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

Comparing libev/ev.pod (file contents):
Revision 1.309 by root, Thu Oct 21 09:23:21 2010 UTC vs.
Revision 1.310 by root, Thu Oct 21 12:32:47 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
…		…
292		292
293	=back	293	=back
294		294
295	=head1 FUNCTIONS CONTROLLING THE EVENT LOOP	295	=head1 FUNCTIONS CONTROLLING THE EVENT LOOP
296		296
297	An event loop is described by a C<struct ev_loop *> (the C<struct>	297	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>	298	I<not> optional in case unless libev 3 compatibility is disabled, as libev
299	I<function>).	299	3 had an C<ev_loop> function colliding with the struct name).
300		300
301	The library knows two types of such loops, the I<default> loop, which	301	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	302	supports signals and child events, and dynamically created event loops
303	not.	303	which do not.
304		304
305	=over 4	305	=over 4
306		306
307	=item struct ev_loop *ev_default_loop (unsigned int flags)	307	=item struct ev_loop *ev_default_loop (unsigned int flags)
308		308
…		…
606	Like C<ev_default_destroy>, but destroys an event loop created by an	606	Like C<ev_default_destroy>, but destroys an event loop created by an
607	earlier call to C<ev_loop_new>.	607	earlier call to C<ev_loop_new>.
608		608
609	=item ev_default_fork ()	609	=item ev_default_fork ()
610		610
611	This function sets a flag that causes subsequent C<ev_loop> iterations	611	This function sets a flag that causes subsequent C<ev_run> iterations
612	to reinitialise the kernel state for backends that have one. Despite the	612	to reinitialise the kernel state for backends that have one. Despite the
613	name, you can call it anytime, but it makes most sense after forking, in	613	name, you can call it anytime, but it makes most sense after forking, in
614	the child process (or both child and parent, but that again makes little	614	the child process (or both child and parent, but that again makes little
615	sense). You I<must> call it in the child before using any of the libev	615	sense). You I<must> call it in the child before using any of the libev
616	functions, and it will only take effect at the next C<ev_loop> iteration.	616	functions, and it will only take effect at the next C<ev_run> iteration.
617		617
618	Again, you I<have> to call it on I<any> loop that you want to re-use after	618	Again, you I<have> to call it on I<any> loop that you want to re-use after
619	a fork, I<even if you do not plan to use the loop in the parent>. This is	619	a fork, I<even if you do not plan to use the loop in the parent>. This is
620	because some kernel interfaces cough I<kqueue> cough do funny things	620	because some kernel interfaces cough I<kqueue> cough do funny things
621	during fork.	621	during fork.
622		622
623	On the other hand, you only need to call this function in the child	623	On the other hand, you only need to call this function in the child
624	process if and only if you want to use the event loop in the child. If you	624	process if and only if you want to use the event loop in the child. If
625	just fork+exec or create a new loop in the child, you don't have to call	625	you just fork+exec or create a new loop in the child, you don't have to
626	it at all.	626	call it at all (in fact, C<epoll> is so badly broken that it makes a
		627	difference, but libev will usually detect this case on its own and do a
		628	costly reset of the backend).
627		629
628	The function itself is quite fast and it's usually not a problem to call	630	The function itself is quite fast and it's usually not a problem to call
629	it just in case after a fork. To make this easy, the function will fit in	631	it just in case after a fork. To make this easy, the function will fit in
630	quite nicely into a call to C<pthread_atfork>:	632	quite nicely into a call to C<pthread_atfork>:
631		633
…		…
643	Returns true when the given loop is, in fact, the default loop, and false	645	Returns true when the given loop is, in fact, the default loop, and false
644	otherwise.	646	otherwise.
645		647
646	=item unsigned int ev_iteration (loop)	648	=item unsigned int ev_iteration (loop)
647		649
648	Returns the current iteration count for the loop, which is identical to	650	Returns the current iteration count for the event loop, which is identical
649	the number of times libev did poll for new events. It starts at C<0> and	651	to the number of times libev did poll for new events. It starts at C<0>
650	happily wraps around with enough iterations.	652	and happily wraps around with enough iterations.
651		653
652	This value can sometimes be useful as a generation counter of sorts (it	654	This value can sometimes be useful as a generation counter of sorts (it
653	"ticks" the number of loop iterations), as it roughly corresponds with	655	"ticks" the number of loop iterations), as it roughly corresponds with
654	C<ev_prepare> and C<ev_check> calls - and is incremented between the	656	C<ev_prepare> and C<ev_check> calls - and is incremented between the
655	prepare and check phases.	657	prepare and check phases.
656		658
657	=item unsigned int ev_depth (loop)	659	=item unsigned int ev_depth (loop)
658		660
659	Returns the number of times C<ev_loop> was entered minus the number of	661	Returns the number of times C<ev_run> was entered minus the number of
660	times C<ev_loop> was exited, in other words, the recursion depth.	662	times C<ev_run> was exited, in other words, the recursion depth.
661		663
662	Outside C<ev_loop>, this number is zero. In a callback, this number is	664	Outside C<ev_run>, this number is zero. In a callback, this number is
663	C<1>, unless C<ev_loop> was invoked recursively (or from another thread),	665	C<1>, unless C<ev_run> was invoked recursively (or from another thread),
664	in which case it is higher.	666	in which case it is higher.
665		667
666	Leaving C<ev_loop> abnormally (setjmp/longjmp, cancelling the thread	668	Leaving C<ev_run> abnormally (setjmp/longjmp, cancelling the thread
667	etc.), doesn't count as "exit" - consider this as a hint to avoid such	669	etc.), doesn't count as "exit" - consider this as a hint to avoid such
668	ungentleman behaviour unless it's really convenient.	670	ungentleman-like behaviour unless it's really convenient.
669		671
670	=item unsigned int ev_backend (loop)	672	=item unsigned int ev_backend (loop)
671		673
672	Returns one of the C<EVBACKEND_*> flags indicating the event backend in	674	Returns one of the C<EVBACKEND_*> flags indicating the event backend in
673	use.	675	use.
…		…
682		684
683	=item ev_now_update (loop)	685	=item ev_now_update (loop)
684		686
685	Establishes the current time by querying the kernel, updating the time	687	Establishes the current time by querying the kernel, updating the time
686	returned by C<ev_now ()> in the progress. This is a costly operation and	688	returned by C<ev_now ()> in the progress. This is a costly operation and
687	is usually done automatically within C<ev_loop ()>.	689	is usually done automatically within C<ev_run ()>.
688		690
689	This function is rarely useful, but when some event callback runs for a	691	This function is rarely useful, but when some event callback runs for a
690	very long time without entering the event loop, updating libev's idea of	692	very long time without entering the event loop, updating libev's idea of
691	the current time is a good idea.	693	the current time is a good idea.
692		694
…		…
694		696
695	=item ev_suspend (loop)	697	=item ev_suspend (loop)
696		698
697	=item ev_resume (loop)	699	=item ev_resume (loop)
698		700
699	These two functions suspend and resume a loop, for use when the loop is	701	These two functions suspend and resume an event loop, for use when the
700	not used for a while and timeouts should not be processed.	702	loop is not used for a while and timeouts should not be processed.
701		703
702	A typical use case would be an interactive program such as a game: When	704	A typical use case would be an interactive program such as a game: When
703	the user presses C<^Z> to suspend the game and resumes it an hour later it	705	the user presses C<^Z> to suspend the game and resumes it an hour later it
704	would be best to handle timeouts as if no time had actually passed while	706	would be best to handle timeouts as if no time had actually passed while
705	the program was suspended. This can be achieved by calling C<ev_suspend>	707	the program was suspended. This can be achieved by calling C<ev_suspend>
…		…
716	without a previous call to C<ev_suspend>.	718	without a previous call to C<ev_suspend>.
717		719
718	Calling C<ev_suspend>/C<ev_resume> has the side effect of updating the	720	Calling C<ev_suspend>/C<ev_resume> has the side effect of updating the
719	event loop time (see C<ev_now_update>).	721	event loop time (see C<ev_now_update>).
720		722
721	=item ev_loop (loop, int flags)	723	=item ev_run (loop, int flags)
722		724
723	Finally, this is it, the event handler. This function usually is called	725	Finally, this is it, the event handler. This function usually is called
724	after you have initialised all your watchers and you want to start	726	after you have initialised all your watchers and you want to start
725	handling events.	727	handling events. It will ask the operating system for any new events, call
		728	the watcher callbacks, an then repeat the whole process indefinitely: This
		729	is why event loops are called I<loops>.
726		730
727	If the flags argument is specified as C<0>, it will not return until	731	If the flags argument is specified as C<0>, it will keep handling events
728	either no event watchers are active anymore or C<ev_unloop> was called.	732	until either no event watchers are active anymore or C<ev_break> was
		733	called.
729		734
730	Please note that an explicit C<ev_unloop> is usually better than	735	Please note that an explicit C<ev_break> is usually better than
731	relying on all watchers to be stopped when deciding when a program has	736	relying on all watchers to be stopped when deciding when a program has
732	finished (especially in interactive programs), but having a program	737	finished (especially in interactive programs), but having a program
733	that automatically loops as long as it has to and no longer by virtue	738	that automatically loops as long as it has to and no longer by virtue
734	of relying on its watchers stopping correctly, that is truly a thing of	739	of relying on its watchers stopping correctly, that is truly a thing of
735	beauty.	740	beauty.
736		741
737	A flags value of C<EVLOOP_NONBLOCK> will look for new events, will handle	742	A flags value of C<EVRUN_NOWAIT> will look for new events, will handle
738	those events and any already outstanding ones, but will not block your	743	those events and any already outstanding ones, but will not wait and
739	process in case there are no events and will return after one iteration of	744	block your process in case there are no events and will return after one
740	the loop.	745	iteration of the loop. This is sometimes useful to poll and handle new
		746	events while doing lengthy calculations, to keep the program responsive.
741		747
742	A flags value of C<EVLOOP_ONESHOT> will look for new events (waiting if	748	A flags value of C<EVRUN_ONCE> will look for new events (waiting if
743	necessary) and will handle those and any already outstanding ones. It	749	necessary) and will handle those and any already outstanding ones. It
744	will block your process until at least one new event arrives (which could	750	will block your process until at least one new event arrives (which could
745	be an event internal to libev itself, so there is no guarantee that a	751	be an event internal to libev itself, so there is no guarantee that a
746	user-registered callback will be called), and will return after one	752	user-registered callback will be called), and will return after one
747	iteration of the loop.	753	iteration of the loop.
748		754
749	This is useful if you are waiting for some external event in conjunction	755	This is useful if you are waiting for some external event in conjunction
750	with something not expressible using other libev watchers (i.e. "roll your	756	with something not expressible using other libev watchers (i.e. "roll your
751	own C<ev_loop>"). However, a pair of C<ev_prepare>/C<ev_check> watchers is	757	own C<ev_run>"). However, a pair of C<ev_prepare>/C<ev_check> watchers is
752	usually a better approach for this kind of thing.	758	usually a better approach for this kind of thing.
753		759
754	Here are the gory details of what C<ev_loop> does:	760	Here are the gory details of what C<ev_run> does:
755		761
		762	- Increment loop depth.
		763	- Reset the ev_break status.
756	- Before the first iteration, call any pending watchers.	764	- Before the first iteration, call any pending watchers.
		765	LOOP:
757	* If EVFLAG_FORKCHECK was used, check for a fork.	766	- If EVFLAG_FORKCHECK was used, check for a fork.
758	- If a fork was detected (by any means), queue and call all fork watchers.	767	- If a fork was detected (by any means), queue and call all fork watchers.
759	- Queue and call all prepare watchers.	768	- Queue and call all prepare watchers.
		769	- If ev_break was called, goto FINISH.
760	- If we have been forked, detach and recreate the kernel state	770	- If we have been forked, detach and recreate the kernel state
761	as to not disturb the other process.	771	as to not disturb the other process.
762	- Update the kernel state with all outstanding changes.	772	- Update the kernel state with all outstanding changes.
763	- Update the "event loop time" (ev_now ()).	773	- Update the "event loop time" (ev_now ()).
764	- Calculate for how long to sleep or block, if at all	774	- Calculate for how long to sleep or block, if at all
765	(active idle watchers, EVLOOP_NONBLOCK or not having	775	(active idle watchers, EVRUN_NOWAIT or not having
766	any active watchers at all will result in not sleeping).	776	any active watchers at all will result in not sleeping).
767	- Sleep if the I/O and timer collect interval say so.	777	- Sleep if the I/O and timer collect interval say so.
		778	- Increment loop iteration counter.
768	- Block the process, waiting for any events.	779	- Block the process, waiting for any events.
769	- Queue all outstanding I/O (fd) events.	780	- Queue all outstanding I/O (fd) events.
770	- Update the "event loop time" (ev_now ()), and do time jump adjustments.	781	- Update the "event loop time" (ev_now ()), and do time jump adjustments.
771	- Queue all expired timers.	782	- Queue all expired timers.
772	- Queue all expired periodics.	783	- Queue all expired periodics.
773	- Unless any events are pending now, queue all idle watchers.	784	- Queue all idle watchers with priority higher than that of pending events.
774	- Queue all check watchers.	785	- Queue all check watchers.
775	- Call all queued watchers in reverse order (i.e. check watchers first).	786	- Call all queued watchers in reverse order (i.e. check watchers first).
776	Signals and child watchers are implemented as I/O watchers, and will	787	Signals and child watchers are implemented as I/O watchers, and will
777	be handled here by queueing them when their watcher gets executed.	788	be handled here by queueing them when their watcher gets executed.
778	- If ev_unloop has been called, or EVLOOP_ONESHOT or EVLOOP_NONBLOCK	789	- If ev_break has been called, or EVRUN_ONCE or EVRUN_NOWAIT
779	were used, or there are no active watchers, return, otherwise	790	were used, or there are no active watchers, goto FINISH, otherwise
780	continue with step *.	791	continue with step LOOP.
		792	FINISH:
		793	- Reset the ev_break status iff it was EVBREAK_ONE.
		794	- Decrement the loop depth.
		795	- Return.
781		796
782	Example: Queue some jobs and then loop until no events are outstanding	797	Example: Queue some jobs and then loop until no events are outstanding
783	anymore.	798	anymore.
784		799
785	... queue jobs here, make sure they register event watchers as long	800	... queue jobs here, make sure they register event watchers as long
786	... as they still have work to do (even an idle watcher will do..)	801	... as they still have work to do (even an idle watcher will do..)
787	ev_loop (my_loop, 0);	802	ev_run (my_loop, 0);
788	... jobs done or somebody called unloop. yeah!	803	... jobs done or somebody called unloop. yeah!
789		804
790	=item ev_unloop (loop, how)	805	=item ev_break (loop, how)
791		806
792	Can be used to make a call to C<ev_loop> return early (but only after it	807	Can be used to make a call to C<ev_run> return early (but only after it
793	has processed all outstanding events). The C<how> argument must be either	808	has processed all outstanding events). The C<how> argument must be either
794	C<EVUNLOOP_ONE>, which will make the innermost C<ev_loop> call return, or	809	C<EVBREAK_ONE>, which will make the innermost C<ev_run> call return, or
795	C<EVUNLOOP_ALL>, which will make all nested C<ev_loop> calls return.	810	C<EVBREAK_ALL>, which will make all nested C<ev_run> calls return.
796		811
797	This "unloop state" will be cleared when entering C<ev_loop> again.	812	This "unloop state" will be cleared when entering C<ev_run> again.
798		813
799	It is safe to call C<ev_unloop> from outside any C<ev_loop> calls.	814	It is safe to call C<ev_break> from outside any C<ev_run> calls. ##TODO##
800		815
801	=item ev_ref (loop)	816	=item ev_ref (loop)
802		817
803	=item ev_unref (loop)	818	=item ev_unref (loop)
804		819
805	Ref/unref can be used to add or remove a reference count on the event	820	Ref/unref can be used to add or remove a reference count on the event
806	loop: Every watcher keeps one reference, and as long as the reference	821	loop: Every watcher keeps one reference, and as long as the reference
807	count is nonzero, C<ev_loop> will not return on its own.	822	count is nonzero, C<ev_run> will not return on its own.
808		823
809	This is useful when you have a watcher that you never intend to	824	This is useful when you have a watcher that you never intend to
810	unregister, but that nevertheless should not keep C<ev_loop> from	825	unregister, but that nevertheless should not keep C<ev_run> from
811	returning. In such a case, call C<ev_unref> after starting, and C<ev_ref>	826	returning. In such a case, call C<ev_unref> after starting, and C<ev_ref>
812	before stopping it.	827	before stopping it.
813		828
814	As an example, libev itself uses this for its internal signal pipe: It	829	As an example, libev itself uses this for its internal signal pipe: It
815	is not visible to the libev user and should not keep C<ev_loop> from	830	is not visible to the libev user and should not keep C<ev_run> from
816	exiting if no event watchers registered by it are active. It is also an	831	exiting if no event watchers registered by it are active. It is also an
817	excellent way to do this for generic recurring timers or from within	832	excellent way to do this for generic recurring timers or from within
818	third-party libraries. Just remember to I<unref after start> and I<ref	833	third-party libraries. Just remember to I<unref after start> and I<ref
819	before stop> (but only if the watcher wasn't active before, or was active	834	before stop> (but only if the watcher wasn't active before, or was active
820	before, respectively. Note also that libev might stop watchers itself	835	before, respectively. Note also that libev might stop watchers itself
821	(e.g. non-repeating timers) in which case you have to C<ev_ref>	836	(e.g. non-repeating timers) in which case you have to C<ev_ref>
822	in the callback).	837	in the callback).
823		838
824	Example: Create a signal watcher, but keep it from keeping C<ev_loop>	839	Example: Create a signal watcher, but keep it from keeping C<ev_run>
825	running when nothing else is active.	840	running when nothing else is active.
826		841
827	ev_signal exitsig;	842	ev_signal exitsig;
828	ev_signal_init (&exitsig, sig_cb, SIGINT);	843	ev_signal_init (&exitsig, sig_cb, SIGINT);
829	ev_signal_start (loop, &exitsig);	844	ev_signal_start (loop, &exitsig);
…		…
892	ev_set_io_collect_interval (EV_DEFAULT_UC_ 0.01);	907	ev_set_io_collect_interval (EV_DEFAULT_UC_ 0.01);
893		908
894	=item ev_invoke_pending (loop)	909	=item ev_invoke_pending (loop)
895		910
896	This call will simply invoke all pending watchers while resetting their	911	This call will simply invoke all pending watchers while resetting their
897	pending state. Normally, C<ev_loop> does this automatically when required,	912	pending state. Normally, C<ev_run> does this automatically when required,
898	but when overriding the invoke callback this call comes handy.	913	but when overriding the invoke callback this call comes handy.
899		914
900	=item int ev_pending_count (loop)	915	=item int ev_pending_count (loop)
901		916
902	Returns the number of pending watchers - zero indicates that no watchers	917	Returns the number of pending watchers - zero indicates that no watchers
903	are pending.	918	are pending.
904		919
905	=item ev_set_invoke_pending_cb (loop, void (*invoke_pending_cb)(EV_P))	920	=item ev_set_invoke_pending_cb (loop, void (*invoke_pending_cb)(EV_P))
906		921
907	This overrides the invoke pending functionality of the loop: Instead of	922	This overrides the invoke pending functionality of the loop: Instead of
908	invoking all pending watchers when there are any, C<ev_loop> will call	923	invoking all pending watchers when there are any, C<ev_run> will call
909	this callback instead. This is useful, for example, when you want to	924	this callback instead. This is useful, for example, when you want to
910	invoke the actual watchers inside another context (another thread etc.).	925	invoke the actual watchers inside another context (another thread etc.).
911		926
912	If you want to reset the callback, use C<ev_invoke_pending> as new	927	If you want to reset the callback, use C<ev_invoke_pending> as new
913	callback.	928	callback.
…		…
916		931
917	Sometimes you want to share the same loop between multiple threads. This	932	Sometimes you want to share the same loop between multiple threads. This
918	can be done relatively simply by putting mutex_lock/unlock calls around	933	can be done relatively simply by putting mutex_lock/unlock calls around
919	each call to a libev function.	934	each call to a libev function.
920		935
921	However, C<ev_loop> can run an indefinite time, so it is not feasible to	936	However, C<ev_run> can run an indefinite time, so it is not feasible
922	wait for it to return. One way around this is to wake up the loop via	937	to wait for it to return. One way around this is to wake up the event
923	C<ev_unloop> and C<av_async_send>, another way is to set these I<release>	938	loop via C<ev_break> and C<av_async_send>, another way is to set these
924	and I<acquire> callbacks on the loop.	939	I<release> and I<acquire> callbacks on the loop.
925		940
926	When set, then C<release> will be called just before the thread is	941	When set, then C<release> will be called just before the thread is
927	suspended waiting for new events, and C<acquire> is called just	942	suspended waiting for new events, and C<acquire> is called just
928	afterwards.	943	afterwards.
929		944
…		…
932		947
933	While event loop modifications are allowed between invocations of	948	While event loop modifications are allowed between invocations of
934	C<release> and C<acquire> (that's their only purpose after all), no	949	C<release> and C<acquire> (that's their only purpose after all), no
935	modifications done will affect the event loop, i.e. adding watchers will	950	modifications done will affect the event loop, i.e. adding watchers will
936	have no effect on the set of file descriptors being watched, or the time	951	have no effect on the set of file descriptors being watched, or the time
937	waited. Use an C<ev_async> watcher to wake up C<ev_loop> when you want it	952	waited. Use an C<ev_async> watcher to wake up C<ev_run> when you want it
938	to take note of any changes you made.	953	to take note of any changes you made.
939		954
940	In theory, threads executing C<ev_loop> will be async-cancel safe between	955	In theory, threads executing C<ev_run> will be async-cancel safe between
941	invocations of C<release> and C<acquire>.	956	invocations of C<release> and C<acquire>.
942		957
943	See also the locking example in the C<THREADS> section later in this	958	See also the locking example in the C<THREADS> section later in this
944	document.	959	document.
945		960
…		…
982	become readable, you would create an C<ev_io> watcher for that:	997	become readable, you would create an C<ev_io> watcher for that:
983		998
984	static void my_cb (struct ev_loop loop, ev_io w, int revents)	999	static void my_cb (struct ev_loop loop, ev_io w, int revents)
985	{	1000	{
986	ev_io_stop (w);	1001	ev_io_stop (w);
987	ev_unloop (loop, EVUNLOOP_ALL);	1002	ev_break (loop, EVBREAK_ALL);
988	}	1003	}
989		1004
990	struct ev_loop *loop = ev_default_loop (0);	1005	struct ev_loop *loop = ev_default_loop (0);
991		1006
992	ev_io stdin_watcher;	1007	ev_io stdin_watcher;
993		1008
994	ev_init (&stdin_watcher, my_cb);	1009	ev_init (&stdin_watcher, my_cb);
995	ev_io_set (&stdin_watcher, STDIN_FILENO, EV_READ);	1010	ev_io_set (&stdin_watcher, STDIN_FILENO, EV_READ);
996	ev_io_start (loop, &stdin_watcher);	1011	ev_io_start (loop, &stdin_watcher);
997		1012
998	ev_loop (loop, 0);	1013	ev_run (loop, 0);
999		1014
1000	As you can see, you are responsible for allocating the memory for your	1015	As you can see, you are responsible for allocating the memory for your
1001	watcher structures (and it is I<usually> a bad idea to do this on the	1016	watcher structures (and it is I<usually> a bad idea to do this on the
1002	stack).	1017	stack).
1003		1018
…		…
1067		1082
1068	=item C<EV_PREPARE>	1083	=item C<EV_PREPARE>
1069		1084
1070	=item C<EV_CHECK>	1085	=item C<EV_CHECK>
1071		1086
1072	All C<ev_prepare> watchers are invoked just I<before> C<ev_loop> starts	1087	All C<ev_prepare> watchers are invoked just I<before> C<ev_run> starts
1073	to gather new events, and all C<ev_check> watchers are invoked just after	1088	to gather new events, and all C<ev_check> watchers are invoked just after
1074	C<ev_loop> has gathered them, but before it invokes any callbacks for any	1089	C<ev_run> has gathered them, but before it invokes any callbacks for any
1075	received events. Callbacks of both watcher types can start and stop as	1090	received events. Callbacks of both watcher types can start and stop as
1076	many watchers as they want, and all of them will be taken into account	1091	many watchers as they want, and all of them will be taken into account
1077	(for example, a C<ev_prepare> watcher might start an idle watcher to keep	1092	(for example, a C<ev_prepare> watcher might start an idle watcher to keep
1078	C<ev_loop> from blocking).	1093	C<ev_run> from blocking).
1079		1094
1080	=item C<EV_EMBED>	1095	=item C<EV_EMBED>
1081		1096
1082	The embedded event loop specified in the C<ev_embed> watcher needs attention.	1097	The embedded event loop specified in the C<ev_embed> watcher needs attention.
1083		1098
…		…
1624	...	1639	...
1625	struct ev_loop *loop = ev_default_init (0);	1640	struct ev_loop *loop = ev_default_init (0);
1626	ev_io stdin_readable;	1641	ev_io stdin_readable;
1627	ev_io_init (&stdin_readable, stdin_readable_cb, STDIN_FILENO, EV_READ);	1642	ev_io_init (&stdin_readable, stdin_readable_cb, STDIN_FILENO, EV_READ);
1628	ev_io_start (loop, &stdin_readable);	1643	ev_io_start (loop, &stdin_readable);
1629	ev_loop (loop, 0);	1644	ev_run (loop, 0);
1630		1645
1631		1646
1632	=head2 C<ev_timer> - relative and optionally repeating timeouts	1647	=head2 C<ev_timer> - relative and optionally repeating timeouts
1633		1648
1634	Timer watchers are simple relative timers that generate an event after a	1649	Timer watchers are simple relative timers that generate an event after a
…		…
1643	The callback is guaranteed to be invoked only I<after> its timeout has	1658	The callback is guaranteed to be invoked only I<after> its timeout has
1644	passed (not I<at>, so on systems with very low-resolution clocks this	1659	passed (not I<at>, so on systems with very low-resolution clocks this
1645	might introduce a small delay). If multiple timers become ready during the	1660	might introduce a small delay). If multiple timers become ready during the
1646	same loop iteration then the ones with earlier time-out values are invoked	1661	same loop iteration then the ones with earlier time-out values are invoked
1647	before ones of the same priority with later time-out values (but this is	1662	before ones of the same priority with later time-out values (but this is
1648	no longer true when a callback calls C<ev_loop> recursively).	1663	no longer true when a callback calls C<ev_run> recursively).
1649		1664
1650	=head3 Be smart about timeouts	1665	=head3 Be smart about timeouts
1651		1666
1652	Many real-world problems involve some kind of timeout, usually for error	1667	Many real-world problems involve some kind of timeout, usually for error
1653	recovery. A typical example is an HTTP request - if the other side hangs,	1668	recovery. A typical example is an HTTP request - if the other side hangs,
…		…
1824		1839
1825	=head3 The special problem of time updates	1840	=head3 The special problem of time updates
1826		1841
1827	Establishing the current time is a costly operation (it usually takes at	1842	Establishing the current time is a costly operation (it usually takes at
1828	least two system calls): EV therefore updates its idea of the current	1843	least two system calls): EV therefore updates its idea of the current
1829	time only before and after C<ev_loop> collects new events, which causes a	1844	time only before and after C<ev_run> collects new events, which causes a
1830	growing difference between C<ev_now ()> and C<ev_time ()> when handling	1845	growing difference between C<ev_now ()> and C<ev_time ()> when handling
1831	lots of events in one iteration.	1846	lots of events in one iteration.
1832		1847
1833	The relative timeouts are calculated relative to the C<ev_now ()>	1848	The relative timeouts are calculated relative to the C<ev_now ()>
1834	time. This is usually the right thing as this timestamp refers to the time	1849	time. This is usually the right thing as this timestamp refers to the time
…		…
1951	}	1966	}
1952		1967
1953	ev_timer mytimer;	1968	ev_timer mytimer;
1954	ev_timer_init (&mytimer, timeout_cb, 0., 10.); /* note, only repeat used */	1969	ev_timer_init (&mytimer, timeout_cb, 0., 10.); /* note, only repeat used */
1955	ev_timer_again (&mytimer); /* start timer */	1970	ev_timer_again (&mytimer); /* start timer */
1956	ev_loop (loop, 0);	1971	ev_run (loop, 0);
1957		1972
1958	// and in some piece of code that gets executed on any "activity":	1973	// and in some piece of code that gets executed on any "activity":
1959	// reset the timeout to start ticking again at 10 seconds	1974	// reset the timeout to start ticking again at 10 seconds
1960	ev_timer_again (&mytimer);	1975	ev_timer_again (&mytimer);
1961		1976
…		…
1987		2002
1988	As with timers, the callback is guaranteed to be invoked only when the	2003	As with timers, the callback is guaranteed to be invoked only when the
1989	point in time where it is supposed to trigger has passed. If multiple	2004	point in time where it is supposed to trigger has passed. If multiple
1990	timers become ready during the same loop iteration then the ones with	2005	timers become ready during the same loop iteration then the ones with
1991	earlier time-out values are invoked before ones with later time-out values	2006	earlier time-out values are invoked before ones with later time-out values
1992	(but this is no longer true when a callback calls C<ev_loop> recursively).	2007	(but this is no longer true when a callback calls C<ev_run> recursively).
1993		2008
1994	=head3 Watcher-Specific Functions and Data Members	2009	=head3 Watcher-Specific Functions and Data Members
1995		2010
1996	=over 4	2011	=over 4
1997		2012
…		…
2235	Example: Try to exit cleanly on SIGINT.	2250	Example: Try to exit cleanly on SIGINT.
2236		2251
2237	static void	2252	static void
2238	sigint_cb (struct ev_loop loop, ev_signal w, int revents)	2253	sigint_cb (struct ev_loop loop, ev_signal w, int revents)
2239	{	2254	{
2240	ev_unloop (loop, EVUNLOOP_ALL);	2255	ev_break (loop, EVBREAK_ALL);
2241	}	2256	}
2242		2257
2243	ev_signal signal_watcher;	2258	ev_signal signal_watcher;
2244	ev_signal_init (&signal_watcher, sigint_cb, SIGINT);	2259	ev_signal_init (&signal_watcher, sigint_cb, SIGINT);
2245	ev_signal_start (loop, &signal_watcher);	2260	ev_signal_start (loop, &signal_watcher);
…		…
2631		2646
2632	Prepare and check watchers are usually (but not always) used in pairs:	2647	Prepare and check watchers are usually (but not always) used in pairs:
2633	prepare watchers get invoked before the process blocks and check watchers	2648	prepare watchers get invoked before the process blocks and check watchers
2634	afterwards.	2649	afterwards.
2635		2650
2636	You I<must not> call C<ev_loop> or similar functions that enter	2651	You I<must not> call C<ev_run> or similar functions that enter
2637	the current event loop from either C<ev_prepare> or C<ev_check>	2652	the current event loop from either C<ev_prepare> or C<ev_check>
2638	watchers. Other loops than the current one are fine, however. The	2653	watchers. Other loops than the current one are fine, however. The
2639	rationale behind this is that you do not need to check for recursion in	2654	rationale behind this is that you do not need to check for recursion in
2640	those watchers, i.e. the sequence will always be C<ev_prepare>, blocking,	2655	those watchers, i.e. the sequence will always be C<ev_prepare>, blocking,
2641	C<ev_check> so if you have one watcher of each kind they will always be	2656	C<ev_check> so if you have one watcher of each kind they will always be
…		…
2809		2824
2810	if (timeout >= 0)	2825	if (timeout >= 0)
2811	// create/start timer	2826	// create/start timer
2812		2827
2813	// poll	2828	// poll
2814	ev_loop (EV_A_ 0);	2829	ev_run (EV_A_ 0);
2815		2830
2816	// stop timer again	2831	// stop timer again
2817	if (timeout >= 0)	2832	if (timeout >= 0)
2818	ev_timer_stop (EV_A_ &to);	2833	ev_timer_stop (EV_A_ &to);
2819		2834
…		…
2897	if you do not want that, you need to temporarily stop the embed watcher).	2912	if you do not want that, you need to temporarily stop the embed watcher).
2898		2913
2899	=item ev_embed_sweep (loop, ev_embed *)	2914	=item ev_embed_sweep (loop, ev_embed *)
2900		2915
2901	Make a single, non-blocking sweep over the embedded loop. This works	2916	Make a single, non-blocking sweep over the embedded loop. This works
2902	similarly to C<ev_loop (embedded_loop, EVLOOP_NONBLOCK)>, but in the most	2917	similarly to C<ev_run (embedded_loop, EVRUN_NOWAIT)>, but in the most
2903	appropriate way for embedded loops.	2918	appropriate way for embedded loops.
2904		2919
2905	=item struct ev_loop *other [read-only]	2920	=item struct ev_loop *other [read-only]
2906		2921
2907	The embedded event loop.	2922	The embedded event loop.
…		…
3013	=back	3028	=back
3014		3029
3015		3030
3016	=head2 C<ev_async> - how to wake up an event loop	3031	=head2 C<ev_async> - how to wake up an event loop
3017		3032
3018	In general, you cannot use an C<ev_loop> from multiple threads or other	3033	In general, you cannot use an C<ev_run> from multiple threads or other
3019	asynchronous sources such as signal handlers (as opposed to multiple event	3034	asynchronous sources such as signal handlers (as opposed to multiple event
3020	loops - those are of course safe to use in different threads).	3035	loops - those are of course safe to use in different threads).
3021		3036
3022	Sometimes, however, you need to wake up an event loop you do not control,	3037	Sometimes, however, you need to wake up an event loop you do not control,
3023	for example because it belongs to another thread. This is what C<ev_async>	3038	for example because it belongs to another thread. This is what C<ev_async>
…		…
3530	loop argument"). The C<EV_A> form is used when this is the sole argument,	3545	loop argument"). The C<EV_A> form is used when this is the sole argument,
3531	C<EV_A_> is used when other arguments are following. Example:	3546	C<EV_A_> is used when other arguments are following. Example:
3532		3547
3533	ev_unref (EV_A);	3548	ev_unref (EV_A);
3534	ev_timer_add (EV_A_ watcher);	3549	ev_timer_add (EV_A_ watcher);
3535	ev_loop (EV_A_ 0);	3550	ev_run (EV_A_ 0);
3536		3551
3537	It assumes the variable C<loop> of type C<struct ev_loop *> is in scope,	3552	It assumes the variable C<loop> of type C<struct ev_loop *> is in scope,
3538	which is often provided by the following macro.	3553	which is often provided by the following macro.
3539		3554
3540	=item C<EV_P>, C<EV_P_>	3555	=item C<EV_P>, C<EV_P_>
…		…
3580	}	3595	}
3581		3596
3582	ev_check check;	3597	ev_check check;
3583	ev_check_init (&check, check_cb);	3598	ev_check_init (&check, check_cb);
3584	ev_check_start (EV_DEFAULT_ &check);	3599	ev_check_start (EV_DEFAULT_ &check);
3585	ev_loop (EV_DEFAULT_ 0);	3600	ev_run (EV_DEFAULT_ 0);
3586		3601
3587	=head1 EMBEDDING	3602	=head1 EMBEDDING
3588		3603
3589	Libev can (and often is) directly embedded into host	3604	Libev can (and often is) directly embedded into host
3590	applications. Examples of applications that embed it include the Deliantra	3605	applications. Examples of applications that embed it include the Deliantra
…		…
3681	to a compiled library. All other symbols change the ABI, which means all	3696	to a compiled library. All other symbols change the ABI, which means all
3682	users of libev and the libev code itself must be compiled with compatible	3697	users of libev and the libev code itself must be compiled with compatible
3683	settings.	3698	settings.
3684		3699
3685	=over 4	3700	=over 4
		3701
		3702	=item EV_COMPAT3 (h)
		3703
		3704	Backwards compatibility is a major concern for libev. This is why this
		3705	release of libev comes with wrappers for the functions and symbols that
		3706	have been renamed between libev version 3 and 4.
		3707
		3708	You can disable these wrappers (to test compatibility with future
		3709	versions) by defining C<EV_COMPAT3> to C<0> when compiling your
		3710	sources. This has the additional advantage that you can drop the C<struct>
		3711	from C<struct ev_loop> declarations, as libev will provide an C<ev_loop>
		3712	typedef in that case.
		3713
		3714	In some future version, the default for C<EV_COMPAT3> will become C<0>,
		3715	and in some even more future version the compatibility code will be
		3716	removed completely.
3686		3717
3687	=item EV_STANDALONE (h)	3718	=item EV_STANDALONE (h)
3688		3719
3689	Must always be C<1> if you do not use autoconf configuration, which	3720	Must always be C<1> if you do not use autoconf configuration, which
3690	keeps libev from including F<config.h>, and it also defines dummy	3721	keeps libev from including F<config.h>, and it also defines dummy
…		…
4265	userdata *u = ev_userdata (EV_A);	4296	userdata *u = ev_userdata (EV_A);
4266	pthread_mutex_lock (&u->lock);	4297	pthread_mutex_lock (&u->lock);
4267	}	4298	}
4268		4299
4269	The event loop thread first acquires the mutex, and then jumps straight	4300	The event loop thread first acquires the mutex, and then jumps straight
4270	into C<ev_loop>:	4301	into C<ev_run>:
4271		4302
4272	void *	4303	void *
4273	l_run (void *thr_arg)	4304	l_run (void *thr_arg)
4274	{	4305	{
4275	struct ev_loop loop = (struct ev_loop )thr_arg;	4306	struct ev_loop loop = (struct ev_loop )thr_arg;
4276		4307
4277	l_acquire (EV_A);	4308	l_acquire (EV_A);
4278	pthread_setcanceltype (PTHREAD_CANCEL_ASYNCHRONOUS, 0);	4309	pthread_setcanceltype (PTHREAD_CANCEL_ASYNCHRONOUS, 0);
4279	ev_loop (EV_A_ 0);	4310	ev_run (EV_A_ 0);
4280	l_release (EV_A);	4311	l_release (EV_A);
4281		4312
4282	return 0;	4313	return 0;
4283	}	4314	}
4284		4315
…		…
4336		4367
4337	=head3 COROUTINES	4368	=head3 COROUTINES
4338		4369
4339	Libev is very accommodating to coroutines ("cooperative threads"):	4370	Libev is very accommodating to coroutines ("cooperative threads"):
4340	libev fully supports nesting calls to its functions from different	4371	libev fully supports nesting calls to its functions from different
4341	coroutines (e.g. you can call C<ev_loop> on the same loop from two	4372	coroutines (e.g. you can call C<ev_run> on the same loop from two
4342	different coroutines, and switch freely between both coroutines running	4373	different coroutines, and switch freely between both coroutines running
4343	the loop, as long as you don't confuse yourself). The only exception is	4374	the loop, as long as you don't confuse yourself). The only exception is
4344	that you must not do this from C<ev_periodic> reschedule callbacks.	4375	that you must not do this from C<ev_periodic> reschedule callbacks.
4345		4376
4346	Care has been taken to ensure that libev does not keep local state inside	4377	Care has been taken to ensure that libev does not keep local state inside
4347	C<ev_loop>, and other calls do not usually allow for coroutine switches as	4378	C<ev_run>, and other calls do not usually allow for coroutine switches as
4348	they do not call any callbacks.	4379	they do not call any callbacks.
4349		4380
4350	=head2 COMPILER WARNINGS	4381	=head2 COMPILER WARNINGS
4351		4382
4352	Depending on your compiler and compiler settings, you might get no or a	4383	Depending on your compiler and compiler settings, you might get no or a
…		…
4729	compatibility, so most programs should still compile. Those might be	4760	compatibility, so most programs should still compile. Those might be
4730	removed in later versions of libev, so better update early than late.	4761	removed in later versions of libev, so better update early than late.
4731		4762
4732	=over 4	4763	=over 4
4733		4764
4734	=item C<ev_loop_count> renamed to C<ev_iteration>	4765	=item function/symbol renames
4735		4766
4736	=item C<ev_loop_depth> renamed to C<ev_depth>	4767	A number of functions and symbols have been renamed:
4737		4768
4738	=item C<ev_loop_verify> renamed to C<ev_verify>	4769	ev_loop => ev_run
		4770	EVLOOP_NONBLOCK => EVRUN_NOWAIT
		4771	EVLOOP_ONESHOT => EVRUN_ONCE
		4772
		4773	ev_unloop => ev_break
		4774	EVUNLOOP_CANCEL => EVBREAK_CANCEL
		4775	EVUNLOOP_ONE => EVBREAK_ONE
		4776	EVUNLOOP_ALL => EVBREAK_ALL
		4777
		4778	EV_TIMEOUT => EV_TIMER
		4779
		4780	ev_loop_count => ev_iteration
		4781	ev_loop_depth => ev_depth
		4782	ev_loop_verify => ev_verify
4739		4783
4740	Most functions working on C<struct ev_loop> objects don't have an	4784	Most functions working on C<struct ev_loop> objects don't have an
4741	C<ev_loop_> prefix, so it was removed. Note that C<ev_loop_fork> is	4785	C<ev_loop_> prefix, so it was removed; C<ev_loop>, C<ev_unloop> and
		4786	associated constants have been renamed to not collide with the C<struct
		4787	ev_loop> anymore and C<EV_TIMER> now follows the same naming scheme
		4788	as all other watcher types. Note that C<ev_loop_fork> is still called
4742	still called C<ev_loop_fork> because it would otherwise clash with the	4789	C<ev_loop_fork> because it would otherwise clash with the C<ev_fork>
4743	C<ev_fork> typedef.	4790	typedef.
4744		4791
4745	=item C<EV_TIMEOUT> renamed to C<EV_TIMER> in C<revents>	4792	=item C<EV_COMPAT3> backwards compatibility mechanism
4746		4793
4747	This is a simple rename - all other watcher types use their name	4794	The backward compatibility mechanism can be controlled by
4748	as revents flag, and now C<ev_timer> does, too.	4795	C<EV_COMPAT3>. See L<PREPROCESSOR SYMBOLS/MACROS> in the L<EMBEDDING>
4749		4796	section.
4750	Both C<EV_TIMER> and C<EV_TIMEOUT> symbols were present in 3.x versions
4751	and continue to be present for the foreseeable future, so this is mostly a
4752	documentation change.
4753		4797
4754	=item C<EV_MINIMAL> mechanism replaced by C<EV_FEATURES>	4798	=item C<EV_MINIMAL> mechanism replaced by C<EV_FEATURES>
4755		4799
4756	The preprocessor symbol C<EV_MINIMAL> has been replaced by a different	4800	The preprocessor symbol C<EV_MINIMAL> has been replaced by a different
4757	mechanism, C<EV_FEATURES>. Programs using C<EV_MINIMAL> usually compile	4801	mechanism, C<EV_FEATURES>. Programs using C<EV_MINIMAL> usually compile

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Comparing libev/ev.pod (file contents): Revision 1.309 by root, Thu Oct 21 09:23:21 2010 UTC vs. Revision 1.310 by root, Thu Oct 21 12:32:47 2010 UTC

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Comparing libev/ev.pod (file contents):
Revision 1.309 by root, Thu Oct 21 09:23:21 2010 UTC vs.
Revision 1.310 by root, Thu Oct 21 12:32:47 2010 UTC