package org.lttng.ust.agent.utils;
+import static org.lttng.ust.agent.utils.ShellUtils.executeCommand;
+
import java.io.IOException;
-import java.lang.ProcessBuilder.Redirect;
import java.nio.file.FileVisitResult;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.UUID;
import java.util.stream.Collectors;
+/**
+ * Java representation of a LTTng tracing session. It uses the command-line
+ * "lttng" tool to manipulate the session. Creating an instance will run
+ * "lttng create", close()'ing it will run "lttng destroy".
+ *
+ * @author Alexandre Montplaisir
+ */
public class LttngSession implements AutoCloseable {
+ /**
+ * Tracing domains as they are defined by lttng-tools
+ */
public enum Domain {
- JUL("-j"),
+ /** The JUL (java.util.logging) domain */
+ JUL("-j"), /** The log4j (org.apache.log4j) domain */
LOG4J("-l");
private final String flag;
this.flag = flag;
}
+ /**
+ * @return The corresponding command-line flag to pass to options like
+ * "lttng enable-event"
+ */
public String flag() {
return flag;
}
private volatile boolean channelCreated = false;
+ /**
+ * Constructor to create a new LTTng tracing session.
+ *
+ * @param sessionName
+ * The name of the session to use. It can be null, in which case
+ * we will provide a unique random name.
+ * @param domain
+ * The tracing domain of this session
+ */
public LttngSession(String sessionName, Domain domain) {
if (sessionName != null) {
this.sessionName = sessionName;
"-s", sessionName));
}
+ /**
+ * Start tracing
+ *
+ * @return If the command executed successfully (return code = 0).
+ */
public boolean start() {
/*
* We have to enable a channel for 'lttng start' to work. However, we
* @return The output of Babeltrace on the session's current trace
*/
public List<String> view() {
- return MiscTestUtils.getOutputFromCommand(Arrays.asList("lttng", "view", sessionName));
+ return ShellUtils.getOutputFromCommand(true, Arrays.asList("lttng", "view", sessionName));
}
/**
return true;
}
- /**
- * Just to test the environment / stdout are working correctly
- */
- public static void main(String[] args) {
- List<String> command = Arrays.asList("ls", "-l");
- executeCommand(command);
- }
-
- private static boolean executeCommand(List<String> command) {
- try {
- ProcessBuilder builder = new ProcessBuilder(command);
- builder.redirectErrorStream(true);
- builder.redirectOutput(Redirect.INHERIT);
-
- Process p = builder.start();
- int ret = p.waitFor();
- return (ret == 0);
-
- } catch (IOException | InterruptedException e) {
- return false;
- }
- }
}