2000-08-18 Ross Johnson <rpj@special.ise.canberra.edu.au>

	* mutex.c (pthread_mutex_destroy): Check that the mutex isn't
	held; invalidate the mutex as early as possible to avoid
	contention; not perfect - FIXME!

	* rwlock.c (pthread_rwlock_init): Remove redundant assignment
	to "rw".
	(pthread_rwlock_destroy): Invalidate the rwlock before
	freeing up any of it's resources - to avoid contention.

	* private.c (ptw32_tkAssocCreate): Change assoc->lock
	to use a dynamically initialised mutex - only consumes
	a W32 mutex or critical section when first used,
	not before.

	* mutex.c (pthread_mutex_init): Remove redundant assignment
	to "mx".
	(pthread_mutexattr_destroy): Set attribute to NULL
	before freeing it's memory - to avoid contention.

1 files changed, 7 insertions, 4 deletions

diff --git a/rwlock.c b/rwlock.c
index d02461c..4353847 100644
--- a/rwlock.c
+++ b/rwlock.c
@@ -94,8 +94,6 @@ pthread_rwlock_init(pthread_rwlock_t *rwlock, const pthread_rwlockattr_t *attr)
         return EINVAL;
       }
 
-    rw = *rwlock;
-
     rw = (pthread_rwlock_t) calloc(1, sizeof(*rw));
 
     if (rw == NULL)
@@ -182,14 +180,19 @@ pthread_rwlock_destroy(pthread_rwlock_t *rwlock)
           }
         else
           {
+            /*
+             * Need to NULL this before we start freeing up
+             * and destroying it's components.
+             */
+            *rwlock = NULL;
             rw->rw_magic = 0;
+
             (void) pthread_mutex_unlock(&(rw->rw_lock));
+
             (void) pthread_cond_destroy(&(rw->rw_condreaders));
             (void) pthread_cond_destroy(&(rw->rw_condwriters));
             (void) pthread_mutex_destroy(&(rw->rw_lock));
- 
             free(rw);
-            *rwlock = NULL;
            }
       }
     else