New features for valgrind:

1. ST: Support /api/v1/valgrind for leaking check.
2. ST: Support /api/v1/valgrind?check=full|added|changed|new|quick

To use Valgrind to detect memory leaks in SRS, even though Valgrind hooks are supported in ST, there are still many false positives. A more reasonable approach is to have Valgrind report incremental memory leaks. This way, global and static variables can be avoided, and detection can be achieved without exiting the program. Follow these steps:

1. Compile SRS with Valgrind support: ./configure --valgrind=on && make
2. Start SRS with memory leak detection enabled: valgrind --leak-check=full ./objs/srs -c conf/console.conf
3. Trigger memory detection by using curl to access the API and generate calibration data. There will still be many false positives, but these can be ignored: curl http://127.0.0.1:1985/api/v1/valgrind?check=added
4. Perform load testing or test the suspected leaking functionality, such as RTMP streaming: ffmpeg -re -i doc/source.flv -c copy -f flv rtmp://127.0.0.1/live/livestream
5. Stop streaming and wait for SRS to clean up the Source memory, approximately 30 seconds.
6. Perform incremental memory leak detection. The reported leaks will be very accurate at this point: curl http://127.0.0.1:1985/api/v1/valgrind?check=added

Note: To avoid interference from the HTTP request itself on Valgrind, SRS uses a separate coroutine to perform periodic checks. Therefore, after accessing the API, you may need to wait a few seconds for the detection to be triggered.

Co-authored-by: Jacob Su suzp1984@gmail.com