pg.ddx.io pgsql-hackers@postgresql.org mailing list archive
help / color / mirror / Atom feed[PATCH v5 1/3] Prevent internal error at concurrent CREATE OR REPLACE FUNCTION
1+ messages / 1 participants
[nested] [flat]
* [PATCH v5 1/3] Prevent internal error at concurrent CREATE OR REPLACE FUNCTION
@ 2025-03-31 09:46 Yugo Nagata <nagata@sraoss.co.jp>
0 siblings, 0 replies; 1+ messages in thread
From: Yugo Nagata @ 2025-03-31 09:46 UTC (permalink / raw)
Previously, concurrent CREATE OR REPLACE FUNCTION commands could fail
with an internal error "tuple concurrently updated". This occurred
because multiple sessions attempted to modify the same catalog tuple
simultaneously.
To prevent this, ensure that an exclusive lock on the function object
is acquired earlier in the process.
Additionally, if the target function is dropped by another session while
waiting for the lock, a new function is created instead.
---
src/backend/catalog/pg_proc.c | 40 ++++++++++++++++++++++++++++-------
1 file changed, 32 insertions(+), 8 deletions(-)
inline patch 1: src/backend/catalog/pg_proc.c (+32/-8 lines) download inline-1.patch
diff --git a/src/backend/catalog/pg_proc.c b/src/backend/catalog/pg_proc.c
index 5fdcf24d5f8..734508c7f58 100644
--- a/src/backend/catalog/pg_proc.c
+++ b/src/backend/catalog/pg_proc.c
@@ -34,6 +34,7 @@
#include "parser/parse_coerce.h"
#include "pgstat.h"
#include "rewrite/rewriteHandler.h"
+#include "storage/lmgr.h"
#include "tcop/pquery.h"
#include "tcop/tcopprot.h"
#include "utils/acl.h"
@@ -383,24 +384,47 @@ ProcedureCreate(const char *procedureName,
tupDesc = RelationGetDescr(rel);
/* Check for pre-existing definition */
- oldtup = SearchSysCache3(PROCNAMEARGSNSP,
- PointerGetDatum(procedureName),
- PointerGetDatum(parameterTypes),
- ObjectIdGetDatum(procNamespace));
+ oldtup = SearchSysCacheCopy3(PROCNAMEARGSNSP,
+ PointerGetDatum(procedureName),
+ PointerGetDatum(parameterTypes),
+ ObjectIdGetDatum(procNamespace));
if (HeapTupleIsValid(oldtup))
{
/* There is one; okay to replace it? */
Form_pg_proc oldproc = (Form_pg_proc) GETSTRUCT(oldtup);
- Datum proargnames;
- bool isnull;
- const char *dropcmd;
if (!replace)
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_FUNCTION),
errmsg("function \"%s\" already exists with same argument types",
procedureName)));
+
+ heap_freetuple(oldtup);
+
+ /* Lock the function so nobody else can do anything with it. */
+ LockDatabaseObject(ProcedureRelationId, oldproc->oid, 0, AccessExclusiveLock);
+
+ /*
+ * It is possible that by the time we acquire the lock on function,
+ * concurrent DDL has removed it. We can test this by checking the
+ * existence of function. We get the tuple again to avoid the risk
+ * of function definition getting changed.
+ */
+ oldtup = SearchSysCacheCopy3(PROCNAMEARGSNSP,
+ PointerGetDatum(procedureName),
+ PointerGetDatum(parameterTypes),
+ ObjectIdGetDatum(procNamespace));
+ }
+
+ if (HeapTupleIsValid(oldtup))
+ {
+
+ Form_pg_proc oldproc = (Form_pg_proc) GETSTRUCT(oldtup);
+ Datum proargnames;
+ bool isnull;
+ const char *dropcmd;
+
if (!object_ownercheck(ProcedureRelationId, oldproc->oid, proowner))
aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_FUNCTION,
procedureName);
@@ -585,7 +609,7 @@ ProcedureCreate(const char *procedureName,
tup = heap_modify_tuple(oldtup, tupDesc, values, nulls, replaces);
CatalogTupleUpdate(rel, &tup->t_self, tup);
- ReleaseSysCache(oldtup);
+ heap_freetuple(oldtup);
is_update = true;
}
else
--
2.43.0
only message in thread
Thread overview: 1+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2025-03-31 09:46 [PATCH v5 1/3] Prevent internal error at concurrent CREATE OR REPLACE FUNCTION Yugo Nagata <nagata@sraoss.co.jp>
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox