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Comparing libev/ev.3 (file contents):
Revision 1.115 by root, Wed Jun 26 00:01:46 2019 UTC vs.
Revision 1.118 by root, Sat Dec 21 16:11:51 2019 UTC

… …
131.\} 131.\}
132.rm #[ #] #H #V #F C 132.rm #[ #] #H #V #F C
133.\" ======================================================================== 133.\" ========================================================================
134.\" 134.\"
135.IX Title "LIBEV 3" 135.IX Title "LIBEV 3"
136.TH LIBEV 3 "2019-06-25" "libev-4.25" "libev - high performance full featured event loop" 136.TH LIBEV 3 "2019-12-21" "libev-4.31" "libev - high performance full featured event loop"
137.\" For nroff, turn off justification. Always turn off hyphenation; it makes 137.\" For nroff, turn off justification. Always turn off hyphenation; it makes
138.\" way too many mistakes in technical documents. 138.\" way too many mistakes in technical documents.
139.if n .ad l 139.if n .ad l
140.nh 140.nh
141.SH "NAME" 141.SH "NAME"
… …
606want to handle signals only in specific threads and want to avoid libev 606want to handle signals only in specific threads and want to avoid libev
607unblocking the signals. 607unblocking the signals.
608.Sp 608.Sp
609It's also required by \s-1POSIX\s0 in a threaded program, as libev calls 609It's also required by \s-1POSIX\s0 in a threaded program, as libev calls
610\&\f(CW\*(C`sigprocmask\*(C'\fR, whose behaviour is officially unspecified. 610\&\f(CW\*(C`sigprocmask\*(C'\fR, whose behaviour is officially unspecified.
611.ie n .IP """EVFLAG_NOTIMERFD""" 4
612.el .IP "\f(CWEVFLAG_NOTIMERFD\fR" 4
613.IX Item "EVFLAG_NOTIMERFD"
614When this flag is specified, the libev will avoid using a \f(CW\*(C`timerfd\*(C'\fR to
615detect time jumps. It will still be able to detect time jumps, but takes
616longer and has a lower accuracy in doing so, but saves a file descriptor
617per loop.
611.Sp 618.Sp
612This flag's behaviour will become the default in future versions of libev. 619The current implementation only tries to use a \f(CW\*(C`timerfd\*(C'\fR when the first
620\&\f(CW\*(C`ev_periodic\*(C'\fR watcher is started and falls back on other methods if it
621cannot be created, but this behaviour might change in the future.
613.ie n .IP """EVBACKEND_SELECT"" (value 1, portable select backend)" 4 622.ie n .IP """EVBACKEND_SELECT"" (value 1, portable select backend)" 4
614.el .IP "\f(CWEVBACKEND_SELECT\fR (value 1, portable select backend)" 4 623.el .IP "\f(CWEVBACKEND_SELECT\fR (value 1, portable select backend)" 4
615.IX Item "EVBACKEND_SELECT (value 1, portable select backend)" 624.IX Item "EVBACKEND_SELECT (value 1, portable select backend)"
616This is your standard \fBselect\fR\|(2) backend. Not \fIcompletely\fR standard, as 625This is your standard \fBselect\fR\|(2) backend. Not \fIcompletely\fR standard, as
617libev tries to roll its own fd_set with no limits on the number of fds, 626libev tries to roll its own fd_set with no limits on the number of fds,
… …
1654.IX Subsection "WATCHER PRIORITY MODELS" 1663.IX Subsection "WATCHER PRIORITY MODELS"
1655Many event loops support \fIwatcher priorities\fR, which are usually small 1664Many event loops support \fIwatcher priorities\fR, which are usually small
1656integers that influence the ordering of event callback invocation 1665integers that influence the ordering of event callback invocation
1657between watchers in some way, all else being equal. 1666between watchers in some way, all else being equal.
1658.PP 1667.PP
1659In libev, Watcher priorities can be set using \f(CW\*(C`ev_set_priority\*(C'\fR. See its 1668In libev, watcher priorities can be set using \f(CW\*(C`ev_set_priority\*(C'\fR. See its
1660description for the more technical details such as the actual priority 1669description for the more technical details such as the actual priority
1661range. 1670range.
1662.PP 1671.PP
1663There are two common ways how these these priorities are being interpreted 1672There are two common ways how these these priorities are being interpreted
1664by event loops: 1673by event loops:
… …
1871reuse the same code path. 1880reuse the same code path.
1872.PP 1881.PP
1873\fIThe special problem of fork\fR 1882\fIThe special problem of fork\fR
1874.IX Subsection "The special problem of fork" 1883.IX Subsection "The special problem of fork"
1875.PP 1884.PP
1876Some backends (epoll, kqueue, probably linuxaio) do not support \f(CW\*(C`fork ()\*(C'\fR 1885Some backends (epoll, kqueue, linuxaio, iouring) do not support \f(CW\*(C`fork ()\*(C'\fR
1877at all or exhibit useless behaviour. Libev fully supports fork, but needs 1886at all or exhibit useless behaviour. Libev fully supports fork, but needs
1878to be told about it in the child if you want to continue to use it in the 1887to be told about it in the child if you want to continue to use it in the
1879child. 1888child.
1880.PP 1889.PP
1881To support fork in your child processes, you have to call \f(CW\*(C`ev_loop_fork 1890To support fork in your child processes, you have to call \f(CW\*(C`ev_loop_fork
… …
4624\& 4633\&
4625\& ev_select.c only when select backend is enabled 4634\& ev_select.c only when select backend is enabled
4626\& ev_poll.c only when poll backend is enabled 4635\& ev_poll.c only when poll backend is enabled
4627\& ev_epoll.c only when the epoll backend is enabled 4636\& ev_epoll.c only when the epoll backend is enabled
4628\& ev_linuxaio.c only when the linux aio backend is enabled 4637\& ev_linuxaio.c only when the linux aio backend is enabled
4638\& ev_iouring.c only when the linux io_uring backend is enabled
4629\& ev_kqueue.c only when the kqueue backend is enabled 4639\& ev_kqueue.c only when the kqueue backend is enabled
4630\& ev_port.c only when the solaris port backend is enabled 4640\& ev_port.c only when the solaris port backend is enabled
4631.Ve 4641.Ve
4632.PP 4642.PP
4633\&\fIev.c\fR includes the backend files directly when enabled, so you only need 4643\&\fIev.c\fR includes the backend files directly when enabled, so you only need
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4746higher, as it simplifies linking (no need for \f(CW\*(C`\-lrt\*(C'\fR). 4756higher, as it simplifies linking (no need for \f(CW\*(C`\-lrt\*(C'\fR).
4747.IP "\s-1EV_USE_NANOSLEEP\s0" 4 4757.IP "\s-1EV_USE_NANOSLEEP\s0" 4
4748.IX Item "EV_USE_NANOSLEEP" 4758.IX Item "EV_USE_NANOSLEEP"
4749If defined to be \f(CW1\fR, libev will assume that \f(CW\*(C`nanosleep ()\*(C'\fR is available 4759If defined to be \f(CW1\fR, libev will assume that \f(CW\*(C`nanosleep ()\*(C'\fR is available
4750and will use it for delays. Otherwise it will use \f(CW\*(C`select ()\*(C'\fR. 4760and will use it for delays. Otherwise it will use \f(CW\*(C`select ()\*(C'\fR.
4761.IP "\s-1EV_USE_EVENTFD\s0" 4
4762.IX Item "EV_USE_EVENTFD"
4763If defined to be \f(CW1\fR, then libev will assume that \f(CW\*(C`eventfd ()\*(C'\fR is
4764available and will probe for kernel support at runtime. This will improve
4765\&\f(CW\*(C`ev_signal\*(C'\fR and \f(CW\*(C`ev_async\*(C'\fR performance and reduce resource consumption.
4766If undefined, it will be enabled if the headers indicate GNU/Linux + Glibc
47672.7 or newer, otherwise disabled.
4768.IP "\s-1EV_USE_SIGNALFD\s0" 4
4769.IX Item "EV_USE_SIGNALFD"
4770If defined to be \f(CW1\fR, then libev will assume that \f(CW\*(C`signalfd ()\*(C'\fR is
4771available and will probe for kernel support at runtime. This enables
4772the use of \s-1EVFLAG_SIGNALFD\s0 for faster and simpler signal handling. If
4773undefined, it will be enabled if the headers indicate GNU/Linux + Glibc
47742.7 or newer, otherwise disabled.
4775.IP "\s-1EV_USE_TIMERFD\s0" 4
4776.IX Item "EV_USE_TIMERFD"
4777If defined to be \f(CW1\fR, then libev will assume that \f(CW\*(C`timerfd ()\*(C'\fR is
4778available and will probe for kernel support at runtime. This allows
4779libev to detect time jumps accurately. If undefined, it will be enabled
4780if the headers indicate GNU/Linux + Glibc 2.8 or newer and define
4781\&\f(CW\*(C`TFD_TIMER_CANCEL_ON_SET\*(C'\fR, otherwise disabled.
4751.IP "\s-1EV_USE_EVENTFD\s0" 4 4782.IP "\s-1EV_USE_EVENTFD\s0" 4
4752.IX Item "EV_USE_EVENTFD" 4783.IX Item "EV_USE_EVENTFD"
4753If defined to be \f(CW1\fR, then libev will assume that \f(CW\*(C`eventfd ()\*(C'\fR is 4784If defined to be \f(CW1\fR, then libev will assume that \f(CW\*(C`eventfd ()\*(C'\fR is
4754available and will probe for kernel support at runtime. This will improve 4785available and will probe for kernel support at runtime. This will improve
4755\&\f(CW\*(C`ev_signal\*(C'\fR and \f(CW\*(C`ev_async\*(C'\fR performance and reduce resource consumption. 4786\&\f(CW\*(C`ev_signal\*(C'\fR and \f(CW\*(C`ev_async\*(C'\fR performance and reduce resource consumption.
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4816otherwise another method will be used as fallback. This is the preferred 4847otherwise another method will be used as fallback. This is the preferred
4817backend for GNU/Linux systems. If undefined, it will be enabled if the 4848backend for GNU/Linux systems. If undefined, it will be enabled if the
4818headers indicate GNU/Linux + Glibc 2.4 or newer, otherwise disabled. 4849headers indicate GNU/Linux + Glibc 2.4 or newer, otherwise disabled.
4819.IP "\s-1EV_USE_LINUXAIO\s0" 4 4850.IP "\s-1EV_USE_LINUXAIO\s0" 4
4820.IX Item "EV_USE_LINUXAIO" 4851.IX Item "EV_USE_LINUXAIO"
4852If defined to be \f(CW1\fR, libev will compile in support for the Linux aio
4853backend (\f(CW\*(C`EV_USE_EPOLL\*(C'\fR must also be enabled). If undefined, it will be
4854enabled on linux, otherwise disabled.
4855.IP "\s-1EV_USE_IOURING\s0" 4
4856.IX Item "EV_USE_IOURING"
4821If defined to be \f(CW1\fR, libev will compile in support for the Linux 4857If defined to be \f(CW1\fR, libev will compile in support for the Linux
4822aio backend. Due to it's currenbt limitations it has to be requested 4858io_uring backend (\f(CW\*(C`EV_USE_EPOLL\*(C'\fR must also be enabled). Due to it's
4823explicitly. If undefined, it will be enabled on linux, otherwise 4859current limitations it has to be requested explicitly. If undefined, it
4824disabled. 4860will be enabled on linux, otherwise disabled.
4825.IP "\s-1EV_USE_KQUEUE\s0" 4 4861.IP "\s-1EV_USE_KQUEUE\s0" 4
4826.IX Item "EV_USE_KQUEUE" 4862.IX Item "EV_USE_KQUEUE"
4827If defined to be \f(CW1\fR, libev will compile in support for the \s-1BSD\s0 style 4863If defined to be \f(CW1\fR, libev will compile in support for the \s-1BSD\s0 style
4828\&\f(CW\*(C`kqueue\*(C'\fR(2) backend. Its actual availability will be detected at runtime, 4864\&\f(CW\*(C`kqueue\*(C'\fR(2) backend. Its actual availability will be detected at runtime,
4829otherwise another method will be used as fallback. This is the preferred 4865otherwise another method will be used as fallback. This is the preferred

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