ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/IO-AIO/AIO.pm
(Generate patch)

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.84 by root, Sat Oct 28 00:17:30 2006 UTC vs.
Revision 1.105 by root, Sun Mar 25 00:20:27 2007 UTC

… …
5=head1 SYNOPSIS 5=head1 SYNOPSIS
6 6
7 use IO::AIO; 7 use IO::AIO;
8 8
9 aio_open "/etc/passwd", O_RDONLY, 0, sub { 9 aio_open "/etc/passwd", O_RDONLY, 0, sub {
10 my ($fh) = @_; 10 my $fh = shift
11 or die "/etc/passwd: $!";
11 ... 12 ...
12 }; 13 };
13 14
14 aio_unlink "/tmp/file", sub { }; 15 aio_unlink "/tmp/file", sub { };
15 16
… …
50 51
51=head1 DESCRIPTION 52=head1 DESCRIPTION
52 53
53This module implements asynchronous I/O using whatever means your 54This module implements asynchronous I/O using whatever means your
54operating system supports. 55operating system supports.
56
57Asynchronous means that operations that can normally block your program
58(e.g. reading from disk) will be done asynchronously: the operation
59will still block, but you can do something else in the meantime. This
60is extremely useful for programs that need to stay interactive even
61when doing heavy I/O (GUI programs, high performance network servers
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
64on a RAID volume or over NFS when you do a number of stat operations
65concurrently.
66
67While most of this works on all types of file descriptors (for example
68sockets), using these functions on file descriptors that support
69nonblocking operation (again, sockets, pipes etc.) is very inefficient or
70might not work (aio_read fails on sockets/pipes/fifos). Use an event loop
71for that (such as the L<Event|Event> module): IO::AIO will naturally fit
72into such an event loop itself.
55 73
56In this version, a number of threads are started that execute your 74In this version, a number of threads are started that execute your
57requests and signal their completion. You don't need thread support 75requests and signal their completion. You don't need thread support
58in perl, and the threads created by this module will not be visible 76in perl, and the threads created by this module will not be visible
59to perl. In the future, this module might make use of the native aio 77to perl. In the future, this module might make use of the native aio
60functions available on many operating systems. However, they are often 78functions available on many operating systems. However, they are often
61not well-supported or restricted (Linux doesn't allow them on normal 79not well-supported or restricted (GNU/Linux doesn't allow them on normal
62files currently, for example), and they would only support aio_read and 80files currently, for example), and they would only support aio_read and
63aio_write, so the remaining functionality would have to be implemented 81aio_write, so the remaining functionality would have to be implemented
64using threads anyway. 82using threads anyway.
65 83
66Although the module will work with in the presence of other (Perl-) 84Although the module will work with in the presence of other (Perl-)
67threads, it is currently not reentrant in any way, so use appropriate 85threads, it is currently not reentrant in any way, so use appropriate
68locking yourself, always call C<poll_cb> from within the same thread, or 86locking yourself, always call C<poll_cb> from within the same thread, or
69never call C<poll_cb> (or other C<aio_> functions) recursively. 87never call C<poll_cb> (or other C<aio_> functions) recursively.
70 88
89=head2 EXAMPLE
90
91This is a simple example that uses the Event module and loads
92F</etc/passwd> asynchronously:
93
94 use Fcntl;
95 use Event;
96 use IO::AIO;
97
98 # register the IO::AIO callback with Event
99 Event->io (fd => IO::AIO::poll_fileno,
100 poll => 'r',
101 cb => \&IO::AIO::poll_cb);
102
103 # queue the request to open /etc/passwd
104 aio_open "/etc/passwd", O_RDONLY, 0, sub {
105 my $fh = shift
106 or die "error while opening: $!";
107
108 # stat'ing filehandles is generally non-blocking
109 my $size = -s $fh;
110
111 # queue a request to read the file
112 my $contents;
113 aio_read $fh, 0, $size, $contents, 0, sub {
114 $_[0] == $size
115 or die "short read: $!";
116
117 close $fh;
118
119 # file contents now in $contents
120 print $contents;
121
122 # exit event loop and program
123 Event::unloop;
124 };
125 };
126
127 # possibly queue up other requests, or open GUI windows,
128 # check for sockets etc. etc.
129
130 # process events as long as there are some:
131 Event::loop;
132
71=head1 REQUEST ANATOMY AND LIFETIME 133=head1 REQUEST ANATOMY AND LIFETIME
72 134
73Every C<aio_*> function creates a request. which is a C data structure not 135Every C<aio_*> function creates a request. which is a C data structure not
74directly visible to Perl. 136directly visible to Perl.
75 137
… …
116Request has reached the end of its lifetime and holds no resources anymore 178Request has reached the end of its lifetime and holds no resources anymore
117(except possibly for the Perl object, but its connection to the actual 179(except possibly for the Perl object, but its connection to the actual
118aio request is severed and calling its methods will either do nothing or 180aio request is severed and calling its methods will either do nothing or
119result in a runtime error). 181result in a runtime error).
120 182
183=back
184
121=cut 185=cut
122 186
123package IO::AIO; 187package IO::AIO;
124 188
125no warnings; 189no warnings;
126use strict 'vars'; 190use strict 'vars';
127 191
128use base 'Exporter'; 192use base 'Exporter';
129 193
130BEGIN { 194BEGIN {
131 our $VERSION = '2.0'; 195 our $VERSION = '2.33';
132 196
133 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat 197 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat
134 aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink 198 aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink
135 aio_fsync aio_fdatasync aio_readahead aio_rename aio_link aio_move 199 aio_readlink aio_fsync aio_fdatasync aio_readahead aio_rename aio_link
136 aio_copy aio_group aio_nop aio_mknod); 200 aio_move aio_copy aio_group aio_nop aio_mknod aio_load aio_rmtree aio_mkdir);
137 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); 201 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block));
138 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 202 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
139 min_parallel max_parallel nreqs nready npending); 203 min_parallel max_parallel max_idle
204 nreqs nready npending nthreads
205 max_poll_time max_poll_reqs);
140 206
141 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 207 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
142 208
143 require XSLoader; 209 require XSLoader;
144 XSLoader::load ("IO::AIO", $VERSION); 210 XSLoader::load ("IO::AIO", $VERSION);
145} 211}
146 212
147=head1 FUNCTIONS 213=head1 FUNCTIONS
148 214
149=head2 AIO FUNCTIONS 215=head2 AIO REQUEST FUNCTIONS
150 216
151All the C<aio_*> calls are more or less thin wrappers around the syscall 217All the C<aio_*> calls are more or less thin wrappers around the syscall
152with the same name (sans C<aio_>). The arguments are similar or identical, 218with the same name (sans C<aio_>). The arguments are similar or identical,
153and they all accept an additional (and optional) C<$callback> argument 219and they all accept an additional (and optional) C<$callback> argument
154which must be a code reference. This code reference will get called with 220which must be a code reference. This code reference will get called with
… …
157syscall has been executed asynchronously. 223syscall has been executed asynchronously.
158 224
159All functions expecting a filehandle keep a copy of the filehandle 225All functions expecting a filehandle keep a copy of the filehandle
160internally until the request has finished. 226internally until the request has finished.
161 227
162All requests return objects of type L<IO::AIO::REQ> that allow further 228All functions return request objects of type L<IO::AIO::REQ> that allow
163manipulation of those requests while they are in-flight. 229further manipulation of those requests while they are in-flight.
164 230
165The pathnames you pass to these routines I<must> be absolute and 231The pathnames you pass to these routines I<must> be absolute and
166encoded in byte form. The reason for the former is that at the time the 232encoded as octets. The reason for the former is that at the time the
167request is being executed, the current working directory could have 233request is being executed, the current working directory could have
168changed. Alternatively, you can make sure that you never change the 234changed. Alternatively, you can make sure that you never change the
169current working directory. 235current working directory anywhere in the program and then use relative
236paths.
170 237
171To encode pathnames to byte form, either make sure you either: a) 238To encode pathnames as octets, either make sure you either: a) always pass
172always pass in filenames you got from outside (command line, readdir 239in filenames you got from outside (command line, readdir etc.) without
173etc.), b) are ASCII or ISO 8859-1, c) use the Encode module and encode 240tinkering, b) are ASCII or ISO 8859-1, c) use the Encode module and encode
174your pathnames to the locale (or other) encoding in effect in the user 241your pathnames to the locale (or other) encoding in effect in the user
175environment, d) use Glib::filename_from_unicode on unicode filenames or e) 242environment, d) use Glib::filename_from_unicode on unicode filenames or e)
176use something else. 243use something else to ensure your scalar has the correct contents.
244
245This works, btw. independent of the internal UTF-8 bit, which IO::AIO
246handles correctly wether it is set or not.
177 247
178=over 4 248=over 4
179 249
180=item $prev_pri = aioreq_pri [$pri] 250=item $prev_pri = aioreq_pri [$pri]
181 251
… …
204 }; 274 };
205 275
206=item aioreq_nice $pri_adjust 276=item aioreq_nice $pri_adjust
207 277
208Similar to C<aioreq_pri>, but subtracts the given value from the current 278Similar to C<aioreq_pri>, but subtracts the given value from the current
209priority, so effects are cumulative. 279priority, so the effect is cumulative.
210 280
211=item aio_open $pathname, $flags, $mode, $callback->($fh) 281=item aio_open $pathname, $flags, $mode, $callback->($fh)
212 282
213Asynchronously open or create a file and call the callback with a newly 283Asynchronously open or create a file and call the callback with a newly
214created filehandle for the file. 284created filehandle for the file.
… …
220list. They are the same as used by C<sysopen>. 290list. They are the same as used by C<sysopen>.
221 291
222Likewise, C<$mode> specifies the mode of the newly created file, if it 292Likewise, C<$mode> specifies the mode of the newly created file, if it
223didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>, 293didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>,
224except that it is mandatory (i.e. use C<0> if you don't create new files, 294except that it is mandatory (i.e. use C<0> if you don't create new files,
225and C<0666> or C<0777> if you do). 295and C<0666> or C<0777> if you do). Note that the C<$mode> will be modified
296by the umask in effect then the request is being executed, so better never
297change the umask.
226 298
227Example: 299Example:
228 300
229 aio_open "/etc/passwd", O_RDONLY, 0, sub { 301 aio_open "/etc/passwd", O_RDONLY, 0, sub {
230 if ($_[0]) { 302 if ($_[0]) {
… …
331Asynchronously unlink (delete) a file and call the callback with the 403Asynchronously unlink (delete) a file and call the callback with the
332result code. 404result code.
333 405
334=item aio_mknod $path, $mode, $dev, $callback->($status) 406=item aio_mknod $path, $mode, $dev, $callback->($status)
335 407
408[EXPERIMENTAL]
409
336Asynchronously create a device node (or fifo). See mknod(2). 410Asynchronously create a device node (or fifo). See mknod(2).
337 411
338The only portable (POSIX) way of calling this function is: 412The only (POSIX-) portable way of calling this function is:
339 413
340 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... 414 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...
341 415
342=item aio_link $srcpath, $dstpath, $callback->($status) 416=item aio_link $srcpath, $dstpath, $callback->($status)
343 417
… …
347=item aio_symlink $srcpath, $dstpath, $callback->($status) 421=item aio_symlink $srcpath, $dstpath, $callback->($status)
348 422
349Asynchronously create a new symbolic link to the existing object at C<$srcpath> at 423Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
350the path C<$dstpath> and call the callback with the result code. 424the path C<$dstpath> and call the callback with the result code.
351 425
426=item aio_readlink $path, $callback->($link)
427
428Asynchronously read the symlink specified by C<$path> and pass it to
429the callback. If an error occurs, nothing or undef gets passed to the
430callback.
431
352=item aio_rename $srcpath, $dstpath, $callback->($status) 432=item aio_rename $srcpath, $dstpath, $callback->($status)
353 433
354Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as 434Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
355rename(2) and call the callback with the result code. 435rename(2) and call the callback with the result code.
436
437=item aio_mkdir $pathname, $mode, $callback->($status)
438
439Asynchronously mkdir (create) a directory and call the callback with
440the result code. C<$mode> will be modified by the umask at the time the
441request is executed, so do not change your umask.
356 442
357=item aio_rmdir $pathname, $callback->($status) 443=item aio_rmdir $pathname, $callback->($status)
358 444
359Asynchronously rmdir (delete) a directory and call the callback with the 445Asynchronously rmdir (delete) a directory and call the callback with the
360result code. 446result code.
… …
365directory (i.e. opendir + readdir + closedir). The entries will not be 451directory (i.e. opendir + readdir + closedir). The entries will not be
366sorted, and will B<NOT> include the C<.> and C<..> entries. 452sorted, and will B<NOT> include the C<.> and C<..> entries.
367 453
368The callback a single argument which is either C<undef> or an array-ref 454The callback a single argument which is either C<undef> or an array-ref
369with the filenames. 455with the filenames.
456
457=item aio_load $path, $data, $callback->($status)
458
459This is a composite request that tries to fully load the given file into
460memory. Status is the same as with aio_read.
461
462=cut
463
464sub aio_load($$;$) {
465 aio_block {
466 my ($path, undef, $cb) = @_;
467 my $data = \$_[1];
468
469 my $pri = aioreq_pri;
470 my $grp = aio_group $cb;
471
472 aioreq_pri $pri;
473 add $grp aio_open $path, O_RDONLY, 0, sub {
474 my $fh = shift
475 or return $grp->result (-1);
476
477 aioreq_pri $pri;
478 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
479 $grp->result ($_[0]);
480 };
481 };
482
483 $grp
484 }
485}
370 486
371=item aio_copy $srcpath, $dstpath, $callback->($status) 487=item aio_copy $srcpath, $dstpath, $callback->($status)
372 488
373Try to copy the I<file> (directories not supported as either source or 489Try to copy the I<file> (directories not supported as either source or
374destination) from C<$srcpath> to C<$dstpath> and call the callback with 490destination) from C<$srcpath> to C<$dstpath> and call the callback with
… …
384errors are being ignored. 500errors are being ignored.
385 501
386=cut 502=cut
387 503
388sub aio_copy($$;$) { 504sub aio_copy($$;$) {
505 aio_block {
389 my ($src, $dst, $cb) = @_; 506 my ($src, $dst, $cb) = @_;
390 507
391 my $pri = aioreq_pri; 508 my $pri = aioreq_pri;
392 my $grp = aio_group $cb; 509 my $grp = aio_group $cb;
393 510
394 aioreq_pri $pri; 511 aioreq_pri $pri;
395 add $grp aio_open $src, O_RDONLY, 0, sub { 512 add $grp aio_open $src, O_RDONLY, 0, sub {
396 if (my $src_fh = $_[0]) { 513 if (my $src_fh = $_[0]) {
397 my @stat = stat $src_fh; 514 my @stat = stat $src_fh;
398 515
399 aioreq_pri $pri; 516 aioreq_pri $pri;
400 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub { 517 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
401 if (my $dst_fh = $_[0]) { 518 if (my $dst_fh = $_[0]) {
402 aioreq_pri $pri; 519 aioreq_pri $pri;
403 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 520 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
404 if ($_[0] == $stat[7]) { 521 if ($_[0] == $stat[7]) {
405 $grp->result (0); 522 $grp->result (0);
406 close $src_fh; 523 close $src_fh;
407 524
408 # those should not normally block. should. should. 525 # those should not normally block. should. should.
409 utime $stat[8], $stat[9], $dst; 526 utime $stat[8], $stat[9], $dst;
410 chmod $stat[2] & 07777, $dst_fh; 527 chmod $stat[2] & 07777, $dst_fh;
411 chown $stat[4], $stat[5], $dst_fh; 528 chown $stat[4], $stat[5], $dst_fh;
412 close $dst_fh; 529 close $dst_fh;
413 } else { 530 } else {
414 $grp->result (-1); 531 $grp->result (-1);
415 close $src_fh; 532 close $src_fh;
416 close $dst_fh; 533 close $dst_fh;
417 534
418 aioreq $pri; 535 aioreq $pri;
419 add $grp aio_unlink $dst; 536 add $grp aio_unlink $dst;
537 }
420 } 538 };
539 } else {
540 $grp->result (-1);
421 }; 541 }
422 } else {
423 $grp->result (-1);
424 } 542 },
543
544 } else {
545 $grp->result (-1);
425 }, 546 }
426
427 } else {
428 $grp->result (-1);
429 } 547 };
548
549 $grp
430 }; 550 }
431
432 $grp
433} 551}
434 552
435=item aio_move $srcpath, $dstpath, $callback->($status) 553=item aio_move $srcpath, $dstpath, $callback->($status)
436 554
437Try to move the I<file> (directories not supported as either source or 555Try to move the I<file> (directories not supported as either source or
… …
443that is successful, unlinking the C<$srcpath>. 561that is successful, unlinking the C<$srcpath>.
444 562
445=cut 563=cut
446 564
447sub aio_move($$;$) { 565sub aio_move($$;$) {
566 aio_block {
448 my ($src, $dst, $cb) = @_; 567 my ($src, $dst, $cb) = @_;
449 568
450 my $pri = aioreq_pri; 569 my $pri = aioreq_pri;
451 my $grp = aio_group $cb; 570 my $grp = aio_group $cb;
452 571
453 aioreq_pri $pri; 572 aioreq_pri $pri;
454 add $grp aio_rename $src, $dst, sub { 573 add $grp aio_rename $src, $dst, sub {
455 if ($_[0] && $! == EXDEV) { 574 if ($_[0] && $! == EXDEV) {
456 aioreq_pri $pri; 575 aioreq_pri $pri;
457 add $grp aio_copy $src, $dst, sub { 576 add $grp aio_copy $src, $dst, sub {
577 $grp->result ($_[0]);
578
579 if (!$_[0]) {
580 aioreq_pri $pri;
581 add $grp aio_unlink $src;
582 }
583 };
584 } else {
458 $grp->result ($_[0]); 585 $grp->result ($_[0]);
459
460 if (!$_[0]) {
461 aioreq_pri $pri;
462 add $grp aio_unlink $src;
463 }
464 }; 586 }
465 } else {
466 $grp->result ($_[0]);
467 } 587 };
588
589 $grp
468 }; 590 }
469
470 $grp
471} 591}
472 592
473=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 593=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
474 594
475Scans a directory (similar to C<aio_readdir>) but additionally tries to 595Scans a directory (similar to C<aio_readdir>) but additionally tries to
… …
522as those tend to return 0 or 1 as link counts, which disables the 642as those tend to return 0 or 1 as link counts, which disables the
523directory counting heuristic. 643directory counting heuristic.
524 644
525=cut 645=cut
526 646
527sub aio_scandir($$$) { 647sub aio_scandir($$;$) {
648 aio_block {
528 my ($path, $maxreq, $cb) = @_; 649 my ($path, $maxreq, $cb) = @_;
529 650
530 my $pri = aioreq_pri; 651 my $pri = aioreq_pri;
531 652
532 my $grp = aio_group $cb; 653 my $grp = aio_group $cb;
533 654
534 $maxreq = 4 if $maxreq <= 0; 655 $maxreq = 4 if $maxreq <= 0;
535 656
536 # stat once 657 # stat once
537 aioreq_pri $pri;
538 add $grp aio_stat $path, sub {
539 return $grp->result () if $_[0];
540 my $now = time;
541 my $hash1 = join ":", (stat _)[0,1,3,7,9];
542
543 # read the directory entries
544 aioreq_pri $pri; 658 aioreq_pri $pri;
545 add $grp aio_readdir $path, sub { 659 add $grp aio_stat $path, sub {
546 my $entries = shift
547 or return $grp->result (); 660 return $grp->result () if $_[0];
661 my $now = time;
662 my $hash1 = join ":", (stat _)[0,1,3,7,9];
548 663
549 # stat the dir another time 664 # read the directory entries
550 aioreq_pri $pri; 665 aioreq_pri $pri;
666 add $grp aio_readdir $path, sub {
667 my $entries = shift
668 or return $grp->result ();
669
670 # stat the dir another time
671 aioreq_pri $pri;
551 add $grp aio_stat $path, sub { 672 add $grp aio_stat $path, sub {
552 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 673 my $hash2 = join ":", (stat _)[0,1,3,7,9];
553 674
554 my $ndirs; 675 my $ndirs;
555 676
556 # take the slow route if anything looks fishy 677 # take the slow route if anything looks fishy
557 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 678 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
558 $ndirs = -1; 679 $ndirs = -1;
559 } else { 680 } else {
560 # if nlink == 2, we are finished 681 # if nlink == 2, we are finished
561 # on non-posix-fs's, we rely on nlink < 2 682 # on non-posix-fs's, we rely on nlink < 2
562 $ndirs = (stat _)[3] - 2 683 $ndirs = (stat _)[3] - 2
563 or return $grp->result ([], $entries); 684 or return $grp->result ([], $entries);
564 } 685 }
565 686
566 # sort into likely dirs and likely nondirs 687 # sort into likely dirs and likely nondirs
567 # dirs == files without ".", short entries first 688 # dirs == files without ".", short entries first
568 $entries = [map $_->[0], 689 $entries = [map $_->[0],
569 sort { $b->[1] cmp $a->[1] } 690 sort { $b->[1] cmp $a->[1] }
570 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length], 691 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
571 @$entries]; 692 @$entries];
572 693
573 my (@dirs, @nondirs); 694 my (@dirs, @nondirs);
574 695
575 my $statgrp = add $grp aio_group sub { 696 my $statgrp = add $grp aio_group sub {
576 $grp->result (\@dirs, \@nondirs); 697 $grp->result (\@dirs, \@nondirs);
577 }; 698 };
578 699
579 limit $statgrp $maxreq; 700 limit $statgrp $maxreq;
580 feed $statgrp sub { 701 feed $statgrp sub {
581 return unless @$entries; 702 return unless @$entries;
582 my $entry = pop @$entries; 703 my $entry = pop @$entries;
583 704
584 aioreq_pri $pri; 705 aioreq_pri $pri;
585 add $statgrp aio_stat "$path/$entry/.", sub { 706 add $statgrp aio_stat "$path/$entry/.", sub {
586 if ($_[0] < 0) { 707 if ($_[0] < 0) {
587 push @nondirs, $entry; 708 push @nondirs, $entry;
588 } else { 709 } else {
589 # need to check for real directory 710 # need to check for real directory
590 aioreq_pri $pri; 711 aioreq_pri $pri;
591 add $statgrp aio_lstat "$path/$entry", sub { 712 add $statgrp aio_lstat "$path/$entry", sub {
592 if (-d _) { 713 if (-d _) {
593 push @dirs, $entry; 714 push @dirs, $entry;
594 715
595 unless (--$ndirs) { 716 unless (--$ndirs) {
596 push @nondirs, @$entries; 717 push @nondirs, @$entries;
597 feed $statgrp; 718 feed $statgrp;
719 }
720 } else {
721 push @nondirs, $entry;
598 } 722 }
599 } else {
600 push @nondirs, $entry;
601 } 723 }
602 } 724 }
603 } 725 };
604 }; 726 };
605 }; 727 };
606 }; 728 };
607 }; 729 };
730
731 $grp
608 }; 732 }
733}
609 734
735=item aio_rmtree $path, $callback->($status)
736
737Delete a directory tree starting (and including) C<$path>, return the
738status of the final C<rmdir> only. This is a composite request that
739uses C<aio_scandir> to recurse into and rmdir directories, and unlink
740everything else.
741
742=cut
743
744sub aio_rmtree;
745sub aio_rmtree($;$) {
746 aio_block {
747 my ($path, $cb) = @_;
748
749 my $pri = aioreq_pri;
750 my $grp = aio_group $cb;
751
752 aioreq_pri $pri;
753 add $grp aio_scandir $path, 0, sub {
754 my ($dirs, $nondirs) = @_;
755
756 my $dirgrp = aio_group sub {
757 add $grp aio_rmdir $path, sub {
758 $grp->result ($_[0]);
759 };
760 };
761
762 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
763 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
764
765 add $grp $dirgrp;
766 };
767
610 $grp 768 $grp
769 }
611} 770}
612 771
613=item aio_fsync $fh, $callback->($status) 772=item aio_fsync $fh, $callback->($status)
614 773
615Asynchronously call fsync on the given filehandle and call the callback 774Asynchronously call fsync on the given filehandle and call the callback
… …
829 988
830=back 989=back
831 990
832=head2 SUPPORT FUNCTIONS 991=head2 SUPPORT FUNCTIONS
833 992
993=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
994
834=over 4 995=over 4
835 996
836=item $fileno = IO::AIO::poll_fileno 997=item $fileno = IO::AIO::poll_fileno
837 998
838Return the I<request result pipe file descriptor>. This filehandle must be 999Return the I<request result pipe file descriptor>. This filehandle must be
… …
842 1003
843See C<poll_cb> for an example. 1004See C<poll_cb> for an example.
844 1005
845=item IO::AIO::poll_cb 1006=item IO::AIO::poll_cb
846 1007
847Process all outstanding events on the result pipe. You have to call this 1008Process some outstanding events on the result pipe. You have to call this
848regularly. Returns the number of events processed. Returns immediately 1009regularly. Returns the number of events processed. Returns immediately
849when no events are outstanding. 1010when no events are outstanding. The amount of events processed depends on
1011the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
850 1012
851If not all requests were processed for whatever reason, the filehandle 1013If not all requests were processed for whatever reason, the filehandle
852will still be ready when C<poll_cb> returns. 1014will still be ready when C<poll_cb> returns.
853 1015
854Example: Install an Event watcher that automatically calls 1016Example: Install an Event watcher that automatically calls
… …
856 1018
857 Event->io (fd => IO::AIO::poll_fileno, 1019 Event->io (fd => IO::AIO::poll_fileno,
858 poll => 'r', async => 1, 1020 poll => 'r', async => 1,
859 cb => \&IO::AIO::poll_cb); 1021 cb => \&IO::AIO::poll_cb);
860 1022
861=item IO::AIO::poll_some $max_requests 1023=item IO::AIO::max_poll_reqs $nreqs
862 1024
863Similar to C<poll_cb>, but only processes up to C<$max_requests> requests 1025=item IO::AIO::max_poll_time $seconds
864at a time.
865 1026
866Useful if you want to ensure some level of interactiveness when perl is 1027These set the maximum number of requests (default C<0>, meaning infinity)
867not fast enough to process all requests in time. 1028that are being processed by C<IO::AIO::poll_cb> in one call, respectively
1029the maximum amount of time (default C<0>, meaning infinity) spent in
1030C<IO::AIO::poll_cb> to process requests (more correctly the mininum amount
1031of time C<poll_cb> is allowed to use).
1032
1033Setting C<max_poll_time> to a non-zero value creates an overhead of one
1034syscall per request processed, which is not normally a problem unless your
1035callbacks are really really fast or your OS is really really slow (I am
1036not mentioning Solaris here). Using C<max_poll_reqs> incurs no overhead.
1037
1038Setting these is useful if you want to ensure some level of
1039interactiveness when perl is not fast enough to process all requests in
1040time.
1041
1042For interactive programs, values such as C<0.01> to C<0.1> should be fine.
868 1043
869Example: Install an Event watcher that automatically calls 1044Example: Install an Event watcher that automatically calls
870IO::AIO::poll_some with low priority, to ensure that other parts of the 1045IO::AIO::poll_cb with low priority, to ensure that other parts of the
871program get the CPU sometimes even under high AIO load. 1046program get the CPU sometimes even under high AIO load.
872 1047
1048 # try not to spend much more than 0.1s in poll_cb
1049 IO::AIO::max_poll_time 0.1;
1050
1051 # use a low priority so other tasks have priority
873 Event->io (fd => IO::AIO::poll_fileno, 1052 Event->io (fd => IO::AIO::poll_fileno,
874 poll => 'r', nice => 1, 1053 poll => 'r', nice => 1,
875 cb => sub { IO::AIO::poll_some 256 }); 1054 cb => &IO::AIO::poll_cb);
876 1055
877=item IO::AIO::poll_wait 1056=item IO::AIO::poll_wait
878 1057
1058If there are any outstanding requests and none of them in the result
879Wait till the result filehandle becomes ready for reading (simply does a 1059phase, wait till the result filehandle becomes ready for reading (simply
880C<select> on the filehandle. This is useful if you want to synchronously wait 1060does a C<select> on the filehandle. This is useful if you want to
881for some requests to finish). 1061synchronously wait for some requests to finish).
882 1062
883See C<nreqs> for an example. 1063See C<nreqs> for an example.
884 1064
1065=item IO::AIO::poll
1066
1067Waits until some requests have been handled.
1068
1069Returns the number of requests processed, but is otherwise strictly
1070equivalent to:
1071
1072 IO::AIO::poll_wait, IO::AIO::poll_cb
1073
885=item IO::AIO::nreqs 1074=item IO::AIO::flush
886 1075
887Returns the number of requests currently in the ready, execute or pending 1076Wait till all outstanding AIO requests have been handled.
888states (i.e. for which their callback has not been invoked yet).
889 1077
890Example: wait till there are no outstanding requests anymore: 1078Strictly equivalent to:
891 1079
892 IO::AIO::poll_wait, IO::AIO::poll_cb 1080 IO::AIO::poll_wait, IO::AIO::poll_cb
893 while IO::AIO::nreqs; 1081 while IO::AIO::nreqs;
894 1082
895=item IO::AIO::nready 1083=back
896 1084
897Returns the number of requests currently in the ready state (not yet 1085=head3 CONTROLLING THE NUMBER OF THREADS
898executed).
899 1086
900=item IO::AIO::npending 1087=over
901
902Returns the number of requests currently in the pending state (executed,
903but not yet processed by poll_cb).
904
905=item IO::AIO::flush
906
907Wait till all outstanding AIO requests have been handled.
908
909Strictly equivalent to:
910
911 IO::AIO::poll_wait, IO::AIO::poll_cb
912 while IO::AIO::nreqs;
913
914=item IO::AIO::poll
915
916Waits until some requests have been handled.
917
918Strictly equivalent to:
919
920 IO::AIO::poll_wait, IO::AIO::poll_cb
921 if IO::AIO::nreqs;
922 1088
923=item IO::AIO::min_parallel $nthreads 1089=item IO::AIO::min_parallel $nthreads
924 1090
925Set the minimum number of AIO threads to C<$nthreads>. The current 1091Set the minimum number of AIO threads to C<$nthreads>. The current
926default is C<8>, which means eight asynchronous operations can execute 1092default is C<8>, which means eight asynchronous operations can execute
927concurrently at any one time (the number of outstanding requests, 1093concurrently at any one time (the number of outstanding requests,
928however, is unlimited). 1094however, is unlimited).
929 1095
930IO::AIO starts threads only on demand, when an AIO request is queued and 1096IO::AIO starts threads only on demand, when an AIO request is queued and
931no free thread exists. 1097no free thread exists. Please note that queueing up a hundred requests can
1098create demand for a hundred threads, even if it turns out that everything
1099is in the cache and could have been processed faster by a single thread.
932 1100
933It is recommended to keep the number of threads relatively low, as some 1101It is recommended to keep the number of threads relatively low, as some
934Linux kernel versions will scale negatively with the number of threads 1102Linux kernel versions will scale negatively with the number of threads
935(higher parallelity => MUCH higher latency). With current Linux 2.6 1103(higher parallelity => MUCH higher latency). With current Linux 2.6
936versions, 4-32 threads should be fine. 1104versions, 4-32 threads should be fine.
… …
950This module automatically runs C<max_parallel 0> at program end, to ensure 1118This module automatically runs C<max_parallel 0> at program end, to ensure
951that all threads are killed and that there are no outstanding requests. 1119that all threads are killed and that there are no outstanding requests.
952 1120
953Under normal circumstances you don't need to call this function. 1121Under normal circumstances you don't need to call this function.
954 1122
1123=item IO::AIO::max_idle $nthreads
1124
1125Limit the number of threads (default: 4) that are allowed to idle (i.e.,
1126threads that did not get a request to process within 10 seconds). That
1127means if a thread becomes idle while C<$nthreads> other threads are also
1128idle, it will free its resources and exit.
1129
1130This is useful when you allow a large number of threads (e.g. 100 or 1000)
1131to allow for extremely high load situations, but want to free resources
1132under normal circumstances (1000 threads can easily consume 30MB of RAM).
1133
1134The default is probably ok in most situations, especially if thread
1135creation is fast. If thread creation is very slow on your system you might
1136want to use larger values.
1137
955=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1138=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs
956 1139
957This is a very bad function to use in interactive programs because it 1140This is a very bad function to use in interactive programs because it
958blocks, and a bad way to reduce concurrency because it is inexact: Better 1141blocks, and a bad way to reduce concurrency because it is inexact: Better
959use an C<aio_group> together with a feed callback. 1142use an C<aio_group> together with a feed callback.
… …
970C<max_oustsanding> is mainly useful in simple scripts (with low values) or 1153C<max_oustsanding> is mainly useful in simple scripts (with low values) or
971as a stop gap to shield against fatal memory overflow (with large values). 1154as a stop gap to shield against fatal memory overflow (with large values).
972 1155
973=back 1156=back
974 1157
1158=head3 STATISTICAL INFORMATION
1159
1160=over
1161
1162=item IO::AIO::nreqs
1163
1164Returns the number of requests currently in the ready, execute or pending
1165states (i.e. for which their callback has not been invoked yet).
1166
1167Example: wait till there are no outstanding requests anymore:
1168
1169 IO::AIO::poll_wait, IO::AIO::poll_cb
1170 while IO::AIO::nreqs;
1171
1172=item IO::AIO::nready
1173
1174Returns the number of requests currently in the ready state (not yet
1175executed).
1176
1177=item IO::AIO::npending
1178
1179Returns the number of requests currently in the pending state (executed,
1180but not yet processed by poll_cb).
1181
1182=back
1183
975=cut 1184=cut
976 1185
977# support function to convert a fd into a perl filehandle 1186# support function to convert a fd into a perl filehandle
978sub _fd2fh { 1187sub _fd2fh {
979 return undef if $_[0] < 0; 1188 return undef if $_[0] < 0;
… …
990 *$sym 1199 *$sym
991} 1200}
992 1201
993min_parallel 8; 1202min_parallel 8;
994 1203
995END { 1204END { flush }
996 min_parallel 1;
997 flush;
998};
999 1205
10001; 12061;
1001 1207
1002=head2 FORK BEHAVIOUR 1208=head2 FORK BEHAVIOUR
1003 1209

Diff Legend

– Removed lines
+ Added lines
< Changed lines
> Changed lines