Github user JoshRosen commented on a diff in the pull request:
https://github.com/apache/spark/pull/3661#discussion_r22007092
--- Diff:
streaming/src/main/scala/org/apache/spark/streaming/ContextWaiter.scala ---
@@ -17,30 +17,63 @@
package org.apache.spark.streaming
+import java.util.concurrent.TimeUnit
+import java.util.concurrent.locks.ReentrantLock
+
private[streaming] class ContextWaiter {
+
+ private val lock = new ReentrantLock()
+ private val condition = lock.newCondition()
+
+ // Guarded by "lock"
private var error: Throwable = null
- private var stopped: Boolean = false
- def notifyError(e: Throwable) = synchronized {
- error = e
- notifyAll()
- }
+ // Guarded by "lock"
+ private var stopped: Boolean = false
- def notifyStop() = synchronized {
- stopped = true
- notifyAll()
+ def notifyError(e: Throwable): Unit = {
+ lock.lock()
+ try {
+ error = e
+ condition.signalAll()
+ } finally {
+ lock.unlock()
+ }
}
- def waitForStopOrError(timeout: Long = -1) = synchronized {
- // If already had error, then throw it
- if (error != null) {
- throw error
+ def notifyStop(): Unit = {
+ lock.lock()
+ try {
+ stopped = true
+ condition.signalAll()
+ } finally {
+ lock.unlock()
}
+ }
- // If not already stopped, then wait
- if (!stopped) {
- if (timeout < 0) wait() else wait(timeout)
+ /**
+ * Return `true` if it's stopped; or throw the reported error if
`notifyError` has been called; or
+ * `false` if the waiting time detectably elapsed before return from the
method.
+ */
+ def waitForStopOrError(timeout: Long = -1): Boolean = {
--- End diff --
I considered whether this should throw `TimeoutException` instead of
signaling failure via a boolean, but I guess this is sort of like
`Object.wait()` or `Condition.wait()`, both of which don't throw exceptions.
Also, it looks like the usages of this in `StreamingContext` support this
theory:
```scala
/**
* Wait for the execution to stop. Any exceptions that occurs during the
execution
* will be thrown in this thread.
*/
def awaitTermination() {
waiter.waitForStopOrError()
}
/**
* Wait for the execution to stop. Any exceptions that occurs during the
execution
* will be thrown in this thread.
* @param timeout time to wait in milliseconds
*/
def awaitTermination(timeout: Long) {
waiter.waitForStopOrError(timeout)
}
```
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at [email protected] or file a JIRA ticket
with INFRA.
---
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
