[FLINK-12478] Decompose monolithic run-loops in StreamTask implementations into step-wise calls

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Implemented
• Fix Version/s: 1.9.0
• Component/s: Runtime / Task
• Labels: pull-request-available
• Assignee: Stefan Richter
• Reporter: Stefan Richter
• Created: 10/May/19 09:34
• Updated: 23/May/19 07:44
• Resolved: 23/May/19 07:44

Description

As a first step to introduce a mailbox model, we need to split up the monolithic loops in stream task implementations into stepwise actions. The step-wise actions are still run in a loop, but give us the opportunity to check the mailbox between each step in the future. This mailbox will be added to the loop in a later subtasks.

We also exclude breaking the stream sources into steps because this is not possible before FLIP-27 is implemented and we need to be compatible to the current source function interface.

Issue Links

• links to: GitHub Pull Request #8409