[GROOVY-9320] Support serializable lambda expression

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.0.0-rc-2
• Assignee: Daniel Sun
• Reporter: Daniel Sun
• Created: 27/Nov/19 11:16
• Updated: 29/Jul/23 13:04
• Resolved: 04/Dec/19 23:31

Description

Here is a word count example for Flink.

As groovy's lambda expression is not serializable, the following code has to be replaced with sum(1) as workaround, or java.io.NotSerializableException: Non-serializable lambda will be raised.

https://github.com/danielsun1106/flink-wordcount/blob/0.1/src/main/groovy/me/sunlan/flinklabs/wordcount/WordCount.groovy#L49

We need generate a synthetic method $deserializeLambda$ in bytecode like the following:

  private static synthetic $deserializeLambda$(Ljava/lang/invoke/SerializedLambda;)Ljava/lang/Object;
   L0
    LINENUMBER 3 L0
    ALOAD 0
    INVOKEVIRTUAL java/lang/invoke/SerializedLambda.getImplMethodName ()Ljava/lang/String;
    ASTORE 1
    ICONST_M1
    ISTORE 2
    ALOAD 1
    INVOKEVIRTUAL java/lang/String.hashCode ()I
    LOOKUPSWITCH
      -50212388: L1
      default: L2
   L1
   FRAME APPEND [java/lang/String I]
    ALOAD 1
    LDC "lambda$main$9f099bdf$1"
    INVOKEVIRTUAL java/lang/String.equals (Ljava/lang/Object;)Z
    IFEQ L2
    ICONST_0
    ISTORE 2
   L2
   FRAME SAME
    ILOAD 2
    LOOKUPSWITCH
      0: L3
      default: L4
   L3
   FRAME SAME
    ALOAD 0
    INVOKEVIRTUAL java/lang/invoke/SerializedLambda.getImplMethodKind ()I
    BIPUSH 6
    IF_ICMPNE L4
    ALOAD 0
    INVOKEVIRTUAL java/lang/invoke/SerializedLambda.getFunctionalInterfaceClass ()Ljava/lang/String;
    LDC "java/lang/Runnable"
    INVOKEVIRTUAL java/lang/Object.equals (Ljava/lang/Object;)Z
    IFEQ L4
    ALOAD 0
    INVOKEVIRTUAL java/lang/invoke/SerializedLambda.getFunctionalInterfaceMethodName ()Ljava/lang/String;
    LDC "run"
    INVOKEVIRTUAL java/lang/Object.equals (Ljava/lang/Object;)Z
    IFEQ L4
    ALOAD 0
    INVOKEVIRTUAL java/lang/invoke/SerializedLambda.getFunctionalInterfaceMethodSignature ()Ljava/lang/String;
    LDC "()V"
    INVOKEVIRTUAL java/lang/Object.equals (Ljava/lang/Object;)Z
    IFEQ L4
    ALOAD 0
    INVOKEVIRTUAL java/lang/invoke/SerializedLambda.getImplClass ()Ljava/lang/String;
    LDC "Test"
    INVOKEVIRTUAL java/lang/Object.equals (Ljava/lang/Object;)Z
    IFEQ L4
    ALOAD 0
    INVOKEVIRTUAL java/lang/invoke/SerializedLambda.getImplMethodSignature ()Ljava/lang/String;
    LDC "()V"
    INVOKEVIRTUAL java/lang/Object.equals (Ljava/lang/Object;)Z
    IFEQ L4
    INVOKEDYNAMIC run()Ljava/lang/Runnable; [
      // handle kind 0x6 : INVOKESTATIC
      java/lang/invoke/LambdaMetafactory.altMetafactory(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;[Ljava/lang/Object;)Ljava/lang/invoke/CallSite;
      // arguments:
      ()V, 
      // handle kind 0x6 : INVOKESTATIC
      Test.lambda$main$9f099bdf$1()V, 
      ()V, 
      5, 
      0
    ]
    ARETURN
   L4
   FRAME CHOP 2
    NEW java/lang/IllegalArgumentException
    DUP
    LDC "Invalid lambda deserialization"
    INVOKESPECIAL java/lang/IllegalArgumentException.<init> (Ljava/lang/String;)V
    ATHROW
    MAXSTACK = 3
    MAXLOCALS = 3

Issue Links

• is cloned by: GROOVY-9322 Support serializable method reference
• relates to: GROOVY-11137 Improve support for union and intersection types
• links to: GitHub Pull Request #1110