package com.codahale.metrics.jvm;
import com.codahale.metrics.Gauge;
import com.codahale.metrics.Metric;
import com.codahale.metrics.MetricSet;
import java.lang.management.ManagementFactory;
import java.lang.management.ThreadInfo;
import java.lang.management.ThreadMXBean;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import static com.codahale.metrics.MetricRegistry.name;
public class ThreadStatesGaugeSet implements MetricSet {
private final static int STACK_TRACE_DEPTH = 0;
private final ThreadMXBean threads;
private final ThreadDeadlockDetector deadlockDetector;
public ThreadStatesGaugeSet() {
this(ManagementFactory.getThreadMXBean(), new ThreadDeadlockDetector());
}
public ThreadStatesGaugeSet(ThreadMXBean threads,
ThreadDeadlockDetector deadlockDetector) {
this.threads = threads;
this.deadlockDetector = deadlockDetector;
}
@Override
public Map<String, Metric> getMetrics() {
final Map<String, Metric> gauges = new HashMap<>();
for (final Thread.State state : Thread.State.values()) {
gauges.put(name(state.toString().toLowerCase(), "count"),
(Gauge<Object>) () -> getThreadCount(state));
}
gauges.put("count", (Gauge<Integer>) threads::getThreadCount);
gauges.put("daemon.count", (Gauge<Integer>) threads::getDaemonThreadCount);
gauges.put("deadlock.count", (Gauge<Integer>) () -> deadlockDetector.getDeadlockedThreads().size());
gauges.put("deadlocks", (Gauge<Set<String>>) deadlockDetector::getDeadlockedThreads);
return Collections.unmodifiableMap(gauges);
}
private int getThreadCount(Thread.State state) {
final ThreadInfo[] allThreads = getThreadInfo();
int count = 0;
for (ThreadInfo info : allThreads) {
if (info != null && info.getThreadState() == state) {
count++;
}
}
return count;
}
ThreadInfo[] getThreadInfo() {
return threads.getThreadInfo(threads.getAllThreadIds(), STACK_TRACE_DEPTH);
}
}