--- /dev/null 2019-02-07 20:54:51.336000000 +0300 +++ new/src/share/classes/jdk/jfr/internal/OldObjectSample.java 2019-02-08 18:32:32.418291512 +0300 @@ -0,0 +1,98 @@ +/* + * Copyright (c) 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 java.util.HashMap; +import java.util.List; +import java.util.Map; + +import jdk.jfr.Enabled; +import jdk.jfr.RecordingState; +import jdk.jfr.internal.settings.CutoffSetting; +import jdk.jfr.internal.test.WhiteBox; + +// The Old Object event could have been implemented as a periodic event, but +// due to chunk rotations and how settings are calculated when multiple recordings +// are running at the same time, it would lead to unacceptable overhead. +// +// Instead, the event is only emitted before a recording stops and +// if that recording has the event enabled. +// +// This requires special handling and the purpose of this class is to provide that +// +public final class OldObjectSample { + + private static final String EVENT_NAME = Type.EVENT_NAME_PREFIX + "OldObjectSample"; + private static final String OLD_OBJECT_CUTOFF = EVENT_NAME + "#" + Cutoff.NAME; + private static final String OLD_OBJECT_ENABLED = EVENT_NAME + "#" + Enabled.NAME; + + // Emit if old object is enabled in recoding with cutoff for that recording + public static void emit(PlatformRecording recording) { + if (isEnabled(recording)) { + long nanos = CutoffSetting.parseValueSafe(recording.getSettings().get(OLD_OBJECT_CUTOFF)); + long ticks = Utils.nanosToTicks(nanos); + JVM.getJVM().emitOldObjectSamples(ticks, WhiteBox.getWriteAllObjectSamples()); + } + } + + // Emit if old object is enabled for at least one recording, and use the largest + // cutoff for an enabled recoding + public static void emit(List recordings, Boolean pathToGcRoots) { + boolean enabled = false; + long cutoffNanos = Boolean.TRUE.equals(pathToGcRoots) ? Long.MAX_VALUE : 0L; + for (PlatformRecording r : recordings) { + if (r.getState() == RecordingState.RUNNING) { + if (isEnabled(r)) { + enabled = true; + long c = CutoffSetting.parseValueSafe(r.getSettings().get(OLD_OBJECT_CUTOFF)); + cutoffNanos = Math.max(c, cutoffNanos); + } + } + } + if (enabled) { + long ticks = Utils.nanosToTicks(cutoffNanos); + JVM.getJVM().emitOldObjectSamples(ticks, WhiteBox.getWriteAllObjectSamples()); + } + } + + public static void updateSettingPathToGcRoots(Map s, Boolean pathToGcRoots) { + if (pathToGcRoots != null) { + s.put(OLD_OBJECT_CUTOFF, pathToGcRoots ? "infinity" : "0 ns"); + } + } + + public static Map createSettingsForSnapshot(PlatformRecording recording, Boolean pathToGcRoots) { + Map settings = new HashMap<>(recording.getSettings()); + updateSettingPathToGcRoots(settings, pathToGcRoots); + return settings; + } + + private static boolean isEnabled(PlatformRecording r) { + Map settings = r.getSettings(); + String s = settings.get(OLD_OBJECT_ENABLED); + return "true".equals(s); + } +}