fixed the memory leak under Python 2.7

* contributed by jferrara: http://sourceforge.net/projects/pycam/forums/forum/860184/topic/4753623


git-svn-id: https://pycam.svn.sourceforge.net/svnroot/pycam/trunk@1223 bbaffbd6-741e-11dd-a85d-61de82d9cad9

src/pycam/Utils/threading.py

@@ -629,14 +629,19 @@ def run_in_parallel_local(func, args, unordered=False,
             imap_func = pool.imap_unordered
         else:
             imap_func = pool.imap
-        # Beware: we may not return "pool.imap" or "pool.imap_unordered"
-        # directly. It would somehow loose the focus and just hang infinitely.
-        # Thus we wrap our own generator around it.
-        for result in imap_func(func, args):
-            if callback and callback():
-                # cancel requested
-                break
-            yield result
+        # We need to use try/finally here to ensure the garbage collection
+        # of "pool". Otherwise a memory overflow is caused for Python 2.7.
+        try:
+            # Beware: we may not return "pool.imap" or "pool.imap_unordered"
+            # directly. It would somehow loose the focus and just hang infinitely.
+            # Thus we wrap our own generator around it.
+            for result in imap_func(func, args):
+                if callback and callback():
+                    # cancel requested
+                    break
+                yield result
+        finally:
+            pool.terminate()
     else:
         for arg in args:
             if callback and callback():