我把 RunSuspend.kt 的内容拷贝到我自己的文件中：

@SinceKotlin("1.3")
internal fun runSuspend(block: suspend () -> Unit) {
    val run = RunSuspend()
    block.startCoroutine(run)
    run.await()
}

private class RunSuspend : Continuation<Unit> {
    override val context: CoroutineContext
        get() = EmptyCoroutineContext

    var result: Result<Unit>? = null

    override fun resumeWith(result: Result<Unit>) = synchronized(this) {
        this.result = result
        @Suppress("PLATFORM_CLASS_MAPPED_TO_KOTLIN") (this as Object).notifyAll()
    }

    fun await() = synchronized(this) {
        while (true) {
            when (val result = this.result) {
                null -> @Suppress("PLATFORM_CLASS_MAPPED_TO_KOTLIN") (this as Object).wait()
                else -> {
                    result.getOrThrow() // throw up failure
                    return
                }
            }
        }
    }
}

然后反编译：

public final class RunSuspend1Kt {
   @SinceKotlin(
      version = "1.3"
   )
   public static final void runSuspend(@NotNull Function1 block) {
      Intrinsics.checkParameterIsNotNull(block, "block");
      RunSuspend run = new RunSuspend();
      ContinuationKt.startCoroutine(block, (Continuation)run);
      run.await();
   }
}

发现 runSuspend 的参数变成了一个 Function1 实例了；

但是在 kotlin 里面是一个 block: suspend () -> Unit

我在跟踪 suspend main 的时候也发现这个问题了，这是为什么呢？为啥不是一个 Continuation 呢？？？