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_trylock.c | |
parent | b007ce7cc6971e4bd4cd91c558efd3d4603d941d (diff) | |
download | glibc-683040c3b2c7dc2bc08045202a0a0b46d143b3cb.zip glibc-683040c3b2c7dc2bc08045202a0a0b46d143b3cb.tar.gz glibc-683040c3b2c7dc2bc08045202a0a0b46d143b3cb.tar.bz2 |
* 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_trylock.c')
-rw-r--r-- | nptl/pthread_mutex_trylock.c | 130 |
1 files changed, 73 insertions, 57 deletions
diff --git a/nptl/pthread_mutex_trylock.c b/nptl/pthread_mutex_trylock.c index ae73ecc..5a13ea6 100644 --- a/nptl/pthread_mutex_trylock.c +++ b/nptl/pthread_mutex_trylock.c @@ -1,4 +1,4 @@ -/* Copyright (C) 2002, 2003, 2005 Free Software Foundation, Inc. +/* 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. @@ -28,6 +28,7 @@ int __pthread_mutex_trylock (mutex) pthread_mutex_t *mutex; { + int oldval; pid_t id = THREAD_GETMEM (THREAD_SELF, tid); switch (__builtin_expect (mutex->__data.__kind, PTHREAD_MUTEX_TIMED_NP)) @@ -77,73 +78,88 @@ __pthread_mutex_trylock (mutex) case PTHREAD_MUTEX_ROBUST_PRIVATE_RECURSIVE_NP: - /* Check whether we already hold the mutex. */ - if (abs (mutex->__data.__owner) == id) - { - /* 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. */ - if (lll_mutex_trylock (mutex->__data.__lock) == 0) - { - mutex->__data.__count = 1; - - goto robust; - } - - break; - 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; - - /* FALLTHROUGH */ - case PTHREAD_MUTEX_ROBUST_PRIVATE_NP: case PTHREAD_MUTEX_ROBUST_PRIVATE_ADAPTIVE_NP: - if (lll_mutex_trylock (mutex->__data.__lock) != 0) - break; - - 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; - } - - /* This mutex is either healthy or we can try to recover it. */ - assert (mutex->__data.__owner == 0 - || mutex->__data.__owner == PTHREAD_MUTEX_OWNERDEAD); - - /* Record the ownership. */ - int retval = 0; - if (__builtin_expect (mutex->__data.__owner - == PTHREAD_MUTEX_OWNERDEAD, 0)) + oldval = mutex->__data.__lock; + do { - retval = EOWNERDEAD; - /* We signal ownership of a not yet recovered robust - mutex by storing the negative thread ID. */ - id = -id; + 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; + } + + /* 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 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; + } + + 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; + + 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; + + ++mutex->__data.__count; + + return 0; + } + } + + oldval = lll_robust_mutex_trylock (mutex->__data.__lock, id); + if (oldval != 0 && (oldval & FUTEX_OWNER_DIED) == 0) + return EBUSY; + + robust: + 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); + return ENOTRECOVERABLE; + } } + while ((oldval & FUTEX_OWNER_DIED) != 0); ENQUEUE_MUTEX (mutex); mutex->__data.__owner = id; ++mutex->__data.__nusers; + mutex->__data.__count = 1; + + return 0; - return retval -; default: /* Correct code cannot set any other type. */ return EINVAL; |