pthread_spin_trylock was not returning EBUSY on multi CPU machines.

2 files changed, 11 insertions, 10 deletions

diff --git a/ChangeLog b/ChangeLog
index ab8ab92..07b04a4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2001-10-08  Ross Johnson  <rpj@setup1.ise.canberra.edu.au>
+
+	* spin.c (pthread_spin_trylock): Was not returning
+	EBUSY for multi CPU machines.
+
 2001-08-24  Ross Johnson  <rpj@setup1.ise.canberra.edu.au>
 
 	* condvar.c (pthread_cond_destroy): Remove cv element
diff --git a/spin.c b/spin.c
index 458bb7a..d2d795f 100644
--- a/spin.c
+++ b/spin.c
@@ -284,17 +284,13 @@ pthread_spin_trylock(pthread_spinlock_t *lock)
         }
     }
 
-  if ((_LONG) PTW32_SPIN_UNLOCKED ==
-      InterlockedCompareExchange((_LPLONG) &(s->interlock),
-                                 (_LONG) PTW32_SPIN_LOCKED,
-                                 (_LONG) PTW32_SPIN_UNLOCKED ) )
-    {
-      return 0;
-    }
-
-  if (s->interlock == PTW32_SPIN_USE_MUTEX)
+  switch ((long) InterlockedCompareExchange((_LPLONG) &(s->interlock),
+                                            (_LONG) PTW32_SPIN_LOCKED,
+                                            (_LONG) PTW32_SPIN_UNLOCKED ))
     {
-      return pthread_mutex_trylock(&(s->u.mutex));
+      case PTW32_SPIN_UNLOCKED:  return 0;
+      case PTW32_SPIN_LOCKED:    return EBUSY;
+      case PTW32_SPIN_USE_MUTEX: return pthread_mutex_trylock(&(s->u.mutex));
     }
 
   return EINVAL;