Android Makers -- Concurrency doesn’t have to be hard: Kotlin Coroutines & Channels

Presentation of the fundamentals of Kotlin Coroutines, Channels and Flows presented at Android Makers'19
*NOTE* Several animations are not present in this slide deck; the presentation switched between live coding and slides

Transcript

1. Jag Saund Concurrency doesn’t have to be hard:
 Kotlin Coroutines & Channels
2. Loaders Threads AsyncTask Callbacks Futures RxJava Functional Functional Reactive
3. Loaders Threads AsyncTask Callbacks Futures RxJava Functional Functional Reactive Coroutines and Channels Communicating Sequential Processes (CSP)
5. https://jagstalk.page.link/examples
6. https://jagstalk.page.link/examples
7. https://jagstalk.page.link/examples
8. fun main() { val orders = listOf( Menu.Cappuccino(CoffeeBean.Regular, Milk.Whole), Menu.Cappuccino(CoffeeBean.Premium, Milk.Breve), Menu.Cappuccino(CoffeeBean.Regular, Milk.NonFat), Menu.Cappuccino(CoffeeBean.Decaf, Milk.Whole), Menu.Cappuccino(CoffeeBean.Regular, Milk.NonFat), Menu.Cappuccino(CoffeeBean.Decaf, Milk.NonFat) ) } https://jagstalk.page.link/examples
9. fun main() { val orders = listOf(...) } https://jagstalk.page.link/examples
10. fun main() { val orders = listOf(...) orders.forEach { } } https://jagstalk.page.link/examples
11. fun main() { val orders = listOf(...) orders.forEach { val groundBeans = grindCoffeeBeans(it.beans) } } https://jagstalk.page.link/examples
12. fun main() { val orders = listOf(...) orders.forEach { val groundBeans = grindCoffeeBeans(it.beans) val espresso = pullEspressoShot(groundBeans) } } https://jagstalk.page.link/examples
13. fun main() { val orders = listOf(...) orders.forEach { val groundBeans = grindCoffeeBeans(it.beans) val espresso = pullEspressoShot(groundBeans) val steamedMilk = steamMilk(it.milk) } } https://jagstalk.page.link/examples
14. fun main() { val orders = listOf(...) orders.forEach { val groundBeans = grindCoffeeBeans(it.beans) val espresso = pullEspressoShot(groundBeans) val steamedMilk = steamMilk(it.milk) val cappuccino = makeCappuccino(it, espresso, steamedMilk) } } https://jagstalk.page.link/examples
15. fun main() { val orders = listOf(...) orders.forEach { val groundBeans = grindCoffeeBeans(it.beans) val espresso = pullEspressoShot(groundBeans) val steamedMilk = steamMilk(it.milk) val cappuccino = makeCappuccino(it, espresso, steamedMilk) log("serve: $cappuccino") } } https://jagstalk.page.link/examples
16. fun main() { val orders = listOf(...) val time = measureTimeMillis { orders.forEach { val groundBeans = grindCoffeeBeans(it.beans) val espresso = pullEspressoShot(groundBeans) val steamedMilk = steamMilk(it.milk) val cappuccino = makeCappuccino(it, espresso, steamedMilk) log("serve: $cappuccino") } } log("time: $time ms") } https://jagstalk.page.link/examples
17. fun main() { val orders = listOf(...) val time = measureTimeMillis { orders.forEach { val groundBeans = grindCoffeeBeans(it.beans) val espresso = pullEspressoShot(groundBeans) val steamedMilk = steamMilk(it.milk) val cappuccino = makeCappuccino(it, espresso, steamedMilk) log("serve: $cappuccino") } } log("time: $time ms") } https://jagstalk.page.link/examples
18. fun main() {...} private fun grindCoffeeBeans(beans: CoffeeBean): CoffeeBean.GroundBeans { log("grinding coffee beans") sleep(1000) return CoffeeBean.GroundBeans(beans) } private fun pullEspressoShot(groundBeans: CoffeeBean.GroundBeans): Espresso { log("pulling espresso shot") sleep(600) return Espresso(groundBeans) } private fun steamMilk(milk: Milk): Milk.SteamedMilk { log("steaming milk") sleep(300) return Milk.SteamedMilk(milk) } private fun makeCappuccino(order: Menu.Cappuccino, espresso: Espresso, steamedMilk: Milk.SteamedMilk): Beverage.Cappuccino { log("making cappuccino") sleep(100) return Beverage.Cappuccino(order, espresso, steamedMilk) } https://jagstalk.page.link/examples
19. fun main() { val orders = listOf(...) val time = measureTimeMillis { orders.forEach { val groundBeans = grindCoffeeBeans(it.beans) val espresso = pullEspressoShot(groundBeans) val steamedMilk = steamMilk(it.milk) val cappuccino = makeCappuccino(it, espresso, steamedMilk) log("serve: $cappuccino") } } log("time: $time ms") } private fun grindCoffeeBeans(beans: CoffeeBean): CoffeeBean.GroundBeans { ... } private fun pullEspressoShot(groundBeans: CoffeeBean.GroundBeans): Espresso { ... } private fun steamMilk(milk: Milk): Milk.SteamedMilk { ... } private fun makeCappuccino(order: Menu.Cappuccino, espresso: Espresso, steamedMilk: Milk.SteamedMilk): Beverage.Cappuccino { ... } https://jagstalk.page.link/examples
20. https://jagstalk.page.link/examples
21. https://jagstalk.page.link/examples
22. fun main() { val orders = listOf(...) val time = measureTimeMillis { } log("time: $time ms") } private fun processOrders(orders: List<Menu.Cappuccino>) { } orders.forEach { val groundBeans = grindCoffeeBeans(it.beans) val espresso = pullEspressoShot(groundBeans) val steamedMilk = steamMilk(it.milk) val cappuccino = makeCappuccino(it, espresso, steamedMilk) log("serve: $cappuccino") } https://jagstalk.page.link/examples
23. private fun processOrders(orders: List<Menu.Cappuccino>) { } fun main() { val orders = listOf(...) val time = measureTimeMillis { processOrders(orders) } log("time: $time ms") } https://jagstalk.page.link/examples orders.forEach { val groundBeans = grindCoffeeBeans(it.beans) val espresso = pullEspressoShot(groundBeans) val steamedMilk = steamMilk(it.milk) val cappuccino = makeCappuccino(it, espresso, steamedMilk) log("serve: $cappuccino") }
24. fun main() { val orders = listOf(...) val time = measureTimeMillis { launch { processOrders(orders) } launch { processOrders(orders) } } log("time: $time ms”) } private fun processOrders(orders: List<Menu.Cappuccino>) { orders.forEach { val groundBeans = grindCoffeeBeans(it.beans()) val espresso = pullEspressoShot(groundBeans) val steamedMilk = steamMilk(it.milk()) val cappuccino = makeCappuccino(it, espresso, steamedMilk) log("serve: $cappuccino") } } https://jagstalk.page.link/examples
25. fun main() = runBlocking { val orders = listOf(...) val time = measureTimeMillis { launch { processOrders(orders) } launch { processOrders(orders) } } log("time: $time ms”) } private fun processOrders(orders: List<Menu.Cappuccino>) { orders.forEach { val groundBeans = grindCoffeeBeans(it.beans()) val espresso = pullEspressoShot(groundBeans) val steamedMilk = steamMilk(it.milk()) val cappuccino = makeCappuccino(it, espresso, steamedMilk) log("serve: $cappuccino") } } https://jagstalk.page.link/examples
26. fun main() = runBlocking { val orders = listOf(...) val time = measureTimeMillis { launch(CoroutineName("barista-1")) { processOrders(orders) } launch(CoroutineName("barista-2")) { processOrders(orders) } } log("time: $time ms”) } private fun processOrders(orders: List<Menu.Cappuccino>) { orders.forEach { val groundBeans = grindCoffeeBeans(it.beans()) val espresso = pullEspressoShot(groundBeans) val steamedMilk = steamMilk(it.milk()) val cappuccino = makeCappuccino(it, espresso, steamedMilk) log("serve: $cappuccino") } } https://jagstalk.page.link/examples
27. fun main() = runBlocking { val orders = listOf(...) val time = measureTimeMillis { launch(CoroutineName("barista-1")) { processOrders(orders) } launch(CoroutineName("barista-2")) { processOrders(orders) } } log("time: $time ms”) } private fun processOrders(orders: List<Menu.Cappuccino>) { orders.forEach { val groundBeans = grindCoffeeBeans(it.beans()) val espresso = pullEspressoShot(groundBeans) val steamedMilk = steamMilk(it.milk()) val cappuccino = makeCappuccino(it, espresso, steamedMilk) log("serve: $cappuccino") } } https://jagstalk.page.link/examples
28. private fun grindCoffeeBeans(beans: CoffeeBean): CoffeeBean.GroundBeans { log("grinding coffee beans") sleep(1000) return CoffeeBean.GroundBeans(beans) } private fun pullEspressoShot(groundBeans: CoffeeBean.GroundBeans): Espresso { log("pulling espresso shot") sleep(600) return Espresso(groundBeans) } private fun steamMilk(milk: Milk): Milk.SteamedMilk { log("steaming milk") sleep(300) return Milk.SteamedMilk(milk) } private fun makeCappuccino(order: Menu.Cappuccino, espresso: Espresso, steamedMilk: Milk.SteamedMilk): Beverage.Cappuccino { log("making cappuccino") sleep(100) return Beverage.Cappuccino(order, espresso, steamedMilk) } fun main() {...} https://jagstalk.page.link/examples
29. private suspend fun grindCoffeeBeans(beans: CoffeeBean): CoffeeBean.GroundBeans { log("grinding coffee beans") delay(1000) return CoffeeBean.GroundBeans(beans) } private suspend fun pullEspressoShot(groundBeans: CoffeeBean.GroundBeans): Espresso { log("pulling espresso shot") delay(600) return Espresso(groundBeans) } private suspend fun steamMilk(milk: Milk): Milk.SteamedMilk { log("steaming milk") delay(300) return Milk.SteamedMilk(milk) } private suspend fun makeCappuccino(order: Menu.Cappuccino, espresso: Espresso, steamedMilk: Milk.SteamedMilk): Beverage.Cappuccino { log("making cappuccino") delay(100) return Beverage.Cappuccino(order, espresso, steamedMilk) } fun main() {...} https://jagstalk.page.link/examples
30. fun main() {...} private suspend fun grindCoffeeBeans(beans: CoffeeBean): CoffeeBean.GroundBeans { log("grinding coffee beans") delay(1000) return CoffeeBean.GroundBeans(beans) } private suspend fun pullEspressoShot(groundBeans: CoffeeBean.GroundBeans): Espresso { log("pulling espresso shot") delay(600) return Espresso(groundBeans) } private suspend fun steamMilk(milk: Milk): Milk.SteamedMilk { log("steaming milk") delay(300) return Milk.SteamedMilk(milk) } private suspend fun makeCappuccino(order: Menu.Cappuccino, espresso: Espresso, steamedMilk: Milk.SteamedMilk): Beverage.Cappuccino { log("making cappuccino") delay(100) return Beverage.Cappuccino(order, espresso, steamedMilk) } https://jagstalk.page.link/examples
31. private suspend fun grindCoffeeBeans(beans: CoffeeBean): CoffeeBean.GroundBeans { ... } private suspend fun pullEspressoShot(groundBeans: CoffeeBean.GroundBeans): Espresso { ... } private suspend fun steamMilk(milk: Milk): Milk.SteamedMilk { ... } private suspend fun makeCappuccino(order: Menu.Cappuccino, espresso: Espresso, steamedMilk: Milk.SteamedMilk): Beverage.Cappuccino { ... } fun main() {...} https://jagstalk.page.link/examples
32. private fun processOrders(orders: List<Menu.Cappuccino>) { orders.forEach { val groundBeans = grindCoffeeBeans(it.beans()) val espresso = pullEspressoShot(groundBeans) val steamedMilk = steamMilk(it.milk()) val cappuccino = makeCappuccino(it, espresso, steamedMilk) log("serve: $cappuccino") } } private suspend fun grindCoffeeBeans(beans: CoffeeBean): CoffeeBean.GroundBeans { ... } private suspend fun pullEspressoShot(groundBeans: CoffeeBean.GroundBeans): Espresso { ... } private suspend fun steamMilk(milk: Milk): Milk.SteamedMilk { ... } private suspend fun makeCappuccino(order: Menu.Cappuccino, espresso: Espresso, steamedMilk: Milk.SteamedMilk): Beverage.Cappuccino { ... } fun main() {...} https://jagstalk.page.link/examples
33. private suspend fun processOrders(orders: List<Menu.Cappuccino>) { orders.forEach { val groundBeans = grindCoffeeBeans(it.beans()) val espresso = pullEspressoShot(groundBeans) val steamedMilk = steamMilk(it.milk()) val cappuccino = makeCappuccino(it, espresso, steamedMilk) log("serve: $cappuccino") } } private suspend fun grindCoffeeBeans(beans: CoffeeBean): CoffeeBean.GroundBeans { ... } private suspend fun pullEspressoShot(groundBeans: CoffeeBean.GroundBeans): Espresso { ... } private suspend fun steamMilk(milk: Milk): Milk.SteamedMilk { ... } private suspend fun makeCappuccino(order: Menu.Cappuccino, espresso: Espresso, steamedMilk: Milk.SteamedMilk): Beverage.Cappuccino { ... } fun main() {...} https://jagstalk.page.link/examples
34. fun main() = runBlocking { val orders = listOf(...) val time = measureTimeMillis { launch(CoroutineName("barista-1")) { processOrders(orders) } launch(CoroutineName("barista-2")) { processOrders(orders) } } log("time: $time ms”) } private suspend fun processOrders(orders: List<Menu.Cappuccino>) { orders.forEach { val groundBeans = grindCoffeeBeans(it.beans()) val espresso = pullEspressoShot(groundBeans) val steamedMilk = steamMilk(it.milk()) val cappuccino = makeCappuccino(it, espresso, steamedMilk) log("serve: $cappuccino") } } private suspend fun grindCoffeeBeans(beans: CoffeeBean): CoffeeBean.GroundBeans { ... } private suspend fun pullEspressoShot(groundBeans: CoffeeBean.GroundBeans): Espresso { ... } private suspend fun steamMilk(milk: Milk): Milk.SteamedMilk { ... } private suspend fun makeCappuccino(order: Menu.Cappuccino, espresso: Espresso, steamedMilk: Milk.SteamedMilk): Beverage.Cappuccino { ... } https://jagstalk.page.link/examples
35. fun main() = runBlocking { val orders = listOf(...) val time = measureTimeMillis { coroutineScope { launch(CoroutineName("barista-1")) { processOrders(orders) } launch(CoroutineName("barista-2")) { processOrders(orders) } } } log("time: $time ms”) } private suspend fun processOrders(orders: List<Menu.Cappuccino>) { orders.forEach { val groundBeans = grindCoffeeBeans(it.beans()) val espresso = pullEspressoShot(groundBeans) val steamedMilk = steamMilk(it.milk()) val cappuccino = makeCappuccino(it, espresso, steamedMilk) log("serve: $cappuccino") } } private suspend fun grindCoffeeBeans(beans: CoffeeBean): CoffeeBean.GroundBeans { ... } private suspend fun pullEspressoShot(groundBeans: CoffeeBean.GroundBeans): Espresso { ... } private suspend fun steamMilk(milk: Milk): Milk.SteamedMilk { ... } private suspend fun makeCappuccino(order: Menu.Cappuccino, espresso: Espresso, steamedMilk: Milk.SteamedMilk): Beverage.Cappuccino { ... } https://jagstalk.page.link/examples
36. https://jagstalk.page.link/examples Sender Coroutine Receiver Coroutine Channel
37. https://jagstalk.page.link/examples Sender Coroutine Receiver Coroutine Channel Data
38. https://jagstalk.page.link/examples Sender Coroutine (suspended) Receiver Coroutine Channel Data Z Z Z
39. https://jagstalk.page.link/examples Sender Coroutine (suspended) Receiver Coroutine (busy) Channel Data Z Z Z
40. https://jagstalk.page.link/examples Sender Coroutine Receiver Coroutine Channel
41. https://jagstalk.page.link/examples Sender Coroutine Receiver Coroutine Channel
42. https://jagstalk.page.link/examples Receiver Coroutine Channel Sender Coroutine (suspended) Z Z Z
43. https://jagstalk.page.link/examples Receiver Coroutine (suspended) Channel Sender Coroutine Z Z Z
44. https://jagstalk.page.link/examples Conflated Channel Sender Coroutine Receiver Coroutine (busy)
45. fun main() = runBlocking { val orders = listOf(...) val time = measureTimeMillis { coroutineScope { launch(CoroutineName("barista-1")) { processOrders(orders) } launch(CoroutineName("barista-2")) { processOrders(orders) } } } log("time: $time ms”) } val ordersChannel = Channel<Menu>() orders.forEach { ordersChannel.send(it) } https://jagstalk.page.link/examples
46. fun main() = runBlocking { val orders = listOf(...) val time = measureTimeMillis { coroutineScope { launch(CoroutineName("barista-1")) { processOrders(orders) } launch(CoroutineName("barista-2")) { processOrders(orders) } } } log("time: $time ms”) } val ordersChannel = Channel<Menu>() orders.forEach { ordersChannel.send(it) } https://jagstalk.page.link/examples
47. fun main() = runBlocking { val orders = listOf(...) val time = measureTimeMillis { coroutineScope { launch(CoroutineName("barista-1")) { processOrders(ordersChannel) } launch(CoroutineName("barista-2")) { processOrders(ordersChannel) } } } log("time: $time ms”) } private suspend fun processOrders(ordersChannel: Channel<Menu.Cappuccino>) { ordersChannel.consumeEach { val groundBeans = grindCoffeeBeans(it.beans()) val espresso = pullEspressoShot(groundBeans) val steamedMilk = steamMilk(it.milk()) val cappuccino = makeCappuccino(it, espresso, steamedMilk) log("serve: $cappuccino") } } val ordersChannel = Channel<Menu>() orders.forEach { ordersChannel.send(it) } https://jagstalk.page.link/examples
48. private suspend fun processOrders(ordersChannel: Channel<Menu.Cappuccino>) { ordersChannel.consumeEach { val groundBeans = grindCoffeeBeans(it.beans()) val espresso = pullEspressoShot(groundBeans) val steamedMilk = steamMilk(it.milk()) val cappuccino = makeCappuccino(it, espresso, steamedMilk) log("serve: $cappuccino") } } fun main() = runBlocking { val orders = listOf(...) val time = measureTimeMillis { coroutineScope { launch(CoroutineName("barista-1")) { processOrders(ordersChannel) } launch(CoroutineName("barista-2")) { processOrders(ordersChannel) } } } log("time: $time ms”) } val ordersChannel = Channel<Menu>() orders.forEach { ordersChannel.send(it) } https://jagstalk.page.link/examples
49. val ordersChannel = Channel<Menu>() orders.forEach { ordersChannel.send(it) } fun main() = runBlocking { val orders = listOf(...) val time = measureTimeMillis { coroutineScope { launch(CoroutineName("barista-1")) { processOrders(ordersChannel) } launch(CoroutineName("barista-2")) { processOrders(ordersChannel) } } } log("time: $time ms”) } private suspend fun processOrders(ordersChannel: Channel<Menu.Cappuccino>) { ordersChannel.consumeEach { val groundBeans = grindCoffeeBeans(it.beans()) val espresso = pullEspressoShot(groundBeans) val steamedMilk = steamMilk(it.milk()) val cappuccino = makeCappuccino(it, espresso, steamedMilk) log("serve: $cappuccino") } } https://jagstalk.page.link/examples
50. main coroutine val ordersChannel = Channel<Menu>() orders.forEach { ordersChannel.send(it) } fun main() = runBlocking { val orders = listOf(...) val time = measureTimeMillis { coroutineScope { launch(CoroutineName("barista-1")) { processOrders(ordersChannel) } launch(CoroutineName("barista-2")) { processOrders(ordersChannel) } } } log("time: $time ms”) } private suspend fun processOrders(ordersChannel: Channel<Menu.Cappuccino>) { ordersChannel.consumeEach { val groundBeans = grindCoffeeBeans(it.beans()) val espresso = pullEspressoShot(groundBeans) val steamedMilk = steamMilk(it.milk()) val cappuccino = makeCappuccino(it, espresso, steamedMilk) log("serve: $cappuccino") } } https://jagstalk.page.link/examples
51. main coroutine channel main coroutine val ordersChannel = Channel<Menu>() orders.forEach { ordersChannel.send(it) } fun main() = runBlocking { val orders = listOf(...) val time = measureTimeMillis { coroutineScope { launch(CoroutineName("barista-1")) { processOrders(ordersChannel) } launch(CoroutineName("barista-2")) { processOrders(ordersChannel) } } } log("time: $time ms”) } private suspend fun processOrders(ordersChannel: Channel<Menu.Cappuccino>) { ordersChannel.consumeEach { val groundBeans = grindCoffeeBeans(it.beans()) val espresso = pullEspressoShot(groundBeans) val steamedMilk = steamMilk(it.milk()) val cappuccino = makeCappuccino(it, espresso, steamedMilk) log("serve: $cappuccino") } } https://jagstalk.page.link/examples
52. main coroutine channel val ordersChannel = Channel<Menu>() orders.forEach { ordersChannel.send(it) } fun main() = runBlocking { val orders = listOf(...) val time = measureTimeMillis { coroutineScope { launch(CoroutineName("barista-1")) { processOrders(ordersChannel) } launch(CoroutineName("barista-2")) { processOrders(ordersChannel) } } } log("time: $time ms”) } private suspend fun processOrders(ordersChannel: Channel<Menu.Cappuccino>) { ordersChannel.consumeEach { val groundBeans = grindCoffeeBeans(it.beans()) val espresso = pullEspressoShot(groundBeans) val steamedMilk = steamMilk(it.milk()) val cappuccino = makeCappuccino(it, espresso, steamedMilk) log("serve: $cappuccino") } } https://jagstalk.page.link/examples
53. main coroutine channel val ordersChannel = Channel<Menu>() orders.forEach { ordersChannel.send(it) } fun main() = runBlocking { val orders = listOf(...) val time = measureTimeMillis { coroutineScope { launch(CoroutineName("barista-1")) { processOrders(ordersChannel) } launch(CoroutineName("barista-2")) { processOrders(ordersChannel) } } } log("time: $time ms”) } private suspend fun processOrders(ordersChannel: Channel<Menu.Cappuccino>) { ordersChannel.consumeEach { val groundBeans = grindCoffeeBeans(it.beans()) val espresso = pullEspressoShot(groundBeans) val steamedMilk = steamMilk(it.milk()) val cappuccino = makeCappuccino(it, espresso, steamedMilk) log("serve: $cappuccino") } } https://jagstalk.page.link/examples
54. main coroutine (suspended) channel val ordersChannel = Channel<Menu>() orders.forEach { ordersChannel.send(it) } fun main() = runBlocking { val orders = listOf(...) val time = measureTimeMillis { coroutineScope { launch(CoroutineName("barista-1")) { processOrders(ordersChannel) } launch(CoroutineName("barista-2")) { processOrders(ordersChannel) } } } log("time: $time ms”) } private suspend fun processOrders(ordersChannel: Channel<Menu.Cappuccino>) { ordersChannel.consumeEach { val groundBeans = grindCoffeeBeans(it.beans()) val espresso = pullEspressoShot(groundBeans) val steamedMilk = steamMilk(it.milk()) val cappuccino = makeCappuccino(it, espresso, steamedMilk) log("serve: $cappuccino") } } https://jagstalk.page.link/examples
55. val ordersChannel = Channel<Menu>() orders.forEach { ordersChannel.send(it) } fun main() = runBlocking { val orders = listOf(...) val time = measureTimeMillis { coroutineScope { launch(CoroutineName("barista-1")) { processOrders(ordersChannel) } launch(CoroutineName("barista-2")) { processOrders(ordersChannel) } } } log("time: $time ms”) } private suspend fun processOrders(ordersChannel: Channel<Menu.Cappuccino>) { ordersChannel.consumeEach { val groundBeans = grindCoffeeBeans(it.beans()) val espresso = pullEspressoShot(groundBeans) val steamedMilk = steamMilk(it.milk()) val cappuccino = makeCappuccino(it, espresso, steamedMilk) log("serve: $cappuccino") } } https://jagstalk.page.link/examples
56. fun main() = runBlocking { val orders = listOf(...) val time = measureTimeMillis { coroutineScope { launch(CoroutineName("barista-1")) { processOrders(ordersChannel) } launch(CoroutineName("barista-2")) { processOrders(ordersChannel) } } } log("time: $time ms") } val ordersChannel = Channel<Menu.Cappuccino>() launch(CoroutineName("cashier")) { orders.forEach { ordersChannel.send(it) } } private suspend fun processOrders(ordersChannel: Channel<Menu.Cappuccino>) { ordersChannel.consumeEach { val groundBeans = grindCoffeeBeans(it.beans()) val espresso = pullEspressoShot(groundBeans) val steamedMilk = steamMilk(it.milk()) val cappuccino = makeCappuccino(it, espresso, steamedMilk) log("serve: $cappuccino") } } https://jagstalk.page.link/examples
57. fun main() = runBlocking { val orders = listOf(...) val time = measureTimeMillis { coroutineScope { launch(CoroutineName("barista-1")) { processOrders(ordersChannel) } launch(CoroutineName("barista-2")) { processOrders(ordersChannel) } } } log("time: $time ms") } val ordersChannel = produce(CoroutineName("cashier")) { orders.forEach { send(it) } } private suspend fun processOrders(ordersChannel: Channel<Menu.Cappuccino>) { ordersChannel.consumeEach { val groundBeans = grindCoffeeBeans(it.beans()) val espresso = pullEspressoShot(groundBeans) val steamedMilk = steamMilk(it.milk()) val cappuccino = makeCappuccino(it, espresso, steamedMilk) log("serve: $cappuccino") } } https://jagstalk.page.link/examples
58. fun main() = runBlocking { val orders = listOf(...) val time = measureTimeMillis { coroutineScope { launch(CoroutineName("barista-1")) { processOrders(ordersChannel) } launch(CoroutineName("barista-2")) { processOrders(ordersChannel) } } } log("time: $time ms") } val ordersChannel = produce(CoroutineName("cashier")) { orders.forEach { send(it) } } private suspend fun processOrders(ordersChannel: Channel<Menu.Cappuccino>) { ordersChannel.consumeEach { val groundBeans = grindCoffeeBeans(it.beans()) val espresso = pullEspressoShot(groundBeans) val steamedMilk = steamMilk(it.milk()) val cappuccino = makeCappuccino(it, espresso, steamedMilk) log("serve: $cappuccino") } } https://jagstalk.page.link/examples produce coroutine
59. Cashier Barista 1 Barista 2 suspended suspended https://jagstalk.page.link/examples
60. Cashier Barista 1 Barista 2 suspended suspended https://jagstalk.page.link/examples
61. Cashier Barista 1 Barista 2 active suspended https://jagstalk.page.link/examples
62. Cashier Barista 1 Barista 2 active suspended https://jagstalk.page.link/examples
63. Cashier Barista 1 Barista 2 active suspended https://jagstalk.page.link/examples
64. Cashier Barista 1 Barista 2 active active https://jagstalk.page.link/examples
65. Cashier Barista 1 Barista 2 active active https://jagstalk.page.link/examples
66. Cashier Barista 1 Barista 2 active active suspended https://jagstalk.page.link/examples
67. Cashier Barista 1 Barista 2 suspended active active https://jagstalk.page.link/examples
68. Cashier Barista 1 Barista 2 suspended active active https://jagstalk.page.link/examples
69. Cashier Barista 1 Barista 2 active active active https://jagstalk.page.link/examples
70. Cashier Barista 1 Barista 2 active active suspended https://jagstalk.page.link/examples
71. Cashier Barista 1 Barista 2 active active Close Channel https://jagstalk.page.link/examples
72. Cashier Barista 1 Barista 2 https://jagstalk.page.link/examples
73. https://jagstalk.page.link/examples
74. class EspressoMachine { suspend fun pullEspressoShot(groundBeans: CoffeeBean.GroundBeans): Espresso { TODO("pull espresso shot not implemented") } suspend fun steamMilk(milk: Milk): Milk.SteamedMilk { TODO("steam milk not implemented") } } https://jagstalk.page.link/examples
75. class EspressoMachine { suspend fun pullEspressoShot(groundBeans: CoffeeBean.GroundBeans): Espresso { TODO("pull espresso shot not implemented") } suspend fun steamMilk(milk: Milk): Milk.SteamedMilk { TODO("steam milk not implemented") } private suspend fun processEspressoShot(groundBeans: CoffeeBean.GroundBeans): Espresso { log("pulling espresso shot") delay(600) return Espresso(groundBeans) } private suspend fun processSteamMilk(milk: Milk): Milk.SteamedMilk { log("steaming milk") delay(300) return Milk.SteamedMilk(milk) } } https://jagstalk.page.link/examples
76. class EspressoMachine { suspend fun pullEspressoShot(groundBeans: CoffeeBean.GroundBeans): Espresso { TODO("pull espresso shot not implemented") } suspend fun steamMilk(milk: Milk): Milk.SteamedMilk { TODO("steam milk not implemented") } } private suspend fun processEspressoShot(groundBeans: CoffeeBean.GroundBeans): Espresso {...} private suspend fun processSteamMilk(milk: Milk): Milk.SteamedMilk {…} https://jagstalk.page.link/examples
77. Portafilter 1 Portafilter 2 Barista https://jagstalk.page.link/examples
78. Portafilter 1 Portafilter 2 Barista https://jagstalk.page.link/examples ?
79. Portafilter 1 Portafilter 2 Barista https://jagstalk.page.link/examples Coroutine Coroutine ?
80. Portafilter 1 Portafilter 2 Barista https://jagstalk.page.link/examples Coroutine Coroutine Channel Channel ?
81. https://jagstalk.page.link/examples actor coroutine channel
82. class EspressoMachine { private val portafilterOne: SendChannel<CoffeeBean.GroundBeans> = actor { consumeEach { groundBeans -> val espresso = processEspressoShot(groundBeans) TODO("deliver espresso shot to sender") } } suspend fun pullEspressoShot(groundBeans: CoffeeBean.GroundBeans): Espresso { TODO("pull espresso shot not implemented") } suspend fun steamMilk(milk: Milk): Milk.SteamedMilk { TODO("steam milk not implemented") } } private suspend fun processEspressoShot(groundBeans: CoffeeBean.GroundBeans): Espresso {...} private suspend fun processSteamMilk(milk: Milk): Milk.SteamedMilk {…} https://jagstalk.page.link/examples
83. class EspressoMachine { private val portafilterOne: SendChannel<CoffeeBean.GroundBeans> = actor { consumeEach { groundBeans -> val espresso = processEspressoShot(groundBeans) TODO("deliver espresso shot to sender") } }
 private val portafilterTwo: SendChannel<CoffeeBean.GroundBeans> = actor { consumeEach { groundBeans -> val espresso = processEspressoShot(groundBeans) TODO("deliver espresso shot to sender") } } suspend fun pullEspressoShot(groundBeans: CoffeeBean.GroundBeans): Espresso { TODO("pull espresso shot not implemented") } suspend fun steamMilk(milk: Milk): Milk.SteamedMilk { TODO("steam milk not implemented") } private suspend fun processEspressoShot(groundBeans: CoffeeBean.GroundBeans): Espresso {...} private suspend fun processSteamMilk(milk: Milk): Milk.SteamedMilk {...} } https://jagstalk.page.link/examples
84. Portafilter 1 Portafilter 2 Barista https://jagstalk.page.link/examples ?
85. Portafilter 1 Portafilter 2 Barista select https://jagstalk.page.link/examples
86. Barista Portafilter 1 Portafilter 2 select Select Like a switch statement Works on Send and Receive Shape Data Flow https://jagstalk.page.link/examples
87. class EspressoMachine { private val portafilterOne: SendChannel<CoffeeBean.GroundBeans> = actor { consumeEach { groundBeans -> val espresso = processEspressoShot(groundBeans) TODO("deliver espresso shot to sender") } }
 private val portafilterTwo: SendChannel<CoffeeBean.GroundBeans> = actor { consumeEach { groundBeans -> val espresso = processEspressoShot(groundBeans) TODO("deliver espresso shot to sender") } } suspend fun pullEspressoShot(groundBeans: CoffeeBean.GroundBeans): Espresso { TODO("pull espresso shot not implemented") } suspend fun steamMilk(milk: Milk): Milk.SteamedMilk { TODO("steam milk not implemented") } private suspend fun processEspressoShot(groundBeans: CoffeeBean.GroundBeans): Espresso {...} private suspend fun processSteamMilk(milk: Milk): Milk.SteamedMilk {...} } https://jagstalk.page.link/examples
88. class EspressoMachine { private val portafilterOne: SendChannel<CoffeeBean.GroundBeans> = actor {...}
 private val portafilterTwo: SendChannel<CoffeeBean.GroundBeans> = actor {...} suspend fun pullEspressoShot(groundBeans: CoffeeBean.GroundBeans): Espresso { return select { portafilterOne.onSend(groundBeans) { TODO("sent to portafilter one - wait for result") } portafilterTwo.onSend(groundBeans) { TODO("sent to portafilter two - wait for result") } } } ... } https://jagstalk.page.link/examples
89. Portafilter 1 Portafilter 2 Barista select https://jagstalk.page.link/examples
90. class EspressoMachine { private val portafilterOne: SendChannel<CoffeeBean.GroundBeans> = actor {...}
 private val portafilterTwo: SendChannel<CoffeeBean.GroundBeans> = actor {...} suspend fun pullEspressoShot(groundBeans: CoffeeBean.GroundBeans): Espresso { return select { portafilterOne.onSend(groundBeans) { TODO("sent to portafilter one - wait for result") } portafilterTwo.onSend(groundBeans) { TODO("sent to portafilter two - wait for result") } } } ... } https://jagstalk.page.link/examples
91. class EspressoMachine { private data class EspressoShotRequest( val deferredEspressoShot: CompletableDeferred<Espresso>, val groundBeans: CoffeeBean.GroundBeans ) private val portafilterOne: SendChannel<CoffeeBean.GroundBeans> = actor {...}
 private val portafilterTwo: SendChannel<CoffeeBean.GroundBeans> = actor {...} suspend fun pullEspressoShot(groundBeans: CoffeeBean.GroundBeans): Espresso { return select { portafilterOne.onSend(groundBeans) { TODO("sent to portafilter one - wait for result") } portafilterTwo.onSend(groundBeans) { TODO("sent to portafilter two - wait for result") } } } ... } https://jagstalk.page.link/examples
92. class EspressoMachine { private data class EspressoShotRequest( val deferredEspressoShot: CompletableDeferred<Espresso>, val groundBeans: CoffeeBean.GroundBeans ) private val portafilterOne: SendChannel<EspressoShotRequest> = actor { consumeEach { request -> val espresso = processEspressoShot(request.groundBeans) request.deferredEspressoShot.complete(espresso) } } private val portafilterTwo: SendChannel<EspressoShotRequest> = actor {...} suspend fun pullEspressoShot(groundBeans: CoffeeBean.GroundBeans): Espresso { return select { portafilterOne.onSend(groundBeans) { TODO("sent to portafilter one - wait for result") } portafilterTwo.onSend(request) { TODO("sent to portafilter two - wait for result") } } } ... } https://jagstalk.page.link/examples
93. class EspressoMachine { private data class EspressoShotRequest( val deferredEspressoShot: CompletableDeferred<Espresso>, val groundBeans: CoffeeBean.GroundBeans ) private val portafilterOne: SendChannel<EspressoShotRequest> = actor { consumeEach { request -> val espresso = processEspressoShot(request.groundBeans) request.deferredEspressoShot.complete(espresso) } } private val portafilterTwo: SendChannel<EspressoShotRequest> = actor {...} suspend fun pullEspressoShot(groundBeans: CoffeeBean.GroundBeans): Espresso { val request = EspressoShotRequest(CompletableDeferred(), groundBeans) return select { portafilterOne.onSend(request) { request.deferredEspressoShot.await() } portafilterTwo.onSend(request) { TODO("sent to portafilter two - wait for result") } } } ... } https://jagstalk.page.link/examples
94. class EspressoMachine(scope: CoroutineScope): CoroutineScope by scope { private data class EspressoShotRequest( val deferredEspressoShot: CompletableDeferred<Espresso>, val groundBeans: CoffeeBean.GroundBeans ) private val portafilterOne: SendChannel<EspressoShotRequest> = actor { consumeEach { request -> val espresso = processEspressoShot(request.groundBeans) request.deferredEspressoShot.complete(espresso) } } private val portafilterTwo: SendChannel<EspressoShotRequest> = actor {...} suspend fun pullEspressoShot(groundBeans: CoffeeBean.GroundBeans): Espresso { val request = EspressoShotRequest(CompletableDeferred(), groundBeans) return select { portafilterOne.onSend(request) { request.deferredEspressoShot.await() } portafilterTwo.onSend(request) { TODO("sent to portafilter two - wait for result") } } } ... } https://jagstalk.page.link/examples
95. class EspressoMachine(scope: CoroutineScope): CoroutineScope by scope { ... } fun main() = runBlocking { ... val espressoMachine = EspressoMachine(this) val time = measureTimeMillis { coroutineScope { launch(CoroutineName("barista-1")) { processOrders(ordersChannel, espressoMachine) } launch(CoroutineName("barista-2")) { processOrders(ordersChannel, espressoMachine) } } } log("time: $time ms") } private suspend fun processOrders(orders: ReceiveChannel<Menu.Cappuccino>, espressoMachine: EspressoMachine) { orders.consumeEach { val groundBeans = grindCoffeeBeans(it.beans()) val espresso = espressoMachine.pullEspressoShot(groundBeans) val steamedMilk = espressoMachine.steamMilk(it.milk()) val cappuccino = makeCappuccino(it, espresso, steamedMilk) log("serve: $cappuccino") } } https://jagstalk.page.link/examples
96. private suspend fun processOrders(orders: ReceiveChannel<Menu.Cappuccino>, espressoMachine: EspressoMachine) { orders.consumeEach { val groundBeans = grindCoffeeBeans(it.beans()) val espressoDeferred = async { espressoMachine.pullEspressoShot(groundBeans) } val steamedMilkDeferred = async { espressoMachine.steamMilk(it.milk()) } val cappuccino = makeCappuccino( it, espresso, steamedMilk) log("serve: $cappuccino") } } https://jagstalk.page.link/examples
97. private suspend fun processOrders(orders: ReceiveChannel<Menu.Cappuccino>, espressoMachine: EspressoMachine) { orders.consumeEach { val groundBeans = grindCoffeeBeans(it.beans()) val espressoDeferred = async { espressoMachine.pullEspressoShot(groundBeans) } val steamedMilkDeferred = async { espressoMachine.steamMilk(it.milk()) } val cappuccino = makeCappuccino( it, espressoDeferred.await(), steamedMilkDeferred.await()) log("serve: $cappuccino") } } https://jagstalk.page.link/examples
98. private suspend fun processOrders(orders: ReceiveChannel<Menu.Cappuccino>, espressoMachine: EspressoMachine) { orders.consumeEach { val groundBeans = grindCoffeeBeans(it.beans()) coroutineScope { val espressoDeferred = async { espressoMachine.pullEspressoShot(groundBeans) } val steamedMilkDeferred = async { espressoMachine.steamMilk(it.milk()) } val cappuccino = makeCappuccino( it, espressoDeferred.await(), steamedMilkDeferred.await()) } log("serve: $cappuccino") } } https://jagstalk.page.link/examples
99. Flow Channels are for Hot Streams Flow is for Cold Streams Flow is activated with collect https://jagstalk.page.link/examples
100. https://jagstalk.page.link/examples fun main() = runBlocking { val orders = listOf(...) val ordersChannel = produce(CoroutineName("cashier")) { orders.forEach { send(it) } } val espressoMachine = EspressoMachine(this) val time = measureTimeMillis { coroutineScope { launch(CoroutineName("barista-1")) { processOrders(ordersChannel, espressoMachine) } launch(CoroutineName("barista-2")) { processOrders(ordersChannel, espressoMachine) } } } log("time: $time ms") espressoMachine.destroy() }
101. https://jagstalk.page.link/examples fun main() = runBlocking { val orders = listOf(...) val ordersChannel = produce(CoroutineName("cashier")) { orders.forEach { send(it) } } val espressoMachine = EspressoMachine(this) val time = measureTimeMillis { coroutineScope { launch(CoroutineName("barista-1")) { processOrders(ordersChannel, espressoMachine) } launch(CoroutineName("barista-2")) { processOrders(ordersChannel, espressoMachine) } } } log("time: $time ms") espressoMachine.destroy() }
102. https://jagstalk.page.link/examples fun main() = runBlocking { val orders = listOf(...) val ordersFlow: Flow<Menu.Cappuccino> = orders.asFlow() val espressoMachine = EspressoMachine(this) val time = measureTimeMillis { coroutineScope { launch(CoroutineName("barista-1")) { processOrders(ordersChannel, espressoMachine) } launch(CoroutineName("barista-2")) { processOrders(ordersChannel, espressoMachine) } } } log("time: $time ms") espressoMachine.destroy() }
103. https://jagstalk.page.link/examples fun main() = runBlocking { val orders = listOf(...) val ordersFlow: Flow<Menu.Cappuccino> = orders.asFlow() val espressoMachine = EspressoMachine(this) val time = measureTimeMillis { coroutineScope { launch(CoroutineName("barista-1")) { processOrders(ordersChannel, espressoMachine) } launch(CoroutineName("barista-2")) { processOrders(ordersChannel, espressoMachine) } } } log("time: $time ms") espressoMachine.destroy() }
104. https://jagstalk.page.link/examples private suspend fun processOrders(orders: ReceiveChannel<Menu.Cappuccino>, espressoMachine: EspressoMachine) { orders.consumeEach { val groundBeans = grindCoffeeBeans(it.beans()) coroutineScope { val espressoDeferred = async { espressoMachine.pullEspressoShot(groundBeans) } val steamedMilkDeferred = async { espressoMachine.steamMilk(it.milk()) } val cappuccino = makeCappuccino(it, espressoDeferred.await(), steamedMilkDeferred.await()) log("serve: $cappuccino") } } } fun main() = runBlocking { val orders = listOf(...) val ordersFlow: Flow<Menu.Cappuccino> = orders.asFlow() val espressoMachine = EspressoMachine(this) val time = measureTimeMillis { ... } log("time: $time ms") espressoMachine.destroy() }
105. https://jagstalk.page.link/examples private suspend fun processOrders(orders: Flow<Menu.Cappuccino>, espressoMachine: EspressoMachine) { orders.consumeEach { val groundBeans = grindCoffeeBeans(it.beans()) coroutineScope { val espressoDeferred = async { espressoMachine.pullEspressoShot(groundBeans) } val steamedMilkDeferred = async { espressoMachine.steamMilk(it.milk()) } val cappuccino = makeCappuccino(it, espressoDeferred.await(), steamedMilkDeferred.await()) log("serve: $cappuccino") } } } fun main() = runBlocking { val orders = listOf(...) val ordersFlow: Flow<Menu.Cappuccino> = orders.asFlow() val espressoMachine = EspressoMachine(this) val time = measureTimeMillis { ... } log("time: $time ms") espressoMachine.destroy() }
106. https://jagstalk.page.link/examples private suspend fun processOrders(orders: Flow<Menu.Cappuccino>, espressoMachine: EspressoMachine) { orders.consumeEach { val groundBeans = grindCoffeeBeans(it.beans()) coroutineScope { val espressoDeferred = async { espressoMachine.pullEspressoShot(groundBeans) } val steamedMilkDeferred = async { espressoMachine.steamMilk(it.milk()) } val cappuccino = makeCappuccino(it, espressoDeferred.await(), steamedMilkDeferred.await()) log("serve: $cappuccino") } } } fun main() = runBlocking { val orders = listOf(...) val ordersFlow: Flow<Menu.Cappuccino> = orders.asFlow() val espressoMachine = EspressoMachine(this) val time = measureTimeMillis { ... } log("time: $time ms") espressoMachine.destroy() }
107. https://jagstalk.page.link/examples private suspend fun processOrders(orders: Flow<Menu.Cappuccino>, espressoMachine: EspressoMachine) { orders.map { val groundBeans = grindCoffeeBeans(it.beans()) coroutineScope { val espressoDeferred = async { espressoMachine.pullEspressoShot(groundBeans) } val steamedMilkDeferred = async { espressoMachine.steamMilk(it.milk()) } val cappuccino = makeCappuccino(it, espressoDeferred.await(), steamedMilkDeferred.await()) log("serve: $cappuccino") } } } fun main() = runBlocking { val orders = listOf(...) val ordersFlow: Flow<Menu.Cappuccino> = orders.asFlow() val espressoMachine = EspressoMachine(this) val time = measureTimeMillis { ... } log("time: $time ms") espressoMachine.destroy() }
108. https://jagstalk.page.link/examples private suspend fun processOrders(orders: Flow<Menu.Cappuccino>, espressoMachine: EspressoMachine) { orders.map { val groundBeans = grindCoffeeBeans(it.beans()) coroutineScope { val espressoDeferred = async { espressoMachine.pullEspressoShot(groundBeans) } val steamedMilkDeferred = async { espressoMachine.steamMilk(it.milk()) } val cappuccino = makeCappuccino(it, espressoDeferred.await(), steamedMilkDeferred.await()) log("serve: $cappuccino") } } } fun main() = runBlocking { val orders = listOf(...) val ordersFlow: Flow<Menu.Cappuccino> = orders.asFlow() val espressoMachine = EspressoMachine(this) val time = measureTimeMillis { ... } log("time: $time ms") espressoMachine.destroy() }
109. https://jagstalk.page.link/examples private suspend fun processOrders(orders: Flow<Menu.Cappuccino>, espressoMachine: EspressoMachine) { orders.map { val groundBeans = grindCoffeeBeans(it.beans()) coroutineScope { val espressoDeferred = async { espressoMachine.pullEspressoShot(groundBeans) } val steamedMilkDeferred = async { espressoMachine.steamMilk(it.milk()) } makeCappuccino(it, espressoDeferred.await(), steamedMilkDeferred.await()) } } } fun main() = runBlocking { val orders = listOf(...) val ordersFlow: Flow<Menu.Cappuccino> = orders.asFlow() val espressoMachine = EspressoMachine(this) val time = measureTimeMillis { ... } log("time: $time ms") espressoMachine.destroy() }
110. https://jagstalk.page.link/examples private suspend fun processOrders(orders: Flow<Menu.Cappuccino>, espressoMachine: EspressoMachine): Flow<Beverage.Cappuccino> = orders.map { val groundBeans = grindCoffeeBeans(it.beans()) coroutineScope { val espressoDeferred = async { espressoMachine.pullEspressoShot(groundBeans) } val steamedMilkDeferred = async { espressoMachine.steamMilk(it.milk()) } makeCappuccino(it, espressoDeferred.await(), steamedMilkDeferred.await()) } } fun main() = runBlocking { val orders = listOf(...) val ordersFlow: Flow<Menu.Cappuccino> = orders.asFlow() val espressoMachine = EspressoMachine(this) val time = measureTimeMillis { ... } log("time: $time ms") espressoMachine.destroy() }
111. https://jagstalk.page.link/examples private suspend fun processOrders(orders: Flow<Menu.Cappuccino>, espressoMachine: EspressoMachine): Flow<Beverage.Cappuccino> { ...
 } fun main() = runBlocking { val orders = listOf(...) val ordersFlow: Flow<Menu.Cappuccino> = orders.asFlow() val espressoMachine = EspressoMachine(this) val time = measureTimeMillis { coroutineScope { launch(CoroutineName("barista-1")) { processOrders(ordersChannel, espressoMachine) } launch(CoroutineName("barista-2")) { processOrders(ordersChannel, espressoMachine) } } } log("time: $time ms") espressoMachine.destroy() }
112. https://jagstalk.page.link/examples private suspend fun processOrders(orders: Flow<Menu.Cappuccino>, espressoMachine: EspressoMachine): Flow<Beverage.Cappuccino> { ...
 } fun main() = runBlocking { val orders = listOf(...) val ordersFlow: Flow<Menu.Cappuccino> = orders.asFlow() val espressoMachine = EspressoMachine(this) val time = measureTimeMillis { flowOf( processOrders(ordersFlow, espressoMachine), processOrders(ordersFlow, espressoMachine) ) } log("time: $time ms") espressoMachine.destroy() }
113. https://jagstalk.page.link/examples private suspend fun processOrders(orders: Flow<Menu.Cappuccino>, espressoMachine: EspressoMachine): Flow<Beverage.Cappuccino> { ...
 } fun main() = runBlocking { val orders = listOf(...) val ordersFlow: Flow<Menu.Cappuccino> = orders.asFlow() val espressoMachine = EspressoMachine(this) val time = measureTimeMillis { flowOf( processOrders(ordersFlow, espressoMachine), processOrders(ordersFlow, espressoMachine) ) .flattenMerge() } log("time: $time ms") espressoMachine.destroy() }
114. https://jagstalk.page.link/examples private suspend fun processOrders(orders: Flow<Menu.Cappuccino>, espressoMachine: EspressoMachine): Flow<Beverage.Cappuccino> { ...
 } fun main() = runBlocking { val orders = listOf(...) val ordersFlow: Flow<Menu.Cappuccino> = orders.asFlow() val espressoMachine = EspressoMachine(this) val time = measureTimeMillis { flowOf( processOrders(ordersFlow, espressoMachine), processOrders(ordersFlow, espressoMachine) ) .flattenMerge() .collect { cappuccino -> log("serve: $cappuccino") } } log("time: $time ms") espressoMachine.destroy() }
115. https://jagstalk.page.link/examples fun main() = runBlocking { val orders = listOf(...) val ordersFlow: Flow<Menu.Cappuccino> = orders.asFlow() .produceIn(this) .asFlow() val espressoMachine = EspressoMachine(this) val time = measureTimeMillis { flowOf( processOrders(ordersFlow, espressoMachine), processOrders(ordersFlow, espressoMachine) ) .flattenMerge() .collect { cappuccino -> log("serve: $cappuccino") } } log("time: $time ms") espressoMachine.destroy() }
116. https://jagstalk.page.link/examples fun main() = runBlocking { val orders = listOf(...) val ordersFlow: Flow<Menu.Cappuccino> = orders.asFlow() .produceIn(this) .asFlow() val espressoMachine = EspressoMachine(this) val time = measureTimeMillis { flowOf( processOrders(ordersFlow, espressoMachine), processOrders(ordersFlow, espressoMachine) ) .flattenMerge() .collect { cappuccino -> log("serve: $cappuccino") } } log("time: $time ms") espressoMachine.destroy() } private fun <T> ReceiveChannel<T>.asFlow(): Flow<T> = flow { consumeEach { value -> emit(value) } }
117. https://jagstalk.page.link/examples
118. https://jagstalk.page.link/examples
119. Q&A Concurrency doesn’t have to be hard: Kotlin Coroutines & Channels