Disassembly of groovy's generated code for @singleton

gistfile1.java

/* groovy */

import groovy.transform.CompileStatic

@CompileStatic
@Singleton
class RegularSingleton {
	void foo() { println 'foo' }
}

@CompileStatic
@Singleton(lazy=true)
class LazySingleton {
	void bar() { println 'bar' }
}

/* disassembly of RegularSingleton */

import groovy.lang.GroovyObject;
import groovy.lang.MetaClass;
import org.codehaus.groovy.runtime.DefaultGroovyMethods;

public class RegularSingleton
  implements GroovyObject
{
  public static final RegularSingleton instance;
  
  private RegularSingleton()
  {
    RegularSingleton this;
    MetaClass localMetaClass = $getStaticMetaClass();
    this.metaClass = localMetaClass;
    if ((instance != null ? 1 : 0) != 0) {
      throw ((Throwable)new RuntimeException("Can't instantiate singleton RegularSingleton. Use RegularSingleton.instance"));
    }
  }
  
  public void foo()
  {
    DefaultGroovyMethods.println(this, "foo");null;
  }
  
  public static RegularSingleton getInstance()
  {
    return instance;
    return null;
  }
  
  static
  {
    __$swapInit();
    Long localLong1 = Long.valueOf(0L);
    __timeStamp__239_neverHappen1411637903931 = localLong1.longValue();
    Long localLong2 = Long.valueOf(1411637903931L);
    __timeStamp = localLong2.longValue();
    RegularSingleton localRegularSingleton = new RegularSingleton();
    instance = localRegularSingleton;
  }
}

/* disassembly of LazySingleton */

import groovy.lang.GroovyObject;
import groovy.lang.MetaClass;
import org.codehaus.groovy.runtime.BytecodeInterface8;
import org.codehaus.groovy.runtime.ScriptBytecodeAdapter;
import org.codehaus.groovy.runtime.callsite.CallSite;

public class LazySingleton
  implements GroovyObject
{
  private static volatile LazySingleton instance;
  
  private LazySingleton()
  {
    LazySingleton this;
    CallSite[] arrayOfCallSite = $getCallSiteArray();
    MetaClass localMetaClass = $getStaticMetaClass();
    this.metaClass = localMetaClass;
    if ((!BytecodeInterface8.isOrigZ()) || (BytecodeInterface8.disabledStandardMetaClass()))
    {
      if (ScriptBytecodeAdapter.compareNotEqual(instance, null)) {
        throw ((Throwable)arrayOfCallSite[0].callConstructor(RuntimeException.class, "Can't instantiate singleton LazySingleton. Use LazySingleton.instance"));
      }
    }
    else if (ScriptBytecodeAdapter.compareNotEqual(instance, null)) {
      throw ((Throwable)arrayOfCallSite[1].callConstructor(RuntimeException.class, "Can't instantiate singleton LazySingleton. Use LazySingleton.instance"));
    }
  }
  
  public void bar()
  {
    CallSite[] arrayOfCallSite = $getCallSiteArray();arrayOfCallSite[2].callCurrent(this, "bar");
  }
  
  public static LazySingleton getInstance()
  {
    CallSite[] arrayOfCallSite = $getCallSiteArray();
    if ((!BytecodeInterface8.isOrigZ()) || (__$stMC) || (BytecodeInterface8.disabledStandardMetaClass()))
    {
      if (ScriptBytecodeAdapter.compareNotEqual(instance, null)) {
        return instance;
      } else {
        synchronized (LazySingleton.class)
        {
          if (ScriptBytecodeAdapter.compareNotEqual(instance, null))
          {
            LazySingleton localLazySingleton2 = instance;
            return localLazySingleton2;
          }
          else
          {
            Object localObject1 = arrayOfCallSite[3].callConstructor(LazySingleton.class);
            instance = (LazySingleton)ScriptBytecodeAdapter.castToType(localObject1, LazySingleton.class);
            LazySingleton localLazySingleton3 = (LazySingleton)ScriptBytecodeAdapter.castToType(localObject1, LazySingleton.class);
            return localLazySingleton3;
          }
        }
      }
    }
    else if (ScriptBytecodeAdapter.compareNotEqual(instance, null)) {
      return instance;
    } else {
      synchronized (LazySingleton.class)
      {
        if (ScriptBytecodeAdapter.compareNotEqual(instance, null))
        {
          LazySingleton localLazySingleton5 = instance;
          return localLazySingleton5;
        }
        else
        {
          Object localObject2 = arrayOfCallSite[4].callConstructor(LazySingleton.class);
          instance = (LazySingleton)ScriptBytecodeAdapter.castToType(localObject2, LazySingleton.class);
          LazySingleton localLazySingleton6 = (LazySingleton)ScriptBytecodeAdapter.castToType(localObject2, LazySingleton.class);
          return localLazySingleton6;
        }
      }
    }
    return null;
  }
  
  static
  {
    __$swapInit();
    Long localLong1 = Long.valueOf(0L);
    __timeStamp__239_neverHappen1411637853476 = localLong1.longValue();
    Long localLong2 = Long.valueOf(1411637853476L);
    __timeStamp = localLong2.longValue();
  }
}