… | |
… | |
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 |
29 | # AnyEvent integration (EV, Event, Glib, Tk, urxvt, pureperl...) |
30 | open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!"; |
30 | open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!"; |
31 | my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb }); |
31 | my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb }); |
|
|
32 | |
|
|
33 | # EV integration |
|
|
34 | my $w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
32 | |
35 | |
33 | # Event integration |
36 | # Event integration |
34 | Event->io (fd => IO::AIO::poll_fileno, |
37 | Event->io (fd => IO::AIO::poll_fileno, |
35 | poll => 'r', |
38 | poll => 'r', |
36 | cb => \&IO::AIO::poll_cb); |
39 | cb => \&IO::AIO::poll_cb); |
… | |
… | |
61 | faster on a RAID volume or over NFS when you do a number of stat |
64 | faster on a RAID volume or over NFS when you do a number of stat |
62 | operations concurrently. |
65 | operations concurrently. |
63 | |
66 | |
64 | While most of this works on all types of file descriptors (for example |
67 | While most of this works on all types of file descriptors (for example |
65 | sockets), using these functions on file descriptors that support |
68 | sockets), using these functions on file descriptors that support |
66 | nonblocking operation (again, sockets, pipes etc.) is very inefficient |
69 | 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 |
70 | Use an event loop for that (such as the Event module): IO::AIO will |
69 | into such an event loop itself. |
71 | naturally fit into such an event loop itself. |
70 | |
72 | |
71 | In this version, a number of threads are started that execute your |
73 | 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 |
74 | 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 |
75 | 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 |
76 | 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 |
78 | 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 |
79 | files currently, for example), and they would only support aio_read and |
78 | aio_write, so the remaining functionality would have to be implemented |
80 | aio_write, so the remaining functionality would have to be implemented |
79 | using threads anyway. |
81 | using threads anyway. |
80 | |
82 | |
81 | Although the module will work with in the presence of other (Perl-) |
83 | 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 |
84 | 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 |
85 | yourself, always call "poll_cb" from within the same thread, or never |
84 | never call "poll_cb" (or other "aio_" functions) recursively. |
86 | call "poll_cb" (or other "aio_" functions) recursively. |
85 | |
87 | |
86 | EXAMPLE |
88 | EXAMPLE |
87 | This is a simple example that uses the Event module and loads |
89 | This is a simple example that uses the Event module and loads |
88 | /etc/passwd asynchronously: |
90 | /etc/passwd asynchronously: |
89 | |
91 | |
… | |
… | |
242 | They are the same as used by "sysopen". |
244 | They are the same as used by "sysopen". |
243 | |
245 | |
244 | Likewise, $mode specifies the mode of the newly created file, if it |
246 | 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 |
247 | 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 |
248 | "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). |
249 | create new files, and 0666 or 0777 if you do). Note that the $mode |
|
|
250 | will be modified by the umask in effect then the request is being |
|
|
251 | executed, so better never change the umask. |
248 | |
252 | |
249 | Example: |
253 | Example: |
250 | |
254 | |
251 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
255 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
252 | if ($_[0]) { |
256 | if ($_[0]) { |
… | |
… | |
257 | } |
261 | } |
258 | }; |
262 | }; |
259 | |
263 | |
260 | aio_close $fh, $callback->($status) |
264 | aio_close $fh, $callback->($status) |
261 | Asynchronously close a file and call the callback with the result |
265 | Asynchronously close a file and call the callback with the result |
262 | code. *WARNING:* although accepted, you should not pass in a perl |
266 | code. |
263 | filehandle here, as perl will likely close the file descriptor |
|
|
264 | another time when the filehandle is destroyed. Normally, you can |
|
|
265 | safely call perls "close" or just let filehandles go out of scope. |
|
|
266 | |
267 | |
267 | This is supposed to be a bug in the API, so that might change. It's |
268 | Unfortunately, you can't do this to perl. Perl *insists* very |
268 | therefore best to avoid this function. |
269 | strongly on closing the file descriptor associated with the |
|
|
270 | filehandle itself. Here is what aio_close will try: |
|
|
271 | |
|
|
272 | 1. dup()licate the fd |
|
|
273 | 2. asynchronously close() the duplicated fd |
|
|
274 | 3. dup()licate the fd once more |
|
|
275 | 4. let perl close() the filehandle |
|
|
276 | 5. asynchronously close the duplicated fd |
|
|
277 | |
|
|
278 | The idea is that the first close() flushes stuff to disk that |
|
|
279 | closing an fd will flush, so when perl closes the fd, nothing much |
|
|
280 | will need to be flushed. The second async. close() will then flush |
|
|
281 | stuff to disk that closing the last fd to the file will flush. |
|
|
282 | |
|
|
283 | Just FYI, SuSv3 has this to say on close: |
|
|
284 | |
|
|
285 | All outstanding record locks owned by the process on the file |
|
|
286 | associated with the file descriptor shall be removed. |
|
|
287 | |
|
|
288 | If fildes refers to a socket, close() shall cause the socket to be |
|
|
289 | destroyed. ... close() shall block for up to the current linger |
|
|
290 | interval until all data is transmitted. |
|
|
291 | [this actually sounds like a specification bug, but who knows] |
|
|
292 | |
|
|
293 | And at least Linux additionally actually flushes stuff on every |
|
|
294 | close, even when the file itself is still open. |
|
|
295 | |
|
|
296 | Sounds enourmously inefficient and complicated? Yes... please show |
|
|
297 | me how to nuke perl's fd out of existence... |
269 | |
298 | |
270 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
299 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
271 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
300 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
272 | Reads or writes "length" bytes from the specified "fh" and "offset" |
301 | Reads or writes $length bytes from the specified $fh and $offset |
273 | into the scalar given by "data" and offset "dataoffset" and calls |
302 | 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 |
303 | callback without the actual number of bytes read (or -1 on error, |
275 | error, just like the syscall). |
304 | just like the syscall). |
|
|
305 | |
|
|
306 | If $offset is undefined, then the current file descriptor offset |
|
|
307 | will be used (and updated), otherwise the file descriptor offset |
|
|
308 | will not be changed by these calls. |
|
|
309 | |
|
|
310 | If $length is undefined in "aio_write", use the remaining length of |
|
|
311 | $data. |
|
|
312 | |
|
|
313 | If $dataoffset is less than zero, it will be counted from the end of |
|
|
314 | $data. |
276 | |
315 | |
277 | The $data scalar *MUST NOT* be modified in any way while the request |
316 | 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 |
317 | is outstanding. Modifying it can result in segfaults or World War |
279 | necessary/optional hardware is installed). |
318 | III (if the necessary/optional hardware is installed). |
280 | |
319 | |
281 | Example: Read 15 bytes at offset 7 into scalar $buffer, starting at |
320 | Example: Read 15 bytes at offset 7 into scalar $buffer, starting at |
282 | offset 0 within the scalar: |
321 | offset 0 within the scalar: |
283 | |
322 | |
284 | aio_read $fh, 7, 15, $buffer, 0, sub { |
323 | aio_read $fh, 7, 15, $buffer, 0, sub { |
… | |
… | |
342 | aio_stat "/etc/passwd", sub { |
381 | aio_stat "/etc/passwd", sub { |
343 | $_[0] and die "stat failed: $!"; |
382 | $_[0] and die "stat failed: $!"; |
344 | print "size is ", -s _, "\n"; |
383 | print "size is ", -s _, "\n"; |
345 | }; |
384 | }; |
346 | |
385 | |
|
|
386 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
|
|
387 | Works like perl's "utime" function (including the special case of |
|
|
388 | $atime and $mtime being undef). Fractional times are supported if |
|
|
389 | the underlying syscalls support them. |
|
|
390 | |
|
|
391 | When called with a pathname, uses utimes(2) if available, otherwise |
|
|
392 | utime(2). If called on a file descriptor, uses futimes(2) if |
|
|
393 | available, otherwise returns ENOSYS, so this is not portable. |
|
|
394 | |
|
|
395 | Examples: |
|
|
396 | |
|
|
397 | # set atime and mtime to current time (basically touch(1)): |
|
|
398 | aio_utime "path", undef, undef; |
|
|
399 | # set atime to current time and mtime to beginning of the epoch: |
|
|
400 | aio_utime "path", time, undef; # undef==0 |
|
|
401 | |
|
|
402 | aio_chown $fh_or_path, $uid, $gid, $callback->($status) |
|
|
403 | Works like perl's "chown" function, except that "undef" for either |
|
|
404 | $uid or $gid is being interpreted as "do not change" (but -1 can |
|
|
405 | also be used). |
|
|
406 | |
|
|
407 | Examples: |
|
|
408 | |
|
|
409 | # same as "chown root path" in the shell: |
|
|
410 | aio_chown "path", 0, -1; |
|
|
411 | # same as above: |
|
|
412 | aio_chown "path", 0, undef; |
|
|
413 | |
|
|
414 | aio_truncate $fh_or_path, $offset, $callback->($status) |
|
|
415 | Works like truncate(2) or ftruncate(2). |
|
|
416 | |
|
|
417 | aio_chmod $fh_or_path, $mode, $callback->($status) |
|
|
418 | Works like perl's "chmod" function. |
|
|
419 | |
347 | aio_unlink $pathname, $callback->($status) |
420 | aio_unlink $pathname, $callback->($status) |
348 | Asynchronously unlink (delete) a file and call the callback with the |
421 | Asynchronously unlink (delete) a file and call the callback with the |
349 | result code. |
422 | result code. |
350 | |
423 | |
351 | aio_mknod $path, $mode, $dev, $callback->($status) |
424 | aio_mknod $path, $mode, $dev, $callback->($status) |
… | |
… | |
373 | |
446 | |
374 | aio_rename $srcpath, $dstpath, $callback->($status) |
447 | aio_rename $srcpath, $dstpath, $callback->($status) |
375 | Asynchronously rename the object at $srcpath to $dstpath, just as |
448 | Asynchronously rename the object at $srcpath to $dstpath, just as |
376 | rename(2) and call the callback with the result code. |
449 | rename(2) and call the callback with the result code. |
377 | |
450 | |
|
|
451 | aio_mkdir $pathname, $mode, $callback->($status) |
|
|
452 | Asynchronously mkdir (create) a directory and call the callback with |
|
|
453 | the result code. $mode will be modified by the umask at the time the |
|
|
454 | request is executed, so do not change your umask. |
|
|
455 | |
378 | aio_rmdir $pathname, $callback->($status) |
456 | aio_rmdir $pathname, $callback->($status) |
379 | Asynchronously rmdir (delete) a directory and call the callback with |
457 | Asynchronously rmdir (delete) a directory and call the callback with |
380 | the result code. |
458 | the result code. |
381 | |
459 | |
382 | aio_readdir $pathname, $callback->($entries) |
460 | aio_readdir $pathname, $callback->($entries) |
… | |
… | |
384 | entire directory (i.e. opendir + readdir + closedir). The entries |
462 | entire directory (i.e. opendir + readdir + closedir). The entries |
385 | will not be sorted, and will NOT include the "." and ".." entries. |
463 | will not be sorted, and will NOT include the "." and ".." entries. |
386 | |
464 | |
387 | The callback a single argument which is either "undef" or an |
465 | The callback a single argument which is either "undef" or an |
388 | array-ref with the filenames. |
466 | array-ref with the filenames. |
|
|
467 | |
|
|
468 | aio_load $path, $data, $callback->($status) |
|
|
469 | This is a composite request that tries to fully load the given file |
|
|
470 | into memory. Status is the same as with aio_read. |
389 | |
471 | |
390 | aio_copy $srcpath, $dstpath, $callback->($status) |
472 | aio_copy $srcpath, $dstpath, $callback->($status) |
391 | Try to copy the *file* (directories not supported as either source |
473 | Try to copy the *file* (directories not supported as either source |
392 | or destination) from $srcpath to $dstpath and call the callback with |
474 | or destination) from $srcpath to $dstpath and call the callback with |
393 | the 0 (error) or -1 ok. |
475 | the 0 (error) or -1 ok. |
… | |
… | |
461 | |
543 | |
462 | It will also likely work on non-POSIX filesystems with reduced |
544 | It will also likely work on non-POSIX filesystems with reduced |
463 | efficiency as those tend to return 0 or 1 as link counts, which |
545 | efficiency as those tend to return 0 or 1 as link counts, which |
464 | disables the directory counting heuristic. |
546 | disables the directory counting heuristic. |
465 | |
547 | |
|
|
548 | aio_rmtree $path, $callback->($status) |
|
|
549 | Delete a directory tree starting (and including) $path, return the |
|
|
550 | status of the final "rmdir" only. This is a composite request that |
|
|
551 | uses "aio_scandir" to recurse into and rmdir directories, and unlink |
|
|
552 | everything else. |
|
|
553 | |
|
|
554 | aio_sync $callback->($status) |
|
|
555 | Asynchronously call sync and call the callback when finished. |
|
|
556 | |
466 | aio_fsync $fh, $callback->($status) |
557 | aio_fsync $fh, $callback->($status) |
467 | Asynchronously call fsync on the given filehandle and call the |
558 | Asynchronously call fsync on the given filehandle and call the |
468 | callback with the fsync result code. |
559 | callback with the fsync result code. |
469 | |
560 | |
470 | aio_fdatasync $fh, $callback->($status) |
561 | aio_fdatasync $fh, $callback->($status) |
471 | Asynchronously call fdatasync on the given filehandle and call the |
562 | Asynchronously call fdatasync on the given filehandle and call the |
472 | callback with the fdatasync result code. |
563 | callback with the fdatasync result code. |
473 | |
564 | |
474 | If this call isn't available because your OS lacks it or it couldn't |
565 | If this call isn't available because your OS lacks it or it couldn't |
475 | be detected, it will be emulated by calling "fsync" instead. |
566 | be detected, it will be emulated by calling "fsync" instead. |
|
|
567 | |
|
|
568 | aio_pathsync $path, $callback->($status) |
|
|
569 | This request tries to open, fsync and close the given path. This is |
|
|
570 | a composite request intended tosync directories after directory |
|
|
571 | operations (E.g. rename). This might not work on all operating |
|
|
572 | systems or have any specific effect, but usually it makes sure that |
|
|
573 | directory changes get written to disc. It works for anything that |
|
|
574 | can be opened for read-only, not just directories. |
|
|
575 | |
|
|
576 | Passes 0 when everything went ok, and -1 on error. |
476 | |
577 | |
477 | aio_group $callback->(...) |
578 | aio_group $callback->(...) |
478 | This is a very special aio request: Instead of doing something, it |
579 | This is a very special aio request: Instead of doing something, it |
479 | is a container for other aio requests, which is useful if you want |
580 | is a container for other aio requests, which is useful if you want |
480 | to bundle many requests into a single, composite, request with a |
581 | to bundle many requests into a single, composite, request with a |
… | |
… | |
562 | }; |
663 | }; |
563 | |
664 | |
564 | This makes it very easy to create composite requests (see the source of |
665 | This makes it very easy to create composite requests (see the source of |
565 | "aio_move" for an application) that work and feel like simple requests. |
666 | "aio_move" for an application) that work and feel like simple requests. |
566 | |
667 | |
567 | * The IO::AIO::GRP objects will be cleaned up during calls to |
668 | * The IO::AIO::GRP objects will be cleaned up during calls to |
568 | "IO::AIO::poll_cb", just like any other request. |
669 | "IO::AIO::poll_cb", just like any other request. |
|
|
670 | |
569 | * They can be canceled like any other request. Canceling will cancel not |
671 | * They can be canceled like any other request. Canceling will cancel |
570 | only the request itself, but also all requests it contains. |
672 | not only the request itself, but also all requests it contains. |
|
|
673 | |
571 | * They can also can also be added to other IO::AIO::GRP objects. |
674 | * They can also can also be added to other IO::AIO::GRP objects. |
|
|
675 | |
572 | * You must not add requests to a group from within the group callback |
676 | * You must not add requests to a group from within the group callback |
573 | (or any later time). |
677 | (or any later time). |
574 | |
678 | |
575 | Their lifetime, simplified, looks like this: when they are empty, they |
679 | Their lifetime, simplified, looks like this: when they are empty, they |
576 | will finish very quickly. If they contain only requests that are in the |
680 | will finish very quickly. If they contain only requests that are in the |
577 | "done" state, they will also finish. Otherwise they will continue to |
681 | "done" state, they will also finish. Otherwise they will continue to |
578 | exist. |
682 | exist. |
… | |
… | |
595 | request itself. Useful when you queued a lot of events but got a |
699 | request itself. Useful when you queued a lot of events but got a |
596 | result early. |
700 | result early. |
597 | |
701 | |
598 | $grp->result (...) |
702 | $grp->result (...) |
599 | Set the result value(s) that will be passed to the group callback |
703 | Set the result value(s) that will be passed to the group callback |
600 | when all subrequests have finished and set thre groups errno to the |
704 | when all subrequests have finished and set the groups errno to the |
601 | current value of errno (just like calling "errno" without an error |
705 | current value of errno (just like calling "errno" without an error |
602 | number). By default, no argument will be passed and errno is zero. |
706 | number). By default, no argument will be passed and errno is zero. |
603 | |
707 | |
604 | $grp->errno ([$errno]) |
708 | $grp->errno ([$errno]) |
605 | Sets the group errno value to $errno, or the current value of errno |
709 | Sets the group errno value to $errno, or the current value of errno |
… | |
… | |
791 | $oldmaxreqs = IO::AIO::max_outstanding $maxreqs |
895 | $oldmaxreqs = IO::AIO::max_outstanding $maxreqs |
792 | This is a very bad function to use in interactive programs because |
896 | This is a very bad function to use in interactive programs because |
793 | it blocks, and a bad way to reduce concurrency because it is |
897 | it blocks, and a bad way to reduce concurrency because it is |
794 | inexact: Better use an "aio_group" together with a feed callback. |
898 | inexact: Better use an "aio_group" together with a feed callback. |
795 | |
899 | |
796 | Sets the maximum number of outstanding requests to $nreqs. If you to |
900 | Sets the maximum number of outstanding requests to $nreqs. If you do |
797 | queue up more than this number of requests, the next call to the |
901 | queue up more than this number of requests, the next call to the |
798 | "poll_cb" (and "poll_some" and other functions calling "poll_cb") |
902 | "poll_cb" (and "poll_some" and other functions calling "poll_cb") |
799 | function will block until the limit is no longer exceeded. |
903 | function will block until the limit is no longer exceeded. |
800 | |
904 | |
801 | The default value is very large, so there is no practical limit on |
905 | The default value is very large, so there is no practical limit on |
… | |
… | |
847 | bytes of memory. In addition, stat requests need a stat buffer (possibly |
951 | bytes of memory. In addition, stat requests need a stat buffer (possibly |
848 | a few hundred bytes), readdir requires a result buffer and so on. Perl |
952 | a few hundred bytes), readdir requires a result buffer and so on. Perl |
849 | scalars and other data passed into aio requests will also be locked and |
953 | scalars and other data passed into aio requests will also be locked and |
850 | will consume memory till the request has entered the done state. |
954 | will consume memory till the request has entered the done state. |
851 | |
955 | |
852 | This is now awfully much, so queuing lots of requests is not usually a |
956 | This is not awfully much, so queuing lots of requests is not usually a |
853 | problem. |
957 | problem. |
854 | |
958 | |
855 | Per-thread usage: |
959 | Per-thread usage: |
856 | |
960 | |
857 | In the execution phase, some aio requests require more memory for |
961 | In the execution phase, some aio requests require more memory for |