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

Comparing libev/ev.pod (file contents):
Revision 1.66 by root, Mon Dec 3 13:41:25 2007 UTC vs.
Revision 1.90 by root, Thu Dec 20 01:18:37 2007 UTC

…		…
47		47
48	return 0;	48	return 0;
49	}	49	}
50		50
51	=head1 DESCRIPTION	51	=head1 DESCRIPTION
		52
		53	The newest version of this document is also available as a html-formatted
		54	web page you might find easier to navigate when reading it for the first
		55	time: L<http://cvs.schmorp.de/libev/ev.html>.
52		56
53	Libev is an event loop: you register interest in certain events (such as a	57	Libev is an event loop: you register interest in certain events (such as a
54	file descriptor being readable or a timeout occuring), and it will manage	58	file descriptor being readable or a timeout occuring), and it will manage
55	these event sources and provide your program with events.	59	these event sources and provide your program with events.
56		60
…		…
94	Libev represents time as a single floating point number, representing the	98	Libev represents time as a single floating point number, representing the
95	(fractional) number of seconds since the (POSIX) epoch (somewhere near	99	(fractional) number of seconds since the (POSIX) epoch (somewhere near
96	the beginning of 1970, details are complicated, don't ask). This type is	100	the beginning of 1970, details are complicated, don't ask). This type is
97	called C<ev_tstamp>, which is what you should use too. It usually aliases	101	called C<ev_tstamp>, which is what you should use too. It usually aliases
98	to the C<double> type in C, and when you need to do any calculations on	102	to the C<double> type in C, and when you need to do any calculations on
99	it, you should treat it as such.	103	it, you should treat it as some floatingpoint value. Unlike the name
		104	component C<stamp> might indicate, it is also used for time differences
		105	throughout libev.
100		106
101	=head1 GLOBAL FUNCTIONS	107	=head1 GLOBAL FUNCTIONS
102		108
103	These functions can be called anytime, even before initialising the	109	These functions can be called anytime, even before initialising the
104	library in any way.	110	library in any way.
…		…
113		119
114	=item int ev_version_major ()	120	=item int ev_version_major ()
115		121
116	=item int ev_version_minor ()	122	=item int ev_version_minor ()
117		123
118	You can find out the major and minor version numbers of the library	124	You can find out the major and minor ABI version numbers of the library
119	you linked against by calling the functions C<ev_version_major> and	125	you linked against by calling the functions C<ev_version_major> and
120	C<ev_version_minor>. If you want, you can compare against the global	126	C<ev_version_minor>. If you want, you can compare against the global
121	symbols C<EV_VERSION_MAJOR> and C<EV_VERSION_MINOR>, which specify the	127	symbols C<EV_VERSION_MAJOR> and C<EV_VERSION_MINOR>, which specify the
122	version of the library your program was compiled against.	128	version of the library your program was compiled against.
123		129
		130	These version numbers refer to the ABI version of the library, not the
		131	release version.
		132
124	Usually, it's a good idea to terminate if the major versions mismatch,	133	Usually, it's a good idea to terminate if the major versions mismatch,
125	as this indicates an incompatible change. Minor versions are usually	134	as this indicates an incompatible change. Minor versions are usually
126	compatible to older versions, so a larger minor version alone is usually	135	compatible to older versions, so a larger minor version alone is usually
127	not a problem.	136	not a problem.
128		137
129	Example: Make sure we haven't accidentally been linked against the wrong	138	Example: Make sure we haven't accidentally been linked against the wrong
130	version.	139	version.
…		…
322		331
323	=item C<EVBACKEND_KQUEUE> (value 8, most BSD clones)	332	=item C<EVBACKEND_KQUEUE> (value 8, most BSD clones)
324		333
325	Kqueue deserves special mention, as at the time of this writing, it	334	Kqueue deserves special mention, as at the time of this writing, it
326	was broken on all BSDs except NetBSD (usually it doesn't work with	335	was broken on all BSDs except NetBSD (usually it doesn't work with
327	anything but sockets and pipes, except on Darwin, where of course its	336	anything but sockets and pipes, except on Darwin, where of course it's
328	completely useless). For this reason its not being "autodetected"	337	completely useless). For this reason it's not being "autodetected"
329	unless you explicitly specify it explicitly in the flags (i.e. using	338	unless you explicitly specify it explicitly in the flags (i.e. using
330	C<EVBACKEND_KQUEUE>).	339	C<EVBACKEND_KQUEUE>).
331		340
332	It scales in the same way as the epoll backend, but the interface to the	341	It scales in the same way as the epoll backend, but the interface to the
333	kernel is more efficient (which says nothing about its actual speed, of	342	kernel is more efficient (which says nothing about its actual speed, of
…		…
395	Destroys the default loop again (frees all memory and kernel state	404	Destroys the default loop again (frees all memory and kernel state
396	etc.). None of the active event watchers will be stopped in the normal	405	etc.). None of the active event watchers will be stopped in the normal
397	sense, so e.g. C<ev_is_active> might still return true. It is your	406	sense, so e.g. C<ev_is_active> might still return true. It is your
398	responsibility to either stop all watchers cleanly yoursef I<before>	407	responsibility to either stop all watchers cleanly yoursef I<before>
399	calling this function, or cope with the fact afterwards (which is usually	408	calling this function, or cope with the fact afterwards (which is usually
400	the easiest thing, youc na just ignore the watchers and/or C<free ()> them	409	the easiest thing, you can just ignore the watchers and/or C<free ()> them
401	for example).	410	for example).
		411
		412	Note that certain global state, such as signal state, will not be freed by
		413	this function, and related watchers (such as signal and child watchers)
		414	would need to be stopped manually.
		415
		416	In general it is not advisable to call this function except in the
		417	rare occasion where you really need to free e.g. the signal handling
		418	pipe fds. If you need dynamically allocated loops it is better to use
		419	C<ev_loop_new> and C<ev_loop_destroy>).
402		420
403	=item ev_loop_destroy (loop)	421	=item ev_loop_destroy (loop)
404		422
405	Like C<ev_default_destroy>, but destroys an event loop created by an	423	Like C<ev_default_destroy>, but destroys an event loop created by an
406	earlier call to C<ev_loop_new>.	424	earlier call to C<ev_loop_new>.
…		…
482	libev watchers. However, a pair of C<ev_prepare>/C<ev_check> watchers is	500	libev watchers. However, a pair of C<ev_prepare>/C<ev_check> watchers is
483	usually a better approach for this kind of thing.	501	usually a better approach for this kind of thing.
484		502
485	Here are the gory details of what C<ev_loop> does:	503	Here are the gory details of what C<ev_loop> does:
486		504
		505	- Before the first iteration, call any pending watchers.
487	* If there are no active watchers (reference count is zero), return.	506	* If there are no active watchers (reference count is zero), return.
488	- Queue prepare watchers and then call all outstanding watchers.	507	- Queue all prepare watchers and then call all outstanding watchers.
489	- If we have been forked, recreate the kernel state.	508	- If we have been forked, recreate the kernel state.
490	- Update the kernel state with all outstanding changes.	509	- Update the kernel state with all outstanding changes.
491	- Update the "event loop time".	510	- Update the "event loop time".
492	- Calculate for how long to block.	511	- Calculate for how long to block.
493	- Block the process, waiting for any events.	512	- Block the process, waiting for any events.
…		…
732	=item bool ev_is_pending (ev_TYPE *watcher)	751	=item bool ev_is_pending (ev_TYPE *watcher)
733		752
734	Returns a true value iff the watcher is pending, (i.e. it has outstanding	753	Returns a true value iff the watcher is pending, (i.e. it has outstanding
735	events but its callback has not yet been invoked). As long as a watcher	754	events but its callback has not yet been invoked). As long as a watcher
736	is pending (but not active) you must not call an init function on it (but	755	is pending (but not active) you must not call an init function on it (but
737	C<ev_TYPE_set> is safe) and you must make sure the watcher is available to	756	C<ev_TYPE_set> is safe), you must not change its priority, and you must
738	libev (e.g. you cnanot C<free ()> it).	757	make sure the watcher is available to libev (e.g. you cannot C<free ()>
		758	it).
739		759
740	=item callback ev_cb (ev_TYPE *watcher)	760	=item callback ev_cb (ev_TYPE *watcher)
741		761
742	Returns the callback currently set on the watcher.	762	Returns the callback currently set on the watcher.
743		763
744	=item ev_cb_set (ev_TYPE *watcher, callback)	764	=item ev_cb_set (ev_TYPE *watcher, callback)
745		765
746	Change the callback. You can change the callback at virtually any time	766	Change the callback. You can change the callback at virtually any time
747	(modulo threads).	767	(modulo threads).
		768
		769	=item ev_set_priority (ev_TYPE *watcher, priority)
		770
		771	=item int ev_priority (ev_TYPE *watcher)
		772
		773	Set and query the priority of the watcher. The priority is a small
		774	integer between C<EV_MAXPRI> (default: C<2>) and C<EV_MINPRI>
		775	(default: C<-2>). Pending watchers with higher priority will be invoked
		776	before watchers with lower priority, but priority will not keep watchers
		777	from being executed (except for C<ev_idle> watchers).
		778
		779	This means that priorities are I<only> used for ordering callback
		780	invocation after new events have been received. This is useful, for
		781	example, to reduce latency after idling, or more often, to bind two
		782	watchers on the same event and make sure one is called first.
		783
		784	If you need to suppress invocation when higher priority events are pending
		785	you need to look at C<ev_idle> watchers, which provide this functionality.
		786
		787	You I<must not> change the priority of a watcher as long as it is active or
		788	pending.
		789
		790	The default priority used by watchers when no priority has been set is
		791	always C<0>, which is supposed to not be too high and not be too low :).
		792
		793	Setting a priority outside the range of C<EV_MINPRI> to C<EV_MAXPRI> is
		794	fine, as long as you do not mind that the priority value you query might
		795	or might not have been adjusted to be within valid range.
		796
		797	=item ev_invoke (loop, ev_TYPE *watcher, int revents)
		798
		799	Invoke the C<watcher> with the given C<loop> and C<revents>. Neither
		800	C<loop> nor C<revents> need to be valid as long as the watcher callback
		801	can deal with that fact.
		802
		803	=item int ev_clear_pending (loop, ev_TYPE *watcher)
		804
		805	If the watcher is pending, this function returns clears its pending status
		806	and returns its C<revents> bitset (as if its callback was invoked). If the
		807	watcher isn't pending it does nothing and returns C<0>.
748		808
749	=back	809	=back
750		810
751		811
752	=head2 ASSOCIATING CUSTOM DATA WITH A WATCHER	812	=head2 ASSOCIATING CUSTOM DATA WITH A WATCHER
…		…
858	it is best to always use non-blocking I/O: An extra C<read>(2) returning	918	it is best to always use non-blocking I/O: An extra C<read>(2) returning
859	C<EAGAIN> is far preferable to a program hanging until some data arrives.	919	C<EAGAIN> is far preferable to a program hanging until some data arrives.
860		920
861	If you cannot run the fd in non-blocking mode (for example you should not	921	If you cannot run the fd in non-blocking mode (for example you should not
862	play around with an Xlib connection), then you have to seperately re-test	922	play around with an Xlib connection), then you have to seperately re-test
863	wether a file descriptor is really ready with a known-to-be good interface	923	whether a file descriptor is really ready with a known-to-be good interface
864	such as poll (fortunately in our Xlib example, Xlib already does this on	924	such as poll (fortunately in our Xlib example, Xlib already does this on
865	its own, so its quite safe to use).	925	its own, so its quite safe to use).
		926
		927	=head3 The special problem of disappearing file descriptors
		928
		929	Some backends (e.g kqueue, epoll) need to be told about closing a file
		930	descriptor (either by calling C<close> explicitly or by any other means,
		931	such as C<dup>). The reason is that you register interest in some file
		932	descriptor, but when it goes away, the operating system will silently drop
		933	this interest. If another file descriptor with the same number then is
		934	registered with libev, there is no efficient way to see that this is, in
		935	fact, a different file descriptor.
		936
		937	To avoid having to explicitly tell libev about such cases, libev follows
		938	the following policy: Each time C<ev_io_set> is being called, libev
		939	will assume that this is potentially a new file descriptor, otherwise
		940	it is assumed that the file descriptor stays the same. That means that
		941	you I<have> to call C<ev_io_set> (or C<ev_io_init>) when you change the
		942	descriptor even if the file descriptor number itself did not change.
		943
		944	This is how one would do it normally anyway, the important point is that
		945	the libev application should not optimise around libev but should leave
		946	optimisations to libev.
		947
		948
		949	=head3 Watcher-Specific Functions
866		950
867	=over 4	951	=over 4
868		952
869	=item ev_io_init (ev_io *, callback, int fd, int events)	953	=item ev_io_init (ev_io *, callback, int fd, int events)
870		954
…		…
923	ev_timer_set (&timer, after + ev_now () - ev_time (), 0.);	1007	ev_timer_set (&timer, after + ev_now () - ev_time (), 0.);
924		1008
925	The callback is guarenteed to be invoked only when its timeout has passed,	1009	The callback is guarenteed to be invoked only when its timeout has passed,
926	but if multiple timers become ready during the same loop iteration then	1010	but if multiple timers become ready during the same loop iteration then
927	order of execution is undefined.	1011	order of execution is undefined.
		1012
		1013	=head3 Watcher-Specific Functions and Data Members
928		1014
929	=over 4	1015	=over 4
930		1016
931	=item ev_timer_init (ev_timer *, callback, ev_tstamp after, ev_tstamp repeat)	1017	=item ev_timer_init (ev_timer *, callback, ev_tstamp after, ev_tstamp repeat)
932		1018
…		…
1028	but on wallclock time (absolute time). You can tell a periodic watcher	1114	but on wallclock time (absolute time). You can tell a periodic watcher
1029	to trigger "at" some specific point in time. For example, if you tell a	1115	to trigger "at" some specific point in time. For example, if you tell a
1030	periodic watcher to trigger in 10 seconds (by specifiying e.g. C<ev_now ()	1116	periodic watcher to trigger in 10 seconds (by specifiying e.g. C<ev_now ()
1031	+ 10.>) and then reset your system clock to the last year, then it will	1117	+ 10.>) and then reset your system clock to the last year, then it will
1032	take a year to trigger the event (unlike an C<ev_timer>, which would trigger	1118	take a year to trigger the event (unlike an C<ev_timer>, which would trigger
1033	roughly 10 seconds later and of course not if you reset your system time	1119	roughly 10 seconds later).
1034	again).
1035		1120
1036	They can also be used to implement vastly more complex timers, such as	1121	They can also be used to implement vastly more complex timers, such as
1037	triggering an event on eahc midnight, local time.	1122	triggering an event on each midnight, local time or other, complicated,
		1123	rules.
1038		1124
1039	As with timers, the callback is guarenteed to be invoked only when the	1125	As with timers, the callback is guarenteed to be invoked only when the
1040	time (C<at>) has been passed, but if multiple periodic timers become ready	1126	time (C<at>) has been passed, but if multiple periodic timers become ready
1041	during the same loop iteration then order of execution is undefined.	1127	during the same loop iteration then order of execution is undefined.
1042		1128
		1129	=head3 Watcher-Specific Functions and Data Members
		1130
1043	=over 4	1131	=over 4
1044		1132
1045	=item ev_periodic_init (ev_periodic *, callback, ev_tstamp at, ev_tstamp interval, reschedule_cb)	1133	=item ev_periodic_init (ev_periodic *, callback, ev_tstamp at, ev_tstamp interval, reschedule_cb)
1046		1134
1047	=item ev_periodic_set (ev_periodic *, ev_tstamp after, ev_tstamp repeat, reschedule_cb)	1135	=item ev_periodic_set (ev_periodic *, ev_tstamp after, ev_tstamp repeat, reschedule_cb)
…		…
1049	Lots of arguments, lets sort it out... There are basically three modes of	1137	Lots of arguments, lets sort it out... There are basically three modes of
1050	operation, and we will explain them from simplest to complex:	1138	operation, and we will explain them from simplest to complex:
1051		1139
1052	=over 4	1140	=over 4
1053		1141
1054	=item * absolute timer (interval = reschedule_cb = 0)	1142	=item * absolute timer (at = time, interval = reschedule_cb = 0)
1055		1143
1056	In this configuration the watcher triggers an event at the wallclock time	1144	In this configuration the watcher triggers an event at the wallclock time
1057	C<at> and doesn't repeat. It will not adjust when a time jump occurs,	1145	C<at> and doesn't repeat. It will not adjust when a time jump occurs,
1058	that is, if it is to be run at January 1st 2011 then it will run when the	1146	that is, if it is to be run at January 1st 2011 then it will run when the
1059	system time reaches or surpasses this time.	1147	system time reaches or surpasses this time.
1060		1148
1061	=item * non-repeating interval timer (interval > 0, reschedule_cb = 0)	1149	=item * non-repeating interval timer (at = offset, interval > 0, reschedule_cb = 0)
1062		1150
1063	In this mode the watcher will always be scheduled to time out at the next	1151	In this mode the watcher will always be scheduled to time out at the next
1064	C<at + N * interval> time (for some integer N) and then repeat, regardless	1152	C<at + N * interval> time (for some integer N, which can also be negative)
1065	of any time jumps.	1153	and then repeat, regardless of any time jumps.
1066		1154
1067	This can be used to create timers that do not drift with respect to system	1155	This can be used to create timers that do not drift with respect to system
1068	time:	1156	time:
1069		1157
1070	ev_periodic_set (&periodic, 0., 3600., 0);	1158	ev_periodic_set (&periodic, 0., 3600., 0);
…		…
1076		1164
1077	Another way to think about it (for the mathematically inclined) is that	1165	Another way to think about it (for the mathematically inclined) is that
1078	C<ev_periodic> will try to run the callback in this mode at the next possible	1166	C<ev_periodic> will try to run the callback in this mode at the next possible
1079	time where C<time = at (mod interval)>, regardless of any time jumps.	1167	time where C<time = at (mod interval)>, regardless of any time jumps.
1080		1168
		1169	For numerical stability it is preferable that the C<at> value is near
		1170	C<ev_now ()> (the current time), but there is no range requirement for
		1171	this value.
		1172
1081	=item * manual reschedule mode (reschedule_cb = callback)	1173	=item * manual reschedule mode (at and interval ignored, reschedule_cb = callback)
1082		1174
1083	In this mode the values for C<interval> and C<at> are both being	1175	In this mode the values for C<interval> and C<at> are both being
1084	ignored. Instead, each time the periodic watcher gets scheduled, the	1176	ignored. Instead, each time the periodic watcher gets scheduled, the
1085	reschedule callback will be called with the watcher as first, and the	1177	reschedule callback will be called with the watcher as first, and the
1086	current time as second argument.	1178	current time as second argument.
1087		1179
1088	NOTE: I<This callback MUST NOT stop or destroy any periodic watcher,	1180	NOTE: I<This callback MUST NOT stop or destroy any periodic watcher,
1089	ever, or make any event loop modifications>. If you need to stop it,	1181	ever, or make any event loop modifications>. If you need to stop it,
1090	return C<now + 1e30> (or so, fudge fudge) and stop it afterwards (e.g. by	1182	return C<now + 1e30> (or so, fudge fudge) and stop it afterwards (e.g. by
1091	starting a prepare watcher).	1183	starting an C<ev_prepare> watcher, which is legal).
1092		1184
1093	Its prototype is C<ev_tstamp (reschedule_cb)(struct ev_periodic w,	1185	Its prototype is C<ev_tstamp (reschedule_cb)(struct ev_periodic w,
1094	ev_tstamp now)>, e.g.:	1186	ev_tstamp now)>, e.g.:
1095		1187
1096	static ev_tstamp my_rescheduler (struct ev_periodic *w, ev_tstamp now)	1188	static ev_tstamp my_rescheduler (struct ev_periodic *w, ev_tstamp now)
…		…
1119	Simply stops and restarts the periodic watcher again. This is only useful	1211	Simply stops and restarts the periodic watcher again. This is only useful
1120	when you changed some parameters or the reschedule callback would return	1212	when you changed some parameters or the reschedule callback would return
1121	a different time than the last time it was called (e.g. in a crond like	1213	a different time than the last time it was called (e.g. in a crond like
1122	program when the crontabs have changed).	1214	program when the crontabs have changed).
1123		1215
		1216	=item ev_tstamp offset [read-write]
		1217
		1218	When repeating, this contains the offset value, otherwise this is the
		1219	absolute point in time (the C<at> value passed to C<ev_periodic_set>).
		1220
		1221	Can be modified any time, but changes only take effect when the periodic
		1222	timer fires or C<ev_periodic_again> is being called.
		1223
1124	=item ev_tstamp interval [read-write]	1224	=item ev_tstamp interval [read-write]
1125		1225
1126	The current interval value. Can be modified any time, but changes only	1226	The current interval value. Can be modified any time, but changes only
1127	take effect when the periodic timer fires or C<ev_periodic_again> is being	1227	take effect when the periodic timer fires or C<ev_periodic_again> is being
1128	called.	1228	called.
…		…
1130	=item ev_tstamp (reschedule_cb)(struct ev_periodic w, ev_tstamp now) [read-write]	1230	=item ev_tstamp (reschedule_cb)(struct ev_periodic w, ev_tstamp now) [read-write]
1131		1231
1132	The current reschedule callback, or C<0>, if this functionality is	1232	The current reschedule callback, or C<0>, if this functionality is
1133	switched off. Can be changed any time, but changes only take effect when	1233	switched off. Can be changed any time, but changes only take effect when
1134	the periodic timer fires or C<ev_periodic_again> is being called.	1234	the periodic timer fires or C<ev_periodic_again> is being called.
		1235
		1236	=item ev_tstamp at [read-only]
		1237
		1238	When active, contains the absolute time that the watcher is supposed to
		1239	trigger next.
1135		1240
1136	=back	1241	=back
1137		1242
1138	Example: Call a callback every hour, or, more precisely, whenever the	1243	Example: Call a callback every hour, or, more precisely, whenever the
1139	system clock is divisible by 3600. The callback invocation times have	1244	system clock is divisible by 3600. The callback invocation times have
…		…
1181	with the kernel (thus it coexists with your own signal handlers as long	1286	with the kernel (thus it coexists with your own signal handlers as long
1182	as you don't register any with libev). Similarly, when the last signal	1287	as you don't register any with libev). Similarly, when the last signal
1183	watcher for a signal is stopped libev will reset the signal handler to	1288	watcher for a signal is stopped libev will reset the signal handler to
1184	SIG_DFL (regardless of what it was set to before).	1289	SIG_DFL (regardless of what it was set to before).
1185		1290
		1291	=head3 Watcher-Specific Functions and Data Members
		1292
1186	=over 4	1293	=over 4
1187		1294
1188	=item ev_signal_init (ev_signal *, callback, int signum)	1295	=item ev_signal_init (ev_signal *, callback, int signum)
1189		1296
1190	=item ev_signal_set (ev_signal *, int signum)	1297	=item ev_signal_set (ev_signal *, int signum)
…		…
1201		1308
1202	=head2 C<ev_child> - watch out for process status changes	1309	=head2 C<ev_child> - watch out for process status changes
1203		1310
1204	Child watchers trigger when your process receives a SIGCHLD in response to	1311	Child watchers trigger when your process receives a SIGCHLD in response to
1205	some child status changes (most typically when a child of yours dies).	1312	some child status changes (most typically when a child of yours dies).
		1313
		1314	=head3 Watcher-Specific Functions and Data Members
1206		1315
1207	=over 4	1316	=over 4
1208		1317
1209	=item ev_child_init (ev_child *, callback, int pid)	1318	=item ev_child_init (ev_child *, callback, int pid)
1210		1319
…		…
1278	reader). Inotify will be used to give hints only and should not change the	1387	reader). Inotify will be used to give hints only and should not change the
1279	semantics of C<ev_stat> watchers, which means that libev sometimes needs	1388	semantics of C<ev_stat> watchers, which means that libev sometimes needs
1280	to fall back to regular polling again even with inotify, but changes are	1389	to fall back to regular polling again even with inotify, but changes are
1281	usually detected immediately, and if the file exists there will be no	1390	usually detected immediately, and if the file exists there will be no
1282	polling.	1391	polling.
		1392
		1393	=head3 Watcher-Specific Functions and Data Members
1283		1394
1284	=over 4	1395	=over 4
1285		1396
1286	=item ev_stat_init (ev_stat , callback, const char path, ev_tstamp interval)	1397	=item ev_stat_init (ev_stat , callback, const char path, ev_tstamp interval)
1287		1398
…		…
1351	ev_stat_start (loop, &passwd);	1462	ev_stat_start (loop, &passwd);
1352		1463
1353		1464
1354	=head2 C<ev_idle> - when you've got nothing better to do...	1465	=head2 C<ev_idle> - when you've got nothing better to do...
1355		1466
1356	Idle watchers trigger events when there are no other events are pending	1467	Idle watchers trigger events when no other events of the same or higher
1357	(prepare, check and other idle watchers do not count). That is, as long	1468	priority are pending (prepare, check and other idle watchers do not
1358	as your process is busy handling sockets or timeouts (or even signals,	1469	count).
1359	imagine) it will not be triggered. But when your process is idle all idle	1470
1360	watchers are being called again and again, once per event loop iteration -	1471	That is, as long as your process is busy handling sockets or timeouts
		1472	(or even signals, imagine) of the same or higher priority it will not be
		1473	triggered. But when your process is idle (or only lower-priority watchers
		1474	are pending), the idle watchers are being called once per event loop
1361	until stopped, that is, or your process receives more events and becomes	1475	iteration - until stopped, that is, or your process receives more events
1362	busy.	1476	and becomes busy again with higher priority stuff.
1363		1477
1364	The most noteworthy effect is that as long as any idle watchers are	1478	The most noteworthy effect is that as long as any idle watchers are
1365	active, the process will not block when waiting for new events.	1479	active, the process will not block when waiting for new events.
1366		1480
1367	Apart from keeping your process non-blocking (which is a useful	1481	Apart from keeping your process non-blocking (which is a useful
1368	effect on its own sometimes), idle watchers are a good place to do	1482	effect on its own sometimes), idle watchers are a good place to do
1369	"pseudo-background processing", or delay processing stuff to after the	1483	"pseudo-background processing", or delay processing stuff to after the
1370	event loop has handled all outstanding events.	1484	event loop has handled all outstanding events.
		1485
		1486	=head3 Watcher-Specific Functions and Data Members
1371		1487
1372	=over 4	1488	=over 4
1373		1489
1374	=item ev_idle_init (ev_signal *, callback)	1490	=item ev_idle_init (ev_signal *, callback)
1375		1491
…		…
1433	with priority higher than or equal to the event loop and one coroutine	1549	with priority higher than or equal to the event loop and one coroutine
1434	of lower priority, but only once, using idle watchers to keep the event	1550	of lower priority, but only once, using idle watchers to keep the event
1435	loop from blocking if lower-priority coroutines are active, thus mapping	1551	loop from blocking if lower-priority coroutines are active, thus mapping
1436	low-priority coroutines to idle/background tasks).	1552	low-priority coroutines to idle/background tasks).
1437		1553
		1554	It is recommended to give C<ev_check> watchers highest (C<EV_MAXPRI>)
		1555	priority, to ensure that they are being run before any other watchers
		1556	after the poll. Also, C<ev_check> watchers (and C<ev_prepare> watchers,
		1557	too) should not activate ("feed") events into libev. While libev fully
		1558	supports this, they will be called before other C<ev_check> watchers did
		1559	their job. As C<ev_check> watchers are often used to embed other event
		1560	loops those other event loops might be in an unusable state until their
		1561	C<ev_check> watcher ran (always remind yourself to coexist peacefully with
		1562	others).
		1563
		1564	=head3 Watcher-Specific Functions and Data Members
		1565
1438	=over 4	1566	=over 4
1439		1567
1440	=item ev_prepare_init (ev_prepare *, callback)	1568	=item ev_prepare_init (ev_prepare *, callback)
1441		1569
1442	=item ev_check_init (ev_check *, callback)	1570	=item ev_check_init (ev_check *, callback)
…		…
1445	parameters of any kind. There are C<ev_prepare_set> and C<ev_check_set>	1573	parameters of any kind. There are C<ev_prepare_set> and C<ev_check_set>
1446	macros, but using them is utterly, utterly and completely pointless.	1574	macros, but using them is utterly, utterly and completely pointless.
1447		1575
1448	=back	1576	=back
1449		1577
1450	Example: To include a library such as adns, you would add IO watchers	1578	There are a number of principal ways to embed other event loops or modules
1451	and a timeout watcher in a prepare handler, as required by libadns, and	1579	into libev. Here are some ideas on how to include libadns into libev
		1580	(there is a Perl module named C<EV::ADNS> that does this, which you could
		1581	use for an actually working example. Another Perl module named C<EV::Glib>
		1582	embeds a Glib main context into libev, and finally, C<Glib::EV> embeds EV
		1583	into the Glib event loop).
		1584
		1585	Method 1: Add IO watchers and a timeout watcher in a prepare handler,
1452	in a check watcher, destroy them and call into libadns. What follows is	1586	and in a check watcher, destroy them and call into libadns. What follows
1453	pseudo-code only of course:	1587	is pseudo-code only of course. This requires you to either use a low
		1588	priority for the check watcher or use C<ev_clear_pending> explicitly, as
		1589	the callbacks for the IO/timeout watchers might not have been called yet.
1454		1590
1455	static ev_io iow [nfd];	1591	static ev_io iow [nfd];
1456	static ev_timer tw;	1592	static ev_timer tw;
1457		1593
1458	static void	1594	static void
1459	io_cb (ev_loop loop, ev_io w, int revents)	1595	io_cb (ev_loop loop, ev_io w, int revents)
1460	{	1596	{
1461	// set the relevant poll flags
1462	// could also call adns_processreadable etc. here
1463	struct pollfd fd = (struct pollfd )w->data;
1464	if (revents & EV_READ ) fd->revents \|= fd->events & POLLIN;
1465	if (revents & EV_WRITE) fd->revents \|= fd->events & POLLOUT;
1466	}	1597	}
1467		1598
1468	// create io watchers for each fd and a timer before blocking	1599	// create io watchers for each fd and a timer before blocking
1469	static void	1600	static void
1470	adns_prepare_cb (ev_loop loop, ev_prepare w, int revents)	1601	adns_prepare_cb (ev_loop loop, ev_prepare w, int revents)
…		…
1476		1607
1477	/* the callback is illegal, but won't be called as we stop during check */	1608	/* the callback is illegal, but won't be called as we stop during check */
1478	ev_timer_init (&tw, 0, timeout * 1e-3);	1609	ev_timer_init (&tw, 0, timeout * 1e-3);
1479	ev_timer_start (loop, &tw);	1610	ev_timer_start (loop, &tw);
1480		1611
1481	// create on ev_io per pollfd	1612	// create one ev_io per pollfd
1482	for (int i = 0; i < nfd; ++i)	1613	for (int i = 0; i < nfd; ++i)
1483	{	1614	{
1484	ev_io_init (iow + i, io_cb, fds [i].fd,	1615	ev_io_init (iow + i, io_cb, fds [i].fd,
1485	((fds [i].events & POLLIN ? EV_READ : 0)	1616	((fds [i].events & POLLIN ? EV_READ : 0)
1486	\| (fds [i].events & POLLOUT ? EV_WRITE : 0)));	1617	\| (fds [i].events & POLLOUT ? EV_WRITE : 0)));
1487		1618
1488	fds [i].revents = 0;	1619	fds [i].revents = 0;
1489	iow [i].data = fds + i;
1490	ev_io_start (loop, iow + i);	1620	ev_io_start (loop, iow + i);
1491	}	1621	}
1492	}	1622	}
1493		1623
1494	// stop all watchers after blocking	1624	// stop all watchers after blocking
…		…
1496	adns_check_cb (ev_loop loop, ev_check w, int revents)	1626	adns_check_cb (ev_loop loop, ev_check w, int revents)
1497	{	1627	{
1498	ev_timer_stop (loop, &tw);	1628	ev_timer_stop (loop, &tw);
1499		1629
1500	for (int i = 0; i < nfd; ++i)	1630	for (int i = 0; i < nfd; ++i)
		1631	{
		1632	// set the relevant poll flags
		1633	// could also call adns_processreadable etc. here
		1634	struct pollfd *fd = fds + i;
		1635	int revents = ev_clear_pending (iow + i);
		1636	if (revents & EV_READ ) fd->revents \|= fd->events & POLLIN;
		1637	if (revents & EV_WRITE) fd->revents \|= fd->events & POLLOUT;
		1638
		1639	// now stop the watcher
1501	ev_io_stop (loop, iow + i);	1640	ev_io_stop (loop, iow + i);
		1641	}
1502		1642
1503	adns_afterpoll (adns, fds, nfd, timeval_from (ev_now (loop));	1643	adns_afterpoll (adns, fds, nfd, timeval_from (ev_now (loop));
		1644	}
		1645
		1646	Method 2: This would be just like method 1, but you run C<adns_afterpoll>
		1647	in the prepare watcher and would dispose of the check watcher.
		1648
		1649	Method 3: If the module to be embedded supports explicit event
		1650	notification (adns does), you can also make use of the actual watcher
		1651	callbacks, and only destroy/create the watchers in the prepare watcher.
		1652
		1653	static void
		1654	timer_cb (EV_P_ ev_timer *w, int revents)
		1655	{
		1656	adns_state ads = (adns_state)w->data;
		1657	update_now (EV_A);
		1658
		1659	adns_processtimeouts (ads, &tv_now);
		1660	}
		1661
		1662	static void
		1663	io_cb (EV_P_ ev_io *w, int revents)
		1664	{
		1665	adns_state ads = (adns_state)w->data;
		1666	update_now (EV_A);
		1667
		1668	if (revents & EV_READ ) adns_processreadable (ads, w->fd, &tv_now);
		1669	if (revents & EV_WRITE) adns_processwriteable (ads, w->fd, &tv_now);
		1670	}
		1671
		1672	// do not ever call adns_afterpoll
		1673
		1674	Method 4: Do not use a prepare or check watcher because the module you
		1675	want to embed is too inflexible to support it. Instead, youc na override
		1676	their poll function. The drawback with this solution is that the main
		1677	loop is now no longer controllable by EV. The C<Glib::EV> module does
		1678	this.
		1679
		1680	static gint
		1681	event_poll_func (GPollFD *fds, guint nfds, gint timeout)
		1682	{
		1683	int got_events = 0;
		1684
		1685	for (n = 0; n < nfds; ++n)
		1686	// create/start io watcher that sets the relevant bits in fds[n] and increment got_events
		1687
		1688	if (timeout >= 0)
		1689	// create/start timer
		1690
		1691	// poll
		1692	ev_loop (EV_A_ 0);
		1693
		1694	// stop timer again
		1695	if (timeout >= 0)
		1696	ev_timer_stop (EV_A_ &to);
		1697
		1698	// stop io watchers again - their callbacks should have set
		1699	for (n = 0; n < nfds; ++n)
		1700	ev_io_stop (EV_A_ iow [n]);
		1701
		1702	return got_events;
1504	}	1703	}
1505		1704
1506		1705
1507	=head2 C<ev_embed> - when one backend isn't enough...	1706	=head2 C<ev_embed> - when one backend isn't enough...
1508		1707
…		…
1572	ev_embed_start (loop_hi, &embed);	1771	ev_embed_start (loop_hi, &embed);
1573	}	1772	}
1574	else	1773	else
1575	loop_lo = loop_hi;	1774	loop_lo = loop_hi;
1576		1775
		1776	=head3 Watcher-Specific Functions and Data Members
		1777
1577	=over 4	1778	=over 4
1578		1779
1579	=item ev_embed_init (ev_embed , callback, struct ev_loop embedded_loop)	1780	=item ev_embed_init (ev_embed , callback, struct ev_loop embedded_loop)
1580		1781
1581	=item ev_embed_set (ev_embed , callback, struct ev_loop embedded_loop)	1782	=item ev_embed_set (ev_embed , callback, struct ev_loop embedded_loop)
…		…
1607	event loop blocks next and before C<ev_check> watchers are being called,	1808	event loop blocks next and before C<ev_check> watchers are being called,
1608	and only in the child after the fork. If whoever good citizen calling	1809	and only in the child after the fork. If whoever good citizen calling
1609	C<ev_default_fork> cheats and calls it in the wrong process, the fork	1810	C<ev_default_fork> cheats and calls it in the wrong process, the fork
1610	handlers will be invoked, too, of course.	1811	handlers will be invoked, too, of course.
1611		1812
		1813	=head3 Watcher-Specific Functions and Data Members
		1814
1612	=over 4	1815	=over 4
1613		1816
1614	=item ev_fork_init (ev_signal *, callback)	1817	=item ev_fork_init (ev_signal *, callback)
1615		1818
1616	Initialises and configures the fork watcher - it has no parameters of any	1819	Initialises and configures the fork watcher - it has no parameters of any
…		…
1712		1915
1713	To use it,	1916	To use it,
1714		1917
1715	#include <ev++.h>	1918	#include <ev++.h>
1716		1919
1717	(it is not installed by default). This automatically includes F<ev.h>	1920	This automatically includes F<ev.h> and puts all of its definitions (many
1718	and puts all of its definitions (many of them macros) into the global	1921	of them macros) into the global namespace. All C++ specific things are
1719	namespace. All C++ specific things are put into the C<ev> namespace.	1922	put into the C<ev> namespace. It should support all the same embedding
		1923	options as F<ev.h>, most notably C<EV_MULTIPLICITY>.
1720		1924
1721	It should support all the same embedding options as F<ev.h>, most notably	1925	Care has been taken to keep the overhead low. The only data member the C++
1722	C<EV_MULTIPLICITY>.	1926	classes add (compared to plain C-style watchers) is the event loop pointer
		1927	that the watcher is associated with (or no additional members at all if
		1928	you disable C<EV_MULTIPLICITY> when embedding libev).
		1929
		1930	Currently, functions, and static and non-static member functions can be
		1931	used as callbacks. Other types should be easy to add as long as they only
		1932	need one additional pointer for context. If you need support for other
		1933	types of functors please contact the author (preferably after implementing
		1934	it).
1723		1935
1724	Here is a list of things available in the C<ev> namespace:	1936	Here is a list of things available in the C<ev> namespace:
1725		1937
1726	=over 4	1938	=over 4
1727		1939
…		…
1743		1955
1744	All of those classes have these methods:	1956	All of those classes have these methods:
1745		1957
1746	=over 4	1958	=over 4
1747		1959
1748	=item ev::TYPE::TYPE (object , object::method )	1960	=item ev::TYPE::TYPE ()
1749		1961
1750	=item ev::TYPE::TYPE (object , object::method , struct ev_loop *)	1962	=item ev::TYPE::TYPE (struct ev_loop *)
1751		1963
1752	=item ev::TYPE::~TYPE	1964	=item ev::TYPE::~TYPE
1753		1965
1754	The constructor takes a pointer to an object and a method pointer to	1966	The constructor (optionally) takes an event loop to associate the watcher
1755	the event handler callback to call in this class. The constructor calls	1967	with. If it is omitted, it will use C<EV_DEFAULT>.
1756	C<ev_init> for you, which means you have to call the C<set> method	1968
1757	before starting it. If you do not specify a loop then the constructor	1969	The constructor calls C<ev_init> for you, which means you have to call the
1758	automatically associates the default loop with this watcher.	1970	C<set> method before starting it.
		1971
		1972	It will not set a callback, however: You have to call the templated C<set>
		1973	method to set a callback before you can start the watcher.
		1974
		1975	(The reason why you have to use a method is a limitation in C++ which does
		1976	not allow explicit template arguments for constructors).
1759		1977
1760	The destructor automatically stops the watcher if it is active.	1978	The destructor automatically stops the watcher if it is active.
		1979
		1980	=item w->set<class, &class::method> (object *)
		1981
		1982	This method sets the callback method to call. The method has to have a
		1983	signature of C<void (*)(ev_TYPE &, int)>, it receives the watcher as
		1984	first argument and the C<revents> as second. The object must be given as
		1985	parameter and is stored in the C<data> member of the watcher.
		1986
		1987	This method synthesizes efficient thunking code to call your method from
		1988	the C callback that libev requires. If your compiler can inline your
		1989	callback (i.e. it is visible to it at the place of the C<set> call and
		1990	your compiler is good :), then the method will be fully inlined into the
		1991	thunking function, making it as fast as a direct C callback.
		1992
		1993	Example: simple class declaration and watcher initialisation
		1994
		1995	struct myclass
		1996	{
		1997	void io_cb (ev::io &w, int revents) { }
		1998	}
		1999
		2000	myclass obj;
		2001	ev::io iow;
		2002	iow.set <myclass, &myclass::io_cb> (&obj);
		2003
		2004	=item w->set<function> (void *data = 0)
		2005
		2006	Also sets a callback, but uses a static method or plain function as
		2007	callback. The optional C<data> argument will be stored in the watcher's
		2008	C<data> member and is free for you to use.
		2009
		2010	The prototype of the C<function> must be C<void (*)(ev::TYPE &w, int)>.
		2011
		2012	See the method-C<set> above for more details.
		2013
		2014	Example:
		2015
		2016	static void io_cb (ev::io &w, int revents) { }
		2017	iow.set <io_cb> ();
1761		2018
1762	=item w->set (struct ev_loop *)	2019	=item w->set (struct ev_loop *)
1763		2020
1764	Associates a different C<struct ev_loop> with this watcher. You can only	2021	Associates a different C<struct ev_loop> with this watcher. You can only
1765	do this when the watcher is inactive (and not pending either).	2022	do this when the watcher is inactive (and not pending either).
1766		2023
1767	=item w->set ([args])	2024	=item w->set ([args])
1768		2025
1769	Basically the same as C<ev_TYPE_set>, with the same args. Must be	2026	Basically the same as C<ev_TYPE_set>, with the same args. Must be
1770	called at least once. Unlike the C counterpart, an active watcher gets	2027	called at least once. Unlike the C counterpart, an active watcher gets
1771	automatically stopped and restarted.	2028	automatically stopped and restarted when reconfiguring it with this
		2029	method.
1772		2030
1773	=item w->start ()	2031	=item w->start ()
1774		2032
1775	Starts the watcher. Note that there is no C<loop> argument as the	2033	Starts the watcher. Note that there is no C<loop> argument, as the
1776	constructor already takes the loop.	2034	constructor already stores the event loop.
1777		2035
1778	=item w->stop ()	2036	=item w->stop ()
1779		2037
1780	Stops the watcher if it is active. Again, no C<loop> argument.	2038	Stops the watcher if it is active. Again, no C<loop> argument.
1781		2039
1782	=item w->again () C<ev::timer>, C<ev::periodic> only	2040	=item w->again () (C<ev::timer>, C<ev::periodic> only)
1783		2041
1784	For C<ev::timer> and C<ev::periodic>, this invokes the corresponding	2042	For C<ev::timer> and C<ev::periodic>, this invokes the corresponding
1785	C<ev_TYPE_again> function.	2043	C<ev_TYPE_again> function.
1786		2044
1787	=item w->sweep () C<ev::embed> only	2045	=item w->sweep () (C<ev::embed> only)
1788		2046
1789	Invokes C<ev_embed_sweep>.	2047	Invokes C<ev_embed_sweep>.
1790		2048
1791	=item w->update () C<ev::stat> only	2049	=item w->update () (C<ev::stat> only)
1792		2050
1793	Invokes C<ev_stat_stat>.	2051	Invokes C<ev_stat_stat>.
1794		2052
1795	=back	2053	=back
1796		2054
…		…
1806		2064
1807	myclass ();	2065	myclass ();
1808	}	2066	}
1809		2067
1810	myclass::myclass (int fd)	2068	myclass::myclass (int fd)
1811	: io (this, &myclass::io_cb),
1812	idle (this, &myclass::idle_cb)
1813	{	2069	{
		2070	io .set <myclass, &myclass::io_cb > (this);
		2071	idle.set <myclass, &myclass::idle_cb> (this);
		2072
1814	io.start (fd, ev::READ);	2073	io.start (fd, ev::READ);
1815	}	2074	}
1816		2075
1817		2076
1818	=head1 MACRO MAGIC	2077	=head1 MACRO MAGIC
1819		2078
1820	Libev can be compiled with a variety of options, the most fundemantal is	2079	Libev can be compiled with a variety of options, the most fundamantal
1821	C<EV_MULTIPLICITY>. This option determines wether (most) functions and	2080	of which is C<EV_MULTIPLICITY>. This option determines whether (most)
1822	callbacks have an initial C<struct ev_loop *> argument.	2081	functions and callbacks have an initial C<struct ev_loop *> argument.
1823		2082
1824	To make it easier to write programs that cope with either variant, the	2083	To make it easier to write programs that cope with either variant, the
1825	following macros are defined:	2084	following macros are defined:
1826		2085
1827	=over 4	2086	=over 4
…		…
1860	loop, if multiple loops are supported ("ev loop default").	2119	loop, if multiple loops are supported ("ev loop default").
1861		2120
1862	=back	2121	=back
1863		2122
1864	Example: Declare and initialise a check watcher, utilising the above	2123	Example: Declare and initialise a check watcher, utilising the above
1865	macros so it will work regardless of wether multiple loops are supported	2124	macros so it will work regardless of whether multiple loops are supported
1866	or not.	2125	or not.
1867		2126
1868	static void	2127	static void
1869	check_cb (EV_P_ ev_timer *w, int revents)	2128	check_cb (EV_P_ ev_timer *w, int revents)
1870	{	2129	{
…		…
1991		2250
1992	If defined to be C<1>, libev will try to detect the availability of the	2251	If defined to be C<1>, libev will try to detect the availability of the
1993	realtime clock option at compiletime (and assume its availability at	2252	realtime clock option at compiletime (and assume its availability at
1994	runtime if successful). Otherwise no use of the realtime clock option will	2253	runtime if successful). Otherwise no use of the realtime clock option will
1995	be attempted. This effectively replaces C<gettimeofday> by C<clock_get	2254	be attempted. This effectively replaces C<gettimeofday> by C<clock_get
1996	(CLOCK_REALTIME, ...)> and will not normally affect correctness. See tzhe note about libraries	2255	(CLOCK_REALTIME, ...)> and will not normally affect correctness. See the
1997	in the description of C<EV_USE_MONOTONIC>, though.	2256	note about libraries in the description of C<EV_USE_MONOTONIC>, though.
1998		2257
1999	=item EV_USE_SELECT	2258	=item EV_USE_SELECT
2000		2259
2001	If undefined or defined to be C<1>, libev will compile in support for the	2260	If undefined or defined to be C<1>, libev will compile in support for the
2002	C<select>(2) backend. No attempt at autodetection will be done: if no	2261	C<select>(2) backend. No attempt at autodetection will be done: if no
…		…
2095	will have the C<struct ev_loop *> as first argument, and you can create	2354	will have the C<struct ev_loop *> as first argument, and you can create
2096	additional independent event loops. Otherwise there will be no support	2355	additional independent event loops. Otherwise there will be no support
2097	for multiple event loops and there is no first event loop pointer	2356	for multiple event loops and there is no first event loop pointer
2098	argument. Instead, all functions act on the single default loop.	2357	argument. Instead, all functions act on the single default loop.
2099		2358
		2359	=item EV_MINPRI
		2360
		2361	=item EV_MAXPRI
		2362
		2363	The range of allowed priorities. C<EV_MINPRI> must be smaller or equal to
		2364	C<EV_MAXPRI>, but otherwise there are no non-obvious limitations. You can
		2365	provide for more priorities by overriding those symbols (usually defined
		2366	to be C<-2> and C<2>, respectively).
		2367
		2368	When doing priority-based operations, libev usually has to linearly search
		2369	all the priorities, so having many of them (hundreds) uses a lot of space
		2370	and time, so using the defaults of five priorities (-2 .. +2) is usually
		2371	fine.
		2372
		2373	If your embedding app does not need any priorities, defining these both to
		2374	C<0> will save some memory and cpu.
		2375
2100	=item EV_PERIODIC_ENABLE	2376	=item EV_PERIODIC_ENABLE
2101		2377
2102	If undefined or defined to be C<1>, then periodic timers are supported. If	2378	If undefined or defined to be C<1>, then periodic timers are supported. If
		2379	defined to be C<0>, then they are not. Disabling them saves a few kB of
		2380	code.
		2381
		2382	=item EV_IDLE_ENABLE
		2383
		2384	If undefined or defined to be C<1>, then idle watchers are supported. If
2103	defined to be C<0>, then they are not. Disabling them saves a few kB of	2385	defined to be C<0>, then they are not. Disabling them saves a few kB of
2104	code.	2386	code.
2105		2387
2106	=item EV_EMBED_ENABLE	2388	=item EV_EMBED_ENABLE
2107		2389
…		…
2162	and the way callbacks are invoked and set. Must expand to a struct member	2444	and the way callbacks are invoked and set. Must expand to a struct member
2163	definition and a statement, respectively. See the F<ev.v> header file for	2445	definition and a statement, respectively. See the F<ev.v> header file for
2164	their default definitions. One possible use for overriding these is to	2446	their default definitions. One possible use for overriding these is to
2165	avoid the C<struct ev_loop *> as first argument in all cases, or to use	2447	avoid the C<struct ev_loop *> as first argument in all cases, or to use
2166	method calls instead of plain function calls in C++.	2448	method calls instead of plain function calls in C++.
		2449
		2450	=head2 EXPORTED API SYMBOLS
		2451
		2452	If you need to re-export the API (e.g. via a dll) and you need a list of
		2453	exported symbols, you can use the provided F<Symbol.*> files which list
		2454	all public symbols, one per line:
		2455
		2456	Symbols.ev for libev proper
		2457	Symbols.event for the libevent emulation
		2458
		2459	This can also be used to rename all public symbols to avoid clashes with
		2460	multiple versions of libev linked together (which is obviously bad in
		2461	itself, but sometimes it is inconvinient to avoid this).
		2462
		2463	A sed comamnd like this will create wrapper C<#define>'s that you need to
		2464	include before including F<ev.h>:
		2465
		2466	<Symbols.ev sed -e "s/.*/#define & myprefix_&/" >wrap.h
		2467
		2468	This would create a file F<wrap.h> which essentially looks like this:
		2469
		2470	#define ev_backend myprefix_ev_backend
		2471	#define ev_check_start myprefix_ev_check_start
		2472	#define ev_check_stop myprefix_ev_check_stop
		2473	...
2167		2474
2168	=head2 EXAMPLES	2475	=head2 EXAMPLES
2169		2476
2170	For a real-world example of a program the includes libev	2477	For a real-world example of a program the includes libev
2171	verbatim, you can have a look at the EV perl module	2478	verbatim, you can have a look at the EV perl module
…		…
2200		2507
2201	In this section the complexities of (many of) the algorithms used inside	2508	In this section the complexities of (many of) the algorithms used inside
2202	libev will be explained. For complexity discussions about backends see the	2509	libev will be explained. For complexity discussions about backends see the
2203	documentation for C<ev_default_init>.	2510	documentation for C<ev_default_init>.
2204		2511
		2512	All of the following are about amortised time: If an array needs to be
		2513	extended, libev needs to realloc and move the whole array, but this
		2514	happens asymptotically never with higher number of elements, so O(1) might
		2515	mean it might do a lengthy realloc operation in rare cases, but on average
		2516	it is much faster and asymptotically approaches constant time.
		2517
2205	=over 4	2518	=over 4
2206		2519
2207	=item Starting and stopping timer/periodic watchers: O(log skipped_other_timers)	2520	=item Starting and stopping timer/periodic watchers: O(log skipped_other_timers)
2208		2521
		2522	This means that, when you have a watcher that triggers in one hour and
		2523	there are 100 watchers that would trigger before that then inserting will
		2524	have to skip those 100 watchers.
		2525
2209	=item Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)	2526	=item Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)
2210		2527
		2528	That means that for changing a timer costs less than removing/adding them
		2529	as only the relative motion in the event queue has to be paid for.
		2530
2211	=item Starting io/check/prepare/idle/signal/child watchers: O(1)	2531	=item Starting io/check/prepare/idle/signal/child watchers: O(1)
2212		2532
		2533	These just add the watcher into an array or at the head of a list.
2213	=item Stopping check/prepare/idle watchers: O(1)	2534	=item Stopping check/prepare/idle watchers: O(1)
2214		2535
2215	=item Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % EV_PID_HASHSIZE))	2536	=item Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % EV_PID_HASHSIZE))
2216		2537
		2538	These watchers are stored in lists then need to be walked to find the
		2539	correct watcher to remove. The lists are usually short (you don't usually
		2540	have many watchers waiting for the same fd or signal).
		2541
2217	=item Finding the next timer per loop iteration: O(1)	2542	=item Finding the next timer per loop iteration: O(1)
2218		2543
2219	=item Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)	2544	=item Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)
2220		2545
		2546	A change means an I/O watcher gets started or stopped, which requires
		2547	libev to recalculate its status (and possibly tell the kernel).
		2548
2221	=item Activating one watcher: O(1)	2549	=item Activating one watcher: O(1)
2222		2550
		2551	=item Priority handling: O(number_of_priorities)
		2552
		2553	Priorities are implemented by allocating some space for each
		2554	priority. When doing priority-based operations, libev usually has to
		2555	linearly search all the priorities.
		2556
2223	=back	2557	=back
2224		2558
2225		2559
2226	=head1 AUTHOR	2560	=head1 AUTHOR
2227		2561

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Comparing libev/ev.pod (file contents): Revision 1.66 by root, Mon Dec 3 13:41:25 2007 UTC vs. Revision 1.90 by root, Thu Dec 20 01:18:37 2007 UTC

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Comparing libev/ev.pod (file contents):
Revision 1.66 by root, Mon Dec 3 13:41:25 2007 UTC vs.
Revision 1.90 by root, Thu Dec 20 01:18:37 2007 UTC