-
Notifications
You must be signed in to change notification settings - Fork 28.9k
[SPARK-5214][Core] Add EventLoop and change DAGScheduler to an EventLoop #4016
New issue
Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.
By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.
Already on GitHub? Sign in to your account
Closed
Closed
Changes from all commits
Commits
Show all changes
9 commits
Select commit
Hold shift + click to select a range
3b2e59c
Add EventLoop and change DAGScheduler to an EventLoop
zsxwing 1f73eac
Fix the import order
zsxwing 55fb6f6
Add private[spark] to EventLoop
zsxwing 37f79c6
Fix docs
zsxwing 227bf33
Add a stop flag and some tests
zsxwing 460f7b3
Use volatile instead of Atomic things in unit tests
zsxwing dba35b2
Add a test that onReceive swallows InterruptException
zsxwing 5cfac83
Remove null check of eventProcessLoop
zsxwing aefa1ce
Add protected to on*** methods
zsxwing File filter
Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
There are no files selected for viewing
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
124 changes: 124 additions & 0 deletions
124
core/src/main/scala/org/apache/spark/util/EventLoop.scala
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,124 @@ | ||
| /* | ||
| * 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 java.util.concurrent.atomic.AtomicBoolean | ||
| import java.util.concurrent.{BlockingQueue, LinkedBlockingDeque} | ||
|
|
||
| import scala.util.control.NonFatal | ||
|
|
||
| import org.apache.spark.Logging | ||
|
|
||
| /** | ||
| * An event loop to receive events from the caller and process all events in the event thread. It | ||
| * will start an exclusive event thread to process all events. | ||
| * | ||
| * Note: The event queue will grow indefinitely. So subclasses should make sure `onReceive` can | ||
| * handle events in time to avoid the potential OOM. | ||
| */ | ||
| private[spark] abstract class EventLoop[E](name: String) extends Logging { | ||
|
|
||
| private val eventQueue: BlockingQueue[E] = new LinkedBlockingDeque[E]() | ||
|
|
||
| private val stopped = new AtomicBoolean(false) | ||
|
|
||
| private val eventThread = new Thread(name) { | ||
| setDaemon(true) | ||
|
|
||
| override def run(): Unit = { | ||
| try { | ||
| while (!stopped.get) { | ||
| val event = eventQueue.take() | ||
| try { | ||
| onReceive(event) | ||
| } catch { | ||
| case NonFatal(e) => { | ||
| try { | ||
| onError(e) | ||
| } catch { | ||
| case NonFatal(e) => logError("Unexpected error in " + name, e) | ||
| } | ||
| } | ||
| } | ||
| } | ||
| } catch { | ||
| case ie: InterruptedException => // exit even if eventQueue is not empty | ||
| case NonFatal(e) => logError("Unexpected error in " + name, e) | ||
| } | ||
| } | ||
|
|
||
| } | ||
|
|
||
| def start(): Unit = { | ||
| if (stopped.get) { | ||
| throw new IllegalStateException(name + " has already been stopped") | ||
| } | ||
| // Call onStart before starting the event thread to make sure it happens before onReceive | ||
| onStart() | ||
| eventThread.start() | ||
| } | ||
|
|
||
| def stop(): Unit = { | ||
| if (stopped.compareAndSet(false, true)) { | ||
| eventThread.interrupt() | ||
| eventThread.join() | ||
| // Call onStop after the event thread exits to make sure onReceive happens before onStop | ||
| onStop() | ||
| } else { | ||
| // Keep quiet to allow calling `stop` multiple times. | ||
| } | ||
| } | ||
|
|
||
| /** | ||
| * Put the event into the event queue. The event thread will process it later. | ||
| */ | ||
| def post(event: E): Unit = { | ||
| eventQueue.put(event) | ||
| } | ||
|
|
||
| /** | ||
| * Return if the event thread has already been started but not yet stopped. | ||
| */ | ||
| def isActive: Boolean = eventThread.isAlive | ||
|
|
||
| /** | ||
| * Invoked when `start()` is called but before the event thread starts. | ||
| */ | ||
| protected def onStart(): Unit = {} | ||
|
|
||
| /** | ||
| * Invoked when `stop()` is called and the event thread exits. | ||
| */ | ||
| protected def onStop(): Unit = {} | ||
|
|
||
| /** | ||
| * Invoked in the event thread when polling events from the event queue. | ||
| * | ||
| * Note: Should avoid calling blocking actions in `onReceive`, or the event thread will be blocked | ||
| * and cannot process events in time. If you want to call some blocking actions, run them in | ||
| * another thread. | ||
| */ | ||
| protected def onReceive(event: E): Unit | ||
|
|
||
| /** | ||
| * Invoked if `onReceive` throws any non fatal error. Any non fatal error thrown from `onError` | ||
| * will be ignored. | ||
| */ | ||
| protected def onError(e: Throwable): Unit | ||
|
|
||
| } | ||
Oops, something went wrong.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
mark as DeveloperAPI?
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
This is a private class. We only need to mark developer API's for exposed classes.