1 /*
2 * Copyright 2008-2010 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
24
25 import java.io.ByteArrayOutputStream;
26 import java.io.IOException;
27 import java.io.OutputStream;
28 import java.io.PrintWriter;
29 import java.io.StringWriter;
30
31 import java.lang.reflect.Method;
32 import java.net.URI;
33 import java.util.Arrays;
34 import java.util.Vector;
35
36 import javax.tools.Diagnostic;
37 import javax.tools.DiagnosticCollector;
38 import javax.tools.FileObject;
39 import javax.tools.ForwardingJavaFileManager;
40 import javax.tools.JavaCompiler;
41 import javax.tools.JavaCompiler.CompilationTask;
42 import javax.tools.JavaFileManager;
43 import javax.tools.JavaFileObject;
44 import javax.tools.JavaFileObject.Kind;
45 import javax.tools.SimpleJavaFileObject;
46 import javax.tools.StandardJavaFileManager;
47 import javax.tools.ToolProvider;
48
49 /*
50 * @test SortMethodsTest
51 * @bug 6925573
52 * @summary verify that class loading does not need quadratic time with regard to the number of class
53 methods.
54 * @run main SortMethodsTest
55 * @author volker.simonis@gmail.com
56 */
57
58 public class SortMethodsTest {
59
60 static String createClass(String name, int nrOfMethods) {
61 StringWriter sw = new StringWriter();
62 PrintWriter pw = new PrintWriter(sw);
63 pw.println("public class " + name + "{");
64 for (int i = 0; i < nrOfMethods; i++) {
65 pw.println(" public void m" + i + "() {}");
66 }
67 pw.println(" public static String sayHello() {");
68 pw.println(" return \"Hello from class \" + " + name +
69 ".class.getName() + \" with \" + " + name +
70 ".class.getDeclaredMethods().length + \" methods\";");
71 pw.println(" }");
72 pw.println("}");
73 pw.close();
74 return sw.toString();
75 }
76
77 public static void main(String args[]) {
78
79 JavaCompiler comp = ToolProvider.getSystemJavaCompiler();
80 DiagnosticCollector<JavaFileObject> diags = new DiagnosticCollector<JavaFileObject>();
81 final String cName = new String("ManyMethodsClass");
82 Vector<Long> results = new Vector<Long>();
83
84 for (int i = 6; i < 600000; i*=10) {
85 String klass = createClass(cName, i);
86 JavaMemoryFileObject file = new JavaMemoryFileObject(cName, klass);
87 MemoryFileManager mfm = new MemoryFileManager(comp.getStandardFileManager(diags, null, null), file);
88 CompilationTask task = comp.getTask(null, mfm, diags, null, null, Arrays.asList(file));
89
90 if (task.call()) {
91 try {
92 MemoryClassLoader mcl = new MemoryClassLoader(file);
93 long start = System.nanoTime();
94 Class<? extends Object> c = Class.forName(cName, true, mcl);
95 long end = System.nanoTime();
96 results.add(end - start);
97 Method m = c.getDeclaredMethod("sayHello", new Class[0]);
98 String ret = (String)m.invoke(null, new Object[0]);
99 System.out.println(ret + " (loaded and resloved in " + (end - start) + "ns)");
100 } catch (Exception e) {
101 System.err.println(e);
102 }
103 }
104 else {
105 System.out.println(klass);
106 System.out.println();
107 for (Diagnostic diag : diags.getDiagnostics()) {
108 System.out.println(diag.getCode() + "\n" + diag.getKind() + "\n" + diag.getPosition());
109 System.out.println(diag.getSource() + "\n" + diag.getMessage(null));
110 }
111 }
112 }
113
114 long lastRatio = 0;
115 for (int i = 2; i < results.size(); i++) {
116 long normalized1 = Math.max(results.get(i-1) - results.get(0), 1);
117 long normalized2 = Math.max(results.get(i) - results.get(0), 1);
118 long ratio = normalized2/normalized1;
119 lastRatio = ratio;
120 System.out.println("10 x more methods requires " + ratio + " x more time");
121 }
122 // The following is just vague estimation but seems to work on current x86_64 and sparcv9 machines
123 if (lastRatio > 80) {
124 throw new RuntimeException("ATTENTION: it seems that class loading needs quadratic time with regard to the number of class methods!!!");
125 }
126 }
127 }
128
129 class JavaMemoryFileObject extends SimpleJavaFileObject {
130
131 private final String code;
132 private ByteArrayOutputStream byteCode;
133
134 JavaMemoryFileObject(String name, String code) {
135 super(URI.create("string:///" + name.replace('.','/') + Kind.SOURCE.extension), Kind.SOURCE);
136 this.code = code;
137 }
138
139 @Override
140 public CharSequence getCharContent(boolean ignoreEncodingErrors) {
141 return code;
142 }
143
144 @Override
145 public OutputStream openOutputStream() {
146 byteCode = new ByteArrayOutputStream();
147 return byteCode;
148 }
149
150 byte[] getByteCode() {
151 return byteCode.toByteArray();
152 }
153 }
154
155 class MemoryClassLoader extends ClassLoader {
156
157 private final JavaMemoryFileObject jfo;
158
159 public MemoryClassLoader(JavaMemoryFileObject jfo) {
160 this.jfo = jfo;
161 }
162
163 public Class findClass(String name) {
164 byte[] b = jfo.getByteCode();
165 return defineClass(name, b, 0, b.length);
166 }
167 }
168
169 class MemoryFileManager extends ForwardingJavaFileManager<JavaFileManager> {
170
171 private final JavaFileObject jfo;
172
173 public MemoryFileManager(StandardJavaFileManager jfm, JavaFileObject jfo) {
174 super(jfm);
175 this.jfo = jfo;
176 }
177
178 @Override
179 public FileObject getFileForInput(Location location, String packageName,
180 String relativeName) throws IOException {
181 return jfo;
182 }
183
184 @Override
185 public JavaFileObject getJavaFileForOutput(Location location, String qualifiedName,
186 Kind kind, FileObject outputFile) throws IOException {
187 return jfo;
188 }
189
190 }