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. The nmethod stores a 34 * weak reference to an instance of this class. This is necessary to keep the nmethod from being 35 * unloaded while the associated {@link HotSpotNmethod} instance is alive. 36 * <p> 37 * Note that there is no (current) way for the reference from an nmethod to a {@link HotSpotNmethod} 38 * instance to be anything but weak. This is due to the fact that HotSpot does not treat nmethods as 39 * strong GC roots. 40 */ 41 public class HotSpotNmethod extends HotSpotInstalledCode { 42 43 /** 44 * This (indirect) Method* reference is safe since class redefinition preserves all methods 45 * associated with nmethods in the code cache. 46 */ 47 private final HotSpotResolvedJavaMethod method; 48 49 private final boolean isDefault; 50 51 public HotSpotNmethod(HotSpotResolvedJavaMethod method, String name, boolean isDefault) { 52 super(name); 53 this.method = method; 54 this.isDefault = isDefault; 55 } 56 57 public boolean isDefault() { 58 return isDefault; 59 } 60 61 public ResolvedJavaMethod getMethod() { 62 return method; 63 } 64 65 @Override 66 public void invalidate() { 67 compilerToVM().invalidateInstalledCode(this); 68 } 69 70 @Override 71 public String toString() { 72 return String.format("InstalledNmethod[method=%s, codeBlob=0x%x, isDefault=%b, name=%s]", method, getAddress(), isDefault, name); 73 } 74 75 protected boolean checkThreeObjectArgs() { 76 assert method.getSignature().getParameterCount(!method.isStatic()) == 3; 77 assert method.getSignature().getParameterKind(0) == JavaKind.Object; 78 assert method.getSignature().getParameterKind(1) == JavaKind.Object; 79 assert !method.isStatic() || method.getSignature().getParameterKind(2) == JavaKind.Object; 80 return true; 81 } 82 83 private boolean checkArgs(Object... args) { 84 JavaType[] sig = method.toParameterTypes(); 85 assert args.length == sig.length : method.format("%H.%n(%p): expected ") + sig.length + " args, got " + args.length; 86 for (int i = 0; i < sig.length; i++) { 87 Object arg = args[i]; 88 if (arg == null) { 89 assert sig[i].getJavaKind() == JavaKind.Object : method.format("%H.%n(%p): expected arg ") + i + " to be Object, not " + sig[i]; 90 } else if (sig[i].getJavaKind() != JavaKind.Object) { 91 assert sig[i].getJavaKind().toBoxedJavaClass() == arg.getClass() : method.format("%H.%n(%p): expected arg ") + i + " to be " + sig[i] + ", not " + arg.getClass(); 92 } 93 } 94 return true; 95 } 96 97 @Override 98 public Object executeVarargs(Object... args) throws InvalidInstalledCodeException { 99 assert checkArgs(args); 100 return compilerToVM().executeInstalledCode(args, this); 101 } 102 103 @Override 104 public long getStart() { 105 return isValid() ? super.getStart() : 0; 106 } 107 }