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4 | <head> |
4 | <head> |
5 | <title>libev</title> |
5 | <title>libev</title> |
6 | <meta name="description" content="Pod documentation for libev" /> |
6 | <meta name="description" content="Pod documentation for libev" /> |
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13 | <div class="pod"> |
14 | <!-- INDEX START --> |
14 | <!-- INDEX START --> |
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21 | <li><a href="#CONVENTIONS">CONVENTIONS</a></li> |
21 | <li><a href="#CONVENTIONS">CONVENTIONS</a></li> |
22 | <li><a href="#TIME_REPRESENTATION">TIME REPRESENTATION</a></li> |
22 | <li><a href="#TIME_REPRESENTATION">TIME REPRESENTATION</a></li> |
23 | <li><a href="#GLOBAL_FUNCTIONS">GLOBAL FUNCTIONS</a></li> |
23 | <li><a href="#GLOBAL_FUNCTIONS">GLOBAL FUNCTIONS</a></li> |
24 | <li><a href="#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP">FUNCTIONS CONTROLLING THE EVENT LOOP</a></li> |
24 | <li><a href="#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP">FUNCTIONS CONTROLLING THE EVENT LOOP</a></li> |
25 | <li><a href="#ANATOMY_OF_A_WATCHER">ANATOMY OF A WATCHER</a> |
25 | <li><a href="#ANATOMY_OF_A_WATCHER">ANATOMY OF A WATCHER</a> |
26 | <ul><li><a href="#SUMMARY_OF_GENERIC_WATCHER_FUNCTIONS">SUMMARY OF GENERIC WATCHER FUNCTIONS</a></li> |
26 | <ul><li><a href="#GENERIC_WATCHER_FUNCTIONS">GENERIC WATCHER FUNCTIONS</a></li> |
27 | <li><a href="#ASSOCIATING_CUSTOM_DATA_WITH_A_WATCH">ASSOCIATING CUSTOM DATA WITH A WATCHER</a></li> |
27 | <li><a href="#ASSOCIATING_CUSTOM_DATA_WITH_A_WATCH">ASSOCIATING CUSTOM DATA WITH A WATCHER</a></li> |
28 | </ul> |
28 | </ul> |
29 | </li> |
29 | </li> |
30 | <li><a href="#WATCHER_TYPES">WATCHER TYPES</a> |
30 | <li><a href="#WATCHER_TYPES">WATCHER TYPES</a> |
31 | <ul><li><a href="#code_ev_io_code_is_this_file_descrip"><code>ev_io</code> - is this file descriptor readable or writable</a></li> |
31 | <ul><li><a href="#code_ev_io_code_is_this_file_descrip"><code>ev_io</code> - is this file descriptor readable or writable?</a></li> |
32 | <li><a href="#code_ev_timer_code_relative_and_opti"><code>ev_timer</code> - relative and optionally recurring timeouts</a></li> |
32 | <li><a href="#code_ev_timer_code_relative_and_opti"><code>ev_timer</code> - relative and optionally repeating timeouts</a></li> |
33 | <li><a href="#code_ev_periodic_code_to_cron_or_not"><code>ev_periodic</code> - to cron or not to cron</a></li> |
33 | <li><a href="#code_ev_periodic_code_to_cron_or_not"><code>ev_periodic</code> - to cron or not to cron?</a></li> |
34 | <li><a href="#code_ev_signal_code_signal_me_when_a"><code>ev_signal</code> - signal me when a signal gets signalled</a></li> |
34 | <li><a href="#code_ev_signal_code_signal_me_when_a"><code>ev_signal</code> - signal me when a signal gets signalled!</a></li> |
35 | <li><a href="#code_ev_child_code_wait_for_pid_stat"><code>ev_child</code> - wait for pid status changes</a></li> |
35 | <li><a href="#code_ev_child_code_watch_out_for_pro"><code>ev_child</code> - watch out for process status changes</a></li> |
36 | <li><a href="#code_ev_idle_code_when_you_ve_got_no"><code>ev_idle</code> - when you've got nothing better to do</a></li> |
36 | <li><a href="#code_ev_idle_code_when_you_ve_got_no"><code>ev_idle</code> - when you've got nothing better to do...</a></li> |
37 | <li><a href="#code_ev_prepare_code_and_code_ev_che"><code>ev_prepare</code> and <code>ev_check</code> - customise your event loop</a></li> |
37 | <li><a href="#code_ev_prepare_code_and_code_ev_che"><code>ev_prepare</code> and <code>ev_check</code> - customise your event loop!</a></li> |
38 | <li><a href="#code_ev_embed_code_when_one_backend_"><code>ev_embed</code> - when one backend isn't enough</a></li> |
38 | <li><a href="#code_ev_embed_code_when_one_backend_"><code>ev_embed</code> - when one backend isn't enough...</a></li> |
39 | </ul> |
39 | </ul> |
40 | </li> |
40 | </li> |
41 | <li><a href="#OTHER_FUNCTIONS">OTHER FUNCTIONS</a></li> |
41 | <li><a href="#OTHER_FUNCTIONS">OTHER FUNCTIONS</a></li> |
42 | <li><a href="#LIBEVENT_EMULATION">LIBEVENT EMULATION</a></li> |
42 | <li><a href="#LIBEVENT_EMULATION">LIBEVENT EMULATION</a></li> |
43 | <li><a href="#C_SUPPORT">C++ SUPPORT</a></li> |
43 | <li><a href="#C_SUPPORT">C++ SUPPORT</a></li> |
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44 | <li><a href="#EMBEDDING">EMBEDDING</a> |
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|
45 | <ul><li><a href="#FILESETS">FILESETS</a> |
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46 | <ul><li><a href="#CORE_EVENT_LOOP">CORE EVENT LOOP</a></li> |
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47 | <li><a href="#LIBEVENT_COMPATIBILITY_API">LIBEVENT COMPATIBILITY API</a></li> |
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48 | <li><a href="#AUTOCONF_SUPPORT">AUTOCONF SUPPORT</a></li> |
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|
49 | </ul> |
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50 | </li> |
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51 | <li><a href="#PREPROCESSOR_SYMBOLS_MACROS">PREPROCESSOR SYMBOLS/MACROS</a></li> |
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52 | <li><a href="#EXAMPLES">EXAMPLES</a></li> |
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53 | </ul> |
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54 | </li> |
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55 | <li><a href="#COMPLEXITIES">COMPLEXITIES</a></li> |
44 | <li><a href="#AUTHOR">AUTHOR</a> |
56 | <li><a href="#AUTHOR">AUTHOR</a> |
45 | </li> |
57 | </li> |
46 | </ul><hr /> |
58 | </ul><hr /> |
47 | <!-- INDEX END --> |
59 | <!-- INDEX END --> |
48 | |
60 | |
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502 | |
514 | |
503 | </pre> |
515 | </pre> |
504 | </dd> |
516 | </dd> |
505 | </dl> |
517 | </dl> |
506 | |
518 | |
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519 | |
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520 | |
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521 | |
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522 | |
507 | </div> |
523 | </div> |
508 | <h1 id="ANATOMY_OF_A_WATCHER">ANATOMY OF A WATCHER</h1><p><a href="#TOP" class="toplink">Top</a></p> |
524 | <h1 id="ANATOMY_OF_A_WATCHER">ANATOMY OF A WATCHER</h1><p><a href="#TOP" class="toplink">Top</a></p> |
509 | <div id="ANATOMY_OF_A_WATCHER_CONTENT"> |
525 | <div id="ANATOMY_OF_A_WATCHER_CONTENT"> |
510 | <p>A watcher is a structure that you create and register to record your |
526 | <p>A watcher is a structure that you create and register to record your |
511 | interest in some event. For instance, if you want to wait for STDIN to |
527 | interest in some event. For instance, if you want to wait for STDIN to |
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601 | programs, though, so beware.</p> |
617 | programs, though, so beware.</p> |
602 | </dd> |
618 | </dd> |
603 | </dl> |
619 | </dl> |
604 | |
620 | |
605 | </div> |
621 | </div> |
606 | <h2 id="SUMMARY_OF_GENERIC_WATCHER_FUNCTIONS">SUMMARY OF GENERIC WATCHER FUNCTIONS</h2> |
622 | <h2 id="GENERIC_WATCHER_FUNCTIONS">GENERIC WATCHER FUNCTIONS</h2> |
607 | <div id="SUMMARY_OF_GENERIC_WATCHER_FUNCTIONS-2"> |
623 | <div id="GENERIC_WATCHER_FUNCTIONS_CONTENT"> |
608 | <p>In the following description, <code>TYPE</code> stands for the watcher type, |
624 | <p>In the following description, <code>TYPE</code> stands for the watcher type, |
609 | e.g. <code>timer</code> for <code>ev_timer</code> watchers and <code>io</code> for <code>ev_io</code> watchers.</p> |
625 | e.g. <code>timer</code> for <code>ev_timer</code> watchers and <code>io</code> for <code>ev_io</code> watchers.</p> |
610 | <dl> |
626 | <dl> |
611 | <dt><code>ev_init</code> (ev_TYPE *watcher, callback)</dt> |
627 | <dt><code>ev_init</code> (ev_TYPE *watcher, callback)</dt> |
612 | <dd> |
628 | <dd> |
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616 | the type-specific <code>ev_TYPE_set</code> macro afterwards to initialise the |
632 | the type-specific <code>ev_TYPE_set</code> macro afterwards to initialise the |
617 | type-specific parts. For each type there is also a <code>ev_TYPE_init</code> macro |
633 | type-specific parts. For each type there is also a <code>ev_TYPE_init</code> macro |
618 | which rolls both calls into one.</p> |
634 | which rolls both calls into one.</p> |
619 | <p>You can reinitialise a watcher at any time as long as it has been stopped |
635 | <p>You can reinitialise a watcher at any time as long as it has been stopped |
620 | (or never started) and there are no pending events outstanding.</p> |
636 | (or never started) and there are no pending events outstanding.</p> |
621 | <p>The callbakc is always of type <code>void (*)(ev_loop *loop, ev_TYPE *watcher, |
637 | <p>The callback is always of type <code>void (*)(ev_loop *loop, ev_TYPE *watcher, |
622 | int revents)</code>.</p> |
638 | int revents)</code>.</p> |
623 | </dd> |
639 | </dd> |
624 | <dt><code>ev_TYPE_set</code> (ev_TYPE *, [args])</dt> |
640 | <dt><code>ev_TYPE_set</code> (ev_TYPE *, [args])</dt> |
625 | <dd> |
641 | <dd> |
626 | <p>This macro initialises the type-specific parts of a watcher. You need to |
642 | <p>This macro initialises the type-specific parts of a watcher. You need to |
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723 | |
739 | |
724 | |
740 | |
725 | |
741 | |
726 | |
742 | |
727 | </div> |
743 | </div> |
728 | <h2 id="code_ev_io_code_is_this_file_descrip"><code>ev_io</code> - is this file descriptor readable or writable</h2> |
744 | <h2 id="code_ev_io_code_is_this_file_descrip"><code>ev_io</code> - is this file descriptor readable or writable?</h2> |
729 | <div id="code_ev_io_code_is_this_file_descrip-2"> |
745 | <div id="code_ev_io_code_is_this_file_descrip-2"> |
730 | <p>I/O watchers check whether a file descriptor is readable or writable |
746 | <p>I/O watchers check whether a file descriptor is readable or writable |
731 | in each iteration of the event loop (This behaviour is called |
747 | in each iteration of the event loop, or, more precisely, when reading |
732 | level-triggering because you keep receiving events as long as the |
748 | would not block the process and writing would at least be able to write |
733 | condition persists. Remember you can stop the watcher if you don't want to |
749 | some data. This behaviour is called level-triggering because you keep |
734 | act on the event and neither want to receive future events).</p> |
750 | receiving events as long as the condition persists. Remember you can stop |
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751 | the watcher if you don't want to act on the event and neither want to |
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752 | receive future events.</p> |
735 | <p>In general you can register as many read and/or write event watchers per |
753 | <p>In general you can register as many read and/or write event watchers per |
736 | fd as you want (as long as you don't confuse yourself). Setting all file |
754 | fd as you want (as long as you don't confuse yourself). Setting all file |
737 | descriptors to non-blocking mode is also usually a good idea (but not |
755 | descriptors to non-blocking mode is also usually a good idea (but not |
738 | required if you know what you are doing).</p> |
756 | required if you know what you are doing).</p> |
739 | <p>You have to be careful with dup'ed file descriptors, though. Some backends |
757 | <p>You have to be careful with dup'ed file descriptors, though. Some backends |
740 | (the linux epoll backend is a notable example) cannot handle dup'ed file |
758 | (the linux epoll backend is a notable example) cannot handle dup'ed file |
741 | descriptors correctly if you register interest in two or more fds pointing |
759 | descriptors correctly if you register interest in two or more fds pointing |
742 | to the same underlying file/socket etc. description (that is, they share |
760 | to the same underlying file/socket/etc. description (that is, they share |
743 | the same underlying "file open").</p> |
761 | the same underlying "file open").</p> |
744 | <p>If you must do this, then force the use of a known-to-be-good backend |
762 | <p>If you must do this, then force the use of a known-to-be-good backend |
745 | (at the time of this writing, this includes only <code>EVBACKEND_SELECT</code> and |
763 | (at the time of this writing, this includes only <code>EVBACKEND_SELECT</code> and |
746 | <code>EVBACKEND_POLL</code>).</p> |
764 | <code>EVBACKEND_POLL</code>).</p> |
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|
765 | <p>Another thing you have to watch out for is that it is quite easy to |
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766 | receive "spurious" readyness notifications, that is your callback might |
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767 | be called with <code>EV_READ</code> but a subsequent <code>read</code>(2) will actually block |
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768 | because there is no data. Not only are some backends known to create a |
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769 | lot of those (for example solaris ports), it is very easy to get into |
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770 | this situation even with a relatively standard program structure. Thus |
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771 | it is best to always use non-blocking I/O: An extra <code>read</code>(2) returning |
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772 | <code>EAGAIN</code> is far preferable to a program hanging until some data arrives.</p> |
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773 | <p>If you cannot run the fd in non-blocking mode (for example you should not |
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774 | play around with an Xlib connection), then you have to seperately re-test |
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775 | wether a file descriptor is really ready with a known-to-be good interface |
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776 | such as poll (fortunately in our Xlib example, Xlib already does this on |
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777 | its own, so its quite safe to use).</p> |
747 | <dl> |
778 | <dl> |
748 | <dt>ev_io_init (ev_io *, callback, int fd, int events)</dt> |
779 | <dt>ev_io_init (ev_io *, callback, int fd, int events)</dt> |
749 | <dt>ev_io_set (ev_io *, int fd, int events)</dt> |
780 | <dt>ev_io_set (ev_io *, int fd, int events)</dt> |
750 | <dd> |
781 | <dd> |
751 | <p>Configures an <code>ev_io</code> watcher. The fd is the file descriptor to rceeive |
782 | <p>Configures an <code>ev_io</code> watcher. The <code>fd</code> is the file descriptor to |
752 | events for and events is either <code>EV_READ</code>, <code>EV_WRITE</code> or <code>EV_READ | |
783 | rceeive events for and events is either <code>EV_READ</code>, <code>EV_WRITE</code> or |
753 | EV_WRITE</code> to receive the given events.</p> |
784 | <code>EV_READ | EV_WRITE</code> to receive the given events.</p> |
754 | <p>Please note that most of the more scalable backend mechanisms (for example |
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755 | epoll and solaris ports) can result in spurious readyness notifications |
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756 | for file descriptors, so you practically need to use non-blocking I/O (and |
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757 | treat callback invocation as hint only), or retest separately with a safe |
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758 | interface before doing I/O (XLib can do this), or force the use of either |
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759 | <code>EVBACKEND_SELECT</code> or <code>EVBACKEND_POLL</code>, which don't suffer from this |
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760 | problem. Also note that it is quite easy to have your callback invoked |
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761 | when the readyness condition is no longer valid even when employing |
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762 | typical ways of handling events, so its a good idea to use non-blocking |
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763 | I/O unconditionally.</p> |
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764 | </dd> |
785 | </dd> |
765 | </dl> |
786 | </dl> |
766 | <p>Example: call <code>stdin_readable_cb</code> when STDIN_FILENO has become, well |
787 | <p>Example: call <code>stdin_readable_cb</code> when STDIN_FILENO has become, well |
767 | readable, but only once. Since it is likely line-buffered, you could |
788 | readable, but only once. Since it is likely line-buffered, you could |
768 | attempt to read a whole line in the callback:</p> |
789 | attempt to read a whole line in the callback:</p> |
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784 | |
805 | |
785 | |
806 | |
786 | </pre> |
807 | </pre> |
787 | |
808 | |
788 | </div> |
809 | </div> |
789 | <h2 id="code_ev_timer_code_relative_and_opti"><code>ev_timer</code> - relative and optionally recurring timeouts</h2> |
810 | <h2 id="code_ev_timer_code_relative_and_opti"><code>ev_timer</code> - relative and optionally repeating timeouts</h2> |
790 | <div id="code_ev_timer_code_relative_and_opti-2"> |
811 | <div id="code_ev_timer_code_relative_and_opti-2"> |
791 | <p>Timer watchers are simple relative timers that generate an event after a |
812 | <p>Timer watchers are simple relative timers that generate an event after a |
792 | given time, and optionally repeating in regular intervals after that.</p> |
813 | given time, and optionally repeating in regular intervals after that.</p> |
793 | <p>The timers are based on real time, that is, if you register an event that |
814 | <p>The timers are based on real time, that is, if you register an event that |
794 | times out after an hour and you reset your system clock to last years |
815 | times out after an hour and you reset your system clock to last years |
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870 | |
891 | |
871 | |
892 | |
872 | </pre> |
893 | </pre> |
873 | |
894 | |
874 | </div> |
895 | </div> |
875 | <h2 id="code_ev_periodic_code_to_cron_or_not"><code>ev_periodic</code> - to cron or not to cron</h2> |
896 | <h2 id="code_ev_periodic_code_to_cron_or_not"><code>ev_periodic</code> - to cron or not to cron?</h2> |
876 | <div id="code_ev_periodic_code_to_cron_or_not-2"> |
897 | <div id="code_ev_periodic_code_to_cron_or_not-2"> |
877 | <p>Periodic watchers are also timers of a kind, but they are very versatile |
898 | <p>Periodic watchers are also timers of a kind, but they are very versatile |
878 | (and unfortunately a bit complex).</p> |
899 | (and unfortunately a bit complex).</p> |
879 | <p>Unlike <code>ev_timer</code>'s, they are not based on real time (or relative time) |
900 | <p>Unlike <code>ev_timer</code>'s, they are not based on real time (or relative time) |
880 | but on wallclock time (absolute time). You can tell a periodic watcher |
901 | but on wallclock time (absolute time). You can tell a periodic watcher |
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999 | |
1020 | |
1000 | |
1021 | |
1001 | </pre> |
1022 | </pre> |
1002 | |
1023 | |
1003 | </div> |
1024 | </div> |
1004 | <h2 id="code_ev_signal_code_signal_me_when_a"><code>ev_signal</code> - signal me when a signal gets signalled</h2> |
1025 | <h2 id="code_ev_signal_code_signal_me_when_a"><code>ev_signal</code> - signal me when a signal gets signalled!</h2> |
1005 | <div id="code_ev_signal_code_signal_me_when_a-2"> |
1026 | <div id="code_ev_signal_code_signal_me_when_a-2"> |
1006 | <p>Signal watchers will trigger an event when the process receives a specific |
1027 | <p>Signal watchers will trigger an event when the process receives a specific |
1007 | signal one or more times. Even though signals are very asynchronous, libev |
1028 | signal one or more times. Even though signals are very asynchronous, libev |
1008 | will try it's best to deliver signals synchronously, i.e. as part of the |
1029 | will try it's best to deliver signals synchronously, i.e. as part of the |
1009 | normal event processing, like any other event.</p> |
1030 | normal event processing, like any other event.</p> |
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1025 | |
1046 | |
1026 | |
1047 | |
1027 | |
1048 | |
1028 | |
1049 | |
1029 | </div> |
1050 | </div> |
1030 | <h2 id="code_ev_child_code_wait_for_pid_stat"><code>ev_child</code> - wait for pid status changes</h2> |
1051 | <h2 id="code_ev_child_code_watch_out_for_pro"><code>ev_child</code> - watch out for process status changes</h2> |
1031 | <div id="code_ev_child_code_wait_for_pid_stat-2"> |
1052 | <div id="code_ev_child_code_watch_out_for_pro-2"> |
1032 | <p>Child watchers trigger when your process receives a SIGCHLD in response to |
1053 | <p>Child watchers trigger when your process receives a SIGCHLD in response to |
1033 | some child status changes (most typically when a child of yours dies).</p> |
1054 | some child status changes (most typically when a child of yours dies).</p> |
1034 | <dl> |
1055 | <dl> |
1035 | <dt>ev_child_init (ev_child *, callback, int pid)</dt> |
1056 | <dt>ev_child_init (ev_child *, callback, int pid)</dt> |
1036 | <dt>ev_child_set (ev_child *, int pid)</dt> |
1057 | <dt>ev_child_set (ev_child *, int pid)</dt> |
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1058 | |
1079 | |
1059 | |
1080 | |
1060 | </pre> |
1081 | </pre> |
1061 | |
1082 | |
1062 | </div> |
1083 | </div> |
1063 | <h2 id="code_ev_idle_code_when_you_ve_got_no"><code>ev_idle</code> - when you've got nothing better to do</h2> |
1084 | <h2 id="code_ev_idle_code_when_you_ve_got_no"><code>ev_idle</code> - when you've got nothing better to do...</h2> |
1064 | <div id="code_ev_idle_code_when_you_ve_got_no-2"> |
1085 | <div id="code_ev_idle_code_when_you_ve_got_no-2"> |
1065 | <p>Idle watchers trigger events when there are no other events are pending |
1086 | <p>Idle watchers trigger events when there are no other events are pending |
1066 | (prepare, check and other idle watchers do not count). That is, as long |
1087 | (prepare, check and other idle watchers do not count). That is, as long |
1067 | as your process is busy handling sockets or timeouts (or even signals, |
1088 | as your process is busy handling sockets or timeouts (or even signals, |
1068 | imagine) it will not be triggered. But when your process is idle all idle |
1089 | imagine) it will not be triggered. But when your process is idle all idle |
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1101 | |
1122 | |
1102 | |
1123 | |
1103 | </pre> |
1124 | </pre> |
1104 | |
1125 | |
1105 | </div> |
1126 | </div> |
1106 | <h2 id="code_ev_prepare_code_and_code_ev_che"><code>ev_prepare</code> and <code>ev_check</code> - customise your event loop</h2> |
1127 | <h2 id="code_ev_prepare_code_and_code_ev_che"><code>ev_prepare</code> and <code>ev_check</code> - customise your event loop!</h2> |
1107 | <div id="code_ev_prepare_code_and_code_ev_che-2"> |
1128 | <div id="code_ev_prepare_code_and_code_ev_che-2"> |
1108 | <p>Prepare and check watchers are usually (but not always) used in tandem: |
1129 | <p>Prepare and check watchers are usually (but not always) used in tandem: |
1109 | prepare watchers get invoked before the process blocks and check watchers |
1130 | prepare watchers get invoked before the process blocks and check watchers |
1110 | afterwards.</p> |
1131 | afterwards.</p> |
|
|
1132 | <p>You <i>must not</i> call <code>ev_loop</code> or similar functions that enter |
|
|
1133 | the current event loop from either <code>ev_prepare</code> or <code>ev_check</code> |
|
|
1134 | watchers. Other loops than the current one are fine, however. The |
|
|
1135 | rationale behind this is that you do not need to check for recursion in |
|
|
1136 | those watchers, i.e. the sequence will always be <code>ev_prepare</code>, blocking, |
|
|
1137 | <code>ev_check</code> so if you have one watcher of each kind they will always be |
|
|
1138 | called in pairs bracketing the blocking call.</p> |
1111 | <p>Their main purpose is to integrate other event mechanisms into libev and |
1139 | <p>Their main purpose is to integrate other event mechanisms into libev and |
1112 | their use is somewhat advanced. This could be used, for example, to track |
1140 | their use is somewhat advanced. This could be used, for example, to track |
1113 | variable changes, implement your own watchers, integrate net-snmp or a |
1141 | variable changes, implement your own watchers, integrate net-snmp or a |
1114 | coroutine library and lots more.</p> |
1142 | coroutine library and lots more. They are also occasionally useful if |
|
|
1143 | you cache some data and want to flush it before blocking (for example, |
|
|
1144 | in X programs you might want to do an <code>XFlush ()</code> in an <code>ev_prepare</code> |
|
|
1145 | watcher).</p> |
1115 | <p>This is done by examining in each prepare call which file descriptors need |
1146 | <p>This is done by examining in each prepare call which file descriptors need |
1116 | to be watched by the other library, registering <code>ev_io</code> watchers for |
1147 | to be watched by the other library, registering <code>ev_io</code> watchers for |
1117 | them and starting an <code>ev_timer</code> watcher for any timeouts (many libraries |
1148 | them and starting an <code>ev_timer</code> watcher for any timeouts (many libraries |
1118 | provide just this functionality). Then, in the check watcher you check for |
1149 | provide just this functionality). Then, in the check watcher you check for |
1119 | any events that occured (by checking the pending status of all watchers |
1150 | any events that occured (by checking the pending status of all watchers |
… | |
… | |
1135 | <p>Initialises and configures the prepare or check watcher - they have no |
1166 | <p>Initialises and configures the prepare or check watcher - they have no |
1136 | parameters of any kind. There are <code>ev_prepare_set</code> and <code>ev_check_set</code> |
1167 | parameters of any kind. There are <code>ev_prepare_set</code> and <code>ev_check_set</code> |
1137 | macros, but using them is utterly, utterly and completely pointless.</p> |
1168 | macros, but using them is utterly, utterly and completely pointless.</p> |
1138 | </dd> |
1169 | </dd> |
1139 | </dl> |
1170 | </dl> |
1140 | <p>Example: *TODO*.</p> |
1171 | <p>Example: To include a library such as adns, you would add IO watchers |
|
|
1172 | and a timeout watcher in a prepare handler, as required by libadns, and |
|
|
1173 | in a check watcher, destroy them and call into libadns. What follows is |
|
|
1174 | pseudo-code only of course:</p> |
|
|
1175 | <pre> static ev_io iow [nfd]; |
|
|
1176 | static ev_timer tw; |
1141 | |
1177 | |
|
|
1178 | static void |
|
|
1179 | io_cb (ev_loop *loop, ev_io *w, int revents) |
|
|
1180 | { |
|
|
1181 | // set the relevant poll flags |
|
|
1182 | // could also call adns_processreadable etc. here |
|
|
1183 | struct pollfd *fd = (struct pollfd *)w->data; |
|
|
1184 | if (revents & EV_READ ) fd->revents |= fd->events & POLLIN; |
|
|
1185 | if (revents & EV_WRITE) fd->revents |= fd->events & POLLOUT; |
|
|
1186 | } |
1142 | |
1187 | |
|
|
1188 | // create io watchers for each fd and a timer before blocking |
|
|
1189 | static void |
|
|
1190 | adns_prepare_cb (ev_loop *loop, ev_prepare *w, int revents) |
|
|
1191 | { |
|
|
1192 | int timeout = 3600000;truct pollfd fds [nfd]; |
|
|
1193 | // actual code will need to loop here and realloc etc. |
|
|
1194 | adns_beforepoll (ads, fds, &nfd, &timeout, timeval_from (ev_time ())); |
1143 | |
1195 | |
|
|
1196 | /* the callback is illegal, but won't be called as we stop during check */ |
|
|
1197 | ev_timer_init (&tw, 0, timeout * 1e-3); |
|
|
1198 | ev_timer_start (loop, &tw); |
1144 | |
1199 | |
|
|
1200 | // create on ev_io per pollfd |
|
|
1201 | for (int i = 0; i < nfd; ++i) |
|
|
1202 | { |
|
|
1203 | ev_io_init (iow + i, io_cb, fds [i].fd, |
|
|
1204 | ((fds [i].events & POLLIN ? EV_READ : 0) |
|
|
1205 | | (fds [i].events & POLLOUT ? EV_WRITE : 0))); |
1145 | |
1206 | |
|
|
1207 | fds [i].revents = 0; |
|
|
1208 | iow [i].data = fds + i; |
|
|
1209 | ev_io_start (loop, iow + i); |
|
|
1210 | } |
|
|
1211 | } |
|
|
1212 | |
|
|
1213 | // stop all watchers after blocking |
|
|
1214 | static void |
|
|
1215 | adns_check_cb (ev_loop *loop, ev_check *w, int revents) |
|
|
1216 | { |
|
|
1217 | ev_timer_stop (loop, &tw); |
|
|
1218 | |
|
|
1219 | for (int i = 0; i < nfd; ++i) |
|
|
1220 | ev_io_stop (loop, iow + i); |
|
|
1221 | |
|
|
1222 | adns_afterpoll (adns, fds, nfd, timeval_from (ev_now (loop)); |
|
|
1223 | } |
|
|
1224 | |
|
|
1225 | |
|
|
1226 | |
|
|
1227 | |
|
|
1228 | </pre> |
|
|
1229 | |
1146 | </div> |
1230 | </div> |
1147 | <h2 id="code_ev_embed_code_when_one_backend_"><code>ev_embed</code> - when one backend isn't enough</h2> |
1231 | <h2 id="code_ev_embed_code_when_one_backend_"><code>ev_embed</code> - when one backend isn't enough...</h2> |
1148 | <div id="code_ev_embed_code_when_one_backend_-2"> |
1232 | <div id="code_ev_embed_code_when_one_backend_-2"> |
1149 | <p>This is a rather advanced watcher type that lets you embed one event loop |
1233 | <p>This is a rather advanced watcher type that lets you embed one event loop |
1150 | into another (currently only <code>ev_io</code> events are supported in the embedded |
1234 | into another (currently only <code>ev_io</code> events are supported in the embedded |
1151 | loop, other types of watchers might be handled in a delayed or incorrect |
1235 | loop, other types of watchers might be handled in a delayed or incorrect |
1152 | fashion and must not be used).</p> |
1236 | fashion and must not be used).</p> |
… | |
… | |
1402 | } |
1486 | } |
1403 | |
1487 | |
1404 | </pre> |
1488 | </pre> |
1405 | |
1489 | |
1406 | </div> |
1490 | </div> |
|
|
1491 | <h1 id="EMBEDDING">EMBEDDING</h1><p><a href="#TOP" class="toplink">Top</a></p> |
|
|
1492 | <div id="EMBEDDING_CONTENT"> |
|
|
1493 | <p>Libev can (and often is) directly embedded into host |
|
|
1494 | applications. Examples of applications that embed it include the Deliantra |
|
|
1495 | Game Server, the EV perl module, the GNU Virtual Private Ethernet (gvpe) |
|
|
1496 | and rxvt-unicode.</p> |
|
|
1497 | <p>The goal is to enable you to just copy the neecssary files into your |
|
|
1498 | source directory without having to change even a single line in them, so |
|
|
1499 | you can easily upgrade by simply copying (or having a checked-out copy of |
|
|
1500 | libev somewhere in your source tree).</p> |
|
|
1501 | |
|
|
1502 | </div> |
|
|
1503 | <h2 id="FILESETS">FILESETS</h2> |
|
|
1504 | <div id="FILESETS_CONTENT"> |
|
|
1505 | <p>Depending on what features you need you need to include one or more sets of files |
|
|
1506 | in your app.</p> |
|
|
1507 | |
|
|
1508 | </div> |
|
|
1509 | <h3 id="CORE_EVENT_LOOP">CORE EVENT LOOP</h3> |
|
|
1510 | <div id="CORE_EVENT_LOOP_CONTENT"> |
|
|
1511 | <p>To include only the libev core (all the <code>ev_*</code> functions), with manual |
|
|
1512 | configuration (no autoconf):</p> |
|
|
1513 | <pre> #define EV_STANDALONE 1 |
|
|
1514 | #include "ev.c" |
|
|
1515 | |
|
|
1516 | </pre> |
|
|
1517 | <p>This will automatically include <cite>ev.h</cite>, too, and should be done in a |
|
|
1518 | single C source file only to provide the function implementations. To use |
|
|
1519 | it, do the same for <cite>ev.h</cite> in all files wishing to use this API (best |
|
|
1520 | done by writing a wrapper around <cite>ev.h</cite> that you can include instead and |
|
|
1521 | where you can put other configuration options):</p> |
|
|
1522 | <pre> #define EV_STANDALONE 1 |
|
|
1523 | #include "ev.h" |
|
|
1524 | |
|
|
1525 | </pre> |
|
|
1526 | <p>Both header files and implementation files can be compiled with a C++ |
|
|
1527 | compiler (at least, thats a stated goal, and breakage will be treated |
|
|
1528 | as a bug).</p> |
|
|
1529 | <p>You need the following files in your source tree, or in a directory |
|
|
1530 | in your include path (e.g. in libev/ when using -Ilibev):</p> |
|
|
1531 | <pre> ev.h |
|
|
1532 | ev.c |
|
|
1533 | ev_vars.h |
|
|
1534 | ev_wrap.h |
|
|
1535 | |
|
|
1536 | ev_win32.c required on win32 platforms only |
|
|
1537 | |
|
|
1538 | ev_select.c only when select backend is enabled (which is by default) |
|
|
1539 | ev_poll.c only when poll backend is enabled (disabled by default) |
|
|
1540 | ev_epoll.c only when the epoll backend is enabled (disabled by default) |
|
|
1541 | ev_kqueue.c only when the kqueue backend is enabled (disabled by default) |
|
|
1542 | ev_port.c only when the solaris port backend is enabled (disabled by default) |
|
|
1543 | |
|
|
1544 | </pre> |
|
|
1545 | <p><cite>ev.c</cite> includes the backend files directly when enabled, so you only need |
|
|
1546 | to compile this single file.</p> |
|
|
1547 | |
|
|
1548 | </div> |
|
|
1549 | <h3 id="LIBEVENT_COMPATIBILITY_API">LIBEVENT COMPATIBILITY API</h3> |
|
|
1550 | <div id="LIBEVENT_COMPATIBILITY_API_CONTENT"> |
|
|
1551 | <p>To include the libevent compatibility API, also include:</p> |
|
|
1552 | <pre> #include "event.c" |
|
|
1553 | |
|
|
1554 | </pre> |
|
|
1555 | <p>in the file including <cite>ev.c</cite>, and:</p> |
|
|
1556 | <pre> #include "event.h" |
|
|
1557 | |
|
|
1558 | </pre> |
|
|
1559 | <p>in the files that want to use the libevent API. This also includes <cite>ev.h</cite>.</p> |
|
|
1560 | <p>You need the following additional files for this:</p> |
|
|
1561 | <pre> event.h |
|
|
1562 | event.c |
|
|
1563 | |
|
|
1564 | </pre> |
|
|
1565 | |
|
|
1566 | </div> |
|
|
1567 | <h3 id="AUTOCONF_SUPPORT">AUTOCONF SUPPORT</h3> |
|
|
1568 | <div id="AUTOCONF_SUPPORT_CONTENT"> |
|
|
1569 | <p>Instead of using <code>EV_STANDALONE=1</code> and providing your config in |
|
|
1570 | whatever way you want, you can also <code>m4_include([libev.m4])</code> in your |
|
|
1571 | <cite>configure.ac</cite> and leave <code>EV_STANDALONE</code> undefined. <cite>ev.c</cite> will then |
|
|
1572 | include <cite>config.h</cite> and configure itself accordingly.</p> |
|
|
1573 | <p>For this of course you need the m4 file:</p> |
|
|
1574 | <pre> libev.m4 |
|
|
1575 | |
|
|
1576 | </pre> |
|
|
1577 | |
|
|
1578 | </div> |
|
|
1579 | <h2 id="PREPROCESSOR_SYMBOLS_MACROS">PREPROCESSOR SYMBOLS/MACROS</h2> |
|
|
1580 | <div id="PREPROCESSOR_SYMBOLS_MACROS_CONTENT"> |
|
|
1581 | <p>Libev can be configured via a variety of preprocessor symbols you have to define |
|
|
1582 | before including any of its files. The default is not to build for multiplicity |
|
|
1583 | and only include the select backend.</p> |
|
|
1584 | <dl> |
|
|
1585 | <dt>EV_STANDALONE</dt> |
|
|
1586 | <dd> |
|
|
1587 | <p>Must always be <code>1</code> if you do not use autoconf configuration, which |
|
|
1588 | keeps libev from including <cite>config.h</cite>, and it also defines dummy |
|
|
1589 | implementations for some libevent functions (such as logging, which is not |
|
|
1590 | supported). It will also not define any of the structs usually found in |
|
|
1591 | <cite>event.h</cite> that are not directly supported by the libev core alone.</p> |
|
|
1592 | </dd> |
|
|
1593 | <dt>EV_USE_MONOTONIC</dt> |
|
|
1594 | <dd> |
|
|
1595 | <p>If defined to be <code>1</code>, libev will try to detect the availability of the |
|
|
1596 | monotonic clock option at both compiletime and runtime. Otherwise no use |
|
|
1597 | of the monotonic clock option will be attempted. If you enable this, you |
|
|
1598 | usually have to link against librt or something similar. Enabling it when |
|
|
1599 | the functionality isn't available is safe, though, althoguh you have |
|
|
1600 | to make sure you link against any libraries where the <code>clock_gettime</code> |
|
|
1601 | function is hiding in (often <cite>-lrt</cite>).</p> |
|
|
1602 | </dd> |
|
|
1603 | <dt>EV_USE_REALTIME</dt> |
|
|
1604 | <dd> |
|
|
1605 | <p>If defined to be <code>1</code>, libev will try to detect the availability of the |
|
|
1606 | realtime clock option at compiletime (and assume its availability at |
|
|
1607 | runtime if successful). Otherwise no use of the realtime clock option will |
|
|
1608 | be attempted. This effectively replaces <code>gettimeofday</code> by <code>clock_get |
|
|
1609 | (CLOCK_REALTIME, ...)</code> and will not normally affect correctness. See tzhe note about libraries |
|
|
1610 | in the description of <code>EV_USE_MONOTONIC</code>, though.</p> |
|
|
1611 | </dd> |
|
|
1612 | <dt>EV_USE_SELECT</dt> |
|
|
1613 | <dd> |
|
|
1614 | <p>If undefined or defined to be <code>1</code>, libev will compile in support for the |
|
|
1615 | <code>select</code>(2) backend. No attempt at autodetection will be done: if no |
|
|
1616 | other method takes over, select will be it. Otherwise the select backend |
|
|
1617 | will not be compiled in.</p> |
|
|
1618 | </dd> |
|
|
1619 | <dt>EV_SELECT_USE_FD_SET</dt> |
|
|
1620 | <dd> |
|
|
1621 | <p>If defined to <code>1</code>, then the select backend will use the system <code>fd_set</code> |
|
|
1622 | structure. This is useful if libev doesn't compile due to a missing |
|
|
1623 | <code>NFDBITS</code> or <code>fd_mask</code> definition or it misguesses the bitset layout on |
|
|
1624 | exotic systems. This usually limits the range of file descriptors to some |
|
|
1625 | low limit such as 1024 or might have other limitations (winsocket only |
|
|
1626 | allows 64 sockets). The <code>FD_SETSIZE</code> macro, set before compilation, might |
|
|
1627 | influence the size of the <code>fd_set</code> used.</p> |
|
|
1628 | </dd> |
|
|
1629 | <dt>EV_SELECT_IS_WINSOCKET</dt> |
|
|
1630 | <dd> |
|
|
1631 | <p>When defined to <code>1</code>, the select backend will assume that |
|
|
1632 | select/socket/connect etc. don't understand file descriptors but |
|
|
1633 | wants osf handles on win32 (this is the case when the select to |
|
|
1634 | be used is the winsock select). This means that it will call |
|
|
1635 | <code>_get_osfhandle</code> on the fd to convert it to an OS handle. Otherwise, |
|
|
1636 | it is assumed that all these functions actually work on fds, even |
|
|
1637 | on win32. Should not be defined on non-win32 platforms.</p> |
|
|
1638 | </dd> |
|
|
1639 | <dt>EV_USE_POLL</dt> |
|
|
1640 | <dd> |
|
|
1641 | <p>If defined to be <code>1</code>, libev will compile in support for the <code>poll</code>(2) |
|
|
1642 | backend. Otherwise it will be enabled on non-win32 platforms. It |
|
|
1643 | takes precedence over select.</p> |
|
|
1644 | </dd> |
|
|
1645 | <dt>EV_USE_EPOLL</dt> |
|
|
1646 | <dd> |
|
|
1647 | <p>If defined to be <code>1</code>, libev will compile in support for the Linux |
|
|
1648 | <code>epoll</code>(7) backend. Its availability will be detected at runtime, |
|
|
1649 | otherwise another method will be used as fallback. This is the |
|
|
1650 | preferred backend for GNU/Linux systems.</p> |
|
|
1651 | </dd> |
|
|
1652 | <dt>EV_USE_KQUEUE</dt> |
|
|
1653 | <dd> |
|
|
1654 | <p>If defined to be <code>1</code>, libev will compile in support for the BSD style |
|
|
1655 | <code>kqueue</code>(2) backend. Its actual availability will be detected at runtime, |
|
|
1656 | otherwise another method will be used as fallback. This is the preferred |
|
|
1657 | backend for BSD and BSD-like systems, although on most BSDs kqueue only |
|
|
1658 | supports some types of fds correctly (the only platform we found that |
|
|
1659 | supports ptys for example was NetBSD), so kqueue might be compiled in, but |
|
|
1660 | not be used unless explicitly requested. The best way to use it is to find |
|
|
1661 | out whether kqueue supports your type of fd properly and use an embedded |
|
|
1662 | kqueue loop.</p> |
|
|
1663 | </dd> |
|
|
1664 | <dt>EV_USE_PORT</dt> |
|
|
1665 | <dd> |
|
|
1666 | <p>If defined to be <code>1</code>, libev will compile in support for the Solaris |
|
|
1667 | 10 port style backend. Its availability will be detected at runtime, |
|
|
1668 | otherwise another method will be used as fallback. This is the preferred |
|
|
1669 | backend for Solaris 10 systems.</p> |
|
|
1670 | </dd> |
|
|
1671 | <dt>EV_USE_DEVPOLL</dt> |
|
|
1672 | <dd> |
|
|
1673 | <p>reserved for future expansion, works like the USE symbols above.</p> |
|
|
1674 | </dd> |
|
|
1675 | <dt>EV_H</dt> |
|
|
1676 | <dd> |
|
|
1677 | <p>The name of the <cite>ev.h</cite> header file used to include it. The default if |
|
|
1678 | undefined is <code><ev.h></code> in <cite>event.h</cite> and <code>"ev.h"</code> in <cite>ev.c</cite>. This |
|
|
1679 | can be used to virtually rename the <cite>ev.h</cite> header file in case of conflicts.</p> |
|
|
1680 | </dd> |
|
|
1681 | <dt>EV_CONFIG_H</dt> |
|
|
1682 | <dd> |
|
|
1683 | <p>If <code>EV_STANDALONE</code> isn't <code>1</code>, this variable can be used to override |
|
|
1684 | <cite>ev.c</cite>'s idea of where to find the <cite>config.h</cite> file, similarly to |
|
|
1685 | <code>EV_H</code>, above.</p> |
|
|
1686 | </dd> |
|
|
1687 | <dt>EV_EVENT_H</dt> |
|
|
1688 | <dd> |
|
|
1689 | <p>Similarly to <code>EV_H</code>, this macro can be used to override <cite>event.c</cite>'s idea |
|
|
1690 | of how the <cite>event.h</cite> header can be found.</p> |
|
|
1691 | </dd> |
|
|
1692 | <dt>EV_PROTOTYPES</dt> |
|
|
1693 | <dd> |
|
|
1694 | <p>If defined to be <code>0</code>, then <cite>ev.h</cite> will not define any function |
|
|
1695 | prototypes, but still define all the structs and other symbols. This is |
|
|
1696 | occasionally useful if you want to provide your own wrapper functions |
|
|
1697 | around libev functions.</p> |
|
|
1698 | </dd> |
|
|
1699 | <dt>EV_MULTIPLICITY</dt> |
|
|
1700 | <dd> |
|
|
1701 | <p>If undefined or defined to <code>1</code>, then all event-loop-specific functions |
|
|
1702 | will have the <code>struct ev_loop *</code> as first argument, and you can create |
|
|
1703 | additional independent event loops. Otherwise there will be no support |
|
|
1704 | for multiple event loops and there is no first event loop pointer |
|
|
1705 | argument. Instead, all functions act on the single default loop.</p> |
|
|
1706 | </dd> |
|
|
1707 | <dt>EV_PERIODICS</dt> |
|
|
1708 | <dd> |
|
|
1709 | <p>If undefined or defined to be <code>1</code>, then periodic timers are supported, |
|
|
1710 | otherwise not. This saves a few kb of code.</p> |
|
|
1711 | </dd> |
|
|
1712 | <dt>EV_COMMON</dt> |
|
|
1713 | <dd> |
|
|
1714 | <p>By default, all watchers have a <code>void *data</code> member. By redefining |
|
|
1715 | this macro to a something else you can include more and other types of |
|
|
1716 | members. You have to define it each time you include one of the files, |
|
|
1717 | though, and it must be identical each time.</p> |
|
|
1718 | <p>For example, the perl EV module uses something like this:</p> |
|
|
1719 | <pre> #define EV_COMMON \ |
|
|
1720 | SV *self; /* contains this struct */ \ |
|
|
1721 | SV *cb_sv, *fh /* note no trailing ";" */ |
|
|
1722 | |
|
|
1723 | </pre> |
|
|
1724 | </dd> |
|
|
1725 | <dt>EV_CB_DECLARE (type)</dt> |
|
|
1726 | <dt>EV_CB_INVOKE (watcher, revents)</dt> |
|
|
1727 | <dt>ev_set_cb (ev, cb)</dt> |
|
|
1728 | <dd> |
|
|
1729 | <p>Can be used to change the callback member declaration in each watcher, |
|
|
1730 | and the way callbacks are invoked and set. Must expand to a struct member |
|
|
1731 | definition and a statement, respectively. See the <cite>ev.v</cite> header file for |
|
|
1732 | their default definitions. One possible use for overriding these is to |
|
|
1733 | avoid the <code>struct ev_loop *</code> as first argument in all cases, or to use |
|
|
1734 | method calls instead of plain function calls in C++.</p> |
|
|
1735 | |
|
|
1736 | </div> |
|
|
1737 | <h2 id="EXAMPLES">EXAMPLES</h2> |
|
|
1738 | <div id="EXAMPLES_CONTENT"> |
|
|
1739 | <p>For a real-world example of a program the includes libev |
|
|
1740 | verbatim, you can have a look at the EV perl module |
|
|
1741 | (<a href="http://software.schmorp.de/pkg/EV.html">http://software.schmorp.de/pkg/EV.html</a>). It has the libev files in |
|
|
1742 | the <cite>libev/</cite> subdirectory and includes them in the <cite>EV/EVAPI.h</cite> (public |
|
|
1743 | interface) and <cite>EV.xs</cite> (implementation) files. Only the <cite>EV.xs</cite> file |
|
|
1744 | will be compiled. It is pretty complex because it provides its own header |
|
|
1745 | file.</p> |
|
|
1746 | <p>The usage in rxvt-unicode is simpler. It has a <cite>ev_cpp.h</cite> header file |
|
|
1747 | that everybody includes and which overrides some autoconf choices:</p> |
|
|
1748 | <pre> #define EV_USE_POLL 0 |
|
|
1749 | #define EV_MULTIPLICITY 0 |
|
|
1750 | #define EV_PERIODICS 0 |
|
|
1751 | #define EV_CONFIG_H <config.h> |
|
|
1752 | |
|
|
1753 | #include "ev++.h" |
|
|
1754 | |
|
|
1755 | </pre> |
|
|
1756 | <p>And a <cite>ev_cpp.C</cite> implementation file that contains libev proper and is compiled:</p> |
|
|
1757 | <pre> #include "ev_cpp.h" |
|
|
1758 | #include "ev.c" |
|
|
1759 | |
|
|
1760 | |
|
|
1761 | |
|
|
1762 | |
|
|
1763 | </pre> |
|
|
1764 | |
|
|
1765 | </div> |
|
|
1766 | <h1 id="COMPLEXITIES">COMPLEXITIES</h1><p><a href="#TOP" class="toplink">Top</a></p> |
|
|
1767 | <div id="COMPLEXITIES_CONTENT"> |
|
|
1768 | <p>In this section the complexities of (many of) the algorithms used inside |
|
|
1769 | libev will be explained. For complexity discussions about backends see the |
|
|
1770 | documentation for <code>ev_default_init</code>.</p> |
|
|
1771 | <p> |
|
|
1772 | <dl> |
|
|
1773 | <dt>Starting and stopping timer/periodic watchers: O(log skipped_other_timers)</dt> |
|
|
1774 | <dt>Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)</dt> |
|
|
1775 | <dt>Starting io/check/prepare/idle/signal/child watchers: O(1)</dt> |
|
|
1776 | <dt>Stopping check/prepare/idle watchers: O(1)</dt> |
|
|
1777 | <dt>Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % 16))</dt> |
|
|
1778 | <dt>Finding the next timer per loop iteration: O(1)</dt> |
|
|
1779 | <dt>Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)</dt> |
|
|
1780 | <dt>Activating one watcher: O(1)</dt> |
|
|
1781 | </dl> |
|
|
1782 | </p> |
|
|
1783 | |
|
|
1784 | |
|
|
1785 | |
|
|
1786 | |
|
|
1787 | |
|
|
1788 | </div> |
1407 | <h1 id="AUTHOR">AUTHOR</h1><p><a href="#TOP" class="toplink">Top</a></p> |
1789 | <h1 id="AUTHOR">AUTHOR</h1><p><a href="#TOP" class="toplink">Top</a></p> |
1408 | <div id="AUTHOR_CONTENT"> |
1790 | <div id="AUTHOR_CONTENT"> |
1409 | <p>Marc Lehmann <libev@schmorp.de>.</p> |
1791 | <p>Marc Lehmann <libev@schmorp.de>.</p> |
1410 | |
1792 | |
1411 | </div> |
1793 | </div> |
1412 | </div></body> |
1794 | </div></body> |
1413 | </html> |
1795 | </html> |