Hi,
On 8/9/23 9:56 AM, Michael Paquier wrote:
On Tue, Aug 08, 2023 at 10:16:37AM +0200, Drouvot, Bertrand wrote:
Please find attached v3 adding the wait event types.
+-- There will surely be at least 9 wait event types, 240 wait events and at
+-- least 27 related to WAL
+select count(distinct(wait_event_type)) > 8 as ok_type,
+ count(*) > 239 as ok,
+ count(*) FILTER (WHERE description like '%WAL%') > 26 AS ok_wal_desc
+from pg_wait_event;
The point is to check the execution of this function, so this could be
simpler, like that or a GROUP BY clause with the event type:
SELECT count(*) > 0 FROM pg_wait_event;
SELECT wait_event_type, count(*) > 0 AS has_data FROM pg_wait_event
GROUP BY wait_event_type ORDER BY wait_event_type;
Thanks for looking at it!
Right, so v4 attached is just testing "SELECT count(*) > 0 FROM pg_wait_event;",
that does look enough to test.
+ printf $ic "\tmemset(values, 0, sizeof(values));\n";
+ printf $ic "\tmemset(nulls, 0, sizeof(nulls));\n\n";
+ printf $ic "\tvalues[0] = CStringGetTextDatum(\"%s\");\n", $last;
+ printf $ic "\tvalues[1] = CStringGetTextDatum(\"%s\");\n",
$wev->[1];
+ printf $ic "\tvalues[2] = CStringGetTextDatum(\"%s\");\n\n",
$new_desc;
That's overcomplicated for some code generated. Wouldn't it be
simpler to generate a list of elements, with the code inserting the
tuples materialized looping over it?
Yeah, agree thanks!
In v4, the perl script now appends the wait events in a List that way:
"
printf $ic "\telement = (wait_event_element *)
palloc(sizeof(wait_event_element));\n";
printf $ic "\telement->wait_event_type = \"%s\";\n", $last;
printf $ic "\telement->wait_event_name = \"%s\";\n", $wev->[1];
printf $ic "\telement->wait_event_description = \"%s\";\n\n",
$new_desc;
printf $ic "\twait_event = lappend(wait_event, element);\n\n";
"
And the C function pg_get_wait_events() now iterates over this List.
+ my $new_desc = substr $wev->[2], 1, -2;
+ $new_desc =~ s/'/\\'/g;
+ $new_desc =~ s/<.*>(.*?)<.*>/$1/g;
+ $new_desc =~ s/<xref linkend="guc-(.*?)"\/>/$1/g;
+ $new_desc =~ s/; see.*$//;
Better to document what this does,
good idea...
I had to turn them "on" one by one to recall why they are there...;-)
Done in v4.
the contents produced look good.
yeap
+ rename($ictmp, "$output_path/pg_wait_event_insert.c")
+ || die "rename: $ictmp to $output_path/pg_wait_event_insert.c: $!";
# seems nicer to not add that as an include path for the whole backend.
waitevent_sources = files(
'wait_event.c',
+ 'pg_wait_event.c',
)
This could use a name referring to SQL functions, say
wait_event_funcs.c, with a wait_event_data.c or a
wait_event_funcs_data.c?
That sounds better indeed, thanks! v4 is using wait_event_funcs.c and
wait_event_funcs_data.c.
+ # Don't generate .c (except pg_wait_event_insert.c) and .h files for
+ # Extension, LWLock and Lock, these are handled independently.
+ my $is_exception = $waitclass eq 'WaitEventExtension' ||
+ $waitclass eq 'WaitEventLWLock' ||
+ $waitclass eq 'WaitEventLock';
Perhaps it would be cleaner to use a separate loop?
Agree that's worth it given the fact that iterating one more time is not that
costly here.
Regards,
--
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com
From aa3e81810daaba7b1b2e05219ef662f2fd0607f8 Mon Sep 17 00:00:00 2001
From: bdrouvotAWS <bdrou...@amazon.com>
Date: Sat, 5 Aug 2023 12:39:42 +0000
Subject: [PATCH v4] pg_wait_event
Adding a new system view, namely pg_wait_event, that describes the wait events.
---
doc/src/sgml/system-views.sgml | 64 +++++++++++++++++
src/backend/catalog/system_views.sql | 3 +
src/backend/utils/activity/.gitignore | 1 +
src/backend/utils/activity/Makefile | 6 +-
.../activity/generate-wait_event_types.pl | 46 ++++++++++++-
src/backend/utils/activity/meson.build | 1 +
src/backend/utils/activity/wait_event_funcs.c | 69 +++++++++++++++++++
src/include/catalog/pg_proc.dat | 6 ++
src/include/utils/meson.build | 4 +-
src/test/regress/expected/rules.out | 4 ++
src/test/regress/expected/sysviews.out | 7 ++
src/test/regress/sql/sysviews.sql | 3 +
src/tools/msvc/clean.bat | 1 +
13 files changed, 209 insertions(+), 6 deletions(-)
24.4% doc/src/sgml/
58.5% src/backend/utils/activity/
5.9% src/include/catalog/
4.1% src/test/regress/expected/
6.9% src/
diff --git a/doc/src/sgml/system-views.sgml b/doc/src/sgml/system-views.sgml
index 57b228076e..ed26c8326f 100644
--- a/doc/src/sgml/system-views.sgml
+++ b/doc/src/sgml/system-views.sgml
@@ -221,6 +221,11 @@
<entry>views</entry>
</row>
+ <row>
+ <entry><link
linkend="view-pg-wait-event"><structname>pg_wait_event</structname></link></entry>
+ <entry>wait events</entry>
+ </row>
+
</tbody>
</tgroup>
</table>
@@ -4825,4 +4830,63 @@ SELECT * FROM pg_locks pl LEFT JOIN pg_prepared_xacts ppx
</table>
</sect1>
+
+ <sect1 id="view-pg-wait-event">
+ <title><structname>pg_wait_event</structname></title>
+
+ <indexterm zone="view-pg-wait-event">
+ <primary>pg_wait_event</primary>
+ </indexterm>
+
+ <para>
+ The view <structname>pg_wait_event</structname> provides description about
the
+ wait events.
+ </para>
+
+ <table>
+ <title><structname>pg_wait_event</structname> Columns</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ Column Type
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>wait_event_type</structfield> <type>text</type>
+ </para>
+ <para>
+ Wait event type
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>wait_event_name</structfield> <type>text</type>
+ </para>
+ <para>
+ Wait event name
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>description</structfield> <type>texte</type>
+ </para>
+ <para>
+ Wait event description
+ </para></entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </sect1>
+
</chapter>
diff --git a/src/backend/catalog/system_views.sql
b/src/backend/catalog/system_views.sql
index af65af6bdd..f86a4dd770 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -1342,3 +1342,6 @@ CREATE VIEW pg_stat_subscription_stats AS
ss.stats_reset
FROM pg_subscription as s,
pg_stat_get_subscription_stats(s.oid) as ss;
+
+CREATE VIEW pg_wait_event AS
+ SELECT * FROM pg_get_wait_events() AS we;
diff --git a/src/backend/utils/activity/.gitignore
b/src/backend/utils/activity/.gitignore
index d77079285b..bd0c0c7772 100644
--- a/src/backend/utils/activity/.gitignore
+++ b/src/backend/utils/activity/.gitignore
@@ -1,2 +1,3 @@
/pgstat_wait_event.c
/wait_event_types.h
+/wait_event_funcs_data.c
diff --git a/src/backend/utils/activity/Makefile
b/src/backend/utils/activity/Makefile
index f1117745d4..289afe7c2d 100644
--- a/src/backend/utils/activity/Makefile
+++ b/src/backend/utils/activity/Makefile
@@ -32,10 +32,14 @@ OBJS = \
pgstat_subscription.o \
pgstat_wal.o \
pgstat_xact.o \
+ wait_event_funcs.o \
wait_event.o
include $(top_srcdir)/src/backend/common.mk
+wait_event_funcs.o: wait_event_funcs_data.c
+wait_event_funcs_data.c: wait_event_types.h
+
wait_event.o: pgstat_wait_event.c
pgstat_wait_event.c: wait_event_types.h
touch $@
@@ -44,4 +48,4 @@ wait_event_types.h:
$(top_srcdir)/src/backend/utils/activity/wait_event_names.tx
$(PERL) $(srcdir)/generate-wait_event_types.pl --code $<
maintainer-clean: clean
- rm -f wait_event_types.h pgstat_wait_event.c
+ rm -f wait_event_types.h pgstat_wait_event.c wait_event_funcs_data.c
diff --git a/src/backend/utils/activity/generate-wait_event_types.pl
b/src/backend/utils/activity/generate-wait_event_types.pl
index 56335e8730..6f4fcd22d2 100644
--- a/src/backend/utils/activity/generate-wait_event_types.pl
+++ b/src/backend/utils/activity/generate-wait_event_types.pl
@@ -4,6 +4,7 @@
# Generate wait events support files from wait_event_names.txt:
# - wait_event_types.h (if --code is passed)
# - pgstat_wait_event.c (if --code is passed)
+# - wait_event_funcs_data.c (if --code is passed)
# - wait_event_types.sgml (if --docs is passed)
#
# Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
@@ -98,8 +99,10 @@ if ($gen_code)
# multiple times.
my $htmp = "$output_path/wait_event_types.h.tmp$$";
my $ctmp = "$output_path/pgstat_wait_event.c.tmp$$";
+ my $wctmp = "$output_path/wait_event_funcs_data.c.tmp$$";
open my $h, '>', $htmp or die "Could not open $htmp: $!";
open my $c, '>', $ctmp or die "Could not open $ctmp: $!";
+ open my $wc, '>', $wctmp or die "Could not open $wctmp: $!";
my $header_comment =
'/*-------------------------------------------------------------------------
@@ -129,12 +132,14 @@ if ($gen_code)
printf $c $header_comment, 'pgstat_wait_event.c';
+ printf $wc $header_comment, 'wait_event_funcs_data.c';
+
+ # Generate the pgstat_wait_event.c and wait_event_types.h files
# uc() is being used to force the comparison to be case-insensitive.
foreach my $waitclass (sort { uc($a) cmp uc($b) } keys %hashwe)
{
-
- # Don't generate .c and .h files for Extension, LWLock and
- # Lock, these are handled independently.
+ # Don't generate the pgstat_wait_event.c and wait_event_types.h
files
+ # for Extension, LWLock and Lock, these are handled
independently.
next
if ( $waitclass eq 'WaitEventExtension'
|| $waitclass eq 'WaitEventLWLock'
@@ -183,14 +188,49 @@ if ($gen_code)
printf $c "}\n\n";
}
+ # Generate the wait_event_funcs_data.c file
+ # uc() is being used to force the comparison to be case-insensitive.
+ foreach my $waitclass (sort { uc($a) cmp uc($b) } keys %hashwe)
+ {
+ my $last = $waitclass;
+ $last =~ s/^WaitEvent//;
+
+ foreach my $wev (@{ $hashwe{$waitclass} })
+ {
+ my $new_desc = substr $wev->[2], 1, -2;
+ # put an escape \ in front of '
+ $new_desc =~ s/'/\\'/g;
+
+ # just keep text from <whatever>text</wahtever>
+ $new_desc =~ s/<.*>(.*?)<.*>/$1/g;
+
+ # just keep text from <xref linkend="text"/>
+ $new_desc =~ s/<xref linkend="guc-(.*?)"\/>/$1/g;
+
+ # remove any "see <xref linkend="text"/>"
+ $new_desc =~ s/; see.*$//;
+
+ printf $wc "\telement = (wait_event_element *)
palloc(sizeof(wait_event_element));\n";
+
+ printf $wc "\telement->wait_event_type = \"%s\";\n",
$last;
+ printf $wc "\telement->wait_event_name = \"%s\";\n",
$wev->[1];
+ printf $wc "\telement->wait_event_description =
\"%s\";\n\n", $new_desc;
+
+ printf $wc "\twait_event = lappend(wait_event,
element);\n\n";
+ }
+ }
+
printf $h "#endif /* WAIT_EVENT_TYPES_H */\n";
close $h;
close $c;
+ close $wc;
rename($htmp, "$output_path/wait_event_types.h")
|| die "rename: $htmp to $output_path/wait_event_types.h: $!";
rename($ctmp, "$output_path/pgstat_wait_event.c")
|| die "rename: $ctmp to $output_path/pgstat_wait_event.c: $!";
+ rename($wctmp, "$output_path/wait_event_funcs_data.c")
+ || die "rename: $ctmp to $output_path/wait_event_funcs_data.c: $!";
}
# Generate the .sgml file.
elsif ($gen_docs)
diff --git a/src/backend/utils/activity/meson.build
b/src/backend/utils/activity/meson.build
index 9633f3623c..46a27e7548 100644
--- a/src/backend/utils/activity/meson.build
+++ b/src/backend/utils/activity/meson.build
@@ -23,6 +23,7 @@ backend_sources += files(
# seems nicer to not add that as an include path for the whole backend.
waitevent_sources = files(
'wait_event.c',
+ 'wait_event_funcs.c',
)
wait_event = static_library('wait_event_names',
diff --git a/src/backend/utils/activity/wait_event_funcs.c
b/src/backend/utils/activity/wait_event_funcs.c
new file mode 100644
index 0000000000..3e27a637e9
--- /dev/null
+++ b/src/backend/utils/activity/wait_event_funcs.c
@@ -0,0 +1,69 @@
+/* ----------
+ * wait_event_funcs.c
+ * Wait event reporting infrastructure.
+ *
+ * Copyright (c) 2001-2023, PostgreSQL Global Development Group
+ *
+ *
+ * IDENTIFICATION
+ * src/backend/utils/activity/wait_event_funcs.c
+ *
+ * NOTES
+ *
+ * The "wait_event_funcs_data.c" included in this file is generated by
+ * src/backend/utils/activity/generate-wait_event_types.pl
+ *
+ */
+#include "postgres.h"
+
+#include "funcapi.h"
+#include "utils/builtins.h"
+
+/*
+ * This function lists the wait events and their descriptions.
+ *
+ * The system view pg_wait_event provides a user interface to this
+ * SRF.
+ */
+Datum
+pg_get_wait_events(PG_FUNCTION_ARGS)
+{
+#define NUM_WAIT_EVENT_TABLES_ELEM 3
+ ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
+ Datum values[NUM_WAIT_EVENT_TABLES_ELEM];
+ bool nulls[NUM_WAIT_EVENT_TABLES_ELEM];
+ List *wait_event = NIL;
+ ListCell *cell;
+
+ typedef struct
+ {
+ char *wait_event_type;
+ char *wait_event_name;
+ char *wait_event_description;
+ } wait_event_element;
+
+ wait_event_element *element = NULL;
+ /* Build tuplestore to hold the result rows */
+ InitMaterializedSRF(fcinfo, 0);
+
+ /* Populate the wait_event List */
+ #include "wait_event_funcs_data.c"
+
+ /* Iterate over the list of wait events */
+ foreach(cell, wait_event)
+ {
+
+ wait_event_element *elem = lfirst(cell);
+
+ memset(values, 0, sizeof(values));
+ memset(nulls, 0, sizeof(nulls));
+
+ values[0] = CStringGetTextDatum(elem->wait_event_type);
+ values[1] = CStringGetTextDatum(elem->wait_event_name);
+ values[2] = CStringGetTextDatum(elem->wait_event_description);
+
+ tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc,
values, nulls);
+ }
+
+ return (Datum) 0;
+}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 6996073989..6d10d2e5be 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -5417,6 +5417,12 @@
proargmodes =>
'{i,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o}',
proargnames =>
'{pid,datid,pid,usesysid,application_name,state,query,wait_event_type,wait_event,xact_start,query_start,backend_start,state_change,client_addr,client_hostname,client_port,backend_xid,backend_xmin,backend_type,ssl,sslversion,sslcipher,sslbits,ssl_client_dn,ssl_client_serial,ssl_issuer_dn,gss_auth,gss_princ,gss_enc,gss_delegation,leader_pid,query_id}',
prosrc => 'pg_stat_get_activity' },
+{ oid => '8403', descr => 'describe wait events',
+ proname => 'pg_get_wait_events', procost => '10', prorows => '100',
+ proretset => 't', provolatile => 's', prorettype => 'record',
+ proargtypes => '', proallargtypes => '{text,text,text}',
+ proargmodes => '{o,o,o}', proargnames =>
'{wait_event_type,wait_event_name,description}',
+ prosrc => 'pg_get_wait_events' },
{ oid => '3318',
descr => 'statistics: information about progress of backends running
maintenance command',
proname => 'pg_stat_get_progress_info', prorows => '100', proretset => 't',
diff --git a/src/include/utils/meson.build b/src/include/utils/meson.build
index 6de5d93799..c179478611 100644
--- a/src/include/utils/meson.build
+++ b/src/include/utils/meson.build
@@ -1,6 +1,6 @@
# Copyright (c) 2022-2023, PostgreSQL Global Development Group
-wait_event_output = ['wait_event_types.h', 'pgstat_wait_event.c']
+wait_event_output = ['wait_event_types.h', 'pgstat_wait_event.c',
'wait_event_funcs_data.c']
wait_event_target = custom_target('wait_event_names',
input: files('../../backend/utils/activity/wait_event_names.txt'),
output: wait_event_output,
@@ -11,7 +11,7 @@ wait_event_target = custom_target('wait_event_names',
],
build_by_default: true,
install: true,
- install_dir: [dir_include_server / 'utils', false],
+ install_dir: [dir_include_server / 'utils', false, false],
)
wait_event_types_h = wait_event_target[0]
diff --git a/src/test/regress/expected/rules.out
b/src/test/regress/expected/rules.out
index e07afcd4aa..f160cb5642 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -2631,6 +2631,10 @@ pg_views| SELECT n.nspname AS schemaname,
FROM (pg_class c
LEFT JOIN pg_namespace n ON ((n.oid = c.relnamespace)))
WHERE (c.relkind = 'v'::"char");
+pg_wait_event| SELECT wait_event_type,
+ wait_event_name,
+ description
+ FROM pg_get_wait_events() we(wait_event_type, wait_event_name, description);
SELECT tablename, rulename, definition FROM pg_rules
WHERE schemaname = 'pg_catalog'
ORDER BY tablename, rulename;
diff --git a/src/test/regress/expected/sysviews.out
b/src/test/regress/expected/sysviews.out
index 001c6e7eb9..7ace77d714 100644
--- a/src/test/regress/expected/sysviews.out
+++ b/src/test/regress/expected/sysviews.out
@@ -134,6 +134,13 @@ select name, setting from pg_settings where name like
'enable%';
enable_tidscan | on
(21 rows)
+-- There is wait event descriptions
+select count(*) > 0 as ok FROM pg_wait_event;
+ ok
+----
+ t
+(1 row)
+
-- Test that the pg_timezone_names and pg_timezone_abbrevs views are
-- more-or-less working. We can't test their contents in any great detail
-- without the outputs changing anytime IANA updates the underlying data,
diff --git a/src/test/regress/sql/sysviews.sql
b/src/test/regress/sql/sysviews.sql
index 351e469c77..643dfcc1d3 100644
--- a/src/test/regress/sql/sysviews.sql
+++ b/src/test/regress/sql/sysviews.sql
@@ -55,6 +55,9 @@ select count(*) = 0 as ok from pg_stat_wal_receiver;
-- a regression test run.
select name, setting from pg_settings where name like 'enable%';
+-- There is wait event descriptions
+select count(*) > 0 as ok FROM pg_wait_event;
+
-- Test that the pg_timezone_names and pg_timezone_abbrevs views are
-- more-or-less working. We can't test their contents in any great detail
-- without the outputs changing anytime IANA updates the underlying data,
diff --git a/src/tools/msvc/clean.bat b/src/tools/msvc/clean.bat
index 7cb23ea894..ac8da581e4 100755
--- a/src/tools/msvc/clean.bat
+++ b/src/tools/msvc/clean.bat
@@ -55,6 +55,7 @@ if exist src\include\catalog\header-stamp del /q
src\include\catalog\header-stam
if exist doc\src\sgml\version.sgml del /q doc\src\sgml\version.sgml
if %DIST%==1 if exist src\backend\utils\activity\pgstat_wait_event.c del /q
src\backend\utils\activity\pgstat_wait_event.c
+if %DIST%==1 if exist src\backend\utils\activity\wait_event_funcs_data.c del
/q src\backend\utils\activity\wait_event_funcs_data.c
if %DIST%==1 if exist src\backend\utils\activity\wait_event_types.h del /q
src\backend\utils\activity\wait_event_types.h
if %DIST%==1 if exist src\backend\utils\fmgroids.h del /q
src\backend\utils\fmgroids.h
if %DIST%==1 if exist src\backend\utils\fmgrprotos.h del /q
src\backend\utils\fmgrprotos.h
--
2.34.1
