Lambda comparison between Java and Kotlin

JavaLambdaTest.java

public class JavaLambdaTest
{
    public int i;

    public void runTask(Runnable f)
    {
        f.run();
    }

    public void run()
    {
        runTask(() -> i += 1);
    }
}

javap-of-KotlinLambdaTest

  public final void runTask(kotlin.jvm.functions.Function0<kotlin.Unit>);
    descriptor: (Lkotlin/jvm/functions/Function0;)V
    flags: ACC_PUBLIC, ACC_FINAL
    Code:
      stack=2, locals=2, args_size=2
         0: aload_1
         1: ldc           #20                 // String f
         3: invokestatic  #26                 // Method kotlin/jvm/internal/Intrinsics.checkParameterIsNotNull:(Ljava/lang/Object;Ljava/lang/String;)V
         6: aload_1
         7: invokeinterface #32,  1           // InterfaceMethod kotlin/jvm/functions/Function0.invoke:()Ljava/lang/Object;
        12: pop
        13: return
      LocalVariableTable:
        Start  Length  Slot  Name   Signature
            0      14     0  this   Lorg/komamitsu/tinylisp/KotlinLambdaTest;
            0      14     1     f   Lkotlin/jvm/functions/Function0;
      LineNumberTable:
        line 7: 6
        line 8: 13
    Signature: #65                          // (Lkotlin/jvm/functions/Function0<Lkotlin/Unit;>;)V
    RuntimeInvisibleParameterAnnotations:
      0:
        0: #18()

  public final void run();
    descriptor: ()V
    flags: ACC_PUBLIC, ACC_FINAL
    Code:
      stack=4, locals=1, args_size=1
         0: aload_0
         1: new           #37                 // class org/komamitsu/tinylisp/KotlinLambdaTest$run$1
         4: dup
         5: aload_0
         6: invokespecial #41                 // Method org/komamitsu/tinylisp/KotlinLambdaTest$run$1."<init>":(Lorg/komamitsu/tinylisp/KotlinLambdaTest;)V
         9: checkcast     #28                 // class kotlin/jvm/functions/Function0
        12: invokevirtual #43                 // Method runTask:(Lkotlin/jvm/functions/Function0;)V
        15: return
      LocalVariableTable:
        Start  Length  Slot  Name   Signature
            0      16     0  this   Lorg/komamitsu/tinylisp/KotlinLambdaTest;
      LineNumberTable:
        line 11: 0
        line 12: 15

javap-op-JavaLambdaTest

  public void runTask(java.lang.Runnable);
    descriptor: (Ljava/lang/Runnable;)V
    flags: ACC_PUBLIC
    Code:
      stack=1, locals=2, args_size=2
         0: aload_1
         1: invokeinterface #2,  1            // InterfaceMethod java/lang/Runnable.run:()V
         6: return
      LineNumberTable:
        line 12: 0
        line 13: 6
      LocalVariableTable:
        Start  Length  Slot  Name   Signature
            0       7     0  this   Lorg/komamitsu/tinylisp/JavaLambdaTest;
            0       7     1     f   Ljava/lang/Runnable;

  public void run();
    descriptor: ()V
    flags: ACC_PUBLIC
    Code:
      stack=2, locals=1, args_size=1
         0: aload_0
         1: aload_0
         2: invokedynamic #3,  0              // InvokeDynamic #0:run:(Lorg/komamitsu/tinylisp/JavaLambdaTest;)Ljava/lang/Runnable;
         7: invokevirtual #4                  // Method runTask:(Ljava/lang/Runnable;)V
        10: return
      LineNumberTable:
        line 17: 0
        line 18: 10
      LocalVariableTable:
        Start  Length  Slot  Name   Signature
            0      11     0  this   Lorg/komamitsu/tinylisp/JavaLambdaTest;

  private void lambda$run$0();
    descriptor: ()V
    flags: ACC_PRIVATE, ACC_SYNTHETIC
    Code:
      stack=3, locals=1, args_size=1
         0: aload_0
         1: dup
         2: getfield      #5                  // Field i:I
         5: iconst_1
         6: iadd
         7: putfield      #5                  // Field i:I
        10: return
      LineNumberTable:
        line 17: 0
      LocalVariableTable:
        Start  Length  Slot  Name   Signature
            0      11     0  this   Lorg/komamitsu/tinylisp/JavaLambdaTest;

KotlinLambdaTest.kt

class KotlinLambdaTest {
    var i: Int = 0

    fun runTask(f: () -> Unit) {
        f.invoke()
    }

    fun run() {
        runTask({ i += 1 })
    }
}