On Tue, 20 Sep 2022 13:08:20 GMT, Adam Sotona <asot...@openjdk.org> wrote:
> Parsing performance of `j.l.c.MethodTypeDescriptor::ofDescriptor` can be > significantly improved and add performance boost to intensive users. > > Two main reasons have been identified and fixed in this patch: > > First glitch is late insertion of return type to the first position of > `j.u.ArrayList`, causing all previously parsed parameter types to shift using > `System::arraycopy`. > > Proposed patch inserts a placeholder for the return type first and replaces > it with return type later. > > Second performance degradation is in > `MethodTypeDescriptor::skipOverFieldSignature`, where each identified class > descriptor is exactly located by `String::indexOf`, extracted by > `String::substring`, and passed for for the purpose of verification to > `ConstantUtils::verifyUnqualifiedClassName`. > > Proposed patch inlines the unqualified class name verification into > `ConstantUtils::skipOverFieldSignature` parsing loop and so eliminates calls > of `String::indexOf` and `String::substring`. Package private method > `ConstantUtils::verifyUnqualifiedClassName` has no other use within the > package, so it is removed. > > Please review proposed performance improving patch. > > Thanks, > Adam JMH-measured performance boost of the patch when parsing single MethodTypeDesc with 8 Objects as method arguments is 33%. ------------- PR: https://git.openjdk.org/jdk/pull/10358