python: Handle interpreter shutdown.

* lang/python/pyme/core.py: Avoid races at interpreter shutdown.  This
silences the most annoying occurrences, however this problem also
affects the SWIG generated code, which might indicate that the real
problem is somewhere else.  If so, this change can be easily reverted.

Signed-off-by: Justus Winter <[email protected]>

1 files changed, 22 insertions, 8 deletions

diff --git a/lang/python/pyme/core.py b/lang/python/pyme/core.py
index fd4802ec..2a37ba35 100644
--- a/lang/python/pyme/core.py
+++ b/lang/python/pyme/core.py
@@ -66,21 +66,29 @@ class Context(GpgmeWrapper):
         self.last_progresscb = None
 
     def __del__(self):
+        if not pygpgme:
+            # At interpreter shutdown, pygpgme is set to NONE.
+            return
+
         self._free_passcb()
         self._free_progresscb()
-        if self.own:
+        if self.own and pygpgme.gpgme_release:
             pygpgme.gpgme_release(self.wrapped)
 
     def _free_passcb(self):
         if self.last_passcb != None:
-            pygpgme.pygpgme_clear_generic_cb(self.last_passcb)
-            pygpgme.delete_PyObject_p_p(self.last_passcb)
+            if pygpgme.pygpgme_clear_generic_cb:
+                pygpgme.pygpgme_clear_generic_cb(self.last_passcb)
+            if pygpgme.delete_PyObject_p_p:
+                pygpgme.delete_PyObject_p_p(self.last_passcb)
             self.last_passcb = None
 
     def _free_progresscb(self):
         if self.last_progresscb != None:
-            pygpgme.pygpgme_clear_generic_cb(self.last_progresscb)
-            pygpgme.delete_PyObject_p_p(self.last_progresscb)
+            if pygpgme.pygpgme_clear_generic_cb:
+                pygpgme.pygpgme_clear_generic_cb(self.last_progresscb)
+            if pygpgme.delete_PyObject_p_p:
+                pygpgme.delete_PyObject_p_p(self.last_progresscb)
             self.last_progresscb = None
 
     def op_keylist_all(self, *args, **kwargs):
@@ -292,14 +300,20 @@ class Data(GpgmeWrapper):
             self.new()
 
     def __del__(self):
-        if self.wrapped != None:
+        if not pygpgme:
+            # At interpreter shutdown, pygpgme is set to NONE.
+            return
+
+        if self.wrapped != None and pygpgme.gpgme_data_release:
             pygpgme.gpgme_data_release(self.wrapped)
         self._free_readcb()
 
     def _free_readcb(self):
         if self.last_readcb != None:
-            pygpgme.pygpgme_clear_generic_cb(self.last_readcb)
-            pygpgme.delete_PyObject_p_p(self.last_readcb)
+            if pygpgme.pygpgme_clear_generic_cb:
+                pygpgme.pygpgme_clear_generic_cb(self.last_readcb)
+            if pygpgme.delete_PyObject_p_p:
+                pygpgme.delete_PyObject_p_p(self.last_readcb)
             self.last_readcb = None
 
     def new(self):