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da8308fe AM |
1 | package org.lttng.ust.agent.utils; |
2 | ||
3 | import java.io.IOException; | |
4 | import java.lang.ProcessBuilder.Redirect; | |
5 | import java.nio.file.Files; | |
6 | import java.nio.file.Path; | |
7 | import java.util.Arrays; | |
8 | import java.util.List; | |
9 | import java.util.stream.Collectors; | |
10 | ||
11 | public final class LttngSessionControl { | |
12 | ||
13 | private LttngSessionControl() {} | |
14 | ||
15 | public enum Domain { | |
16 | JUL("-j"), | |
17 | LOG4J("-l"); | |
18 | ||
19 | private final String flag; | |
20 | ||
21 | private Domain(String flag) { | |
22 | this.flag = flag; | |
23 | } | |
24 | ||
25 | public String flag() { | |
26 | return flag; | |
27 | } | |
28 | } | |
29 | ||
30 | // ------------------------------------------------------------------------ | |
31 | // Public utility methods | |
32 | // ------------------------------------------------------------------------ | |
33 | ||
34 | /** | |
35 | * Setup a LTTng session by enabling certain events (or none). | |
36 | * | |
37 | * @param sessionName | |
38 | * The name of the session to create. May be null to use the | |
39 | * default one from lttng-tools. | |
40 | * @param domain | |
41 | * The tracing domain | |
42 | * @param enabledEvents | |
43 | * The list of events to enable. May be null or empty, to not | |
44 | * enable any events. | |
45 | * @return If the command executed successfully (return code = 0). | |
46 | */ | |
47 | public static boolean setupSession(String sessionName, Domain domain, String... enabledEvents) { | |
48 | String[] createCommand = (sessionName == null ? | |
49 | new String[] { "lttng", "create" } : | |
50 | new String[] { "lttng", "create", sessionName} | |
51 | ); | |
52 | ||
53 | String eventsToEnable = (enabledEvents == null || enabledEvents.length == 0 ? | |
54 | /* | |
55 | * We have to enable a channel for 'lttng start' to work. | |
56 | * However, we cannot enable a channel directly, see | |
57 | * https://bugs.lttng.org/issues/894 . Instead we will enable an | |
58 | * event we know does not exist | |
59 | */ | |
60 | "non-event" : | |
61 | Arrays.stream(enabledEvents).collect(Collectors.joining(",")) | |
62 | ); | |
63 | ||
64 | return executeCommands(new String[][] { | |
65 | createCommand, | |
66 | { "lttng", "enable-event", domain.flag(), eventsToEnable}, | |
67 | { "lttng", "start" } | |
68 | }); | |
69 | } | |
70 | ||
71 | /** | |
72 | * Setup a LTTng session with all events enabled (lttng enable-event -a). | |
73 | * | |
74 | * @param sessionName | |
75 | * The name of the session to create. May be null to use the | |
76 | * default one from lttng-tools. | |
77 | * @param domain | |
78 | * The tracing domain | |
79 | * @return If the command executed successfully (return code = 0). | |
80 | */ | |
81 | public static boolean setupSessionAllEvents(String sessionName, Domain domain) { | |
82 | String[] createCommand = (sessionName == null ? | |
83 | new String[] { "lttng", "create" } : | |
84 | new String[] { "lttng", "create", sessionName} | |
85 | ); | |
86 | ||
87 | return executeCommands(new String[][] { | |
88 | createCommand, | |
89 | { "lttng", "enable-event", domain.flag(), "-a" }, | |
90 | { "lttng", "start" } | |
91 | }); | |
92 | } | |
93 | ||
94 | /** | |
95 | * Stop the current tracing session | |
96 | * | |
97 | * @return If the command executed successfully (return code = 0). | |
98 | */ | |
99 | public static boolean stopSession() { | |
100 | return executeCommand(new String[] { "lttng", "stop" }); | |
101 | } | |
102 | ||
103 | public static List<String> viewSession() { | |
104 | return getOutputFromCommand(new String[] { "lttng", "view" }); | |
105 | } | |
106 | ||
107 | /** | |
108 | * Destroy the current tracing session | |
109 | * | |
110 | * @return If the command executed successfully (return code = 0). | |
111 | */ | |
112 | public static boolean destroySession() { | |
113 | return executeCommand(new String[] { "lttng", "destroy" }); | |
114 | } | |
115 | ||
116 | // ------------------------------------------------------------------------ | |
117 | // Private helper methods | |
118 | // ------------------------------------------------------------------------ | |
119 | ||
120 | private static boolean executeCommands(String [][] commands) { | |
121 | for (String[] command : commands) { | |
122 | if (executeCommand(command) == false) { | |
123 | return false; | |
124 | } | |
125 | } | |
126 | return true; | |
127 | } | |
128 | ||
129 | /** | |
130 | * Just to test the environment / stdout are working correctly | |
131 | */ | |
132 | public static void main(String[] args) { | |
133 | executeCommand(new String[] {"ls", "-l"}); | |
134 | } | |
135 | ||
136 | private static boolean executeCommand(String[] command) { | |
137 | try { | |
138 | ProcessBuilder builder = new ProcessBuilder(command); | |
139 | builder.redirectErrorStream(true); | |
140 | builder.redirectOutput(Redirect.INHERIT); | |
141 | ||
142 | Process p = builder.start(); | |
143 | int ret = p.waitFor(); | |
144 | return (ret == 0); | |
145 | ||
146 | } catch (IOException | InterruptedException e) { | |
147 | return false; | |
148 | } | |
149 | } | |
150 | ||
151 | private static List<String> getOutputFromCommand(String[] command) { | |
152 | try { | |
153 | Path tempFile = Files.createTempFile("test-output", null); | |
154 | ||
155 | ProcessBuilder builder = new ProcessBuilder(command); | |
156 | builder.redirectErrorStream(true); | |
157 | builder.redirectOutput(Redirect.to(tempFile.toFile())); | |
158 | ||
159 | Process p = builder.start(); | |
160 | p.waitFor(); | |
161 | ||
162 | List<String> lines = Files.readAllLines(tempFile); | |
163 | Files.delete(tempFile); | |
164 | ||
165 | /* Also print the output to the console */ | |
166 | lines.stream().forEach(s -> System.out.println(s)); | |
167 | ||
168 | return lines; | |
169 | ||
170 | } catch (IOException | InterruptedException e) { | |
171 | return null; | |
172 | } | |
173 | } | |
174 | } |