7100935: win32: memmove is not atomic but is used for pd_conjoint_*_atomic operations

Summary: replace the call to memmove by a simple copy loop
Reviewed-by: dholmes, kvn, never
Contributed-by: axel.siebenborn@sap.com, volker.simonis@gmail.com

src/cpu/sparc/vm/copy_sparc.hpp

 /*
- * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2011, 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
@@ -82,13 +82,35 @@ static void pd_conjoint_bytes_atomic(void* from, void* to, size_t count) {
 }
 
 static void pd_conjoint_jshorts_atomic(jshort* from, jshort* to, size_t count) {
-  // FIXME
-  (void)memmove(to, from, count << LogBytesPerShort);
+  if (from > to) {
+    while (count-- > 0) {
+      // Copy forwards
+      *to++ = *from++;
+    }
+  } else {
+    from += count - 1;
+    to   += count - 1;
+    while (count-- > 0) {
+      // Copy backwards
+      *to-- = *from--;
+    }
+  }
 }
 
 static void pd_conjoint_jints_atomic(jint* from, jint* to, size_t count) {
-  // FIXME
-  (void)memmove(to, from, count << LogBytesPerInt);
+  if (from > to) {
+    while (count-- > 0) {
+      // Copy forwards
+      *to++ = *from++;
+    }
+  } else {
+    from += count - 1;
+    to   += count - 1;
+    while (count-- > 0) {
+      // Copy backwards
+      *to-- = *from--;
+    }
+  }
 }
 
 static void pd_conjoint_jlongs_atomic(jlong* from, jlong* to, size_t count) {

src/os_cpu/windows_x86/vm/copy_windows_x86.inline.hpp

 /*
- * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2011, 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
@@ -85,13 +85,35 @@ static void pd_conjoint_bytes_atomic(void* from, void* to, size_t count) {
 }
 
 static void pd_conjoint_jshorts_atomic(jshort* from, jshort* to, size_t count) {
-  // FIXME
-  (void)memmove(to, from, count << LogBytesPerShort);
+  if (from > to) {
+    while (count-- > 0) {
+      // Copy forwards
+      *to++ = *from++;
+    }
+  } else {
+    from += count - 1;
+    to   += count - 1;
+    while (count-- > 0) {
+      // Copy backwards
+      *to-- = *from--;
+    }
+  }
 }
 
 static void pd_conjoint_jints_atomic(jint* from, jint* to, size_t count) {
-  // FIXME
-  (void)memmove(to, from, count << LogBytesPerInt);
+  if (from > to) {
+    while (count-- > 0) {
+      // Copy forwards
+      *to++ = *from++;
+    }
+  } else {
+    from += count - 1;
+    to   += count - 1;
+    while (count-- > 0) {
+      // Copy backwards
+      *to-- = *from--;
+    }
+  }
 }
 
 static void pd_conjoint_jlongs_atomic(jlong* from, jlong* to, size_t count) {

test/runtime/7100935/TestConjointAtomicArraycopy.java

+/*
+ * Copyright 2011 SAP AG.  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 TestConjointAtomicArraycopy
+ * @bug 7100935
+ * @summary verify that oops are copied element-wise atomic
+ * @run main/othervm -Xint TestConjointAtomicArraycopy
+ * @run main/othervm -Xcomp -Xbatch TestConjointAtomicArraycopy
+ * @author axel.siebenborn@sap.com
+ */
+
+public class TestConjointAtomicArraycopy {
+
+  static volatile Object [] testArray = new Object [4];
+
+  static short[] a1 = new short[8];
+  static short[] a2 = new short[8];
+  static short[] a3 = new short[8];
+
+  static volatile boolean keepRunning = true;
+
+  static void testOopsCopy() throws InterruptedException{
+
+  }
+
+  public static void main(String[] args ) throws InterruptedException{
+    for (int i = 0; i < testArray.length; i++){
+      testArray[i] = new String("A");
+    }
+
+    Thread writer = new Thread (new Runnable(){
+      public void run(){
+        for (int i = 0 ; i < 1000000; i++) {
+          System.arraycopy(testArray, 1, testArray, 0, 3);
+          testArray[2] = new String("a");
+        }
+      }
+    });
+
+    Thread reader = new Thread( new Runnable(){
+      public void run(){
+        while (keepRunning){
+          String name = testArray[2].getClass().getName();
+          if(!(name.endsWith("String"))){
+            throw new RuntimeException("got wrong class name");
+          }
+        }
+      }
+    });
+    keepRunning = true;
+    reader.start();
+    writer.start();
+    writer.join();
+    keepRunning = false;
+    reader.join();
+  }
+}

test/runtime/7100935/TestShortArraycopy.java

+/*
+ * Copyright 2011 SAP AG.  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 TestShortArraycopy
+ * @bug 7100935
+ * @summary  verify that shorts are copied element-wise atomic.
+ * @run main/othervm -Xint TestShortArraycopy
+ * @run main/othervm -Xcomp -Xbatch TestShortArraycopy
+ * @author volker.simonis@gmail.com
+ */
+
+public class TestShortArraycopy {
+
+  static short[] a1 = new short[8];
+  static short[] a2 = new short[8];
+  static short[] a3 = new short[8];
+
+  static volatile boolean keepRunning = true;
+
+  public static void main(String[] args) throws InterruptedException {
+
+    for (int i = 0; i < a1.length ; i++) {
+      a1[i] = (short)0xffff;
+      a2[i] = (short)0xffff;
+      a3[i] = (short)0x0000;
+    }
+    Thread reader = new Thread() {
+      public void run() {
+        while (keepRunning) {
+          for (int j = 0; j < a1.length; j++) {
+            short s = a1[j];
+            if (s != (short)0xffff && s != (short)0x0000) {
+              System.out.println("Error: s = " + s);
+              throw new RuntimeException("wrong result");
+
+            }
+          }
+        }
+      }
+    };
+    Thread writer = new Thread() {
+      public void run() {
+        for (int i = 0; i < 1000000; i++) {
+          System.arraycopy(a2, 5, a1, 3, 3);
+          System.arraycopy(a3, 5, a1, 3, 3);
+        }
+      }
+    };
+    keepRunning = true;
+    reader.start();
+    writer.start();
+    writer.join();
+    keepRunning = false;
+    reader.join();
+  }
+}