org.apache.spark.streaming.util.RecurringTimer.scala Maven / Gradle / Ivy
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/*
* 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 org.apache.spark.streaming.util
import org.apache.spark.internal.Logging
import org.apache.spark.util.{Clock, SystemClock}
private[streaming]
class RecurringTimer(clock: Clock, period: Long, callback: (Long) => Unit, name: String)
extends Logging {
private val thread = new Thread("RecurringTimer - " + name) {
setDaemon(true)
override def run(): Unit = { loop }
}
@volatile private var prevTime = -1L
@volatile private var nextTime = -1L
@volatile private var stopped = false
/**
* Get the time when this timer will fire if it is started right now.
* The time will be a multiple of this timer's period and more than
* current system time.
*/
def getStartTime(): Long = {
(math.floor(clock.getTimeMillis().toDouble / period) + 1).toLong * period
}
/**
* Get the time when the timer will fire if it is restarted right now.
* This time depends on when the timer was started the first time, and was stopped
* for whatever reason. The time must be a multiple of this timer's period and
* more than current time.
*/
def getRestartTime(originalStartTime: Long): Long = {
val gap = clock.getTimeMillis() - originalStartTime
(math.floor(gap.toDouble / period).toLong + 1) * period + originalStartTime
}
/**
* Start at the given start time.
*/
def start(startTime: Long): Long = synchronized {
nextTime = startTime
thread.start()
logInfo("Started timer for " + name + " at time " + nextTime)
nextTime
}
/**
* Start at the earliest time it can start based on the period.
*/
def start(): Long = {
start(getStartTime())
}
/**
* Stop the timer, and return the last time the callback was made.
*
* @param interruptTimer True will interrupt the callback if it is in progress (not guaranteed to
* give correct time in this case). False guarantees that there will be at
* least one callback after `stop` has been called.
*/
def stop(interruptTimer: Boolean): Long = synchronized {
if (!stopped) {
stopped = true
if (interruptTimer) {
thread.interrupt()
}
thread.join()
logInfo("Stopped timer for " + name + " after time " + prevTime)
}
prevTime
}
private def triggerActionForNextInterval(): Unit = {
clock.waitTillTime(nextTime)
callback(nextTime)
prevTime = nextTime
nextTime += period
logDebug("Callback for " + name + " called at time " + prevTime)
}
/**
* Repeatedly call the callback every interval.
*/
private def loop(): Unit = {
try {
while (!stopped) {
triggerActionForNextInterval()
}
triggerActionForNextInterval()
} catch {
case e: InterruptedException =>
}
}
}
private[streaming]
object RecurringTimer extends Logging {
def main(args: Array[String]): Unit = {
var lastRecurTime = 0L
val period = 1000
def onRecur(time: Long): Unit = {
val currentTime = System.currentTimeMillis()
logInfo("" + currentTime + ": " + (currentTime - lastRecurTime))
lastRecurTime = currentTime
}
val timer = new RecurringTimer(new SystemClock(), period, onRecur, "Test")
timer.start()
Thread.sleep(30 * 1000)
timer.stop(true)
}
}