#!/usr/bin/perl
use strict;
use warnings;
use threads;
use Thread::Queue;
use Thread::Semaphore;

# Create terminal watcher

print "Create terminal watcher...\n";

my $Q_stdin = Thread::Queue->new ;
my $S_stdin = Thread::Semaphore->new(0) ;

print "fileno(STDIN) = ", fileno(STDIN), "\n" ;

async {
    $S_stdin->down() ;
    print "Reading STDIN, fileno=", fileno(STDIN), "\n" ;
    while (defined( $_ = <STDIN> )) {
        chomp ;
        print "\n+IN : '$_'\n" ;
        $Q_stdin->enqueue( $_ ) ;
    };
}->detach;

close STDIN ;                          ### no longer our business       <<<<
print "STDIN is: ", defined(fileno(STDIN)) ? 'open' : 'closed', "\n" ;

$S_stdin->up() ;
my $Q_found = Thread::Queue->new;

my $cmd;
my $quit_flag = 1;
print "Awaiting commands...\n";
MAIN_LOOP: while ($quit_flag) {
    sleep(1); # Reduce load
    # Process commands
    while (defined ($cmd = $Q_stdin->dequeue_nb)) {
        chomp $cmd;
        if ($cmd =~ /^q/i) {
            print "Resolving open threads\n";
            $quit_flag = 0;
        } else {
            async {
                  $Q_found->enqueue( $cmd ) ;
                }->detach;
            #$Q_found->enqueue( $cmd ) ; # using this in place of async works
        }
    }
    # Print announcements
    while (defined(my $output = $Q_found->dequeue_nb)) {
        print "+OUT: '$output'\n";
    }
}