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8ab5c06b | 1 | /* |
c0c0989a | 2 | * SPDX-License-Identifier: MIT |
8ab5c06b | 3 | * |
c0c0989a MJ |
4 | * Copyright (C) 2016 EfficiOS Inc. |
5 | * Copyright (C) 2016 Alexandre Montplaisir <alexmonthy@efficios.com> | |
8ab5c06b AM |
6 | */ |
7 | ||
8 | import java.io.IOException; | |
9 | import java.util.logging.Handler; | |
10 | import java.util.logging.Logger; | |
11 | ||
12 | import org.lttng.ust.agent.context.ContextInfoManager; | |
13 | import org.lttng.ust.agent.context.IContextInfoRetriever; | |
14 | import org.lttng.ust.agent.jul.LttngLogHandler; | |
15 | ||
16 | /** | |
17 | * Example program defining a application context retriever, which allows | |
18 | * attaching application-defined contexts to trace events. | |
19 | * | |
20 | * FIXME Use custom context names, and several names/types | |
21 | * | |
22 | * <p> | |
23 | * Usage: | |
24 | * <ul> | |
25 | * <li>$ lttng create</li> | |
26 | * <li>$ lttng enable-event -j -a</li> | |
27 | * <li>$ lttng add-context -j -t '$app.myprovider:mystringcontext'</li> | |
28 | * <li>$ lttng add-context -j -t '$app.myprovider:myshortcontext'</li> | |
29 | * <li>$ lttng start</li> | |
30 | * <li>(run this program)</li> | |
31 | * <li>$ lttng stop</li> | |
32 | * <li>$ lttng view</li> | |
33 | * <li>$ lttng destroy</li> | |
34 | * </ul> | |
35 | * </p> | |
36 | * | |
37 | * The events present in the resulting trace should carry the context | |
38 | * information defined in the example retriever. | |
39 | * | |
40 | * @author Alexandre Montplaisir | |
41 | */ | |
42 | public class ApplicationContextExample { | |
43 | ||
44 | /** Class-wide JUL logger object */ | |
45 | private static final Logger LOGGER = Logger.getLogger(ApplicationContextExample.class.getName()); | |
46 | ||
47 | private static final String RETRIEVER_NAME = "myprovider"; | |
48 | private static final String CONTEXT_NAME_STRING = "mystringcontext"; | |
49 | private static final String CONTEXT_NAME_SHORT = "myshortcontext"; | |
50 | ||
51 | private static class ExampleContextInfoRetriever implements IContextInfoRetriever { | |
52 | ||
53 | @Override | |
54 | public Object retrieveContextInfo(String key) { | |
e01dcb20 | 55 | if (CONTEXT_NAME_SHORT.equals(key)) { |
8ab5c06b | 56 | return (short) 42; |
e01dcb20 | 57 | } else if (CONTEXT_NAME_STRING.equals(key)) { |
8ab5c06b | 58 | return "context-value!"; |
e01dcb20 | 59 | } else { |
8ab5c06b AM |
60 | return null; |
61 | } | |
62 | } | |
63 | ||
64 | } | |
65 | ||
66 | /** | |
67 | * Application start | |
68 | * | |
69 | * @param args | |
70 | * Command-line arguments | |
71 | * @throws IOException | |
72 | * @throws InterruptedException | |
73 | */ | |
74 | public static void main(String args[]) throws IOException, InterruptedException { | |
75 | /* Instantiate and attach a logger object */ | |
76 | Handler lttngHandler = new LttngLogHandler(); | |
77 | LOGGER.addHandler(lttngHandler); | |
78 | ||
79 | /* Instantiate and register the context retriever */ | |
80 | IContextInfoRetriever cir = new ExampleContextInfoRetriever(); | |
81 | ContextInfoManager.getInstance().registerContextInfoRetriever(RETRIEVER_NAME, cir); | |
82 | ||
83 | /* | |
84 | * Make sure you have a LTTng session running with the appropriate | |
85 | * events and contexts enabled! See the class Javadoc. | |
86 | */ | |
87 | ||
88 | /* Trigger a tracing event using the JUL Logger created before. */ | |
89 | LOGGER.info("Log event #1"); | |
90 | LOGGER.warning("Log event #2"); | |
91 | LOGGER.severe("Log event #3"); | |
92 | ||
93 | /* Unregister our context retriever, and dispose the log handler */ | |
94 | ContextInfoManager.getInstance().unregisterContextInfoRetriever(RETRIEVER_NAME); | |
95 | lttngHandler.close(); | |
96 | } | |
97 | } |