Github user NicoK commented on a diff in the pull request: https://github.com/apache/flink/pull/4509#discussion_r143232200 --- Diff: flink-runtime/src/main/java/org/apache/flink/runtime/io/network/partition/consumer/RemoteInputChannel.java --- @@ -331,37 +353,41 @@ public int getNumberOfAvailableBuffers() { */ @Override public boolean notifyBufferAvailable(Buffer buffer) { - checkState(isWaitingForFloatingBuffers.get(), "This channel should be waiting for floating buffers."); + checkState(isWaitingForFloatingBuffers, "This channel should be waiting for floating buffers."); + boolean needMoreBuffers; synchronized (availableBuffers) { // Important: the isReleased check should be inside the synchronized block. - if (isReleased.get() || availableBuffers.size() >= senderBacklog.get()) { - isWaitingForFloatingBuffers.set(false); + if (isReleased.get() || availableBuffers.size() >= senderBacklog.get() + initialCredit) { + isWaitingForFloatingBuffers = false; buffer.recycle(); return false; } availableBuffers.add(buffer); - if (unannouncedCredit.getAndAdd(1) == 0) { - notifyCreditAvailable(); - } - - if (availableBuffers.size() >= senderBacklog.get()) { - isWaitingForFloatingBuffers.set(false); - return false; + if (availableBuffers.size() >= senderBacklog.get() + initialCredit) { + isWaitingForFloatingBuffers = false; + needMoreBuffers = false; } else { - return true; + needMoreBuffers = true; } } + + if (unannouncedCredit.getAndAdd(1) == 0) { + notifyCreditAvailable(); + } + + return needMoreBuffers; } @Override public void notifyBufferDestroyed() { - if (!isWaitingForFloatingBuffers.compareAndSet(true, false)) { - throw new IllegalStateException("This channel should be waiting for floating buffers currently."); + if (!isWaitingForFloatingBuffers) { + throw new IllegalStateException("This channel should be waiting for floating buffers."); --- End diff -- use `Preconditions.checkState()` here?
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