SF bug 128713: type(mmap_object) blew up on Linux.

Lib/tempfile.py

@@ -89,6 +89,7 @@ elif os.name == 'mac':
 else:
     template = 'tmp' # XXX might choose a better one
 
+_pidcache = {}
 def gettempprefix():
     """Function to calculate a prefix of the filename to use.
 
@@ -96,9 +97,15 @@ def gettempprefix():
     notion, so that concurrent processes don't generate the same prefix.
     """
 
-    global template
     if template is None:
-        return '@' + `os.getpid()` + '.'
+        p = os.getpid()
+        t = _pidcache.get(p, 0)
+        if t:
+            return t
+        if len(_pidcache) > 100:    # stop unbounded growth
+            _pidcache.clear()
+        t = _pidcache[p] = '@' + `p` + '.'
+        return t
     else:
         return template
 

Lib/test/output/test_mmap

@@ -1,4 +1,5 @@
 test_mmap
+<type 'mmap'>
   Position of foo: 1.0 pages
   Length of file: 2.0 pages
   Contents of byte 0: '\000'

Lib/test/test_mmap.py

@@ -18,6 +18,8 @@ def test_both():
     f.close()
 
     # Simple sanity checks
+
+    print type(m)  # SF bug 128713:  segfaulted on Linux
     print '  Position of foo:', string.find(m, 'foo') / float(PAGESIZE), 'pages'
     assert string.find(m, 'foo') == PAGESIZE
 

Modules/mmapmodule.c

@@ -841,9 +841,6 @@ new_mmap_object(PyObject *self, PyObject *args)
 	int fileno;
 	HANDLE fh = 0;
 
-	/* Patch the object type */
-	mmap_object_type.ob_type = &PyType_Type;
-
 	if (!PyArg_ParseTuple(args,
 			  "iO|z",
 			  &fileno,
@@ -956,6 +953,10 @@ DL_EXPORT(void)
 initmmap(void)
 {
 	PyObject *dict, *module;
+
+	/* Patch the object type */
+	mmap_object_type.ob_type = &PyType_Type;
+
 	module = Py_InitModule ("mmap", mmap_functions);
 	dict = PyModule_GetDict (module);
 	mmap_module_error = PyExc_EnvironmentError;