… | |
… | |
24 | $req->cancel; # cancel request if still in queue |
24 | $req->cancel; # cancel request if still in queue |
25 | |
25 | |
26 | my $grp = aio_group sub { print "all stats done\n" }; |
26 | my $grp = aio_group sub { print "all stats done\n" }; |
27 | add $grp aio_stat "..." for ...; |
27 | add $grp aio_stat "..." for ...; |
28 | |
28 | |
|
|
29 | # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...) |
|
|
30 | use AnyEvent::AIO; |
|
|
31 | |
29 | # AnyEvent integration |
32 | # EV integration |
30 | open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!"; |
33 | my $w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
31 | my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb }); |
|
|
32 | |
34 | |
33 | # Event integration |
35 | # Event integration |
34 | Event->io (fd => IO::AIO::poll_fileno, |
36 | Event->io (fd => IO::AIO::poll_fileno, |
35 | poll => 'r', |
37 | poll => 'r', |
36 | cb => \&IO::AIO::poll_cb); |
38 | cb => \&IO::AIO::poll_cb); |
… | |
… | |
173 | All the "aio_*" calls are more or less thin wrappers around the syscall |
175 | All the "aio_*" calls are more or less thin wrappers around the syscall |
174 | with the same name (sans "aio_"). The arguments are similar or |
176 | with the same name (sans "aio_"). The arguments are similar or |
175 | identical, and they all accept an additional (and optional) $callback |
177 | identical, and they all accept an additional (and optional) $callback |
176 | argument which must be a code reference. This code reference will get |
178 | argument which must be a code reference. This code reference will get |
177 | called with the syscall return code (e.g. most syscalls return -1 on |
179 | called with the syscall return code (e.g. most syscalls return -1 on |
178 | error, unlike perl, which usually delivers "false") as it's sole |
180 | error, unlike perl, which usually delivers "false") as its sole argument |
179 | argument when the given syscall has been executed asynchronously. |
181 | after the given syscall has been executed asynchronously. |
180 | |
182 | |
181 | All functions expecting a filehandle keep a copy of the filehandle |
183 | All functions expecting a filehandle keep a copy of the filehandle |
182 | internally until the request has finished. |
184 | internally until the request has finished. |
183 | |
185 | |
184 | All functions return request objects of type IO::AIO::REQ that allow |
186 | All functions return request objects of type IO::AIO::REQ that allow |
… | |
… | |
197 | the user environment, d) use Glib::filename_from_unicode on unicode |
199 | the user environment, d) use Glib::filename_from_unicode on unicode |
198 | filenames or e) use something else to ensure your scalar has the correct |
200 | filenames or e) use something else to ensure your scalar has the correct |
199 | contents. |
201 | contents. |
200 | |
202 | |
201 | This works, btw. independent of the internal UTF-8 bit, which IO::AIO |
203 | This works, btw. independent of the internal UTF-8 bit, which IO::AIO |
202 | handles correctly wether it is set or not. |
204 | handles correctly whether it is set or not. |
203 | |
205 | |
204 | $prev_pri = aioreq_pri [$pri] |
206 | $prev_pri = aioreq_pri [$pri] |
205 | Returns the priority value that would be used for the next request |
207 | Returns the priority value that would be used for the next request |
206 | and, if $pri is given, sets the priority for the next aio request. |
208 | and, if $pri is given, sets the priority for the next aio request. |
207 | |
209 | |
… | |
… | |
262 | Asynchronously close a file and call the callback with the result |
264 | Asynchronously close a file and call the callback with the result |
263 | code. |
265 | code. |
264 | |
266 | |
265 | Unfortunately, you can't do this to perl. Perl *insists* very |
267 | Unfortunately, you can't do this to perl. Perl *insists* very |
266 | strongly on closing the file descriptor associated with the |
268 | strongly on closing the file descriptor associated with the |
267 | filehandle itself. Here is what aio_close will try: |
269 | filehandle itself. |
268 | |
270 | |
269 | 1. dup()licate the fd |
271 | Therefore, "aio_close" will not close the filehandle - instead it |
270 | 2. asynchronously close() the duplicated fd |
272 | will use dup2 to overwrite the file descriptor with the write-end of |
271 | 3. dup()licate the fd once more |
273 | a pipe (the pipe fd will be created on demand and will be cached). |
272 | 4. let perl close() the filehandle |
|
|
273 | 5. asynchronously close the duplicated fd |
|
|
274 | |
274 | |
275 | The idea is that the first close() flushes stuff to disk that |
275 | Or in other words: the file descriptor will be closed, but it will |
276 | closing an fd will flush, so when perl closes the fd, nothing much |
276 | not be free for reuse until the perl filehandle is closed. |
277 | will need to be flushed. The second async. close() will then flush |
|
|
278 | stuff to disk that closing the last fd to the file will flush. |
|
|
279 | |
|
|
280 | Just FYI, SuSv3 has this to say on close: |
|
|
281 | |
|
|
282 | All outstanding record locks owned by the process on the file |
|
|
283 | associated with the file descriptor shall be removed. |
|
|
284 | |
|
|
285 | If fildes refers to a socket, close() shall cause the socket to be |
|
|
286 | destroyed. ... close() shall block for up to the current linger |
|
|
287 | interval until all data is transmitted. |
|
|
288 | [this actually sounds like a specification bug, but who knows] |
|
|
289 | |
|
|
290 | And at least Linux additionally actually flushes stuff on every |
|
|
291 | close, even when the file itself is still open. |
|
|
292 | |
|
|
293 | Sounds enourmously inefficient and complicated? Yes... please show |
|
|
294 | me how to nuke perl's fd out of existence... |
|
|
295 | |
277 | |
296 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
278 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
297 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
279 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
298 | Reads or writes $length bytes from the specified $fh and $offset |
280 | Reads or writes $length bytes from the specified $fh and $offset |
299 | into the scalar given by $data and offset $dataoffset and calls the |
281 | into the scalar given by $data and offset $dataoffset and calls the |
… | |
… | |
469 | aio_copy $srcpath, $dstpath, $callback->($status) |
451 | aio_copy $srcpath, $dstpath, $callback->($status) |
470 | Try to copy the *file* (directories not supported as either source |
452 | Try to copy the *file* (directories not supported as either source |
471 | or destination) from $srcpath to $dstpath and call the callback with |
453 | or destination) from $srcpath to $dstpath and call the callback with |
472 | the 0 (error) or -1 ok. |
454 | the 0 (error) or -1 ok. |
473 | |
455 | |
474 | This is a composite request that it creates the destination file |
456 | This is a composite request that creates the destination file with |
475 | with mode 0200 and copies the contents of the source file into it |
457 | mode 0200 and copies the contents of the source file into it using |
476 | using "aio_sendfile", followed by restoring atime, mtime, access |
458 | "aio_sendfile", followed by restoring atime, mtime, access mode and |
477 | mode and uid/gid, in that order. |
459 | uid/gid, in that order. |
478 | |
460 | |
479 | If an error occurs, the partial destination file will be unlinked, |
461 | If an error occurs, the partial destination file will be unlinked, |
480 | if possible, except when setting atime, mtime, access mode and |
462 | if possible, except when setting atime, mtime, access mode and |
481 | uid/gid, where errors are being ignored. |
463 | uid/gid, where errors are being ignored. |
482 | |
464 | |
483 | aio_move $srcpath, $dstpath, $callback->($status) |
465 | aio_move $srcpath, $dstpath, $callback->($status) |
484 | Try to move the *file* (directories not supported as either source |
466 | Try to move the *file* (directories not supported as either source |
485 | or destination) from $srcpath to $dstpath and call the callback with |
467 | or destination) from $srcpath to $dstpath and call the callback with |
486 | the 0 (error) or -1 ok. |
468 | the 0 (error) or -1 ok. |
487 | |
469 | |
488 | This is a composite request that tries to rename(2) the file first. |
470 | This is a composite request that tries to rename(2) the file first; |
489 | If rename files with "EXDEV", it copies the file with "aio_copy" |
471 | if rename fails with "EXDEV", it copies the file with "aio_copy" |
490 | and, if that is successful, unlinking the $srcpath. |
472 | and, if that is successful, unlinks the $srcpath. |
491 | |
473 | |
492 | aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
474 | aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
493 | Scans a directory (similar to "aio_readdir") but additionally tries |
475 | Scans a directory (similar to "aio_readdir") but additionally tries |
494 | to efficiently separate the entries of directory $path into two sets |
476 | to efficiently separate the entries of directory $path into two sets |
495 | of names, directories you can recurse into (directories), and ones |
477 | of names, directories you can recurse into (directories), and ones |
… | |
… | |
546 | Delete a directory tree starting (and including) $path, return the |
528 | Delete a directory tree starting (and including) $path, return the |
547 | status of the final "rmdir" only. This is a composite request that |
529 | status of the final "rmdir" only. This is a composite request that |
548 | uses "aio_scandir" to recurse into and rmdir directories, and unlink |
530 | uses "aio_scandir" to recurse into and rmdir directories, and unlink |
549 | everything else. |
531 | everything else. |
550 | |
532 | |
|
|
533 | aio_sync $callback->($status) |
|
|
534 | Asynchronously call sync and call the callback when finished. |
|
|
535 | |
551 | aio_fsync $fh, $callback->($status) |
536 | aio_fsync $fh, $callback->($status) |
552 | Asynchronously call fsync on the given filehandle and call the |
537 | Asynchronously call fsync on the given filehandle and call the |
553 | callback with the fsync result code. |
538 | callback with the fsync result code. |
554 | |
539 | |
555 | aio_fdatasync $fh, $callback->($status) |
540 | aio_fdatasync $fh, $callback->($status) |
556 | Asynchronously call fdatasync on the given filehandle and call the |
541 | Asynchronously call fdatasync on the given filehandle and call the |
557 | callback with the fdatasync result code. |
542 | callback with the fdatasync result code. |
558 | |
543 | |
559 | If this call isn't available because your OS lacks it or it couldn't |
544 | If this call isn't available because your OS lacks it or it couldn't |
560 | be detected, it will be emulated by calling "fsync" instead. |
545 | be detected, it will be emulated by calling "fsync" instead. |
|
|
546 | |
|
|
547 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
|
|
548 | Sync the data portion of the file specified by $offset and $length |
|
|
549 | to disk (but NOT the metadata), by calling the Linux-specific |
|
|
550 | sync_file_range call. If sync_file_range is not available or it |
|
|
551 | returns ENOSYS, then fdatasync or fsync is being substituted. |
|
|
552 | |
|
|
553 | $flags can be a combination of |
|
|
554 | "IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE", |
|
|
555 | "IO::AIO::SYNC_FILE_RANGE_WRITE" and |
|
|
556 | "IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER": refer to the sync_file_range |
|
|
557 | manpage for details. |
|
|
558 | |
|
|
559 | aio_pathsync $path, $callback->($status) |
|
|
560 | This request tries to open, fsync and close the given path. This is |
|
|
561 | a composite request intended to sync directories after directory |
|
|
562 | operations (E.g. rename). This might not work on all operating |
|
|
563 | systems or have any specific effect, but usually it makes sure that |
|
|
564 | directory changes get written to disc. It works for anything that |
|
|
565 | can be opened for read-only, not just directories. |
|
|
566 | |
|
|
567 | Passes 0 when everything went ok, and -1 on error. |
561 | |
568 | |
562 | aio_group $callback->(...) |
569 | aio_group $callback->(...) |
563 | This is a very special aio request: Instead of doing something, it |
570 | This is a very special aio request: Instead of doing something, it |
564 | is a container for other aio requests, which is useful if you want |
571 | is a container for other aio requests, which is useful if you want |
565 | to bundle many requests into a single, composite, request with a |
572 | to bundle many requests into a single, composite, request with a |
… | |
… | |
647 | }; |
654 | }; |
648 | |
655 | |
649 | This makes it very easy to create composite requests (see the source of |
656 | This makes it very easy to create composite requests (see the source of |
650 | "aio_move" for an application) that work and feel like simple requests. |
657 | "aio_move" for an application) that work and feel like simple requests. |
651 | |
658 | |
652 | * The IO::AIO::GRP objects will be cleaned up during calls to |
659 | * The IO::AIO::GRP objects will be cleaned up during calls to |
653 | "IO::AIO::poll_cb", just like any other request. |
660 | "IO::AIO::poll_cb", just like any other request. |
|
|
661 | |
654 | * They can be canceled like any other request. Canceling will cancel not |
662 | * They can be canceled like any other request. Canceling will cancel |
655 | only the request itself, but also all requests it contains. |
663 | not only the request itself, but also all requests it contains. |
|
|
664 | |
656 | * They can also can also be added to other IO::AIO::GRP objects. |
665 | * They can also can also be added to other IO::AIO::GRP objects. |
|
|
666 | |
657 | * You must not add requests to a group from within the group callback |
667 | * You must not add requests to a group from within the group callback |
658 | (or any later time). |
668 | (or any later time). |
659 | |
669 | |
660 | Their lifetime, simplified, looks like this: when they are empty, they |
670 | Their lifetime, simplified, looks like this: when they are empty, they |
661 | will finish very quickly. If they contain only requests that are in the |
671 | will finish very quickly. If they contain only requests that are in the |
662 | "done" state, they will also finish. Otherwise they will continue to |
672 | "done" state, they will also finish. Otherwise they will continue to |
663 | exist. |
673 | exist. |
664 | |
674 | |
665 | That means after creating a group you have some time to add requests. |
675 | That means after creating a group you have some time to add requests |
666 | And in the callbacks of those requests, you can add further requests to |
676 | (precisely before the callback has been invoked, which is only done |
667 | the group. And only when all those requests have finished will the the |
677 | within the "poll_cb"). And in the callbacks of those requests, you can |
668 | group itself finish. |
678 | add further requests to the group. And only when all those requests have |
|
|
679 | finished will the the group itself finish. |
669 | |
680 | |
670 | add $grp ... |
681 | add $grp ... |
671 | $grp->add (...) |
682 | $grp->add (...) |
672 | Add one or more requests to the group. Any type of IO::AIO::REQ can |
683 | Add one or more requests to the group. Any type of IO::AIO::REQ can |
673 | be added, including other groups, as long as you do not create |
684 | be added, including other groups, as long as you do not create |
… | |
… | |
680 | request itself. Useful when you queued a lot of events but got a |
691 | request itself. Useful when you queued a lot of events but got a |
681 | result early. |
692 | result early. |
682 | |
693 | |
683 | $grp->result (...) |
694 | $grp->result (...) |
684 | Set the result value(s) that will be passed to the group callback |
695 | Set the result value(s) that will be passed to the group callback |
685 | when all subrequests have finished and set thre groups errno to the |
696 | when all subrequests have finished and set the groups errno to the |
686 | current value of errno (just like calling "errno" without an error |
697 | current value of errno (just like calling "errno" without an error |
687 | number). By default, no argument will be passed and errno is zero. |
698 | number). By default, no argument will be passed and errno is zero. |
688 | |
699 | |
689 | $grp->errno ([$errno]) |
700 | $grp->errno ([$errno]) |
690 | Sets the group errno value to $errno, or the current value of errno |
701 | Sets the group errno value to $errno, or the current value of errno |
… | |
… | |
716 | does not impose any limits). |
727 | does not impose any limits). |
717 | |
728 | |
718 | If the feed does not queue more requests when called, it will be |
729 | If the feed does not queue more requests when called, it will be |
719 | automatically removed from the group. |
730 | automatically removed from the group. |
720 | |
731 | |
721 | If the feed limit is 0, it will be set to 2 automatically. |
732 | If the feed limit is 0 when this method is called, it will be set to |
|
|
733 | 2 automatically. |
722 | |
734 | |
723 | Example: |
735 | Example: |
724 | |
736 | |
725 | # stat all files in @files, but only ever use four aio requests concurrently: |
737 | # stat all files in @files, but only ever use four aio requests concurrently: |
726 | |
738 | |
… | |
… | |
736 | limit $grp $num |
748 | limit $grp $num |
737 | Sets the feeder limit for the group: The feeder will be called |
749 | Sets the feeder limit for the group: The feeder will be called |
738 | whenever the group contains less than this many requests. |
750 | whenever the group contains less than this many requests. |
739 | |
751 | |
740 | Setting the limit to 0 will pause the feeding process. |
752 | Setting the limit to 0 will pause the feeding process. |
|
|
753 | |
|
|
754 | The default value for the limit is 0, but note that setting a feeder |
|
|
755 | automatically bumps it up to 2. |
741 | |
756 | |
742 | SUPPORT FUNCTIONS |
757 | SUPPORT FUNCTIONS |
743 | EVENT PROCESSING AND EVENT LOOP INTEGRATION |
758 | EVENT PROCESSING AND EVENT LOOP INTEGRATION |
744 | $fileno = IO::AIO::poll_fileno |
759 | $fileno = IO::AIO::poll_fileno |
745 | Return the *request result pipe file descriptor*. This filehandle |
760 | Return the *request result pipe file descriptor*. This filehandle |
… | |
… | |
749 | |
764 | |
750 | See "poll_cb" for an example. |
765 | See "poll_cb" for an example. |
751 | |
766 | |
752 | IO::AIO::poll_cb |
767 | IO::AIO::poll_cb |
753 | Process some outstanding events on the result pipe. You have to call |
768 | Process some outstanding events on the result pipe. You have to call |
754 | this regularly. Returns the number of events processed. Returns |
769 | this regularly. Returns 0 if all events could be processed, or -1 if |
755 | immediately when no events are outstanding. The amount of events |
770 | it returned earlier for whatever reason. Returns immediately when no |
|
|
771 | events are outstanding. The amount of events processed depends on |
756 | processed depends on the settings of "IO::AIO::max_poll_req" and |
772 | the settings of "IO::AIO::max_poll_req" and |
757 | "IO::AIO::max_poll_time". |
773 | "IO::AIO::max_poll_time". |
758 | |
774 | |
759 | If not all requests were processed for whatever reason, the |
775 | If not all requests were processed for whatever reason, the |
760 | filehandle will still be ready when "poll_cb" returns. |
776 | filehandle will still be ready when "poll_cb" returns, so normally |
|
|
777 | you don't have to do anything special to have it called later. |
761 | |
778 | |
762 | Example: Install an Event watcher that automatically calls |
779 | Example: Install an Event watcher that automatically calls |
763 | IO::AIO::poll_cb with high priority: |
780 | IO::AIO::poll_cb with high priority: |
764 | |
781 | |
765 | Event->io (fd => IO::AIO::poll_fileno, |
782 | Event->io (fd => IO::AIO::poll_fileno, |
… | |
… | |
871 | |
888 | |
872 | The default is probably ok in most situations, especially if thread |
889 | The default is probably ok in most situations, especially if thread |
873 | creation is fast. If thread creation is very slow on your system you |
890 | creation is fast. If thread creation is very slow on your system you |
874 | might want to use larger values. |
891 | might want to use larger values. |
875 | |
892 | |
876 | $oldmaxreqs = IO::AIO::max_outstanding $maxreqs |
893 | IO::AIO::max_outstanding $maxreqs |
877 | This is a very bad function to use in interactive programs because |
894 | This is a very bad function to use in interactive programs because |
878 | it blocks, and a bad way to reduce concurrency because it is |
895 | it blocks, and a bad way to reduce concurrency because it is |
879 | inexact: Better use an "aio_group" together with a feed callback. |
896 | inexact: Better use an "aio_group" together with a feed callback. |
880 | |
897 | |
881 | Sets the maximum number of outstanding requests to $nreqs. If you do |
898 | Sets the maximum number of outstanding requests to $nreqs. If you do |
… | |
… | |
885 | |
902 | |
886 | The default value is very large, so there is no practical limit on |
903 | The default value is very large, so there is no practical limit on |
887 | the number of outstanding requests. |
904 | the number of outstanding requests. |
888 | |
905 | |
889 | You can still queue as many requests as you want. Therefore, |
906 | You can still queue as many requests as you want. Therefore, |
890 | "max_oustsanding" is mainly useful in simple scripts (with low |
907 | "max_outstanding" is mainly useful in simple scripts (with low |
891 | values) or as a stop gap to shield against fatal memory overflow |
908 | values) or as a stop gap to shield against fatal memory overflow |
892 | (with large values). |
909 | (with large values). |
893 | |
910 | |
894 | STATISTICAL INFORMATION |
911 | STATISTICAL INFORMATION |
895 | IO::AIO::nreqs |
912 | IO::AIO::nreqs |
… | |
… | |
945 | |
962 | |
946 | KNOWN BUGS |
963 | KNOWN BUGS |
947 | Known bugs will be fixed in the next release. |
964 | Known bugs will be fixed in the next release. |
948 | |
965 | |
949 | SEE ALSO |
966 | SEE ALSO |
950 | Coro::AIO. |
967 | AnyEvent::AIO for easy integration into event loops, Coro::AIO for a |
|
|
968 | more natural syntax. |
951 | |
969 | |
952 | AUTHOR |
970 | AUTHOR |
953 | Marc Lehmann <schmorp@schmorp.de> |
971 | Marc Lehmann <schmorp@schmorp.de> |
954 | http://home.schmorp.de/ |
972 | http://home.schmorp.de/ |
955 | |
973 | |