// Return thread IDs of deadlocked threads or null if any.
// It finds deadlocks involving only monitors if it's a Tiger VM.
// Otherwise, it finds deadlocks involving both monitors and
// the concurrent locks.
public long[] findDeadlockedThreads() throws IOException {
ThreadMXBean tm = getThreadMXBean();
if (supportsLockUsage && tm.isSynchronizerUsageSupported()) {
return tm.findDeadlockedThreads();
} else {
return tm.findMonitorDeadlockedThreads();
}
}
