Does RxJava frequently switch threads with performance loss?

Question

ref：https://github.com/ReactiveX/RxAndroid/issues/420

in this context:

//pseudo-code
websocket(Callback(data){
     //websocket very frequent data in no main thread
     Observable.just(data)
                                .observeOn(Schedulers.computation())
                                .subscribe(data -> {
                                    //computation thread
                                    map2Obj(data);
                                });
});


//computation
void map2Obj(data){
    //....

    then change to main thread
}

------------------the blow is ExecutorService implementation model-----------------------------------

in this context:

//pseudo-code
 static ExecutorService mExecutorService;
    static {
        mExecutorService = Executors.newFixedThreadPool(8);
    }

websocket(Callback(data){
     //websocket very frequent data in no main thread。change to other compute thread to prevent block "the thread of getting data"。in run() execute map2Obj(data)
        mExecutorService.execute(new NewFixThread(str));
});


//computation
void map2Obj(data){
    //....

    then change to main thread
}

RxJava is better or java Executors?why?

Thx!!!!!

Answer 1

It switches threads as often as you need it to.

And no more.

Your sample code will continually move data from the main thread to another thread. This will cause a performance loss of a few microseconds each time, depending on how and when threads have to be created.

Exactly as you told it to.