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Comparing libev/ev.pod (file contents):
Revision 1.56 by root, Wed Nov 28 11:15:55 2007 UTC vs.
Revision 1.58 by root, Wed Nov 28 11:31:34 2007 UTC

… …
63details of the event, and then hand it over to libev by I<starting> the 63details of the event, and then hand it over to libev by I<starting> the
64watcher. 64watcher.
65 65
66=head1 FEATURES 66=head1 FEATURES
67 67
68Libev supports C<select>, C<poll>, the linux-specific C<epoll>, the 68Libev supports C<select>, C<poll>, the Linux-specific C<epoll>, the
69bsd-specific C<kqueue> and the solaris-specific event port mechanisms 69BSD-specific C<kqueue> and the Solaris-specific event port mechanisms
70for file descriptor events (C<ev_io>), relative timers (C<ev_timer>), 70for file descriptor events (C<ev_io>), the Linux C<inotify> interface
71(for C<ev_stat>), relative timers (C<ev_timer>), absolute timers
71absolute timers with customised rescheduling (C<ev_periodic>), synchronous 72with customised rescheduling (C<ev_periodic>), synchronous signals
72signals (C<ev_signal>), process status change events (C<ev_child>), and 73(C<ev_signal>), process status change events (C<ev_child>), and event
73event watchers dealing with the event loop mechanism itself (C<ev_idle>, 74watchers dealing with the event loop mechanism itself (C<ev_idle>,
74C<ev_embed>, C<ev_prepare> and C<ev_check> watchers) as well as 75C<ev_embed>, C<ev_prepare> and C<ev_check> watchers) as well as
75file watchers (C<ev_stat>) and even limited support for fork events 76file watchers (C<ev_stat>) and even limited support for fork events
76(C<ev_fork>). 77(C<ev_fork>).
77 78
78It also is quite fast (see this 79It also is quite fast (see this
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1222not exist" is signified by the C<st_nlink> field being zero (which is 1223not exist" is signified by the C<st_nlink> field being zero (which is
1223otherwise always forced to be at least one) and all the other fields of 1224otherwise always forced to be at least one) and all the other fields of
1224the stat buffer having unspecified contents. 1225the stat buffer having unspecified contents.
1225 1226
1226Since there is no standard to do this, the portable implementation simply 1227Since there is no standard to do this, the portable implementation simply
1227calls C<stat (2)> regulalry on the path to see if it changed somehow. You 1228calls C<stat (2)> regularly on the path to see if it changed somehow. You
1228can specify a recommended polling interval for this case. If you specify 1229can specify a recommended polling interval for this case. If you specify
1229a polling interval of C<0> (highly recommended!) then a I<suitable, 1230a polling interval of C<0> (highly recommended!) then a I<suitable,
1230unspecified default> value will be used (which you can expect to be around 1231unspecified default> value will be used (which you can expect to be around
1231five seconds, although this might change dynamically). Libev will also 1232five seconds, although this might change dynamically). Libev will also
1232impose a minimum interval which is currently around C<0.1>, but thats 1233impose a minimum interval which is currently around C<0.1>, but thats
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1234 1235
1235This watcher type is not meant for massive numbers of stat watchers, 1236This watcher type is not meant for massive numbers of stat watchers,
1236as even with OS-supported change notifications, this can be 1237as even with OS-supported change notifications, this can be
1237resource-intensive. 1238resource-intensive.
1238 1239
1239At the time of this writing, no specific OS backends are implemented, but 1240At the time of this writing, only the Linux inotify interface is
1240if demand increases, at least a kqueue and inotify backend will be added. 1241implemented (implementing kqueue support is left as an exercise for the
1242reader). Inotify will be used to give hints only and should not change the
1243semantics of C<ev_stat> watchers, which means that libev sometimes needs
1244to fall back to regular polling again even with inotify, but changes are
1245usually detected immediately, and if the file exists there will be no
1246polling.
1241 1247
1242=over 4 1248=over 4
1243 1249
1244=item ev_stat_init (ev_stat *, callback, const char *path, ev_tstamp interval) 1250=item ev_stat_init (ev_stat *, callback, const char *path, ev_tstamp interval)
1245 1251

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