force memory barrier on unlock.

Former-commit-id: 4e0eed1c3fd3aebe5b9f82ad085aa968dd40869e

src/lock.h

@@ -45,5 +45,5 @@
         return 0;
         }
     #define lock_trylock( l ) ( ( *(l) ) ? 1 : __sync_val_compare_and_swap( l , 0 , 1 ) )
-    #define lock_unlock( l ) ( __sync_lock_test_and_set( l , 0 ) != 1 )
+    #define lock_unlock( l ) ( __sync_val_compare_and_swap( l , 1 , 0 ) != 1 )
 #endif

src/runner.c

@@ -1526,7 +1526,7 @@ struct task *queue_gettask ( struct queue *q , int blocking , int keep ) {
             
                 /* Bubble-up. */
                 q->count = qcount - 1;
-                for ( ; k < qcount ; k++)
+                for ( ; k < qcount - 1 ; k++ )
                     qtid[k] = qtid[k+1];
             
                 }