1 files changed, 21 insertions, 0 deletions
diff --git a/rwlock.c b/rwlock.c
index cc85b7f..c2d85d8 100644
--- a/rwlock.c
+++ b/rwlock.c
@@ -378,8 +378,24 @@ pthread_rwlock_wrlock(pthread_rwlock_t * rwlock)
 
         if (rwl->nSharedAccessCount > 0) 
           {
+            /*
+             * pthread_rwlock_wrlock() is not a cancelation point
+             * so temporarily prevent pthread_cond_wait() from being one.
+             */
+            pthread_t self = pthread_self();
+            int cancelType = pthread_getcanceltype(self);
+            int oldCancelState;
+
             rwl->nCompletedSharedAccessCount = -rwl->nSharedAccessCount;
 
+            if (cancelType == PTHREAD_CANCEL_DEFERRED)
+              {
+                oldCancelState =
+                  pthread_setcancelstate(self,
+                                         PTHREAD_CANCEL_DISABLED);
+              }
+
+            /* Could still be PTHREAD_CANCEL_ASYNCHRONOUS. */
             pthread_cleanup_push(ptw32_rwlock_cancelwrwait, (void*)rwl);
 
             do 
@@ -389,6 +405,11 @@ pthread_rwlock_wrlock(pthread_rwlock_t * rwlock)
               }
             while (result == 0 && rwl->nCompletedSharedAccessCount < 0);
 
+            if (cancelType == PTHREAD_CANCEL_DEFERRED)
+              {
+                pthread_setcancelstate(self, oldCancelState);
+              }
+
             pthread_cleanup_pop ((result != 0) ? 1 : 0);
 
             if (result == 0)