| 1 | package org.lttng.ust.agent.utils; |
| 2 | |
| 3 | import java.io.IOException; |
| 4 | import java.lang.ProcessBuilder.Redirect; |
| 5 | import java.nio.file.FileVisitResult; |
| 6 | import java.nio.file.Files; |
| 7 | import java.nio.file.Path; |
| 8 | import java.nio.file.Paths; |
| 9 | import java.nio.file.SimpleFileVisitor; |
| 10 | import java.nio.file.attribute.BasicFileAttributes; |
| 11 | import java.util.ArrayList; |
| 12 | import java.util.Arrays; |
| 13 | import java.util.List; |
| 14 | import java.util.stream.Collectors; |
| 15 | |
| 16 | public final class LttngSessionControl { |
| 17 | |
| 18 | private LttngSessionControl() {} |
| 19 | |
| 20 | public enum Domain { |
| 21 | JUL("-j"), |
| 22 | LOG4J("-l"); |
| 23 | |
| 24 | private final String flag; |
| 25 | |
| 26 | private Domain(String flag) { |
| 27 | this.flag = flag; |
| 28 | } |
| 29 | |
| 30 | public String flag() { |
| 31 | return flag; |
| 32 | } |
| 33 | } |
| 34 | |
| 35 | // ------------------------------------------------------------------------ |
| 36 | // Public utility methods |
| 37 | // ------------------------------------------------------------------------ |
| 38 | |
| 39 | /** |
| 40 | * Setup a LTTng session by enabling certain events (or none). |
| 41 | * |
| 42 | * @param sessionName |
| 43 | * The name of the session to create. May be null to use the |
| 44 | * default one from lttng-tools. |
| 45 | * @param domain |
| 46 | * The tracing domain |
| 47 | * @param enabledEvents |
| 48 | * The list of events to enable. May be null or empty, to not |
| 49 | * enable any events. |
| 50 | * @return If the command executed successfully (return code = 0). |
| 51 | */ |
| 52 | public static boolean setupSession(String sessionName, Domain domain, String... enabledEvents) { |
| 53 | String[] createCommand = (sessionName == null ? |
| 54 | new String[] { "lttng", "create" } : |
| 55 | new String[] { "lttng", "create", sessionName} |
| 56 | ); |
| 57 | |
| 58 | String eventsToEnable = (enabledEvents == null || enabledEvents.length == 0 ? |
| 59 | /* |
| 60 | * We have to enable a channel for 'lttng start' to work. |
| 61 | * However, we cannot enable a channel directly, see |
| 62 | * https://bugs.lttng.org/issues/894 . Instead we will enable an |
| 63 | * event we know does not exist |
| 64 | */ |
| 65 | "non-event" : |
| 66 | Arrays.stream(enabledEvents).collect(Collectors.joining(",")) |
| 67 | ); |
| 68 | |
| 69 | return executeCommands(new String[][] { |
| 70 | createCommand, |
| 71 | { "lttng", "enable-event", domain.flag(), eventsToEnable}, |
| 72 | { "lttng", "start" } |
| 73 | }); |
| 74 | } |
| 75 | |
| 76 | /** |
| 77 | * Setup a LTTng session with all events enabled (lttng enable-event -a). |
| 78 | * |
| 79 | * @param sessionName |
| 80 | * The name of the session to create. May be null to use the |
| 81 | * default one from lttng-tools. |
| 82 | * @param domain |
| 83 | * The tracing domain |
| 84 | * @return If the command executed successfully (return code = 0). |
| 85 | */ |
| 86 | public static boolean setupSessionAllEvents(String sessionName, Domain domain) { |
| 87 | String[] createCommand = (sessionName == null ? |
| 88 | new String[] { "lttng", "create" } : |
| 89 | new String[] { "lttng", "create", sessionName} |
| 90 | ); |
| 91 | |
| 92 | return executeCommands(new String[][] { |
| 93 | createCommand, |
| 94 | { "lttng", "enable-event", domain.flag(), "-a" }, |
| 95 | { "lttng", "start" } |
| 96 | }); |
| 97 | } |
| 98 | |
| 99 | /** |
| 100 | * Send a separate enable-event command. |
| 101 | * |
| 102 | * @param sessionName |
| 103 | * Name of the session in which to enable events. Use null for |
| 104 | * current session. |
| 105 | * @param domain |
| 106 | * The tracing domain |
| 107 | * @param enabledEvents |
| 108 | * The list of events to enable. Should not be null or empty |
| 109 | * @return If the command executed successfully (return code = 0). |
| 110 | */ |
| 111 | public static boolean enableEvents(String sessionName, Domain domain, String... enabledEvents) { |
| 112 | if (enabledEvents == null || enabledEvents.length == 0) { |
| 113 | throw new IllegalArgumentException(); |
| 114 | } |
| 115 | List<String> command = new ArrayList<String>(); |
| 116 | command.add("lttng"); |
| 117 | command.add("enable-event"); |
| 118 | command.add(domain.flag()); |
| 119 | command.add(Arrays.stream(enabledEvents).collect(Collectors.joining(","))); |
| 120 | if (sessionName != null) { |
| 121 | command.add("-s"); |
| 122 | command.add(sessionName); |
| 123 | } |
| 124 | return executeCommand(command.toArray(new String[0])); |
| 125 | } |
| 126 | |
| 127 | /** |
| 128 | * Send a disable-event command. Used to disable events that were previously |
| 129 | * enabled. |
| 130 | * |
| 131 | * @param sessionName |
| 132 | * Name of the session in which to disable events. Use null for |
| 133 | * current session. |
| 134 | * @param domain |
| 135 | * The tracing domain |
| 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 static boolean disableEvents(String sessionName, Domain domain, String... disabledEvents) { |
| 141 | if (disabledEvents == null || disabledEvents.length == 0) { |
| 142 | throw new IllegalArgumentException(); |
| 143 | } |
| 144 | List<String> command = new ArrayList<String>(); |
| 145 | command.add("lttng"); |
| 146 | command.add("disable-event"); |
| 147 | command.add(domain.flag()); |
| 148 | command.add(Arrays.stream(disabledEvents).collect(Collectors.joining(","))); |
| 149 | if (sessionName != null) { |
| 150 | command.add("-s"); |
| 151 | command.add(sessionName); |
| 152 | } |
| 153 | return executeCommand(command.toArray(new String[0])); |
| 154 | } |
| 155 | |
| 156 | /** |
| 157 | * Stop the current tracing session |
| 158 | * |
| 159 | * @param sessionName |
| 160 | * The name of the session to stop. Use null for the current |
| 161 | * session. |
| 162 | * @return If the command executed successfully (return code = 0). |
| 163 | */ |
| 164 | public static boolean stopSession(String sessionName) { |
| 165 | List<String> command = new ArrayList<String>(); |
| 166 | command.add("lttng"); |
| 167 | command.add("stop"); |
| 168 | if (sessionName != null) { |
| 169 | command.add(sessionName); |
| 170 | } |
| 171 | return executeCommand(command.toArray(new String[0])); |
| 172 | } |
| 173 | |
| 174 | /** |
| 175 | * Issue a "lttng view" command on the provided session, and returns its |
| 176 | * output. This effectively returns the current content of the trace in text |
| 177 | * form. |
| 178 | * |
| 179 | * @param sessionName |
| 180 | * The name of the session to print. Use null for the current |
| 181 | * session. |
| 182 | * @return The output of Babeltrace on the session's current trace |
| 183 | */ |
| 184 | public static List<String> viewSession(String sessionName) { |
| 185 | List<String> command = new ArrayList<String>(); |
| 186 | command.add("lttng"); |
| 187 | command.add("view"); |
| 188 | if (sessionName != null) { |
| 189 | command.add(sessionName); |
| 190 | } |
| 191 | return getOutputFromCommand(command.toArray(new String[0])); |
| 192 | } |
| 193 | |
| 194 | /** |
| 195 | * Destroy the current tracing session |
| 196 | * |
| 197 | * @param sessionName |
| 198 | * The name of the session to destroy. Use null for the current |
| 199 | * session. |
| 200 | * @return If the command executed successfully (return code = 0). |
| 201 | */ |
| 202 | public static boolean destroySession(String sessionName) { |
| 203 | List<String> command = new ArrayList<String>(); |
| 204 | command.add("lttng"); |
| 205 | command.add("destroy"); |
| 206 | if (sessionName != null) { |
| 207 | command.add(sessionName); |
| 208 | } |
| 209 | return executeCommand(command.toArray(new String[0])); |
| 210 | } |
| 211 | |
| 212 | /** |
| 213 | * Try destroying the given tracing session, fail silently if there is no |
| 214 | * session. |
| 215 | * |
| 216 | * @param sessionName |
| 217 | * The name of the session to destroy. Use null for the current |
| 218 | * session. |
| 219 | */ |
| 220 | public static void tryDestroySession(String sessionName) { |
| 221 | getOutputFromCommand(false, new String[] { "lttng", "destroy" }); |
| 222 | } |
| 223 | |
| 224 | /** |
| 225 | * Outside of the scope of lttng-tools, but this utility method can be used |
| 226 | * to delete all traces currently under ~/lttng-traces/. This can be used by |
| 227 | * tests to cleanup a trace they have created. |
| 228 | * |
| 229 | * @return True if the command completes successfully, false if there was an |
| 230 | * error. |
| 231 | */ |
| 232 | public static boolean deleteAllTracee() { |
| 233 | String tracesDir = new String(System.getProperty("user.home") + "/lttng-traces/"); |
| 234 | return deleteDirectory(Paths.get(tracesDir)); |
| 235 | } |
| 236 | |
| 237 | private static boolean deleteDirectory(Path directory) { |
| 238 | try { |
| 239 | Files.walkFileTree(directory, new SimpleFileVisitor<Path>() { |
| 240 | @Override |
| 241 | public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException { |
| 242 | Files.delete(file); |
| 243 | return FileVisitResult.CONTINUE; |
| 244 | } |
| 245 | |
| 246 | @Override |
| 247 | public FileVisitResult postVisitDirectory(Path dir, IOException exc) throws IOException { |
| 248 | Files.delete(dir); |
| 249 | return FileVisitResult.CONTINUE; |
| 250 | } |
| 251 | }); |
| 252 | } catch (IOException e) { |
| 253 | /* At least we tried... */ |
| 254 | return false; |
| 255 | } |
| 256 | return true; |
| 257 | } |
| 258 | |
| 259 | // ------------------------------------------------------------------------ |
| 260 | // Private helper methods |
| 261 | // ------------------------------------------------------------------------ |
| 262 | |
| 263 | private static boolean executeCommands(String [][] commands) { |
| 264 | for (String[] command : commands) { |
| 265 | if (executeCommand(command) == false) { |
| 266 | return false; |
| 267 | } |
| 268 | } |
| 269 | return true; |
| 270 | } |
| 271 | |
| 272 | /** |
| 273 | * Just to test the environment / stdout are working correctly |
| 274 | */ |
| 275 | public static void main(String[] args) { |
| 276 | executeCommand(new String[] {"ls", "-l"}); |
| 277 | } |
| 278 | |
| 279 | private static boolean executeCommand(String[] command) { |
| 280 | try { |
| 281 | ProcessBuilder builder = new ProcessBuilder(command); |
| 282 | builder.redirectErrorStream(true); |
| 283 | builder.redirectOutput(Redirect.INHERIT); |
| 284 | |
| 285 | Process p = builder.start(); |
| 286 | int ret = p.waitFor(); |
| 287 | return (ret == 0); |
| 288 | |
| 289 | } catch (IOException | InterruptedException e) { |
| 290 | return false; |
| 291 | } |
| 292 | } |
| 293 | |
| 294 | private static List<String> getOutputFromCommand(String[] command) { |
| 295 | return getOutputFromCommand(true, command); |
| 296 | } |
| 297 | |
| 298 | private static List<String> getOutputFromCommand(boolean print, String[] command) { |
| 299 | try { |
| 300 | Path tempFile = Files.createTempFile("test-output", null); |
| 301 | |
| 302 | ProcessBuilder builder = new ProcessBuilder(command); |
| 303 | builder.redirectErrorStream(true); |
| 304 | builder.redirectOutput(Redirect.to(tempFile.toFile())); |
| 305 | |
| 306 | Process p = builder.start(); |
| 307 | p.waitFor(); |
| 308 | |
| 309 | List<String> lines = Files.readAllLines(tempFile); |
| 310 | Files.delete(tempFile); |
| 311 | |
| 312 | if (print) { |
| 313 | /* Also print the output to the console */ |
| 314 | lines.stream().forEach(s -> System.out.println(s)); |
| 315 | } |
| 316 | |
| 317 | return lines; |
| 318 | |
| 319 | } catch (IOException | InterruptedException e) { |
| 320 | return null; |
| 321 | } |
| 322 | } |
| 323 | } |