liblttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/client/ILttngTcpClientListener.java

   1 /*
   2  * Copyright (C) 2015 - EfficiOS Inc., Alexandre Montplaisir <alexmonthy@efficios.com>
   3  *
   4  * This library is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU Lesser General Public License, version 2.1 only,
   6  * as published by the Free Software Foundation.
   7  *
   8  * This library is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
  11  * for more details.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public License
  14  * along with this library; if not, write to the Free Software Foundation,
  15  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  16  */
  17
  18 package org.lttng.ust.agent.client;
  19
  20 /**
  21  * TCP client listener interface.
  22  *
  23  * This interface contains callbacks that are called when the TCP client
  24  * receives commands from the session daemon. These callbacks will define what
  25  * do to with each command.
  26  *
  27  * @author Alexandre Montplaisir
  28  */
  29 public interface ILttngTcpClientListener {
  30
  31         /**
  32          * Callback for the TCP client to notify the listener agent that a request
  33          * for enabling an event was sent from the session daemon.
  34          *
  35          * @param eventName
  36          *            The name of the event that was requested to be enabled.
  37          * @return Since we do not track individual sessions, right now this command
  38          *         cannot fail. It will always return true.
  39          */
  40         boolean eventEnabled(String eventName);
  41
  42         /**
  43          * Callback for the TCP client to notify the listener agent that a request
  44          * for disabling an event was sent from the session daemon.
  45          *
  46          * @param eventName
  47          *            The name of the event that was requested to be disabled.
  48          * @return True if the command completed successfully, false if we should
  49          *         report an error (event was not enabled, etc.)
  50          */
  51         boolean eventDisabled(String eventName);
  52
  53         /**
  54          * List the all events currently enabled in the current tracing sessions.
  55          *
  56          * @return The list of enabled events
  57          */
  58         Iterable<String> listEnabledEvents();
  59 }