NAME

       ZeroMQ::Poller - Convenient socket polling object

SYNOPSIS

         use ZeroMQ qw/:all/;

         my $cxt = ZeroMQ::Context->new()
         my $sock = ZeroMQ::Socket->new($cxt, ZMQ_REP);
         $sock->bind("inproc://amazingsocket");

         my $poller = ZeroMQ::Poller->new(
           {
             name      => 'amazing',
             socket    => $sock,
             events    => ZMQ_POLLIN,
             callback  => sub { do_something_amazing },
           },
         );

         $poller->poll();
         do_another_amazing_thing() if $poller->has_event(0);
         do_a_third_amazing_thing() if $poller->has_event('amazing');

DESCRIPTION

       A "ZeroMQ::Poller" watches zero or more sockets for events and signals that these have
       occurred in several ways.  Given a list of sockets and events to watch for, it can
       directly invoke a callback or simply raise a flag.

METHODS

   new(@poll_items)
       Creates a new "ZeroMQ::Poller"

       The constructor accepts a list of hash references ("poll items"), each of which specifies
       a socket or file descriptor to watch and what to watch it for.  In addition, each poll
       item may specify a callback to invoke or a name by which it may be queried.  The accepted
       keys are:

       socket
           Contains the "ZeroMQ::Socket" item to poll.

       fd  Contains the file descriptor to poll.  One of "socket" or "fd" is required; "socket"
           has precedence.

       events
           Some combination of "ZMQ_POLLIN", "ZMQ_POLLOUT", and "ZMQ_POLLERR"; the events to
           trap.

       callback
           A coderef taking no arguments and emitting no return value, invoked when the specified
           events occur on the socket or file descriptor.  Optional.

       name
           A string, naming the poll item for later use with "has_event".

   poll($timeout)
       Blocks until there is activity or the given timeout is reached.  If no timeout or a
       negative timeout is specified, blocks indefinitely.  If a timeout is given, it is
       interpreted as microseconds.

   has_event($index)
   has_event($name)
       Returns true if the poll item at the given index or with the given name reported activity
       during the last call to "poll".