(new thread)
On Tue, Jan 02, 2024 at 10:34:11AM -0500, Robert Haas wrote:
> On Wed, Dec 27, 2023 at 10:36 AM Nathan Bossart
> <nathandboss...@gmail.com> wrote:
>> Thanks! I also noticed that WALSummarizerLock probably needs a mention in
>> wait_event_names.txt.
>
> Fixed.
I think we're supposed to omit the "Lock" suffix in wait_event_names.txt.
> It seems like it would be good if there were an automated cross-check
> between lwlocknames.txt and wait_event_names.txt.
+1. Here's a hastily-thrown-together patch for that. I basically copied
003_check_guc.pl and adjusted it for this purpose. This test only checks
that everything in lwlocknames.txt has a matching entry in
wait_event_names.txt. It doesn't check that everything in the predefined
LWLock section of wait_event_names.txt has an entry in lwlocknames.txt.
AFAICT that would be a little more difficult because you can't distinguish
between the two in pg_wait_events.
Even with this test, I worry that we could easily forget to add entries in
wait_event_names.txt for the non-predefined locks, but I don't presently
have a proposal for how to prevent that.
--
Nathan Bossart
Amazon Web Services: https://aws.amazon.com
>From 5031b55d8e1095ca919fe9a088ec0539b28984fc Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nat...@postgresql.org>
Date: Tue, 2 Jan 2024 11:19:20 -0600
Subject: [PATCH v1 1/1] verify wait events for all lwlocks
---
.../utils/activity/wait_event_names.txt | 2 +-
src/test/modules/test_misc/meson.build | 1 +
.../modules/test_misc/t/005_check_lwlock.pl | 51 +++++++++++++++++++
3 files changed, 53 insertions(+), 1 deletion(-)
create mode 100644 src/test/modules/test_misc/t/005_check_lwlock.pl
diff --git a/src/backend/utils/activity/wait_event_names.txt b/src/backend/utils/activity/wait_event_names.txt
index d876f8a667..f61ec3e59d 100644
--- a/src/backend/utils/activity/wait_event_names.txt
+++ b/src/backend/utils/activity/wait_event_names.txt
@@ -324,7 +324,7 @@ XactTruncation "Waiting to execute <function>pg_xact_status</function> or update
WrapLimitsVacuum "Waiting to update limits on transaction id and multixact consumption."
NotifyQueueTail "Waiting to update limit on <command>NOTIFY</command> message storage."
WaitEventExtension "Waiting to read or update custom wait events information for extensions."
-WALSummarizerLock "Waiting to read or update WAL summarization state."
+WALSummarizer "Waiting to read or update WAL summarization state."
XactBuffer "Waiting for I/O on a transaction status SLRU buffer."
CommitTsBuffer "Waiting for I/O on a commit timestamp SLRU buffer."
diff --git a/src/test/modules/test_misc/meson.build b/src/test/modules/test_misc/meson.build
index 911084ac0f..13bc6cb423 100644
--- a/src/test/modules/test_misc/meson.build
+++ b/src/test/modules/test_misc/meson.build
@@ -10,6 +10,7 @@ tests += {
't/002_tablespace.pl',
't/003_check_guc.pl',
't/004_io_direct.pl',
+ 't/005_check_lwlock.pl',
],
},
}
diff --git a/src/test/modules/test_misc/t/005_check_lwlock.pl b/src/test/modules/test_misc/t/005_check_lwlock.pl
new file mode 100644
index 0000000000..aff83e879e
--- /dev/null
+++ b/src/test/modules/test_misc/t/005_check_lwlock.pl
@@ -0,0 +1,51 @@
+# Tests to cross-check the consistency of pg_wait_events with lwlocknames.h.
+
+use strict;
+use warnings FATAL => 'all';
+use PostgreSQL::Test::Cluster;
+use PostgreSQL::Test::Utils;
+use Test::More;
+
+my $node = PostgreSQL::Test::Cluster->new('main');
+$node->init;
+$node->start;
+
+# Grab the names of all the LWLocks from pg_wait_events.
+my $all_lwlocks = $node->safe_psql(
+ 'postgres',
+ "SELECT name FROM pg_wait_events WHERE type = 'LWLock'");
+my @all_lwlocks_array = split("\n", $all_lwlocks);
+
+# Find the location of lwlocknames.h.
+my $include_dir = $node->config_data('--includedir');
+my $lwlocknames_file = "$include_dir/server/storage/lwlocknames.h";
+
+# Read the list of locks from lwlocknames.h.
+my $num_tests = 0;
+my @lwlocks_found;
+open(my $contents, '<', $lwlocknames_file)
+ || die "Could not open $lwlocknames_file: $!";
+while (my $line = <$contents>)
+{
+ if ($line =~ m/^#define ([a-zA-Z]+)Lock .*/)
+ {
+ push @lwlocks_found, $1;
+ }
+}
+close $contents;
+
+# Cross-check that all the locks found in lwlocknames.h have matching entries
+# in pg_wait_events.
+my %all_lwlocks_hash = map { $_ => 1 } @all_lwlocks_array;
+my @missing_from_wait_events = grep(!$all_lwlocks_hash{$_}, @lwlocks_found);
+is(scalar(@missing_from_wait_events),
+ 0, "no LWLocks missing from pg_wait_events");
+
+foreach my $lwlock (@missing_from_wait_events)
+{
+ print(
+ "found $lwlock in lwlocknames.h, missing from wait_event_names.txt\n"
+ );
+}
+
+done_testing();
--
2.25.1
