On Sat, 24 May 2025 06:57:56 GMT, Alan Bateman <al...@openjdk.org> wrote:
> Updates the thread dump generated by HotSpotDiagnosticMXBean.dumpThreads and > jcmd Thread.dump_to_file to include thread state and lock information. Also > update the HotSpotDiagnosticMXBean.dumpThreads API description to link to a > description of the JSON format dump as that format is intended to be > parseable/read by tools. > > This PR is dependent on > [pull/25425](https://github.com/openjdk/jdk/pull/25425). As noted in that PR, > the changes accumulated in the loom repo, and have been split up to make it > easier to review. > > The changes include some re-implementation of ThreadDumper. This is because > it used PrintStream and didn't fail if there was an I/O error, e.g. file > system full. Furthermore, the indentation to pretty print the json was > fragile and hard to maintain so this is changed to use a supporting writer > class to do this. > > Test coverage is significantly expanded, including updating the test library > that is used by several tests to parse the thread dump. > > Testing: tier1-6 src/java.base/share/classes/jdk/internal/vm/ThreadDumper.java line 56: > 54: * thread dump to a file or byte array in plain text or JSON format. > 55: */ > 56: public class ThreadDumper { Suggestion: public final class ThreadDumper { src/java.base/share/classes/jdk/internal/vm/ThreadDumper.java line 375: > 373: * This class is not intended to be a fully featured JSON writer. > 374: */ > 375: private static class JsonWriter { Suggestion: private static final class JsonWriter { private static final class Node { src/java.base/share/classes/jdk/internal/vm/ThreadSnapshot.java line 33: > 31: * Represents a snapshot of information about a Thread. > 32: */ > 33: class ThreadSnapshot { Suggestion: final class ThreadSnapshot { src/java.base/share/classes/jdk/internal/vm/ThreadSnapshot.java line 182: > 180: */ > 181: private class ThreadLock { > 182: private static final OwnedLockType[] lockTypeValues = > OwnedLockType.values(); // cache Suggestion: @Stable private static final OwnedLockType[] lockTypeValues = OwnedLockType.values(); test/jdk/com/sun/management/HotSpotDiagnosticMXBean/DumpThreadsWithEliminatedLock.java line 83: > 81: sb.append(System.currentTimeMillis()); > 82: String s = sb.toString(); > 83: ref.set(s); Suggestion: ref.set( new StringBuffer() .append(System.currentTimeMillis()) .toString()); ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/25429#discussion_r2105771285 PR Review Comment: https://git.openjdk.org/jdk/pull/25429#discussion_r2105771656 PR Review Comment: https://git.openjdk.org/jdk/pull/25429#discussion_r2105770924 PR Review Comment: https://git.openjdk.org/jdk/pull/25429#discussion_r2105771148 PR Review Comment: https://git.openjdk.org/jdk/pull/25429#discussion_r2105771949
