diff --git a/src/backend/utils/mmgr/portalmem.c b/src/backend/utils/mmgr/portalmem.c
index f7b26cdd974e55573f20f7e50c2e7fcadeb42787..64b29906d9c175e12effcaef4f281ea8a510f22f 100644
--- a/src/backend/utils/mmgr/portalmem.c
+++ b/src/backend/utils/mmgr/portalmem.c
@@ -12,7 +12,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/utils/mmgr/portalmem.c,v 1.118 2010/02/26 02:01:14 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/mmgr/portalmem.c,v 1.119 2010/07/05 09:27:17 heikki Exp $
*
*-------------------------------------------------------------------------
*/
@@ -376,6 +376,28 @@ PortalCreateHoldStore(Portal portal)
MemoryContextSwitchTo(oldcxt);
}
+/*
+ * PinPortal
+ * Protect a portal from dropping.
+ */
+void
+PinPortal(Portal portal)
+{
+ if (portal->portalPinned)
+ elog(ERROR, "portal already pinned");
+
+ portal->portalPinned = true;
+}
+
+void
+UnpinPortal(Portal portal)
+{
+ if (!portal->portalPinned)
+ elog(ERROR, "portal not pinned");
+
+ portal->portalPinned = false;
+}
+
/*
* PortalDrop
* Destroy the portal.
@@ -385,9 +407,16 @@ PortalDrop(Portal portal, bool isTopCommit)
{
AssertArg(PortalIsValid(portal));
- /* Not sure if this case can validly happen or not... */
- if (portal->status == PORTAL_ACTIVE)
- elog(ERROR, "cannot drop active portal");
+ /*
+ * Don't allow dropping a pinned portal, it's still needed by whoever
+ * pinned it. Not sure if the PORTAL_ACTIVE case can validly happen or
+ * not...
+ */
+ if (portal->portalPinned ||
+ portal->status == PORTAL_ACTIVE)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_CURSOR_STATE),
+ errmsg("cannot drop active portal \"%s\"", portal->name)));
/*
* Remove portal from hash table. Because we do this first, we will not
@@ -630,6 +659,13 @@ AtCommit_Portals(void)
continue;
}
+ /*
+ * There should be no pinned portals anymore. Complain if someone
+ * leaked one.
+ */
+ if (portal->portalPinned)
+ elog(ERROR, "cannot commit while a portal is pinned");
+
/*
* Do nothing to cursors held over from a previous transaction
* (including holdable ones just frozen by CommitHoldablePortals).
@@ -738,7 +774,15 @@ AtCleanup_Portals(void)
continue;
}
- /* Else zap it. */
+ /*
+ * If a portal is still pinned, forcibly unpin it. PortalDrop will
+ * not let us drop the portal otherwise. Whoever pinned the portal
+ * was interrupted by the abort too and won't try to use it anymore.
+ */
+ if (portal->portalPinned)
+ portal->portalPinned = false;
+
+ /* Zap it. */
PortalDrop(portal, false);
}
}
diff --git a/src/include/utils/portal.h b/src/include/utils/portal.h
index 75101a782bf47412dd95c8db272dc543b5c85518..30214e68f3ae26a14980d1fb407d264426b8d1f0 100644
--- a/src/include/utils/portal.h
+++ b/src/include/utils/portal.h
@@ -39,7 +39,7 @@
* Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/utils/portal.h,v 1.82 2010/01/02 16:58:10 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/utils/portal.h,v 1.83 2010/07/05 09:27:17 heikki Exp $
*
*-------------------------------------------------------------------------
*/
@@ -133,6 +133,7 @@ typedef struct PortalData
/* Status data */
PortalStatus status; /* see above */
+ bool portalPinned; /* a pinned portal can't be dropped */
/* If not NULL, Executor is active; call ExecutorEnd eventually: */
QueryDesc *queryDesc; /* info needed for executor invocation */
@@ -199,6 +200,8 @@ extern void AtSubAbort_Portals(SubTransactionId mySubid,
extern void AtSubCleanup_Portals(SubTransactionId mySubid);
extern Portal CreatePortal(const char *name, bool allowDup, bool dupSilent);
extern Portal CreateNewPortal(void);
+extern void PinPortal(Portal portal);
+extern void UnpinPortal(Portal portal);
extern void PortalDrop(Portal portal, bool isTopCommit);
extern Portal GetPortalByName(const char *name);
extern void PortalDefineQuery(Portal portal,
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index 3342e79150c38fe7ea038e0dd5beedcc15a49ac9..d1af4a6e5fbeece6e90d73c7d0833a4e0e2939f3 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.259 2010/06/21 09:47:29 heikki Exp $
+ * $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.260 2010/07/05 09:27:18 heikki Exp $
*
*-------------------------------------------------------------------------
*/
@@ -2002,20 +2002,11 @@ exec_stmt_forc(PLpgSQL_execstate *estate, PLpgSQL_stmt_forc *stmt)
rc = exec_for_query(estate, (PLpgSQL_stmt_forq *) stmt, portal, false);
/* ----------
- * Close portal. The statements executed in the loop might've closed the
- * cursor already, rendering our portal pointer invalid, so we mustn't
- * trust the pointer.
+ * Close portal, and restore cursor variable if it was initially NULL.
* ----------
*/
- portal = SPI_cursor_find(portalname);
- if (portal == NULL)
- ereport(ERROR,
- (errcode(ERRCODE_UNDEFINED_CURSOR),
- errmsg("cursor \"%s\" closed unexpectedly",
- portalname)));
SPI_cursor_close(portal);
- /* Restore cursor variable if it was initially NULL. */
if (curname == NULL)
{
free_var(curvar);
@@ -4278,13 +4269,6 @@ exec_run_select(PLpgSQL_execstate *estate,
* exec_for_query --- execute body of FOR loop for each row from a portal
*
* Used by exec_stmt_fors, exec_stmt_forc and exec_stmt_dynfors
- *
- * If the portal is for a cursor that's visible to user code, the statements
- * we execute might move or close the cursor. You must pass prefetch_ok=false
- * in that case to disable optimizations that rely on the portal staying
- * unchanged over execution of the user statements.
- * NB: With prefetch_ok=false, the portal pointer might point to garbage
- * after the call. Caller beware!
*/
static int
exec_for_query(PLpgSQL_execstate *estate, PLpgSQL_stmt_forq *stmt,
@@ -4296,10 +4280,6 @@ exec_for_query(PLpgSQL_execstate *estate, PLpgSQL_stmt_forq *stmt,
bool found = false;
int rc = PLPGSQL_RC_OK;
int n;
- const char *portalname;
-
- /* Remember portal name so that we can re-find it */
- portalname = portal->name;
/*
* Determine if we assign to a record or a row
@@ -4311,6 +4291,12 @@ exec_for_query(PLpgSQL_execstate *estate, PLpgSQL_stmt_forq *stmt,
else
elog(ERROR, "unsupported target");
+ /*
+ * Make sure the portal doesn't get closed by the user statements
+ * we execute.
+ */
+ PinPortal(portal);
+
/*
* Fetch the initial tuple(s). If prefetching is allowed then we grab a
* few more rows to avoid multiple trips through executor startup
@@ -4408,22 +4394,8 @@ exec_for_query(PLpgSQL_execstate *estate, PLpgSQL_stmt_forq *stmt,
/*
* Fetch more tuples. If prefetching is allowed, grab 50 at a time.
- * Otherwise the statements executed in the loop might've moved or
- * even closed the cursor, so check that the cursor is still open,
- * and fetch only one row at a time.
*/
- if (prefetch_ok)
- SPI_cursor_fetch(portal, true, 50);
- else
- {
- portal = SPI_cursor_find(portalname);
- if (portal == NULL)
- ereport(ERROR,
- (errcode(ERRCODE_UNDEFINED_CURSOR),
- errmsg("cursor \"%s\" closed unexpectedly",
- portalname)));
- SPI_cursor_fetch(portal, true, 1);
- }
+ SPI_cursor_fetch(portal, true, prefetch_ok ? 50 : 1);
tuptab = SPI_tuptable;
n = SPI_processed;
}
@@ -4435,6 +4407,8 @@ loop_exit:
*/
SPI_freetuptable(tuptab);
+ UnpinPortal(portal);
+
/*
* Set the FOUND variable to indicate the result of executing the loop
* (namely, whether we looped one or more times). This must be set last so