… | |
… | |
82 | |
82 | |
83 | =head1 WHAT TO READ WHEN IN A HURRY |
83 | =head1 WHAT TO READ WHEN IN A HURRY |
84 | |
84 | |
85 | This manual tries to be very detailed, but unfortunately, this also makes |
85 | This manual tries to be very detailed, but unfortunately, this also makes |
86 | it very long. If you just want to know the basics of libev, I suggest |
86 | it very long. If you just want to know the basics of libev, I suggest |
87 | reading L<ANATOMY OF A WATCHER>, then the L<EXAMPLE PROGRAM> above and |
87 | reading L</ANATOMY OF A WATCHER>, then the L</EXAMPLE PROGRAM> above and |
88 | look up the missing functions in L<GLOBAL FUNCTIONS> and the C<ev_io> and |
88 | look up the missing functions in L</GLOBAL FUNCTIONS> and the C<ev_io> and |
89 | C<ev_timer> sections in L<WATCHER TYPES>. |
89 | C<ev_timer> sections in L</WATCHER TYPES>. |
90 | |
90 | |
91 | =head1 ABOUT LIBEV |
91 | =head1 ABOUT LIBEV |
92 | |
92 | |
93 | Libev is an event loop: you register interest in certain events (such as a |
93 | Libev is an event loop: you register interest in certain events (such as a |
94 | file descriptor being readable or a timeout occurring), and it will manage |
94 | file descriptor being readable or a timeout occurring), and it will manage |
… | |
… | |
569 | kernel is more efficient (which says nothing about its actual speed, of |
569 | kernel is more efficient (which says nothing about its actual speed, of |
570 | course). While stopping, setting and starting an I/O watcher does never |
570 | course). While stopping, setting and starting an I/O watcher does never |
571 | cause an extra system call as with C<EVBACKEND_EPOLL>, it still adds up to |
571 | cause an extra system call as with C<EVBACKEND_EPOLL>, it still adds up to |
572 | two event changes per incident. Support for C<fork ()> is very bad (you |
572 | two event changes per incident. Support for C<fork ()> is very bad (you |
573 | might have to leak fd's on fork, but it's more sane than epoll) and it |
573 | might have to leak fd's on fork, but it's more sane than epoll) and it |
574 | drops fds silently in similarly hard-to-detect cases |
574 | drops fds silently in similarly hard-to-detect cases. |
575 | |
575 | |
576 | This backend usually performs well under most conditions. |
576 | This backend usually performs well under most conditions. |
577 | |
577 | |
578 | While nominally embeddable in other event loops, this doesn't work |
578 | While nominally embeddable in other event loops, this doesn't work |
579 | everywhere, so you might need to test for this. And since it is broken |
579 | everywhere, so you might need to test for this. And since it is broken |
… | |
… | |
764 | |
764 | |
765 | This function is rarely useful, but when some event callback runs for a |
765 | This function is rarely useful, but when some event callback runs for a |
766 | very long time without entering the event loop, updating libev's idea of |
766 | very long time without entering the event loop, updating libev's idea of |
767 | the current time is a good idea. |
767 | the current time is a good idea. |
768 | |
768 | |
769 | See also L<The special problem of time updates> in the C<ev_timer> section. |
769 | See also L</The special problem of time updates> in the C<ev_timer> section. |
770 | |
770 | |
771 | =item ev_suspend (loop) |
771 | =item ev_suspend (loop) |
772 | |
772 | |
773 | =item ev_resume (loop) |
773 | =item ev_resume (loop) |
774 | |
774 | |
… | |
… | |
1318 | |
1318 | |
1319 | =item callback ev_cb (ev_TYPE *watcher) |
1319 | =item callback ev_cb (ev_TYPE *watcher) |
1320 | |
1320 | |
1321 | Returns the callback currently set on the watcher. |
1321 | Returns the callback currently set on the watcher. |
1322 | |
1322 | |
1323 | =item ev_cb_set (ev_TYPE *watcher, callback) |
1323 | =item ev_set_cb (ev_TYPE *watcher, callback) |
1324 | |
1324 | |
1325 | Change the callback. You can change the callback at virtually any time |
1325 | Change the callback. You can change the callback at virtually any time |
1326 | (modulo threads). |
1326 | (modulo threads). |
1327 | |
1327 | |
1328 | =item ev_set_priority (ev_TYPE *watcher, int priority) |
1328 | =item ev_set_priority (ev_TYPE *watcher, int priority) |
… | |
… | |
1346 | or might not have been clamped to the valid range. |
1346 | or might not have been clamped to the valid range. |
1347 | |
1347 | |
1348 | The default priority used by watchers when no priority has been set is |
1348 | The default priority used by watchers when no priority has been set is |
1349 | always C<0>, which is supposed to not be too high and not be too low :). |
1349 | always C<0>, which is supposed to not be too high and not be too low :). |
1350 | |
1350 | |
1351 | See L<WATCHER PRIORITY MODELS>, below, for a more thorough treatment of |
1351 | See L</WATCHER PRIORITY MODELS>, below, for a more thorough treatment of |
1352 | priorities. |
1352 | priorities. |
1353 | |
1353 | |
1354 | =item ev_invoke (loop, ev_TYPE *watcher, int revents) |
1354 | =item ev_invoke (loop, ev_TYPE *watcher, int revents) |
1355 | |
1355 | |
1356 | Invoke the C<watcher> with the given C<loop> and C<revents>. Neither |
1356 | Invoke the C<watcher> with the given C<loop> and C<revents>. Neither |
… | |
… | |
1381 | See also C<ev_feed_fd_event> and C<ev_feed_signal_event> for related |
1381 | See also C<ev_feed_fd_event> and C<ev_feed_signal_event> for related |
1382 | functions that do not need a watcher. |
1382 | functions that do not need a watcher. |
1383 | |
1383 | |
1384 | =back |
1384 | =back |
1385 | |
1385 | |
1386 | See also the L<ASSOCIATING CUSTOM DATA WITH A WATCHER> and L<BUILDING YOUR |
1386 | See also the L</ASSOCIATING CUSTOM DATA WITH A WATCHER> and L</BUILDING YOUR |
1387 | OWN COMPOSITE WATCHERS> idioms. |
1387 | OWN COMPOSITE WATCHERS> idioms. |
1388 | |
1388 | |
1389 | =head2 WATCHER STATES |
1389 | =head2 WATCHER STATES |
1390 | |
1390 | |
1391 | There are various watcher states mentioned throughout this manual - |
1391 | There are various watcher states mentioned throughout this manual - |
… | |
… | |
1393 | transition between them will be described in more detail - and while these |
1393 | transition between them will be described in more detail - and while these |
1394 | rules might look complicated, they usually do "the right thing". |
1394 | rules might look complicated, they usually do "the right thing". |
1395 | |
1395 | |
1396 | =over 4 |
1396 | =over 4 |
1397 | |
1397 | |
1398 | =item initialiased |
1398 | =item initialised |
1399 | |
1399 | |
1400 | Before a watcher can be registered with the event loop it has to be |
1400 | Before a watcher can be registered with the event loop it has to be |
1401 | initialised. This can be done with a call to C<ev_TYPE_init>, or calls to |
1401 | initialised. This can be done with a call to C<ev_TYPE_init>, or calls to |
1402 | C<ev_init> followed by the watcher-specific C<ev_TYPE_set> function. |
1402 | C<ev_init> followed by the watcher-specific C<ev_TYPE_set> function. |
1403 | |
1403 | |
… | |
… | |
2136 | =item If the timer is repeating, make the C<repeat> value the new timeout |
2136 | =item If the timer is repeating, make the C<repeat> value the new timeout |
2137 | and start the timer, if necessary. |
2137 | and start the timer, if necessary. |
2138 | |
2138 | |
2139 | =back |
2139 | =back |
2140 | |
2140 | |
2141 | This sounds a bit complicated, see L<Be smart about timeouts>, above, for a |
2141 | This sounds a bit complicated, see L</Be smart about timeouts>, above, for a |
2142 | usage example. |
2142 | usage example. |
2143 | |
2143 | |
2144 | =item ev_tstamp ev_timer_remaining (loop, ev_timer *) |
2144 | =item ev_tstamp ev_timer_remaining (loop, ev_timer *) |
2145 | |
2145 | |
2146 | Returns the remaining time until a timer fires. If the timer is active, |
2146 | Returns the remaining time until a timer fires. If the timer is active, |
… | |
… | |
2606 | |
2606 | |
2607 | =head2 C<ev_stat> - did the file attributes just change? |
2607 | =head2 C<ev_stat> - did the file attributes just change? |
2608 | |
2608 | |
2609 | This watches a file system path for attribute changes. That is, it calls |
2609 | This watches a file system path for attribute changes. That is, it calls |
2610 | C<stat> on that path in regular intervals (or when the OS says it changed) |
2610 | C<stat> on that path in regular intervals (or when the OS says it changed) |
2611 | and sees if it changed compared to the last time, invoking the callback if |
2611 | and sees if it changed compared to the last time, invoking the callback |
2612 | it did. |
2612 | if it did. Starting the watcher C<stat>'s the file, so only changes that |
|
|
2613 | happen after the watcher has been started will be reported. |
2613 | |
2614 | |
2614 | The path does not need to exist: changing from "path exists" to "path does |
2615 | The path does not need to exist: changing from "path exists" to "path does |
2615 | not exist" is a status change like any other. The condition "path does not |
2616 | not exist" is a status change like any other. The condition "path does not |
2616 | exist" (or more correctly "path cannot be stat'ed") is signified by the |
2617 | exist" (or more correctly "path cannot be stat'ed") is signified by the |
2617 | C<st_nlink> field being zero (which is otherwise always forced to be at |
2618 | C<st_nlink> field being zero (which is otherwise always forced to be at |
… | |
… | |
2858 | |
2859 | |
2859 | This mode of operation can be useful together with an C<ev_check> watcher, |
2860 | This mode of operation can be useful together with an C<ev_check> watcher, |
2860 | to do something on each event loop iteration - for example to balance load |
2861 | to do something on each event loop iteration - for example to balance load |
2861 | between different connections. |
2862 | between different connections. |
2862 | |
2863 | |
2863 | See L<Abusing an C<ev_check> watcher for its side-effect> for a longer |
2864 | See L</Abusing an ev_check watcher for its side-effect> for a longer |
2864 | example. |
2865 | example. |
2865 | |
2866 | |
2866 | =head3 Watcher-Specific Functions and Data Members |
2867 | =head3 Watcher-Specific Functions and Data Members |
2867 | |
2868 | |
2868 | =over 4 |
2869 | =over 4 |
… | |
… | |
2881 | callback, free it. Also, use no error checking, as usual. |
2882 | callback, free it. Also, use no error checking, as usual. |
2882 | |
2883 | |
2883 | static void |
2884 | static void |
2884 | idle_cb (struct ev_loop *loop, ev_idle *w, int revents) |
2885 | idle_cb (struct ev_loop *loop, ev_idle *w, int revents) |
2885 | { |
2886 | { |
|
|
2887 | // stop the watcher |
|
|
2888 | ev_idle_stop (loop, w); |
|
|
2889 | |
|
|
2890 | // now we can free it |
2886 | free (w); |
2891 | free (w); |
|
|
2892 | |
2887 | // now do something you wanted to do when the program has |
2893 | // now do something you wanted to do when the program has |
2888 | // no longer anything immediate to do. |
2894 | // no longer anything immediate to do. |
2889 | } |
2895 | } |
2890 | |
2896 | |
2891 | ev_idle *idle_watcher = malloc (sizeof (ev_idle)); |
2897 | ev_idle *idle_watcher = malloc (sizeof (ev_idle)); |
… | |
… | |
2957 | |
2963 | |
2958 | Using an C<ev_check> watcher is almost enough: it will be called on the |
2964 | Using an C<ev_check> watcher is almost enough: it will be called on the |
2959 | next event loop iteration. However, that isn't as soon as possible - |
2965 | next event loop iteration. However, that isn't as soon as possible - |
2960 | without external events, your C<ev_check> watcher will not be invoked. |
2966 | without external events, your C<ev_check> watcher will not be invoked. |
2961 | |
2967 | |
2962 | |
|
|
2963 | This is where C<ev_idle> watchers come in handy - all you need is a |
2968 | This is where C<ev_idle> watchers come in handy - all you need is a |
2964 | single global idle watcher that is active as long as you have one active |
2969 | single global idle watcher that is active as long as you have one active |
2965 | C<ev_check> watcher. The C<ev_idle> watcher makes sure the event loop |
2970 | C<ev_check> watcher. The C<ev_idle> watcher makes sure the event loop |
2966 | will not sleep, and the C<ev_check> watcher makes sure a callback gets |
2971 | will not sleep, and the C<ev_check> watcher makes sure a callback gets |
2967 | invoked. Neither watcher alone can do that. |
2972 | invoked. Neither watcher alone can do that. |
… | |
… | |
3173 | |
3178 | |
3174 | =over 4 |
3179 | =over 4 |
3175 | |
3180 | |
3176 | =item ev_embed_init (ev_embed *, callback, struct ev_loop *embedded_loop) |
3181 | =item ev_embed_init (ev_embed *, callback, struct ev_loop *embedded_loop) |
3177 | |
3182 | |
3178 | =item ev_embed_set (ev_embed *, callback, struct ev_loop *embedded_loop) |
3183 | =item ev_embed_set (ev_embed *, struct ev_loop *embedded_loop) |
3179 | |
3184 | |
3180 | Configures the watcher to embed the given loop, which must be |
3185 | Configures the watcher to embed the given loop, which must be |
3181 | embeddable. If the callback is C<0>, then C<ev_embed_sweep> will be |
3186 | embeddable. If the callback is C<0>, then C<ev_embed_sweep> will be |
3182 | invoked automatically, otherwise it is the responsibility of the callback |
3187 | invoked automatically, otherwise it is the responsibility of the callback |
3183 | to invoke it (it will continue to be called until the sweep has been done, |
3188 | to invoke it (it will continue to be called until the sweep has been done, |
… | |
… | |
3246 | |
3251 | |
3247 | =head2 C<ev_fork> - the audacity to resume the event loop after a fork |
3252 | =head2 C<ev_fork> - the audacity to resume the event loop after a fork |
3248 | |
3253 | |
3249 | Fork watchers are called when a C<fork ()> was detected (usually because |
3254 | Fork watchers are called when a C<fork ()> was detected (usually because |
3250 | whoever is a good citizen cared to tell libev about it by calling |
3255 | whoever is a good citizen cared to tell libev about it by calling |
3251 | C<ev_default_fork> or C<ev_loop_fork>). The invocation is done before the |
3256 | C<ev_loop_fork>). The invocation is done before the event loop blocks next |
3252 | event loop blocks next and before C<ev_check> watchers are being called, |
3257 | and before C<ev_check> watchers are being called, and only in the child |
3253 | and only in the child after the fork. If whoever good citizen calling |
3258 | after the fork. If whoever good citizen calling C<ev_default_fork> cheats |
3254 | C<ev_default_fork> cheats and calls it in the wrong process, the fork |
3259 | and calls it in the wrong process, the fork handlers will be invoked, too, |
3255 | handlers will be invoked, too, of course. |
3260 | of course. |
3256 | |
3261 | |
3257 | =head3 The special problem of life after fork - how is it possible? |
3262 | =head3 The special problem of life after fork - how is it possible? |
3258 | |
3263 | |
3259 | Most uses of C<fork()> consist of forking, then some simple calls to set |
3264 | Most uses of C<fork()> consist of forking, then some simple calls to set |
3260 | up/change the process environment, followed by a call to C<exec()>. This |
3265 | up/change the process environment, followed by a call to C<exec()>. This |
… | |
… | |
3654 | already been invoked. |
3659 | already been invoked. |
3655 | |
3660 | |
3656 | A common way around all these issues is to make sure that |
3661 | A common way around all these issues is to make sure that |
3657 | C<start_new_request> I<always> returns before the callback is invoked. If |
3662 | C<start_new_request> I<always> returns before the callback is invoked. If |
3658 | C<start_new_request> immediately knows the result, it can artificially |
3663 | C<start_new_request> immediately knows the result, it can artificially |
3659 | delay invoking the callback by e.g. using a C<prepare> or C<idle> watcher |
3664 | delay invoking the callback by using a C<prepare> or C<idle> watcher for |
3660 | for example, or more sneakily, by reusing an existing (stopped) watcher |
3665 | example, or more sneakily, by reusing an existing (stopped) watcher and |
3661 | and pushing it into the pending queue: |
3666 | pushing it into the pending queue: |
3662 | |
3667 | |
3663 | ev_set_cb (watcher, callback); |
3668 | ev_set_cb (watcher, callback); |
3664 | ev_feed_event (EV_A_ watcher, 0); |
3669 | ev_feed_event (EV_A_ watcher, 0); |
3665 | |
3670 | |
3666 | This way, C<start_new_request> can safely return before the callback is |
3671 | This way, C<start_new_request> can safely return before the callback is |
… | |
… | |
3674 | |
3679 | |
3675 | This brings the problem of exiting - a callback might want to finish the |
3680 | This brings the problem of exiting - a callback might want to finish the |
3676 | main C<ev_run> call, but not the nested one (e.g. user clicked "Quit", but |
3681 | main C<ev_run> call, but not the nested one (e.g. user clicked "Quit", but |
3677 | a modal "Are you sure?" dialog is still waiting), or just the nested one |
3682 | a modal "Are you sure?" dialog is still waiting), or just the nested one |
3678 | and not the main one (e.g. user clocked "Ok" in a modal dialog), or some |
3683 | and not the main one (e.g. user clocked "Ok" in a modal dialog), or some |
3679 | other combination: In these cases, C<ev_break> will not work alone. |
3684 | other combination: In these cases, a simple C<ev_break> will not work. |
3680 | |
3685 | |
3681 | The solution is to maintain "break this loop" variable for each C<ev_run> |
3686 | The solution is to maintain "break this loop" variable for each C<ev_run> |
3682 | invocation, and use a loop around C<ev_run> until the condition is |
3687 | invocation, and use a loop around C<ev_run> until the condition is |
3683 | triggered, using C<EVRUN_ONCE>: |
3688 | triggered, using C<EVRUN_ONCE>: |
3684 | |
3689 | |
… | |
… | |
3870 | called): |
3875 | called): |
3871 | |
3876 | |
3872 | void |
3877 | void |
3873 | wait_for_event (ev_watcher *w) |
3878 | wait_for_event (ev_watcher *w) |
3874 | { |
3879 | { |
3875 | ev_cb_set (w) = current_coro; |
3880 | ev_set_cb (w, current_coro); |
3876 | switch_to (libev_coro); |
3881 | switch_to (libev_coro); |
3877 | } |
3882 | } |
3878 | |
3883 | |
3879 | That basically suspends the coroutine inside C<wait_for_event> and |
3884 | That basically suspends the coroutine inside C<wait_for_event> and |
3880 | continues the libev coroutine, which, when appropriate, switches back to |
3885 | continues the libev coroutine, which, when appropriate, switches back to |
… | |
… | |
3883 | You can do similar tricks if you have, say, threads with an event queue - |
3888 | You can do similar tricks if you have, say, threads with an event queue - |
3884 | instead of storing a coroutine, you store the queue object and instead of |
3889 | instead of storing a coroutine, you store the queue object and instead of |
3885 | switching to a coroutine, you push the watcher onto the queue and notify |
3890 | switching to a coroutine, you push the watcher onto the queue and notify |
3886 | any waiters. |
3891 | any waiters. |
3887 | |
3892 | |
3888 | To embed libev, see L<EMBEDDING>, but in short, it's easiest to create two |
3893 | To embed libev, see L</EMBEDDING>, but in short, it's easiest to create two |
3889 | files, F<my_ev.h> and F<my_ev.c> that include the respective libev files: |
3894 | files, F<my_ev.h> and F<my_ev.c> that include the respective libev files: |
3890 | |
3895 | |
3891 | // my_ev.h |
3896 | // my_ev.h |
3892 | #define EV_CB_DECLARE(type) struct my_coro *cb; |
3897 | #define EV_CB_DECLARE(type) struct my_coro *cb; |
3893 | #define EV_CB_INVOKE(watcher) switch_to ((watcher)->cb); |
3898 | #define EV_CB_INVOKE(watcher) switch_to ((watcher)->cb); |
… | |
… | |
3945 | libev sources can be compiled as C++. Therefore, code that uses the C API |
3950 | libev sources can be compiled as C++. Therefore, code that uses the C API |
3946 | will work fine. |
3951 | will work fine. |
3947 | |
3952 | |
3948 | Proper exception specifications might have to be added to callbacks passed |
3953 | Proper exception specifications might have to be added to callbacks passed |
3949 | to libev: exceptions may be thrown only from watcher callbacks, all |
3954 | to libev: exceptions may be thrown only from watcher callbacks, all |
3950 | other callbacks (allocator, syserr, loop acquire/release and periodioc |
3955 | other callbacks (allocator, syserr, loop acquire/release and periodic |
3951 | reschedule callbacks) must not throw exceptions, and might need a C<throw |
3956 | reschedule callbacks) must not throw exceptions, and might need a C<throw |
3952 | ()> specification. If you have code that needs to be compiled as both C |
3957 | ()> specification. If you have code that needs to be compiled as both C |
3953 | and C++ you can use the C<EV_THROW> macro for this: |
3958 | and C++ you can use the C<EV_THROW> macro for this: |
3954 | |
3959 | |
3955 | static void |
3960 | static void |
… | |
… | |
4116 | Associates a different C<struct ev_loop> with this watcher. You can only |
4121 | Associates a different C<struct ev_loop> with this watcher. You can only |
4117 | do this when the watcher is inactive (and not pending either). |
4122 | do this when the watcher is inactive (and not pending either). |
4118 | |
4123 | |
4119 | =item w->set ([arguments]) |
4124 | =item w->set ([arguments]) |
4120 | |
4125 | |
4121 | Basically the same as C<ev_TYPE_set>, with the same arguments. Either this |
4126 | Basically the same as C<ev_TYPE_set> (except for C<ev::embed> watchers>), |
4122 | method or a suitable start method must be called at least once. Unlike the |
4127 | with the same arguments. Either this method or a suitable start method |
4123 | C counterpart, an active watcher gets automatically stopped and restarted |
4128 | must be called at least once. Unlike the C counterpart, an active watcher |
4124 | when reconfiguring it with this method. |
4129 | gets automatically stopped and restarted when reconfiguring it with this |
|
|
4130 | method. |
|
|
4131 | |
|
|
4132 | For C<ev::embed> watchers this method is called C<set_embed>, to avoid |
|
|
4133 | clashing with the C<set (loop)> method. |
4125 | |
4134 | |
4126 | =item w->start () |
4135 | =item w->start () |
4127 | |
4136 | |
4128 | Starts the watcher. Note that there is no C<loop> argument, as the |
4137 | Starts the watcher. Note that there is no C<loop> argument, as the |
4129 | constructor already stores the event loop. |
4138 | constructor already stores the event loop. |
… | |
… | |
4232 | =item Lua |
4241 | =item Lua |
4233 | |
4242 | |
4234 | Brian Maher has written a partial interface to libev for lua (at the |
4243 | Brian Maher has written a partial interface to libev for lua (at the |
4235 | time of this writing, only C<ev_io> and C<ev_timer>), to be found at |
4244 | time of this writing, only C<ev_io> and C<ev_timer>), to be found at |
4236 | L<http://github.com/brimworks/lua-ev>. |
4245 | L<http://github.com/brimworks/lua-ev>. |
|
|
4246 | |
|
|
4247 | =item Javascript |
|
|
4248 | |
|
|
4249 | Node.js (L<http://nodejs.org>) uses libev as the underlying event library. |
|
|
4250 | |
|
|
4251 | =item Others |
|
|
4252 | |
|
|
4253 | There are others, and I stopped counting. |
4237 | |
4254 | |
4238 | =back |
4255 | =back |
4239 | |
4256 | |
4240 | |
4257 | |
4241 | =head1 MACRO MAGIC |
4258 | =head1 MACRO MAGIC |
… | |
… | |
4540 | |
4557 | |
4541 | If programs implement their own fd to handle mapping on win32, then this |
4558 | If programs implement their own fd to handle mapping on win32, then this |
4542 | macro can be used to override the C<close> function, useful to unregister |
4559 | macro can be used to override the C<close> function, useful to unregister |
4543 | file descriptors again. Note that the replacement function has to close |
4560 | file descriptors again. Note that the replacement function has to close |
4544 | the underlying OS handle. |
4561 | the underlying OS handle. |
|
|
4562 | |
|
|
4563 | =item EV_USE_WSASOCKET |
|
|
4564 | |
|
|
4565 | If defined to be C<1>, libev will use C<WSASocket> to create its internal |
|
|
4566 | communication socket, which works better in some environments. Otherwise, |
|
|
4567 | the normal C<socket> function will be used, which works better in other |
|
|
4568 | environments. |
4545 | |
4569 | |
4546 | =item EV_USE_POLL |
4570 | =item EV_USE_POLL |
4547 | |
4571 | |
4548 | If defined to be C<1>, libev will compile in support for the C<poll>(2) |
4572 | If defined to be C<1>, libev will compile in support for the C<poll>(2) |
4549 | backend. Otherwise it will be enabled on non-win32 platforms. It |
4573 | backend. Otherwise it will be enabled on non-win32 platforms. It |
… | |
… | |
4594 | different cpus (or different cpu cores). This reduces dependencies |
4618 | different cpus (or different cpu cores). This reduces dependencies |
4595 | and makes libev faster. |
4619 | and makes libev faster. |
4596 | |
4620 | |
4597 | =item EV_NO_THREADS |
4621 | =item EV_NO_THREADS |
4598 | |
4622 | |
4599 | If defined to be C<1>, libev will assume that it will never be called |
4623 | If defined to be C<1>, libev will assume that it will never be called from |
4600 | from different threads, which is a stronger assumption than C<EV_NO_SMP>, |
4624 | different threads (that includes signal handlers), which is a stronger |
4601 | above. This reduces dependencies and makes libev faster. |
4625 | assumption than C<EV_NO_SMP>, above. This reduces dependencies and makes |
|
|
4626 | libev faster. |
4602 | |
4627 | |
4603 | =item EV_ATOMIC_T |
4628 | =item EV_ATOMIC_T |
4604 | |
4629 | |
4605 | Libev requires an integer type (suitable for storing C<0> or C<1>) whose |
4630 | Libev requires an integer type (suitable for storing C<0> or C<1>) whose |
4606 | access is atomic and serialised with respect to other threads or signal |
4631 | access is atomic with respect to other threads or signal contexts. No |
4607 | contexts. No such type is easily found in the C language, so you can |
4632 | such type is easily found in the C language, so you can provide your own |
4608 | provide your own type that you know is safe for your purposes. It is used |
4633 | type that you know is safe for your purposes. It is used both for signal |
4609 | both for signal handler "locking" as well as for signal and thread safety |
4634 | handler "locking" as well as for signal and thread safety in C<ev_async> |
4610 | in C<ev_async> watchers. |
4635 | watchers. |
4611 | |
4636 | |
4612 | In the absence of this define, libev will use C<sig_atomic_t volatile> |
4637 | In the absence of this define, libev will use C<sig_atomic_t volatile> |
4613 | (from F<signal.h>), which is usually good enough on most platforms, |
4638 | (from F<signal.h>), which is usually good enough on most platforms. |
4614 | although strictly speaking using a type that also implies a memory fence |
|
|
4615 | is required. |
|
|
4616 | |
4639 | |
4617 | =item EV_H (h) |
4640 | =item EV_H (h) |
4618 | |
4641 | |
4619 | The name of the F<ev.h> header file used to include it. The default if |
4642 | The name of the F<ev.h> header file used to include it. The default if |
4620 | undefined is C<"ev.h"> in F<event.h>, F<ev.c> and F<ev++.h>. This can be |
4643 | undefined is C<"ev.h"> in F<event.h>, F<ev.c> and F<ev++.h>. This can be |
… | |
… | |
4988 | default loop and triggering an C<ev_async> watcher from the default loop |
5011 | default loop and triggering an C<ev_async> watcher from the default loop |
4989 | watcher callback into the event loop interested in the signal. |
5012 | watcher callback into the event loop interested in the signal. |
4990 | |
5013 | |
4991 | =back |
5014 | =back |
4992 | |
5015 | |
4993 | See also L<THREAD LOCKING EXAMPLE>. |
5016 | See also L</THREAD LOCKING EXAMPLE>. |
4994 | |
5017 | |
4995 | =head3 COROUTINES |
5018 | =head3 COROUTINES |
4996 | |
5019 | |
4997 | Libev is very accommodating to coroutines ("cooperative threads"): |
5020 | Libev is very accommodating to coroutines ("cooperative threads"): |
4998 | libev fully supports nesting calls to its functions from different |
5021 | libev fully supports nesting calls to its functions from different |
… | |
… | |
5289 | thread" or will block signals process-wide, both behaviours would |
5312 | thread" or will block signals process-wide, both behaviours would |
5290 | be compatible with libev. Interaction between C<sigprocmask> and |
5313 | be compatible with libev. Interaction between C<sigprocmask> and |
5291 | C<pthread_sigmask> could complicate things, however. |
5314 | C<pthread_sigmask> could complicate things, however. |
5292 | |
5315 | |
5293 | The most portable way to handle signals is to block signals in all threads |
5316 | The most portable way to handle signals is to block signals in all threads |
5294 | except the initial one, and run the default loop in the initial thread as |
5317 | except the initial one, and run the signal handling loop in the initial |
5295 | well. |
5318 | thread as well. |
5296 | |
5319 | |
5297 | =item C<long> must be large enough for common memory allocation sizes |
5320 | =item C<long> must be large enough for common memory allocation sizes |
5298 | |
5321 | |
5299 | To improve portability and simplify its API, libev uses C<long> internally |
5322 | To improve portability and simplify its API, libev uses C<long> internally |
5300 | instead of C<size_t> when allocating its data structures. On non-POSIX |
5323 | instead of C<size_t> when allocating its data structures. On non-POSIX |
… | |
… | |
5404 | =over 4 |
5427 | =over 4 |
5405 | |
5428 | |
5406 | =item C<EV_COMPAT3> backwards compatibility mechanism |
5429 | =item C<EV_COMPAT3> backwards compatibility mechanism |
5407 | |
5430 | |
5408 | The backward compatibility mechanism can be controlled by |
5431 | The backward compatibility mechanism can be controlled by |
5409 | C<EV_COMPAT3>. See L<PREPROCESSOR SYMBOLS/MACROS> in the L<EMBEDDING> |
5432 | C<EV_COMPAT3>. See L</PREPROCESSOR SYMBOLS/MACROS> in the L</EMBEDDING> |
5410 | section. |
5433 | section. |
5411 | |
5434 | |
5412 | =item C<ev_default_destroy> and C<ev_default_fork> have been removed |
5435 | =item C<ev_default_destroy> and C<ev_default_fork> have been removed |
5413 | |
5436 | |
5414 | These calls can be replaced easily by their C<ev_loop_xxx> counterparts: |
5437 | These calls can be replaced easily by their C<ev_loop_xxx> counterparts: |
… | |
… | |
5457 | =over 4 |
5480 | =over 4 |
5458 | |
5481 | |
5459 | =item active |
5482 | =item active |
5460 | |
5483 | |
5461 | A watcher is active as long as it has been started and not yet stopped. |
5484 | A watcher is active as long as it has been started and not yet stopped. |
5462 | See L<WATCHER STATES> for details. |
5485 | See L</WATCHER STATES> for details. |
5463 | |
5486 | |
5464 | =item application |
5487 | =item application |
5465 | |
5488 | |
5466 | In this document, an application is whatever is using libev. |
5489 | In this document, an application is whatever is using libev. |
5467 | |
5490 | |
… | |
… | |
5503 | watchers and events. |
5526 | watchers and events. |
5504 | |
5527 | |
5505 | =item pending |
5528 | =item pending |
5506 | |
5529 | |
5507 | A watcher is pending as soon as the corresponding event has been |
5530 | A watcher is pending as soon as the corresponding event has been |
5508 | detected. See L<WATCHER STATES> for details. |
5531 | detected. See L</WATCHER STATES> for details. |
5509 | |
5532 | |
5510 | =item real time |
5533 | =item real time |
5511 | |
5534 | |
5512 | The physical time that is observed. It is apparently strictly monotonic :) |
5535 | The physical time that is observed. It is apparently strictly monotonic :) |
5513 | |
5536 | |