> > This is missing the necessary adjustments in backend/nodes/ (copy and
> > equal funcs). Also the NOWAIT keyword must be added to the list of
> > nonreserved keywords near the bottom of gram.y.
>
> Thanks for the review. I'll work on this.
Here is the revised patch.
--
Tatsuo Ishii
===================================================================
RCS file: /cvsroot/pgsql-server/doc/src/sgml/ref/lock.sgml,v
retrieving revision 1.40
diff -c -r1.40 lock.sgml
*** doc/src/sgml/ref/lock.sgml 14 Dec 2003 00:05:29 -0000 1.40
--- doc/src/sgml/ref/lock.sgml 10 Mar 2004 01:35:18 -0000
***************
*** 20,26 ****
<refsynopsisdiv>
<synopsis>
! LOCK [ TABLE ] <replaceable class="PARAMETER">name</replaceable> [, ...] [ IN
<replaceable class="PARAMETER">lockmode</replaceable> MODE ]
where <replaceable class="PARAMETER">lockmode</replaceable> is one of:
--- 20,26 ----
<refsynopsisdiv>
<synopsis>
! LOCK [ TABLE ] <replaceable class="PARAMETER">name</replaceable> [, ...] [ IN
<replaceable class="PARAMETER">lockmode</replaceable> MODE ] [ NOWAIT ]
where <replaceable class="PARAMETER">lockmode</replaceable> is one of:
***************
*** 34,41 ****
<para>
<command>LOCK TABLE</command> obtains a table-level lock, waiting if
! necessary for any conflicting locks to be released. Once obtained,
! the lock is held for the remainder of the current transaction.
(There is no <command>UNLOCK TABLE</command> command; locks are always
released at transaction end.)
</para>
--- 34,43 ----
<para>
<command>LOCK TABLE</command> obtains a table-level lock, waiting if
! necessary for any conflicting locks to be released.
! If <literal>NOWAIT</literal> is given, <command>LOCK TABLE</command>
! does not wait for acquiring lock, and throws an error instead.
! Once obtained, the lock is held for the remainder of the current transaction.
(There is no <command>UNLOCK TABLE</command> command; locks are always
released at transaction end.)
</para>
Index: src/backend/access/heap/heapam.c
===================================================================
RCS file: /cvsroot/pgsql-server/src/backend/access/heap/heapam.c,v
retrieving revision 1.162
diff -c -r1.162 heapam.c
*** src/backend/access/heap/heapam.c 16 Jan 2004 20:51:30 -0000 1.162
--- src/backend/access/heap/heapam.c 10 Mar 2004 01:35:21 -0000
***************
*** 464,469 ****
--- 464,496 ----
return r;
}
+ Relation
+ conditional_relation_open(Oid relationId, LOCKMODE lockmode, bool nowait)
+ {
+ Relation r;
+
+ Assert(lockmode >= NoLock && lockmode < MAX_LOCKMODES);
+
+ /* The relcache does all the real work... */
+ r = RelationIdGetRelation(relationId);
+
+ if (!RelationIsValid(r))
+ elog(ERROR, "could not open relation with OID %u", relationId);
+
+ if (lockmode != NoLock)
+ {
+ if (nowait)
+ {
+ if (!ConditionalLockRelation(r, lockmode))
+ elog(ERROR, "could not aquire relation lock");
+ }
+ else
+ LockRelation(r, lockmode);
+ }
+
+ return r;
+ }
+
/* ----------------
* relation_openrv - open any relation specified by a RangeVar
*
Index: src/backend/commands/lockcmds.c
===================================================================
RCS file: /cvsroot/pgsql-server/src/backend/commands/lockcmds.c,v
retrieving revision 1.8
diff -c -r1.8 lockcmds.c
*** src/backend/commands/lockcmds.c 29 Nov 2003 19:51:47 -0000 1.8
--- src/backend/commands/lockcmds.c 10 Mar 2004 01:35:21 -0000
***************
*** 59,65 ****
aclcheck_error(aclresult, ACL_KIND_CLASS,
get_rel_name(reloid));
! rel = relation_open(reloid, lockstmt->mode);
/* Currently, we only allow plain tables to be locked */
if (rel->rd_rel->relkind != RELKIND_RELATION)
--- 59,65 ----
aclcheck_error(aclresult, ACL_KIND_CLASS,
get_rel_name(reloid));
! rel = conditional_relation_open(reloid, lockstmt->mode,
lockstmt->nowait);
/* Currently, we only allow plain tables to be locked */
if (rel->rd_rel->relkind != RELKIND_RELATION)
Index: src/backend/nodes/copyfuncs.c
===================================================================
RCS file: /cvsroot/pgsql-server/src/backend/nodes/copyfuncs.c,v
retrieving revision 1.277
diff -c -r1.277 copyfuncs.c
*** src/backend/nodes/copyfuncs.c 14 Jan 2004 23:01:54 -0000 1.277
--- src/backend/nodes/copyfuncs.c 10 Mar 2004 01:35:25 -0000
***************
*** 2316,2321 ****
--- 2316,2322 ----
COPY_NODE_FIELD(relations);
COPY_SCALAR_FIELD(mode);
+ COPY_SCALAR_FIELD(nowait);
return newnode;
}
Index: src/backend/nodes/equalfuncs.c
===================================================================
RCS file: /cvsroot/pgsql-server/src/backend/nodes/equalfuncs.c,v
retrieving revision 1.215
diff -c -r1.215 equalfuncs.c
*** src/backend/nodes/equalfuncs.c 14 Jan 2004 23:01:55 -0000 1.215
--- src/backend/nodes/equalfuncs.c 10 Mar 2004 01:35:28 -0000
***************
*** 1252,1257 ****
--- 1252,1258 ----
{
COMPARE_NODE_FIELD(relations);
COMPARE_SCALAR_FIELD(mode);
+ COMPARE_SCALAR_FIELD(nowait);
return true;
}
Index: src/backend/parser/gram.y
===================================================================
RCS file: /cvsroot/pgsql-server/src/backend/parser/gram.y,v
retrieving revision 2.447
diff -c -r2.447 gram.y
*** src/backend/parser/gram.y 9 Mar 2004 05:05:41 -0000 2.447
--- src/backend/parser/gram.y 10 Mar 2004 01:35:42 -0000
***************
*** 169,174 ****
--- 169,175 ----
%type <ival> opt_lock lock_type cast_context
%type <boolean> opt_force opt_or_replace transaction_access_mode
opt_grant_grant_option opt_revoke_grant_option
+ opt_nowait
%type <boolean> like_including_defaults
***************
*** 375,381 ****
MATCH MAXVALUE MINUTE_P MINVALUE MODE MONTH_P MOVE
NAMES NATIONAL NATURAL NCHAR NEW NEXT NO NOCREATEDB
! NOCREATEUSER NONE NOT NOTHING NOTIFY NOTNULL NULL_P
NULLIF NUMERIC
OBJECT_P OF OFF OFFSET OIDS OLD ON ONLY OPERATOR OPTION OR
--- 376,382 ----
MATCH MAXVALUE MINUTE_P MINVALUE MODE MONTH_P MOVE
NAMES NATIONAL NATURAL NCHAR NEW NEXT NO NOCREATEDB
! NOCREATEUSER NONE NOT NOTHING NOTIFY NOTNULL NOWAIT NULL_P
NULLIF NUMERIC
OBJECT_P OF OFF OFFSET OIDS OLD ON ONLY OPERATOR OPTION OR
***************
*** 4347,4358 ****
}
;
! LockStmt: LOCK_P opt_table qualified_name_list opt_lock
{
LockStmt *n = makeNode(LockStmt);
n->relations = $3;
n->mode = $4;
$$ = (Node *)n;
}
;
--- 4348,4360 ----
}
;
! LockStmt: LOCK_P opt_table qualified_name_list opt_lock opt_nowait
{
LockStmt *n = makeNode(LockStmt);
n->relations = $3;
n->mode = $4;
+ n->nowait = $5;
$$ = (Node *)n;
}
;
***************
*** 4371,4376 ****
--- 4373,4382 ----
| ACCESS EXCLUSIVE { $$ =
AccessExclusiveLock; }
;
+ opt_nowait: NOWAIT { $$ = TRUE; }
+ | /*EMPTY*/ { $$ =
FALSE; }
+ ;
+
/*****************************************************************************
*
***************
*** 7683,7688 ****
--- 7689,7695 ----
| LOCALTIMESTAMP
| NEW
| NOT
+ | NOWAIT
| NULL_P
| OFF
| OFFSET
Index: src/backend/parser/keywords.c
===================================================================
RCS file: /cvsroot/pgsql-server/src/backend/parser/keywords.c,v
retrieving revision 1.146
diff -c -r1.146 keywords.c
*** src/backend/parser/keywords.c 9 Mar 2004 05:05:41 -0000 1.146
--- src/backend/parser/keywords.c 10 Mar 2004 01:35:42 -0000
***************
*** 213,218 ****
--- 213,219 ----
{"nothing", NOTHING},
{"notify", NOTIFY},
{"notnull", NOTNULL},
+ {"nowait", NOWAIT},
{"null", NULL_P},
{"nullif", NULLIF},
{"numeric", NUMERIC},
Index: src/include/access/heapam.h
===================================================================
RCS file: /cvsroot/pgsql-server/src/include/access/heapam.h,v
retrieving revision 1.86
diff -c -r1.86 heapam.h
*** src/include/access/heapam.h 29 Nov 2003 22:40:55 -0000 1.86
--- src/include/access/heapam.h 10 Mar 2004 01:35:46 -0000
***************
*** 129,134 ****
--- 129,135 ----
/* heapam.c */
extern Relation relation_open(Oid relationId, LOCKMODE lockmode);
+ extern Relation conditional_relation_open(Oid relationId, LOCKMODE lockmode, bool
nowait);
extern Relation relation_openrv(const RangeVar *relation, LOCKMODE lockmode);
extern Relation relation_openr(const char *sysRelationName, LOCKMODE lockmode);
extern void relation_close(Relation relation, LOCKMODE lockmode);
Index: src/include/nodes/parsenodes.h
===================================================================
RCS file: /cvsroot/pgsql-server/src/include/nodes/parsenodes.h,v
retrieving revision 1.253
diff -c -r1.253 parsenodes.h
*** src/include/nodes/parsenodes.h 14 Jan 2004 23:01:55 -0000 1.253
--- src/include/nodes/parsenodes.h 10 Mar 2004 01:35:49 -0000
***************
*** 1619,1624 ****
--- 1619,1625 ----
NodeTag type;
List *relations; /* relations to lock */
int mode; /* lock mode */
+ bool nowait; /* no wait mode */
} LockStmt;
/* ----------------------
---------------------------(end of broadcast)---------------------------
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