src/java.base/share/classes/jdk/internal/misc/Unsafe.java

rev 57826 : 8237521: Memory Access API fixes for 32-bit
Reviewed-by: mcimadamore, dholmes

@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 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

@@ -582,10 +582,21 @@
 
 
     /// wrappers for malloc, realloc, free:
 
     /**
+     * Round up allocation size to a multiple of HeapWordSize.
+     */
+    private long alignToHeapWordSize(long bytes) {
+        if (bytes >= 0) {
+            return (bytes + ADDRESS_SIZE - 1) & ~(ADDRESS_SIZE - 1);
+        } else {
+            throw invalidInput();
+        }
+    }
+
+    /**
      * Allocates a new block of native memory, of the given size in bytes.  The
      * contents of the memory are uninitialized; they will generally be
      * garbage.  The resulting native pointer will never be zero, and will be
      * aligned for all value types.  Dispose of this memory by calling {@link
      * #freeMemory}, or resize it with {@link #reallocateMemory}.

@@ -606,10 +617,12 @@
      *
      * @see #getByte(long)
      * @see #putByte(long, byte)
      */
     public long allocateMemory(long bytes) {
+        bytes = alignToHeapWordSize(bytes);
+
         allocateMemoryChecks(bytes);
 
         if (bytes == 0) {
             return 0;
         }

@@ -659,10 +672,12 @@
      * @throws OutOfMemoryError if the allocation is refused by the system
      *
      * @see #allocateMemory
      */
     public long reallocateMemory(long address, long bytes) {
+        bytes = alignToHeapWordSize(bytes);
+
         reallocateMemoryChecks(address, bytes);
 
         if (bytes == 0) {
             freeMemory(address);
             return 0;