[ViewVC] Diff of: cvs/libev/ev.3

Comparing libev/ev.3 (file contents):
Revision 1.1 by root, Tue Nov 13 03:11:57 2007 UTC vs.
Revision 1.9 by root, Fri Nov 23 16:17:12 2007 UTC

…		…
127	.\}	127	.\}
128	.rm #[ #] #H #V #F C	128	.rm #[ #] #H #V #F C
129	.\" ========================================================================	129	.\" ========================================================================
130	.\"	130	.\"
131	.IX Title ""<STANDARD INPUT>" 1"	131	.IX Title ""<STANDARD INPUT>" 1"
132	.TH "<STANDARD INPUT>" 1 "2007-11-13" "perl v5.8.8" "User Contributed Perl Documentation"	132	.TH "<STANDARD INPUT>" 1 "2007-11-23" "perl v5.8.8" "User Contributed Perl Documentation"
133	.SH "NAME"	133	.SH "NAME"
134	libev \- a high performance full\-featured event loop written in C	134	libev \- a high performance full\-featured event loop written in C
135	.SH "SYNOPSIS"	135	.SH "SYNOPSIS"
136	.IX Header "SYNOPSIS"	136	.IX Header "SYNOPSIS"
137	.Vb 1	137	.Vb 1
…		…
173	.IX Header "TIME REPRESENTATION"	173	.IX Header "TIME REPRESENTATION"
174	Libev represents time as a single floating point number, representing the	174	Libev represents time as a single floating point number, representing the
175	(fractional) number of seconds since the (\s-1POSIX\s0) epoch (somewhere near	175	(fractional) number of seconds since the (\s-1POSIX\s0) epoch (somewhere near
176	the beginning of 1970, details are complicated, don't ask). This type is	176	the beginning of 1970, details are complicated, don't ask). This type is
177	called \f(CW\(C`ev_tstamp\(C'\fR, which is what you should use too. It usually aliases	177	called \f(CW\(C`ev_tstamp\(C'\fR, which is what you should use too. It usually aliases
178	to the double type in C.	178	to the \f(CW\(C`double\(C'\fR type in C, and when you need to do any calculations on
		179	it, you should treat it as such.
179	.SH "GLOBAL FUNCTIONS"	180	.SH "GLOBAL FUNCTIONS"
180	.IX Header "GLOBAL FUNCTIONS"	181	.IX Header "GLOBAL FUNCTIONS"
181	These functions can be called anytime, even before initialising the	182	These functions can be called anytime, even before initialising the
182	library in any way.	183	library in any way.
183	.IP "ev_tstamp ev_time ()" 4	184	.IP "ev_tstamp ev_time ()" 4
184	.IX Item "ev_tstamp ev_time ()"	185	.IX Item "ev_tstamp ev_time ()"
185	Returns the current time as libev would use it.	186	Returns the current time as libev would use it. Please note that the
		187	\&\f(CW\(C`ev_now\(C'\fR function is usually faster and also often returns the timestamp
		188	you actually want to know.
186	.IP "int ev_version_major ()" 4	189	.IP "int ev_version_major ()" 4
187	.IX Item "int ev_version_major ()"	190	.IX Item "int ev_version_major ()"
188	.PD 0	191	.PD 0
189	.IP "int ev_version_minor ()" 4	192	.IP "int ev_version_minor ()" 4
190	.IX Item "int ev_version_minor ()"	193	.IX Item "int ev_version_minor ()"
…		…
197	.Sp	200	.Sp
198	Usually, it's a good idea to terminate if the major versions mismatch,	201	Usually, it's a good idea to terminate if the major versions mismatch,
199	as this indicates an incompatible change. Minor versions are usually	202	as this indicates an incompatible change. Minor versions are usually
200	compatible to older versions, so a larger minor version alone is usually	203	compatible to older versions, so a larger minor version alone is usually
201	not a problem.	204	not a problem.
		205	.Sp
		206	Example: make sure we haven't accidentally been linked against the wrong
		207	version:
		208	.Sp
		209	.Vb 3
		210	\& assert (("libev version mismatch",
		211	\& ev_version_major () == EV_VERSION_MAJOR
		212	\& && ev_version_minor () >= EV_VERSION_MINOR));
		213	.Ve
		214	.IP "unsigned int ev_supported_backends ()" 4
		215	.IX Item "unsigned int ev_supported_backends ()"
		216	Return the set of all backends (i.e. their corresponding \f(CW\(C`EV_BACKEND_\*(C'\fR
		217	value) compiled into this binary of libev (independent of their
		218	availability on the system you are running on). See \f(CW\(C`ev_default_loop\(C'\fR for
		219	a description of the set values.
		220	.Sp
		221	Example: make sure we have the epoll method, because yeah this is cool and
		222	a must have and can we have a torrent of it please!!!11
		223	.Sp
		224	.Vb 2
		225	\& assert (("sorry, no epoll, no sex",
		226	\& ev_supported_backends () & EVBACKEND_EPOLL));
		227	.Ve
		228	.IP "unsigned int ev_recommended_backends ()" 4
		229	.IX Item "unsigned int ev_recommended_backends ()"
		230	Return the set of all backends compiled into this binary of libev and also
		231	recommended for this platform. This set is often smaller than the one
		232	returned by \f(CW\(C`ev_supported_backends\(C'\fR, as for example kqueue is broken on
		233	most BSDs and will not be autodetected unless you explicitly request it
		234	(assuming you know what you are doing). This is the set of backends that
		235	libev will probe for if you specify no backends explicitly.
202	.IP "ev_set_allocator (void (cb)(void *ptr, long size))" 4	236	.IP "ev_set_allocator (void (cb)(void *ptr, long size))" 4
203	.IX Item "ev_set_allocator (void (cb)(void *ptr, long size))"	237	.IX Item "ev_set_allocator (void (cb)(void *ptr, long size))"
204	Sets the allocation function to use (the prototype is similar to the	238	Sets the allocation function to use (the prototype is similar to the
205	realloc C function, the semantics are identical). It is used to allocate	239	realloc C function, the semantics are identical). It is used to allocate
206	and free memory (no surprises here). If it returns zero when memory	240	and free memory (no surprises here). If it returns zero when memory
…		…
208	destructive action. The default is your system realloc function.	242	destructive action. The default is your system realloc function.
209	.Sp	243	.Sp
210	You could override this function in high-availability programs to, say,	244	You could override this function in high-availability programs to, say,
211	free some memory if it cannot allocate memory, to use a special allocator,	245	free some memory if it cannot allocate memory, to use a special allocator,
212	or even to sleep a while and retry until some memory is available.	246	or even to sleep a while and retry until some memory is available.
		247	.Sp
		248	Example: replace the libev allocator with one that waits a bit and then
		249	retries: better than mine).
		250	.Sp
		251	.Vb 6
		252	\& static void *
		253	\& persistent_realloc (void *ptr, long size)
		254	\& {
		255	\& for (;;)
		256	\& {
		257	\& void *newptr = realloc (ptr, size);
		258	.Ve
		259	.Sp
		260	.Vb 2
		261	\& if (newptr)
		262	\& return newptr;
		263	.Ve
		264	.Sp
		265	.Vb 3
		266	\& sleep (60);
		267	\& }
		268	\& }
		269	.Ve
		270	.Sp
		271	.Vb 2
		272	\& ...
		273	\& ev_set_allocator (persistent_realloc);
		274	.Ve
213	.IP "ev_set_syserr_cb (void (cb)(const char msg));" 4	275	.IP "ev_set_syserr_cb (void (cb)(const char msg));" 4
214	.IX Item "ev_set_syserr_cb (void (cb)(const char msg));"	276	.IX Item "ev_set_syserr_cb (void (cb)(const char msg));"
215	Set the callback function to call on a retryable syscall error (such	277	Set the callback function to call on a retryable syscall error (such
216	as failed select, poll, epoll_wait). The message is a printable string	278	as failed select, poll, epoll_wait). The message is a printable string
217	indicating the system call or subsystem causing the problem. If this	279	indicating the system call or subsystem causing the problem. If this
218	callback is set, then libev will expect it to remedy the sitution, no	280	callback is set, then libev will expect it to remedy the sitution, no
219	matter what, when it returns. That is, libev will generally retry the	281	matter what, when it returns. That is, libev will generally retry the
220	requested operation, or, if the condition doesn't go away, do bad stuff	282	requested operation, or, if the condition doesn't go away, do bad stuff
221	(such as abort).	283	(such as abort).
		284	.Sp
		285	Example: do the same thing as libev does internally:
		286	.Sp
		287	.Vb 6
		288	\& static void
		289	\& fatal_error (const char *msg)
		290	\& {
		291	\& perror (msg);
		292	\& abort ();
		293	\& }
		294	.Ve
		295	.Sp
		296	.Vb 2
		297	\& ...
		298	\& ev_set_syserr_cb (fatal_error);
		299	.Ve
222	.SH "FUNCTIONS CONTROLLING THE EVENT LOOP"	300	.SH "FUNCTIONS CONTROLLING THE EVENT LOOP"
223	.IX Header "FUNCTIONS CONTROLLING THE EVENT LOOP"	301	.IX Header "FUNCTIONS CONTROLLING THE EVENT LOOP"
224	An event loop is described by a \f(CW\(C`struct ev_loop \*(C'\fR. The library knows two	302	An event loop is described by a \f(CW\(C`struct ev_loop \*(C'\fR. The library knows two
225	types of such loops, the \fIdefault\fR loop, which supports signals and child	303	types of such loops, the \fIdefault\fR loop, which supports signals and child
226	events, and dynamically created loops which do not.	304	events, and dynamically created loops which do not.
…		…
234	.IP "struct ev_loop *ev_default_loop (unsigned int flags)" 4	312	.IP "struct ev_loop *ev_default_loop (unsigned int flags)" 4
235	.IX Item "struct ev_loop *ev_default_loop (unsigned int flags)"	313	.IX Item "struct ev_loop *ev_default_loop (unsigned int flags)"
236	This will initialise the default event loop if it hasn't been initialised	314	This will initialise the default event loop if it hasn't been initialised
237	yet and return it. If the default loop could not be initialised, returns	315	yet and return it. If the default loop could not be initialised, returns
238	false. If it already was initialised it simply returns it (and ignores the	316	false. If it already was initialised it simply returns it (and ignores the
239	flags).	317	flags. If that is troubling you, check \f(CW\(C`ev_backend ()\(C'\fR afterwards).
240	.Sp	318	.Sp
241	If you don't know what event loop to use, use the one returned from this	319	If you don't know what event loop to use, use the one returned from this
242	function.	320	function.
243	.Sp	321	.Sp
244	The flags argument can be used to specify special behaviour or specific	322	The flags argument can be used to specify special behaviour or specific
245	backends to use, and is usually specified as 0 (or \s-1EVFLAG_AUTO\s0).	323	backends to use, and is usually specified as \f(CW0\fR (or \f(CW\(C`EVFLAG_AUTO\(C'\fR).
246	.Sp	324	.Sp
247	It supports the following flags:	325	The following flags are supported:
248	.RS 4	326	.RS 4
249	.ie n .IP """EVFLAG_AUTO""" 4	327	.ie n .IP """EVFLAG_AUTO""" 4
250	.el .IP "\f(CWEVFLAG_AUTO\fR" 4	328	.el .IP "\f(CWEVFLAG_AUTO\fR" 4
251	.IX Item "EVFLAG_AUTO"	329	.IX Item "EVFLAG_AUTO"
252	The default flags value. Use this if you have no clue (it's the right	330	The default flags value. Use this if you have no clue (it's the right
…		…
258	or setgid) then libev will \fInot\fR look at the environment variable	336	or setgid) then libev will \fInot\fR look at the environment variable
259	\&\f(CW\(C`LIBEV_FLAGS\(C'\fR. Otherwise (the default), this environment variable will	337	\&\f(CW\(C`LIBEV_FLAGS\(C'\fR. Otherwise (the default), this environment variable will
260	override the flags completely if it is found in the environment. This is	338	override the flags completely if it is found in the environment. This is
261	useful to try out specific backends to test their performance, or to work	339	useful to try out specific backends to test their performance, or to work
262	around bugs.	340	around bugs.
263	.ie n .IP """EVMETHOD_SELECT"" (portable select backend)" 4	341	.ie n .IP """EVBACKEND_SELECT"" (value 1, portable select backend)" 4
264	.el .IP "\f(CWEVMETHOD_SELECT\fR (portable select backend)" 4	342	.el .IP "\f(CWEVBACKEND_SELECT\fR (value 1, portable select backend)" 4
265	.IX Item "EVMETHOD_SELECT (portable select backend)"	343	.IX Item "EVBACKEND_SELECT (value 1, portable select backend)"
266	.PD 0	344	This is your standard \fIselect\fR\\|(2) backend. Not \fIcompletely\fR standard, as
		345	libev tries to roll its own fd_set with no limits on the number of fds,
		346	but if that fails, expect a fairly low limit on the number of fds when
		347	using this backend. It doesn't scale too well (O(highest_fd)), but its usually
		348	the fastest backend for a low number of fds.
267	.ie n .IP """EVMETHOD_POLL"" (poll backend, available everywhere except on windows)" 4	349	.ie n .IP """EVBACKEND_POLL"" (value 2, poll backend, available everywhere except on windows)" 4
268	.el .IP "\f(CWEVMETHOD_POLL\fR (poll backend, available everywhere except on windows)" 4	350	.el .IP "\f(CWEVBACKEND_POLL\fR (value 2, poll backend, available everywhere except on windows)" 4
269	.IX Item "EVMETHOD_POLL (poll backend, available everywhere except on windows)"	351	.IX Item "EVBACKEND_POLL (value 2, poll backend, available everywhere except on windows)"
		352	And this is your standard \fIpoll\fR\\|(2) backend. It's more complicated than
		353	select, but handles sparse fds better and has no artificial limit on the
		354	number of fds you can use (except it will slow down considerably with a
		355	lot of inactive fds). It scales similarly to select, i.e. O(total_fds).
270	.ie n .IP """EVMETHOD_EPOLL"" (linux only)" 4	356	.ie n .IP """EVBACKEND_EPOLL"" (value 4, Linux)" 4
271	.el .IP "\f(CWEVMETHOD_EPOLL\fR (linux only)" 4	357	.el .IP "\f(CWEVBACKEND_EPOLL\fR (value 4, Linux)" 4
272	.IX Item "EVMETHOD_EPOLL (linux only)"	358	.IX Item "EVBACKEND_EPOLL (value 4, Linux)"
273	.ie n .IP """EVMETHOD_KQUEUE"" (some bsds only)" 4	359	For few fds, this backend is a bit little slower than poll and select,
274	.el .IP "\f(CWEVMETHOD_KQUEUE\fR (some bsds only)" 4	360	but it scales phenomenally better. While poll and select usually scale like
275	.IX Item "EVMETHOD_KQUEUE (some bsds only)"	361	O(total_fds) where n is the total number of fds (or the highest fd), epoll scales
		362	either O(1) or O(active_fds).
		363	.Sp
		364	While stopping and starting an I/O watcher in the same iteration will
		365	result in some caching, there is still a syscall per such incident
		366	(because the fd could point to a different file description now), so its
		367	best to avoid that. Also, \fIdup()\fRed file descriptors might not work very
		368	well if you register events for both fds.
		369	.Sp
		370	Please note that epoll sometimes generates spurious notifications, so you
		371	need to use non-blocking I/O or other means to avoid blocking when no data
		372	(or space) is available.
		373	.ie n .IP """EVBACKEND_KQUEUE"" (value 8, most \s-1BSD\s0 clones)" 4
		374	.el .IP "\f(CWEVBACKEND_KQUEUE\fR (value 8, most \s-1BSD\s0 clones)" 4
		375	.IX Item "EVBACKEND_KQUEUE (value 8, most BSD clones)"
		376	Kqueue deserves special mention, as at the time of this writing, it
		377	was broken on all BSDs except NetBSD (usually it doesn't work with
		378	anything but sockets and pipes, except on Darwin, where of course its
		379	completely useless). For this reason its not being \(L"autodetected\(R"
		380	unless you explicitly specify it explicitly in the flags (i.e. using
		381	\&\f(CW\(C`EVBACKEND_KQUEUE\(C'\fR).
		382	.Sp
		383	It scales in the same way as the epoll backend, but the interface to the
		384	kernel is more efficient (which says nothing about its actual speed, of
		385	course). While starting and stopping an I/O watcher does not cause an
		386	extra syscall as with epoll, it still adds up to four event changes per
		387	incident, so its best to avoid that.
276	.ie n .IP """EVMETHOD_DEVPOLL"" (solaris 8 only)" 4	388	.ie n .IP """EVBACKEND_DEVPOLL"" (value 16, Solaris 8)" 4
277	.el .IP "\f(CWEVMETHOD_DEVPOLL\fR (solaris 8 only)" 4	389	.el .IP "\f(CWEVBACKEND_DEVPOLL\fR (value 16, Solaris 8)" 4
278	.IX Item "EVMETHOD_DEVPOLL (solaris 8 only)"	390	.IX Item "EVBACKEND_DEVPOLL (value 16, Solaris 8)"
		391	This is not implemented yet (and might never be).
279	.ie n .IP """EVMETHOD_PORT"" (solaris 10 only)" 4	392	.ie n .IP """EVBACKEND_PORT"" (value 32, Solaris 10)" 4
280	.el .IP "\f(CWEVMETHOD_PORT\fR (solaris 10 only)" 4	393	.el .IP "\f(CWEVBACKEND_PORT\fR (value 32, Solaris 10)" 4
281	.IX Item "EVMETHOD_PORT (solaris 10 only)"	394	.IX Item "EVBACKEND_PORT (value 32, Solaris 10)"
282	.PD	395	This uses the Solaris 10 port mechanism. As with everything on Solaris,
283	If one or more of these are ored into the flags value, then only these	396	it's really slow, but it still scales very well (O(active_fds)).
284	backends will be tried (in the reverse order as given here). If one are	397	.Sp
285	specified, any backend will do.	398	Please note that solaris ports can result in a lot of spurious
		399	notifications, so you need to use non-blocking I/O or other means to avoid
		400	blocking when no data (or space) is available.
		401	.ie n .IP """EVBACKEND_ALL""" 4
		402	.el .IP "\f(CWEVBACKEND_ALL\fR" 4
		403	.IX Item "EVBACKEND_ALL"
		404	Try all backends (even potentially broken ones that wouldn't be tried
		405	with \f(CW\(C`EVFLAG_AUTO\(C'\fR). Since this is a mask, you can do stuff such as
		406	\&\f(CW\(C`EVBACKEND_ALL & ~EVBACKEND_KQUEUE\(C'\fR.
286	.RE	407	.RE
287	.RS 4	408	.RS 4
		409	.Sp
		410	If one or more of these are ored into the flags value, then only these
		411	backends will be tried (in the reverse order as given here). If none are
		412	specified, most compiled-in backend will be tried, usually in reverse
		413	order of their flag values :)
		414	.Sp
		415	The most typical usage is like this:
		416	.Sp
		417	.Vb 2
		418	\& if (!ev_default_loop (0))
		419	\& fatal ("could not initialise libev, bad $LIBEV_FLAGS in environment?");
		420	.Ve
		421	.Sp
		422	Restrict libev to the select and poll backends, and do not allow
		423	environment settings to be taken into account:
		424	.Sp
		425	.Vb 1
		426	\& ev_default_loop (EVBACKEND_POLL \| EVBACKEND_SELECT \| EVFLAG_NOENV);
		427	.Ve
		428	.Sp
		429	Use whatever libev has to offer, but make sure that kqueue is used if
		430	available (warning, breaks stuff, best use only with your own private
		431	event loop and only if you know the \s-1OS\s0 supports your types of fds):
		432	.Sp
		433	.Vb 1
		434	\& ev_default_loop (ev_recommended_backends () \| EVBACKEND_KQUEUE);
		435	.Ve
288	.RE	436	.RE
289	.IP "struct ev_loop *ev_loop_new (unsigned int flags)" 4	437	.IP "struct ev_loop *ev_loop_new (unsigned int flags)" 4
290	.IX Item "struct ev_loop *ev_loop_new (unsigned int flags)"	438	.IX Item "struct ev_loop *ev_loop_new (unsigned int flags)"
291	Similar to \f(CW\(C`ev_default_loop\(C'\fR, but always creates a new event loop that is	439	Similar to \f(CW\(C`ev_default_loop\(C'\fR, but always creates a new event loop that is
292	always distinct from the default loop. Unlike the default loop, it cannot	440	always distinct from the default loop. Unlike the default loop, it cannot
293	handle signal and child watchers, and attempts to do so will be greeted by	441	handle signal and child watchers, and attempts to do so will be greeted by
294	undefined behaviour (or a failed assertion if assertions are enabled).	442	undefined behaviour (or a failed assertion if assertions are enabled).
		443	.Sp
		444	Example: try to create a event loop that uses epoll and nothing else.
		445	.Sp
		446	.Vb 3
		447	\& struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL \| EVFLAG_NOENV);
		448	\& if (!epoller)
		449	\& fatal ("no epoll found here, maybe it hides under your chair");
		450	.Ve
295	.IP "ev_default_destroy ()" 4	451	.IP "ev_default_destroy ()" 4
296	.IX Item "ev_default_destroy ()"	452	.IX Item "ev_default_destroy ()"
297	Destroys the default loop again (frees all memory and kernel state	453	Destroys the default loop again (frees all memory and kernel state
298	etc.). This stops all registered event watchers (by not touching them in	454	etc.). This stops all registered event watchers (by not touching them in
299	any way whatsoever, although you cannot rely on this :).	455	any way whatsoever, although you cannot rely on this :).
…		…
306	This function reinitialises the kernel state for backends that have	462	This function reinitialises the kernel state for backends that have
307	one. Despite the name, you can call it anytime, but it makes most sense	463	one. Despite the name, you can call it anytime, but it makes most sense
308	after forking, in either the parent or child process (or both, but that	464	after forking, in either the parent or child process (or both, but that
309	again makes little sense).	465	again makes little sense).
310	.Sp	466	.Sp
311	You \fImust\fR call this function after forking if and only if you want to	467	You \fImust\fR call this function in the child process after forking if and
312	use the event library in both processes. If you just fork+exec, you don't	468	only if you want to use the event library in both processes. If you just
313	have to call it.	469	fork+exec, you don't have to call it.
314	.Sp	470	.Sp
315	The function itself is quite fast and it's usually not a problem to call	471	The function itself is quite fast and it's usually not a problem to call
316	it just in case after a fork. To make this easy, the function will fit in	472	it just in case after a fork. To make this easy, the function will fit in
317	quite nicely into a call to \f(CW\(C`pthread_atfork\(C'\fR:	473	quite nicely into a call to \f(CW\(C`pthread_atfork\(C'\fR:
318	.Sp	474	.Sp
319	.Vb 1	475	.Vb 1
320	\& pthread_atfork (0, 0, ev_default_fork);	476	\& pthread_atfork (0, 0, ev_default_fork);
321	.Ve	477	.Ve
		478	.Sp
		479	At the moment, \f(CW\(C`EVBACKEND_SELECT\(C'\fR and \f(CW\(C`EVBACKEND_POLL\(C'\fR are safe to use
		480	without calling this function, so if you force one of those backends you
		481	do not need to care.
322	.IP "ev_loop_fork (loop)" 4	482	.IP "ev_loop_fork (loop)" 4
323	.IX Item "ev_loop_fork (loop)"	483	.IX Item "ev_loop_fork (loop)"
324	Like \f(CW\(C`ev_default_fork\(C'\fR, but acts on an event loop created by	484	Like \f(CW\(C`ev_default_fork\(C'\fR, but acts on an event loop created by
325	\&\f(CW\(C`ev_loop_new\(C'\fR. Yes, you have to call this on every allocated event loop	485	\&\f(CW\(C`ev_loop_new\(C'\fR. Yes, you have to call this on every allocated event loop
326	after fork, and how you do this is entirely your own problem.	486	after fork, and how you do this is entirely your own problem.
327	.IP "unsigned int ev_method (loop)" 4	487	.IP "unsigned int ev_backend (loop)" 4
328	.IX Item "unsigned int ev_method (loop)"	488	.IX Item "unsigned int ev_backend (loop)"
329	Returns one of the \f(CW\(C`EVMETHOD_\*(C'\fR flags indicating the event backend in	489	Returns one of the \f(CW\(C`EVBACKEND_\*(C'\fR flags indicating the event backend in
330	use.	490	use.
331	.IP "ev_tstamp ev_now (loop)" 4	491	.IP "ev_tstamp ev_now (loop)" 4
332	.IX Item "ev_tstamp ev_now (loop)"	492	.IX Item "ev_tstamp ev_now (loop)"
333	Returns the current \(L"event loop time\(R", which is the time the event loop	493	Returns the current \(L"event loop time\(R", which is the time the event loop
334	got events and started processing them. This timestamp does not change	494	received events and started processing them. This timestamp does not
335	as long as callbacks are being processed, and this is also the base time	495	change as long as callbacks are being processed, and this is also the base
336	used for relative timers. You can treat it as the timestamp of the event	496	time used for relative timers. You can treat it as the timestamp of the
337	occuring (or more correctly, the mainloop finding out about it).	497	event occuring (or more correctly, libev finding out about it).
338	.IP "ev_loop (loop, int flags)" 4	498	.IP "ev_loop (loop, int flags)" 4
339	.IX Item "ev_loop (loop, int flags)"	499	.IX Item "ev_loop (loop, int flags)"
340	Finally, this is it, the event handler. This function usually is called	500	Finally, this is it, the event handler. This function usually is called
341	after you initialised all your watchers and you want to start handling	501	after you initialised all your watchers and you want to start handling
342	events.	502	events.
343	.Sp	503	.Sp
344	If the flags argument is specified as 0, it will not return until either	504	If the flags argument is specified as \f(CW0\fR, it will not return until
345	no event watchers are active anymore or \f(CW\(C`ev_unloop\(C'\fR was called.	505	either no event watchers are active anymore or \f(CW\(C`ev_unloop\(C'\fR was called.
		506	.Sp
		507	Please note that an explicit \f(CW\(C`ev_unloop\(C'\fR is usually better than
		508	relying on all watchers to be stopped when deciding when a program has
		509	finished (especially in interactive programs), but having a program that
		510	automatically loops as long as it has to and no longer by virtue of
		511	relying on its watchers stopping correctly is a thing of beauty.
346	.Sp	512	.Sp
347	A flags value of \f(CW\(C`EVLOOP_NONBLOCK\(C'\fR will look for new events, will handle	513	A flags value of \f(CW\(C`EVLOOP_NONBLOCK\(C'\fR will look for new events, will handle
348	those events and any outstanding ones, but will not block your process in	514	those events and any outstanding ones, but will not block your process in
349	case there are no events and will return after one iteration of the loop.	515	case there are no events and will return after one iteration of the loop.
350	.Sp	516	.Sp
351	A flags value of \f(CW\(C`EVLOOP_ONESHOT\(C'\fR will look for new events (waiting if	517	A flags value of \f(CW\(C`EVLOOP_ONESHOT\(C'\fR will look for new events (waiting if
352	neccessary) and will handle those and any outstanding ones. It will block	518	neccessary) and will handle those and any outstanding ones. It will block
353	your process until at least one new event arrives, and will return after	519	your process until at least one new event arrives, and will return after
354	one iteration of the loop.	520	one iteration of the loop. This is useful if you are waiting for some
		521	external event in conjunction with something not expressible using other
		522	libev watchers. However, a pair of \f(CW\(C`ev_prepare\(C'\fR/\f(CW\(C`ev_check\(C'\fR watchers is
		523	usually a better approach for this kind of thing.
355	.Sp	524	.Sp
356	This flags value could be used to implement alternative looping	525	Here are the gory details of what \f(CW\(C`ev_loop\(C'\fR does:
357	constructs, but the \f(CW\(C`prepare\(C'\fR and \f(CW\(C`check\(C'\fR watchers provide a better and	526	.Sp
358	more generic mechanism.	527	.Vb 18
		528	\& * If there are no active watchers (reference count is zero), return.
		529	\& - Queue prepare watchers and then call all outstanding watchers.
		530	\& - If we have been forked, recreate the kernel state.
		531	\& - Update the kernel state with all outstanding changes.
		532	\& - Update the "event loop time".
		533	\& - Calculate for how long to block.
		534	\& - Block the process, waiting for any events.
		535	\& - Queue all outstanding I/O (fd) events.
		536	\& - Update the "event loop time" and do time jump handling.
		537	\& - Queue all outstanding timers.
		538	\& - Queue all outstanding periodics.
		539	\& - If no events are pending now, queue all idle watchers.
		540	\& - Queue all check watchers.
		541	\& - Call all queued watchers in reverse order (i.e. check watchers first).
		542	\& Signals and child watchers are implemented as I/O watchers, and will
		543	\& be handled here by queueing them when their watcher gets executed.
		544	\& - If ev_unloop has been called or EVLOOP_ONESHOT or EVLOOP_NONBLOCK
		545	\& were used, return, otherwise continue with step *.
		546	.Ve
		547	.Sp
		548	Example: queue some jobs and then loop until no events are outsanding
		549	anymore.
		550	.Sp
		551	.Vb 4
		552	\& ... queue jobs here, make sure they register event watchers as long
		553	\& ... as they still have work to do (even an idle watcher will do..)
		554	\& ev_loop (my_loop, 0);
		555	\& ... jobs done. yeah!
		556	.Ve
359	.IP "ev_unloop (loop, how)" 4	557	.IP "ev_unloop (loop, how)" 4
360	.IX Item "ev_unloop (loop, how)"	558	.IX Item "ev_unloop (loop, how)"
361	Can be used to make a call to \f(CW\(C`ev_loop\(C'\fR return early (but only after it	559	Can be used to make a call to \f(CW\(C`ev_loop\(C'\fR return early (but only after it
362	has processed all outstanding events). The \f(CW\(C`how\(C'\fR argument must be either	560	has processed all outstanding events). The \f(CW\(C`how\(C'\fR argument must be either
363	\&\f(CW\(C`EVUNLOOP_ONE\(C'\fR, which will make the innermost \f(CW\(C`ev_loop\(C'\fR call return, or	561	\&\f(CW\(C`EVUNLOOP_ONE\(C'\fR, which will make the innermost \f(CW\(C`ev_loop\(C'\fR call return, or
…		…
376	example, libev itself uses this for its internal signal pipe: It is not	574	example, libev itself uses this for its internal signal pipe: It is not
377	visible to the libev user and should not keep \f(CW\(C`ev_loop\(C'\fR from exiting if	575	visible to the libev user and should not keep \f(CW\(C`ev_loop\(C'\fR from exiting if
378	no event watchers registered by it are active. It is also an excellent	576	no event watchers registered by it are active. It is also an excellent
379	way to do this for generic recurring timers or from within third-party	577	way to do this for generic recurring timers or from within third-party
380	libraries. Just remember to \fIunref after start\fR and \fIref before stop\fR.	578	libraries. Just remember to \fIunref after start\fR and \fIref before stop\fR.
		579	.Sp
		580	Example: create a signal watcher, but keep it from keeping \f(CW\(C`ev_loop\(C'\fR
		581	running when nothing else is active.
		582	.Sp
		583	.Vb 4
		584	\& struct dv_signal exitsig;
		585	\& ev_signal_init (&exitsig, sig_cb, SIGINT);
		586	\& ev_signal_start (myloop, &exitsig);
		587	\& evf_unref (myloop);
		588	.Ve
		589	.Sp
		590	Example: for some weird reason, unregister the above signal handler again.
		591	.Sp
		592	.Vb 2
		593	\& ev_ref (myloop);
		594	\& ev_signal_stop (myloop, &exitsig);
		595	.Ve
381	.SH "ANATOMY OF A WATCHER"	596	.SH "ANATOMY OF A WATCHER"
382	.IX Header "ANATOMY OF A WATCHER"	597	.IX Header "ANATOMY OF A WATCHER"
383	A watcher is a structure that you create and register to record your	598	A watcher is a structure that you create and register to record your
384	interest in some event. For instance, if you want to wait for \s-1STDIN\s0 to	599	interest in some event. For instance, if you want to wait for \s-1STDIN\s0 to
385	become readable, you would create an \f(CW\(C`ev_io\(C'\fR watcher for that:	600	become readable, you would create an \f(CW\(C`ev_io\(C'\fR watcher for that:
…		…
421	)\(C'\fR), and you can stop watching for events at any time by calling the	636	)\(C'\fR), and you can stop watching for events at any time by calling the
422	corresponding stop function (\f(CW\(C`ev_<type>_stop (loop, watcher )\*(C'\fR.	637	corresponding stop function (\f(CW\(C`ev_<type>_stop (loop, watcher )\*(C'\fR.
423	.PP	638	.PP
424	As long as your watcher is active (has been started but not stopped) you	639	As long as your watcher is active (has been started but not stopped) you
425	must not touch the values stored in it. Most specifically you must never	640	must not touch the values stored in it. Most specifically you must never
426	reinitialise it or call its set method.	641	reinitialise it or call its set macro.
427	.PP	642	.PP
428	You can check whether an event is active by calling the \f(CW\*(C`ev_is_active	643	You can check whether an event is active by calling the \f(CW\*(C`ev_is_active
429	(watcher )\(C'\fR macro. To see whether an event is outstanding (but the	644	(watcher )\(C'\fR macro. To see whether an event is outstanding (but the
430	callback for it has not been called yet) you can use the \f(CW\*(C`ev_is_pending	645	callback for it has not been called yet) you can use the \f(CW\*(C`ev_is_pending
431	(watcher )\(C'\fR macro.	646	(watcher )\(C'\fR macro.
…		…
551	descriptors correctly if you register interest in two or more fds pointing	766	descriptors correctly if you register interest in two or more fds pointing
552	to the same underlying file/socket etc. description (that is, they share	767	to the same underlying file/socket etc. description (that is, they share
553	the same underlying \(L"file open\(R").	768	the same underlying \(L"file open\(R").
554	.PP	769	.PP
555	If you must do this, then force the use of a known-to-be-good backend	770	If you must do this, then force the use of a known-to-be-good backend
556	(at the time of this writing, this includes only \s-1EVMETHOD_SELECT\s0 and	771	(at the time of this writing, this includes only \f(CW\(C`EVBACKEND_SELECT\(C'\fR and
557	\&\s-1EVMETHOD_POLL\s0).	772	\&\f(CW\(C`EVBACKEND_POLL\(C'\fR).
558	.IP "ev_io_init (ev_io *, callback, int fd, int events)" 4	773	.IP "ev_io_init (ev_io *, callback, int fd, int events)" 4
559	.IX Item "ev_io_init (ev_io *, callback, int fd, int events)"	774	.IX Item "ev_io_init (ev_io *, callback, int fd, int events)"
560	.PD 0	775	.PD 0
561	.IP "ev_io_set (ev_io *, int fd, int events)" 4	776	.IP "ev_io_set (ev_io *, int fd, int events)" 4
562	.IX Item "ev_io_set (ev_io *, int fd, int events)"	777	.IX Item "ev_io_set (ev_io *, int fd, int events)"
563	.PD	778	.PD
564	Configures an \f(CW\(C`ev_io\(C'\fR watcher. The fd is the file descriptor to rceeive	779	Configures an \f(CW\(C`ev_io\(C'\fR watcher. The fd is the file descriptor to rceeive
565	events for and events is either \f(CW\(C`EV_READ\(C'\fR, \f(CW\(C`EV_WRITE\(C'\fR or \f(CW\*(C`EV_READ \|	780	events for and events is either \f(CW\(C`EV_READ\(C'\fR, \f(CW\(C`EV_WRITE\(C'\fR or \f(CW\*(C`EV_READ \|
566	EV_WRITE\*(C'\fR to receive the given events.	781	EV_WRITE\*(C'\fR to receive the given events.
		782	.Sp
		783	Please note that most of the more scalable backend mechanisms (for example
		784	epoll and solaris ports) can result in spurious readyness notifications
		785	for file descriptors, so you practically need to use non-blocking I/O (and
		786	treat callback invocation as hint only), or retest separately with a safe
		787	interface before doing I/O (XLib can do this), or force the use of either
		788	\&\f(CW\(C`EVBACKEND_SELECT\(C'\fR or \f(CW\(C`EVBACKEND_POLL\(C'\fR, which don't suffer from this
		789	problem. Also note that it is quite easy to have your callback invoked
		790	when the readyness condition is no longer valid even when employing
		791	typical ways of handling events, so its a good idea to use non-blocking
		792	I/O unconditionally.
		793	.PP
		794	Example: call \f(CW\(C`stdin_readable_cb\(C'\fR when \s-1STDIN_FILENO\s0 has become, well
		795	readable, but only once. Since it is likely line\-buffered, you could
		796	attempt to read a whole line in the callback:
		797	.PP
		798	.Vb 6
		799	\& static void
		800	\& stdin_readable_cb (struct ev_loop loop, struct ev_io w, int revents)
		801	\& {
		802	\& ev_io_stop (loop, w);
		803	\& .. read from stdin here (or from w->fd) and haqndle any I/O errors
		804	\& }
		805	.Ve
		806	.PP
		807	.Vb 6
		808	\& ...
		809	\& struct ev_loop *loop = ev_default_init (0);
		810	\& struct ev_io stdin_readable;
		811	\& ev_io_init (&stdin_readable, stdin_readable_cb, STDIN_FILENO, EV_READ);
		812	\& ev_io_start (loop, &stdin_readable);
		813	\& ev_loop (loop, 0);
		814	.Ve
567	.ie n .Sh """ev_timer"" \- relative and optionally recurring timeouts"	815	.ie n .Sh """ev_timer"" \- relative and optionally recurring timeouts"
568	.el .Sh "\f(CWev_timer\fP \- relative and optionally recurring timeouts"	816	.el .Sh "\f(CWev_timer\fP \- relative and optionally recurring timeouts"
569	.IX Subsection "ev_timer - relative and optionally recurring timeouts"	817	.IX Subsection "ev_timer - relative and optionally recurring timeouts"
570	Timer watchers are simple relative timers that generate an event after a	818	Timer watchers are simple relative timers that generate an event after a
571	given time, and optionally repeating in regular intervals after that.	819	given time, and optionally repeating in regular intervals after that.
572	.PP	820	.PP
573	The timers are based on real time, that is, if you register an event that	821	The timers are based on real time, that is, if you register an event that
574	times out after an hour and you reset your system clock to last years	822	times out after an hour and you reset your system clock to last years
575	time, it will still time out after (roughly) and hour. \(L"Roughly\(R" because	823	time, it will still time out after (roughly) and hour. \(L"Roughly\(R" because
576	detecting time jumps is hard, and soem inaccuracies are unavoidable (the	824	detecting time jumps is hard, and some inaccuracies are unavoidable (the
577	monotonic clock option helps a lot here).	825	monotonic clock option helps a lot here).
578	.PP	826	.PP
579	The relative timeouts are calculated relative to the \f(CW\(C`ev_now ()\(C'\fR	827	The relative timeouts are calculated relative to the \f(CW\(C`ev_now ()\(C'\fR
580	time. This is usually the right thing as this timestamp refers to the time	828	time. This is usually the right thing as this timestamp refers to the time
581	of the event triggering whatever timeout you are modifying/starting. If	829	of the event triggering whatever timeout you are modifying/starting. If
582	you suspect event processing to be delayed and you need to base the timeout	830	you suspect event processing to be delayed and you \fIneed\fR to base the timeout
583	on the current time, use something like this to adjust for this:	831	on the current time, use something like this to adjust for this:
584	.PP	832	.PP
585	.Vb 1	833	.Vb 1
586	\& ev_timer_set (&timer, after + ev_now () - ev_time (), 0.);	834	\& ev_timer_set (&timer, after + ev_now () - ev_time (), 0.);
587	.Ve	835	.Ve
		836	.PP
		837	The callback is guarenteed to be invoked only when its timeout has passed,
		838	but if multiple timers become ready during the same loop iteration then
		839	order of execution is undefined.
588	.IP "ev_timer_init (ev_timer *, callback, ev_tstamp after, ev_tstamp repeat)" 4	840	.IP "ev_timer_init (ev_timer *, callback, ev_tstamp after, ev_tstamp repeat)" 4
589	.IX Item "ev_timer_init (ev_timer *, callback, ev_tstamp after, ev_tstamp repeat)"	841	.IX Item "ev_timer_init (ev_timer *, callback, ev_tstamp after, ev_tstamp repeat)"
590	.PD 0	842	.PD 0
591	.IP "ev_timer_set (ev_timer *, ev_tstamp after, ev_tstamp repeat)" 4	843	.IP "ev_timer_set (ev_timer *, ev_tstamp after, ev_tstamp repeat)" 4
592	.IX Item "ev_timer_set (ev_timer *, ev_tstamp after, ev_tstamp repeat)"	844	.IX Item "ev_timer_set (ev_timer *, ev_tstamp after, ev_tstamp repeat)"
…		…
617	seconds of inactivity on the socket. The easiest way to do this is to	869	seconds of inactivity on the socket. The easiest way to do this is to
618	configure an \f(CW\(C`ev_timer\(C'\fR with after=repeat=60 and calling ev_timer_again each	870	configure an \f(CW\(C`ev_timer\(C'\fR with after=repeat=60 and calling ev_timer_again each
619	time you successfully read or write some data. If you go into an idle	871	time you successfully read or write some data. If you go into an idle
620	state where you do not expect data to travel on the socket, you can stop	872	state where you do not expect data to travel on the socket, you can stop
621	the timer, and again will automatically restart it if need be.	873	the timer, and again will automatically restart it if need be.
		874	.PP
		875	Example: create a timer that fires after 60 seconds.
		876	.PP
		877	.Vb 5
		878	\& static void
		879	\& one_minute_cb (struct ev_loop loop, struct ev_timer w, int revents)
		880	\& {
		881	\& .. one minute over, w is actually stopped right here
		882	\& }
		883	.Ve
		884	.PP
		885	.Vb 3
		886	\& struct ev_timer mytimer;
		887	\& ev_timer_init (&mytimer, one_minute_cb, 60., 0.);
		888	\& ev_timer_start (loop, &mytimer);
		889	.Ve
		890	.PP
		891	Example: create a timeout timer that times out after 10 seconds of
		892	inactivity.
		893	.PP
		894	.Vb 5
		895	\& static void
		896	\& timeout_cb (struct ev_loop loop, struct ev_timer w, int revents)
		897	\& {
		898	\& .. ten seconds without any activity
		899	\& }
		900	.Ve
		901	.PP
		902	.Vb 4
		903	\& struct ev_timer mytimer;
		904	\& ev_timer_init (&mytimer, timeout_cb, 0., 10.); /* note, only repeat used */
		905	\& ev_timer_again (&mytimer); /* start timer */
		906	\& ev_loop (loop, 0);
		907	.Ve
		908	.PP
		909	.Vb 3
		910	\& // and in some piece of code that gets executed on any "activity":
		911	\& // reset the timeout to start ticking again at 10 seconds
		912	\& ev_timer_again (&mytimer);
		913	.Ve
622	.ie n .Sh """ev_periodic"" \- to cron or not to cron"	914	.ie n .Sh """ev_periodic"" \- to cron or not to cron"
623	.el .Sh "\f(CWev_periodic\fP \- to cron or not to cron"	915	.el .Sh "\f(CWev_periodic\fP \- to cron or not to cron"
624	.IX Subsection "ev_periodic - to cron or not to cron"	916	.IX Subsection "ev_periodic - to cron or not to cron"
625	Periodic watchers are also timers of a kind, but they are very versatile	917	Periodic watchers are also timers of a kind, but they are very versatile
626	(and unfortunately a bit complex).	918	(and unfortunately a bit complex).
…		…
634	roughly 10 seconds later and of course not if you reset your system time	926	roughly 10 seconds later and of course not if you reset your system time
635	again).	927	again).
636	.PP	928	.PP
637	They can also be used to implement vastly more complex timers, such as	929	They can also be used to implement vastly more complex timers, such as
638	triggering an event on eahc midnight, local time.	930	triggering an event on eahc midnight, local time.
		931	.PP
		932	As with timers, the callback is guarenteed to be invoked only when the
		933	time (\f(CW\(C`at\(C'\fR) has been passed, but if multiple periodic timers become ready
		934	during the same loop iteration then order of execution is undefined.
639	.IP "ev_periodic_init (ev_periodic *, callback, ev_tstamp at, ev_tstamp interval, reschedule_cb)" 4	935	.IP "ev_periodic_init (ev_periodic *, callback, ev_tstamp at, ev_tstamp interval, reschedule_cb)" 4
640	.IX Item "ev_periodic_init (ev_periodic *, callback, ev_tstamp at, ev_tstamp interval, reschedule_cb)"	936	.IX Item "ev_periodic_init (ev_periodic *, callback, ev_tstamp at, ev_tstamp interval, reschedule_cb)"
641	.PD 0	937	.PD 0
642	.IP "ev_periodic_set (ev_periodic *, ev_tstamp after, ev_tstamp repeat, reschedule_cb)" 4	938	.IP "ev_periodic_set (ev_periodic *, ev_tstamp after, ev_tstamp repeat, reschedule_cb)" 4
643	.IX Item "ev_periodic_set (ev_periodic *, ev_tstamp after, ev_tstamp repeat, reschedule_cb)"	939	.IX Item "ev_periodic_set (ev_periodic *, ev_tstamp after, ev_tstamp repeat, reschedule_cb)"
…		…
714	.IX Item "ev_periodic_again (loop, ev_periodic *)"	1010	.IX Item "ev_periodic_again (loop, ev_periodic *)"
715	Simply stops and restarts the periodic watcher again. This is only useful	1011	Simply stops and restarts the periodic watcher again. This is only useful
716	when you changed some parameters or the reschedule callback would return	1012	when you changed some parameters or the reschedule callback would return
717	a different time than the last time it was called (e.g. in a crond like	1013	a different time than the last time it was called (e.g. in a crond like
718	program when the crontabs have changed).	1014	program when the crontabs have changed).
		1015	.PP
		1016	Example: call a callback every hour, or, more precisely, whenever the
		1017	system clock is divisible by 3600. The callback invocation times have
		1018	potentially a lot of jittering, but good long-term stability.
		1019	.PP
		1020	.Vb 5
		1021	\& static void
		1022	\& clock_cb (struct ev_loop loop, struct ev_io w, int revents)
		1023	\& {
		1024	\& ... its now a full hour (UTC, or TAI or whatever your clock follows)
		1025	\& }
		1026	.Ve
		1027	.PP
		1028	.Vb 3
		1029	\& struct ev_periodic hourly_tick;
		1030	\& ev_periodic_init (&hourly_tick, clock_cb, 0., 3600., 0);
		1031	\& ev_periodic_start (loop, &hourly_tick);
		1032	.Ve
		1033	.PP
		1034	Example: the same as above, but use a reschedule callback to do it:
		1035	.PP
		1036	.Vb 1
		1037	\& #include <math.h>
		1038	.Ve
		1039	.PP
		1040	.Vb 5
		1041	\& static ev_tstamp
		1042	\& my_scheduler_cb (struct ev_periodic *w, ev_tstamp now)
		1043	\& {
		1044	\& return fmod (now, 3600.) + 3600.;
		1045	\& }
		1046	.Ve
		1047	.PP
		1048	.Vb 1
		1049	\& ev_periodic_init (&hourly_tick, clock_cb, 0., 0., my_scheduler_cb);
		1050	.Ve
		1051	.PP
		1052	Example: call a callback every hour, starting now:
		1053	.PP
		1054	.Vb 4
		1055	\& struct ev_periodic hourly_tick;
		1056	\& ev_periodic_init (&hourly_tick, clock_cb,
		1057	\& fmod (ev_now (loop), 3600.), 3600., 0);
		1058	\& ev_periodic_start (loop, &hourly_tick);
		1059	.Ve
719	.ie n .Sh """ev_signal"" \- signal me when a signal gets signalled"	1060	.ie n .Sh """ev_signal"" \- signal me when a signal gets signalled"
720	.el .Sh "\f(CWev_signal\fP \- signal me when a signal gets signalled"	1061	.el .Sh "\f(CWev_signal\fP \- signal me when a signal gets signalled"
721	.IX Subsection "ev_signal - signal me when a signal gets signalled"	1062	.IX Subsection "ev_signal - signal me when a signal gets signalled"
722	Signal watchers will trigger an event when the process receives a specific	1063	Signal watchers will trigger an event when the process receives a specific
723	signal one or more times. Even though signals are very asynchronous, libev	1064	signal one or more times. Even though signals are very asynchronous, libev
…		…
753	\&\fIany\fR process if \f(CW\(C`pid\(C'\fR is specified as \f(CW0\fR). The callback can look	1094	\&\fIany\fR process if \f(CW\(C`pid\(C'\fR is specified as \f(CW0\fR). The callback can look
754	at the \f(CW\(C`rstatus\(C'\fR member of the \f(CW\(C`ev_child\(C'\fR watcher structure to see	1095	at the \f(CW\(C`rstatus\(C'\fR member of the \f(CW\(C`ev_child\(C'\fR watcher structure to see
755	the status word (use the macros from \f(CW\(C`sys/wait.h\(C'\fR and see your systems	1096	the status word (use the macros from \f(CW\(C`sys/wait.h\(C'\fR and see your systems
756	\&\f(CW\(C`waitpid\(C'\fR documentation). The \f(CW\(C`rpid\(C'\fR member contains the pid of the	1097	\&\f(CW\(C`waitpid\(C'\fR documentation). The \f(CW\(C`rpid\(C'\fR member contains the pid of the
757	process causing the status change.	1098	process causing the status change.
		1099	.PP
		1100	Example: try to exit cleanly on \s-1SIGINT\s0 and \s-1SIGTERM\s0.
		1101	.PP
		1102	.Vb 5
		1103	\& static void
		1104	\& sigint_cb (struct ev_loop loop, struct ev_signal w, int revents)
		1105	\& {
		1106	\& ev_unloop (loop, EVUNLOOP_ALL);
		1107	\& }
		1108	.Ve
		1109	.PP
		1110	.Vb 3
		1111	\& struct ev_signal signal_watcher;
		1112	\& ev_signal_init (&signal_watcher, sigint_cb, SIGINT);
		1113	\& ev_signal_start (loop, &sigint_cb);
		1114	.Ve
758	.ie n .Sh """ev_idle"" \- when you've got nothing better to do"	1115	.ie n .Sh """ev_idle"" \- when you've got nothing better to do"
759	.el .Sh "\f(CWev_idle\fP \- when you've got nothing better to do"	1116	.el .Sh "\f(CWev_idle\fP \- when you've got nothing better to do"
760	.IX Subsection "ev_idle - when you've got nothing better to do"	1117	.IX Subsection "ev_idle - when you've got nothing better to do"
761	Idle watchers trigger events when there are no other events are pending	1118	Idle watchers trigger events when there are no other events are pending
762	(prepare, check and other idle watchers do not count). That is, as long	1119	(prepare, check and other idle watchers do not count). That is, as long
…		…
776	.IP "ev_idle_init (ev_signal *, callback)" 4	1133	.IP "ev_idle_init (ev_signal *, callback)" 4
777	.IX Item "ev_idle_init (ev_signal *, callback)"	1134	.IX Item "ev_idle_init (ev_signal *, callback)"
778	Initialises and configures the idle watcher \- it has no parameters of any	1135	Initialises and configures the idle watcher \- it has no parameters of any
779	kind. There is a \f(CW\(C`ev_idle_set\(C'\fR macro, but using it is utterly pointless,	1136	kind. There is a \f(CW\(C`ev_idle_set\(C'\fR macro, but using it is utterly pointless,
780	believe me.	1137	believe me.
		1138	.PP
		1139	Example: dynamically allocate an \f(CW\(C`ev_idle\(C'\fR, start it, and in the
		1140	callback, free it. Alos, use no error checking, as usual.
		1141	.PP
		1142	.Vb 7
		1143	\& static void
		1144	\& idle_cb (struct ev_loop loop, struct ev_idle w, int revents)
		1145	\& {
		1146	\& free (w);
		1147	\& // now do something you wanted to do when the program has
		1148	\& // no longer asnything immediate to do.
		1149	\& }
		1150	.Ve
		1151	.PP
		1152	.Vb 3
		1153	\& struct ev_idle *idle_watcher = malloc (sizeof (struct ev_idle));
		1154	\& ev_idle_init (idle_watcher, idle_cb);
		1155	\& ev_idle_start (loop, idle_cb);
		1156	.Ve
781	.ie n .Sh """ev_prepare""\fP and \f(CW""ev_check"" \- customise your event loop"	1157	.ie n .Sh """ev_prepare""\fP and \f(CW""ev_check"" \- customise your event loop"
782	.el .Sh "\f(CWev_prepare\fP and \f(CWev_check\fP \- customise your event loop"	1158	.el .Sh "\f(CWev_prepare\fP and \f(CWev_check\fP \- customise your event loop"
783	.IX Subsection "ev_prepare and ev_check - customise your event loop"	1159	.IX Subsection "ev_prepare and ev_check - customise your event loop"
784	Prepare and check watchers are usually (but not always) used in tandem:	1160	Prepare and check watchers are usually (but not always) used in tandem:
785	prepare watchers get invoked before the process blocks and check watchers	1161	prepare watchers get invoked before the process blocks and check watchers
…		…
813	.IX Item "ev_check_init (ev_check *, callback)"	1189	.IX Item "ev_check_init (ev_check *, callback)"
814	.PD	1190	.PD
815	Initialises and configures the prepare or check watcher \- they have no	1191	Initialises and configures the prepare or check watcher \- they have no
816	parameters of any kind. There are \f(CW\(C`ev_prepare_set\(C'\fR and \f(CW\(C`ev_check_set\(C'\fR	1192	parameters of any kind. There are \f(CW\(C`ev_prepare_set\(C'\fR and \f(CW\(C`ev_check_set\(C'\fR
817	macros, but using them is utterly, utterly and completely pointless.	1193	macros, but using them is utterly, utterly and completely pointless.
		1194	.PP
		1195	Example: TODO.
818	.SH "OTHER FUNCTIONS"	1196	.SH "OTHER FUNCTIONS"
819	.IX Header "OTHER FUNCTIONS"	1197	.IX Header "OTHER FUNCTIONS"
820	There are some other functions of possible interest. Described. Here. Now.	1198	There are some other functions of possible interest. Described. Here. Now.
821	.IP "ev_once (loop, int fd, int events, ev_tstamp timeout, callback)" 4	1199	.IP "ev_once (loop, int fd, int events, ev_tstamp timeout, callback)" 4
822	.IX Item "ev_once (loop, int fd, int events, ev_tstamp timeout, callback)"	1200	.IX Item "ev_once (loop, int fd, int events, ev_tstamp timeout, callback)"

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Comparing libev/ev.3 (file contents): Revision 1.1 by root, Tue Nov 13 03:11:57 2007 UTC vs. Revision 1.9 by root, Fri Nov 23 16:17:12 2007 UTC

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Comparing libev/ev.3 (file contents):
Revision 1.1 by root, Tue Nov 13 03:11:57 2007 UTC vs.
Revision 1.9 by root, Fri Nov 23 16:17:12 2007 UTC