… | |
… | |
1218 | with a watcher-specific start function (C<< ev_TYPE_start (loop, watcher |
1218 | with a watcher-specific start function (C<< ev_TYPE_start (loop, watcher |
1219 | *) >>), and you can stop watching for events at any time by calling the |
1219 | *) >>), and you can stop watching for events at any time by calling the |
1220 | corresponding stop function (C<< ev_TYPE_stop (loop, watcher *) >>. |
1220 | corresponding stop function (C<< ev_TYPE_stop (loop, watcher *) >>. |
1221 | |
1221 | |
1222 | As long as your watcher is active (has been started but not stopped) you |
1222 | As long as your watcher is active (has been started but not stopped) you |
1223 | must not touch the values stored in it. Most specifically you must never |
1223 | must not touch the values stored in it except when explicitly documented |
1224 | reinitialise it or call its C<ev_TYPE_set> macro. |
1224 | otherwise. Most specifically you must never reinitialise it or call its |
|
|
1225 | C<ev_TYPE_set> macro. |
1225 | |
1226 | |
1226 | Each and every callback receives the event loop pointer as first, the |
1227 | Each and every callback receives the event loop pointer as first, the |
1227 | registered watcher structure as second, and a bitset of received events as |
1228 | registered watcher structure as second, and a bitset of received events as |
1228 | third argument. |
1229 | third argument. |
1229 | |
1230 | |
… | |
… | |
1648 | |
1649 | |
1649 | This section describes each watcher in detail, but will not repeat |
1650 | This section describes each watcher in detail, but will not repeat |
1650 | information given in the last section. Any initialisation/set macros, |
1651 | information given in the last section. Any initialisation/set macros, |
1651 | functions and members specific to the watcher type are explained. |
1652 | functions and members specific to the watcher type are explained. |
1652 | |
1653 | |
1653 | Members are additionally marked with either I<[read-only]>, meaning that, |
1654 | Most members are additionally marked with either I<[read-only]>, meaning |
1654 | while the watcher is active, you can look at the member and expect some |
1655 | that, while the watcher is active, you can look at the member and expect |
1655 | sensible content, but you must not modify it (you can modify it while the |
1656 | some sensible content, but you must not modify it (you can modify it while |
1656 | watcher is stopped to your hearts content), or I<[read-write]>, which |
1657 | the watcher is stopped to your hearts content), or I<[read-write]>, which |
1657 | means you can expect it to have some sensible content while the watcher |
1658 | means you can expect it to have some sensible content while the watcher is |
1658 | is active, but you can also modify it. Modifying it may not do something |
1659 | active, but you can also modify it (within the same thread as the event |
|
|
1660 | loop, i.e. without creating data races). Modifying it may not do something |
1659 | sensible or take immediate effect (or do anything at all), but libev will |
1661 | sensible or take immediate effect (or do anything at all), but libev will |
1660 | not crash or malfunction in any way. |
1662 | not crash or malfunction in any way. |
1661 | |
1663 | |
|
|
1664 | In any case, the documentation for each member will explain what the |
|
|
1665 | effects are, and if there are any additional access restrictions. |
1662 | |
1666 | |
1663 | =head2 C<ev_io> - is this file descriptor readable or writable? |
1667 | =head2 C<ev_io> - is this file descriptor readable or writable? |
1664 | |
1668 | |
1665 | I/O watchers check whether a file descriptor is readable or writable |
1669 | I/O watchers check whether a file descriptor is readable or writable |
1666 | in each iteration of the event loop, or, more precisely, when reading |
1670 | in each iteration of the event loop, or, more precisely, when reading |
… | |
… | |
1826 | =item ev_io_init (ev_io *, callback, int fd, int events) |
1830 | =item ev_io_init (ev_io *, callback, int fd, int events) |
1827 | |
1831 | |
1828 | =item ev_io_set (ev_io *, int fd, int events) |
1832 | =item ev_io_set (ev_io *, int fd, int events) |
1829 | |
1833 | |
1830 | Configures an C<ev_io> watcher. The C<fd> is the file descriptor to |
1834 | Configures an C<ev_io> watcher. The C<fd> is the file descriptor to |
1831 | receive events for and C<events> is either C<EV_READ>, C<EV_WRITE> or |
1835 | receive events for and C<events> is either C<EV_READ>, C<EV_WRITE>, both |
1832 | C<EV_READ | EV_WRITE>, to express the desire to receive the given events. |
1836 | C<EV_READ | EV_WRITE> or C<0>, to express the desire to receive the given |
|
|
1837 | events. |
1833 | |
1838 | |
1834 | =item int fd [read-only] |
1839 | Note that setting the C<events> to C<0> and starting the watcher is |
|
|
1840 | supported, but not specially optimized - if your program sometimes happens |
|
|
1841 | to generate this combination this is fine, but if it is easy to avoid |
|
|
1842 | starting an io watcher watching for no events you should do so. |
1835 | |
1843 | |
1836 | The file descriptor being watched. |
1844 | =item ev_io_modify (ev_io *, int events) |
1837 | |
1845 | |
|
|
1846 | Similar to C<ev_io_set>, but only changes the requested events. Using this |
|
|
1847 | might be faster with some backends, as libev can assume that the C<fd> |
|
|
1848 | still refers to the same underlying file description, something it cannot |
|
|
1849 | do when using C<ev_io_set>. |
|
|
1850 | |
|
|
1851 | =item int fd [no-modify] |
|
|
1852 | |
|
|
1853 | The file descriptor being watched. While it can be read at any time, you |
|
|
1854 | must not modify this member even when the watcher is stopped - always use |
|
|
1855 | C<ev_io_set> for that. |
|
|
1856 | |
1838 | =item int events [read-only] |
1857 | =item int events [no-modify] |
1839 | |
1858 | |
1840 | The events being watched. |
1859 | The set of events the fd is being watched for, among other flags. Remember |
|
|
1860 | that this is a bit set - to test for C<EV_READ>, use C<< w->events & |
|
|
1861 | EV_READ >>, and similarly for C<EV_WRITE>. |
|
|
1862 | |
|
|
1863 | As with C<fd>, you must not modify this member even when the watcher is |
|
|
1864 | stopped, always use C<ev_io_set> or C<ev_io_modify> for that. |
1841 | |
1865 | |
1842 | =back |
1866 | =back |
1843 | |
1867 | |
1844 | =head3 Examples |
1868 | =head3 Examples |
1845 | |
1869 | |
… | |
… | |
4243 | method. |
4267 | method. |
4244 | |
4268 | |
4245 | For C<ev::embed> watchers this method is called C<set_embed>, to avoid |
4269 | For C<ev::embed> watchers this method is called C<set_embed>, to avoid |
4246 | clashing with the C<set (loop)> method. |
4270 | clashing with the C<set (loop)> method. |
4247 | |
4271 | |
|
|
4272 | For C<ev::io> watchers there is an additional C<set> method that acepts a |
|
|
4273 | new event mask only, and internally calls C<ev_io_modfify>. |
|
|
4274 | |
4248 | =item w->start () |
4275 | =item w->start () |
4249 | |
4276 | |
4250 | Starts the watcher. Note that there is no C<loop> argument, as the |
4277 | Starts the watcher. Note that there is no C<loop> argument, as the |
4251 | constructor already stores the event loop. |
4278 | constructor already stores the event loop. |
4252 | |
4279 | |