Github user NicoK commented on a diff in the pull request: https://github.com/apache/flink/pull/4499#discussion_r140833417 --- Diff: flink-runtime/src/test/java/org/apache/flink/runtime/io/network/partition/consumer/RemoteInputChannelTest.java --- @@ -281,6 +286,73 @@ public void testProducerFailedException() throws Exception { ch.getNextBuffer(); } + /** + * Tests {@link RemoteInputChannel#recycle(MemorySegment)}, verifying the exclusive segment is + * recycled to available buffers directly and it triggers notify of announced credit. + */ + @Test + public void testRecycleExclusiveBufferBeforeReleased() throws Exception { + final SingleInputGate inputGate = mock(SingleInputGate.class); + final RemoteInputChannel inputChannel = spy(createRemoteInputChannel(inputGate)); + + // Recycle exclusive segment + inputChannel.recycle(MemorySegmentFactory.getFactory().allocateUnpooledSegment(1024, inputChannel)); + + assertEquals("There should have one available buffer after recycle.", + 1, inputChannel.getNumberOfAvailableBuffers()); + verify(inputChannel, times(1)).notifyCreditAvailable(); --- End diff -- can you add one more `inputChannel.recycle(MemorySegmentFactory.getFactory().allocateUnpooledSegment(1024, inputChannel))` call and verify `inputChannel.getNumberOfAvailableBuffers()` and that `notifyCreditAvailable()` is not called again?
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