Github user NicoK commented on a diff in the pull request:
https://github.com/apache/flink/pull/4509#discussion_r152234362
--- Diff:
flink-runtime/src/main/java/org/apache/flink/runtime/io/network/partition/consumer/RemoteInputChannel.java
---
@@ -287,17 +290,22 @@ void notifyCreditAvailable() {
}
/**
- * Exclusive buffer is recycled to this input channel directly and it
may trigger notify
- * credit to producer.
+ * Exclusive buffer is recycled to this input channel directly and it
may trigger return extra
+ * floating buffer and notify increased credit to the producer.
*
* @param segment The exclusive segment of this channel.
*/
@Override
public void recycle(MemorySegment segment) {
- synchronized (availableBuffers) {
- // Important: the isReleased check should be inside the
synchronized block.
- // that way the segment can also be returned to global
pool after added into
- // the available queue during releasing all resources.
+ boolean floatingBufferRecycled = false;
+
+ synchronized (bufferQueue) {
+ final int numRequiredBuffers = senderBacklog +
initialCredit;
+ checkState(bufferQueue.getAvailableBufferSize() <=
numRequiredBuffers,
+ "The number of available buffers " +
bufferQueue.getAvailableBufferSize() + " should not exceed " +
numRequiredBuffers);
+
+ // Important: check the isReleased state inside
synchronized block, so there is no
+ // race condition when recycle and releaseAllResources
running in parallel.
if (isReleased.get()) {
try {
inputGate.returnExclusiveSegments(Arrays.asList(segment));
--- End diff --
now that I see it, it should rather be
`inputGate.returnExclusiveSegments(Collections.singletonList(segment));`
---
