lttng-tools-java/src/main/java/org/lttng/tools/LttngCommandLineSession.java

   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
  19 package org.lttng.tools;
  20
  21 import static org.lttng.tools.utils.ShellUtils.executeCommand;
  22
  23 import java.util.ArrayList;
  24 import java.util.Arrays;
  25 import java.util.List;
  26 import java.util.UUID;
  27 import java.util.stream.Collectors;
  28
  29 import org.lttng.tools.utils.ShellUtils;
  30
  31 /**
  32  * Implementation of {@link ILttngSession} which uses the command-line "lttng"
  33  * tool to manipulate the session. Creating an instance will run "lttng create",
  34  * close()'ing it will run "lttng destroy".
  35  *
  36  * @author Alexandre Montplaisir
  37  */
  38 class LttngCommandLineSession implements ILttngSession {
  39
  40     private final String sessionName;
  41     private final Domain domain;
  42
  43     private volatile boolean channelCreated = false;
  44
  45     /**
  46      * Constructor to create a new LTTng tracing session.
  47      *
  48      * @param sessionName
  49      *            The name of the session to use. It can be null, in which case
  50      *            we will provide a unique random name.
  51      * @param domain
  52      *            The tracing domain of this session
  53      */
  54     public LttngCommandLineSession(String sessionName, Domain domain) {
  55         if (sessionName != null) {
  56             this.sessionName = sessionName;
  57         } else {
  58             this.sessionName = UUID.randomUUID().toString();
  59         }
  60         this.domain = domain;
  61
  62         /* Create the session in LTTng */
  63         executeCommand(Arrays.asList("lttng", "create", this.sessionName));
  64     }
  65
  66     @Override
  67     public void close() {
  68         /* Destroy the session */
  69         executeCommand(Arrays.asList("lttng", "destroy", sessionName));
  70      // FIXME also delete the trace we generated ?
  71     }
  72
  73     @Override
  74     public boolean enableEvent(String eventName, String loglevel, boolean loglevelOnly, String filter) {
  75         channelCreated = true;
  76
  77         List<String> command = new ArrayList<>();
  78         command.add("lttng");
  79         command.add("enable-event");
  80         command.add(domain.flag());
  81         command.add(eventName);
  82
  83         if (loglevel != null) {
  84             if (loglevelOnly) {
  85                 command.add("--loglevel-only");
  86             } else {
  87                 command.add("--loglevel");
  88             }
  89             command.add(loglevel);
  90         }
  91
  92         if (filter != null) {
  93             command.add("--filter");
  94             command.add(filter);
  95         }
  96
  97         command.add("-s");
  98         command.add(sessionName);
  99
 100         return executeCommand(command);
 101     }
 102
 103     @Override
 104     public boolean enableAllEvents() {
 105         channelCreated = true;
 106         return executeCommand(Arrays.asList(
 107                 "lttng", "enable-event", domain.flag(), "-a", "-s", sessionName));
 108     }
 109
 110     @Override
 111     public boolean enableEvents(String... enabledEvents) {
 112         if (enabledEvents == null || enabledEvents.length == 0) {
 113             throw new IllegalArgumentException();
 114         }
 115         channelCreated = true;
 116         return executeCommand(Arrays.asList(
 117                 "lttng", "enable-event", domain.flag(),
 118                 Arrays.stream(enabledEvents).collect(Collectors.joining(",")),
 119                 "-s", sessionName));
 120     }
 121
 122     @Override
 123     public boolean disableEvents(String... disabledEvents) {
 124         if (disabledEvents == null || disabledEvents.length == 0) {
 125             throw new IllegalArgumentException();
 126         }
 127         return executeCommand(Arrays.asList(
 128                 "lttng", "disable-event", domain.flag(),
 129                 Arrays.stream(disabledEvents).collect(Collectors.joining(",")),
 130                 "-s", sessionName));
 131     }
 132
 133     @Override
 134     public boolean disableAllEvents() {
 135         return executeCommand(Arrays.asList(
 136                 "lttng", "disable-event", domain.flag(), "-a", "-s", sessionName));
 137     }
 138
 139     @Override
 140     public boolean start() {
 141         /*
 142          * We have to enable a channel for 'lttng start' to work. However, we
 143          * cannot enable a channel directly, see
 144          * https://bugs.lttng.org/issues/894 . Instead we will enable an event
 145          * we know does not exist
 146          */
 147         if (!channelCreated) {
 148             enableEvents("non-event");
 149         }
 150         return executeCommand(Arrays.asList("lttng", "start", sessionName));
 151     }
 152
 153     @Override
 154     public boolean stop() {
 155         return executeCommand(Arrays.asList("lttng", "stop", sessionName));
 156     }
 157
 158     @Override
 159     public List<String> view() {
 160         return ShellUtils.getOutputFromCommand(true, Arrays.asList("lttng", "view", sessionName));
 161     }
 162 }