Use portal pinning in PL/Perl and PL/Python

PL/pgSQL "pins" internally generated portals so that user code cannot
close them by guessing their names.  Add this functionality to PL/Perl
and PL/Python as well, preventing users from manually closing cursors
created by spi_query and plpy.cursor, respectively.  (PL/Tcl does not
currently offer any cursor functionality.)

diff --git a/src/pl/plperl/plperl.c b/src/pl/plperl/plperl.c
index 41fd0ba42148f3836514b943948eb778343aa6a6..10feef11cf3c245caf9577ce605afb9a2e861af6 100644 (file)
--- a/src/pl/plperl/plperl.c
+++ b/src/pl/plperl/plperl.c
@@ -3406,6 +3406,8 @@ plperl_spi_query(char *query)
                 SPI_result_code_string(SPI_result));
        cursor = cstr2sv(portal->name);
 
+       PinPortal(portal);
+
        /* Commit the inner transaction, return to outer xact context */
        ReleaseCurrentSubTransaction();
        MemoryContextSwitchTo(oldcontext);
@@ -3469,6 +3471,7 @@ plperl_spi_fetchrow(char *cursor)
            SPI_cursor_fetch(p, true, 1);
            if (SPI_processed == 0)
            {
+               UnpinPortal(p);
                SPI_cursor_close(p);
                row = &PL_sv_undef;
            }
@@ -3520,7 +3523,10 @@ plperl_spi_cursor_close(char *cursor)
    p = SPI_cursor_find(cursor);
 
    if (p)
+   {
+       UnpinPortal(p);
        SPI_cursor_close(p);
+   }
 }
 
 SV *
@@ -3884,6 +3890,8 @@ plperl_spi_query_prepared(char *query, int argc, SV **argv)
 
        cursor = cstr2sv(portal->name);
 
+       PinPortal(portal);
+
        /* Commit the inner transaction, return to outer xact context */
        ReleaseCurrentSubTransaction();
        MemoryContextSwitchTo(oldcontext);

diff --git a/src/pl/plpython/plpy_cursorobject.c b/src/pl/plpython/plpy_cursorobject.c
index 9467f648082dbffd92dd35578d694cb0df1778e8..a527585b81829eb5791f3f6e866136b72d7659f8 100644 (file)
--- a/src/pl/plpython/plpy_cursorobject.c
+++ b/src/pl/plpython/plpy_cursorobject.c
@@ -151,6 +151,8 @@ PLy_cursor_query(const char *query)
 
        cursor->portalname = MemoryContextStrdup(cursor->mcxt, portal->name);
 
+       PinPortal(portal);
+
        PLy_spi_subtransaction_commit(oldcontext, oldowner);
    }
    PG_CATCH();
@@ -266,6 +268,8 @@ PLy_cursor_plan(PyObject *ob, PyObject *args)
 
        cursor->portalname = MemoryContextStrdup(cursor->mcxt, portal->name);
 
+       PinPortal(portal);
+
        PLy_spi_subtransaction_commit(oldcontext, oldowner);
    }
    PG_CATCH();
@@ -317,7 +321,10 @@ PLy_cursor_dealloc(PyObject *arg)
        portal = GetPortalByName(cursor->portalname);
 
        if (PortalIsValid(portal))
+       {
+           UnpinPortal(portal);
            SPI_cursor_close(portal);
+       }
        cursor->closed = true;
    }
    if (cursor->mcxt)
@@ -508,6 +515,7 @@ PLy_cursor_close(PyObject *self, PyObject *unused)
            return NULL;
        }
 
+       UnpinPortal(portal);
        SPI_cursor_close(portal);
        cursor->closed = true;
    }