kafka.utils.ShutdownableThread.scala Maven / Gradle / Ivy
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package kafka.utils
import java.util.concurrent.{CountDownLatch, TimeUnit}
import org.apache.kafka.common.internals.FatalExitError
abstract class ShutdownableThread(val name: String, val isInterruptible: Boolean = true)
extends Thread(name) with Logging {
this.setDaemon(false)
this.logIdent = "[" + name + "]: "
private val shutdownInitiated = new CountDownLatch(1)
private val shutdownComplete = new CountDownLatch(1)
@volatile private var isStarted: Boolean = false
def shutdown(): Unit = {
initiateShutdown()
awaitShutdown()
}
def isShutdownInitiated: Boolean = shutdownInitiated.getCount == 0
def isShutdownComplete: Boolean = shutdownComplete.getCount == 0
/**
* @return true if there has been an unexpected error and the thread shut down
*/
// mind that run() might set both when we're shutting down the broker
// but the return value of this function at that point wouldn't matter
def isThreadFailed: Boolean = isShutdownComplete && !isShutdownInitiated
def initiateShutdown(): Boolean = {
this.synchronized {
if (isRunning) {
info("Shutting down")
shutdownInitiated.countDown()
if (isInterruptible)
interrupt()
true
} else
false
}
}
/**
* After calling initiateShutdown(), use this API to wait until the shutdown is complete
*/
def awaitShutdown(): Unit = {
if (!isShutdownInitiated)
throw new IllegalStateException("initiateShutdown() was not called before awaitShutdown()")
else {
if (isStarted)
shutdownComplete.await()
info("Shutdown completed")
}
}
/**
* Causes the current thread to wait until the shutdown is initiated,
* or the specified waiting time elapses.
*
* @param timeout
* @param unit
*/
def pause(timeout: Long, unit: TimeUnit): Unit = {
if (shutdownInitiated.await(timeout, unit))
trace("shutdownInitiated latch count reached zero. Shutdown called.")
}
/**
* This method is repeatedly invoked until the thread shuts down or this method throws an exception
*/
def doWork(): Unit
override def run(): Unit = {
isStarted = true
info("Starting")
try {
while (isRunning)
doWork()
} catch {
case e: FatalExitError =>
shutdownInitiated.countDown()
shutdownComplete.countDown()
info("Stopped")
Exit.exit(e.statusCode())
case e: Throwable =>
if (isRunning)
error("Error due to", e)
} finally {
shutdownComplete.countDown()
}
info("Stopped")
}
def isRunning: Boolean = !isShutdownInitiated
}