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	/*
	* 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.internal;

	import static jdk.jfr.internal.LogLevel.INFO;
	import static jdk.jfr.internal.LogLevel.TRACE;
	import static jdk.jfr.internal.LogLevel.WARN;
	import static jdk.jfr.internal.LogTag.JFR;
	import static jdk.jfr.internal.LogTag.JFR_SYSTEM;

	import java.io.IOException;
	import java.security.AccessControlContext;
	import java.security.AccessController;
	import java.time.Duration;
	import java.time.Instant;
	import java.util.ArrayList;
	import java.util.Collections;
	import java.util.HashMap;
	import java.util.HashSet;
	import java.util.List;
	import java.util.Map;
	import java.util.Set;
	import java.util.Timer;
	import java.util.TimerTask;
	import java.util.concurrent.CopyOnWriteArrayList;

	import jdk.jfr.EventType;
	import jdk.jfr.FlightRecorder;
	import jdk.jfr.FlightRecorderListener;
	import jdk.jfr.Recording;
	import jdk.jfr.RecordingState;
	import jdk.jfr.events.ActiveRecordingEvent;
	import jdk.jfr.events.ActiveSettingEvent;
	import jdk.jfr.internal.SecuritySupport.SecureRecorderListener;
	import jdk.jfr.internal.instrument.JDKEvents;

	public final class PlatformRecorder {

	private final List<PlatformRecording> recordings = new ArrayList<>();
	private final static List<SecureRecorderListener> changeListeners = new ArrayList<>();
	private final Repository repository;
	private final Timer timer;
	private final static JVM jvm = JVM.getJVM();
	private final EventType activeRecordingEvent;
	private final EventType activeSettingEvent;
	private final Thread shutdownHook;

	private long recordingCounter = 0;
	private RepositoryChunk currentChunk;

	public PlatformRecorder() throws Exception {
	repository = Repository.getRepository();
	Logger.log(JFR_SYSTEM, INFO, "Initialized disk repository");
	repository.ensureRepository();
	jvm.createNativeJFR();
	Logger.log(JFR_SYSTEM, INFO, "Created native");
	JDKEvents.initialize();
	Logger.log(JFR_SYSTEM, INFO, "Registered JDK events");
	JDKEvents.addInstrumentation();
	startDiskMonitor();
	SecuritySupport.registerEvent(ActiveRecordingEvent.class);
	activeRecordingEvent = EventType.getEventType(ActiveRecordingEvent.class);
	SecuritySupport.registerEvent(ActiveSettingEvent.class);
	activeSettingEvent = EventType.getEventType(ActiveSettingEvent.class);
	shutdownHook = SecuritySupport.createThreadWitNoPermissions("JFR: Shutdown Hook", new ShutdownHook(this));
	SecuritySupport.setUncaughtExceptionHandler(shutdownHook, new ShutdownHook.ExceptionHandler());
	SecuritySupport.registerShutdownHook(shutdownHook);
	timer = createTimer();
	}

	private static Timer createTimer() {
	try {
	List<Timer> result = new CopyOnWriteArrayList<>();
	Thread t = SecuritySupport.createThreadWitNoPermissions("Permissionless thread", ()-> {
	result.add(new Timer("JFR Recording Scheduler", true));
	});
	t.start();
	t.join();
	return result.get(0);
	} catch (InterruptedException e) {
	throw new IllegalStateException("Not able to create timer task. " + e.getMessage(), e);
	}
	}

	public synchronized PlatformRecording newRecording(Map<String, String> settings) {
	return newRecording(settings, ++recordingCounter);
	}

	// To be used internally when doing dumps.
	// Caller must have recorder lock and close recording before releasing lock
	public PlatformRecording newTemporaryRecording() {
	if(!Thread.holdsLock(this)) {
	throw new InternalError("Caller must have recorder lock");
	}
	return newRecording(new HashMap<>(), 0);
	}

	private synchronized PlatformRecording newRecording(Map<String, String> settings, long id) {
	PlatformRecording recording = new PlatformRecording(this, id);
	if (!settings.isEmpty()) {
	recording.setSettings(settings);
	}
	recordings.add(recording);
	return recording;
	}

	synchronized void finish(PlatformRecording recording) {
	if (recording.getState() == RecordingState.RUNNING) {
	recording.stop("Recording closed");
	}
	recordings.remove(recording);
	}

	public synchronized List<PlatformRecording> getRecordings() {
	return Collections.unmodifiableList(new ArrayList<PlatformRecording>(recordings));
	}

	public synchronized static void addListener(FlightRecorderListener changeListener) {
	AccessControlContext context = AccessController.getContext();
	SecureRecorderListener sl = new SecureRecorderListener(context, changeListener);
	boolean runInitialized;
	synchronized (PlatformRecorder.class) {
	runInitialized = FlightRecorder.isInitialized();
	changeListeners.add(sl);
	}
	if (runInitialized) {
	sl.recorderInitialized(FlightRecorder.getFlightRecorder());
	}
	}

	public synchronized static boolean removeListener(FlightRecorderListener changeListener) {
	for (SecureRecorderListener s : new ArrayList<>(changeListeners)) {
	if (s.getChangeListener() == changeListener) {
	changeListeners.remove(s);
	return true;
	}
	}
	return false;
	}

	static synchronized List<FlightRecorderListener> getListeners() {
	return new ArrayList<>(changeListeners);
	}

	Timer getTimer() {
	return timer;
	}

	public static void notifyRecorderInitialized(FlightRecorder recorder) {
	Logger.log(JFR_SYSTEM, TRACE, "Notifying listeners that Flight Recorder is initialized");
	for (FlightRecorderListener r : getListeners()) {
	r.recorderInitialized(recorder);
	}
	}

	// called by shutdown hook
	synchronized void destroy() {
	try {
	timer.cancel();
	} catch (Exception ex) {
	Logger.log(JFR_SYSTEM, WARN, "Shutdown hook could not cancel timer");
	}

	for (PlatformRecording p : getRecordings()) {
	if (p.getState() == RecordingState.RUNNING) {
	try {
	p.stop("Shutdown");
	} catch (Exception ex) {
	Logger.log(JFR, WARN, "Recording " + p.getName() + ":" + p.getId() + " could not be stopped");
	}
	}
	}

	JDKEvents.remove();

	if (jvm.hasNativeJFR()) {
	if (jvm.isRecording()) {
	jvm.endRecording_();
	}
	jvm.destroyNativeJFR();
	}
	repository.clear();
	}

	synchronized void start(PlatformRecording recording) {
	// State can only be NEW or DELAYED because of previous checks
	Instant now = Instant.now();
	recording.setStartTime(now);
	recording.updateTimer();
	Duration duration = recording.getDuration();
	if (duration != null) {
	recording.setStopTime(now.plus(duration));
	}
	boolean toDisk = recording.isToDisk();
	boolean beginPhysical = true;
	for (PlatformRecording s : getRecordings()) {
	if (s.getState() == RecordingState.RUNNING) {
	beginPhysical = false;
	if (s.isToDisk()) {
	toDisk = true;
	}
	}
	}
	if (beginPhysical) {
	RepositoryChunk newChunk = null;
	if (toDisk) {
	newChunk = repository.newChunk(now);
	MetadataRepository.getInstance().setOutput(newChunk.getUnfishedFile().toString());
	} else {
	MetadataRepository.getInstance().setOutput(null);
	}
	currentChunk = newChunk;
	jvm.beginRecording_();
	recording.setState(RecordingState.RUNNING);
	updateSettings();
	writeMetaEvents();
	} else {
	RepositoryChunk newChunk = null;
	if (toDisk) {
	newChunk = repository.newChunk(now);
	RequestEngine.doChunkEnd();
	MetadataRepository.getInstance().setOutput(newChunk.getUnfishedFile().toString());
	}
	recording.setState(RecordingState.RUNNING);
	updateSettings();
	writeMetaEvents();
	if (currentChunk != null) {
	finishChunk(currentChunk, now, recording);
	}
	currentChunk = newChunk;
	}

	RequestEngine.doChunkBegin();
	}

	synchronized void stop(PlatformRecording recording) {
	RecordingState state = recording.getState();

	if (Utils.isAfter(state, RecordingState.RUNNING)) {
	throw new IllegalStateException("Can't stop an already stopped recording.");
	}
	if (Utils.isBefore(state, RecordingState.RUNNING)) {
	throw new IllegalStateException("Recording must be started before it can be stopped.");
	}
	Instant now = Instant.now();
	boolean toDisk = false;
	boolean endPhysical = true;
	for (PlatformRecording s : getRecordings()) {
	RecordingState rs = s.getState();
	if (s != recording && RecordingState.RUNNING == rs) {
	endPhysical = false;
	if (s.isToDisk()) {
	toDisk = true;
	}
	}
	}
	OldObjectSample.emit(recording);

	if (endPhysical) {
	RequestEngine.doChunkEnd();
	if (recording.isToDisk()) {
	if (currentChunk != null) {
	MetadataRepository.getInstance().setOutput(null);
	finishChunk(currentChunk, now, null);
	currentChunk = null;
	}
	} else {
	// last memory
	dumpMemoryToDestination(recording);
	}
	jvm.endRecording_();
	disableEvents();
	} else {
	RepositoryChunk newChunk = null;
	RequestEngine.doChunkEnd();
	updateSettingsButIgnoreRecording(recording);
	if (toDisk) {
	newChunk = repository.newChunk(now);
	MetadataRepository.getInstance().setOutput(newChunk.getUnfishedFile().toString());
	} else {
	MetadataRepository.getInstance().setOutput(null);
	}
	writeMetaEvents();
	if (currentChunk != null) {
	finishChunk(currentChunk, now, null);
	}
	currentChunk = newChunk;
	RequestEngine.doChunkBegin();
	}
	recording.setState(RecordingState.STOPPED);
	}

	private void dumpMemoryToDestination(PlatformRecording recording) {
	WriteableUserPath dest = recording.getDestination();
	if (dest != null) {
	MetadataRepository.getInstance().setOutput(dest.getRealPathText());
	recording.clearDestination();
	}
	}
	private void disableEvents() {
	MetadataRepository.getInstance().disableEvents();
	}

	void updateSettings() {
	updateSettingsButIgnoreRecording(null);
	}

	void updateSettingsButIgnoreRecording(PlatformRecording ignoreMe) {
	List<PlatformRecording> recordings = getRunningRecordings();
	List<Map<String, String>> list = new ArrayList<>(recordings.size());
	for (PlatformRecording r : recordings) {
	if (r != ignoreMe) {
	list.add(r.getSettings());
	}
	}
	MetadataRepository.getInstance().setSettings(list);
	}

	synchronized void rotateDisk() {
	Instant now = Instant.now();
	RepositoryChunk newChunk = repository.newChunk(now);
	RequestEngine.doChunkEnd();
	MetadataRepository.getInstance().setOutput(newChunk.getUnfishedFile().toString());
	writeMetaEvents();
	if (currentChunk != null) {
	finishChunk(currentChunk, now, null);
	}
	currentChunk = newChunk;
	RequestEngine.doChunkBegin();
	}

	private List<PlatformRecording> getRunningRecordings() {
	List<PlatformRecording> runningRecordings = new ArrayList<>();
	for (PlatformRecording recording : getRecordings()) {
	if (recording.getState() == RecordingState.RUNNING) {
	runningRecordings.add(recording);
	}
	}
	return runningRecordings;
	}

	private List<RepositoryChunk> makeChunkList(Instant startTime, Instant endTime) {
	Set<RepositoryChunk> chunkSet = new HashSet<>();
	for (PlatformRecording r : getRecordings()) {
	chunkSet.addAll(r.getChunks());
	}
	if (chunkSet.size() > 0) {
	List<RepositoryChunk> chunks = new ArrayList<>(chunkSet.size());
	for (RepositoryChunk rc : chunkSet) {
	if (rc.inInterval(startTime, endTime)) {
	chunks.add(rc);
	}
	}
	// nlog(n), should be able to do nlog(k) with a priority queue,
	// where k = number of recordings, n = number of chunks
	Collections.sort(chunks, RepositoryChunk.END_TIME_COMPARATOR);
	return chunks;
	}

	return Collections.emptyList();
	}

	private void startDiskMonitor() {
	Thread t = SecuritySupport.createThreadWitNoPermissions("JFR Periodic Tasks", () -> periodicTask());
	SecuritySupport.setDaemonThread(t, true);
	t.start();
	}

	private void finishChunk(RepositoryChunk chunk, Instant time, PlatformRecording ignoreMe) {
	chunk.finish(time);
	for (PlatformRecording r : getRecordings()) {
	if (r != ignoreMe && r.getState() == RecordingState.RUNNING) {
	r.appendChunk(chunk);
	}
	}
	}

	private void writeMetaEvents() {

	if (activeRecordingEvent.isEnabled()) {
	for (PlatformRecording r : getRecordings()) {
	if (r.getState() == RecordingState.RUNNING && r.shouldWriteMetadataEvent()) {
	ActiveRecordingEvent event = new ActiveRecordingEvent();
	event.id = r.getId();
	event.name = r.getName();
	WriteableUserPath p = r.getDestination();
	event.destination = p == null ? null : p.getRealPathText();
	Duration d = r.getDuration();
	event.recordingDuration = d == null ? Long.MAX_VALUE : d.toMillis();
	Duration age = r.getMaxAge();
	event.maxAge = age == null ? Long.MAX_VALUE : age.toMillis();
	Long size = r.getMaxSize();
	event.maxSize = size == null ? Long.MAX_VALUE : size;
	Instant start = r.getStartTime();
	event.recordingStart = start == null ? Long.MAX_VALUE : start.toEpochMilli();
	event.commit();
	}
	}
	}
	if (activeSettingEvent.isEnabled()) {
	for (EventControl ec : MetadataRepository.getInstance().getEventControls()) {
	ec.writeActiveSettingEvent();
	}
	}
	}

	private void periodicTask() {
	if (!jvm.hasNativeJFR()) {
	return;
	}
	while (true) {
	synchronized (this) {
	if (jvm.shouldRotateDisk()) {
	rotateDisk();
	}
	}
	long minDelta = RequestEngine.doPeriodic();
	long wait = Math.min(minDelta, Options.getWaitInterval());
	takeNap(wait);
	}
	}

	private void takeNap(long duration) {
	try {
	synchronized (JVM.FILE_DELTA_CHANGE) {
	JVM.FILE_DELTA_CHANGE.wait(duration < 10 ? 10 : duration);
	}
	} catch (InterruptedException e) {
	e.printStackTrace();
	}
	}

	synchronized Recording newCopy(PlatformRecording r, boolean stop) {
	Recording newRec = new Recording();
	PlatformRecording copy = PrivateAccess.getInstance().getPlatformRecording(newRec);
	copy.setSettings(r.getSettings());
	copy.setMaxAge(r.getMaxAge());
	copy.setMaxSize(r.getMaxSize());
	copy.setDumpOnExit(r.getDumpOnExit());
	copy.setName("Clone of " + r.getName());
	copy.setToDisk(r.isToDisk());
	copy.setInternalDuration(r.getDuration());
	copy.setStartTime(r.getStartTime());
	copy.setStopTime(r.getStopTime());

	if (r.getState() == RecordingState.NEW) {
	return newRec;
	}
	if (r.getState() == RecordingState.DELAYED) {
	copy.scheduleStart(r.getStartTime());
	return newRec;
	}
	copy.setState(r.getState());
	// recording has started, copy chunks
	for (RepositoryChunk c : r.getChunks()) {
	copy.add(c);
	}
	if (r.getState() == RecordingState.RUNNING) {
	if (stop) {
	copy.stop("Stopped when cloning recording '" + r.getName() + "'");
	} else {
	if (r.getStopTime() != null) {
	TimerTask stopTask = copy.createStopTask();
	copy.setStopTask(copy.createStopTask());
	getTimer().schedule(stopTask, r.getStopTime().toEpochMilli());
	}
	}
	}
	return newRec;
	}

	public synchronized void fillWithRecordedData(PlatformRecording target, Boolean pathToGcRoots) {
	boolean running = false;
	boolean toDisk = false;

	for (PlatformRecording r : recordings) {
	if (r.getState() == RecordingState.RUNNING) {
	running = true;
	if (r.isToDisk()) {
	toDisk = true;
	}
	}
	}
	// If needed, flush data from memory
	if (running) {
	if (toDisk) {
	OldObjectSample.emit(recordings, pathToGcRoots);
	rotateDisk();
	} else {
	try (PlatformRecording snapshot = newTemporaryRecording()) {
	snapshot.setToDisk(true);
	snapshot.setShouldWriteActiveRecordingEvent(false);
	snapshot.start();
	OldObjectSample.emit(recordings, pathToGcRoots);
	snapshot.stop("Snapshot dump");
	fillWithDiskChunks(target);
	}
	return;
	}
	}
	fillWithDiskChunks(target);
	}

	private void fillWithDiskChunks(PlatformRecording target) {
	for (RepositoryChunk c : makeChunkList(null, null)) {
	target.add(c);
	}
	target.setState(RecordingState.STOPPED);
	Instant startTime = null;
	Instant endTime = null;

	for (RepositoryChunk c : target.getChunks()) {
	if (startTime == null \|\| c.getStartTime().isBefore(startTime)) {
	startTime = c.getStartTime();
	}
	if (endTime == null \|\| c.getEndTime().isAfter(endTime)) {
	endTime = c.getEndTime();
	}
	}
	Instant now = Instant.now();
	if (startTime == null) {
	startTime = now;
	}
	if (endTime == null) {
	endTime = now;
	}
	target.setStartTime(startTime);
	target.setStopTime(endTime);
	target.setInternalDuration(Duration.between(startTime, endTime));
	}
	}

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