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2b408e85 AM |
1 | /* |
2 | * Copyright (C) 2015, EfficiOS Inc., Alexandre Montplaisir <alexmonthy@efficios.com> | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation; either version 2 of the License, or | |
7 | * (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License along | |
15 | * with this program; if not, write to the Free Software Foundation, Inc., | |
16 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. | |
17 | */ | |
18 | ||
8576633f AM |
19 | package org.lttng.ust.agent.utils; |
20 | ||
21 | import java.io.IOException; | |
22 | import java.lang.ProcessBuilder.Redirect; | |
23 | import java.nio.file.FileVisitResult; | |
24 | import java.nio.file.Files; | |
25 | import java.nio.file.Path; | |
26 | import java.nio.file.Paths; | |
27 | import java.nio.file.SimpleFileVisitor; | |
28 | import java.nio.file.attribute.BasicFileAttributes; | |
29 | import java.util.Arrays; | |
30 | import java.util.List; | |
31 | import java.util.UUID; | |
32 | import java.util.stream.Collectors; | |
33 | ||
8a0613fa AM |
34 | /** |
35 | * Java representation of a LTTng tracing session. It uses the command-line | |
36 | * "lttng" tool to manipulate the session. Creating an instance will run | |
37 | * "lttng create", close()'ing it will run "lttng destroy". | |
38 | * | |
39 | * @author Alexandre Montplaisir | |
40 | */ | |
8576633f AM |
41 | public class LttngSession implements AutoCloseable { |
42 | ||
8a0613fa AM |
43 | /** |
44 | * Tracing domains as they are defined by lttng-tools | |
45 | */ | |
8576633f | 46 | public enum Domain { |
8a0613fa AM |
47 | /** The JUL (java.util.logging) domain */ |
48 | JUL("-j"), /** The log4j (org.apache.log4j) domain */ | |
8576633f AM |
49 | LOG4J("-l"); |
50 | ||
51 | private final String flag; | |
52 | ||
53 | private Domain(String flag) { | |
54 | this.flag = flag; | |
55 | } | |
56 | ||
8a0613fa AM |
57 | /** |
58 | * @return The corresponding command-line flag to pass to options like | |
59 | * "lttng enable-event" | |
60 | */ | |
8576633f AM |
61 | public String flag() { |
62 | return flag; | |
63 | } | |
64 | } | |
65 | ||
66 | private final String sessionName; | |
67 | private final Domain domain; | |
68 | ||
69 | private volatile boolean channelCreated = false; | |
70 | ||
8a0613fa AM |
71 | /** |
72 | * Constructor to create a new LTTng tracing session. | |
73 | * | |
74 | * @param sessionName | |
75 | * The name of the session to use. It can be null, in which case | |
76 | * we will provide a unique random name. | |
77 | * @param domain | |
78 | * The tracing domain of this session | |
79 | */ | |
8576633f AM |
80 | public LttngSession(String sessionName, Domain domain) { |
81 | if (sessionName != null) { | |
82 | this.sessionName = sessionName; | |
83 | } else { | |
84 | this.sessionName = UUID.randomUUID().toString(); | |
85 | } | |
86 | this.domain = domain; | |
87 | ||
88 | /* Create the session in LTTng */ | |
89 | executeCommand(Arrays.asList("lttng", "create", this.sessionName)); | |
90 | } | |
91 | ||
92 | @Override | |
93 | public void close() { | |
94 | /* Destroy the session */ | |
95 | executeCommand(Arrays.asList("lttng", "destroy", sessionName)); | |
96 | // FIXME also delete the trace we generated ? | |
97 | } | |
98 | ||
99 | // ------------------------------------------------------------------------ | |
100 | // Public methods | |
101 | // ------------------------------------------------------------------------ | |
102 | ||
103 | /** | |
104 | * Enable all events in the given session (enable-event -a) | |
105 | * | |
106 | * @return If the command executed successfully (return code = 0). | |
107 | */ | |
108 | public boolean enableAllEvents() { | |
109 | channelCreated = true; | |
110 | return executeCommand(Arrays.asList( | |
111 | "lttng", "enable-event", domain.flag(), "-a", "-s", sessionName)); | |
112 | } | |
113 | ||
114 | /** | |
115 | * Enable individual event(s). | |
116 | * | |
117 | * @param enabledEvents | |
118 | * The list of events to enable. Should not be null or empty | |
119 | * @return If the command executed successfully (return code = 0). | |
120 | */ | |
121 | public boolean enableEvents(String... enabledEvents) { | |
122 | if (enabledEvents == null || enabledEvents.length == 0) { | |
123 | throw new IllegalArgumentException(); | |
124 | } | |
125 | channelCreated = true; | |
126 | return executeCommand(Arrays.asList( | |
127 | "lttng", "enable-event", domain.flag(), | |
128 | Arrays.stream(enabledEvents).collect(Collectors.joining(",")), | |
129 | "-s", sessionName)); | |
130 | } | |
131 | ||
132 | /** | |
133 | * Send a disable-event command. Used to disable events that were previously | |
134 | * enabled. | |
135 | * | |
136 | * @param disabledEvents | |
137 | * The list of disabled events. Should not be null or empty | |
138 | * @return If the command executed successfully (return code = 0). | |
139 | */ | |
140 | public boolean disableEvents(String... disabledEvents) { | |
141 | if (disabledEvents == null || disabledEvents.length == 0) { | |
142 | throw new IllegalArgumentException(); | |
143 | } | |
144 | return executeCommand(Arrays.asList( | |
145 | "lttng", "disable-event", domain.flag(), | |
146 | Arrays.stream(disabledEvents).collect(Collectors.joining(",")), | |
147 | "-s", sessionName)); | |
148 | } | |
149 | ||
8a0613fa AM |
150 | /** |
151 | * Start tracing | |
152 | * | |
153 | * @return If the command executed successfully (return code = 0). | |
154 | */ | |
8576633f AM |
155 | public boolean start() { |
156 | /* | |
157 | * We have to enable a channel for 'lttng start' to work. However, we | |
158 | * cannot enable a channel directly, see | |
159 | * https://bugs.lttng.org/issues/894 . Instead we will enable an event | |
160 | * we know does not exist | |
161 | */ | |
162 | if (!channelCreated) { | |
163 | enableEvents("non-event"); | |
164 | } | |
165 | return executeCommand(Arrays.asList("lttng", "start", sessionName)); | |
166 | } | |
167 | ||
168 | /** | |
169 | * Stop the tracing session | |
170 | * | |
171 | * @return If the command executed successfully (return code = 0). | |
172 | */ | |
173 | public boolean stop() { | |
174 | return executeCommand(Arrays.asList("lttng", "stop", sessionName)); | |
175 | } | |
176 | ||
177 | /** | |
178 | * Issue a "lttng view" command on the session, and returns its output. This | |
179 | * effectively returns the current content of the trace in text form. | |
180 | * | |
181 | * @return The output of Babeltrace on the session's current trace | |
182 | */ | |
183 | public List<String> view() { | |
24b260d9 | 184 | return MiscTestUtils.getOutputFromCommand(Arrays.asList("lttng", "view", sessionName)); |
8576633f AM |
185 | } |
186 | ||
e41ec02a AM |
187 | /** |
188 | * Utility method to destroy all existing sessions. Useful when first | |
189 | * setting up a test to make sure no existing session interferes. | |
190 | */ | |
191 | public static void destroyAllSessions() { | |
192 | executeCommand(Arrays.asList("lttng", "destroy", "-a")); | |
193 | } | |
194 | ||
8576633f AM |
195 | /** |
196 | * Outside of the scope of lttng-tools, but this utility method can be used | |
197 | * to delete all traces currently under ~/lttng-traces/. This can be used by | |
198 | * tests to cleanup a trace they have created. | |
199 | * | |
200 | * @return True if the command completes successfully, false if there was an | |
201 | * error. | |
202 | */ | |
203 | public static boolean deleteAllTracee() { | |
204 | String tracesDir = new String(System.getProperty("user.home") + "/lttng-traces/"); | |
205 | return deleteDirectory(Paths.get(tracesDir)); | |
206 | } | |
207 | ||
208 | // ------------------------------------------------------------------------ | |
209 | // Private helper methods | |
210 | // ------------------------------------------------------------------------ | |
211 | ||
212 | private static boolean deleteDirectory(Path directory) { | |
213 | try { | |
214 | Files.walkFileTree(directory, new SimpleFileVisitor<Path>() { | |
215 | @Override | |
216 | public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException { | |
217 | Files.delete(file); | |
218 | return FileVisitResult.CONTINUE; | |
219 | } | |
220 | ||
221 | @Override | |
222 | public FileVisitResult postVisitDirectory(Path dir, IOException exc) throws IOException { | |
223 | Files.delete(dir); | |
224 | return FileVisitResult.CONTINUE; | |
225 | } | |
226 | }); | |
227 | } catch (IOException e) { | |
228 | /* At least we tried... */ | |
229 | return false; | |
230 | } | |
231 | return true; | |
232 | } | |
233 | ||
234 | /** | |
8a0613fa AM |
235 | * Simple command to test that the environment / stdout are working |
236 | * correctly. | |
237 | * | |
238 | * @param args | |
239 | * Command-line arguments | |
8576633f AM |
240 | */ |
241 | public static void main(String[] args) { | |
242 | List<String> command = Arrays.asList("ls", "-l"); | |
243 | executeCommand(command); | |
244 | } | |
245 | ||
246 | private static boolean executeCommand(List<String> command) { | |
247 | try { | |
248 | ProcessBuilder builder = new ProcessBuilder(command); | |
249 | builder.redirectErrorStream(true); | |
250 | builder.redirectOutput(Redirect.INHERIT); | |
251 | ||
252 | Process p = builder.start(); | |
253 | int ret = p.waitFor(); | |
254 | return (ret == 0); | |
255 | ||
256 | } catch (IOException | InterruptedException e) { | |
257 | return false; | |
258 | } | |
259 | } | |
260 | } |