NAME

       Coro::Event - do events the coro-way, with Event

SYNOPSIS

        use Coro;
        use Coro::Event;

        sub keyboard : Coro {
           my $w = Coro::Event->io(fd => \*STDIN, poll => 'r');
           while() {
              print "cmd> ";
              my $ev = $w->next; my $cmd = <STDIN>;
              unloop unless $cmd ne "";
              print "data> ";
              my $ev = $w->next; my $data = <STDIN>;
           }
        }

        loop;

        # wait for input on stdin for one second
        Coro::Event::do_io (fd => \*STDIN, timeout => 1) & Event::Watcher::R
           or die "no input received";

        # use a separate thread for event processing, if impossible in main:
        Coro::async { Event::loop };

DESCRIPTION

       This module enables you to create programs using the powerful Event model (and module),
       while retaining the linear style known from simple or threaded programs.

       This module provides a method and a function for every watcher type (flavour) (see Event).
       The only difference between these and the watcher constructors from Event is that you do
       not specify a callback function - it will be managed by this module.

       Your application should just create all necessary threads and then call "Event::loop".

       Please note that even programs or modules (such as Coro::Handle) that use "traditional"
       event-based/continuation style will run more efficient with this module then when using
       only Event.

WARNING

       Please note that Event does not support multithreading. That means that you MUST NOT block
       in an event callback. Again: In Event callbacks, you must never ever call a Coro function
       that blocks the current thread.

       While this seems to work superficially, it will eventually cause memory corruption and
       often results in deadlocks.

       Best practise is to always use Coro::unblock_sub for your callbacks.

SEMANTICS

       Whenever Event blocks (e.g. in a call to "one_event", "loop" etc.), this module cede's to
       all other threads with the same or higher priority. When any threads of lower priority are
       ready, it will not block but run one of them and then check for events.

       The effect is that coroutines with the same or higher priority than the blocking coroutine
       will keep Event from checking for events, while coroutines with lower priority are being
       run, but Event checks for new events after every cede. Note that for this to work you
       actually need to run the event loop in some thread.

FUNCTIONS

       $w = Coro::Event->flavour (args...)
           Create and return a watcher of the given type.

           Examples:

             my $reader = Coro::Event->io (fd => $filehandle, poll => 'r');
             $reader->next;

       $w->next
           Wait for and return the next event of the event queue of the watcher. The returned
           event objects support two methods only: "hits" and "got", both of which return
           integers: the number this watcher was hit for this event, and the mask of poll events
           received.

       do_flavour args...
           Create a watcher of the given type and immediately call its next method, returning the
           event.

           This is less efficient then calling the constructor once and the next method often,
           but it does save typing sometimes.

       sweep
           Similar to Event::one_event and Event::sweep: The idle task is called once (this has
           the effect of jumping back into the Event loop once to serve new events).

           The reason this function exists is that you sometimes want to serve events while doing
           other work. Calling "Coro::cede" does not work because "cede" implies that the current
           coroutine is runnable and does not call into the Event dispatcher.

AUTHOR/SUPPORT/CONTACT

          Marc A. Lehmann <schmorp@schmorp.de>
          http://software.schmorp.de/pkg/Coro.html