dschneider-pivotal commented on code in PR #7751: URL: https://github.com/apache/geode/pull/7751#discussion_r890618589
########## geode-core/src/main/java/org/apache/geode/internal/monitoring/ThreadsMonitoringProcess.java: ########## @@ -119,30 +120,87 @@ private int checkForStuckThreads(Collection<AbstractExecutor> executors, long cu return result; } - @VisibleForTesting - public static Map<Long, ThreadInfo> createThreadInfoMap(Set<Long> stuckThreadIds) { - /* - * NOTE: at least some implementations of getThreadInfo(long[], boolean, boolean) - * will core dump if the long array contains a duplicate value. - * That is why stuckThreadIds is a Set instead of a List. - */ + /** + * If set to true, then the JVM will be asked for what locks a thread holds. + * This is extra expensive to ask for on some JVMs so be careful setting this to true. + */ + private static final boolean SHOW_LOCKS = Boolean.getBoolean("gemfire.threadmonitor.showLocks"); + /** + * If set to true, then the JVM will be asked for all potential stuck threads with one call. + * Since getThreadInfo on many JVMs, stops ALL threads from running, and since getting info + * on multiple threads with one call is additional work, setting this can cause an extra long + * stop the world that can then cause other problems (like a forced disconnect). + * So be careful setting this to true. + */ + private static final boolean BATCH_CALLS = Boolean.getBoolean("gemfire.threadmonitor.batchCalls"); + + private static Map<Long, ThreadInfo> createThreadInfoMap(Set<Long> stuckThreadIds) { + return createThreadInfoMap(stuckThreadIds, SHOW_LOCKS, BATCH_CALLS); + } + + public static Map<Long, ThreadInfo> createThreadInfoMap(Set<Long> stuckThreadIds, + boolean showLocks, boolean batchCalls) { + return createThreadInfoMap(ManagementFactory.getThreadMXBean(), stuckThreadIds, showLocks, + batchCalls); + } + + static Map<Long, ThreadInfo> createThreadInfoMap(ThreadMXBean threadMXBean, + Set<Long> stuckThreadIds, + final boolean showLocks, final boolean batchCalls) { if (stuckThreadIds.isEmpty()) { return Collections.emptyMap(); } + logger.info( + "Obtaining ThreadInfo for {} threads. Configuration: showLocks={} batchCalls={}. This is an expensive operation for the JVM and on most JVMs causes all threads to be paused.", + stuckThreadIds.size(), showLocks, batchCalls); + Map<Long, ThreadInfo> result = new HashMap<>(); + if (batchCalls) { + createThreadInfoMapUsingSingleCall(threadMXBean, stuckThreadIds, showLocks, result); + } else { + for (long id : stuckThreadIds) { + ThreadInfo threadInfo = createThreadInfoForSinglePid(threadMXBean, showLocks, id); + if (threadInfo != null) { + result.put(threadInfo.getThreadId(), threadInfo); + } + } + } + logger.info("finished obtaining ThreadInfo"); + return result; + } + + private static ThreadInfo createThreadInfoForSinglePid( Review Comment: yes, done -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: notifications-unsubscr...@geode.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org