[FLINK-16972] Fix non-blocking output availability logic.

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.12.0
• Fix Version/s: 1.12.0
• Component/s: Runtime / Network
• Labels: pull-request-available
• Assignee: Arvid Heise
• Reporter: Arvid Heise
• Created: 03/Apr/20 11:54
• Updated: 22/Jun/21 14:06
• Resolved: 08/Oct/20 06:12

Description

Non-blocking output is currently blocking, as unavailability in `LocalBufferPool` is only signaled when the first unavailable buffer is being requested.

Issue Links

• causes: FLINK-19964 Gelly ITCase stuck on Azure in HITSITCase.testPrintWithRMatGraph
• incorporates: FLINK-19400 Removed unused BufferPoolOwner
• links to: GitHub Pull Request #13499