| /* |
| * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * 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, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package jdk.jfr; |
| |
| import static jdk.jfr.internal.LogLevel.DEBUG; |
| import static jdk.jfr.internal.LogLevel.INFO; |
| import static jdk.jfr.internal.LogTag.JFR; |
| |
| import java.security.AccessControlContext; |
| import java.security.AccessController; |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Objects; |
| |
| import jdk.jfr.internal.JVM; |
| import jdk.jfr.internal.JVMSupport; |
| import jdk.jfr.internal.LogLevel; |
| import jdk.jfr.internal.Logger; |
| import jdk.jfr.internal.MetadataRepository; |
| import jdk.jfr.internal.Options; |
| import jdk.jfr.internal.PlatformRecorder; |
| import jdk.jfr.internal.PlatformRecording; |
| import jdk.jfr.internal.Repository; |
| import jdk.jfr.internal.RequestEngine; |
| import jdk.jfr.internal.Utils; |
| |
| /** |
| * Class for accessing, controlling, and managing Flight Recorder. |
| * <p> |
| * This class provides the methods necessary for creating, starting, stopping, |
| * and destroying recordings. |
| * |
| * @since 9 |
| */ |
| public final class FlightRecorder { |
| private static volatile FlightRecorder platformRecorder; |
| private static volatile boolean initialized; |
| private final PlatformRecorder internal; |
| |
| private FlightRecorder(PlatformRecorder internal) { |
| this.internal = internal; |
| } |
| |
| /** |
| * Returns an immutable list of the available recordings. |
| * <p> |
| * A recording becomes available when it is created. It becomes unavailable when it |
| * is in the {@code CLOSED} state, typically after a call to |
| * {@link Recording#close()}. |
| * |
| * @return a list of recordings, not {@code null} |
| */ |
| public List<Recording> getRecordings() { |
| List<Recording> recs = new ArrayList<>(); |
| for (PlatformRecording internal : internal.getRecordings()) { |
| recs.add(internal.getRecording()); |
| } |
| return Collections.unmodifiableList(recs); |
| } |
| |
| /** |
| * Creates a snapshot of all available recorded data. |
| * <p> |
| * A snapshot is a synthesized recording in a {@code STOPPPED} state. If no data is |
| * available, a recording with size {@code 0} is returned. |
| * <p> |
| * A snapshot provides stable access to data for later operations (for example, |
| * operations to change the interval or to reduce the data size). |
| * <p> |
| * The following example shows how to create a snapshot and write a subset of the data to a file. |
| * |
| * <pre> |
| * <code> |
| * try (Recording snapshot = FlightRecorder.getFlightRecorder().takeSnapshot()) { |
| * if (snapshot.getSize() > 0) { |
| * snapshot.setMaxSize(100_000_000); |
| * snapshot.setMaxAge(Duration.ofMinutes(5)); |
| * snapshot.dump(Paths.get("snapshot.jfr")); |
| * } |
| * } |
| * </code> |
| * </pre> |
| * |
| * The caller must close the recording when access to the data is no longer |
| * needed. |
| * |
| * @return a snapshot of all available recording data, not {@code null} |
| */ |
| public Recording takeSnapshot() { |
| return internal.newSnapshot(); |
| } |
| |
| /** |
| * Registers an event class. |
| * <p> |
| * If the event class is already registered, then the invocation of this method is |
| * ignored. |
| * |
| * @param eventClass the event class to register, not {@code null} |
| * |
| * @throws IllegalArgumentException if class is abstract or not a subclass |
| * of {@link Event} |
| * @throws SecurityException if a security manager exists and the caller |
| * does not have {@code FlightRecorderPermission("registerEvent")} |
| */ |
| public static void register(Class<? extends Event> eventClass) { |
| Objects.requireNonNull(eventClass); |
| if (JVMSupport.isNotAvailable()) { |
| return; |
| } |
| Utils.ensureValidEventSubclass(eventClass); |
| MetadataRepository.getInstance().register(eventClass); |
| } |
| |
| /** |
| * Unregisters an event class. |
| * <p> |
| * If the event class is not registered, then the invocation of this method is |
| * ignored. |
| * |
| * @param eventClass the event class to unregistered, not {@code null} |
| * @throws IllegalArgumentException if a class is abstract or not a subclass |
| * of {@link Event} |
| * |
| * @throws SecurityException if a security manager exists and the caller |
| * does not have {@code FlightRecorderPermission("registerEvent")} |
| */ |
| public static void unregister(Class<? extends Event> eventClass) { |
| Objects.requireNonNull(eventClass); |
| if (JVMSupport.isNotAvailable()) { |
| return; |
| } |
| Utils.ensureValidEventSubclass(eventClass); |
| MetadataRepository.getInstance().unregister(eventClass); |
| } |
| |
| /** |
| * Returns the Flight Recorder for the platform. |
| * |
| * @return a Flight Recorder instance, 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 exists and the caller does |
| * not have {@code FlightRecorderPermission("accessFlightRecorder")} |
| */ |
| public static FlightRecorder getFlightRecorder() throws IllegalStateException, SecurityException { |
| synchronized (PlatformRecorder.class) { |
| Utils.checkAccessFlightRecorder(); |
| JVMSupport.ensureWithIllegalStateException(); |
| if (platformRecorder == null) { |
| try { |
| platformRecorder = new FlightRecorder(new PlatformRecorder()); |
| } catch (IllegalStateException ise) { |
| throw ise; |
| } catch (Exception e) { |
| throw new IllegalStateException("Can't create Flight Recorder. " + e.getMessage(), e); |
| } |
| // Must be in synchronized block to prevent instance leaking out |
| // before initialization is done |
| initialized = true; |
| Logger.log(JFR, INFO, "Flight Recorder initialized"); |
| Logger.log(JFR, DEBUG, "maxchunksize: " + Options.getMaxChunkSize()+ " bytes"); |
| Logger.log(JFR, DEBUG, "memorysize: " + Options.getMemorySize()+ " bytes"); |
| Logger.log(JFR, DEBUG, "globalbuffersize: " + Options.getGlobalBufferSize()+ " bytes"); |
| Logger.log(JFR, DEBUG, "globalbuffercount: " + Options.getGlobalBufferCount()); |
| Logger.log(JFR, DEBUG, "dumppath: " + Options.getDumpPath()); |
| Logger.log(JFR, DEBUG, "samplethreads: " + Options.getSampleThreads()); |
| Logger.log(JFR, DEBUG, "stackdepth: " + Options.getStackDepth()); |
| Logger.log(JFR, DEBUG, "threadbuffersize: " + Options.getThreadBufferSize()); |
| Logger.log(JFR, LogLevel.INFO, "Created repository " + Repository.getRepository().getRepositoryPath().toString()); |
| PlatformRecorder.notifyRecorderInitialized(platformRecorder); |
| } |
| } |
| return platformRecorder; |
| } |
| |
| /** |
| * Adds a hook for a periodic event. |
| * <p> |
| * The implementation of the hook should return as soon as possible, to |
| * avoid blocking other Flight Recorder operations. The hook should emit |
| * one or more events of the specified type. When a hook is added, the |
| * interval at which the call is invoked is configurable using the |
| * {@code "period"} setting. |
| * |
| * @param eventClass the class that the hook should run for, not {@code null} |
| * @param hook the hook, not {@code null} |
| * @throws IllegalArgumentException if a class is not a subclass of |
| * {@link Event}, is abstract, or the hook is already added |
| * @throws IllegalStateException if the event class has the |
| * {@code Registered(false)} annotation and is not registered manually |
| * @throws SecurityException if a security manager exists and the caller |
| * does not have {@code FlightRecorderPermission("registerEvent")} |
| */ |
| public static void addPeriodicEvent(Class<? extends Event> eventClass, Runnable hook) throws SecurityException { |
| Objects.requireNonNull(eventClass); |
| Objects.requireNonNull(hook); |
| if (JVMSupport.isNotAvailable()) { |
| return; |
| } |
| |
| Utils.ensureValidEventSubclass(eventClass); |
| Utils.checkRegisterPermission(); |
| AccessControlContext acc = AccessController.getContext(); |
| RequestEngine.addHook(acc, EventType.getEventType(eventClass).getPlatformEventType(), hook); |
| } |
| |
| /** |
| * Removes a hook for a periodic event. |
| * |
| * @param hook the hook to remove, not {@code null} |
| * @return {@code true} if hook is removed, {@code false} otherwise |
| * @throws SecurityException if a security manager exists and the caller |
| * does not have {@code FlightRecorderPermission("registerEvent")} |
| */ |
| public static boolean removePeriodicEvent(Runnable hook) throws SecurityException { |
| Objects.requireNonNull(hook); |
| Utils.checkRegisterPermission(); |
| if (JVMSupport.isNotAvailable()) { |
| return false; |
| } |
| return RequestEngine.removeHook(hook); |
| } |
| |
| /** |
| * Returns an immutable list that contains all currently registered events. |
| * <p> |
| * By default, events are registered when they are first used, typically |
| * when an event object is allocated. To ensure an event is visible early, |
| * registration can be triggered by invoking the |
| * {@link FlightRecorder#register(Class)} method. |
| * |
| * @return list of events, not {@code null} |
| */ |
| public List<EventType> getEventTypes() { |
| return Collections.unmodifiableList(MetadataRepository.getInstance().getRegisteredEventTypes()); |
| } |
| |
| /** |
| * Adds a recorder listener and captures the {@code AccessControlContext} to |
| * use when invoking the listener. |
| * <p> |
| * If Flight Recorder is already initialized when the listener is added, then the method |
| * {@link FlightRecorderListener#recorderInitialized(FlightRecorder)} method is |
| * invoked before returning from this method. |
| * |
| * @param changeListener the listener to add, not {@code null} |
| * |
| * @throws SecurityException if a security manager exists and the caller |
| * does not have |
| * {@code FlightRecorderPermission("accessFlightRecorder")} |
| */ |
| public static void addListener(FlightRecorderListener changeListener) { |
| Objects.requireNonNull(changeListener); |
| Utils.checkAccessFlightRecorder(); |
| if (JVMSupport.isNotAvailable()) { |
| return; |
| } |
| PlatformRecorder.addListener(changeListener); |
| } |
| |
| /** |
| * Removes a recorder listener. |
| * <p> |
| * If the same listener is added multiple times, only one instance is |
| * removed. |
| * |
| * @param changeListener listener to remove, not {@code null} |
| * |
| * @throws SecurityException if a security manager exists and the caller |
| * does not have |
| * {@code FlightRecorderPermission("accessFlightRecorder")} |
| * |
| * @return {@code true}, if the listener could be removed, {@code false} |
| * otherwise |
| */ |
| public static boolean removeListener(FlightRecorderListener changeListener) { |
| Objects.requireNonNull(changeListener); |
| Utils.checkAccessFlightRecorder(); |
| if (JVMSupport.isNotAvailable()) { |
| return false; |
| } |
| |
| return PlatformRecorder.removeListener(changeListener); |
| } |
| |
| /** |
| * Returns {@code true} if the Java Virtual Machine (JVM) has Flight Recorder capabilities. |
| * <p> |
| * This method can quickly check whether Flight Recorder can be |
| * initialized, without actually doing the initialization work. The value may |
| * change during runtime and it is not safe to cache it. |
| * |
| * @return {@code true}, if Flight Recorder is available, {@code false} |
| * otherwise |
| * |
| * @see FlightRecorderListener for callback when Flight Recorder is |
| * initialized |
| */ |
| public static boolean isAvailable() { |
| if (JVMSupport.isNotAvailable()) { |
| return false; |
| } |
| return JVM.getJVM().isAvailable(); |
| } |
| |
| /** |
| * Returns {@code true} if Flight Recorder is initialized. |
| * |
| * @return {@code true}, if Flight Recorder is initialized, |
| * {@code false} otherwise |
| * |
| * @see FlightRecorderListener for callback when Flight Recorder is |
| * initialized |
| */ |
| public static boolean isInitialized() { |
| return initialized; |
| } |
| |
| // package private |
| PlatformRecording newInternalRecording(Map<String, String> settings) { |
| return internal.newRecording(settings); |
| } |
| |
| } |
