RFR: 8142334: Improve lazy initialization of java.lang.invoke

[Claes Redestad]

Hi Peter,

nice catch:

http://cr.openjdk.java.net/~redestad/8142334/webrev.02

/Claes

On 2015-11-09 20:26, Peter Levart wrote:
> Hi Claes,
>
> I see you apply this pattern consistently:
>
>     private static NamedFunction getConstantFunction(int idx) {
>         NamedFunction function = FUNCTIONS[idx];
>         if (function != null) {
>             return function;
>         }
>         return makeConstantFunction(idx);
>     }
>
>
>     private static NamedFunction makeConstantFunction(int idx) {
>         try {
>             switch (idx) {
>                 case NF_internalMemberName:
>                     return setCachedFunction(idx, new 
> NamedFunction(DirectMethodHandle.class
> .getDeclaredMethod("internalMemberName", Object.class)));
>             ...
>
>
>
> You could move a repeatable call to setCachedFuncion from individual 
> cases of makeConstantFunction to getConstantFunction:
>
>     private static NamedFunction getConstantFunction(int idx) {
>         NamedFunction function = FUNCTIONS[idx];
>         if (function != null) {
>             return function;
>         }
>         return setCachedFunction(idx, makeConstantFunction(idx));
>     }
>
>     private static NamedFunction makeConstantFunction(int idx) {
>         try {
>             switch (idx) {
>                 case NF_internalMemberName:
>                     return new 
> NamedFunction(DirectMethodHandle.class.getDeclaredMethod("internalMemberName", 
> Object.class));
>             ...
>
>
>
> Regards, Peter
>
> On 11/09/2015 06:51 PM, Claes Redestad wrote:
>> Hi,
>>
>> across java.lang.invoke there are a number of inner Lazy classes 
>> whose purpose is to defer initialization of various internally used 
>> NamedFunctions and MethodHandles until first usage. The issue is that 
>> once *any* function or handle in these classes are referenced they're 
>> all initialized, which somewhat defeats the purpose.
>>
>> By moving to per-MethodHandle and per-NamedFunction lazy 
>> initialization, similar to existing code in 
>> java.lang.invoke.Invokers, we improve the laziness generally: for a 
>> jigsaw Hello World the number of LambdaForms created drops from 74 to 
>> 46, reducing heap occupancy for a minimal application and measurably 
>> improving startup time.
>>
>> Webrev: http://cr.openjdk.java.net/~redestad/8142334/webrev.01
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8142334
>>
>> /Claes
>>
>