… | |
… | |
47 | |
47 | |
48 | return 0; |
48 | return 0; |
49 | } |
49 | } |
50 | |
50 | |
51 | =head1 DESCRIPTION |
51 | =head1 DESCRIPTION |
|
|
52 | |
|
|
53 | The newest version of this document is also available as a html-formatted |
|
|
54 | web page you might find easier to navigate when reading it for the first |
|
|
55 | time: L<http://cvs.schmorp.de/libev/ev.html>. |
52 | |
56 | |
53 | Libev is an event loop: you register interest in certain events (such as a |
57 | Libev is an event loop: you register interest in certain events (such as a |
54 | file descriptor being readable or a timeout occuring), and it will manage |
58 | file descriptor being readable or a timeout occuring), and it will manage |
55 | these event sources and provide your program with events. |
59 | these event sources and provide your program with events. |
56 | |
60 | |
… | |
… | |
274 | a fork, you can also make libev check for a fork in each iteration by |
278 | a fork, you can also make libev check for a fork in each iteration by |
275 | enabling this flag. |
279 | enabling this flag. |
276 | |
280 | |
277 | This works by calling C<getpid ()> on every iteration of the loop, |
281 | This works by calling C<getpid ()> on every iteration of the loop, |
278 | and thus this might slow down your event loop if you do a lot of loop |
282 | and thus this might slow down your event loop if you do a lot of loop |
279 | iterations and little real work, but is usually not noticable (on my |
283 | iterations and little real work, but is usually not noticeable (on my |
280 | Linux system for example, C<getpid> is actually a simple 5-insn sequence |
284 | Linux system for example, C<getpid> is actually a simple 5-insn sequence |
281 | without a syscall and thus I<very> fast, but my Linux system also has |
285 | without a syscall and thus I<very> fast, but my Linux system also has |
282 | C<pthread_atfork> which is even faster). |
286 | C<pthread_atfork> which is even faster). |
283 | |
287 | |
284 | The big advantage of this flag is that you can forget about fork (and |
288 | The big advantage of this flag is that you can forget about fork (and |
… | |
… | |
429 | =item ev_loop_fork (loop) |
433 | =item ev_loop_fork (loop) |
430 | |
434 | |
431 | Like C<ev_default_fork>, but acts on an event loop created by |
435 | Like C<ev_default_fork>, but acts on an event loop created by |
432 | C<ev_loop_new>. Yes, you have to call this on every allocated event loop |
436 | C<ev_loop_new>. Yes, you have to call this on every allocated event loop |
433 | after fork, and how you do this is entirely your own problem. |
437 | after fork, and how you do this is entirely your own problem. |
|
|
438 | |
|
|
439 | =item unsigned int ev_loop_count (loop) |
|
|
440 | |
|
|
441 | Returns the count of loop iterations for the loop, which is identical to |
|
|
442 | the number of times libev did poll for new events. It starts at C<0> and |
|
|
443 | happily wraps around with enough iterations. |
|
|
444 | |
|
|
445 | This value can sometimes be useful as a generation counter of sorts (it |
|
|
446 | "ticks" the number of loop iterations), as it roughly corresponds with |
|
|
447 | C<ev_prepare> and C<ev_check> calls. |
434 | |
448 | |
435 | =item unsigned int ev_backend (loop) |
449 | =item unsigned int ev_backend (loop) |
436 | |
450 | |
437 | Returns one of the C<EVBACKEND_*> flags indicating the event backend in |
451 | Returns one of the C<EVBACKEND_*> flags indicating the event backend in |
438 | use. |
452 | use. |
… | |
… | |
722 | =item bool ev_is_pending (ev_TYPE *watcher) |
736 | =item bool ev_is_pending (ev_TYPE *watcher) |
723 | |
737 | |
724 | 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 |
725 | 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 |
726 | 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 |
727 | 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 |
728 | 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). |
729 | |
744 | |
730 | =item callback ev_cb (ev_TYPE *watcher) |
745 | =item callback ev_cb (ev_TYPE *watcher) |
731 | |
746 | |
732 | Returns the callback currently set on the watcher. |
747 | Returns the callback currently set on the watcher. |
733 | |
748 | |
734 | =item ev_cb_set (ev_TYPE *watcher, callback) |
749 | =item ev_cb_set (ev_TYPE *watcher, callback) |
735 | |
750 | |
736 | Change the callback. You can change the callback at virtually any time |
751 | Change the callback. You can change the callback at virtually any time |
737 | (modulo threads). |
752 | (modulo threads). |
|
|
753 | |
|
|
754 | =item ev_set_priority (ev_TYPE *watcher, priority) |
|
|
755 | |
|
|
756 | =item int ev_priority (ev_TYPE *watcher) |
|
|
757 | |
|
|
758 | Set and query the priority of the watcher. The priority is a small |
|
|
759 | integer between C<EV_MAXPRI> (default: C<2>) and C<EV_MINPRI> |
|
|
760 | (default: C<-2>). Pending watchers with higher priority will be invoked |
|
|
761 | before watchers with lower priority, but priority will not keep watchers |
|
|
762 | from being executed (except for C<ev_idle> watchers). |
|
|
763 | |
|
|
764 | This means that priorities are I<only> used for ordering callback |
|
|
765 | invocation after new events have been received. This is useful, for |
|
|
766 | example, to reduce latency after idling, or more often, to bind two |
|
|
767 | watchers on the same event and make sure one is called first. |
|
|
768 | |
|
|
769 | If you need to suppress invocation when higher priority events are pending |
|
|
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. |
|
|
774 | |
|
|
775 | The default priority used by watchers when no priority has been set is |
|
|
776 | always C<0>, which is supposed to not be too high and not be too low :). |
|
|
777 | |
|
|
778 | Setting a priority outside the range of C<EV_MINPRI> to C<EV_MAXPRI> is |
|
|
779 | fine, as long as you do not mind that the priority value you query might |
|
|
780 | or might not have been adjusted to be within valid range. |
|
|
781 | |
|
|
782 | =item ev_invoke (loop, ev_TYPE *watcher, int revents) |
|
|
783 | |
|
|
784 | Invoke the C<watcher> with the given C<loop> and C<revents>. Neither |
|
|
785 | C<loop> nor C<revents> need to be valid as long as the watcher callback |
|
|
786 | can deal with that fact. |
|
|
787 | |
|
|
788 | =item int ev_clear_pending (loop, ev_TYPE *watcher) |
|
|
789 | |
|
|
790 | If the watcher is pending, this function returns clears its pending status |
|
|
791 | and returns its C<revents> bitset (as if its callback was invoked). If the |
|
|
792 | watcher isn't pending it does nothing and returns C<0>. |
738 | |
793 | |
739 | =back |
794 | =back |
740 | |
795 | |
741 | |
796 | |
742 | =head2 ASSOCIATING CUSTOM DATA WITH A WATCHER |
797 | =head2 ASSOCIATING CUSTOM DATA WITH A WATCHER |
… | |
… | |
848 | it is best to always use non-blocking I/O: An extra C<read>(2) returning |
903 | it is best to always use non-blocking I/O: An extra C<read>(2) returning |
849 | C<EAGAIN> is far preferable to a program hanging until some data arrives. |
904 | C<EAGAIN> is far preferable to a program hanging until some data arrives. |
850 | |
905 | |
851 | If you cannot run the fd in non-blocking mode (for example you should not |
906 | If you cannot run the fd in non-blocking mode (for example you should not |
852 | play around with an Xlib connection), then you have to seperately re-test |
907 | play around with an Xlib connection), then you have to seperately re-test |
853 | wether a file descriptor is really ready with a known-to-be good interface |
908 | whether a file descriptor is really ready with a known-to-be good interface |
854 | such as poll (fortunately in our Xlib example, Xlib already does this on |
909 | such as poll (fortunately in our Xlib example, Xlib already does this on |
855 | its own, so its quite safe to use). |
910 | its own, so its quite safe to use). |
856 | |
911 | |
857 | =over 4 |
912 | =over 4 |
858 | |
913 | |
… | |
… | |
1341 | ev_stat_start (loop, &passwd); |
1396 | ev_stat_start (loop, &passwd); |
1342 | |
1397 | |
1343 | |
1398 | |
1344 | =head2 C<ev_idle> - when you've got nothing better to do... |
1399 | =head2 C<ev_idle> - when you've got nothing better to do... |
1345 | |
1400 | |
1346 | Idle watchers trigger events when there are no other events are pending |
1401 | Idle watchers trigger events when no other events of the same or higher |
1347 | (prepare, check and other idle watchers do not count). That is, as long |
1402 | priority are pending (prepare, check and other idle watchers do not |
1348 | as your process is busy handling sockets or timeouts (or even signals, |
1403 | count). |
1349 | imagine) it will not be triggered. But when your process is idle all idle |
1404 | |
1350 | watchers are being called again and again, once per event loop iteration - |
1405 | That is, as long as your process is busy handling sockets or timeouts |
|
|
1406 | (or even signals, imagine) of the same or higher priority it will not be |
|
|
1407 | triggered. But when your process is idle (or only lower-priority watchers |
|
|
1408 | are pending), the idle watchers are being called once per event loop |
1351 | until stopped, that is, or your process receives more events and becomes |
1409 | iteration - until stopped, that is, or your process receives more events |
1352 | busy. |
1410 | and becomes busy again with higher priority stuff. |
1353 | |
1411 | |
1354 | The most noteworthy effect is that as long as any idle watchers are |
1412 | The most noteworthy effect is that as long as any idle watchers are |
1355 | active, the process will not block when waiting for new events. |
1413 | active, the process will not block when waiting for new events. |
1356 | |
1414 | |
1357 | Apart from keeping your process non-blocking (which is a useful |
1415 | Apart from keeping your process non-blocking (which is a useful |
… | |
… | |
1702 | |
1760 | |
1703 | To use it, |
1761 | To use it, |
1704 | |
1762 | |
1705 | #include <ev++.h> |
1763 | #include <ev++.h> |
1706 | |
1764 | |
1707 | (it is not installed by default). This automatically includes F<ev.h> |
1765 | This automatically includes F<ev.h> and puts all of its definitions (many |
1708 | and puts all of its definitions (many of them macros) into the global |
1766 | of them macros) into the global namespace. All C++ specific things are |
1709 | namespace. All C++ specific things are put into the C<ev> namespace. |
1767 | put into the C<ev> namespace. It should support all the same embedding |
|
|
1768 | options as F<ev.h>, most notably C<EV_MULTIPLICITY>. |
1710 | |
1769 | |
1711 | It should support all the same embedding options as F<ev.h>, most notably |
1770 | Care has been taken to keep the overhead low. The only data member the C++ |
1712 | C<EV_MULTIPLICITY>. |
1771 | classes add (compared to plain C-style watchers) is the event loop pointer |
|
|
1772 | that the watcher is associated with (or no additional members at all if |
|
|
1773 | you disable C<EV_MULTIPLICITY> when embedding libev). |
|
|
1774 | |
|
|
1775 | Currently, functions, and static and non-static member functions can be |
|
|
1776 | used as callbacks. Other types should be easy to add as long as they only |
|
|
1777 | need one additional pointer for context. If you need support for other |
|
|
1778 | types of functors please contact the author (preferably after implementing |
|
|
1779 | it). |
1713 | |
1780 | |
1714 | Here is a list of things available in the C<ev> namespace: |
1781 | Here is a list of things available in the C<ev> namespace: |
1715 | |
1782 | |
1716 | =over 4 |
1783 | =over 4 |
1717 | |
1784 | |
… | |
… | |
1733 | |
1800 | |
1734 | All of those classes have these methods: |
1801 | All of those classes have these methods: |
1735 | |
1802 | |
1736 | =over 4 |
1803 | =over 4 |
1737 | |
1804 | |
1738 | =item ev::TYPE::TYPE (object *, object::method *) |
1805 | =item ev::TYPE::TYPE () |
1739 | |
1806 | |
1740 | =item ev::TYPE::TYPE (object *, object::method *, struct ev_loop *) |
1807 | =item ev::TYPE::TYPE (struct ev_loop *) |
1741 | |
1808 | |
1742 | =item ev::TYPE::~TYPE |
1809 | =item ev::TYPE::~TYPE |
1743 | |
1810 | |
1744 | The constructor takes a pointer to an object and a method pointer to |
1811 | The constructor (optionally) takes an event loop to associate the watcher |
1745 | the event handler callback to call in this class. The constructor calls |
1812 | with. If it is omitted, it will use C<EV_DEFAULT>. |
1746 | C<ev_init> for you, which means you have to call the C<set> method |
1813 | |
1747 | before starting it. If you do not specify a loop then the constructor |
1814 | The constructor calls C<ev_init> for you, which means you have to call the |
1748 | automatically associates the default loop with this watcher. |
1815 | C<set> method before starting it. |
|
|
1816 | |
|
|
1817 | It will not set a callback, however: You have to call the templated C<set> |
|
|
1818 | method 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 |
|
|
1821 | not allow explicit template arguments for constructors). |
1749 | |
1822 | |
1750 | The destructor automatically stops the watcher if it is active. |
1823 | The destructor automatically stops the watcher if it is active. |
|
|
1824 | |
|
|
1825 | =item w->set<class, &class::method> (object *) |
|
|
1826 | |
|
|
1827 | This method sets the callback method to call. The method has to have a |
|
|
1828 | signature of C<void (*)(ev_TYPE &, int)>, it receives the watcher as |
|
|
1829 | first argument and the C<revents> as second. The object must be given as |
|
|
1830 | parameter and is stored in the C<data> member of the watcher. |
|
|
1831 | |
|
|
1832 | This method synthesizes efficient thunking code to call your method from |
|
|
1833 | the C callback that libev requires. If your compiler can inline your |
|
|
1834 | callback (i.e. it is visible to it at the place of the C<set> call and |
|
|
1835 | your compiler is good :), then the method will be fully inlined into the |
|
|
1836 | thunking function, making it as fast as a direct C callback. |
|
|
1837 | |
|
|
1838 | Example: 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 | |
|
|
1851 | Also sets a callback, but uses a static method or plain function as |
|
|
1852 | callback. The optional C<data> argument will be stored in the watcher's |
|
|
1853 | C<data> member and is free for you to use. |
|
|
1854 | |
|
|
1855 | See the method-C<set> above for more details. |
1751 | |
1856 | |
1752 | =item w->set (struct ev_loop *) |
1857 | =item w->set (struct ev_loop *) |
1753 | |
1858 | |
1754 | Associates a different C<struct ev_loop> with this watcher. You can only |
1859 | Associates a different C<struct ev_loop> with this watcher. You can only |
1755 | do this when the watcher is inactive (and not pending either). |
1860 | do this when the watcher is inactive (and not pending either). |
1756 | |
1861 | |
1757 | =item w->set ([args]) |
1862 | =item w->set ([args]) |
1758 | |
1863 | |
1759 | Basically the same as C<ev_TYPE_set>, with the same args. Must be |
1864 | Basically the same as C<ev_TYPE_set>, with the same args. Must be |
1760 | called at least once. Unlike the C counterpart, an active watcher gets |
1865 | called at least once. Unlike the C counterpart, an active watcher gets |
1761 | automatically stopped and restarted. |
1866 | automatically stopped and restarted when reconfiguring it with this |
|
|
1867 | method. |
1762 | |
1868 | |
1763 | =item w->start () |
1869 | =item w->start () |
1764 | |
1870 | |
1765 | Starts the watcher. Note that there is no C<loop> argument as the |
1871 | Starts the watcher. Note that there is no C<loop> argument, as the |
1766 | constructor already takes the loop. |
1872 | constructor already stores the event loop. |
1767 | |
1873 | |
1768 | =item w->stop () |
1874 | =item w->stop () |
1769 | |
1875 | |
1770 | Stops the watcher if it is active. Again, no C<loop> argument. |
1876 | Stops the watcher if it is active. Again, no C<loop> argument. |
1771 | |
1877 | |
… | |
… | |
1796 | |
1902 | |
1797 | myclass (); |
1903 | myclass (); |
1798 | } |
1904 | } |
1799 | |
1905 | |
1800 | myclass::myclass (int fd) |
1906 | myclass::myclass (int fd) |
1801 | : io (this, &myclass::io_cb), |
|
|
1802 | idle (this, &myclass::idle_cb) |
|
|
1803 | { |
1907 | { |
|
|
1908 | io .set <myclass, &myclass::io_cb > (this); |
|
|
1909 | idle.set <myclass, &myclass::idle_cb> (this); |
|
|
1910 | |
1804 | io.start (fd, ev::READ); |
1911 | io.start (fd, ev::READ); |
1805 | } |
1912 | } |
1806 | |
1913 | |
1807 | |
1914 | |
1808 | =head1 MACRO MAGIC |
1915 | =head1 MACRO MAGIC |
1809 | |
1916 | |
1810 | Libev can be compiled with a variety of options, the most fundemantal is |
1917 | Libev can be compiled with a variety of options, the most fundemantal is |
1811 | C<EV_MULTIPLICITY>. This option determines wether (most) functions and |
1918 | C<EV_MULTIPLICITY>. This option determines whether (most) functions and |
1812 | callbacks have an initial C<struct ev_loop *> argument. |
1919 | callbacks have an initial C<struct ev_loop *> argument. |
1813 | |
1920 | |
1814 | To make it easier to write programs that cope with either variant, the |
1921 | To make it easier to write programs that cope with either variant, the |
1815 | following macros are defined: |
1922 | following macros are defined: |
1816 | |
1923 | |
… | |
… | |
1850 | loop, if multiple loops are supported ("ev loop default"). |
1957 | loop, if multiple loops are supported ("ev loop default"). |
1851 | |
1958 | |
1852 | =back |
1959 | =back |
1853 | |
1960 | |
1854 | Example: Declare and initialise a check watcher, utilising the above |
1961 | Example: Declare and initialise a check watcher, utilising the above |
1855 | macros so it will work regardless of wether multiple loops are supported |
1962 | macros so it will work regardless of whether multiple loops are supported |
1856 | or not. |
1963 | or not. |
1857 | |
1964 | |
1858 | static void |
1965 | static void |
1859 | check_cb (EV_P_ ev_timer *w, int revents) |
1966 | check_cb (EV_P_ ev_timer *w, int revents) |
1860 | { |
1967 | { |
… | |
… | |
2085 | will have the C<struct ev_loop *> as first argument, and you can create |
2192 | will have the C<struct ev_loop *> as first argument, and you can create |
2086 | additional independent event loops. Otherwise there will be no support |
2193 | additional independent event loops. Otherwise there will be no support |
2087 | for multiple event loops and there is no first event loop pointer |
2194 | for multiple event loops and there is no first event loop pointer |
2088 | argument. Instead, all functions act on the single default loop. |
2195 | argument. Instead, all functions act on the single default loop. |
2089 | |
2196 | |
|
|
2197 | =item EV_MINPRI |
|
|
2198 | |
|
|
2199 | =item EV_MAXPRI |
|
|
2200 | |
|
|
2201 | The range of allowed priorities. C<EV_MINPRI> must be smaller or equal to |
|
|
2202 | C<EV_MAXPRI>, but otherwise there are no non-obvious limitations. You can |
|
|
2203 | provide for more priorities by overriding those symbols (usually defined |
|
|
2204 | to be C<-2> and C<2>, respectively). |
|
|
2205 | |
|
|
2206 | When doing priority-based operations, libev usually has to linearly search |
|
|
2207 | all the priorities, so having many of them (hundreds) uses a lot of space |
|
|
2208 | and time, so using the defaults of five priorities (-2 .. +2) is usually |
|
|
2209 | fine. |
|
|
2210 | |
|
|
2211 | If your embedding app does not need any priorities, defining these both to |
|
|
2212 | C<0> will save some memory and cpu. |
|
|
2213 | |
2090 | =item EV_PERIODIC_ENABLE |
2214 | =item EV_PERIODIC_ENABLE |
2091 | |
2215 | |
2092 | If undefined or defined to be C<1>, then periodic timers are supported. If |
2216 | If undefined or defined to be C<1>, then periodic timers are supported. If |
|
|
2217 | defined to be C<0>, then they are not. Disabling them saves a few kB of |
|
|
2218 | code. |
|
|
2219 | |
|
|
2220 | =item EV_IDLE_ENABLE |
|
|
2221 | |
|
|
2222 | If undefined or defined to be C<1>, then idle watchers are supported. If |
2093 | defined to be C<0>, then they are not. Disabling them saves a few kB of |
2223 | defined to be C<0>, then they are not. Disabling them saves a few kB of |
2094 | code. |
2224 | code. |
2095 | |
2225 | |
2096 | =item EV_EMBED_ENABLE |
2226 | =item EV_EMBED_ENABLE |
2097 | |
2227 | |
… | |
… | |
2190 | |
2320 | |
2191 | In this section the complexities of (many of) the algorithms used inside |
2321 | In this section the complexities of (many of) the algorithms used inside |
2192 | libev will be explained. For complexity discussions about backends see the |
2322 | libev will be explained. For complexity discussions about backends see the |
2193 | documentation for C<ev_default_init>. |
2323 | documentation for C<ev_default_init>. |
2194 | |
2324 | |
|
|
2325 | All of the following are about amortised time: If an array needs to be |
|
|
2326 | extended, libev needs to realloc and move the whole array, but this |
|
|
2327 | happens asymptotically never with higher number of elements, so O(1) might |
|
|
2328 | mean it might do a lengthy realloc operation in rare cases, but on average |
|
|
2329 | it is much faster and asymptotically approaches constant time. |
|
|
2330 | |
2195 | =over 4 |
2331 | =over 4 |
2196 | |
2332 | |
2197 | =item Starting and stopping timer/periodic watchers: O(log skipped_other_timers) |
2333 | =item Starting and stopping timer/periodic watchers: O(log skipped_other_timers) |
2198 | |
2334 | |
|
|
2335 | This means that, when you have a watcher that triggers in one hour and |
|
|
2336 | there are 100 watchers that would trigger before that then inserting will |
|
|
2337 | have to skip those 100 watchers. |
|
|
2338 | |
2199 | =item Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers) |
2339 | =item Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers) |
2200 | |
2340 | |
|
|
2341 | That means that for changing a timer costs less than removing/adding them |
|
|
2342 | as only the relative motion in the event queue has to be paid for. |
|
|
2343 | |
2201 | =item Starting io/check/prepare/idle/signal/child watchers: O(1) |
2344 | =item Starting io/check/prepare/idle/signal/child watchers: O(1) |
2202 | |
2345 | |
|
|
2346 | These just add the watcher into an array or at the head of a list. |
2203 | =item Stopping check/prepare/idle watchers: O(1) |
2347 | =item Stopping check/prepare/idle watchers: O(1) |
2204 | |
2348 | |
2205 | =item Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % EV_PID_HASHSIZE)) |
2349 | =item Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % EV_PID_HASHSIZE)) |
2206 | |
2350 | |
|
|
2351 | These watchers are stored in lists then need to be walked to find the |
|
|
2352 | correct watcher to remove. The lists are usually short (you don't usually |
|
|
2353 | have many watchers waiting for the same fd or signal). |
|
|
2354 | |
2207 | =item Finding the next timer per loop iteration: O(1) |
2355 | =item Finding the next timer per loop iteration: O(1) |
2208 | |
2356 | |
2209 | =item Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd) |
2357 | =item Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd) |
2210 | |
2358 | |
|
|
2359 | A change means an I/O watcher gets started or stopped, which requires |
|
|
2360 | libev to recalculate its status (and possibly tell the kernel). |
|
|
2361 | |
2211 | =item Activating one watcher: O(1) |
2362 | =item Activating one watcher: O(1) |
2212 | |
2363 | |
|
|
2364 | =item Priority handling: O(number_of_priorities) |
|
|
2365 | |
|
|
2366 | Priorities are implemented by allocating some space for each |
|
|
2367 | priority. When doing priority-based operations, libev usually has to |
|
|
2368 | linearly search all the priorities. |
|
|
2369 | |
2213 | =back |
2370 | =back |
2214 | |
2371 | |
2215 | |
2372 | |
2216 | =head1 AUTHOR |
2373 | =head1 AUTHOR |
2217 | |
2374 | |