Memory leak

[yacine-ser]

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🐛 Describe the bug

When using the version 0.40.1, our builds fail with the following error

an FAILURE: Build failed with an exception.
* What went wrong:
GC overhead limit exceeded

After adding +HeapDumpOnOutOfMemoryError to the jvmargs and analysing the hprof we got the following report from Eclipse MAT

Note :
Current jvmargs in our gradle.properties
org.gradle.jvmargs=-Xmx4096m -XX:+HeapDumpOnOutOfMemoryError

⚠️ Current behavior

After multiple builds we have to restart the gradle deamon because it is taking most of the allowed allocated memory.
Not stopping it result in very slow builds and the above mentioned error.

✅ Expected behavior

That our build time remains consistent

💣 Steps to reproduce

N/A

📱 Tech info

N/A

[yacine-ser]

Additional info :
The version 0.40.0 is not affected by this issue.
It seems to be a side effect of this change

[LouisCAD]

Hello, thank you for the report, I was suspecting that we had a memory leak issue but had failed to find where to look exactly.

I'll try to pinpoint where it's rooted, starting from the information you provided, and I hope we can find a solution for the next release.

[soywiz-invideo]

Quick update:
We found that another gradle plugin was the one that caused most the huge leak, though it was not obvious. It looked that refreshVersions had some leaked instances (added instances between each ./gradlew call), but those aren't retaining too much memory and is really minor at least in 0.40.0 👍

And indeed confirmed that after bumping to 0.40.1 there is a huge leak with gradle. Pretty huge because we have lots of modules and dependencies, so maybe it is more noticeable than normal.

We are using refreshVersions 0.40.0, and we have a pretty big leak just running ./gradlew, diffing two gradle heaps we found this (in the case it is helpful):

Click to expand

GC root seems to be Gradle listenerManager:

And here a different one:

[LouisCAD]

I now have a reproducer in CI (see #546) and I'll be working on fixing this this week.

Thank you a lot for the help in pinpointing this.
It's related to code inside UsedPluginsHolder and triggers when refreshVersions manages the version of another Gradle plugin.

[LouisCAD]

Fixed in 0.40.2.
Thank you!