Code review for NOWAIT patch: downgrade NOWAIT from fully reserved keyword

to unreserved keyword, use ereport not elog, assign a separate error code
for 'could not obtain lock' so that applications will be able to detect
that case cleanly.

diff --git a/doc/src/sgml/errcodes.sgml b/doc/src/sgml/errcodes.sgml
index 950f97151bc3aab325a64b37b143e30e215bd21a..7bcff2c1d90870d8cb53e01e8961507eda7da2b7 100644 (file)
--- a/doc/src/sgml/errcodes.sgml
+++ b/doc/src/sgml/errcodes.sgml
@@ -1,4 +1,4 @@
-
+
 
 
  <productname>PostgreSQL</productname> Error Codes
@@ -1099,6 +1099,11 @@
 CANT CHANGE RUNTIME PARAM
 
 
+
+55P03
+LOCK NOT AVAILABLE
+
+
 
 
 Class 57

diff --git a/doc/src/sgml/ref/lock.sgml b/doc/src/sgml/ref/lock.sgml
index cab378ec95cb12d6da61a2914eab9d3c2e9c879c..34e01c82a58edab66938d4455e0dd9f26346b0d7 100644 (file)
--- a/doc/src/sgml/ref/lock.sgml
+++ b/doc/src/sgml/ref/lock.sgml
@@ -1,5 +1,5 @@
 
 
@@ -37,7 +37,7 @@ where lockmode is one of:
    if necessary for any conflicting locks to be released.  If
    NOWAIT is specified, LOCK
    TABLE does not wait to acquire the desired lock: if it
-   cannot be immediately acquired, the transaction is aborted and an
+   cannot be acquired immediately, the command is aborted and an
    error is emitted.  Once obtained, the lock is held for the
    remainder of the current transaction.  (There is no UNLOCK
    TABLE command; locks are always released at transaction

diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index b8d38cc86baebec63d589df85c604fe52be3bbb2..a5426d089a9045867bcaa469a42426f15a154716 100644 (file)
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *   $PostgreSQL: pgsql/src/backend/access/heap/heapam.c,v 1.176 2004/09/17 18:09:55 tgl Exp $
+ *   $PostgreSQL: pgsql/src/backend/access/heap/heapam.c,v 1.177 2004/10/01 16:39:54 tgl Exp $
  *
  *
  * INTERFACE ROUTINES
@@ -465,6 +465,13 @@ relation_open(Oid relationId, LOCKMODE lockmode)
    return r;
 }
 
+/* ----------------
+ *     conditional_relation_open - open with option not to wait
+ *
+ *     As above, but if nowait is true, then throw an error rather than
+ *     waiting when the lock is not immediately obtainable.
+ * ----------------
+ */
 Relation
 conditional_relation_open(Oid relationId, LOCKMODE lockmode, bool nowait)
 {
@@ -483,7 +490,10 @@ conditional_relation_open(Oid relationId, LOCKMODE lockmode, bool nowait)
        if (nowait)
        {
            if (!ConditionalLockRelation(r, lockmode))
-               elog(ERROR, "could not acquire relation lock");
+               ereport(ERROR,
+                       (errcode(ERRCODE_LOCK_NOT_AVAILABLE),
+                        errmsg("could not obtain lock on \"%s\"",
+                               RelationGetRelationName(r))));
        }
        else
            LockRelation(r, lockmode);

diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 8f1b393d29a084f8e2f5221f37fba14874532969..5a12bf118919d65a08b4e241b4d7a9e6ec014125 100644 (file)
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *   $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.477 2004/09/30 00:24:20 tgl Exp $
+ *   $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.478 2004/10/01 16:39:59 tgl Exp $
  *
  * HISTORY
  *   AUTHOR            DATE            MAJOR EVENT
@@ -7727,6 +7727,7 @@ unreserved_keyword:
            | NOCREATEUSER
            | NOTHING
            | NOTIFY
+           | NOWAIT
            | OBJECT_P
            | OF
            | OIDS
@@ -7944,7 +7945,6 @@ reserved_keyword:
            | LOCALTIMESTAMP
            | NEW
            | NOT
-           | NOWAIT
            | NULL_P
            | OFF
            | OFFSET

diff --git a/src/include/utils/errcodes.h b/src/include/utils/errcodes.h
index 5ef9461f444fc4219f0e9cf523efbd8289ca18ed..a43f6991da77134e723286db7d3b39fc8a471c29 100644 (file)
--- a/src/include/utils/errcodes.h
+++ b/src/include/utils/errcodes.h
@@ -11,7 +11,7 @@
  *
  * Copyright (c) 2003, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/include/utils/errcodes.h,v 1.15 2004/08/29 05:06:58 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/utils/errcodes.h,v 1.16 2004/10/01 16:40:04 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -308,6 +308,7 @@
 #define ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE   MAKE_SQLSTATE('5','5', '0','0','0')
 #define ERRCODE_OBJECT_IN_USE              MAKE_SQLSTATE('5','5', '0','0','6')
 #define ERRCODE_CANT_CHANGE_RUNTIME_PARAM  MAKE_SQLSTATE('5','5', 'P','0','2')
+#define ERRCODE_LOCK_NOT_AVAILABLE         MAKE_SQLSTATE('5','5', 'P','0','3')
 
 /* Class 57 - Operator Intervention (class borrowed from DB2) */
 #define ERRCODE_OPERATOR_INTERVENTION      MAKE_SQLSTATE('5','7', '0','0','0')

diff --git a/src/pl/plpgsql/src/plerrcodes.h b/src/pl/plpgsql/src/plerrcodes.h
index 5ad86ed07ed1a1ae1f5ff74f80a8666d05f14682..d5893c6ed6de045d3cea01b0c62498db2777e9ad 100644 (file)
--- a/src/pl/plpgsql/src/plerrcodes.h
+++ b/src/pl/plpgsql/src/plerrcodes.h
@@ -9,7 +9,7 @@
  *
  * Copyright (c) 2003, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/pl/plpgsql/src/plerrcodes.h,v 1.4 2004/08/29 05:07:01 momjian Exp $
+ * $PostgreSQL: pgsql/src/pl/plpgsql/src/plerrcodes.h,v 1.5 2004/10/01 16:40:05 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -659,6 +659,10 @@
    "cant_change_runtime_param", ERRCODE_CANT_CHANGE_RUNTIME_PARAM
 },
 
+{
+   "lock_not_available", ERRCODE_LOCK_NOT_AVAILABLE
+},
+
 {
    "operator_intervention", ERRCODE_OPERATOR_INTERVENTION
 },