问Linux Perl线程SerialPort关闭然后重新打开

EN

my $dev;
my $port = "/dev/ttyACM0";
my $run :shared = 0;
my $thr;
my $read_thr;

sub port_init
{
    $dev = Device::SerialPort->new($port, 1) || die "Cannot open $port: $!\n";

    $dev->baudrate(115200);
    ...

    $run = 1;
}

sub read_port  # read async
{
    my $str;
    while ($run == 1)
    {
        $str = $dev->lookfor;
        if ($str ne "")
        {
            print "recv: $str\n";
        }
        sleep 0.5;
    }
}

sub write_port
{
    my $msg = shift;
    if ($run == 1)
    {
        $dev->write($msg."\r");
    }
}

sub close_port
{
    $run = 0;
    $dev->close;
}

# Main
port_init();
$read_thr = threads->new(\&read_port);
$read_thr->detach();

if ("event1 occurs") # send cmd to port
{
    $thr = threads->new(\&write_port, "ATI"); # works, response received
    $thr->detach();
}

if ("event2 occurs") # another application is requesting the port
{
    $thr = threads->new(\&close_port);
    $thr->detach();

    # wait till application has finished

    port_init();

    $read_thr = threads->new(\&read_port);
    $read_thr->detach();

    # send cmd to port, doesn't work
    $thr = threads->new(\&write_port, "ATI");
    $thr->detach();

}