[FLINK-17823] Resolve the race condition while releasing RemoteInputChannel

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 1.11.0
• Fix Version/s: 1.11.0
• Component/s: Runtime / Network
• Labels: pull-request-available
• Assignee: Zhijiang
• Reporter: Zhijiang
• Created: 20/May/20 04:16
• Updated: 16/Oct/20 10:53
• Resolved: 22/May/20 03:08

Description

RemoteInputChannel#releaseAllResources might be called by canceler thread. Meanwhile, the task thread can also call RemoteInputChannel#getNextBuffer. There probably cause two potential problems:

• Task thread might get null buffer after canceler thread already released all the buffers, then it might cause misleading NPE in getNextBuffer.
• Task thread and canceler thread might pull the same buffer concurrently, which causes unexpected exception when the same buffer is recycled twice.

The solution is to properly synchronize the buffer queue in release method to avoid the same buffer pulled by both canceler thread and task thread. And in getNextBuffer method, we add some explicit checks to avoid misleading NPE and hint some valid exceptions.

Issue Links

• links to: GitHub Pull Request #12261
• links to: GitHub Pull Request #12430