Initialize ThreadLocalRandom.seeder at run time.

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jdk/RandomAccessors.java

@@ -0,0 +1,97 @@
+/*
+ * Copyright (c) 2020, 2020, 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 com.oracle.svm.core.jdk;
+
+import java.util.concurrent.atomic.AtomicLong;
+
+/**
+ * RandomAccessors initializes a seeder at run time, on first access. The mechanism is used by both
+ * SplittableRandomAccessors and ThreadLocalRandomAccessors since they share the same seeder
+ * initialization logic, but use a different implementation of mix64().
+ */
+public abstract class RandomAccessors {
+
+    /*
+     * We read the value of java.util.secureRandomSeed deliberately during image generation, so that
+     * the SecureRandom code is only reachable and included in the image when requested by the
+     * application.
+     */
+    private static final boolean SECURE_SEED = java.security.AccessController.doPrivileged(
+                    new java.security.PrivilegedAction<Boolean>() {
+                        @Override
+                        public Boolean run() {
+                            return Boolean.getBoolean("java.util.secureRandomSeed");
+                        }
+                    });
+
+    private volatile AtomicLong seeder;
+
+    protected AtomicLong getOrInitializeSeeder() {
+        AtomicLong result = seeder;
+        if (result == null) {
+            result = initialize();
+        }
+        return result;
+    }
+
+    // Checkstyle: allow synchronization
+    /**
+     * It is important that this synchronization is on an instance method and not on a static
+     * method. A static synchronized method will lock the java.lang.Class object and SVM currently
+     * uses a secondary storage map for locking on classes. Syncronizing on a class object can lead
+     * to recursive locking problems when this particular code is called from the constructor of
+     * JavaVMOperation.
+     */
+    private synchronized AtomicLong initialize() {
+        AtomicLong result = seeder;
+        if (result != null) {
+            return result;
+        }
+
+        /*
+         * The code below to compute the seed is taken from the original
+         * SplittableRandom.initialSeed()/ThreadLocalRandom.initialSeed() implementation.
+         */
+        long seed;
+        if (SECURE_SEED) {
+            byte[] seedBytes = java.security.SecureRandom.getSeed(8);
+            seed = seedBytes[0] & 0xffL;
+            for (int i = 1; i < 8; ++i) {
+                seed = (seed << 8) | (seedBytes[i] & 0xffL);
+            }
+        } else {
+            seed = mix64(System.currentTimeMillis()) ^ mix64(System.nanoTime());
+        }
+
+        result = new AtomicLong(seed);
+        seeder = result;
+        return result;
+
+    }
+    // Checkstyle: disallow synchronization
+
+    abstract long mix64(long l);
+}

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jdk/RandomNumbersFeature.java

@@ -24,13 +24,12 @@
  */
 package com.oracle.svm.core.jdk;
 
-import java.util.concurrent.ThreadLocalRandom;
-
-import com.oracle.svm.core.annotate.AutomaticFeature;
 import org.graalvm.nativeimage.ImageSingletons;
 import org.graalvm.nativeimage.hosted.Feature;
 import org.graalvm.nativeimage.impl.RuntimeClassInitializationSupport;
 
+import com.oracle.svm.core.annotate.AutomaticFeature;
+
 @AutomaticFeature
 public class RandomNumbersFeature implements Feature {
 
@@ -41,6 +40,5 @@ public void duringSetup(DuringSetupAccess access) {
          * values properly. Otherwise the numbers generated will be fixed for each generated image.
          */
         ImageSingletons.lookup(RuntimeClassInitializationSupport.class).rerunInitialization(access.findClassByName("java.lang.Math$RandomNumberGeneratorHolder"), "for random number generator");
-        ImageSingletons.lookup(RuntimeClassInitializationSupport.class).rerunInitialization(ThreadLocalRandom.class, "for random number generator");
     }
 }

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jdk/SplittableRandomAccessors.java

@@ -34,76 +34,28 @@
 @TargetClass(java.util.SplittableRandom.class)
 final class Target_java_util_SplittableRandom {
 
+    /**
+     * The seed generator for default constructors is initialized at run time, on first access, to
+     * prevent baking in an initial seed from the build system.
+     */
     @Alias @InjectAccessors(SplittableRandomAccessors.class)//
     private static AtomicLong defaultGen;
 
     @Alias
     static native long mix64(long z);
 }
 
-public class SplittableRandomAccessors {
-
-    /*
-     * We run this code deliberately during image generation, so that the SecureRandom code is only
-     * reachable and included in the image when requested by the application.
-     */
-    private static final boolean SECURE_SEED = java.security.AccessController.doPrivileged(
-                    new java.security.PrivilegedAction<Boolean>() {
-                        @Override
-                        public Boolean run() {
-                            return Boolean.getBoolean("java.util.secureRandomSeed");
-                        }
-                    });
+public class SplittableRandomAccessors extends RandomAccessors {
 
-    private static volatile AtomicLong defaultGen;
+    private static final SplittableRandomAccessors SINGLETON = new SplittableRandomAccessors();
 
     /** The get-accessor for SplittableRandom.defaultGen. */
     public static AtomicLong getDefaultGen() {
-        AtomicLong result = defaultGen;
-        if (result == null) {
-            result = initialize();
-        }
-        return result;
-    }
-
-    private static class Lock {
+        return SINGLETON.getOrInitializeSeeder();
     }
 
-    private static final Lock lock = new Lock();
-
-    // Checkstyle: allow synchronization
-    private static AtomicLong initialize() {
-        /**
-         * Lock on an instance instead of a java.lang.Class object because SVM currently uses a
-         * secondary storage map for locking on classes, which in this particular case can lead to
-         * recursive locking problems when this code is called from the constructor of
-         * JavaVMOperation.
-         */
-        synchronized (lock) {
-            AtomicLong result = defaultGen;
-            if (result != null) {
-                return result;
-            }
-
-            /*
-             * The code below to compute the seed is taken from the original
-             * SplittableRandom.initialSeed() implementation.
-             */
-            long seed;
-            if (SECURE_SEED) {
-                byte[] seedBytes = java.security.SecureRandom.getSeed(8);
-                seed = seedBytes[0] & 0xffL;
-                for (int i = 1; i < 8; ++i) {
-                    seed = (seed << 8) | (seedBytes[i] & 0xffL);
-                }
-            } else {
-                seed = Target_java_util_SplittableRandom.mix64(System.currentTimeMillis()) ^ Target_java_util_SplittableRandom.mix64(System.nanoTime());
-            }
-
-            result = new AtomicLong(seed);
-            defaultGen = result;
-            return result;
-        }
+    @Override
+    long mix64(long l) {
+        return Target_java_util_SplittableRandom.mix64(l);
     }
-    // Checkstyle: disallow synchronization
 }

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jdk/ThreadLocalRandomAccessors.java

@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2020, 2020, 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 com.oracle.svm.core.jdk;
+
+import java.util.concurrent.atomic.AtomicLong;
+
+import com.oracle.svm.core.annotate.Alias;
+import com.oracle.svm.core.annotate.InjectAccessors;
+import com.oracle.svm.core.annotate.TargetClass;
+
+@TargetClass(java.util.concurrent.ThreadLocalRandom.class)
+final class Target_java_util_concurrent_ThreadLocalRandom {
+
+    /**
+     * The seed generator for default constructors is initialized at run time, on first access, to
+     * prevent baking in an initial seed from the build system.
+     */
+    @Alias @InjectAccessors(ThreadLocalRandomAccessors.class)//
+    private static AtomicLong seeder;
+
+    @Alias
+    static native long mix64(long z);
+
+}
+
+public class ThreadLocalRandomAccessors extends RandomAccessors {
+
+    private static final ThreadLocalRandomAccessors SINGLETON = new ThreadLocalRandomAccessors();
+
+    /** The get-accessor for ThreadLocalRandom.seeder. */
+    public static AtomicLong getSeeder() {
+        return SINGLETON.getOrInitializeSeeder();
+    }
+
+    @Override
+    long mix64(long l) {
+        return Target_java_util_concurrent_ThreadLocalRandom.mix64(l);
+    }
+}

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/monitor/MultiThreadedMonitorSupport.java

@@ -140,9 +140,10 @@ public class MultiThreadedMonitorSupport extends MonitorSupport {
              * The map access in MultiThreadedMonitorSupport.getOrCreateMonitorFromMap() calls
              * System.identityHashCode() which on the slow path calls
              * IdentityHashCodeSupport.generateIdentityHashCode(). The hashcode generation calls
-             * SplittableRandomAccessors.initialize() which synchronizes on the a Lock object.
+             * SplittableRandomAccessors.initialize() which synchronizes on an instance of
+             * SplittableRandomAccessors.
              */
-            monitorTypes.add(Class.forName("com.oracle.svm.core.jdk.SplittableRandomAccessors$Lock"));
+            monitorTypes.add(Class.forName("com.oracle.svm.core.jdk.SplittableRandomAccessors"));
 
             FORCE_MONITOR_SLOT_TYPES = Collections.unmodifiableSet(monitorTypes);
         } catch (ClassNotFoundException e) {