1 /*
2 * Copyright (c) 2013, 2018, 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
25 package org.graalvm.compiler.hotspot.test;
26
27 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.config;
28 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.referentOffset;
29
30 import java.lang.ref.WeakReference;
31
32 import org.graalvm.compiler.debug.DebugContext;
33 import org.graalvm.compiler.hotspot.GraalHotSpotVMConfig;
34 import org.graalvm.compiler.hotspot.nodes.G1PostWriteBarrier;
35 import org.graalvm.compiler.hotspot.nodes.G1PreWriteBarrier;
36 import org.graalvm.compiler.hotspot.nodes.G1ReferentFieldReadBarrier;
37 import org.graalvm.compiler.hotspot.nodes.SerialWriteBarrier;
38 import org.graalvm.compiler.hotspot.phases.WriteBarrierAdditionPhase;
39 import org.graalvm.compiler.nodes.StructuredGraph;
40 import org.graalvm.compiler.nodes.StructuredGraph.AllowAssumptions;
41 import org.graalvm.compiler.nodes.memory.HeapAccess.BarrierType;
42 import org.graalvm.compiler.nodes.memory.ReadNode;
43 import org.graalvm.compiler.nodes.memory.WriteNode;
44 import org.graalvm.compiler.nodes.memory.address.OffsetAddressNode;
45 import org.graalvm.compiler.nodes.spi.LoweringTool;
46 import org.graalvm.compiler.phases.OptimisticOptimizations;
47 import org.graalvm.compiler.phases.common.CanonicalizerPhase;
48 import org.graalvm.compiler.phases.common.GuardLoweringPhase;
49 import org.graalvm.compiler.phases.common.LoweringPhase;
50 import org.graalvm.compiler.phases.common.inlining.InliningPhase;
51 import org.graalvm.compiler.phases.common.inlining.policy.InlineEverythingPolicy;
52 import org.graalvm.compiler.phases.tiers.HighTierContext;
53 import org.graalvm.compiler.phases.tiers.MidTierContext;
54 import org.junit.Assert;
55 import org.junit.Test;
56
57 import jdk.vm.ci.hotspot.HotSpotInstalledCode;
58 import jdk.vm.ci.meta.JavaConstant;
59 import jdk.vm.ci.meta.ResolvedJavaMethod;
60 import sun.misc.Unsafe;
61
62 /**
63 * The following unit tests assert the presence of write barriers for both Serial and G1 GCs.
64 * Normally, the tests check for compile time inserted barriers. However, there are the cases of
65 * unsafe loads of the java.lang.ref.Reference.referent field where runtime checks have to be
66 * performed also. For those cases, the unit tests check the presence of the compile-time inserted
67 * barriers. Concerning the runtime checks, the results of variable inputs (object types and
68 * offsets) passed as input parameters can be checked against printed output from the G1 write
69 * barrier snippets. The runtime checks have been validated offline.
70 */
71 public class WriteBarrierAdditionTest extends HotSpotGraalCompilerTest {
72
73 private final GraalHotSpotVMConfig config = runtime().getVMConfig();
74 private static final long referentOffset = referentOffset();
75
76 public static class Container {
77
78 public Container a;
79 public Container b;
80 }
81
82 /**
83 * Expected 2 barriers for the Serial GC and 4 for G1 (2 pre + 2 post).
84 */
85 @Test
86 public void test1() throws Exception {
87 testHelper("test1Snippet", (config.useG1GC) ? 4 : 2);
88 }
89
90 public static void test1Snippet() {
91 Container main = new Container();
92 Container temp1 = new Container();
93 Container temp2 = new Container();
94 main.a = temp1;
95 main.b = temp2;
96 }
97
98 /**
99 * Expected 4 barriers for the Serial GC and 8 for G1 (4 pre + 4 post).
100 */
101 @Test
102 public void test2() throws Exception {
103 testHelper("test2Snippet", config.useG1GC ? 8 : 4);
104 }
105
106 public static void test2Snippet(boolean test) {
107 Container main = new Container();
108 Container temp1 = new Container();
109 Container temp2 = new Container();
110 for (int i = 0; i < 10; i++) {
111 if (test) {
112 main.a = temp1;
113 main.b = temp2;
114 } else {
115 main.a = temp2;
116 main.b = temp1;
117 }
118 }
119 }
120
121 /**
122 * Expected 4 barriers for the Serial GC and 8 for G1 (4 pre + 4 post).
123 */
124 @Test
125 public void test3() throws Exception {
126 testHelper("test3Snippet", config.useG1GC ? 8 : 4);
127 }
128
129 public static void test3Snippet() {
130 Container[] main = new Container[10];
131 Container temp1 = new Container();
132 Container temp2 = new Container();
133 for (int i = 0; i < 10; i++) {
134 main[i].a = main[i].b = temp1;
135 }
136
137 for (int i = 0; i < 10; i++) {
138 main[i].a = main[i].b = temp2;
139 }
140 }
141
142 /**
143 * Expected 2 barriers for the Serial GC and 5 for G1 (3 pre + 2 post) The (2 or 4) barriers are
144 * emitted while initializing the fields of the WeakReference instance. The extra pre barrier of
145 * G1 concerns the read of the referent field.
146 */
147 @Test
148 public void test4() throws Exception {
149 testHelper("test4Snippet", config.useG1GC ? 5 : 2);
150 }
151
152 public static Object test4Snippet() {
153 WeakReference<Object> weakRef = new WeakReference<>(new Object());
154 return weakRef.get();
155 }
156
157 static WeakReference<Object> wr = new WeakReference<>(new Object());
158 static Container con = new Container();
159
160 /**
161 * Expected 4 barriers for the Serial GC and 9 for G1 (1 ref + 4 pre + 4 post). In this test, we
162 * load the correct offset of the WeakReference object so naturally we assert the presence of
163 * the pre barrier.
164 */
165 @Test
166 public void test5() throws Exception {
167 testHelper("test5Snippet", config.useG1GC ? 1 : 0);
168 }
169
170 public static Object test5Snippet() throws Exception {
171 return UNSAFE.getObject(wr, config(null).useCompressedOops ? 12L : 16L);
172 }
173
174 /**
175 * The following test concerns the runtime checks of the unsafe loads. In this test, we unsafely
176 * load the java.lang.ref.Reference.referent field so the pre barier has to be executed.
177 */
178 @Test
179 public void test6() throws Exception {
180 test2("testUnsafeLoad", UNSAFE, wr, Long.valueOf(referentOffset), null);
181 }
182
183 /**
184 * The following test concerns the runtime checks of the unsafe loads. In this test, we unsafely
185 * load a matching offset of a wrong object so the pre barier must not be executed.
186 */
187 @Test
188 public void test7() throws Exception {
189 test2("testUnsafeLoad", UNSAFE, con, Long.valueOf(referentOffset), null);
190 }
191
192 /**
193 * The following test concerns the runtime checks of the unsafe loads. In this test, we unsafely
194 * load a non-matching offset field of the java.lang.ref.Reference object so the pre barier must
195 * not be executed.
196 */
197 @Test
198 public void test8() throws Exception {
199 test2("testUnsafeLoad", UNSAFE, wr, Long.valueOf(config.useCompressedOops ? 20 : 32), null);
200 }
201
202 /**
203 * The following test concerns the runtime checks of the unsafe loads. In this test, we unsafely
204 * load a matching offset+disp field of the java.lang.ref.Reference object so the pre barier
205 * must be executed.
206 */
207 @Test
208 public void test10() throws Exception {
209 test2("testUnsafeLoad", UNSAFE, wr, Long.valueOf(config.useCompressedOops ? 6 : 8), Integer.valueOf(config.useCompressedOops ? 6 : 8));
210 }
211
212 /**
213 * The following test concerns the runtime checks of the unsafe loads. In this test, we unsafely
214 * load a non-matching offset+disp field of the java.lang.ref.Reference object so the pre barier
215 * must not be executed.
216 */
217 @Test
218 public void test9() throws Exception {
219 test2("testUnsafeLoad", UNSAFE, wr, Long.valueOf(config.useCompressedOops ? 10 : 16), Integer.valueOf(config.useCompressedOops ? 10 : 16));
220 }
221
222 static Object[] src = new Object[1];
223 static Object[] dst = new Object[1];
224
225 static {
226 for (int i = 0; i < src.length; i++) {
227 src[i] = new Object();
228 }
229 for (int i = 0; i < dst.length; i++) {
230 dst[i] = new Object();
231 }
232 }
233
234 public static void testArrayCopy(Object a, Object b, Object c) throws Exception {
235 System.arraycopy(a, 0, b, 0, (int) c);
236 }
237
238 @Test
239 public void test11() throws Exception {
240 test2("testArrayCopy", src, dst, dst.length);
241 }
242
243 public static Object testUnsafeLoad(Unsafe theUnsafe, Object a, Object b, Object c) throws Exception {
244 final int offset = (c == null ? 0 : ((Integer) c).intValue());
245 final long displacement = (b == null ? 0 : ((Long) b).longValue());
246 return theUnsafe.getObject(a, offset + displacement);
247 }
248
249 private HotSpotInstalledCode getInstalledCode(String name, boolean withUnsafePrefix) throws Exception {
250 final ResolvedJavaMethod javaMethod = withUnsafePrefix ? getResolvedJavaMethod(WriteBarrierAdditionTest.class, name, Unsafe.class, Object.class, Object.class, Object.class)
251 : getResolvedJavaMethod(WriteBarrierAdditionTest.class, name, Object.class, Object.class, Object.class);
252 final HotSpotInstalledCode installedCode = (HotSpotInstalledCode) getCode(javaMethod);
253 return installedCode;
254 }
255
256 @SuppressWarnings("try")
257 private void testHelper(final String snippetName, final int expectedBarriers) throws Exception, SecurityException {
258 ResolvedJavaMethod snippet = getResolvedJavaMethod(snippetName);
259 DebugContext debug = getDebugContext();
260 try (DebugContext.Scope s = debug.scope("WriteBarrierAdditionTest", snippet)) {
261 StructuredGraph graph = parseEager(snippet, AllowAssumptions.NO, debug);
262 HighTierContext highContext = getDefaultHighTierContext();
263 MidTierContext midContext = new MidTierContext(getProviders(), getTargetProvider(), OptimisticOptimizations.ALL, graph.getProfilingInfo());
264 new InliningPhase(new InlineEverythingPolicy(), new CanonicalizerPhase()).apply(graph, highContext);
265 new CanonicalizerPhase().apply(graph, highContext);
266 new LoweringPhase(new CanonicalizerPhase(), LoweringTool.StandardLoweringStage.HIGH_TIER).apply(graph, highContext);
267 new GuardLoweringPhase().apply(graph, midContext);
268 new LoweringPhase(new CanonicalizerPhase(), LoweringTool.StandardLoweringStage.MID_TIER).apply(graph, midContext);
269 new WriteBarrierAdditionPhase(config).apply(graph);
270 debug.dump(DebugContext.BASIC_LEVEL, graph, "After Write Barrier Addition");
271
272 int barriers = 0;
273 if (config.useG1GC) {
274 barriers = graph.getNodes().filter(G1ReferentFieldReadBarrier.class).count() + graph.getNodes().filter(G1PreWriteBarrier.class).count() +
275 graph.getNodes().filter(G1PostWriteBarrier.class).count();
276 } else {
277 barriers = graph.getNodes().filter(SerialWriteBarrier.class).count();
278 }
279 if (expectedBarriers != barriers) {
280 Assert.assertEquals(getScheduledGraphString(graph), expectedBarriers, barriers);
281 }
282 for (WriteNode write : graph.getNodes().filter(WriteNode.class)) {
283 if (config.useG1GC) {
284 if (write.getBarrierType() != BarrierType.NONE) {
285 Assert.assertEquals(1, write.successors().count());
286 Assert.assertTrue(write.next() instanceof G1PostWriteBarrier);
287 Assert.assertTrue(write.predecessor() instanceof G1PreWriteBarrier);
288 }
289 } else {
290 if (write.getBarrierType() != BarrierType.NONE) {
291 Assert.assertEquals(1, write.successors().count());
292 Assert.assertTrue(write.next() instanceof SerialWriteBarrier);
293 }
294 }
295 }
296
297 for (ReadNode read : graph.getNodes().filter(ReadNode.class)) {
298 if (read.getBarrierType() != BarrierType.NONE) {
299 Assert.assertTrue(read.getAddress() instanceof OffsetAddressNode);
300 JavaConstant constDisp = ((OffsetAddressNode) read.getAddress()).getOffset().asJavaConstant();
301 Assert.assertNotNull(constDisp);
302 Assert.assertEquals(referentOffset, constDisp.asLong());
303 Assert.assertTrue(config.useG1GC);
304 Assert.assertEquals(BarrierType.PRECISE, read.getBarrierType());
305 Assert.assertTrue(read.next() instanceof G1ReferentFieldReadBarrier);
306 }
307 }
308 } catch (Throwable e) {
309 throw debug.handle(e);
310 }
311 }
312
313 private void test2(final String snippet, Object... args) throws Exception {
314 HotSpotInstalledCode code = getInstalledCode(snippet, args[0] instanceof Unsafe);
315 code.executeVarargs(args);
316 }
317 }