[IOTDB-6256] Deadlock when calling FLUSH

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: master branch
• Component/s: Core/Engine
• Labels: Deadlock flush pull-request-available
• Assignee: Tian Jiang
• Reporter: Tian Jiang
• Created: 23/Nov/23 11:36
• Updated: 24/Nov/23 01:34
• Resolved: 24/Nov/23 01:34

Description

There is a deadlock issue which can be triggered by the FLUSH command in the following condition:

1. The main thread constructs sub-threads of closing tsfiles.

2. The last sub-thread is near its end and removes itself from ''closingSequenceTsFileProcessors''. Then the main thread breaks the while loop, holds ''closeStroageGroupCondition'', and uses ''future.get'' to wait for the sub-thread.

3. Unfortunately, since the main thread holds the condition, the sub-thread cannot hold it and gets stuck. The main thread is also blocked by the sub-thread through "future.get", so there is a deadlock.

 

The solution is simple: there is no need for the main thread to wait for the sub-threads while holding the condition, and the waiting can be done outside of the synchronization block.

Issue Links

• links to: GitHub Pull Request #11611