From a9c4c9cd52b3fde9aed016cbc5d684ab2ad968ef Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Tue, 17 May 2005 21:46:11 +0000
Subject: [PATCH] Extend the pg_locks system view so that it can fully display
all lock types, as per recent discussion.
---
contrib/userlock/user_locks.c | 6 +-
doc/src/sgml/catalogs.sgml | 113 ++++++++++++++++++++++----
src/backend/catalog/system_views.sql | 8 +-
src/backend/utils/adt/lockfuncs.c | 116 ++++++++++++++++++++++-----
src/include/catalog/catversion.h | 4 +-
src/include/catalog/pg_proc.h | 4 +-
src/test/regress/expected/rules.out | 2 +-
7 files changed, 204 insertions(+), 49 deletions(-)
diff --git a/contrib/userlock/user_locks.c b/contrib/userlock/user_locks.c
index 207610084b1..418daf212e6 100644
--- a/contrib/userlock/user_locks.c
+++ b/contrib/userlock/user_locks.c
@@ -19,9 +19,9 @@
#define SET_LOCKTAG_USERLOCK(locktag,id1,id2) \
- ((locktag).locktag_field1 = (id1), \
- (locktag).locktag_field2 = (id2), \
- (locktag).locktag_field3 = MyDatabaseId, \
+ ((locktag).locktag_field1 = MyDatabaseId, \
+ (locktag).locktag_field2 = (id1), \
+ (locktag).locktag_field3 = (id2), \
(locktag).locktag_field4 = 0, \
(locktag).locktag_type = LOCKTAG_USERLOCK)
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 0aa12d4eae5..544f9b758d3 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -1,6 +1,6 @@
<!--
Documentation of the system catalogs, directed toward PostgreSQL developers
- $PostgreSQL: pgsql/doc/src/sgml/catalogs.sgml,v 2.101 2005/05/06 14:28:53 tgl Exp $
+ $PostgreSQL: pgsql/doc/src/sgml/catalogs.sgml,v 2.102 2005/05/17 21:46:09 tgl Exp $
-->
<chapter id="catalogs">
@@ -4040,15 +4040,18 @@
lockable object may
appear many times, if multiple transactions are holding or waiting
for locks on it. However, an object that currently has no locks on it
- will not appear at all. A lockable object is either a relation (e.g., a
- table) or a transaction ID.
+ will not appear at all.
</para>
<para>
- Note that this view includes only table-level
- locks, not row-level ones. If a transaction is waiting for a
- row-level lock, it will appear in the view as waiting for the
- transaction ID of the current holder of that row lock.
+ There are several distinct types of lockable objects:
+ whole relations (e.g., tables), individual pages of relations,
+ individual tuples of relations,
+ transaction IDs,
+ and general database objects (identified by class OID and object OID,
+ in the same way as in <structname>pg_description</structname> or
+ <structname>pg_depend</structname>). Also, the right to extend a
+ relation is represented as a separate lockable object.
</para>
<table>
@@ -4065,12 +4068,18 @@
</thead>
<tbody>
<row>
- <entry><structfield>relation</structfield></entry>
- <entry><type>oid</type></entry>
- <entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.oid</literal></entry>
+ <entry><structfield>locktype</structfield></entry>
+ <entry><type>text</type></entry>
+ <entry></entry>
<entry>
- OID of the locked relation, or NULL if the lockable object
- is a transaction ID
+ type of the lockable object:
+ <literal>relation</>,
+ <literal>extend</>,
+ <literal>page</>,
+ <literal>tuple</>,
+ <literal>transaction</>,
+ <literal>object</>, or
+ <literal>userlock</>
</entry>
</row>
<row>
@@ -4078,9 +4087,35 @@
<entry><type>oid</type></entry>
<entry><literal><link linkend="catalog-pg-database"><structname>pg_database</structname></link>.oid</literal></entry>
<entry>
- OID of the database in which the locked relation exists, or
- zero if the locked relation is a globally-shared table, or
- NULL if the lockable object is a transaction ID
+ OID of the database in which the object exists, or
+ zero if the object is a globally-shared object, or
+ NULL if the object is a transaction ID
+ </entry>
+ </row>
+ <row>
+ <entry><structfield>relation</structfield></entry>
+ <entry><type>oid</type></entry>
+ <entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.oid</literal></entry>
+ <entry>
+ OID of the relation, or NULL if the object is not
+ a relation or part of a relation
+ </entry>
+ </row>
+ <row>
+ <entry><structfield>page</structfield></entry>
+ <entry><type>integer</type></entry>
+ <entry></entry>
+ <entry>
+ page number within the relation, or NULL if the object
+ is not a tuple or relation page
+ </entry>
+ </row>
+ <row>
+ <entry><structfield>tuple</structfield></entry>
+ <entry><type>smallint</type></entry>
+ <entry></entry>
+ <entry>
+ tuple number within the page, or NULL if the object is not a tuple
</entry>
</row>
<row>
@@ -4088,14 +4123,43 @@
<entry><type>xid</type></entry>
<entry></entry>
<entry>
- ID of a transaction, or NULL if the lockable object is a relation
+ ID of a transaction, or NULL if the object is not a transaction ID
+ </entry>
+ </row>
+ <row>
+ <entry><structfield>classid</structfield></entry>
+ <entry><type>oid</type></entry>
+ <entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.oid</literal></entry>
+ <entry>
+ OID of the system catalog containing the object, or NULL if the
+ object is not a general database object
+ </entry>
+ </row>
+ <row>
+ <entry><structfield>objid</structfield></entry>
+ <entry><type>oid</type></entry>
+ <entry>any OID column</entry>
+ <entry>
+ OID of the object within its system catalog, or NULL if the
+ object is not a general database object
+ </entry>
+ </row>
+ <row>
+ <entry><structfield>objsubid</structfield></entry>
+ <entry><type>smallint</type></entry>
+ <entry></entry>
+ <entry>
+ For a table column, this is the column number (the
+ <structfield>classid</> and <structfield>objid</> refer to the
+ table itself). For all other object types, this column is
+ zero. NULL if the object is not a general database object
</entry>
</row>
<row>
<entry><structfield>pid</structfield></entry>
<entry><type>integer</type></entry>
<entry></entry>
- <entry>process ID of a server process holding or awaiting this
+ <entry>process ID of the server process holding or awaiting this
lock</entry>
</row>
<row>
@@ -4133,6 +4197,21 @@
terminates and releases its locks.
</para>
+ <para>
+ Although tuples are a lockable type of object,
+ information about row-level locks is stored on disk, not in memory,
+ and therefore row-level locks normally do not appear in this view.
+ If a transaction is waiting for a
+ row-level lock, it will usually appear in the view as waiting for the
+ transaction ID of the current holder of that row lock.
+ </para>
+
+ <para>
+ If user-defined locks are in use, they are displayed using the columns
+ for general database objects. However, the actual meaning of the lock
+ fields in such cases is up to the user.
+ </para>
+
<para>
When the <structname>pg_locks</structname> view is accessed, the
internal lock manager data structures are momentarily locked, and
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index 1bf0f1657d5..d66bb780b4f 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -3,7 +3,7 @@
*
* Copyright (c) 1996-2005, PostgreSQL Global Development Group
*
- * $PostgreSQL: pgsql/src/backend/catalog/system_views.sql,v 1.12 2005/05/09 11:31:32 neilc Exp $
+ * $PostgreSQL: pgsql/src/backend/catalog/system_views.sql,v 1.13 2005/05/17 21:46:09 tgl Exp $
*/
CREATE VIEW pg_user AS
@@ -261,8 +261,10 @@ CREATE VIEW pg_stat_database AS
CREATE VIEW pg_locks AS
SELECT *
- FROM pg_lock_status() AS L(relation oid, database oid,
- transaction xid, pid int4, mode text, granted boolean);
+ FROM pg_lock_status() AS L
+ (locktype text, database oid, relation oid, page int4, tuple int2,
+ transaction xid, classid oid, objid oid, objsubid int2,
+ pid int4, mode text, granted boolean);
CREATE VIEW pg_settings AS
SELECT *
diff --git a/src/backend/utils/adt/lockfuncs.c b/src/backend/utils/adt/lockfuncs.c
index 6878662b79f..e941ec2d3d8 100644
--- a/src/backend/utils/adt/lockfuncs.c
+++ b/src/backend/utils/adt/lockfuncs.c
@@ -6,7 +6,7 @@
* Copyright (c) 2002-2005, PostgreSQL Global Development Group
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/utils/adt/lockfuncs.c,v 1.17 2005/04/29 22:28:24 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/adt/lockfuncs.c,v 1.18 2005/05/17 21:46:10 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -20,6 +20,17 @@
#include "utils/builtins.h"
+/* This must match enum LockTagType! */
+static const char * const LockTagTypeNames[] = {
+ "relation",
+ "extend",
+ "page",
+ "tuple",
+ "transaction",
+ "object",
+ "userlock"
+};
+
/* Working status for pg_lock_status */
typedef struct
{
@@ -53,18 +64,30 @@ pg_lock_status(PG_FUNCTION_ARGS)
/* build tupdesc for result tuples */
/* this had better match pg_locks view in system_views.sql */
- tupdesc = CreateTemplateTupleDesc(6, false);
- TupleDescInitEntry(tupdesc, (AttrNumber) 1, "relation",
- OIDOID, -1, 0);
+ tupdesc = CreateTemplateTupleDesc(12, false);
+ TupleDescInitEntry(tupdesc, (AttrNumber) 1, "locktype",
+ TEXTOID, -1, 0);
TupleDescInitEntry(tupdesc, (AttrNumber) 2, "database",
OIDOID, -1, 0);
- TupleDescInitEntry(tupdesc, (AttrNumber) 3, "transaction",
+ TupleDescInitEntry(tupdesc, (AttrNumber) 3, "relation",
+ OIDOID, -1, 0);
+ TupleDescInitEntry(tupdesc, (AttrNumber) 4, "page",
+ INT4OID, -1, 0);
+ TupleDescInitEntry(tupdesc, (AttrNumber) 5, "tuple",
+ INT2OID, -1, 0);
+ TupleDescInitEntry(tupdesc, (AttrNumber) 6, "transaction",
XIDOID, -1, 0);
- TupleDescInitEntry(tupdesc, (AttrNumber) 4, "pid",
+ TupleDescInitEntry(tupdesc, (AttrNumber) 7, "classid",
+ OIDOID, -1, 0);
+ TupleDescInitEntry(tupdesc, (AttrNumber) 8, "objid",
+ OIDOID, -1, 0);
+ TupleDescInitEntry(tupdesc, (AttrNumber) 9, "objsubid",
+ INT2OID, -1, 0);
+ TupleDescInitEntry(tupdesc, (AttrNumber) 10, "pid",
INT4OID, -1, 0);
- TupleDescInitEntry(tupdesc, (AttrNumber) 5, "mode",
+ TupleDescInitEntry(tupdesc, (AttrNumber) 11, "mode",
TEXTOID, -1, 0);
- TupleDescInitEntry(tupdesc, (AttrNumber) 6, "granted",
+ TupleDescInitEntry(tupdesc, (AttrNumber) 12, "granted",
BOOLOID, -1, 0);
funcctx->tuple_desc = BlessTupleDesc(tupdesc);
@@ -93,8 +116,10 @@ pg_lock_status(PG_FUNCTION_ARGS)
PGPROC *proc;
bool granted;
LOCKMODE mode = 0;
- Datum values[6];
- char nulls[6];
+ const char *locktypename;
+ char tnbuf[32];
+ Datum values[12];
+ char nulls[12];
HeapTuple tuple;
Datum result;
@@ -155,30 +180,79 @@ pg_lock_status(PG_FUNCTION_ARGS)
MemSet(values, 0, sizeof(values));
MemSet(nulls, ' ', sizeof(nulls));
+ if (lock->tag.locktag_type <= LOCKTAG_USERLOCK)
+ locktypename = LockTagTypeNames[lock->tag.locktag_type];
+ else
+ {
+ snprintf(tnbuf, sizeof(tnbuf), "unknown %d",
+ (int) lock->tag.locktag_type);
+ locktypename = tnbuf;
+ }
+ values[0] = DirectFunctionCall1(textin,
+ CStringGetDatum(locktypename));
+
+
switch (lock->tag.locktag_type)
{
case LOCKTAG_RELATION:
case LOCKTAG_RELATION_EXTEND:
+ values[1] = ObjectIdGetDatum(lock->tag.locktag_field1);
+ values[2] = ObjectIdGetDatum(lock->tag.locktag_field2);
+ nulls[3] = 'n';
+ nulls[4] = 'n';
+ nulls[5] = 'n';
+ nulls[6] = 'n';
+ nulls[7] = 'n';
+ nulls[8] = 'n';
+ break;
case LOCKTAG_PAGE:
+ values[1] = ObjectIdGetDatum(lock->tag.locktag_field1);
+ values[2] = ObjectIdGetDatum(lock->tag.locktag_field2);
+ values[3] = UInt32GetDatum(lock->tag.locktag_field3);
+ nulls[4] = 'n';
+ nulls[5] = 'n';
+ nulls[6] = 'n';
+ nulls[7] = 'n';
+ nulls[8] = 'n';
+ break;
case LOCKTAG_TUPLE:
- values[0] = ObjectIdGetDatum(lock->tag.locktag_field2);
values[1] = ObjectIdGetDatum(lock->tag.locktag_field1);
- nulls[2] = 'n';
+ values[2] = ObjectIdGetDatum(lock->tag.locktag_field2);
+ values[3] = UInt32GetDatum(lock->tag.locktag_field3);
+ values[4] = UInt16GetDatum(lock->tag.locktag_field4);
+ nulls[5] = 'n';
+ nulls[6] = 'n';
+ nulls[7] = 'n';
+ nulls[8] = 'n';
break;
case LOCKTAG_TRANSACTION:
- nulls[0] = 'n';
+ values[5] = TransactionIdGetDatum(lock->tag.locktag_field1);
nulls[1] = 'n';
- values[2] = TransactionIdGetDatum(lock->tag.locktag_field1);
+ nulls[2] = 'n';
+ nulls[3] = 'n';
+ nulls[4] = 'n';
+ nulls[6] = 'n';
+ nulls[7] = 'n';
+ nulls[8] = 'n';
+ break;
+ case LOCKTAG_OBJECT:
+ case LOCKTAG_USERLOCK:
+ default: /* treat unknown locktags like OBJECT */
+ values[1] = ObjectIdGetDatum(lock->tag.locktag_field1);
+ values[6] = ObjectIdGetDatum(lock->tag.locktag_field2);
+ values[7] = ObjectIdGetDatum(lock->tag.locktag_field3);
+ values[8] = Int16GetDatum(lock->tag.locktag_field4);
+ nulls[2] = 'n';
+ nulls[3] = 'n';
+ nulls[4] = 'n';
+ nulls[5] = 'n';
break;
- default:
- /* XXX Ignore all other lock types for now */
- continue;
}
- values[3] = Int32GetDatum(proc->pid);
- values[4] = DirectFunctionCall1(textin,
- CStringGetDatum(GetLockmodeName(mode)));
- values[5] = BoolGetDatum(granted);
+ values[9] = Int32GetDatum(proc->pid);
+ values[10] = DirectFunctionCall1(textin,
+ CStringGetDatum(GetLockmodeName(mode)));
+ values[11] = BoolGetDatum(granted);
tuple = heap_formtuple(funcctx->tuple_desc, values, nulls);
result = HeapTupleGetDatum(tuple);
diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index 2579b032a59..dd1c29ab02b 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -37,7 +37,7 @@
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.267 2005/05/09 11:31:34 neilc Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.268 2005/05/17 21:46:10 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -53,6 +53,6 @@
*/
/* yyyymmddN */
-#define CATALOG_VERSION_NO 200505091
+#define CATALOG_VERSION_NO 200505171
#endif
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index 13468fc5beb..a3f50ea8902 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.361 2005/05/09 11:31:34 neilc Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.362 2005/05/17 21:46:10 tgl Exp $
*
* NOTES
* The script catalog/genbki.sh reads this file and generates .bki
@@ -2999,7 +2999,7 @@ DATA(insert OID = 2078 ( set_config PGNSP PGUID 12 f f f f v 3 25 "25 25 16" _
DESCR("SET X as a function");
DATA(insert OID = 2084 ( pg_show_all_settings PGNSP PGUID 12 f f t t s 0 2249 "" _null_ _null_ _null_ show_all_settings - _null_ ));
DESCR("SHOW ALL as a function");
-DATA(insert OID = 1371 ( pg_lock_status PGNSP PGUID 12 f f f t v 0 2249 "" _null_ _null_ _null_ pg_lock_status - _null_ ));
+DATA(insert OID = 1371 ( pg_lock_status PGNSP PGUID 12 f f t t v 0 2249 "" _null_ _null_ _null_ pg_lock_status - _null_ ));
DESCR("view system lock information");
DATA(insert OID = 2079 ( pg_table_is_visible PGNSP PGUID 12 f f t f s 1 16 "26" _null_ _null_ _null_ pg_table_is_visible - _null_ ));
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index 5e3ca10faeb..5eccf2d44a0 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -1278,7 +1278,7 @@ SELECT viewname, definition FROM pg_views WHERE schemaname <> 'information_schem
--------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
iexit | SELECT ih.name, ih.thepath, interpt_pp(ih.thepath, r.thepath) AS exit FROM ihighway ih, ramp r WHERE (ih.thepath ## r.thepath);
pg_indexes | SELECT n.nspname AS schemaname, c.relname AS tablename, i.relname AS indexname, t.spcname AS "tablespace", pg_get_indexdef(i.oid) AS indexdef FROM ((((pg_index x JOIN pg_class c ON ((c.oid = x.indrelid))) JOIN pg_class i ON ((i.oid = x.indexrelid))) LEFT JOIN pg_namespace n ON ((n.oid = c.relnamespace))) LEFT JOIN pg_tablespace t ON ((t.oid = i.reltablespace))) WHERE ((c.relkind = 'r'::"char") AND (i.relkind = 'i'::"char"));
- pg_locks | SELECT l.relation, l."database", l."transaction", l.pid, l."mode", l.granted FROM pg_lock_status() l(relation oid, "database" oid, "transaction" xid, pid integer, "mode" text, granted boolean);
+ pg_locks | SELECT l.locktype, l."database", l.relation, l.page, l.tuple, l."transaction", l.classid, l.objid, l.objsubid, l.pid, l."mode", l.granted FROM pg_lock_status() l(locktype text, "database" oid, relation oid, page integer, tuple smallint, "transaction" xid, classid oid, objid oid, objsubid smallint, pid integer, "mode" text, granted boolean);
pg_rules | SELECT n.nspname AS schemaname, c.relname AS tablename, r.rulename, pg_get_ruledef(r.oid) AS definition FROM ((pg_rewrite r JOIN pg_class c ON ((c.oid = r.ev_class))) LEFT JOIN pg_namespace n ON ((n.oid = c.relnamespace))) WHERE (r.rulename <> '_RETURN'::name);
pg_settings | SELECT a.name, a.setting, a.category, a.short_desc, a.extra_desc, a.context, a.vartype, a.source, a.min_val, a.max_val FROM pg_show_all_settings() a(name text, setting text, category text, short_desc text, extra_desc text, context text, vartype text, source text, min_val text, max_val text);
pg_stat_activity | SELECT d.oid AS datid, d.datname, pg_stat_get_backend_pid(s.backendid) AS procpid, pg_stat_get_backend_userid(s.backendid) AS usesysid, u.usename, pg_stat_get_backend_activity(s.backendid) AS current_query, pg_stat_get_backend_activity_start(s.backendid) AS query_start, pg_stat_get_backend_start(s.backendid) AS backend_start, pg_stat_get_backend_client_addr(s.backendid) AS client_addr, pg_stat_get_backend_client_port(s.backendid) AS client_port FROM pg_database d, (SELECT pg_stat_get_backend_idset() AS backendid) s, pg_shadow u WHERE ((pg_stat_get_backend_dbid(s.backendid) = d.oid) AND (pg_stat_get_backend_userid(s.backendid) = u.usesysid));
--
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