Drop the dependency on the ThreadLock distribution, by using Python's thread module instead.

buildout.cfg

@@ -41,7 +41,6 @@ eggs =
     Persistence
     Record
     RestrictedPython
-    ThreadLock
     initgroups
     tempstorage
     ZopeUndo

doc/CHANGES.rst

@@ -11,6 +11,9 @@ Trunk (unreleased)
 Restructuring
 +++++++++++++
 
+- Drop the dependency on the ThreadLock distribution, by using Python's thread
+  module instead.
+
 - Removed Zope2's own mkzeoinstance script. If you want to set up ZEO instances
   please install the zope.mkzeoinstance and use its script.
 

setup.py

@@ -66,7 +66,6 @@ setup(name='Zope2',
       'Persistence',
       'Record',
       'RestrictedPython',
-      'ThreadLock',
       'ZConfig',
       'ZODB3',
       'ZopeUndo',

src/Shared/DC/ZRDB/THUNK.py

@@ -11,11 +11,13 @@
 #
 ##############################################################################
 
-import TM, ThreadLock
+import thread
+
+import TM
 from TM import Surrogate
 import transaction
 
-thunk_lock=ThreadLock.allocate_lock()
+thunk_lock = thread.allocate_lock()
 
 class THUNKED_TM(TM.TM):
     """A big heavy hammer for handling non-thread safe DAs
@@ -35,14 +37,16 @@ class THUNKED_TM(TM.TM):
 
     def tpc_finish(self, *ignored):
         if self._registered:
-            try: self._finish()
+            try:
+                self._finish()
             finally:
                 thunk_lock.release()
                 self._registered=0
 
     def abort(self, *ignored):
         if self._registered:
-            try: self._abort()
+            try:
+                self._abort()
             finally:
                 thunk_lock.release()
                 self._registered=0

versions.cfg

@@ -14,7 +14,6 @@ Persistence = 2.13.1
 Record = 2.13.0
 RestrictedPython = 3.5.2
 tempstorage = 2.11.2
-ThreadLock = 2.13.0
 ZopeUndo = 2.12.0
 
 # Zope2 dependencies