src/share/vm/runtime/jniHandles.cpp

rev 13287 : 8175318: Performance issue regarding local JNI references
Summary: Avoid unnecessary repeated clears.
Reviewed-by:
rev 13288 : [mq]: reviews

*** 442,451 ****
--- 442,460 ----
      for (JNIHandleBlock* current = _next; current != NULL;
           current = current->_next) {
        assert(current->_last == NULL, "only first block should have _last set");
        assert(current->_free_list == NULL,
               "only first block should have _free_list set");
+       if (current->_top == 0) {
+         // All blocks after the first clear trailing block are already cleared.
+ #ifdef ASSERT
+         for (current = current->_next; current != NULL; current = current->_next) {
+           assert(current->_top == 0, "trailing blocks must already be cleared");
+         }
+ #endif
+         break;
+       }
        current->_top = 0;
        if (ZapJNIHandleArea) current->zap();
      }
      // Clear initial block
      _free_list = NULL;