panda.lang.ThreadMonitor Maven / Gradle / Ivy
package panda.lang;
/**
* Monitors a thread, interrupting it of it reaches the specified timout.
*
* This works by sleeping until the specified timout amount and then
* interrupting the thread being monitored. If the thread being monitored
* completes its work before being interrupted, it should interrupt()
* the monitor thread.
*
*
*
* long timeoutInMillis = 1000;
* try {
* Thread monitor = ThreadMonitor.start(timeoutInMillis);
* // do some work here
* ThreadMonitor.stop(monitor);
* } catch (InterruptedException e) {
* // timed amount was reached
* }
*
*/
public class ThreadMonitor implements Runnable {
private final Thread thread;
private final long timeout;
/**
* Start monitoring the current thread.
*
* @param timeout The timout amount in milliseconds or no timeout if the value is zero or less
* @return The monitor thread or {@code null} if the timout amount is not greater than zero
*/
public static Thread start(long timeout) {
return start(Thread.currentThread(), timeout);
}
/**
* Start monitoring the specified thread.
*
* @param thread The thread The thread to monitor
* @param timeout The timout amount in milliseconds or no timeout if the value is zero or less
* @return The monitor thread or {@code null} if the timout amount is not greater than zero
*/
public static Thread start(Thread thread, long timeout) {
Thread monitor = null;
if (timeout > 0) {
ThreadMonitor timout = new ThreadMonitor(thread, timeout);
monitor = new Thread(timout, ThreadMonitor.class.getSimpleName());
monitor.setDaemon(true);
monitor.start();
}
return monitor;
}
/**
* Stop monitoring the specified thread.
*
* @param thread The monitor thread, may be {@code null}
*/
public static void stop(Thread thread) {
if (thread != null) {
thread.interrupt();
}
}
/**
* Construct and new monitor.
*
* @param thread The thread to monitor
* @param timeout The timout amount in milliseconds
*/
private ThreadMonitor(Thread thread, long timeout) {
this.thread = thread;
this.timeout = timeout;
}
/**
* Sleep until the specified timout amount and then interrupt the thread being monitored.
*
* @see Runnable#run()
*/
public void run() {
try {
Thread.sleep(timeout);
thread.interrupt();
}
catch (InterruptedException e) {
// timeout not reached
}
}
}