1 /*
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3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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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
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13  * accompanied this code).
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23 
24 
25 package org.graalvm.compiler.replacements.test;
26 
27 import org.graalvm.compiler.api.directives.GraalDirectives;
28 import org.graalvm.compiler.bytecode.BytecodeProvider;
29 import org.graalvm.compiler.debug.DebugCloseable;
30 import org.graalvm.compiler.debug.DebugContext;
31 import org.graalvm.compiler.debug.GraalError;
32 import org.graalvm.compiler.nodes.ValueNode;
33 import org.graalvm.compiler.nodes.graphbuilderconf.GraphBuilderContext;
34 import org.graalvm.compiler.nodes.graphbuilderconf.InvocationPlugin;
35 import org.graalvm.compiler.nodes.graphbuilderconf.InvocationPlugins;
36 import org.graalvm.compiler.nodes.graphbuilderconf.InvocationPlugins.Registration;
37 import org.graalvm.compiler.replacements.Snippets;
38 import org.graalvm.compiler.word.Word;
39 import org.junit.Test;
40 
41 import jdk.vm.ci.meta.ResolvedJavaMethod;
42 
43 public class PointerTrackingTest extends ReplacementsTest implements Snippets {
44 
45     @Test
testTracking()46     public void testTracking() {
47         Result result = executeActual(getResolvedJavaMethod("trackingSnippet"), null, new Object());
48         assertEquals(new Result("OK", null), result);
49     }
50 
trackingSnippet(Object obj)51     public static String trackingSnippet(Object obj) {
52         long trackedBeforeGC = getTrackedPointer(obj);
53         long untrackedBeforeGC = getUntrackedPointer(obj);
54 
55         int i = 0;
56         while (untrackedBeforeGC == getTrackedPointer(obj)) {
57             System.gc();
58             if (i++ > 100) {
59                 return "Timeout! Object didn't move after 100 GCs.";
60             }
61         }
62 
63         long trackedAfterGC = getTrackedPointer(obj);
64         long untrackedAfterGC = getUntrackedPointer(obj);
65 
66         if (untrackedBeforeGC == untrackedAfterGC) {
67             /*
68              * The untracked pointer isn't supposed to be updated, so it should be different before
69              * and after GC.
70              */
71             return "untrackedBeforeGC == untrackedAfterGC";
72         }
73         if (trackedBeforeGC != trackedAfterGC) {
74             /*
75              * The trackedBeforeGC variable should be updated to the new location by the GC, so it
76              * should be equal to trackedAfterGC.
77              */
78             return "trackedBeforeGC != trackedAfterGC";
79         }
80 
81         return "OK";
82     }
83 
84     @Test(expected = GraalError.class)
85     @SuppressWarnings("try")
testVerification()86     public void testVerification() {
87         DebugContext debug = getDebugContext();
88         try (DebugCloseable d = debug.disableIntercept(); DebugContext.Scope s = debug.scope("PointerTrackingTest")) {
89             compile(getResolvedJavaMethod("verificationSnippet"), null);
90         }
91     }
92 
verificationSnippet(Object obj)93     public static long verificationSnippet(Object obj) {
94         long value = getTrackedPointer(obj) * 7 + 3;
95 
96         /*
97          * Ensure usage before and after GC to force the value to be alive across the safepoint.
98          * This should lead to a compiler error, since value can not be tracked in the reference
99          * map.
100          */
101         GraalDirectives.blackhole(value);
102         System.gc();
103         return value;
104     }
105 
getTrackedPointer(@uppressWarningsR) Object obj)106     static long getTrackedPointer(@SuppressWarnings("unused") Object obj) {
107         throw GraalError.shouldNotReachHere("should be intrinsified");
108     }
109 
getUntrackedPointer(@uppressWarningsR) Object obj)110     static long getUntrackedPointer(@SuppressWarnings("unused") Object obj) {
111         throw GraalError.shouldNotReachHere("should be intrinsified");
112     }
113 
getTrackedPointerIntrinsic(Object obj)114     static long getTrackedPointerIntrinsic(Object obj) {
115         return Word.objectToTrackedPointer(obj).rawValue();
116     }
117 
getUntrackedPointerIntrinsic(Object obj)118     static long getUntrackedPointerIntrinsic(Object obj) {
119         return Word.objectToUntrackedPointer(obj).rawValue();
120     }
121 
register(Registration r, String fnName)122     private void register(Registration r, String fnName) {
123         ResolvedJavaMethod intrinsic = getResolvedJavaMethod(fnName + "Intrinsic");
124         BytecodeProvider bytecodeProvider = getSystemClassLoaderBytecodeProvider();
125         r.register1(fnName, Object.class, new InvocationPlugin() {
126             @Override
127             public boolean apply(GraphBuilderContext b, ResolvedJavaMethod targetMethod, Receiver receiver, ValueNode arg) {
128                 return b.intrinsify(bytecodeProvider, targetMethod, intrinsic, receiver, new ValueNode[]{arg});
129             }
130         });
131     }
132 
133     @Override
registerInvocationPlugins(InvocationPlugins invocationPlugins)134     protected void registerInvocationPlugins(InvocationPlugins invocationPlugins) {
135         Registration r = new Registration(invocationPlugins, PointerTrackingTest.class);
136 
137         register(r, "getTrackedPointer");
138         register(r, "getUntrackedPointer");
139     }
140 }
141