… | |
… | |
300 | An event loop is described by a C<struct ev_loop *> (the C<struct> is |
300 | An event loop is described by a C<struct ev_loop *> (the C<struct> is |
301 | I<not> optional in this case unless libev 3 compatibility is disabled, as |
301 | I<not> optional in this case unless libev 3 compatibility is disabled, as |
302 | libev 3 had an C<ev_loop> function colliding with the struct name). |
302 | libev 3 had an C<ev_loop> function colliding with the struct name). |
303 | |
303 | |
304 | The library knows two types of such loops, the I<default> loop, which |
304 | The library knows two types of such loops, the I<default> loop, which |
305 | supports signals and child events, and dynamically created event loops |
305 | supports child process events, and dynamically created event loops which |
306 | which do not. |
306 | do not. |
307 | |
307 | |
308 | =over 4 |
308 | =over 4 |
309 | |
309 | |
310 | =item struct ev_loop *ev_default_loop (unsigned int flags) |
310 | =item struct ev_loop *ev_default_loop (unsigned int flags) |
311 | |
311 | |
… | |
… | |
341 | |
341 | |
342 | Example: Restrict libev to the select and poll backends, and do not allow |
342 | Example: Restrict libev to the select and poll backends, and do not allow |
343 | environment settings to be taken into account: |
343 | environment settings to be taken into account: |
344 | |
344 | |
345 | ev_default_loop (EVBACKEND_POLL | EVBACKEND_SELECT | EVFLAG_NOENV); |
345 | ev_default_loop (EVBACKEND_POLL | EVBACKEND_SELECT | EVFLAG_NOENV); |
346 | |
|
|
347 | Example: Use whatever libev has to offer, but make sure that kqueue is |
|
|
348 | used if available (warning, breaks stuff, best use only with your own |
|
|
349 | private event loop and only if you know the OS supports your types of |
|
|
350 | fds): |
|
|
351 | |
|
|
352 | ev_default_loop (ev_recommended_backends () | EVBACKEND_KQUEUE); |
|
|
353 | |
346 | |
354 | =item struct ev_loop *ev_loop_new (unsigned int flags) |
347 | =item struct ev_loop *ev_loop_new (unsigned int flags) |
355 | |
348 | |
356 | This will create and initialise a new event loop object. If the loop |
349 | This will create and initialise a new event loop object. If the loop |
357 | could not be initialised, returns false. |
350 | could not be initialised, returns false. |
… | |
… | |
589 | Example: Try to create a event loop that uses epoll and nothing else. |
582 | Example: Try to create a event loop that uses epoll and nothing else. |
590 | |
583 | |
591 | struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV); |
584 | struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV); |
592 | if (!epoller) |
585 | if (!epoller) |
593 | fatal ("no epoll found here, maybe it hides under your chair"); |
586 | fatal ("no epoll found here, maybe it hides under your chair"); |
|
|
587 | |
|
|
588 | Example: Use whatever libev has to offer, but make sure that kqueue is |
|
|
589 | used if available. |
|
|
590 | |
|
|
591 | struct ev_loop *loop = ev_loop_new (ev_recommended_backends () | EVBACKEND_KQUEUE); |
594 | |
592 | |
595 | =item ev_loop_destroy (loop) |
593 | =item ev_loop_destroy (loop) |
596 | |
594 | |
597 | Destroys an event loop object (frees all memory and kernel state |
595 | Destroys an event loop object (frees all memory and kernel state |
598 | etc.). None of the active event watchers will be stopped in the normal |
596 | etc.). None of the active event watchers will be stopped in the normal |
… | |
… | |
1114 | =item C<EV_FORK> |
1112 | =item C<EV_FORK> |
1115 | |
1113 | |
1116 | The event loop has been resumed in the child process after fork (see |
1114 | The event loop has been resumed in the child process after fork (see |
1117 | C<ev_fork>). |
1115 | C<ev_fork>). |
1118 | |
1116 | |
|
|
1117 | =item C<EV_CLEANUP> |
|
|
1118 | |
|
|
1119 | The event loop is about to be destroyed (see C<ev_cleanup>). |
|
|
1120 | |
1119 | =item C<EV_ASYNC> |
1121 | =item C<EV_ASYNC> |
1120 | |
1122 | |
1121 | The given async watcher has been asynchronously notified (see C<ev_async>). |
1123 | The given async watcher has been asynchronously notified (see C<ev_async>). |
1122 | |
1124 | |
1123 | =item C<EV_CUSTOM> |
1125 | =item C<EV_CUSTOM> |
… | |
… | |
3092 | |
3094 | |
3093 | =head3 Watcher-Specific Functions and Data Members |
3095 | =head3 Watcher-Specific Functions and Data Members |
3094 | |
3096 | |
3095 | =over 4 |
3097 | =over 4 |
3096 | |
3098 | |
3097 | =item ev_fork_init (ev_signal *, callback) |
3099 | =item ev_fork_init (ev_fork *, callback) |
3098 | |
3100 | |
3099 | Initialises and configures the fork watcher - it has no parameters of any |
3101 | Initialises and configures the fork watcher - it has no parameters of any |
3100 | kind. There is a C<ev_fork_set> macro, but using it is utterly pointless, |
3102 | kind. There is a C<ev_fork_set> macro, but using it is utterly pointless, |
3101 | believe me. |
3103 | really. |
3102 | |
3104 | |
3103 | =back |
3105 | =back |
|
|
3106 | |
|
|
3107 | |
|
|
3108 | =head2 C<ev_cleanup> - even the best things end |
|
|
3109 | |
|
|
3110 | Cleanup watchers are called just before the event loop is being destroyed |
|
|
3111 | by a call to C<ev_loop_destroy>. |
|
|
3112 | |
|
|
3113 | While there is no guarantee that the event loop gets destroyed, cleanup |
|
|
3114 | watchers provide a convenient method to install cleanup hooks for your |
|
|
3115 | program, worker threads and so on - you just to make sure to destroy the |
|
|
3116 | loop when you want them to be invoked. |
|
|
3117 | |
|
|
3118 | Cleanup watchers are invoked in the same way as any other watcher. Unlike |
|
|
3119 | all other watchers, they do not keep a reference to the event loop (which |
|
|
3120 | makes a lot of sense if you think about it). Like all other watchers, you |
|
|
3121 | can call libev functions in the callback, except C<ev_cleanup_start>. |
|
|
3122 | |
|
|
3123 | =head3 Watcher-Specific Functions and Data Members |
|
|
3124 | |
|
|
3125 | =over 4 |
|
|
3126 | |
|
|
3127 | =item ev_cleanup_init (ev_cleanup *, callback) |
|
|
3128 | |
|
|
3129 | Initialises and configures the cleanup watcher - it has no parameters of |
|
|
3130 | any kind. There is a C<ev_cleanup_set> macro, but using it is utterly |
|
|
3131 | pointless, I assure you. |
|
|
3132 | |
|
|
3133 | =back |
|
|
3134 | |
|
|
3135 | Example: Register an atexit handler to destroy the default loop, so any |
|
|
3136 | cleanup functions are called. |
|
|
3137 | |
|
|
3138 | static void |
|
|
3139 | program_exits (void) |
|
|
3140 | { |
|
|
3141 | ev_loop_destroy (EV_DEFAULT_UC); |
|
|
3142 | } |
|
|
3143 | |
|
|
3144 | ... |
|
|
3145 | atexit (program_exits); |
3104 | |
3146 | |
3105 | |
3147 | |
3106 | =head2 C<ev_async> - how to wake up an event loop |
3148 | =head2 C<ev_async> - how to wake up an event loop |
3107 | |
3149 | |
3108 | In general, you cannot use an C<ev_run> from multiple threads or other |
3150 | In general, you cannot use an C<ev_run> from multiple threads or other |
… | |
… | |
4715 | structure (guaranteed by POSIX but not by ISO C for example), but it also |
4757 | structure (guaranteed by POSIX but not by ISO C for example), but it also |
4716 | assumes that the same (machine) code can be used to call any watcher |
4758 | assumes that the same (machine) code can be used to call any watcher |
4717 | callback: The watcher callbacks have different type signatures, but libev |
4759 | callback: The watcher callbacks have different type signatures, but libev |
4718 | calls them using an C<ev_watcher *> internally. |
4760 | calls them using an C<ev_watcher *> internally. |
4719 | |
4761 | |
|
|
4762 | =item pointer accesses must be thread-atomic |
|
|
4763 | |
|
|
4764 | Accessing a pointer value must be atomic, it must both be readable and |
|
|
4765 | writable in one piece - this is the case on all current architectures. |
|
|
4766 | |
4720 | =item C<sig_atomic_t volatile> must be thread-atomic as well |
4767 | =item C<sig_atomic_t volatile> must be thread-atomic as well |
4721 | |
4768 | |
4722 | The type C<sig_atomic_t volatile> (or whatever is defined as |
4769 | The type C<sig_atomic_t volatile> (or whatever is defined as |
4723 | C<EV_ATOMIC_T>) must be atomic with respect to accesses from different |
4770 | C<EV_ATOMIC_T>) must be atomic with respect to accesses from different |
4724 | threads. This is not part of the specification for C<sig_atomic_t>, but is |
4771 | threads. This is not part of the specification for C<sig_atomic_t>, but is |
… | |
… | |
4830 | =back |
4877 | =back |
4831 | |
4878 | |
4832 | |
4879 | |
4833 | =head1 PORTING FROM LIBEV 3.X TO 4.X |
4880 | =head1 PORTING FROM LIBEV 3.X TO 4.X |
4834 | |
4881 | |
4835 | The major version 4 introduced some minor incompatible changes to the API. |
4882 | The major version 4 introduced some incompatible changes to the API. |
4836 | |
4883 | |
4837 | At the moment, the C<ev.h> header file tries to implement superficial |
4884 | At the moment, the C<ev.h> header file provides compatibility definitions |
4838 | compatibility, so most programs should still compile. Those might be |
4885 | for all changes, so most programs should still compile. The compatibility |
4839 | removed in later versions of libev, so better update early than late. |
4886 | layer might be removed in later versions of libev, so better update to the |
|
|
4887 | new API early than late. |
4840 | |
4888 | |
4841 | =over 4 |
4889 | =over 4 |
4842 | |
4890 | |
|
|
4891 | =item C<EV_COMPAT3> backwards compatibility mechanism |
|
|
4892 | |
|
|
4893 | The backward compatibility mechanism can be controlled by |
|
|
4894 | C<EV_COMPAT3>. See L<PREPROCESSOR SYMBOLS/MACROS> in the L<EMBEDDING> |
|
|
4895 | section. |
|
|
4896 | |
4843 | =item C<ev_default_destroy> and C<ev_default_fork> have been removed |
4897 | =item C<ev_default_destroy> and C<ev_default_fork> have been removed |
4844 | |
4898 | |
4845 | These calls can be replaced easily by their C<ev_loop_xxx> counterparts: |
4899 | These calls can be replaced easily by their C<ev_loop_xxx> counterparts: |
4846 | |
4900 | |
4847 | ev_loop_destroy (EV_DEFAULT); |
4901 | ev_loop_destroy (EV_DEFAULT_UC); |
4848 | ev_loop_fork (EV_DEFAULT); |
4902 | ev_loop_fork (EV_DEFAULT); |
4849 | |
4903 | |
4850 | =item function/symbol renames |
4904 | =item function/symbol renames |
4851 | |
4905 | |
4852 | A number of functions and symbols have been renamed: |
4906 | A number of functions and symbols have been renamed: |
… | |
… | |
4872 | ev_loop> anymore and C<EV_TIMER> now follows the same naming scheme |
4926 | ev_loop> anymore and C<EV_TIMER> now follows the same naming scheme |
4873 | as all other watcher types. Note that C<ev_loop_fork> is still called |
4927 | as all other watcher types. Note that C<ev_loop_fork> is still called |
4874 | C<ev_loop_fork> because it would otherwise clash with the C<ev_fork> |
4928 | C<ev_loop_fork> because it would otherwise clash with the C<ev_fork> |
4875 | typedef. |
4929 | typedef. |
4876 | |
4930 | |
4877 | =item C<EV_COMPAT3> backwards compatibility mechanism |
|
|
4878 | |
|
|
4879 | The backward compatibility mechanism can be controlled by |
|
|
4880 | C<EV_COMPAT3>. See L<PREPROCESSOR SYMBOLS/MACROS> in the L<EMBEDDING> |
|
|
4881 | section. |
|
|
4882 | |
|
|
4883 | =item C<EV_MINIMAL> mechanism replaced by C<EV_FEATURES> |
4931 | =item C<EV_MINIMAL> mechanism replaced by C<EV_FEATURES> |
4884 | |
4932 | |
4885 | The preprocessor symbol C<EV_MINIMAL> has been replaced by a different |
4933 | The preprocessor symbol C<EV_MINIMAL> has been replaced by a different |
4886 | mechanism, C<EV_FEATURES>. Programs using C<EV_MINIMAL> usually compile |
4934 | mechanism, C<EV_FEATURES>. Programs using C<EV_MINIMAL> usually compile |
4887 | and work, but the library code will of course be larger. |
4935 | and work, but the library code will of course be larger. |
… | |
… | |
4961 | |
5009 | |
4962 | =back |
5010 | =back |
4963 | |
5011 | |
4964 | =head1 AUTHOR |
5012 | =head1 AUTHOR |
4965 | |
5013 | |
4966 | Marc Lehmann <libev@schmorp.de>, with repeated corrections by Mikael Magnusson. |
5014 | Marc Lehmann <libev@schmorp.de>, with repeated corrections by Mikael |
|
|
5015 | Magnusson and Emanuele Giaquinta. |
4967 | |
5016 | |