+ * The following example shows how to create a recording stream that prints + * CPU usage and information about garbage collections. + * + *
+ *
+ * try (RecordingStream r = new RecordingStream()) {
+ * r.enable("jdk.GarbageCollection");
+ * r.enable("jdk.CPULoad").withPeriod(Duration.ofSeconds(1));
+ * r.onEvent(System.out::println);
+ * r.start();
+ * }
+ *
+ *
+ *
+ * @throws IllegalStateException if Flight Recorder can't be created (for
+ * example, if the Java Virtual Machine (JVM) lacks Flight Recorder
+ * support, or if the file repository can't be created or accessed)
+ *
+ * @throws SecurityException if a security manager exists and the caller
+ * does not have
+ * {@code FlightRecorderPermission("accessFlightRecorder")}
+ */
+ public RecordingStream() {
+ Utils.checkAccessFlightRecorder();
+ AccessControlContext acc = AccessController.getContext();
+ this.recording = new Recording();
+ this.recording.setFlushInterval(Duration.ofMillis(1000));
+ try {
+ this.stream = new EventDirectoryStream(acc);
+ } catch (IOException ioe) {
+ throw new IllegalStateException(ioe.getMessage());
+ }
+ }
+
+ /**
+ * Creates a recording stream using settings from a configuration.
+ * + * The following example shows how to create a recording stream that uses a + * predefined configuration. + * + *
+ *
+ * Configuration c = Configuration.getConfiguration("default");
+ * try (RecordingStream r = new RecordingStream(c)) {
+ * r.onEvent(System.out::println);
+ * r.start();
+ * }
+ *
+ *
+ *
+ * @param configuration configuration that contains the settings to be use,
+ * not {@code null}
+ *
+ * @throws IllegalStateException if Flight Recorder can't be created (for
+ * example, if the Java Virtual Machine (JVM) lacks Flight Recorder
+ * support, or if the file repository can't be created or accessed)
+ *
+ * @throws SecurityException if a security manager is used and
+ * FlightRecorderPermission "accessFlightRecorder" is not set.
+ *
+ * @see Configuration
+ */
+ public RecordingStream(Configuration configuration) {
+ this();
+ recording.setSettings(configuration.getSettings());
+ }
+
+ /**
+ * Enables the event with the specified name.
+ * + * If multiple events have the same name (for example, the same class is + * loaded in different class loaders), then all events that match the name + * are enabled. To enable a specific class, use the {@link #enable(Class)} + * method or a {@code String} representation of the event type ID. + * + * @param name the settings for the event, not {@code null} + * + * @return an event setting for further configuration, not {@code null} + * + * @see EventType + */ + public EventSettings enable(String name) { + return recording.enable(name); + } + + /** + * Enables event. + * + * @param eventClass the event to enable, not {@code null} + * + * @throws IllegalArgumentException if {@code eventClass} is an abstract + * class or not a subclass of {@link Event} + * + * @return an event setting for further configuration, not {@code null} + */ + public EventSettings enable(Class eventClass) { + return recording.enable(eventClass); + } + + /** + * Disables event with the specified name. + *
+ * If multiple events with same name (for example, the same class is loaded + * in different class loaders), then all events that match the name is + * disabled. To disable a specific class, use the {@link #disable(Class)} + * method or a {@code String} representation of the event type ID. + * + * @param name the settings for the event, not {@code null} + * + * @return an event setting for further configuration, not {@code null} + * + */ + public EventSettings disable(String name) { + return recording.disable(name); + } + + /** + * Disables event. + * + * @param eventClass the event to enable, not {@code null} + * + * @throws IllegalArgumentException if {@code eventClass} is an abstract + * class or not a subclass of {@link Event} + * + * @return an event setting for further configuration, not {@code null} + * + */ + public EventSettings disable(Class eventClass) { + return recording.disable(eventClass); + } + /** + * Determines how far back data is kept for the stream if the stream can't + * keep up. + *
+ * To control the amount of recording data stored on disk, the maximum + * length of time to retain the data can be specified. Data stored on disk + * that is older than the specified length of time is removed by the Java + * Virtual Machine (JVM). + *
+ * If neither maximum limit or the maximum age is set, the size of the
+ * recording may grow indefinitely if events are on
+ *
+ * @param maxAge the length of time that data is kept, or {@code null} if
+ * infinite
+ *
+ * @throws IllegalArgumentException if maxAge is negative
+ *
+ * @throws IllegalStateException if the recording is in the {@code CLOSED}
+ * state
+ */
+ public void setMaxAge(Duration maxAge) {
+ recording.setMaxAge(maxAge);
+ }
+
+ /**
+ * Determines how much data is kept in the disk repository if the stream
+ * can't keep up.
+ *
+ * To control the amount of recording data that is stored on disk, the + * maximum amount of data to retain can be specified. When the maximum limit + * is exceeded, the Java Virtual Machine (JVM) removes the oldest chunk to + * make room for a more recent chunk. + *
+ * If neither maximum limit or the maximum age is set, the size of the
+ * recording may grow indefinitely.
+ *
+ * @param maxSize the amount of data to retain, {@code 0} if infinite
+ *
+ * @throws IllegalArgumentException if maxSize is negative
+ *
+ * @throws IllegalStateException if the recording is in {@code CLOSED} state
+ */
+ public void setMaxSize(long maxSize) {
+ recording.setMaxSize(maxSize);
+ }
+
+ @Override
+ public void onEvent(String eventName, Consumerinterval is negative
+ *
+ * @throws IllegalStateException if the stream is closed
+ */
+ public void setInterval(Duration duration) {
+ recording.setFlushInterval(duration);
+ }
+
+ @Override
+ public void awaitTermination() {
+ stream.awaitTermination();
+ }
+}