RFR: 8296746: NativePRNG SecureRandom doesn't scale with threads

Thu Nov 10 01:26:54 UTC 2022

NativePRNG SecureRandom doesn’t scale with number of threads. The performance starts dropping as we increase the number of threads. Even going from 1 thread to 2 threads shows significant drop. The bottleneck is the singleton RandomIO instance. Making the RandomIO ThreadLocal helps in removing this bottleneck.

Here are the jmh  thrpt ops/s data for SecureRandomBench.nextBytes, algorithm=NativePRNGNonBlocking, datasize=64, notshared:

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<head>

<meta name=ProgId content=Excel.Sheet>
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<body link="#0563C1" vlink="#954F72">

#threads | singleton RandomIO | ThreadLocal RandomIO
-- | -- | --
1 | 1269133 | 1279088
2 | 862923 | 1362066
3 | 819734 | 1630522
4 | 809128 | 1614500
5 | 821514 | 1594965
6 | 808795 | 1545045
7 | 783050 | 1499388
8 | 787236 | 1470004

</body>

</html>

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Commit messages:
 - cleanup
 - removed print statements
 - Initial change with Sandhya's patch

Changes: https://git.openjdk.org/jdk/pull/11069/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=11069&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8296746
  Stats: 30 lines in 1 file changed: 3 ins; 0 del; 27 mod
  Patch: https://git.openjdk.org/jdk/pull/11069.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11069/head:pull/11069

PR: https://git.openjdk.org/jdk/pull/11069