… | |
… | |
345 | useful to try out specific backends to test their performance, or to work |
345 | useful to try out specific backends to test their performance, or to work |
346 | around bugs. |
346 | around bugs. |
347 | |
347 | |
348 | =item C<EVFLAG_FORKCHECK> |
348 | =item C<EVFLAG_FORKCHECK> |
349 | |
349 | |
350 | Instead of calling C<ev_default_fork> or C<ev_loop_fork> manually after |
350 | Instead of calling C<ev_loop_fork> manually after a fork, you can also |
351 | a fork, you can also make libev check for a fork in each iteration by |
351 | make libev check for a fork in each iteration by enabling this flag. |
352 | enabling this flag. |
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|
353 | |
352 | |
354 | This works by calling C<getpid ()> on every iteration of the loop, |
353 | This works by calling C<getpid ()> on every iteration of the loop, |
355 | and thus this might slow down your event loop if you do a lot of loop |
354 | and thus this might slow down your event loop if you do a lot of loop |
356 | iterations and little real work, but is usually not noticeable (on my |
355 | iterations and little real work, but is usually not noticeable (on my |
357 | GNU/Linux system for example, C<getpid> is actually a simple 5-insn sequence |
356 | GNU/Linux system for example, C<getpid> is actually a simple 5-insn sequence |
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… | |
611 | name, you can call it anytime, but it makes most sense after forking, in |
610 | name, you can call it anytime, but it makes most sense after forking, in |
612 | the child process (or both child and parent, but that again makes little |
611 | the child process (or both child and parent, but that again makes little |
613 | sense). You I<must> call it in the child before using any of the libev |
612 | sense). You I<must> call it in the child before using any of the libev |
614 | functions, and it will only take effect at the next C<ev_loop> iteration. |
613 | functions, and it will only take effect at the next C<ev_loop> iteration. |
615 | |
614 | |
|
|
615 | Again, you I<have> to call it on I<any> loop that you want to re-use after |
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|
616 | a fork, I<even if you do not plan to use the loop in the parent>. This is |
|
|
617 | because some kernel interfaces *cough* I<kqueue> *cough* do funny things |
|
|
618 | during fork. |
|
|
619 | |
616 | On the other hand, you only need to call this function in the child |
620 | On the other hand, you only need to call this function in the child |
617 | process if and only if you want to use the event library in the child. If |
621 | process if and only if you want to use the event loop in the child. If you |
618 | you just fork+exec, you don't have to call it at all. |
622 | just fork+exec or create a new loop in the child, you don't have to call |
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|
623 | it at all. |
619 | |
624 | |
620 | The function itself is quite fast and it's usually not a problem to call |
625 | The function itself is quite fast and it's usually not a problem to call |
621 | it just in case after a fork. To make this easy, the function will fit in |
626 | it just in case after a fork. To make this easy, the function will fit in |
622 | quite nicely into a call to C<pthread_atfork>: |
627 | quite nicely into a call to C<pthread_atfork>: |
623 | |
628 | |
… | |
… | |
625 | |
630 | |
626 | =item ev_loop_fork (loop) |
631 | =item ev_loop_fork (loop) |
627 | |
632 | |
628 | Like C<ev_default_fork>, but acts on an event loop created by |
633 | Like C<ev_default_fork>, but acts on an event loop created by |
629 | C<ev_loop_new>. Yes, you have to call this on every allocated event loop |
634 | C<ev_loop_new>. Yes, you have to call this on every allocated event loop |
630 | after fork that you want to re-use in the child, and how you do this is |
635 | after fork that you want to re-use in the child, and how you keep track of |
631 | entirely your own problem. |
636 | them is entirely your own problem. |
632 | |
637 | |
633 | =item int ev_is_default_loop (loop) |
638 | =item int ev_is_default_loop (loop) |
634 | |
639 | |
635 | Returns true when the given loop is, in fact, the default loop, and false |
640 | Returns true when the given loop is, in fact, the default loop, and false |
636 | otherwise. |
641 | otherwise. |
637 | |
642 | |
638 | =item unsigned int ev_loop_count (loop) |
643 | =item unsigned int ev_iteration (loop) |
639 | |
644 | |
640 | Returns the count of loop iterations for the loop, which is identical to |
645 | Returns the current iteration count for the loop, which is identical to |
641 | the number of times libev did poll for new events. It starts at C<0> and |
646 | the number of times libev did poll for new events. It starts at C<0> and |
642 | happily wraps around with enough iterations. |
647 | happily wraps around with enough iterations. |
643 | |
648 | |
644 | This value can sometimes be useful as a generation counter of sorts (it |
649 | This value can sometimes be useful as a generation counter of sorts (it |
645 | "ticks" the number of loop iterations), as it roughly corresponds with |
650 | "ticks" the number of loop iterations), as it roughly corresponds with |
646 | C<ev_prepare> and C<ev_check> calls. |
651 | C<ev_prepare> and C<ev_check> calls - and is incremented between the |
|
|
652 | prepare and check phases. |
647 | |
653 | |
648 | =item unsigned int ev_loop_depth (loop) |
654 | =item unsigned int ev_depth (loop) |
649 | |
655 | |
650 | Returns the number of times C<ev_loop> was entered minus the number of |
656 | Returns the number of times C<ev_loop> was entered minus the number of |
651 | times C<ev_loop> was exited, in other words, the recursion depth. |
657 | times C<ev_loop> was exited, in other words, the recursion depth. |
652 | |
658 | |
653 | Outside C<ev_loop>, this number is zero. In a callback, this number is |
659 | Outside C<ev_loop>, this number is zero. In a callback, this number is |
654 | C<1>, unless C<ev_loop> was invoked recursively (or from another thread), |
660 | C<1>, unless C<ev_loop> was invoked recursively (or from another thread), |
655 | in which case it is higher. |
661 | in which case it is higher. |
656 | |
662 | |
657 | Leaving C<ev_loop> abnormally (setjmp/longjmp, cancelling the thread |
663 | Leaving C<ev_loop> abnormally (setjmp/longjmp, cancelling the thread |
658 | etc.), doesn't count as exit. |
664 | etc.), doesn't count as "exit" - consider this as a hint to avoid such |
|
|
665 | ungentleman behaviour unless it's really convenient. |
659 | |
666 | |
660 | =item unsigned int ev_backend (loop) |
667 | =item unsigned int ev_backend (loop) |
661 | |
668 | |
662 | Returns one of the C<EVBACKEND_*> flags indicating the event backend in |
669 | Returns one of the C<EVBACKEND_*> flags indicating the event backend in |
663 | use. |
670 | use. |
… | |
… | |
4618 | involves iterating over all running async watchers or all signal numbers. |
4625 | involves iterating over all running async watchers or all signal numbers. |
4619 | |
4626 | |
4620 | =back |
4627 | =back |
4621 | |
4628 | |
4622 | |
4629 | |
4623 | =head1 PORTING FROM 3.X TO 4.X |
4630 | =head1 PORTING FROM LIBEV 3.X TO 4.X |
4624 | |
4631 | |
4625 | The major version 4 introduced some minor incompatible changes to the API. |
4632 | The major version 4 introduced some minor incompatible changes to the API. |
4626 | |
4633 | |
|
|
4634 | At the moment, the C<ev.h> header file tries to implement superficial |
|
|
4635 | compatibility, so most programs should still compile. Those might be |
|
|
4636 | removed in later versions of libev, so better update early than late. |
|
|
4637 | |
4627 | =over 4 |
4638 | =over 4 |
4628 | |
4639 | |
|
|
4640 | =item C<ev_loop_count> renamed to C<ev_iteration> |
|
|
4641 | |
|
|
4642 | =item C<ev_loop_depth> renamed to C<ev_depth> |
|
|
4643 | |
|
|
4644 | =item C<ev_loop_verify> renamed to C<ev_verify> |
|
|
4645 | |
|
|
4646 | Most functions working on C<struct ev_loop> objects don't have an |
|
|
4647 | C<ev_loop_> prefix, so it was removed. Note that C<ev_loop_fork> is |
|
|
4648 | still called C<ev_loop_fork> because it would otherwise clash with the |
|
|
4649 | C<ev_frok> typedef. |
|
|
4650 | |
4629 | =item C<EV_TIMEOUT> replaced by C<EV_TIMER> in C<revents> |
4651 | =item C<EV_TIMEOUT> renamed to C<EV_TIMER> in C<revents> |
4630 | |
4652 | |
4631 | This is a simple rename - all other watcher types use their name |
4653 | This is a simple rename - all other watcher types use their name |
4632 | as revents flag, and now C<ev_timer> does, too. |
4654 | as revents flag, and now C<ev_timer> does, too. |
4633 | |
4655 | |
4634 | Both C<EV_TIMER> and C<EV_TIMEOUT> symbols were present in 3.x versions |
4656 | Both C<EV_TIMER> and C<EV_TIMEOUT> symbols were present in 3.x versions |