[Jython-checkins] jython: memoryview: correct double acquisition of export

[jeff.allen]

http://hg.python.org/jython/rev/360eb0a402fe
changeset:   7148:360eb0a402fe
parent:      7146:4af2f4241912
user:        Jeff Allen <ja.py at farowl.co.uk>
date:        Fri Nov 01 22:58:33 2013 +0000
summary:
  memoryview: correct double acquisition of export
Added test to test_bytes to show that a released memoryview
no longer locks its underlying object (Jython only, in v2.7).

files:
  Lib/test/test_bytes.py                |   5 +++
  src/org/python/core/PyMemoryView.java |  20 +++++++-------
  2 files changed, 15 insertions(+), 10 deletions(-)


diff --git a/Lib/test/test_bytes.py b/Lib/test/test_bytes.py
--- a/Lib/test/test_bytes.py
+++ b/Lib/test/test_bytes.py
@@ -886,6 +886,11 @@
         self.assertRaises(BufferError, delslice)
         self.assertEqual(b, orig)
 
+        if test.test_support.is_jython:
+            # Show that releasing v releases the bytearray for size change
+            v.release()
+            b.pop()
+
     def test_empty_bytearray(self):
         # Issue #7561: operations on empty bytearrays could crash in many
         # situations, due to a fragile implementation of the
diff --git a/src/org/python/core/PyMemoryView.java b/src/org/python/core/PyMemoryView.java
--- a/src/org/python/core/PyMemoryView.java
+++ b/src/org/python/core/PyMemoryView.java
@@ -38,14 +38,19 @@
     private boolean hashCacheValid = false;
 
     /**
-     * Construct a PyMemoryView from a PyBuffer interface. The buffer so obtained will be writable
-     * if the underlying object permits it. The <code>memoryview</code> takes a new lease on the
-     * <code>PyBuffer</code>.
+     * Construct a <code>PyMemoryView</code> from an object bearing the {@link BufferProtocol}
+     * interface. If this object is already an exported buffer, the <code>memoryview</code> takes a
+     * new lease on it. The buffer so obtained will be writable if the underlying object permits it.
      *
      * @param pybuf buffer exported by some underlying object
      */
-    public PyMemoryView(PyBuffer pybuf) {
+    public PyMemoryView(BufferProtocol pybuf) {
         super(TYPE);
+        /*
+         * Ask for the full set of facilities (strides, indirect, etc.) from the object in case they
+         * are necessary for navigation, but only ask for read access. If the object is writable,
+         * the PyBuffer will be writable.
+         */
         backing = pybuf.getBuffer(PyBUF.FULL_RO);
     }
 
@@ -63,12 +68,7 @@
         PyObject obj = ap.getPyObject(0);
 
         if (obj instanceof BufferProtocol) {
-            /*
-             * Ask for the full set of facilities (strides, indirect, etc.) from the object in case
-             * they are necessary for navigation, but only ask for read access. If the object is
-             * writable, the PyBuffer will be writable.
-             */
-            return new PyMemoryView(((BufferProtocol)obj).getBuffer(PyBUF.FULL_RO));
+            return new PyMemoryView((BufferProtocol)obj);
         } else {
             throw Py.TypeError("cannot make memory view because object does not have "
                     + "the buffer interface");

-- 
Repository URL: http://hg.python.org/jython