# Copyright (c) 2026, PostgreSQL Global Development Group
#
# Rows 6-8 of coverage-matrix.txt: barrier waits on a primary behind a session blocked in
# ClientWrite (pg_enable_data_checksums(), DROP DATABASE with the session on another database,
# DROP DATABASE with a walsender stuck in a base backup).  Prints one "ROW ..." line per case.
# Run inside a PostgreSQL source tree (unpatched, + v6 or + v2): copy to src/test/recovery/t/
# without the .txt suffix, then:
#   make -C src/test/recovery check PROVE_TESTS=t/090_barrier_primary_rows.pl PROVE_FLAGS=-v
# Env: GUC (one extra postgresql.conf line, e.g. GUC='procsignal_barrier_timeout = 2s' for v2),
#      WINDOW (seconds, default 15), REPS (default 3).
use strict;
use warnings FATAL => 'all';
use PostgreSQL::Test::Cluster;
use PostgreSQL::Test::Utils;
use Test::More;
use Time::HiRes qw(time usleep);

my $WINDOW = $ENV{WINDOW} // 15;
my $REPS   = $ENV{REPS}   // 3;
my $copy   = "COPY (SELECT generate_series(1, 1000000000), repeat('x', 200)) TO STDOUT";
my $node   = PostgreSQL::Test::Cluster->new('p');
$node->init(allows_streaming => 1, no_data_checksums => 1);
$node->append_conf('postgresql.conf', $ENV{GUC}) if $ENV{GUC};
$node->start;
$node->safe_psql('postgres', 'CREATE DATABASE other');

sub psql_bg {
	my ($db, $app, $sql, $out) = @_;
	IPC::Run::start(
		[   'psql', '--no-psqlrc', '--quiet',
			'--dbname'  => $node->connstr($db) . " application_name=$app",
			'--command' => $sql
		],
		'>'  => $out,
		'2>' => \my $e);
}

sub pid_of {
	my ($app) = @_;
	$node->poll_query_until('postgres',
		"SELECT wait_event = 'ClientWrite' FROM pg_stat_activity WHERE application_name = '$app'")
	  or die "no $app";
	$node->safe_psql('postgres',
		"SELECT pid FROM pg_stat_activity WHERE application_name = '$app'");
}

# Wake the session until it stays blocked: a woken backend can still fit one more send on a
# Unix-domain socket, reach CHECK_FOR_INTERRUPTS() and absorb a pending barrier.
sub settle {
	my ($pid) = @_;
	for my $i (0 .. 20) {
		my $o = -s $node->logfile;
		$node->safe_psql('postgres', "SELECT pg_log_backend_memory_contexts($pid)");
		usleep(500_000);
		return unless $node->log_contains("logging memory contexts of PID $pid", $o);
		$node->poll_query_until('postgres',
			"SELECT wait_event = 'ClientWrite' FROM pg_stat_activity WHERE pid = $pid");
	}
	die "never settled";
}

sub judge {
	my ($what, $pid, $done, $off) = @_;
	my $t0 = time;
	my $t;
	while (time - $t0 < $WINDOW) {
		if ($done->()) { $t = time - $t0; last; }
		usleep(20_000);
	}
	my $term = $node->log_contains("terminating process $pid ", $off) ? 1 : 0;
	my $rel  = '-';
	if (!defined $t) {
		$node->safe_psql('postgres', "SELECT pg_terminate_backend($pid)");
		my $t1 = time;
		usleep(5_000) until $done->() || time - $t1 > 60;
		$rel = sprintf('%.0fms', 1000 * (time - $t1));
	}
	diag(
		sprintf(
			"ROW %s: %s terminated_by_timeout=%d manual_release=%s",
			$what, defined $t ? sprintf('CLEARED %.0fms', 1000 * $t) : "HUNG >${WINDOW}s",
			$term, $rel));
	pass($what);
}

for my $r (1 .. $REPS) {
	$node->safe_psql('postgres', "CREATE DATABASE d$r; CREATE DATABASE w$r");
	my $o   = '';
	my $h   = psql_bg('other', "s_drop$r", $copy, \$o);
	my $pid = pid_of("s_drop$r");
	settle($pid);
	my $off = -s $node->logfile;
	my $oo  = '';
	my $op  = psql_bg('postgres', 'op', "DROP DATABASE d$r", \$oo);
	judge(
		'DROP DATABASE (session on another db)',               $pid,
		sub { $op->pump_nb if $op->pumpable; !$op->pumpable }, $off);
	$h->kill_kill;

	$o   = '';
	$h   = psql_bg('postgres', "s_cs$r", $copy, \$o);
	$pid = pid_of("s_cs$r");
	settle($pid);
	$off = -s $node->logfile;
	$node->safe_psql('postgres', 'SELECT pg_enable_data_checksums()');
	judge(
		'pg_enable_data_checksums()',
		$pid,
		sub {
			$node->safe_psql('postgres',
				"SELECT setting FROM pg_settings WHERE name = 'data_checksums'") eq 'on';
		},
		$off);
	$h->kill_kill;
	$node->safe_psql('postgres', 'SELECT pg_disable_data_checksums()');
	$node->poll_query_until('postgres',
		"SELECT setting = 'off' FROM pg_settings WHERE name = 'data_checksums'")
	  or die;

	my ($bo, $be) = ('', '');
	$h = IPC::Run::start(
		[   'pg_basebackup',
			'--pgdata'     => '-',
			'--format'     => 'tar',
			'--wal-method' => 'none',
			'--checkpoint' => 'fast',
			'--dbname'     => $node->connstr('postgres') . " application_name=s_ws$r"
		],
		'>'  => \$bo,
		'2>' => \$be);
	$pid = pid_of("s_ws$r");
	settle($pid);
	$off = -s $node->logfile;
	$oo  = '';
	$op  = psql_bg('postgres', 'op', "DROP DATABASE w$r", \$oo);
	judge(
		'DROP DATABASE (walsender in a base backup)',          $pid,
		sub { $op->pump_nb if $op->pumpable; !$op->pumpable }, $off);
	$h->kill_kill;
	$node->poll_query_until('postgres',
		"SELECT count(*) = 0 FROM pg_stat_activity WHERE application_name LIKE 's\\_%'");
}
done_testing();