src/share/classes/java/lang/invoke/BoundMethodHandle.java

rev 10274 : 8050052: Small cleanups in java.lang.invoke code
Reviewed-by: ?
rev 10276 : 8050166: Get rid of some package-private methods on arguments in j.l.i.MethodHandle
Reviewed-by: vlivanov, ?
Contributed-by: john.r.rose@oracle.com
rev 10279 : 8050057: Improve caching of MethodHandle reinvokers
Reviewed-by: vlivanov, ?
Contributed-by: john.r.rose@oracle.com

*** 115,124 ****
--- 115,149 ----
          MethodType type = type().dropParameterTypes(pos, pos + 1);
          LambdaForm form = internalForm().bind(1+pos, speciesData());
          return copyWithExtendD(type, form, value);
      }
  
+     @Override
+     BoundMethodHandle rebind() {
+         if (!tooComplex()) {
+             return this;
+         }
+         return makeReinvoker(this);
+     }
+ 
+     private boolean tooComplex() {
+         return (fieldCount() > FIELD_COUNT_THRESHOLD ||
+                 form.expressionCount() > FORM_EXPRESSION_THRESHOLD);
+     }
+     private static int FIELD_COUNT_THRESHOLD = 12;  // largest convenient BMH field count
+     private static int FORM_EXPRESSION_THRESHOLD = 24;  // largest convenient BMH expression count
+ 
+     /**
+      * A reinvoker MH has this form:
+      * {@code lambda (bmh, arg*) { thismh = bmh[0]; invokeBasic(thismh, arg*) }}
+      */
+     static BoundMethodHandle makeReinvoker(MethodHandle target) {
+         LambdaForm form = DelegatingMethodHandle.makeReinvokerForm(
+                 target, MethodTypeForm.LF_REBIND, Species_L.SPECIES_DATA.getterFunction(0) );
+         return Species_L.make(target.type(), form, target);
+     }
+ 
      /**
       * Return the {@link SpeciesData} instance representing this BMH species. All subclasses must provide a
       * static field containing this value, and they must accordingly implement this method.
       */
      /*non-public*/ abstract SpeciesData speciesData();
*** 166,184 ****
      /*non-public*/ abstract BoundMethodHandle copyWithExtendI(MethodType mt, LambdaForm lf, int    narg);
      /*non-public*/ abstract BoundMethodHandle copyWithExtendJ(MethodType mt, LambdaForm lf, long   narg);
      /*non-public*/ abstract BoundMethodHandle copyWithExtendF(MethodType mt, LambdaForm lf, float  narg);
      /*non-public*/ abstract BoundMethodHandle copyWithExtendD(MethodType mt, LambdaForm lf, double narg);
  
-     // The following is a grossly irregular hack:
-     @Override MethodHandle reinvokerTarget() {
-         try {
-             return (MethodHandle) arg(0);
-         } catch (Throwable ex) {
-             throw newInternalError(ex);
-         }
-     }
- 
      //
      // concrete BMH classes required to close bootstrap loops
      //
  
      private  // make it private to force users to access the enclosing class first
--- 191,200 ----
*** 186,197 ****
          final Object argL0;
          private Species_L(MethodType mt, LambdaForm lf, Object argL0) {
              super(mt, lf);
              this.argL0 = argL0;
          }
-         // The following is a grossly irregular hack:
-         @Override MethodHandle reinvokerTarget() { return (MethodHandle) argL0; }
          @Override
          /*non-public*/ SpeciesData speciesData() {
              return SPECIES_DATA;
          }
          @Override
--- 202,211 ----
*** 567,586 ****
  
              mv.visitInsn(RETURN);
              mv.visitMaxs(0, 0);
              mv.visitEnd();
  
-             // emit implementation of reinvokerTarget()
-             mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "reinvokerTarget", "()" + MH_SIG, null, null);
-             mv.visitCode();
-             mv.visitVarInsn(ALOAD, 0);
-             mv.visitFieldInsn(GETFIELD, className, "argL0", JLO_SIG);
-             mv.visitTypeInsn(CHECKCAST, MH);
-             mv.visitInsn(ARETURN);
-             mv.visitMaxs(0, 0);
-             mv.visitEnd();
- 
              // emit implementation of speciesData()
              mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "speciesData", MYSPECIES_DATA_SIG, null, null);
              mv.visitCode();
              mv.visitFieldInsn(GETSTATIC, className, "SPECIES_DATA", SPECIES_DATA_SIG);
              mv.visitInsn(ARETURN);
--- 581,590 ----