LinuxDebuggerLocal has worker thread (LinuxDebuggerLocalWorkerThread) to call ptrace(2) because it have to call from same thread.
LinuxDebuggerLocalWorkerThread does not have queue, so it depends on synchronized statement as following: https://github.com/openjdk/jdk/blob/66d9961cbd83dbfca20b0af3c20693438d4aff3f/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/linux/LinuxDebuggerLocal.java#L156-L192 If `execute()` is called in same time, `task` would be broken. Fortunately all of caller of `execute()` are guarded with `synchronized` now. But task worker should be more robustness. I used `Executors::newSingleThreadExecutor`, so we don't need to take care task queue. I tested this change with serviceability/sa jtreg tests on Linux x64. ------------- Commit messages: - 8264639: SA: Worker thread for ptrace on Linux should be more robustness Changes: https://git.openjdk.java.net/jdk/pull/3321/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=3321&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8264639 Stats: 172 lines in 1 file changed: 17 ins; 108 del; 47 mod Patch: https://git.openjdk.java.net/jdk/pull/3321.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/3321/head:pull/3321 PR: https://git.openjdk.java.net/jdk/pull/3321
