1643     abstract MethodHandle copyWith(MethodType mt, LambdaForm lf);
1644 
1645     /** Require this method handle to be a BMH, or else replace it with a "wrapper" BMH.
1646      *  Many transforms are implemented only for BMHs.
1647      *  @return a behaviorally equivalent BMH
1648      */
1649     abstract BoundMethodHandle rebind();
1650 
1651     /**
1652      * Replace the old lambda form of this method handle with a new one.
1653      * The new one must be functionally equivalent to the old one.
1654      * Threads may continue running the old form indefinitely,
1655      * but it is likely that the new one will be preferred for new executions.
1656      * Use with discretion.
1657      */
1658     /*non-public*/
1659     void updateForm(LambdaForm newForm) {
1660         assert(newForm.customized == null || newForm.customized == this);
1661         if (form == newForm)  return;
1662         newForm.prepare();  // as in MethodHandle.<init>
1663         UNSAFE.putObject(this, FORM_OFFSET, newForm);
1664         UNSAFE.fullFence();
1665     }
1666 
1667     /** Craft a LambdaForm customized for this particular MethodHandle */
1668     /*non-public*/
1669     void customize() {

1670         if (form.customized == null) {
1671             LambdaForm newForm = form.customize(this);
1672             updateForm(newForm);
1673         } else {
1674             assert(form.customized == this);
1675         }
1676     }
1677 
1678     private static final long FORM_OFFSET
1679             = UNSAFE.objectFieldOffset(MethodHandle.class, "form");
1680 }

1643     abstract MethodHandle copyWith(MethodType mt, LambdaForm lf);
1644 
1645     /** Require this method handle to be a BMH, or else replace it with a "wrapper" BMH.
1646      *  Many transforms are implemented only for BMHs.
1647      *  @return a behaviorally equivalent BMH
1648      */
1649     abstract BoundMethodHandle rebind();
1650 
1651     /**
1652      * Replace the old lambda form of this method handle with a new one.
1653      * The new one must be functionally equivalent to the old one.
1654      * Threads may continue running the old form indefinitely,
1655      * but it is likely that the new one will be preferred for new executions.
1656      * Use with discretion.
1657      */
1658     /*non-public*/
1659     void updateForm(LambdaForm newForm) {
1660         assert(newForm.customized == null || newForm.customized == this);
1661         if (form == newForm)  return;
1662         newForm.prepare();  // as in MethodHandle.<init>
1663         UNSAFE.putObjectVolatile(this, FORM_OFFSET, newForm);

1664     }
1665 
1666     /** Craft a LambdaForm customized for this particular MethodHandle */
1667     /*non-public*/
1668     void customize() {
1669         final LambdaForm form = this.form;
1670         if (form.customized == null) {
1671             LambdaForm newForm = form.customize(this);
1672             updateForm(newForm);
1673         } else {
1674             assert(form.customized == this);
1675         }
1676     }
1677 
1678     private static final long FORM_OFFSET
1679             = UNSAFE.objectFieldOffset(MethodHandle.class, "form");
1680 }