8263742: (bf) MappedByteBuffer.force() should use the capacity as its upper bound

Reviewed-by: adinn, alanb

Author: Brian Burkhalter

src/java.base/share/classes/java/nio/MappedByteBuffer.java

@@ -232,9 +232,9 @@ public final MappedByteBuffer force() {
         if (fd == null) {
             return this;
         }
-        int limit = limit();
-        if (isSync || ((address != 0) && (limit != 0))) {
-            return force(0, limit);
+        int capacity = capacity();
+        if (isSync || ((address != 0) && (capacity != 0))) {
+            return force(0, capacity);
         }
         return this;
     }
@@ -267,11 +267,11 @@ public final MappedByteBuffer force() {
      * @param  index
      *         The index of the first byte in the buffer region that is
      *         to be written back to storage; must be non-negative
-     *         and less than limit()
+     *         and less than {@code capacity()}
      *
      * @param  length
      *         The length of the region in bytes; must be non-negative
-     *         and no larger than limit() - index
+     *         and no larger than {@code capacity() - index}
      *
      * @throws IndexOutOfBoundsException
      *         if the preconditions on the index and length do not
@@ -289,10 +289,10 @@ public final MappedByteBuffer force(int index, int length) {
         if (fd == null) {
             return this;
         }
-        int limit = limit();
-        if ((address != 0) && (limit != 0)) {
+        int capacity = capacity();
+        if ((address != 0) && (capacity != 0)) {
             // check inputs
-            Objects.checkFromIndexSize(index, length, limit);
+            Objects.checkFromIndexSize(index, length, capacity);
             SCOPED_MEMORY_ACCESS.force(scope(), fd, address, isSync, index, length);
         }
         return this;