Wang Shuo 10cae04108 [SPARK-30285][CORE] Fix deadlock between LiveListenerBus#stop and AsyncEventQueue#removeListenerOnError ... ### What changes were proposed in this pull request? There is a deadlock between `LiveListenerBus#stop` and `AsyncEventQueue#removeListenerOnError`. We can reproduce as follows: 1. Post some events to `LiveListenerBus` 2. Call `LiveListenerBus#stop` and hold the synchronized lock of `bus`(5e92301723/core/src/main/scala/org/apache/spark/scheduler/LiveListenerBus.scala (L229)), waiting until all the events are processed by listeners, then remove all the queues 3. Event queue would drain out events by posting to its listeners. If a listener is interrupted, it will call `AsyncEventQueue#removeListenerOnError`, inside it will call `bus.removeListener`(7b1b60c758/core/src/main/scala/org/apache/spark/scheduler/AsyncEventQueue.scala (L207)), trying to acquire synchronized lock of bus, resulting in deadlock This PR removes the `synchronized` from `LiveListenerBus.stop` because underlying data structures themselves are thread-safe. ### Why are the changes needed? To fix deadlock. ### Does this PR introduce any user-facing change? No. ### How was this patch tested? New UT. Closes #26924 from wangshuo128/event-queue-race-condition. Authored-by: Wang Shuo <wangshuo128@gmail.com> Signed-off-by: Marcelo Vanzin <vanzin@cloudera.com>		2020-01-02 16:40:22 -08:00
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benchmarks	[SPARK-29576][CORE] Use Spark's CompressionCodec for Ser/Deser of MapOutputStatus	2019-10-23 18:17:37 -07:00
src	[SPARK-30285][CORE] Fix deadlock between LiveListenerBus#stop and AsyncEventQueue#removeListenerOnError	2020-01-02 16:40:22 -08:00
pom.xml	[INFRA] Reverts commit 56dcd79 and c216ef1	2019-12-16 19:57:44 -07:00