Memory leak / high CPU

[borkdude]

Repro:

$ clj -J-Xmx1g
Clojure 1.10.1
user=> (require '[clj-kondo.core :as clj-kondo])
nil
user=> (dotimes [i 10] (do (clj-kondo/run! {:lint ["src"]})))
nil
user=> (dotimes [i 10] (do (clj-kondo/run! {:lint ["src"]})))
nil
user=> (dotimes [i 10] (do (clj-kondo/run! {:lint ["src"]})))
nil
user=> (dotimes [i 10] (do (clj-kondo/run! {:lint ["src"]})))
nil
user=> (dotimes [i 10] (do (clj-kondo/run! {:lint ["src"]})))
user=> (dotimes [i 10] (do (clj-kondo/run! {:lint ["src"]})))
Execution error (OutOfMemoryError) at (REPL:1).
Java heap space

This is reported by VSCode users where clj-kondo is running as a long lived process.

Cause: we were holding on to a ctx argument in the hooks namespace by memoizing over it, which contains the entire linting state.

[borkdude]

Fixed with edfe1ff.

Proof:

$ clj -J-Xmx1g
Clojure 1.10.1
user=> (require '[clj-kondo.core :as clj-kondo])
nil
user=> (do (dotimes [i 100] (prn i) (clj-kondo/run! {:lint ["src"]})) (System/gc))

Monitor the Java process:

$ jps -m
$ top -pid 43477

No OOM, memory is back to reasonable amount after final GC.

[borkdude]

Update to 2020.09.10-20201007.185225-22 to fix the problem.