Merged revisions 83921 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/branches/py3k

........
  r83921 | antoine.pitrou | 2010-08-10 01:39:31 +0200 (mar., 10 août 2010) | 4 lines

  Issue #6915: Under Windows, os.listdir() didn't release the Global
  Interpreter Lock around all system calls.  Original patch by Ryan Kelly.
........
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index cb3075b..d6e491c 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -2270,7 +2270,9 @@
                 free(wnamebuf);
                 return NULL;
             }
+            Py_BEGIN_ALLOW_THREADS
             hFindFile = FindFirstFileW(wnamebuf, &wFileData);
+            Py_END_ALLOW_THREADS
             if (hFindFile == INVALID_HANDLE_VALUE) {
                 int error = GetLastError();
                 if (error == ERROR_FILE_NOT_FOUND) {
@@ -2348,7 +2350,9 @@
     if ((d = PyList_New(0)) == NULL)
         return NULL;
 
+    Py_BEGIN_ALLOW_THREADS
     hFindFile = FindFirstFile(namebuf, &FileData);
+    Py_END_ALLOW_THREADS
     if (hFindFile == INVALID_HANDLE_VALUE) {
         int error = GetLastError();
         if (error == ERROR_FILE_NOT_FOUND)