diff options
author | Ulrich Drepper <drepper@redhat.com> | 2006-02-15 17:20:33 +0000 |
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committer | Ulrich Drepper <drepper@redhat.com> | 2006-02-15 17:20:33 +0000 |
commit | 683040c3b2c7dc2bc08045202a0a0b46d143b3cb (patch) | |
tree | fcd73510f2bcfcdf57078331d800db4217db759b /nptl/pthread_mutex_lock.c | |
parent | * allocatestack.c (allocate_stack): Initialize robust_list. (diff) | |
download | glibc-683040c3b2c7dc2bc08045202a0a0b46d143b3cb.tar.gz glibc-683040c3b2c7dc2bc08045202a0a0b46d143b3cb.tar.bz2 glibc-683040c3b2c7dc2bc08045202a0a0b46d143b3cb.zip |
* sysdeps/unix/sysv/linux/not-cancel.h (__openat_not_cancel,
__openat64_not_cancel): Remove prototypes.
(__openat_nocancel, __openat64_nocancel): New prototypes or defines.
(openat_not_cancel, openat_not_cancel_3, openat64_not_cancel,
openat64_not_cancel_3): Use them.
Diffstat (limited to 'nptl/pthread_mutex_lock.c')
-rw-r--r-- | nptl/pthread_mutex_lock.c | 113 |
1 files changed, 69 insertions, 44 deletions
diff --git a/nptl/pthread_mutex_lock.c b/nptl/pthread_mutex_lock.c index 420711a4d4..dd22567c71 100644 --- a/nptl/pthread_mutex_lock.c +++ b/nptl/pthread_mutex_lock.c @@ -1,4 +1,4 @@ -/* Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc. +/* Copyright (C) 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper <drepper@redhat.com>, 2002. @@ -27,6 +27,7 @@ #ifndef LLL_MUTEX_LOCK # define LLL_MUTEX_LOCK(mutex) lll_mutex_lock (mutex) # define LLL_MUTEX_TRYLOCK(mutex) lll_mutex_trylock (mutex) +# define LLL_ROBUST_MUTEX_LOCK(mutex, id) lll_robust_mutex_lock (mutex, id) #endif @@ -36,6 +37,7 @@ __pthread_mutex_lock (mutex) { assert (sizeof (mutex->__size) >= sizeof (mutex->__data)); + int oldval; pid_t id = THREAD_GETMEM (THREAD_SELF, tid); int retval = 0; @@ -107,60 +109,83 @@ __pthread_mutex_lock (mutex) break; case PTHREAD_MUTEX_ROBUST_PRIVATE_RECURSIVE_NP: - /* Check whether we already hold the mutex. */ - if (abs (mutex->__data.__owner) == id) + case PTHREAD_MUTEX_ROBUST_PRIVATE_ERRORCHECK_NP: + case PTHREAD_MUTEX_ROBUST_PRIVATE_NP: + case PTHREAD_MUTEX_ROBUST_PRIVATE_ADAPTIVE_NP: + oldval = mutex->__data.__lock; + do { - /* Just bump the counter. */ - if (__builtin_expect (mutex->__data.__count + 1 == 0, 0)) - /* Overflow of the counter. */ - return EAGAIN; - - ++mutex->__data.__count; - - return 0; - } - - /* We have to get the mutex. */ - LLL_MUTEX_LOCK (mutex->__data.__lock); + if ((oldval & FUTEX_OWNER_DIED) != 0) + { + /* The previous owner died. Try locking the mutex. */ + int newval; + while ((newval + = atomic_compare_and_exchange_val_acq (&mutex->__data.__lock, + id, oldval)) + != oldval) + { + if ((newval & FUTEX_OWNER_DIED) == 0) + goto normal; + oldval = newval; + } - mutex->__data.__count = 1; + /* We got the mutex. */ + mutex->__data.__count = 1; + /* But it is inconsistent unless marked otherwise. */ + mutex->__data.__owner = PTHREAD_MUTEX_INCONSISTENT; + + ENQUEUE_MUTEX (mutex); + + /* 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. If we are not supposed + to increment __nusers we actually have to decrement + it here. */ +#ifdef NO_INCR + --mutex->__data.__nusers; +#endif - goto robust; + return EOWNERDEAD; + } - case PTHREAD_MUTEX_ROBUST_PRIVATE_ERRORCHECK_NP: - /* Check whether we already hold the mutex. */ - if (__builtin_expect (abs (mutex->__data.__owner) == id, 0)) - return EDEADLK; + normal: + /* Check whether we already hold the mutex. */ + if (__builtin_expect ((mutex->__data.__lock & FUTEX_TID_MASK) + == id, 0)) + { + if (mutex->__data.__kind + == PTHREAD_MUTEX_ROBUST_PRIVATE_ERRORCHECK_NP) + return EDEADLK; - /* FALLTHROUGH */ + if (mutex->__data.__kind + == PTHREAD_MUTEX_ROBUST_PRIVATE_RECURSIVE_NP) + { + /* Just bump the counter. */ + if (__builtin_expect (mutex->__data.__count + 1 == 0, 0)) + /* Overflow of the counter. */ + return EAGAIN; - case PTHREAD_MUTEX_ROBUST_PRIVATE_NP: - case PTHREAD_MUTEX_ROBUST_PRIVATE_ADAPTIVE_NP: - LLL_MUTEX_LOCK (mutex->__data.__lock); + ++mutex->__data.__count; - robust: - if (__builtin_expect (mutex->__data.__owner - == PTHREAD_MUTEX_NOTRECOVERABLE, 0)) - { - /* This mutex is now not recoverable. */ - mutex->__data.__count = 0; - lll_mutex_unlock (mutex->__data.__lock); - return ENOTRECOVERABLE; - } + return 0; + } + } - /* This mutex is either healthy or we can try to recover it. */ - assert (mutex->__data.__owner == 0 - || mutex->__data.__owner == PTHREAD_MUTEX_OWNERDEAD); + oldval = LLL_ROBUST_MUTEX_LOCK (mutex->__data.__lock, id); - if (__builtin_expect (mutex->__data.__owner - == PTHREAD_MUTEX_OWNERDEAD, 0)) - { - retval = EOWNERDEAD; - /* We signal ownership of a not yet recovered robust mutex - by storing the negative thread ID. */ - id = -id; + if (__builtin_expect (mutex->__data.__owner + == PTHREAD_MUTEX_NOTRECOVERABLE, 0)) + { + /* This mutex is now not recoverable. */ + mutex->__data.__count = 0; + lll_mutex_unlock (mutex->__data.__lock); + return ENOTRECOVERABLE; + } } + while ((oldval & FUTEX_OWNER_DIED) != 0); + mutex->__data.__count = 1; ENQUEUE_MUTEX (mutex); break; |