Attached is a simple patch that fixes a minor problem in PL/Python: in
PLy_spi_execute_plan(), we invoke the input function for a Postgres data
type. If that function elog's (which is quite possible), PL/Python leaks
references to two temporary Python objects. The fix seems easy, albeit a
bit ugly: the reference count on one of the temporary objects can be
decremented before calling the function. A pointer that points into the
second object is passed to the input function itself, so we have to
PG_CATCH() the elog and decrement the refcount then.
Since the problem might actually occur in practice and the fix seems to
have little chance of inducing a regression, I'm thinking of applying
this to both HEAD and back branches. Barring any objections I'll do that
later today or early tomorrow.
-Neil
Index: src/pl/plpython/plpython.c
===================================================================
RCS file: /Users/neilc/postgres/cvs_root/pgsql/src/pl/plpython/plpython.c,v
retrieving revision 1.67
diff -c -r1.67 plpython.c
*** src/pl/plpython/plpython.c 26 Dec 2005 04:28:48 -0000 1.67
--- src/pl/plpython/plpython.c 29 Dec 2005 16:49:54 -0000
***************
*** 2,8 ****
* plpython.c - python as a procedural language for PostgreSQL
*
* This software is copyright by Andrew Bosma
! * but is really shameless cribbed from pltcl.c by Jan Weick, and
* plperl.c by Mark Hollomon.
*
* The author hereby grants permission to use, copy, modify,
--- 2,8 ----
* plpython.c - python as a procedural language for PostgreSQL
*
* This software is copyright by Andrew Bosma
! * but is really shameless cribbed from pltcl.c by Jan Wieck, and
* plperl.c by Mark Hollomon.
*
* The author hereby grants permission to use, copy, modify,
***************
*** 1996,2002 ****
int i,
rv;
PLyPlanObject *plan;
- char *nulls;
MemoryContext oldcontext;
if (list != NULL)
--- 1996,2001 ----
***************
*** 2018,2024 ****
if (nargs != plan->nargs)
{
char *sv;
-
PyObject *so = PyObject_Str(list);
if (!so)
--- 2017,2022 ----
***************
*** 2036,2048 ****
oldcontext = CurrentMemoryContext;
PG_TRY();
{
! nulls = palloc(nargs * sizeof(char));
for (i = 0; i < nargs; i++)
{
PyObject *elem,
*so;
- char *sv;
elem = PySequence_GetItem(list, i);
if (elem != Py_None)
--- 2034,2045 ----
oldcontext = CurrentMemoryContext;
PG_TRY();
{
! char *nulls = palloc(nargs * sizeof(char));
for (i = 0; i < nargs; i++)
{
PyObject *elem,
*so;
elem = PySequence_GetItem(list, i);
if (elem != Py_None)
***************
*** 2051,2070 ****
if (!so)
PLy_elog(ERROR, "function \"%s\" could not execute plan",
PLy_procedure_name(PLy_curr_procedure));
! sv = PyString_AsString(so);
! /*
! * FIXME -- if this elogs, we have Python reference leak
! */
! plan->values[i] =
! FunctionCall3(&(plan->args[i].out.d.typfunc),
! CStringGetDatum(sv),
! ObjectIdGetDatum(plan->args[i].out.d.typioparam),
! Int32GetDatum(-1));
! Py_DECREF(so);
! Py_DECREF(elem);
nulls[i] = ' ';
}
else
--- 2048,2073 ----
if (!so)
PLy_elog(ERROR, "function \"%s\" could not execute plan",
PLy_procedure_name(PLy_curr_procedure));
! Py_DECREF(elem);
! PG_TRY();
! {
! char *sv = PyString_AsString(so);
! plan->values[i] =
! FunctionCall3(&(plan->args[i].out.d.typfunc),
! CStringGetDatum(sv),
! ObjectIdGetDatum(plan->args[i].out.d.typioparam),
! Int32GetDatum(-1));
! }
! PG_CATCH();
! {
! Py_DECREF(so);
! PG_RE_THROW();
! }
! PG_END_TRY();
+ Py_DECREF(so);
nulls[i] = ' ';
}
else
