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Revision 1.90 by root, Mon Apr 2 23:14:40 2012 UTC vs.
Revision 1.97 by root, Mon Feb 18 03:20:28 2013 UTC

1.\" Automatically generated by Pod::Man 2.23 (Pod::Simple 3.14) 1.\" Automatically generated by Pod::Man 2.25 (Pod::Simple 3.16)
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122.\} 122.\}
123.rm #[ #] #H #V #F C 123.rm #[ #] #H #V #F C
124.\" ======================================================================== 124.\" ========================================================================
125.\" 125.\"
126.IX Title "LIBEV 3" 126.IX Title "LIBEV 3"
127.TH LIBEV 3 "2012-04-03" "libev-4.11" "libev - high performance full featured event loop" 127.TH LIBEV 3 "2013-02-18" "libev-4.11" "libev - high performance full featured event loop"
128.\" For nroff, turn off justification. Always turn off hyphenation; it makes 128.\" For nroff, turn off justification. Always turn off hyphenation; it makes
129.\" way too many mistakes in technical documents. 129.\" way too many mistakes in technical documents.
130.if n .ad l 130.if n .ad l
131.nh 131.nh
132.SH "NAME" 132.SH "NAME"
… …
367current system. To find which embeddable backends might be supported on 367current system. To find which embeddable backends might be supported on
368the current system, you would need to look at \f(CW\*(C`ev_embeddable_backends () 368the current system, you would need to look at \f(CW\*(C`ev_embeddable_backends ()
369& ev_supported_backends ()\*(C'\fR, likewise for recommended ones. 369& ev_supported_backends ()\*(C'\fR, likewise for recommended ones.
370.Sp 370.Sp
371See the description of \f(CW\*(C`ev_embed\*(C'\fR watchers for more info. 371See the description of \f(CW\*(C`ev_embed\*(C'\fR watchers for more info.
372.IP "ev_set_allocator (void *(*cb)(void *ptr, long size))" 4 372.IP "ev_set_allocator (void *(*cb)(void *ptr, long size) throw ())" 4
373.IX Item "ev_set_allocator (void *(*cb)(void *ptr, long size))" 373.IX Item "ev_set_allocator (void *(*cb)(void *ptr, long size) throw ())"
374Sets the allocation function to use (the prototype is similar \- the 374Sets the allocation function to use (the prototype is similar \- the
375semantics are identical to the \f(CW\*(C`realloc\*(C'\fR C89/SuS/POSIX function). It is 375semantics are identical to the \f(CW\*(C`realloc\*(C'\fR C89/SuS/POSIX function). It is
376used to allocate and free memory (no surprises here). If it returns zero 376used to allocate and free memory (no surprises here). If it returns zero
377when memory needs to be allocated (\f(CW\*(C`size != 0\*(C'\fR), the library might abort 377when memory needs to be allocated (\f(CW\*(C`size != 0\*(C'\fR), the library might abort
378or take some potentially destructive action. 378or take some potentially destructive action.
… …
404\& } 404\& }
405\& 405\&
406\& ... 406\& ...
407\& ev_set_allocator (persistent_realloc); 407\& ev_set_allocator (persistent_realloc);
408.Ve 408.Ve
409.IP "ev_set_syserr_cb (void (*cb)(const char *msg))" 4 409.IP "ev_set_syserr_cb (void (*cb)(const char *msg) throw ())" 4
410.IX Item "ev_set_syserr_cb (void (*cb)(const char *msg))" 410.IX Item "ev_set_syserr_cb (void (*cb)(const char *msg) throw ())"
411Set the callback function to call on a retryable system call error (such 411Set the callback function to call on a retryable system call error (such
412as failed select, poll, epoll_wait). The message is a printable string 412as failed select, poll, epoll_wait). The message is a printable string
413indicating the system call or subsystem causing the problem. If this 413indicating the system call or subsystem causing the problem. If this
414callback is set, then libev will expect it to remedy the situation, no 414callback is set, then libev will expect it to remedy the situation, no
415matter what, when it returns. That is, libev will generally retry the 415matter what, when it returns. That is, libev will generally retry the
… …
687kernel is more efficient (which says nothing about its actual speed, of 687kernel is more efficient (which says nothing about its actual speed, of
688course). While stopping, setting and starting an I/O watcher does never 688course). While stopping, setting and starting an I/O watcher does never
689cause an extra system call as with \f(CW\*(C`EVBACKEND_EPOLL\*(C'\fR, it still adds up to 689cause an extra system call as with \f(CW\*(C`EVBACKEND_EPOLL\*(C'\fR, it still adds up to
690two event changes per incident. Support for \f(CW\*(C`fork ()\*(C'\fR is very bad (you 690two event changes per incident. Support for \f(CW\*(C`fork ()\*(C'\fR is very bad (you
691might have to leak fd's on fork, but it's more sane than epoll) and it 691might have to leak fd's on fork, but it's more sane than epoll) and it
692drops fds silently in similarly hard-to-detect cases 692drops fds silently in similarly hard-to-detect cases.
693.Sp 693.Sp
694This backend usually performs well under most conditions. 694This backend usually performs well under most conditions.
695.Sp 695.Sp
696While nominally embeddable in other event loops, this doesn't work 696While nominally embeddable in other event loops, this doesn't work
697everywhere, so you might need to test for this. And since it is broken 697everywhere, so you might need to test for this. And since it is broken
… …
1140this callback instead. This is useful, for example, when you want to 1140this callback instead. This is useful, for example, when you want to
1141invoke the actual watchers inside another context (another thread etc.). 1141invoke the actual watchers inside another context (another thread etc.).
1142.Sp 1142.Sp
1143If you want to reset the callback, use \f(CW\*(C`ev_invoke_pending\*(C'\fR as new 1143If you want to reset the callback, use \f(CW\*(C`ev_invoke_pending\*(C'\fR as new
1144callback. 1144callback.
1145.IP "ev_set_loop_release_cb (loop, void (*release)(\s-1EV_P\s0), void (*acquire)(\s-1EV_P\s0))" 4 1145.IP "ev_set_loop_release_cb (loop, void (*release)(\s-1EV_P\s0) throw (), void (*acquire)(\s-1EV_P\s0) throw ())" 4
1146.IX Item "ev_set_loop_release_cb (loop, void (*release)(EV_P), void (*acquire)(EV_P))" 1146.IX Item "ev_set_loop_release_cb (loop, void (*release)(EV_P) throw (), void (*acquire)(EV_P) throw ())"
1147Sometimes you want to share the same loop between multiple threads. This 1147Sometimes you want to share the same loop between multiple threads. This
1148can be done relatively simply by putting mutex_lock/unlock calls around 1148can be done relatively simply by putting mutex_lock/unlock calls around
1149each call to a libev function. 1149each call to a libev function.
1150.Sp 1150.Sp
1151However, \f(CW\*(C`ev_run\*(C'\fR can run an indefinite time, so it is not feasible 1151However, \f(CW\*(C`ev_run\*(C'\fR can run an indefinite time, so it is not feasible
… …
1299.PD 0 1299.PD 0
1300.ie n .IP """EV_CHECK""" 4 1300.ie n .IP """EV_CHECK""" 4
1301.el .IP "\f(CWEV_CHECK\fR" 4 1301.el .IP "\f(CWEV_CHECK\fR" 4
1302.IX Item "EV_CHECK" 1302.IX Item "EV_CHECK"
1303.PD 1303.PD
1304All \f(CW\*(C`ev_prepare\*(C'\fR watchers are invoked just \fIbefore\fR \f(CW\*(C`ev_run\*(C'\fR starts 1304All \f(CW\*(C`ev_prepare\*(C'\fR watchers are invoked just \fIbefore\fR \f(CW\*(C`ev_run\*(C'\fR starts to
1305to gather new events, and all \f(CW\*(C`ev_check\*(C'\fR watchers are invoked just after 1305gather new events, and all \f(CW\*(C`ev_check\*(C'\fR watchers are queued (not invoked)
1306\&\f(CW\*(C`ev_run\*(C'\fR has gathered them, but before it invokes any callbacks for any 1306just after \f(CW\*(C`ev_run\*(C'\fR has gathered them, but before it queues any callbacks
1307for any received events. That means \f(CW\*(C`ev_prepare\*(C'\fR watchers are the last
1308watchers invoked before the event loop sleeps or polls for new events, and
1309\&\f(CW\*(C`ev_check\*(C'\fR watchers will be invoked before any other watchers of the same
1310or lower priority within an event loop iteration.
1311.Sp
1307received events. Callbacks of both watcher types can start and stop as 1312Callbacks of both watcher types can start and stop as many watchers as
1308many watchers as they want, and all of them will be taken into account 1313they want, and all of them will be taken into account (for example, a
1309(for example, a \f(CW\*(C`ev_prepare\*(C'\fR watcher might start an idle watcher to keep 1314\&\f(CW\*(C`ev_prepare\*(C'\fR watcher might start an idle watcher to keep \f(CW\*(C`ev_run\*(C'\fR from
1310\&\f(CW\*(C`ev_run\*(C'\fR from blocking). 1315blocking).
1311.ie n .IP """EV_EMBED""" 4 1316.ie n .IP """EV_EMBED""" 4
1312.el .IP "\f(CWEV_EMBED\fR" 4 1317.el .IP "\f(CWEV_EMBED\fR" 4
1313.IX Item "EV_EMBED" 1318.IX Item "EV_EMBED"
1314The embedded event loop specified in the \f(CW\*(C`ev_embed\*(C'\fR watcher needs attention. 1319The embedded event loop specified in the \f(CW\*(C`ev_embed\*(C'\fR watcher needs attention.
1315.ie n .IP """EV_FORK""" 4 1320.ie n .IP """EV_FORK""" 4
… …
1436make sure the watcher is available to libev (e.g. you cannot \f(CW\*(C`free ()\*(C'\fR 1441make sure the watcher is available to libev (e.g. you cannot \f(CW\*(C`free ()\*(C'\fR
1437it). 1442it).
1438.IP "callback ev_cb (ev_TYPE *watcher)" 4 1443.IP "callback ev_cb (ev_TYPE *watcher)" 4
1439.IX Item "callback ev_cb (ev_TYPE *watcher)" 1444.IX Item "callback ev_cb (ev_TYPE *watcher)"
1440Returns the callback currently set on the watcher. 1445Returns the callback currently set on the watcher.
1441.IP "ev_cb_set (ev_TYPE *watcher, callback)" 4 1446.IP "ev_set_cb (ev_TYPE *watcher, callback)" 4
1442.IX Item "ev_cb_set (ev_TYPE *watcher, callback)" 1447.IX Item "ev_set_cb (ev_TYPE *watcher, callback)"
1443Change the callback. You can change the callback at virtually any time 1448Change the callback. You can change the callback at virtually any time
1444(modulo threads). 1449(modulo threads).
1445.IP "ev_set_priority (ev_TYPE *watcher, int priority)" 4 1450.IP "ev_set_priority (ev_TYPE *watcher, int priority)" 4
1446.IX Item "ev_set_priority (ev_TYPE *watcher, int priority)" 1451.IX Item "ev_set_priority (ev_TYPE *watcher, int priority)"
1447.PD 0 1452.PD 0
… …
1503.IX Subsection "WATCHER STATES" 1508.IX Subsection "WATCHER STATES"
1504There are various watcher states mentioned throughout this manual \- 1509There are various watcher states mentioned throughout this manual \-
1505active, pending and so on. In this section these states and the rules to 1510active, pending and so on. In this section these states and the rules to
1506transition between them will be described in more detail \- and while these 1511transition between them will be described in more detail \- and while these
1507rules might look complicated, they usually do \*(L"the right thing\*(R". 1512rules might look complicated, they usually do \*(L"the right thing\*(R".
1508.IP "initialiased" 4 1513.IP "initialised" 4
1509.IX Item "initialiased" 1514.IX Item "initialised"
1510Before a watcher can be registered with the event loop it has to be 1515Before a watcher can be registered with the event loop it has to be
1511initialised. This can be done with a call to \f(CW\*(C`ev_TYPE_init\*(C'\fR, or calls to 1516initialised. This can be done with a call to \f(CW\*(C`ev_TYPE_init\*(C'\fR, or calls to
1512\&\f(CW\*(C`ev_init\*(C'\fR followed by the watcher-specific \f(CW\*(C`ev_TYPE_set\*(C'\fR function. 1517\&\f(CW\*(C`ev_init\*(C'\fR followed by the watcher-specific \f(CW\*(C`ev_TYPE_set\*(C'\fR function.
1513.Sp 1518.Sp
1514In this state it is simply some block of memory that is suitable for 1519In this state it is simply some block of memory that is suitable for
… …
1994\& callback (EV_P_ ev_timer *w, int revents) 1999\& callback (EV_P_ ev_timer *w, int revents)
1995\& { 2000\& {
1996\& // calculate when the timeout would happen 2001\& // calculate when the timeout would happen
1997\& ev_tstamp after = last_activity \- ev_now (EV_A) + timeout; 2002\& ev_tstamp after = last_activity \- ev_now (EV_A) + timeout;
1998\& 2003\&
1999\& // if negative, it means we the timeout already occured 2004\& // if negative, it means we the timeout already occurred
2000\& if (after < 0.) 2005\& if (after < 0.)
2001\& { 2006\& {
2002\& // timeout occurred, take action 2007\& // timeout occurred, take action
2003\& } 2008\& }
2004\& else 2009\& else
… …
2023.Sp 2028.Sp
2024Otherwise, we now the earliest time at which the timeout would trigger, 2029Otherwise, we now the earliest time at which the timeout would trigger,
2025and simply start the timer with this timeout value. 2030and simply start the timer with this timeout value.
2026.Sp 2031.Sp
2027In other words, each time the callback is invoked it will check whether 2032In other words, each time the callback is invoked it will check whether
2028the timeout cocured. If not, it will simply reschedule itself to check 2033the timeout occurred. If not, it will simply reschedule itself to check
2029again at the earliest time it could time out. Rinse. Repeat. 2034again at the earliest time it could time out. Rinse. Repeat.
2030.Sp 2035.Sp
2031This scheme causes more callback invocations (about one every 60 seconds 2036This scheme causes more callback invocations (about one every 60 seconds
2032minus half the average time between activity), but virtually no calls to 2037minus half the average time between activity), but virtually no calls to
2033libev to change the timeout. 2038libev to change the timeout.
… …
2051\& last_activity = ev_now (EV_A); 2056\& last_activity = ev_now (EV_A);
2052.Ve 2057.Ve
2053.Sp 2058.Sp
2054When your timeout value changes, then the timeout can be changed by simply 2059When your timeout value changes, then the timeout can be changed by simply
2055providing a new value, stopping the timer and calling the callback, which 2060providing a new value, stopping the timer and calling the callback, which
2056will agaion do the right thing (for example, time out immediately :). 2061will again do the right thing (for example, time out immediately :).
2057.Sp 2062.Sp
2058.Vb 3 2063.Vb 3
2059\& timeout = new_value; 2064\& timeout = new_value;
2060\& ev_timer_stop (EV_A_ &timer); 2065\& ev_timer_stop (EV_A_ &timer);
2061\& callback (EV_A_ &timer, 0); 2066\& callback (EV_A_ &timer, 0);
… …
2735.ie n .SS """ev_stat"" \- did the file attributes just change?" 2740.ie n .SS """ev_stat"" \- did the file attributes just change?"
2736.el .SS "\f(CWev_stat\fP \- did the file attributes just change?" 2741.el .SS "\f(CWev_stat\fP \- did the file attributes just change?"
2737.IX Subsection "ev_stat - did the file attributes just change?" 2742.IX Subsection "ev_stat - did the file attributes just change?"
2738This watches a file system path for attribute changes. That is, it calls 2743This watches a file system path for attribute changes. That is, it calls
2739\&\f(CW\*(C`stat\*(C'\fR on that path in regular intervals (or when the \s-1OS\s0 says it changed) 2744\&\f(CW\*(C`stat\*(C'\fR on that path in regular intervals (or when the \s-1OS\s0 says it changed)
2740and sees if it changed compared to the last time, invoking the callback if 2745and sees if it changed compared to the last time, invoking the callback
2741it did. 2746if it did. Starting the watcher \f(CW\*(C`stat\*(C'\fR's the file, so only changes that
2747happen after the watcher has been started will be reported.
2742.PP 2748.PP
2743The path does not need to exist: changing from \*(L"path exists\*(R" to \*(L"path does 2749The path does not need to exist: changing from \*(L"path exists\*(R" to \*(L"path does
2744not exist\*(R" is a status change like any other. The condition \*(L"path does not 2750not exist\*(R" is a status change like any other. The condition \*(L"path does not
2745exist\*(R" (or more correctly \*(L"path cannot be stat'ed\*(R") is signified by the 2751exist\*(R" (or more correctly \*(L"path cannot be stat'ed\*(R") is signified by the
2746\&\f(CW\*(C`st_nlink\*(C'\fR field being zero (which is otherwise always forced to be at 2752\&\f(CW\*(C`st_nlink\*(C'\fR field being zero (which is otherwise always forced to be at
… …
2977Apart from keeping your process non-blocking (which is a useful 2983Apart from keeping your process non-blocking (which is a useful
2978effect on its own sometimes), idle watchers are a good place to do 2984effect on its own sometimes), idle watchers are a good place to do
2979\&\*(L"pseudo-background processing\*(R", or delay processing stuff to after the 2985\&\*(L"pseudo-background processing\*(R", or delay processing stuff to after the
2980event loop has handled all outstanding events. 2986event loop has handled all outstanding events.
2981.PP 2987.PP
2988\fIAbusing an \f(CI\*(C`ev_idle\*(C'\fI watcher for its side-effect\fR
2989.IX Subsection "Abusing an ev_idle watcher for its side-effect"
2990.PP
2991As long as there is at least one active idle watcher, libev will never
2992sleep unnecessarily. Or in other words, it will loop as fast as possible.
2993For this to work, the idle watcher doesn't need to be invoked at all \- the
2994lowest priority will do.
2995.PP
2996This mode of operation can be useful together with an \f(CW\*(C`ev_check\*(C'\fR watcher,
2997to do something on each event loop iteration \- for example to balance load
2998between different connections.
2999.PP
3000See \*(L"Abusing an ev_check watcher for its side-effect\*(R" for a longer
3001example.
3002.PP
2982\fIWatcher-Specific Functions and Data Members\fR 3003\fIWatcher-Specific Functions and Data Members\fR
2983.IX Subsection "Watcher-Specific Functions and Data Members" 3004.IX Subsection "Watcher-Specific Functions and Data Members"
2984.IP "ev_idle_init (ev_idle *, callback)" 4 3005.IP "ev_idle_init (ev_idle *, callback)" 4
2985.IX Item "ev_idle_init (ev_idle *, callback)" 3006.IX Item "ev_idle_init (ev_idle *, callback)"
2986Initialises and configures the idle watcher \- it has no parameters of any 3007Initialises and configures the idle watcher \- it has no parameters of any
… …
2991.IX Subsection "Examples" 3012.IX Subsection "Examples"
2992.PP 3013.PP
2993Example: Dynamically allocate an \f(CW\*(C`ev_idle\*(C'\fR watcher, start it, and in the 3014Example: Dynamically allocate an \f(CW\*(C`ev_idle\*(C'\fR watcher, start it, and in the
2994callback, free it. Also, use no error checking, as usual. 3015callback, free it. Also, use no error checking, as usual.
2995.PP 3016.PP
2996.Vb 7 3017.Vb 5
2997\& static void 3018\& static void
2998\& idle_cb (struct ev_loop *loop, ev_idle *w, int revents) 3019\& idle_cb (struct ev_loop *loop, ev_idle *w, int revents)
2999\& { 3020\& {
3021\& // stop the watcher
3022\& ev_idle_stop (loop, w);
3023\&
3024\& // now we can free it
3000\& free (w); 3025\& free (w);
3026\&
3001\& // now do something you wanted to do when the program has 3027\& // now do something you wanted to do when the program has
3002\& // no longer anything immediate to do. 3028\& // no longer anything immediate to do.
3003\& } 3029\& }
3004\& 3030\&
3005\& ev_idle *idle_watcher = malloc (sizeof (ev_idle)); 3031\& ev_idle *idle_watcher = malloc (sizeof (ev_idle));
… …
3007\& ev_idle_start (loop, idle_watcher); 3033\& ev_idle_start (loop, idle_watcher);
3008.Ve 3034.Ve
3009.ie n .SS """ev_prepare"" and ""ev_check"" \- customise your event loop!" 3035.ie n .SS """ev_prepare"" and ""ev_check"" \- customise your event loop!"
3010.el .SS "\f(CWev_prepare\fP and \f(CWev_check\fP \- customise your event loop!" 3036.el .SS "\f(CWev_prepare\fP and \f(CWev_check\fP \- customise your event loop!"
3011.IX Subsection "ev_prepare and ev_check - customise your event loop!" 3037.IX Subsection "ev_prepare and ev_check - customise your event loop!"
3012Prepare and check watchers are usually (but not always) used in pairs: 3038Prepare and check watchers are often (but not always) used in pairs:
3013prepare watchers get invoked before the process blocks and check watchers 3039prepare watchers get invoked before the process blocks and check watchers
3014afterwards. 3040afterwards.
3015.PP 3041.PP
3016You \fImust not\fR call \f(CW\*(C`ev_run\*(C'\fR or similar functions that enter 3042You \fImust not\fR call \f(CW\*(C`ev_run\*(C'\fR or similar functions that enter
3017the current event loop from either \f(CW\*(C`ev_prepare\*(C'\fR or \f(CW\*(C`ev_check\*(C'\fR 3043the current event loop from either \f(CW\*(C`ev_prepare\*(C'\fR or \f(CW\*(C`ev_check\*(C'\fR
… …
3045with priority higher than or equal to the event loop and one coroutine 3071with priority higher than or equal to the event loop and one coroutine
3046of lower priority, but only once, using idle watchers to keep the event 3072of lower priority, but only once, using idle watchers to keep the event
3047loop from blocking if lower-priority coroutines are active, thus mapping 3073loop from blocking if lower-priority coroutines are active, thus mapping
3048low-priority coroutines to idle/background tasks). 3074low-priority coroutines to idle/background tasks).
3049.PP 3075.PP
3050It is recommended to give \f(CW\*(C`ev_check\*(C'\fR watchers highest (\f(CW\*(C`EV_MAXPRI\*(C'\fR) 3076When used for this purpose, it is recommended to give \f(CW\*(C`ev_check\*(C'\fR watchers
3051priority, to ensure that they are being run before any other watchers 3077highest (\f(CW\*(C`EV_MAXPRI\*(C'\fR) priority, to ensure that they are being run before
3052after the poll (this doesn't matter for \f(CW\*(C`ev_prepare\*(C'\fR watchers). 3078any other watchers after the poll (this doesn't matter for \f(CW\*(C`ev_prepare\*(C'\fR
3079watchers).
3053.PP 3080.PP
3054Also, \f(CW\*(C`ev_check\*(C'\fR watchers (and \f(CW\*(C`ev_prepare\*(C'\fR watchers, too) should not 3081Also, \f(CW\*(C`ev_check\*(C'\fR watchers (and \f(CW\*(C`ev_prepare\*(C'\fR watchers, too) should not
3055activate (\*(L"feed\*(R") events into libev. While libev fully supports this, they 3082activate (\*(L"feed\*(R") events into libev. While libev fully supports this, they
3056might get executed before other \f(CW\*(C`ev_check\*(C'\fR watchers did their job. As 3083might get executed before other \f(CW\*(C`ev_check\*(C'\fR watchers did their job. As
3057\&\f(CW\*(C`ev_check\*(C'\fR watchers are often used to embed other (non-libev) event 3084\&\f(CW\*(C`ev_check\*(C'\fR watchers are often used to embed other (non-libev) event
3058loops those other event loops might be in an unusable state until their 3085loops those other event loops might be in an unusable state until their
3059\&\f(CW\*(C`ev_check\*(C'\fR watcher ran (always remind yourself to coexist peacefully with 3086\&\f(CW\*(C`ev_check\*(C'\fR watcher ran (always remind yourself to coexist peacefully with
3060others). 3087others).
3088.PP
3089\fIAbusing an \f(CI\*(C`ev_check\*(C'\fI watcher for its side-effect\fR
3090.IX Subsection "Abusing an ev_check watcher for its side-effect"
3091.PP
3092\&\f(CW\*(C`ev_check\*(C'\fR (and less often also \f(CW\*(C`ev_prepare\*(C'\fR) watchers can also be
3093useful because they are called once per event loop iteration. For
3094example, if you want to handle a large number of connections fairly, you
3095normally only do a bit of work for each active connection, and if there
3096is more work to do, you wait for the next event loop iteration, so other
3097connections have a chance of making progress.
3098.PP
3099Using an \f(CW\*(C`ev_check\*(C'\fR watcher is almost enough: it will be called on the
3100next event loop iteration. However, that isn't as soon as possible \-
3101without external events, your \f(CW\*(C`ev_check\*(C'\fR watcher will not be invoked.
3102.PP
3103This is where \f(CW\*(C`ev_idle\*(C'\fR watchers come in handy \- all you need is a
3104single global idle watcher that is active as long as you have one active
3105\&\f(CW\*(C`ev_check\*(C'\fR watcher. The \f(CW\*(C`ev_idle\*(C'\fR watcher makes sure the event loop
3106will not sleep, and the \f(CW\*(C`ev_check\*(C'\fR watcher makes sure a callback gets
3107invoked. Neither watcher alone can do that.
3061.PP 3108.PP
3062\fIWatcher-Specific Functions and Data Members\fR 3109\fIWatcher-Specific Functions and Data Members\fR
3063.IX Subsection "Watcher-Specific Functions and Data Members" 3110.IX Subsection "Watcher-Specific Functions and Data Members"
3064.IP "ev_prepare_init (ev_prepare *, callback)" 4 3111.IP "ev_prepare_init (ev_prepare *, callback)" 4
3065.IX Item "ev_prepare_init (ev_prepare *, callback)" 3112.IX Item "ev_prepare_init (ev_prepare *, callback)"
… …
3270\fIWatcher-Specific Functions and Data Members\fR 3317\fIWatcher-Specific Functions and Data Members\fR
3271.IX Subsection "Watcher-Specific Functions and Data Members" 3318.IX Subsection "Watcher-Specific Functions and Data Members"
3272.IP "ev_embed_init (ev_embed *, callback, struct ev_loop *embedded_loop)" 4 3319.IP "ev_embed_init (ev_embed *, callback, struct ev_loop *embedded_loop)" 4
3273.IX Item "ev_embed_init (ev_embed *, callback, struct ev_loop *embedded_loop)" 3320.IX Item "ev_embed_init (ev_embed *, callback, struct ev_loop *embedded_loop)"
3274.PD 0 3321.PD 0
3275.IP "ev_embed_set (ev_embed *, callback, struct ev_loop *embedded_loop)" 4 3322.IP "ev_embed_set (ev_embed *, struct ev_loop *embedded_loop)" 4
3276.IX Item "ev_embed_set (ev_embed *, callback, struct ev_loop *embedded_loop)" 3323.IX Item "ev_embed_set (ev_embed *, struct ev_loop *embedded_loop)"
3277.PD 3324.PD
3278Configures the watcher to embed the given loop, which must be 3325Configures the watcher to embed the given loop, which must be
3279embeddable. If the callback is \f(CW0\fR, then \f(CW\*(C`ev_embed_sweep\*(C'\fR will be 3326embeddable. If the callback is \f(CW0\fR, then \f(CW\*(C`ev_embed_sweep\*(C'\fR will be
3280invoked automatically, otherwise it is the responsibility of the callback 3327invoked automatically, otherwise it is the responsibility of the callback
3281to invoke it (it will continue to be called until the sweep has been done, 3328to invoke it (it will continue to be called until the sweep has been done,
… …
3344.ie n .SS """ev_fork"" \- the audacity to resume the event loop after a fork" 3391.ie n .SS """ev_fork"" \- the audacity to resume the event loop after a fork"
3345.el .SS "\f(CWev_fork\fP \- the audacity to resume the event loop after a fork" 3392.el .SS "\f(CWev_fork\fP \- the audacity to resume the event loop after a fork"
3346.IX Subsection "ev_fork - the audacity to resume the event loop after a fork" 3393.IX Subsection "ev_fork - the audacity to resume the event loop after a fork"
3347Fork watchers are called when a \f(CW\*(C`fork ()\*(C'\fR was detected (usually because 3394Fork watchers are called when a \f(CW\*(C`fork ()\*(C'\fR was detected (usually because
3348whoever is a good citizen cared to tell libev about it by calling 3395whoever is a good citizen cared to tell libev about it by calling
3349\&\f(CW\*(C`ev_default_fork\*(C'\fR or \f(CW\*(C`ev_loop_fork\*(C'\fR). The invocation is done before the 3396\&\f(CW\*(C`ev_loop_fork\*(C'\fR). The invocation is done before the event loop blocks next
3350event loop blocks next and before \f(CW\*(C`ev_check\*(C'\fR watchers are being called, 3397and before \f(CW\*(C`ev_check\*(C'\fR watchers are being called, and only in the child
3351and only in the child after the fork. If whoever good citizen calling 3398after the fork. If whoever good citizen calling \f(CW\*(C`ev_default_fork\*(C'\fR cheats
3352\&\f(CW\*(C`ev_default_fork\*(C'\fR cheats and calls it in the wrong process, the fork 3399and calls it in the wrong process, the fork handlers will be invoked, too,
3353handlers will be invoked, too, of course. 3400of course.
3354.PP 3401.PP
3355\fIThe special problem of life after fork \- how is it possible?\fR 3402\fIThe special problem of life after fork \- how is it possible?\fR
3356.IX Subsection "The special problem of life after fork - how is it possible?" 3403.IX Subsection "The special problem of life after fork - how is it possible?"
3357.PP 3404.PP
3358Most uses of \f(CW\*(C`fork()\*(C'\fR consist of forking, then some simple calls to set 3405Most uses of \f(CW\*(C`fork()\*(C'\fR consist of forking, then some simple calls to set
… …
3444it by calling \f(CW\*(C`ev_async_send\*(C'\fR, which is thread\- and signal safe. 3491it by calling \f(CW\*(C`ev_async_send\*(C'\fR, which is thread\- and signal safe.
3445.PP 3492.PP
3446This functionality is very similar to \f(CW\*(C`ev_signal\*(C'\fR watchers, as signals, 3493This functionality is very similar to \f(CW\*(C`ev_signal\*(C'\fR watchers, as signals,
3447too, are asynchronous in nature, and signals, too, will be compressed 3494too, are asynchronous in nature, and signals, too, will be compressed
3448(i.e. the number of callback invocations may be less than the number of 3495(i.e. the number of callback invocations may be less than the number of
3449\&\f(CW\*(C`ev_async_sent\*(C'\fR calls). In fact, you could use signal watchers as a kind 3496\&\f(CW\*(C`ev_async_send\*(C'\fR calls). In fact, you could use signal watchers as a kind
3450of \*(L"global async watchers\*(R" by using a watcher on an otherwise unused 3497of \*(L"global async watchers\*(R" by using a watcher on an otherwise unused
3451signal, and \f(CW\*(C`ev_feed_signal\*(C'\fR to signal this watcher from another thread, 3498signal, and \f(CW\*(C`ev_feed_signal\*(C'\fR to signal this watcher from another thread,
3452even without knowing which loop owns the signal. 3499even without knowing which loop owns the signal.
3453.PP 3500.PP
3454\fIQueueing\fR 3501\fIQueueing\fR
… …
3735already been invoked. 3782already been invoked.
3736.PP 3783.PP
3737A common way around all these issues is to make sure that 3784A common way around all these issues is to make sure that
3738\&\f(CW\*(C`start_new_request\*(C'\fR \fIalways\fR returns before the callback is invoked. If 3785\&\f(CW\*(C`start_new_request\*(C'\fR \fIalways\fR returns before the callback is invoked. If
3739\&\f(CW\*(C`start_new_request\*(C'\fR immediately knows the result, it can artificially 3786\&\f(CW\*(C`start_new_request\*(C'\fR immediately knows the result, it can artificially
3740delay invoking the callback by e.g. using a \f(CW\*(C`prepare\*(C'\fR or \f(CW\*(C`idle\*(C'\fR watcher 3787delay invoking the callback by using a \f(CW\*(C`prepare\*(C'\fR or \f(CW\*(C`idle\*(C'\fR watcher for
3741for example, or more sneakily, by reusing an existing (stopped) watcher 3788example, or more sneakily, by reusing an existing (stopped) watcher and
3742and pushing it into the pending queue: 3789pushing it into the pending queue:
3743.PP 3790.PP
3744.Vb 2 3791.Vb 2
3745\& ev_set_cb (watcher, callback); 3792\& ev_set_cb (watcher, callback);
3746\& ev_feed_event (EV_A_ watcher, 0); 3793\& ev_feed_event (EV_A_ watcher, 0);
3747.Ve 3794.Ve
… …
3756.PP 3803.PP
3757This brings the problem of exiting \- a callback might want to finish the 3804This brings the problem of exiting \- a callback might want to finish the
3758main \f(CW\*(C`ev_run\*(C'\fR call, but not the nested one (e.g. user clicked \*(L"Quit\*(R", but 3805main \f(CW\*(C`ev_run\*(C'\fR call, but not the nested one (e.g. user clicked \*(L"Quit\*(R", but
3759a modal \*(L"Are you sure?\*(R" dialog is still waiting), or just the nested one 3806a modal \*(L"Are you sure?\*(R" dialog is still waiting), or just the nested one
3760and not the main one (e.g. user clocked \*(L"Ok\*(R" in a modal dialog), or some 3807and not the main one (e.g. user clocked \*(L"Ok\*(R" in a modal dialog), or some
3761other combination: In these cases, \f(CW\*(C`ev_break\*(C'\fR will not work alone. 3808other combination: In these cases, a simple \f(CW\*(C`ev_break\*(C'\fR will not work.
3762.PP 3809.PP
3763The solution is to maintain \*(L"break this loop\*(R" variable for each \f(CW\*(C`ev_run\*(C'\fR 3810The solution is to maintain \*(L"break this loop\*(R" variable for each \f(CW\*(C`ev_run\*(C'\fR
3764invocation, and use a loop around \f(CW\*(C`ev_run\*(C'\fR until the condition is 3811invocation, and use a loop around \f(CW\*(C`ev_run\*(C'\fR until the condition is
3765triggered, using \f(CW\*(C`EVRUN_ONCE\*(C'\fR: 3812triggered, using \f(CW\*(C`EVRUN_ONCE\*(C'\fR:
3766.PP 3813.PP
… …
3971.PP 4018.PP
3972.Vb 6 4019.Vb 6
3973\& void 4020\& void
3974\& wait_for_event (ev_watcher *w) 4021\& wait_for_event (ev_watcher *w)
3975\& { 4022\& {
3976\& ev_cb_set (w) = current_coro; 4023\& ev_set_cb (w, current_coro);
3977\& switch_to (libev_coro); 4024\& switch_to (libev_coro);
3978\& } 4025\& }
3979.Ve 4026.Ve
3980.PP 4027.PP
3981That basically suspends the coroutine inside \f(CW\*(C`wait_for_event\*(C'\fR and 4028That basically suspends the coroutine inside \f(CW\*(C`wait_for_event\*(C'\fR and
… …
3985You can do similar tricks if you have, say, threads with an event queue \- 4032You can do similar tricks if you have, say, threads with an event queue \-
3986instead of storing a coroutine, you store the queue object and instead of 4033instead of storing a coroutine, you store the queue object and instead of
3987switching to a coroutine, you push the watcher onto the queue and notify 4034switching to a coroutine, you push the watcher onto the queue and notify
3988any waiters. 4035any waiters.
3989.PP 4036.PP
3990To embed libev, see \s-1EMBEDDING\s0, but in short, it's easiest to create two 4037To embed libev, see \*(L"\s-1EMBEDDING\s0\*(R", but in short, it's easiest to create two
3991files, \fImy_ev.h\fR and \fImy_ev.c\fR that include the respective libev files: 4038files, \fImy_ev.h\fR and \fImy_ev.c\fR that include the respective libev files:
3992.PP 4039.PP
3993.Vb 4 4040.Vb 4
3994\& // my_ev.h 4041\& // my_ev.h
3995\& #define EV_CB_DECLARE(type) struct my_coro *cb; 4042\& #define EV_CB_DECLARE(type) struct my_coro *cb;
… …
4034.IP "\(bu" 4 4081.IP "\(bu" 4
4035The libev emulation is \fInot\fR \s-1ABI\s0 compatible to libevent, you need 4082The libev emulation is \fInot\fR \s-1ABI\s0 compatible to libevent, you need
4036to use the libev header file and library. 4083to use the libev header file and library.
4037.SH "\*(C+ SUPPORT" 4084.SH "\*(C+ SUPPORT"
4038.IX Header " SUPPORT" 4085.IX Header " SUPPORT"
4086.SS "C \s-1API\s0"
4087.IX Subsection "C API"
4088The normal C \s-1API\s0 should work fine when used from \*(C+: both ev.h and the
4089libev sources can be compiled as \*(C+. Therefore, code that uses the C \s-1API\s0
4090will work fine.
4091.PP
4092Proper exception specifications might have to be added to callbacks passed
4093to libev: exceptions may be thrown only from watcher callbacks, all
4094other callbacks (allocator, syserr, loop acquire/release and periodic
4095reschedule callbacks) must not throw exceptions, and might need a \f(CW\*(C`throw
4096()\*(C'\fR specification. If you have code that needs to be compiled as both C
4097and \*(C+ you can use the \f(CW\*(C`EV_THROW\*(C'\fR macro for this:
4098.PP
4099.Vb 6
4100\& static void
4101\& fatal_error (const char *msg) EV_THROW
4102\& {
4103\& perror (msg);
4104\& abort ();
4105\& }
4106\&
4107\& ...
4108\& ev_set_syserr_cb (fatal_error);
4109.Ve
4110.PP
4111The only \s-1API\s0 functions that can currently throw exceptions are \f(CW\*(C`ev_run\*(C'\fR,
4112\&\f(CW\*(C`ev_invoke\*(C'\fR, \f(CW\*(C`ev_invoke_pending\*(C'\fR and \f(CW\*(C`ev_loop_destroy\*(C'\fR (the latter
4113because it runs cleanup watchers).
4114.PP
4115Throwing exceptions in watcher callbacks is only supported if libev itself
4116is compiled with a \*(C+ compiler or your C and \*(C+ environments allow
4117throwing exceptions through C libraries (most do).
4118.SS "\*(C+ \s-1API\s0"
4119.IX Subsection " API"
4039Libev comes with some simplistic wrapper classes for \*(C+ that mainly allow 4120Libev comes with some simplistic wrapper classes for \*(C+ that mainly allow
4040you to use some convenience methods to start/stop watchers and also change 4121you to use some convenience methods to start/stop watchers and also change
4041the callback model to a model using method callbacks on objects. 4122the callback model to a model using method callbacks on objects.
4042.PP 4123.PP
4043To use it, 4124To use it,
… …
4181.IX Item "w->set (loop)" 4262.IX Item "w->set (loop)"
4182Associates a different \f(CW\*(C`struct ev_loop\*(C'\fR with this watcher. You can only 4263Associates a different \f(CW\*(C`struct ev_loop\*(C'\fR with this watcher. You can only
4183do this when the watcher is inactive (and not pending either). 4264do this when the watcher is inactive (and not pending either).
4184.IP "w\->set ([arguments])" 4 4265.IP "w\->set ([arguments])" 4
4185.IX Item "w->set ([arguments])" 4266.IX Item "w->set ([arguments])"
4186Basically the same as \f(CW\*(C`ev_TYPE_set\*(C'\fR, with the same arguments. Either this 4267Basically the same as \f(CW\*(C`ev_TYPE_set\*(C'\fR (except for \f(CW\*(C`ev::embed\*(C'\fR watchers>),
4187method or a suitable start method must be called at least once. Unlike the 4268with the same arguments. Either this method or a suitable start method
4188C counterpart, an active watcher gets automatically stopped and restarted 4269must be called at least once. Unlike the C counterpart, an active watcher
4189when reconfiguring it with this method. 4270gets automatically stopped and restarted when reconfiguring it with this
4271method.
4272.Sp
4273For \f(CW\*(C`ev::embed\*(C'\fR watchers this method is called \f(CW\*(C`set_embed\*(C'\fR, to avoid
4274clashing with the \f(CW\*(C`set (loop)\*(C'\fR method.
4190.IP "w\->start ()" 4 4275.IP "w\->start ()" 4
4191.IX Item "w->start ()" 4276.IX Item "w->start ()"
4192Starts the watcher. Note that there is no \f(CW\*(C`loop\*(C'\fR argument, as the 4277Starts the watcher. Note that there is no \f(CW\*(C`loop\*(C'\fR argument, as the
4193constructor already stores the event loop. 4278constructor already stores the event loop.
4194.IP "w\->start ([arguments])" 4 4279.IP "w\->start ([arguments])" 4
… …
4284.IP "Lua" 4 4369.IP "Lua" 4
4285.IX Item "Lua" 4370.IX Item "Lua"
4286Brian Maher has written a partial interface to libev for lua (at the 4371Brian Maher has written a partial interface to libev for lua (at the
4287time of this writing, only \f(CW\*(C`ev_io\*(C'\fR and \f(CW\*(C`ev_timer\*(C'\fR), to be found at 4372time of this writing, only \f(CW\*(C`ev_io\*(C'\fR and \f(CW\*(C`ev_timer\*(C'\fR), to be found at
4288http://github.com/brimworks/lua\-ev <http://github.com/brimworks/lua-ev>. 4373http://github.com/brimworks/lua\-ev <http://github.com/brimworks/lua-ev>.
4374.IP "Javascript" 4
4375.IX Item "Javascript"
4376Node.js (<http://nodejs.org>) uses libev as the underlying event library.
4377.IP "Others" 4
4378.IX Item "Others"
4379There are others, and I stopped counting.
4289.SH "MACRO MAGIC" 4380.SH "MACRO MAGIC"
4290.IX Header "MACRO MAGIC" 4381.IX Header "MACRO MAGIC"
4291Libev can be compiled with a variety of options, the most fundamental 4382Libev can be compiled with a variety of options, the most fundamental
4292of which is \f(CW\*(C`EV_MULTIPLICITY\*(C'\fR. This option determines whether (most) 4383of which is \f(CW\*(C`EV_MULTIPLICITY\*(C'\fR. This option determines whether (most)
4293functions and callbacks have an initial \f(CW\*(C`struct ev_loop *\*(C'\fR argument. 4384functions and callbacks have an initial \f(CW\*(C`struct ev_loop *\*(C'\fR argument.
… …
4588.IX Item "EV_WIN32_CLOSE_FD(fd)" 4679.IX Item "EV_WIN32_CLOSE_FD(fd)"
4589If programs implement their own fd to handle mapping on win32, then this 4680If programs implement their own fd to handle mapping on win32, then this
4590macro can be used to override the \f(CW\*(C`close\*(C'\fR function, useful to unregister 4681macro can be used to override the \f(CW\*(C`close\*(C'\fR function, useful to unregister
4591file descriptors again. Note that the replacement function has to close 4682file descriptors again. Note that the replacement function has to close
4592the underlying \s-1OS\s0 handle. 4683the underlying \s-1OS\s0 handle.
4684.IP "\s-1EV_USE_WSASOCKET\s0" 4
4685.IX Item "EV_USE_WSASOCKET"
4686If defined to be \f(CW1\fR, libev will use \f(CW\*(C`WSASocket\*(C'\fR to create its internal
4687communication socket, which works better in some environments. Otherwise,
4688the normal \f(CW\*(C`socket\*(C'\fR function will be used, which works better in other
4689environments.
4593.IP "\s-1EV_USE_POLL\s0" 4 4690.IP "\s-1EV_USE_POLL\s0" 4
4594.IX Item "EV_USE_POLL" 4691.IX Item "EV_USE_POLL"
4595If defined to be \f(CW1\fR, libev will compile in support for the \f(CW\*(C`poll\*(C'\fR(2) 4692If defined to be \f(CW1\fR, libev will compile in support for the \f(CW\*(C`poll\*(C'\fR(2)
4596backend. Otherwise it will be enabled on non\-win32 platforms. It 4693backend. Otherwise it will be enabled on non\-win32 platforms. It
4597takes precedence over select. 4694takes precedence over select.
… …
4640from different threads, which is a stronger assumption than \f(CW\*(C`EV_NO_SMP\*(C'\fR, 4737from different threads, which is a stronger assumption than \f(CW\*(C`EV_NO_SMP\*(C'\fR,
4641above. This reduces dependencies and makes libev faster. 4738above. This reduces dependencies and makes libev faster.
4642.IP "\s-1EV_ATOMIC_T\s0" 4 4739.IP "\s-1EV_ATOMIC_T\s0" 4
4643.IX Item "EV_ATOMIC_T" 4740.IX Item "EV_ATOMIC_T"
4644Libev requires an integer type (suitable for storing \f(CW0\fR or \f(CW1\fR) whose 4741Libev requires an integer type (suitable for storing \f(CW0\fR or \f(CW1\fR) whose
4645access is atomic and serialised with respect to other threads or signal 4742access is atomic with respect to other threads or signal contexts. No
4646contexts. No such type is easily found in the C language, so you can 4743such type is easily found in the C language, so you can provide your own
4647provide your own type that you know is safe for your purposes. It is used 4744type that you know is safe for your purposes. It is used both for signal
4648both for signal handler \*(L"locking\*(R" as well as for signal and thread safety 4745handler \*(L"locking\*(R" as well as for signal and thread safety in \f(CW\*(C`ev_async\*(C'\fR
4649in \f(CW\*(C`ev_async\*(C'\fR watchers. 4746watchers.
4650.Sp 4747.Sp
4651In the absence of this define, libev will use \f(CW\*(C`sig_atomic_t volatile\*(C'\fR 4748In the absence of this define, libev will use \f(CW\*(C`sig_atomic_t volatile\*(C'\fR
4652(from \fIsignal.h\fR), which is usually good enough on most platforms, 4749(from \fIsignal.h\fR), which is usually good enough on most platforms.
4653although strictly speaking using a type that also implies a memory fence
4654is required.
4655.IP "\s-1EV_H\s0 (h)" 4 4750.IP "\s-1EV_H\s0 (h)" 4
4656.IX Item "EV_H (h)" 4751.IX Item "EV_H (h)"
4657The name of the \fIev.h\fR header file used to include it. The default if 4752The name of the \fIev.h\fR header file used to include it. The default if
4658undefined is \f(CW"ev.h"\fR in \fIevent.h\fR, \fIev.c\fR and \fIev++.h\fR. This can be 4753undefined is \f(CW"ev.h"\fR in \fIevent.h\fR, \fIev.c\fR and \fIev++.h\fR. This can be
4659used to virtually rename the \fIev.h\fR header file in case of conflicts. 4754used to virtually rename the \fIev.h\fR header file in case of conflicts.
… …
4726\& #define EV_CHILD_ENABLE 1 4821\& #define EV_CHILD_ENABLE 1
4727\& #define EV_ASYNC_ENABLE 1 4822\& #define EV_ASYNC_ENABLE 1
4728.Ve 4823.Ve
4729.Sp 4824.Sp
4730The actual value is a bitset, it can be a combination of the following 4825The actual value is a bitset, it can be a combination of the following
4731values: 4826values (by default, all of these are enabled):
4732.RS 4 4827.RS 4
4733.ie n .IP "1 \- faster/larger code" 4 4828.ie n .IP "1 \- faster/larger code" 4
4734.el .IP "\f(CW1\fR \- faster/larger code" 4 4829.el .IP "\f(CW1\fR \- faster/larger code" 4
4735.IX Item "1 - faster/larger code" 4830.IX Item "1 - faster/larger code"
4736Use larger code to speed up some operations. 4831Use larger code to speed up some operations.
… …
4739code size by roughly 30% on amd64). 4834code size by roughly 30% on amd64).
4740.Sp 4835.Sp
4741When optimising for size, use of compiler flags such as \f(CW\*(C`\-Os\*(C'\fR with 4836When optimising for size, use of compiler flags such as \f(CW\*(C`\-Os\*(C'\fR with
4742gcc is recommended, as well as \f(CW\*(C`\-DNDEBUG\*(C'\fR, as libev contains a number of 4837gcc is recommended, as well as \f(CW\*(C`\-DNDEBUG\*(C'\fR, as libev contains a number of
4743assertions. 4838assertions.
4839.Sp
4840The default is off when \f(CW\*(C`_\|_OPTIMIZE_SIZE_\|_\*(C'\fR is defined by your compiler
4841(e.g. gcc with \f(CW\*(C`\-Os\*(C'\fR).
4744.ie n .IP "2 \- faster/larger data structures" 4 4842.ie n .IP "2 \- faster/larger data structures" 4
4745.el .IP "\f(CW2\fR \- faster/larger data structures" 4 4843.el .IP "\f(CW2\fR \- faster/larger data structures" 4
4746.IX Item "2 - faster/larger data structures" 4844.IX Item "2 - faster/larger data structures"
4747Replaces the small 2\-heap for timer management by a faster 4\-heap, larger 4845Replaces the small 2\-heap for timer management by a faster 4\-heap, larger
4748hash table sizes and so on. This will usually further increase code size 4846hash table sizes and so on. This will usually further increase code size
4749and can additionally have an effect on the size of data structures at 4847and can additionally have an effect on the size of data structures at
4750runtime. 4848runtime.
4849.Sp
4850The default is off when \f(CW\*(C`_\|_OPTIMIZE_SIZE_\|_\*(C'\fR is defined by your compiler
4851(e.g. gcc with \f(CW\*(C`\-Os\*(C'\fR).
4751.ie n .IP "4 \- full \s-1API\s0 configuration" 4 4852.ie n .IP "4 \- full \s-1API\s0 configuration" 4
4752.el .IP "\f(CW4\fR \- full \s-1API\s0 configuration" 4 4853.el .IP "\f(CW4\fR \- full \s-1API\s0 configuration" 4
4753.IX Item "4 - full API configuration" 4854.IX Item "4 - full API configuration"
4754This enables priorities (sets \f(CW\*(C`EV_MAXPRI\*(C'\fR=2 and \f(CW\*(C`EV_MINPRI\*(C'\fR=\-2), and 4855This enables priorities (sets \f(CW\*(C`EV_MAXPRI\*(C'\fR=2 and \f(CW\*(C`EV_MINPRI\*(C'\fR=\-2), and
4755enables multiplicity (\f(CW\*(C`EV_MULTIPLICITY\*(C'\fR=1). 4856enables multiplicity (\f(CW\*(C`EV_MULTIPLICITY\*(C'\fR=1).
… …
5315thread\*(R" or will block signals process-wide, both behaviours would 5416thread\*(R" or will block signals process-wide, both behaviours would
5316be compatible with libev. Interaction between \f(CW\*(C`sigprocmask\*(C'\fR and 5417be compatible with libev. Interaction between \f(CW\*(C`sigprocmask\*(C'\fR and
5317\&\f(CW\*(C`pthread_sigmask\*(C'\fR could complicate things, however. 5418\&\f(CW\*(C`pthread_sigmask\*(C'\fR could complicate things, however.
5318.Sp 5419.Sp
5319The most portable way to handle signals is to block signals in all threads 5420The most portable way to handle signals is to block signals in all threads
5320except the initial one, and run the default loop in the initial thread as 5421except the initial one, and run the signal handling loop in the initial
5321well. 5422thread as well.
5322.ie n .IP """long"" must be large enough for common memory allocation sizes" 4 5423.ie n .IP """long"" must be large enough for common memory allocation sizes" 4
5323.el .IP "\f(CWlong\fR must be large enough for common memory allocation sizes" 4 5424.el .IP "\f(CWlong\fR must be large enough for common memory allocation sizes" 4
5324.IX Item "long must be large enough for common memory allocation sizes" 5425.IX Item "long must be large enough for common memory allocation sizes"
5325To improve portability and simplify its \s-1API\s0, libev uses \f(CW\*(C`long\*(C'\fR internally 5426To improve portability and simplify its \s-1API\s0, libev uses \f(CW\*(C`long\*(C'\fR internally
5326instead of \f(CW\*(C`size_t\*(C'\fR when allocating its data structures. On non-POSIX 5427instead of \f(CW\*(C`size_t\*(C'\fR when allocating its data structures. On non-POSIX
… …
5416new \s-1API\s0 early than late. 5517new \s-1API\s0 early than late.
5417.ie n .IP """EV_COMPAT3"" backwards compatibility mechanism" 4 5518.ie n .IP """EV_COMPAT3"" backwards compatibility mechanism" 4
5418.el .IP "\f(CWEV_COMPAT3\fR backwards compatibility mechanism" 4 5519.el .IP "\f(CWEV_COMPAT3\fR backwards compatibility mechanism" 4
5419.IX Item "EV_COMPAT3 backwards compatibility mechanism" 5520.IX Item "EV_COMPAT3 backwards compatibility mechanism"
5420The backward compatibility mechanism can be controlled by 5521The backward compatibility mechanism can be controlled by
5421\&\f(CW\*(C`EV_COMPAT3\*(C'\fR. See \*(L"\s-1MACROS\s0\*(R" in \s-1PREPROCESSOR\s0 \s-1SYMBOLS\s0 in the \s-1EMBEDDING\s0 5522\&\f(CW\*(C`EV_COMPAT3\*(C'\fR. See \*(L"\s-1PREPROCESSOR\s0 \s-1SYMBOLS/MACROS\s0\*(R" in the \*(L"\s-1EMBEDDING\s0\*(R"
5422section. 5523section.
5423.ie n .IP """ev_default_destroy"" and ""ev_default_fork"" have been removed" 4 5524.ie n .IP """ev_default_destroy"" and ""ev_default_fork"" have been removed" 4
5424.el .IP "\f(CWev_default_destroy\fR and \f(CWev_default_fork\fR have been removed" 4 5525.el .IP "\f(CWev_default_destroy\fR and \f(CWev_default_fork\fR have been removed" 4
5425.IX Item "ev_default_destroy and ev_default_fork have been removed" 5526.IX Item "ev_default_destroy and ev_default_fork have been removed"
5426These calls can be replaced easily by their \f(CW\*(C`ev_loop_xxx\*(C'\fR counterparts: 5527These calls can be replaced easily by their \f(CW\*(C`ev_loop_xxx\*(C'\fR counterparts:

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