spark UninterruptibleThread 源码

spark UninterruptibleThread 代码

文件路径：/core/src/main/scala/org/apache/spark/util/UninterruptibleThread.scala

/*
 * 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.util

import javax.annotation.concurrent.GuardedBy

/**
 * A special Thread that provides "runUninterruptibly" to allow running codes without being
 * interrupted by `Thread.interrupt()`. If `Thread.interrupt()` is called during runUninterruptibly
 * is running, it won't set the interrupted status. Instead, setting the interrupted status will be
 * deferred until it's returning from "runUninterruptibly".
 *
 * Note: "runUninterruptibly" should be called only in `this` thread.
 */
private[spark] class UninterruptibleThread(
    target: Runnable,
    name: String) extends Thread(target, name) {

  def this(name: String) = {
    this(null, name)
  }

  /** A monitor to protect "uninterruptible" and "interrupted" */
  private val uninterruptibleLock = new Object

  /**
   * Indicates if `this`  thread are in the uninterruptible status. If so, interrupting
   * "this" will be deferred until `this`  enters into the interruptible status.
   */
  @GuardedBy("uninterruptibleLock")
  private var uninterruptible = false

  /**
   * Indicates if we should interrupt `this` when we are leaving the uninterruptible zone.
   */
  @GuardedBy("uninterruptibleLock")
  private var shouldInterruptThread = false

  /**
   * Run `f` uninterruptibly in `this` thread. The thread won't be interrupted before returning
   * from `f`.
   *
   * Note: this method should be called only in `this` thread.
   */
  def runUninterruptibly[T](f: => T): T = {
    if (Thread.currentThread() != this) {
      throw new IllegalStateException(s"Call runUninterruptibly in a wrong thread. " +
        s"Expected: $this but was ${Thread.currentThread()}")
    }

    if (uninterruptibleLock.synchronized { uninterruptible }) {
      // We are already in the uninterruptible status. So just run "f" and return
      return f
    }

    uninterruptibleLock.synchronized {
      // Clear the interrupted status if it's set.
      shouldInterruptThread = Thread.interrupted() || shouldInterruptThread
      uninterruptible = true
    }
    try {
      f
    } finally {
      uninterruptibleLock.synchronized {
        uninterruptible = false
        if (shouldInterruptThread) {
          // Recover the interrupted status
          super.interrupt()
          shouldInterruptThread = false
        }
      }
    }
  }

  /**
   * Interrupt `this` thread if possible. If `this` is in the uninterruptible status, it won't be
   * interrupted until it enters into the interruptible status.
   */
  override def interrupt(): Unit = {
    uninterruptibleLock.synchronized {
      if (uninterruptible) {
        shouldInterruptThread = true
      } else {
        super.interrupt()
      }
    }
  }
}

相关信息

spark 源码目录

相关文章

spark AccumulatorV2 源码

spark ByteBufferInputStream 源码

spark ByteBufferOutputStream 源码

spark CausedBy 源码

spark Clock 源码

spark ClosureCleaner 源码

spark CollectionsUtils 源码

spark CommandLineUtils 源码

spark CompletionIterator 源码

spark DependencyUtils 源码