RFR: 8170467: (reflect) Optimize SignatureParser's use of StringBuilders (original) (raw)

Peter Levart peter.levart at gmail.com
Tue Nov 29 16:57:06 UTC 2016

Hi,

What about not using StringBuilder at all?

http://cr.openjdk.java.net/~plevart/jdk9-dev/8170467_SignatureParser/webrev.01/

There's also some mockery in getNext()/current()/advance() that uses exceptions for control flow which can be fixed while changing this part of code. The asserts in getNext()/current()/advance() could even fail if getNext()/advance() was called after already returning EOI (== character ':')...

Regards, Peter

On 11/29/2016 03:03 PM, Claes Redestad wrote:

Hi Andrej,

On 2016-11-29 14:39, Andrej Golovnin wrote: Hi Claes,

76 public static final int CLASSNAMESBSIZE = 48; Why is this constant public? Good catch, made it private. Btw. for our product this value is too small. We have packages with longer names. I would use 64. :-) There's no one size fits all: something around 48 is likely to help most common cases, while not noticeably penalizing shorter names. I'd consider it a bad move to regress apps with short-to-normal names to get a small gain on apps with very long names Thanks! /Claes

Best regards, Andrej Golovnin On Tue, Nov 29, 2016 at 2:18 PM, Claes Redestad <claes.redestad at oracle.com> wrote: Hi,

please review this patch provided by Max Kanat-Alexander[1] to improve performance of sun.reflect.generics.parser.SignatureParser by reducing number of StringBuilders created and the rate at which they are resized during typical usage. Webrev: http://cr.openjdk.java.net/~redestad/8170467/webrev.01/ Bug: https://bugs.openjdk.java.net/browse/JDK-8170467 Thanks! /Claes [1] http://mail.openjdk.java.net/pipermail/core-libs-dev/2016-November/045046.html

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