… | |
… | |
374 | |
374 | |
375 | =item C<EVFLAG_SIGNALFD> |
375 | =item C<EVFLAG_SIGNALFD> |
376 | |
376 | |
377 | When this flag is specified, then libev will attempt to use the |
377 | When this flag is specified, then libev will attempt to use the |
378 | I<signalfd> API for it's C<ev_signal> (and C<ev_child>) watchers. This API |
378 | I<signalfd> API for it's C<ev_signal> (and C<ev_child>) watchers. This API |
379 | delivers signals synchronously, which makes is both faster and might make |
379 | delivers signals synchronously, which makes it both faster and might make |
380 | it possible to get the queued signal data. |
380 | it possible to get the queued signal data. It can also simplify signal |
|
|
381 | handling with threads, as long as you properly block signals in your |
|
|
382 | threads that are not interested in handling them. |
381 | |
383 | |
382 | Signalfd will not be used by default as this changes your signal mask, and |
384 | Signalfd will not be used by default as this changes your signal mask, and |
383 | there are a lot of shoddy libraries and programs (glib's threadpool for |
385 | there are a lot of shoddy libraries and programs (glib's threadpool for |
384 | example) that can't properly initialise their signal masks. |
386 | example) that can't properly initialise their signal masks. |
385 | |
387 | |
… | |
… | |
1865 | Returns the remaining time until a timer fires. If the timer is active, |
1867 | Returns the remaining time until a timer fires. If the timer is active, |
1866 | then this time is relative to the current event loop time, otherwise it's |
1868 | then this time is relative to the current event loop time, otherwise it's |
1867 | the timeout value currently configured. |
1869 | the timeout value currently configured. |
1868 | |
1870 | |
1869 | That is, after an C<ev_timer_set (w, 5, 7)>, C<ev_timer_remaining> returns |
1871 | That is, after an C<ev_timer_set (w, 5, 7)>, C<ev_timer_remaining> returns |
1870 | C<5>. When the timer is started and one second passes, C<ev_timer_remain> |
1872 | C<5>. When the timer is started and one second passes, C<ev_timer_remaining> |
1871 | will return C<4>. When the timer expires and is restarted, it will return |
1873 | will return C<4>. When the timer expires and is restarted, it will return |
1872 | roughly C<7> (likely slightly less as callback invocation takes some time, |
1874 | roughly C<7> (likely slightly less as callback invocation takes some time, |
1873 | too), and so on. |
1875 | too), and so on. |
1874 | |
1876 | |
1875 | =item ev_tstamp repeat [read-write] |
1877 | =item ev_tstamp repeat [read-write] |
… | |
… | |
2160 | In current versions of libev, the signal will not be blocked indefinitely |
2162 | In current versions of libev, the signal will not be blocked indefinitely |
2161 | unless you use the C<signalfd> API (C<EV_SIGNALFD>). While this reduces |
2163 | unless you use the C<signalfd> API (C<EV_SIGNALFD>). While this reduces |
2162 | the window of opportunity for problems, it will not go away, as libev |
2164 | the window of opportunity for problems, it will not go away, as libev |
2163 | I<has> to modify the signal mask, at least temporarily. |
2165 | I<has> to modify the signal mask, at least temporarily. |
2164 | |
2166 | |
2165 | So I can't stress this enough I<if you do not reset your signal mask |
2167 | So I can't stress this enough: I<If you do not reset your signal mask when |
2166 | when you expect it to be empty, you have a race condition in your |
2168 | you expect it to be empty, you have a race condition in your code>. This |
2167 | program>. This is not a libev-specific thing, this is true for most event |
2169 | is not a libev-specific thing, this is true for most event libraries. |
2168 | libraries. |
|
|
2169 | |
2170 | |
2170 | =head3 Watcher-Specific Functions and Data Members |
2171 | =head3 Watcher-Specific Functions and Data Members |
2171 | |
2172 | |
2172 | =over 4 |
2173 | =over 4 |
2173 | |
2174 | |
… | |
… | |
3450 | Erkki Seppala has written Ocaml bindings for libev, to be found at |
3451 | Erkki Seppala has written Ocaml bindings for libev, to be found at |
3451 | L<http://modeemi.cs.tut.fi/~flux/software/ocaml-ev/>. |
3452 | L<http://modeemi.cs.tut.fi/~flux/software/ocaml-ev/>. |
3452 | |
3453 | |
3453 | =item Lua |
3454 | =item Lua |
3454 | |
3455 | |
3455 | Brian Maher has written a partial interface to libev |
3456 | Brian Maher has written a partial interface to libev for lua (at the |
3456 | for lua (only C<ev_io> and C<ev_timer>), to be found at |
3457 | time of this writing, only C<ev_io> and C<ev_timer>), to be found at |
3457 | L<http://github.com/brimworks/lua-ev>. |
3458 | L<http://github.com/brimworks/lua-ev>. |
3458 | |
3459 | |
3459 | =back |
3460 | =back |
3460 | |
3461 | |
3461 | |
3462 | |
… | |
… | |
3616 | libev.m4 |
3617 | libev.m4 |
3617 | |
3618 | |
3618 | =head2 PREPROCESSOR SYMBOLS/MACROS |
3619 | =head2 PREPROCESSOR SYMBOLS/MACROS |
3619 | |
3620 | |
3620 | Libev can be configured via a variety of preprocessor symbols you have to |
3621 | Libev can be configured via a variety of preprocessor symbols you have to |
3621 | define before including any of its files. The default in the absence of |
3622 | define before including (or compiling) any of its files. The default in |
3622 | autoconf is documented for every option. |
3623 | the absence of autoconf is documented for every option. |
|
|
3624 | |
|
|
3625 | Symbols marked with "(h)" do not change the ABI, and can have different |
|
|
3626 | values when compiling libev vs. including F<ev.h>, so it is permissible |
|
|
3627 | to redefine them before including F<ev.h> without breakign compatibility |
|
|
3628 | to a compiled library. All other symbols change the ABI, which means all |
|
|
3629 | users of libev and the libev code itself must be compiled with compatible |
|
|
3630 | settings. |
3623 | |
3631 | |
3624 | =over 4 |
3632 | =over 4 |
3625 | |
3633 | |
3626 | =item EV_STANDALONE |
3634 | =item EV_STANDALONE (h) |
3627 | |
3635 | |
3628 | Must always be C<1> if you do not use autoconf configuration, which |
3636 | Must always be C<1> if you do not use autoconf configuration, which |
3629 | keeps libev from including F<config.h>, and it also defines dummy |
3637 | keeps libev from including F<config.h>, and it also defines dummy |
3630 | implementations for some libevent functions (such as logging, which is not |
3638 | implementations for some libevent functions (such as logging, which is not |
3631 | supported). It will also not define any of the structs usually found in |
3639 | supported). It will also not define any of the structs usually found in |
… | |
… | |
3781 | as well as for signal and thread safety in C<ev_async> watchers. |
3789 | as well as for signal and thread safety in C<ev_async> watchers. |
3782 | |
3790 | |
3783 | In the absence of this define, libev will use C<sig_atomic_t volatile> |
3791 | In the absence of this define, libev will use C<sig_atomic_t volatile> |
3784 | (from F<signal.h>), which is usually good enough on most platforms. |
3792 | (from F<signal.h>), which is usually good enough on most platforms. |
3785 | |
3793 | |
3786 | =item EV_H |
3794 | =item EV_H (h) |
3787 | |
3795 | |
3788 | The name of the F<ev.h> header file used to include it. The default if |
3796 | The name of the F<ev.h> header file used to include it. The default if |
3789 | undefined is C<"ev.h"> in F<event.h>, F<ev.c> and F<ev++.h>. This can be |
3797 | undefined is C<"ev.h"> in F<event.h>, F<ev.c> and F<ev++.h>. This can be |
3790 | used to virtually rename the F<ev.h> header file in case of conflicts. |
3798 | used to virtually rename the F<ev.h> header file in case of conflicts. |
3791 | |
3799 | |
3792 | =item EV_CONFIG_H |
3800 | =item EV_CONFIG_H (h) |
3793 | |
3801 | |
3794 | If C<EV_STANDALONE> isn't C<1>, this variable can be used to override |
3802 | If C<EV_STANDALONE> isn't C<1>, this variable can be used to override |
3795 | F<ev.c>'s idea of where to find the F<config.h> file, similarly to |
3803 | F<ev.c>'s idea of where to find the F<config.h> file, similarly to |
3796 | C<EV_H>, above. |
3804 | C<EV_H>, above. |
3797 | |
3805 | |
3798 | =item EV_EVENT_H |
3806 | =item EV_EVENT_H (h) |
3799 | |
3807 | |
3800 | Similarly to C<EV_H>, this macro can be used to override F<event.c>'s idea |
3808 | Similarly to C<EV_H>, this macro can be used to override F<event.c>'s idea |
3801 | of how the F<event.h> header can be found, the default is C<"event.h">. |
3809 | of how the F<event.h> header can be found, the default is C<"event.h">. |
3802 | |
3810 | |
3803 | =item EV_PROTOTYPES |
3811 | =item EV_PROTOTYPES (h) |
3804 | |
3812 | |
3805 | If defined to be C<0>, then F<ev.h> will not define any function |
3813 | If defined to be C<0>, then F<ev.h> will not define any function |
3806 | prototypes, but still define all the structs and other symbols. This is |
3814 | prototypes, but still define all the structs and other symbols. This is |
3807 | occasionally useful if you want to provide your own wrapper functions |
3815 | occasionally useful if you want to provide your own wrapper functions |
3808 | around libev functions. |
3816 | around libev functions. |
… | |
… | |
3830 | fine. |
3838 | fine. |
3831 | |
3839 | |
3832 | If your embedding application does not need any priorities, defining these |
3840 | If your embedding application does not need any priorities, defining these |
3833 | both to C<0> will save some memory and CPU. |
3841 | both to C<0> will save some memory and CPU. |
3834 | |
3842 | |
3835 | =item EV_PERIODIC_ENABLE |
3843 | =item EV_PERIODIC_ENABLE, EV_IDLE_ENABLE, EV_EMBED_ENABLE, EV_STAT_ENABLE, |
|
|
3844 | EV_PREPARE_ENABLE, EV_CHECK_ENABLE, EV_FORK_ENABLE, EV_SIGNAL_ENABLE, |
|
|
3845 | EV_ASYNC_ENABLE, EV_CHILD_ENABLE. |
3836 | |
3846 | |
3837 | If undefined or defined to be C<1>, then periodic timers are supported. If |
3847 | If undefined or defined to be C<1> (and the platform supports it), then |
3838 | defined to be C<0>, then they are not. Disabling them saves a few kB of |
3848 | the respective watcher type is supported. If defined to be C<0>, then it |
3839 | code. |
3849 | is not. Disabling watcher types mainly saves codesize. |
3840 | |
|
|
3841 | =item EV_IDLE_ENABLE |
|
|
3842 | |
|
|
3843 | If undefined or defined to be C<1>, then idle watchers are supported. If |
|
|
3844 | defined to be C<0>, then they are not. Disabling them saves a few kB of |
|
|
3845 | code. |
|
|
3846 | |
|
|
3847 | =item EV_EMBED_ENABLE |
|
|
3848 | |
|
|
3849 | If undefined or defined to be C<1>, then embed watchers are supported. If |
|
|
3850 | defined to be C<0>, then they are not. Embed watchers rely on most other |
|
|
3851 | watcher types, which therefore must not be disabled. |
|
|
3852 | |
|
|
3853 | =item EV_STAT_ENABLE |
|
|
3854 | |
|
|
3855 | If undefined or defined to be C<1>, then stat watchers are supported. If |
|
|
3856 | defined to be C<0>, then they are not. |
|
|
3857 | |
|
|
3858 | =item EV_FORK_ENABLE |
|
|
3859 | |
|
|
3860 | If undefined or defined to be C<1>, then fork watchers are supported. If |
|
|
3861 | defined to be C<0>, then they are not. |
|
|
3862 | |
|
|
3863 | =item EV_ASYNC_ENABLE |
|
|
3864 | |
|
|
3865 | If undefined or defined to be C<1>, then async watchers are supported. If |
|
|
3866 | defined to be C<0>, then they are not. |
|
|
3867 | |
3850 | |
3868 | =item EV_MINIMAL |
3851 | =item EV_MINIMAL |
3869 | |
3852 | |
3870 | If you need to shave off some kilobytes of code at the expense of some |
3853 | If you need to shave off some kilobytes of code at the expense of some |
3871 | speed (but with the full API), define this symbol to C<1>. Currently this |
3854 | speed (but with the full API), define this symbol to C<1>. Currently this |
… | |
… | |
3873 | on amd64. It also selects a much smaller 2-heap for timer management over |
3856 | on amd64. It also selects a much smaller 2-heap for timer management over |
3874 | the default 4-heap. |
3857 | the default 4-heap. |
3875 | |
3858 | |
3876 | You can save even more by disabling watcher types you do not need |
3859 | You can save even more by disabling watcher types you do not need |
3877 | and setting C<EV_MAXPRI> == C<EV_MINPRI>. Also, disabling C<assert> |
3860 | and setting C<EV_MAXPRI> == C<EV_MINPRI>. Also, disabling C<assert> |
3878 | (C<-DNDEBUG>) will usually reduce code size a lot. |
3861 | (C<-DNDEBUG>) will usually reduce code size a lot. Disabling inotify, |
|
|
3862 | eventfd and signalfd will further help, and disabling backends one doesn't |
|
|
3863 | need (e.g. poll, epoll, kqueue, ports) will help further. |
3879 | |
3864 | |
3880 | Defining C<EV_MINIMAL> to C<2> will additionally reduce the core API to |
3865 | Defining C<EV_MINIMAL> to C<2> will additionally reduce the core API to |
3881 | provide a bare-bones event library. See C<ev.h> for details on what parts |
3866 | provide a bare-bones event library. See C<ev.h> for details on what parts |
3882 | of the API are still available, and do not complain if this subset changes |
3867 | of the API are still available, and do not complain if this subset changes |
3883 | over time. |
3868 | over time. |
|
|
3869 | |
|
|
3870 | This example set of settings reduces the compiled size of libev from |
|
|
3871 | 23.9Kb to 7.7Kb on my GNU/Linux amd64 system (and leaves little |
|
|
3872 | in - there is also an effect on the amount of memory used). With |
|
|
3873 | an intelligent-enough linker (gcc+binutils do this when you use |
|
|
3874 | C<-Wl,--gc-sections -ffunction-sections>) further unused functions might |
|
|
3875 | be left out as well automatically - a binary starting a timer and an I/O |
|
|
3876 | watcher then might come out at only 5Kb. |
|
|
3877 | |
|
|
3878 | // tuning and API changes |
|
|
3879 | #define EV_MINIMAL 2 |
|
|
3880 | #define EV_MULTIPLICITY 0 |
|
|
3881 | #define EV_MINPRI 0 |
|
|
3882 | #define EV_MAXPRI 0 |
|
|
3883 | |
|
|
3884 | // OS-specific backends |
|
|
3885 | #define EV_USE_INOTIFY 0 |
|
|
3886 | #define EV_USE_EVENTFD 0 |
|
|
3887 | #define EV_USE_SIGNALFD 0 |
|
|
3888 | #define EV_USE_REALTIME 0 |
|
|
3889 | #define EV_USE_MONOTONIC 0 |
|
|
3890 | #define EV_USE_CLOCK_SYSCALL 0 |
|
|
3891 | |
|
|
3892 | // disable all backends except select |
|
|
3893 | #define EV_USE_POLL 0 |
|
|
3894 | #define EV_USE_PORT 0 |
|
|
3895 | #define EV_USE_KQUEUE 0 |
|
|
3896 | #define EV_USE_EPOLL 0 |
|
|
3897 | |
|
|
3898 | // disable all watcher types that cna be disabled |
|
|
3899 | #define EV_STAT_ENABLE 0 |
|
|
3900 | #define EV_PERIODIC_ENABLE 0 |
|
|
3901 | #define EV_IDLE_ENABLE 0 |
|
|
3902 | #define EV_CHECK_ENABLE 0 |
|
|
3903 | #define EV_PREPARE_ENABLE 0 |
|
|
3904 | #define EV_FORK_ENABLE 0 |
|
|
3905 | #define EV_SIGNAL_ENABLE 0 |
|
|
3906 | #define EV_CHILD_ENABLE 0 |
|
|
3907 | #define EV_ASYNC_ENABLE 0 |
|
|
3908 | #define EV_EMBED_ENABLE 0 |
|
|
3909 | |
|
|
3910 | =item EV_AVOID_STDIO |
|
|
3911 | |
|
|
3912 | If this is set to C<1> at compiletime, then libev will avoid using stdio |
|
|
3913 | functions (printf, scanf, perror etc.). This will increase the codesize |
|
|
3914 | somewhat, but if your program doesn't otherwise depend on stdio and your |
|
|
3915 | libc allows it, this avoids linking in the stdio library which is quite |
|
|
3916 | big. |
|
|
3917 | |
|
|
3918 | Note that error messages might become less precise when this option is |
|
|
3919 | enabled. |
3884 | |
3920 | |
3885 | =item EV_NSIG |
3921 | =item EV_NSIG |
3886 | |
3922 | |
3887 | The highest supported signal number, +1 (or, the number of |
3923 | The highest supported signal number, +1 (or, the number of |
3888 | signals): Normally, libev tries to deduce the maximum number of signals |
3924 | signals): Normally, libev tries to deduce the maximum number of signals |