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authorUlrich Drepper <drepper@redhat.com>2006-02-15 17:20:33 +0000
committerUlrich Drepper <drepper@redhat.com>2006-02-15 17:20:33 +0000
commit683040c3b2c7dc2bc08045202a0a0b46d143b3cb (patch)
treefcd73510f2bcfcdf57078331d800db4217db759b /nptl/pthread_mutex_lock.c
parentb007ce7cc6971e4bd4cd91c558efd3d4603d941d (diff)
downloadglibc-683040c3b2c7dc2bc08045202a0a0b46d143b3cb.tar.gz
* 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.c113
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;