LoggerRuntime.java
1/*******************************************************************************
2 * Copyright (c) 2009, 2010 Mountainminds GmbH & Co. KG and Contributors
3 * All rights reserved. This program and the accompanying materials
4 * are made available under the terms of the Eclipse Public License v1.0
5 * which accompanies this distribution, and is available at
6 * http://www.eclipse.org/legal/epl-v10.html
7 *
8 * Contributors:
9 * Marc R. Hoffmann - initial API and implementation
10 *
11 * $Id: $
12 *******************************************************************************/
13package org.jacoco.core.runtime;
14
15import java.util.logging.Handler;
16import java.util.logging.Level;
17import java.util.logging.LogRecord;
18import java.util.logging.Logger;
19
20import org.jacoco.core.instr.InstrSupport;
21import org.objectweb.asm.MethodVisitor;
22import org.objectweb.asm.Opcodes;
23
24/**
25 * This {@link IRuntime} implementation uses the Java logging API to report
26 * coverage data.
27 * <p>
28 *
29 * The implementation uses a dedicated log channel. Instrumented classes call
30 * {@link Logger#log(Level, String, Object[])} with the class identifier in the
31 * first slot of the parameter array. The runtime implements a {@link Handler}
32 * for this channel that puts the probe data structure into the first slot of
33 * the parameter array.
34 *
35 * @author Marc R. Hoffmann
36 * @version $Revision: $
37 */
38public class LoggerRuntime extends AbstractRuntime {
39
40 private static final String CHANNEL = "jacoco-runtime";
41
42 private final String key;
43
44 private final Logger logger;
45
46 private final Handler handler;
47
48 /**
49 * Creates a new runtime.
50 */
51 public LoggerRuntime() {
52 this.key = Integer.toHexString(hashCode());
53 this.logger = configureLogger();
54 this.handler = new RuntimeHandler();
55 }
56
57 private Logger configureLogger() {
58 final Logger l = Logger.getLogger(CHANNEL);
59 l.setUseParentHandlers(false);
60 l.setLevel(Level.ALL);
61 return l;
62 }
63
64 public int generateDataAccessor(final long classid, final String classname,
65 final int probecount, final MethodVisitor mv) {
66
67 // The data accessor performs the following steps:
68 //
69 // final Object[] args = new Object[3];
70 // args[0] = Long.valueOf(classid);
71 // args[1] = classname;
72 // args[2] = Integer.valueOf(probecount);
73 // Logger.getLogger(CHANNEL).log(Level.INFO, key, args);
74 // final byte[] probedata = (byte[]) args[0];
75 //
76 // Note that local variable 'args' is used at two places. As were not
77 // allowed to allocate local variables we have to keep this value with
78 // DUP and SWAP operations on the operand stack.
79
80 // 1. Create parameter array:
81
82 ExecutionDataAccess.generateArgumentArray(classid, classname,
83 probecount, mv);
84
85 // Stack[0]: [Ljava/lang/Object;
86
87 mv.visitInsn(Opcodes.DUP);
88
89 // Stack[1]: [Ljava/lang/Object;
90 // Stack[0]: [Ljava/lang/Object;
91
92 // 2. Call Logger:
93
94 mv.visitLdcInsn(CHANNEL);
95 mv.visitMethodInsn(Opcodes.INVOKESTATIC, "java/util/logging/Logger",
96 "getLogger", "(Ljava/lang/String;)Ljava/util/logging/Logger;");
97
98 // Stack[2]: Ljava/util/logging/Logger;
99 // Stack[1]: [Ljava/lang/Object;
100 // Stack[0]: [Ljava/lang/Object;
101
102 mv.visitInsn(Opcodes.SWAP);
103
104 // Stack[2]: [Ljava/lang/Object;
105 // Stack[1]: Ljava/util/logging/Logger;
106 // Stack[0]: [Ljava/lang/Object;
107
108 mv.visitFieldInsn(Opcodes.GETSTATIC, "java/util/logging/Level", "INFO",
109 "Ljava/util/logging/Level;");
110
111 // Stack[3]: Ljava/util/logging/Level;
112 // Stack[2]: [Ljava/lang/Object;
113 // Stack[1]: Ljava/util/logging/Logger;
114 // Stack[0]: [Ljava/lang/Object;
115
116 mv.visitInsn(Opcodes.SWAP);
117
118 // Stack[3]: [Ljava/lang/Object;
119 // Stack[2]: Ljava/util/logging/Level;
120 // Stack[1]: Ljava/util/logging/Logger;
121 // Stack[0]: [Ljava/lang/Object;
122
123 mv.visitLdcInsn(key);
124
125 // Stack[4]: Ljava/lang/String;
126 // Stack[3]: [Ljava/lang/Object;
127 // Stack[2]: Ljava/util/logging/Level;
128 // Stack[1]: Ljava/util/logging/Logger;
129 // Stack[0]: [Ljava/lang/Object;
130
131 mv.visitInsn(Opcodes.SWAP);
132
133 // Stack[4]: [Ljava/lang/Object;
134 // Stack[3]: Ljava/lang/String;
135 // Stack[2]: Ljava/util/logging/Level;
136 // Stack[1]: Ljava/util/logging/Logger;
137 // Stack[0]: [Ljava/lang/Object;
138
139 mv
140 .visitMethodInsn(Opcodes.INVOKEVIRTUAL,
141 "java/util/logging/Logger", "log",
142 "(Ljava/util/logging/Level;Ljava/lang/String;[Ljava/lang/Object;)V");
143
144 // Stack[0]: [Ljava/lang/Object;
145
146 // 3. Load data structure from parameter array:
147
148 mv.visitInsn(Opcodes.ICONST_0);
149 mv.visitInsn(Opcodes.AALOAD);
150 mv.visitTypeInsn(Opcodes.CHECKCAST, InstrSupport.DATAFIELD_DESC);
151
152 // Stack[0]: [Z
153
154 return 5; // Maximum local stack size is 5
155 }
156
157 public void startup() {
158 this.logger.addHandler(handler);
159 }
160
161 public void shutdown() {
162 this.logger.removeHandler(handler);
163 }
164
165 private class RuntimeHandler extends Handler {
166
167 @Override
168 public void publish(final LogRecord record) {
169 if (key.equals(record.getMessage())) {
170 access.getExecutionData(record.getParameters());
171 }
172 }
173
174 @Override
175 public void flush() {
176 }
177
178 @Override
179 public void close() throws SecurityException {
180 // The Java logging framework removes and closes all handlers on JVM
181 // shutdown. As soon as our handler has been removed, all classes
182 // that might get instrumented during shutdown (e.g. loaded by other
183 // shutdown hooks) will fail to initialize. Therefore we add ourself
184 // again here. This is a nasty hack that might fail in some Java
185 // implementations.
186 logger.addHandler(handler);
187 }
188 }
189
190}