Delay operator will leak memory

[ubnt-michals]

RxJS version: 5 and 6

Code to reproduce:
5

const { Observable } = require('rxjs');

const setup = delay => Observable.timer(1)
  .repeatWhen(notifications => notifications.delay(delay))
  .subscribe();

let instances = 100;
while (instances--) {
  setup(100);
}

6

const { timer } = require('rxjs');
const { repeatWhen, delay } = require('rxjs/operators');

const setup = d => timer(1)
  .pipe(
    repeatWhen(notifications => notifications.pipe(delay(d)))
  )
  .subscribe();

let instances = 100;
while (instances--) {
  setup(100);
}

Expected behavior:
Memory shouldn't grow

Actual behavior:
Memory grows indefinitely

Additional information:
Have fix and will provide PR

[benlesh]

I'm not sure this is a problem with delay so much as it might be a problem with repeatWhen. The recursive nature of what you're doing here is suspect.

[ubnt-michals]

Where is the recursion? I running asynchronous action and resubscribing it with delay.

In synchronous code it would be something like

while(true) {
  doStuff()
  sleep(1)
}

The code above when replaced with

timer(1)
  .pipe(
    repeatWhen(notifications => notifications.pipe(mergeMapTo(timer(d))))
  )
  .subscribe();

is not leaking.

[ubnt-michals]

Fixed in #3605

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.