select_select(): Closing bug #448351 the easy way, i.e. by changing

    the "#ifdef MS_WINDOWS" to "#ifdef SELECT_USES_HEAP" and by
    setting SELECT_USES_HEAP when FD_SETSIZE > 1024.

    The indirection seems useful since this subtly changes the path
    that "normal" Windows programs take (where Timmie sez FD_SETSIZE =
    512).  If that's a problem for Windows, he has only one place to
    change.

diff --git a/Modules/selectmodule.c b/Modules/selectmodule.c
index c92dc7f18ab9bf602e4e3626d7a2bd46e91e9f05..285f6f046c734ad8b805653062dc9b80659c80ba 100644 (file)
--- a/Modules/selectmodule.c
+++ b/Modules/selectmodule.c
@@ -181,18 +181,31 @@ set2list(fd_set *set, pylist fd2obj[FD_SETSIZE + 3])
        return NULL;
 }
 
-    
+#undef SELECT_USES_HEAP
+#if FD_SETSIZE > 1024
+#define SELECT_USES_HEAP
+#endif /* FD_SETSIZE > 1024 */
+
 static PyObject *
 select_select(PyObject *self, PyObject *args)
 {
-#ifdef MS_WINDOWS
+#ifdef SELECT_USES_HEAP
        /* This would be an awful lot of stack space on Windows! */
        pylist *rfd2obj, *wfd2obj, *efd2obj;
-#else
+#else  /* !SELECT_USES_HEAP */
+       /* XXX: Why, oh why does this add 3?!  As far as anyone can tell,
+        * it should only add 1 for the sentinel.
+        *
+        * XXX: All this should probably be implemented as follows:
+        * - find the highest descriptor we're interested in
+        * - add one
+        * - that's the size
+        * See: Stevens, APitUE, $12.5.1
+        */
        pylist rfd2obj[FD_SETSIZE + 3];
        pylist wfd2obj[FD_SETSIZE + 3];
        pylist efd2obj[FD_SETSIZE + 3];
-#endif
+#endif /* SELECT_USES_HEAP */
        PyObject *ifdlist, *ofdlist, *efdlist;
        PyObject *ret = NULL;
        PyObject *tout = Py_None;
@@ -237,7 +250,7 @@ select_select(PyObject *self, PyObject *args)
                return NULL;
        }
 
-#ifdef MS_WINDOWS
+#ifdef SELECT_USES_HEAP
        /* Allocate memory for the lists */
        rfd2obj = PyMem_NEW(pylist, FD_SETSIZE + 3);
        wfd2obj = PyMem_NEW(pylist, FD_SETSIZE + 3);
@@ -248,7 +261,7 @@ select_select(PyObject *self, PyObject *args)
                if (efd2obj) PyMem_DEL(efd2obj);
                return NULL;
        }
-#endif
+#endif /* SELECT_USES_HEAP */
        /* Convert lists to fd_sets, and get maximum fd number
         * propagates the Python exception set in list2set()
         */
@@ -302,11 +315,11 @@ select_select(PyObject *self, PyObject *args)
        reap_obj(rfd2obj);
        reap_obj(wfd2obj);
        reap_obj(efd2obj);
-#ifdef MS_WINDOWS
+#ifdef SELECT_USES_HEAP
        PyMem_DEL(rfd2obj);
        PyMem_DEL(wfd2obj);
        PyMem_DEL(efd2obj);
-#endif
+#endif /* SELECT_USES_HEAP */
        return ret;
 }