1 /* 2 * Copyright (c) 2018, 2020, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package jdk.jfr.internal; 27 28 import java.util.HashMap; 29 import java.util.List; 30 import java.util.Map; 31 32 import jdk.jfr.Enabled; 33 import jdk.jfr.RecordingState; 34 import jdk.jfr.internal.settings.CutoffSetting; 35 import jdk.jfr.internal.test.WhiteBox; 36 37 // The Old Object event could have been implemented as a periodic event, but 38 // due to chunk rotations and how settings are calculated when multiple recordings 39 // are running at the same time, it would lead to unacceptable overhead. 40 // 41 // Instead, the event is only emitted before a recording stops and 42 // if that recording has the event enabled. 43 // 44 // This requires special handling and the purpose of this class is to provide that 45 // 46 public final class OldObjectSample { 47 48 private static final String EVENT_NAME = Type.EVENT_NAME_PREFIX + "OldObjectSample"; 49 private static final String OLD_OBJECT_CUTOFF = EVENT_NAME + "#" + Cutoff.NAME; 50 private static final String OLD_OBJECT_ENABLED = EVENT_NAME + "#" + Enabled.NAME; 51 52 // Emit if old object is enabled in recording with cutoff for that recording emit(PlatformRecording recording)53 public static void emit(PlatformRecording recording) { 54 if (isEnabled(recording)) { 55 long nanos = CutoffSetting.parseValueSafe(recording.getSettings().get(OLD_OBJECT_CUTOFF)); 56 long ticks = Utils.nanosToTicks(nanos); 57 emit(ticks); 58 } 59 } 60 61 62 // Emit if old object is enabled for at least one recording, and use the largest 63 // cutoff for an enabled recording emit(List<PlatformRecording> recordings, Boolean pathToGcRoots)64 public static void emit(List<PlatformRecording> recordings, Boolean pathToGcRoots) { 65 boolean enabled = false; 66 long cutoffNanos = Boolean.TRUE.equals(pathToGcRoots) ? Long.MAX_VALUE : 0L; 67 for (PlatformRecording r : recordings) { 68 if (r.getState() == RecordingState.RUNNING) { 69 if (isEnabled(r)) { 70 enabled = true; 71 long c = CutoffSetting.parseValueSafe(r.getSettings().get(OLD_OBJECT_CUTOFF)); 72 cutoffNanos = Math.max(c, cutoffNanos); 73 } 74 } 75 } 76 if (enabled) { 77 long ticks = Utils.nanosToTicks(cutoffNanos); 78 emit(ticks); 79 } 80 } 81 emit(long ticks)82 private static void emit(long ticks) { 83 boolean emitAll = WhiteBox.getWriteAllObjectSamples(); 84 boolean skipBFS = WhiteBox.getSkipBFS(); 85 JVM.getJVM().emitOldObjectSamples(ticks, emitAll, skipBFS); 86 } 87 updateSettingPathToGcRoots(Map<String, String> s, Boolean pathToGcRoots)88 public static void updateSettingPathToGcRoots(Map<String, String> s, Boolean pathToGcRoots) { 89 if (pathToGcRoots != null) { 90 s.put(OLD_OBJECT_CUTOFF, pathToGcRoots ? "infinity" : "0 ns"); 91 } 92 } 93 createSettingsForSnapshot(PlatformRecording recording, Boolean pathToGcRoots)94 public static Map<String, String> createSettingsForSnapshot(PlatformRecording recording, Boolean pathToGcRoots) { 95 Map<String, String> settings = new HashMap<>(recording.getSettings()); 96 updateSettingPathToGcRoots(settings, pathToGcRoots); 97 return settings; 98 } 99 isEnabled(PlatformRecording r)100 private static boolean isEnabled(PlatformRecording r) { 101 Map<String, String> settings = r.getSettings(); 102 String s = settings.get(OLD_OBJECT_ENABLED); 103 return "true".equals(s); 104 } 105 } 106