From 66126f9687a03ab61b6be7709324fd7e2ecac8bd Mon Sep 17 00:00:00 2001 From: Tatsuo Ishii Date: Sun, 23 Apr 2006 01:12:58 +0000 Subject: [PATCH] Add new contrib function pgrowlocks. See README.pgrowlocks for more details. --- contrib/pgrowlocks/Makefile | 25 +++ contrib/pgrowlocks/README.pgrowlocks | 98 +++++++++ contrib/pgrowlocks/README.pgrowlocks.euc_jp | 121 +++++++++++ contrib/pgrowlocks/pgrowlocks.c | 228 ++++++++++++++++++++ contrib/pgrowlocks/pgrowlocks.sql.in | 16 ++ 5 files changed, 488 insertions(+) create mode 100644 contrib/pgrowlocks/Makefile create mode 100644 contrib/pgrowlocks/README.pgrowlocks create mode 100644 contrib/pgrowlocks/README.pgrowlocks.euc_jp create mode 100644 contrib/pgrowlocks/pgrowlocks.c create mode 100644 contrib/pgrowlocks/pgrowlocks.sql.in diff --git a/contrib/pgrowlocks/Makefile b/contrib/pgrowlocks/Makefile new file mode 100644 index 0000000000..2bff839455 --- /dev/null +++ b/contrib/pgrowlocks/Makefile @@ -0,0 +1,25 @@ +#------------------------------------------------------------------------- +# +# pgrowlocks Makefile +# +# $PostgreSQL: pgsql/contrib/pgrowlocks/Makefile,v 1.1 2006/04/23 01:12:58 ishii Exp $ +# +#------------------------------------------------------------------------- + +SRCS = pgrowlocks.c + +MODULE_big = pgrowlocks +OBJS = $(SRCS:.c=.o) +DOCS = README.pgrowlocks README.pgrowlocks.euc_jp +DATA_built = pgrowlocks.sql + +ifdef USE_PGXS +PGXS = $(shell pg_config --pgxs) +include $(PGXS) +else +subdir = contrib/pgrowlocks +top_builddir = ../.. +include $(top_builddir)/src/Makefile.global +include $(top_srcdir)/contrib/contrib-global.mk +endif + diff --git a/contrib/pgrowlocks/README.pgrowlocks b/contrib/pgrowlocks/README.pgrowlocks new file mode 100644 index 0000000000..ebaea4ca5a --- /dev/null +++ b/contrib/pgrowlocks/README.pgrowlocks @@ -0,0 +1,98 @@ +$PostgreSQL: pgsql/contrib/pgrowlocks/README.pgrowlocks,v 1.1 2006/04/23 01:12:58 ishii Exp $ + +pgrowlocks README Tatsuo Ishii + +1. What is pgrowlocks? + + pgrowlocks shows row locking information for specified table. + + pgrowlocks returns following data type: + +CREATE TYPE pgrowlocks_type AS ( + locked_row TID, -- row TID + lock_type TEXT, -- lock type + locker XID, -- locking XID + multi bool, -- multi XID? + xids xid[], -- multi XIDs + pids INTEGER[] -- locker's process id +); + + Here is a sample execution of pgrowlocks: + +test=# SELECT * FROM pgrowlocks('t1'); + locked_row | lock_type | locker | multi | xids | pids +------------+-----------+--------+-------+-----------+--------------- + (0,1) | Shared | 19 | t | {804,805} | {29066,29068} + (0,2) | Shared | 19 | t | {804,805} | {29066,29068} + (0,3) | Exclusive | 804 | f | {804} | {29066} + (0,4) | Exclusive | 804 | f | {804} | {29066} +(4 rows) + + locked_row -- tuple ID(TID) of each locked rows + lock_type -- "Shared" for shared lock, "Exclusive" for exclusive lock + locker -- transaction ID of locker (note 1) + multi -- "t" if locker is a multi transaction, otherwise "f" + xids -- XIDs of lockers (note 2) + pids -- process ids of locking backends + + note1: if the locker is multi transaction, it represents the multi ID + + note2: if the locker is multi, multiple data are shown + +2. Installing pgrowlocks + + Installing pgrowlocks requires PostgreSQL 8.0 or later source tree. + + $ cd /usr/local/src/postgresql-8.1/contrib + $ tar xfz /tmp/pgrowlocks-1.0.tar.gz + + If you are using PostgreSQL 8.0, you need to modify pgrowlocks source code. + Around line 61, you will see: + + #undef MAKERANGEVARFROMNAMELIST_HAS_TWO_ARGS + + change this to: + + #define MAKERANGEVARFROMNAMELIST_HAS_TWO_ARGS + + $ make + $ make install + + $ psql -e -f pgrowlocks.sql test + +3. How to use pgrowlocks + + The calling sequence for pgrowlocks is as follows: + + CREATE OR REPLACE FUNCTION pgrowlocks(text) RETURNS pgrowlocks_type + AS 'MODULE_PATHNAME', 'pgrowlocks' + LANGUAGE 'c' WITH (isstrict); + + The parameter is a name of table. pgrowlocks returns type pgrowlocks_type. + + pgrowlocks grab AccessShareLock for the target table and read each + row one by one to get the row locking information. You should + notice that: + + 1) if the table is exclusive locked by someone else, pgrowlocks + will be blocked. + + 2) pgrowlocks may show incorrect information if there's a new + lock or a lock is freeed while its execution. + + pgrowlocks does not show the contents of locked rows. If you want + to take a look at the row contents at the same time, you could do + something like this: + + SELECT * FROM accounts AS a, pgrowlocks('accounts') AS p WHERE p.locked_ row = a.ctid; + + +4. License + + pgrowlocks is distribute under (modified) BSD license described in + the source file. + +5. History + + 2006/03/21 pgrowlocks version 1.1 released (tested on 8.2 current) + 2005/08/22 pgrowlocks version 1.0 released diff --git a/contrib/pgrowlocks/README.pgrowlocks.euc_jp b/contrib/pgrowlocks/README.pgrowlocks.euc_jp new file mode 100644 index 0000000000..de7a7c5166 --- /dev/null +++ b/contrib/pgrowlocks/README.pgrowlocks.euc_jp @@ -0,0 +1,121 @@ +$PostgreSQL: pgsql/contrib/pgrowlocks/README.pgrowlocks.euc_jp,v 1.1 2006/04/23 01:12:58 ishii Exp $ + +pgrowlocks README 石井達夫 + +1. pgrowlocksとは + + pgrowlocksは，指定されたテーブルの行ロックに関する情報を表示します． + + pgrowlocksの返す型は，以下のようになります． + +CREATE TYPE pgrowlocks_type AS ( + locked_row TID, -- row TID + lock_type TEXT, -- lock type + locker XID, -- locking XID + multi bool, -- multi XID? + xids xid[], -- multi XIDs + pids INTEGER[] -- locker's process id +); + + 実行例を示します． + +test=# SELECT * FROM pgrowlocks('t1'); + locked_row | lock_type | locker | multi | xids | pids +------------+-----------+--------+-------+-----------+--------------- + (0,1) | Shared | 19 | t | {804,805} | {29066,29068} + (0,2) | Shared | 19 | t | {804,805} | {29066,29068} + (0,3) | Exclusive | 804 | f | {804} | {29066} + (0,4) | Exclusive | 804 | f | {804} | {29066} +(4 rows) + + 各項目の説明です． + + locked_row -- ロックされた行のタプルID(TID) + lock_type -- 共有ロックなら"Shared"，排他ロックなら"Exclusive" + locker -- ロックをかけているトランザクションID[注1] + multi -- lockerがマルチトランザクションならtそうでなければf + xids -- ロックをかけているトランザクションID[注2] + pids -- ロックをかけているバックエンドプロセスのプロセスID[注2] + + [注1: lockerがマルチなら，トランザクションIDではなくてマルチIDになり + ます．] + + [注2: lockerがマルチの場合，複数のデータが表示されます．] + +2. pgrowlocksのインストール + + pgrowlocksのインストールには，PostgreSQLをインストールしたときのソー + スツリーが必要です．今のところ対応しているバージョンはPostgreSQL + 8.0以降です． + + ここではPostgreSQLのソースは/usr/local/src/postgresql-8.1/に展開さ + れているものとします． + + 1) pgrowlocksのソースを展開します．ソースファイルは + /tmp/pgrowlocks-1.0.tar.gzに置いてあるものとします． + + $ cd /usr/local/src/postgresql-8.1/contrib + $ tar xfz pgrowlocks-1.0.tar.gz + + 2) PostgreSQL 8.0の場合は，ソースの一部に修正が必要です． + pgrowlocks.cの61行目辺りに + + #undef MAKERANGEVARFROMNAMELIST_HAS_TWO_ARGS + + というのがあるので，これを + + #define MAKERANGEVARFROMNAMELIST_HAS_TWO_ARGS + + に書き換えます(undef->defineにします)． + + 3) コンパイルして関数の共有ライブラリをインストールします． + + $ make + $ make install + + 4) ユーザ定義関数を登録します． + + $ psql -e -f /usr/local/pgsql/share/contrib/pgrowlocks.sql test + + この例では"test"というデータベースに登録していますが，もし他のデー + タベースに登録する場合はここを読み替えてください． + +3. pgrowlocksの使い方 + + pgrowlocksの呼び出し形式は以下です． + + CREATE OR REPLACE FUNCTION pgrowlocks(text) RETURNS pgrowlocks_type + AS 'MODULE_PATHNAME', 'pgrowlocks' + LANGUAGE 'c' WITH (isstrict); + + 第一引数: テーブル名 + + 関数の戻りはpgrowlocks_type型です． + + pgrowlocksはテーブルにAccessShareLockロックをかけ，1行ずつ読み出し + ては行ロックがかかっているかどうかチェックします．以下の点に注意し + てください． + + 1) 該当テーブルに排他ロックがかかっていると，pgrowlocksの実行はブロッ + クされます． + + 2) pgrowlocksの実行中に新たにかかったり，解除された行ロックに関する + 情報はpgrowlocksの実行結果に反映されていない可能性があります． + + + pgrowlocksはロックされた行の内容は表示しません．行内容を見たい場合 + は，テーブルをpgrowlocksのlocked_rows列で結合します．例を示します． + + SELECT * FROM accounts AS a, pgrowlocks('accounts') AS p WHERE p.locked_ row = a.ctid; + + +4. pgrowlocksのライセンス条件について + + pgrowlocks.cの冒頭に書いてある通りです(修正BSDライセンスに準じてい + ます)．また，pgrowlocks は完全に無保証です．pgrowlocks を使用したこ + とによって生じるいかなる結果に関しても責任を負いません． + +5. 改訂履歴 + + 2006/03/21 pgrowlocks バージョン 1.1リリース(8.2 currentでテスト) + 2005/08/22 pgrowlocks バージョン 1.0リリース diff --git a/contrib/pgrowlocks/pgrowlocks.c b/contrib/pgrowlocks/pgrowlocks.c new file mode 100644 index 0000000000..51035e4015 --- /dev/null +++ b/contrib/pgrowlocks/pgrowlocks.c @@ -0,0 +1,228 @@ +/* + * $PostgreSQL: pgsql/contrib/pgrowlocks/pgrowlocks.c,v 1.1 2006/04/23 01:12:58 ishii Exp $ + * + * Copyright (c) 2005-2006 Tatsuo Ishii + * + * Permission to use, copy, modify, and distribute this software and + * its documentation for any purpose, without fee, and without a + * written agreement is hereby granted, provided that the above + * copyright notice and this paragraph and the following two + * paragraphs appear in all copies. + * + * IN NO EVENT SHALL THE AUTHOR BE LIABLE TO ANY PARTY FOR DIRECT, + * INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING + * LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS + * DOCUMENTATION, EVEN IF THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED + * OF THE POSSIBILITY OF SUCH DAMAGE. + * + * THE AUTHOR SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS + * IS" BASIS, AND THE AUTHOR HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE, + * SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. + */ + +#include "postgres.h" + +#include "funcapi.h" +#include "access/heapam.h" +#include "access/transam.h" +#include "catalog/namespace.h" +#include "catalog/pg_type.h" +#include "storage/proc.h" +#include "utils/builtins.h" + +#ifdef HEAP_XMAX_SHARED_LOCK +#include "access/multixact.h" +#include "storage/procarray.h" +#endif + +PG_FUNCTION_INFO_V1(pgrowlocks); + +extern Datum pgrowlocks(PG_FUNCTION_ARGS); + +/* ---------- + * pgrowlocks: + * returns tids of rows being locked + * + * C FUNCTION definition + * pgrowlocks(text) returns set of pgrowlocks_type + * see pgrowlocks.sql for pgrowlocks_type + * ---------- + */ + +#define DUMMY_TUPLE "public.pgrowlocks_type" +#define NCHARS 32 + +/* + * define this if makeRangeVarFromNameList() has two arguments. As far + * as I know, this only happens in 8.0.x. + */ +#undef MAKERANGEVARFROMNAMELIST_HAS_TWO_ARGS + +typedef struct { + HeapScanDesc scan; + int ncolumns; +} MyData; + +Datum +pgrowlocks(PG_FUNCTION_ARGS) +{ + FuncCallContext *funcctx; + HeapScanDesc scan; + HeapTuple tuple; + TupleDesc tupdesc; + AttInMetadata *attinmeta; + Datum result; + MyData *mydata; + Relation rel; + + if (SRF_IS_FIRSTCALL()) + { + text *relname; + RangeVar *relrv; + MemoryContext oldcontext; + + funcctx = SRF_FIRSTCALL_INIT(); + oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx); + + tupdesc = RelationNameGetTupleDesc(DUMMY_TUPLE); + attinmeta = TupleDescGetAttInMetadata(tupdesc); + funcctx->attinmeta = attinmeta; + + relname = PG_GETARG_TEXT_P(0); +#ifdef MAKERANGEVARFROMNAMELIST_HAS_TWO_ARGS + relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname, "pgrowlocks")); + +#else + relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname)); +#endif + rel = heap_openrv(relrv, AccessShareLock); + scan = heap_beginscan(rel, SnapshotNow, 0, NULL); + mydata = palloc(sizeof(*mydata)); + mydata->scan = scan; + mydata->ncolumns = tupdesc->natts; + funcctx->user_fctx = mydata; + + MemoryContextSwitchTo(oldcontext); + } + + funcctx = SRF_PERCALL_SETUP(); + attinmeta = funcctx->attinmeta; + mydata = (MyData *)funcctx->user_fctx; + scan = mydata->scan; + + /* scan the relation */ + while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL) + { + /* must hold a buffer lock to call HeapTupleSatisfiesUpdate */ + LockBuffer(scan->rs_cbuf, BUFFER_LOCK_SHARE); + + if (HeapTupleSatisfiesUpdate(tuple->t_data, GetCurrentCommandId(), scan->rs_cbuf) + == HeapTupleBeingUpdated) + { + + char **values; + int i; + + values = (char **) palloc(mydata->ncolumns * sizeof(char *)); + + i = 0; + values[i++] = (char *)DirectFunctionCall1(tidout, PointerGetDatum(&tuple->t_self)); + +#ifdef HEAP_XMAX_SHARED_LOCK + if (tuple->t_data->t_infomask & HEAP_XMAX_SHARED_LOCK) + values[i++] = pstrdup("Shared"); + else + values[i++] = pstrdup("Exclusive"); +#else + values[i++] = pstrdup("Exclusive"); +#endif + values[i] = palloc(NCHARS*sizeof(char)); + snprintf(values[i++], NCHARS, "%d", HeapTupleHeaderGetXmax(tuple->t_data)); +#ifdef HEAP_XMAX_SHARED_LOCK + if (tuple->t_data->t_infomask & HEAP_XMAX_IS_MULTI) + { + TransactionId *xids; + int nxids; + int j; + int isValidXid = 0; /* any valid xid ever exists? */ + + values[i++] = pstrdup("true"); + nxids = GetMultiXactIdMembers(HeapTupleHeaderGetXmax(tuple->t_data), &xids); + if (nxids == -1) + { + elog(ERROR, "GetMultiXactIdMembers returns error"); + } + + values[i] = palloc(NCHARS*nxids); + values[i+1] = palloc(NCHARS*nxids); + strcpy(values[i], "{"); + strcpy(values[i+1], "{"); + + for (j=0;jt_data)); + + values[i] = palloc(NCHARS*sizeof(char)); + snprintf(values[i++], NCHARS, "{%d}", BackendXidGetPid(HeapTupleHeaderGetXmax(tuple->t_data))); + } + +#else + values[i++] = pstrdup("false"); + values[i++] = pstrdup("{}"); + values[i++] = pstrdup("{}"); +#endif + + LockBuffer(scan->rs_cbuf, BUFFER_LOCK_UNLOCK); + + /* build a tuple */ + tuple = BuildTupleFromCStrings(attinmeta, values); + + /* make the tuple into a datum */ + result = HeapTupleGetDatum(tuple); + + /* Clean up */ + for (i = 0; i < mydata->ncolumns; i++) + pfree(values[i]); + pfree(values); + + SRF_RETURN_NEXT(funcctx, result); + } + else + { + LockBuffer(scan->rs_cbuf, BUFFER_LOCK_UNLOCK); + } + } + + heap_endscan(scan); + heap_close(scan->rs_rd, AccessShareLock); + + SRF_RETURN_DONE(funcctx); +} diff --git a/contrib/pgrowlocks/pgrowlocks.sql.in b/contrib/pgrowlocks/pgrowlocks.sql.in new file mode 100644 index 0000000000..0607c44349 --- /dev/null +++ b/contrib/pgrowlocks/pgrowlocks.sql.in @@ -0,0 +1,16 @@ +-- Adjust this setting to control where the objects get created. +SET search_path = public; + +CREATE TYPE pgrowlocks_type AS ( + locked_row TID, -- row TID + lock_type TEXT, -- lock type + locker XID, -- locking XID + multi bool, -- multi XID? + xids xid[], -- multi XIDs + pids INTEGER[] -- locker's process id +); + +CREATE OR REPLACE FUNCTION pgrowlocks(text) +RETURNS setof pgrowlocks_type +AS 'MODULE_PATHNAME', 'pgrowlocks' +LANGUAGE 'C' STRICT;