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Comparing libev/ev.pod (file contents):
Revision 1.436 by root, Sun Oct 11 15:46:42 2015 UTC vs.
Revision 1.439 by root, Tue Mar 1 19:19:25 2016 UTC

… …
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>.
693 693
694In addition, if you want to reuse a loop (via this function of 694In addition, if you want to reuse a loop (via this function or
695C<EVFLAG_FORKCHECK>), you I<also> have to ignore C<SIGPIPE>. 695C<EVFLAG_FORKCHECK>), you I<also> have to ignore C<SIGPIPE>.
696 696
697Again, 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
698a 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
699because some kernel interfaces *cough* I<kqueue> *cough* do funny things 699because some kernel interfaces *cough* I<kqueue> *cough* do funny things
… …
2209Periodic 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
2210(and unfortunately a bit complex). 2210(and unfortunately a bit complex).
2211 2211
2212Unlike 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
2213relative time, the physical time that passes) but on wall clock time 2213relative time, the physical time that passes) but on wall clock time
2214(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
2215difference 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
2216time, 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
2217wrist-watch). 2217wrist-watch).
2218 2218
2219You 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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5300structure (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
5301assumes 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
5302callback: The watcher callbacks have different type signatures, but libev 5302callback: The watcher callbacks have different type signatures, but libev
5303calls them using an C<ev_watcher *> internally. 5303calls them using an C<ev_watcher *> internally.
5304 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
5305=item pointer accesses must be thread-atomic 5310=item pointer accesses must be thread-atomic
5306 5311
5307Accessing 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
5308writable in one piece - this is the case on all current architectures. 5313writable in one piece - this is the case on all current architectures.
5309 5314

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