> Enhance `ResourceParsingClassHierarchyResolver.getClassInfo` to use > `ClassReaderImpl` to improve performance. Previously this method inflated and > stored all UTF-8 entries in the constant pool and later accessed the array of > strings to try finding the name of the superclass. `ClassReaderImpl` instead > stores constant pool offsets and later lazily reads/inflates UTF8 entries as > needed. > > I’ve ran all tier 1 tests and tests within `test/jdk/jdk/classfile` on the > latest version of this change, and they all pass. > > I ran some informal performance testing to see if these changes led to any > improvement. I created a .class file with several thousand unique strings in > a String array to deliberately enlarge the number of UTF-8 entries in the > constant pool. I then benchmarked the performance of running a process nearly > identical to `ClassHierarchyInfoTest.testClassLoaderParsingResolver` on this > custom class over 200 runs using JMH. The results are as follows. > > | Version | Avg Time (ns/op) | Δ vs Before | > |--------|------------------:|-------------| > | **Before** | 1,483,671.539 ± 3,477.744 | — | > | **After** | 1,380,064.517 ± 3,482.434 | ≈ 7.0% faster |
Trevor Bond has updated the pull request incrementally with one additional commit since the last revision: Remove unnecessary imports ------------- Changes: - all: https://git.openjdk.org/jdk/pull/28458/files - new: https://git.openjdk.org/jdk/pull/28458/files/c906c061..a990cd30 Webrevs: - full: https://webrevs.openjdk.org/?repo=jdk&pr=28458&range=01 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=28458&range=00-01 Stats: 6 lines in 1 file changed: 0 ins; 5 del; 1 mod Patch: https://git.openjdk.org/jdk/pull/28458.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/28458/head:pull/28458 PR: https://git.openjdk.org/jdk/pull/28458
