Based on async-profiler 2.8.3

This is not a fork of async-profiler. This is a work derived from async-profiler but tailored very specifically for Datadog needs. If you need a full-fledged Java profiler head back to async-profiler

1. JDK 8 or later (required for building)
2. Gradle (included in wrapper)
3. C++ compiler (gcc/g++ or clang)
4. Make (included in XCode on Macos)
5. Google Test (for unit testing)
   • On Ubuntu/Debian: sudo apt install libgtest-dev
   • On macOS: brew install googletest
   • On Alpine: apk add gtest-dev
6. clang-format 11 (for code formatting)
   • On Ubuntu/Debian: sudo apt install clang-format-11
   • On macOS: brew install clang-format-11
   • On Alpine: apk add clang-format-11

1. Clone the repository:

git clone https://github.com/DataDog/java-profiler.git
cd java-profiler

2. Build a release version of the project:

./gradle buildRelease

The resulting artifact will be in ddprof-lib/build/libs/ddprof-<version>.jar

The project includes both Java and C++ unit tests. You can run them using:

# Run all tests
./gradlew test

# Run specific test configurations
./gradlew testRelease  # Run release build tests
./gradlew testDebug    # Run debug build tests
./gradlew testAsan     # Run tests with ASan
./gradlew testTsan     # Run tests with TSan

# Run C++ unit tests only
./gradlew gtestDebug   # Run C++ tests in debug mode
./gradlew gtestRelease # Run C++ tests in release mode

• Skip all tests: ./gradlew build -Pskip-tests
• Keep JFR recordings: ./gradlew test -PkeepJFRs
• Skip native build: ./gradlew build -Pskip-native
• Skip C++ tests: ./gradlew build -Pskip-gtest

The project uses several tools for code quality:

1. clang-format for C++ code formatting
2. scan-build for static analysis
3. cppcheck for additional C++ checks

Run code quality checks:

# Run scan-build (this will use the scan-build binary)
./gradlew scanBuild

# Run cppcheck (if configured)
./gradlew cppcheck

# Run spotless (including code formatting)
./gradlew spotlessApply

!TODO!

The project includes JMH-based stress tests:

# Run all stress tests
./gradlew :ddprof-stresstest:runStressTests

### Common Issues
1. If you encounter strange crashes Asan:
   ```bash
   sudo sysctl vm.mmap_rnd_bits=28

2. For ASan/TSan issues, ensure you have the required libraries installed:
   • ASan: libasan
   • TSan: libtsan

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Run tests: ./gradlew test
5. Submit a pull request

This project is licensed under the Apache License 2.0 - see the LICENSE file for details.

Download the latest version of dd-trace-java and add -Ddd.profiling.ddprof.debug.lib. Example of a command line:

DD_SERVICE=your-service DD_TRACE_DEBUG=true java -javaagent:./temp/dd-java-agent.jar -Ddd.profiling.enabled=true -Ddd.profiling.ddprof.enabled=true -Ddd.profiling.ddprof.liveheap.enabled=true -Ddd.profiling.upload.period=10 -Ddd.profiling.start-force-first=true -Ddd.profiling.ddprof.debug.lib=~/dd/java-profiler/ddprof-lib/build/lib/main/debug/linux/x64/libjavaProfiler.so -XX:ErrorFile=${PWD}/hs_err_pid%p.log -XX:OnError='java -jar temp/dd-java-agent.jar uploadCrash hs_err_pid%p.log' -jar ./temp/renaissance-gpl-0.15.0.jar akka-uct -r 5

For dd-trace-java you just need to set the ddprof.jar project property. Eg. you can run the gradle build like this - ./gradlew clean -Pddprof.jar=file://<path-to-artifact.jar> :dd-java-agent:shadowJar- which will result in a customdd-java-agent.jar` build containing your test version of Java profiler.

Although this project still shares the git history with the upstream the code structure is different. This makes it dificult to reliably cherry-pick the upstream changes. To make this easier we have a script that will prepare the upstream repository and add it as 'cherry' remote to this repository. This way you can cherry-pick the changes from the upstream repository with (relative) ease.

./utils/init_cherrypick_repo.sh # you need to run this only once

./utils/cherry.sh <commit>
# ... resolve conflicts, if any
./utils/cherry.sh --continue # to commit the resolved conflicts