From a334319f6530564d22e775935d9c91663623a1b4 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Wed, 22 Dec 2004 20:10:10 +0000 Subject: (CFLAGS-tst-align.c): Add -mpreferred-stack-boundary=4. --- nptl/pthread_mutex_trylock.c | 327 ++----------------------------------------- 1 file changed, 11 insertions(+), 316 deletions(-) (limited to 'nptl/pthread_mutex_trylock.c') diff --git a/nptl/pthread_mutex_trylock.c b/nptl/pthread_mutex_trylock.c index 66aca8e4b2..7008af3d97 100644 --- a/nptl/pthread_mutex_trylock.c +++ b/nptl/pthread_mutex_trylock.c @@ -1,4 +1,4 @@ -/* Copyright (C) 2002, 2003, 2005, 2006, 2007 Free Software Foundation, Inc. +/* Copyright (C) 2002, 2003 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper , 2002. @@ -17,9 +17,7 @@ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ -#include #include -#include #include "pthreadP.h" #include @@ -28,13 +26,13 @@ int __pthread_mutex_trylock (mutex) pthread_mutex_t *mutex; { - int oldval; - pid_t id = THREAD_GETMEM (THREAD_SELF, tid); + pid_t id; switch (__builtin_expect (mutex->__data.__kind, PTHREAD_MUTEX_TIMED_NP)) { /* Recursive mutex. */ case PTHREAD_MUTEX_RECURSIVE_NP: + id = THREAD_GETMEM (THREAD_SELF, tid); /* Check whether we already hold the mutex. */ if (mutex->__data.__owner == id) { @@ -58,323 +56,20 @@ __pthread_mutex_trylock (mutex) break; case PTHREAD_MUTEX_ERRORCHECK_NP: - /* Check whether we already hold the mutex. */ - if (__builtin_expect (mutex->__data.__owner == id, 0)) - return EDEADLK; - - /* FALLTHROUGH */ - + /* Error checking mutex. We do not check for deadlocks. */ + default: + /* Correct code cannot set any other type. */ case PTHREAD_MUTEX_TIMED_NP: case PTHREAD_MUTEX_ADAPTIVE_NP: /* Normal mutex. */ - if (lll_mutex_trylock (mutex->__data.__lock) != 0) - break; - - /* Record the ownership. */ - mutex->__data.__owner = id; - ++mutex->__data.__nusers; - - return 0; - - - case PTHREAD_MUTEX_ROBUST_RECURSIVE_NP: - case PTHREAD_MUTEX_ROBUST_ERRORCHECK_NP: - case PTHREAD_MUTEX_ROBUST_NORMAL_NP: - case PTHREAD_MUTEX_ROBUST_ADAPTIVE_NP: - THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, - &mutex->__data.__list.__next); - - oldval = mutex->__data.__lock; - do + if (lll_mutex_trylock (mutex->__data.__lock) == 0) { - again: - if ((oldval & FUTEX_OWNER_DIED) != 0) - { - /* The previous owner died. Try locking the mutex. */ - int newval = id | (oldval & FUTEX_WAITERS); - - newval - = atomic_compare_and_exchange_val_acq (&mutex->__data.__lock, - newval, oldval); - - if (newval != oldval) - { - oldval = newval; - goto again; - } - - /* We got the mutex. */ - mutex->__data.__count = 1; - /* But it is inconsistent unless marked otherwise. */ - mutex->__data.__owner = PTHREAD_MUTEX_INCONSISTENT; - - ENQUEUE_MUTEX (mutex); - THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL); - - /* Note that we deliberately exist here. If we fall - through to the end of the function __nusers would be - incremented which is not correct because the old - owner has to be discounted. */ - return EOWNERDEAD; - } - - /* Check whether we already hold the mutex. */ - if (__builtin_expect ((oldval & FUTEX_TID_MASK) == id, 0)) - { - if (mutex->__data.__kind - == PTHREAD_MUTEX_ROBUST_ERRORCHECK_NP) - { - THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, - NULL); - return EDEADLK; - } - - if (mutex->__data.__kind - == PTHREAD_MUTEX_ROBUST_RECURSIVE_NP) - { - THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, - NULL); - - /* Just bump the counter. */ - if (__builtin_expect (mutex->__data.__count + 1 == 0, 0)) - /* Overflow of the counter. */ - return EAGAIN; - - ++mutex->__data.__count; - - return 0; - } - } - - oldval = lll_robust_mutex_trylock (mutex->__data.__lock, id); - if (oldval != 0 && (oldval & FUTEX_OWNER_DIED) == 0) - { - THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL); - - return EBUSY; - } + /* Record the ownership. */ + mutex->__data.__owner = THREAD_GETMEM (THREAD_SELF, tid); + ++mutex->__data.__nusers; - if (__builtin_expect (mutex->__data.__owner - == PTHREAD_MUTEX_NOTRECOVERABLE, 0)) - { - /* This mutex is now not recoverable. */ - mutex->__data.__count = 0; - if (oldval == id) - lll_mutex_unlock (mutex->__data.__lock); - THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL); - return ENOTRECOVERABLE; - } + return 0; } - while ((oldval & FUTEX_OWNER_DIED) != 0); - - ENQUEUE_MUTEX (mutex); - THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL); - - mutex->__data.__owner = id; - ++mutex->__data.__nusers; - mutex->__data.__count = 1; - - return 0; - - case PTHREAD_MUTEX_PI_RECURSIVE_NP: - case PTHREAD_MUTEX_PI_ERRORCHECK_NP: - case PTHREAD_MUTEX_PI_NORMAL_NP: - case PTHREAD_MUTEX_PI_ADAPTIVE_NP: - case PTHREAD_MUTEX_PI_ROBUST_RECURSIVE_NP: - case PTHREAD_MUTEX_PI_ROBUST_ERRORCHECK_NP: - case PTHREAD_MUTEX_PI_ROBUST_NORMAL_NP: - case PTHREAD_MUTEX_PI_ROBUST_ADAPTIVE_NP: - { - int kind = mutex->__data.__kind & PTHREAD_MUTEX_KIND_MASK_NP; - int robust = mutex->__data.__kind & PTHREAD_MUTEX_ROBUST_NORMAL_NP; - - if (robust) - /* 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)); - - oldval = mutex->__data.__lock; - - /* Check whether we already hold the mutex. */ - if (__builtin_expect ((oldval & FUTEX_TID_MASK) == id, 0)) - { - if (kind == PTHREAD_MUTEX_ERRORCHECK_NP) - { - THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL); - return EDEADLK; - } - - if (kind == PTHREAD_MUTEX_RECURSIVE_NP) - { - THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL); - - /* Just bump the counter. */ - if (__builtin_expect (mutex->__data.__count + 1 == 0, 0)) - /* Overflow of the counter. */ - return EAGAIN; - - ++mutex->__data.__count; - - return 0; - } - } - - oldval - = atomic_compare_and_exchange_val_acq (&mutex->__data.__lock, - id, 0); - - if (oldval != 0) - { - if ((oldval & FUTEX_OWNER_DIED) == 0) - { - THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL); - - return EBUSY; - } - - assert (robust); - - /* The mutex owner died. The kernel will now take care of - everything. */ - INTERNAL_SYSCALL_DECL (__err); - int e = INTERNAL_SYSCALL (futex, __err, 4, &mutex->__data.__lock, - FUTEX_TRYLOCK_PI, 0, 0); - - if (INTERNAL_SYSCALL_ERROR_P (e, __err) - && INTERNAL_SYSCALL_ERRNO (e, __err) == EWOULDBLOCK) - { - THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL); - - return EBUSY; - } - - oldval = mutex->__data.__lock; - } - - if (__builtin_expect (oldval & FUTEX_OWNER_DIED, 0)) - { - atomic_and (&mutex->__data.__lock, ~FUTEX_OWNER_DIED); - - /* We got the mutex. */ - mutex->__data.__count = 1; - /* But it is inconsistent unless marked otherwise. */ - mutex->__data.__owner = PTHREAD_MUTEX_INCONSISTENT; - - ENQUEUE_MUTEX (mutex); - THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL); - - /* Note that we deliberately exit here. If we fall - through to the end of the function __nusers would be - incremented which is not correct because the old owner - has to be discounted. */ - return EOWNERDEAD; - } - - if (robust - && __builtin_expect (mutex->__data.__owner - == PTHREAD_MUTEX_NOTRECOVERABLE, 0)) - { - /* This mutex is now not recoverable. */ - mutex->__data.__count = 0; - - INTERNAL_SYSCALL_DECL (__err); - INTERNAL_SYSCALL (futex, __err, 4, &mutex->__data.__lock, - FUTEX_UNLOCK_PI, 0, 0); - - THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL); - return ENOTRECOVERABLE; - } - - if (robust) - { - ENQUEUE_MUTEX_PI (mutex); - THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL); - } - - mutex->__data.__owner = id; - ++mutex->__data.__nusers; - mutex->__data.__count = 1; - - return 0; - } - - case PTHREAD_MUTEX_PP_RECURSIVE_NP: - case PTHREAD_MUTEX_PP_ERRORCHECK_NP: - case PTHREAD_MUTEX_PP_NORMAL_NP: - case PTHREAD_MUTEX_PP_ADAPTIVE_NP: - { - int kind = mutex->__data.__kind & PTHREAD_MUTEX_KIND_MASK_NP; - - oldval = mutex->__data.__lock; - - /* Check whether we already hold the mutex. */ - if (mutex->__data.__owner == id) - { - if (kind == PTHREAD_MUTEX_ERRORCHECK_NP) - return EDEADLK; - - if (kind == PTHREAD_MUTEX_RECURSIVE_NP) - { - /* Just bump the counter. */ - if (__builtin_expect (mutex->__data.__count + 1 == 0, 0)) - /* Overflow of the counter. */ - return EAGAIN; - - ++mutex->__data.__count; - - return 0; - } - } - - int oldprio = -1, ceilval; - do - { - int ceiling = (oldval & PTHREAD_MUTEX_PRIO_CEILING_MASK) - >> PTHREAD_MUTEX_PRIO_CEILING_SHIFT; - - if (__pthread_current_priority () > ceiling) - { - if (oldprio != -1) - __pthread_tpp_change_priority (oldprio, -1); - return EINVAL; - } - - int retval = __pthread_tpp_change_priority (oldprio, ceiling); - if (retval) - return retval; - - ceilval = ceiling << PTHREAD_MUTEX_PRIO_CEILING_SHIFT; - oldprio = ceiling; - - oldval - = atomic_compare_and_exchange_val_acq (&mutex->__data.__lock, - ceilval | 1, ceilval); - - if (oldval == ceilval) - break; - } - while ((oldval & PTHREAD_MUTEX_PRIO_CEILING_MASK) != ceilval); - - if (oldval != ceilval) - { - __pthread_tpp_change_priority (oldprio, -1); - break; - } - - assert (mutex->__data.__owner == 0); - /* Record the ownership. */ - mutex->__data.__owner = id; - ++mutex->__data.__nusers; - mutex->__data.__count = 1; - - return 0; - } - break; - - default: - /* Correct code cannot set any other type. */ - return EINVAL; } return EBUSY; -- cgit v1.2.3-65-gdbad