New
Method tracing and system-wide process sampling
v4.2
Features
- Java Method Tracing and Latency Profiling
- #1421: Latency profiling
- #1435: Allow wildcards in Instrument profiling engine
- #1499:
--traceoption with per-method latency threshold
- System-wide process sampling on Linux
- #1411:
--procoption to recordprofiler.ProcessSampleevents
- #1411:
- VMStructs stack walker by default
- #1539: Use VMStructs stack walking mode by default
- #1537: Support
comptaskandvtablefeatures - #1517: Use JavaFrameAnchor to find top Java frame
- #1449: Special handling of prologue and epilogue of compiled methods
Improvements
- #1475: Add
CPUTimeSampleevent support to jfrconv - #1414: Per-thread flamegraph option in JFR heatmap converter
- #1526: Expose JfrReader dictionary that maps osThreadId to javaThreadId
- #1448: Thread name in OpenTelemetry output
- #1413: Add
time_nanosandduration_nanosto OTLP profiles - #1450: Unwind dylib stubs as empty frames on macOS
- #1416: Add synthetic symbols for Mach-O stubs/trampolines
- Allow cross-compilation for 32-bit platforms
Bug fixes
- #1515: Fix UnsatisfiedLinkError when tmpdir is set to a relative path
- #1500: Detect if
calloccallsmallocfor nativemem profiling - #1427: Re-implement SafeAccess crash protection
- #1417: Two wall-clock profilers interfere with each other
Project Infrastructure
- #1527: GHA: replace macos-13 with macos-15-intel
- #1510: Add option to retry tests
- #1508: Add more GHA jobs to cover JDK versions on ARM
- #1502: Fix job dependencies between integration tests and builds
- #1466: Add Liberica JDK on Alpaquita Linux to the CI
- Made integration tests more stable overall