kotlin协程

  companion object {
        @JvmStatic
        fun main(args: Array<String>) = runBlocking {
            val p = StringBuilder()
            p.append("1")
            var list = ArrayList<String>()
            println("""开始""")
            println("" + list!!.size)
            println("" + list?.size)

            launch {
                val a = GlobalScope.launch {
                    val thread1 = withContext(Dispatchers.IO) {
                        println("thread1" + Thread.currentThread().name)
                        Thread.sleep(1000)
                    }

                    val thread2 = withContext(Dispatchers.Unconfined) {
                        println("thread2" + Thread.currentThread().name)
                    }
                }

                val b = async {
                    Thread.sleep(5000)
                    println("async run")
                }
                a.join()
                println("I m done")
            }
            println("finish")
        }
    }

创建两个协程 a ，b a有两个子耗时的suspend函数

async{}是可以开启一个异步协程的，相对于launch{}，async{}返回的是带返回值的Job，public interface Deferred : Job T就是返回值，通过await获得该返回值。

launch{
val a = async{ 耗时1s …}.await();
val b = async{ 耗时5s …}.await();
}
}
后续继续学习补充