=item int ev_version_minor ()
-You can find out the major and minor API/ABI version numbers of the library
+You can find out the major and minor ABI version numbers of the library
you linked against by calling the functions C<ev_version_major> and
C<ev_version_minor>. If you want, you can compare against the global
symbols C<EV_VERSION_MAJOR> and C<EV_VERSION_MINOR>, which specify the
version of the library your program was compiled against.
-These version numbers refer to the API and ABI version of the library, not
-the release version.
+These version numbers refer to the ABI version of the library, not the
+release version.
Usually, it's a good idea to terminate if the major versions mismatch,
as this indicates an incompatible change. Minor versions are usually
such as poll (fortunately in our Xlib example, Xlib already does this on
its own, so its quite safe to use).
+=head3 The special problem of disappearing file descriptors
+
+Some backends (e.g kqueue, epoll) need to be told about closing a file
+descriptor (either by calling C<close> explicitly or by any other means,
+such as C<dup>). The reason is that you register interest in some file
+descriptor, but when it goes away, the operating system will silently drop
+this interest. If another file descriptor with the same number then is
+registered with libev, there is no efficient way to see that this is, in
+fact, a different file descriptor.
+
+To avoid having to explicitly tell libev about such cases, libev follows
+the following policy: Each time C<ev_io_set> is being called, libev
+will assume that this is potentially a new file descriptor, otherwise
+it is assumed that the file descriptor stays the same. That means that
+you I<have> to call C<ev_io_set> (or C<ev_io_init>) when you change the
+descriptor even if the file descriptor number itself did not change.
+
+This is how one would do it normally anyway, the important point is that
+the libev application should not optimise around libev but should leave
+optimisations to libev.
+
+
+=head3 Watcher-Specific Functions
+
=over 4
=item ev_io_init (ev_io *, callback, int fd, int events)
but if multiple timers become ready during the same loop iteration then
order of execution is undefined.
+=head3 Watcher-Specific Functions and Data Members
+
=over 4
=item ev_timer_init (ev_timer *, callback, ev_tstamp after, ev_tstamp repeat)
time (C<at>) has been passed, but if multiple periodic timers become ready
during the same loop iteration then order of execution is undefined.
+=head3 Watcher-Specific Functions and Data Members
+
=over 4
=item ev_periodic_init (ev_periodic *, callback, ev_tstamp at, ev_tstamp interval, reschedule_cb)
switched off. Can be changed any time, but changes only take effect when
the periodic timer fires or C<ev_periodic_again> is being called.
+=item ev_tstamp at [read-only]
+
+When active, contains the absolute time that the watcher is supposed to
+trigger next.
+
=back
Example: Call a callback every hour, or, more precisely, whenever the
watcher for a signal is stopped libev will reset the signal handler to
SIG_DFL (regardless of what it was set to before).
+=head3 Watcher-Specific Functions and Data Members
+
=over 4
=item ev_signal_init (ev_signal *, callback, int signum)
Child watchers trigger when your process receives a SIGCHLD in response to
some child status changes (most typically when a child of yours dies).
+=head3 Watcher-Specific Functions and Data Members
+
=over 4
=item ev_child_init (ev_child *, callback, int pid)
usually detected immediately, and if the file exists there will be no
polling.
+=head3 Watcher-Specific Functions and Data Members
+
=over 4
=item ev_stat_init (ev_stat *, callback, const char *path, ev_tstamp interval)
"pseudo-background processing", or delay processing stuff to after the
event loop has handled all outstanding events.
+=head3 Watcher-Specific Functions and Data Members
+
=over 4
=item ev_idle_init (ev_signal *, callback)
C<ev_check> watcher ran (always remind yourself to coexist peacefully with
others).
+=head3 Watcher-Specific Functions and Data Members
+
=over 4
=item ev_prepare_init (ev_prepare *, callback)
else
loop_lo = loop_hi;
+=head3 Watcher-Specific Functions and Data Members
+
=over 4
=item ev_embed_init (ev_embed *, callback, struct ev_loop *embedded_loop)
C<ev_default_fork> cheats and calls it in the wrong process, the fork
handlers will be invoked, too, of course.
+=head3 Watcher-Specific Functions and Data Members
+
=over 4
=item ev_fork_init (ev_signal *, callback)
Stops the watcher if it is active. Again, no C<loop> argument.
-=item w->again () C<ev::timer>, C<ev::periodic> only
+=item w->again () (C<ev::timer>, C<ev::periodic> only)
For C<ev::timer> and C<ev::periodic>, this invokes the corresponding
C<ev_TYPE_again> function.
-=item w->sweep () C<ev::embed> only
+=item w->sweep () (C<ev::embed> only)
Invokes C<ev_embed_sweep>.
-=item w->update () C<ev::stat> only
+=item w->update () (C<ev::stat> only)
Invokes C<ev_stat_stat>.
=head1 MACRO MAGIC
-Libev can be compiled with a variety of options, the most fundemantal is
-C<EV_MULTIPLICITY>. This option determines whether (most) functions and
-callbacks have an initial C<struct ev_loop *> argument.
+Libev can be compiled with a variety of options, the most fundamantal
+of which is C<EV_MULTIPLICITY>. This option determines whether (most)
+functions and callbacks have an initial C<struct ev_loop *> argument.
To make it easier to write programs that cope with either variant, the
following macros are defined:
projects / software / libev.git / blobdiff