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Diffstat (limited to 'core/src/main/scala/org/apache/spark/util/UninterruptibleThread.scala')
-rw-r--r-- | core/src/main/scala/org/apache/spark/util/UninterruptibleThread.scala | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/core/src/main/scala/org/apache/spark/util/UninterruptibleThread.scala b/core/src/main/scala/org/apache/spark/util/UninterruptibleThread.scala new file mode 100644 index 0000000000..4dcf95177a --- /dev/null +++ b/core/src/main/scala/org/apache/spark/util/UninterruptibleThread.scala @@ -0,0 +1,112 @@ +/* + * 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(name: String) extends Thread(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`. + * + * If this method finds that `interrupt` is called before calling `f` and it's not inside another + * `runUninterruptibly`, it will throw `InterruptedException`. + * + * 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. + if (Thread.interrupted() || shouldInterruptThread) { + shouldInterruptThread = false + // Since it's interrupted, we don't need to run `f` which may be a long computation. + // Throw InterruptedException as we don't have a T to return. + throw new InterruptedException() + } + uninterruptible = true + } + try { + f + } finally { + uninterruptibleLock.synchronized { + uninterruptible = false + if (shouldInterruptThread) { + // Recover the interrupted status + super.interrupt() + shouldInterruptThread = false + } + } + } + } + + /** + * Tests whether `interrupt()` has been called. + */ + override def isInterrupted: Boolean = { + super.isInterrupted || uninterruptibleLock.synchronized { shouldInterruptThread } + } + + /** + * 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() + } + } + } +} |