… | |
… | |
736 | =item bool ev_is_pending (ev_TYPE *watcher) |
736 | =item bool ev_is_pending (ev_TYPE *watcher) |
737 | |
737 | |
738 | Returns a true value iff the watcher is pending, (i.e. it has outstanding |
738 | Returns a true value iff the watcher is pending, (i.e. it has outstanding |
739 | events but its callback has not yet been invoked). As long as a watcher |
739 | events but its callback has not yet been invoked). As long as a watcher |
740 | is pending (but not active) you must not call an init function on it (but |
740 | is pending (but not active) you must not call an init function on it (but |
741 | C<ev_TYPE_set> is safe) and you must make sure the watcher is available to |
741 | C<ev_TYPE_set> is safe), you must not change its priority, and you must |
742 | libev (e.g. you cnanot C<free ()> it). |
742 | make sure the watcher is available to libev (e.g. you cannot C<free ()> |
|
|
743 | it). |
743 | |
744 | |
744 | =item callback ev_cb (ev_TYPE *watcher) |
745 | =item callback ev_cb (ev_TYPE *watcher) |
745 | |
746 | |
746 | Returns the callback currently set on the watcher. |
747 | Returns the callback currently set on the watcher. |
747 | |
748 | |
… | |
… | |
765 | example, to reduce latency after idling, or more often, to bind two |
766 | example, to reduce latency after idling, or more often, to bind two |
766 | watchers on the same event and make sure one is called first. |
767 | watchers on the same event and make sure one is called first. |
767 | |
768 | |
768 | If you need to suppress invocation when higher priority events are pending |
769 | If you need to suppress invocation when higher priority events are pending |
769 | you need to look at C<ev_idle> watchers, which provide this functionality. |
770 | you need to look at C<ev_idle> watchers, which provide this functionality. |
|
|
771 | |
|
|
772 | You I<must not> change the priority of a watcher as long as it is active or |
|
|
773 | pending. |
770 | |
774 | |
771 | The default priority used by watchers when no priority has been set is |
775 | The default priority used by watchers when no priority has been set is |
772 | always C<0>, which is supposed to not be too high and not be too low :). |
776 | always C<0>, which is supposed to not be too high and not be too low :). |
773 | |
777 | |
774 | Setting a priority outside the range of C<EV_MINPRI> to C<EV_MAXPRI> is |
778 | Setting a priority outside the range of C<EV_MINPRI> to C<EV_MAXPRI> is |
… | |
… | |
1744 | |
1748 | |
1745 | To use it, |
1749 | To use it, |
1746 | |
1750 | |
1747 | #include <ev++.h> |
1751 | #include <ev++.h> |
1748 | |
1752 | |
1749 | (it is not installed by default). This automatically includes F<ev.h> |
1753 | This automatically includes F<ev.h> and puts all of its definitions (many |
1750 | and puts all of its definitions (many of them macros) into the global |
1754 | of them macros) into the global namespace. All C++ specific things are |
1751 | namespace. All C++ specific things are put into the C<ev> namespace. |
1755 | put into the C<ev> namespace. It should support all the same embedding |
|
|
1756 | options as F<ev.h>, most notably C<EV_MULTIPLICITY>. |
1752 | |
1757 | |
1753 | It should support all the same embedding options as F<ev.h>, most notably |
1758 | Care has been taken to keep the overhead low. The only data member the C++ |
1754 | C<EV_MULTIPLICITY>. |
1759 | classes add (compared to plain C-style watchers) is the event loop pointer |
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|
1760 | that the watcher is associated with (or no additional members at all if |
|
|
1761 | you disable C<EV_MULTIPLICITY> when embedding libev). |
|
|
1762 | |
|
|
1763 | Currently, functions, and static and non-static member functions can be |
|
|
1764 | used as callbacks. Other types should be easy to add as long as they only |
|
|
1765 | need one additional pointer for context. If you need support for other |
|
|
1766 | types of functors please contact the author (preferably after implementing |
|
|
1767 | it). |
1755 | |
1768 | |
1756 | Here is a list of things available in the C<ev> namespace: |
1769 | Here is a list of things available in the C<ev> namespace: |
1757 | |
1770 | |
1758 | =over 4 |
1771 | =over 4 |
1759 | |
1772 | |
… | |
… | |
1775 | |
1788 | |
1776 | All of those classes have these methods: |
1789 | All of those classes have these methods: |
1777 | |
1790 | |
1778 | =over 4 |
1791 | =over 4 |
1779 | |
1792 | |
1780 | =item ev::TYPE::TYPE (object *, object::method *) |
1793 | =item ev::TYPE::TYPE () |
1781 | |
1794 | |
1782 | =item ev::TYPE::TYPE (object *, object::method *, struct ev_loop *) |
1795 | =item ev::TYPE::TYPE (struct ev_loop *) |
1783 | |
1796 | |
1784 | =item ev::TYPE::~TYPE |
1797 | =item ev::TYPE::~TYPE |
1785 | |
1798 | |
1786 | The constructor takes a pointer to an object and a method pointer to |
1799 | The constructor (optionally) takes an event loop to associate the watcher |
1787 | the event handler callback to call in this class. The constructor calls |
1800 | with. If it is omitted, it will use C<EV_DEFAULT>. |
1788 | C<ev_init> for you, which means you have to call the C<set> method |
1801 | |
1789 | before starting it. If you do not specify a loop then the constructor |
1802 | The constructor calls C<ev_init> for you, which means you have to call the |
1790 | automatically associates the default loop with this watcher. |
1803 | C<set> method before starting it. |
|
|
1804 | |
|
|
1805 | It will not set a callback, however: You have to call the templated C<set> |
|
|
1806 | method to set a callback before you can start the watcher. |
|
|
1807 | |
|
|
1808 | (The reason why you have to use a method is a limitation in C++ which does |
|
|
1809 | not allow explicit template arguments for constructors). |
1791 | |
1810 | |
1792 | The destructor automatically stops the watcher if it is active. |
1811 | The destructor automatically stops the watcher if it is active. |
|
|
1812 | |
|
|
1813 | =item w->set<class, &class::method> (object *) |
|
|
1814 | |
|
|
1815 | This method sets the callback method to call. The method has to have a |
|
|
1816 | signature of C<void (*)(ev_TYPE &, int)>, it receives the watcher as |
|
|
1817 | first argument and the C<revents> as second. The object must be given as |
|
|
1818 | parameter and is stored in the C<data> member of the watcher. |
|
|
1819 | |
|
|
1820 | This method synthesizes efficient thunking code to call your method from |
|
|
1821 | the C callback that libev requires. If your compiler can inline your |
|
|
1822 | callback (i.e. it is visible to it at the place of the C<set> call and |
|
|
1823 | your compiler is good :), then the method will be fully inlined into the |
|
|
1824 | thunking function, making it as fast as a direct C callback. |
|
|
1825 | |
|
|
1826 | Example: simple class declaration and watcher initialisation |
|
|
1827 | |
|
|
1828 | struct myclass |
|
|
1829 | { |
|
|
1830 | void io_cb (ev::io &w, int revents) { } |
|
|
1831 | } |
|
|
1832 | |
|
|
1833 | myclass obj; |
|
|
1834 | ev::io iow; |
|
|
1835 | iow.set <myclass, &myclass::io_cb> (&obj); |
|
|
1836 | |
|
|
1837 | =item w->set (void (*function)(watcher &w, int), void *data = 0) |
|
|
1838 | |
|
|
1839 | Also sets a callback, but uses a static method or plain function as |
|
|
1840 | callback. The optional C<data> argument will be stored in the watcher's |
|
|
1841 | C<data> member and is free for you to use. |
|
|
1842 | |
|
|
1843 | See the method-C<set> above for more details. |
1793 | |
1844 | |
1794 | =item w->set (struct ev_loop *) |
1845 | =item w->set (struct ev_loop *) |
1795 | |
1846 | |
1796 | Associates a different C<struct ev_loop> with this watcher. You can only |
1847 | Associates a different C<struct ev_loop> with this watcher. You can only |
1797 | do this when the watcher is inactive (and not pending either). |
1848 | do this when the watcher is inactive (and not pending either). |
1798 | |
1849 | |
1799 | =item w->set ([args]) |
1850 | =item w->set ([args]) |
1800 | |
1851 | |
1801 | Basically the same as C<ev_TYPE_set>, with the same args. Must be |
1852 | Basically the same as C<ev_TYPE_set>, with the same args. Must be |
1802 | called at least once. Unlike the C counterpart, an active watcher gets |
1853 | called at least once. Unlike the C counterpart, an active watcher gets |
1803 | automatically stopped and restarted. |
1854 | automatically stopped and restarted when reconfiguring it with this |
|
|
1855 | method. |
1804 | |
1856 | |
1805 | =item w->start () |
1857 | =item w->start () |
1806 | |
1858 | |
1807 | Starts the watcher. Note that there is no C<loop> argument as the |
1859 | Starts the watcher. Note that there is no C<loop> argument, as the |
1808 | constructor already takes the loop. |
1860 | constructor already stores the event loop. |
1809 | |
1861 | |
1810 | =item w->stop () |
1862 | =item w->stop () |
1811 | |
1863 | |
1812 | Stops the watcher if it is active. Again, no C<loop> argument. |
1864 | Stops the watcher if it is active. Again, no C<loop> argument. |
1813 | |
1865 | |
… | |
… | |
1838 | |
1890 | |
1839 | myclass (); |
1891 | myclass (); |
1840 | } |
1892 | } |
1841 | |
1893 | |
1842 | myclass::myclass (int fd) |
1894 | myclass::myclass (int fd) |
1843 | : io (this, &myclass::io_cb), |
|
|
1844 | idle (this, &myclass::idle_cb) |
|
|
1845 | { |
1895 | { |
|
|
1896 | io .set <myclass, &myclass::io_cb > (this); |
|
|
1897 | idle.set <myclass, &myclass::idle_cb> (this); |
|
|
1898 | |
1846 | io.start (fd, ev::READ); |
1899 | io.start (fd, ev::READ); |
1847 | } |
1900 | } |
1848 | |
1901 | |
1849 | |
1902 | |
1850 | =head1 MACRO MAGIC |
1903 | =head1 MACRO MAGIC |