但是在示例代码中，它看起来会阻塞下一个进程，因为println（"Coroutine scope is over"）在完成coroutineScope中的代码块之前不会执行。
import kotlinx.coroutines.*
fun main() = runBlocking { // this: CoroutineScope
launch {
delay(200L)
println("Task from runBlocking")
}
coroutineScope { // Creates a coroutine scope
launch {
delay(500L)
println("Task from nested launch")
}
delay(100L)
println("Task from coroutine scope") // This line will be printed before the nested launch
}
println("Coroutine scope is over") // This line is not printed until the nested launch completes
}
我知道runBlock会等到它的所有子级完成。所以在我的理解中，runBlock应该在执行println（"Coroutine scope is over"）行后等待coroutineScope完成。
为什么在这个例子中coroutineScope会阻塞线程？
CoroutineScope挂起了CoroutineScope作用域，因此“println（"Coroutine scope is over"）”行将在上一个协程作用域完成后执行。你可以看到协程作用域的代码：
public suspend fun <R> coroutineScope(block: suspend CoroutineScope.() -> R): R {
contract {
callsInPlace(block, InvocationKind.EXACTLY_ONCE)
}
return suspendCoroutineUninterceptedOrReturn { uCont ->
val coroutine = ScopeCoroutine(uCont.context, uCont)
coroutine.startUndispatchedOrReturn(coroutine, block)
}}
