thread._local, threading.local Python issue 1868 & 3710

Modules/threadmodule.c

 
 /* Thread module */
 /* Interface to Sjoerd's portable C thread library */
 
 #include "Python.h"
 
 #ifndef WITH_THREAD
 #error "Error!  The rest of Python is not compiled with thread support."
 #error "Rerun configure, adding a --with-threads option."
 #error "Then run `make clean' followed by `make'."
@@ skipping 186 matching lines @@
         if (localdict == NULL)
                 goto err;
 
         tdict = PyThreadState_GetDict();
         if (tdict == NULL) {
                 PyErr_SetString(PyExc_SystemError,
                                 "Couldn't get thread-state dictionary");
                 goto err;
         }
 
-        if (PyDict_SetItem(tdict, self->key, localdict) < 0)
+        if (PyDict_SetItem(tdict, self->key, localdict) < 0) {
+                Py_DECREF(localdict);
                 goto err;
+        }
         Py_DECREF(localdict);
 
         return (PyObject *)self;
 
   err:
         Py_DECREF(self);
         return NULL;
 }
 
 static int
@@ skipping 73 matching lines @@
         return ldict;
 }
 
 static int
 local_setattro(localobject *self, PyObject *name, PyObject *v)
 {
         PyObject *ldict = _ldict(self);
         if (ldict == NULL) 
                 return -1;
 
-        return PyDict_SetItem(ldict, name, v);
+        if (v != NULL) {
+                return PyDict_SetItem(ldict, name, v);
+        } else {
+                int res;
+                res = PyDict_DelItem(ldict, name);
+                if ((res < 0) && PyErr_ExceptionMatches(PyExc_KeyError)) {
+                        PyErr_SetObject(PyExc_AttributeError, name);
+                }
+                return res;
+        }
 }
 
 static PyObject *
 local_getdict(localobject *self, void *closure)
 {
         PyObject *ldict = _ldict(self);
         if (ldict == NULL) {
                 PyErr_SetString(PyExc_AttributeError, "__dict__");
                 return NULL;
         }
@@ skipping 381 matching lines @@
         Py_INCREF(&Locktype);
         PyDict_SetItemString(d, "LockType", (PyObject *)&Locktype);
 
         Py_INCREF(&localtype);
         if (PyModule_AddObject(m, "_local", (PyObject *)&localtype) < 0)
                 return;
 
         /* Initialize the C thread library */
         PyThread_init_thread();
 }