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

Comparing libev/ev.pod (file contents):
Revision 1.454 by root, Tue Jun 25 05:17:50 2019 UTC vs.
Revision 1.457 by root, Fri Sep 6 22:17:52 2019 UTC

… …
159When libev detects a usage error such as a negative timer interval, then 159When libev detects a usage error such as a negative timer interval, then
160it will print a diagnostic message and abort (via the C<assert> mechanism, 160it will print a diagnostic message and abort (via the C<assert> mechanism,
161so C<NDEBUG> will disable this checking): these are programming errors in 161so C<NDEBUG> will disable this checking): these are programming errors in
162the libev caller and need to be fixed there. 162the libev caller and need to be fixed there.
163 163
164Via the C<EV_FREQUENT> macro you can compile in and/or enable extensive
165consistency checking code inside libev that can be used to check for
166internal inconsistencies, suually caused by application bugs.
167
164Libev also has a few internal error-checking C<assert>ions, and also has 168Libev also has a few internal error-checking C<assert>ions. These do not
165extensive consistency checking code. These do not trigger under normal
166circumstances, as they indicate either a bug in libev or worse. 169trigger under normal circumstances, as they indicate either a bug in libev
170or worse.
167 171
168 172
169=head1 GLOBAL FUNCTIONS 173=head1 GLOBAL FUNCTIONS
170 174
171These functions can be called anytime, even before initialising the 175These functions can be called anytime, even before initialising the
… …
1531 1535
1532Many event loops support I<watcher priorities>, which are usually small 1536Many event loops support I<watcher priorities>, which are usually small
1533integers that influence the ordering of event callback invocation 1537integers that influence the ordering of event callback invocation
1534between watchers in some way, all else being equal. 1538between watchers in some way, all else being equal.
1535 1539
1536In libev, Watcher priorities can be set using C<ev_set_priority>. See its 1540In libev, watcher priorities can be set using C<ev_set_priority>. See its
1537description for the more technical details such as the actual priority 1541description for the more technical details such as the actual priority
1538range. 1542range.
1539 1543
1540There are two common ways how these these priorities are being interpreted 1544There are two common ways how these these priorities are being interpreted
1541by event loops: 1545by event loops:
… …
1745when you rarely read from a file instead of from a socket, and want to 1749when you rarely read from a file instead of from a socket, and want to
1746reuse the same code path. 1750reuse the same code path.
1747 1751
1748=head3 The special problem of fork 1752=head3 The special problem of fork
1749 1753
1750Some backends (epoll, kqueue, probably linuxaio) do not support C<fork ()> 1754Some backends (epoll, kqueue, linuxaio, iouring) do not support C<fork ()>
1751at all or exhibit useless behaviour. Libev fully supports fork, but needs 1755at all or exhibit useless behaviour. Libev fully supports fork, but needs
1752to be told about it in the child if you want to continue to use it in the 1756to be told about it in the child if you want to continue to use it in the
1753child. 1757child.
1754 1758
1755To support fork in your child processes, you have to call C<ev_loop_fork 1759To support fork in your child processes, you have to call C<ev_loop_fork
… …
4480 4484
4481 ev_select.c only when select backend is enabled 4485 ev_select.c only when select backend is enabled
4482 ev_poll.c only when poll backend is enabled 4486 ev_poll.c only when poll backend is enabled
4483 ev_epoll.c only when the epoll backend is enabled 4487 ev_epoll.c only when the epoll backend is enabled
4484 ev_linuxaio.c only when the linux aio backend is enabled 4488 ev_linuxaio.c only when the linux aio backend is enabled
4489 ev_iouring.c only when the linux io_uring backend is enabled
4485 ev_kqueue.c only when the kqueue backend is enabled 4490 ev_kqueue.c only when the kqueue backend is enabled
4486 ev_port.c only when the solaris port backend is enabled 4491 ev_port.c only when the solaris port backend is enabled
4487 4492
4488F<ev.c> includes the backend files directly when enabled, so you only need 4493F<ev.c> includes the backend files directly when enabled, so you only need
4489to compile this single file. 4494to compile this single file.
… …
4682backend for GNU/Linux systems. If undefined, it will be enabled if the 4687backend for GNU/Linux systems. If undefined, it will be enabled if the
4683headers indicate GNU/Linux + Glibc 2.4 or newer, otherwise disabled. 4688headers indicate GNU/Linux + Glibc 2.4 or newer, otherwise disabled.
4684 4689
4685=item EV_USE_LINUXAIO 4690=item EV_USE_LINUXAIO
4686 4691
4692If defined to be C<1>, libev will compile in support for the Linux aio
4693backend (C<EV_USE_EPOLL> must also be enabled). If undefined, it will be
4694enabled on linux, otherwise disabled.
4695
4696=item EV_USE_IOURING
4697
4687If defined to be C<1>, libev will compile in support for the Linux 4698If defined to be C<1>, libev will compile in support for the Linux
4688aio backend. Due to it's currenbt limitations it has to be requested 4699io_uring backend (C<EV_USE_EPOLL> must also be enabled). Due to it's
4689explicitly. If undefined, it will be enabled on linux, otherwise 4700current limitations it has to be requested explicitly. If undefined, it
4690disabled. 4701will be enabled on linux, otherwise disabled.
4691 4702
4692=item EV_USE_KQUEUE 4703=item EV_USE_KQUEUE
4693 4704
4694If defined to be C<1>, libev will compile in support for the BSD style 4705If defined to be C<1>, libev will compile in support for the BSD style
4695C<kqueue>(2) backend. Its actual availability will be detected at runtime, 4706C<kqueue>(2) backend. Its actual availability will be detected at runtime,
… …
4973called. If set to C<2>, then the internal verification code will be 4984called. If set to C<2>, then the internal verification code will be
4974called once per loop, which can slow down libev. If set to C<3>, then the 4985called once per loop, which can slow down libev. If set to C<3>, then the
4975verification code will be called very frequently, which will slow down 4986verification code will be called very frequently, which will slow down
4976libev considerably. 4987libev considerably.
4977 4988
4989Verification errors are reported via C's C<assert> mechanism, so if you
4990disable that (e.g. by defining C<NDEBUG>) then no errors will be reported.
4991
4978The default is C<1>, unless C<EV_FEATURES> overrides it, in which case it 4992The default is C<1>, unless C<EV_FEATURES> overrides it, in which case it
4979will be C<0>. 4993will be C<0>.
4980 4994
4981=item EV_COMMON 4995=item EV_COMMON
4982 4996

Diff Legend

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