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Comparing libev/ev.pod (file contents):
Revision 1.240 by root, Sat Apr 25 14:12:48 2009 UTC vs.
Revision 1.244 by root, Mon Jun 29 04:41:34 2009 UTC

1184 #include <stddef.h> 1184 #include <stddef.h>
1185 1185
1186 static void 1186 static void
1187 t1_cb (EV_P_ ev_timer *w, int revents) 1187 t1_cb (EV_P_ ev_timer *w, int revents)
1188 { 1188 {
1189 struct my_biggy big = (struct my_biggy * 1189 struct my_biggy big = (struct my_biggy *)
1190 (((char *)w) - offsetof (struct my_biggy, t1)); 1190 (((char *)w) - offsetof (struct my_biggy, t1));
1191 } 1191 }
1192 1192
1193 static void 1193 static void
1194 t2_cb (EV_P_ ev_timer *w, int revents) 1194 t2_cb (EV_P_ ev_timer *w, int revents)
1195 { 1195 {
1196 struct my_biggy big = (struct my_biggy * 1196 struct my_biggy big = (struct my_biggy *)
1197 (((char *)w) - offsetof (struct my_biggy, t2)); 1197 (((char *)w) - offsetof (struct my_biggy, t2));
1198 } 1198 }
1199 1199
1200=head2 WATCHER PRIORITY MODELS 1200=head2 WATCHER PRIORITY MODELS
1201 1201
1277 // with the default priority are receiving events. 1277 // with the default priority are receiving events.
1278 ev_idle_start (EV_A_ &idle); 1278 ev_idle_start (EV_A_ &idle);
1279 } 1279 }
1280 1280
1281 static void 1281 static void
1282 idle-cb (EV_P_ ev_idle *w, int revents) 1282 idle_cb (EV_P_ ev_idle *w, int revents)
1283 { 1283 {
1284 // actual processing 1284 // actual processing
1285 read (STDIN_FILENO, ...); 1285 read (STDIN_FILENO, ...);
1286 1286
1287 // have to start the I/O watcher again, as 1287 // have to start the I/O watcher again, as
1523C<after> argument to C<ev_timer_set>, and only ever use the C<repeat> 1523C<after> argument to C<ev_timer_set>, and only ever use the C<repeat>
1524member and C<ev_timer_again>. 1524member and C<ev_timer_again>.
1525 1525
1526At start: 1526At start:
1527 1527
1528 ev_timer_init (timer, callback); 1528 ev_init (timer, callback);
1529 timer->repeat = 60.; 1529 timer->repeat = 60.;
1530 ev_timer_again (loop, timer); 1530 ev_timer_again (loop, timer);
1531 1531
1532Each time there is some activity: 1532Each time there is some activity:
1533 1533
1595 1595
1596To start the timer, simply initialise the watcher and set C<last_activity> 1596To start the timer, simply initialise the watcher and set C<last_activity>
1597to the current time (meaning we just have some activity :), then call the 1597to the current time (meaning we just have some activity :), then call the
1598callback, which will "do the right thing" and start the timer: 1598callback, which will "do the right thing" and start the timer:
1599 1599
1600 ev_timer_init (timer, callback); 1600 ev_init (timer, callback);
1601 last_activity = ev_now (loop); 1601 last_activity = ev_now (loop);
1602 callback (loop, timer, EV_TIMEOUT); 1602 callback (loop, timer, EV_TIMEOUT);
1603 1603
1604And when there is some activity, simply store the current time in 1604And when there is some activity, simply store the current time in
1605C<last_activity>, no libev calls at all: 1605C<last_activity>, no libev calls at all:
2002some child status changes (most typically when a child of yours dies or 2002some child status changes (most typically when a child of yours dies or
2003exits). It is permissible to install a child watcher I<after> the child 2003exits). It is permissible to install a child watcher I<after> the child
2004has been forked (which implies it might have already exited), as long 2004has been forked (which implies it might have already exited), as long
2005as the event loop isn't entered (or is continued from a watcher), i.e., 2005as the event loop isn't entered (or is continued from a watcher), i.e.,
2006forking and then immediately registering a watcher for the child is fine, 2006forking and then immediately registering a watcher for the child is fine,
2007but forking and registering a watcher a few event loop iterations later is 2007but forking and registering a watcher a few event loop iterations later or
2008not. 2008in the next callback invocation is not.
2009 2009
2010Only the default event loop is capable of handling signals, and therefore 2010Only the default event loop is capable of handling signals, and therefore
2011you can only register child watchers in the default event loop. 2011you can only register child watchers in the default event loop.
2012 2012
2013=head3 Process Interaction 2013=head3 Process Interaction
2368 // no longer anything immediate to do. 2368 // no longer anything immediate to do.
2369 } 2369 }
2370 2370
2371 ev_idle *idle_watcher = malloc (sizeof (ev_idle)); 2371 ev_idle *idle_watcher = malloc (sizeof (ev_idle));
2372 ev_idle_init (idle_watcher, idle_cb); 2372 ev_idle_init (idle_watcher, idle_cb);
2373 ev_idle_start (loop, idle_cb); 2373 ev_idle_start (loop, idle_watcher);
2374 2374
2375 2375
2376=head2 C<ev_prepare> and C<ev_check> - customise your event loop! 2376=head2 C<ev_prepare> and C<ev_check> - customise your event loop!
2377 2377
2378Prepare and check watchers are usually (but not always) used in pairs: 2378Prepare and check watchers are usually (but not always) used in pairs:
2471 struct pollfd fds [nfd]; 2471 struct pollfd fds [nfd];
2472 // actual code will need to loop here and realloc etc. 2472 // actual code will need to loop here and realloc etc.
2473 adns_beforepoll (ads, fds, &nfd, &timeout, timeval_from (ev_time ())); 2473 adns_beforepoll (ads, fds, &nfd, &timeout, timeval_from (ev_time ()));
2474 2474
2475 /* the callback is illegal, but won't be called as we stop during check */ 2475 /* the callback is illegal, but won't be called as we stop during check */
2476 ev_timer_init (&tw, 0, timeout * 1e-3); 2476 ev_timer_init (&tw, 0, timeout * 1e-3, 0.);
2477 ev_timer_start (loop, &tw); 2477 ev_timer_start (loop, &tw);
2478 2478
2479 // create one ev_io per pollfd 2479 // create one ev_io per pollfd
2480 for (int i = 0; i < nfd; ++i) 2480 for (int i = 0; i < nfd; ++i)
2481 { 2481 {
3935way (note also that glib is the slowest event library known to man). 3935way (note also that glib is the slowest event library known to man).
3936 3936
3937There is no supported compilation method available on windows except 3937There is no supported compilation method available on windows except
3938embedding it into other applications. 3938embedding it into other applications.
3939 3939
3940Sensible signal handling is officially unsupported by Microsoft - libev
3941tries its best, but under most conditions, signals will simply not work.
3942
3940Not a libev limitation but worth mentioning: windows apparently doesn't 3943Not a libev limitation but worth mentioning: windows apparently doesn't
3941accept large writes: instead of resulting in a partial write, windows will 3944accept large writes: instead of resulting in a partial write, windows will
3942either accept everything or return C<ENOBUFS> if the buffer is too large, 3945either accept everything or return C<ENOBUFS> if the buffer is too large,
3943so make sure you only write small amounts into your sockets (less than a 3946so make sure you only write small amounts into your sockets (less than a
3944megabyte seems safe, but this apparently depends on the amount of memory 3947megabyte seems safe, but this apparently depends on the amount of memory
3948the abysmal performance of winsockets, using a large number of sockets 3951the abysmal performance of winsockets, using a large number of sockets
3949is not recommended (and not reasonable). If your program needs to use 3952is not recommended (and not reasonable). If your program needs to use
3950more than a hundred or so sockets, then likely it needs to use a totally 3953more than a hundred or so sockets, then likely it needs to use a totally
3951different implementation for windows, as libev offers the POSIX readiness 3954different implementation for windows, as libev offers the POSIX readiness
3952notification model, which cannot be implemented efficiently on windows 3955notification model, which cannot be implemented efficiently on windows
3953(Microsoft monopoly games). 3956(due to Microsoft monopoly games).
3954 3957
3955A typical way to use libev under windows is to embed it (see the embedding 3958A typical way to use libev under windows is to embed it (see the embedding
3956section for details) and use the following F<evwrap.h> header file instead 3959section for details) and use the following F<evwrap.h> header file instead
3957of F<ev.h>: 3960of F<ev.h>:
3958 3961
3994 3997
3995Early versions of winsocket's select only supported waiting for a maximum 3998Early versions of winsocket's select only supported waiting for a maximum
3996of C<64> handles (probably owning to the fact that all windows kernels 3999of C<64> handles (probably owning to the fact that all windows kernels
3997can only wait for C<64> things at the same time internally; Microsoft 4000can only wait for C<64> things at the same time internally; Microsoft
3998recommends spawning a chain of threads and wait for 63 handles and the 4001recommends spawning a chain of threads and wait for 63 handles and the
3999previous thread in each. Great). 4002previous thread in each. Sounds great!).
4000 4003
4001Newer versions support more handles, but you need to define C<FD_SETSIZE> 4004Newer versions support more handles, but you need to define C<FD_SETSIZE>
4002to some high number (e.g. C<2048>) before compiling the winsocket select 4005to some high number (e.g. C<2048>) before compiling the winsocket select
4003call (which might be in libev or elsewhere, for example, perl does its own 4006call (which might be in libev or elsewhere, for example, perl and many
4004select emulation on windows). 4007other interpreters do their own select emulation on windows).
4005 4008
4006Another limit is the number of file descriptors in the Microsoft runtime 4009Another limit is the number of file descriptors in the Microsoft runtime
4007libraries, which by default is C<64> (there must be a hidden I<64> fetish 4010libraries, which by default is C<64> (there must be a hidden I<64>
4008or something like this inside Microsoft). You can increase this by calling 4011fetish or something like this inside Microsoft). You can increase this
4009C<_setmaxstdio>, which can increase this limit to C<2048> (another 4012by calling C<_setmaxstdio>, which can increase this limit to C<2048>
4010arbitrary limit), but is broken in many versions of the Microsoft runtime 4013(another arbitrary limit), but is broken in many versions of the Microsoft
4011libraries.
4012
4013This might get you to about C<512> or C<2048> sockets (depending on 4014runtime libraries. This might get you to about C<512> or C<2048> sockets
4014windows version and/or the phase of the moon). To get more, you need to 4015(depending on windows version and/or the phase of the moon). To get more,
4015wrap all I/O functions and provide your own fd management, but the cost of 4016you need to wrap all I/O functions and provide your own fd management, but
4016calling select (O(n²)) will likely make this unworkable. 4017the cost of calling select (O(n²)) will likely make this unworkable.
4017 4018
4018=back 4019=back
4019 4020
4020=head2 PORTABILITY REQUIREMENTS 4021=head2 PORTABILITY REQUIREMENTS
4021 4022

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