Future<?> localTimer = timer;
    // Try to cancel the timer as an optimization.
    // timer may be null if this call to run was by the timer task since there is no happens-before
    // edge between the assignment to timer and an execution of the timer task.
    if (localTimer != null) {
      localTimer.cancel(false);
    }

    delegateRef = null;
    timer = null;
  }

### Timer changes

Go 1.23 makes two significant changes to the implementation of
[time.Timer] and [time.Ticker].

First, `Timer`s and `Ticker`s that are no longer referred to by the program
become eligible for garbage collection immediately, even if their
`Stop` methods have not been called.
Earlier versions of Go did not collect unstopped `Timer`s until after
they had fired and never collected unstopped `Ticker`s.

import org.codelibs.core.misc.DynamicProperties;
import org.codelibs.core.timer.TimeoutManager;
import org.codelibs.core.timer.TimeoutTask;
import org.codelibs.fess.Constants;
import org.codelibs.fess.crawler.client.FesenClient;
import org.codelibs.fess.es.client.SearchEngineClient;
import org.codelibs.fess.exception.ContainerNotAvailableException;
import org.codelibs.fess.timer.SystemMonitorTarget;
import org.codelibs.fess.util.ComponentUtil;

	// Wait for opened connection to be closed up to Shutdown timeout.
	shutdownTimeout := srv.ShutdownTimeout
	shutdownTimer := time.NewTimer(shutdownTimeout)
	defer shutdownTimer.Stop()

	timer := time.NewTimer(nextPollInterval())
	defer timer.Stop()
	for {
		select {
		case <-shutdownTimer.C:
			if atomic.LoadInt32(&srv.requestCount) <= 0 {
				return nil
			}

			// Write all running goroutines.

import java.util.Map;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.codelibs.core.lang.StringUtil;
import org.codelibs.core.timer.TimeoutManager;
import org.codelibs.core.timer.TimeoutTarget;
import org.codelibs.core.timer.TimeoutTask;
import org.codelibs.fess.Constants;
import org.codelibs.fess.es.config.exbhv.JobLogBhv;
import org.codelibs.fess.es.config.exbhv.ScheduledJobBhv;

 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.timer;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.function.Supplier;

import org.apache.commons.io.output.ByteArrayOutputStream;
import org.apache.commons.text.StringEscapeUtils;
import org.codelibs.core.timer.TimeoutTarget;
import org.codelibs.fess.Constants;

		}
		if maxWait > 0 && wantSleep > maxWait {
			wantSleep = maxWait
		}
		timer := time.NewTimer(wantSleep)
		select {
		case <-ctx.Done():
			if !timer.Stop() {
				<-timer.C
				if d.isScanner {
					globalScannerMetrics.incTime(scannerMetricYield, wantSleep)
				}
			}
			return
		case <-timer.C:
			if d.isScanner {
				globalScannerMetrics.incTime(scannerMetricYield, wantSleep)

import org.codelibs.core.log.Logger;

/**
 * Timerを扱うクラスです。
 *
 * @author higa
 *
 */
public class TimeoutManager implements Runnable {

    private static final Logger logger = Logger.getLogger(TimeoutManager.class);

    /**
     * シングルトンのためのインスタンスです。
     */
    protected static final TimeoutManager instance = new TimeoutManager();

    /**
     * Timerのための{@link Thread}です。
     */

    protected File baseDir;

    private Timer destoryTimer;

    @PostConstruct
    public void init() {
        if (logger.isDebugEnabled()) {
            logger.debug("Initialize {}", this.getClass().getSimpleName());
        }
        if (baseDir == null) {
            baseDir = new File(System.getProperty("java.io.tmpdir"));
        }

import org.codelibs.core.timer.TimeoutManager;
import org.codelibs.core.timer.TimeoutTask;
import org.codelibs.fess.Constants;
import org.codelibs.fess.crawler.client.FesenClient;
import org.codelibs.fess.es.client.SearchEngineClient;
import org.codelibs.fess.exception.ContainerNotAvailableException;
import org.codelibs.fess.helper.SuggestHelper;
import org.codelibs.fess.timer.SystemMonitorTarget;