test/jdk/jdk/jfr/event/compiler/TestAllocInNewTLAB.java
changeset 50113 caf115bb98ad
child 51214 67736b4846a0
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/jdk/jdk/jfr/event/compiler/TestAllocInNewTLAB.java	Tue May 15 20:24:34 2018 +0200
@@ -0,0 +1,126 @@
+/*
+ * Copyright (c) 2013, 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.event.compiler;
+
+import static java.lang.Math.floor;
+import static jdk.test.lib.Asserts.assertGreaterThanOrEqual;
+import static jdk.test.lib.Asserts.assertLessThanOrEqual;
+
+import java.time.Duration;
+
+import jdk.jfr.Recording;
+import jdk.jfr.consumer.RecordedEvent;
+import jdk.test.lib.jfr.EventNames;
+import jdk.test.lib.jfr.Events;
+
+/*
+ * @test
+ * @summary Test that event is triggered when an object is allocated in a new TLAB.
+ * @key jfr
+ * @library /test/lib
+ * @run main/othervm -XX:+UseTLAB -XX:TLABSize=100k -XX:-ResizeTLAB -XX:TLABRefillWasteFraction=1 jdk.jfr.event.compiler.TestAllocInNewTLAB
+ * @run main/othervm -XX:+UseTLAB -XX:TLABSize=100k -XX:-ResizeTLAB -XX:TLABRefillWasteFraction=1 -XX:-FastTLABRefill jdk.jfr.event.compiler.TestAllocInNewTLAB
+ * @run main/othervm -XX:+UseTLAB -XX:TLABSize=100k -XX:-ResizeTLAB -XX:TLABRefillWasteFraction=1 -Xint jdk.jfr.event.compiler.TestAllocInNewTLAB
+ */
+
+/**
+ * Test that when an object is allocated in a new Thread Local Allocation Buffer (TLAB)
+ * an event will be triggered. The test is done for C1-compiler,
+ * C2-compiler (-XX:-FastTLABRefill) and interpreted mode (-Xint).
+ *
+ * To force objects to be allocated in a new TLAB:
+ *      the size of TLAB is set to 100k (-XX:TLABSize=100k);
+ *      the size of allocated objects is set to 100k minus 16 bytes overhead;
+ *      max TLAB waste at refill is set to minimum (-XX:TLABRefillWasteFraction=1),
+ *          to provoke a new TLAB creation.
+ */
+public class TestAllocInNewTLAB {
+    private final static String EVENT_NAME = EventNames.ObjectAllocationInNewTLAB;
+
+    private static final int BYTE_ARRAY_OVERHEAD = 16; // Extra bytes used by a byte array.
+    private static final int OBJECT_SIZE  = 100 * 1024;
+    private static final int OBJECT_SIZE_ALT = OBJECT_SIZE + 8; // Object size in case of disabled CompressedOops
+    private static final int OBJECTS_TO_ALLOCATE = 100;
+    private static final String BYTE_ARRAY_CLASS_NAME = new byte[0].getClass().getName();
+    private static final int INITIAL_TLAB_SIZE = 100 * 1024;
+
+    // make sure allocation isn't dead code eliminated
+    public static byte[] tmp;
+
+    public static void main(String[] args) throws Exception {
+        Recording recording = new Recording();
+        recording.enable(EVENT_NAME).withThreshold(Duration.ofMillis(0));
+
+        recording.start();
+        System.gc();
+        for (int i = 0; i < OBJECTS_TO_ALLOCATE; ++i) {
+            tmp = new byte[OBJECT_SIZE - BYTE_ARRAY_OVERHEAD];
+        }
+        recording.stop();
+
+        int countAllTlabs = 0;  // Count all matching tlab allocations.
+        int countFullTlabs = 0; // Count matching tlab allocations with full tlab size.
+        for (RecordedEvent event : Events.fromRecording(recording)) {
+            if (!EVENT_NAME.equals(event.getEventType().getName())) {
+                continue;
+            }
+            System.out.println("Event:" + event);
+
+            long allocationSize = Events.assertField(event, "allocationSize").atLeast(1L).getValue();
+            long tlabSize = Events.assertField(event, "tlabSize").atLeast(allocationSize).getValue();
+            String className = Events.assertField(event, "objectClass.name").notEmpty().getValue();
+
+            boolean isMyEvent = Thread.currentThread().getId() == event.getThread().getJavaThreadId()
+                 && className.equals(BYTE_ARRAY_CLASS_NAME)
+                 && (allocationSize == OBJECT_SIZE || allocationSize == OBJECT_SIZE_ALT);
+            if (isMyEvent) {
+                countAllTlabs++;
+                if (tlabSize == INITIAL_TLAB_SIZE + OBJECT_SIZE || tlabSize == INITIAL_TLAB_SIZE + OBJECT_SIZE_ALT) {
+                    countFullTlabs++;
+                }
+            }
+        }
+
+        int minCount = (int) floor(OBJECTS_TO_ALLOCATE * 0.80);
+        assertGreaterThanOrEqual(countAllTlabs, minCount, "Too few tlab objects allocated");
+        assertLessThanOrEqual(countAllTlabs, OBJECTS_TO_ALLOCATE, "Too many tlab objects allocated");
+
+        // For most GCs we expect the size of each tlab to be
+        // INITIAL_TLAB_SIZE + ALLOCATION_SIZE, but that is not always true for G1.
+        // G1 may use a smaller tlab size if the full tlab does not fit in the
+        // selected memory region.
+        //
+        // For example, if a G1 memory region has room for 4.7 tlabs,
+        // then the first 4 tlabs will have the expected size,
+        // but the fifth tlab would only have a size of 0.7*expected.
+        //
+        // It is only the last tlab in each region that has a smaller size.
+        // This means that at least 50% of the allocated tlabs should
+        // have the expected size (1 full tlab, and 1 fractional tlab).
+        assertGreaterThanOrEqual(2*countFullTlabs, countAllTlabs, "Too many fractional tlabs.");
+    }
+
+}