+1 On 2013-06-26, at 6:44 AM, Hannes Wallnoefer <[email protected]> wrote:
> Please review JDK-8019157 - Avoid calling ScriptObject.setProto() if possible: > > http://cr.openjdk.java.net/~hannesw/8019157/ > > Bug description pasted below for your convenience. > > Calling ScriptObject.setProto() is quite expensive. One expensive part is > invalidating the object's property map, which involves a WeakHashMap lookup > in PropertyMap.checkProtoHistory(). > > Invaliding the property map is necessary if the property map may be in use > with other prototypes. However, many built-in objects including arrays (in > fact all built-ins except for Object) are always constructed with the same > combination of prototype and property map. > > In this case we can significantly improve object creation overhead by > providing a way to directly set both prototype and property map. > > Thanks, > Hannes
