v4.2

Features

• Java Method Tracing and Latency Profiling
  • #1421: Latency profiling
  • #1435: Allow wildcards in Instrument profiling engine
  • #1499: --trace option with per-method latency threshold
• System-wide process sampling on Linux
  • #1411: --proc option to record profiler.ProcessSample events
• VMStructs stack walker by default
  • #1539: Use VMStructs stack walking mode by default
  • #1537: Support comptask and vtable features
  • #1517: Use JavaFrameAnchor to find top Java frame
  • #1449: Special handling of prologue and epilogue of compiled methods

Improvements

• #1475: Add CPUTimeSample event 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_nanos and duration_nanos to 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 calloc calls malloc for 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