[Zodb-checkins] SVN: ZODB/branches/3.3/ Merge revs 27788 and 27795
from Zope trunk.
Tim Peters
tim.one at comcast.net
Fri Oct 8 16:42:59 EDT 2004
Log message for revision 27796:
Merge revs 27788 and 27795 from Zope trunk.
See Collector #1350.
ghostify() and unghostify() detect one form of thread insanity
now. In a debug build, they abort the process if it happens.
In a release build, unghostify() raises SystemError, and
ghostify() ignores it (ghostify() can't raise an exception).
Changed:
U ZODB/branches/3.3/NEWS.txt
U ZODB/branches/3.3/src/persistent/cPersistence.c
-=-
Modified: ZODB/branches/3.3/NEWS.txt
===================================================================
--- ZODB/branches/3.3/NEWS.txt 2004-10-08 20:18:34 UTC (rev 27795)
+++ ZODB/branches/3.3/NEWS.txt 2004-10-08 20:42:58 UTC (rev 27796)
@@ -1,3 +1,22 @@
+What's new in ZODB3 3.3.1?
+==========================
+Release date: xx-xxx-2004
+
+persistent
+----------
+
+Collector #1350: ZODB has a default one-thread-per-connection model, and
+two threads should never do operations on a single connection
+simultaneously. However, ZODB can't detect violations, and this happened
+in an early stage of Zope 2.8 development. The low-level ``ghostify()``
+and ``unghostify()`` routines in ``cPerisistence.c`` were changed to give
+some help in detecting this when it happens. In a debug build, both abort
+the process if thread interference is detected. This is extreme, but
+impossible to overlook. In a release build, ``unghostify()`` raises
+``SystemError`` if thread damage is detected; ``ghostify()`` ignores the
+problem in a release build (``ghostify()`` is supposed to be so simple that
+it "can't fail").
+
What's new in ZODB3 3.3?
========================
Release date: 06-Oct-2004
Modified: ZODB/branches/3.3/src/persistent/cPersistence.c
===================================================================
--- ZODB/branches/3.3/src/persistent/cPersistence.c 2004-10-08 20:18:34 UTC (rev 27795)
+++ ZODB/branches/3.3/src/persistent/cPersistence.c 2004-10-08 20:42:58 UTC (rev 27796)
@@ -58,6 +58,24 @@
return 0;
}
+#ifdef Py_DEBUG
+static void
+fatal_1350(cPersistentObject *self, const char *caller, const char *detail)
+{
+ char buf[1000];
+
+ PyOS_snprintf(buf, sizeof(buf),
+ "cPersistence.c %s(): object at %p with type %.200s\n"
+ "%s.\n"
+ "The only known cause is multiple threads trying to ghost and\n"
+ "unghost the object simultaneously.\n"
+ "That's not legal, but ZODB can't stop it.\n"
+ "See Collector #1350.\n",
+ caller, self, self->ob_type->tp_name, detail);
+ Py_FatalError(buf);
+}
+#endif
+
static void ghostify(cPersistentObject*);
/* Load the state of the object, unghostifying it. Upon success, return 1.
@@ -88,6 +106,18 @@
}
self->state = cPersistent_UPTODATE_STATE;
Py_DECREF(r);
+ if (self->cache && self->ring.r_next == NULL) {
+#ifdef Py_DEBUG
+ fatal_1350(self, "unghostify",
+ "is not in the cache despite that we just "
+ "unghostified it");
+#else
+ PyErr_Format(PyExc_SystemError, "object at %p with type "
+ "%.200s not in the cache despite that we just "
+ "unghostified it", self, self->ob_type->tp_name);
+ return -1;
+#endif
+ }
}
return 1;
}
@@ -134,13 +164,19 @@
return;
}
- /* If the cache is still active, we must unlink the object. */
- if (self->ring.r_next) {
- /* if we're ghostifying an object, we better have some non-ghosts */
- assert(self->cache->non_ghost_count > 0);
- self->cache->non_ghost_count--;
- ring_del(&self->ring);
+ if (self->ring.r_next == NULL) {
+ /* There's no way to raise an error in this routine. */
+#ifdef Py_DEBUG
+ fatal_1350(self, "ghostify", "claims to be in a cache but isn't");
+#else
+ return;
+#endif
}
+
+ /* If we're ghostifying an object, we better have some non-ghosts. */
+ assert(self->cache->non_ghost_count > 0);
+ self->cache->non_ghost_count--;
+ ring_del(&self->ring);
self->state = cPersistent_GHOST_STATE;
dictptr = _PyObject_GetDictPtr((PyObject *)self);
if (dictptr && *dictptr) {
@@ -249,7 +285,7 @@
return slotnames;
}
- slotnames = PyObject_CallFunctionObjArgs(copy_reg_slotnames,
+ slotnames = PyObject_CallFunctionObjArgs(copy_reg_slotnames,
(PyObject*)cls, NULL);
if (slotnames && !(slotnames == Py_None || PyList_Check(slotnames))) {
PyErr_SetString(PyExc_TypeError,
@@ -257,7 +293,7 @@
Py_DECREF(slotnames);
return NULL;
}
-
+
return slotnames;
}
@@ -288,7 +324,7 @@
if (PyObject_SetItem(copy, key, value) < 0)
goto err;
}
-
+
return copy;
err:
Py_DECREF(copy);
@@ -366,13 +402,13 @@
}
}
- if (n)
+ if (n)
state = Py_BuildValue("(NO)", state, slots);
end:
Py_XDECREF(slotnames);
Py_XDECREF(slots);
-
+
return state;
}
@@ -381,12 +417,12 @@
{
PyObject *key, *value;
int pos = 0;
-
+
if (!PyDict_Check(dict)) {
PyErr_SetString(PyExc_TypeError, "Expected dictionary");
return -1;
}
-
+
while (PyDict_Next(dict, &pos, &key, &value)) {
if (PyObject_SetAttr(self, key, value) < 0)
return -1;
@@ -451,7 +487,7 @@
return Py_None;
}
-static char pickle___reduce__doc[] =
+static char pickle___reduce__doc[] =
"Reduce an object to contituent parts for serialization\n"
;
@@ -475,18 +511,18 @@
PyErr_Clear();
l = 0;
}
-
+
args = PyTuple_New(l+1);
if (args == NULL)
goto end;
-
+
Py_INCREF(self->ob_type);
PyTuple_SET_ITEM(args, 0, (PyObject*)(self->ob_type));
for (i = 0; i < l; i++) {
Py_INCREF(PyTuple_GET_ITEM(bargs, i));
PyTuple_SET_ITEM(args, i+1, PyTuple_GET_ITEM(bargs, i));
}
-
+
state = PyObject_CallMethodObjArgs(self, py___getstate__, NULL);
if (!state)
goto end;
@@ -680,7 +716,7 @@
}
else
result = Py_True;
-
+
Py_INCREF(result);
Done:
@@ -688,7 +724,7 @@
return result;
}
-/*
+/*
XXX we should probably not allow assignment of __class__ and __dict__.
*/
@@ -1012,7 +1048,7 @@
{"__getstate__", (PyCFunction)Per__getstate__, METH_NOARGS,
pickle___getstate__doc },
{"__setstate__", (PyCFunction)pickle___setstate__, METH_O,
- pickle___setstate__doc},
+ pickle___setstate__doc},
{"__reduce__", (PyCFunction)pickle___reduce__, METH_NOARGS,
pickle___reduce__doc},
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