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

Comparing libev/ev.pod (file contents):
Revision 1.67 by root, Fri Dec 7 16:44:12 2007 UTC vs.
Revision 1.91 by root, Thu Dec 20 07:12:57 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
…		…
762	watchers on the same event and make sure one is called first.	782	watchers on the same event and make sure one is called first.
763		783
764	If you need to suppress invocation when higher priority events are pending	784	If you need to suppress invocation when higher priority events are pending
765	you need to look at C<ev_idle> watchers, which provide this functionality.	785	you need to look at C<ev_idle> watchers, which provide this functionality.
766		786
		787	You I<must not> change the priority of a watcher as long as it is active or
		788	pending.
		789
767	The default priority used by watchers when no priority has been set is	790	The default priority used by watchers when no priority has been set is
768	always C<0>, which is supposed to not be too high and not be too low :).	791	always C<0>, which is supposed to not be too high and not be too low :).
769		792
770	Setting a priority outside the range of C<EV_MINPRI> to C<EV_MAXPRI> is	793	Setting a priority outside the range of C<EV_MINPRI> to C<EV_MAXPRI> is
771	fine, as long as you do not mind that the priority value you query might	794	fine, as long as you do not mind that the priority value you query might
772	or might not have been adjusted to be within valid range.	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>.
773		808
774	=back	809	=back
775		810
776		811
777	=head2 ASSOCIATING CUSTOM DATA WITH A WATCHER	812	=head2 ASSOCIATING CUSTOM DATA WITH A WATCHER
…		…
883	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
884	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.
885		920
886	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
887	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
888	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
889	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
890	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
891		950
892	=over 4	951	=over 4
893		952
894	=item ev_io_init (ev_io *, callback, int fd, int events)	953	=item ev_io_init (ev_io *, callback, int fd, int events)
895		954
…		…
948	ev_timer_set (&timer, after + ev_now () - ev_time (), 0.);	1007	ev_timer_set (&timer, after + ev_now () - ev_time (), 0.);
949		1008
950	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,
951	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
952	order of execution is undefined.	1011	order of execution is undefined.
		1012
		1013	=head3 Watcher-Specific Functions and Data Members
953		1014
954	=over 4	1015	=over 4
955		1016
956	=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)
957		1018
…		…
1053	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
1054	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
1055	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 ()
1056	+ 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
1057	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
1058	roughly 10 seconds later and of course not if you reset your system time	1119	roughly 10 seconds later).
1059	again).
1060		1120
1061	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
1062	triggering an event on eahc midnight, local time.	1122	triggering an event on each midnight, local time or other, complicated,
		1123	rules.
1063		1124
1064	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
1065	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
1066	during the same loop iteration then order of execution is undefined.	1127	during the same loop iteration then order of execution is undefined.
1067		1128
		1129	=head3 Watcher-Specific Functions and Data Members
		1130
1068	=over 4	1131	=over 4
1069		1132
1070	=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)
1071		1134
1072	=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)
…		…
1074	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
1075	operation, and we will explain them from simplest to complex:	1138	operation, and we will explain them from simplest to complex:
1076		1139
1077	=over 4	1140	=over 4
1078		1141
1079	=item * absolute timer (interval = reschedule_cb = 0)	1142	=item * absolute timer (at = time, interval = reschedule_cb = 0)
1080		1143
1081	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
1082	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,
1083	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
1084	system time reaches or surpasses this time.	1147	system time reaches or surpasses this time.
1085		1148
1086	=item * non-repeating interval timer (interval > 0, reschedule_cb = 0)	1149	=item * non-repeating interval timer (at = offset, interval > 0, reschedule_cb = 0)
1087		1150
1088	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
1089	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)
1090	of any time jumps.	1153	and then repeat, regardless of any time jumps.
1091		1154
1092	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
1093	time:	1156	time:
1094		1157
1095	ev_periodic_set (&periodic, 0., 3600., 0);	1158	ev_periodic_set (&periodic, 0., 3600., 0);
…		…
1101		1164
1102	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
1103	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
1104	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.
1105		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
1106	=item * manual reschedule mode (reschedule_cb = callback)	1173	=item * manual reschedule mode (at and interval ignored, reschedule_cb = callback)
1107		1174
1108	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
1109	ignored. Instead, each time the periodic watcher gets scheduled, the	1176	ignored. Instead, each time the periodic watcher gets scheduled, the
1110	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
1111	current time as second argument.	1178	current time as second argument.
1112		1179
1113	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,
1114	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,
1115	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
1116	starting a prepare watcher).	1183	starting an C<ev_prepare> watcher, which is legal).
1117		1184
1118	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,
1119	ev_tstamp now)>, e.g.:	1186	ev_tstamp now)>, e.g.:
1120		1187
1121	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)
…		…
1144	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
1145	when you changed some parameters or the reschedule callback would return	1212	when you changed some parameters or the reschedule callback would return
1146	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
1147	program when the crontabs have changed).	1214	program when the crontabs have changed).
1148		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
1149	=item ev_tstamp interval [read-write]	1224	=item ev_tstamp interval [read-write]
1150		1225
1151	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
1152	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
1153	called.	1228	called.
…		…
1155	=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]
1156		1231
1157	The current reschedule callback, or C<0>, if this functionality is	1232	The current reschedule callback, or C<0>, if this functionality is
1158	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
1159	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.
1160		1240
1161	=back	1241	=back
1162		1242
1163	Example: Call a callback every hour, or, more precisely, whenever the	1243	Example: Call a callback every hour, or, more precisely, whenever the
1164	system clock is divisible by 3600. The callback invocation times have	1244	system clock is divisible by 3600. The callback invocation times have
…		…
1206	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
1207	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
1208	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
1209	SIG_DFL (regardless of what it was set to before).	1289	SIG_DFL (regardless of what it was set to before).
1210		1290
		1291	=head3 Watcher-Specific Functions and Data Members
		1292
1211	=over 4	1293	=over 4
1212		1294
1213	=item ev_signal_init (ev_signal *, callback, int signum)	1295	=item ev_signal_init (ev_signal *, callback, int signum)
1214		1296
1215	=item ev_signal_set (ev_signal *, int signum)	1297	=item ev_signal_set (ev_signal *, int signum)
…		…
1226		1308
1227	=head2 C<ev_child> - watch out for process status changes	1309	=head2 C<ev_child> - watch out for process status changes
1228		1310
1229	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
1230	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
1231		1315
1232	=over 4	1316	=over 4
1233		1317
1234	=item ev_child_init (ev_child *, callback, int pid)	1318	=item ev_child_init (ev_child *, callback, int pid)
1235		1319
…		…
1303	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
1304	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
1305	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
1306	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
1307	polling.	1391	polling.
		1392
		1393	=head3 Watcher-Specific Functions and Data Members
1308		1394
1309	=over 4	1395	=over 4
1310		1396
1311	=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)
1312		1398
…		…
1395	Apart from keeping your process non-blocking (which is a useful	1481	Apart from keeping your process non-blocking (which is a useful
1396	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
1397	"pseudo-background processing", or delay processing stuff to after the	1483	"pseudo-background processing", or delay processing stuff to after the
1398	event loop has handled all outstanding events.	1484	event loop has handled all outstanding events.
1399		1485
		1486	=head3 Watcher-Specific Functions and Data Members
		1487
1400	=over 4	1488	=over 4
1401		1489
1402	=item ev_idle_init (ev_signal *, callback)	1490	=item ev_idle_init (ev_signal *, callback)
1403		1491
1404	Initialises and configures the idle watcher - it has no parameters of any	1492	Initialises and configures the idle watcher - it has no parameters of any
…		…
1461	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
1462	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
1463	loop from blocking if lower-priority coroutines are active, thus mapping	1551	loop from blocking if lower-priority coroutines are active, thus mapping
1464	low-priority coroutines to idle/background tasks).	1552	low-priority coroutines to idle/background tasks).
1465		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
1466	=over 4	1566	=over 4
1467		1567
1468	=item ev_prepare_init (ev_prepare *, callback)	1568	=item ev_prepare_init (ev_prepare *, callback)
1469		1569
1470	=item ev_check_init (ev_check *, callback)	1570	=item ev_check_init (ev_check *, callback)
…		…
1473	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>
1474	macros, but using them is utterly, utterly and completely pointless.	1574	macros, but using them is utterly, utterly and completely pointless.
1475		1575
1476	=back	1576	=back
1477		1577
1478	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
1479	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,
1480	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
1481	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.
1482		1590
1483	static ev_io iow [nfd];	1591	static ev_io iow [nfd];
1484	static ev_timer tw;	1592	static ev_timer tw;
1485		1593
1486	static void	1594	static void
1487	io_cb (ev_loop loop, ev_io w, int revents)	1595	io_cb (ev_loop loop, ev_io w, int revents)
1488	{	1596	{
1489	// set the relevant poll flags
1490	// could also call adns_processreadable etc. here
1491	struct pollfd fd = (struct pollfd )w->data;
1492	if (revents & EV_READ ) fd->revents \|= fd->events & POLLIN;
1493	if (revents & EV_WRITE) fd->revents \|= fd->events & POLLOUT;
1494	}	1597	}
1495		1598
1496	// create io watchers for each fd and a timer before blocking	1599	// create io watchers for each fd and a timer before blocking
1497	static void	1600	static void
1498	adns_prepare_cb (ev_loop loop, ev_prepare w, int revents)	1601	adns_prepare_cb (ev_loop loop, ev_prepare w, int revents)
…		…
1504		1607
1505	/* 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 */
1506	ev_timer_init (&tw, 0, timeout * 1e-3);	1609	ev_timer_init (&tw, 0, timeout * 1e-3);
1507	ev_timer_start (loop, &tw);	1610	ev_timer_start (loop, &tw);
1508		1611
1509	// create on ev_io per pollfd	1612	// create one ev_io per pollfd
1510	for (int i = 0; i < nfd; ++i)	1613	for (int i = 0; i < nfd; ++i)
1511	{	1614	{
1512	ev_io_init (iow + i, io_cb, fds [i].fd,	1615	ev_io_init (iow + i, io_cb, fds [i].fd,
1513	((fds [i].events & POLLIN ? EV_READ : 0)	1616	((fds [i].events & POLLIN ? EV_READ : 0)
1514	\| (fds [i].events & POLLOUT ? EV_WRITE : 0)));	1617	\| (fds [i].events & POLLOUT ? EV_WRITE : 0)));
1515		1618
1516	fds [i].revents = 0;	1619	fds [i].revents = 0;
1517	iow [i].data = fds + i;
1518	ev_io_start (loop, iow + i);	1620	ev_io_start (loop, iow + i);
1519	}	1621	}
1520	}	1622	}
1521		1623
1522	// stop all watchers after blocking	1624	// stop all watchers after blocking
…		…
1524	adns_check_cb (ev_loop loop, ev_check w, int revents)	1626	adns_check_cb (ev_loop loop, ev_check w, int revents)
1525	{	1627	{
1526	ev_timer_stop (loop, &tw);	1628	ev_timer_stop (loop, &tw);
1527		1629
1528	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
1529	ev_io_stop (loop, iow + i);	1640	ev_io_stop (loop, iow + i);
		1641	}
1530		1642
1531	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;
1532	}	1703	}
1533		1704
1534		1705
1535	=head2 C<ev_embed> - when one backend isn't enough...	1706	=head2 C<ev_embed> - when one backend isn't enough...
1536		1707
…		…
1600	ev_embed_start (loop_hi, &embed);	1771	ev_embed_start (loop_hi, &embed);
1601	}	1772	}
1602	else	1773	else
1603	loop_lo = loop_hi;	1774	loop_lo = loop_hi;
1604		1775
		1776	=head3 Watcher-Specific Functions and Data Members
		1777
1605	=over 4	1778	=over 4
1606		1779
1607	=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)
1608		1781
1609	=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)
…		…
1618		1791
1619	Make a single, non-blocking sweep over the embedded loop. This works	1792	Make a single, non-blocking sweep over the embedded loop. This works
1620	similarly to C<ev_loop (embedded_loop, EVLOOP_NONBLOCK)>, but in the most	1793	similarly to C<ev_loop (embedded_loop, EVLOOP_NONBLOCK)>, but in the most
1621	apropriate way for embedded loops.	1794	apropriate way for embedded loops.
1622		1795
1623	=item struct ev_loop *loop [read-only]	1796	=item struct ev_loop *other [read-only]
1624		1797
1625	The embedded event loop.	1798	The embedded event loop.
1626		1799
1627	=back	1800	=back
1628		1801
…		…
1635	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,
1636	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
1637	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
1638	handlers will be invoked, too, of course.	1811	handlers will be invoked, too, of course.
1639		1812
		1813	=head3 Watcher-Specific Functions and Data Members
		1814
1640	=over 4	1815	=over 4
1641		1816
1642	=item ev_fork_init (ev_signal *, callback)	1817	=item ev_fork_init (ev_signal *, callback)
1643		1818
1644	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
…		…
1740		1915
1741	To use it,	1916	To use it,
1742		1917
1743	#include <ev++.h>	1918	#include <ev++.h>
1744		1919
1745	(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
1746	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
1747	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>.
1748		1924
1749	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++
1750	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).
1751		1935
1752	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:
1753		1937
1754	=over 4	1938	=over 4
1755		1939
…		…
1771		1955
1772	All of those classes have these methods:	1956	All of those classes have these methods:
1773		1957
1774	=over 4	1958	=over 4
1775		1959
1776	=item ev::TYPE::TYPE (object , object::method )	1960	=item ev::TYPE::TYPE ()
1777		1961
1778	=item ev::TYPE::TYPE (object , object::method , struct ev_loop *)	1962	=item ev::TYPE::TYPE (struct ev_loop *)
1779		1963
1780	=item ev::TYPE::~TYPE	1964	=item ev::TYPE::~TYPE
1781		1965
1782	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
1783	the event handler callback to call in this class. The constructor calls	1967	with. If it is omitted, it will use C<EV_DEFAULT>.
1784	C<ev_init> for you, which means you have to call the C<set> method	1968
1785	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
1786	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).
1787		1977
1788	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> ();
1789		2018
1790	=item w->set (struct ev_loop *)	2019	=item w->set (struct ev_loop *)
1791		2020
1792	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
1793	do this when the watcher is inactive (and not pending either).	2022	do this when the watcher is inactive (and not pending either).
1794		2023
1795	=item w->set ([args])	2024	=item w->set ([args])
1796		2025
1797	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
1798	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
1799	automatically stopped and restarted.	2028	automatically stopped and restarted when reconfiguring it with this
		2029	method.
1800		2030
1801	=item w->start ()	2031	=item w->start ()
1802		2032
1803	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
1804	constructor already takes the loop.	2034	constructor already stores the event loop.
1805		2035
1806	=item w->stop ()	2036	=item w->stop ()
1807		2037
1808	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.
1809		2039
1810	=item w->again () C<ev::timer>, C<ev::periodic> only	2040	=item w->again () (C<ev::timer>, C<ev::periodic> only)
1811		2041
1812	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
1813	C<ev_TYPE_again> function.	2043	C<ev_TYPE_again> function.
1814		2044
1815	=item w->sweep () C<ev::embed> only	2045	=item w->sweep () (C<ev::embed> only)
1816		2046
1817	Invokes C<ev_embed_sweep>.	2047	Invokes C<ev_embed_sweep>.
1818		2048
1819	=item w->update () C<ev::stat> only	2049	=item w->update () (C<ev::stat> only)
1820		2050
1821	Invokes C<ev_stat_stat>.	2051	Invokes C<ev_stat_stat>.
1822		2052
1823	=back	2053	=back
1824		2054
…		…
1834		2064
1835	myclass ();	2065	myclass ();
1836	}	2066	}
1837		2067
1838	myclass::myclass (int fd)	2068	myclass::myclass (int fd)
1839	: io (this, &myclass::io_cb),
1840	idle (this, &myclass::idle_cb)
1841	{	2069	{
		2070	io .set <myclass, &myclass::io_cb > (this);
		2071	idle.set <myclass, &myclass::idle_cb> (this);
		2072
1842	io.start (fd, ev::READ);	2073	io.start (fd, ev::READ);
1843	}	2074	}
1844		2075
1845		2076
1846	=head1 MACRO MAGIC	2077	=head1 MACRO MAGIC
1847		2078
1848	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
1849	C<EV_MULTIPLICITY>. This option determines wether (most) functions and	2080	of which is C<EV_MULTIPLICITY>. This option determines whether (most)
1850	callbacks have an initial C<struct ev_loop *> argument.	2081	functions and callbacks have an initial C<struct ev_loop *> argument.
1851		2082
1852	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
1853	following macros are defined:	2084	following macros are defined:
1854		2085
1855	=over 4	2086	=over 4
…		…
1888	loop, if multiple loops are supported ("ev loop default").	2119	loop, if multiple loops are supported ("ev loop default").
1889		2120
1890	=back	2121	=back
1891		2122
1892	Example: Declare and initialise a check watcher, utilising the above	2123	Example: Declare and initialise a check watcher, utilising the above
1893	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
1894	or not.	2125	or not.
1895		2126
1896	static void	2127	static void
1897	check_cb (EV_P_ ev_timer *w, int revents)	2128	check_cb (EV_P_ ev_timer *w, int revents)
1898	{	2129	{
…		…
1909	Libev can (and often is) directly embedded into host	2140	Libev can (and often is) directly embedded into host
1910	applications. Examples of applications that embed it include the Deliantra	2141	applications. Examples of applications that embed it include the Deliantra
1911	Game Server, the EV perl module, the GNU Virtual Private Ethernet (gvpe)	2142	Game Server, the EV perl module, the GNU Virtual Private Ethernet (gvpe)
1912	and rxvt-unicode.	2143	and rxvt-unicode.
1913		2144
1914	The goal is to enable you to just copy the neecssary files into your	2145	The goal is to enable you to just copy the necessary files into your
1915	source directory without having to change even a single line in them, so	2146	source directory without having to change even a single line in them, so
1916	you can easily upgrade by simply copying (or having a checked-out copy of	2147	you can easily upgrade by simply copying (or having a checked-out copy of
1917	libev somewhere in your source tree).	2148	libev somewhere in your source tree).
1918		2149
1919	=head2 FILESETS	2150	=head2 FILESETS
…		…
2019		2250
2020	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
2021	realtime clock option at compiletime (and assume its availability at	2252	realtime clock option at compiletime (and assume its availability at
2022	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
2023	be attempted. This effectively replaces C<gettimeofday> by C<clock_get	2254	be attempted. This effectively replaces C<gettimeofday> by C<clock_get
2024	(CLOCK_REALTIME, ...)> and will not normally affect correctness. See tzhe note about libraries	2255	(CLOCK_REALTIME, ...)> and will not normally affect correctness. See the
2025	in the description of C<EV_USE_MONOTONIC>, though.	2256	note about libraries in the description of C<EV_USE_MONOTONIC>, though.
2026		2257
2027	=item EV_USE_SELECT	2258	=item EV_USE_SELECT
2028		2259
2029	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
2030	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
…		…
2123	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
2124	additional independent event loops. Otherwise there will be no support	2355	additional independent event loops. Otherwise there will be no support
2125	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
2126	argument. Instead, all functions act on the single default loop.	2357	argument. Instead, all functions act on the single default loop.
2127		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
2128	=item EV_PERIODIC_ENABLE	2376	=item EV_PERIODIC_ENABLE
2129		2377
2130	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
2131	defined to be C<0>, then they are not. Disabling them saves a few kB of	2379	defined to be C<0>, then they are not. Disabling them saves a few kB of
2132	code.	2380	code.
…		…
2196	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
2197	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
2198	their default definitions. One possible use for overriding these is to	2446	their default definitions. One possible use for overriding these is to
2199	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
2200	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	...
2201		2474
2202	=head2 EXAMPLES	2475	=head2 EXAMPLES
2203		2476
2204	For a real-world example of a program the includes libev	2477	For a real-world example of a program the includes libev
2205	verbatim, you can have a look at the EV perl module	2478	verbatim, you can have a look at the EV perl module
…		…
2234		2507
2235	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
2236	libev will be explained. For complexity discussions about backends see the	2509	libev will be explained. For complexity discussions about backends see the
2237	documentation for C<ev_default_init>.	2510	documentation for C<ev_default_init>.
2238		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
2239	=over 4	2518	=over 4
2240		2519
2241	=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)
2242		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
2243	=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)
2244		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
2245	=item Starting io/check/prepare/idle/signal/child watchers: O(1)	2531	=item Starting io/check/prepare/idle/signal/child watchers: O(1)
2246		2532
		2533	These just add the watcher into an array or at the head of a list.
2247	=item Stopping check/prepare/idle watchers: O(1)	2534	=item Stopping check/prepare/idle watchers: O(1)
2248		2535
2249	=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))
2250		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
2251	=item Finding the next timer per loop iteration: O(1)	2542	=item Finding the next timer per loop iteration: O(1)
2252		2543
2253	=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)
2254		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
2255	=item Activating one watcher: O(1)	2549	=item Activating one watcher: O(1)
2256		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
2257	=back	2557	=back
2258		2558
2259		2559
2260	=head1 AUTHOR	2560	=head1 AUTHOR
2261		2561

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Comparing libev/ev.pod (file contents): Revision 1.67 by root, Fri Dec 7 16:44:12 2007 UTC vs. Revision 1.91 by root, Thu Dec 20 07:12:57 2007 UTC

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Comparing libev/ev.pod (file contents):
Revision 1.67 by root, Fri Dec 7 16:44:12 2007 UTC vs.
Revision 1.91 by root, Thu Dec 20 07:12:57 2007 UTC