Add option to specify timeout seconds to BackgroundPsql.pm.

Previously, a background psql session uses the default timeout and it
cannot be overridden. This change adds a new option to set the timeout
during start.

There are no users of this new option. It is needed for an upcoming
patch adding tests for XID wraparound.

Reviewed-by: Daniel Gustafsson, Noah Misch
Discussion: https://postgr.es/m/C9CF2F76-0D81-4C9D-9832-202BE8517056%40yesql.se

src/test/perl/PostgreSQL/Test/BackgroundPsql.pm

@@ -68,7 +68,7 @@ use Test::More;
 
 =over
 
-=item PostgreSQL::Test::BackgroundPsql->new(interactive, @params)
+=item PostgreSQL::Test::BackgroundPsql->new(interactive, @psql_params, timeout)
 
 Builds a new object of class C<PostgreSQL::Test::BackgroundPsql> for either
 an interactive or background session and starts it. If C<interactive> is
@@ -81,7 +81,7 @@ string. For C<interactive> sessions, IO::Pty is required.
 sub new
 {
 	my $class = shift;
-	my ($interactive, $psql_params) = @_;
+	my ($interactive, $psql_params, $timeout) = @_;
 	my $psql = {
 		'stdin' => '',
 		'stdout' => '',
@@ -96,8 +96,10 @@ sub new
 	  "Forbidden caller of constructor: package: $package, file: $file:$line"
 	  unless $package->isa('PostgreSQL::Test::Cluster');
 
-	$psql->{timeout} =
-	  IPC::Run::timeout($PostgreSQL::Test::Utils::timeout_default);
+	$psql->{timeout} = IPC::Run::timeout(
+		defined($timeout)
+		? $timeout
+		: $PostgreSQL::Test::Utils::timeout_default);
 
 	if ($interactive)
 	{

src/test/perl/PostgreSQL/Test/Cluster.pm

@@ -2028,8 +2028,6 @@ sub psql
 
 Invoke B<psql> on B<$dbname> and return a BackgroundPsql object.
 
-A timeout of $PostgreSQL::Test::Utils::timeout_default is set up.
-
 psql is invoked in tuples-only unaligned mode with reading of B<.psqlrc>
 disabled.  That may be overridden by passing extra psql parameters.
 
@@ -2047,6 +2045,11 @@ By default, the B<psql> method invokes the B<psql> program with ON_ERROR_STOP=1
 set, so SQL execution is stopped at the first error and exit code 3 is
 returned.  Set B<on_error_stop> to 0 to ignore errors instead.
 
+=item timeout => 'interval'
+
+Set a timeout for a background psql session. By default, timeout of
+$PostgreSQL::Test::Utils::timeout_default is set up.
+
 =item replication => B<value>
 
 If set, add B<replication=value> to the conninfo string.
@@ -2068,6 +2071,7 @@ sub background_psql
 	local %ENV = $self->_get_env();
 
 	my $replication = $params{replication};
+	my $timeout = undef;
 
 	my @psql_params = (
 		$self->installed_command('psql'),
@@ -2079,12 +2083,13 @@ sub background_psql
 		'-');
 
 	$params{on_error_stop} = 1 unless defined $params{on_error_stop};
+	$timeout = $params{timeout} if defined $params{timeout};
 
 	push @psql_params, '-v', 'ON_ERROR_STOP=1' if $params{on_error_stop};
 	push @psql_params, @{ $params{extra_params} }
 	  if defined $params{extra_params};
 
-	return PostgreSQL::Test::BackgroundPsql->new(0, \@psql_params);
+	return PostgreSQL::Test::BackgroundPsql->new(0, \@psql_params, $timeout);
 }
 
 =pod