v4.0

Features

• #895, #905: jfrconv binary and numerous converter enhancements
• #944: Interactive Heatmap
• #1064: Native memory leak profiler
• #1002: An option to display instruction addresses
• #1007: Optimize wall clock profiling
• #1073: Productize VMStructs-based stack walker: --cstack vm/vmx
• #1169: C API for accessing thread-local profiling context

Improvements

• #923: Support JDK 23+
• #952: Solve musl and glibc compatibility issues; link libstdc++ statically
• #955: --libpath option to specify path to libasyncProfiler.so in a container
• #1018: --grain converter option to coarsen flame graphs
• #1046: --nostop option to continue profiling outside --begin/--end window
• #1178: --inverted option to flip flame graphs vertically
• #1009: Allows collecting allocation and live object traces at the same time
• #925: An option to accumulate JFR events in memory instead of flushing to a file
• #929: Load symbols from debuginfod cache
• #982: Sample contended locks by overflowing interval bucket
• #993: Filter native frames in allocation profile
• #896: FlameGraph: Alt+Click to remove stacks
• #1097: FlameGraph: N/Shift+N to navigate through search results
• #1182: Retain by-thread grouping when reversing FlameGraph
• #1167: Log when no samples are collected
• #1044: Fall back to ctimer for CPU profiling when perf_events are unavailable
• #1068: Count missed samples when estimating total CPU time in ctimer mode
• #1142: Use counter-timer register for timestamps on ARM64
• #1123: Support clock=tsc without a JVM
• #1070: Demangle Rust v0 symbols
• #1007: Use ExecutionSample event for CPU profiling and WallClockSample for Wall clock profiling
• #1011: Obtain can_generate_sampled_object_alloc_events JVMTI capability only when needed
• #1013: Intercept java.util.concurrent locks more efficiently
• #759: Discover available profiling signal automatically
• #884: Record event timestamps early
• #885: Print error message if JVM fails to load libasyncProfiler
• #892: Resolve tracepoint id in asprof
• Suppress dynamic attach warning on JDK 21+

Bug fixes

• #1143: Crash on macOS when using thread filter
• #1125: Fixed parsing concurrently loaded libraries
• #1095: jfr print fails when a recording has empty pools
• #1084: Fixed Logging related races
• #1074: Parse both .rela.dyn and .rela.plt sections
• #1003: Support both tracefs and debugfs for kernel tracepoints
• #986: Profiling output respects loglevel
• #981: Avoid JVM crash by deleting JNI refs after GetMethodDeclaringClass
• #934: Fix crash on Zing in a native thread
• #843: Fix race between parsing and concurrent unloading of shared libraries
• #1147, #1151: Deadlocks with jemalloc and tcmalloc profilers
• Stack walking fixes for ARM64
• Converter fixes for jfrsync profiles
• Fixed parsing non-PIC executables and shared objects with non-standard section layout
• Fixed recursion in pthread_create when using native profiling API
• Fixed crashes on Alpine when profiling native apps
• Fixed warnings with -Xcheck:jni
• Fixed "Unsupported JVM" on OpenJ9 JDK 21
• Fixed DefineClass crash on OpenJ9
• JfrReader should handle custom events properly
• Handle truncated JFRs

Project Infrastructure

• Restructure and update documentation
• Implement test framework; add new integration tests
• Unit test framework for C++ code
• Run CI on all supported platforms
• Test multiple JDK versions in CI
• Add GHA to validate license headers
• Add Markdown checker and formatter
• Add Issue and Pull Request templates
• Add Contributing Guidelines and Code of Conduct
• Run static analyzer and fix found issues (#1034, #1039, #1049, #1051, #1098)
• Provide Dockerfile for building async-profiler release packages
• Publish nightly builds automatically