> Can I please get a review of this change which seeks to implement the > enhancement noted in https://bugs.openjdk.java.net/browse/JDK-8153133? > > The commit in this PR uses the `StackWalker` API to dump the stacktrace of > the thread. A few things to note about this change: > > - Previously, the dumped stacktrace would be preceded by a line (from the > `Exception` instance) which would state `java.lang.Exception: Stack trace` > and the rest of the lines would be the stacktrace. The change in this PR does > a small (unrelated) enhacement which now includes the thread name in the > message. So something like `MainThread Stack trace` where `MainThread` is the > name of the thread whose stacktrace is being dumped. The linked JBS doesn't > mention this change as a necessity but I decided to include it in this PR > since I've always missed the thread name in that dumped stacktrace and since > we are now using the StackWalker API, the mention of `java.lang.Exception: > ...` line in the thread dump will no longer make sense (unless we wanted > backward compatibility) > - The change doesn't use lambda to allow `Thread.dumpStack()` to be called > (for debugging purposes) from places where lambda usage might be too early. > - The change also includes a fallback to use the > `Exception.printStackTrace()` to allow for calls to `Thread.dumpStack()` when > `StackWalker` class itself is being initialized. > > The PR also includes a new jtreg test which verifies this change. The test > has 3 test actions - one without security manager, one with security manager > and one with `java.security.debug=access,stack` to exercise the case where > Thread.dumpStack() gets called during StackWalker class initialization. > > The linked JBS issue notes that it would be good to use the StackWalker API > even in the `Thread.getStackTrace` implementation. This PR however doesn't > include that change because I wanted to tackle that separately since I think > that would need to run some performance benchmarks to evaluate any > performance changes. The current `Thread.dumpStack` method clearly states > that it is meant for debugging purposes so I haven't run any kind of > performance benchmarks on this change.
Jaikiran Pai has updated the pull request incrementally with one additional commit since the last revision: fix jcheck failure - convert tab to space ------------- Changes: - all: https://git.openjdk.java.net/jdk/pull/6292/files - new: https://git.openjdk.java.net/jdk/pull/6292/files/aa5f6288..95739ab4 Webrevs: - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=6292&range=02 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=6292&range=01-02 Stats: 6 lines in 1 file changed: 0 ins; 0 del; 6 mod Patch: https://git.openjdk.java.net/jdk/pull/6292.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/6292/head:pull/6292 PR: https://git.openjdk.java.net/jdk/pull/6292
