From 8c75ad436f75fc629b61f601ba884c8f9313c9af Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Thu, 5 Nov 2015 13:52:30 -0500 Subject: Fix memory leaks in PL/Python. Previously, plpython was in the habit of allocating a lot of stuff in TopMemoryContext, and it was very slipshod about making sure that stuff got cleaned up; in particular, use of TopMemoryContext as fn_mcxt for function calls represents an unfixable leak, since we generally don't know what the called function might have allocated in fn_mcxt. This results in session-lifespan leakage in certain usage scenarios, as for example in a case reported by Ed Behn back in July. To fix, get rid of all the retail allocations in TopMemoryContext. All long-lived allocations are now made in sub-contexts that are associated with specific objects (either pl/python procedures, or Python-visible objects such as cursors and plans). We can clean these up when the associated object is deleted. I went so far as to get rid of PLy_malloc completely. There were a couple of places where it could still have been used safely, but on the whole it was just an invitation to bad coding. Haribabu Kommi, based on a draft patch by Heikki Linnakangas; some further work by me --- src/pl/plpython/plpy_cursorobject.c | 30 +++++++++++++++++++++--------- 1 file changed, 21 insertions(+), 9 deletions(-) (limited to 'src/pl/plpython/plpy_cursorobject.c') diff --git a/src/pl/plpython/plpy_cursorobject.c b/src/pl/plpython/plpy_cursorobject.c index 2c458d35fdb..103571ba15c 100644 --- a/src/pl/plpython/plpy_cursorobject.c +++ b/src/pl/plpython/plpy_cursorobject.c @@ -8,6 +8,7 @@ #include "access/xact.h" #include "mb/pg_wchar.h" +#include "utils/memutils.h" #include "plpython.h" @@ -111,7 +112,12 @@ PLy_cursor_query(const char *query) return NULL; cursor->portalname = NULL; cursor->closed = false; - PLy_typeinfo_init(&cursor->result); + cursor->mcxt = AllocSetContextCreate(TopMemoryContext, + "PL/Python cursor context", + ALLOCSET_DEFAULT_MINSIZE, + ALLOCSET_DEFAULT_INITSIZE, + ALLOCSET_DEFAULT_MAXSIZE); + PLy_typeinfo_init(&cursor->result, cursor->mcxt); oldcontext = CurrentMemoryContext; oldowner = CurrentResourceOwner; @@ -139,7 +145,7 @@ PLy_cursor_query(const char *query) elog(ERROR, "SPI_cursor_open() failed: %s", SPI_result_code_string(SPI_result)); - cursor->portalname = PLy_strdup(portal->name); + cursor->portalname = MemoryContextStrdup(cursor->mcxt, portal->name); PLy_spi_subtransaction_commit(oldcontext, oldowner); } @@ -200,7 +206,12 @@ PLy_cursor_plan(PyObject *ob, PyObject *args) return NULL; cursor->portalname = NULL; cursor->closed = false; - PLy_typeinfo_init(&cursor->result); + cursor->mcxt = AllocSetContextCreate(TopMemoryContext, + "PL/Python cursor context", + ALLOCSET_DEFAULT_MINSIZE, + ALLOCSET_DEFAULT_INITSIZE, + ALLOCSET_DEFAULT_MAXSIZE); + PLy_typeinfo_init(&cursor->result, cursor->mcxt); oldcontext = CurrentMemoryContext; oldowner = CurrentResourceOwner; @@ -261,7 +272,7 @@ PLy_cursor_plan(PyObject *ob, PyObject *args) elog(ERROR, "SPI_cursor_open() failed: %s", SPI_result_code_string(SPI_result)); - cursor->portalname = PLy_strdup(portal->name); + cursor->portalname = MemoryContextStrdup(cursor->mcxt, portal->name); PLy_spi_subtransaction_commit(oldcontext, oldowner); } @@ -315,12 +326,13 @@ PLy_cursor_dealloc(PyObject *arg) if (PortalIsValid(portal)) SPI_cursor_close(portal); + cursor->closed = true; + } + if (cursor->mcxt) + { + MemoryContextDelete(cursor->mcxt); + cursor->mcxt = NULL; } - - PLy_free(cursor->portalname); - cursor->portalname = NULL; - - PLy_typeinfo_dealloc(&cursor->result); arg->ob_type->tp_free(arg); } -- cgit v1.2.3