v1-0001-pg_wait_event.patch

From c56ce13af7193bf0d679ec0a7533ab686464f34e Mon Sep 17 00:00:00 2001
From: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Date: Tue, 1 Aug 2023 03:55:51 +0000
Subject: [PATCH v1] pg_wait_event

Adding a new shared catalog relation, namely pg_wait_event, that describes the
wait events.

The content is auto-generated with generate-wait_event_types.pl.
---
 doc/src/sgml/catalogs.sgml                    | 62 ++++++++++++++++++
 src/backend/catalog/.gitignore                |  1 +
 src/backend/catalog/Makefile                  | 13 ++--
 src/backend/catalog/catalog.c                 |  4 +-
 .../activity/generate-wait_event_types.pl     | 65 ++++++++++++++++++-
 src/include/catalog/catversion.h              |  2 +-
 src/include/catalog/pg_wait_event.h           | 45 +++++++++++++
 7 files changed, 184 insertions(+), 8 deletions(-)
  26.7% doc/src/sgml/
  16.5% src/backend/catalog/
  33.6% src/backend/utils/activity/
  23.0% src/include/catalog/

diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 307ad88b50..f181a5cedb 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -369,6 +369,11 @@
       <entry><link linkend="catalog-pg-user-mapping"><structname>pg_user_mapping</structname></link></entry>
       <entry>mappings of users to foreign servers</entry>
      </row>
+
+     <row>
+      <entry><link linkend="catalog-pg-wait-event"><structname>pg_wait_event</structname></link></entry>
+      <entry>wait events description</entry>
+     </row>
     </tbody>
    </tgroup>
   </table>
@@ -9668,4 +9673,61 @@ SCRAM-SHA-256$<replaceable>&lt;iteration count&gt;</replaceable>:<replaceable>&l
   </table>
  </sect1>
 
+
+ <sect1 id="catalog-pg-wait-event">
+  <title><structname>pg_wait_event</structname></title>
+
+  <indexterm zone="catalog-pg-wait-event">
+   <primary>pg_wait_event</primary>
+  </indexterm>
+
+  <para>
+   The catalog <structname>pg_wait_event</structname> stores description about
+   the wait events.
+  </para>
+
+  <para>
+   Unlike most system catalogs, <structname>pg_wait_event</structname>
+   is shared across all databases of a cluster: there is only one
+   copy of <structname>pg_wait_event</structname> per cluster, not
+   one per database.
+  </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_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>text</type>
+      </para>
+      <para>
+       Wait event description
+      </para></entry>
+     </row>
+    </tbody>
+   </tgroup>
+  </table>
+ </sect1>
+
 </chapter>
diff --git a/src/backend/catalog/.gitignore b/src/backend/catalog/.gitignore
index 237ff54165..7f2f3045dc 100644
--- a/src/backend/catalog/.gitignore
+++ b/src/backend/catalog/.gitignore
@@ -4,3 +4,4 @@
 /system_constraints.sql
 /pg_*_d.h
 /bki-stamp
+/pg_wait_event.dat
diff --git a/src/backend/catalog/Makefile b/src/backend/catalog/Makefile
index a60107bf94..68a97fbdcd 100644
--- a/src/backend/catalog/Makefile
+++ b/src/backend/catalog/Makefile
@@ -72,7 +72,8 @@ CATALOG_HEADERS := \
 	pg_collation.h pg_parameter_acl.h pg_partitioned_table.h \
 	pg_range.h pg_transform.h \
 	pg_sequence.h pg_publication.h pg_publication_namespace.h \
-	pg_publication_rel.h pg_subscription.h pg_subscription_rel.h
+	pg_publication_rel.h pg_subscription.h pg_subscription_rel.h \
+	pg_wait_event.h
 
 GENERATED_HEADERS := $(CATALOG_HEADERS:%.h=%_d.h) schemapg.h system_fk_info.h
 
@@ -89,9 +90,13 @@ POSTGRES_BKI_DATA = $(addprefix $(top_srcdir)/src/include/catalog/,\
 	pg_ts_template.dat pg_type.dat \
 	)
 
-all: distprep generated-header-symlinks
+all: distprep generated-header-symlinks pg_wait_event.dat
 
-distprep: bki-stamp
+pg_wait_event.dat:
+	$(PERL) $(top_srcdir)/src/backend/utils/activity/generate-wait_event_types.pl --data $(top_srcdir)/src/backend/utils/activity/wait_event_names.txt
+	$(LN_S) "$(top_srcdir)/src/backend/catalog/pg_wait_event.dat" '$(top_srcdir)/src/include/catalog/pg_wait_event.dat'
+
+distprep: pg_wait_event.dat bki-stamp
 
 .PHONY: generated-header-symlinks
 
@@ -143,4 +148,4 @@ uninstall-data:
 clean:
 
 maintainer-clean: clean
-	rm -f bki-stamp postgres.bki system_constraints.sql $(GENERATED_HEADERS)
+	rm -f pg_wait_event.dat bki-stamp postgres.bki system_constraints.sql $(GENERATED_HEADERS) $(top_srcdir)/src/include/catalog/pg_wait_event.dat
diff --git a/src/backend/catalog/catalog.c b/src/backend/catalog/catalog.c
index 1bf6c5633c..da12247551 100644
--- a/src/backend/catalog/catalog.c
+++ b/src/backend/catalog/catalog.c
@@ -41,6 +41,7 @@
 #include "catalog/pg_subscription.h"
 #include "catalog/pg_tablespace.h"
 #include "catalog/pg_type.h"
+#include "catalog/pg_wait_event.h"
 #include "miscadmin.h"
 #include "storage/fd.h"
 #include "utils/fmgroids.h"
@@ -255,7 +256,8 @@ IsSharedRelation(Oid relationId)
 		relationId == SharedDescriptionRelationId ||
 		relationId == SharedSecLabelRelationId ||
 		relationId == SubscriptionRelationId ||
-		relationId == TableSpaceRelationId)
+		relationId == TableSpaceRelationId ||
+		relationId == WaitEventRelationId)
 		return true;
 	/* These are their indexes */
 	if (relationId == AuthIdOidIndexId ||
diff --git a/src/backend/utils/activity/generate-wait_event_types.pl b/src/backend/utils/activity/generate-wait_event_types.pl
index 56335e8730..81f21eaf44 100644
--- a/src/backend/utils/activity/generate-wait_event_types.pl
+++ b/src/backend/utils/activity/generate-wait_event_types.pl
@@ -5,6 +5,7 @@
 # - wait_event_types.h (if --code is passed)
 # - pgstat_wait_event.c (if --code is passed)
 # - wait_event_types.sgml (if --docs is passed)
+# - pg_wait_event.dat (if --data is passed)
 #
 # Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
 # Portions Copyright (c) 1994, Regents of the University of California
@@ -20,6 +21,7 @@ use Getopt::Long;
 my $output_path = '.';
 my $gen_docs = 0;
 my $gen_code = 0;
+my $gen_data = 0;
 
 my $continue = "\n";
 my %hashwe;
@@ -27,14 +29,21 @@ my %hashwe;
 GetOptions(
 	'outdir:s' => \$output_path,
 	'docs' => \$gen_docs,
+	'data' => \$gen_data,
 	'code' => \$gen_code) || usage();
 
-die "Needs to specify --docs or --code"
-  if (!$gen_docs && !$gen_code);
+die "Needs to specify --docs, --code or --data"
+  if (!$gen_docs && !$gen_code && !$gen_data);
 
 die "Not possible to specify --docs and --code simultaneously"
   if ($gen_docs && $gen_code);
 
+die "Not possible to specify --docs and --data simultaneously"
+  if ($gen_docs && $gen_data);
+
+die "Not possible to specify --code and --data simultaneously"
+  if ($gen_code && $gen_data);
+
 open my $wait_event_names, '<', $ARGV[0] or die;
 
 my @lines;
@@ -239,7 +248,59 @@ elsif ($gen_docs)
 	rename($stmp, "$output_path/wait_event_types.sgml")
 	  || die "rename: $stmp to $output_path/wait_event_types.sgml: $!";
 }
+# Generate the .dat file.
+elsif ($gen_data)
+{
 
+	# Include PID in suffix in case parallel make runs this script
+	# multiple times.
+	my $dtmp = "$output_path/pg_wait_event.dat.tmp$$";
+	open my $d, '>', $dtmp or die "Could not open $dtmp: $!";
+
+	my $data_header_comment =
+'#----------------------------------------------------------------------
+#
+# %s
+#    Initial contents of the pg_wait_event system catalog.
+#
+# Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
+# Portions Copyright (c) 1994, Regents of the University of California
+#
+# NOTES
+#  ******************************
+#  *** DO NOT EDIT THIS FILE! ***
+#  ******************************
+#
+#  It has been GENERATED by src/backend/utils/activity/generate-wait_event_types.pl
+#
+#----------------------------------------------------------------------
+';
+
+	printf $d $data_header_comment, 'pg_wait_event.dat';
+	printf $d "[\n\n";
+
+	# uc() is being used to force the comparison to be case-insensitive.
+	foreach my $waitclass (sort { uc($a) cmp uc($b) } keys %hashwe)
+	{
+		foreach my $wev (@{ $hashwe{$waitclass} })
+		{
+			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;
+			$new_desc =~ s/; see.*$//;
+
+			printf $d "{ wait_event_name => '$wev->[1]', description => '%s' },\n",
+						$new_desc;
+		}
+	}
+
+	printf $d "\n]";
+	close $d;
+
+	rename($dtmp, "$output_path/pg_wait_event.dat")
+	  || die "rename: $dtmp to $output_path/pg_wait_event.dat: $!";
+}
 close $wait_event_names;
 
 sub usage
diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index f507b49bb2..5a534771ed 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -57,6 +57,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	202307261
+#define CATALOG_VERSION_NO	202308011
 
 #endif
diff --git a/src/include/catalog/pg_wait_event.h b/src/include/catalog/pg_wait_event.h
new file mode 100644
index 0000000000..9647d45bd1
--- /dev/null
+++ b/src/include/catalog/pg_wait_event.h
@@ -0,0 +1,45 @@
+/*-------------------------------------------------------------------------
+ *
+ * pg_wait_event.h
+ *	  definition of the "wait event" system catalog (pg_wait_event)
+ *
+ *
+ * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/catalog/pg_wait_event.h
+ *
+ * NOTES
+ *	  The Catalog.pm module reads this file and derives schema
+ *	  information.
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef PG_SE_H
+#define PG_WAIT_EVENT_H
+
+#include "catalog/genbki.h"
+#include "catalog/pg_wait_event_d.h"
+
+/* ----------------
+ *		pg_wait_event definition.  cpp turns this into
+ *		typedef struct FormData_pg_wait_event
+ * ----------------
+ */
+CATALOG(pg_wait_event,8403,WaitEventRelationId) BKI_SHARED_RELATION
+{
+#ifdef CATALOG_VARLEN			/* variable-length fields start here */
+	text		wait_event_name BKI_FORCE_NOT_NULL;
+
+	text		description BKI_FORCE_NOT_NULL;
+#endif
+} FormData_pg_wait_event;
+
+/* ----------------
+ *      Form_pg_wait_event corresponds to a pointer to a tuple with
+ *      the format of pg_wait_event relation.
+ * ----------------
+ */
+typedef FormData_pg_wait_event * Form_pg_wait_event;
+
+#endif							/* PG_WAIT_EVENT_H */
-- 
2.34.1