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

Comparing libev/ev.pod (file contents):
Revision 1.438 by root, Tue Jan 12 05:52:44 2016 UTC vs.
Revision 1.441 by root, Thu Jul 13 10:46:52 2017 UTC

… …
411make libev check for a fork in each iteration by enabling this flag. 411make libev check for a fork in each iteration by enabling this flag.
412 412
413This works by calling C<getpid ()> on every iteration of the loop, 413This works by calling C<getpid ()> on every iteration of the loop,
414and thus this might slow down your event loop if you do a lot of loop 414and thus this might slow down your event loop if you do a lot of loop
415iterations and little real work, but is usually not noticeable (on my 415iterations and little real work, but is usually not noticeable (on my
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
417without a system call and thus I<very> fast, but my GNU/Linux system also has 417sequence without a system call and thus I<very> fast, but my GNU/Linux
418C<pthread_atfork> which is even faster). 418system also has C<pthread_atfork> which is even faster). (Update: glibc
419versions 2.25 apparently removed the C<getpid> optimisation again).
419 420
420The big advantage of this flag is that you can forget about fork (and 421The big advantage of this flag is that you can forget about fork (and
421forget about forgetting to tell libev about forking, although you still 422forget about forgetting to tell libev about forking, although you still
422have to ignore C<SIGPIPE>) when you use this flag. 423have to ignore C<SIGPIPE>) when you use this flag.
423 424
… …
4386 ev_vars.h 4387 ev_vars.h
4387 ev_wrap.h 4388 ev_wrap.h
4388 4389
4389 ev_win32.c required on win32 platforms only 4390 ev_win32.c required on win32 platforms only
4390 4391
4391 ev_select.c only when select backend is enabled (which is enabled by default) 4392 ev_select.c only when select backend is enabled
4392 ev_poll.c only when poll backend is enabled (disabled by default) 4393 ev_poll.c only when poll backend is enabled
4393 ev_epoll.c only when the epoll backend is enabled (disabled by default) 4394 ev_epoll.c only when the epoll backend is enabled
4394 ev_kqueue.c only when the kqueue backend is enabled (disabled by default) 4395 ev_kqueue.c only when the kqueue backend is enabled
4395 ev_port.c only when the solaris port backend is enabled (disabled by default) 4396 ev_port.c only when the solaris port backend is enabled
4396 4397
4397F<ev.c> includes the backend files directly when enabled, so you only need 4398F<ev.c> includes the backend files directly when enabled, so you only need
4398to compile this single file. 4399to compile this single file.
4399 4400
4400=head3 LIBEVENT COMPATIBILITY API 4401=head3 LIBEVENT COMPATIBILITY API
… …
5300structure (guaranteed by POSIX but not by ISO C for example), but it also 5301structure (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 5302assumes that the same (machine) code can be used to call any watcher
5302callback: The watcher callbacks have different type signatures, but libev 5303callback: The watcher callbacks have different type signatures, but libev
5303calls them using an C<ev_watcher *> internally. 5304calls them using an C<ev_watcher *> internally.
5304 5305
5306=item null pointers and integer zero are represented by 0 bytes
5307
5308Libev uses C<memset> to initialise structs and arrays to C<0> bytes, and
5309relies on this setting pointers and integers to null.
5310
5305=item pointer accesses must be thread-atomic 5311=item pointer accesses must be thread-atomic
5306 5312
5307Accessing a pointer value must be atomic, it must both be readable and 5313Accessing a pointer value must be atomic, it must both be readable and
5308writable in one piece - this is the case on all current architectures. 5314writable in one piece - this is the case on all current architectures.
5309 5315

Diff Legend

– Removed lines
+ Added lines
< Changed lines
> Changed lines