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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

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 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

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 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package jdk.jfr;

/**

 * Callback interface to monitor Flight Recorder's life cycle.

 *

 * @since 8

 */

public interface FlightRecorderListener {

    /**

     * Receives notification when Flight Recorder is initialized.

     * <p>

     * This method is also be invoked when a listener is added to an already

     * initialized Flight Recorder.

     * <p>

     * This method allows clients to implement their own initialization mechanism

     * that is executed before a {@code FlightRecorder} instance is returned by

     * {@code FlightRecorder#getFlightRecorder()}.

     *

     * @implNote This method should return as soon as possible, to avoid blocking

     *           initialization of Flight Recorder. To avoid deadlocks or unexpected

     *           behavior, this method should not call

     *           {@link FlightRecorder#getFlightRecorder()} or start new recordings.

     *

     * @implSpec The default implementation of this method is empty.

     *

     * @param recorder Flight Recorder instance, not {@code null}

     *

     * @see FlightRecorder#addListener(FlightRecorderListener)

     */

    default void recorderInitialized(FlightRecorder recorder) {

    }

    /**

     * Receives notification when the state of a recording changes.

     * <p>

     * Callback is invoked when a recording reaches the {@code RUNNING},

     * {@code STOPPED} and {@code CLOSED} state.

     *

     * @implNote The implementation of this method should return as soon as possible

     *           to avoid blocking normal operation of Flight Recorder.

     *

     * @implSpec The default implementation of this method is empty.

     *

     * @param recording the recording where the state change occurred, not

     *        {@code null}

     *

     * @see FlightRecorder#addListener(FlightRecorderListener)

     * @see RecordingState

     *

     */

    default void recordingStateChanged(Recording recording) {

    }

}