… | |
… | |
62 | etc.), but can also be used to easily do operations in parallel that are |
62 | etc.), but can also be used to easily do operations in parallel that are |
63 | normally done sequentially, e.g. stat'ing many files, which is much faster |
63 | normally done sequentially, e.g. stat'ing many files, which is much faster |
64 | on a RAID volume or over NFS when you do a number of stat operations |
64 | on a RAID volume or over NFS when you do a number of stat operations |
65 | concurrently. |
65 | concurrently. |
66 | |
66 | |
67 | 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 |
68 | sockets), using these functions on file descriptors that support |
68 | example sockets), using these functions on file descriptors that |
69 | nonblocking operation (again, sockets, pipes etc.) is very inefficient or |
69 | support nonblocking operation (again, sockets, pipes etc.) is very |
70 | might not work (aio_read fails on sockets/pipes/fifos). Use an event loop |
70 | inefficient. Use an event loop for that (such as the L<Event|Event> |
71 | for that (such as the L<Event|Event> module): IO::AIO will naturally fit |
71 | module): IO::AIO will naturally fit into such an event loop itself. |
72 | into such an event loop itself. |
|
|
73 | |
72 | |
74 | 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 |
75 | requests and signal their completion. You don't need thread support |
74 | requests and signal their completion. You don't need thread support |
76 | in perl, and the threads created by this module will not be visible |
75 | in perl, and the threads created by this module will not be visible |
77 | to perl. In the future, this module might make use of the native aio |
76 | to perl. In the future, this module might make use of the native aio |
… | |
… | |
79 | 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 |
80 | 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 |
81 | aio_write, so the remaining functionality would have to be implemented |
80 | aio_write, so the remaining functionality would have to be implemented |
82 | using threads anyway. |
81 | using threads anyway. |
83 | |
82 | |
84 | 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, |
85 | 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 |
86 | locking yourself, always call C<poll_cb> from within the same thread, or |
85 | yourself, always call C<poll_cb> from within the same thread, or never |
87 | never call C<poll_cb> (or other C<aio_> functions) recursively. |
86 | call C<poll_cb> (or other C<aio_> functions) recursively. |
88 | |
87 | |
89 | =head2 EXAMPLE |
88 | =head2 EXAMPLE |
90 | |
89 | |
91 | This is a simple example that uses the Event module and loads |
90 | This is a simple example that uses the Event module and loads |
92 | F</etc/passwd> asynchronously: |
91 | F</etc/passwd> asynchronously: |
… | |
… | |
190 | use strict 'vars'; |
189 | use strict 'vars'; |
191 | |
190 | |
192 | use base 'Exporter'; |
191 | use base 'Exporter'; |
193 | |
192 | |
194 | BEGIN { |
193 | BEGIN { |
195 | our $VERSION = '2.32'; |
194 | our $VERSION = '2.4'; |
196 | |
195 | |
197 | our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat |
196 | our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat |
198 | aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink |
197 | aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink |
199 | aio_readlink aio_fsync aio_fdatasync aio_readahead aio_rename aio_link |
198 | aio_readlink aio_fsync aio_fdatasync aio_readahead aio_rename aio_link |
200 | aio_move aio_copy aio_group aio_nop aio_mknod aio_load aio_rmtree aio_mkdir); |
199 | aio_move aio_copy aio_group aio_nop aio_mknod aio_load aio_rmtree aio_mkdir |
|
|
200 | aio_chown aio_chmod aio_utime aio_truncate); |
201 | our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block)); |
201 | our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block)); |
202 | our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush |
202 | our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush |
203 | min_parallel max_parallel max_idle |
203 | min_parallel max_parallel max_idle |
204 | nreqs nready npending nthreads |
204 | nreqs nready npending nthreads |
205 | max_poll_time max_poll_reqs); |
205 | max_poll_time max_poll_reqs); |
… | |
… | |
271 | aio_read $_[0], ..., sub { |
271 | aio_read $_[0], ..., sub { |
272 | ... |
272 | ... |
273 | }; |
273 | }; |
274 | }; |
274 | }; |
275 | |
275 | |
|
|
276 | |
276 | =item aioreq_nice $pri_adjust |
277 | =item aioreq_nice $pri_adjust |
277 | |
278 | |
278 | Similar to C<aioreq_pri>, but subtracts the given value from the current |
279 | Similar to C<aioreq_pri>, but subtracts the given value from the current |
279 | priority, so the effect is cumulative. |
280 | priority, so the effect is cumulative. |
|
|
281 | |
280 | |
282 | |
281 | =item aio_open $pathname, $flags, $mode, $callback->($fh) |
283 | =item aio_open $pathname, $flags, $mode, $callback->($fh) |
282 | |
284 | |
283 | Asynchronously open or create a file and call the callback with a newly |
285 | Asynchronously open or create a file and call the callback with a newly |
284 | created filehandle for the file. |
286 | created filehandle for the file. |
… | |
… | |
305 | } else { |
307 | } else { |
306 | die "open failed: $!\n"; |
308 | die "open failed: $!\n"; |
307 | } |
309 | } |
308 | }; |
310 | }; |
309 | |
311 | |
|
|
312 | |
310 | =item aio_close $fh, $callback->($status) |
313 | =item aio_close $fh, $callback->($status) |
311 | |
314 | |
312 | Asynchronously close a file and call the callback with the result |
315 | Asynchronously close a file and call the callback with the result |
313 | code. I<WARNING:> although accepted, you should not pass in a perl |
316 | code. I<WARNING:> although accepted, you should not pass in a perl |
314 | filehandle here, as perl will likely close the file descriptor another |
317 | filehandle here, as perl will likely close the file descriptor another |
… | |
… | |
316 | C<close> or just let filehandles go out of scope. |
319 | C<close> or just let filehandles go out of scope. |
317 | |
320 | |
318 | This is supposed to be a bug in the API, so that might change. It's |
321 | This is supposed to be a bug in the API, so that might change. It's |
319 | therefore best to avoid this function. |
322 | therefore best to avoid this function. |
320 | |
323 | |
|
|
324 | |
321 | =item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
325 | =item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
322 | |
326 | |
323 | =item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
327 | =item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
324 | |
328 | |
325 | Reads or writes C<length> bytes from the specified C<fh> and C<offset> |
329 | Reads or writes C<$length> bytes from the specified C<$fh> and C<$offset> |
326 | into the scalar given by C<data> and offset C<dataoffset> and calls the |
330 | into the scalar given by C<$data> and offset C<$dataoffset> and calls the |
327 | callback without the actual number of bytes read (or -1 on error, just |
331 | callback without the actual number of bytes read (or -1 on error, just |
328 | like the syscall). |
332 | like the syscall). |
329 | |
333 | |
|
|
334 | If C<$offset> is undefined, then the current file offset will be used (and |
|
|
335 | updated), otherwise the file offset will not be changed by these calls. |
|
|
336 | |
|
|
337 | If C<$length> is undefined in C<aio_write>, use the remaining length of C<$data>. |
|
|
338 | |
|
|
339 | If C<$dataoffset> is less than zero, it will be counted from the end of |
|
|
340 | C<$data>. |
|
|
341 | |
330 | The C<$data> scalar I<MUST NOT> be modified in any way while the request |
342 | The C<$data> scalar I<MUST NOT> be modified in any way while the request |
331 | is outstanding. Modifying it can result in segfaults or WW3 (if the |
343 | is outstanding. Modifying it can result in segfaults or World War III (if |
332 | necessary/optional hardware is installed). |
344 | the necessary/optional hardware is installed). |
333 | |
345 | |
334 | Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at |
346 | Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at |
335 | offset C<0> within the scalar: |
347 | offset C<0> within the scalar: |
336 | |
348 | |
337 | aio_read $fh, 7, 15, $buffer, 0, sub { |
349 | aio_read $fh, 7, 15, $buffer, 0, sub { |
338 | $_[0] > 0 or die "read error: $!"; |
350 | $_[0] > 0 or die "read error: $!"; |
339 | print "read $_[0] bytes: <$buffer>\n"; |
351 | print "read $_[0] bytes: <$buffer>\n"; |
340 | }; |
352 | }; |
|
|
353 | |
341 | |
354 | |
342 | =item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
355 | =item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
343 | |
356 | |
344 | Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts |
357 | Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts |
345 | reading at byte offset C<$in_offset>, and starts writing at the current |
358 | reading at byte offset C<$in_offset>, and starts writing at the current |
… | |
… | |
359 | C<$in_fh> than are written, and there is no way to find out how many |
372 | C<$in_fh> than are written, and there is no way to find out how many |
360 | bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only |
373 | bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only |
361 | provides the number of bytes written to C<$out_fh>. Only if the result |
374 | provides the number of bytes written to C<$out_fh>. Only if the result |
362 | value equals C<$length> one can assume that C<$length> bytes have been |
375 | value equals C<$length> one can assume that C<$length> bytes have been |
363 | read. |
376 | read. |
|
|
377 | |
364 | |
378 | |
365 | =item aio_readahead $fh,$offset,$length, $callback->($retval) |
379 | =item aio_readahead $fh,$offset,$length, $callback->($retval) |
366 | |
380 | |
367 | C<aio_readahead> populates the page cache with data from a file so that |
381 | C<aio_readahead> populates the page cache with data from a file so that |
368 | subsequent reads from that file will not block on disk I/O. The C<$offset> |
382 | subsequent reads from that file will not block on disk I/O. The C<$offset> |
… | |
… | |
374 | file. The current file offset of the file is left unchanged. |
388 | file. The current file offset of the file is left unchanged. |
375 | |
389 | |
376 | If that syscall doesn't exist (likely if your OS isn't Linux) it will be |
390 | If that syscall doesn't exist (likely if your OS isn't Linux) it will be |
377 | emulated by simply reading the data, which would have a similar effect. |
391 | emulated by simply reading the data, which would have a similar effect. |
378 | |
392 | |
|
|
393 | |
379 | =item aio_stat $fh_or_path, $callback->($status) |
394 | =item aio_stat $fh_or_path, $callback->($status) |
380 | |
395 | |
381 | =item aio_lstat $fh, $callback->($status) |
396 | =item aio_lstat $fh, $callback->($status) |
382 | |
397 | |
383 | Works like perl's C<stat> or C<lstat> in void context. The callback will |
398 | Works like perl's C<stat> or C<lstat> in void context. The callback will |
… | |
… | |
396 | aio_stat "/etc/passwd", sub { |
411 | aio_stat "/etc/passwd", sub { |
397 | $_[0] and die "stat failed: $!"; |
412 | $_[0] and die "stat failed: $!"; |
398 | print "size is ", -s _, "\n"; |
413 | print "size is ", -s _, "\n"; |
399 | }; |
414 | }; |
400 | |
415 | |
|
|
416 | |
|
|
417 | =item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
|
|
418 | |
|
|
419 | Works like perl's C<utime> function (including the special case of $atime |
|
|
420 | and $mtime being undef). Fractional times are supported if the underlying |
|
|
421 | syscalls support them. |
|
|
422 | |
|
|
423 | When called with a pathname, uses utimes(2) if available, otherwise |
|
|
424 | utime(2). If called on a file descriptor, uses futimes(2) if available, |
|
|
425 | otherwise returns ENOSYS, so this is not portable. |
|
|
426 | |
|
|
427 | Examples: |
|
|
428 | |
|
|
429 | # set atime and mtime to current time (basically touch(1)): |
|
|
430 | aio_utime "path", undef, undef; |
|
|
431 | # set atime to current time and mtime to beginning of the epoch: |
|
|
432 | aio_utime "path", time, undef; # undef==0 |
|
|
433 | |
|
|
434 | |
|
|
435 | =item aio_chown $fh_or_path, $uid, $gid, $callback->($status) |
|
|
436 | |
|
|
437 | Works like perl's C<chown> function, except that C<undef> for either $uid |
|
|
438 | or $gid is being interpreted as "do not change" (but -1 can also be used). |
|
|
439 | |
|
|
440 | Examples: |
|
|
441 | |
|
|
442 | # same as "chown root path" in the shell: |
|
|
443 | aio_chown "path", 0, -1; |
|
|
444 | # same as above: |
|
|
445 | aio_chown "path", 0, undef; |
|
|
446 | |
|
|
447 | |
|
|
448 | =item aio_truncate $fh_or_path, $offset, $callback->($status) |
|
|
449 | |
|
|
450 | Works like truncate(2) or ftruncate(2). |
|
|
451 | |
|
|
452 | |
|
|
453 | =item aio_chmod $fh_or_path, $mode, $callback->($status) |
|
|
454 | |
|
|
455 | Works like perl's C<chmod> function. |
|
|
456 | |
|
|
457 | |
401 | =item aio_unlink $pathname, $callback->($status) |
458 | =item aio_unlink $pathname, $callback->($status) |
402 | |
459 | |
403 | Asynchronously unlink (delete) a file and call the callback with the |
460 | Asynchronously unlink (delete) a file and call the callback with the |
404 | result code. |
461 | result code. |
405 | |
462 | |
|
|
463 | |
406 | =item aio_mknod $path, $mode, $dev, $callback->($status) |
464 | =item aio_mknod $path, $mode, $dev, $callback->($status) |
407 | |
465 | |
408 | [EXPERIMENTAL] |
466 | [EXPERIMENTAL] |
409 | |
467 | |
410 | Asynchronously create a device node (or fifo). See mknod(2). |
468 | Asynchronously create a device node (or fifo). See mknod(2). |
411 | |
469 | |
412 | The only (POSIX-) portable way of calling this function is: |
470 | The only (POSIX-) portable way of calling this function is: |
413 | |
471 | |
414 | aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
472 | aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
|
|
473 | |
415 | |
474 | |
416 | =item aio_link $srcpath, $dstpath, $callback->($status) |
475 | =item aio_link $srcpath, $dstpath, $callback->($status) |
417 | |
476 | |
418 | Asynchronously create a new link to the existing object at C<$srcpath> at |
477 | Asynchronously create a new link to the existing object at C<$srcpath> at |
419 | the path C<$dstpath> and call the callback with the result code. |
478 | the path C<$dstpath> and call the callback with the result code. |
420 | |
479 | |
|
|
480 | |
421 | =item aio_symlink $srcpath, $dstpath, $callback->($status) |
481 | =item aio_symlink $srcpath, $dstpath, $callback->($status) |
422 | |
482 | |
423 | Asynchronously create a new symbolic link to the existing object at C<$srcpath> at |
483 | Asynchronously create a new symbolic link to the existing object at C<$srcpath> at |
424 | the path C<$dstpath> and call the callback with the result code. |
484 | the path C<$dstpath> and call the callback with the result code. |
|
|
485 | |
425 | |
486 | |
426 | =item aio_readlink $path, $callback->($link) |
487 | =item aio_readlink $path, $callback->($link) |
427 | |
488 | |
428 | Asynchronously read the symlink specified by C<$path> and pass it to |
489 | Asynchronously read the symlink specified by C<$path> and pass it to |
429 | the callback. If an error occurs, nothing or undef gets passed to the |
490 | the callback. If an error occurs, nothing or undef gets passed to the |
430 | callback. |
491 | callback. |
431 | |
492 | |
|
|
493 | |
432 | =item aio_rename $srcpath, $dstpath, $callback->($status) |
494 | =item aio_rename $srcpath, $dstpath, $callback->($status) |
433 | |
495 | |
434 | Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as |
496 | Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as |
435 | rename(2) and call the callback with the result code. |
497 | rename(2) and call the callback with the result code. |
|
|
498 | |
436 | |
499 | |
437 | =item aio_mkdir $pathname, $mode, $callback->($status) |
500 | =item aio_mkdir $pathname, $mode, $callback->($status) |
438 | |
501 | |
439 | Asynchronously mkdir (create) a directory and call the callback with |
502 | Asynchronously mkdir (create) a directory and call the callback with |
440 | the result code. C<$mode> will be modified by the umask at the time the |
503 | the result code. C<$mode> will be modified by the umask at the time the |
441 | request is executed, so do not change your umask. |
504 | request is executed, so do not change your umask. |
442 | |
505 | |
|
|
506 | |
443 | =item aio_rmdir $pathname, $callback->($status) |
507 | =item aio_rmdir $pathname, $callback->($status) |
444 | |
508 | |
445 | Asynchronously rmdir (delete) a directory and call the callback with the |
509 | Asynchronously rmdir (delete) a directory and call the callback with the |
446 | result code. |
510 | result code. |
|
|
511 | |
447 | |
512 | |
448 | =item aio_readdir $pathname, $callback->($entries) |
513 | =item aio_readdir $pathname, $callback->($entries) |
449 | |
514 | |
450 | Unlike the POSIX call of the same name, C<aio_readdir> reads an entire |
515 | Unlike the POSIX call of the same name, C<aio_readdir> reads an entire |
451 | directory (i.e. opendir + readdir + closedir). The entries will not be |
516 | directory (i.e. opendir + readdir + closedir). The entries will not be |
452 | sorted, and will B<NOT> include the C<.> and C<..> entries. |
517 | sorted, and will B<NOT> include the C<.> and C<..> entries. |
453 | |
518 | |
454 | The callback a single argument which is either C<undef> or an array-ref |
519 | The callback a single argument which is either C<undef> or an array-ref |
455 | with the filenames. |
520 | with the filenames. |
|
|
521 | |
456 | |
522 | |
457 | =item aio_load $path, $data, $callback->($status) |
523 | =item aio_load $path, $data, $callback->($status) |
458 | |
524 | |
459 | This is a composite request that tries to fully load the given file into |
525 | This is a composite request that tries to fully load the given file into |
460 | memory. Status is the same as with aio_read. |
526 | memory. Status is the same as with aio_read. |
… | |
… | |
469 | my $pri = aioreq_pri; |
535 | my $pri = aioreq_pri; |
470 | my $grp = aio_group $cb; |
536 | my $grp = aio_group $cb; |
471 | |
537 | |
472 | aioreq_pri $pri; |
538 | aioreq_pri $pri; |
473 | add $grp aio_open $path, O_RDONLY, 0, sub { |
539 | add $grp aio_open $path, O_RDONLY, 0, sub { |
474 | my ($fh) = @_ |
540 | my $fh = shift |
475 | or return $grp->result (-1); |
541 | or return $grp->result (-1); |
476 | |
542 | |
477 | aioreq_pri $pri; |
543 | aioreq_pri $pri; |
478 | add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub { |
544 | add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub { |
479 | $grp->result ($_[0]); |
545 | $grp->result ($_[0]); |
… | |
… | |
1078 | Strictly equivalent to: |
1144 | Strictly equivalent to: |
1079 | |
1145 | |
1080 | IO::AIO::poll_wait, IO::AIO::poll_cb |
1146 | IO::AIO::poll_wait, IO::AIO::poll_cb |
1081 | while IO::AIO::nreqs; |
1147 | while IO::AIO::nreqs; |
1082 | |
1148 | |
|
|
1149 | =back |
|
|
1150 | |
1083 | =head3 CONTROLLING THE NUMBER OF THREADS |
1151 | =head3 CONTROLLING THE NUMBER OF THREADS |
|
|
1152 | |
|
|
1153 | =over |
1084 | |
1154 | |
1085 | =item IO::AIO::min_parallel $nthreads |
1155 | =item IO::AIO::min_parallel $nthreads |
1086 | |
1156 | |
1087 | Set the minimum number of AIO threads to C<$nthreads>. The current |
1157 | Set the minimum number of AIO threads to C<$nthreads>. The current |
1088 | default is C<8>, which means eight asynchronous operations can execute |
1158 | default is C<8>, which means eight asynchronous operations can execute |
… | |
… | |
1147 | |
1217 | |
1148 | You can still queue as many requests as you want. Therefore, |
1218 | You can still queue as many requests as you want. Therefore, |
1149 | C<max_oustsanding> is mainly useful in simple scripts (with low values) or |
1219 | C<max_oustsanding> is mainly useful in simple scripts (with low values) or |
1150 | as a stop gap to shield against fatal memory overflow (with large values). |
1220 | as a stop gap to shield against fatal memory overflow (with large values). |
1151 | |
1221 | |
|
|
1222 | =back |
|
|
1223 | |
1152 | =head3 STATISTICAL INFORMATION |
1224 | =head3 STATISTICAL INFORMATION |
|
|
1225 | |
|
|
1226 | =over |
1153 | |
1227 | |
1154 | =item IO::AIO::nreqs |
1228 | =item IO::AIO::nreqs |
1155 | |
1229 | |
1156 | Returns the number of requests currently in the ready, execute or pending |
1230 | Returns the number of requests currently in the ready, execute or pending |
1157 | states (i.e. for which their callback has not been invoked yet). |
1231 | states (i.e. for which their callback has not been invoked yet). |
… | |
… | |
1221 | bytes of memory. In addition, stat requests need a stat buffer (possibly |
1295 | bytes of memory. In addition, stat requests need a stat buffer (possibly |
1222 | a few hundred bytes), readdir requires a result buffer and so on. Perl |
1296 | a few hundred bytes), readdir requires a result buffer and so on. Perl |
1223 | scalars and other data passed into aio requests will also be locked and |
1297 | scalars and other data passed into aio requests will also be locked and |
1224 | will consume memory till the request has entered the done state. |
1298 | will consume memory till the request has entered the done state. |
1225 | |
1299 | |
1226 | This is now awfully much, so queuing lots of requests is not usually a |
1300 | This is not awfully much, so queuing lots of requests is not usually a |
1227 | problem. |
1301 | problem. |
1228 | |
1302 | |
1229 | Per-thread usage: |
1303 | Per-thread usage: |
1230 | |
1304 | |
1231 | In the execution phase, some aio requests require more memory for |
1305 | In the execution phase, some aio requests require more memory for |