[ViewVC] Diff of: cvs/EV/README

Comparing EV/README (file contents):
Revision 1.22 by root, Mon Jan 28 12:24:05 2008 UTC vs.
Revision 1.30 by root, Thu Oct 23 04:56:49 2008 UTC

 NAME
     EV - perl interface to libev, a high performance full-featured event
     loop
 SYNOPSIS
-      use EV;
+       use EV;
+   # TIMERS
+   my $w = EV::timer 2, 0, sub {
+          warn "is called after 2s";
+       };
+   my $w = EV::timer 2, 2, sub {
+          warn "is called roughly every 2s (repeat = 2)";
+       };
+   undef $w; # destroy event watcher again
+   my $w = EV::periodic 0, 60, 0, sub {
+          warn "is called every minute, on the minute, exactly";
+       };
+   # IO
+   my $w = EV::io *STDIN, EV::READ, sub {
+          my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
+          warn "stdin is readable, you entered: ", <STDIN>;
+       };
+   # SIGNALS
+   my $w = EV::signal 'QUIT', sub {
+          warn "sigquit received\n";
+       };
+   # CHILD/PID STATUS CHANGES
-  # TIMERS
+   my $w = EV::child 666, 0, sub {
+          my ($w, $revents) = @_;
+          my $status = $w->rstatus;
+       };
-  my $w = EV::timer 2, 0, sub {
-         warn "is called after 2s";
-      };
-  my $w = EV::timer 2, 2, sub {
-         warn "is called roughly every 2s (repeat = 2)";
-      };
-  undef $w; # destroy event watcher again
-  my $w = EV::periodic 0, 60, 0, sub {
-         warn "is called every minute, on the minute, exactly";
-      };
-  # IO
-  my $w = EV::io *STDIN, EV::READ, sub {
-         my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
-         warn "stdin is readable, you entered: ", <STDIN>;
-      };
-  # SIGNALS
-  my $w = EV::signal 'QUIT', sub {
-         warn "sigquit received\n";
-      };
-  # CHILD/PID STATUS CHANGES
-      my $w = EV::child 666, 0, sub {
-         my ($w, $revents) = @_;
-         my $status = $w->rstatus;
-      };
-      # STAT CHANGES
+   # STAT CHANGES
-      my $w = EV::stat "/etc/passwd", 10, sub {
+       my $w = EV::stat "/etc/passwd", 10, sub {
-         my ($w, $revents) = @_;
+          my ($w, $revents) = @_;
-         warn $w->path, " has changed somehow.\n";
+          warn $w->path, " has changed somehow.\n";
-      };
+       };
-  # MAINLOOP
+   # MAINLOOP
-      EV::loop;           # loop until EV::unloop is called or all watchers stop
+       EV::loop;           # loop until EV::unloop is called or all watchers stop
-      EV::loop EV::LOOP_ONESHOT;  # block until at least one event could be handled
+       EV::loop EV::LOOP_ONESHOT;  # block until at least one event could be handled
-      EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block
+       EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block
 DESCRIPTION
     This module provides an interface to libev
     (<http://software.schmorp.de/pkg/libev.html>). While the documentation
     below is comprehensive, one might also consult the documentation of
-    libev itself (<http://cvs.schmorp.de/libev/ev.html>) for more subtle
+    libev itself (<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod> or
-    details on watcher semantics or some discussion on the available
+    perldoc EV::libev) for more subtle details on watcher semantics or some
-    backends, or how to force a specific backend with "LIBEV_FLAGS", or just
+    discussion on the available backends, or how to force a specific backend
-    about in any case because it has much more detailed information.
+    with "LIBEV_FLAGS", or just about in any case because it has much more
+    detailed information.
+    This module is very fast and scalable. It is actually so fast that you
+    can use it through the AnyEvent module, stay portable to other event
+    loops (if you don't rely on any watcher types not available through it)
+    and still be faster than with any other event loop currently supported
+    in Perl.
+  MODULE EXPORTS
+    This module does not export any symbols.
 EVENT LOOPS
     EV supports multiple event loops: There is a single "default event loop"
     that can handle everything including signals and child watchers, and any
     number of "dynamic event loops" that can use different backends (with
     default loop as this is fastest (perl-wise), best supported by other
     modules (e.g. AnyEvent or Coro) and most portable event loop.
     For specific programs you can create additional event loops dynamically.
+    If you want to take avdantage of kqueue (which often works properly for
+    sockets only) even though the default loop doesn't enable it, you can
+    *embed* a kqueue loop into the default loop: running the default loop
+    will then also service the kqueue loop to some extent. See the example
+    in the section about embed watchers for an example on how to achieve
+    that.
     $loop = new EV::loop [$flags]
         Create a new event loop as per the specified flags. Please refer to
         the "ev_loop_new ()" function description in the libev documentation
         (<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTI
-        ONS>) for more info.
+        ONS>, or locally-installed as EV::libev manpage) for more info.
         The loop will automatically be destroyed when it is no longer
         referenced by any watcher and the loop object goes out of scope.
-        Using "EV::FLAG_FORKCHECK" is recommended, as only the default event
+        If you are not embedding the loop, then Using "EV::FLAG_FORKCHECK"
-        loop is protected by this module.
+        is recommended, as only the default event loop is protected by this
+        module. If you *are* embedding this loop in the default loop, this
+        is not necessary, as "EV::embed" automatically does the right thing
+        on fork.
     $loop->loop_fork
         Must be called after a fork in the child, before entering or
         continuing the event loop. An alternative is to use
-        "EV::FLAG_FORKCHECK" which calls this fucntion automatically, at
+        "EV::FLAG_FORKCHECK" which calls this function automatically, at
         some performance loss (refer to the libev documentation).
+    $loop->loop_verify
+        Calls "ev_verify" to make internal consistency checks (for debugging
+        libev) and abort the program if any data structures were found to be
+        corrupted.
     $loop = EV::default_loop [$flags]
-        Return the default loop (which is a singleton object).
+        Return the default loop (which is a singleton object). Since this
+        module already creates the default loop with default flags,
+        specifying flags here will not have any effect unless you destroy
+        the default loop first, which isn't supported. So in short: don't do
+        it, and if you break it, you get to keep the pieces.
 BASIC INTERFACE
     $EV::DIED
         Must contain a reference to a function that is called when a
         callback throws an exception (with $@ containing the error). The
     $loop->set_timeout_collect_interval ($time)
         These advanced functions set the minimum block interval when polling
         for I/O events and the minimum wait interval for timer events. See
         the libev documentation at
         <http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONT
-        ROLLING_THE_EVENT_LOOP> for a more detailed discussion.
+        ROLLING_THE_EVENT_LOOP> (locally installed as EV::libev) for a more
+        detailed discussion.
 WATCHER OBJECTS
     A watcher is an object that gets created to record your interest in some
     event. For instance, if you want to wait for STDIN to become readable,
     you would create an EV::io watcher for that:
-      my $watcher = EV::io *STDIN, EV::READ, sub {
+       my $watcher = EV::io *STDIN, EV::READ, sub {
-         my ($watcher, $revents) = @_;
+          my ($watcher, $revents) = @_;
-         warn "yeah, STDIN should now be readable without blocking!\n"
+          warn "yeah, STDIN should now be readable without blocking!\n"
-      };
+       };
     All watchers can be active (waiting for events) or inactive (paused).
     Only active watchers will have their callbacks invoked. All callbacks
     will be called with at least two arguments: the watcher and a bitmask of
     received events.
         Example: Register an I/O watcher for some UDP socket but do not keep
         the event loop from running just because of that watcher.
            my $udp_socket = ...
            my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
-           $1000udp_watcher->keepalive (0);
+           $udp_watcher->keepalive (0);
     $loop = $w->loop
         Return the loop that this watcher is attached to.
 WATCHER TYPES
             This time simply fires at the wallclock time $at and doesn't
             repeat. It will not adjust when a time jump occurs, that is, if
             it is to be run at January 1st 2011 then it will run when the
             system time reaches or surpasses this time.
-        *   non-repeating interval timer ($interval > 0, $reschedule_cb = 0)
+        *   repeating interval timer ($interval > 0, $reschedule_cb = 0)
             In this mode the watcher will always be scheduled to time out at
             the next "$at + N * $interval" time (for some integer N) and
             then repeat, regardless of any time jumps.
             each time the periodic watcher gets scheduled, the reschedule
             callback ($reschedule_cb) will be called with the watcher as
             first, and the current time as second argument.
             *This callback MUST NOT stop or destroy this or any other
+            periodic watcher, ever, and MUST NOT call any event loop
-            periodic watcher, ever*. If you need to stop it, return 1e30 and
+            functions or methods*. If you need to stop it, return 1e30 and
-            stop it afterwards.
+            stop it afterwards. You may create and start a "EV::prepare"
+            watcher for this task.
             It must return the next time to trigger, based on the passed
-            time value (that is, the lowest time value larger than to the
+            time value (that is, the lowest time value larger than or equal
-            second argument). It will usually be called just before the
+            to to the second argument). It will usually be called just
-            callback will be triggered, but might be called at other times,
+            before the callback will be triggered, but might be called at
-            too.
+            other times, too.
             This can be used to create very complex timers, such as a timer
             that triggers on each midnight, local time (actually 24 hours
             after the last midnight, to keep the example simple. If you know
             a way to do it correctly in about the same space (without
     embedded loop, other types of watchers might be handled in a delayed or
     incorrect fashion and must not be used).
     See the libev documentation at
     <http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code
-    _when_one_backend_> for more details.
+    _when_one_backend_> (locally installed as EV::libev) for more details.
     In short, this watcher is most useful on BSD systems without working
     kqueue to still be able to handle a large number of sockets:
-      my $socket_loop;
+       my $socket_loop;
-      # check wether we use SELECT or POLL _and_ KQUEUE is supported
+   # check wether we use SELECT or POLL _and_ KQUEUE is supported
-      if (
+       if (
-        (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT))
+         (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT))
-        && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
+         && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
-      ) {
+       ) {
-        # use kqueue for sockets
+         # use kqueue for sockets
-        $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV;
+         $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV;
-      }
+       }
-      # use the default loop otherwise
+   # use the default loop otherwise
-      $socket_loop ||= EV::default_loop;
+       $socket_loop ||= EV::default_loop;
-    $w = EV::embed $otherloop, $callback
+    $w = EV::embed $otherloop[, $callback]
-    $w = EV::embed_ns $otherloop, $callback
+    $w = EV::embed_ns $otherloop[, $callback]
-    $w = $loop->embed ($otherloop, $callback)
+    $w = $loop->embed ($otherloop[, $callback])
-    $w = $loop->embed_ns ($otherloop, $callback)
+    $w = $loop->embed_ns ($otherloop[, $callback])
         Call the callback when the embedded event loop ($otherloop) has any
-        I/O activity. The $callback should alwas be specified as "undef" in
+        I/O activity. The $callback is optional: if it is missing, then the
-        this version of EV, which means the embedded event loop will be
+        embedded event loop will be managed automatically (which is
-        managed automatically.
+        recommended), otherwise you have to invoke "sweep" yourself.
         The "embed_ns" variant doesn't start (activate) the newly created
         watcher.
+   ASYNC WATCHERS - how to wake up another event loop
+    Async watchers are provided by EV, but have little use in perl directly,
+    as perl neither supports threads nor direct access to signal handlers or
+    other contexts where they could be of value.
+    It is, however, possible to use them from the XS level.
+    Please see the libev documentation for further details.
+    $w = EV::async $callback
+    $w = EV::async_ns $callback
+    $w->send
+    $bool = $w->async_pending
 PERL SIGNALS
     While Perl signal handling (%SIG) is not affected by EV, the behaviour
     with EV is as the same as any other C library: Perl-signals will only be
     handled when Perl runs, which means your signal handler might be invoked
     course.
 SEE ALSO
     EV::ADNS (asynchronous DNS), Glib::EV (makes Glib/Gtk2 use EV as event
     loop), EV::Glib (embed Glib into EV), Coro::EV (efficient coroutines
-    with EV), Net::SNMP::EV (asynchronous SNMP).
+    with EV), Net::SNMP::EV (asynchronous SNMP), AnyEvent for event-loop
+    agnostic and portable event driven programming.
 AUTHOR
-     Marc Lehmann <schmorp@schmorp.de>
+       Marc Lehmann <schmorp@schmorp.de>
-     http://home.schmorp.de/
+       http://home.schmorp.de/

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Comparing EV/README (file contents): Revision 1.22 by root, Mon Jan 28 12:24:05 2008 UTC vs. Revision 1.30 by root, Thu Oct 23 04:56:49 2008 UTC

Diff Legend

Comparing EV/README (file contents):
Revision 1.22 by root, Mon Jan 28 12:24:05 2008 UTC vs.
Revision 1.30 by root, Thu Oct 23 04:56:49 2008 UTC