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Revision 1.94 by root, Wed Nov 8 02:01:02 2006 UTC vs.
Revision 1.117 by root, Sat Oct 6 14:05:19 2007 UTC

62etc.), but can also be used to easily do operations in parallel that are 62etc.), but can also be used to easily do operations in parallel that are
63normally done sequentially, e.g. stat'ing many files, which is much faster 63normally done sequentially, e.g. stat'ing many files, which is much faster
64on a RAID volume or over NFS when you do a number of stat operations 64on a RAID volume or over NFS when you do a number of stat operations
65concurrently. 65concurrently.
66 66
67While most of this works on all types of file descriptors (for example 67While most of this works on all types of file descriptors (for
68sockets), using these functions on file descriptors that support 68example sockets), using these functions on file descriptors that
69nonblocking operation (again, sockets, pipes etc.) is very inefficient or 69support nonblocking operation (again, sockets, pipes etc.) is very
70might not work (aio_read fails on sockets/pipes/fifos). Use an event loop 70inefficient. Use an event loop for that (such as the L<Event|Event>
71for that (such as the L<Event|Event> module): IO::AIO will naturally fit 71module): IO::AIO will naturally fit into such an event loop itself.
72into such an event loop itself.
73 72
74In this version, a number of threads are started that execute your 73In this version, a number of threads are started that execute your
75requests and signal their completion. You don't need thread support 74requests and signal their completion. You don't need thread support
76in perl, and the threads created by this module will not be visible 75in perl, and the threads created by this module will not be visible
77to perl. In the future, this module might make use of the native aio 76to perl. In the future, this module might make use of the native aio
79not well-supported or restricted (GNU/Linux doesn't allow them on normal 78not well-supported or restricted (GNU/Linux doesn't allow them on normal
80files currently, for example), and they would only support aio_read and 79files currently, for example), and they would only support aio_read and
81aio_write, so the remaining functionality would have to be implemented 80aio_write, so the remaining functionality would have to be implemented
82using threads anyway. 81using threads anyway.
83 82
84Although the module will work with in the presence of other (Perl-) 83Although the module will work in the presence of other (Perl-) threads,
85threads, it is currently not reentrant in any way, so use appropriate 84it is currently not reentrant in any way, so use appropriate locking
86locking yourself, always call C<poll_cb> from within the same thread, or 85yourself, always call C<poll_cb> from within the same thread, or never
87never call C<poll_cb> (or other C<aio_> functions) recursively. 86call C<poll_cb> (or other C<aio_> functions) recursively.
88 87
89=head2 EXAMPLE 88=head2 EXAMPLE
90 89
91This is a simple example that uses the Event module and loads 90This is a simple example that uses the Event module and loads
92F</etc/passwd> asynchronously: 91F</etc/passwd> asynchronously:
184 183
185=cut 184=cut
186 185
187package IO::AIO; 186package IO::AIO;
188 187
188use Carp ();
189
189no warnings; 190no warnings;
190use strict 'vars'; 191use strict 'vars';
191 192
192use base 'Exporter'; 193use base 'Exporter';
193 194
194BEGIN { 195BEGIN {
195 our $VERSION = '2.2'; 196 our $VERSION = '2.51';
196 197
197 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat 198 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 199 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 200 aio_readlink aio_fsync aio_fdatasync aio_readahead aio_rename aio_link
200 aio_move aio_copy aio_group aio_nop aio_mknod); 201 aio_move aio_copy aio_group aio_nop aio_mknod aio_load aio_rmtree aio_mkdir
202 aio_chown aio_chmod aio_utime aio_truncate);
201 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); 203 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block));
202 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 204 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
203 min_parallel max_parallel max_idle 205 min_parallel max_parallel max_idle
204 nreqs nready npending nthreads 206 nreqs nready npending nthreads
205 max_poll_time max_poll_reqs); 207 max_poll_time max_poll_reqs);
206 208
271 aio_read $_[0], ..., sub { 273 aio_read $_[0], ..., sub {
272 ... 274 ...
273 }; 275 };
274 }; 276 };
275 277
278
276=item aioreq_nice $pri_adjust 279=item aioreq_nice $pri_adjust
277 280
278Similar to C<aioreq_pri>, but subtracts the given value from the current 281Similar to C<aioreq_pri>, but subtracts the given value from the current
279priority, so the effect is cumulative. 282priority, so the effect is cumulative.
283
280 284
281=item aio_open $pathname, $flags, $mode, $callback->($fh) 285=item aio_open $pathname, $flags, $mode, $callback->($fh)
282 286
283Asynchronously open or create a file and call the callback with a newly 287Asynchronously open or create a file and call the callback with a newly
284created filehandle for the file. 288created filehandle for the file.
290list. They are the same as used by C<sysopen>. 294list. They are the same as used by C<sysopen>.
291 295
292Likewise, C<$mode> specifies the mode of the newly created file, if it 296Likewise, C<$mode> specifies the mode of the newly created file, if it
293didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>, 297didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>,
294except that it is mandatory (i.e. use C<0> if you don't create new files, 298except that it is mandatory (i.e. use C<0> if you don't create new files,
295and C<0666> or C<0777> if you do). 299and C<0666> or C<0777> if you do). Note that the C<$mode> will be modified
300by the umask in effect then the request is being executed, so better never
301change the umask.
296 302
297Example: 303Example:
298 304
299 aio_open "/etc/passwd", O_RDONLY, 0, sub { 305 aio_open "/etc/passwd", O_RDONLY, 0, sub {
300 if ($_[0]) { 306 if ($_[0]) {
303 } else { 309 } else {
304 die "open failed: $!\n"; 310 die "open failed: $!\n";
305 } 311 }
306 }; 312 };
307 313
314
308=item aio_close $fh, $callback->($status) 315=item aio_close $fh, $callback->($status)
309 316
310Asynchronously close a file and call the callback with the result 317Asynchronously close a file and call the callback with the result
311code. I<WARNING:> although accepted, you should not pass in a perl 318code.
312filehandle here, as perl will likely close the file descriptor another
313time when the filehandle is destroyed. Normally, you can safely call perls
314C<close> or just let filehandles go out of scope.
315 319
316This is supposed to be a bug in the API, so that might change. It's 320Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
317therefore best to avoid this function. 321closing the file descriptor associated with the filehandle itself. Here is
322what aio_close will try:
323
324 1. dup()licate the fd
325 2. asynchronously close() the duplicated fd
326 3. dup()licate the fd once more
327 4. let perl close() the filehandle
328 5. asynchronously close the duplicated fd
329
330The idea is that the first close() flushes stuff to disk that closing an
331fd will flush, so when perl closes the fd, nothing much will need to be
332flushed. The second async. close() will then flush stuff to disk that
333closing the last fd to the file will flush.
334
335Just FYI, SuSv3 has this to say on close:
336
337 All outstanding record locks owned by the process on the file
338 associated with the file descriptor shall be removed.
339
340 If fildes refers to a socket, close() shall cause the socket to be
341 destroyed. ... close() shall block for up to the current linger
342 interval until all data is transmitted.
343 [this actually sounds like a specification bug, but who knows]
344
345And at least Linux additionally actually flushes stuff on every close,
346even when the file itself is still open.
347
348Sounds enourmously inefficient and complicated? Yes... please show me how
349to nuke perl's fd out of existence...
350
351=cut
352
353sub aio_close($;$) {
354 aio_block {
355 my ($fh, $cb) = @_;
356
357 my $pri = aioreq_pri;
358 my $grp = aio_group $cb;
359
360 my $fd = fileno $fh;
361
362 defined $fd or Carp::croak "aio_close called with fd-less filehandle";
363
364 # if the dups fail we will simply get EBADF
365 my $fd2 = _dup $fd;
366 aioreq_pri $pri;
367 add $grp _aio_close $fd2, sub {
368 my $fd2 = _dup $fd;
369 close $fh;
370 aioreq_pri $pri;
371 add $grp _aio_close $fd2, sub {
372 $grp->result ($_[0]);
373 };
374 };
375
376 $grp
377 }
378}
379
318 380
319=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 381=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
320 382
321=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 383=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
322 384
323Reads or writes C<length> bytes from the specified C<fh> and C<offset> 385Reads or writes C<$length> bytes from the specified C<$fh> and C<$offset>
324into the scalar given by C<data> and offset C<dataoffset> and calls the 386into the scalar given by C<$data> and offset C<$dataoffset> and calls the
325callback without the actual number of bytes read (or -1 on error, just 387callback without the actual number of bytes read (or -1 on error, just
326like the syscall). 388like the syscall).
327 389
390If C<$offset> is undefined, then the current file descriptor offset will
391be used (and updated), otherwise the file descriptor offset will not be
392changed by these calls.
393
394If C<$length> is undefined in C<aio_write>, use the remaining length of C<$data>.
395
396If C<$dataoffset> is less than zero, it will be counted from the end of
397C<$data>.
398
328The C<$data> scalar I<MUST NOT> be modified in any way while the request 399The C<$data> scalar I<MUST NOT> be modified in any way while the request
329is outstanding. Modifying it can result in segfaults or WW3 (if the 400is outstanding. Modifying it can result in segfaults or World War III (if
330necessary/optional hardware is installed). 401the necessary/optional hardware is installed).
331 402
332Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at 403Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
333offset C<0> within the scalar: 404offset C<0> within the scalar:
334 405
335 aio_read $fh, 7, 15, $buffer, 0, sub { 406 aio_read $fh, 7, 15, $buffer, 0, sub {
336 $_[0] > 0 or die "read error: $!"; 407 $_[0] > 0 or die "read error: $!";
337 print "read $_[0] bytes: <$buffer>\n"; 408 print "read $_[0] bytes: <$buffer>\n";
338 }; 409 };
410
339 411
340=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) 412=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
341 413
342Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts 414Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
343reading at byte offset C<$in_offset>, and starts writing at the current 415reading at byte offset C<$in_offset>, and starts writing at the current
357C<$in_fh> than are written, and there is no way to find out how many 429C<$in_fh> than are written, and there is no way to find out how many
358bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only 430bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
359provides the number of bytes written to C<$out_fh>. Only if the result 431provides the number of bytes written to C<$out_fh>. Only if the result
360value equals C<$length> one can assume that C<$length> bytes have been 432value equals C<$length> one can assume that C<$length> bytes have been
361read. 433read.
434
362 435
363=item aio_readahead $fh,$offset,$length, $callback->($retval) 436=item aio_readahead $fh,$offset,$length, $callback->($retval)
364 437
365C<aio_readahead> populates the page cache with data from a file so that 438C<aio_readahead> populates the page cache with data from a file so that
366subsequent reads from that file will not block on disk I/O. The C<$offset> 439subsequent reads from that file will not block on disk I/O. The C<$offset>
372file. The current file offset of the file is left unchanged. 445file. The current file offset of the file is left unchanged.
373 446
374If that syscall doesn't exist (likely if your OS isn't Linux) it will be 447If that syscall doesn't exist (likely if your OS isn't Linux) it will be
375emulated by simply reading the data, which would have a similar effect. 448emulated by simply reading the data, which would have a similar effect.
376 449
450
377=item aio_stat $fh_or_path, $callback->($status) 451=item aio_stat $fh_or_path, $callback->($status)
378 452
379=item aio_lstat $fh, $callback->($status) 453=item aio_lstat $fh, $callback->($status)
380 454
381Works like perl's C<stat> or C<lstat> in void context. The callback will 455Works like perl's C<stat> or C<lstat> in void context. The callback will
394 aio_stat "/etc/passwd", sub { 468 aio_stat "/etc/passwd", sub {
395 $_[0] and die "stat failed: $!"; 469 $_[0] and die "stat failed: $!";
396 print "size is ", -s _, "\n"; 470 print "size is ", -s _, "\n";
397 }; 471 };
398 472
473
474=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
475
476Works like perl's C<utime> function (including the special case of $atime
477and $mtime being undef). Fractional times are supported if the underlying
478syscalls support them.
479
480When called with a pathname, uses utimes(2) if available, otherwise
481utime(2). If called on a file descriptor, uses futimes(2) if available,
482otherwise returns ENOSYS, so this is not portable.
483
484Examples:
485
486 # set atime and mtime to current time (basically touch(1)):
487 aio_utime "path", undef, undef;
488 # set atime to current time and mtime to beginning of the epoch:
489 aio_utime "path", time, undef; # undef==0
490
491
492=item aio_chown $fh_or_path, $uid, $gid, $callback->($status)
493
494Works like perl's C<chown> function, except that C<undef> for either $uid
495or $gid is being interpreted as "do not change" (but -1 can also be used).
496
497Examples:
498
499 # same as "chown root path" in the shell:
500 aio_chown "path", 0, -1;
501 # same as above:
502 aio_chown "path", 0, undef;
503
504
505=item aio_truncate $fh_or_path, $offset, $callback->($status)
506
507Works like truncate(2) or ftruncate(2).
508
509
510=item aio_chmod $fh_or_path, $mode, $callback->($status)
511
512Works like perl's C<chmod> function.
513
514
399=item aio_unlink $pathname, $callback->($status) 515=item aio_unlink $pathname, $callback->($status)
400 516
401Asynchronously unlink (delete) a file and call the callback with the 517Asynchronously unlink (delete) a file and call the callback with the
402result code. 518result code.
403 519
520
404=item aio_mknod $path, $mode, $dev, $callback->($status) 521=item aio_mknod $path, $mode, $dev, $callback->($status)
405 522
406[EXPERIMENTAL] 523[EXPERIMENTAL]
407 524
408Asynchronously create a device node (or fifo). See mknod(2). 525Asynchronously create a device node (or fifo). See mknod(2).
409 526
410The only (POSIX-) portable way of calling this function is: 527The only (POSIX-) portable way of calling this function is:
411 528
412 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... 529 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...
530
413 531
414=item aio_link $srcpath, $dstpath, $callback->($status) 532=item aio_link $srcpath, $dstpath, $callback->($status)
415 533
416Asynchronously create a new link to the existing object at C<$srcpath> at 534Asynchronously create a new link to the existing object at C<$srcpath> at
417the path C<$dstpath> and call the callback with the result code. 535the path C<$dstpath> and call the callback with the result code.
418 536
537
419=item aio_symlink $srcpath, $dstpath, $callback->($status) 538=item aio_symlink $srcpath, $dstpath, $callback->($status)
420 539
421Asynchronously create a new symbolic link to the existing object at C<$srcpath> at 540Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
422the path C<$dstpath> and call the callback with the result code. 541the path C<$dstpath> and call the callback with the result code.
542
423 543
424=item aio_readlink $path, $callback->($link) 544=item aio_readlink $path, $callback->($link)
425 545
426Asynchronously read the symlink specified by C<$path> and pass it to 546Asynchronously read the symlink specified by C<$path> and pass it to
427the callback. If an error occurs, nothing or undef gets passed to the 547the callback. If an error occurs, nothing or undef gets passed to the
428callback. 548callback.
429 549
550
430=item aio_rename $srcpath, $dstpath, $callback->($status) 551=item aio_rename $srcpath, $dstpath, $callback->($status)
431 552
432Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as 553Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
433rename(2) and call the callback with the result code. 554rename(2) and call the callback with the result code.
434 555
556
557=item aio_mkdir $pathname, $mode, $callback->($status)
558
559Asynchronously mkdir (create) a directory and call the callback with
560the result code. C<$mode> will be modified by the umask at the time the
561request is executed, so do not change your umask.
562
563
435=item aio_rmdir $pathname, $callback->($status) 564=item aio_rmdir $pathname, $callback->($status)
436 565
437Asynchronously rmdir (delete) a directory and call the callback with the 566Asynchronously rmdir (delete) a directory and call the callback with the
438result code. 567result code.
568
439 569
440=item aio_readdir $pathname, $callback->($entries) 570=item aio_readdir $pathname, $callback->($entries)
441 571
442Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 572Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
443directory (i.e. opendir + readdir + closedir). The entries will not be 573directory (i.e. opendir + readdir + closedir). The entries will not be
444sorted, and will B<NOT> include the C<.> and C<..> entries. 574sorted, and will B<NOT> include the C<.> and C<..> entries.
445 575
446The callback a single argument which is either C<undef> or an array-ref 576The callback a single argument which is either C<undef> or an array-ref
447with the filenames. 577with the filenames.
578
579
580=item aio_load $path, $data, $callback->($status)
581
582This is a composite request that tries to fully load the given file into
583memory. Status is the same as with aio_read.
584
585=cut
586
587sub aio_load($$;$) {
588 aio_block {
589 my ($path, undef, $cb) = @_;
590 my $data = \$_[1];
591
592 my $pri = aioreq_pri;
593 my $grp = aio_group $cb;
594
595 aioreq_pri $pri;
596 add $grp aio_open $path, O_RDONLY, 0, sub {
597 my $fh = shift
598 or return $grp->result (-1);
599
600 aioreq_pri $pri;
601 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
602 $grp->result ($_[0]);
603 };
604 };
605
606 $grp
607 }
608}
448 609
449=item aio_copy $srcpath, $dstpath, $callback->($status) 610=item aio_copy $srcpath, $dstpath, $callback->($status)
450 611
451Try to copy the I<file> (directories not supported as either source or 612Try to copy the I<file> (directories not supported as either source or
452destination) from C<$srcpath> to C<$dstpath> and call the callback with 613destination) from C<$srcpath> to C<$dstpath> and call the callback with
462errors are being ignored. 623errors are being ignored.
463 624
464=cut 625=cut
465 626
466sub aio_copy($$;$) { 627sub aio_copy($$;$) {
628 aio_block {
467 my ($src, $dst, $cb) = @_; 629 my ($src, $dst, $cb) = @_;
468 630
469 my $pri = aioreq_pri; 631 my $pri = aioreq_pri;
470 my $grp = aio_group $cb; 632 my $grp = aio_group $cb;
471 633
472 aioreq_pri $pri; 634 aioreq_pri $pri;
473 add $grp aio_open $src, O_RDONLY, 0, sub { 635 add $grp aio_open $src, O_RDONLY, 0, sub {
474 if (my $src_fh = $_[0]) { 636 if (my $src_fh = $_[0]) {
475 my @stat = stat $src_fh; 637 my @stat = stat $src_fh;
476 638
477 aioreq_pri $pri; 639 aioreq_pri $pri;
478 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub { 640 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
479 if (my $dst_fh = $_[0]) { 641 if (my $dst_fh = $_[0]) {
480 aioreq_pri $pri; 642 aioreq_pri $pri;
481 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 643 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
482 if ($_[0] == $stat[7]) { 644 if ($_[0] == $stat[7]) {
483 $grp->result (0); 645 $grp->result (0);
484 close $src_fh; 646 close $src_fh;
485 647
486 # those should not normally block. should. should. 648 # those should not normally block. should. should.
487 utime $stat[8], $stat[9], $dst; 649 utime $stat[8], $stat[9], $dst;
488 chmod $stat[2] & 07777, $dst_fh; 650 chmod $stat[2] & 07777, $dst_fh;
489 chown $stat[4], $stat[5], $dst_fh; 651 chown $stat[4], $stat[5], $dst_fh;
490 close $dst_fh; 652 close $dst_fh;
491 } else { 653 } else {
492 $grp->result (-1); 654 $grp->result (-1);
493 close $src_fh; 655 close $src_fh;
494 close $dst_fh; 656 close $dst_fh;
495 657
496 aioreq $pri; 658 aioreq $pri;
497 add $grp aio_unlink $dst; 659 add $grp aio_unlink $dst;
660 }
498 } 661 };
662 } else {
663 $grp->result (-1);
499 }; 664 }
500 } else {
501 $grp->result (-1);
502 } 665 },
666
667 } else {
668 $grp->result (-1);
503 }, 669 }
504
505 } else {
506 $grp->result (-1);
507 } 670 };
671
672 $grp
508 }; 673 }
509
510 $grp
511} 674}
512 675
513=item aio_move $srcpath, $dstpath, $callback->($status) 676=item aio_move $srcpath, $dstpath, $callback->($status)
514 677
515Try to move the I<file> (directories not supported as either source or 678Try to move the I<file> (directories not supported as either source or
521that is successful, unlinking the C<$srcpath>. 684that is successful, unlinking the C<$srcpath>.
522 685
523=cut 686=cut
524 687
525sub aio_move($$;$) { 688sub aio_move($$;$) {
689 aio_block {
526 my ($src, $dst, $cb) = @_; 690 my ($src, $dst, $cb) = @_;
527 691
528 my $pri = aioreq_pri; 692 my $pri = aioreq_pri;
529 my $grp = aio_group $cb; 693 my $grp = aio_group $cb;
530 694
531 aioreq_pri $pri; 695 aioreq_pri $pri;
532 add $grp aio_rename $src, $dst, sub { 696 add $grp aio_rename $src, $dst, sub {
533 if ($_[0] && $! == EXDEV) { 697 if ($_[0] && $! == EXDEV) {
534 aioreq_pri $pri; 698 aioreq_pri $pri;
535 add $grp aio_copy $src, $dst, sub { 699 add $grp aio_copy $src, $dst, sub {
700 $grp->result ($_[0]);
701
702 if (!$_[0]) {
703 aioreq_pri $pri;
704 add $grp aio_unlink $src;
705 }
706 };
707 } else {
536 $grp->result ($_[0]); 708 $grp->result ($_[0]);
537
538 if (!$_[0]) {
539 aioreq_pri $pri;
540 add $grp aio_unlink $src;
541 }
542 }; 709 }
543 } else {
544 $grp->result ($_[0]);
545 } 710 };
711
712 $grp
546 }; 713 }
547
548 $grp
549} 714}
550 715
551=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 716=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
552 717
553Scans a directory (similar to C<aio_readdir>) but additionally tries to 718Scans a directory (similar to C<aio_readdir>) but additionally tries to
600as those tend to return 0 or 1 as link counts, which disables the 765as those tend to return 0 or 1 as link counts, which disables the
601directory counting heuristic. 766directory counting heuristic.
602 767
603=cut 768=cut
604 769
605sub aio_scandir($$$) { 770sub aio_scandir($$;$) {
771 aio_block {
606 my ($path, $maxreq, $cb) = @_; 772 my ($path, $maxreq, $cb) = @_;
607 773
608 my $pri = aioreq_pri; 774 my $pri = aioreq_pri;
609 775
610 my $grp = aio_group $cb; 776 my $grp = aio_group $cb;
611 777
612 $maxreq = 4 if $maxreq <= 0; 778 $maxreq = 4 if $maxreq <= 0;
613 779
614 # stat once 780 # stat once
615 aioreq_pri $pri;
616 add $grp aio_stat $path, sub {
617 return $grp->result () if $_[0];
618 my $now = time;
619 my $hash1 = join ":", (stat _)[0,1,3,7,9];
620
621 # read the directory entries
622 aioreq_pri $pri; 781 aioreq_pri $pri;
623 add $grp aio_readdir $path, sub { 782 add $grp aio_stat $path, sub {
624 my $entries = shift
625 or return $grp->result (); 783 return $grp->result () if $_[0];
784 my $now = time;
785 my $hash1 = join ":", (stat _)[0,1,3,7,9];
626 786
627 # stat the dir another time 787 # read the directory entries
628 aioreq_pri $pri; 788 aioreq_pri $pri;
789 add $grp aio_readdir $path, sub {
790 my $entries = shift
791 or return $grp->result ();
792
793 # stat the dir another time
794 aioreq_pri $pri;
629 add $grp aio_stat $path, sub { 795 add $grp aio_stat $path, sub {
630 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 796 my $hash2 = join ":", (stat _)[0,1,3,7,9];
631 797
632 my $ndirs; 798 my $ndirs;
633 799
634 # take the slow route if anything looks fishy 800 # take the slow route if anything looks fishy
635 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 801 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
636 $ndirs = -1; 802 $ndirs = -1;
637 } else { 803 } else {
638 # if nlink == 2, we are finished 804 # if nlink == 2, we are finished
639 # on non-posix-fs's, we rely on nlink < 2 805 # on non-posix-fs's, we rely on nlink < 2
640 $ndirs = (stat _)[3] - 2 806 $ndirs = (stat _)[3] - 2
641 or return $grp->result ([], $entries); 807 or return $grp->result ([], $entries);
642 } 808 }
643 809
644 # sort into likely dirs and likely nondirs 810 # sort into likely dirs and likely nondirs
645 # dirs == files without ".", short entries first 811 # dirs == files without ".", short entries first
646 $entries = [map $_->[0], 812 $entries = [map $_->[0],
647 sort { $b->[1] cmp $a->[1] } 813 sort { $b->[1] cmp $a->[1] }
648 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length], 814 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
649 @$entries]; 815 @$entries];
650 816
651 my (@dirs, @nondirs); 817 my (@dirs, @nondirs);
652 818
653 my $statgrp = add $grp aio_group sub { 819 my $statgrp = add $grp aio_group sub {
654 $grp->result (\@dirs, \@nondirs); 820 $grp->result (\@dirs, \@nondirs);
655 }; 821 };
656 822
657 limit $statgrp $maxreq; 823 limit $statgrp $maxreq;
658 feed $statgrp sub { 824 feed $statgrp sub {
659 return unless @$entries; 825 return unless @$entries;
660 my $entry = pop @$entries; 826 my $entry = pop @$entries;
661 827
662 aioreq_pri $pri; 828 aioreq_pri $pri;
663 add $statgrp aio_stat "$path/$entry/.", sub { 829 add $statgrp aio_stat "$path/$entry/.", sub {
664 if ($_[0] < 0) { 830 if ($_[0] < 0) {
665 push @nondirs, $entry; 831 push @nondirs, $entry;
666 } else { 832 } else {
667 # need to check for real directory 833 # need to check for real directory
668 aioreq_pri $pri; 834 aioreq_pri $pri;
669 add $statgrp aio_lstat "$path/$entry", sub { 835 add $statgrp aio_lstat "$path/$entry", sub {
670 if (-d _) { 836 if (-d _) {
671 push @dirs, $entry; 837 push @dirs, $entry;
672 838
673 unless (--$ndirs) { 839 unless (--$ndirs) {
674 push @nondirs, @$entries; 840 push @nondirs, @$entries;
675 feed $statgrp; 841 feed $statgrp;
842 }
843 } else {
844 push @nondirs, $entry;
676 } 845 }
677 } else {
678 push @nondirs, $entry;
679 } 846 }
680 } 847 }
681 } 848 };
682 }; 849 };
683 }; 850 };
684 }; 851 };
685 }; 852 };
853
854 $grp
686 }; 855 }
856}
687 857
858=item aio_rmtree $path, $callback->($status)
859
860Delete a directory tree starting (and including) C<$path>, return the
861status of the final C<rmdir> only. This is a composite request that
862uses C<aio_scandir> to recurse into and rmdir directories, and unlink
863everything else.
864
865=cut
866
867sub aio_rmtree;
868sub aio_rmtree($;$) {
869 aio_block {
870 my ($path, $cb) = @_;
871
872 my $pri = aioreq_pri;
873 my $grp = aio_group $cb;
874
875 aioreq_pri $pri;
876 add $grp aio_scandir $path, 0, sub {
877 my ($dirs, $nondirs) = @_;
878
879 my $dirgrp = aio_group sub {
880 add $grp aio_rmdir $path, sub {
881 $grp->result ($_[0]);
882 };
883 };
884
885 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
886 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
887
888 add $grp $dirgrp;
889 };
890
688 $grp 891 $grp
892 }
689} 893}
690 894
691=item aio_fsync $fh, $callback->($status) 895=item aio_fsync $fh, $callback->($status)
692 896
693Asynchronously call fsync on the given filehandle and call the callback 897Asynchronously call fsync on the given filehandle and call the callback
997Strictly equivalent to: 1201Strictly equivalent to:
998 1202
999 IO::AIO::poll_wait, IO::AIO::poll_cb 1203 IO::AIO::poll_wait, IO::AIO::poll_cb
1000 while IO::AIO::nreqs; 1204 while IO::AIO::nreqs;
1001 1205
1206=back
1207
1002=head3 CONTROLLING THE NUMBER OF THREADS 1208=head3 CONTROLLING THE NUMBER OF THREADS
1209
1210=over
1003 1211
1004=item IO::AIO::min_parallel $nthreads 1212=item IO::AIO::min_parallel $nthreads
1005 1213
1006Set the minimum number of AIO threads to C<$nthreads>. The current 1214Set the minimum number of AIO threads to C<$nthreads>. The current
1007default is C<8>, which means eight asynchronous operations can execute 1215default is C<8>, which means eight asynchronous operations can execute
1055This is a very bad function to use in interactive programs because it 1263This is a very bad function to use in interactive programs because it
1056blocks, and a bad way to reduce concurrency because it is inexact: Better 1264blocks, and a bad way to reduce concurrency because it is inexact: Better
1057use an C<aio_group> together with a feed callback. 1265use an C<aio_group> together with a feed callback.
1058 1266
1059Sets the maximum number of outstanding requests to C<$nreqs>. If you 1267Sets the maximum number of outstanding requests to C<$nreqs>. If you
1060to queue up more than this number of requests, the next call to the 1268do queue up more than this number of requests, the next call to the
1061C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>) 1269C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
1062function will block until the limit is no longer exceeded. 1270function will block until the limit is no longer exceeded.
1063 1271
1064The default value is very large, so there is no practical limit on the 1272The default value is very large, so there is no practical limit on the
1065number of outstanding requests. 1273number of outstanding requests.
1066 1274
1067You can still queue as many requests as you want. Therefore, 1275You can still queue as many requests as you want. Therefore,
1068C<max_oustsanding> is mainly useful in simple scripts (with low values) or 1276C<max_oustsanding> is mainly useful in simple scripts (with low values) or
1069as a stop gap to shield against fatal memory overflow (with large values). 1277as a stop gap to shield against fatal memory overflow (with large values).
1070 1278
1279=back
1280
1071=head3 STATISTICAL INFORMATION 1281=head3 STATISTICAL INFORMATION
1282
1283=over
1072 1284
1073=item IO::AIO::nreqs 1285=item IO::AIO::nreqs
1074 1286
1075Returns the number of requests currently in the ready, execute or pending 1287Returns the number of requests currently in the ready, execute or pending
1076states (i.e. for which their callback has not been invoked yet). 1288states (i.e. for which their callback has not been invoked yet).
1092 1304
1093=back 1305=back
1094 1306
1095=cut 1307=cut
1096 1308
1097# support function to convert a fd into a perl filehandle
1098sub _fd2fh {
1099 return undef if $_[0] < 0;
1100
1101 # try to generate nice filehandles
1102 my $sym = "IO::AIO::fd#$_[0]";
1103 local *$sym;
1104
1105 open *$sym, "+<&=$_[0]" # usually works under any unix
1106 or open *$sym, "<&=$_[0]" # cygwin needs this
1107 or open *$sym, ">&=$_[0]" # or this
1108 or return undef;
1109
1110 *$sym
1111}
1112
1113min_parallel 8; 1309min_parallel 8;
1114 1310
1115END { 1311END { flush }
1116 min_parallel 1;
1117 flush;
1118};
1119 1312
11201; 13131;
1121 1314
1122=head2 FORK BEHAVIOUR 1315=head2 FORK BEHAVIOUR
1123 1316
1143bytes of memory. In addition, stat requests need a stat buffer (possibly 1336bytes of memory. In addition, stat requests need a stat buffer (possibly
1144a few hundred bytes), readdir requires a result buffer and so on. Perl 1337a few hundred bytes), readdir requires a result buffer and so on. Perl
1145scalars and other data passed into aio requests will also be locked and 1338scalars and other data passed into aio requests will also be locked and
1146will consume memory till the request has entered the done state. 1339will consume memory till the request has entered the done state.
1147 1340
1148This is now awfully much, so queuing lots of requests is not usually a 1341This is not awfully much, so queuing lots of requests is not usually a
1149problem. 1342problem.
1150 1343
1151Per-thread usage: 1344Per-thread usage:
1152 1345
1153In the execution phase, some aio requests require more memory for 1346In the execution phase, some aio requests require more memory for

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