1 /*
   2  * Copyright (c) 2011, 2015, 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 package jdk.vm.ci.hotspot;
  24 
  25 import static jdk.vm.ci.hotspot.CompilerToVM.compilerToVM;
  26 import jdk.vm.ci.code.InstalledCode;
  27 import jdk.vm.ci.code.InvalidInstalledCodeException;
  28 import jdk.vm.ci.meta.JavaKind;
  29 import jdk.vm.ci.meta.JavaType;
  30 import jdk.vm.ci.meta.ResolvedJavaMethod;
  31 
  32 /**
  33  * Implementation of {@link InstalledCode} for code installed as an nmethod.
  34  *
  35  * When a {@link HotSpotNmethod} dies, it triggers unloading of the nmethod unless
  36  * {@link #isDefault() == true}.
  37  */
  38 public class HotSpotNmethod extends HotSpotInstalledCode {
  39 
  40     /**
  41      * This (indirect) Method* reference is safe since class redefinition preserves all methods
  42      * associated with nmethods in the code cache.
  43      */
  44     private final HotSpotResolvedJavaMethod method;
  45 
  46     private final boolean isDefault;
  47 
  48     public HotSpotNmethod(HotSpotResolvedJavaMethod method, String name, boolean isDefault) {
  49         super(name);
  50         this.method = method;
  51         this.isDefault = isDefault;
  52     }
  53 
  54     /**
  55      * Determines if the nmethod associated with this object is the compiled entry point for
  56      * {@link #getMethod()}. If {@code false}, then the nmethod is unloaded when the VM determines
  57      * this object has died.
  58      */
  59     public boolean isDefault() {
  60         return isDefault;
  61     }
  62 
  63     public ResolvedJavaMethod getMethod() {
  64         return method;
  65     }
  66 
  67     @Override
  68     public void invalidate() {
  69         compilerToVM().invalidateInstalledCode(this);
  70     }
  71 
  72     @Override
  73     public String toString() {
  74         return String.format("InstalledNmethod[method=%s, codeBlob=0x%x, isDefault=%b, name=%s]", method, getAddress(), isDefault, name);
  75     }
  76 
  77     protected boolean checkThreeObjectArgs() {
  78         assert method.getSignature().getParameterCount(!method.isStatic()) == 3;
  79         assert method.getSignature().getParameterKind(0) == JavaKind.Object;
  80         assert method.getSignature().getParameterKind(1) == JavaKind.Object;
  81         assert !method.isStatic() || method.getSignature().getParameterKind(2) == JavaKind.Object;
  82         return true;
  83     }
  84 
  85     private boolean checkArgs(Object... args) {
  86         JavaType[] sig = method.toParameterTypes();
  87         assert args.length == sig.length : method.format("%H.%n(%p): expected ") + sig.length + " args, got " + args.length;
  88         for (int i = 0; i < sig.length; i++) {
  89             Object arg = args[i];
  90             if (arg == null) {
  91                 assert sig[i].getJavaKind() == JavaKind.Object : method.format("%H.%n(%p): expected arg ") + i + " to be Object, not " + sig[i];
  92             } else if (sig[i].getJavaKind() != JavaKind.Object) {
  93                 assert sig[i].getJavaKind().toBoxedJavaClass() == arg.getClass() : method.format("%H.%n(%p): expected arg ") + i + " to be " + sig[i] + ", not " + arg.getClass();
  94             }
  95         }
  96         return true;
  97     }
  98 
  99     @Override
 100     public Object executeVarargs(Object... args) throws InvalidInstalledCodeException {
 101         assert checkArgs(args);
 102         return compilerToVM().executeInstalledCode(args, this);
 103     }
 104 
 105     @Override
 106     public long getStart() {
 107         return isValid() ? super.getStart() : 0;
 108     }
 109 }