closes bpo-36139: release GIL around munmap(). (pythonGH-12073)

Author: sorcio

Misc/NEWS.d/next/Library/2019-03-06-13-07-29.bpo-36139.6kedum.rst

@@ -0,0 +1 @@
+Release GIL when closing :class:`~mmap.mmap` objects.

Modules/mmapmodule.c

@@ -117,6 +117,7 @@ typedef struct {
 static void
 mmap_object_dealloc(mmap_object *m_obj)
 {
+ Py_BEGIN_ALLOW_THREADS
 #ifdef MS_WINDOWS
  if (m_obj->data != NULL)
  UnmapViewOfFile (m_obj->data);
@@ -135,6 +136,7 @@ mmap_object_dealloc(mmap_object *m_obj)
  munmap(m_obj->data, m_obj->size);
  }
 #endif /* UNIX */
+ Py_END_ALLOW_THREADS
 
  if (m_obj->weakreflist != NULL)
  PyObject_ClearWeakRefs((PyObject *) m_obj);
@@ -157,28 +159,37 @@ mmap_close_method(mmap_object *self, PyObject *unused)
  again.
  TODO - should we check for errors in the close operations???
  */
- if (self->data != NULL) {
- UnmapViewOfFile(self->data);
- self->data = NULL;
+ HANDLE map_handle = self->map_handle;
+ HANDLE file_handle = self->file_handle;
+ char *data = self->data;
+ self->map_handle = NULL;
+ self->file_handle = INVALID_HANDLE_VALUE;
+ self->data = NULL;
+ Py_BEGIN_ALLOW_THREADS
+ if (data != NULL) {
+ UnmapViewOfFile(data);
  }
- if (self->map_handle != NULL) {
- CloseHandle(self->map_handle);
- self->map_handle = NULL;
+ if (map_handle != NULL) {
+ CloseHandle(map_handle);
  }
- if (self->file_handle != INVALID_HANDLE_VALUE) {
- CloseHandle(self->file_handle);
- self->file_handle = INVALID_HANDLE_VALUE;
+ if (file_handle != INVALID_HANDLE_VALUE) {
+ CloseHandle(file_handle);
  }
+ Py_END_ALLOW_THREADS
 #endif /* MS_WINDOWS */
 
 #ifdef UNIX
- if (0 <= self->fd)
-  (void) close(self->fd);
+ int fd = self->fd;
+ char *data = self->data;
  self->fd = -1;
- if (self->data != NULL) {
- munmap(self->data, self->size);
- self->data = NULL;
+ self->data = NULL;
+ Py_BEGIN_ALLOW_THREADS
+ if (0 <= fd)
+ (void) close(fd);
+ if (data != NULL) {
+ munmap(data, self->size);
  }
+ Py_END_ALLOW_THREADS
 #endif
 
  Py_RETURN_NONE;