Memory leaks in Zipline

[evtuhovaleksander]

Hello

We are facing an issue that zipline leaks 500-600kb every "cycle" of usage.

Is there any examples

• of correct usage ZiplineScope and ZiplineScoped?
• how we must correctly close services and zipline
• how we must correctly close services and zipline when service contains Flows?

We thought that we are doing something wrong with closing pipeline. So we downloaded current world-clock example.

• we see continious leaks of memory
• sometimes we see lots of messages from EventListener of leaked callbacks
• after we close zipline and open next instance we see even more info about leaked callbacks

We modified example

//val serviceName = endpoint.generatePassByReferenceName()
val serviceName = endpoint.generatePassByReferenceName() + "____" + value.adapter.simpleName // to see what object is leaked

// to catch leak events
class LeakerLis: EventListener() {
  override fun serviceLeaked(zipline: Zipline, name: String) {
    super.serviceLeaked(zipline, name)
    println("LEAKED____$name")
  }
}

// we disabled hot reload
scope.launch(ziplineDispatcher + SupervisorJob()) {
    val loadResultFlow: LoadResult = ziplineLoader.loadOnce(
      applicationName = "world-clock",
      freshnessChecker = DefaultFreshnessCheckerNotFresh,
      manifestUrl=manifestUrl,
      initializer = { zipline: Zipline ->
        zipline.bind("WorldClockHost", host)
      },
    )
    var previousJob: Job? = null
    previousJob?.cancel()
    val result = loadResultFlow
    if (result is LoadResult.Success) {
      val zipline = result.zipline
      val presenter = zipline.take<WorldClockPresenter>("WorldClockPresenter")
      val job = launch {
        models.emitAll(presenter.models(events))
      }
      job.invokeOnCompletion {
        presenter.close()
        // TODO(jwilson): make this safe.
        zipline.close()
      }
      previousJob = job
    }
  }

After this changes we launch
and some times (even without closing zipline) we see

LEAKED____zipline/guest-8192____SuspendCallback
LEAKED____zipline/guest-8080____SuspendCallback
LEAKED____zipline/guest-7928____SuspendCallback
LEAKED____zipline/guest-8124____SuspendCallback
LEAKED____zipline/guest-8116____SuspendCallback

after closing and reopening screen we can see even more messages of that kind

sample project is at
https://github.com/evtuhovaleksander/zipline/tree/leaks_example

[evtuhovaleksander]

@JakeWharton and @swankjesse we are begging for help