1 /*
   2  * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 package execution;
  25 
  26 import hierarchies.TypeHierarchy;
  27 import scenarios.Scenario;
  28 
  29 import java.lang.invoke.MethodHandle;
  30 import java.lang.invoke.MethodHandles;
  31 import java.lang.invoke.MethodType;
  32 
  33 /**
  34  * Executes test scenario using {@link MethodHandle#invoke(Object...)}.
  35  * Delegates execution to the given {@link Execution} by creating
  36  * new test scenario, see {@link Scenario}
  37  */
  38 public class MethodHandleDelegate<T  extends TypeHierarchy.I, R> implements Execution<T, R> {
  39     private final Execution<T, R> delegate;
  40 
  41     public MethodHandleDelegate(Execution<T, R> delegate) {
  42         this.delegate = delegate;
  43     }
  44 
  45     @Override
  46     public void execute(Scenario<T, R> scenario) {
  47         delegate.execute(new MHScenario<T, R>(scenario));
  48     }
  49 
  50     @Override
  51     public String getName() {
  52         return "MethodHandleDelegate # " + delegate.getName();
  53     }
  54 
  55     private static class MHScenario<T extends TypeHierarchy.I, R> extends Scenario<T, R> {
  56         private final Scenario<T, R> scenario;
  57         private static final MethodHandle METHOD_HANDLE_RUN;
  58 
  59         static {
  60             MethodHandles.Lookup lookup = MethodHandles.lookup();
  61             MethodType methodType = MethodType.methodType(Object.class, TypeHierarchy.I.class);
  62 
  63             try {
  64                 METHOD_HANDLE_RUN = lookup.findVirtual(Scenario.class, "run", methodType);
  65             } catch (NoSuchMethodException | IllegalAccessException e) {
  66                 System.err.println("Failed to get target method run() with " + e);
  67                 e.printStackTrace();
  68                 throw new RuntimeException(e);
  69             }
  70         }
  71 
  72         /**
  73          * Constructor
  74          *
  75          * @param scenario test scenario to be executed
  76          */
  77         private MHScenario(Scenario<T, R> scenario) {
  78             super("MethodHandle::" + scenario.getName(), scenario.profilingType, scenario.hierarchy);
  79             this.scenario = scenario;
  80         }
  81 
  82         /**
  83          * Runs {@link Scenario#run(T)} with {@link MethodHandle#invoke(Object...)}
  84          *
  85          * @param t subject of the test
  86          * @return  result of the underlying {@link Scenario#run(T)} invocation
  87          */
  88         @SuppressWarnings("unchecked")
  89         @Override
  90         public R run(T t) {
  91             try {
  92                 return (R) METHOD_HANDLE_RUN.invoke(scenario, t);
  93             } catch (Throwable thr) {
  94                 System.err.println(scenario.getName()
  95                         + " failed to invoke target method run() with " + thr);
  96                 throw new RuntimeException("Invocation failed", thr);
  97             }
  98         }
  99 
 100         @Override
 101         public void check(R r, T t) {
 102             scenario.check(r, t);
 103         }
 104     }
 105 }