[ARROW-2558] [Plasma] avoid walk through all the objects when a client disconnects

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 0.10.0
• Component/s: C++ - Plasma
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/18907
• Assignee: Zhijun Fu
• Reporter: Zhijun Fu
• Created: 09/May/18 07:17
• Updated: 11/Jan/23 07:21
• Resolved: 15/May/18 22:54

Description

Currently plasma stores list-of-clients in ObjectTableEntry, which is used to track which clients are using a given object, this serves for two purposes:

• If an object is in use.
• If the client trying to abort an object is the one who created it.

A problem with list-of-clients approach is that when a client disconnects, we need to walk through all the objects and remove the client pointer from the list for each object.

Instead, we could add a reference count in ObjectTableEntry, and store list-of-object-ids in client structure. This could both goals that the original approach is targeting, while when a client disconnects, it just walk through its object-ids and dereference each ObjectTableEntry, there's no need to walk through all objects.

Issue Links

• links to: GitHub Pull Request #2015