This document discusses the observeOn and subscribeOn operators in RxJava. ObserveOn sets the Scheduler on which observers will observe the Observable. SubscribeOn sets the Scheduler on which the Observable will emit items. Several examples are provided to illustrate the difference between the two operators and how they affect the threading of Observable execution. Links to additional documentation resources on RxJava operators are also included.

1. Creating Operators
정경호
moltak

2. Creating Operators
observeOn/subscribeOn
Practice

3. 초심으로 돌아가서…
화내지 말아주세요 ㅠ_ㅠ

4. Creating Operators
• Create
• Defer
• Empty/Never/Throw
• From
• Interval
• Just
• Range
• Repeat
• Start
• Timer

5. https://github.com/gdgand/android-rxjava/tree/master/
2016-06-22_operators_creating

6. observeOn, subscribeOn
Observable 이 동작할 Scheduler 를 지정
해당 Observable 을 observe(관찰) 할 옵저버의
Scheduler를 지정
http://reactivex.io/documentation/operators/observeon.html
http://reactivex.io/documentation/operators/subscribeon.html

7. map 1 --> main
subscribe --> main
observeOn

8. observeOn

9. map 1 --> main
subscribe --> RxIoScheduler-2
observeOn

10. observeOn

11. map 1 --> main
map 2 --> main
subscribe --> RxIoScheduler-2
observeOn

12. observeOn

13. observeOn

14. map 1 --> main
map 2 --> RxIoScheduler-2
subscribe --> RxIoScheduler-2
observeOn

15. • ObserveOn
• Observer (operator 혹은 subscriber) 의 observe(관찰, 혹은 동작)
스레드 지정
• observeOn 이 호출 된 후 ‘다시’ 호출되기 전까지 유지됨.
observeOn

16. 동작되는 스레드를 아시겠나요?
observeOn

17. map 1 --> main
map 2 --> RxIoScheduler-2
map 3 --> RxNewThreadScheduler-3
subscribe --> RxNewThreadScheduler-3
observeOn
동작되는 스레드를 아시겠나요?

18. subscribeOn
map 1 --> main
subscribe --> main

19. subscribeOn

20. subscribeOn
map 1 --> RxIoScheduler-2
subscribe --> RxIoScheduler-2

21. subscribeOn
무슨 의미일까…?

22. subscribeOn

23. subscribeOn
observable --> RxIoScheduler-2
map 1 --> RxIoScheduler-2
subscribe --> RxIoScheduler-2

24. subscribeOn
observable --> RxIoScheduler-2
map 1 --> RxNewThreadScheduler-1
subscribe --> RxComputationScheduler-3

25. • subscribeOn
• Observable 의 데이터 emit 의 스레드를 지정.
• 여러번 subscribeOn을 하더라도 최초에 호출한 스레드를 유지함.
subscribeOn

26. “끝”

27. • http://goo.gl/ztz2as
• http://docs.couchbase.com/developer/java-2.0/observables.html
• http://reactivex.io/documentation/operators.html#creating
• https://github.com/ReactiveX/RxJava/wiki/Creating-Observables
• http://reactivex.io/documentation/contract.html
• http://reactivex.io/documentation/observable.html
• http://tomstechnicalblog.blogspot.kr/2016/02/rxjava-understanding-observeon-and.html
• http://reactivex.io/documentation/operators/observeon.html
• http://reactivex.io/documentation/operators/subscribeon.html
• https://github.com/square/retrofit/blob/d04f3a50e41ca01d22f370ac4f332f6ddf4ba9fe/retrofit-adapters/
rxjava/src/main/java/retrofit2/adapter/rxjava/RxJavaCallAdapterFactory.java