diff options
Diffstat (limited to 'src/backend/parser/parse_clause.c')
| -rw-r--r-- | src/backend/parser/parse_clause.c | 37 |
1 files changed, 31 insertions, 6 deletions
diff --git a/src/backend/parser/parse_clause.c b/src/backend/parser/parse_clause.c index 38dc3ea0976..60521d13475 100644 --- a/src/backend/parser/parse_clause.c +++ b/src/backend/parser/parse_clause.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/parser/parse_clause.c,v 1.70 2000/10/07 00:58:17 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/parser/parse_clause.c,v 1.71 2000/11/08 22:09:58 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -88,6 +88,34 @@ makeRangeTable(ParseState *pstate, List *frmList) } /* + * lockTargetTable + * Find the target relation of INSERT/UPDATE/DELETE and acquire write + * lock on it. This must be done before building the range table, + * in case the target is also mentioned as a source relation --- we + * want to be sure to grab the write lock before any read lock. + * + * The ParseState's link to the target relcache entry is also set here. + */ +void +lockTargetTable(ParseState *pstate, char *relname) +{ + /* Close old target; this could only happen for multi-action rules */ + if (pstate->p_target_relation != NULL) + heap_close(pstate->p_target_relation, NoLock); + pstate->p_target_relation = NULL; + pstate->p_target_rangetblentry = NULL; /* setTargetTable will set this */ + + /* + * Open target rel and grab suitable lock (which we will hold till + * end of transaction). + * + * analyze.c will eventually do the corresponding heap_close(), + * but *not* release the lock. + */ + pstate->p_target_relation = heap_openr(relname, RowExclusiveLock); +} + +/* * setTargetTable * Add the target relation of INSERT/UPDATE/DELETE to the range table, * and make the special links to it in the ParseState. @@ -133,13 +161,10 @@ setTargetTable(ParseState *pstate, char *relname, bool inh, bool inJoinSet) if (inJoinSet) addRTEtoJoinList(pstate, rte); - /* This could only happen for multi-action rules */ - if (pstate->p_target_relation != NULL) - heap_close(pstate->p_target_relation, AccessShareLock); + /* lockTargetTable should have been called earlier */ + Assert(pstate->p_target_relation != NULL); pstate->p_target_rangetblentry = rte; - pstate->p_target_relation = heap_open(rte->relid, AccessShareLock); - /* will close relation later, see analyze.c */ } |