fish.payara.microprofile.metrics.impl.ConcurrentGaugeImpl Maven / Gradle / Ivy

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 *     may not use this file except in compliance with the License.  You can
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package fish.payara.microprofile.metrics.impl;

import java.util.concurrent.atomic.AtomicInteger;
import javax.enterprise.inject.Vetoed;

import org.eclipse.microprofile.metrics.ConcurrentGauge;

/**
 * Implementation of ConcurrentGauge from Microprofile Metrics
 *
 * @see ConcurrentGauge
 * @since 5.193
 */
@Vetoed
public class ConcurrentGaugeImpl extends CompleteMinuteMinMaxTracker implements ConcurrentGauge {

    /**
     * The number of threads currently executing the annotated method.
     */
    private final AtomicInteger threads = new AtomicInteger();

    public ConcurrentGaugeImpl() {
        this(Clock.DEFAULT);
    }

    public ConcurrentGaugeImpl(Clock clock) {
        super(clock);
    }

    /**
     * Increment the counter by one.
     */
    @Override
    public void inc() {
        threads.incrementAndGet();
        updateMaxValue(threads.longValue());
    }

    @Override
    public void dec() {
        threads.decrementAndGet();
        updateMinValue(threads.longValue());
    }

    /**
     * Returns the counter's current value.
     *
     * @return the counter's current value
     */
    @Override
    public long getCount() {
        return threads.get();
    }

    @Override
    public long getMax() {
        Long max = getMaxValue();
        return max == null ? 0L : max.longValue();
    }

    @Override
    public long getMin() {
        Long min = getMinValue();
        return min == null ? 0L : min.longValue();
    }

    @Override
    public String toString() {
        return "ConcurrentGauge[" + getCount() + "]";
    }
}