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Comparing libev/ev.pod (file contents):
Revision 1.81 by root, Wed Dec 12 04:53:58 2007 UTC vs.
Revision 1.87 by root, Tue Dec 18 01:37:46 2007 UTC

98Libev represents time as a single floating point number, representing the 98Libev represents time as a single floating point number, representing the
99(fractional) number of seconds since the (POSIX) epoch (somewhere near 99(fractional) number of seconds since the (POSIX) epoch (somewhere near
100the beginning of 1970, details are complicated, don't ask). This type is 100the beginning of 1970, details are complicated, don't ask). This type is
101called C<ev_tstamp>, which is what you should use too. It usually aliases 101called C<ev_tstamp>, which is what you should use too. It usually aliases
102to the C<double> type in C, and when you need to do any calculations on 102to the C<double> type in C, and when you need to do any calculations on
103it, you should treat it as such. 103it, you should treat it as some floatingpoint value. Unlike the name
104component C<stamp> might indicate, it is also used for time differences
105throughout libev.
104 106
105=head1 GLOBAL FUNCTIONS 107=head1 GLOBAL FUNCTIONS
106 108
107These functions can be called anytime, even before initialising the 109These functions can be called anytime, even before initialising the
108library in any way. 110library in any way.
402Destroys the default loop again (frees all memory and kernel state 404Destroys the default loop again (frees all memory and kernel state
403etc.). None of the active event watchers will be stopped in the normal 405etc.). None of the active event watchers will be stopped in the normal
404sense, so e.g. C<ev_is_active> might still return true. It is your 406sense, so e.g. C<ev_is_active> might still return true. It is your
405responsibility to either stop all watchers cleanly yoursef I<before> 407responsibility to either stop all watchers cleanly yoursef I<before>
406calling this function, or cope with the fact afterwards (which is usually 408calling this function, or cope with the fact afterwards (which is usually
407the easiest thing, youc na just ignore the watchers and/or C<free ()> them 409the easiest thing, you can just ignore the watchers and/or C<free ()> them
408for example). 410for example).
411
412Not that certain global state, such as signal state, will not be freed by
413this function, and related watchers (such as signal and child watchers)
414would need to be stopped manually.
415
416In general it is not advisable to call this function except in the
417rare occasion where you really need to free e.g. the signal handling
418pipe fds. If you need dynamically allocated loops it is better to use
419C<ev_loop_new> and C<ev_loop_destroy>).
409 420
410=item ev_loop_destroy (loop) 421=item ev_loop_destroy (loop)
411 422
412Like C<ev_default_destroy>, but destroys an event loop created by an 423Like C<ev_default_destroy>, but destroys an event loop created by an
413earlier call to C<ev_loop_new>. 424earlier call to C<ev_loop_new>.
933This is how one would do it normally anyway, the important point is that 944This is how one would do it normally anyway, the important point is that
934the libev application should not optimise around libev but should leave 945the libev application should not optimise around libev but should leave
935optimisations to libev. 946optimisations to libev.
936 947
937 948
949=head3 Watcher-Specific Functions
950
938=over 4 951=over 4
939 952
940=item ev_io_init (ev_io *, callback, int fd, int events) 953=item ev_io_init (ev_io *, callback, int fd, int events)
941 954
942=item ev_io_set (ev_io *, int fd, int events) 955=item ev_io_set (ev_io *, int fd, int events)
994 ev_timer_set (&timer, after + ev_now () - ev_time (), 0.); 1007 ev_timer_set (&timer, after + ev_now () - ev_time (), 0.);
995 1008
996The callback is guarenteed to be invoked only when its timeout has passed, 1009The callback is guarenteed to be invoked only when its timeout has passed,
997but if multiple timers become ready during the same loop iteration then 1010but if multiple timers become ready during the same loop iteration then
998order of execution is undefined. 1011order of execution is undefined.
1012
1013=head3 Watcher-Specific Functions and Data Members
999 1014
1000=over 4 1015=over 4
1001 1016
1002=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)
1003 1018
1109 1124
1110As with timers, the callback is guarenteed to be invoked only when the 1125As with timers, the callback is guarenteed to be invoked only when the
1111time (C<at>) has been passed, but if multiple periodic timers become ready 1126time (C<at>) has been passed, but if multiple periodic timers become ready
1112during the same loop iteration then order of execution is undefined. 1127during the same loop iteration then order of execution is undefined.
1113 1128
1129=head3 Watcher-Specific Functions and Data Members
1130
1114=over 4 1131=over 4
1115 1132
1116=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)
1117 1134
1118=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)
1213=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]
1214 1231
1215The current reschedule callback, or C<0>, if this functionality is 1232The current reschedule callback, or C<0>, if this functionality is
1216switched off. Can be changed any time, but changes only take effect when 1233switched off. Can be changed any time, but changes only take effect when
1217the periodic timer fires or C<ev_periodic_again> is being called. 1234the periodic timer fires or C<ev_periodic_again> is being called.
1235
1236=item ev_tstamp at [read-only]
1237
1238When active, contains the absolute time that the watcher is supposed to
1239trigger next.
1218 1240
1219=back 1241=back
1220 1242
1221Example: Call a callback every hour, or, more precisely, whenever the 1243Example: Call a callback every hour, or, more precisely, whenever the
1222system clock is divisible by 3600. The callback invocation times have 1244system clock is divisible by 3600. The callback invocation times have
1264with the kernel (thus it coexists with your own signal handlers as long 1286with the kernel (thus it coexists with your own signal handlers as long
1265as you don't register any with libev). Similarly, when the last signal 1287as you don't register any with libev). Similarly, when the last signal
1266watcher for a signal is stopped libev will reset the signal handler to 1288watcher for a signal is stopped libev will reset the signal handler to
1267SIG_DFL (regardless of what it was set to before). 1289SIG_DFL (regardless of what it was set to before).
1268 1290
1291=head3 Watcher-Specific Functions and Data Members
1292
1269=over 4 1293=over 4
1270 1294
1271=item ev_signal_init (ev_signal *, callback, int signum) 1295=item ev_signal_init (ev_signal *, callback, int signum)
1272 1296
1273=item ev_signal_set (ev_signal *, int signum) 1297=item ev_signal_set (ev_signal *, int signum)
1284 1308
1285=head2 C<ev_child> - watch out for process status changes 1309=head2 C<ev_child> - watch out for process status changes
1286 1310
1287Child watchers trigger when your process receives a SIGCHLD in response to 1311Child watchers trigger when your process receives a SIGCHLD in response to
1288some child status changes (most typically when a child of yours dies). 1312some child status changes (most typically when a child of yours dies).
1313
1314=head3 Watcher-Specific Functions and Data Members
1289 1315
1290=over 4 1316=over 4
1291 1317
1292=item ev_child_init (ev_child *, callback, int pid) 1318=item ev_child_init (ev_child *, callback, int pid)
1293 1319
1361reader). Inotify will be used to give hints only and should not change the 1387reader). Inotify will be used to give hints only and should not change the
1362semantics of C<ev_stat> watchers, which means that libev sometimes needs 1388semantics of C<ev_stat> watchers, which means that libev sometimes needs
1363to fall back to regular polling again even with inotify, but changes are 1389to fall back to regular polling again even with inotify, but changes are
1364usually detected immediately, and if the file exists there will be no 1390usually detected immediately, and if the file exists there will be no
1365polling. 1391polling.
1392
1393=head3 Watcher-Specific Functions and Data Members
1366 1394
1367=over 4 1395=over 4
1368 1396
1369=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)
1370 1398
1453Apart from keeping your process non-blocking (which is a useful 1481Apart from keeping your process non-blocking (which is a useful
1454effect on its own sometimes), idle watchers are a good place to do 1482effect on its own sometimes), idle watchers are a good place to do
1455"pseudo-background processing", or delay processing stuff to after the 1483"pseudo-background processing", or delay processing stuff to after the
1456event loop has handled all outstanding events. 1484event loop has handled all outstanding events.
1457 1485
1486=head3 Watcher-Specific Functions and Data Members
1487
1458=over 4 1488=over 4
1459 1489
1460=item ev_idle_init (ev_signal *, callback) 1490=item ev_idle_init (ev_signal *, callback)
1461 1491
1462Initialises and configures the idle watcher - it has no parameters of any 1492Initialises and configures the idle watcher - it has no parameters of any
1529their job. As C<ev_check> watchers are often used to embed other event 1559their job. As C<ev_check> watchers are often used to embed other event
1530loops those other event loops might be in an unusable state until their 1560loops those other event loops might be in an unusable state until their
1531C<ev_check> watcher ran (always remind yourself to coexist peacefully with 1561C<ev_check> watcher ran (always remind yourself to coexist peacefully with
1532others). 1562others).
1533 1563
1564=head3 Watcher-Specific Functions and Data Members
1565
1534=over 4 1566=over 4
1535 1567
1536=item ev_prepare_init (ev_prepare *, callback) 1568=item ev_prepare_init (ev_prepare *, callback)
1537 1569
1538=item ev_check_init (ev_check *, callback) 1570=item ev_check_init (ev_check *, callback)
1739 ev_embed_start (loop_hi, &embed); 1771 ev_embed_start (loop_hi, &embed);
1740 } 1772 }
1741 else 1773 else
1742 loop_lo = loop_hi; 1774 loop_lo = loop_hi;
1743 1775
1776=head3 Watcher-Specific Functions and Data Members
1777
1744=over 4 1778=over 4
1745 1779
1746=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)
1747 1781
1748=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)
1774event loop blocks next and before C<ev_check> watchers are being called, 1808event loop blocks next and before C<ev_check> watchers are being called,
1775and only in the child after the fork. If whoever good citizen calling 1809and only in the child after the fork. If whoever good citizen calling
1776C<ev_default_fork> cheats and calls it in the wrong process, the fork 1810C<ev_default_fork> cheats and calls it in the wrong process, the fork
1777handlers will be invoked, too, of course. 1811handlers will be invoked, too, of course.
1778 1812
1813=head3 Watcher-Specific Functions and Data Members
1814
1779=over 4 1815=over 4
1780 1816
1781=item ev_fork_init (ev_signal *, callback) 1817=item ev_fork_init (ev_signal *, callback)
1782 1818
1783Initialises and configures the fork watcher - it has no parameters of any 1819Initialises and configures the fork watcher - it has no parameters of any
1999 2035
2000=item w->stop () 2036=item w->stop ()
2001 2037
2002Stops the watcher if it is active. Again, no C<loop> argument. 2038Stops the watcher if it is active. Again, no C<loop> argument.
2003 2039
2004=item w->again () C<ev::timer>, C<ev::periodic> only 2040=item w->again () (C<ev::timer>, C<ev::periodic> only)
2005 2041
2006For C<ev::timer> and C<ev::periodic>, this invokes the corresponding 2042For C<ev::timer> and C<ev::periodic>, this invokes the corresponding
2007C<ev_TYPE_again> function. 2043C<ev_TYPE_again> function.
2008 2044
2009=item w->sweep () C<ev::embed> only 2045=item w->sweep () (C<ev::embed> only)
2010 2046
2011Invokes C<ev_embed_sweep>. 2047Invokes C<ev_embed_sweep>.
2012 2048
2013=item w->update () C<ev::stat> only 2049=item w->update () (C<ev::stat> only)
2014 2050
2015Invokes C<ev_stat_stat>. 2051Invokes C<ev_stat_stat>.
2016 2052
2017=back 2053=back
2018 2054
2038 } 2074 }
2039 2075
2040 2076
2041=head1 MACRO MAGIC 2077=head1 MACRO MAGIC
2042 2078
2043Libev can be compiled with a variety of options, the most fundemantal is 2079Libev can be compiled with a variety of options, the most fundamantal
2044C<EV_MULTIPLICITY>. This option determines whether (most) functions and 2080of which is C<EV_MULTIPLICITY>. This option determines whether (most)
2045callbacks have an initial C<struct ev_loop *> argument. 2081functions and callbacks have an initial C<struct ev_loop *> argument.
2046 2082
2047To make it easier to write programs that cope with either variant, the 2083To make it easier to write programs that cope with either variant, the
2048following macros are defined: 2084following macros are defined:
2049 2085
2050=over 4 2086=over 4

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