.

bigfile/_file_zodb.pyx

@@ -113,7 +113,6 @@ cdef public class _ZBigFile(BigFile) [object _ZBigFile, type _ZBigFile_Type]:
             if zf.wfileh == nil:
                 zconn = zf.zself._p_jar
                 assert zconn is not None
-                # XXX locking? or rely on that ZODB objects for zconn must be used from under 1 thread only?
 
                 # join zconn to wconn; link to wconn from _ZBigFile
                 pywconn   = pywconnOf(zconn)
@@ -127,14 +126,14 @@ cdef public class _ZBigFile(BigFile) [object _ZBigFile, type _ZBigFile_Type]:
 
 # pywconnOf establishes and returns (py) wcfs.Conn associated with zconn.
 #
-# returned wcfs.Conn will be maintained to keep in sync with zconn.
+# returned wcfs.Conn will be maintained to keep in sync with zconn, and will be
+# closed when zconn is destroyed.
 #
-# XXX closed on zconn dealloc ?
-# XXX simultaneous call?
-# XXX move -> .py ?
+# It is invalid to make simultaneous calls to pywconnOf with the same zconn.
+# (in ZODB/py objects for zconn must be used from under 1 thread only).
 cdef wcfs.PyConn pywconnOf(zconn):
     assert isinstance(zconn, ZConnection)
-    assert zconn.opened     # XXX needed?
+    assert zconn.opened
 
     # XXX locking
     wconn = getattr(zconn, '_wcfs_wconn', None)
@@ -164,8 +163,7 @@ class ZSync:
     # .wconn        (py) wcfs.Connection
 
     def __init__(zsync, zconn, wconn):
-        #print('ZSync %r %r' % (zconn, wconn))
-        assert zconn.open
+        assert zconn.opened
         zsync.wconn     = wconn
         zsync.zconn_ref = weakref.ref(zconn, zsync.on_zconn_dealloc)
 
@@ -183,7 +181,5 @@ class ZSync:
     # DB resyncs .zconn onto new database view.
     # -> resync .wconn to updated database view of ZODB connection.
     def on_connection_resync(zsync):
-        #print('\nZZZSync.resync %r %r' % (zsync.zconn, zsync.wconn))
-        #import traceback; traceback.print_stack()
         zconn = zsync.zconn_ref()
         zsync.wconn.resync(zconn_at(zconn))