What has been done with this report/fix? ---------------------------------------------------------------------------
Daniel Popowich wrote: > > The following bug has been logged online: > > Bug reference: 5842 > Logged by: Daniel Popowich > Email address: danielpopow...@gmail.com > PostgreSQL version: 8.4.6 > Operating system: x86_64-pc-linux-gnu (Ubuntu 10.04.1) > Description: Memory leak in PL/Python when taking slices of results > Details: > > There is a memory leak in PL/Python when taking slices of results. This was > first discussed in pgsql-general: > > http://archives.postgresql.org/pgsql-general/2011-01/msg00367.php > > Thanks to Alex Hunsaker for pinpointing the problem to slices. The > following code (a modification of Alex's) demonstrates the problem well...in > a database with plpythonu installed: > > -- leaks big time > CREATE or replace FUNCTION py_leak() RETURNS void > LANGUAGE plpythonu > AS $$ > results = plpy.execute("""select generate_series(0, 1000000)""") > slice_creates_leak = results[:] > for r in slice_creates_leak: > pass > return > $$; > > -- does not leak > CREATE or replace FUNCTION py_no_leak() RETURNS void > LANGUAGE plpythonu > AS $$ > results = plpy.execute("""select generate_series(0, 1000000)""") > for noleak in results: > pass > return > $$; > > > I traced the bug to PLy_result_slice() in src/pl/plpython/plpython.c. That > function calls the python API function PyList_GetSlice() and erroneously > increments the reference count before returning the result to the caller. > PyList_GetSlice returns a *new* reference, not a borrowed one, so it should > just return the object as-is. > > A patch is attached below. > > Cheers, > > Dan Popowich > > > ---------------------------------------------------------------------- > > > *** src/pl/plpython/plpython.c~ 2010-12-13 21:59:19.000000000 -0500 > --- src/pl/plpython/plpython.c 2011-01-18 11:18:28.857831733 -0500 > *************** > *** 2328,2341 **** > static PyObject * > PLy_result_slice(PyObject *arg, Py_ssize_t lidx, Py_ssize_t hidx) > { > - PyObject *rv; > PLyResultObject *ob = (PLyResultObject *) arg; > > ! rv = PyList_GetSlice(ob->rows, lidx, hidx); > ! if (rv == NULL) > ! return NULL; > ! Py_INCREF(rv); > ! return rv; > } > > static int > --- 2328,2336 ---- > static PyObject * > PLy_result_slice(PyObject *arg, Py_ssize_t lidx, Py_ssize_t hidx) > { > PLyResultObject *ob = (PLyResultObject *) arg; > > ! return PyList_GetSlice(ob->rows, lidx, hidx); > } > > static int > > -- > Sent via pgsql-bugs mailing list (pgsql-b...@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-bugs -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
