| 1 | /* |
| 2 | * Copyright (C) 2013 - David Goulet <dgoulet@efficios.com> |
| 3 | * |
| 4 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
| 5 | * of this software and associated documentation files (the "Software"), to |
| 6 | * deal in the Software without restriction, including without limitation the |
| 7 | * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or |
| 8 | * sell copies of the Software, and to permit persons to whom the Software is |
| 9 | * furnished to do so, subject to the following conditions: |
| 10 | * |
| 11 | * The above copyright notice and this permission notice shall be included in |
| 12 | * all copies or substantial portions of the Software. |
| 13 | * |
| 14 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 15 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 16 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| 17 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 18 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| 19 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
| 20 | * IN THE SOFTWARE. |
| 21 | */ |
| 22 | |
| 23 | import java.io.IOException; |
| 24 | import java.util.logging.Level; |
| 25 | import java.util.logging.Logger; |
| 26 | |
| 27 | /* |
| 28 | * That's the import you need being the path in the liblttng-ust-jul Jar file. |
| 29 | */ |
| 30 | import org.lttng.ust.agent.LTTngAgent; |
| 31 | |
| 32 | public class Hello |
| 33 | { |
| 34 | /* Of course :) */ |
| 35 | private static final int answer = 42; |
| 36 | |
| 37 | /* |
| 38 | * Static reference to the LTTngAgent. Used to dispose of it at the end |
| 39 | * which is recommended but not mandatory to do. |
| 40 | */ |
| 41 | private static LTTngAgent lttngAgent; |
| 42 | |
| 43 | public static void main(String args[]) throws Exception |
| 44 | { |
| 45 | /* |
| 46 | * For this example, a custom "hello" logger is created. Note that JUL |
| 47 | * has a default "global" that can also be used. |
| 48 | */ |
| 49 | Logger helloLog = Logger.getLogger("hello"); |
| 50 | |
| 51 | /* |
| 52 | * Get the LTTngAgent singelton reference. This will also initialize |
| 53 | * the Agent and make it register to the session daemon if available. |
| 54 | * When this returns, the Agent is registered and fully ready. If no |
| 55 | * session daemon is found, it will return and retry every 3 seconds in |
| 56 | * the background. TCP is used for communication. |
| 57 | * |
| 58 | * Note that the LTTngAgent once registered is a seperate thread in |
| 59 | * your Java application. |
| 60 | */ |
| 61 | lttngAgent = LTTngAgent.getLTTngAgent(); |
| 62 | |
| 63 | /* |
| 64 | * Gives you time to do some lttng commands before any event is hit. |
| 65 | */ |
| 66 | Thread.sleep(5000); |
| 67 | |
| 68 | /* Trigger a tracing event using the JUL Logger created before. */ |
| 69 | helloLog.info("Hello World, the answer is " + answer); |
| 70 | |
| 71 | /* |
| 72 | * From this point on, the above message will be collected in the trace |
| 73 | * if the event "hello" is enabled for the JUL domain using the lttng |
| 74 | * command line or the lttng-ctl API. For instance: |
| 75 | * |
| 76 | * $ lttng enable-event -j hello |
| 77 | * |
| 78 | * A new logger is created here and fired after. The Agent has an |
| 79 | * internal timer that is fired every 5 seconds in order to enable |
| 80 | * events that were not found at first but might need to be enabled |
| 81 | * when new Logger appears. Unfortunately, there is no way right now to |
| 82 | * get notify of that so we have to actively poll. |
| 83 | * |
| 84 | * Using the --all command for instance, it will make this Logger |
| 85 | * available in a LTTng trace after the internal Agent's timer is |
| 86 | * fired. (lttng enable-event -a -j). |
| 87 | */ |
| 88 | Logger helloLogDelayed = Logger.getLogger("hello_delay"); |
| 89 | |
| 90 | System.out.println("Firing hello delay in 10 seconds..."); |
| 91 | Thread.sleep(10000); |
| 92 | helloLogDelayed.info("Hello World delayed..."); |
| 93 | |
| 94 | System.out.println("Cleaning Hello"); |
| 95 | |
| 96 | /* |
| 97 | * Again, this is highly recommended so the session daemon socket gets |
| 98 | * cleaned up explicitely but it is not mandatory to do this step. |
| 99 | */ |
| 100 | lttngAgent.dispose(); |
| 101 | } |
| 102 | } |