Concurrencia de corrutina de Kotlin/conmutación en paralelo y en serie, CoroutineScope y await
import kotlinx.coroutines.CoroutineScope
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.delay
import kotlinx.coroutines.launch
import java.time.LocalTime
fun main(args: Array<String>) {
println("${LocalTime.now()} - main start")
CoroutineScope(Dispatchers.Default).launch {
// 并发执行
this.launch {
println("${LocalTime.now()} A start")
delay(1000)
println("${LocalTime.now()} A end")
}
this.launch {
println("${LocalTime.now()} B start")
delay(1500)
println("${LocalTime.now()} B end")
}
}
println("${LocalTime.now()} - main end")
}
La salida muestra que después de las salidas principales, ni A ni B salen. CoroutineScope(Dispatchers.IO).launch La nueva tarea no bloquea el proceso de ejecución de la tarea principal principal.
Si cambia a runBlocking (Dispatchers.IO):
import kotlinx.coroutines.*
import java.time.LocalTime
fun main(args: Array<String>) {
println("${LocalTime.now()} - main start")
runBlocking(Dispatchers.IO) {
// 并发执行
this.launch {
println("${LocalTime.now()} A start")
delay(1000)
println("${LocalTime.now()} A end")
}
this.launch {
println("${LocalTime.now()} B start")
delay(1500)
println("${LocalTime.now()} B end")
}
}
println("${LocalTime.now()} - main end")
}
mira asíncrono
import kotlinx.coroutines.*
import java.time.LocalTime
fun main(args: Array<String>) {
println("${LocalTime.now()} - main start")
CoroutineScope(Dispatchers.IO).launch() {
// 并发执行
this.async {
println("${LocalTime.now()} A start")
delay(1000)
println("${LocalTime.now()} A end")
}
this.async {
println("${LocalTime.now()} B start")
delay(1500)
println("${LocalTime.now()} B end")
}
}
println("${LocalTime.now()} - main end")
}
Si el hilo principal descansa durante 1000 ms:
import kotlinx.coroutines.*
import java.time.LocalTime
fun main(args: Array<String>) {
println("${LocalTime.now()} - main start")
CoroutineScope(Dispatchers.IO).launch() {
// 并发执行
this.async {
println("${LocalTime.now()} A start")
delay(1000)
println("${LocalTime.now()} A end")
}
this.async {
println("${LocalTime.now()} B start")
delay(1500)
println("${LocalTime.now()} B end")
}
}
Thread.sleep(1000)
println("${LocalTime.now()} - main end")
}
import kotlinx.coroutines.*
import java.time.LocalTime
fun main(args: Array<String>) {
println("${LocalTime.now()} - main start")
runBlocking {
CoroutineScope(Dispatchers.IO).launch() {
val task1 = this.async {
println("${LocalTime.now()} A start")
delay(1000)
println("${LocalTime.now()} A end")
"task1 return"
}
val task2 = this.async {
println("${LocalTime.now()} B start")
delay(1500)
println("${LocalTime.now()} B end")
"task2 return"
}
val t1 = task1.await()
println("${LocalTime.now()} $t1")
val t2 = task2.await()
println("${LocalTime.now()} $t2")
}
}
println("${LocalTime.now()} - main end")
}
En general, la importancia de CoroutineScope(Dispatchers.IO).launch() es iniciar un nuevo subproceso sin bloquear el subproceso principal principal, porque
entender esperar
import kotlinx.coroutines.*
import java.time.LocalTime
fun main(args: Array<String>) {
println("${LocalTime.now()} - main start")
runBlocking {
//launch() {
val task1 = this.async {
println("${LocalTime.now()} A start")
delay(3000)
println("${LocalTime.now()} A end")
"task1 return"
}
val task2 = this.async {
println("${LocalTime.now()} B start")
delay(1000)
println("${LocalTime.now()} B end")
"task2 return"
}
val t1 = task1.await()
println("${LocalTime.now()} $t1")
val t2 = task2.await()
println("${LocalTime.now()} $t2")
//}
}
println("${LocalTime.now()} - main end")
}
Aunque la tarea 2 se completa pronto, debido a la espera, debe esperar a que regrese la tarea 1.