Add weakref support to the thread.lock type.
diff --git a/Doc/library/weakref.rst b/Doc/library/weakref.rst
index 5dcb030..a1a3314 100644
--- a/Doc/library/weakref.rst
+++ b/Doc/library/weakref.rst
@@ -65,6 +65,9 @@
.. versionchanged:: 2.4
Added support for files, sockets, arrays, and patterns.
+.. versionchanged:: 2.7
+ Added support for thread.lock and threading.Lock.
+
Several built-in types such as :class:`list` and :class:`dict` do not directly
support weak references but can add support through subclassing::
diff --git a/Misc/NEWS b/Misc/NEWS
index 8977e19..7bb0d5e 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -359,6 +359,8 @@
Library
-------
+- The thread.lock type now supports weak references.
+
- Issue #1356969: Add missing info methods in Tix.HList.
- Issue #1522587: New constants and methods for the Tix.Grid widget.
diff --git a/Modules/threadmodule.c b/Modules/threadmodule.c
index e7638bb..ad84a1e 100644
--- a/Modules/threadmodule.c
+++ b/Modules/threadmodule.c
@@ -3,6 +3,7 @@
/* Interface to Sjoerd's portable C thread library */
#include "Python.h"
+#include "structmember.h" /* offsetof */
#ifndef WITH_THREAD
#error "Error! The rest of Python is not compiled with thread support."
@@ -20,12 +21,15 @@
typedef struct {
PyObject_HEAD
PyThread_type_lock lock_lock;
+ PyObject *in_weakreflist;
} lockobject;
static void
lock_dealloc(lockobject *self)
{
assert(self->lock_lock);
+ if (self->in_weakreflist != NULL)
+ PyObject_ClearWeakRefs((PyObject *) self);
/* Unlock the lock so it's safe to free it */
PyThread_acquire_lock(self->lock_lock, 0);
PyThread_release_lock(self->lock_lock);
@@ -140,12 +144,12 @@
0, /* tp_getattro */
0, /* tp_setattro */
0, /* tp_as_buffer */
- 0, /* tp_flags */
+ Py_TPFLAGS_HAVE_WEAKREFS, /* tp_flags */
0, /* tp_doc */
0, /* tp_traverse */
0, /* tp_clear */
0, /* tp_richcompare */
- 0, /* tp_weaklistoffset */
+ offsetof(lockobject, in_weakreflist), /* tp_weaklistoffset */
0, /* tp_iter */
0, /* tp_iternext */
lock_methods, /* tp_methods */
@@ -159,6 +163,7 @@
if (self == NULL)
return NULL;
self->lock_lock = PyThread_allocate_lock();
+ self->in_weakreflist = NULL;
if (self->lock_lock == NULL) {
PyObject_Del(self);
self = NULL;