… | |
… | |
79 | our $VERSION = '2.0'; |
79 | our $VERSION = '2.0'; |
80 | |
80 | |
81 | our @EXPORT = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat |
81 | our @EXPORT = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat |
82 | aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink |
82 | aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink |
83 | aio_fsync aio_fdatasync aio_readahead aio_rename aio_link aio_move |
83 | aio_fsync aio_fdatasync aio_readahead aio_rename aio_link aio_move |
84 | aio_group); |
84 | aio_group aio_nop); |
85 | our @EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel max_outstanding nreqs); |
85 | our @EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel max_outstanding nreqs); |
86 | |
86 | |
87 | @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; |
87 | @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; |
88 | |
88 | |
89 | require XSLoader; |
89 | require XSLoader; |
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… | |
352 | Scans a directory (similar to C<aio_readdir>) but additionally tries to |
352 | Scans a directory (similar to C<aio_readdir>) but additionally tries to |
353 | separate the entries of directory C<$path> into two sets of names, ones |
353 | separate the entries of directory C<$path> into two sets of names, ones |
354 | you can recurse into (directories or links to them), and ones you cannot |
354 | you can recurse into (directories or links to them), and ones you cannot |
355 | recurse into (everything else). |
355 | recurse into (everything else). |
356 | |
356 | |
357 | C<aio_scandir> is a composite request that consists of many sub |
357 | C<aio_scandir> is a composite request that creates of many sub requests_ |
358 | requests. C<$maxreq> specifies the maximum number of outstanding aio |
358 | C<$maxreq> specifies the maximum number of outstanding aio requests that |
359 | requests that this function generates. If it is C<< <= 0 >>, then a |
359 | this function generates. If it is C<< <= 0 >>, then a suitable default |
360 | suitable default will be chosen (currently 8). |
360 | will be chosen (currently 6). |
361 | |
361 | |
362 | On error, the callback is called without arguments, otherwise it receives |
362 | On error, the callback is called without arguments, otherwise it receives |
363 | two array-refs with path-relative entry names. |
363 | two array-refs with path-relative entry names. |
364 | |
364 | |
365 | Example: |
365 | Example: |
… | |
… | |
404 | sub aio_scandir($$$) { |
404 | sub aio_scandir($$$) { |
405 | my ($path, $maxreq, $cb) = @_; |
405 | my ($path, $maxreq, $cb) = @_; |
406 | |
406 | |
407 | my $grp = aio_group $cb; |
407 | my $grp = aio_group $cb; |
408 | |
408 | |
409 | $maxreq = 8 if $maxreq <= 0; |
409 | $maxreq = 6 if $maxreq <= 0; |
410 | |
410 | |
411 | # stat once |
411 | # stat once |
412 | add $grp aio_stat $path, sub { |
412 | add $grp aio_stat $path, sub { |
413 | return $grp->result () if $_[0]; |
413 | return $grp->result () if $_[0]; |
414 | my $now = time; |
414 | my $now = time; |
… | |
… | |
533 | add $grp |
533 | add $grp |
534 | (aio_stat ...), |
534 | (aio_stat ...), |
535 | (aio_stat ...), |
535 | (aio_stat ...), |
536 | ...; |
536 | ...; |
537 | |
537 | |
|
|
538 | =item aio_nop $callback->() |
|
|
539 | |
|
|
540 | This is a special request - it does nothing in itself and is only used for |
|
|
541 | side effects, such as when you want to add a dummy request to a group so |
|
|
542 | that finishing the requests in the group depends on executing the given |
|
|
543 | code. |
|
|
544 | |
|
|
545 | While this request does nothing, it still goes through the execution |
|
|
546 | phase and still requires a worker thread. Thus, the callback will not |
|
|
547 | be executed immediately but only after other requests in the queue have |
|
|
548 | entered their execution phase. This can be used to measure request |
|
|
549 | latency. |
|
|
550 | |
538 | =item IO::AIO::aio_sleep $fractional_seconds, $callback->() *NOT EXPORTED* |
551 | =item IO::AIO::aio_sleep $fractional_seconds, $callback->() *NOT EXPORTED* |
539 | |
552 | |
540 | Mainly used for debugging and benchmarking, this aio request puts one of |
553 | Mainly used for debugging and benchmarking, this aio request puts one of |
541 | the request workers to sleep for the given time. |
554 | the request workers to sleep for the given time. |
542 | |
555 | |
… | |
… | |
603 | }; |
616 | }; |
604 | |
617 | |
605 | This makes it very easy to create composite requests (see the source of |
618 | This makes it very easy to create composite requests (see the source of |
606 | C<aio_move> for an application) that work and feel like simple requests. |
619 | C<aio_move> for an application) that work and feel like simple requests. |
607 | |
620 | |
|
|
621 | =over 4 |
|
|
622 | |
608 | The IO::AIO::GRP objects will be cleaned up during calls to |
623 | =item * The IO::AIO::GRP objects will be cleaned up during calls to |
609 | C<IO::AIO::poll_cb>, just like any other request. |
624 | C<IO::AIO::poll_cb>, just like any other request. |
610 | |
625 | |
611 | They can be canceled like any other request. Canceling will cancel not |
626 | =item * They can be canceled like any other request. Canceling will cancel not |
612 | only the request itself, but also all requests it contains. |
627 | only the request itself, but also all requests it contains. |
613 | |
628 | |
614 | They can also can also be added to other IO::AIO::GRP objects. |
629 | =item * They can also can also be added to other IO::AIO::GRP objects. |
615 | |
630 | |
616 | You must not add requests to a group from within the group callback (or |
631 | =item * You must not add requests to a group from within the group callback (or |
617 | any later time). |
632 | any later time). |
|
|
633 | |
|
|
634 | =item * This does not harmonise well with C<max_outstanding>, so best do |
|
|
635 | not combine C<aio_group> with it. Groups and feeders are recommended for |
|
|
636 | this kind of concurrency-limiting. |
|
|
637 | |
|
|
638 | =back |
618 | |
639 | |
619 | Their lifetime, simplified, looks like this: when they are empty, they |
640 | Their lifetime, simplified, looks like this: when they are empty, they |
620 | will finish very quickly. If they contain only requests that are in the |
641 | will finish very quickly. If they contain only requests that are in the |
621 | C<done> state, they will also finish. Otherwise they will continue to |
642 | C<done> state, they will also finish. Otherwise they will continue to |
622 | exist. |
643 | exist. |
… | |
… | |
752 | IO::AIO::poll_wait, IO::AIO::poll_cb |
773 | IO::AIO::poll_wait, IO::AIO::poll_cb |
753 | if IO::AIO::nreqs; |
774 | if IO::AIO::nreqs; |
754 | |
775 | |
755 | =item IO::AIO::min_parallel $nthreads |
776 | =item IO::AIO::min_parallel $nthreads |
756 | |
777 | |
757 | Set the minimum number of AIO threads to C<$nthreads>. The current default |
778 | Set the minimum number of AIO threads to C<$nthreads>. The current |
758 | is C<4>, which means four asynchronous operations can be done at one time |
779 | default is C<8>, which means eight asynchronous operations can execute |
759 | (the number of outstanding operations, however, is unlimited). |
780 | concurrently at any one time (the number of outstanding requests, |
|
|
781 | however, is unlimited). |
760 | |
782 | |
761 | IO::AIO starts threads only on demand, when an AIO request is queued and |
783 | IO::AIO starts threads only on demand, when an AIO request is queued and |
762 | no free thread exists. |
784 | no free thread exists. |
763 | |
785 | |
764 | It is recommended to keep the number of threads low, as some Linux |
786 | It is recommended to keep the number of threads relatively low, as some |
765 | kernel versions will scale negatively with the number of threads (higher |
787 | Linux kernel versions will scale negatively with the number of threads |
766 | parallelity => MUCH higher latency). With current Linux 2.6 versions, 4-32 |
788 | (higher parallelity => MUCH higher latency). With current Linux 2.6 |
767 | threads should be fine. |
789 | versions, 4-32 threads should be fine. |
768 | |
790 | |
769 | Under most circumstances you don't need to call this function, as the |
791 | Under most circumstances you don't need to call this function, as the |
770 | module selects a default that is suitable for low to moderate load. |
792 | module selects a default that is suitable for low to moderate load. |
771 | |
793 | |
772 | =item IO::AIO::max_parallel $nthreads |
794 | =item IO::AIO::max_parallel $nthreads |
… | |
… | |
783 | |
805 | |
784 | Under normal circumstances you don't need to call this function. |
806 | Under normal circumstances you don't need to call this function. |
785 | |
807 | |
786 | =item $oldnreqs = IO::AIO::max_outstanding $nreqs |
808 | =item $oldnreqs = IO::AIO::max_outstanding $nreqs |
787 | |
809 | |
|
|
810 | [DEPRECATED] |
|
|
811 | |
788 | Sets the maximum number of outstanding requests to C<$nreqs>. If you |
812 | Sets the maximum number of outstanding requests to C<$nreqs>. If you |
789 | try to queue up more than this number of requests, the caller will block until |
813 | try to queue up more than this number of requests, the caller will block until |
790 | some requests have been handled. |
814 | some requests have been handled. |
791 | |
815 | |
792 | The default is very large, so normally there is no practical limit. If you |
816 | The default is very large, so normally there is no practical limit. If you |
793 | queue up many requests in a loop it often improves speed if you set |
817 | queue up many requests in a loop it often improves speed if you set |
794 | this to a relatively low number, such as C<100>. |
818 | this to a relatively low number, such as C<100>. |
|
|
819 | |
|
|
820 | This function does not work well together with C<aio_group>'s, and their |
|
|
821 | feeder interface is better suited to limiting concurrency, so do not use |
|
|
822 | this function. |
795 | |
823 | |
796 | Under normal circumstances you don't need to call this function. |
824 | Under normal circumstances you don't need to call this function. |
797 | |
825 | |
798 | =back |
826 | =back |
799 | |
827 | |
… | |
… | |
813 | or return undef; |
841 | or return undef; |
814 | |
842 | |
815 | *$sym |
843 | *$sym |
816 | } |
844 | } |
817 | |
845 | |
818 | min_parallel 4; |
846 | min_parallel 8; |
819 | |
847 | |
820 | END { |
848 | END { |
821 | max_parallel 0; |
849 | max_parallel 0; |
822 | } |
850 | } |
823 | |
851 | |