[SPARK-12690][CORE] Fix NPE in UnsafeInMemorySorter.free()

I hit the exception below. The `UnsafeKVExternalSorter` does pass `null` as the consumer when creating an `UnsafeInMemorySorter`. Normally the NPE doesn't occur because the `inMemSorter` is set to null later and the `free()` method is not called. It happens when there is another exception like OOM thrown before setting `inMemSorter` to null. Anyway, we can add the null check to avoid it.

```
ERROR spark.TaskContextImpl: Error in TaskCompletionListener
java.lang.NullPointerException
        at org.apache.spark.util.collection.unsafe.sort.UnsafeInMemorySorter.free(UnsafeInMemorySorter.java:110)
        at org.apache.spark.util.collection.unsafe.sort.UnsafeExternalSorter.cleanupResources(UnsafeExternalSorter.java:288)
        at org.apache.spark.util.collection.unsafe.sort.UnsafeExternalSorter$1.onTaskCompletion(UnsafeExternalSorter.java:141)
        at org.apache.spark.TaskContextImpl$$anonfun$markTaskCompleted$1.apply(TaskContextImpl.scala:79)
        at org.apache.spark.TaskContextImpl$$anonfun$markTaskCompleted$1.apply(TaskContextImpl.scala:77)
        at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59)
        at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:47)
        at org.apache.spark.TaskContextImpl.markTaskCompleted(TaskContextImpl.scala:77)
        at org.apache.spark.scheduler.Task.run(Task.scala:91)
        at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:213)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
        at java.lang.Thread.run(Thread.java:722)
```

Author: Carson Wang <carson.wang@intel.com>

Closes #10637 from carsonwang/FixNPE.
This commit is contained in:
Carson Wang 2016-01-13 13:28:39 -08:00 committed by Josh Rosen
parent cbbcd8e425
commit eabc7b8ee7

View file

@ -116,8 +116,10 @@ public final class UnsafeInMemorySorter {
* Free the memory used by pointer array.
*/
public void free() {
consumer.freeArray(array);
array = null;
if (consumer != null) {
consumer.freeArray(array);
array = null;
}
}
public void reset() {