jmx-dev RFR: 8360599: [TESTBUG] DumpThreadsWithEliminatedLock.java fails because of unstable inlining

[Richard Reingruber]

This PR adds CompileCommands to the test DumpThreadsWithEliminatedLock.java to force inlining of java/lang/String*.* methods. This will make inlining more stable to allow for the expected lock elimination based on c2 escape analysis.

Forcing inlining of java/lang/StringBuffer.* wasn't sufficient on x86_64. With that the test still failed with TieredCompilation disabled.

Testing: x86_64, ppc64

Failed inlining on x86_64 with TieredCompilation disabled:


make test TEST=com/sun/management/HotSpotDiagnosticMXBean/DumpThreadsWithEliminatedLock.java TEST_VM_OPTS="-XX:-TieredCompilation -XX:+UnlockDiagnosticVMOptions -XX:CompileCommand=PrintInlining,DumpThreadsWithEliminatedLock.*" JTREG=TIMEOUT_FACTOR=0.1

[...]

STDOUT:
CompileCommand: PrintInlining DumpThreadsWithEliminatedLock.* bool PrintInlining = true
                            @ 1   java.util.concurrent.atomic.AtomicBoolean::get (13 bytes)   inline (hot)
                            @ 11   java.lang.StringBuffer::<init> (7 bytes)   inline (hot)   late inline succeeded (string method)
                              @ 3   java.lang.AbstractStringBuilder::<init> (39 bytes)   inline (hot)
                                @ 1   java.lang.Object::<init> (1 bytes)   inline (hot)
                            @ 16   java.lang.System::currentTimeMillis (0 bytes)   (intrinsic)
              s             @ 19   java.lang.StringBuffer::append (13 bytes)   failed to inline: already compiled into a big method
              s             @ 24   java.lang.StringBuffer::toString (44 bytes)   inline (hot)   late inline succeeded (string method)
              s               @ 1   java.lang.StringBuffer::length (5 bytes)   accessor
                              @ 24   java.lang.String::<init> (98 bytes)   failed to inline: already compiled into a big method
                            @ 30   java.util.concurrent.atomic.AtomicReference::set (6 bytes)   accessor
2025-07-02T09:25:53.396634900Z Attempt 1, found: false
2025-07-02T09:25:53.415673072Z Attempt 2, found: false
2025-07-02T09:25:53.418876867Z Attempt 3, found: false

[...]

-------------

Commit messages:
 - Force inlining of String*.* methods
 - Force inlining of StringBuffer methods

Changes: https://git.openjdk.org/jdk/pull/26033/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=26033&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8360599
  Stats: 4 lines in 1 file changed: 0 ins; 0 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/26033.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26033/head:pull/26033

PR: https://git.openjdk.org/jdk/pull/26033