--- /dev/null	2020-01-02 04:43:18.583999853 +0000
+++ new/src/share/classes/jdk/jfr/internal/settings/PeriodSetting.java	2020-01-30 06:27:35.781362459 +0000
@@ -0,0 +1,136 @@
+/*
+ * 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.settings;
+
+import java.util.Objects;
+import java.util.Set;
+
+import jdk.jfr.Description;
+import jdk.jfr.Label;
+import jdk.jfr.MetadataDefinition;
+import jdk.jfr.Name;
+import jdk.jfr.internal.PlatformEventType;
+import jdk.jfr.internal.Control;
+import jdk.jfr.internal.Type;
+import jdk.jfr.internal.Utils;
+
+@MetadataDefinition
+@Label("Period")
+@Description("Record event at interval")
+@Name(Type.SETTINGS_PREFIX + "Period")
+public final class PeriodSetting extends Control {
+    private static final long typeId = Type.getTypeId(PeriodSetting.class);
+
+    public static final String EVERY_CHUNK = "everyChunk";
+    public static final String BEGIN_CHUNK = "beginChunk";
+    public static final String END_CHUNK = "endChunk";
+    public static final String NAME = "period";
+    private final PlatformEventType eventType;
+    private String value = EVERY_CHUNK;
+
+    public PeriodSetting(PlatformEventType eventType, String defaultValue) {
+        super(defaultValue);
+        this.eventType = Objects.requireNonNull(eventType);
+    }
+
+    @Override
+    public String combine(Set<String> values) {
+
+        boolean beginChunk = false;
+        boolean endChunk = false;
+        Long min = null;
+        String text = null;
+        for (String value : values) {
+            switch (value) {
+            case EVERY_CHUNK:
+                beginChunk = true;
+                endChunk = true;
+                break;
+            case BEGIN_CHUNK:
+                beginChunk = true;
+                break;
+            case END_CHUNK:
+                endChunk = true;
+                break;
+            default:
+                long l = Utils.parseTimespanWithInfinity(value);
+                // Always accept first specified value
+                if (min == null) {
+                    text = value;
+                    min = l;
+                } else {
+                    if (l < min) {
+                        text = value;
+                        min = l;
+                    }
+                }
+            }
+        }
+        // A specified interval trumps *_CHUNK
+        if (min != null) {
+            return text;
+        }
+        if (beginChunk && !endChunk) {
+            return BEGIN_CHUNK;
+        }
+        if (!beginChunk && endChunk) {
+            return END_CHUNK;
+        }
+        return EVERY_CHUNK; // also default
+    }
+
+    @Override
+    public void setValue(String value) {
+        switch (value) {
+        case EVERY_CHUNK:
+            eventType.setPeriod(0, true, true);
+            break;
+        case BEGIN_CHUNK:
+            eventType.setPeriod(0, true, false);
+            break;
+        case END_CHUNK:
+            eventType.setPeriod(0, false, true);
+            break;
+        default:
+            long nanos = Utils.parseTimespanWithInfinity(value);
+            if (nanos != Long.MAX_VALUE) {
+                eventType.setPeriod(nanos / 1_000_000, false, false);
+            } else {
+                eventType.setPeriod(Long.MAX_VALUE, false, false);
+            }
+        }
+        this.value = value;
+    }
+
+    @Override
+    public String getValue() {
+        return value;
+    }
+
+    public static boolean isType(long typeId) {
+        return PeriodSetting.typeId == typeId;
+    }
+}