Description

krackers

opened on Jun 16, 2022

Issue body actions

Before opening the issue, have you...?

• Searched for existing issues
• Looked through the wiki
• Updated MonitorControl to the latest version (if applicable)

Describe the bug

In this file https://github.com/MonitorControl/MonitorControl/blob/main/MonitorControl/Support/Arm64DDC.swift (and possibly the intel version), I don't see any CFRelease/IOObjectRelease calls, despite the fact that the docs say you must release the iterator and any objects as you iterate through them. But I'm not 100% familiar with swift, does it wrap iokit to take care of these things for you?

Also you should consider using CFSTR macro instead of CFStringCreateWithCString for the string constants that are fixed, so that way you avoid any runtime allocation entirely

Note that I have not traced through instruments to see how big of an impact this is

Steps to reproduce

• Read through code
• Notice no cfrelease/ioobject release calls

Expected behavior

• cfrelease/ioobjectrelease calls added as appropriate

Anything else?

No response

Environment Information (please complete the following information)

- macOS Version 12.4
- MacBook Pro (16-inch, 2021
- Apple Silicon: Yes
- Monitor Control versions: Should affect anything that supports m1?

Activity

1. waydabber commented on Jun 16, 2022

   

   waydabber

   on Jun 16, 2022

   Member

   More actions

   HI @krackers - yes, all objects returned by IOKitLib should be released with this function when access to them is no longer needed.. I did not see any practical downside of skipping this in Arm64DDC even while running the app for prolonged time (the effect seems to be minimal), but still, it is proper to call IOObjectRelease on the iterators as advised. I don't think there is any special swift related mechanism is in place to do this with IOKit objects, so it's just an omission on my part (sorry about that). Thanks for pointing it out!

   IntelDDC does this better, but that is thanks to @reitermarkus, not me, I just took most of his code and repurposed it for MonitorControl.

   Please, feel free to contribute to the code or fix/improve whatever you feel must be improved! :)
2. waydabber

   added

   Type: Enhancement

   on Jun 16, 2022
3. waydabber

   assigned

   krackers

   on Jun 16, 2022
4. waydabber

   added a commit that references this issue on Sep 18, 2022

   Implement #1087 (Possible memory leak in arm64ddc?)

   389d587
5. waydabber commented on Sep 18, 2022

   

   waydabber

   on Sep 18, 2022

   Member

   More actions

   Made the proposed changes: #1181
6. waydabber

   added

   doneWork on this issue is complete. Will be available on next releaseWork on this issue is complete. Will be available on next release

   on Sep 18, 2022
7. waydabber

   closed this as completedon Sep 18, 2022
8. waydabber

   added a commit that references this issue on Sep 18, 2022

   Fixed "Possible memory leak in Arm64ddc? #1087"

   d0c4bbf

Issue actions