org.apache.spark.util.Clock Scala Examples

The following examples show how to use org.apache.spark.util.Clock. You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example.
Example 1
Source File: ProcessingTimeExecutorSuite.scala    From drizzle-spark   with Apache License 2.0 5 votes vote down vote up 
package org.apache.spark.sql.execution.streaming

import java.util.concurrent.{CountDownLatch, TimeUnit}

import org.apache.spark.SparkFunSuite
import org.apache.spark.sql.streaming.ProcessingTime
import org.apache.spark.util.{Clock, ManualClock, SystemClock}

class ProcessingTimeExecutorSuite extends SparkFunSuite {

  test("nextBatchTime") {
    val processingTimeExecutor = ProcessingTimeExecutor(ProcessingTime(100))
    assert(processingTimeExecutor.nextBatchTime(0) === 100)
    assert(processingTimeExecutor.nextBatchTime(1) === 100)
    assert(processingTimeExecutor.nextBatchTime(99) === 100)
    assert(processingTimeExecutor.nextBatchTime(100) === 200)
    assert(processingTimeExecutor.nextBatchTime(101) === 200)
    assert(processingTimeExecutor.nextBatchTime(150) === 200)
  }

  test("calling nextBatchTime with the result of a previous call should return the next interval") {
    val intervalMS = 100
    val processingTimeExecutor = ProcessingTimeExecutor(ProcessingTime(intervalMS))

    val ITERATION = 10
    var nextBatchTime: Long = 0
    for (it <- 1 to ITERATION) {
      nextBatchTime = processingTimeExecutor.nextBatchTime(nextBatchTime)
    }

    // nextBatchTime should be 1000
    assert(nextBatchTime === intervalMS * ITERATION)
  }

  private def testBatchTermination(intervalMs: Long): Unit = {
    var batchCounts = 0
    val processingTimeExecutor = ProcessingTimeExecutor(ProcessingTime(intervalMs))
    processingTimeExecutor.execute(() => {
      batchCounts += 1
      // If the batch termination works well, batchCounts should be 3 after `execute`
      batchCounts < 3
    })
    assert(batchCounts === 3)
  }

  test("batch termination") {
    testBatchTermination(0)
    testBatchTermination(10)
  }

  test("notifyBatchFallingBehind") {
    val clock = new ManualClock()
    @volatile var batchFallingBehindCalled = false
    val latch = new CountDownLatch(1)
    val t = new Thread() {
      override def run(): Unit = {
        val processingTimeExecutor = new ProcessingTimeExecutor(ProcessingTime(100), clock) {
          override def notifyBatchFallingBehind(realElapsedTimeMs: Long): Unit = {
            batchFallingBehindCalled = true
          }
        }
        processingTimeExecutor.execute(() => {
          latch.countDown()
          clock.waitTillTime(200)
          false
        })
      }
    }
    t.start()
    // Wait until the batch is running so that we don't call `advance` too early
    assert(latch.await(10, TimeUnit.SECONDS), "the batch has not yet started in 10 seconds")
    clock.advance(200)
    t.join()
    assert(batchFallingBehindCalled === true)
  }
}
Example 2
Source File: RecurringTimer.scala    From drizzle-spark   with Apache License 2.0 5 votes vote down vote up 
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() { loop }
  }

  @volatile private var prevTime = -1L
  @volatile private var nextTime = -1L
  @volatile private var stopped = false

  
  private def loop() {
    try {
      while (!stopped) {
        triggerActionForNextInterval()
      }
      triggerActionForNextInterval()
    } catch {
      case e: InterruptedException =>
    }
  }
}

private[streaming]
object RecurringTimer extends Logging {

  def main(args: Array[String]) {
    var lastRecurTime = 0L
    val period = 1000

    def onRecur(time: Long) {
      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)
  }
}
Example 3
Source File: MetricsReporter.scala    From sparkoscope   with Apache License 2.0 5 votes vote down vote up 
package org.apache.spark.sql.execution.streaming

import java.{util => ju}

import scala.collection.mutable

import com.codahale.metrics.{Gauge, MetricRegistry}

import org.apache.spark.internal.Logging
import org.apache.spark.metrics.source.{Source => CodahaleSource}
import org.apache.spark.util.Clock


class MetricsReporter(
    stream: StreamExecution,
    override val sourceName: String) extends CodahaleSource with Logging {

  override val metricRegistry: MetricRegistry = new MetricRegistry

  // Metric names should not have . in them, so that all the metrics of a query are identified
  // together in Ganglia as a single metric group
  registerGauge("inputRate-total", () => stream.lastProgress.inputRowsPerSecond)
  registerGauge("processingRate-total", () => stream.lastProgress.inputRowsPerSecond)
  registerGauge("latency", () => stream.lastProgress.durationMs.get("triggerExecution").longValue())

  private def registerGauge[T](name: String, f: () => T)(implicit num: Numeric[T]): Unit = {
    synchronized {
      metricRegistry.register(name, new Gauge[T] {
        override def getValue: T = f()
      })
    }
  }
}
Example 4
Source File: ProcessingTimeExecutorSuite.scala    From sparkoscope   with Apache License 2.0 5 votes vote down vote up 
package org.apache.spark.sql.execution.streaming

import java.util.concurrent.{CountDownLatch, TimeUnit}

import org.apache.spark.SparkFunSuite
import org.apache.spark.sql.streaming.ProcessingTime
import org.apache.spark.util.{Clock, ManualClock, SystemClock}

class ProcessingTimeExecutorSuite extends SparkFunSuite {

  test("nextBatchTime") {
    val processingTimeExecutor = ProcessingTimeExecutor(ProcessingTime(100))
    assert(processingTimeExecutor.nextBatchTime(0) === 100)
    assert(processingTimeExecutor.nextBatchTime(1) === 100)
    assert(processingTimeExecutor.nextBatchTime(99) === 100)
    assert(processingTimeExecutor.nextBatchTime(100) === 200)
    assert(processingTimeExecutor.nextBatchTime(101) === 200)
    assert(processingTimeExecutor.nextBatchTime(150) === 200)
  }

  test("calling nextBatchTime with the result of a previous call should return the next interval") {
    val intervalMS = 100
    val processingTimeExecutor = ProcessingTimeExecutor(ProcessingTime(intervalMS))

    val ITERATION = 10
    var nextBatchTime: Long = 0
    for (it <- 1 to ITERATION) {
      nextBatchTime = processingTimeExecutor.nextBatchTime(nextBatchTime)
    }

    // nextBatchTime should be 1000
    assert(nextBatchTime === intervalMS * ITERATION)
  }

  private def testBatchTermination(intervalMs: Long): Unit = {
    var batchCounts = 0
    val processingTimeExecutor = ProcessingTimeExecutor(ProcessingTime(intervalMs))
    processingTimeExecutor.execute(() => {
      batchCounts += 1
      // If the batch termination works well, batchCounts should be 3 after `execute`
      batchCounts < 3
    })
    assert(batchCounts === 3)
  }

  test("batch termination") {
    testBatchTermination(0)
    testBatchTermination(10)
  }

  test("notifyBatchFallingBehind") {
    val clock = new ManualClock()
    @volatile var batchFallingBehindCalled = false
    val latch = new CountDownLatch(1)
    val t = new Thread() {
      override def run(): Unit = {
        val processingTimeExecutor = new ProcessingTimeExecutor(ProcessingTime(100), clock) {
          override def notifyBatchFallingBehind(realElapsedTimeMs: Long): Unit = {
            batchFallingBehindCalled = true
          }
        }
        processingTimeExecutor.execute(() => {
          latch.countDown()
          clock.waitTillTime(200)
          false
        })
      }
    }
    t.start()
    // Wait until the batch is running so that we don't call `advance` too early
    assert(latch.await(10, TimeUnit.SECONDS), "the batch has not yet started in 10 seconds")
    clock.advance(200)
    t.join()
    assert(batchFallingBehindCalled === true)
  }
}
Example 5
Source File: RecurringTimer.scala    From sparkoscope   with Apache License 2.0 5 votes vote down vote up 
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() { loop }
  }

  @volatile private var prevTime = -1L
  @volatile private var nextTime = -1L
  @volatile private var stopped = false

  
  private def loop() {
    try {
      while (!stopped) {
        triggerActionForNextInterval()
      }
      triggerActionForNextInterval()
    } catch {
      case e: InterruptedException =>
    }
  }
}

private[streaming]
object RecurringTimer extends Logging {

  def main(args: Array[String]) {
    var lastRecurTime = 0L
    val period = 1000

    def onRecur(time: Long) {
      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)
  }
}
Example 6
Source File: MetricsReporter.scala    From multi-tenancy-spark   with Apache License 2.0 5 votes vote down vote up 
package org.apache.spark.sql.execution.streaming

import java.{util => ju}

import scala.collection.mutable

import com.codahale.metrics.{Gauge, MetricRegistry}

import org.apache.spark.internal.Logging
import org.apache.spark.metrics.source.{Source => CodahaleSource}
import org.apache.spark.util.Clock


class MetricsReporter(
    stream: StreamExecution,
    override val sourceName: String) extends CodahaleSource with Logging {

  override val metricRegistry: MetricRegistry = new MetricRegistry

  // Metric names should not have . in them, so that all the metrics of a query are identified
  // together in Ganglia as a single metric group
  registerGauge("inputRate-total", () => stream.lastProgress.inputRowsPerSecond)
  registerGauge("processingRate-total", () => stream.lastProgress.inputRowsPerSecond)
  registerGauge("latency", () => stream.lastProgress.durationMs.get("triggerExecution").longValue())

  private def registerGauge[T](name: String, f: () => T)(implicit num: Numeric[T]): Unit = {
    synchronized {
      metricRegistry.register(name, new Gauge[T] {
        override def getValue: T = f()
      })
    }
  }
}
Example 7
Source File: ProcessingTimeExecutorSuite.scala    From multi-tenancy-spark   with Apache License 2.0 5 votes vote down vote up 
package org.apache.spark.sql.execution.streaming

import java.util.concurrent.{CountDownLatch, TimeUnit}

import org.apache.spark.SparkFunSuite
import org.apache.spark.sql.streaming.ProcessingTime
import org.apache.spark.util.{Clock, ManualClock, SystemClock}

class ProcessingTimeExecutorSuite extends SparkFunSuite {

  test("nextBatchTime") {
    val processingTimeExecutor = ProcessingTimeExecutor(ProcessingTime(100))
    assert(processingTimeExecutor.nextBatchTime(0) === 100)
    assert(processingTimeExecutor.nextBatchTime(1) === 100)
    assert(processingTimeExecutor.nextBatchTime(99) === 100)
    assert(processingTimeExecutor.nextBatchTime(100) === 200)
    assert(processingTimeExecutor.nextBatchTime(101) === 200)
    assert(processingTimeExecutor.nextBatchTime(150) === 200)
  }

  test("calling nextBatchTime with the result of a previous call should return the next interval") {
    val intervalMS = 100
    val processingTimeExecutor = ProcessingTimeExecutor(ProcessingTime(intervalMS))

    val ITERATION = 10
    var nextBatchTime: Long = 0
    for (it <- 1 to ITERATION) {
      nextBatchTime = processingTimeExecutor.nextBatchTime(nextBatchTime)
    }

    // nextBatchTime should be 1000
    assert(nextBatchTime === intervalMS * ITERATION)
  }

  private def testBatchTermination(intervalMs: Long): Unit = {
    var batchCounts = 0
    val processingTimeExecutor = ProcessingTimeExecutor(ProcessingTime(intervalMs))
    processingTimeExecutor.execute(() => {
      batchCounts += 1
      // If the batch termination works well, batchCounts should be 3 after `execute`
      batchCounts < 3
    })
    assert(batchCounts === 3)
  }

  test("batch termination") {
    testBatchTermination(0)
    testBatchTermination(10)
  }

  test("notifyBatchFallingBehind") {
    val clock = new ManualClock()
    @volatile var batchFallingBehindCalled = false
    val latch = new CountDownLatch(1)
    val t = new Thread() {
      override def run(): Unit = {
        val processingTimeExecutor = new ProcessingTimeExecutor(ProcessingTime(100), clock) {
          override def notifyBatchFallingBehind(realElapsedTimeMs: Long): Unit = {
            batchFallingBehindCalled = true
          }
        }
        processingTimeExecutor.execute(() => {
          latch.countDown()
          clock.waitTillTime(200)
          false
        })
      }
    }
    t.start()
    // Wait until the batch is running so that we don't call `advance` too early
    assert(latch.await(10, TimeUnit.SECONDS), "the batch has not yet started in 10 seconds")
    clock.advance(200)
    t.join()
    assert(batchFallingBehindCalled === true)
  }
}
Example 8
Source File: RecurringTimer.scala    From multi-tenancy-spark   with Apache License 2.0 5 votes vote down vote up 
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() { loop }
  }

  @volatile private var prevTime = -1L
  @volatile private var nextTime = -1L
  @volatile private var stopped = false

  
  private def loop() {
    try {
      while (!stopped) {
        triggerActionForNextInterval()
      }
      triggerActionForNextInterval()
    } catch {
      case e: InterruptedException =>
    }
  }
}

private[streaming]
object RecurringTimer extends Logging {

  def main(args: Array[String]) {
    var lastRecurTime = 0L
    val period = 1000

    def onRecur(time: Long) {
      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)
  }
}
Example 9
Source File: RecurringTimer.scala    From iolap   with Apache License 2.0 5 votes vote down vote up 
package org.apache.spark.streaming.util

import org.apache.spark.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() { loop }
  }

  @volatile private var prevTime = -1L
  @volatile private var nextTime = -1L
  @volatile private var stopped = false

  
  private def loop() {
    try {
      while (!stopped) {
        clock.waitTillTime(nextTime)
        callback(nextTime)
        prevTime = nextTime
        nextTime += period
        logDebug("Callback for " + name + " called at time " + prevTime)
      }
    } catch {
      case e: InterruptedException =>
    }
  }
}

private[streaming]
object RecurringTimer {

  def main(args: Array[String]) {
    var lastRecurTime = 0L
    val period = 1000

    def onRecur(time: Long) {
      val currentTime = System.currentTimeMillis()
      println("" + currentTime + ": " + (currentTime - lastRecurTime))
      lastRecurTime = currentTime
    }
    val timer = new  RecurringTimer(new SystemClock(), period, onRecur, "Test")
    timer.start()
    Thread.sleep(30 * 1000)
    timer.stop(true)
  }
}
Example 10
Source File: RecurringTimer.scala    From spark1.52   with Apache License 2.0 5 votes vote down vote up 
package org.apache.spark.streaming.util

import org.apache.spark.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() { loop }
  }

  @volatile private var prevTime = -1L
  @volatile private var nextTime = -1L
  @volatile private var stopped = false

  
  private def loop() {
    try {
      while (!stopped) {
        triggerActionForNextInterval()
      }
      triggerActionForNextInterval()
    } catch {
      case e: InterruptedException =>
    }
  }
}

private[streaming]
object RecurringTimer extends Logging {

  def main(args: Array[String]) {
    var lastRecurTime = 0L
    val period = 1000

    def onRecur(time: Long) {
      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)
  }
}
Example 11
Source File: DriverServiceBootstrapStep.scala    From Spark-2.3.1   with Apache License 2.0 5 votes vote down vote up 
package org.apache.spark.deploy.k8s.submit.steps

import scala.collection.JavaConverters._

import io.fabric8.kubernetes.api.model.ServiceBuilder

import org.apache.spark.SparkConf
import org.apache.spark.deploy.k8s.Config._
import org.apache.spark.deploy.k8s.Constants._
import org.apache.spark.deploy.k8s.submit.KubernetesDriverSpec
import org.apache.spark.internal.Logging
import org.apache.spark.util.Clock


private[spark] class DriverServiceBootstrapStep(
    resourceNamePrefix: String,
    driverLabels: Map[String, String],
    sparkConf: SparkConf,
    clock: Clock) extends DriverConfigurationStep with Logging {

  import DriverServiceBootstrapStep._

  override def configureDriver(driverSpec: KubernetesDriverSpec): KubernetesDriverSpec = {
    require(sparkConf.getOption(DRIVER_BIND_ADDRESS_KEY).isEmpty,
      s"$DRIVER_BIND_ADDRESS_KEY is not supported in Kubernetes mode, as the driver's bind " +
      "address is managed and set to the driver pod's IP address.")
    require(sparkConf.getOption(DRIVER_HOST_KEY).isEmpty,
      s"$DRIVER_HOST_KEY is not supported in Kubernetes mode, as the driver's hostname will be " +
      "managed via a Kubernetes service.")

    val preferredServiceName = s"$resourceNamePrefix$DRIVER_SVC_POSTFIX"
    val resolvedServiceName = if (preferredServiceName.length <= MAX_SERVICE_NAME_LENGTH) {
      preferredServiceName
    } else {
      val randomServiceId = clock.getTimeMillis()
      val shorterServiceName = s"spark-$randomServiceId$DRIVER_SVC_POSTFIX"
      logWarning(s"Driver's hostname would preferably be $preferredServiceName, but this is " +
        s"too long (must be <= $MAX_SERVICE_NAME_LENGTH characters). Falling back to use " +
        s"$shorterServiceName as the driver service's name.")
      shorterServiceName
    }

    val driverPort = sparkConf.getInt("spark.driver.port", DEFAULT_DRIVER_PORT)
    val driverBlockManagerPort = sparkConf.getInt(
        org.apache.spark.internal.config.DRIVER_BLOCK_MANAGER_PORT.key, DEFAULT_BLOCKMANAGER_PORT)
    val driverService = new ServiceBuilder()
      .withNewMetadata()
        .withName(resolvedServiceName)
        .endMetadata()
      .withNewSpec()
        .withClusterIP("None")
        .withSelector(driverLabels.asJava)
        .addNewPort()
          .withName(DRIVER_PORT_NAME)
          .withPort(driverPort)
          .withNewTargetPort(driverPort)
          .endPort()
        .addNewPort()
          .withName(BLOCK_MANAGER_PORT_NAME)
          .withPort(driverBlockManagerPort)
          .withNewTargetPort(driverBlockManagerPort)
          .endPort()
        .endSpec()
      .build()

    val namespace = sparkConf.get(KUBERNETES_NAMESPACE)
    val driverHostname = s"${driverService.getMetadata.getName}.$namespace.svc"
    val resolvedSparkConf = driverSpec.driverSparkConf.clone()
      .set(DRIVER_HOST_KEY, driverHostname)
      .set("spark.driver.port", driverPort.toString)
      .set(
        org.apache.spark.internal.config.DRIVER_BLOCK_MANAGER_PORT, driverBlockManagerPort)

    driverSpec.copy(
      driverSparkConf = resolvedSparkConf,
      otherKubernetesResources = driverSpec.otherKubernetesResources ++ Seq(driverService))
  }
}

private[spark] object DriverServiceBootstrapStep {
  val DRIVER_BIND_ADDRESS_KEY = org.apache.spark.internal.config.DRIVER_BIND_ADDRESS.key
  val DRIVER_HOST_KEY = org.apache.spark.internal.config.DRIVER_HOST_ADDRESS.key
  val DRIVER_SVC_POSTFIX = "-driver-svc"
  val MAX_SERVICE_NAME_LENGTH = 63
}
Example 12
Source File: RecurringTimer.scala    From Spark-2.3.1   with Apache License 2.0 5 votes vote down vote up 
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() { loop }
  }

  @volatile private var prevTime = -1L
  @volatile private var nextTime = -1L
  @volatile private var stopped = false

  
  private def loop() {
    try {
      while (!stopped) {
        triggerActionForNextInterval()
      }
      triggerActionForNextInterval()
    } catch {
      case e: InterruptedException =>
    }
  }
}

private[streaming]
object RecurringTimer extends Logging {

  def main(args: Array[String]) {
    var lastRecurTime = 0L
    val period = 1000

    def onRecur(time: Long) {
      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)
  }
}
Example 13
Source File: RecurringTimer.scala    From BigDatalog   with Apache License 2.0 5 votes vote down vote up 
package org.apache.spark.streaming.util

import org.apache.spark.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() { loop }
  }

  @volatile private var prevTime = -1L
  @volatile private var nextTime = -1L
  @volatile private var stopped = false

  
  private def loop() {
    try {
      while (!stopped) {
        triggerActionForNextInterval()
      }
      triggerActionForNextInterval()
    } catch {
      case e: InterruptedException =>
    }
  }
}

private[streaming]
object RecurringTimer extends Logging {

  def main(args: Array[String]) {
    var lastRecurTime = 0L
    val period = 1000

    def onRecur(time: Long) {
      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)
  }
}
Example 14
Source File: RecurringTimer.scala    From spark-sql-server   with Apache License 2.0 5 votes vote down vote up 
package org.apache.spark.sql.server.util

import org.apache.spark.internal.Logging
import org.apache.spark.util.Clock

private[server]
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() { loop }
  }

  @volatile private var prevTime = -1L
  @volatile private var nextTime = -1L
  @volatile private var stopped = false

  
  private def loop() {
    try {
      while (!stopped) {
        triggerActionForNextInterval()
      }
      triggerActionForNextInterval()
    } catch {
      case e: InterruptedException =>
    }
  }
}