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

Comparing libev/ev.pod (file contents):
Revision 1.35 by root, Fri Nov 23 19:35:09 2007 UTC vs.
Revision 1.36 by root, Sat Nov 24 07:14:26 2007 UTC

…		…
505	*) >>), and you can stop watching for events at any time by calling the	505	*) >>), and you can stop watching for events at any time by calling the
506	corresponding stop function (C<< ev_<type>_stop (loop, watcher *) >>.	506	corresponding stop function (C<< ev_<type>_stop (loop, watcher *) >>.
507		507
508	As long as your watcher is active (has been started but not stopped) you	508	As long as your watcher is active (has been started but not stopped) you
509	must not touch the values stored in it. Most specifically you must never	509	must not touch the values stored in it. Most specifically you must never
510	reinitialise it or call its set macro.	510	reinitialise it or call its C<set> macro.
511
512	You can check whether an event is active by calling the C<ev_is_active
513	(watcher *)> macro. To see whether an event is outstanding (but the
514	callback for it has not been called yet) you can use the C<ev_is_pending
515	(watcher *)> macro.
516		511
517	Each and every callback receives the event loop pointer as first, the	512	Each and every callback receives the event loop pointer as first, the
518	registered watcher structure as second, and a bitset of received events as	513	registered watcher structure as second, and a bitset of received events as
519	third argument.	514	third argument.
520		515
…		…
576	your callbacks is well-written it can just attempt the operation and cope	571	your callbacks is well-written it can just attempt the operation and cope
577	with the error from read() or write(). This will not work in multithreaded	572	with the error from read() or write(). This will not work in multithreaded
578	programs, though, so beware.	573	programs, though, so beware.
579		574
580	=back	575	=back
		576
		577	=head2 SUMMARY OF GENERIC WATCHER FUNCTIONS
		578
		579	In the following description, C<TYPE> stands for the watcher type,
		580	e.g. C<timer> for C<ev_timer> watchers and C<io> for C<ev_io> watchers.
		581
		582	=over 4
		583
		584	=item C<ev_init> (ev_TYPE *watcher, callback)
		585
		586	This macro initialises the generic portion of a watcher. The contents
		587	of the watcher object can be arbitrary (so C<malloc> will do). Only
		588	the generic parts of the watcher are initialised, you I<need> to call
		589	the type-specific C<ev_TYPE_set> macro afterwards to initialise the
		590	type-specific parts. For each type there is also a C<ev_TYPE_init> macro
		591	which rolls both calls into one.
		592
		593	You can reinitialise a watcher at any time as long as it has been stopped
		594	(or never started) and there are no pending events outstanding.
		595
		596	The callbakc is always of type C<void ()(ev_loop loop, ev_TYPE *watcher,
		597	int revents)>.
		598
		599	=item C<ev_TYPE_set> (ev_TYPE *, [args])
		600
		601	This macro initialises the type-specific parts of a watcher. You need to
		602	call C<ev_init> at least once before you call this macro, but you can
		603	call C<ev_TYPE_set> any number of times. You must not, however, call this
		604	macro on a watcher that is active (it can be pending, however, which is a
		605	difference to the C<ev_init> macro).
		606
		607	Although some watcher types do not have type-specific arguments
		608	(e.g. C<ev_prepare>) you still need to call its C<set> macro.
		609
		610	=item C<ev_TYPE_init> (ev_TYPE *watcher, callback, [args])
		611
		612	This convinience macro rolls both C<ev_init> and C<ev_TYPE_set> macro
		613	calls into a single call. This is the most convinient method to initialise
		614	a watcher. The same limitations apply, of course.
		615
		616	=item C<ev_TYPE_start> (loop , ev_TYPE watcher)
		617
		618	Starts (activates) the given watcher. Only active watchers will receive
		619	events. If the watcher is already active nothing will happen.
		620
		621	=item C<ev_TYPE_stop> (loop , ev_TYPE watcher)
		622
		623	Stops the given watcher again (if active) and clears the pending
		624	status. It is possible that stopped watchers are pending (for example,
		625	non-repeating timers are being stopped when they become pending), but
		626	C<ev_TYPE_stop> ensures that the watcher is neither active nor pending. If
		627	you want to free or reuse the memory used by the watcher it is therefore a
		628	good idea to always call its C<ev_TYPE_stop> function.
		629
		630	=item bool ev_is_active (ev_TYPE *watcher)
		631
		632	Returns a true value iff the watcher is active (i.e. it has been started
		633	and not yet been stopped). As long as a watcher is active you must not modify
		634	it.
		635
		636	=item bool ev_is_pending (ev_TYPE *watcher)
		637
		638	Returns a true value iff the watcher is pending, (i.e. it has outstanding
		639	events but its callback has not yet been invoked). As long as a watcher
		640	is pending (but not active) you must not call an init function on it (but
		641	C<ev_TYPE_set> is safe) and you must make sure the watcher is available to
		642	libev (e.g. you cnanot C<free ()> it).
		643
		644	=item callback = ev_cb (ev_TYPE *watcher)
		645
		646	Returns the callback currently set on the watcher.
		647
		648	=item ev_cb_set (ev_TYPE *watcher, callback)
		649
		650	Change the callback. You can change the callback at virtually any time
		651	(modulo threads).
		652
		653	=back
		654
581		655
582	=head2 ASSOCIATING CUSTOM DATA WITH A WATCHER	656	=head2 ASSOCIATING CUSTOM DATA WITH A WATCHER
583		657
584	Each watcher has, by default, a member C<void *data> that you can change	658	Each watcher has, by default, a member C<void *data> that you can change
585	and read at any time, libev will completely ignore it. This can be used	659	and read at any time, libev will completely ignore it. This can be used
…		…
1058		1132
1059		1133
1060	=head2 C<ev_embed> - when one backend isn't enough	1134	=head2 C<ev_embed> - when one backend isn't enough
1061		1135
1062	This is a rather advanced watcher type that lets you embed one event loop	1136	This is a rather advanced watcher type that lets you embed one event loop
1063	into another.	1137	into another (currently only C<ev_io> events are supported in the embedded
		1138	loop, other types of watchers might be handled in a delayed or incorrect
		1139	fashion and must not be used).
1064		1140
1065	There are primarily two reasons you would want that: work around bugs and	1141	There are primarily two reasons you would want that: work around bugs and
1066	prioritise I/O.	1142	prioritise I/O.
1067		1143
1068	As an example for a bug workaround, the kqueue backend might only support	1144	As an example for a bug workaround, the kqueue backend might only support
…		…
1076	As for prioritising I/O: rarely you have the case where some fds have	1152	As for prioritising I/O: rarely you have the case where some fds have
1077	to be watched and handled very quickly (with low latency), and even	1153	to be watched and handled very quickly (with low latency), and even
1078	priorities and idle watchers might have too much overhead. In this case	1154	priorities and idle watchers might have too much overhead. In this case
1079	you would put all the high priority stuff in one loop and all the rest in	1155	you would put all the high priority stuff in one loop and all the rest in
1080	a second one, and embed the second one in the first.	1156	a second one, and embed the second one in the first.
		1157
		1158	As long as the watcher is active, the callback will be invoked every time
		1159	there might be events pending in the embedded loop. The callback must then
		1160	call C<ev_embed_sweep (mainloop, watcher)> to make a single sweep and invoke
		1161	their callbacks (you could also start an idle watcher to give the embedded
		1162	loop strictly lower priority for example). You can also set the callback
		1163	to C<0>, in which case the embed watcher will automatically execute the
		1164	embedded loop sweep.
1081		1165
1082	As long as the watcher is started it will automatically handle events. The	1166	As long as the watcher is started it will automatically handle events. The
1083	callback will be invoked whenever some events have been handled. You can	1167	callback will be invoked whenever some events have been handled. You can
1084	set the callback to C<0> to avoid having to specify one if you are not	1168	set the callback to C<0> to avoid having to specify one if you are not
1085	interested in that.	1169	interested in that.
…		…
1117	else	1201	else
1118	loop_lo = loop_hi;	1202	loop_lo = loop_hi;
1119		1203
1120	=over 4	1204	=over 4
1121		1205
1122	=item ev_embed_init (ev_embed , callback, struct ev_loop loop)	1206	=item ev_embed_init (ev_embed , callback, struct ev_loop embedded_loop)
1123		1207
1124	=item ev_embed_set (ev_embed , callback, struct ev_loop loop)	1208	=item ev_embed_set (ev_embed , callback, struct ev_loop embedded_loop)
1125		1209
1126	Configures the watcher to embed the given loop, which must be embeddable.	1210	Configures the watcher to embed the given loop, which must be
		1211	embeddable. If the callback is C<0>, then C<ev_embed_sweep> will be
		1212	invoked automatically, otherwise it is the responsibility of the callback
		1213	to invoke it (it will continue to be called until the sweep has been done,
		1214	if you do not want thta, you need to temporarily stop the embed watcher).
		1215
		1216	=item ev_embed_sweep (loop, ev_embed *)
		1217
		1218	Make a single, non-blocking sweep over the embedded loop. This works
		1219	similarly to C<ev_loop (embedded_loop, EVLOOP_NONBLOCK)>, but in the most
		1220	apropriate way for embedded loops.
1127		1221
1128	=back	1222	=back
1129		1223
1130		1224
1131	=head1 OTHER FUNCTIONS	1225	=head1 OTHER FUNCTIONS
…		…
1164	/* stdin might have data for us, joy! */;	1258	/* stdin might have data for us, joy! */;
1165	}	1259	}
1166		1260
1167	ev_once (STDIN_FILENO, EV_READ, 10., stdin_ready, 0);	1261	ev_once (STDIN_FILENO, EV_READ, 10., stdin_ready, 0);
1168		1262
1169	=item ev_feed_event (loop, watcher, int events)	1263	=item ev_feed_event (ev_loop , watcher , int revents)
1170		1264
1171	Feeds the given event set into the event loop, as if the specified event	1265	Feeds the given event set into the event loop, as if the specified event
1172	had happened for the specified watcher (which must be a pointer to an	1266	had happened for the specified watcher (which must be a pointer to an
1173	initialised but not necessarily started event watcher).	1267	initialised but not necessarily started event watcher).
1174		1268
1175	=item ev_feed_fd_event (loop, int fd, int revents)	1269	=item ev_feed_fd_event (ev_loop *, int fd, int revents)
1176		1270
1177	Feed an event on the given fd, as if a file descriptor backend detected	1271	Feed an event on the given fd, as if a file descriptor backend detected
1178	the given events it.	1272	the given events it.
1179		1273
1180	=item ev_feed_signal_event (loop, int signum)	1274	=item ev_feed_signal_event (ev_loop *loop, int signum)
1181		1275
1182	Feed an event as if the given signal occured (loop must be the default loop!).	1276	Feed an event as if the given signal occured (C<loop> must be the default
		1277	loop!).
1183		1278
1184	=back	1279	=back
1185		1280
1186		1281
1187	=head1 LIBEVENT EMULATION	1282	=head1 LIBEVENT EMULATION

Diff Legend

-–
+Removed lines
-+
+Added lines
-<
+Changed lines
->
+Changed lines

Comparing libev/ev.pod (file contents): Revision 1.35 by root, Fri Nov 23 19:35:09 2007 UTC vs. Revision 1.36 by root, Sat Nov 24 07:14:26 2007 UTC

Diff Legend

Comparing libev/ev.pod (file contents):
Revision 1.35 by root, Fri Nov 23 19:35:09 2007 UTC vs.
Revision 1.36 by root, Sat Nov 24 07:14:26 2007 UTC