BehaviorSubject concurrent use in BattleFrontFeed.java

[akarnokd]

Hi!

I was watching the video of this code base and saw a common mistake in using Subjects:

RxJavaGoT/app/src/main/java/net/tensory/rxjavatalk/repositories/BattleFrontFeed.java

Line 26 in 110c3a2

private BehaviorSubject<Battle> battleSubject = BehaviorSubject.create();

Subjects by default are not thread safe when calling onNext and lines 34:

RxJavaGoT/app/src/main/java/net/tensory/rxjavatalk/repositories/BattleFrontFeed.java

Lines 33 to 34 in 110c3a2

	.delay(EMIT_RATE_SECONDS / 2, TimeUnit.SECONDS)
	.subscribe(battle -> battleSubject.onNext(battle));

and 46:

RxJavaGoT/app/src/main/java/net/tensory/rxjavatalk/repositories/BattleFrontFeed.java

Lines 45 to 46 in 110c3a2

	observable.subscribe(battle -> battleSubject.onNext(battle));

may end up calling it concurrently, which leads to undefined behavior.

Line 26 should look like this instead:

private Subject<Battle> battleSubject = BehaviorSubject.<Battle>create().toSerialized(); 

[aderington]

Hi David,

Thank you so much for pointing this out! We really appreciate you looking over our samples and helping us to improve them (plus we got to learn more about concurrency with Subjects.)

We'll get the examples updated as soon as possible.

Cheers!
Angella Derington