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Comparing libev/ev.pod (file contents):
Revision 1.70 by root, Fri Dec 7 19:23:48 2007 UTC vs.
Revision 1.74 by root, Sat Dec 8 14:12:08 2007 UTC

736=item bool ev_is_pending (ev_TYPE *watcher) 736=item bool ev_is_pending (ev_TYPE *watcher)
737 737
738Returns a true value iff the watcher is pending, (i.e. it has outstanding 738Returns a true value iff the watcher is pending, (i.e. it has outstanding
739events but its callback has not yet been invoked). As long as a watcher 739events but its callback has not yet been invoked). As long as a watcher
740is pending (but not active) you must not call an init function on it (but 740is pending (but not active) you must not call an init function on it (but
741C<ev_TYPE_set> is safe) and you must make sure the watcher is available to 741C<ev_TYPE_set> is safe), you must not change its priority, and you must
742libev (e.g. you cnanot C<free ()> it). 742make sure the watcher is available to libev (e.g. you cannot C<free ()>
743it).
743 744
744=item callback ev_cb (ev_TYPE *watcher) 745=item callback ev_cb (ev_TYPE *watcher)
745 746
746Returns the callback currently set on the watcher. 747Returns the callback currently set on the watcher.
747 748
766watchers on the same event and make sure one is called first. 767watchers on the same event and make sure one is called first.
767 768
768If you need to suppress invocation when higher priority events are pending 769If you need to suppress invocation when higher priority events are pending
769you need to look at C<ev_idle> watchers, which provide this functionality. 770you need to look at C<ev_idle> watchers, which provide this functionality.
770 771
772You I<must not> change the priority of a watcher as long as it is active or
773pending.
774
771The default priority used by watchers when no priority has been set is 775The default priority used by watchers when no priority has been set is
772always C<0>, which is supposed to not be too high and not be too low :). 776always C<0>, which is supposed to not be too high and not be too low :).
773 777
774Setting a priority outside the range of C<EV_MINPRI> to C<EV_MAXPRI> is 778Setting a priority outside the range of C<EV_MINPRI> to C<EV_MAXPRI> is
775fine, as long as you do not mind that the priority value you query might 779fine, as long as you do not mind that the priority value you query might
776or might not have been adjusted to be within valid range. 780or might not have been adjusted to be within valid range.
781
782=item ev_invoke (loop, ev_TYPE *watcher, int revents)
783
784Invoke the C<watcher> with the given C<loop> and C<revents>. Neither
785C<loop> nor C<revents> need to be valid as long as the watcher callback
786can deal with that fact.
787
788=item int ev_clear_pending (loop, ev_TYPE *watcher)
789
790If the watcher is pending, this function returns clears its pending status
791and returns its C<revents> bitset (as if its callback was invoked). If the
792watcher isn't pending it does nothing and returns C<0>.
777 793
778=back 794=back
779 795
780 796
781=head2 ASSOCIATING CUSTOM DATA WITH A WATCHER 797=head2 ASSOCIATING CUSTOM DATA WITH A WATCHER
1744 1760
1745To use it, 1761To use it,
1746 1762
1747 #include <ev++.h> 1763 #include <ev++.h>
1748 1764
1749(it is not installed by default). This automatically includes F<ev.h> 1765This automatically includes F<ev.h> and puts all of its definitions (many
1750and puts all of its definitions (many of them macros) into the global 1766of them macros) into the global namespace. All C++ specific things are
1751namespace. All C++ specific things are put into the C<ev> namespace. 1767put into the C<ev> namespace. It should support all the same embedding
1768options as F<ev.h>, most notably C<EV_MULTIPLICITY>.
1752 1769
1753It should support all the same embedding options as F<ev.h>, most notably 1770Care has been taken to keep the overhead low. The only data member the C++
1754C<EV_MULTIPLICITY>. 1771classes add (compared to plain C-style watchers) is the event loop pointer
1772that the watcher is associated with (or no additional members at all if
1773you disable C<EV_MULTIPLICITY> when embedding libev).
1774
1775Currently, functions, and static and non-static member functions can be
1776used as callbacks. Other types should be easy to add as long as they only
1777need one additional pointer for context. If you need support for other
1778types of functors please contact the author (preferably after implementing
1779it).
1755 1780
1756Here is a list of things available in the C<ev> namespace: 1781Here is a list of things available in the C<ev> namespace:
1757 1782
1758=over 4 1783=over 4
1759 1784
1775 1800
1776All of those classes have these methods: 1801All of those classes have these methods:
1777 1802
1778=over 4 1803=over 4
1779 1804
1780=item ev::TYPE::TYPE (object *, object::method *) 1805=item ev::TYPE::TYPE ()
1781 1806
1782=item ev::TYPE::TYPE (object *, object::method *, struct ev_loop *) 1807=item ev::TYPE::TYPE (struct ev_loop *)
1783 1808
1784=item ev::TYPE::~TYPE 1809=item ev::TYPE::~TYPE
1785 1810
1786The constructor takes a pointer to an object and a method pointer to 1811The constructor (optionally) takes an event loop to associate the watcher
1787the event handler callback to call in this class. The constructor calls 1812with. If it is omitted, it will use C<EV_DEFAULT>.
1788C<ev_init> for you, which means you have to call the C<set> method 1813
1789before starting it. If you do not specify a loop then the constructor 1814The constructor calls C<ev_init> for you, which means you have to call the
1790automatically associates the default loop with this watcher. 1815C<set> method before starting it.
1816
1817It will not set a callback, however: You have to call the templated C<set>
1818method to set a callback before you can start the watcher.
1819
1820(The reason why you have to use a method is a limitation in C++ which does
1821not allow explicit template arguments for constructors).
1791 1822
1792The destructor automatically stops the watcher if it is active. 1823The destructor automatically stops the watcher if it is active.
1824
1825=item w->set<class, &class::method> (object *)
1826
1827This method sets the callback method to call. The method has to have a
1828signature of C<void (*)(ev_TYPE &, int)>, it receives the watcher as
1829first argument and the C<revents> as second. The object must be given as
1830parameter and is stored in the C<data> member of the watcher.
1831
1832This method synthesizes efficient thunking code to call your method from
1833the C callback that libev requires. If your compiler can inline your
1834callback (i.e. it is visible to it at the place of the C<set> call and
1835your compiler is good :), then the method will be fully inlined into the
1836thunking function, making it as fast as a direct C callback.
1837
1838Example: simple class declaration and watcher initialisation
1839
1840 struct myclass
1841 {
1842 void io_cb (ev::io &w, int revents) { }
1843 }
1844
1845 myclass obj;
1846 ev::io iow;
1847 iow.set <myclass, &myclass::io_cb> (&obj);
1848
1849=item w->set (void (*function)(watcher &w, int), void *data = 0)
1850
1851Also sets a callback, but uses a static method or plain function as
1852callback. The optional C<data> argument will be stored in the watcher's
1853C<data> member and is free for you to use.
1854
1855See the method-C<set> above for more details.
1793 1856
1794=item w->set (struct ev_loop *) 1857=item w->set (struct ev_loop *)
1795 1858
1796Associates a different C<struct ev_loop> with this watcher. You can only 1859Associates a different C<struct ev_loop> with this watcher. You can only
1797do this when the watcher is inactive (and not pending either). 1860do this when the watcher is inactive (and not pending either).
1798 1861
1799=item w->set ([args]) 1862=item w->set ([args])
1800 1863
1801Basically the same as C<ev_TYPE_set>, with the same args. Must be 1864Basically the same as C<ev_TYPE_set>, with the same args. Must be
1802called at least once. Unlike the C counterpart, an active watcher gets 1865called at least once. Unlike the C counterpart, an active watcher gets
1803automatically stopped and restarted. 1866automatically stopped and restarted when reconfiguring it with this
1867method.
1804 1868
1805=item w->start () 1869=item w->start ()
1806 1870
1807Starts the watcher. Note that there is no C<loop> argument as the 1871Starts the watcher. Note that there is no C<loop> argument, as the
1808constructor already takes the loop. 1872constructor already stores the event loop.
1809 1873
1810=item w->stop () 1874=item w->stop ()
1811 1875
1812Stops the watcher if it is active. Again, no C<loop> argument. 1876Stops the watcher if it is active. Again, no C<loop> argument.
1813 1877
1838 1902
1839 myclass (); 1903 myclass ();
1840 } 1904 }
1841 1905
1842 myclass::myclass (int fd) 1906 myclass::myclass (int fd)
1843 : io (this, &myclass::io_cb),
1844 idle (this, &myclass::idle_cb)
1845 { 1907 {
1908 io .set <myclass, &myclass::io_cb > (this);
1909 idle.set <myclass, &myclass::idle_cb> (this);
1910
1846 io.start (fd, ev::READ); 1911 io.start (fd, ev::READ);
1847 } 1912 }
1848 1913
1849 1914
1850=head1 MACRO MAGIC 1915=head1 MACRO MAGIC

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