realm-java: Crash: E/REALM: could not create WeakRealmNotifier ALooper message pipe: Too many open files

While trying to determine if I have any memory leaks, I now trigger a garbage collection manually at the end of a long running process (many network requests with Retrofit composed using RxJava).

While running the profiler, I got this error, which seems very similar to #4002

E/REALM: could not create WeakRealmNotifier ALooper message pipe: Too many open files.
E/REALM: uncaught exception in notifier thread: St12system_error: Bad file descriptor
A/libc: Fatal signal 6 (SIGABRT), code -6 in tid 10120 (HandlerThread 1)

I though I should report this. Any idea what could be causing it? #4002 turned out to be a Realm bug.

Is there something I could be doing wrong and trigger this error? I keep Realm connections open only for the time I need them.

Version of Realm and tooling

Realm version(s): 4.3.4

Realm sync feature enabled: no

Android Studio version: 3.0.1

Which Android version and device: Android 7.0, Samsung S7