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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"> |
13 | <div class="pod"> |
14 | <!-- INDEX START --> |
14 | <!-- INDEX START --> |
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17 | <ul><li><a href="#NAME">NAME</a></li> |
17 | <ul><li><a href="#NAME">NAME</a></li> |
18 | <li><a href="#SYNOPSIS">SYNOPSIS</a></li> |
18 | <li><a href="#SYNOPSIS">SYNOPSIS</a></li> |
19 | <li><a href="#DESCRIPTION">DESCRIPTION</a></li> |
19 | <li><a href="#DESCRIPTION">DESCRIPTION</a></li> |
20 | <li><a href="#FEATURES">FEATURES</a></li> |
20 | <li><a href="#FEATURES">FEATURES</a></li> |
21 | <li><a href="#CONVENTIONS">CONVENTIONS</a></li> |
21 | <li><a href="#CONVENTIONS">CONVENTIONS</a></li> |
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22 | <li><a href="#TIME_REPRESENTATION">TIME REPRESENTATION</a></li> |
22 | <li><a href="#TIME_AND_OTHER_GLOBAL_FUNCTIONS">TIME AND OTHER GLOBAL FUNCTIONS</a></li> |
23 | <li><a href="#GLOBAL_FUNCTIONS">GLOBAL FUNCTIONS</a></li> |
23 | <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> |
24 | <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> |
25 | <ul><li><a href="#ASSOCIATING_CUSTOM_DATA_WITH_A_WATCH">ASSOCIATING CUSTOM DATA WITH A WATCHER</a></li> |
26 | <ul><li><a href="#ASSOCIATING_CUSTOM_DATA_WITH_A_WATCH">ASSOCIATING CUSTOM DATA WITH A WATCHER</a></li> |
26 | </ul> |
27 | </ul> |
27 | </li> |
28 | </li> |
28 | <li><a href="#WATCHER_TYPES">WATCHER TYPES</a> |
29 | <li><a href="#WATCHER_TYPES">WATCHER TYPES</a> |
29 | <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> |
30 | <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> |
30 | <li><a href="#code_ev_timer_code_relative_and_opti"><code>ev_timer</code> - relative and optionally recurring timeouts</a></li> |
31 | <li><a href="#code_ev_timer_code_relative_and_opti"><code>ev_timer</code> - relative and optionally recurring timeouts</a></li> |
31 | <li><a href="#code_ev_periodic_code_to_cron_or_not"><code>ev_periodic</code> - to cron or not to cron it</a></li> |
32 | <li><a href="#code_ev_periodic_code_to_cron_or_not"><code>ev_periodic</code> - to cron or not to cron</a></li> |
32 | <li><a href="#code_ev_signal_code_signal_me_when_a"><code>ev_signal</code> - signal me when a signal gets signalled</a></li> |
33 | <li><a href="#code_ev_signal_code_signal_me_when_a"><code>ev_signal</code> - signal me when a signal gets signalled</a></li> |
33 | <li><a href="#code_ev_child_code_wait_for_pid_stat"><code>ev_child</code> - wait for pid status changes</a></li> |
34 | <li><a href="#code_ev_child_code_wait_for_pid_stat"><code>ev_child</code> - wait for pid status changes</a></li> |
34 | <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> |
35 | <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> |
35 | <li><a href="#prepare_and_check_your_hooks_into_th">prepare and check - your hooks into the event loop</a></li> |
36 | <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> |
36 | </ul> |
37 | </ul> |
37 | </li> |
38 | </li> |
38 | <li><a href="#OTHER_FUNCTIONS">OTHER FUNCTIONS</a></li> |
39 | <li><a href="#OTHER_FUNCTIONS">OTHER FUNCTIONS</a></li> |
39 | <li><a href="#AUTHOR">AUTHOR</a> |
40 | <li><a href="#AUTHOR">AUTHOR</a> |
40 | </li> |
41 | </li> |
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87 | support for multiple event loops, then all functions taking an initial |
88 | support for multiple event loops, then all functions taking an initial |
88 | argument of name <code>loop</code> (which is always of type <code>struct ev_loop *</code>) |
89 | argument of name <code>loop</code> (which is always of type <code>struct ev_loop *</code>) |
89 | will not have this argument.</p> |
90 | will not have this argument.</p> |
90 | |
91 | |
91 | </div> |
92 | </div> |
92 | <h1 id="TIME_AND_OTHER_GLOBAL_FUNCTIONS">TIME AND OTHER GLOBAL FUNCTIONS</h1><p><a href="#TOP" class="toplink">Top</a></p> |
93 | <h1 id="TIME_REPRESENTATION">TIME REPRESENTATION</h1><p><a href="#TOP" class="toplink">Top</a></p> |
93 | <div id="TIME_AND_OTHER_GLOBAL_FUNCTIONS_CONT"> |
94 | <div id="TIME_REPRESENTATION_CONTENT"> |
94 | <p>Libev represents time as a single floating point number, representing the |
95 | <p>Libev represents time as a single floating point number, representing the |
95 | (fractional) number of seconds since the (POSIX) epoch (somewhere near |
96 | (fractional) number of seconds since the (POSIX) epoch (somewhere near |
96 | the beginning of 1970, details are complicated, don't ask). This type is |
97 | the beginning of 1970, details are complicated, don't ask). This type is |
97 | called <code>ev_tstamp</code>, which is what you should use too. It usually aliases |
98 | called <code>ev_tstamp</code>, which is what you should use too. It usually aliases |
98 | to the double type in C.</p> |
99 | to the double type in C.</p> |
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100 | |
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101 | </div> |
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102 | <h1 id="GLOBAL_FUNCTIONS">GLOBAL FUNCTIONS</h1><p><a href="#TOP" class="toplink">Top</a></p> |
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103 | <div id="GLOBAL_FUNCTIONS_CONTENT"> |
99 | <dl> |
104 | <dl> |
100 | <dt>ev_tstamp ev_time ()</dt> |
105 | <dt>ev_tstamp ev_time ()</dt> |
101 | <dd> |
106 | <dd> |
102 | <p>Returns the current time as libev would use it.</p> |
107 | <p>Returns the current time as libev would use it.</p> |
103 | </dd> |
108 | </dd> |
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142 | <div id="FUNCTIONS_CONTROLLING_THE_EVENT_LOOP-2"> |
147 | <div id="FUNCTIONS_CONTROLLING_THE_EVENT_LOOP-2"> |
143 | <p>An event loop is described by a <code>struct ev_loop *</code>. The library knows two |
148 | <p>An event loop is described by a <code>struct ev_loop *</code>. The library knows two |
144 | types of such loops, the <i>default</i> loop, which supports signals and child |
149 | types of such loops, the <i>default</i> loop, which supports signals and child |
145 | events, and dynamically created loops which do not.</p> |
150 | events, and dynamically created loops which do not.</p> |
146 | <p>If you use threads, a common model is to run the default event loop |
151 | <p>If you use threads, a common model is to run the default event loop |
147 | in your main thread (or in a separate thrad) and for each thread you |
152 | in your main thread (or in a separate thread) and for each thread you |
148 | create, you also create another event loop. Libev itself does no locking |
153 | create, you also create another event loop. Libev itself does no locking |
149 | whatsoever, so if you mix calls to the same event loop in different |
154 | whatsoever, so if you mix calls to the same event loop in different |
150 | threads, make sure you lock (this is usually a bad idea, though, even if |
155 | threads, make sure you lock (this is usually a bad idea, though, even if |
151 | done correctly, because it's hideous and inefficient).</p> |
156 | done correctly, because it's hideous and inefficient).</p> |
152 | <dl> |
157 | <dl> |
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322 | *)</code>), and you can stop watching for events at any time by calling the |
327 | *)</code>), and you can stop watching for events at any time by calling the |
323 | corresponding stop function (<code>ev_<type>_stop (loop, watcher *)</code>.</p> |
328 | corresponding stop function (<code>ev_<type>_stop (loop, watcher *)</code>.</p> |
324 | <p>As long as your watcher is active (has been started but not stopped) you |
329 | <p>As long as your watcher is active (has been started but not stopped) you |
325 | must not touch the values stored in it. Most specifically you must never |
330 | must not touch the values stored in it. Most specifically you must never |
326 | reinitialise it or call its set method.</p> |
331 | reinitialise it or call its set method.</p> |
327 | <p>You cna check whether an event is active by calling the <code>ev_is_active |
332 | <p>You can check whether an event is active by calling the <code>ev_is_active |
328 | (watcher *)</code> macro. To see whether an event is outstanding (but the |
333 | (watcher *)</code> macro. To see whether an event is outstanding (but the |
329 | callback for it has not been called yet) you cna use the <code>ev_is_pending |
334 | callback for it has not been called yet) you can use the <code>ev_is_pending |
330 | (watcher *)</code> macro.</p> |
335 | (watcher *)</code> macro.</p> |
331 | <p>Each and every callback receives the event loop pointer as first, the |
336 | <p>Each and every callback receives the event loop pointer as first, the |
332 | registered watcher structure as second, and a bitset of received events as |
337 | registered watcher structure as second, and a bitset of received events as |
333 | third argument.</p> |
338 | third argument.</p> |
334 | <p>The rceeived events usually include a single bit per event type received |
339 | <p>The received events usually include a single bit per event type received |
335 | (you can receive multiple events at the same time). The possible bit masks |
340 | (you can receive multiple events at the same time). The possible bit masks |
336 | are:</p> |
341 | are:</p> |
337 | <dl> |
342 | <dl> |
338 | <dt><code>EV_READ</code></dt> |
343 | <dt><code>EV_READ</code></dt> |
339 | <dt><code>EV_WRITE</code></dt> |
344 | <dt><code>EV_WRITE</code></dt> |
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389 | |
394 | |
390 | </div> |
395 | </div> |
391 | <h2 id="ASSOCIATING_CUSTOM_DATA_WITH_A_WATCH">ASSOCIATING CUSTOM DATA WITH A WATCHER</h2> |
396 | <h2 id="ASSOCIATING_CUSTOM_DATA_WITH_A_WATCH">ASSOCIATING CUSTOM DATA WITH A WATCHER</h2> |
392 | <div id="ASSOCIATING_CUSTOM_DATA_WITH_A_WATCH-2"> |
397 | <div id="ASSOCIATING_CUSTOM_DATA_WITH_A_WATCH-2"> |
393 | <p>Each watcher has, by default, a member <code>void *data</code> that you can change |
398 | <p>Each watcher has, by default, a member <code>void *data</code> that you can change |
394 | and read at any time, libev will completely ignore it. This cna be used |
399 | and read at any time, libev will completely ignore it. This can be used |
395 | to associate arbitrary data with your watcher. If you need more data and |
400 | to associate arbitrary data with your watcher. If you need more data and |
396 | don't want to allocate memory and store a pointer to it in that data |
401 | don't want to allocate memory and store a pointer to it in that data |
397 | member, you can also "subclass" the watcher type and provide your own |
402 | member, you can also "subclass" the watcher type and provide your own |
398 | data:</p> |
403 | data:</p> |
399 | <pre> struct my_io |
404 | <pre> struct my_io |
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431 | <h2 id="code_ev_io_code_is_this_file_descrip"><code>ev_io</code> - is this file descriptor readable or writable</h2> |
436 | <h2 id="code_ev_io_code_is_this_file_descrip"><code>ev_io</code> - is this file descriptor readable or writable</h2> |
432 | <div id="code_ev_io_code_is_this_file_descrip-2"> |
437 | <div id="code_ev_io_code_is_this_file_descrip-2"> |
433 | <p>I/O watchers check whether a file descriptor is readable or writable |
438 | <p>I/O watchers check whether a file descriptor is readable or writable |
434 | in each iteration of the event loop (This behaviour is called |
439 | in each iteration of the event loop (This behaviour is called |
435 | level-triggering because you keep receiving events as long as the |
440 | level-triggering because you keep receiving events as long as the |
436 | condition persists. Remember you cna stop the watcher if you don't want to |
441 | condition persists. Remember you can stop the watcher if you don't want to |
437 | act on the event and neither want to receive future events).</p> |
442 | act on the event and neither want to receive future events).</p> |
438 | <p>In general you can register as many read and/or write event watchers oer |
443 | <p>In general you can register as many read and/or write event watchers oer |
439 | fd as you want (as long as you don't confuse yourself). Setting all file |
444 | fd as you want (as long as you don't confuse yourself). Setting all file |
440 | descriptors to non-blocking mode is also usually a good idea (but not |
445 | descriptors to non-blocking mode is also usually a good idea (but not |
441 | required if you know what you are doing).</p> |
446 | required if you know what you are doing).</p> |
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505 | the timer, and again will automatically restart it if need be.</p> |
510 | the timer, and again will automatically restart it if need be.</p> |
506 | </dd> |
511 | </dd> |
507 | </dl> |
512 | </dl> |
508 | |
513 | |
509 | </div> |
514 | </div> |
510 | <h2 id="code_ev_periodic_code_to_cron_or_not"><code>ev_periodic</code> - to cron or not to cron it</h2> |
515 | <h2 id="code_ev_periodic_code_to_cron_or_not"><code>ev_periodic</code> - to cron or not to cron</h2> |
511 | <div id="code_ev_periodic_code_to_cron_or_not-2"> |
516 | <div id="code_ev_periodic_code_to_cron_or_not-2"> |
512 | <p>Periodic watchers are also timers of a kind, but they are very versatile |
517 | <p>Periodic watchers are also timers of a kind, but they are very versatile |
513 | (and unfortunately a bit complex).</p> |
518 | (and unfortunately a bit complex).</p> |
514 | <p>Unlike <code>ev_timer</code>'s, they are not based on real time (or relative time) |
519 | <p>Unlike <code>ev_timer</code>'s, they are not based on real time (or relative time) |
515 | but on wallclock time (absolute time). You can tell a periodic watcher |
520 | but on wallclock time (absolute time). You can tell a periodic watcher |
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565 | reschedule callback will be called with the watcher as first, and the |
570 | reschedule callback will be called with the watcher as first, and the |
566 | current time as second argument.</p> |
571 | current time as second argument.</p> |
567 | <p>NOTE: <i>This callback MUST NOT stop or destroy the periodic or any other |
572 | <p>NOTE: <i>This callback MUST NOT stop or destroy the periodic or any other |
568 | periodic watcher, ever, or make any event loop modifications</i>. If you need |
573 | periodic watcher, ever, or make any event loop modifications</i>. If you need |
569 | to stop it, return <code>now + 1e30</code> (or so, fudge fudge) and stop it afterwards.</p> |
574 | to stop it, return <code>now + 1e30</code> (or so, fudge fudge) and stop it afterwards.</p> |
570 | <p>Also, <i><this callback must always return a time that is later than the |
575 | <p>Also, <i>this callback must always return a time that is later than the |
571 | passed <code>now</code> value </i>>. Not even <code>now</code> itself will be ok.</p> |
576 | passed <code>now</code> value</i>. Not even <code>now</code> itself will be ok.</p> |
572 | <p>Its prototype is c<ev_tstamp (*reschedule_cb)(struct ev_periodic *w, |
577 | <p>Its prototype is <code>ev_tstamp (*reschedule_cb)(struct ev_periodic *w, |
573 | ev_tstamp now)>, e.g.:</p> |
578 | ev_tstamp now)</code>, e.g.:</p> |
574 | <pre> static ev_tstamp my_rescheduler (struct ev_periodic *w, ev_tstamp now) |
579 | <pre> static ev_tstamp my_rescheduler (struct ev_periodic *w, ev_tstamp now) |
575 | { |
580 | { |
576 | return now + 60.; |
581 | return now + 60.; |
577 | } |
582 | } |
578 | |
583 | |
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603 | <div id="code_ev_signal_code_signal_me_when_a-2"> |
608 | <div id="code_ev_signal_code_signal_me_when_a-2"> |
604 | <p>Signal watchers will trigger an event when the process receives a specific |
609 | <p>Signal watchers will trigger an event when the process receives a specific |
605 | signal one or more times. Even though signals are very asynchronous, libev |
610 | signal one or more times. Even though signals are very asynchronous, libev |
606 | will try it's best to deliver signals synchronously, i.e. as part of the |
611 | will try it's best to deliver signals synchronously, i.e. as part of the |
607 | normal event processing, like any other event.</p> |
612 | normal event processing, like any other event.</p> |
608 | <p>You cna configure as many watchers as you like per signal. Only when the |
613 | <p>You can configure as many watchers as you like per signal. Only when the |
609 | first watcher gets started will libev actually register a signal watcher |
614 | first watcher gets started will libev actually register a signal watcher |
610 | with the kernel (thus it coexists with your own signal handlers as long |
615 | with the kernel (thus it coexists with your own signal handlers as long |
611 | as you don't register any with libev). Similarly, when the last signal |
616 | as you don't register any with libev). Similarly, when the last signal |
612 | watcher for a signal is stopped libev will reset the signal handler to |
617 | watcher for a signal is stopped libev will reset the signal handler to |
613 | SIG_DFL (regardless of what it was set to before).</p> |
618 | SIG_DFL (regardless of what it was set to before).</p> |
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630 | <dt>ev_child_set (ev_child *, int pid)</dt> |
635 | <dt>ev_child_set (ev_child *, int pid)</dt> |
631 | <dd> |
636 | <dd> |
632 | <p>Configures the watcher to wait for status changes of process <code>pid</code> (or |
637 | <p>Configures the watcher to wait for status changes of process <code>pid</code> (or |
633 | <i>any</i> process if <code>pid</code> is specified as <code>0</code>). The callback can look |
638 | <i>any</i> process if <code>pid</code> is specified as <code>0</code>). The callback can look |
634 | at the <code>rstatus</code> member of the <code>ev_child</code> watcher structure to see |
639 | at the <code>rstatus</code> member of the <code>ev_child</code> watcher structure to see |
635 | the status word (use the macros from <code>sys/wait.h</code>). The <code>rpid</code> member |
640 | the status word (use the macros from <code>sys/wait.h</code> and see your systems |
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|
641 | <code>waitpid</code> documentation). The <code>rpid</code> member contains the pid of the |
636 | contains the pid of the process causing the status change.</p> |
642 | process causing the status change.</p> |
637 | </dd> |
643 | </dd> |
638 | </dl> |
644 | </dl> |
639 | |
645 | |
640 | </div> |
646 | </div> |
641 | <h2 id="code_ev_idle_code_when_you_ve_got_no"><code>ev_idle</code> - when you've got nothing better to do</h2> |
647 | <h2 id="code_ev_idle_code_when_you_ve_got_no"><code>ev_idle</code> - when you've got nothing better to do</h2> |
642 | <div id="code_ev_idle_code_when_you_ve_got_no-2"> |
648 | <div id="code_ev_idle_code_when_you_ve_got_no-2"> |
643 | <p>Idle watchers trigger events when there are no other I/O or timer (or |
649 | <p>Idle watchers trigger events when there are no other events are pending |
644 | periodic) events pending. That is, as long as your process is busy |
650 | (prepare, check and other idle watchers do not count). That is, as long |
645 | handling sockets or timeouts it will not be called. But when your process |
651 | as your process is busy handling sockets or timeouts (or even signals, |
646 | is idle all idle watchers are being called again and again - until |
652 | imagine) it will not be triggered. But when your process is idle all idle |
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653 | watchers are being called again and again, once per event loop iteration - |
647 | stopped, that is, or your process receives more events.</p> |
654 | until stopped, that is, or your process receives more events and becomes |
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655 | busy.</p> |
648 | <p>The most noteworthy effect is that as long as any idle watchers are |
656 | <p>The most noteworthy effect is that as long as any idle watchers are |
649 | active, the process will not block when waiting for new events.</p> |
657 | active, the process will not block when waiting for new events.</p> |
650 | <p>Apart from keeping your process non-blocking (which is a useful |
658 | <p>Apart from keeping your process non-blocking (which is a useful |
651 | effect on its own sometimes), idle watchers are a good place to do |
659 | effect on its own sometimes), idle watchers are a good place to do |
652 | "pseudo-background processing", or delay processing stuff to after the |
660 | "pseudo-background processing", or delay processing stuff to after the |
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659 | believe me.</p> |
667 | believe me.</p> |
660 | </dd> |
668 | </dd> |
661 | </dl> |
669 | </dl> |
662 | |
670 | |
663 | </div> |
671 | </div> |
664 | <h2 id="prepare_and_check_your_hooks_into_th">prepare and check - your hooks into the event loop</h2> |
672 | <h2 id="code_ev_prepare_code_and_code_ev_che"><code>ev_prepare</code> and <code>ev_check</code> - customise your event loop</h2> |
665 | <div id="prepare_and_check_your_hooks_into_th-2"> |
673 | <div id="code_ev_prepare_code_and_code_ev_che-2"> |
666 | <p>Prepare and check watchers usually (but not always) are used in |
674 | <p>Prepare and check watchers are usually (but not always) used in tandem: |
667 | tandom. Prepare watchers get invoked before the process blocks and check |
675 | Prepare watchers get invoked before the process blocks and check watchers |
668 | watchers afterwards.</p> |
676 | afterwards.</p> |
669 | <p>Their main purpose is to integrate other event mechanisms into libev. This |
677 | <p>Their main purpose is to integrate other event mechanisms into libev. This |
670 | could be used, for example, to track variable changes, implement your own |
678 | could be used, for example, to track variable changes, implement your own |
671 | watchers, integrate net-snmp or a coroutine library and lots more.</p> |
679 | watchers, integrate net-snmp or a coroutine library and lots more.</p> |
672 | <p>This is done by examining in each prepare call which file descriptors need |
680 | <p>This is done by examining in each prepare call which file descriptors need |
673 | to be watched by the other library, registering <code>ev_io</code> watchers for them |
681 | to be watched by the other library, registering <code>ev_io</code> watchers for |
674 | and starting an <code>ev_timer</code> watcher for any timeouts (many libraries provide |
682 | them and starting an <code>ev_timer</code> watcher for any timeouts (many libraries |
675 | just this functionality). Then, in the check watcher you check for any |
683 | provide just this functionality). Then, in the check watcher you check for |
676 | events that occured (by making your callbacks set soem flags for example) |
684 | any events that occured (by checking the pending status of all watchers |
677 | and call back into the library.</p> |
685 | and stopping them) and call back into the library. The I/O and timer |
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686 | callbacks will never actually be called (but must be valid neverthelles, |
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687 | because you never know, you know?).</p> |
678 | <p>As another example, the perl Coro module uses these hooks to integrate |
688 | <p>As another example, the Perl Coro module uses these hooks to integrate |
679 | coroutines into libev programs, by yielding to other active coroutines |
689 | coroutines into libev programs, by yielding to other active coroutines |
680 | during each prepare and only letting the process block if no coroutines |
690 | during each prepare and only letting the process block if no coroutines |
681 | are ready to run.</p> |
691 | are ready to run (its actually more complicated, it only runs coroutines |
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692 | with priority higher than the event loop and one lower priority once, |
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693 | using idle watchers to keep the event loop from blocking if lower-priority |
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694 | coroutines exist, thus mapping low-priority coroutines to idle/background |
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695 | tasks).</p> |
682 | <dl> |
696 | <dl> |
683 | <dt>ev_prepare_init (ev_prepare *, callback)</dt> |
697 | <dt>ev_prepare_init (ev_prepare *, callback)</dt> |
684 | <dt>ev_check_init (ev_check *, callback)</dt> |
698 | <dt>ev_check_init (ev_check *, callback)</dt> |
685 | <dd> |
699 | <dd> |
686 | <p>Initialises and configures the prepare or check watcher - they have no |
700 | <p>Initialises and configures the prepare or check watcher - they have no |
687 | parameters of any kind. There are <code>ev_prepare_set</code> and <code>ev_check_set</code> |
701 | parameters of any kind. There are <code>ev_prepare_set</code> and <code>ev_check_set</code> |
688 | macros, but using them is utterly, utterly pointless.</p> |
702 | macros, but using them is utterly, utterly and completely pointless.</p> |
689 | </dd> |
703 | </dd> |
690 | </dl> |
704 | </dl> |
691 | |
705 | |
692 | </div> |
706 | </div> |
693 | <h1 id="OTHER_FUNCTIONS">OTHER FUNCTIONS</h1><p><a href="#TOP" class="toplink">Top</a></p> |
707 | <h1 id="OTHER_FUNCTIONS">OTHER FUNCTIONS</h1><p><a href="#TOP" class="toplink">Top</a></p> |
694 | <div id="OTHER_FUNCTIONS_CONTENT"> |
708 | <div id="OTHER_FUNCTIONS_CONTENT"> |
695 | <p>There are some other fucntions of possible interest. Described. Here. Now.</p> |
709 | <p>There are some other functions of possible interest. Described. Here. Now.</p> |
696 | <dl> |
710 | <dl> |
697 | <dt>ev_once (loop, int fd, int events, ev_tstamp timeout, callback)</dt> |
711 | <dt>ev_once (loop, int fd, int events, ev_tstamp timeout, callback)</dt> |
698 | <dd> |
712 | <dd> |
699 | <p>This function combines a simple timer and an I/O watcher, calls your |
713 | <p>This function combines a simple timer and an I/O watcher, calls your |
700 | callback on whichever event happens first and automatically stop both |
714 | callback on whichever event happens first and automatically stop both |
701 | watchers. This is useful if you want to wait for a single event on an fd |
715 | watchers. This is useful if you want to wait for a single event on an fd |
702 | or timeout without havign to allocate/configure/start/stop/free one or |
716 | or timeout without havign to allocate/configure/start/stop/free one or |
703 | more watchers yourself.</p> |
717 | more watchers yourself.</p> |
704 | <p>If <code>fd</code> is less than 0, then no I/O watcher will be started and events is |
718 | <p>If <code>fd</code> is less than 0, then no I/O watcher will be started and events |
705 | ignored. Otherwise, an <code>ev_io</code> watcher for the given <code>fd</code> and <code>events</code> set |
719 | is being ignored. Otherwise, an <code>ev_io</code> watcher for the given <code>fd</code> and |
706 | will be craeted and started.</p> |
720 | <code>events</code> set will be craeted and started.</p> |
707 | <p>If <code>timeout</code> is less than 0, then no timeout watcher will be |
721 | <p>If <code>timeout</code> is less than 0, then no timeout watcher will be |
708 | started. Otherwise an <code>ev_timer</code> watcher with after = <code>timeout</code> (and repeat |
722 | started. Otherwise an <code>ev_timer</code> watcher with after = <code>timeout</code> (and |
709 | = 0) will be started.</p> |
723 | repeat = 0) will be started. While <code>0</code> is a valid timeout, it is of |
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724 | dubious value.</p> |
710 | <p>The callback has the type <code>void (*cb)(int revents, void *arg)</code> and |
725 | <p>The callback has the type <code>void (*cb)(int revents, void *arg)</code> and gets |
711 | gets passed an events set (normally a combination of <code>EV_ERROR</code>, <code>EV_READ</code>, |
726 | passed an events set like normal event callbacks (with a combination of |
712 | <code>EV_WRITE</code> or <code>EV_TIMEOUT</code>) and the <code>arg</code> value passed to <code>ev_once</code>:</p> |
727 | <code>EV_ERROR</code>, <code>EV_READ</code>, <code>EV_WRITE</code> or <code>EV_TIMEOUT</code>) and the <code>arg</code> |
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728 | value passed to <code>ev_once</code>:</p> |
713 | <pre> static void stdin_ready (int revents, void *arg) |
729 | <pre> static void stdin_ready (int revents, void *arg) |
714 | { |
730 | { |
715 | if (revents & EV_TIMEOUT) |
731 | if (revents & EV_TIMEOUT) |
716 | /* doh, nothing entered */ |
732 | /* doh, nothing entered */; |
717 | else if (revents & EV_READ) |
733 | else if (revents & EV_READ) |
718 | /* stdin might have data for us, joy! */ |
734 | /* stdin might have data for us, joy! */; |
719 | } |
735 | } |
720 | |
736 | |
721 | ev_once (STDIN_FILENO, EV_READm 10., stdin_ready, 0); |
737 | ev_once (STDIN_FILENO, EV_READ, 10., stdin_ready, 0); |
722 | |
738 | |
723 | </pre> |
739 | </pre> |
724 | </dd> |
740 | </dd> |
725 | <dt>ev_feed_event (loop, watcher, int events)</dt> |
741 | <dt>ev_feed_event (loop, watcher, int events)</dt> |
726 | <dd> |
742 | <dd> |
727 | <p>Feeds the given event set into the event loop, as if the specified event |
743 | <p>Feeds the given event set into the event loop, as if the specified event |
728 | has happened for the specified watcher (which must be a pointer to an |
744 | had happened for the specified watcher (which must be a pointer to an |
729 | initialised but not necessarily active event watcher).</p> |
745 | initialised but not necessarily started event watcher).</p> |
730 | </dd> |
746 | </dd> |
731 | <dt>ev_feed_fd_event (loop, int fd, int revents)</dt> |
747 | <dt>ev_feed_fd_event (loop, int fd, int revents)</dt> |
732 | <dd> |
748 | <dd> |
733 | <p>Feed an event on the given fd, as if a file descriptor backend detected it.</p> |
749 | <p>Feed an event on the given fd, as if a file descriptor backend detected |
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750 | the given events it.</p> |
734 | </dd> |
751 | </dd> |
735 | <dt>ev_feed_signal_event (loop, int signum)</dt> |
752 | <dt>ev_feed_signal_event (loop, int signum)</dt> |
736 | <dd> |
753 | <dd> |
737 | <p>Feed an event as if the given signal occured (loop must be the default loop!).</p> |
754 | <p>Feed an event as if the given signal occured (loop must be the default loop!).</p> |
738 | </dd> |
755 | </dd> |