.rm #[ #] #H #V #F C
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.\"
-.IX Title ""<STANDARD INPUT>" 1"
-.TH "<STANDARD INPUT>" 1 "2007-12-12" "perl v5.8.8" "User Contributed Perl Documentation"
+.IX Title "EV 1"
+.TH EV 1 "2007-12-19" "perl v5.8.8" "User Contributed Perl Documentation"
.SH "NAME"
libev \- a high performance full\-featured event loop written in C
.SH "SYNOPSIS"
the beginning of 1970, details are complicated, don't ask). This type is
called \f(CW\*(C`ev_tstamp\*(C'\fR, which is what you should use too. It usually aliases
to the \f(CW\*(C`double\*(C'\fR type in C, and when you need to do any calculations on
-it, you should treat it as such.
+it, you should treat it as some floatingpoint value. Unlike the name
+component \f(CW\*(C`stamp\*(C'\fR might indicate, it is also used for time differences
+throughout libev.
.SH "GLOBAL FUNCTIONS"
.IX Header "GLOBAL FUNCTIONS"
These functions can be called anytime, even before initialising the
sense, so e.g. \f(CW\*(C`ev_is_active\*(C'\fR might still return true. It is your
responsibility to either stop all watchers cleanly yoursef \fIbefore\fR
calling this function, or cope with the fact afterwards (which is usually
-the easiest thing, youc na just ignore the watchers and/or \f(CW\*(C`free ()\*(C'\fR them
+the easiest thing, you can just ignore the watchers and/or \f(CW\*(C`free ()\*(C'\fR them
for example).
+.Sp
+Not that certain global state, such as signal state, will not be freed by
+this function, and related watchers (such as signal and child watchers)
+would need to be stopped manually.
+.Sp
+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
+\&\f(CW\*(C`ev_loop_new\*(C'\fR and \f(CW\*(C`ev_loop_destroy\*(C'\fR).
.IP "ev_loop_destroy (loop)" 4
.IX Item "ev_loop_destroy (loop)"
Like \f(CW\*(C`ev_default_destroy\*(C'\fR, but destroys an event loop created by an
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.
+.PP
+\fIWatcher-Specific Functions\fR
+.IX Subsection "Watcher-Specific Functions"
.IP "ev_io_init (ev_io *, callback, int fd, int events)" 4
.IX Item "ev_io_init (ev_io *, callback, int fd, int events)"
.PD 0
The callback is guarenteed to be invoked only when its timeout has passed,
but if multiple timers become ready during the same loop iteration then
order of execution is undefined.
+.PP
+\fIWatcher-Specific Functions and Data Members\fR
+.IX Subsection "Watcher-Specific Functions and Data Members"
.IP "ev_timer_init (ev_timer *, callback, ev_tstamp after, ev_tstamp repeat)" 4
.IX Item "ev_timer_init (ev_timer *, callback, ev_tstamp after, ev_tstamp repeat)"
.PD 0
As with timers, the callback is guarenteed to be invoked only when the
time (\f(CW\*(C`at\*(C'\fR) has been passed, but if multiple periodic timers become ready
during the same loop iteration then order of execution is undefined.
+.PP
+\fIWatcher-Specific Functions and Data Members\fR
+.IX Subsection "Watcher-Specific Functions and Data Members"
.IP "ev_periodic_init (ev_periodic *, callback, ev_tstamp at, ev_tstamp interval, reschedule_cb)" 4
.IX Item "ev_periodic_init (ev_periodic *, callback, ev_tstamp at, ev_tstamp interval, reschedule_cb)"
.PD 0
The current reschedule callback, or \f(CW0\fR, if this functionality is
switched off. Can be changed any time, but changes only take effect when
the periodic timer fires or \f(CW\*(C`ev_periodic_again\*(C'\fR is being called.
+.IP "ev_tstamp at [read\-only]" 4
+.IX Item "ev_tstamp at [read-only]"
+When active, contains the absolute time that the watcher is supposed to
+trigger next.
.PP
Example: Call a callback every hour, or, more precisely, whenever the
system clock is divisible by 3600. The callback invocation times have
as you don't register any with libev). Similarly, when the last signal
watcher for a signal is stopped libev will reset the signal handler to
\&\s-1SIG_DFL\s0 (regardless of what it was set to before).
+.PP
+\fIWatcher-Specific Functions and Data Members\fR
+.IX Subsection "Watcher-Specific Functions and Data Members"
.IP "ev_signal_init (ev_signal *, callback, int signum)" 4
.IX Item "ev_signal_init (ev_signal *, callback, int signum)"
.PD 0
.IX Subsection "ev_child - watch out for process status changes"
Child watchers trigger when your process receives a \s-1SIGCHLD\s0 in response to
some child status changes (most typically when a child of yours dies).
+.PP
+\fIWatcher-Specific Functions and Data Members\fR
+.IX Subsection "Watcher-Specific Functions and Data Members"
.IP "ev_child_init (ev_child *, callback, int pid)" 4
.IX Item "ev_child_init (ev_child *, callback, int pid)"
.PD 0
to fall back to regular polling again even with inotify, but changes are
usually detected immediately, and if the file exists there will be no
polling.
+.PP
+\fIWatcher-Specific Functions and Data Members\fR
+.IX Subsection "Watcher-Specific Functions and Data Members"
.IP "ev_stat_init (ev_stat *, callback, const char *path, ev_tstamp interval)" 4
.IX Item "ev_stat_init (ev_stat *, callback, const char *path, ev_tstamp interval)"
.PD 0
effect on its own sometimes), idle watchers are a good place to do
\&\*(L"pseudo\-background processing\*(R", or delay processing stuff to after the
event loop has handled all outstanding events.
+.PP
+\fIWatcher-Specific Functions and Data Members\fR
+.IX Subsection "Watcher-Specific Functions and Data Members"
.IP "ev_idle_init (ev_signal *, callback)" 4
.IX Item "ev_idle_init (ev_signal *, callback)"
Initialises and configures the idle watcher \- it has no parameters of any
loops those other event loops might be in an unusable state until their
\&\f(CW\*(C`ev_check\*(C'\fR watcher ran (always remind yourself to coexist peacefully with
others).
+.PP
+\fIWatcher-Specific Functions and Data Members\fR
+.IX Subsection "Watcher-Specific Functions and Data Members"
.IP "ev_prepare_init (ev_prepare *, callback)" 4
.IX Item "ev_prepare_init (ev_prepare *, callback)"
.PD 0
\& else
\& loop_lo = loop_hi;
.Ve
+.PP
+\fIWatcher-Specific Functions and Data Members\fR
+.IX Subsection "Watcher-Specific Functions and Data Members"
.IP "ev_embed_init (ev_embed *, callback, struct ev_loop *embedded_loop)" 4
.IX Item "ev_embed_init (ev_embed *, callback, struct ev_loop *embedded_loop)"
.PD 0
and only in the child after the fork. If whoever good citizen calling
\&\f(CW\*(C`ev_default_fork\*(C'\fR cheats and calls it in the wrong process, the fork
handlers will be invoked, too, of course.
+.PP
+\fIWatcher-Specific Functions and Data Members\fR
+.IX Subsection "Watcher-Specific Functions and Data Members"
.IP "ev_fork_init (ev_signal *, callback)" 4
.IX Item "ev_fork_init (ev_signal *, callback)"
Initialises and configures the fork watcher \- it has no parameters of any
.IP "w\->stop ()" 4
.IX Item "w->stop ()"
Stops the watcher if it is active. Again, no \f(CW\*(C`loop\*(C'\fR argument.
-.ie n .IP "w\->again () ""ev::timer""\fR, \f(CW""ev::periodic"" only" 4
-.el .IP "w\->again () \f(CWev::timer\fR, \f(CWev::periodic\fR only" 4
-.IX Item "w->again () ev::timer, ev::periodic only"
+.ie n .IP "w\->again () (""ev::timer""\fR, \f(CW""ev::periodic"" only)" 4
+.el .IP "w\->again () (\f(CWev::timer\fR, \f(CWev::periodic\fR only)" 4
+.IX Item "w->again () (ev::timer, ev::periodic only)"
For \f(CW\*(C`ev::timer\*(C'\fR and \f(CW\*(C`ev::periodic\*(C'\fR, this invokes the corresponding
\&\f(CW\*(C`ev_TYPE_again\*(C'\fR function.
-.ie n .IP "w\->sweep () ""ev::embed"" only" 4
-.el .IP "w\->sweep () \f(CWev::embed\fR only" 4
-.IX Item "w->sweep () ev::embed only"
+.ie n .IP "w\->sweep () (""ev::embed"" only)" 4
+.el .IP "w\->sweep () (\f(CWev::embed\fR only)" 4
+.IX Item "w->sweep () (ev::embed only)"
Invokes \f(CW\*(C`ev_embed_sweep\*(C'\fR.
-.ie n .IP "w\->update () ""ev::stat"" only" 4
-.el .IP "w\->update () \f(CWev::stat\fR only" 4
-.IX Item "w->update () ev::stat only"
+.ie n .IP "w\->update () (""ev::stat"" only)" 4
+.el .IP "w\->update () (\f(CWev::stat\fR only)" 4
+.IX Item "w->update () (ev::stat only)"
Invokes \f(CW\*(C`ev_stat_stat\*(C'\fR.
.RE
.RS 4
.Ve
.SH "MACRO MAGIC"
.IX Header "MACRO MAGIC"
-Libev can be compiled with a variety of options, the most fundemantal is
-\&\f(CW\*(C`EV_MULTIPLICITY\*(C'\fR. This option determines whether (most) functions and
-callbacks have an initial \f(CW\*(C`struct ev_loop *\*(C'\fR argument.
+Libev can be compiled with a variety of options, the most fundamantal
+of which is \f(CW\*(C`EV_MULTIPLICITY\*(C'\fR. This option determines whether (most)
+functions and callbacks have an initial \f(CW\*(C`struct ev_loop *\*(C'\fR argument.
.PP
To make it easier to write programs that cope with either variant, the
following macros are defined:
their default definitions. One possible use for overriding these is to
avoid the \f(CW\*(C`struct ev_loop *\*(C'\fR as first argument in all cases, or to use
method calls instead of plain function calls in \*(C+.
+.Sh "\s-1EXPORTED\s0 \s-1API\s0 \s-1SYMBOLS\s0"
+.IX Subsection "EXPORTED API SYMBOLS"
+If you need to re-export the \s-1API\s0 (e.g. via a dll) and you need a list of
+exported symbols, you can use the provided \fISymbol.*\fR files which list
+all public symbols, one per line:
+.Sp
+.Vb 2
+\& Symbols.ev for libev proper
+\& Symbols.event for the libevent emulation
+.Ve
+.Sp
+This can also be used to rename all public symbols to avoid clashes with
+multiple versions of libev linked together (which is obviously bad in
+itself, but sometimes it is inconvinient to avoid this).
+.Sp
+A sed comamnd like this will create wrapper \f(CW\*(C`#define\*(C'\fR's that you need to
+include before including \fIev.h\fR:
+.Sp
+.Vb 1
+\& <Symbols.ev sed -e "s/.*/#define & myprefix_&/" >wrap.h
+.Ve
+.Sp
+This would create a file \fIwrap.h\fR which essentially looks like this:
+.Sp
+.Vb 4
+\& #define ev_backend myprefix_ev_backend
+\& #define ev_check_start myprefix_ev_check_start
+\& #define ev_check_stop myprefix_ev_check_stop
+\& ...
+.Ve
.Sh "\s-1EXAMPLES\s0"
.IX Subsection "EXAMPLES"
For a real-world example of a program the includes libev
projects / software / libev.git / blobdiff