[FLINK-17413] Refactor the usages of ThreadSafeUnaligner#storeNewBuffers

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Duplicate
• Fix Version/s: 1.12.0
• Component/s: Runtime / Checkpointing
• Assignee: Zhijiang
• Reporter: Zhijiang
• Created: 27/Apr/20 10:46
• Updated: 25/Sep/20 17:02
• Resolved: 25/Sep/20 17:02

Description

In current ThreadSafeUnaligner, the variable `storeNewBuffers` has actually two usages. One is for avoiding duplicated counter for processing barrier or notifying received barrier for a respective channel. Another usage is for judging whether the notified buffer should be spilled by writer or not.

In RemoteInputChannel, we already have the states  of `lastRequestedCheckpointId` and `receivedCheckpointId` to control whether the received buffer should be notified to unaligner component. In other words, as long as the `RemoteInputChannel` decides to notify this received buffer, it should be always needed to spill in ThreadSafeUnaligner. So we can remove the related condition inside ThreadSafeUnaligner#notifyBufferReceived and make the semantic of `storeNewBuffers` more clearly.

Issue Links

• is fixed by: FLINK-19026 Improve threading model of Unaligner