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301 lines
8.5 KiB
C
301 lines
8.5 KiB
C
/* Copyright (C) 2002-2012 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <assert.h>
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#include <errno.h>
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#include <stdlib.h>
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#include "pthreadP.h"
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#include <lowlevellock.h>
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#include <stap-probe.h>
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static int
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internal_function
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__pthread_mutex_unlock_full (pthread_mutex_t *mutex, int decr)
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__attribute_noinline__;
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int
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internal_function attribute_hidden
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__pthread_mutex_unlock_usercnt (mutex, decr)
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pthread_mutex_t *mutex;
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int decr;
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{
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int type = PTHREAD_MUTEX_TYPE (mutex);
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if (__builtin_expect (type & ~PTHREAD_MUTEX_KIND_MASK_NP, 0))
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return __pthread_mutex_unlock_full (mutex, decr);
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if (__builtin_expect (type, PTHREAD_MUTEX_TIMED_NP)
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== PTHREAD_MUTEX_TIMED_NP)
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{
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/* Always reset the owner field. */
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normal:
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mutex->__data.__owner = 0;
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if (decr)
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/* One less user. */
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--mutex->__data.__nusers;
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/* Unlock. */
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lll_unlock (mutex->__data.__lock, PTHREAD_MUTEX_PSHARED (mutex));
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LIBC_PROBE (mutex_release, 1, mutex);
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return 0;
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}
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else if (__builtin_expect (type == PTHREAD_MUTEX_RECURSIVE_NP, 1))
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{
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/* Recursive mutex. */
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if (mutex->__data.__owner != THREAD_GETMEM (THREAD_SELF, tid))
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return EPERM;
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if (--mutex->__data.__count != 0)
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/* We still hold the mutex. */
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return 0;
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goto normal;
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}
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else if (__builtin_expect (type == PTHREAD_MUTEX_ADAPTIVE_NP, 1))
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goto normal;
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else
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{
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/* Error checking mutex. */
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assert (type == PTHREAD_MUTEX_ERRORCHECK_NP);
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if (mutex->__data.__owner != THREAD_GETMEM (THREAD_SELF, tid)
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|| ! lll_islocked (mutex->__data.__lock))
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return EPERM;
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goto normal;
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}
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}
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static int
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internal_function
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__pthread_mutex_unlock_full (pthread_mutex_t *mutex, int decr)
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{
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int newowner = 0;
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switch (PTHREAD_MUTEX_TYPE (mutex))
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{
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case PTHREAD_MUTEX_ROBUST_RECURSIVE_NP:
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/* Recursive mutex. */
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if ((mutex->__data.__lock & FUTEX_TID_MASK)
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== THREAD_GETMEM (THREAD_SELF, tid)
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&& __builtin_expect (mutex->__data.__owner
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== PTHREAD_MUTEX_INCONSISTENT, 0))
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{
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if (--mutex->__data.__count != 0)
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/* We still hold the mutex. */
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return ENOTRECOVERABLE;
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goto notrecoverable;
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}
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if (mutex->__data.__owner != THREAD_GETMEM (THREAD_SELF, tid))
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return EPERM;
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if (--mutex->__data.__count != 0)
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/* We still hold the mutex. */
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return 0;
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goto robust;
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case PTHREAD_MUTEX_ROBUST_ERRORCHECK_NP:
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case PTHREAD_MUTEX_ROBUST_NORMAL_NP:
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case PTHREAD_MUTEX_ROBUST_ADAPTIVE_NP:
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if ((mutex->__data.__lock & FUTEX_TID_MASK)
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!= THREAD_GETMEM (THREAD_SELF, tid)
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|| ! lll_islocked (mutex->__data.__lock))
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return EPERM;
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/* If the previous owner died and the caller did not succeed in
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making the state consistent, mark the mutex as unrecoverable
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and make all waiters. */
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if (__builtin_expect (mutex->__data.__owner
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== PTHREAD_MUTEX_INCONSISTENT, 0))
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notrecoverable:
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newowner = PTHREAD_MUTEX_NOTRECOVERABLE;
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robust:
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/* Remove mutex from the list. */
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THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending,
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&mutex->__data.__list.__next);
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DEQUEUE_MUTEX (mutex);
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mutex->__data.__owner = newowner;
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if (decr)
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/* One less user. */
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--mutex->__data.__nusers;
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/* Unlock. */
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lll_robust_unlock (mutex->__data.__lock,
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PTHREAD_ROBUST_MUTEX_PSHARED (mutex));
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THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
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break;
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case PTHREAD_MUTEX_PI_RECURSIVE_NP:
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/* Recursive mutex. */
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if (mutex->__data.__owner != THREAD_GETMEM (THREAD_SELF, tid))
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return EPERM;
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if (--mutex->__data.__count != 0)
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/* We still hold the mutex. */
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return 0;
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goto continue_pi_non_robust;
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case PTHREAD_MUTEX_PI_ROBUST_RECURSIVE_NP:
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/* Recursive mutex. */
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if ((mutex->__data.__lock & FUTEX_TID_MASK)
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== THREAD_GETMEM (THREAD_SELF, tid)
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&& __builtin_expect (mutex->__data.__owner
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== PTHREAD_MUTEX_INCONSISTENT, 0))
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{
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if (--mutex->__data.__count != 0)
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/* We still hold the mutex. */
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return ENOTRECOVERABLE;
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goto pi_notrecoverable;
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}
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if (mutex->__data.__owner != THREAD_GETMEM (THREAD_SELF, tid))
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return EPERM;
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if (--mutex->__data.__count != 0)
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/* We still hold the mutex. */
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return 0;
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goto continue_pi_robust;
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case PTHREAD_MUTEX_PI_ERRORCHECK_NP:
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case PTHREAD_MUTEX_PI_NORMAL_NP:
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case PTHREAD_MUTEX_PI_ADAPTIVE_NP:
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case PTHREAD_MUTEX_PI_ROBUST_ERRORCHECK_NP:
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case PTHREAD_MUTEX_PI_ROBUST_NORMAL_NP:
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case PTHREAD_MUTEX_PI_ROBUST_ADAPTIVE_NP:
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if ((mutex->__data.__lock & FUTEX_TID_MASK)
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!= THREAD_GETMEM (THREAD_SELF, tid)
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|| ! lll_islocked (mutex->__data.__lock))
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return EPERM;
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/* If the previous owner died and the caller did not succeed in
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making the state consistent, mark the mutex as unrecoverable
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and make all waiters. */
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if ((mutex->__data.__kind & PTHREAD_MUTEX_ROBUST_NORMAL_NP) != 0
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&& __builtin_expect (mutex->__data.__owner
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== PTHREAD_MUTEX_INCONSISTENT, 0))
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pi_notrecoverable:
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newowner = PTHREAD_MUTEX_NOTRECOVERABLE;
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if ((mutex->__data.__kind & PTHREAD_MUTEX_ROBUST_NORMAL_NP) != 0)
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{
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continue_pi_robust:
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/* Remove mutex from the list.
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Note: robust PI futexes are signaled by setting bit 0. */
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THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending,
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(void *) (((uintptr_t) &mutex->__data.__list.__next)
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| 1));
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DEQUEUE_MUTEX (mutex);
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}
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continue_pi_non_robust:
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mutex->__data.__owner = newowner;
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if (decr)
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/* One less user. */
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--mutex->__data.__nusers;
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/* Unlock. */
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if ((mutex->__data.__lock & FUTEX_WAITERS) != 0
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|| atomic_compare_and_exchange_bool_rel (&mutex->__data.__lock, 0,
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THREAD_GETMEM (THREAD_SELF,
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tid)))
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{
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int robust = mutex->__data.__kind & PTHREAD_MUTEX_ROBUST_NORMAL_NP;
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int private = (robust
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? PTHREAD_ROBUST_MUTEX_PSHARED (mutex)
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: PTHREAD_MUTEX_PSHARED (mutex));
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INTERNAL_SYSCALL_DECL (__err);
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INTERNAL_SYSCALL (futex, __err, 2, &mutex->__data.__lock,
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__lll_private_flag (FUTEX_UNLOCK_PI, private));
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}
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THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
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break;
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case PTHREAD_MUTEX_PP_RECURSIVE_NP:
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/* Recursive mutex. */
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if (mutex->__data.__owner != THREAD_GETMEM (THREAD_SELF, tid))
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return EPERM;
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if (--mutex->__data.__count != 0)
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/* We still hold the mutex. */
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return 0;
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goto pp;
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case PTHREAD_MUTEX_PP_ERRORCHECK_NP:
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/* Error checking mutex. */
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if (mutex->__data.__owner != THREAD_GETMEM (THREAD_SELF, tid)
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|| (mutex->__data.__lock & ~ PTHREAD_MUTEX_PRIO_CEILING_MASK) == 0)
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return EPERM;
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/* FALLTHROUGH */
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case PTHREAD_MUTEX_PP_NORMAL_NP:
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case PTHREAD_MUTEX_PP_ADAPTIVE_NP:
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/* Always reset the owner field. */
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pp:
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mutex->__data.__owner = 0;
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if (decr)
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/* One less user. */
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--mutex->__data.__nusers;
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/* Unlock. */
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int newval, oldval;
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do
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{
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oldval = mutex->__data.__lock;
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newval = oldval & PTHREAD_MUTEX_PRIO_CEILING_MASK;
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}
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while (atomic_compare_and_exchange_bool_rel (&mutex->__data.__lock,
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newval, oldval));
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if ((oldval & ~PTHREAD_MUTEX_PRIO_CEILING_MASK) > 1)
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lll_futex_wake (&mutex->__data.__lock, 1,
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PTHREAD_MUTEX_PSHARED (mutex));
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int oldprio = newval >> PTHREAD_MUTEX_PRIO_CEILING_SHIFT;
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LIBC_PROBE (mutex_release, 1, mutex);
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return __pthread_tpp_change_priority (oldprio, -1);
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default:
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/* Correct code cannot set any other type. */
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return EINVAL;
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}
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LIBC_PROBE (mutex_release, 1, mutex);
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return 0;
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}
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int
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__pthread_mutex_unlock (mutex)
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pthread_mutex_t *mutex;
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{
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return __pthread_mutex_unlock_usercnt (mutex, 1);
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}
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strong_alias (__pthread_mutex_unlock, pthread_mutex_unlock)
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hidden_def (__pthread_mutex_unlock)
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