GENERIC WATCHER FUNCTIONS

In the following description, TYPE stands for the watcher type, e.g. timer for ev_timer watchers and io for ev_io watchers.

ev_TYPE_set (ev_TYPE *, [args])
callback = ev_cb (ev_TYPE *watcher)
callback ev_cb (ev_TYPE *watcher): Returns the callback currently set on the watcher.
ev_set_priority (ev_TYPE *watcher, priority)
int ev_priority (ev_TYPE *watcher): +
Set and query the priority of the watcher. The priority is a small +integer between EV_MAXPRI (default: 2) and EV_MINPRI +(default: -2). Pending watchers with higher priority will be invoked +before watchers with lower priority, but priority will not keep watchers +from being executed (except for ev_idle watchers).
+
This means that priorities are only used for ordering callback +invocation after new events have been received. This is useful, for +example, to reduce latency after idling, or more often, to bind two +watchers on the same event and make sure one is called first.
+
If you need to suppress invocation when higher priority events are pending +you need to look at ev_idle watchers, which provide this functionality.
+
You must not change the priority of a watcher as long as it is active or +pending.
+
The default priority used by watchers when no priority has been set is +always 0, which is supposed to not be too high and not be too low :).
+
Setting a priority outside the range of EV_MINPRI to EV_MAXPRI is +fine, as long as you do not mind that the priority value you query might +or might not have been adjusted to be within valid range.
+
ev_invoke (loop, ev_TYPE *watcher, int revents): +
Invoke the watcher with the given loop and revents. Neither +loop nor revents need to be valid as long as the watcher callback +can deal with that fact.
+
int ev_clear_pending (loop, ev_TYPE *watcher): +
If the watcher is pending, this function returns clears its pending status +and returns its revents bitset (as if its callback was invoked). If the +watcher isn't pending it does nothing and returns 0.
+


 
 
@@ -707,31 +857,70 @@ can cast it back to your own type:
   }
 
 
-More interesting and less C-conformant ways of catsing your callback type
-have been omitted....
+More interesting and less C-conformant ways of casting your callback type
+instead have been omitted.
+Another common scenario is having some data structure with multiple
+watchers:
+  struct my_biggy
+  {
+    int some_data;
+    ev_timer t1;
+    ev_timer t2;
+  }
+
+
+In this case getting the pointer to my_biggy is a bit more complicated,
+you need to use offsetof:
+  #include <stddef.h>
 
+  static void
+  t1_cb (EV_P_ struct ev_timer *w, int revents)
+  {
+    struct my_biggy big = (struct my_biggy *
+      (((char *)w) - offsetof (struct my_biggy, t1));
+  }
+
+  static void
+  t2_cb (EV_P_ struct ev_timer *w, int revents)
+  {
+    struct my_biggy big = (struct my_biggy *
+      (((char *)w) - offsetof (struct my_biggy, t2));
+  }
 
 
 
 
+
+


-WATCHER TYPES
Top
+WATCHER TYPES
 
 This section describes each watcher in detail, but will not repeat
-information given in the last section.
+information given in the last section. Any initialisation/set macros,
+functions and members specific to the watcher type are explained.
+Members are additionally marked with either [read-only], meaning that,
+while the watcher is active, you can look at the member and expect some
+sensible content, but you must not modify it (you can modify it while the
+watcher is stopped to your hearts content), or [read-write], which
+means you can expect it to have some sensible content while the watcher
+is active, but you can also modify it. Modifying it may not do something
+sensible or take immediate effect (or do anything at all), but libev will
+not crash or malfunction in any way.
 
 
 
 
 
 
-ev_io - is this file descriptor readable or writable
+ev_io - is this file descriptor readable or writable?
 
 I/O watchers check whether a file descriptor is readable or writable
-in each iteration of the event loop (This behaviour is called
-level-triggering because you keep receiving events as long as the
-condition persists. Remember you can stop the watcher if you don't want to
-act on the event and neither want to receive future events).
+in each iteration of the event loop, or, more precisely, when reading
+would not block the process and writing would at least be able to write
+some data. This behaviour is called level-triggering because you keep
+receiving events as long as the condition persists. Remember you can stop
+the watcher if you don't want to act on the event and neither want to
+receive future events.
 In general you can register as many read and/or write event watchers per
 fd as you want (as long as you don't confuse yourself). Setting all file
 descriptors to non-blocking mode is also usually a good idea (but not
@@ -739,33 +928,68 @@ required if you know what you are doing).
 You have to be careful with dup'ed file descriptors, though. Some backends
 (the linux epoll backend is a notable example) cannot handle dup'ed file
 descriptors correctly if you register interest in two or more fds pointing
-to the same underlying file/socket etc. description (that is, they share
+to the same underlying file/socket/etc. description (that is, they share
 the same underlying "file open").
 If you must do this, then force the use of a known-to-be-good backend
 (at the time of this writing, this includes only EVBACKEND_SELECT and
 EVBACKEND_POLL).
+Another thing you have to watch out for is that it is quite easy to
+receive "spurious" readyness notifications, that is your callback might
+be called with EV_READ but a subsequent read(2) will actually block
+because there is no data. Not only are some backends known to create a
+lot of those (for example solaris ports), it is very easy to get into
+this situation even with a relatively standard program structure. Thus
+it is best to always use non-blocking I/O: An extra read(2) returning
+EAGAIN is far preferable to a program hanging until some data arrives.
+If you cannot run the fd in non-blocking mode (for example you should not
+play around with an Xlib connection), then you have to seperately re-test
+whether a file descriptor is really ready with a known-to-be good interface
+such as poll (fortunately in our Xlib example, Xlib already does this on
+its own, so its quite safe to use).
+
+
+The special problem of disappearing file descriptors
+
+Some backends (e.g kqueue, epoll) need to be told about closing a file
+descriptor (either by calling close explicitly or by any other means,
+such as dup). The reason is that you register interest in some file
+descriptor, but when it goes away, the operating system will silently drop
+this interest. If another file descriptor with the same number then is
+registered with libev, there is no efficient way to see that this is, in
+fact, a different file descriptor.
+To avoid having to explicitly tell libev about such cases, libev follows
+the following policy:  Each time ev_io_set is being called, libev
+will assume that this is potentially a new file descriptor, otherwise
+it is assumed that the file descriptor stays the same. That means that
+you have to call ev_io_set (or ev_io_init) when you change the
+descriptor even if the file descriptor number itself did not change.
+This is how one would do it normally anyway, the important point is that
+the libev application should not optimise around libev but should leave
+optimisations to libev.
+
+
+
+
 
 	ev_io_init (ev_io *, callback, int fd, int events)
 	ev_io_set (ev_io *, int fd, int events)
 	
-		Configures an ev_io watcher. The fd is the file descriptor to rceeive
-events for and events is either EV_READ, EV_WRITE or EV_READ |
-EV_WRITE to receive the given events.
-		Please note that most of the more scalable backend mechanisms (for example
-epoll and solaris ports) can result in spurious readyness notifications
-for file descriptors, so you practically need to use non-blocking I/O (and
-treat callback invocation as hint only), or retest separately with a safe
-interface before doing I/O (XLib can do this), or force the use of either
-EVBACKEND_SELECT or EVBACKEND_POLL, which don't suffer from this
-problem. Also note that it is quite easy to have your callback invoked
-when the readyness condition is no longer valid even when employing
-typical ways of handling events, so its a good idea to use non-blocking
-I/O unconditionally.
+		Configures an ev_io watcher. The fd is the file descriptor to
+rceeive events for and events is either EV_READ, EV_WRITE or
+EV_READ | EV_WRITE to receive the given events.
+	
+	int fd [read-only]
+	
+		The file descriptor being watched.
+	
+	int events [read-only]
+	
+		The events being watched.
 	
 
-Example: call stdin_readable_cb when STDIN_FILENO has become, well
+
Example: Call stdin_readable_cb when STDIN_FILENO has become, well
 readable, but only once. Since it is likely line-buffered, you could
-attempt to read a whole line in the callback:
+attempt to read a whole line in the callback.
   static void
   stdin_readable_cb (struct ev_loop *loop, struct ev_io *w, int revents)
   {
@@ -786,7 +1010,7 @@ attempt to read a whole line in the callback:
 
 
 
-ev_timer - relative and optionally recurring timeouts
+ev_timer - relative and optionally repeating timeouts
 
 Timer watchers are simple relative timers that generate an event after a
 given time, and optionally repeating in regular intervals after that.
@@ -824,20 +1048,42 @@ timer will not fire more than once per event loop iteration.
 	
 		This will act as if the timer timed out and restart it again if it is
 repeating. The exact semantics are:
-		If the timer is started but nonrepeating, stop it.
-		If the timer is repeating, either start it if necessary (with the repeat
-value), or reset the running timer to the repeat value.
+		If the timer is pending, its pending status is cleared.
+		If the timer is started but nonrepeating, stop it (as if it timed out).
+		If the timer is repeating, either start it if necessary (with the
+repeat value), or reset the running timer to the repeat value.
 		This sounds a bit complicated, but here is a useful and typical
 example: Imagine you have a tcp connection and you want a so-called idle
 timeout, that is, you want to be called when there have been, say, 60
 seconds of inactivity on the socket. The easiest way to do this is to
-configure an ev_timer with after=repeat=60 and calling ev_timer_again each
-time you successfully read or write some data. If you go into an idle
-state where you do not expect data to travel on the socket, you can stop
-the timer, and again will automatically restart it if need be.
+configure an ev_timer with a repeat value of 60 and then call
+ev_timer_again each time you successfully read or write some data. If
+you go into an idle state where you do not expect data to travel on the
+socket, you can ev_timer_stop the timer, and ev_timer_again will
+automatically restart it if need be.
+		That means you can ignore the after value and ev_timer_start
+altogether and only ever use the repeat value and ev_timer_again:
+   ev_timer_init (timer, callback, 0., 5.);
+   ev_timer_again (loop, timer);
+   ...
+   timer->again = 17.;
+   ev_timer_again (loop, timer);
+   ...
+   timer->again = 10.;
+   ev_timer_again (loop, timer);
+
+
+		This is more slightly efficient then stopping/starting the timer each time
+you want to modify its timeout value.
+	
+	ev_tstamp repeat [read-write]
+	
+		The current repeat value. Will be used each time the watcher times out
+or ev_timer_again is called and determines the next timeout (if any),
+which is also when any modifications are taken into account.
 	
 
-Example: create a timer that fires after 60 seconds.
+Example: Create a timer that fires after 60 seconds.
   static void
   one_minute_cb (struct ev_loop *loop, struct ev_timer *w, int revents)
   {
@@ -849,7 +1095,7 @@ the timer, and again will automatically restart it if need be.
   ev_timer_start (loop, &mytimer);
 
 
-Example: create a timeout timer that times out after 10 seconds of
+
Example: Create a timeout timer that times out after 10 seconds of
 inactivity.
   static void
   timeout_cb (struct ev_loop *loop, struct ev_timer *w, int revents)
@@ -872,20 +1118,20 @@ inactivity.
 
 
 
-ev_periodic - to cron or not to cron
+ev_periodic - to cron or not to cron?
 
 Periodic watchers are also timers of a kind, but they are very versatile
 (and unfortunately a bit complex).
 Unlike ev_timer's, they are not based on real time (or relative time)
 but on wallclock time (absolute time). You can tell a periodic watcher
 to trigger "at" some specific point in time. For example, if you tell a
-periodic watcher to trigger in 10 seconds (by specifiying e.g. c<ev_now ()
-+ 10.>) and then reset your system clock to the last year, then it will
+periodic watcher to trigger in 10 seconds (by specifiying e.g. ev_now ()
++ 10.) and then reset your system clock to the last year, then it will
 take a year to trigger the event (unlike an ev_timer, which would trigger
-roughly 10 seconds later and of course not if you reset your system time
-again).
+roughly 10 seconds later).
 They can also be used to implement vastly more complex timers, such as
-triggering an event on eahc midnight, local time.
+triggering an event on each midnight, local time or other, complicated,
+rules.
 As with timers, the callback is guarenteed to be invoked only when the
 time (at) has been passed, but if multiple periodic timers become ready
 during the same loop iteration then order of execution is undefined.
@@ -897,18 +1143,18 @@ during the same loop iteration then order of execution is undefined.
 operation, and we will explain them from simplest to complex:
 		
 			

-				* absolute timer (interval = reschedule_cb = 0)
+				* absolute timer (at = time, interval = reschedule_cb = 0)
 				
 					In this configuration the watcher triggers an event at the wallclock time
 at and doesn't repeat. It will not adjust when a time jump occurs,
 that is, if it is to be run at January 1st 2011 then it will run when the
 system time reaches or surpasses this time.
 				
-				* non-repeating interval timer (interval > 0, reschedule_cb = 0)
+				* non-repeating interval timer (at = offset, interval > 0, reschedule_cb = 0)
 				
 					In this mode the watcher will always be scheduled to time out at the next
-at + N * interval time (for some integer N) and then repeat, regardless
-of any time jumps.
+at + N * interval time (for some integer N, which can also be negative)
+and then repeat, regardless of any time jumps.
 					This can be used to create timers that do not drift with respect to system
 time:
    ev_periodic_set (&periodic, 0., 3600., 0);
@@ -921,8 +1167,11 @@ by 3600.
 					Another way to think about it (for the mathematically inclined) is that
 ev_periodic will try to run the callback in this mode at the next possible
 time where time = at (mod interval), regardless of any time jumps.
+					For numerical stability it is preferable that the at value is near
+ev_now () (the current time), but there is no range requirement for
+this value.
 				
-				* manual reschedule mode (reschedule_cb = callback)
+				* manual reschedule mode (at and interval ignored, reschedule_cb = callback)
 				
 					In this mode the values for interval and at are both being
 ignored. Instead, each time the periodic watcher gets scheduled, the
@@ -931,7 +1180,7 @@ current time as second argument.
 					NOTE: This callback MUST NOT stop or destroy any periodic watcher,
 ever, or make any event loop modifications. If you need to stop it,
 return now + 1e30 (or so, fudge fudge) and stop it afterwards (e.g. by
-starting a prepare watcher).
+starting an ev_prepare watcher, which is legal).
 					Its prototype is ev_tstamp (*reschedule_cb)(struct ev_periodic *w,
 ev_tstamp now), e.g.:
    static ev_tstamp my_rescheduler (struct ev_periodic *w, ev_tstamp now)
@@ -962,8 +1211,27 @@ when you changed some parameters or the reschedule callback would return
 a different time than the last time it was called (e.g. in a crond like
 program when the crontabs have changed).
 	
+	ev_tstamp offset [read-write]
+	
+		When repeating, this contains the offset value, otherwise this is the
+absolute point in time (the at value passed to ev_periodic_set).
+		Can be modified any time, but changes only take effect when the periodic
+timer fires or ev_periodic_again is being called.
+	
+	ev_tstamp interval [read-write]
+	
+		The current interval value. Can be modified any time, but changes only
+take effect when the periodic timer fires or ev_periodic_again is being
+called.
+	
+	ev_tstamp (*reschedule_cb)(struct ev_periodic *w, ev_tstamp now) [read-write]
+	
+		The current reschedule callback, or 0, if this functionality is
+switched off. Can be changed any time, but changes only take effect when
+the periodic timer fires or ev_periodic_again is being called.
+	
 
-Example: call a callback every hour, or, more precisely, whenever the
+
Example: Call a callback every hour, or, more precisely, whenever the
 system clock is divisible by 3600. The callback invocation times have
 potentially a lot of jittering, but good long-term stability.
   static void
@@ -977,7 +1245,7 @@ potentially a lot of jittering, but good long-term stability.
   ev_periodic_start (loop, &hourly_tick);
 
 
-Example: the same as above, but use a reschedule callback to do it:
+Example: The same as above, but use a reschedule callback to do it:
   #include <math.h>
 
   static ev_tstamp
@@ -989,7 +1257,7 @@ potentially a lot of jittering, but good long-term stability.
   ev_periodic_init (&hourly_tick, clock_cb, 0., 0., my_scheduler_cb);
 
 
-Example: call a callback every hour, starting now:
+Example: Call a callback every hour, starting now:
   struct ev_periodic hourly_tick;
   ev_periodic_init (&hourly_tick, clock_cb,
                     fmod (ev_now (loop), 3600.), 3600., 0);
@@ -1001,7 +1269,7 @@ potentially a lot of jittering, but good long-term stability.
 
 
 
-ev_signal - signal me when a signal gets signalled
+ev_signal - signal me when a signal gets signalled!
 
 Signal watchers will trigger an event when the process receives a specific
 signal one or more times. Even though signals are very asynchronous, libev
@@ -1020,6 +1288,10 @@ SIG_DFL (regardless of what it was set to before).
 		Configures the watcher to trigger on the given signal number (usually one
 of the SIGxxx constants).
 	
+	int signum [read-only]
+	
+		The signal the watcher watches out for.
+	
 
 
 
@@ -1027,8 +1299,8 @@ of the SIGxxx constants).
 
 
 
-ev_child - wait for pid status changes
-
+ev_child - watch out for process status changes
+
 Child watchers trigger when your process receives a SIGCHLD in response to
 some child status changes (most typically when a child of yours dies).
 
@@ -1042,8 +1314,21 @@ the status word (use the macros from sys/wait.h and see your system
 waitpid documentation). The rpid member contains the pid of the
 process causing the status change.
 	
+	int pid [read-only]
+	
+		The process id this watcher watches out for, or 0, meaning any process id.
+	
+	int rpid [read-write]
+	
+		The process id that detected a status change.
+	
+	int rstatus [read-write]
+	
+		The process exit/trace status caused by rpid (see your systems
+waitpid and sys/wait.h documentation for details).
+	
 
-Example: try to exit cleanly on SIGINT and SIGTERM.
+Example: Try to exit cleanly on SIGINT and SIGTERM.
   static void
   sigint_cb (struct ev_loop *loop, struct ev_signal *w, int revents)
   {
@@ -1060,15 +1345,117 @@ process causing the status change.
 
 
 
-ev_idle - when you've got nothing better to do
+ev_stat - did the file attributes just change?
+
+This watches a filesystem path for attribute changes. That is, it calls
+stat regularly (or when the OS says it changed) and sees if it changed
+compared to the last time, invoking the callback if it did.
+The path does not need to exist: changing from "path exists" to "path does
+not exist" is a status change like any other. The condition "path does
+not exist" is signified by the st_nlink field being zero (which is
+otherwise always forced to be at least one) and all the other fields of
+the stat buffer having unspecified contents.
+The path should be absolute and must not end in a slash. If it is
+relative and your working directory changes, the behaviour is undefined.
+Since there is no standard to do this, the portable implementation simply
+calls stat (2) regularly on the path to see if it changed somehow. You
+can specify a recommended polling interval for this case. If you specify
+a polling interval of 0 (highly recommended!) then a suitable,
+unspecified default value will be used (which you can expect to be around
+five seconds, although this might change dynamically). Libev will also
+impose a minimum interval which is currently around 0.1, but thats
+usually overkill.
+This watcher type is not meant for massive numbers of stat watchers,
+as even with OS-supported change notifications, this can be
+resource-intensive.
+At the time of this writing, only the Linux inotify interface is
+implemented (implementing kqueue support is left as an exercise for the
+reader). Inotify will be used to give hints only and should not change the
+semantics of ev_stat watchers, which means that libev sometimes needs
+to fall back to regular polling again even with inotify, but changes are
+usually detected immediately, and if the file exists there will be no
+polling.
+
+	ev_stat_init (ev_stat *, callback, const char *path, ev_tstamp interval)
+	ev_stat_set (ev_stat *, const char *path, ev_tstamp interval)
+	
+		Configures the watcher to wait for status changes of the given
+path. The interval is a hint on how quickly a change is expected to
+be detected and should normally be specified as 0 to let libev choose
+a suitable value. The memory pointed to by path must point to the same
+path for as long as the watcher is active.
+		The callback will be receive EV_STAT when a change was detected,
+relative to the attributes at the time the watcher was started (or the
+last change was detected).
+	
+	ev_stat_stat (ev_stat *)
+	
+		Updates the stat buffer immediately with new values. If you change the
+watched path in your callback, you could call this fucntion to avoid
+detecting this change (while introducing a race condition). Can also be
+useful simply to find out the new values.
+	
+	ev_statdata attr [read-only]
+	
+		The most-recently detected attributes of the file. Although the type is of
+ev_statdata, this is usually the (or one of the) struct stat types
+suitable for your system. If the st_nlink member is 0, then there
+was some error while stating the file.
+	
+	ev_statdata prev [read-only]
+	
+		The previous attributes of the file. The callback gets invoked whenever
+prev != attr.
+	
+	ev_tstamp interval [read-only]
+	
+		The specified interval.
+	
+	const char *path [read-only]
+	
+		The filesystem path that is being watched.
+	
+
+Example: Watch /etc/passwd for attribute changes.
+  static void
+  passwd_cb (struct ev_loop *loop, ev_stat *w, int revents)
+  {
+    /* /etc/passwd changed in some way */
+    if (w->attr.st_nlink)
+      {
+        printf ("passwd current size  %ld\n", (long)w->attr.st_size);
+        printf ("passwd current atime %ld\n", (long)w->attr.st_mtime);
+        printf ("passwd current mtime %ld\n", (long)w->attr.st_mtime);
+      }
+    else
+      /* you shalt not abuse printf for puts */
+      puts ("wow, /etc/passwd is not there, expect problems. "
+            "if this is windows, they already arrived\n");
+  }
+
+  ...
+  ev_stat passwd;
+
+  ev_stat_init (&passwd, passwd_cb, "/etc/passwd");
+  ev_stat_start (loop, &passwd);
+
+
+
+
+
+
+
+ev_idle - when you've got nothing better to do...
 
-Idle watchers trigger events when there are no other events are pending
-(prepare, check and other idle watchers do not count). That is, as long
-as your process is busy handling sockets or timeouts (or even signals,
-imagine) it will not be triggered. But when your process is idle all idle
-watchers are being called again and again, once per event loop iteration -
-until stopped, that is, or your process receives more events and becomes
-busy.
+Idle watchers trigger events when no other events of the same or higher
+priority are pending (prepare, check and other idle watchers do not
+count).
+That is, as long as your process is busy handling sockets or timeouts
+(or even signals, imagine) of the same or higher priority it will not be
+triggered. But when your process is idle (or only lower-priority watchers
+are pending), the idle watchers are being called once per event loop
+iteration - until stopped, that is, or your process receives more events
+and becomes busy again with higher priority stuff.
 The most noteworthy effect is that as long as any idle watchers are
 active, the process will not block when waiting for new events.
 Apart from keeping your process non-blocking (which is a useful
@@ -1083,8 +1470,8 @@ kind. There is a ev_idle_set macro, but using it is utterly pointle
 believe me.
 	
 
-Example: dynamically allocate an ev_idle, start it, and in the
-callback, free it. Alos, use no error checking, as usual.
+Example: Dynamically allocate an ev_idle watcher, start it, and in the
+callback, free it. Also, use no error checking, as usual.
   static void
   idle_cb (struct ev_loop *loop, struct ev_idle *w, int revents)
   {
@@ -1103,15 +1490,25 @@ callback, free it. Alos, use no error checking, as usual.
 
 
 
-ev_prepare and ev_check - customise your event loop
+ev_prepare and ev_check - customise your event loop!
 
 Prepare and check watchers are usually (but not always) used in tandem:
 prepare watchers get invoked before the process blocks and check watchers
 afterwards.
+You must not call ev_loop or similar functions that enter
+the current event loop from either ev_prepare or ev_check
+watchers. Other loops than the current one are fine, however. The
+rationale behind this is that you do not need to check for recursion in
+those watchers, i.e. the sequence will always be ev_prepare, blocking,
+ev_check so if you have one watcher of each kind they will always be
+called in pairs bracketing the blocking call.
 Their main purpose is to integrate other event mechanisms into libev and
 their use is somewhat advanced. This could be used, for example, to track
 variable changes, implement your own watchers, integrate net-snmp or a
-coroutine library and lots more.
+coroutine library and lots more. They are also occasionally useful if
+you cache some data and want to flush it before blocking (for example,
+in X programs you might want to do an XFlush () in an ev_prepare
+watcher).
 This is done by examining in each prepare call which file descriptors need
 to be watched by the other library, registering ev_io watchers for
 them and starting an ev_timer watcher for any timeouts (many libraries
@@ -1128,6 +1525,15 @@ with priority higher than or equal to the event loop and one coroutine
 of lower priority, but only once, using idle watchers to keep the event
 loop from blocking if lower-priority coroutines are active, thus mapping
 low-priority coroutines to idle/background tasks).
+It is recommended to give ev_check watchers highest (EV_MAXPRI)
+priority, to ensure that they are being run before any other watchers
+after the poll. Also, ev_check watchers (and ev_prepare watchers,
+too) should not activate ("feed") events into libev. While libev fully
+supports this, they will be called before other ev_check watchers did
+their job. As ev_check watchers are often used to embed other event
+loops those other event loops might be in an unusable state until their
+ev_check watcher ran (always remind yourself to coexist peacefully with
+others).
 
 	ev_prepare_init (ev_prepare *, callback)
 	ev_check_init (ev_check *, callback)
@@ -1137,14 +1543,137 @@ parameters of any kind. There are ev_prepare_set and ev_check
 macros, but using them is utterly, utterly and completely pointless.
 	
 

-Example: *TODO*.
+There are a number of principal ways to embed other event loops or modules
+into libev. Here are some ideas on how to include libadns into libev
+(there is a Perl module named EV::ADNS that does this, which you could
+use for an actually working example. Another Perl module named EV::Glib
+embeds a Glib main context into libev, and finally, Glib::EV embeds EV
+into the Glib event loop).
+Method 1: Add IO watchers and a timeout watcher in a prepare handler,
+and in a check watcher, destroy them and call into libadns. What follows
+is pseudo-code only of course. This requires you to either use a low
+priority for the check watcher or use ev_clear_pending explicitly, as
+the callbacks for the IO/timeout watchers might not have been called yet.
+  static ev_io iow [nfd];
+  static ev_timer tw;
+
+  static void
+  io_cb (ev_loop *loop, ev_io *w, int revents)
+  {
+  }
+
+  // create io watchers for each fd and a timer before blocking
+  static void
+  adns_prepare_cb (ev_loop *loop, ev_prepare *w, int revents)
+  {
+    int timeout = 3600000;
+    struct pollfd fds [nfd];
+    // actual code will need to loop here and realloc etc.
+    adns_beforepoll (ads, fds, &nfd, &timeout, timeval_from (ev_time ()));
+
+    /* the callback is illegal, but won't be called as we stop during check */
+    ev_timer_init (&tw, 0, timeout * 1e-3);
+    ev_timer_start (loop, &tw);
+
+    // create one ev_io per pollfd
+    for (int i = 0; i < nfd; ++i)
+      {
+        ev_io_init (iow + i, io_cb, fds [i].fd,
+          ((fds [i].events & POLLIN ? EV_READ : 0)
+           | (fds [i].events & POLLOUT ? EV_WRITE : 0)));
+
+        fds [i].revents = 0;
+        ev_io_start (loop, iow + i);
+      }
+  }
+
+  // stop all watchers after blocking
+  static void
+  adns_check_cb (ev_loop *loop, ev_check *w, int revents)
+  {
+    ev_timer_stop (loop, &tw);
+
+    for (int i = 0; i < nfd; ++i)
+      {
+        // set the relevant poll flags
+        // could also call adns_processreadable etc. here
+        struct pollfd *fd = fds + i;
+        int revents = ev_clear_pending (iow + i);
+        if (revents & EV_READ ) fd->revents |= fd->events & POLLIN;
+        if (revents & EV_WRITE) fd->revents |= fd->events & POLLOUT;
+
+        // now stop the watcher
+        ev_io_stop (loop, iow + i);
+      }
+
+    adns_afterpoll (adns, fds, nfd, timeval_from (ev_now (loop));
+  }
+
+
+Method 2: This would be just like method 1, but you run adns_afterpoll
+in the prepare watcher and would dispose of the check watcher.
+Method 3: If the module to be embedded supports explicit event
+notification (adns does), you can also make use of the actual watcher
+callbacks, and only destroy/create the watchers in the prepare watcher.
+  static void
+  timer_cb (EV_P_ ev_timer *w, int revents)
+  {
+    adns_state ads = (adns_state)w->data;
+    update_now (EV_A);
+
+    adns_processtimeouts (ads, &tv_now);
+  }
+
+  static void
+  io_cb (EV_P_ ev_io *w, int revents)
+  {
+    adns_state ads = (adns_state)w->data;
+    update_now (EV_A);
+
+    if (revents & EV_READ ) adns_processreadable  (ads, w->fd, &tv_now);
+    if (revents & EV_WRITE) adns_processwriteable (ads, w->fd, &tv_now);
+  }
+
+  // do not ever call adns_afterpoll
+
+
+Method 4: Do not use a prepare or check watcher because the module you
+want to embed is too inflexible to support it. Instead, youc na override
+their poll function.  The drawback with this solution is that the main
+loop is now no longer controllable by EV. The Glib::EV module does
+this.
+  static gint
+  event_poll_func (GPollFD *fds, guint nfds, gint timeout)
+  {
+    int got_events = 0;
+
+    for (n = 0; n < nfds; ++n)
+      // create/start io watcher that sets the relevant bits in fds[n] and increment got_events
+
+    if (timeout >= 0)
+      // create/start timer
 
+    // poll
+    ev_loop (EV_A_ 0);
 
+    // stop timer again
+    if (timeout >= 0)
+      ev_timer_stop (EV_A_ &to);
 
+    // stop io watchers again - their callbacks should have set
+    for (n = 0; n < nfds; ++n)
+      ev_io_stop (EV_A_ iow [n]);
 
+    return got_events;
+  }
+
+
+
+
+
 
 

-ev_embed - when one backend isn't enough
+ev_embed - when one backend isn't enough...
 
 This is a rather advanced watcher type that lets you embed one event loop
 into another (currently only ev_io events are supported in the embedded
@@ -1222,6 +1751,33 @@ if you do not want thta, you need to temporarily stop the embed watcher).
 similarly to ev_loop (embedded_loop, EVLOOP_NONBLOCK), but in the most
 apropriate way for embedded loops.
 	
+	struct ev_loop *loop [read-only]
+	
+		The embedded event loop.
+	
+
+
+
+
+
+
+
+ev_fork - the audacity to resume the event loop after a fork
+
+Fork watchers are called when a fork () was detected (usually because
+whoever is a good citizen cared to tell libev about it by calling
+ev_default_fork or ev_loop_fork). The invocation is done before the
+event loop blocks next and before ev_check watchers are being called,
+and only in the child after the fork. If whoever good citizen calling
+ev_default_fork cheats and calls it in the wrong process, the fork
+handlers will be invoked, too, of course.
+
+	ev_fork_init (ev_signal *, callback)
+	
+		Initialises and configures the fork watcher - it has no parameters of any
+kind. There is a ev_fork_set macro, but using it is utterly pointless,
+believe me.
+	
 
 
 
@@ -1229,7 +1785,7 @@ apropriate way for embedded loops.
 
 
 
-OTHER FUNCTIONS
Top
+OTHER FUNCTIONS
 
 There are some other functions of possible interest. Described. Here. Now.
 
@@ -1286,7 +1842,7 @@ loop!).
 
 
 
-LIBEVENT EMULATION
Top
+LIBEVENT EMULATION
 
 Libev offers a compatibility emulation layer for libevent. It cannot
 emulate the internals of libevent, so here are some usage hints:
@@ -1306,14 +1862,620 @@ to use the libev header file and library.
 
 
 
-C++ SUPPORT
Top
+C++ SUPPORT
 
-TBD.
+Libev comes with some simplistic wrapper classes for C++ that mainly allow
+you to use some convinience methods to start/stop watchers and also change
+the callback model to a model using method callbacks on objects.
+To use it,
+  #include <ev++.h>
+
+
+This automatically includes ev.h and puts all of its definitions (many
+of them macros) into the global namespace. All C++ specific things are
+put into the ev namespace. It should support all the same embedding
+options as ev.h, most notably EV_MULTIPLICITY.
+Care has been taken to keep the overhead low. The only data member the C++
+classes add (compared to plain C-style watchers) is the event loop pointer
+that the watcher is associated with (or no additional members at all if
+you disable EV_MULTIPLICITY when embedding libev).
+Currently, functions, and static and non-static member functions can be
+used as callbacks. Other types should be easy to add as long as they only
+need one additional pointer for context. If you need support for other
+types of functors please contact the author (preferably after implementing
+it).
+Here is a list of things available in the ev namespace:
+
+	ev::READ, ev::WRITE etc.
+	
+		These are just enum values with the same values as the EV_READ etc.
+macros from ev.h.
+	
+	ev::tstamp, ev::now
+	
+		Aliases to the same types/functions as with the ev_ prefix.
+	
+	ev::io, ev::timer, ev::periodic, ev::idle, ev::sig etc.
+	
+		For each ev_TYPE watcher in ev.h there is a corresponding class of
+the same name in the ev namespace, with the exception of ev_signal
+which is called ev::sig to avoid clashes with the signal macro
+defines by many implementations.
+		All of those classes have these methods:
+		
+			

+				ev::TYPE::TYPE ()
+				ev::TYPE::TYPE (struct ev_loop *)
+				ev::TYPE::~TYPE
+				
+					The constructor (optionally) takes an event loop to associate the watcher
+with. If it is omitted, it will use EV_DEFAULT.
+					The constructor calls ev_init for you, which means you have to call the
+set method before starting it.
+					It will not set a callback, however: You have to call the templated set
+method to set a callback before you can start the watcher.
+					(The reason why you have to use a method is a limitation in C++ which does
+not allow explicit template arguments for constructors).
+					The destructor automatically stops the watcher if it is active.
+				
+				w->set<class, &class::method> (object *)
+				
+					This method sets the callback method to call. The method has to have a
+signature of void (*)(ev_TYPE &, int), it receives the watcher as
+first argument and the revents as second. The object must be given as
+parameter and is stored in the data member of the watcher.
+					This method synthesizes efficient thunking code to call your method from
+the C callback that libev requires. If your compiler can inline your
+callback (i.e. it is visible to it at the place of the set call and
+your compiler is good :), then the method will be fully inlined into the
+thunking function, making it as fast as a direct C callback.
+					Example: simple class declaration and watcher initialisation
+  struct myclass
+  {
+    void io_cb (ev::io &w, int revents) { }
+  }
+
+  myclass obj;
+  ev::io iow;
+  iow.set <myclass, &myclass::io_cb> (&obj);
+
+
+				
+				w->set<function> (void *data = 0)
+				
+					Also sets a callback, but uses a static method or plain function as
+callback. The optional data argument will be stored in the watcher's
+data member and is free for you to use.
+					The prototype of the function must be void (*)(ev::TYPE &w, int).
+					See the method-set above for more details.
+					Example:
+  static void io_cb (ev::io &w, int revents) { }
+  iow.set <io_cb> ();
+
+
+				
+				w->set (struct ev_loop *)
+				
+					Associates a different struct ev_loop with this watcher. You can only
+do this when the watcher is inactive (and not pending either).
+				
+				w->set ([args])
+				
+					Basically the same as ev_TYPE_set, with the same args. Must be
+called at least once. Unlike the C counterpart, an active watcher gets
+automatically stopped and restarted when reconfiguring it with this
+method.
+				
+				w->start ()
+				
+					Starts the watcher. Note that there is no loop argument, as the
+constructor already stores the event loop.
+				
+				w->stop ()
+				
+					Stops the watcher if it is active. Again, no loop argument.
+				
+				w->again ()       ev::timer, ev::periodic only
+				
+					For ev::timer and ev::periodic, this invokes the corresponding
+ev_TYPE_again function.
+				
+				w->sweep ()       ev::embed only
+				
+					Invokes ev_embed_sweep.
+				
+				w->update ()      ev::stat only
+				
+					Invokes ev_stat_stat.
+				
+			
+		
+	
+
+Example: Define a class with an IO and idle watcher, start one of them in
+the constructor.
+  class myclass
+  {
+    ev_io   io;   void io_cb   (ev::io   &w, int revents);
+    ev_idle idle  void idle_cb (ev::idle &w, int revents);
+
+    myclass ();
+  }
+
+  myclass::myclass (int fd)
+  {
+    io  .set <myclass, &myclass::io_cb  > (this);
+    idle.set <myclass, &myclass::idle_cb> (this);
+
+    io.start (fd, ev::READ);
+  }
+
+
+
+
+
+
+
+MACRO MAGIC
+
+Libev can be compiled with a variety of options, the most fundemantal is
+EV_MULTIPLICITY. This option determines whether (most) functions and
+callbacks have an initial struct ev_loop * argument.
+To make it easier to write programs that cope with either variant, the
+following macros are defined:
+
+	EV_A, EV_A_
+	
+		This provides the loop argument for functions, if one is required ("ev
+loop argument"). The EV_A form is used when this is the sole argument,
+EV_A_ is used when other arguments are following. Example:
+  ev_unref (EV_A);
+  ev_timer_add (EV_A_ watcher);
+  ev_loop (EV_A_ 0);
+
+
+		It assumes the variable loop of type struct ev_loop * is in scope,
+which is often provided by the following macro.
+	
+	EV_P, EV_P_
+	
+		This provides the loop parameter for functions, if one is required ("ev
+loop parameter"). The EV_P form is used when this is the sole parameter,
+EV_P_ is used when other parameters are following. Example:
+  // this is how ev_unref is being declared
+  static void ev_unref (EV_P);
+
+  // this is how you can declare your typical callback
+  static void cb (EV_P_ ev_timer *w, int revents)
+
+
+		It declares a parameter loop of type struct ev_loop *, quite
+suitable for use with EV_A.
+	
+	EV_DEFAULT, EV_DEFAULT_
+	
+		Similar to the other two macros, this gives you the value of the default
+loop, if multiple loops are supported ("ev loop default").
+	
+
+Example: Declare and initialise a check watcher, utilising the above
+macros so it will work regardless of whether multiple loops are supported
+or not.
+  static void
+  check_cb (EV_P_ ev_timer *w, int revents)
+  {
+    ev_check_stop (EV_A_ w);
+  }
+
+  ev_check check;
+  ev_check_init (&check, check_cb);
+  ev_check_start (EV_DEFAULT_ &check);
+  ev_loop (EV_DEFAULT_ 0);
+
+
+
+
+EMBEDDING
+
+Libev can (and often is) directly embedded into host
+applications. Examples of applications that embed it include the Deliantra
+Game Server, the EV perl module, the GNU Virtual Private Ethernet (gvpe)
+and rxvt-unicode.
+The goal is to enable you to just copy the neecssary files into your
+source directory without having to change even a single line in them, so
+you can easily upgrade by simply copying (or having a checked-out copy of
+libev somewhere in your source tree).
+
+
+FILESETS
+
+Depending on what features you need you need to include one or more sets of files
+in your app.
+
+
+CORE EVENT LOOP
+
+To include only the libev core (all the ev_* functions), with manual
+configuration (no autoconf):
+  #define EV_STANDALONE 1
+  #include "ev.c"
+
+
+This will automatically include ev.h, too, and should be done in a
+single C source file only to provide the function implementations. To use
+it, do the same for ev.h in all files wishing to use this API (best
+done by writing a wrapper around ev.h that you can include instead and
+where you can put other configuration options):
+  #define EV_STANDALONE 1
+  #include "ev.h"
+
+
+Both header files and implementation files can be compiled with a C++
+compiler (at least, thats a stated goal, and breakage will be treated
+as a bug).
+You need the following files in your source tree, or in a directory
+in your include path (e.g. in libev/ when using -Ilibev):
+  ev.h
+  ev.c
+  ev_vars.h
+  ev_wrap.h
+
+  ev_win32.c      required on win32 platforms only
+
+  ev_select.c     only when select backend is enabled (which is enabled by default)
+  ev_poll.c       only when poll backend is enabled (disabled by default)
+  ev_epoll.c      only when the epoll backend is enabled (disabled by default)
+  ev_kqueue.c     only when the kqueue backend is enabled (disabled by default)
+  ev_port.c       only when the solaris port backend is enabled (disabled by default)
+
+
+ev.c includes the backend files directly when enabled, so you only need
+to compile this single file.
+
+
+LIBEVENT COMPATIBILITY API
+
+To include the libevent compatibility API, also include:
+  #include "event.c"
+
+
+in the file including ev.c, and:
+  #include "event.h"
+
+
+in the files that want to use the libevent API. This also includes ev.h.
+You need the following additional files for this:
+  event.h
+  event.c
+
+
+
+
+AUTOCONF SUPPORT
+
+Instead of using EV_STANDALONE=1 and providing your config in
+whatever way you want, you can also m4_include([libev.m4]) in your
+configure.ac and leave EV_STANDALONE undefined. ev.c will then
+include config.h and configure itself accordingly.
+For this of course you need the m4 file:
+  libev.m4
+
+
+
+
+PREPROCESSOR SYMBOLS/MACROS
+
+Libev can be configured via a variety of preprocessor symbols you have to define
+before including any of its files. The default is not to build for multiplicity
+and only include the select backend.
+
+	EV_STANDALONE
+	
+		Must always be 1 if you do not use autoconf configuration, which
+keeps libev from including config.h, and it also defines dummy
+implementations for some libevent functions (such as logging, which is not
+supported). It will also not define any of the structs usually found in
+event.h that are not directly supported by the libev core alone.
+	
+	EV_USE_MONOTONIC
+	
+		If defined to be 1, libev will try to detect the availability of the
+monotonic clock option at both compiletime and runtime. Otherwise no use
+of the monotonic clock option will be attempted. If you enable this, you
+usually have to link against librt or something similar. Enabling it when
+the functionality isn't available is safe, though, althoguh you have
+to make sure you link against any libraries where the clock_gettime
+function is hiding in (often -lrt).
+	
+	EV_USE_REALTIME
+	
+		If defined to be 1, libev will try to detect the availability of the
+realtime clock option at compiletime (and assume its availability at
+runtime if successful). Otherwise no use of the realtime clock option will
+be attempted. This effectively replaces gettimeofday by clock_get
+(CLOCK_REALTIME, ...) and will not normally affect correctness. See tzhe note about libraries
+in the description of EV_USE_MONOTONIC, though.
+	
+	EV_USE_SELECT
+	
+		If undefined or defined to be 1, libev will compile in support for the
+select(2) backend. No attempt at autodetection will be done: if no
+other method takes over, select will be it. Otherwise the select backend
+will not be compiled in.
+	
+	EV_SELECT_USE_FD_SET
+	
+		If defined to 1, then the select backend will use the system fd_set
+structure. This is useful if libev doesn't compile due to a missing
+NFDBITS or fd_mask definition or it misguesses the bitset layout on
+exotic systems. This usually limits the range of file descriptors to some
+low limit such as 1024 or might have other limitations (winsocket only
+allows 64 sockets). The FD_SETSIZE macro, set before compilation, might
+influence the size of the fd_set used.
+	
+	EV_SELECT_IS_WINSOCKET
+	
+		When defined to 1, the select backend will assume that
+select/socket/connect etc. don't understand file descriptors but
+wants osf handles on win32 (this is the case when the select to
+be used is the winsock select). This means that it will call
+_get_osfhandle on the fd to convert it to an OS handle. Otherwise,
+it is assumed that all these functions actually work on fds, even
+on win32. Should not be defined on non-win32 platforms.
+	
+	EV_USE_POLL
+	
+		If defined to be 1, libev will compile in support for the poll(2)
+backend. Otherwise it will be enabled on non-win32 platforms. It
+takes precedence over select.
+	
+	EV_USE_EPOLL
+	
+		If defined to be 1, libev will compile in support for the Linux
+epoll(7) backend. Its availability will be detected at runtime,
+otherwise another method will be used as fallback. This is the
+preferred backend for GNU/Linux systems.
+	
+	EV_USE_KQUEUE
+	
+		If defined to be 1, libev will compile in support for the BSD style
+kqueue(2) backend. Its actual availability will be detected at runtime,
+otherwise another method will be used as fallback. This is the preferred
+backend for BSD and BSD-like systems, although on most BSDs kqueue only
+supports some types of fds correctly (the only platform we found that
+supports ptys for example was NetBSD), so kqueue might be compiled in, but
+not be used unless explicitly requested. The best way to use it is to find
+out whether kqueue supports your type of fd properly and use an embedded
+kqueue loop.
+	
+	EV_USE_PORT
+	
+		If defined to be 1, libev will compile in support for the Solaris
+10 port style backend. Its availability will be detected at runtime,
+otherwise another method will be used as fallback. This is the preferred
+backend for Solaris 10 systems.
+	
+	EV_USE_DEVPOLL
+	
+		reserved for future expansion, works like the USE symbols above.
+	
+	EV_USE_INOTIFY
+	
+		If defined to be 1, libev will compile in support for the Linux inotify
+interface to speed up ev_stat watchers. Its actual availability will
+be detected at runtime.
+	
+	EV_H
+	
+		The name of the ev.h header file used to include it. The default if
+undefined is <ev.h> in event.h and "ev.h" in ev.c. This
+can be used to virtually rename the ev.h header file in case of conflicts.
+	
+	EV_CONFIG_H
+	
+		If EV_STANDALONE isn't 1, this variable can be used to override
+ev.c's idea of where to find the config.h file, similarly to
+EV_H, above.
+	
+	EV_EVENT_H
+	
+		Similarly to EV_H, this macro can be used to override event.c's idea
+of how the event.h header can be found.
+	
+	EV_PROTOTYPES
+	
+		If defined to be 0, then ev.h will not define any function
+prototypes, but still define all the structs and other symbols. This is
+occasionally useful if you want to provide your own wrapper functions
+around libev functions.
+	
+	EV_MULTIPLICITY
+	
+		If undefined or defined to 1, then all event-loop-specific functions
+will have the struct ev_loop * as first argument, and you can create
+additional independent event loops. Otherwise there will be no support
+for multiple event loops and there is no first event loop pointer
+argument. Instead, all functions act on the single default loop.
+	
+	EV_MINPRI
+	EV_MAXPRI
+	
+		The range of allowed priorities. EV_MINPRI must be smaller or equal to
+EV_MAXPRI, but otherwise there are no non-obvious limitations. You can
+provide for more priorities by overriding those symbols (usually defined
+to be -2 and 2, respectively).
+		When doing priority-based operations, libev usually has to linearly search
+all the priorities, so having many of them (hundreds) uses a lot of space
+and time, so using the defaults of five priorities (-2 .. +2) is usually
+fine.
+		If your embedding app does not need any priorities, defining these both to
+0 will save some memory and cpu.
+	
+	EV_PERIODIC_ENABLE
+	
+		If undefined or defined to be 1, then periodic timers are supported. If
+defined to be 0, then they are not. Disabling them saves a few kB of
+code.
+	
+	EV_IDLE_ENABLE
+	
+		If undefined or defined to be 1, then idle watchers are supported. If
+defined to be 0, then they are not. Disabling them saves a few kB of
+code.
+	
+	EV_EMBED_ENABLE
+	
+		If undefined or defined to be 1, then embed watchers are supported. If
+defined to be 0, then they are not.
+	
+	EV_STAT_ENABLE
+	
+		If undefined or defined to be 1, then stat watchers are supported. If
+defined to be 0, then they are not.
+	
+	EV_FORK_ENABLE
+	
+		If undefined or defined to be 1, then fork watchers are supported. If
+defined to be 0, then they are not.
+	
+	EV_MINIMAL
+	
+		If you need to shave off some kilobytes of code at the expense of some
+speed, define this symbol to 1. Currently only used for gcc to override
+some inlining decisions, saves roughly 30% codesize of amd64.
+	
+	EV_PID_HASHSIZE
+	
+		ev_child watchers use a small hash table to distribute workload by
+pid. The default size is 16 (or 1 with EV_MINIMAL), usually more
+than enough. If you need to manage thousands of children you might want to
+increase this value (must be a power of two).
+	
+	EV_INOTIFY_HASHSIZE
+	
+		ev_staz watchers use a small hash table to distribute workload by
+inotify watch id. The default size is 16 (or 1 with EV_MINIMAL),
+usually more than enough. If you need to manage thousands of ev_stat
+watchers you might want to increase this value (must be a power of
+two).
+	
+	EV_COMMON
+	
+		By default, all watchers have a void *data member. By redefining
+this macro to a something else you can include more and other types of
+members. You have to define it each time you include one of the files,
+though, and it must be identical each time.
+		For example, the perl EV module uses something like this:
+  #define EV_COMMON                       \
+    SV *self; /* contains this struct */  \
+    SV *cb_sv, *fh /* note no trailing ";" */
+
+
+	
+	EV_CB_DECLARE (type)
+	EV_CB_INVOKE (watcher, revents)
+	ev_set_cb (ev, cb)
+	
+		Can be used to change the callback member declaration in each watcher,
+and the way callbacks are invoked and set. Must expand to a struct member
+definition and a statement, respectively. See the ev.v header file for
+their default definitions. One possible use for overriding these is to
+avoid the struct ev_loop * as first argument in all cases, or to use
+method calls instead of plain function calls in C++.
+
+
+EXAMPLES
+
+		For a real-world example of a program the includes libev
+verbatim, you can have a look at the EV perl module
+(http://software.schmorp.de/pkg/EV.html). It has the libev files in
+the libev/ subdirectory and includes them in the EV/EVAPI.h (public
+interface) and EV.xs (implementation) files. Only the EV.xs file
+will be compiled. It is pretty complex because it provides its own header
+file.
+		The usage in rxvt-unicode is simpler. It has a ev_cpp.h header file
+that everybody includes and which overrides some configure choices:
+  #define EV_MINIMAL 1
+  #define EV_USE_POLL 0
+  #define EV_MULTIPLICITY 0
+  #define EV_PERIODIC_ENABLE 0
+  #define EV_STAT_ENABLE 0
+  #define EV_FORK_ENABLE 0
+  #define EV_CONFIG_H <config.h>
+  #define EV_MINPRI 0
+  #define EV_MAXPRI 0
+
+  #include "ev++.h"
+
+
+		And a ev_cpp.C implementation file that contains libev proper and is compiled:
+  #include "ev_cpp.h"
+  #include "ev.c"
+
+
+
+
+
+
+
+COMPLEXITIES
+
+		In this section the complexities of (many of) the algorithms used inside
+libev will be explained. For complexity discussions about backends see the
+documentation for ev_default_init.
+		All of the following are about amortised time: If an array needs to be
+extended, libev needs to realloc and move the whole array, but this
+happens asymptotically never with higher number of elements, so O(1) might
+mean it might do a lengthy realloc operation in rare cases, but on average
+it is much faster and asymptotically approaches constant time.
+		
+			

+				Starting and stopping timer/periodic watchers: O(log skipped_other_timers)
+				
+					This means that, when you have a watcher that triggers in one hour and
+there are 100 watchers that would trigger before that then inserting will
+have to skip those 100 watchers.
+				
+				Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)
+				
+					That means that for changing a timer costs less than removing/adding them
+as only the relative motion in the event queue has to be paid for.
+				
+				Starting io/check/prepare/idle/signal/child watchers: O(1)
+				
+					These just add the watcher into an array or at the head of a list.
+=item Stopping check/prepare/idle watchers: O(1)
+				
+				Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % EV_PID_HASHSIZE))
+				
+					These watchers are stored in lists then need to be walked to find the
+correct watcher to remove. The lists are usually short (you don't usually
+have many watchers waiting for the same fd or signal).
+				
+				Finding the next timer per loop iteration: O(1)
+				Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)
+				
+					A change means an I/O watcher gets started or stopped, which requires
+libev to recalculate its status (and possibly tell the kernel).
+				
+				Activating one watcher: O(1)
+				Priority handling: O(number_of_priorities)
+				
+					Priorities are implemented by allocating some space for each
+priority. When doing priority-based operations, libev usually has to
+linearly search all the priorities.
+				
+			
+		
+
+
+
+
 
 
-AUTHOR
Top
+AUTHOR
 
-Marc Lehmann <libev@schmorp.de>.
+		Marc Lehmann <libev@schmorp.de>.

NAME

NAME

SYNOPSIS

SYNOPSIS

DESCRIPTION

EXAMPLE PROGRAM

DESCRIPTION

FEATURES

FEATURES

CONVENTIONS

CONVENTIONS

TIME REPRESENTATION

TIME REPRESENTATION

GLOBAL FUNCTIONS

GLOBAL FUNCTIONS

FUNCTIONS CONTROLLING THE EVENT LOOP

FUNCTIONS CONTROLLING THE EVENT LOOP

ANATOMY OF A WATCHER

ANATOMY OF A WATCHER

SUMMARY OF GENERIC WATCHER FUNCTIONS

GENERIC WATCHER FUNCTIONS

WATCHER TYPES

WATCHER TYPES

ev_io - is this file descriptor readable or writable

ev_io - is this file descriptor readable or writable?

The special problem of disappearing file descriptors

ev_timer - relative and optionally recurring timeouts

ev_timer - relative and optionally repeating timeouts

ev_periodic - to cron or not to cron

ev_periodic - to cron or not to cron?

ev_signal - signal me when a signal gets signalled

ev_signal - signal me when a signal gets signalled!

ev_child - wait for pid status changes

ev_child - watch out for process status changes

ev_idle - when you've got nothing better to do

ev_stat - did the file attributes just change?

ev_idle - when you've got nothing better to do...

ev_prepare and ev_check - customise your event loop

ev_prepare and ev_check - customise your event loop!

ev_embed - when one backend isn't enough

ev_embed - when one backend isn't enough...

ev_fork - the audacity to resume the event loop after a fork

OTHER FUNCTIONS

OTHER FUNCTIONS

LIBEVENT EMULATION

LIBEVENT EMULATION

C++ SUPPORT

C++ SUPPORT

MACRO MAGIC

EMBEDDING

FILESETS

CORE EVENT LOOP

LIBEVENT COMPATIBILITY API

AUTOCONF SUPPORT

PREPROCESSOR SYMBOLS/MACROS

EXAMPLES

COMPLEXITIES

AUTHOR

AUTHOR

`ev_io` - is this file descriptor readable or writable

`ev_io` - is this file descriptor readable or writable?

`ev_timer` - relative and optionally recurring timeouts

`ev_timer` - relative and optionally repeating timeouts

`ev_periodic` - to cron or not to cron

`ev_periodic` - to cron or not to cron?

`ev_signal` - signal me when a signal gets signalled

`ev_signal` - signal me when a signal gets signalled!

`ev_child` - wait for pid status changes

`ev_child` - watch out for process status changes

`ev_idle` - when you've got nothing better to do

`ev_stat` - did the file attributes just change?

`ev_idle` - when you've got nothing better to do...

`ev_prepare` and `ev_check` - customise your event loop

`ev_prepare` and `ev_check` - customise your event loop!

`ev_embed` - when one backend isn't enough

`ev_embed` - when one backend isn't enough...

`ev_fork` - the audacity to resume the event loop after a fork