Asinhrone budućnosti i verteksi

Slide 1

Slide 1 text

DAFEDLOVE | HeapSpace, 2016 1

Slide 2

Slide 2 text

Async java DAFEDLOVE | HeapSpace, 2016 2

Slide 3

Slide 3 text

4 fun fact #1 4 cool fact #2 4 i ovde kao još nešto... DAFEDLOVE | HeapSpace, 2016 3

Slide 4

Slide 4 text

Šta svaki program radi? ulaz, obrada, izlaz DAFEDLOVE | HeapSpace, 2016 4

Slide 5

Slide 5 text

Šta svaki program koristi? Memoriju i CPU DAFEDLOVE | HeapSpace, 2016 5

Slide 6

Slide 6 text

CPU može da radi samo JEDNU stvar DAFEDLOVE | HeapSpace, 2016 6

Slide 7

Slide 7 text

Ups. DAFEDLOVE | HeapSpace, 2016 7

Slide 8

Slide 8 text

Sync IO 4 Dolazi input 4 CPU čeka da se I završi 4 Procesiranje 4 CPU čeka da se O završi DAFEDLOVE | HeapSpace, 2016 8

Slide 9

Slide 9 text

Pravilo CPU ne sme da čeka! DAFEDLOVE | HeapSpace, 2016 9

Slide 10

Slide 10 text

Rešenje Ako CPU čeka IO neka switch context DAFEDLOVE | HeapSpace, 2016 10

Slide 11

Slide 11 text

Multi Threading 4 (Svaki) ulaz ima jedan thread 4 CPU switch threadova dok su oni blokirani na I. 4 Kada CPU izabere thread koji je spreman, započinje obradu DAFEDLOVE | HeapSpace, 2016 11

Slide 12

Slide 12 text

DAFEDLOVE | HeapSpace, 2016 12

Slide 13

Slide 13 text

Gde je tu Java? IO/NIO/NIO2/... DAFEDLOVE | HeapSpace, 2016 13

Slide 14

Slide 14 text

Async Java Executors DAFEDLOVE | HeapSpace, 2016 14

Slide 15

Slide 15 text

ExecutorService executorService = Executors.newFixedThreadPool(10); executorService.execute(new Runnable() { public void run() { System.out.println("Asynchronous task"); } }); executorService.shutdown(); DAFEDLOVE | HeapSpace, 2016 15

Slide 16

Slide 16 text

ExecutorService executorService = Executors.newFixedThreadPool(10); executorService.execute(() -> System.out.println("Asynchronous task") }); executorService.shutdown(); DAFEDLOVE | HeapSpace, 2016 16

Slide 17

Slide 17 text

Pravilo Zaključaj deljene resurse DAFEDLOVE | HeapSpace, 2016 17

Slide 18

Slide 18 text

DAFEDLOVE | HeapSpace, 2016 18

Slide 19

Slide 19 text

DAFEDLOVE | HeapSpace, 2016 19

Slide 20

Slide 20 text

Async Java Lock DAFEDLOVE | HeapSpace, 2016 20

Slide 21

Slide 21 text

synchronized? 4 Jedan monitor po objektu 4 Nema načina da se prekine čekanje za lock 4 Nema time-outa 4 Blok struktura koda 4 Teško je ostvariti multiple lock 4 Nema naprednih lokovanja DAFEDLOVE | HeapSpace, 2016 21

Slide 22

Slide 22 text

Lock lock = new ReentrantLock(); lock.lock(); // critical section lock.unlock(); DAFEDLOVE | HeapSpace, 2016 22

Slide 23

Slide 23 text

ReadWriteLock readWriteLock = new ReentrantReadWriteLock(); readWriteLock.readLock().lock(); // multiple readers, if not writing readWriteLock.readLock().unlock(); readWriteLock.writeLock().lock(); // one writer, if not reading readWriteLock.writeLock().unlock(); DAFEDLOVE | HeapSpace, 2016 23

Slide 24

Slide 24 text

Izazov Multithreading NIJE rešenje DAFEDLOVE | HeapSpace, 2016 24

Slide 25

Slide 25 text

DAFEDLOVE | HeapSpace, 2016 25

Slide 26

Slide 26 text

Scenario 2 threads 3 inputs DAFEDLOVE | HeapSpace, 2016 26

Slide 27

Slide 27 text

DAFEDLOVE | HeapSpace, 2016 27

Slide 28

Slide 28 text

DAFEDLOVE | HeapSpace, 2016 28

Slide 29

Slide 29 text

DAFEDLOVE | HeapSpace, 2016 29

Slide 30

Slide 30 text

DAFEDLOVE | HeapSpace, 2016 30

Slide 31

Slide 31 text

DAFEDLOVE | HeapSpace, 2016 31

Slide 32

Slide 32 text

DAFEDLOVE | HeapSpace, 2016 32

Slide 33

Slide 33 text

DAFEDLOVE | HeapSpace, 2016 33

Slide 34

Slide 34 text

DAFEDLOVE | HeapSpace, 2016 34

Slide 35

Slide 35 text

DAFEDLOVE | HeapSpace, 2016 35

Slide 36

Slide 36 text

DAFEDLOVE | HeapSpace, 2016 36

Slide 37

Slide 37 text

DAFEDLOVE | HeapSpace, 2016 37

Slide 38

Slide 38 text

Multithreading != Concurrent DAFEDLOVE | HeapSpace, 2016 38

Slide 39

Slide 39 text

Rešenje? Async! DAFEDLOVE | HeapSpace, 2016 39

Slide 40

Slide 40 text

DAFEDLOVE | HeapSpace, 2016 40

Slide 41

Slide 41 text

DAFEDLOVE | HeapSpace, 2016 41

Slide 42

Slide 42 text

Async Java Future DAFEDLOVE | HeapSpace, 2016 42

Slide 43

Slide 43 text

Future future = executorService.submit( new Callable() { public Object call() throws Exception { System.out.println("Asynchronous Callable"); return "Callable Result"; } } ); // not blocked, do something! future.get(); // block DAFEDLOVE | HeapSpace, 2016 43

Slide 44

Slide 44 text

Nažalost... DAFEDLOVE | HeapSpace, 2016 44

Slide 45

Slide 45 text

DAFEDLOVE | HeapSpace, 2016 45

Slide 46

Slide 46 text

Your Future sucks! Callback Hell DAFEDLOVE | HeapSpace, 2016 46

Slide 47

Slide 47 text

Async Java 8 CompletableFuture (aka Promise) DAFEDLOVE | HeapSpace, 2016 47

Slide 48

Slide 48 text

CompletableFuture 4 Functional 4 Monadic (chain!) 4 Asynchronous 4 Event-driven 4 Bogat API 4 Tri varijante metoda DAFEDLOVE | HeapSpace, 2016 48

Slide 49

Slide 49 text

CompletableFuture 4 chaining (1 - 1) 4 composition (1 - 1) 4 kombinacija, čekanje na rezultat (2 - 1) 4 kombinacija, javi se posle prvog (2 - 1) 36 metoda!!! DAFEDLOVE | HeapSpace, 2016 49

Slide 50

Slide 50 text

CompletableFuture 4 u istom executoru kao caller 4 u novom Executor 4 u common fork-join pool-u 36 metoda!!! DAFEDLOVE | HeapSpace, 2016 50

Slide 51

Slide 51 text

Kreiraj supplyAsync, runAsync CompletableFuture f = supplyAsync( () -> {sleep(1000); return 42;} ); // do something f.get(); // f.join(); DAFEDLOVE | HeapSpace, 2016 51

Slide 52

Slide 52 text

Nastavi akciju posle thenApply CompletableFuture f2 = f.thenApply((r) -> r*r); DAFEDLOVE | HeapSpace, 2016 52

Slide 53

Slide 53 text

Greške exceptionally, handle f.exceptionally((t) -> 2); DAFEDLOVE | HeapSpace, 2016 53

Slide 54

Slide 54 text

Kombinacija thenCombine CompletableFuture f1 = supplyAsync( () -> {sleep(1000); return 42;} ); CompletableFuture f2 = supplyAsync( () -> {sleep(1000); return 52;} ); f3 = f1.thenCombine(f2, (r1, r2) -> r1 + r2)); DAFEDLOVE | HeapSpace, 2016 54

Slide 55

Slide 55 text

Primer CompletableFuture.supplyAsync( () -> readPage("http://jodd.org/") ) .thenApply( page -> linkParser.getLinks(page)) .thenAcceptAsync( links -> displayPanel.display(links) ); DAFEDLOVE | HeapSpace, 2016 55

Slide 56

Slide 56 text

Primer 8 CompletableFuture.supplyAsync( () -> readPage("http://jodd.org/") ) .thenApply(Parser::getLinks(page)) .thenAcceptAsync(DisplayPanel::display(links)) ); DAFEDLOVE | HeapSpace, 2016 56

Slide 57

Slide 57 text

Poslednji primer CompletableFuture closing = new CompletableFuture<>(); Stream manyStrings = Stream.of("one", "two", "three"); CompletableFuture reduce = manyStrings .parallel() // ! .onClose(() -> closing.complete(">")) .filter(s -> s.length() < 4) .map(CompletableFuture::completedFuture) .reduce(closing, (cf1, cf2) -> cf1.thenCombine( cf2, (BinaryOperator) (s1, s2) -> s1 + s2) ); manyStrings.close(); System.out.println(reduce.get()); DAFEDLOVE | HeapSpace, 2016 57

Slide 58

Slide 58 text

4 @see JavaDoc DAFEDLOVE | HeapSpace, 2016 58

Slide 59

Slide 59 text

C10K DAFEDLOVE | HeapSpace, 2016 59

Slide 60

Slide 60 text

Multi Threading 4 (Svaki) ulaz ima jedan thread 4 CPU switch threadova dok su oni blokirani na I. 4 Kada CPU izabere thread koji je spreman, započinje obradu DAFEDLOVE | HeapSpace, 2016 60

Slide 61

Slide 61 text

Pravilo Za Async je potrebno dvoje ❤ DAFEDLOVE | HeapSpace, 2016 61

Slide 62

Slide 62 text

Async 'Blocking' IO 4 I se skenira periodično dok se ne nađe spreman 4 # tredova << # inputa 4 manji context switch 4 select(), poll() DAFEDLOVE | HeapSpace, 2016 62

Slide 63

Slide 63 text

Async Non-Blocking IO 4 I obaveštava CPU kada je spreman 4 Potreban je samo 1 thread / CPU 4 ne postoji context switch 4 epoll() DAFEDLOVE | HeapSpace, 2016 63

Slide 64

Slide 64 text

Async Java AsynchronousChannel DAFEDLOVE | HeapSpace, 2016 64

Slide 65

Slide 65 text

Async, simplified 1. Make system call to selector 2. if nothing to do, `goto 1` 3. loop through tasks a. if its an `OP_ACCEPT`, system call to accept the connection, save the key b. if its an `OP_READ`, find the key, system call to read the data c. if more tasks `goto 3` 4. `goto 1` DAFEDLOVE | HeapSpace, 2016 65

Slide 66

Slide 66 text

Hello VertX! http://vertx.io/ DAFEDLOVE | HeapSpace, 2016 66

Slide 67

Slide 67 text

VertX 4 Polyglot 4 Jednostavan 4 Skalabilan 4 actor-like concurrency model DAFEDLOVE | HeapSpace, 2016 67

Slide 68

Slide 68 text

Server.java public class Server extends Verticle { public void start() { vertx.createHttpServer().requestHandler( new Handler() { public void handle(HttpServerRequest req) { String file = req.path().equals("/") ? "index.html" : req.path(); req.response().sendFile("webroot/" + file); } }).listen(8080); } } DAFEDLOVE | HeapSpace, 2016 68

Slide 69

Slide 69 text

Server.java public class Server extends Verticle { public void start() { vertx.createHttpServer().requestHandler( req -> { String file = req.path().equals("/") ? "index.html" : req.path(); req.response().sendFile("webroot/" + file); } ).listen(8080); } } DAFEDLOVE | HeapSpace, 2016 69