diff options
Diffstat (limited to 'linuxthreads')
| -rw-r--r-- | linuxthreads/ChangeLog | 10 | ||||
| -rw-r--r-- | linuxthreads/spinlock.c | 12 |
2 files changed, 16 insertions, 6 deletions
diff --git a/linuxthreads/ChangeLog b/linuxthreads/ChangeLog index 2ae14e01d8..93193ae754 100644 --- a/linuxthreads/ChangeLog +++ b/linuxthreads/ChangeLog @@ -1,3 +1,13 @@ +2002-04-24 Steven Munroe <sjmunroe@us.ibm.com> + + * spinlock.c (__pthread_lock): Fix spurious wakeup + handling. Don't clear lowest bit of list pointer as sign the thread + is still on the wait list. Don't restart after spurious wakeup + with spinning to get the lock. + (__pthread_unlock): Take set lowest bit into account when handling + pointer to list elements. + Patch by Steve Munroe <sjmunroe@us.ibm.com>. + 2002-08-28 Roland McGrath <roland@redhat.com> * sysdeps/pthread/timer_routines.c (thread_func): Fix type in cast. diff --git a/linuxthreads/spinlock.c b/linuxthreads/spinlock.c index 582a95c2c2..47107bf9ee 100644 --- a/linuxthreads/spinlock.c +++ b/linuxthreads/spinlock.c @@ -85,8 +85,6 @@ void internal_function __pthread_lock(struct _pthread_fastlock * lock, spurious_wakeup_count = 0; spin_count = 0; -again: - /* On SMP, try spinning to get the lock. */ if (__pthread_smp_kernel) { @@ -114,6 +112,8 @@ again: lock->__spinlock += (spin_count - lock->__spinlock) / 8; } +again: + /* No luck, try once more or suspend. */ do { @@ -130,7 +130,7 @@ again: } if (self != NULL) { - THREAD_SETMEM(self, p_nextlock, (pthread_descr) (oldstatus & ~1L)); + THREAD_SETMEM(self, p_nextlock, (pthread_descr) (oldstatus)); /* Make sure the store in p_nextlock completes before performing the compare-and-swap */ MEMORY_BARRIER(); @@ -214,7 +214,7 @@ again: maxprio = thr->p_priority; } ptr = &(thr->p_nextlock); - thr = *ptr; + thr = (pthread_descr)((long)(thr->p_nextlock) & ~1L); } /* Remove max prio thread from waiting list. */ @@ -226,13 +226,13 @@ again: least significant bit is clear. */ thr = (pthread_descr) (oldstatus & ~1L); if (! __compare_and_swap_with_release_semantics - (&lock->__status, oldstatus, (long)(thr->p_nextlock))) + (&lock->__status, oldstatus, (long)(thr->p_nextlock) & ~1L)) goto again; } else { /* No risk of concurrent access, remove max prio thread normally. But in this case we must also flip the least significant bit of the status to mark the lock as released. */ - thr = *maxptr; + thr = (pthread_descr)((long)*maxptr & ~1L); *maxptr = thr->p_nextlock; /* Ensure deletion from linked list completes before we |