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

Comparing libev/ev.pod (file contents):
Revision 1.305 by root, Thu Oct 14 05:07:04 2010 UTC vs.
Revision 1.321 by sf-exg, Fri Oct 22 10:50:24 2010 UTC

…		…
26	puts ("stdin ready");	26	puts ("stdin ready");
27	// for one-shot events, one must manually stop the watcher	27	// for one-shot events, one must manually stop the watcher
28	// with its corresponding stop function.	28	// with its corresponding stop function.
29	ev_io_stop (EV_A_ w);	29	ev_io_stop (EV_A_ w);
30		30
31	// this causes all nested ev_loop's to stop iterating	31	// this causes all nested ev_run's to stop iterating
32	ev_unloop (EV_A_ EVUNLOOP_ALL);	32	ev_break (EV_A_ EVBREAK_ALL);
33	}	33	}
34		34
35	// another callback, this time for a time-out	35	// another callback, this time for a time-out
36	static void	36	static void
37	timeout_cb (EV_P_ ev_timer *w, int revents)	37	timeout_cb (EV_P_ ev_timer *w, int revents)
38	{	38	{
39	puts ("timeout");	39	puts ("timeout");
40	// this causes the innermost ev_loop to stop iterating	40	// this causes the innermost ev_run to stop iterating
41	ev_unloop (EV_A_ EVUNLOOP_ONE);	41	ev_break (EV_A_ EVBREAK_ONE);
42	}	42	}
43		43
44	int	44	int
45	main (void)	45	main (void)
46	{	46	{
…		…
56	// simple non-repeating 5.5 second timeout	56	// simple non-repeating 5.5 second timeout
57	ev_timer_init (&timeout_watcher, timeout_cb, 5.5, 0.);	57	ev_timer_init (&timeout_watcher, timeout_cb, 5.5, 0.);
58	ev_timer_start (loop, &timeout_watcher);	58	ev_timer_start (loop, &timeout_watcher);
59		59
60	// now wait for events to arrive	60	// now wait for events to arrive
61	ev_loop (loop, 0);	61	ev_run (loop, 0);
62		62
63	// unloop was called, so exit	63	// unloop was called, so exit
64	return 0;	64	return 0;
65	}	65	}
66		66
…		…
124	this argument.	124	this argument.
125		125
126	=head2 TIME REPRESENTATION	126	=head2 TIME REPRESENTATION
127		127
128	Libev represents time as a single floating point number, representing	128	Libev represents time as a single floating point number, representing
129	the (fractional) number of seconds since the (POSIX) epoch (in practise	129	the (fractional) number of seconds since the (POSIX) epoch (in practice
130	somewhere near the beginning of 1970, details are complicated, don't	130	somewhere near the beginning of 1970, details are complicated, don't
131	ask). This type is called C<ev_tstamp>, which is what you should use	131	ask). This type is called C<ev_tstamp>, which is what you should use
132	too. It usually aliases to the C<double> type in C. When you need to do	132	too. It usually aliases to the C<double> type in C. When you need to do
133	any calculations on it, you should treat it as some floating point value.	133	any calculations on it, you should treat it as some floating point value.
134		134
…		…
165		165
166	=item ev_tstamp ev_time ()	166	=item ev_tstamp ev_time ()
167		167
168	Returns the current time as libev would use it. Please note that the	168	Returns the current time as libev would use it. Please note that the
169	C<ev_now> function is usually faster and also often returns the timestamp	169	C<ev_now> function is usually faster and also often returns the timestamp
170	you actually want to know.	170	you actually want to know. Also interesting is the combination of
		171	C<ev_update_now> and C<ev_now>.
171		172
172	=item ev_sleep (ev_tstamp interval)	173	=item ev_sleep (ev_tstamp interval)
173		174
174	Sleep for the given interval: The current thread will be blocked until	175	Sleep for the given interval: The current thread will be blocked until
175	either it is interrupted or the given time interval has passed. Basically	176	either it is interrupted or the given time interval has passed. Basically
…		…
192	as this indicates an incompatible change. Minor versions are usually	193	as this indicates an incompatible change. Minor versions are usually
193	compatible to older versions, so a larger minor version alone is usually	194	compatible to older versions, so a larger minor version alone is usually
194	not a problem.	195	not a problem.
195		196
196	Example: Make sure we haven't accidentally been linked against the wrong	197	Example: Make sure we haven't accidentally been linked against the wrong
197	version (note, however, that this will not detect ABI mismatches :).	198	version (note, however, that this will not detect other ABI mismatches,
		199	such as LFS or reentrancy).
198		200
199	assert (("libev version mismatch",	201	assert (("libev version mismatch",
200	ev_version_major () == EV_VERSION_MAJOR	202	ev_version_major () == EV_VERSION_MAJOR
201	&& ev_version_minor () >= EV_VERSION_MINOR));	203	&& ev_version_minor () >= EV_VERSION_MINOR));
202		204
…		…
213	assert (("sorry, no epoll, no sex",	215	assert (("sorry, no epoll, no sex",
214	ev_supported_backends () & EVBACKEND_EPOLL));	216	ev_supported_backends () & EVBACKEND_EPOLL));
215		217
216	=item unsigned int ev_recommended_backends ()	218	=item unsigned int ev_recommended_backends ()
217		219
218	Return the set of all backends compiled into this binary of libev and also	220	Return the set of all backends compiled into this binary of libev and
219	recommended for this platform. This set is often smaller than the one	221	also recommended for this platform, meaning it will work for most file
		222	descriptor types. This set is often smaller than the one returned by
220	returned by C<ev_supported_backends>, as for example kqueue is broken on	223	C<ev_supported_backends>, as for example kqueue is broken on most BSDs
221	most BSDs and will not be auto-detected unless you explicitly request it	224	and will not be auto-detected unless you explicitly request it (assuming
222	(assuming you know what you are doing). This is the set of backends that	225	you know what you are doing). This is the set of backends that libev will
223	libev will probe for if you specify no backends explicitly.	226	probe for if you specify no backends explicitly.
224		227
225	=item unsigned int ev_embeddable_backends ()	228	=item unsigned int ev_embeddable_backends ()
226		229
227	Returns the set of backends that are embeddable in other event loops. This	230	Returns the set of backends that are embeddable in other event loops. This
228	is the theoretical, all-platform, value. To find which backends	231	value is platform-specific but can include backends not available on the
229	might be supported on the current system, you would need to look at	232	current system. To find which embeddable backends might be supported on
230	C<ev_embeddable_backends () & ev_supported_backends ()>, likewise for	233	the current system, you would need to look at C<ev_embeddable_backends ()
231	recommended ones.	234	& ev_supported_backends ()>, likewise for recommended ones.
232		235
233	See the description of C<ev_embed> watchers for more info.	236	See the description of C<ev_embed> watchers for more info.
234		237
235	=item ev_set_allocator (void (cb)(void *ptr, long size)) [NOT REENTRANT]	238	=item ev_set_allocator (void (cb)(void *ptr, long size)) [NOT REENTRANT]
236		239
…		…
292		295
293	=back	296	=back
294		297
295	=head1 FUNCTIONS CONTROLLING THE EVENT LOOP	298	=head1 FUNCTIONS CONTROLLING THE EVENT LOOP
296		299
297	An event loop is described by a C<struct ev_loop *> (the C<struct>	300	An event loop is described by a C<struct ev_loop *> (the C<struct> is
298	is I<not> optional in this case, as there is also an C<ev_loop>	301	I<not> optional in this case unless libev 3 compatibility is disabled, as
299	I<function>).	302	libev 3 had an C<ev_loop> function colliding with the struct name).
300		303
301	The library knows two types of such loops, the I<default> loop, which	304	The library knows two types of such loops, the I<default> loop, which
302	supports signals and child events, and dynamically created loops which do	305	supports signals and child events, and dynamically created event loops
303	not.	306	which do not.
304		307
305	=over 4	308	=over 4
306		309
307	=item struct ev_loop *ev_default_loop (unsigned int flags)	310	=item struct ev_loop *ev_default_loop (unsigned int flags)
308		311
…		…
439	of course I<doesn't>, and epoll just loves to report events for totally	442	of course I<doesn't>, and epoll just loves to report events for totally
440	I<different> file descriptors (even already closed ones, so one cannot	443	I<different> file descriptors (even already closed ones, so one cannot
441	even remove them from the set) than registered in the set (especially	444	even remove them from the set) than registered in the set (especially
442	on SMP systems). Libev tries to counter these spurious notifications by	445	on SMP systems). Libev tries to counter these spurious notifications by
443	employing an additional generation counter and comparing that against the	446	employing an additional generation counter and comparing that against the
444	events to filter out spurious ones, recreating the set when required.	447	events to filter out spurious ones, recreating the set when required. Last
		448	not least, it also refuses to work with some file descriptors which work
		449	perfectly fine with C<select> (files, many character devices...).
445		450
446	While stopping, setting and starting an I/O watcher in the same iteration	451	While stopping, setting and starting an I/O watcher in the same iteration
447	will result in some caching, there is still a system call per such	452	will result in some caching, there is still a system call per such
448	incident (because the same I<file descriptor> could point to a different	453	incident (because the same I<file descriptor> could point to a different
449	I<file description> now), so its best to avoid that. Also, C<dup ()>'ed	454	I<file description> now), so its best to avoid that. Also, C<dup ()>'ed
…		…
604	Like C<ev_default_destroy>, but destroys an event loop created by an	609	Like C<ev_default_destroy>, but destroys an event loop created by an
605	earlier call to C<ev_loop_new>.	610	earlier call to C<ev_loop_new>.
606		611
607	=item ev_default_fork ()	612	=item ev_default_fork ()
608		613
609	This function sets a flag that causes subsequent C<ev_loop> iterations	614	This function sets a flag that causes subsequent C<ev_run> iterations
610	to reinitialise the kernel state for backends that have one. Despite the	615	to reinitialise the kernel state for backends that have one. Despite the
611	name, you can call it anytime, but it makes most sense after forking, in	616	name, you can call it anytime, but it makes most sense after forking, in
612	the child process (or both child and parent, but that again makes little	617	the child process (or both child and parent, but that again makes little
613	sense). You I<must> call it in the child before using any of the libev	618	sense). You I<must> call it in the child before using any of the libev
614	functions, and it will only take effect at the next C<ev_loop> iteration.	619	functions, and it will only take effect at the next C<ev_run> iteration.
615		620
616	Again, you I<have> to call it on I<any> loop that you want to re-use after	621	Again, you I<have> to call it on I<any> loop that you want to re-use after
617	a fork, I<even if you do not plan to use the loop in the parent>. This is	622	a fork, I<even if you do not plan to use the loop in the parent>. This is
618	because some kernel interfaces cough I<kqueue> cough do funny things	623	because some kernel interfaces cough I<kqueue> cough do funny things
619	during fork.	624	during fork.
620		625
621	On the other hand, you only need to call this function in the child	626	On the other hand, you only need to call this function in the child
622	process if and only if you want to use the event loop in the child. If you	627	process if and only if you want to use the event loop in the child. If
623	just fork+exec or create a new loop in the child, you don't have to call	628	you just fork+exec or create a new loop in the child, you don't have to
624	it at all.	629	call it at all (in fact, C<epoll> is so badly broken that it makes a
		630	difference, but libev will usually detect this case on its own and do a
		631	costly reset of the backend).
625		632
626	The function itself is quite fast and it's usually not a problem to call	633	The function itself is quite fast and it's usually not a problem to call
627	it just in case after a fork. To make this easy, the function will fit in	634	it just in case after a fork. To make this easy, the function will fit in
628	quite nicely into a call to C<pthread_atfork>:	635	quite nicely into a call to C<pthread_atfork>:
629		636
…		…
641	Returns true when the given loop is, in fact, the default loop, and false	648	Returns true when the given loop is, in fact, the default loop, and false
642	otherwise.	649	otherwise.
643		650
644	=item unsigned int ev_iteration (loop)	651	=item unsigned int ev_iteration (loop)
645		652
646	Returns the current iteration count for the loop, which is identical to	653	Returns the current iteration count for the event loop, which is identical
647	the number of times libev did poll for new events. It starts at C<0> and	654	to the number of times libev did poll for new events. It starts at C<0>
648	happily wraps around with enough iterations.	655	and happily wraps around with enough iterations.
649		656
650	This value can sometimes be useful as a generation counter of sorts (it	657	This value can sometimes be useful as a generation counter of sorts (it
651	"ticks" the number of loop iterations), as it roughly corresponds with	658	"ticks" the number of loop iterations), as it roughly corresponds with
652	C<ev_prepare> and C<ev_check> calls - and is incremented between the	659	C<ev_prepare> and C<ev_check> calls - and is incremented between the
653	prepare and check phases.	660	prepare and check phases.
654		661
655	=item unsigned int ev_depth (loop)	662	=item unsigned int ev_depth (loop)
656		663
657	Returns the number of times C<ev_loop> was entered minus the number of	664	Returns the number of times C<ev_run> was entered minus the number of
658	times C<ev_loop> was exited, in other words, the recursion depth.	665	times C<ev_run> was exited, in other words, the recursion depth.
659		666
660	Outside C<ev_loop>, this number is zero. In a callback, this number is	667	Outside C<ev_run>, this number is zero. In a callback, this number is
661	C<1>, unless C<ev_loop> was invoked recursively (or from another thread),	668	C<1>, unless C<ev_run> was invoked recursively (or from another thread),
662	in which case it is higher.	669	in which case it is higher.
663		670
664	Leaving C<ev_loop> abnormally (setjmp/longjmp, cancelling the thread	671	Leaving C<ev_run> abnormally (setjmp/longjmp, cancelling the thread
665	etc.), doesn't count as "exit" - consider this as a hint to avoid such	672	etc.), doesn't count as "exit" - consider this as a hint to avoid such
666	ungentleman behaviour unless it's really convenient.	673	ungentleman-like behaviour unless it's really convenient.
667		674
668	=item unsigned int ev_backend (loop)	675	=item unsigned int ev_backend (loop)
669		676
670	Returns one of the C<EVBACKEND_*> flags indicating the event backend in	677	Returns one of the C<EVBACKEND_*> flags indicating the event backend in
671	use.	678	use.
…		…
680		687
681	=item ev_now_update (loop)	688	=item ev_now_update (loop)
682		689
683	Establishes the current time by querying the kernel, updating the time	690	Establishes the current time by querying the kernel, updating the time
684	returned by C<ev_now ()> in the progress. This is a costly operation and	691	returned by C<ev_now ()> in the progress. This is a costly operation and
685	is usually done automatically within C<ev_loop ()>.	692	is usually done automatically within C<ev_run ()>.
686		693
687	This function is rarely useful, but when some event callback runs for a	694	This function is rarely useful, but when some event callback runs for a
688	very long time without entering the event loop, updating libev's idea of	695	very long time without entering the event loop, updating libev's idea of
689	the current time is a good idea.	696	the current time is a good idea.
690		697
…		…
692		699
693	=item ev_suspend (loop)	700	=item ev_suspend (loop)
694		701
695	=item ev_resume (loop)	702	=item ev_resume (loop)
696		703
697	These two functions suspend and resume a loop, for use when the loop is	704	These two functions suspend and resume an event loop, for use when the
698	not used for a while and timeouts should not be processed.	705	loop is not used for a while and timeouts should not be processed.
699		706
700	A typical use case would be an interactive program such as a game: When	707	A typical use case would be an interactive program such as a game: When
701	the user presses C<^Z> to suspend the game and resumes it an hour later it	708	the user presses C<^Z> to suspend the game and resumes it an hour later it
702	would be best to handle timeouts as if no time had actually passed while	709	would be best to handle timeouts as if no time had actually passed while
703	the program was suspended. This can be achieved by calling C<ev_suspend>	710	the program was suspended. This can be achieved by calling C<ev_suspend>
…		…
714	without a previous call to C<ev_suspend>.	721	without a previous call to C<ev_suspend>.
715		722
716	Calling C<ev_suspend>/C<ev_resume> has the side effect of updating the	723	Calling C<ev_suspend>/C<ev_resume> has the side effect of updating the
717	event loop time (see C<ev_now_update>).	724	event loop time (see C<ev_now_update>).
718		725
719	=item ev_loop (loop, int flags)	726	=item ev_run (loop, int flags)
720		727
721	Finally, this is it, the event handler. This function usually is called	728	Finally, this is it, the event handler. This function usually is called
722	after you have initialised all your watchers and you want to start	729	after you have initialised all your watchers and you want to start
723	handling events.	730	handling events. It will ask the operating system for any new events, call
		731	the watcher callbacks, an then repeat the whole process indefinitely: This
		732	is why event loops are called I<loops>.
724		733
725	If the flags argument is specified as C<0>, it will not return until	734	If the flags argument is specified as C<0>, it will keep handling events
726	either no event watchers are active anymore or C<ev_unloop> was called.	735	until either no event watchers are active anymore or C<ev_break> was
		736	called.
727		737
728	Please note that an explicit C<ev_unloop> is usually better than	738	Please note that an explicit C<ev_break> is usually better than
729	relying on all watchers to be stopped when deciding when a program has	739	relying on all watchers to be stopped when deciding when a program has
730	finished (especially in interactive programs), but having a program	740	finished (especially in interactive programs), but having a program
731	that automatically loops as long as it has to and no longer by virtue	741	that automatically loops as long as it has to and no longer by virtue
732	of relying on its watchers stopping correctly, that is truly a thing of	742	of relying on its watchers stopping correctly, that is truly a thing of
733	beauty.	743	beauty.
734		744
735	A flags value of C<EVLOOP_NONBLOCK> will look for new events, will handle	745	A flags value of C<EVRUN_NOWAIT> will look for new events, will handle
736	those events and any already outstanding ones, but will not block your	746	those events and any already outstanding ones, but will not wait and
737	process in case there are no events and will return after one iteration of	747	block your process in case there are no events and will return after one
738	the loop.	748	iteration of the loop. This is sometimes useful to poll and handle new
		749	events while doing lengthy calculations, to keep the program responsive.
739		750
740	A flags value of C<EVLOOP_ONESHOT> will look for new events (waiting if	751	A flags value of C<EVRUN_ONCE> will look for new events (waiting if
741	necessary) and will handle those and any already outstanding ones. It	752	necessary) and will handle those and any already outstanding ones. It
742	will block your process until at least one new event arrives (which could	753	will block your process until at least one new event arrives (which could
743	be an event internal to libev itself, so there is no guarantee that a	754	be an event internal to libev itself, so there is no guarantee that a
744	user-registered callback will be called), and will return after one	755	user-registered callback will be called), and will return after one
745	iteration of the loop.	756	iteration of the loop.
746		757
747	This is useful if you are waiting for some external event in conjunction	758	This is useful if you are waiting for some external event in conjunction
748	with something not expressible using other libev watchers (i.e. "roll your	759	with something not expressible using other libev watchers (i.e. "roll your
749	own C<ev_loop>"). However, a pair of C<ev_prepare>/C<ev_check> watchers is	760	own C<ev_run>"). However, a pair of C<ev_prepare>/C<ev_check> watchers is
750	usually a better approach for this kind of thing.	761	usually a better approach for this kind of thing.
751		762
752	Here are the gory details of what C<ev_loop> does:	763	Here are the gory details of what C<ev_run> does:
753		764
		765	- Increment loop depth.
		766	- Reset the ev_break status.
754	- Before the first iteration, call any pending watchers.	767	- Before the first iteration, call any pending watchers.
		768	LOOP:
755	* If EVFLAG_FORKCHECK was used, check for a fork.	769	- If EVFLAG_FORKCHECK was used, check for a fork.
756	- If a fork was detected (by any means), queue and call all fork watchers.	770	- If a fork was detected (by any means), queue and call all fork watchers.
757	- Queue and call all prepare watchers.	771	- Queue and call all prepare watchers.
		772	- If ev_break was called, goto FINISH.
758	- If we have been forked, detach and recreate the kernel state	773	- If we have been forked, detach and recreate the kernel state
759	as to not disturb the other process.	774	as to not disturb the other process.
760	- Update the kernel state with all outstanding changes.	775	- Update the kernel state with all outstanding changes.
761	- Update the "event loop time" (ev_now ()).	776	- Update the "event loop time" (ev_now ()).
762	- Calculate for how long to sleep or block, if at all	777	- Calculate for how long to sleep or block, if at all
763	(active idle watchers, EVLOOP_NONBLOCK or not having	778	(active idle watchers, EVRUN_NOWAIT or not having
764	any active watchers at all will result in not sleeping).	779	any active watchers at all will result in not sleeping).
765	- Sleep if the I/O and timer collect interval say so.	780	- Sleep if the I/O and timer collect interval say so.
		781	- Increment loop iteration counter.
766	- Block the process, waiting for any events.	782	- Block the process, waiting for any events.
767	- Queue all outstanding I/O (fd) events.	783	- Queue all outstanding I/O (fd) events.
768	- Update the "event loop time" (ev_now ()), and do time jump adjustments.	784	- Update the "event loop time" (ev_now ()), and do time jump adjustments.
769	- Queue all expired timers.	785	- Queue all expired timers.
770	- Queue all expired periodics.	786	- Queue all expired periodics.
771	- Unless any events are pending now, queue all idle watchers.	787	- Queue all idle watchers with priority higher than that of pending events.
772	- Queue all check watchers.	788	- Queue all check watchers.
773	- Call all queued watchers in reverse order (i.e. check watchers first).	789	- Call all queued watchers in reverse order (i.e. check watchers first).
774	Signals and child watchers are implemented as I/O watchers, and will	790	Signals and child watchers are implemented as I/O watchers, and will
775	be handled here by queueing them when their watcher gets executed.	791	be handled here by queueing them when their watcher gets executed.
776	- If ev_unloop has been called, or EVLOOP_ONESHOT or EVLOOP_NONBLOCK	792	- If ev_break has been called, or EVRUN_ONCE or EVRUN_NOWAIT
777	were used, or there are no active watchers, return, otherwise	793	were used, or there are no active watchers, goto FINISH, otherwise
778	continue with step *.	794	continue with step LOOP.
		795	FINISH:
		796	- Reset the ev_break status iff it was EVBREAK_ONE.
		797	- Decrement the loop depth.
		798	- Return.
779		799
780	Example: Queue some jobs and then loop until no events are outstanding	800	Example: Queue some jobs and then loop until no events are outstanding
781	anymore.	801	anymore.
782		802
783	... queue jobs here, make sure they register event watchers as long	803	... queue jobs here, make sure they register event watchers as long
784	... as they still have work to do (even an idle watcher will do..)	804	... as they still have work to do (even an idle watcher will do..)
785	ev_loop (my_loop, 0);	805	ev_run (my_loop, 0);
786	... jobs done or somebody called unloop. yeah!	806	... jobs done or somebody called unloop. yeah!
787		807
788	=item ev_unloop (loop, how)	808	=item ev_break (loop, how)
789		809
790	Can be used to make a call to C<ev_loop> return early (but only after it	810	Can be used to make a call to C<ev_run> return early (but only after it
791	has processed all outstanding events). The C<how> argument must be either	811	has processed all outstanding events). The C<how> argument must be either
792	C<EVUNLOOP_ONE>, which will make the innermost C<ev_loop> call return, or	812	C<EVBREAK_ONE>, which will make the innermost C<ev_run> call return, or
793	C<EVUNLOOP_ALL>, which will make all nested C<ev_loop> calls return.	813	C<EVBREAK_ALL>, which will make all nested C<ev_run> calls return.
794		814
795	This "unloop state" will be cleared when entering C<ev_loop> again.	815	This "unloop state" will be cleared when entering C<ev_run> again.
796		816
797	It is safe to call C<ev_unloop> from outside any C<ev_loop> calls.	817	It is safe to call C<ev_break> from outside any C<ev_run> calls. ##TODO##
798		818
799	=item ev_ref (loop)	819	=item ev_ref (loop)
800		820
801	=item ev_unref (loop)	821	=item ev_unref (loop)
802		822
803	Ref/unref can be used to add or remove a reference count on the event	823	Ref/unref can be used to add or remove a reference count on the event
804	loop: Every watcher keeps one reference, and as long as the reference	824	loop: Every watcher keeps one reference, and as long as the reference
805	count is nonzero, C<ev_loop> will not return on its own.	825	count is nonzero, C<ev_run> will not return on its own.
806		826
807	This is useful when you have a watcher that you never intend to	827	This is useful when you have a watcher that you never intend to
808	unregister, but that nevertheless should not keep C<ev_loop> from	828	unregister, but that nevertheless should not keep C<ev_run> from
809	returning. In such a case, call C<ev_unref> after starting, and C<ev_ref>	829	returning. In such a case, call C<ev_unref> after starting, and C<ev_ref>
810	before stopping it.	830	before stopping it.
811		831
812	As an example, libev itself uses this for its internal signal pipe: It	832	As an example, libev itself uses this for its internal signal pipe: It
813	is not visible to the libev user and should not keep C<ev_loop> from	833	is not visible to the libev user and should not keep C<ev_run> from
814	exiting if no event watchers registered by it are active. It is also an	834	exiting if no event watchers registered by it are active. It is also an
815	excellent way to do this for generic recurring timers or from within	835	excellent way to do this for generic recurring timers or from within
816	third-party libraries. Just remember to I<unref after start> and I<ref	836	third-party libraries. Just remember to I<unref after start> and I<ref
817	before stop> (but only if the watcher wasn't active before, or was active	837	before stop> (but only if the watcher wasn't active before, or was active
818	before, respectively. Note also that libev might stop watchers itself	838	before, respectively. Note also that libev might stop watchers itself
819	(e.g. non-repeating timers) in which case you have to C<ev_ref>	839	(e.g. non-repeating timers) in which case you have to C<ev_ref>
820	in the callback).	840	in the callback).
821		841
822	Example: Create a signal watcher, but keep it from keeping C<ev_loop>	842	Example: Create a signal watcher, but keep it from keeping C<ev_run>
823	running when nothing else is active.	843	running when nothing else is active.
824		844
825	ev_signal exitsig;	845	ev_signal exitsig;
826	ev_signal_init (&exitsig, sig_cb, SIGINT);	846	ev_signal_init (&exitsig, sig_cb, SIGINT);
827	ev_signal_start (loop, &exitsig);	847	ev_signal_start (loop, &exitsig);
…		…
890	ev_set_io_collect_interval (EV_DEFAULT_UC_ 0.01);	910	ev_set_io_collect_interval (EV_DEFAULT_UC_ 0.01);
891		911
892	=item ev_invoke_pending (loop)	912	=item ev_invoke_pending (loop)
893		913
894	This call will simply invoke all pending watchers while resetting their	914	This call will simply invoke all pending watchers while resetting their
895	pending state. Normally, C<ev_loop> does this automatically when required,	915	pending state. Normally, C<ev_run> does this automatically when required,
896	but when overriding the invoke callback this call comes handy.	916	but when overriding the invoke callback this call comes handy. This
		917	function can be invoked from a watcher - this can be useful for example
		918	when you want to do some lengthy calculation and want to pass further
		919	event handling to another thread (you still have to make sure only one
		920	thread executes within C<ev_invoke_pending> or C<ev_run> of course).
897		921
898	=item int ev_pending_count (loop)	922	=item int ev_pending_count (loop)
899		923
900	Returns the number of pending watchers - zero indicates that no watchers	924	Returns the number of pending watchers - zero indicates that no watchers
901	are pending.	925	are pending.
902		926
903	=item ev_set_invoke_pending_cb (loop, void (*invoke_pending_cb)(EV_P))	927	=item ev_set_invoke_pending_cb (loop, void (*invoke_pending_cb)(EV_P))
904		928
905	This overrides the invoke pending functionality of the loop: Instead of	929	This overrides the invoke pending functionality of the loop: Instead of
906	invoking all pending watchers when there are any, C<ev_loop> will call	930	invoking all pending watchers when there are any, C<ev_run> will call
907	this callback instead. This is useful, for example, when you want to	931	this callback instead. This is useful, for example, when you want to
908	invoke the actual watchers inside another context (another thread etc.).	932	invoke the actual watchers inside another context (another thread etc.).
909		933
910	If you want to reset the callback, use C<ev_invoke_pending> as new	934	If you want to reset the callback, use C<ev_invoke_pending> as new
911	callback.	935	callback.
…		…
914		938
915	Sometimes you want to share the same loop between multiple threads. This	939	Sometimes you want to share the same loop between multiple threads. This
916	can be done relatively simply by putting mutex_lock/unlock calls around	940	can be done relatively simply by putting mutex_lock/unlock calls around
917	each call to a libev function.	941	each call to a libev function.
918		942
919	However, C<ev_loop> can run an indefinite time, so it is not feasible to	943	However, C<ev_run> can run an indefinite time, so it is not feasible
920	wait for it to return. One way around this is to wake up the loop via	944	to wait for it to return. One way around this is to wake up the event
921	C<ev_unloop> and C<av_async_send>, another way is to set these I<release>	945	loop via C<ev_break> and C<av_async_send>, another way is to set these
922	and I<acquire> callbacks on the loop.	946	I<release> and I<acquire> callbacks on the loop.
923		947
924	When set, then C<release> will be called just before the thread is	948	When set, then C<release> will be called just before the thread is
925	suspended waiting for new events, and C<acquire> is called just	949	suspended waiting for new events, and C<acquire> is called just
926	afterwards.	950	afterwards.
927		951
…		…
930		954
931	While event loop modifications are allowed between invocations of	955	While event loop modifications are allowed between invocations of
932	C<release> and C<acquire> (that's their only purpose after all), no	956	C<release> and C<acquire> (that's their only purpose after all), no
933	modifications done will affect the event loop, i.e. adding watchers will	957	modifications done will affect the event loop, i.e. adding watchers will
934	have no effect on the set of file descriptors being watched, or the time	958	have no effect on the set of file descriptors being watched, or the time
935	waited. Use an C<ev_async> watcher to wake up C<ev_loop> when you want it	959	waited. Use an C<ev_async> watcher to wake up C<ev_run> when you want it
936	to take note of any changes you made.	960	to take note of any changes you made.
937		961
938	In theory, threads executing C<ev_loop> will be async-cancel safe between	962	In theory, threads executing C<ev_run> will be async-cancel safe between
939	invocations of C<release> and C<acquire>.	963	invocations of C<release> and C<acquire>.
940		964
941	See also the locking example in the C<THREADS> section later in this	965	See also the locking example in the C<THREADS> section later in this
942	document.	966	document.
943		967
…		…
952	These two functions can be used to associate arbitrary data with a loop,	976	These two functions can be used to associate arbitrary data with a loop,
953	and are intended solely for the C<invoke_pending_cb>, C<release> and	977	and are intended solely for the C<invoke_pending_cb>, C<release> and
954	C<acquire> callbacks described above, but of course can be (ab-)used for	978	C<acquire> callbacks described above, but of course can be (ab-)used for
955	any other purpose as well.	979	any other purpose as well.
956		980
957	=item ev_loop_verify (loop)	981	=item ev_verify (loop)
958		982
959	This function only does something when C<EV_VERIFY> support has been	983	This function only does something when C<EV_VERIFY> support has been
960	compiled in, which is the default for non-minimal builds. It tries to go	984	compiled in, which is the default for non-minimal builds. It tries to go
961	through all internal structures and checks them for validity. If anything	985	through all internal structures and checks them for validity. If anything
962	is found to be inconsistent, it will print an error message to standard	986	is found to be inconsistent, it will print an error message to standard
…		…
973		997
974	In the following description, uppercase C<TYPE> in names stands for the	998	In the following description, uppercase C<TYPE> in names stands for the
975	watcher type, e.g. C<ev_TYPE_start> can mean C<ev_timer_start> for timer	999	watcher type, e.g. C<ev_TYPE_start> can mean C<ev_timer_start> for timer
976	watchers and C<ev_io_start> for I/O watchers.	1000	watchers and C<ev_io_start> for I/O watchers.
977		1001
978	A watcher is a structure that you create and register to record your	1002	A watcher is an opaque structure that you allocate and register to record
979	interest in some event. For instance, if you want to wait for STDIN to	1003	your interest in some event. To make a concrete example, imagine you want
980	become readable, you would create an C<ev_io> watcher for that:	1004	to wait for STDIN to become readable, you would create an C<ev_io> watcher
		1005	for that:
981		1006
982	static void my_cb (struct ev_loop loop, ev_io w, int revents)	1007	static void my_cb (struct ev_loop loop, ev_io w, int revents)
983	{	1008	{
984	ev_io_stop (w);	1009	ev_io_stop (w);
985	ev_unloop (loop, EVUNLOOP_ALL);	1010	ev_break (loop, EVBREAK_ALL);
986	}	1011	}
987		1012
988	struct ev_loop *loop = ev_default_loop (0);	1013	struct ev_loop *loop = ev_default_loop (0);
989		1014
990	ev_io stdin_watcher;	1015	ev_io stdin_watcher;
991		1016
992	ev_init (&stdin_watcher, my_cb);	1017	ev_init (&stdin_watcher, my_cb);
993	ev_io_set (&stdin_watcher, STDIN_FILENO, EV_READ);	1018	ev_io_set (&stdin_watcher, STDIN_FILENO, EV_READ);
994	ev_io_start (loop, &stdin_watcher);	1019	ev_io_start (loop, &stdin_watcher);
995		1020
996	ev_loop (loop, 0);	1021	ev_run (loop, 0);
997		1022
998	As you can see, you are responsible for allocating the memory for your	1023	As you can see, you are responsible for allocating the memory for your
999	watcher structures (and it is I<usually> a bad idea to do this on the	1024	watcher structures (and it is I<usually> a bad idea to do this on the
1000	stack).	1025	stack).
1001		1026
1002	Each watcher has an associated watcher structure (called C<struct ev_TYPE>	1027	Each watcher has an associated watcher structure (called C<struct ev_TYPE>
1003	or simply C<ev_TYPE>, as typedefs are provided for all watcher structs).	1028	or simply C<ev_TYPE>, as typedefs are provided for all watcher structs).
1004		1029
1005	Each watcher structure must be initialised by a call to C<ev_init	1030	Each watcher structure must be initialised by a call to C<ev_init (watcher
1006	(watcher *, callback)>, which expects a callback to be provided. This	1031	*, callback)>, which expects a callback to be provided. This callback is
1007	callback gets invoked each time the event occurs (or, in the case of I/O	1032	invoked each time the event occurs (or, in the case of I/O watchers, each
1008	watchers, each time the event loop detects that the file descriptor given	1033	time the event loop detects that the file descriptor given is readable
1009	is readable and/or writable).	1034	and/or writable).
1010		1035
1011	Each watcher type further has its own C<< ev_TYPE_set (watcher *, ...) >>	1036	Each watcher type further has its own C<< ev_TYPE_set (watcher *, ...) >>
1012	macro to configure it, with arguments specific to the watcher type. There	1037	macro to configure it, with arguments specific to the watcher type. There
1013	is also a macro to combine initialisation and setting in one call: C<<	1038	is also a macro to combine initialisation and setting in one call: C<<
1014	ev_TYPE_init (watcher *, callback, ...) >>.	1039	ev_TYPE_init (watcher *, callback, ...) >>.
…		…
1065		1090
1066	=item C<EV_PREPARE>	1091	=item C<EV_PREPARE>
1067		1092
1068	=item C<EV_CHECK>	1093	=item C<EV_CHECK>
1069		1094
1070	All C<ev_prepare> watchers are invoked just I<before> C<ev_loop> starts	1095	All C<ev_prepare> watchers are invoked just I<before> C<ev_run> starts
1071	to gather new events, and all C<ev_check> watchers are invoked just after	1096	to gather new events, and all C<ev_check> watchers are invoked just after
1072	C<ev_loop> has gathered them, but before it invokes any callbacks for any	1097	C<ev_run> has gathered them, but before it invokes any callbacks for any
1073	received events. Callbacks of both watcher types can start and stop as	1098	received events. Callbacks of both watcher types can start and stop as
1074	many watchers as they want, and all of them will be taken into account	1099	many watchers as they want, and all of them will be taken into account
1075	(for example, a C<ev_prepare> watcher might start an idle watcher to keep	1100	(for example, a C<ev_prepare> watcher might start an idle watcher to keep
1076	C<ev_loop> from blocking).	1101	C<ev_run> from blocking).
1077		1102
1078	=item C<EV_EMBED>	1103	=item C<EV_EMBED>
1079		1104
1080	The embedded event loop specified in the C<ev_embed> watcher needs attention.	1105	The embedded event loop specified in the C<ev_embed> watcher needs attention.
1081		1106
…		…
1109	example it might indicate that a fd is readable or writable, and if your	1134	example it might indicate that a fd is readable or writable, and if your
1110	callbacks is well-written it can just attempt the operation and cope with	1135	callbacks is well-written it can just attempt the operation and cope with
1111	the error from read() or write(). This will not work in multi-threaded	1136	the error from read() or write(). This will not work in multi-threaded
1112	programs, though, as the fd could already be closed and reused for another	1137	programs, though, as the fd could already be closed and reused for another
1113	thing, so beware.	1138	thing, so beware.
		1139
		1140	=back
		1141
		1142	=head2 WATCHER STATES
		1143
		1144	There are various watcher states mentioned throughout this manual -
		1145	active, pending and so on. In this section these states and the rules to
		1146	transition between them will be described in more detail - and while these
		1147	rules might look complicated, they usually do "the right thing".
		1148
		1149	=over 4
		1150
		1151	=item initialiased
		1152
		1153	Before a watcher can be registered with the event looop it has to be
		1154	initialised. This can be done with a call to C<ev_TYPE_init>, or calls to
		1155	C<ev_init> followed by the watcher-specific C<ev_TYPE_set> function.
		1156
		1157	In this state it is simply some block of memory that is suitable for use
		1158	in an event loop. It can be moved around, freed, reused etc. at will.
		1159
		1160	=item started/running/active
		1161
		1162	Once a watcher has been started with a call to C<ev_TYPE_start> it becomes
		1163	property of the event loop, and is actively waiting for events. While in
		1164	this state it cannot be accessed (except in a few documented ways), moved,
		1165	freed or anything else - the only legal thing is to keep a pointer to it,
		1166	and call libev functions on it that are documented to work on active watchers.
		1167
		1168	=item pending
		1169
		1170	If a watcher is active and libev determines that an event it is interested
		1171	in has occurred (such as a timer expiring), it will become pending. It will
		1172	stay in this pending state until either it is stopped or its callback is
		1173	about to be invoked, so it is not normally pending inside the watcher
		1174	callback.
		1175
		1176	The watcher might or might not be active while it is pending (for example,
		1177	an expired non-repeating timer can be pending but no longer active). If it
		1178	is stopped, it can be freely accessed (e.g. by calling C<ev_TYPE_set>),
		1179	but it is still property of the event loop at this time, so cannot be
		1180	moved, freed or reused. And if it is active the rules described in the
		1181	previous item still apply.
		1182
		1183	It is also possible to feed an event on a watcher that is not active (e.g.
		1184	via C<ev_feed_event>), in which case it becomes pending without being
		1185	active.
		1186
		1187	=item stopped
		1188
		1189	A watcher can be stopped implicitly by libev (in which case it might still
		1190	be pending), or explicitly by calling its C<ev_TYPE_stop> function. The
		1191	latter will clear any pending state the watcher might be in, regardless
		1192	of whether it was active or not, so stopping a watcher explicitly before
		1193	freeing it is often a good idea.
		1194
		1195	While stopped (and not pending) the watcher is essentially in the
		1196	initialised state, that is it can be reused, moved, modified in any way
		1197	you wish.
1114		1198
1115	=back	1199	=back
1116		1200
1117	=head2 GENERIC WATCHER FUNCTIONS	1201	=head2 GENERIC WATCHER FUNCTIONS
1118		1202
…		…
1622	...	1706	...
1623	struct ev_loop *loop = ev_default_init (0);	1707	struct ev_loop *loop = ev_default_init (0);
1624	ev_io stdin_readable;	1708	ev_io stdin_readable;
1625	ev_io_init (&stdin_readable, stdin_readable_cb, STDIN_FILENO, EV_READ);	1709	ev_io_init (&stdin_readable, stdin_readable_cb, STDIN_FILENO, EV_READ);
1626	ev_io_start (loop, &stdin_readable);	1710	ev_io_start (loop, &stdin_readable);
1627	ev_loop (loop, 0);	1711	ev_run (loop, 0);
1628		1712
1629		1713
1630	=head2 C<ev_timer> - relative and optionally repeating timeouts	1714	=head2 C<ev_timer> - relative and optionally repeating timeouts
1631		1715
1632	Timer watchers are simple relative timers that generate an event after a	1716	Timer watchers are simple relative timers that generate an event after a
…		…
1641	The callback is guaranteed to be invoked only I<after> its timeout has	1725	The callback is guaranteed to be invoked only I<after> its timeout has
1642	passed (not I<at>, so on systems with very low-resolution clocks this	1726	passed (not I<at>, so on systems with very low-resolution clocks this
1643	might introduce a small delay). If multiple timers become ready during the	1727	might introduce a small delay). If multiple timers become ready during the
1644	same loop iteration then the ones with earlier time-out values are invoked	1728	same loop iteration then the ones with earlier time-out values are invoked
1645	before ones of the same priority with later time-out values (but this is	1729	before ones of the same priority with later time-out values (but this is
1646	no longer true when a callback calls C<ev_loop> recursively).	1730	no longer true when a callback calls C<ev_run> recursively).
1647		1731
1648	=head3 Be smart about timeouts	1732	=head3 Be smart about timeouts
1649		1733
1650	Many real-world problems involve some kind of timeout, usually for error	1734	Many real-world problems involve some kind of timeout, usually for error
1651	recovery. A typical example is an HTTP request - if the other side hangs,	1735	recovery. A typical example is an HTTP request - if the other side hangs,
…		…
1822		1906
1823	=head3 The special problem of time updates	1907	=head3 The special problem of time updates
1824		1908
1825	Establishing the current time is a costly operation (it usually takes at	1909	Establishing the current time is a costly operation (it usually takes at
1826	least two system calls): EV therefore updates its idea of the current	1910	least two system calls): EV therefore updates its idea of the current
1827	time only before and after C<ev_loop> collects new events, which causes a	1911	time only before and after C<ev_run> collects new events, which causes a
1828	growing difference between C<ev_now ()> and C<ev_time ()> when handling	1912	growing difference between C<ev_now ()> and C<ev_time ()> when handling
1829	lots of events in one iteration.	1913	lots of events in one iteration.
1830		1914
1831	The relative timeouts are calculated relative to the C<ev_now ()>	1915	The relative timeouts are calculated relative to the C<ev_now ()>
1832	time. This is usually the right thing as this timestamp refers to the time	1916	time. This is usually the right thing as this timestamp refers to the time
…		…
1949	}	2033	}
1950		2034
1951	ev_timer mytimer;	2035	ev_timer mytimer;
1952	ev_timer_init (&mytimer, timeout_cb, 0., 10.); /* note, only repeat used */	2036	ev_timer_init (&mytimer, timeout_cb, 0., 10.); /* note, only repeat used */
1953	ev_timer_again (&mytimer); /* start timer */	2037	ev_timer_again (&mytimer); /* start timer */
1954	ev_loop (loop, 0);	2038	ev_run (loop, 0);
1955		2039
1956	// and in some piece of code that gets executed on any "activity":	2040	// and in some piece of code that gets executed on any "activity":
1957	// reset the timeout to start ticking again at 10 seconds	2041	// reset the timeout to start ticking again at 10 seconds
1958	ev_timer_again (&mytimer);	2042	ev_timer_again (&mytimer);
1959		2043
…		…
1985		2069
1986	As with timers, the callback is guaranteed to be invoked only when the	2070	As with timers, the callback is guaranteed to be invoked only when the
1987	point in time where it is supposed to trigger has passed. If multiple	2071	point in time where it is supposed to trigger has passed. If multiple
1988	timers become ready during the same loop iteration then the ones with	2072	timers become ready during the same loop iteration then the ones with
1989	earlier time-out values are invoked before ones with later time-out values	2073	earlier time-out values are invoked before ones with later time-out values
1990	(but this is no longer true when a callback calls C<ev_loop> recursively).	2074	(but this is no longer true when a callback calls C<ev_run> recursively).
1991		2075
1992	=head3 Watcher-Specific Functions and Data Members	2076	=head3 Watcher-Specific Functions and Data Members
1993		2077
1994	=over 4	2078	=over 4
1995		2079
…		…
2233	Example: Try to exit cleanly on SIGINT.	2317	Example: Try to exit cleanly on SIGINT.
2234		2318
2235	static void	2319	static void
2236	sigint_cb (struct ev_loop loop, ev_signal w, int revents)	2320	sigint_cb (struct ev_loop loop, ev_signal w, int revents)
2237	{	2321	{
2238	ev_unloop (loop, EVUNLOOP_ALL);	2322	ev_break (loop, EVBREAK_ALL);
2239	}	2323	}
2240		2324
2241	ev_signal signal_watcher;	2325	ev_signal signal_watcher;
2242	ev_signal_init (&signal_watcher, sigint_cb, SIGINT);	2326	ev_signal_init (&signal_watcher, sigint_cb, SIGINT);
2243	ev_signal_start (loop, &signal_watcher);	2327	ev_signal_start (loop, &signal_watcher);
…		…
2629		2713
2630	Prepare and check watchers are usually (but not always) used in pairs:	2714	Prepare and check watchers are usually (but not always) used in pairs:
2631	prepare watchers get invoked before the process blocks and check watchers	2715	prepare watchers get invoked before the process blocks and check watchers
2632	afterwards.	2716	afterwards.
2633		2717
2634	You I<must not> call C<ev_loop> or similar functions that enter	2718	You I<must not> call C<ev_run> or similar functions that enter
2635	the current event loop from either C<ev_prepare> or C<ev_check>	2719	the current event loop from either C<ev_prepare> or C<ev_check>
2636	watchers. Other loops than the current one are fine, however. The	2720	watchers. Other loops than the current one are fine, however. The
2637	rationale behind this is that you do not need to check for recursion in	2721	rationale behind this is that you do not need to check for recursion in
2638	those watchers, i.e. the sequence will always be C<ev_prepare>, blocking,	2722	those watchers, i.e. the sequence will always be C<ev_prepare>, blocking,
2639	C<ev_check> so if you have one watcher of each kind they will always be	2723	C<ev_check> so if you have one watcher of each kind they will always be
…		…
2807		2891
2808	if (timeout >= 0)	2892	if (timeout >= 0)
2809	// create/start timer	2893	// create/start timer
2810		2894
2811	// poll	2895	// poll
2812	ev_loop (EV_A_ 0);	2896	ev_run (EV_A_ 0);
2813		2897
2814	// stop timer again	2898	// stop timer again
2815	if (timeout >= 0)	2899	if (timeout >= 0)
2816	ev_timer_stop (EV_A_ &to);	2900	ev_timer_stop (EV_A_ &to);
2817		2901
…		…
2895	if you do not want that, you need to temporarily stop the embed watcher).	2979	if you do not want that, you need to temporarily stop the embed watcher).
2896		2980
2897	=item ev_embed_sweep (loop, ev_embed *)	2981	=item ev_embed_sweep (loop, ev_embed *)
2898		2982
2899	Make a single, non-blocking sweep over the embedded loop. This works	2983	Make a single, non-blocking sweep over the embedded loop. This works
2900	similarly to C<ev_loop (embedded_loop, EVLOOP_NONBLOCK)>, but in the most	2984	similarly to C<ev_run (embedded_loop, EVRUN_NOWAIT)>, but in the most
2901	appropriate way for embedded loops.	2985	appropriate way for embedded loops.
2902		2986
2903	=item struct ev_loop *other [read-only]	2987	=item struct ev_loop *other [read-only]
2904		2988
2905	The embedded event loop.	2989	The embedded event loop.
…		…
3011	=back	3095	=back
3012		3096
3013		3097
3014	=head2 C<ev_async> - how to wake up an event loop	3098	=head2 C<ev_async> - how to wake up an event loop
3015		3099
3016	In general, you cannot use an C<ev_loop> from multiple threads or other	3100	In general, you cannot use an C<ev_run> from multiple threads or other
3017	asynchronous sources such as signal handlers (as opposed to multiple event	3101	asynchronous sources such as signal handlers (as opposed to multiple event
3018	loops - those are of course safe to use in different threads).	3102	loops - those are of course safe to use in different threads).
3019		3103
3020	Sometimes, however, you need to wake up an event loop you do not control,	3104	Sometimes, however, you need to wake up an event loop you do not control,
3021	for example because it belongs to another thread. This is what C<ev_async>	3105	for example because it belongs to another thread. This is what C<ev_async>
…		…
3389	Associates a different C<struct ev_loop> with this watcher. You can only	3473	Associates a different C<struct ev_loop> with this watcher. You can only
3390	do this when the watcher is inactive (and not pending either).	3474	do this when the watcher is inactive (and not pending either).
3391		3475
3392	=item w->set ([arguments])	3476	=item w->set ([arguments])
3393		3477
3394	Basically the same as C<ev_TYPE_set>, with the same arguments. Must be	3478	Basically the same as C<ev_TYPE_set>, with the same arguments. Either this
3395	called at least once. Unlike the C counterpart, an active watcher gets	3479	method or a suitable start method must be called at least once. Unlike the
3396	automatically stopped and restarted when reconfiguring it with this	3480	C counterpart, an active watcher gets automatically stopped and restarted
3397	method.	3481	when reconfiguring it with this method.
3398		3482
3399	=item w->start ()	3483	=item w->start ()
3400		3484
3401	Starts the watcher. Note that there is no C<loop> argument, as the	3485	Starts the watcher. Note that there is no C<loop> argument, as the
3402	constructor already stores the event loop.	3486	constructor already stores the event loop.
3403		3487
		3488	=item w->start ([arguments])
		3489
		3490	Instead of calling C<set> and C<start> methods separately, it is often
		3491	convenient to wrap them in one call. Uses the same type of arguments as
		3492	the configure C<set> method of the watcher.
		3493
3404	=item w->stop ()	3494	=item w->stop ()
3405		3495
3406	Stops the watcher if it is active. Again, no C<loop> argument.	3496	Stops the watcher if it is active. Again, no C<loop> argument.
3407		3497
3408	=item w->again () (C<ev::timer>, C<ev::periodic> only)	3498	=item w->again () (C<ev::timer>, C<ev::periodic> only)
…		…
3420		3510
3421	=back	3511	=back
3422		3512
3423	=back	3513	=back
3424		3514
3425	Example: Define a class with an IO and idle watcher, start one of them in	3515	Example: Define a class with two I/O and idle watchers, start the I/O
3426	the constructor.	3516	watchers in the constructor.
3427		3517
3428	class myclass	3518	class myclass
3429	{	3519	{
3430	ev::io io ; void io_cb (ev::io &w, int revents);	3520	ev::io io ; void io_cb (ev::io &w, int revents);
		3521	ev::io2 io2 ; void io2_cb (ev::io &w, int revents);
3431	ev::idle idle; void idle_cb (ev::idle &w, int revents);	3522	ev::idle idle; void idle_cb (ev::idle &w, int revents);
3432		3523
3433	myclass (int fd)	3524	myclass (int fd)
3434	{	3525	{
3435	io .set <myclass, &myclass::io_cb > (this);	3526	io .set <myclass, &myclass::io_cb > (this);
		3527	io2 .set <myclass, &myclass::io2_cb > (this);
3436	idle.set <myclass, &myclass::idle_cb> (this);	3528	idle.set <myclass, &myclass::idle_cb> (this);
3437		3529
3438	io.start (fd, ev::READ);	3530	io.set (fd, ev::WRITE); // configure the watcher
		3531	io.start (); // start it whenever convenient
		3532
		3533	io2.start (fd, ev::READ); // set + start in one call
3439	}	3534	}
3440	};	3535	};
3441		3536
3442		3537
3443	=head1 OTHER LANGUAGE BINDINGS	3538	=head1 OTHER LANGUAGE BINDINGS
…		…
3517	loop argument"). The C<EV_A> form is used when this is the sole argument,	3612	loop argument"). The C<EV_A> form is used when this is the sole argument,
3518	C<EV_A_> is used when other arguments are following. Example:	3613	C<EV_A_> is used when other arguments are following. Example:
3519		3614
3520	ev_unref (EV_A);	3615	ev_unref (EV_A);
3521	ev_timer_add (EV_A_ watcher);	3616	ev_timer_add (EV_A_ watcher);
3522	ev_loop (EV_A_ 0);	3617	ev_run (EV_A_ 0);
3523		3618
3524	It assumes the variable C<loop> of type C<struct ev_loop *> is in scope,	3619	It assumes the variable C<loop> of type C<struct ev_loop *> is in scope,
3525	which is often provided by the following macro.	3620	which is often provided by the following macro.
3526		3621
3527	=item C<EV_P>, C<EV_P_>	3622	=item C<EV_P>, C<EV_P_>
…		…
3567	}	3662	}
3568		3663
3569	ev_check check;	3664	ev_check check;
3570	ev_check_init (&check, check_cb);	3665	ev_check_init (&check, check_cb);
3571	ev_check_start (EV_DEFAULT_ &check);	3666	ev_check_start (EV_DEFAULT_ &check);
3572	ev_loop (EV_DEFAULT_ 0);	3667	ev_run (EV_DEFAULT_ 0);
3573		3668
3574	=head1 EMBEDDING	3669	=head1 EMBEDDING
3575		3670
3576	Libev can (and often is) directly embedded into host	3671	Libev can (and often is) directly embedded into host
3577	applications. Examples of applications that embed it include the Deliantra	3672	applications. Examples of applications that embed it include the Deliantra
…		…
3668	to a compiled library. All other symbols change the ABI, which means all	3763	to a compiled library. All other symbols change the ABI, which means all
3669	users of libev and the libev code itself must be compiled with compatible	3764	users of libev and the libev code itself must be compiled with compatible
3670	settings.	3765	settings.
3671		3766
3672	=over 4	3767	=over 4
		3768
		3769	=item EV_COMPAT3 (h)
		3770
		3771	Backwards compatibility is a major concern for libev. This is why this
		3772	release of libev comes with wrappers for the functions and symbols that
		3773	have been renamed between libev version 3 and 4.
		3774
		3775	You can disable these wrappers (to test compatibility with future
		3776	versions) by defining C<EV_COMPAT3> to C<0> when compiling your
		3777	sources. This has the additional advantage that you can drop the C<struct>
		3778	from C<struct ev_loop> declarations, as libev will provide an C<ev_loop>
		3779	typedef in that case.
		3780
		3781	In some future version, the default for C<EV_COMPAT3> will become C<0>,
		3782	and in some even more future version the compatibility code will be
		3783	removed completely.
3673		3784
3674	=item EV_STANDALONE (h)	3785	=item EV_STANDALONE (h)
3675		3786
3676	Must always be C<1> if you do not use autoconf configuration, which	3787	Must always be C<1> if you do not use autoconf configuration, which
3677	keeps libev from including F<config.h>, and it also defines dummy	3788	keeps libev from including F<config.h>, and it also defines dummy
…		…
4027	The default is C<1>, unless C<EV_FEATURES> overrides it, in which case it	4138	The default is C<1>, unless C<EV_FEATURES> overrides it, in which case it
4028	will be C<0>.	4139	will be C<0>.
4029		4140
4030	=item EV_VERIFY	4141	=item EV_VERIFY
4031		4142
4032	Controls how much internal verification (see C<ev_loop_verify ()>) will	4143	Controls how much internal verification (see C<ev_verify ()>) will
4033	be done: If set to C<0>, no internal verification code will be compiled	4144	be done: If set to C<0>, no internal verification code will be compiled
4034	in. If set to C<1>, then verification code will be compiled in, but not	4145	in. If set to C<1>, then verification code will be compiled in, but not
4035	called. If set to C<2>, then the internal verification code will be	4146	called. If set to C<2>, then the internal verification code will be
4036	called once per loop, which can slow down libev. If set to C<3>, then the	4147	called once per loop, which can slow down libev. If set to C<3>, then the
4037	verification code will be called very frequently, which will slow down	4148	verification code will be called very frequently, which will slow down
…		…
4252	userdata *u = ev_userdata (EV_A);	4363	userdata *u = ev_userdata (EV_A);
4253	pthread_mutex_lock (&u->lock);	4364	pthread_mutex_lock (&u->lock);
4254	}	4365	}
4255		4366
4256	The event loop thread first acquires the mutex, and then jumps straight	4367	The event loop thread first acquires the mutex, and then jumps straight
4257	into C<ev_loop>:	4368	into C<ev_run>:
4258		4369
4259	void *	4370	void *
4260	l_run (void *thr_arg)	4371	l_run (void *thr_arg)
4261	{	4372	{
4262	struct ev_loop loop = (struct ev_loop )thr_arg;	4373	struct ev_loop loop = (struct ev_loop )thr_arg;
4263		4374
4264	l_acquire (EV_A);	4375	l_acquire (EV_A);
4265	pthread_setcanceltype (PTHREAD_CANCEL_ASYNCHRONOUS, 0);	4376	pthread_setcanceltype (PTHREAD_CANCEL_ASYNCHRONOUS, 0);
4266	ev_loop (EV_A_ 0);	4377	ev_run (EV_A_ 0);
4267	l_release (EV_A);	4378	l_release (EV_A);
4268		4379
4269	return 0;	4380	return 0;
4270	}	4381	}
4271		4382
…		…
4323		4434
4324	=head3 COROUTINES	4435	=head3 COROUTINES
4325		4436
4326	Libev is very accommodating to coroutines ("cooperative threads"):	4437	Libev is very accommodating to coroutines ("cooperative threads"):
4327	libev fully supports nesting calls to its functions from different	4438	libev fully supports nesting calls to its functions from different
4328	coroutines (e.g. you can call C<ev_loop> on the same loop from two	4439	coroutines (e.g. you can call C<ev_run> on the same loop from two
4329	different coroutines, and switch freely between both coroutines running	4440	different coroutines, and switch freely between both coroutines running
4330	the loop, as long as you don't confuse yourself). The only exception is	4441	the loop, as long as you don't confuse yourself). The only exception is
4331	that you must not do this from C<ev_periodic> reschedule callbacks.	4442	that you must not do this from C<ev_periodic> reschedule callbacks.
4332		4443
4333	Care has been taken to ensure that libev does not keep local state inside	4444	Care has been taken to ensure that libev does not keep local state inside
4334	C<ev_loop>, and other calls do not usually allow for coroutine switches as	4445	C<ev_run>, and other calls do not usually allow for coroutine switches as
4335	they do not call any callbacks.	4446	they do not call any callbacks.
4336		4447
4337	=head2 COMPILER WARNINGS	4448	=head2 COMPILER WARNINGS
4338		4449
4339	Depending on your compiler and compiler settings, you might get no or a	4450	Depending on your compiler and compiler settings, you might get no or a
…		…
4423	=head3 C<kqueue> is buggy	4534	=head3 C<kqueue> is buggy
4424		4535
4425	The kqueue syscall is broken in all known versions - most versions support	4536	The kqueue syscall is broken in all known versions - most versions support
4426	only sockets, many support pipes.	4537	only sockets, many support pipes.
4427		4538
4428	Libev tries to work around this by not using C<kqueue> by default on	4539	Libev tries to work around this by not using C<kqueue> by default on this
4429	this rotten platform, but of course you can still ask for it when creating	4540	rotten platform, but of course you can still ask for it when creating a
4430	a loop.	4541	loop - embedding a socket-only kqueue loop into a select-based one is
		4542	probably going to work well.
4431		4543
4432	=head3 C<poll> is buggy	4544	=head3 C<poll> is buggy
4433		4545
4434	Instead of fixing C<kqueue>, Apple replaced their (working) C<poll>	4546	Instead of fixing C<kqueue>, Apple replaced their (working) C<poll>
4435	implementation by something calling C<kqueue> internally around the 10.5.6	4547	implementation by something calling C<kqueue> internally around the 10.5.6
…		…
4454		4566
4455	=head3 C<errno> reentrancy	4567	=head3 C<errno> reentrancy
4456		4568
4457	The default compile environment on Solaris is unfortunately so	4569	The default compile environment on Solaris is unfortunately so
4458	thread-unsafe that you can't even use components/libraries compiled	4570	thread-unsafe that you can't even use components/libraries compiled
4459	without C<-D_REENTRANT> (as long as they use C<errno>), which, of course,	4571	without C<-D_REENTRANT> in a threaded program, which, of course, isn't
4460	isn't defined by default.	4572	defined by default. A valid, if stupid, implementation choice.
4461		4573
4462	If you want to use libev in threaded environments you have to make sure	4574	If you want to use libev in threaded environments you have to make sure
4463	it's compiled with C<_REENTRANT> defined.	4575	it's compiled with C<_REENTRANT> defined.
4464		4576
4465	=head3 Event port backend	4577	=head3 Event port backend
4466		4578
4467	The scalable event interface for Solaris is called "event ports". Unfortunately,	4579	The scalable event interface for Solaris is called "event
4468	this mechanism is very buggy. If you run into high CPU usage, your program	4580	ports". Unfortunately, this mechanism is very buggy in all major
		4581	releases. If you run into high CPU usage, your program freezes or you get
4469	freezes or you get a large number of spurious wakeups, make sure you have	4582	a large number of spurious wakeups, make sure you have all the relevant
4470	all the relevant and latest kernel patches applied. No, I don't know which	4583	and latest kernel patches applied. No, I don't know which ones, but there
4471	ones, but there are multiple ones.	4584	are multiple ones to apply, and afterwards, event ports actually work
		4585	great.
4472		4586
4473	If you can't get it to work, you can try running the program by setting	4587	If you can't get it to work, you can try running the program by setting
4474	the environment variable C<LIBEV_FLAGS=3> to only allow C<poll> and	4588	the environment variable C<LIBEV_FLAGS=3> to only allow C<poll> and
4475	C<select> backends.	4589	C<select> backends.
4476		4590
4477	=head2 AIX POLL BUG	4591	=head2 AIX POLL BUG
4478		4592
4479	AIX unfortunately has a broken C<poll.h> header. Libev works around	4593	AIX unfortunately has a broken C<poll.h> header. Libev works around
4480	this by trying to avoid the poll backend altogether (i.e. it's not even	4594	this by trying to avoid the poll backend altogether (i.e. it's not even
4481	compiled in), which normally isn't a big problem as C<select> works fine	4595	compiled in), which normally isn't a big problem as C<select> works fine
4482	with large bitsets, and AIX is dead anyway.	4596	with large bitsets on AIX, and AIX is dead anyway.
4483		4597
4484	=head2 WIN32 PLATFORM LIMITATIONS AND WORKAROUNDS	4598	=head2 WIN32 PLATFORM LIMITATIONS AND WORKAROUNDS
4485		4599
4486	=head3 General issues	4600	=head3 General issues
4487		4601
…		…
4624	watchers.	4738	watchers.
4625		4739
4626	=item C<double> must hold a time value in seconds with enough accuracy	4740	=item C<double> must hold a time value in seconds with enough accuracy
4627		4741
4628	The type C<double> is used to represent timestamps. It is required to	4742	The type C<double> is used to represent timestamps. It is required to
4629	have at least 51 bits of mantissa (and 9 bits of exponent), which is good	4743	have at least 51 bits of mantissa (and 9 bits of exponent), which is
4630	enough for at least into the year 4000. This requirement is fulfilled by	4744	good enough for at least into the year 4000 with millisecond accuracy
		4745	(the design goal for libev). This requirement is overfulfilled by
4631	implementations implementing IEEE 754, which is basically all existing	4746	implementations using IEEE 754, which is basically all existing ones. With
4632	ones. With IEEE 754 doubles, you get microsecond accuracy until at least	4747	IEEE 754 doubles, you get microsecond accuracy until at least 2200.
4633	2200.
4634		4748
4635	=back	4749	=back
4636		4750
4637	If you know of other additional requirements drop me a note.	4751	If you know of other additional requirements drop me a note.
4638		4752
…		…
4716	compatibility, so most programs should still compile. Those might be	4830	compatibility, so most programs should still compile. Those might be
4717	removed in later versions of libev, so better update early than late.	4831	removed in later versions of libev, so better update early than late.
4718		4832
4719	=over 4	4833	=over 4
4720		4834
4721	=item C<ev_loop_count> renamed to C<ev_iteration>	4835	=item function/symbol renames
4722		4836
4723	=item C<ev_loop_depth> renamed to C<ev_depth>	4837	A number of functions and symbols have been renamed:
4724		4838
4725	=item C<ev_loop_verify> renamed to C<ev_verify>	4839	ev_loop => ev_run
		4840	EVLOOP_NONBLOCK => EVRUN_NOWAIT
		4841	EVLOOP_ONESHOT => EVRUN_ONCE
		4842
		4843	ev_unloop => ev_break
		4844	EVUNLOOP_CANCEL => EVBREAK_CANCEL
		4845	EVUNLOOP_ONE => EVBREAK_ONE
		4846	EVUNLOOP_ALL => EVBREAK_ALL
		4847
		4848	EV_TIMEOUT => EV_TIMER
		4849
		4850	ev_loop_count => ev_iteration
		4851	ev_loop_depth => ev_depth
		4852	ev_loop_verify => ev_verify
4726		4853
4727	Most functions working on C<struct ev_loop> objects don't have an	4854	Most functions working on C<struct ev_loop> objects don't have an
4728	C<ev_loop_> prefix, so it was removed. Note that C<ev_loop_fork> is	4855	C<ev_loop_> prefix, so it was removed; C<ev_loop>, C<ev_unloop> and
		4856	associated constants have been renamed to not collide with the C<struct
		4857	ev_loop> anymore and C<EV_TIMER> now follows the same naming scheme
		4858	as all other watcher types. Note that C<ev_loop_fork> is still called
4729	still called C<ev_loop_fork> because it would otherwise clash with the	4859	C<ev_loop_fork> because it would otherwise clash with the C<ev_fork>
4730	C<ev_fork> typedef.	4860	typedef.
4731		4861
4732	=item C<EV_TIMEOUT> renamed to C<EV_TIMER> in C<revents>	4862	=item C<EV_COMPAT3> backwards compatibility mechanism
4733		4863
4734	This is a simple rename - all other watcher types use their name	4864	The backward compatibility mechanism can be controlled by
4735	as revents flag, and now C<ev_timer> does, too.	4865	C<EV_COMPAT3>. See L<PREPROCESSOR SYMBOLS/MACROS> in the L<EMBEDDING>
4736		4866	section.
4737	Both C<EV_TIMER> and C<EV_TIMEOUT> symbols were present in 3.x versions
4738	and continue to be present for the foreseeable future, so this is mostly a
4739	documentation change.
4740		4867
4741	=item C<EV_MINIMAL> mechanism replaced by C<EV_FEATURES>	4868	=item C<EV_MINIMAL> mechanism replaced by C<EV_FEATURES>
4742		4869
4743	The preprocessor symbol C<EV_MINIMAL> has been replaced by a different	4870	The preprocessor symbol C<EV_MINIMAL> has been replaced by a different
4744	mechanism, C<EV_FEATURES>. Programs using C<EV_MINIMAL> usually compile	4871	mechanism, C<EV_FEATURES>. Programs using C<EV_MINIMAL> usually compile
…		…
4751		4878
4752	=over 4	4879	=over 4
4753		4880
4754	=item active	4881	=item active
4755		4882
4756	A watcher is active as long as it has been started (has been attached to	4883	A watcher is active as long as it has been started and not yet stopped.
4757	an event loop) but not yet stopped (disassociated from the event loop).	4884	See L<WATCHER STATES> for details.
4758		4885
4759	=item application	4886	=item application
4760		4887
4761	In this document, an application is whatever is using libev.	4888	In this document, an application is whatever is using libev.
		4889
		4890	=item backend
		4891
		4892	The part of the code dealing with the operating system interfaces.
4762		4893
4763	=item callback	4894	=item callback
4764		4895
4765	The address of a function that is called when some event has been	4896	The address of a function that is called when some event has been
4766	detected. Callbacks are being passed the event loop, the watcher that	4897	detected. Callbacks are being passed the event loop, the watcher that
4767	received the event, and the actual event bitset.	4898	received the event, and the actual event bitset.
4768		4899
4769	=item callback invocation	4900	=item callback/watcher invocation
4770		4901
4771	The act of calling the callback associated with a watcher.	4902	The act of calling the callback associated with a watcher.
4772		4903
4773	=item event	4904	=item event
4774		4905
…		…
4793	The model used to describe how an event loop handles and processes	4924	The model used to describe how an event loop handles and processes
4794	watchers and events.	4925	watchers and events.
4795		4926
4796	=item pending	4927	=item pending
4797		4928
4798	A watcher is pending as soon as the corresponding event has been detected,	4929	A watcher is pending as soon as the corresponding event has been
4799	and stops being pending as soon as the watcher will be invoked or its	4930	detected. See L<WATCHER STATES> for details.
4800	pending status is explicitly cleared by the application.
4801
4802	A watcher can be pending, but not active. Stopping a watcher also clears
4803	its pending status.
4804		4931
4805	=item real time	4932	=item real time
4806		4933
4807	The physical time that is observed. It is apparently strictly monotonic :)	4934	The physical time that is observed. It is apparently strictly monotonic :)
4808		4935
…		…
4815	=item watcher	4942	=item watcher
4816		4943
4817	A data structure that describes interest in certain events. Watchers need	4944	A data structure that describes interest in certain events. Watchers need
4818	to be started (attached to an event loop) before they can receive events.	4945	to be started (attached to an event loop) before they can receive events.
4819		4946
4820	=item watcher invocation
4821
4822	The act of calling the callback associated with a watcher.
4823
4824	=back	4947	=back
4825		4948
4826	=head1 AUTHOR	4949	=head1 AUTHOR
4827		4950
4828	Marc Lehmann <libev@schmorp.de>, with repeated corrections by Mikael Magnusson.	4951	Marc Lehmann <libev@schmorp.de>, with repeated corrections by Mikael Magnusson.

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Comparing libev/ev.pod (file contents): Revision 1.305 by root, Thu Oct 14 05:07:04 2010 UTC vs. Revision 1.321 by sf-exg, Fri Oct 22 10:50:24 2010 UTC

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Comparing libev/ev.pod (file contents):
Revision 1.305 by root, Thu Oct 14 05:07:04 2010 UTC vs.
Revision 1.321 by sf-exg, Fri Oct 22 10:50:24 2010 UTC