… | |
… | |
1032 | =item C<EV_WRITE> |
1032 | =item C<EV_WRITE> |
1033 | |
1033 | |
1034 | The file descriptor in the C<ev_io> watcher has become readable and/or |
1034 | The file descriptor in the C<ev_io> watcher has become readable and/or |
1035 | writable. |
1035 | writable. |
1036 | |
1036 | |
1037 | =item C<EV_TIMEOUT> |
1037 | =item C<EV_TIMER> |
1038 | |
1038 | |
1039 | The C<ev_timer> watcher has timed out. |
1039 | The C<ev_timer> watcher has timed out. |
1040 | |
1040 | |
1041 | =item C<EV_PERIODIC> |
1041 | =item C<EV_PERIODIC> |
1042 | |
1042 | |
… | |
… | |
1764 | to the current time (meaning we just have some activity :), then call the |
1764 | to the current time (meaning we just have some activity :), then call the |
1765 | callback, which will "do the right thing" and start the timer: |
1765 | callback, which will "do the right thing" and start the timer: |
1766 | |
1766 | |
1767 | ev_init (timer, callback); |
1767 | ev_init (timer, callback); |
1768 | last_activity = ev_now (loop); |
1768 | last_activity = ev_now (loop); |
1769 | callback (loop, timer, EV_TIMEOUT); |
1769 | callback (loop, timer, EV_TIMER); |
1770 | |
1770 | |
1771 | And when there is some activity, simply store the current time in |
1771 | And when there is some activity, simply store the current time in |
1772 | C<last_activity>, no libev calls at all: |
1772 | C<last_activity>, no libev calls at all: |
1773 | |
1773 | |
1774 | last_actiivty = ev_now (loop); |
1774 | last_actiivty = ev_now (loop); |
… | |
… | |
3179 | |
3179 | |
3180 | If C<timeout> is less than 0, then no timeout watcher will be |
3180 | If C<timeout> is less than 0, then no timeout watcher will be |
3181 | started. Otherwise an C<ev_timer> watcher with after = C<timeout> (and |
3181 | started. Otherwise an C<ev_timer> watcher with after = C<timeout> (and |
3182 | repeat = 0) will be started. C<0> is a valid timeout. |
3182 | repeat = 0) will be started. C<0> is a valid timeout. |
3183 | |
3183 | |
3184 | The callback has the type C<void (*cb)(int revents, void *arg)> and gets |
3184 | The callback has the type C<void (*cb)(int revents, void *arg)> and is |
3185 | passed an C<revents> set like normal event callbacks (a combination of |
3185 | passed an C<revents> set like normal event callbacks (a combination of |
3186 | C<EV_ERROR>, C<EV_READ>, C<EV_WRITE> or C<EV_TIMEOUT>) and the C<arg> |
3186 | C<EV_ERROR>, C<EV_READ>, C<EV_WRITE> or C<EV_TIMER>) and the C<arg> |
3187 | value passed to C<ev_once>. Note that it is possible to receive I<both> |
3187 | value passed to C<ev_once>. Note that it is possible to receive I<both> |
3188 | a timeout and an io event at the same time - you probably should give io |
3188 | a timeout and an io event at the same time - you probably should give io |
3189 | events precedence. |
3189 | events precedence. |
3190 | |
3190 | |
3191 | Example: wait up to ten seconds for data to appear on STDIN_FILENO. |
3191 | Example: wait up to ten seconds for data to appear on STDIN_FILENO. |
3192 | |
3192 | |
3193 | static void stdin_ready (int revents, void *arg) |
3193 | static void stdin_ready (int revents, void *arg) |
3194 | { |
3194 | { |
3195 | if (revents & EV_READ) |
3195 | if (revents & EV_READ) |
3196 | /* stdin might have data for us, joy! */; |
3196 | /* stdin might have data for us, joy! */; |
3197 | else if (revents & EV_TIMEOUT) |
3197 | else if (revents & EV_TIMER) |
3198 | /* doh, nothing entered */; |
3198 | /* doh, nothing entered */; |
3199 | } |
3199 | } |
3200 | |
3200 | |
3201 | ev_once (STDIN_FILENO, EV_READ, 10., stdin_ready, 0); |
3201 | ev_once (STDIN_FILENO, EV_READ, 10., stdin_ready, 0); |
3202 | |
3202 | |
… | |
… | |
3891 | If you need to shave off some kilobytes of code at the expense of some |
3891 | If you need to shave off some kilobytes of code at the expense of some |
3892 | speed (but with the full API), you can define this symbol to request |
3892 | speed (but with the full API), you can define this symbol to request |
3893 | certain subsets of functionality. The default is to enable all features |
3893 | certain subsets of functionality. The default is to enable all features |
3894 | that can be enabled on the platform. |
3894 | that can be enabled on the platform. |
3895 | |
3895 | |
3896 | Note that using autoconf will usually override most of the features, so |
|
|
3897 | using this symbol makes sense mostly when embedding libev. |
|
|
3898 | |
|
|
3899 | A typical way to use this symbol is to define it to C<0> (or to a bitset |
3896 | A typical way to use this symbol is to define it to C<0> (or to a bitset |
3900 | with some broad features you want) and then selectively re-enable |
3897 | with some broad features you want) and then selectively re-enable |
3901 | additional parts you want, for example if you want everything minimal, |
3898 | additional parts you want, for example if you want everything minimal, |
3902 | but multiple event loop support, async and child watchers and the poll |
3899 | but multiple event loop support, async and child watchers and the poll |
3903 | backend, use this: |
3900 | backend, use this: |
… | |
… | |
3934 | =item C<4> - full API configuration |
3931 | =item C<4> - full API configuration |
3935 | |
3932 | |
3936 | This enables priorities (sets C<EV_MAXPRI>=2 and C<EV_MINPRI>=-2), and |
3933 | This enables priorities (sets C<EV_MAXPRI>=2 and C<EV_MINPRI>=-2), and |
3937 | enables multiplicity (C<EV_MULTIPLICITY>=1). |
3934 | enables multiplicity (C<EV_MULTIPLICITY>=1). |
3938 | |
3935 | |
|
|
3936 | =item C<8> - full API |
|
|
3937 | |
3939 | It also enables a lot of the "lesser used" core API functions. See C<ev.h> |
3938 | This enables a lot of the "lesser used" API functions. See C<ev.h> for |
3940 | for details on which parts of the API are still available without this |
3939 | details on which parts of the API are still available without this |
3941 | feature, and do not complain if this subset changes over time. |
3940 | feature, and do not complain if this subset changes over time. |
3942 | |
3941 | |
3943 | =item C<8> - enable all optional watcher types |
3942 | =item C<16> - enable all optional watcher types |
3944 | |
3943 | |
3945 | Enables all optional watcher types. If you want to selectively enable |
3944 | Enables all optional watcher types. If you want to selectively enable |
3946 | only some watcher types other than I/O and timers (e.g. prepare, |
3945 | only some watcher types other than I/O and timers (e.g. prepare, |
3947 | embed, async, child...) you can enable them manually by defining |
3946 | embed, async, child...) you can enable them manually by defining |
3948 | C<EV_watchertype_ENABLE> to C<1> instead. |
3947 | C<EV_watchertype_ENABLE> to C<1> instead. |
3949 | |
3948 | |
3950 | =item C<16> - enable all backends |
3949 | =item C<32> - enable all backends |
3951 | |
3950 | |
3952 | This enables all backends - without this feature, you need to enable at |
3951 | This enables all backends - without this feature, you need to enable at |
3953 | least one backend manually (C<EV_USE_SELECT> is a good choice). |
3952 | least one backend manually (C<EV_USE_SELECT> is a good choice). |
3954 | |
3953 | |
3955 | =item C<32> - enable OS-specific "helper" APIs |
3954 | =item C<64> - enable OS-specific "helper" APIs |
3956 | |
3955 | |
3957 | Enable inotify, eventfd, signalfd and similar OS-specific helper APIs by |
3956 | Enable inotify, eventfd, signalfd and similar OS-specific helper APIs by |
3958 | default. |
3957 | default. |
3959 | |
3958 | |
3960 | =back |
3959 | =back |
3961 | |
3960 | |
3962 | Compiling with C<gcc -Os -DEV_STANDALONE -DEV_USE_EPOLL=1 -DEV_FEATURES=0> |
3961 | Compiling with C<gcc -Os -DEV_STANDALONE -DEV_USE_EPOLL=1 -DEV_FEATURES=0> |
3963 | reduces the compiled size of libev from 24.7Kb to 6.5Kb on my GNU/Linux |
3962 | reduces the compiled size of libev from 24.7Kb code/2.8Kb data to 6.5Kb |
3964 | amd64 system, while still giving you I/O watchers, timers and monotonic |
3963 | code/0.3Kb data on my GNU/Linux amd64 system, while still giving you I/O |
3965 | clock support. |
3964 | watchers, timers and monotonic clock support. |
3966 | |
3965 | |
3967 | With an intelligent-enough linker (gcc+binutils are intelligent enough |
3966 | With an intelligent-enough linker (gcc+binutils are intelligent enough |
3968 | when you use C<-Wl,--gc-sections -ffunction-sections>) functions unused by |
3967 | when you use C<-Wl,--gc-sections -ffunction-sections>) functions unused by |
3969 | your program might be left out as well - a binary starting a timer and an |
3968 | your program might be left out as well - a binary starting a timer and an |
3970 | I/O watcher then might come out at only 5Kb. |
3969 | I/O watcher then might come out at only 5Kb. |
… | |
… | |
4103 | file. |
4102 | file. |
4104 | |
4103 | |
4105 | The usage in rxvt-unicode is simpler. It has a F<ev_cpp.h> header file |
4104 | The usage in rxvt-unicode is simpler. It has a F<ev_cpp.h> header file |
4106 | that everybody includes and which overrides some configure choices: |
4105 | that everybody includes and which overrides some configure choices: |
4107 | |
4106 | |
4108 | #define EV_FEATURES 0 |
4107 | #define EV_FEATURES 8 |
4109 | #define EV_USE_SELECT 1 |
4108 | #define EV_USE_SELECT 1 |
|
|
4109 | #define EV_PREPARE_ENABLE 1 |
|
|
4110 | #define EV_IDLE_ENABLE 1 |
|
|
4111 | #define EV_SIGNAL_ENABLE 1 |
|
|
4112 | #define EV_CHILD_ENABLE 1 |
|
|
4113 | #define EV_USE_STDEXCEPT 0 |
4110 | #define EV_CONFIG_H <config.h> |
4114 | #define EV_CONFIG_H <config.h> |
4111 | |
4115 | |
4112 | #include "ev++.h" |
4116 | #include "ev++.h" |
4113 | |
4117 | |
4114 | And a F<ev_cpp.C> implementation file that contains libev proper and is compiled: |
4118 | And a F<ev_cpp.C> implementation file that contains libev proper and is compiled: |
… | |
… | |
4617 | involves iterating over all running async watchers or all signal numbers. |
4621 | involves iterating over all running async watchers or all signal numbers. |
4618 | |
4622 | |
4619 | =back |
4623 | =back |
4620 | |
4624 | |
4621 | |
4625 | |
|
|
4626 | =head1 PORTING FROM 3.X TO 4.X |
|
|
4627 | |
|
|
4628 | The major version 4 introduced some minor incompatible changes to the API. |
|
|
4629 | |
|
|
4630 | =over 4 |
|
|
4631 | |
|
|
4632 | =item C<EV_TIMEOUT> replaced by C<EV_TIMER> in C<revents> |
|
|
4633 | |
|
|
4634 | This is a simple rename - all other watcher types use their name |
|
|
4635 | as revents flag, and now C<ev_timer> does, too. |
|
|
4636 | |
|
|
4637 | Both C<EV_TIMER> and C<EV_TIMEOUT> symbols were present in 3.x versions |
|
|
4638 | and continue to be present for the forseeable future, so this is mostly a |
|
|
4639 | documentation change. |
|
|
4640 | |
|
|
4641 | =item C<EV_MINIMAL> mechanism replaced by C<EV_FEATURES> |
|
|
4642 | |
|
|
4643 | The preprocessor symbol C<EV_MINIMAL> has been replaced by a different |
|
|
4644 | mechanism, C<EV_FEATURES>. Programs using C<EV_MINIMAL> usually compile |
|
|
4645 | and work, but the library code will of course be larger. |
|
|
4646 | |
|
|
4647 | =back |
|
|
4648 | |
|
|
4649 | |
4622 | =head1 GLOSSARY |
4650 | =head1 GLOSSARY |
4623 | |
4651 | |
4624 | =over 4 |
4652 | =over 4 |
4625 | |
4653 | |
4626 | =item active |
4654 | =item active |
… | |
… | |
4647 | A change of state of some external event, such as data now being available |
4675 | A change of state of some external event, such as data now being available |
4648 | for reading on a file descriptor, time having passed or simply not having |
4676 | for reading on a file descriptor, time having passed or simply not having |
4649 | any other events happening anymore. |
4677 | any other events happening anymore. |
4650 | |
4678 | |
4651 | In libev, events are represented as single bits (such as C<EV_READ> or |
4679 | In libev, events are represented as single bits (such as C<EV_READ> or |
4652 | C<EV_TIMEOUT>). |
4680 | C<EV_TIMER>). |
4653 | |
4681 | |
4654 | =item event library |
4682 | =item event library |
4655 | |
4683 | |
4656 | A software package implementing an event model and loop. |
4684 | A software package implementing an event model and loop. |
4657 | |
4685 | |