my @requests;
while ( ... ) {
    push @requests, ...;

    if (scalar @requests % 3 == 0) {
        &doRequests(\@requests);
    }
}

sub doRequests {
    my $requests = shift;

    my @coro = map {  
        async {
             # here we get LWP::UserAgent object and to request
        }
    } @$requests;
}

##</code><code>##

rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0
rt_sigaction(SIGCHLD, NULL, {SIG_DFL, [], 0}, 8) = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
nanosleep({1211417888, 0}, {1211354002, 168413065}) = ? ERESTART_RESTA
+RTBLOCK (To be restarted)
--- SIGWINCH (Window changed) @ 0 (0) ---
restart_syscall(<... resuming interrupted call ...>) = ? ERESTART_REST
+ARTBLOCK (To be restarted)
--- SIGWINCH (Window changed) @ 0 (0) ---
restart_syscall(<... resuming interrupted call ...>