io.dropwizard.metrics5.jvm.ThreadStatesGaugeSet Maven / Gradle / Ivy

package io.dropwizard.metrics5.jvm;

import io.dropwizard.metrics5.Gauge;
import io.dropwizard.metrics5.Metric;
import io.dropwizard.metrics5.MetricName;
import io.dropwizard.metrics5.MetricRegistry;
import io.dropwizard.metrics5.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;

/**
 * A set of gauges for the number of threads in their various states and deadlock detection.
 */
public class ThreadStatesGaugeSet implements MetricSet {

    // do not compute stack traces.
    private final static int STACK_TRACE_DEPTH = 0;

    private final ThreadMXBean threads;
    private final ThreadDeadlockDetector deadlockDetector;

    /**
     * Creates a new set of gauges using the default MXBeans.
     */
    public ThreadStatesGaugeSet() {
        this(ManagementFactory.getThreadMXBean(), new ThreadDeadlockDetector());
    }

    /**
     * Creates a new set of gauges using the given MXBean and detector.
     *
     * @param threads          a thread MXBean
     * @param deadlockDetector a deadlock detector
     */
    public ThreadStatesGaugeSet(ThreadMXBean threads,
                                ThreadDeadlockDetector deadlockDetector) {
        this.threads = threads;
        this.deadlockDetector = deadlockDetector;
    }

    @Override
    public Map getMetrics() {
        final Map gauges = new HashMap<>();

        for (final Thread.State state : Thread.State.values()) {
            gauges.put(MetricRegistry.name(state.toString().toLowerCase(), "count"),
                    (Gauge