner = PTHREAD_MUTEX_NOTRECOVERABLE;
robust:
/* Remove mutex from the list. */
THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending,
&mutex->__data.__list.__next);
DEQUEUE_MUTEX (mutex);
mutex->__data.__owner = newowner;
if (decr)
/* One less user. */
--mutex->__data.__nusers;
/* Unlock. */
lll_robust_mutex_unlock (mutex->__data.__lock);
THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
break;
case PTHREAD_MUTEX_PI_RECURSIVE_NP:
/* Recursive mutex. */
if (mutex->__data.__owner != THREAD_GETMEM (THREAD_SELF, tid))
return EPERM;
if (--mutex->__data.__count != 0)
/* We still hold the mutex. */
return 0;
goto continue_pi;
case PTHREAD_MUTEX_PI_ROBUST_RECURSIVE_NP:
/* Recursive mutex. */
if ((mutex->__data.__lock & FUTEX_TID_MASK)
== THREAD_GETMEM (THREAD_SELF, tid)
&& __builtin_expect (mutex->__data.__owner
== PTHREAD_MUTEX_INCONSISTENT, 0))
{
if (--mutex->__data.__count != 0)
/* We still hold the mutex. */
return ENOTRECOVERABLE;
goto pi_notrecoverable;
}
if (mutex->__data.__owner != THREAD_GETMEM (THREAD_SELF, tid))
return EPERM;
if (--mutex->__data.__count != 0)
/* We still hold the mutex. */
return 0;
goto continue_pi;
case PTHREAD_MUTEX_PI_ERRORCHECK_NP:
case PTHREAD_MUTEX_PI_NORMAL_NP:
case PTHREAD_MUTEX_PI_ADAPTIVE_NP:
case PTHREAD_MUTEX_PI_ROBUST_ERRORCHECK_NP:
case PTHREAD_MUTEX_PI_ROBUST_NORMAL_NP:
case PTHREAD_MUTEX_PI_ROBUST_ADAPTIVE_NP:
if ((mutex->__data.__lock & FUTEX_TID_MASK)
!= THREAD_GETMEM (THREAD_SELF, tid)
|| ! lll_mutex_islocked (mutex->__data.__lock))
return EPERM;
/* If the previous owner died and the caller did not succeed in
making the state consistent, mark the mutex as unrecoverable
and make all waiters. */
if ((mutex->__data.__kind & PTHREAD_MUTEX_ROBUST_NORMAL_NP) != 0
&& __builtin_expect (mutex->__data.__owner
== PTHREAD_MUTEX_INCONSISTENT, 0))
pi_notrecoverable:
newowner = PTHREAD_MUTEX_NOTRECOVERABLE;
continue_pi:
if ((mutex->__data.__kind & PTHREAD_MUTEX_ROBUST_NORMAL_NP) != 0)
{
/* Remove mutex from the list.
Note: robust PI futexes are signaled by setting bit 0. */
THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending,
(void *) (((uintptr_t) &mutex->__data.__list.__next)
| 1));
DEQUEUE_MUTEX (mutex);
}
mutex->__data.__owner = newowner;
if (decr)
/* One less user. */
--mutex->__data.__nusers;
/* Unlock. */
if ((mutex->__data.__lock & FUTEX_WAITERS) != 0
|| atomic_compare_and_exchange_bool_acq (&mutex->__data.__lock, 0,
THREAD_GETMEM (THREAD_SELF,
tid)))
{
INTERNAL_SYSCALL_DECL (__err);
INTERNAL_SYSCALL (futex, __err, 2, &mutex->__data.__lock,
FUTEX_UNLOCK_PI);
}
THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
break;
default:
/* Correct code cannot set any other type. */
return EINVAL;
}
return 0;
}
int
__pthread_mutex_unlock (mutex)
pthread_mutex_t *mutex;
{
return __pthread_mutex_unlock_usercnt (mutex, 1);
}
strong_alias (__pthread_mutex_unlock, pthread_mutex_unlock)
strong_alias (__pthread_mutex_unlock, __pthread_mutex_unlock_internal)
|
