RFR: 8294062: Improve parsing performance of j.l.c.MethodTypeDesc
Adam Sotona
asotona at openjdk.org
Tue Sep 20 13:18:25 UTC 2022
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
-------------
Commit messages:
- 8294062: Improve parsing performance of j.l.c.MethodTypeDesc
Changes: https://git.openjdk.org/jdk/pull/10358/files
Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10358&range=00
Issue: https://bugs.openjdk.org/browse/JDK-8294062
Stats: 39 lines in 1 file changed: 8 ins; 22 del; 9 mod
Patch: https://git.openjdk.org/jdk/pull/10358.diff
Fetch: git fetch https://git.openjdk.org/jdk pull/10358/head:pull/10358
PR: https://git.openjdk.org/jdk/pull/10358
More information about the core-libs-dev
mailing list