/* Copyright (C) 2002, 2003, 2005-2008, 2009 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, see <http://www.gnu.org/licenses/>. */ #include <assert.h> #include <errno.h> #include <stdlib.h> #include "pthreadP.h" #include <lowlevellock.h> static int internal_function __pthread_mutex_unlock_full (pthread_mutex_t *mutex, int decr) __attribute_noinline__; int internal_function attribute_hidden __pthread_mutex_unlock_usercnt ( pthread_mutex_t *mutex, int decr) { int type = PTHREAD_MUTEX_TYPE (mutex); if (__builtin_expect (type & ~PTHREAD_MUTEX_KIND_MASK_NP, 0)) return __pthread_mutex_unlock_full (mutex, decr); if (__builtin_expect (type, PTHREAD_MUTEX_TIMED_NP) == PTHREAD_MUTEX_TIMED_NP) { /* Always reset the owner field. */ normal: mutex->__data.__owner = 0; if (decr) /* One less user. */ --mutex->__data.__nusers; /* Unlock. */ lll_unlock (mutex->__data.__lock, PTHREAD_MUTEX_PSHARED (mutex)); return 0; } else if (__builtin_expect (type == PTHREAD_MUTEX_RECURSIVE_NP, 1)) { /* 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; } else if (__builtin_expect (type == PTHREAD_MUTEX_ADAPTIVE_NP, 1)) goto normal; else { /* Error checking mutex. */ assert (type == PTHREAD_MUTEX_ERRORCHECK_NP); if (mutex->__data.__owner != THREAD_GETMEM (THREAD_SELF, tid) || ! lll_islocked (mutex->__data.__lock)) return EPERM; goto normal; } } static int internal_function __pthread_mutex_unlock_full (pthread_mutex_t *mutex, int decr) { int newowner = 0; switch (PTHREAD_MUTEX_TYPE (mutex)) { 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_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_unlock (mutex->__data.__lock, PTHREAD_ROBUST_MUTEX_PSHARED (mutex)); 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_non_robust; 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_robust; 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_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; if ((mutex->__data.__kind & PTHREAD_MUTEX_ROBUST_NORMAL_NP) != 0) { continue_pi_robust: /* 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); } continue_pi_non_robust: 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_rel (&mutex->__data.__lock, 0, THREAD_GETMEM (THREAD_SELF, tid))) { int robust = mutex->__data.__kind & PTHREAD_MUTEX_ROBUST_NORMAL_NP; int private = (robust ? PTHREAD_ROBUST_MUTEX_PSHARED (mutex) : PTHREAD_MUTEX_PSHARED (mutex)); INTERNAL_SYSCALL_DECL (__err); INTERNAL_SYSCALL (futex, __err, 2, &mutex->__data.__lock, __lll_private_flag (FUTEX_UNLOCK_PI, private)); } THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL); break; case PTHREAD_MUTEX_PP_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 pp; case PTHREAD_MUTEX_PP_ERRORCHECK_NP: /* Error checking mutex. */ if (mutex->__data.__owner != THREAD_GETMEM (THREAD_SELF, tid) || (mutex->__data.__lock & ~ PTHREAD_MUTEX_PRIO_CEILING_MASK) == 0) return EPERM; /* FALLTHROUGH */ case PTHREAD_MUTEX_PP_NORMAL_NP: case PTHREAD_MUTEX_PP_ADAPTIVE_NP: /* Always reset the owner field. */ pp: mutex->__data.__owner = 0; if (decr) /* One less user. */ --mutex->__data.__nusers; /* Unlock. */ int newval, oldval; do { oldval = mutex->__data.__lock; newval = oldval & PTHREAD_MUTEX_PRIO_CEILING_MASK; } while (atomic_compare_and_exchange_bool_rel (&mutex->__data.__lock, newval, oldval)); if ((oldval & ~PTHREAD_MUTEX_PRIO_CEILING_MASK) > 1) lll_futex_wake (&mutex->__data.__lock, 1, PTHREAD_MUTEX_PSHARED (mutex)); int oldprio = newval >> PTHREAD_MUTEX_PRIO_CEILING_SHIFT; return __pthread_tpp_change_priority (oldprio, -1); default: /* Correct code cannot set any other type. */ return EINVAL; } return 0; } int attribute_protected __pthread_mutex_unlock ( 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)