Coroutine Kyuin

社内勉強会「冬休み前にKotlinのCoroutinesを吸引したい人が集う会」資料

Transcript

1. ౙٳΈલʹ
   ,PUMJOͷ$PSPVUJOFTΛ
   ٵҾ͍ͨ͠ਓ͕ू͏ձ !V[[V
2. झࢫ w೥຤,PUMJOͰ੒Ռग़ͧ͢
   w·ͩ$PSPVUJOFTΑ͘෼͔ͬͯͳ͍ͧ
   w$PSPVUJOFTରԠਓࡐʹͳΔͧ
3. ຊ୊ w ,PUMJOϕʔεͰ࿩͠·͢
   w$PSPVUJOFTͱ͸
   wଞݴޠʹ͓͚ΔBTZODBXBJUͱͷҧ͍
   w࢖͍ํͬ͘͟Γ
   wͱΓ͜ΕϦϯΫू
4. $PSPVUJOFT w,PUMJO͔Βਖ਼ࣜϦϦʔε͞Εͨඇಉظϓϩάϥ ϛϯάͷҝͷػೳ ΋ͪΖΜNVMUJQMBUGPSNରԠ
   wଞݴޠͰ͍͏ॴͷBTZODBXBJU౳ؚ͕·Ε͍ͯΔ
   wଞݴޠͰ͍͏ॴͷDPSPVUJOF HFOFSBUPS ͸
 ,PUMJOͰ͸4FRVFODF5
5. BTZODBXBJU
   $ class Program { static async ValueTask<int> DoSomething(int value) { await Task.Delay(1000); return value * value; } static async Task MainAsync(string[] args) { Console.WriteLine("Start task"); var result = await DoSomething(100); Console.WriteLine($"Result: {result}"); } static void Main(string[] args) => MainAsync(args).Wait(); }
6. BTZODBXBJU
   $ class Program { static async ValueTask<int> DoSomething(int value) { await Task.Delay(1000); return value * value; } static async Task MainAsync(string[] args) { Console.WriteLine("Start task"); var result = await DoSomething(100); Console.WriteLine($"Result: {result}"); } static void Main(string[] args) => MainAsync(args).Wait(); }
7. BTZODBXBJU
   $ class Program { static async ValueTask<int> DoSomething(int value) { await Task.Delay(1000); return value * value; } static async Task MainAsync(string[] args) { Console.WriteLine("Start task"); var result = await DoSomething(100); Console.WriteLine($"Result: {result}"); } static void Main(string[] args) => MainAsync(args).Wait(); }
8. BTZODBXBJU
   &4 function sleep(milliSeconds) { return new Promise(resolve => setTimeout(resolve, milliSeconds)); } async function doSomething(value) { await sleep(1000); return value * value; } (async() => { console.log("Start task."); const result = await doSomething(100); console.log(`Result: ${result}`) })();
9. BTZODBXBJU
   &4 function sleep(milliSeconds) { return new Promise(resolve => setTimeout(resolve, milliSeconds)); } async function doSomething(value) { await sleep(1000); return value * value; } (async() => { console.log("Start task."); const result = await doSomething(100); console.log(`Result: ${result}`) })();
10. BTZODBXBJU
    &4 function sleep(milliSeconds) { return new Promise(resolve => setTimeout(resolve, milliSeconds)); } async function doSomething(value) { await sleep(1000); return value * value; } (async() => { console.log("Start task."); const result = await doSomething(100); console.log(`Result: ${result}`) })();
11. BTZODBXBJU wBTZOD
    GVODUJPOΛ࣮૷ͯ͠
 ݺͼग़͠ଆͰBXBJU͢Δ
12. $PSPVUJOFT suspend fun doSomething(value: Int): Int { delay(1000) return value * value } fun main() = runBlocking { println("Start task") val result = doSomething(100) println("Result: $result") }
13. $PSPVUJOFT suspend fun doSomething(value: Int): Int { delay(1000) return value * value } fun main() = runBlocking { println("Start task") val result = doSomething(100) println("Result: $result") }
14. $PSPVUJOFT suspend fun doSomething(value: Int): Int { delay(1000) return value * value } fun main() = runBlocking { println("Start task") val result = doSomething(100) println("Result: $result") }
15. $PSPVUJOFT wTVTQFOE
    GVODUJPOΛ࣮૷ͯ͠
 ݺͼग़͠ଆ͸ͨͩݺͿ BXBJU
    LFZXPSEͳ͠ 
 
    BTZODBXBJUͳݴޠͰ͸ඇಉظͰ͋Δࣄ͕લఏ
 
    ,PUMJOͰ͸ඇಉظؔ਺Ͱ͸ͳ͘தஅؔ਺ͳͷͰ
 ɹ
    ಉظzతzʹهड़Ͱ͖ΔΑ͏ʹͳ͍ͬͯΔ
 ɹ
    ଞݴޠͷΑ͏ʹಉظඇಉظΛҙࣝ͢Δඞཁ͕ͳ͍
16. ࢖͍ํ w%FQFOEFODJFTͷ௥Ճ
    w$PSPVUJOF4DPQFΛ࣮૷͢Δ
    w$PSPVUJOF4DPQFMBVODIͯ͠
 Α͠ͳʹTVTQFOE
    GVODUJPOΛݺͼग़͢
17. %FQFOEFODJFTͷ௥Ճ w,PUMJOdΛೖΕΔ͚ͩͰ͸࣮࣭࢖͑ͳ͍
 ݴޠͱͯ͠͸௿ϨΠϠʔͳ࢓༷ͷΈಉ͍ࠝͯ͠Δҝ 
 wՃ͑ͯɺ1MBUGPSNʹ߹ΘͤͯϥΠϒϥϦΛ௥Ճ
 implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:1.0.1" implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:1.0.1"
18. $PSPVUJOF4DPQFΛ࣮૷͢Δ wTVTQFOE
    GVODUJPO͸$PSPVUJOFͷத͋Δ͍͸ TVTQFOE
    GVODUJPO͔ΒͷΈར༻Ͱ͖Δ
    w$PSPVUJOF͸$PSPVUJOF4DPQFͷதͰͷΈ
 ىಈͰ͖Δ
    w$PSPVUJOF4DPQFͷ࣮૷͕ඞཁ
19. $PSPVUJOF4DPQFΛ࣮૷͢Δ suspend fun doSomething(value: Int): Int { delay(1000) return value * value } fun main() = runBlocking { println("Start task") val result = doSomething(100) println("Result: $result") } ݱࡏͷ࣮ߦεϨουΛݩʹ CoroutineScopeΛ࡞ͬͯ ࣮ߦ׬ྃ·Ͱ଴ͬͯΔ
20. $PSPVUJOF4DPQFΛ࣮૷͢Δ w࣮૷ͷલʹগ͚ͩ͠ొ৔ਓ෺ͷ੔ཧ
 ਂೖΓ͢ΔͱऴΘΒͳ͍ͷͰগ͚ͩ͠
21. ࣮૷͢Δ্Ͱ࠷௿ݶͷొ৔ਓ෺ w$PSPVUJOF$POUFYU
    
    ϓϩύςΟͱͯ࣋ͭ͠ඞཁ͕͋Δ
    w+PC
    
    MBVODI͢Δ$PSPVUJOFͷϥΠϑαΠΫϧΛ؅ཧ
    w$PSPVUJOF%JTQBUDIFS
    
    ࣮ߦίϯςΩετ 5ISFBE
    FUD
    wଞɺ$PSPVUJOF&YDFQUJPO)BOEMFS౳͍Δ
 ͕Ұ୴์ஔ
22. $PSPVUJOF4DPQFΛ࣮૷͢Δ class SimpleCoroutineScope(ui: CoroutineDispatcher) : CoroutineScope { // ਌JobΛ࡞Δ(࡞Ε) private val job: Job = Job() // σϑΥϧτͷڍಈͱͯ͠
 // ਌Job͸jobϓϩύςΟͷ΍ͭ
 // ࣮ߦίϯςΩετ͸ίϯετϥΫλҾ਺uiΛ༻͍Δ override val coroutineContext: CoroutineContext = job + ui }
23. $PSPVUJOF4DPQFΛ࣮૷͢Δ class SimpleCoroutineScope : CoroutineScope { // ਌JobΛ࡞Δ(࡞Ε) private val job: Job = Job() // σϑΥϧτͷڍಈͱͯ͠
 // ਌Job͸jobϓϩύςΟͷ΍ͭ
 // ࣮ߦίϯςΩετ͸mainϧʔϓΛ༻͍Δ override val coroutineContext: CoroutineContext = job + Dispatchers.Main }
24. $PSPVUJOF4DPQFΛ࣮૷͢Δ class SimpleCoroutineScope : CoroutineScope { // ਌JobΛ࡞Δ(࡞Ε) private val job: Job = Job() // σϑΥϧτͷڍಈͱͯ͠
 // ਌Job͸jobϓϩύςΟͷ΍ͭ
 // ࣮ߦίϯςΩετ͸IO Pool(※Threadͱ͸ݶΒͳ͍)Λ༻͍Δ override val coroutineContext: CoroutineContext = job + Dispatchers.IO }
25. $PSPVUJOF4DPQFMBVODI͢Δ w جຊతͳॴͱͯ͠ MBVODI͢Δͱ$PSPVUJOF͕ى ಈ͢Δ
 $PSPVUJOF͸࣮ࡍ͍ΖΜͳॴͰىಈ͍ͯ͠Δ͚Ͳলུ
    wMBVODIͷલʹొ৔ਓ෺Λʜ
26. ొ৔ਓ෺ w$PSPVUJOF4DPQF
    
    ͖ͬ͞࡞ͬͨ΍ͭ
    
    w$PSPVUJOF$POUFYU
    
    ͖ͬ͞ϓϩύςΟʹ࣋ͨͤͨ΍ͭ
    w$PSPVUJOF
    
    MBVODI౳ʹΑͬͯ࡞ΒΕΔ࣮ࡍʹಈ͍ͯΔ΍ͭ
    
    w+PC
    ུ %JTQBUDIFS
    FUDʜ
    
    ͖ͬ͞આ໌ͨ͠΍ͭ
    wଞɺ$PSPVUJOF4UBSU౳͋Δ͕Ұ୴লུ
27. $PSPVUJOF4DPQFMBVODI͢Δ class SimpleCoroutineScope : CoroutineScope { // ਌JobΛ࡞Δ(࡞Ε) private val job: Job = Job() // σϑΥϧτͷڍಈͱͯ͠
 // ਌Job͸jobϓϩύςΟͷ΍ͭ
 // ࣮ߦίϯςΩετ͸mainϧʔϓΛ༻͍Δ override val coroutineContext: CoroutineContext = job + Dispatchers.Main }
28. $PSPVUJOF4DPQFMBVODI͢Δ class SimpleCoroutineScope : CoroutineScope { private val job: Job = Job() override val coroutineContext: CoroutineContext = job + Dispatchers.Main fun foo() { launch { // ਌Λjob // ࣮ߦίϯςΩετΛmainϧʔϓͱͯ͠ // CoroutineΛىಈ͠ॲཧΛ࣮ߦ͢Δ val result = doSomething() } } }
29. $PSPVUJOF4DPQFMBVODI͢Δ class SimpleCoroutineScope : CoroutineScope { // ਌JobΛ࡞Δ(࡞Ε) private val job: Job = Job() // σϑΥϧτͷڍಈͱͯ͠
 // ਌Job͸jobϓϩύςΟͷ΍ͭ
 // ࣮ߦίϯςΩετ͸IO Pool(※Threadͱ͸ݶΒͳ͍)Λ༻͍Δ override val coroutineContext: CoroutineContext = job + Dispatchers.IO }
30. $PSPVUJOF4DPQFMBVODI͢Δ class SimpleCoroutineScope : CoroutineScope { private val job: Job = Job() override val coroutineContext: CoroutineContext = job + Dispatchers.IO fun foo() { launch { // ਌Λjob // ࣮ߦίϯςΩετΛIO Poolͱͯ͠ // CoroutineΛىಈ͠ॲཧΛ࣮ߦ͢Δ val result = doSomething() } } }
31. $PSPVUJOF4DPQFMBVODI͢Δ wิ଍ɿ͜Ε͸DPNQJMF
    FSSPS
    SFUVSOͰ͖ͳ͍ fun execute(): Int { launch { return doSomething() } }
32. TVTQFOE
    GVODUJPOΛ࣮૷͢Δ suspend fun doSomething(value: Int): Int { delay(1000) return value * value } fun main() = runBlocking { println("Start task") val result = doSomething(100) println("Result: $result") }
33. TVTQFOE
    GVODUJPOΛ࣮૷͢Δ suspend fun doSomething(value: Int): Int { delay(1000) return value * value } fun main() = runBlocking { println("Start task") val result = doSomething(100) println("Result: $result") } ͜Εsuspend function
34. TVTQFOE
    GVODUJPOΛ࣮૷͢Δ function sleep(milliSeconds) { return new Promise(resolve => setTimeout(resolve, milliSeconds)); } async function doSomething(value) { await sleep(1000); return value * value; } (async() => { console.log("Start task."); const result = await doSomething(100); console.log(`Result: ${result}`) })();
35. TVTQFOE
    GVODUJPOΛ࣮૷͢Δ function sleep(milliSeconds) { return new Promise(resolve => setTimeout(resolve, milliSeconds)); } async function doSomething(value) { await sleep(1000); return value * value; } (async() => { console.log("Start task."); const result = await doSomething(100); console.log(`Result: ${result}`) })(); Ԟ஍Ͱ͜Ε૬౰ͷͳʹ͔Λ
 ࣮૷͢Δඞཁ͕͋Δ
36. TVTQFOE
    GVODUJPOΛ࣮૷͢Δ w࣮૷ͷલʹొ৔ਓ෺Λʜ
37. TVTQFOE
    GVODUJPOΛ࣮૷͢Δ wTVTQFOE$PSPVUJOF
    
    TVTQFOE
    GVODUJPOΛ࣮૷͢Δҝͷ
    
    
    
    
    ɹɹɹɹɹɹɹɹɹɹɹɹɹɹɹɹɹ#VJMEFS
    GVODUJPO
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    wଞɺTVTQFOE $PSPVUJOFɺ $POUJOVBUJPO
 γϦʔζ͕͍͔ͭ͋͘Δ͚ͲҰ୴লུ
38. TVTQFOE
    GVODUJPOΛ࣮૷͢Δ suspend fun doSomething(value: Int): Int = suspendCoroutine { continuation -> continuation.resume(value * value) } suspend fun doSomething(value: Int): Int = suspendCoroutine { continuation -> continuation.resumeWithException(Throwable()) }
39. طଘίʔυΛTVTQFOE
    GVO w$14 ͍ΘΏΔDBMMCBDLܗࣜ ͔ΒҠߦ͍ͨ͠৔߹ fun doSomethingAsync(value: Int, listener: Listener) { if (value <= 0) { listener.onError(Throwable()) } else { listener.onSuccess(value) } } suspend fun doSomething(value: Int): Int = suspendCoroutine { doSomethingAsync(value, object : Listener { override fun onSuccess(value: Int) { it.resume(value) } override fun onError(e: Throwable) { it.resumeWithException(e) } }) }
40. طଘίʔυΛTVTQFOE
    GVO w3FBDUJWFd͔ΒҠߦ͍ͨ͠৔߹͸ม׵༻ϥΠϒϥϦΛ࢖͏
 ҎԼ͸3Y+BWBͷྫ 
 fun doSomethingSingle(value: Int): Single<Int> = Single.just(value * value) suspend fun doSomething(value: Int): Int = doSomethingSingle(value).await() implementation "org.jetbrains.kotlinx:kotlinx-coroutines-rx2:1.0.1"
41. ྫ֎र͍͍ͨ launch { try { val result = doSomething() } catch (e: Throwable) { // } } launch { runCatching { doSomething() } // Result<T>͕ฦ٫͞ΕΔ .onSuccess { value -> } .onFailure { throwable -> } } ,PUMJO͔Β௥ՃͷSVO$BUDIJOHਪ঑
42. ࣮ߦίϯςΩετม͍͑ͨ class SimpleCoroutineScope : CoroutineScope { private val job: Job = Job() override val coroutineContext: CoroutineContext = job + Dispatchers.Main fun execute() { launch { // Main runCatching { // Main withContext(Dispatchers.IO) { // IO doSomething() } } .onSuccess { value -> // Main } .onFailure { throwable -> // Main } } } }
43. Ωϟϯηϧ͍ͨ͠ $ static async ValueTask<int> DoSomething(int value, CancellationToken token) { await Task.Delay(1000); token.ThrowIfCancellationRequested(); return value * value; } static async Task MainAsync(string[] args) { Console.WriteLine("Start task"); var cancellable = new CancellationTokenSource(); var task = DoSomething(100, cancellable.Token); cancellable.Cancel(); var result = await task; Console.WriteLine($"result: {result}"); }
44. Ωϟϯηϧ͍ͨ͠ &4 async function doSomething(value, token) { await sleep(1000); await token.rejectIfCancelled(); return value * value; } (async() => { const cancellable = new Cancellable(); const finalize = () => cancellable.cancel(); process.on('exit', finalize); console.log("Start task."); doSomething(100, cancellable.token); console.log(`Result: ${result}`); process.removeListener('exit', finalize); })(); Cancellable.js https://gist.github.com/uzzu/7d6e89fafc4bcde1c6f6d82a3d164409 ˢ͸ྫ͕ѱ͍͕OPEFͰϓϩηεؒ௨৴ͭͭ͠௕ظλεΫ࣮ߦͯͯ͠ʜͳ࣌ͱ͔
45. Ωϟϯηϧ͍ͨ͠ class SimpleCoroutineScope : CoroutineScope { private val job: Job = Job() override val coroutineContext: CoroutineContext = job + Dispatchers.Main fun onDestroy() { job.cancel() } }
46. Ωϟϯηϧ͍ͨ͠ class SimpleCoroutineScope : CoroutineScope { private val job: Job = Job() override val coroutineContext: CoroutineContext = job + Dispatchers.Main fun onDestroy() { job.cancel() } } ࢠͷJob(Coroutine)͕શ෦cancel͞ΕΔ ݸผʹcancel͍ͨ͠έʔεʹ͍ͭͯ͸লུ
47. ͱΓ͜ΕϦϯΫू w$PSPVUJOF
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48. Ұ୴͜͜·Ͱ
49. ଞτϐοΫฉ͖͍ͨࣄ͋Ε͹ޙ΄ͲͲ͏ͧ w "EWBODFE
 3Y+BWBΛར༻࣮ͨ͠૷ͱͷൺֱΛͯ͠ΈΑ͏
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