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Comparing libev/ev.pod (file contents):
Revision 1.435 by root, Tue Apr 21 10:10:57 2015 UTC vs.
Revision 1.440 by root, Tue Jan 31 09:31:43 2017 UTC

… …
416GNU/Linux system for example, C<getpid> is actually a simple 5-insn sequence 416GNU/Linux system for example, C<getpid> is actually a simple 5-insn sequence
417without a system call and thus I<very> fast, but my GNU/Linux system also has 417without a system call and thus I<very> fast, but my GNU/Linux system also has
418C<pthread_atfork> which is even faster). 418C<pthread_atfork> which is even faster).
419 419
420The big advantage of this flag is that you can forget about fork (and 420The big advantage of this flag is that you can forget about fork (and
421forget about forgetting to tell libev about forking) when you use this 421forget about forgetting to tell libev about forking, although you still
422flag. 422have to ignore C<SIGPIPE>) when you use this flag.
423 423
424This flag setting cannot be overridden or specified in the C<LIBEV_FLAGS> 424This flag setting cannot be overridden or specified in the C<LIBEV_FLAGS>
425environment variable. 425environment variable.
426 426
427=item C<EVFLAG_NOINOTIFY> 427=item C<EVFLAG_NOINOTIFY>
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688to reinitialise the kernel state for backends that have one. Despite 688to reinitialise the kernel state for backends that have one. Despite
689the name, you can call it anytime you are allowed to start or stop 689the name, you can call it anytime you are allowed to start or stop
690watchers (except inside an C<ev_prepare> callback), but it makes most 690watchers (except inside an C<ev_prepare> callback), but it makes most
691sense after forking, in the child process. You I<must> call it (or use 691sense after forking, in the child process. You I<must> call it (or use
692C<EVFLAG_FORKCHECK>) in the child before resuming or calling C<ev_run>. 692C<EVFLAG_FORKCHECK>) in the child before resuming or calling C<ev_run>.
693
694In addition, if you want to reuse a loop (via this function or
695C<EVFLAG_FORKCHECK>), you I<also> have to ignore C<SIGPIPE>.
693 696
694Again, you I<have> to call it on I<any> loop that you want to re-use after 697Again, you I<have> to call it on I<any> loop that you want to re-use after
695a fork, I<even if you do not plan to use the loop in the parent>. This is 698a fork, I<even if you do not plan to use the loop in the parent>. This is
696because some kernel interfaces *cough* I<kqueue> *cough* do funny things 699because some kernel interfaces *cough* I<kqueue> *cough* do funny things
697during fork. 700during fork.
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2206Periodic watchers are also timers of a kind, but they are very versatile 2209Periodic watchers are also timers of a kind, but they are very versatile
2207(and unfortunately a bit complex). 2210(and unfortunately a bit complex).
2208 2211
2209Unlike C<ev_timer>, periodic watchers are not based on real time (or 2212Unlike C<ev_timer>, periodic watchers are not based on real time (or
2210relative time, the physical time that passes) but on wall clock time 2213relative time, the physical time that passes) but on wall clock time
2211(absolute time, the thing you can read on your calender or clock). The 2214(absolute time, the thing you can read on your calendar or clock). The
2212difference is that wall clock time can run faster or slower than real 2215difference is that wall clock time can run faster or slower than real
2213time, and time jumps are not uncommon (e.g. when you adjust your 2216time, and time jumps are not uncommon (e.g. when you adjust your
2214wrist-watch). 2217wrist-watch).
2215 2218
2216You can tell a periodic watcher to trigger after some specific point 2219You can tell a periodic watcher to trigger after some specific point
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4383 ev_vars.h 4386 ev_vars.h
4384 ev_wrap.h 4387 ev_wrap.h
4385 4388
4386 ev_win32.c required on win32 platforms only 4389 ev_win32.c required on win32 platforms only
4387 4390
4388 ev_select.c only when select backend is enabled (which is enabled by default) 4391 ev_select.c only when select backend is enabled
4389 ev_poll.c only when poll backend is enabled (disabled by default) 4392 ev_poll.c only when poll backend is enabled
4390 ev_epoll.c only when the epoll backend is enabled (disabled by default) 4393 ev_epoll.c only when the epoll backend is enabled
4391 ev_kqueue.c only when the kqueue backend is enabled (disabled by default) 4394 ev_kqueue.c only when the kqueue backend is enabled
4392 ev_port.c only when the solaris port backend is enabled (disabled by default) 4395 ev_port.c only when the solaris port backend is enabled
4393 4396
4394F<ev.c> includes the backend files directly when enabled, so you only need 4397F<ev.c> includes the backend files directly when enabled, so you only need
4395to compile this single file. 4398to compile this single file.
4396 4399
4397=head3 LIBEVENT COMPATIBILITY API 4400=head3 LIBEVENT COMPATIBILITY API
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5297structure (guaranteed by POSIX but not by ISO C for example), but it also 5300structure (guaranteed by POSIX but not by ISO C for example), but it also
5298assumes that the same (machine) code can be used to call any watcher 5301assumes that the same (machine) code can be used to call any watcher
5299callback: The watcher callbacks have different type signatures, but libev 5302callback: The watcher callbacks have different type signatures, but libev
5300calls them using an C<ev_watcher *> internally. 5303calls them using an C<ev_watcher *> internally.
5301 5304
5305=item null pointers and integer zero are represented by 0 bytes
5306
5307Libev uses C<memset> to initialise structs and arrays to C<0> bytes, and
5308relies on this setting pointers and integers to null.
5309
5302=item pointer accesses must be thread-atomic 5310=item pointer accesses must be thread-atomic
5303 5311
5304Accessing a pointer value must be atomic, it must both be readable and 5312Accessing a pointer value must be atomic, it must both be readable and
5305writable in one piece - this is the case on all current architectures. 5313writable in one piece - this is the case on all current architectures.
5306 5314

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