kotlin: 协程和线程的关系

一，代码：

        binding.button2.setOnClickListener {

            println("点击代码块开始:")

            runBlocking {                // 1
                launch {
                        val threadId = Thread.currentThread().id
                        val threadName = Thread.currentThread().name
                        val context = coroutineContext + CoroutineName("launch1")
                        val dispatcher = context[ContinuationInterceptor]
                        val job = context[Job]
                        val name = context[CoroutineName]
                        val coInfo = "context:"+context+";job:"+job+";name:"+name+";dispatcher:"+dispatcher

                        println("launch内1:线程id:${threadId} 线程name:${threadName}，协程: ${coInfo}")
                        delay(1000)
                }

                launch {
                    val threadId = Thread.currentThread().id
                    val threadName = Thread.currentThread().name
                    val context = coroutineContext + CoroutineName("launch2")
                    val dispatcher = context[ContinuationInterceptor]
                    val job = context[Job]
                    val name = context[CoroutineName]
                    val coInfo = "context:"+context+";job:"+job+";name:"+name+";dispatcher:"+dispatcher

                    println("launch内2:线程id:${threadId} 线程name:${threadName}，协程: ${coInfo}")
                    delay(1000)
                }

                for (i in 0..3) {

                    val threadId = Thread.currentThread().id
                    val threadName = Thread.currentThread().name
                    val context = coroutineContext + CoroutineName("blocking"+i)
                    val dispatcher = context[ContinuationInterceptor]
                    val job = context[Job]
                    val name = context[CoroutineName]

                    val coInfo = "context:"+context+";job:"+job+";name:"+name+";dispatcher:"+dispatcher

                    println("launch外:i:${i},线程id:${threadId} 线程name:${threadName}，协程: ${coInfo}")
                    delay(1000)
                }
            }

            val threadId = Thread.currentThread().id
            val threadName = Thread.currentThread().name

            println("runblocking外:线程id:${threadId} 线程name:${threadName}")

            println("点击代码块结束")
        }

二，测试效果:

从运行结果可以看到:
runblocking内的代码在一个协程内运行
launch内代码会启动一个新的协程运行
而对应的线程一直没变，说明多个协程可以在一个线程内切换运行

I  点击代码块开始:
I  launch外:i:0,线程id:2 线程name:main，协程: context:[BlockingCoroutine{Active}@a697fe9, CoroutineName(blocking0), BlockingEventLoop@b1aa46e];
                                      job:BlockingCoroutine{Active}@a697fe9;name:CoroutineName(blocking0);dispatcher:BlockingEventLoop@b1aa46e
I  launch内1:线程id:2 线程name:main，协程: context:[StandaloneCoroutine{Active}@385b70f, CoroutineName(launch1), BlockingEventLoop@b1aa46e];
                                      job:StandaloneCoroutine{Active}@385b70f;name:CoroutineName(launch1);dispatcher:BlockingEventLoop@b1aa46e
I  launch内2:线程id:2 线程name:main，协程: context:[StandaloneCoroutine{Active}@24fb39c, CoroutineName(launch2), BlockingEventLoop@b1aa46e];
                                      job:StandaloneCoroutine{Active}@24fb39c;name:CoroutineName(launch2);dispatcher:BlockingEventLoop@b1aa46e
I  launch外:i:1,线程id:2 线程name:main，协程: context:[BlockingCoroutine{Active}@a697fe9, CoroutineName(blocking1), BlockingEventLoop@b1aa46e];
                                      job:BlockingCoroutine{Active}@a697fe9;name:CoroutineName(blocking1);dispatcher:BlockingEventLoop@b1aa46e
I  launch外:i:2,线程id:2 线程name:main，协程: context:[BlockingCoroutine{Active}@a697fe9, CoroutineName(blocking2), BlockingEventLoop@b1aa46e];
                                      job:BlockingCoroutine{Active}@a697fe9;name:CoroutineName(blocking2);dispatcher:BlockingEventLoop@b1aa46e
I  launch外:i:3,线程id:2 线程name:main，协程: context:[BlockingCoroutine{Active}@a697fe9, CoroutineName(blocking3), BlockingEventLoop@b1aa46e];
                                      job:BlockingCoroutine{Active}@a697fe9;name:CoroutineName(blocking3);dispatcher:BlockingEventLoop@b1aa46e
I  runblocking外:线程id:2 线程name:main
I  点击代码块结束