Here is the patch I promised (against current). Regression tests all
passed. One thing I have not checked is the doc(lock.sgml). For some
reason I failed to install docbook V4.2 (I have working docbook V3.1
though), and I couldn't test the correctness of the file. Also, it
would be nice if some one checks my English grammer:-)
--
Tatsuo Ishii
> It seems "NOWAIT" is the winner...
> --
> Tatsuo Ishii
>
> > Oracle uses "NOWAIT" so we should go for that one.
> >
> > Regards,
> >
> > Hans
> >
> >
> >
> > Tatsuo Ishii wrote:
> > > If "NOWAIT" is the choice, I could live with it. If there's no
> > > objection, I will go with "NOWAIT", not "NO WAIT".
> > > --
> > > Tatsuo Ishii
> > >
> > >
> > >>Tatsuo Ishii <[EMAIL PROTECTED]> writes:
> > >>
> > >>>LOCK TABLE table NO WAIT is OK for 7.5? If ok, I will make patches
> > >>>against current with some docs changes.
> > >>
> > >>Dept of minor gripes: can we do this without turning "NO" into a
> > >>keyword? Even as a nonreserved word, I think that would be annoying.
> > >>"no" is a common abbreviation for "number" so I think it's likely to
> > >>get used as a column name.
> > >>
> > >>If Oracle spells it "NOWAIT" then I'd be much happier with that...
> > >>
> > >> regards, tom lane
> > >>
> > >
> > >
> > > ---------------------------(end of broadcast)---------------------------
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> > >
> > > http://archives.postgresql.org
> >
> >
> > --
> > Cybertec Geschwinde u Schoenig
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> >
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Index: doc/src/sgml/ref/lock.sgml
===================================================================
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 9 Mar 2004 12:42:31 -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 9 Mar 2004 12:42:33 -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 9 Mar 2004 12:42:34 -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/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 9 Mar 2004 12:42:37 -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;
}
;
***************
*** 4369,4374 ****
--- 4371,4380 ----
| SHARE ROW EXCLUSIVE { $$ =
ShareRowExclusiveLock; }
| EXCLUSIVE { $$ =
ExclusiveLock; }
| ACCESS EXCLUSIVE { $$ =
AccessExclusiveLock; }
+ ;
+
+ opt_nowait: NOWAIT { $$ = TRUE; }
+ | /*EMPTY*/ { $$ =
FALSE; }
;
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 9 Mar 2004 12:42:37 -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 9 Mar 2004 12:42:38 -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 9 Mar 2004 12:42:39 -0000
***************
*** 1619,1624 ****
--- 1619,1625 ----
NodeTag type;
List *relations; /* relations to lock */
int mode; /* lock mode */
+ bool nowait; /* no wait mode */
} LockStmt;
/* ----------------------
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