1 /*
2 * Copyright (c) 2014, 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
24 /*
25 * @test
26 * @bug 8030976 8059226
27 * @library /testlibrary /test/lib /
28 * @modules java.base/jdk.internal.org.objectweb.asm
29 * java.base/jdk.internal.misc
30 * java.compiler
31 * java.management
32 * jdk.jvmstat/sun.jvmstat.monitor
33 * @build TestUnstableIfTrap jdk.test.lib.* compiler.testlibrary.uncommontrap.Verifier
34 * @run driver ClassFileInstaller sun.hotspot.WhiteBox
35 * sun.hotspot.WhiteBox$WhiteBoxPermission
36 * @run main/othervm -Xbatch -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions
37 * -XX:+WhiteBoxAPI -XX:+LogCompilation
38 * -XX:CompileCommand=compileonly,UnstableIfExecutable.test
39 * -XX:LogFile=always_taken_not_fired.xml
40 * TestUnstableIfTrap ALWAYS_TAKEN false
41 * @run main/othervm -Xbatch -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions
42 * -XX:+WhiteBoxAPI -XX:+LogCompilation
43 * -XX:CompileCommand=compileonly,UnstableIfExecutable.test
44 * -XX:LogFile=always_taken_fired.xml
45 * TestUnstableIfTrap ALWAYS_TAKEN true
46 * @run main/othervm -Xbatch -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions
47 * -XX:+WhiteBoxAPI -XX:+LogCompilation
48 * -XX:CompileCommand=compileonly,UnstableIfExecutable.test
49 * -XX:LogFile=never_taken_not_fired.xml
50 * TestUnstableIfTrap NEVER_TAKEN false
51 * @run main/othervm -Xbatch -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions
52 * -XX:+WhiteBoxAPI -XX:+LogCompilation
53 * -XX:CompileCommand=compileonly,UnstableIfExecutable.test
54 * -XX:LogFile=never_taken_fired.xml
55 * TestUnstableIfTrap NEVER_TAKEN true
56 * @run driver compiler.testlibrary.uncommontrap.Verifier always_taken_not_fired.xml
57 * always_taken_fired.xml
58 * never_taken_not_fired.xml
59 * never_taken_fired.xml
60 */
61
62 import java.io.File;
63 import java.io.FileWriter;
64 import java.io.IOException;
65 import java.lang.reflect.Method;
66 import java.util.Properties;
67
68 import jdk.test.lib.ByteCodeLoader;
69 import jdk.test.lib.Platform;
70 import jdk.internal.org.objectweb.asm.ClassVisitor;
71 import jdk.internal.org.objectweb.asm.ClassWriter;
72 import jdk.internal.org.objectweb.asm.Label;
73 import jdk.internal.org.objectweb.asm.MethodVisitor;
74 import static jdk.internal.org.objectweb.asm.Opcodes.*;
75
76 import sun.hotspot.WhiteBox;
77 import compiler.testlibrary.uncommontrap.Verifier;
78
79 public class TestUnstableIfTrap {
80 private static final WhiteBox WB = WhiteBox.getWhiteBox();
81 private static final String CLASS_NAME = "UnstableIfExecutable";
82 private static final String METHOD_NAME = "test";
83 private static final String FIELD_NAME = "field";
84 private static final int ITERATIONS = 1_000_000;
85 // There is no dependency on particular class file version, so it could be
86 // set to any version (if you're updating this test for Java 42).
87 private static final int CLASS_FILE_VERSION = 49;
88 private static final int MAX_TIER = 4;
89 // This test aimed to verify that uncommon trap with reason "unstable_if"
90 // is emitted when method that contain control-flow divergence such that
91 // one of two branches is never taken (and other one is taken always).
92 // C2 will made a decision whether or not the branch was ever taken
93 // depending on method's profile.
94 // If profile was collected for a few method's invocations, then C2 will not
95 // trust in branches' probabilities and the tested trap won't be emitted.
96 // In fact, a method has to be invoked at least 40 time at the day when this
97 // comment was written (see Parse::dynamic_branch_prediction for an actual
98 // value). It would be to implementation dependent to use "40" as
99 // a threshold value in the test, so in order to improve test's robustness
100 // the threshold value is 1000: if the tested method was compiled by C2
101 // before it was invoked 1000 times, then we won't verify that trap was
102 // emitted and fired.
103 private static final int MIN_INVOCATIONS_BEFORE_C2_COMPILATION = 1000;
104 /**
105 * Description of test case parameters and uncommon trap that will
106 * be emitted during tested method compilation.
107 */
108 private static enum TestCaseName {
109 ALWAYS_TAKEN(false, "taken always"),
110 NEVER_TAKEN(true, "taken never");
111 TestCaseName(boolean predicate, String comment) {
112 this.predicate = predicate;
113 this.comment = comment;
114 }
115
116 public final boolean predicate;
117 public final String name = "unstable_if";
118 public final String comment;
119 }
120
121 public static void main(String args[]) {
122 if (args.length != 2) {
123 throw new Error("Expected two arguments: test case name and a "
124 + "boolean determining if uncommon trap should be fired.");
125 }
126 test(TestCaseName.valueOf(args[0]), Boolean.valueOf(args[1]));
127 }
128
129 private static void test(TestCaseName testCase, boolean shouldBeFired) {
130 Method testMethod;
131 Label unstableIfLocation = new Label();
132 boolean shouldBeEmitted;
133 boolean compiledToEarly = false;
134
135 try {
136 Class testClass = ByteCodeLoader.load(CLASS_NAME,
137 generateTest(unstableIfLocation));
138 testMethod = testClass.getDeclaredMethod(METHOD_NAME,
139 boolean.class);
140 for (int i = 0; i < ITERATIONS; i++) {
141 testMethod.invoke(null, testCase.predicate);
142 if (i < MIN_INVOCATIONS_BEFORE_C2_COMPILATION
143 && isMethodCompiledByC2(testMethod)) {
144 compiledToEarly = true;
145 // There is no sense in further invocations: we already
146 // decided to avoid verification.
147 break;
148 }
149 }
150 // We're checking that trap should be emitted (i.e. it was compiled
151 // by C2) before the trap is fired, because otherwise the nmethod
152 // will be deoptimized and isMethodCompiledByC2 will return false.
153 shouldBeEmitted = isMethodCompiledByC2(testMethod)
154 && !compiledToEarly;
155 if (shouldBeFired) {
156 testMethod.invoke(null, !testCase.predicate);
157 }
158 } catch (ReflectiveOperationException e) {
159 throw new Error("Test case should be generated, loaded and executed"
160 + " without any issues.", e);
161 }
162
163 shouldBeFired &= shouldBeEmitted;
164
165 Properties properties = new Properties();
166 properties.setProperty(Verifier.VERIFICATION_SHOULD_BE_SKIPPED,
167 Boolean.toString(compiledToEarly));
168 properties.setProperty(Verifier.UNCOMMON_TRAP_SHOULD_EMITTED,
169 Boolean.toString(shouldBeEmitted));
170 properties.setProperty(Verifier.UNCOMMON_TRAP_SHOULD_FIRED,
171 Boolean.toString(shouldBeFired));
172 properties.setProperty(Verifier.UNCOMMON_TRAP_NAME, testCase.name);
173 properties.setProperty(Verifier.UNCOMMON_TRAP_COMMENT,
174 testCase.comment);
175 properties.setProperty(Verifier.UNCOMMON_TRAP_BCI,
176 Integer.toString(unstableIfLocation.getOffset()));
177
178 properties.list(System.out);
179
180 File f = new File(WB.getStringVMFlag("LogFile") +
181 Verifier.PROPERTIES_FILE_SUFFIX);
182 try (FileWriter wr = new FileWriter(f)) {
183 properties.store(wr, "");
184 } catch (IOException e) {
185 throw new Error("Unable to store test properties.", e);
186 }
187 }
188
189 private static boolean isMethodCompiledByC2(Method m) {
190 boolean isTiered = WB.getBooleanVMFlag("TieredCompilation");
191 boolean isMethodCompiled = WB.isMethodCompiled(m);
192 boolean isMethodCompiledAtMaxTier
193 = WB.getMethodCompilationLevel(m) == MAX_TIER;
194
195 return Platform.isServer() && isMethodCompiled
196 && (!isTiered || isMethodCompiledAtMaxTier);
197 }
198
199 /**
200 * Generates class with name {@code CLASS_NAME}, which will contain a
201 * static method {@code METHOD_NAME}:
202 *
203 * <pre>{@code
204 * public abstract class UnstableIfExecutable {
205 * private static int field = 0;
206 *
207 * public static void test(boolean alwaysTrue) {
208 * if (alwaysTrue) {
209 * field++;
210 * } else {
211 * field--;
212 * }
213 * }
214 * }
215 * }</pre>
216 *
217 * @return generated bytecode.
218 */
219 private static byte[] generateTest(Label unstableIfLocation) {
220 ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_FRAMES);
221
222 cw.visit(CLASS_FILE_VERSION, ACC_PUBLIC | ACC_ABSTRACT, CLASS_NAME,
223 null, "java/lang/Object", null);
224
225 cw.visitField(ACC_PUBLIC | ACC_STATIC | ACC_VOLATILE, FIELD_NAME,
226 "I", null, Integer.valueOf(0));
227
228 generateTestMethod(cw, unstableIfLocation);
229
230 return cw.toByteArray();
231 }
232
233 private static void generateTestMethod(ClassVisitor cv,
234 Label unstableIfLocation) {
235 MethodVisitor mv = cv.visitMethod(ACC_PUBLIC | ACC_STATIC, METHOD_NAME,
236 "(Z)V", null, null);
237 mv.visitCode();
238
239 Label end = new Label();
240 Label falseBranch = new Label();
241
242 // push "field" field's value and 1 to stack
243 mv.visitFieldInsn(GETSTATIC, CLASS_NAME, FIELD_NAME, "I");
244 mv.visitInsn(ICONST_1);
245 // load argument's value
246 mv.visitVarInsn(ILOAD, 0); // alwaysTrue
247 // here is our unstable if
248 mv.visitLabel(unstableIfLocation);
249 mv.visitJumpInsn(IFEQ, falseBranch);
250 // increment on "true"
251 mv.visitInsn(IADD);
252 mv.visitJumpInsn(GOTO, end);
253 // decrement on "false"
254 mv.visitLabel(falseBranch);
255 mv.visitInsn(ISUB);
256 mv.visitLabel(end);
257 // bye bye
258 mv.visitInsn(RETURN);
259
260 mv.visitMaxs(0, 0);
261 mv.visitEnd();
262 }
263 }
264