ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/libev/ev.pod
(Generate patch)

Comparing libev/ev.pod (file contents):
Revision 1.312 by root, Thu Oct 21 15:14:49 2010 UTC vs.
Revision 1.323 by root, Sun Oct 24 18:01:26 2010 UTC

43 43
44 int 44 int
45 main (void) 45 main (void)
46 { 46 {
47 // use the default event loop unless you have special needs 47 // use the default event loop unless you have special needs
48 struct ev_loop *loop = ev_default_loop (0); 48 struct ev_loop *loop = EV_DEFAULT;
49 49
50 // initialise an io watcher, then start it 50 // initialise an io watcher, then start it
51 // this one will watch for stdin to become readable 51 // this one will watch for stdin to become readable
52 ev_io_init (&stdin_watcher, stdin_cb, /*STDIN_FILENO*/ 0, EV_READ); 52 ev_io_init (&stdin_watcher, stdin_cb, /*STDIN_FILENO*/ 0, EV_READ);
53 ev_io_start (loop, &stdin_watcher); 53 ev_io_start (loop, &stdin_watcher);
124this argument. 124this argument.
125 125
126=head2 TIME REPRESENTATION 126=head2 TIME REPRESENTATION
127 127
128Libev represents time as a single floating point number, representing 128Libev represents time as a single floating point number, representing
129the (fractional) number of seconds since the (POSIX) epoch (in practise 129the (fractional) number of seconds since the (POSIX) epoch (in practice
130somewhere near the beginning of 1970, details are complicated, don't 130somewhere near the beginning of 1970, details are complicated, don't
131ask). This type is called C<ev_tstamp>, which is what you should use 131ask). This type is called C<ev_tstamp>, which is what you should use
132too. It usually aliases to the C<double> type in C. When you need to do 132too. It usually aliases to the C<double> type in C. When you need to do
133any calculations on it, you should treat it as some floating point value. 133any calculations on it, you should treat it as some floating point value.
134 134
165 165
166=item ev_tstamp ev_time () 166=item ev_tstamp ev_time ()
167 167
168Returns the current time as libev would use it. Please note that the 168Returns the current time as libev would use it. Please note that the
169C<ev_now> function is usually faster and also often returns the timestamp 169C<ev_now> function is usually faster and also often returns the timestamp
170you actually want to know. 170you actually want to know. Also interesting is the combination of
171C<ev_update_now> and C<ev_now>.
171 172
172=item ev_sleep (ev_tstamp interval) 173=item ev_sleep (ev_tstamp interval)
173 174
174Sleep for the given interval: The current thread will be blocked until 175Sleep for the given interval: The current thread will be blocked until
175either it is interrupted or the given time interval has passed. Basically 176either it is interrupted or the given time interval has passed. Basically
192as this indicates an incompatible change. Minor versions are usually 193as this indicates an incompatible change. Minor versions are usually
193compatible to older versions, so a larger minor version alone is usually 194compatible to older versions, so a larger minor version alone is usually
194not a problem. 195not a problem.
195 196
196Example: Make sure we haven't accidentally been linked against the wrong 197Example: Make sure we haven't accidentally been linked against the wrong
197version (note, however, that this will not detect ABI mismatches :). 198version (note, however, that this will not detect other ABI mismatches,
199such as LFS or reentrancy).
198 200
199 assert (("libev version mismatch", 201 assert (("libev version mismatch",
200 ev_version_major () == EV_VERSION_MAJOR 202 ev_version_major () == EV_VERSION_MAJOR
201 && ev_version_minor () >= EV_VERSION_MINOR)); 203 && ev_version_minor () >= EV_VERSION_MINOR));
202 204
213 assert (("sorry, no epoll, no sex", 215 assert (("sorry, no epoll, no sex",
214 ev_supported_backends () & EVBACKEND_EPOLL)); 216 ev_supported_backends () & EVBACKEND_EPOLL));
215 217
216=item unsigned int ev_recommended_backends () 218=item unsigned int ev_recommended_backends ()
217 219
218Return the set of all backends compiled into this binary of libev and also 220Return the set of all backends compiled into this binary of libev and
219recommended for this platform. This set is often smaller than the one 221also recommended for this platform, meaning it will work for most file
222descriptor types. This set is often smaller than the one returned by
220returned by C<ev_supported_backends>, as for example kqueue is broken on 223C<ev_supported_backends>, as for example kqueue is broken on most BSDs
221most BSDs and will not be auto-detected unless you explicitly request it 224and will not be auto-detected unless you explicitly request it (assuming
222(assuming you know what you are doing). This is the set of backends that 225you know what you are doing). This is the set of backends that libev will
223libev will probe for if you specify no backends explicitly. 226probe for if you specify no backends explicitly.
224 227
225=item unsigned int ev_embeddable_backends () 228=item unsigned int ev_embeddable_backends ()
226 229
227Returns the set of backends that are embeddable in other event loops. This 230Returns the set of backends that are embeddable in other event loops. This
228is the theoretical, all-platform, value. To find which backends 231value is platform-specific but can include backends not available on the
229might be supported on the current system, you would need to look at 232current system. To find which embeddable backends might be supported on
230C<ev_embeddable_backends () & ev_supported_backends ()>, likewise for 233the current system, you would need to look at C<ev_embeddable_backends ()
231recommended ones. 234& ev_supported_backends ()>, likewise for recommended ones.
232 235
233See the description of C<ev_embed> watchers for more info. 236See the description of C<ev_embed> watchers for more info.
234 237
235=item ev_set_allocator (void *(*cb)(void *ptr, long size)) [NOT REENTRANT] 238=item ev_set_allocator (void *(*cb)(void *ptr, long size)) [NOT REENTRANT]
236 239
290 ... 293 ...
291 ev_set_syserr_cb (fatal_error); 294 ev_set_syserr_cb (fatal_error);
292 295
293=back 296=back
294 297
295=head1 FUNCTIONS CONTROLLING THE EVENT LOOP 298=head1 FUNCTIONS CONTROLLING EVENT LOOPS
296 299
297An event loop is described by a C<struct ev_loop *> (the C<struct> is 300An event loop is described by a C<struct ev_loop *> (the C<struct> is
298I<not> optional in this case unless libev 3 compatibility is disabled, as 301I<not> optional in this case unless libev 3 compatibility is disabled, as
299libev 3 had an C<ev_loop> function colliding with the struct name). 302libev 3 had an C<ev_loop> function colliding with the struct name).
300 303
304 307
305=over 4 308=over 4
306 309
307=item struct ev_loop *ev_default_loop (unsigned int flags) 310=item struct ev_loop *ev_default_loop (unsigned int flags)
308 311
309This will initialise the default event loop if it hasn't been initialised 312This returns the "default" event loop object, which is what you should
310yet and return it. If the default loop could not be initialised, returns 313normally use when you just need "the event loop". Event loop objects and
311false. If it already was initialised it simply returns it (and ignores the 314the C<flags> parameter are described in more detail in the entry for
312flags. If that is troubling you, check C<ev_backend ()> afterwards). 315C<ev_loop_new>.
316
317If the default loop is already initialised then this function simply
318returns it (and ignores the flags. If that is troubling you, check
319C<ev_backend ()> afterwards). Otherwise it will create it with the given
320flags, which should almost always be C<0>, unless the caller is also the
321one calling C<ev_run> or otherwise qualifies as "the main program".
313 322
314If you don't know what event loop to use, use the one returned from this 323If you don't know what event loop to use, use the one returned from this
315function. 324function (or via the C<EV_DEFAULT> macro).
316 325
317Note that this function is I<not> thread-safe, so if you want to use it 326Note that this function is I<not> thread-safe, so if you want to use it
318from multiple threads, you have to lock (note also that this is unlikely, 327from multiple threads, you have to employ some kind of mutex (note also
319as loops cannot be shared easily between threads anyway). 328that this case is unlikely, as loops cannot be shared easily between
329threads anyway).
320 330
321The default loop is the only loop that can handle C<ev_signal> and 331The default loop is the only loop that can handle C<ev_child> watchers,
322C<ev_child> watchers, and to do this, it always registers a handler 332and to do this, it always registers a handler for C<SIGCHLD>. If this is
323for C<SIGCHLD>. If this is a problem for your application you can either 333a problem for your application you can either create a dynamic loop with
324create a dynamic loop with C<ev_loop_new> that doesn't do that, or you 334C<ev_loop_new> which doesn't do that, or you can simply overwrite the
325can simply overwrite the C<SIGCHLD> signal handler I<after> calling 335C<SIGCHLD> signal handler I<after> calling C<ev_default_init>.
326C<ev_default_init>. 336
337Example: This is the most typical usage.
338
339 if (!ev_default_loop (0))
340 fatal ("could not initialise libev, bad $LIBEV_FLAGS in environment?");
341
342Example: Restrict libev to the select and poll backends, and do not allow
343environment settings to be taken into account:
344
345 ev_default_loop (EVBACKEND_POLL | EVBACKEND_SELECT | EVFLAG_NOENV);
346
347=item struct ev_loop *ev_loop_new (unsigned int flags)
348
349This will create and initialise a new event loop object. If the loop
350could not be initialised, returns false.
351
352Note that this function I<is> thread-safe, and one common way to use
353libev with threads is indeed to create one loop per thread, and using the
354default loop in the "main" or "initial" thread.
327 355
328The flags argument can be used to specify special behaviour or specific 356The flags argument can be used to specify special behaviour or specific
329backends to use, and is usually specified as C<0> (or C<EVFLAG_AUTO>). 357backends to use, and is usually specified as C<0> (or C<EVFLAG_AUTO>).
330 358
331The following flags are supported: 359The following flags are supported:
549If one or more of the backend flags are or'ed into the flags value, 577If one or more of the backend flags are or'ed into the flags value,
550then only these backends will be tried (in the reverse order as listed 578then only these backends will be tried (in the reverse order as listed
551here). If none are specified, all backends in C<ev_recommended_backends 579here). If none are specified, all backends in C<ev_recommended_backends
552()> will be tried. 580()> will be tried.
553 581
554Example: This is the most typical usage.
555
556 if (!ev_default_loop (0))
557 fatal ("could not initialise libev, bad $LIBEV_FLAGS in environment?");
558
559Example: Restrict libev to the select and poll backends, and do not allow
560environment settings to be taken into account:
561
562 ev_default_loop (EVBACKEND_POLL | EVBACKEND_SELECT | EVFLAG_NOENV);
563
564Example: Use whatever libev has to offer, but make sure that kqueue is
565used if available (warning, breaks stuff, best use only with your own
566private event loop and only if you know the OS supports your types of
567fds):
568
569 ev_default_loop (ev_recommended_backends () | EVBACKEND_KQUEUE);
570
571=item struct ev_loop *ev_loop_new (unsigned int flags)
572
573Similar to C<ev_default_loop>, but always creates a new event loop that is
574always distinct from the default loop.
575
576Note that this function I<is> thread-safe, and one common way to use
577libev with threads is indeed to create one loop per thread, and using the
578default loop in the "main" or "initial" thread.
579
580Example: Try to create a event loop that uses epoll and nothing else. 582Example: Try to create a event loop that uses epoll and nothing else.
581 583
582 struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV); 584 struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV);
583 if (!epoller) 585 if (!epoller)
584 fatal ("no epoll found here, maybe it hides under your chair"); 586 fatal ("no epoll found here, maybe it hides under your chair");
585 587
588Example: Use whatever libev has to offer, but make sure that kqueue is
589used if available.
590
591 struct ev_loop *loop = ev_loop_new (ev_recommended_backends () | EVBACKEND_KQUEUE);
592
586=item ev_default_destroy () 593=item ev_loop_destroy (loop)
587 594
588Destroys the default loop (frees all memory and kernel state etc.). None 595Destroys an event loop object (frees all memory and kernel state
589of the active event watchers will be stopped in the normal sense, so 596etc.). None of the active event watchers will be stopped in the normal
590e.g. C<ev_is_active> might still return true. It is your responsibility to 597sense, so e.g. C<ev_is_active> might still return true. It is your
591either stop all watchers cleanly yourself I<before> calling this function, 598responsibility to either stop all watchers cleanly yourself I<before>
592or cope with the fact afterwards (which is usually the easiest thing, you 599calling this function, or cope with the fact afterwards (which is usually
593can just ignore the watchers and/or C<free ()> them for example). 600the easiest thing, you can just ignore the watchers and/or C<free ()> them
601for example).
594 602
595Note that certain global state, such as signal state (and installed signal 603Note that certain global state, such as signal state (and installed signal
596handlers), will not be freed by this function, and related watchers (such 604handlers), will not be freed by this function, and related watchers (such
597as signal and child watchers) would need to be stopped manually. 605as signal and child watchers) would need to be stopped manually.
598 606
599In general it is not advisable to call this function except in the 607This function is normally used on loop objects allocated by
600rare occasion where you really need to free e.g. the signal handling 608C<ev_loop_new>, but it can also be used on the default loop returned by
609C<ev_default_loop>, in which case it is not thread-safe.
610
611Note that it is not advisable to call this function on the default loop
612except in the rare occasion where you really need to free it's resources.
601pipe fds. If you need dynamically allocated loops it is better to use 613If you need dynamically allocated loops it is better to use C<ev_loop_new>
602C<ev_loop_new> and C<ev_loop_destroy>. 614and C<ev_loop_destroy>.
603 615
604=item ev_loop_destroy (loop) 616=item ev_loop_fork (loop)
605 617
606Like C<ev_default_destroy>, but destroys an event loop created by an
607earlier call to C<ev_loop_new>.
608
609=item ev_default_fork ()
610
611This function sets a flag that causes subsequent C<ev_run> iterations 618This function sets a flag that causes subsequent C<ev_run> iterations to
612to reinitialise the kernel state for backends that have one. Despite the 619reinitialise the kernel state for backends that have one. Despite the
613name, you can call it anytime, but it makes most sense after forking, in 620name, you can call it anytime, but it makes most sense after forking, in
614the child process (or both child and parent, but that again makes little 621the child process. You I<must> call it (or use C<EVFLAG_FORKCHECK>) in the
615sense). You I<must> call it in the child before using any of the libev 622child before resuming or calling C<ev_run>.
616functions, and it will only take effect at the next C<ev_run> iteration.
617 623
618Again, you I<have> to call it on I<any> loop that you want to re-use after 624Again, you I<have> to call it on I<any> loop that you want to re-use after
619a fork, I<even if you do not plan to use the loop in the parent>. This is 625a fork, I<even if you do not plan to use the loop in the parent>. This is
620because some kernel interfaces *cough* I<kqueue> *cough* do funny things 626because some kernel interfaces *cough* I<kqueue> *cough* do funny things
621during fork. 627during fork.
626call it at all (in fact, C<epoll> is so badly broken that it makes a 632call it at all (in fact, C<epoll> is so badly broken that it makes a
627difference, but libev will usually detect this case on its own and do a 633difference, but libev will usually detect this case on its own and do a
628costly reset of the backend). 634costly reset of the backend).
629 635
630The function itself is quite fast and it's usually not a problem to call 636The function itself is quite fast and it's usually not a problem to call
631it just in case after a fork. To make this easy, the function will fit in 637it just in case after a fork.
632quite nicely into a call to C<pthread_atfork>:
633 638
639Example: Automate calling C<ev_loop_fork> on the default loop when
640using pthreads.
641
642 static void
643 post_fork_child (void)
644 {
645 ev_loop_fork (EV_DEFAULT);
646 }
647
648 ...
634 pthread_atfork (0, 0, ev_default_fork); 649 pthread_atfork (0, 0, post_fork_child);
635
636=item ev_loop_fork (loop)
637
638Like C<ev_default_fork>, but acts on an event loop created by
639C<ev_loop_new>. Yes, you have to call this on every allocated event loop
640after fork that you want to re-use in the child, and how you keep track of
641them is entirely your own problem.
642 650
643=item int ev_is_default_loop (loop) 651=item int ev_is_default_loop (loop)
644 652
645Returns true when the given loop is, in fact, the default loop, and false 653Returns true when the given loop is, in fact, the default loop, and false
646otherwise. 654otherwise.
908 916
909=item ev_invoke_pending (loop) 917=item ev_invoke_pending (loop)
910 918
911This call will simply invoke all pending watchers while resetting their 919This call will simply invoke all pending watchers while resetting their
912pending state. Normally, C<ev_run> does this automatically when required, 920pending state. Normally, C<ev_run> does this automatically when required,
913but when overriding the invoke callback this call comes handy. 921but when overriding the invoke callback this call comes handy. This
922function can be invoked from a watcher - this can be useful for example
923when you want to do some lengthy calculation and want to pass further
924event handling to another thread (you still have to make sure only one
925thread executes within C<ev_invoke_pending> or C<ev_run> of course).
914 926
915=item int ev_pending_count (loop) 927=item int ev_pending_count (loop)
916 928
917Returns the number of pending watchers - zero indicates that no watchers 929Returns the number of pending watchers - zero indicates that no watchers
918are pending. 930are pending.
3068disadvantage of having to use multiple event loops (which do not support 3080disadvantage of having to use multiple event loops (which do not support
3069signal watchers). 3081signal watchers).
3070 3082
3071When this is not possible, or you want to use the default loop for 3083When this is not possible, or you want to use the default loop for
3072other reasons, then in the process that wants to start "fresh", call 3084other reasons, then in the process that wants to start "fresh", call
3073C<ev_default_destroy ()> followed by C<ev_default_loop (...)>. Destroying 3085C<ev_loop_destroy (EV_DEFAULT)> followed by C<ev_default_loop (...)>.
3074the default loop will "orphan" (not stop) all registered watchers, so you 3086Destroying the default loop will "orphan" (not stop) all registered
3075have to be careful not to execute code that modifies those watchers. Note 3087watchers, so you have to be careful not to execute code that modifies
3076also that in that case, you have to re-register any signal watchers. 3088those watchers. Note also that in that case, you have to re-register any
3089signal watchers.
3077 3090
3078=head3 Watcher-Specific Functions and Data Members 3091=head3 Watcher-Specific Functions and Data Members
3079 3092
3080=over 4 3093=over 4
3081 3094
4527=head3 C<kqueue> is buggy 4540=head3 C<kqueue> is buggy
4528 4541
4529The kqueue syscall is broken in all known versions - most versions support 4542The kqueue syscall is broken in all known versions - most versions support
4530only sockets, many support pipes. 4543only sockets, many support pipes.
4531 4544
4532Libev tries to work around this by not using C<kqueue> by default on 4545Libev tries to work around this by not using C<kqueue> by default on this
4533this rotten platform, but of course you can still ask for it when creating 4546rotten platform, but of course you can still ask for it when creating a
4534a loop. 4547loop - embedding a socket-only kqueue loop into a select-based one is
4548probably going to work well.
4535 4549
4536=head3 C<poll> is buggy 4550=head3 C<poll> is buggy
4537 4551
4538Instead of fixing C<kqueue>, Apple replaced their (working) C<poll> 4552Instead of fixing C<kqueue>, Apple replaced their (working) C<poll>
4539implementation by something calling C<kqueue> internally around the 10.5.6 4553implementation by something calling C<kqueue> internally around the 10.5.6
4558 4572
4559=head3 C<errno> reentrancy 4573=head3 C<errno> reentrancy
4560 4574
4561The default compile environment on Solaris is unfortunately so 4575The default compile environment on Solaris is unfortunately so
4562thread-unsafe that you can't even use components/libraries compiled 4576thread-unsafe that you can't even use components/libraries compiled
4563without C<-D_REENTRANT> (as long as they use C<errno>), which, of course, 4577without C<-D_REENTRANT> in a threaded program, which, of course, isn't
4564isn't defined by default. 4578defined by default. A valid, if stupid, implementation choice.
4565 4579
4566If you want to use libev in threaded environments you have to make sure 4580If you want to use libev in threaded environments you have to make sure
4567it's compiled with C<_REENTRANT> defined. 4581it's compiled with C<_REENTRANT> defined.
4568 4582
4569=head3 Event port backend 4583=head3 Event port backend
4570 4584
4571The scalable event interface for Solaris is called "event ports". Unfortunately, 4585The scalable event interface for Solaris is called "event
4572this mechanism is very buggy. If you run into high CPU usage, your program 4586ports". Unfortunately, this mechanism is very buggy in all major
4587releases. If you run into high CPU usage, your program freezes or you get
4573freezes or you get a large number of spurious wakeups, make sure you have 4588a large number of spurious wakeups, make sure you have all the relevant
4574all the relevant and latest kernel patches applied. No, I don't know which 4589and latest kernel patches applied. No, I don't know which ones, but there
4575ones, but there are multiple ones. 4590are multiple ones to apply, and afterwards, event ports actually work
4591great.
4576 4592
4577If you can't get it to work, you can try running the program by setting 4593If you can't get it to work, you can try running the program by setting
4578the environment variable C<LIBEV_FLAGS=3> to only allow C<poll> and 4594the environment variable C<LIBEV_FLAGS=3> to only allow C<poll> and
4579C<select> backends. 4595C<select> backends.
4580 4596
4581=head2 AIX POLL BUG 4597=head2 AIX POLL BUG
4582 4598
4583AIX unfortunately has a broken C<poll.h> header. Libev works around 4599AIX unfortunately has a broken C<poll.h> header. Libev works around
4584this by trying to avoid the poll backend altogether (i.e. it's not even 4600this by trying to avoid the poll backend altogether (i.e. it's not even
4585compiled in), which normally isn't a big problem as C<select> works fine 4601compiled in), which normally isn't a big problem as C<select> works fine
4586with large bitsets, and AIX is dead anyway. 4602with large bitsets on AIX, and AIX is dead anyway.
4587 4603
4588=head2 WIN32 PLATFORM LIMITATIONS AND WORKAROUNDS 4604=head2 WIN32 PLATFORM LIMITATIONS AND WORKAROUNDS
4589 4605
4590=head3 General issues 4606=head3 General issues
4591 4607
4820compatibility, so most programs should still compile. Those might be 4836compatibility, so most programs should still compile. Those might be
4821removed in later versions of libev, so better update early than late. 4837removed in later versions of libev, so better update early than late.
4822 4838
4823=over 4 4839=over 4
4824 4840
4841=item C<ev_default_destroy> and C<ev_default_fork> have been removed
4842
4843These calls can be replaced easily by their C<ev_loop_xxx> counterparts:
4844
4845 ev_loop_destroy (EV_DEFAULT);
4846 ev_loop_fork (EV_DEFAULT);
4847
4825=item function/symbol renames 4848=item function/symbol renames
4826 4849
4827A number of functions and symbols have been renamed: 4850A number of functions and symbols have been renamed:
4828 4851
4829 ev_loop => ev_run 4852 ev_loop => ev_run
4868 4891
4869=over 4 4892=over 4
4870 4893
4871=item active 4894=item active
4872 4895
4873A watcher is active as long as it has been started (has been attached to 4896A watcher is active as long as it has been started and not yet stopped.
4874an event loop) but not yet stopped (disassociated from the event loop). 4897See L<WATCHER STATES> for details.
4875 4898
4876=item application 4899=item application
4877 4900
4878In this document, an application is whatever is using libev. 4901In this document, an application is whatever is using libev.
4902
4903=item backend
4904
4905The part of the code dealing with the operating system interfaces.
4879 4906
4880=item callback 4907=item callback
4881 4908
4882The address of a function that is called when some event has been 4909The address of a function that is called when some event has been
4883detected. Callbacks are being passed the event loop, the watcher that 4910detected. Callbacks are being passed the event loop, the watcher that
4884received the event, and the actual event bitset. 4911received the event, and the actual event bitset.
4885 4912
4886=item callback invocation 4913=item callback/watcher invocation
4887 4914
4888The act of calling the callback associated with a watcher. 4915The act of calling the callback associated with a watcher.
4889 4916
4890=item event 4917=item event
4891 4918
4910The model used to describe how an event loop handles and processes 4937The model used to describe how an event loop handles and processes
4911watchers and events. 4938watchers and events.
4912 4939
4913=item pending 4940=item pending
4914 4941
4915A watcher is pending as soon as the corresponding event has been detected, 4942A watcher is pending as soon as the corresponding event has been
4916and stops being pending as soon as the watcher will be invoked or its 4943detected. See L<WATCHER STATES> for details.
4917pending status is explicitly cleared by the application.
4918
4919A watcher can be pending, but not active. Stopping a watcher also clears
4920its pending status.
4921 4944
4922=item real time 4945=item real time
4923 4946
4924The physical time that is observed. It is apparently strictly monotonic :) 4947The physical time that is observed. It is apparently strictly monotonic :)
4925 4948
4932=item watcher 4955=item watcher
4933 4956
4934A data structure that describes interest in certain events. Watchers need 4957A data structure that describes interest in certain events. Watchers need
4935to be started (attached to an event loop) before they can receive events. 4958to be started (attached to an event loop) before they can receive events.
4936 4959
4937=item watcher invocation
4938
4939The act of calling the callback associated with a watcher.
4940
4941=back 4960=back
4942 4961
4943=head1 AUTHOR 4962=head1 AUTHOR
4944 4963
4945Marc Lehmann <libev@schmorp.de>, with repeated corrections by Mikael Magnusson. 4964Marc Lehmann <libev@schmorp.de>, with repeated corrections by Mikael Magnusson.

Diff Legend

Removed lines
+ Added lines
< Changed lines
> Changed lines