59 lines
1.9 KiB
C
59 lines
1.9 KiB
C
--- spinlock.c.orig Tue Mar 27 04:52:56 2001
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+++ spinlock.c Tue Jan 10 09:44:39 2006
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@@ -72,8 +72,6 @@
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#endif
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#if defined HAS_COMPARE_AND_SWAP
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-again:
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-
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/* On SMP, try spinning to get the lock. */
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if (__pthread_smp_kernel) {
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@@ -94,6 +92,8 @@
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lock->__spinlock += (spin_count - lock->__spinlock) / 8;
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}
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+again:
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+
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/* No luck, try once more or suspend. */
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do {
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@@ -110,7 +110,7 @@
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}
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if (self != NULL) {
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- THREAD_SETMEM(self, p_nextlock, (pthread_descr) (oldstatus & ~1L));
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+ THREAD_SETMEM(self, p_nextlock, (pthread_descr) oldstatus);
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/* Make sure the store in p_nextlock completes before performing
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the compare-and-swap */
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MEMORY_BARRIER();
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@@ -188,7 +188,7 @@
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multiprocessor Alphas) could perform such reordering even though
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the loads are dependent. */
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READ_MEMORY_BARRIER();
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- thr = *ptr;
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+ thr = (pthread_descr)((long)(thr->p_nextlock) & ~1L);
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}
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/* Prevent reordering of the load of lock->__status above and
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thr->p_nextlock below */
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@@ -198,17 +198,16 @@
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/* If max prio thread is at head, remove it with compare-and-swap
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to guard against concurrent lock operation. This removal
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also has the side effect of marking the lock as released
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- because the new status comes from thr->p_nextlock whose
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- least significant bit is clear. */
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+ by clearing the least significant bit. */
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thr = (pthread_descr) (oldstatus & ~1L);
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if (! __compare_and_swap_with_release_semantics
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- (&lock->__status, oldstatus, (long)(thr->p_nextlock)))
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+ (&lock->__status, oldstatus, (long)(thr->p_nextlock) & ~1L))
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goto again;
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} else {
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/* No risk of concurrent access, remove max prio thread normally.
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But in this case we must also flip the least significant bit
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of the status to mark the lock as released. */
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- thr = *maxptr;
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+ thr = (pthread_descr)((long)*maxptr & ~1L);
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*maxptr = thr->p_nextlock;
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do {
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