… | |
… | |
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); |
… | |
… | |
61 | faster on a RAID volume or over NFS when you do a number of stat |
63 | faster on a RAID volume or over NFS when you do a number of stat |
62 | operations concurrently. |
64 | operations concurrently. |
63 | |
65 | |
64 | While most of this works on all types of file descriptors (for example |
66 | While most of this works on all types of file descriptors (for example |
65 | sockets), using these functions on file descriptors that support |
67 | sockets), using these functions on file descriptors that support |
66 | nonblocking operation (again, sockets, pipes etc.) is very inefficient |
68 | nonblocking operation (again, sockets, pipes etc.) is very inefficient. |
67 | or might not work (aio_read fails on sockets/pipes/fifos). Use an event |
|
|
68 | loop for that (such as the Event module): IO::AIO will naturally fit |
69 | Use an event loop for that (such as the Event module): IO::AIO will |
69 | into such an event loop itself. |
70 | naturally fit into such an event loop itself. |
70 | |
71 | |
71 | In this version, a number of threads are started that execute your |
72 | In this version, a number of threads are started that execute your |
72 | requests and signal their completion. You don't need thread support in |
73 | requests and signal their completion. You don't need thread support in |
73 | perl, and the threads created by this module will not be visible to |
74 | perl, and the threads created by this module will not be visible to |
74 | perl. In the future, this module might make use of the native aio |
75 | perl. In the future, this module might make use of the native aio |
… | |
… | |
76 | not well-supported or restricted (GNU/Linux doesn't allow them on normal |
77 | not well-supported or restricted (GNU/Linux doesn't allow them on normal |
77 | files currently, for example), and they would only support aio_read and |
78 | files currently, for example), and they would only support aio_read and |
78 | aio_write, so the remaining functionality would have to be implemented |
79 | aio_write, so the remaining functionality would have to be implemented |
79 | using threads anyway. |
80 | using threads anyway. |
80 | |
81 | |
81 | Although the module will work with in the presence of other (Perl-) |
82 | Although the module will work in the presence of other (Perl-) threads, |
82 | threads, it is currently not reentrant in any way, so use appropriate |
83 | it is currently not reentrant in any way, so use appropriate locking |
83 | locking yourself, always call "poll_cb" from within the same thread, or |
84 | yourself, always call "poll_cb" from within the same thread, or never |
84 | never call "poll_cb" (or other "aio_" functions) recursively. |
85 | call "poll_cb" (or other "aio_" functions) recursively. |
85 | |
86 | |
86 | EXAMPLE |
87 | EXAMPLE |
87 | This is a simple example that uses the Event module and loads |
88 | This is a simple example that uses the Event module and loads |
88 | /etc/passwd asynchronously: |
89 | /etc/passwd asynchronously: |
89 | |
90 | |
… | |
… | |
242 | They are the same as used by "sysopen". |
243 | They are the same as used by "sysopen". |
243 | |
244 | |
244 | Likewise, $mode specifies the mode of the newly created file, if it |
245 | Likewise, $mode specifies the mode of the newly created file, if it |
245 | didn't exist and "O_CREAT" has been given, just like perl's |
246 | didn't exist and "O_CREAT" has been given, just like perl's |
246 | "sysopen", except that it is mandatory (i.e. use 0 if you don't |
247 | "sysopen", except that it is mandatory (i.e. use 0 if you don't |
247 | create new files, and 0666 or 0777 if you do). |
248 | create new files, and 0666 or 0777 if you do). Note that the $mode |
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249 | will be modified by the umask in effect then the request is being |
|
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250 | executed, so better never change the umask. |
248 | |
251 | |
249 | Example: |
252 | Example: |
250 | |
253 | |
251 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
254 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
252 | if ($_[0]) { |
255 | if ($_[0]) { |
… | |
… | |
257 | } |
260 | } |
258 | }; |
261 | }; |
259 | |
262 | |
260 | aio_close $fh, $callback->($status) |
263 | aio_close $fh, $callback->($status) |
261 | Asynchronously close a file and call the callback with the result |
264 | Asynchronously close a file and call the callback with the result |
262 | code. *WARNING:* although accepted, you should not pass in a perl |
265 | code. |
263 | filehandle here, as perl will likely close the file descriptor |
|
|
264 | another time when the filehandle is destroyed. Normally, you can |
|
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265 | safely call perls "close" or just let filehandles go out of scope. |
|
|
266 | |
266 | |
267 | This is supposed to be a bug in the API, so that might change. It's |
267 | Unfortunately, you can't do this to perl. Perl *insists* very |
268 | therefore best to avoid this function. |
268 | strongly on closing the file descriptor associated with the |
|
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269 | filehandle itself. |
|
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270 | |
|
|
271 | Therefore, "aio_close" will not close the filehandle - instead it |
|
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272 | will use dup2 to overwrite the file descriptor with the write-end of |
|
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273 | a pipe (the pipe fd will be created on demand and will be cached). |
|
|
274 | |
|
|
275 | Or in other words: the file descriptor will be closed, but it will |
|
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276 | not be free for reuse until the perl filehandle is closed. |
269 | |
277 | |
270 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
278 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
271 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
279 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
272 | Reads or writes "length" bytes from the specified "fh" and "offset" |
280 | Reads or writes $length bytes from the specified $fh and $offset |
273 | into the scalar given by "data" and offset "dataoffset" and calls |
281 | into the scalar given by $data and offset $dataoffset and calls the |
274 | the callback without the actual number of bytes read (or -1 on |
282 | callback without the actual number of bytes read (or -1 on error, |
275 | error, just like the syscall). |
283 | just like the syscall). |
|
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284 | |
|
|
285 | If $offset is undefined, then the current file descriptor offset |
|
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286 | will be used (and updated), otherwise the file descriptor offset |
|
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287 | will not be changed by these calls. |
|
|
288 | |
|
|
289 | If $length is undefined in "aio_write", use the remaining length of |
|
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290 | $data. |
|
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291 | |
|
|
292 | If $dataoffset is less than zero, it will be counted from the end of |
|
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293 | $data. |
276 | |
294 | |
277 | The $data scalar *MUST NOT* be modified in any way while the request |
295 | The $data scalar *MUST NOT* be modified in any way while the request |
278 | is outstanding. Modifying it can result in segfaults or WW3 (if the |
296 | is outstanding. Modifying it can result in segfaults or World War |
279 | necessary/optional hardware is installed). |
297 | III (if the necessary/optional hardware is installed). |
280 | |
298 | |
281 | Example: Read 15 bytes at offset 7 into scalar $buffer, starting at |
299 | Example: Read 15 bytes at offset 7 into scalar $buffer, starting at |
282 | offset 0 within the scalar: |
300 | offset 0 within the scalar: |
283 | |
301 | |
284 | aio_read $fh, 7, 15, $buffer, 0, sub { |
302 | aio_read $fh, 7, 15, $buffer, 0, sub { |
… | |
… | |
342 | aio_stat "/etc/passwd", sub { |
360 | aio_stat "/etc/passwd", sub { |
343 | $_[0] and die "stat failed: $!"; |
361 | $_[0] and die "stat failed: $!"; |
344 | print "size is ", -s _, "\n"; |
362 | print "size is ", -s _, "\n"; |
345 | }; |
363 | }; |
346 | |
364 | |
|
|
365 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
|
|
366 | Works like perl's "utime" function (including the special case of |
|
|
367 | $atime and $mtime being undef). Fractional times are supported if |
|
|
368 | the underlying syscalls support them. |
|
|
369 | |
|
|
370 | When called with a pathname, uses utimes(2) if available, otherwise |
|
|
371 | utime(2). If called on a file descriptor, uses futimes(2) if |
|
|
372 | available, otherwise returns ENOSYS, so this is not portable. |
|
|
373 | |
|
|
374 | Examples: |
|
|
375 | |
|
|
376 | # set atime and mtime to current time (basically touch(1)): |
|
|
377 | aio_utime "path", undef, undef; |
|
|
378 | # set atime to current time and mtime to beginning of the epoch: |
|
|
379 | aio_utime "path", time, undef; # undef==0 |
|
|
380 | |
|
|
381 | aio_chown $fh_or_path, $uid, $gid, $callback->($status) |
|
|
382 | Works like perl's "chown" function, except that "undef" for either |
|
|
383 | $uid or $gid is being interpreted as "do not change" (but -1 can |
|
|
384 | also be used). |
|
|
385 | |
|
|
386 | Examples: |
|
|
387 | |
|
|
388 | # same as "chown root path" in the shell: |
|
|
389 | aio_chown "path", 0, -1; |
|
|
390 | # same as above: |
|
|
391 | aio_chown "path", 0, undef; |
|
|
392 | |
|
|
393 | aio_truncate $fh_or_path, $offset, $callback->($status) |
|
|
394 | Works like truncate(2) or ftruncate(2). |
|
|
395 | |
|
|
396 | aio_chmod $fh_or_path, $mode, $callback->($status) |
|
|
397 | Works like perl's "chmod" function. |
|
|
398 | |
347 | aio_unlink $pathname, $callback->($status) |
399 | aio_unlink $pathname, $callback->($status) |
348 | Asynchronously unlink (delete) a file and call the callback with the |
400 | Asynchronously unlink (delete) a file and call the callback with the |
349 | result code. |
401 | result code. |
350 | |
402 | |
351 | aio_mknod $path, $mode, $dev, $callback->($status) |
403 | aio_mknod $path, $mode, $dev, $callback->($status) |
… | |
… | |
372 | the callback. |
424 | the callback. |
373 | |
425 | |
374 | aio_rename $srcpath, $dstpath, $callback->($status) |
426 | aio_rename $srcpath, $dstpath, $callback->($status) |
375 | Asynchronously rename the object at $srcpath to $dstpath, just as |
427 | Asynchronously rename the object at $srcpath to $dstpath, just as |
376 | rename(2) and call the callback with the result code. |
428 | rename(2) and call the callback with the result code. |
|
|
429 | |
|
|
430 | aio_mkdir $pathname, $mode, $callback->($status) |
|
|
431 | Asynchronously mkdir (create) a directory and call the callback with |
|
|
432 | the result code. $mode will be modified by the umask at the time the |
|
|
433 | request is executed, so do not change your umask. |
377 | |
434 | |
378 | aio_rmdir $pathname, $callback->($status) |
435 | aio_rmdir $pathname, $callback->($status) |
379 | Asynchronously rmdir (delete) a directory and call the callback with |
436 | Asynchronously rmdir (delete) a directory and call the callback with |
380 | the result code. |
437 | the result code. |
381 | |
438 | |
… | |
… | |
465 | |
522 | |
466 | It will also likely work on non-POSIX filesystems with reduced |
523 | It will also likely work on non-POSIX filesystems with reduced |
467 | efficiency as those tend to return 0 or 1 as link counts, which |
524 | efficiency as those tend to return 0 or 1 as link counts, which |
468 | disables the directory counting heuristic. |
525 | disables the directory counting heuristic. |
469 | |
526 | |
|
|
527 | aio_rmtree $path, $callback->($status) |
|
|
528 | Delete a directory tree starting (and including) $path, return the |
|
|
529 | status of the final "rmdir" only. This is a composite request that |
|
|
530 | uses "aio_scandir" to recurse into and rmdir directories, and unlink |
|
|
531 | everything else. |
|
|
532 | |
|
|
533 | aio_sync $callback->($status) |
|
|
534 | Asynchronously call sync and call the callback when finished. |
|
|
535 | |
470 | aio_fsync $fh, $callback->($status) |
536 | aio_fsync $fh, $callback->($status) |
471 | Asynchronously call fsync on the given filehandle and call the |
537 | Asynchronously call fsync on the given filehandle and call the |
472 | callback with the fsync result code. |
538 | callback with the fsync result code. |
473 | |
539 | |
474 | aio_fdatasync $fh, $callback->($status) |
540 | aio_fdatasync $fh, $callback->($status) |
475 | Asynchronously call fdatasync on the given filehandle and call the |
541 | Asynchronously call fdatasync on the given filehandle and call the |
476 | callback with the fdatasync result code. |
542 | callback with the fdatasync result code. |
477 | |
543 | |
478 | 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 |
479 | be detected, it will be emulated by calling "fsync" instead. |
545 | be detected, it will be emulated by calling "fsync" instead. |
|
|
546 | |
|
|
547 | aio_pathsync $path, $callback->($status) |
|
|
548 | This request tries to open, fsync and close the given path. This is |
|
|
549 | a composite request intended tosync directories after directory |
|
|
550 | operations (E.g. rename). This might not work on all operating |
|
|
551 | systems or have any specific effect, but usually it makes sure that |
|
|
552 | directory changes get written to disc. It works for anything that |
|
|
553 | can be opened for read-only, not just directories. |
|
|
554 | |
|
|
555 | Passes 0 when everything went ok, and -1 on error. |
480 | |
556 | |
481 | aio_group $callback->(...) |
557 | aio_group $callback->(...) |
482 | This is a very special aio request: Instead of doing something, it |
558 | This is a very special aio request: Instead of doing something, it |
483 | is a container for other aio requests, which is useful if you want |
559 | is a container for other aio requests, which is useful if you want |
484 | to bundle many requests into a single, composite, request with a |
560 | to bundle many requests into a single, composite, request with a |
… | |
… | |
566 | }; |
642 | }; |
567 | |
643 | |
568 | This makes it very easy to create composite requests (see the source of |
644 | This makes it very easy to create composite requests (see the source of |
569 | "aio_move" for an application) that work and feel like simple requests. |
645 | "aio_move" for an application) that work and feel like simple requests. |
570 | |
646 | |
571 | * The IO::AIO::GRP objects will be cleaned up during calls to |
647 | * The IO::AIO::GRP objects will be cleaned up during calls to |
572 | "IO::AIO::poll_cb", just like any other request. |
648 | "IO::AIO::poll_cb", just like any other request. |
|
|
649 | |
573 | * They can be canceled like any other request. Canceling will cancel not |
650 | * They can be canceled like any other request. Canceling will cancel |
574 | only the request itself, but also all requests it contains. |
651 | not only the request itself, but also all requests it contains. |
|
|
652 | |
575 | * They can also can also be added to other IO::AIO::GRP objects. |
653 | * They can also can also be added to other IO::AIO::GRP objects. |
|
|
654 | |
576 | * You must not add requests to a group from within the group callback |
655 | * You must not add requests to a group from within the group callback |
577 | (or any later time). |
656 | (or any later time). |
578 | |
657 | |
579 | Their lifetime, simplified, looks like this: when they are empty, they |
658 | Their lifetime, simplified, looks like this: when they are empty, they |
580 | will finish very quickly. If they contain only requests that are in the |
659 | will finish very quickly. If they contain only requests that are in the |
581 | "done" state, they will also finish. Otherwise they will continue to |
660 | "done" state, they will also finish. Otherwise they will continue to |
582 | exist. |
661 | exist. |
… | |
… | |
599 | request itself. Useful when you queued a lot of events but got a |
678 | request itself. Useful when you queued a lot of events but got a |
600 | result early. |
679 | result early. |
601 | |
680 | |
602 | $grp->result (...) |
681 | $grp->result (...) |
603 | Set the result value(s) that will be passed to the group callback |
682 | Set the result value(s) that will be passed to the group callback |
604 | when all subrequests have finished and set thre groups errno to the |
683 | when all subrequests have finished and set the groups errno to the |
605 | current value of errno (just like calling "errno" without an error |
684 | current value of errno (just like calling "errno" without an error |
606 | number). By default, no argument will be passed and errno is zero. |
685 | number). By default, no argument will be passed and errno is zero. |
607 | |
686 | |
608 | $grp->errno ([$errno]) |
687 | $grp->errno ([$errno]) |
609 | Sets the group errno value to $errno, or the current value of errno |
688 | Sets the group errno value to $errno, or the current value of errno |
… | |
… | |
668 | |
747 | |
669 | See "poll_cb" for an example. |
748 | See "poll_cb" for an example. |
670 | |
749 | |
671 | IO::AIO::poll_cb |
750 | IO::AIO::poll_cb |
672 | Process some outstanding events on the result pipe. You have to call |
751 | Process some outstanding events on the result pipe. You have to call |
673 | this regularly. Returns the number of events processed. Returns |
752 | this regularly. Returns 0 if all events could be processed, or -1 if |
674 | immediately when no events are outstanding. The amount of events |
753 | it returned earlier for whatever reason. Returns immediately when no |
|
|
754 | events are outstanding. The amount of events processed depends on |
675 | processed depends on the settings of "IO::AIO::max_poll_req" and |
755 | the settings of "IO::AIO::max_poll_req" and |
676 | "IO::AIO::max_poll_time". |
756 | "IO::AIO::max_poll_time". |
677 | |
757 | |
678 | If not all requests were processed for whatever reason, the |
758 | If not all requests were processed for whatever reason, the |
679 | filehandle will still be ready when "poll_cb" returns. |
759 | filehandle will still be ready when "poll_cb" returns, so normally |
|
|
760 | you don't have to do anything special to have it called later. |
680 | |
761 | |
681 | Example: Install an Event watcher that automatically calls |
762 | Example: Install an Event watcher that automatically calls |
682 | IO::AIO::poll_cb with high priority: |
763 | IO::AIO::poll_cb with high priority: |
683 | |
764 | |
684 | Event->io (fd => IO::AIO::poll_fileno, |
765 | Event->io (fd => IO::AIO::poll_fileno, |
… | |
… | |
790 | |
871 | |
791 | The default is probably ok in most situations, especially if thread |
872 | The default is probably ok in most situations, especially if thread |
792 | creation is fast. If thread creation is very slow on your system you |
873 | creation is fast. If thread creation is very slow on your system you |
793 | might want to use larger values. |
874 | might want to use larger values. |
794 | |
875 | |
795 | $oldmaxreqs = IO::AIO::max_outstanding $maxreqs |
876 | IO::AIO::max_outstanding $maxreqs |
796 | This is a very bad function to use in interactive programs because |
877 | This is a very bad function to use in interactive programs because |
797 | it blocks, and a bad way to reduce concurrency because it is |
878 | it blocks, and a bad way to reduce concurrency because it is |
798 | inexact: Better use an "aio_group" together with a feed callback. |
879 | inexact: Better use an "aio_group" together with a feed callback. |
799 | |
880 | |
800 | Sets the maximum number of outstanding requests to $nreqs. If you to |
881 | Sets the maximum number of outstanding requests to $nreqs. If you do |
801 | queue up more than this number of requests, the next call to the |
882 | queue up more than this number of requests, the next call to the |
802 | "poll_cb" (and "poll_some" and other functions calling "poll_cb") |
883 | "poll_cb" (and "poll_some" and other functions calling "poll_cb") |
803 | function will block until the limit is no longer exceeded. |
884 | function will block until the limit is no longer exceeded. |
804 | |
885 | |
805 | The default value is very large, so there is no practical limit on |
886 | The default value is very large, so there is no practical limit on |
806 | the number of outstanding requests. |
887 | the number of outstanding requests. |
807 | |
888 | |
808 | You can still queue as many requests as you want. Therefore, |
889 | You can still queue as many requests as you want. Therefore, |
809 | "max_oustsanding" is mainly useful in simple scripts (with low |
890 | "max_outstanding" is mainly useful in simple scripts (with low |
810 | values) or as a stop gap to shield against fatal memory overflow |
891 | values) or as a stop gap to shield against fatal memory overflow |
811 | (with large values). |
892 | (with large values). |
812 | |
893 | |
813 | STATISTICAL INFORMATION |
894 | STATISTICAL INFORMATION |
814 | IO::AIO::nreqs |
895 | IO::AIO::nreqs |
… | |
… | |
851 | bytes of memory. In addition, stat requests need a stat buffer (possibly |
932 | bytes of memory. In addition, stat requests need a stat buffer (possibly |
852 | a few hundred bytes), readdir requires a result buffer and so on. Perl |
933 | a few hundred bytes), readdir requires a result buffer and so on. Perl |
853 | scalars and other data passed into aio requests will also be locked and |
934 | scalars and other data passed into aio requests will also be locked and |
854 | will consume memory till the request has entered the done state. |
935 | will consume memory till the request has entered the done state. |
855 | |
936 | |
856 | This is now awfully much, so queuing lots of requests is not usually a |
937 | This is not awfully much, so queuing lots of requests is not usually a |
857 | problem. |
938 | problem. |
858 | |
939 | |
859 | Per-thread usage: |
940 | Per-thread usage: |
860 | |
941 | |
861 | In the execution phase, some aio requests require more memory for |
942 | In the execution phase, some aio requests require more memory for |
… | |
… | |
864 | |
945 | |
865 | KNOWN BUGS |
946 | KNOWN BUGS |
866 | Known bugs will be fixed in the next release. |
947 | Known bugs will be fixed in the next release. |
867 | |
948 | |
868 | SEE ALSO |
949 | SEE ALSO |
869 | Coro::AIO. |
950 | AnyEvent::AIO for easy integration into event loops, Coro::AIO for a |
|
|
951 | more natural syntax. |
870 | |
952 | |
871 | AUTHOR |
953 | AUTHOR |
872 | Marc Lehmann <schmorp@schmorp.de> |
954 | Marc Lehmann <schmorp@schmorp.de> |
873 | http://home.schmorp.de/ |
955 | http://home.schmorp.de/ |
874 | |
956 | |