[ViewVC] Diff of: cvs/libev/ev.pod

Comparing libev/ev.pod (file contents):
Revision 1.265 by root, Wed Aug 26 17:11:42 2009 UTC vs.
Revision 1.276 by root, Tue Dec 29 13:11:00 2009 UTC

 Libev is very configurable. In this manual the default (and most common)
 configuration will be described, which supports multiple event loops. For
 more info about various configuration options please have a look at
 B<EMBED> section in this manual. If libev was configured without support
 for multiple event loops, then all functions taking an initial argument of
-name C<loop> (which is always of type C<ev_loop *>) will not have
+name C<loop> (which is always of type C<struct ev_loop *>) will not have
 this argument.
 =head2 TIME REPRESENTATION
 Libev represents time as a single floating point number, representing
 When this flag is specified, then libev will not attempt to use the
 I<inotify> API for it's C<ev_stat> watchers. Apart from debugging and
 testing, this flag can be useful to conserve inotify file descriptors, as
 otherwise each loop using C<ev_stat> watchers consumes one inotify handle.
-=item C<EVFLAG_NOSIGNALFD>
+=item C<EVFLAG_NOSIGFD>
 When this flag is specified, then libev will not attempt to use the
 I<signalfd> API for it's C<ev_signal> (and C<ev_child>) watchers. This is
 probably only useful to work around any bugs in libev. Consequently, this
 flag might go away once the signalfd functionality is considered stable,
 This backend maps C<EV_READ> to C<POLLIN | POLLERR | POLLHUP>, and
 C<EV_WRITE> to C<POLLOUT | POLLERR | POLLHUP>.
 =item C<EVBACKEND_EPOLL>   (value 4, Linux)
+Use the linux-specific epoll(7) interface (for both pre- and post-2.6.9
+kernels).
 For few fds, this backend is a bit little slower than poll and select,
 but it scales phenomenally better. While poll and select usually scale
 like O(total_fds) where n is the total number of fds (or the highest fd),
 epoll scales either O(1) or O(active_fds).
 as signal and child watchers) would need to be stopped manually.
 In general it is not advisable to call this function except in the
 rare occasion where you really need to free e.g. the signal handling
 pipe fds. If you need dynamically allocated loops it is better to use
-C<ev_loop_new> and C<ev_loop_destroy>).
+C<ev_loop_new> and C<ev_loop_destroy>.
 =item ev_loop_destroy (loop)
 Like C<ev_default_destroy>, but destroys an event loop created by an
 earlier call to C<ev_loop_new>.
 event loop time (see C<ev_now_update>).
 =item ev_loop (loop, int flags)
 Finally, this is it, the event handler. This function usually is called
-after you initialised all your watchers and you want to start handling
+after you have initialised all your watchers and you want to start
-events.
+handling events.
 If the flags argument is specified as C<0>, it will not return until
 either no event watchers are active anymore or C<ev_unloop> was called.
 Please note that an explicit C<ev_unloop> is usually better than
 Ref/unref can be used to add or remove a reference count on the event
 loop: Every watcher keeps one reference, and as long as the reference
 count is nonzero, C<ev_loop> will not return on its own.
-If you have a watcher you never unregister that should not keep C<ev_loop>
+This is useful when you have a watcher that you never intend to
-from returning, call ev_unref() after starting, and ev_ref() before
+unregister, but that nevertheless should not keep C<ev_loop> from
+returning. In such a case, call C<ev_unref> after starting, and C<ev_ref>
-stopping it.
+before stopping it.
 As an example, libev itself uses this for its internal signal pipe: It
 is not visible to the libev user and should not keep C<ev_loop> from
 exiting if no event watchers registered by it are active. It is also an
 excellent way to do this for generic recurring timers or from within
 While event loop modifications are allowed between invocations of
 C<release> and C<acquire> (that's their only purpose after all), no
 modifications done will affect the event loop, i.e. adding watchers will
 have no effect on the set of file descriptors being watched, or the time
-waited. USe an C<ev_async> watcher to wake up C<ev_loop> when you want it
+waited. Use an C<ev_async> watcher to wake up C<ev_loop> when you want it
 to take note of any changes you made.
 In theory, threads executing C<ev_loop> will be async-cancel safe between
 invocations of C<release> and C<acquire>.
    ev_io w;
    ev_init (&w, my_cb);
    ev_io_set (&w, STDIN_FILENO, EV_READ);
-=item C<ev_TYPE_set> (ev_TYPE *, [args])
+=item C<ev_TYPE_set> (ev_TYPE *watcher, [args])
 This macro initialises the type-specific parts of a watcher. You need to
 call C<ev_init> at least once before you call this macro, but you can
 call C<ev_TYPE_set> any number of times. You must not, however, call this
 macro on a watcher that is active (it can be pending, however, which is a
 Example: Initialise and set an C<ev_io> watcher in one step.
    ev_io_init (&w, my_cb, STDIN_FILENO, EV_READ);
-=item C<ev_TYPE_start> (loop *, ev_TYPE *watcher)
+=item C<ev_TYPE_start> (loop, ev_TYPE *watcher)
 Starts (activates) the given watcher. Only active watchers will receive
 events. If the watcher is already active nothing will happen.
 Example: Start the C<ev_io> watcher that is being abused as example in this
 whole section.
    ev_io_start (EV_DEFAULT_UC, &w);
-=item C<ev_TYPE_stop> (loop *, ev_TYPE *watcher)
+=item C<ev_TYPE_stop> (loop, ev_TYPE *watcher)
 Stops the given watcher if active, and clears the pending status (whether
 the watcher was active or not).
 It is possible that stopped watchers are pending - for example,
 =item ev_cb_set (ev_TYPE *watcher, callback)
 Change the callback. You can change the callback at virtually any time
 (modulo threads).
-=item ev_set_priority (ev_TYPE *watcher, priority)
+=item ev_set_priority (ev_TYPE *watcher, int priority)
 =item int ev_priority (ev_TYPE *watcher)
 Set and query the priority of the watcher. The priority is a small
 integer between C<EV_MAXPRI> (default: C<2>) and C<EV_MINPRI>
 returns its C<revents> bitset (as if its callback was invoked). If the
 watcher isn't pending it does nothing and returns C<0>.
 Sometimes it can be useful to "poll" a watcher instead of waiting for its
 callback to be invoked, which can be accomplished with this function.
+=item ev_feed_event (loop, ev_TYPE *watcher, int revents)
+Feeds the given event set into the event loop, as if the specified event
+had happened for the specified watcher (which must be a pointer to an
+initialised but not necessarily started event watcher). Obviously you must
+not free the watcher as long as it has pending events.
+Stopping the watcher, letting libev invoke it, or calling
+C<ev_clear_pending> will clear the pending event, even if the watcher was
+not started in the first place.
+See also C<ev_feed_fd_event> and C<ev_feed_signal_event> for related
+functions that do not need a watcher.
 =back
 =head2 ASSOCIATING CUSTOM DATA WITH A WATCHER
 C<repeat> value), or reset the running timer to the C<repeat> value.
 This sounds a bit complicated, see L<Be smart about timeouts>, above, for a
 usage example.
-=item ev_timer_remaining (loop, ev_timer *)
+=item ev_tstamp ev_timer_remaining (loop, ev_timer *)
 Returns the remaining time until a timer fires. If the timer is active,
 then this time is relative to the current event loop time, otherwise it's
 the timeout value currently configured.
 and might or might not set or restore the installed signal handler.
 While this does not matter for the signal disposition (libev never
 sets signals to C<SIG_IGN>, so handlers will be reset to C<SIG_DFL> on
 C<execve>), this matters for the signal mask: many programs do not expect
-many signals to be blocked.
+certain signals to be blocked.
 This means that before calling C<exec> (from the child) you should reset
 the signal mask to whatever "default" you expect (all clear is a good
 choice usually).
+The simplest way to ensure that the signal mask is reset in the child is
+to install a fork handler with C<pthread_atfork> that resets it. That will
+catch fork calls done by libraries (such as the libc) as well.
+In current versions of libev, you can also ensure that the signal mask is
+not blocking any signals (except temporarily, so thread users watch out)
+by specifying the C<EVFLAG_NOSIGFD> when creating the event loop. This
+is not guaranteed for future versions, however.
 =head3 Watcher-Specific Functions and Data Members
 =over 4
 =head3 Queueing
 C<ev_async> does not support queueing of data in any way. The reason
 is that the author does not know of a simple (or any) algorithm for a
 multiple-writer-single-reader queue that works in all cases and doesn't
-need elaborate support such as pthreads.
+need elaborate support such as pthreads or unportable memory access
+semantics.
 That means that if you want to queue data, you have to provide your own
 queue. But at least I can tell you how to implement locking around your
 queue:
        /* doh, nothing entered */;
    }
    ev_once (STDIN_FILENO, EV_READ, 10., stdin_ready, 0);
-=item ev_feed_event (struct ev_loop *, watcher *, int revents)
-Feeds the given event set into the event loop, as if the specified event
-had happened for the specified watcher (which must be a pointer to an
-initialised but not necessarily started event watcher).
-=item ev_feed_fd_event (struct ev_loop *, int fd, int revents)
+=item ev_feed_fd_event (loop, int fd, int revents)
 Feed an event on the given fd, as if a file descriptor backend detected
 the given events it.
-=item ev_feed_signal_event (struct ev_loop *loop, int signum)
+=item ev_feed_signal_event (loop, int signum)
 Feed an event as if the given signal occurred (C<loop> must be the default
 loop!).
 =back
 =over 4
 =item ev::TYPE::TYPE ()
-=item ev::TYPE::TYPE (struct ev_loop *)
+=item ev::TYPE::TYPE (loop)
 =item ev::TYPE::~TYPE
 The constructor (optionally) takes an event loop to associate the watcher
 with. If it is omitted, it will use C<EV_DEFAULT>.
 Example: Use a plain function as callback.
    static void io_cb (ev::io &w, int revents) { }
    iow.set <io_cb> ();
-=item w->set (struct ev_loop *)
+=item w->set (loop)
 Associates a different C<struct ev_loop> with this watcher. You can only
 do this when the watcher is inactive (and not pending either).
 =item w->set ([arguments])

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Comparing libev/ev.pod (file contents): Revision 1.265 by root, Wed Aug 26 17:11:42 2009 UTC vs. Revision 1.276 by root, Tue Dec 29 13:11:00 2009 UTC

Diff Legend

Comparing libev/ev.pod (file contents):
Revision 1.265 by root, Wed Aug 26 17:11:42 2009 UTC vs.
Revision 1.276 by root, Tue Dec 29 13:11:00 2009 UTC