our $VERSION = '0.000038';
use POSIX qw/:sys_wait_h/; <db <args
<server_pid
<watcher_pid
<master_pid
<log_file
<stopped
<eliminated
<detached
<delete_data
};
sub init {
my $self = shift;
$self->{+MASTER_PID} ||= $$;
$self->{+LOG_FILE} = $self->{+DB}->gen_log;
$self->start();
weaken($self->{+DB}) if $self->{+MASTER_PID} == $$;
}
sub start {
my $self = shift;
return if $self->{+SERVER_PID};
my ($rh, $wh);
pipe($rh, $wh) or die "Could not open pipe: $!";
my $pid = fork;
die "Could not fork: $!" unless defined $pid;
if ($pid) {
close($wh);
waitpid($pid, 0);
chomp($self->{+WATCHER_PID} = <$rh>);
chomp($self->{+SERVER_PID} = <$rh>);
close($rh);
die "Did not get watcher pid!" unless $self->{+WATCHER_PID};
die "Did not get server pid!" unless $self->{+SERVER_PID};
return;
}
close($rh);
POSIX::setsid();
setpgrp(0, 0);
$pid = fork;
die "Could not fork: $!" unless defined $pid;
POSIX::_exit(0) if $pid;
$wh->autoflush(1);
print $wh "$$\n";
eval { $self->watch($wh); 1 } or POSIX::_exit(1);
POSIX::_exit(0);
}
sub watch {
my $self = shift;
my ($wh) = @_;
$0 = 'db-quick-watcher';
my $kill = '';
my $hup = 0;
local $SIG{TERM} = sub { $kill = 'TERM' };
local $SIG{INT} = sub { $kill = 'INT' };
local $SIG{HUP} = sub { $hup = 1 };
my $start_pid = $$;
my $pid = $self->spawn();
print $wh "$pid\n";
close($wh);
my $mpid = $self->{+MASTER_PID};
my $spid = $self->{+SERVER_PID} or die "No server pid";
my $ddir = $self->{+DB}->dir;
my $ssig = $self->{+DB}->stop_sig // 'TERM';
exec(
$^X, '-Ilib',
'-e' => "require DBIx::QuickDB::Watcher; DBIx::QuickDB::Watcher->_do_watch()",
master_pid => $mpid,
data_dir => $ddir,
server_pid => $spid,
signal => $ssig,
kill => $kill,
hup => $hup,
);
}
sub _do_watch {
my $class = shift;
$0 = 'db-quick-watcher';
my %params = @ARGV;
my $kill = $params{kill} // '';
my $hup = $params{hup} // 0;
local $SIG{TERM} = sub { $kill = 'TERM' };
local $SIG{INT} = sub { $kill = 'INT' };
local $SIG{HUP} = sub { $hup = 1 };
my $blah;
close(STDIN);
open(STDIN, '<', \$blah) or warn "$!";
my $master_pid = $params{master_pid} or die "No master pid provided";
my $server_pid = $params{server_pid} or die "No server pid provided";
my $data_dir = $params{data_dir} or die "No data dir provided";
my $signal = $params{signal} // 'TERM';
my $hupped = 0;
while (!$kill) {
if ($hup && !$hupped) {
close(STDOUT);
open(STDOUT, '>', \$blah) or warn "$!";
close(STDERR);
open(STDERR, '>', \$blah) or warn "$!";
}
sleep 0.1;
next if kill(0, $master_pid);
$kill = 'TERM';
}
unless (eval { $class->_watcher_terminate(send_sig => $signal, got_sig => $kill, pid => $server_pid, dir => $data_dir); 1 }) {
my $err = $@;
eval { warn $@ };
POSIX::_exit(1);
}
POSIX::_exit(0);
}
sub spawn {
my $self = shift;
croak "Extra spawn" if $self->{+SERVER_PID};
my $db = $self->{+DB};
my $args = $self->{+ARGS} || [];
my $init_pid = $$;
my ($pid, $log_file) = $db->run_command([$db->start_command, @$args], {no_wait => 1, log_file => $self->{+LOG_FILE}});
$self->{+SERVER_PID} = $pid;
$self->{+LOG_FILE} = $log_file;
return $pid;
}
sub _watcher_terminate {
my $class = shift;
my %params = @_;
my $pid = $params{pid} or die "No pid";
my $dir = $params{dir} or die "No dir";
my $got_sig = $params{got_sig};
my $send_sig = $params{send_sig} // $got_sig // 'TERM';
$class->_watcher_kill($send_sig, $pid);
if ($got_sig && $got_sig eq 'TERM') {
my $err = [];
remove_tree($dir, {safe => 1, error => \$err}) if -d $dir;
}
}
sub _watcher_kill {
my $class = shift;
my ($sig, $pid) = @_;
kill($sig, $pid) or die "Could not send kill signal";
my ($check, $exit, $killed);
my $start = time;
until ($check) {
local $?;
my $delta = time - $start;
if ($delta >= 4) {
if ($killed) {
my $delta2 = time - $killed;
next unless $delta2 >= 1;
}
warn "Server taking too long to shut down, sending SIGKILL";
$killed = time;
kill('KILL', $pid);
last if $delta > 8;
}
$check = waitpid($pid, WNOHANG);
$exit = $?;
sleep 0.1;
}
die "PID refused to exit" unless $check;
die "Something else reaped our process" if $check < 0;
die "Reaped the wrong process '$check' instead of '$pid'" if $pid != $check;
return;
}
sub stop {
my $self = shift;
return if $self->{+STOPPED}++;
my $pid = $self->{+WATCHER_PID} or return;
kill('INT', $pid);
}
sub eliminate {
my $self = shift;
return if $self->{+ELIMINATED}++;
my $pid = $self->{+WATCHER_PID} or return;
kill('TERM', $pid);
}
sub detach {
my $self = shift;
return if $self->{+DETACHED}++;
my $pid = $self->{+WATCHER_PID} or return;
kill('HUP', $pid);
}
sub wait {
my $self = shift;
my $pid = $self->{+WATCHER_PID} or return;
my $start = time;
while(kill(0, $pid)) {
my $waited = time - $start;
if ($waited > 10) {
kill('KILL', $pid);
$start = time;
}
sleep 0.02;
}
}
sub DESTROY {
my $self = shift;
if ($self->{+MASTER_PID} == $$) {
$self->eliminate;
$self->wait;
}
else {
unlink($self->{+LOG_FILE}) if $self->{+LOG_FILE};
}
}
1;