8059661: Test SoftReference and OOM behavior

Reviewed-by: tschatzl

hotspot/test/gc/TestSoftReferencesBehaviorOnOOME.java

@@ -0,0 +1,146 @@
+/*
+ * Copyright (c) 2014 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.
+ *
+ * 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.
+ */
+
+/**
+ * @test TestSoftReferencesBehaviorOnOOME
+ * @key gc
+ * @summary Tests that all SoftReferences has been cleared at time of OOM.
+ * @library /testlibrary
+ * @build TestSoftReference
+ * @run main/othervm -Xmx128m TestSoftReferencesBehaviorOnOOME 512 2k
+ * @run main/othervm -Xmx128m TestSoftReferencesBehaviorOnOOME 128k 256k
+ * @run main/othervm -Xmx128m TestSoftReferencesBehaviorOnOOME 2k 32k 10
+ */
+import com.oracle.java.testlibrary.Utils;
+import java.lang.ref.SoftReference;
+import java.util.LinkedList;
+import java.util.Random;
+
+public class TestSoftReferencesBehaviorOnOOME {
+
+    private static final Random rndGenerator = Utils.getRandomInstance();
+
+    public static void main(String[] args) {
+        int semiRefAllocFrequency = DEFAULT_FREQUENCY;
+        long minSize = DEFAULT_MIN_SIZE,
+                maxSize = DEFAULT_MAX_SIZE;
+
+        if ( args.length >= 3 ) {
+            semiRefAllocFrequency = Integer.parseInt(args[2]);
+        }
+
+        if ( args.length >= 2) {
+            maxSize = getBytesCount(args[1]);
+        }
+
+        if ( args.length >= 1) {
+            minSize = getBytesCount(args[0]);
+        }
+
+        new TestSoftReferencesBehaviorOnOOME().softReferencesOom(minSize, maxSize, semiRefAllocFrequency);
+    }
+
+    /**
+     * Test that all SoftReferences has been cleared at time of OOM.
+     */
+    void softReferencesOom(long minSize, long maxSize, int semiRefAllocFrequency) {
+        System.out.format( "minSize = %d, maxSize = %d, freq = %d%n", minSize, maxSize, semiRefAllocFrequency );
+        long counter = 0;
+
+        long multiplier = maxSize - minSize;
+        LinkedList<SoftReference> arrSoftRefs = new LinkedList();
+        LinkedList arrObjects = new LinkedList();
+        long numberOfNotNulledObjects = 0;
+        long oomSoftArraySize = 0;
+
+        try {
+            while (true) {
+                // Keep every Xth object to make sure we hit OOM pretty fast
+                if (counter % semiRefAllocFrequency != 0) {
+                    long allocationSize = ((int) (rndGenerator.nextDouble() * multiplier))
+                            + minSize;
+                    arrObjects.add(new byte[(int)allocationSize]);
+                } else {
+                    arrSoftRefs.add(new SoftReference(new Object()));
+                }
+
+                counter++;
+                if (counter == Long.MAX_VALUE) {
+                    counter = 0;
+                }
+            }
+        } catch (OutOfMemoryError oome) {
+            // Clear allocated ballast, so we don't get another OOM.
+
+            arrObjects = null;
+
+            // Get the number of soft refs first, so we don't trigger
+            // another OOM.
+            oomSoftArraySize = arrSoftRefs.size();
+
+            for (SoftReference sr : arrSoftRefs) {
+                Object o = sr.get();
+
+                if (o != null) {
+                    numberOfNotNulledObjects++;
+                }
+            }
+
+            // Make sure we clear all refs before we return failure
+            arrSoftRefs = null;
+
+            if (numberOfNotNulledObjects > 0) {
+                throw new RuntimeException(numberOfNotNulledObjects + " out of "
+                        + oomSoftArraySize + " SoftReferences was not "
+                        + "null at time of OutOfMemoryError");
+            }
+        } finally {
+            arrSoftRefs = null;
+            arrObjects = null;
+        }
+    }
+
+    private static final long getBytesCount(String arg) {
+        String postfixes = "kMGT";
+        long mod = 1;
+
+        if (arg.trim().length() >= 2) {
+            mod = postfixes.indexOf(
+                    arg.trim().charAt(arg.length() - 1)
+            );
+
+            if (mod != -1) {
+                mod = (long) Math.pow(1024, mod+1);
+                arg = arg.substring(0, arg.length() - 1);
+            } else {
+                mod = 1; // 10^0
+            }
+        }
+
+        return Long.parseLong(arg) * mod;
+    }
+
+    private static final long DEFAULT_MIN_SIZE = 512;
+    private static final long DEFAULT_MAX_SIZE = 1024;
+    private static final int DEFAULT_FREQUENCY = 4;
+}