thread lambda expression in Kotlin-CodePudding

Sample code:

fun main() {
   thread(name = "Worker Thread") {
        for (i in 1..5) {
            println(Thread.currentThread().name)
        }
    }
    println(Thread.currentThread().name)
}

Decompiled bytecode for the above sample:

public final class PracKt {
   public static final void main() {
      ThreadsKt.thread$default(false, false, (ClassLoader)null, "Worker Thread", 0, (Function0)null.INSTANCE, 23, (Object)null);
      Thread var10000 = Thread.currentThread();
      Intrinsics.checkNotNullExpressionValue(var10000, "Thread.currentThread()");
      String var0 = var10000.getName();
      boolean var1 = false;
      System.out.println(var0);
   }

   // $FF: synthetic method
   public static void main(String[] var0) {
      main();
   }
}

Code works fine but I can't understand in decompiled code how thread gets executed without calling start() method. If I try to call thread.start() in sample code, IllegalThreadStateException is thrown.

Where is start() method is getting called if not shown in decompiled code?

CodePudding user response：

As it goes from Kotlin docs. When you're using method thread, created thread is started by default.

fun thread(
    start: Boolean = true,
    isDaemon: Boolean = false,
    contextClassLoader: ClassLoader? = null,
    name: String? = null,
    priority: Int = -1,
    block: () -> Unit
): Thread

To start it explicitly, you should set start flag to false.