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 1.85 by root, Sat Oct 28 01:40:30 2006 UTC vs.
Revision 1.104 by root, Sat Mar 24 19:19:11 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
… …
61etc.), 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
62normally 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
63on 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
64concurrently. 65concurrently.
65 66
66While this works on all types of file descriptors (for example sockets), 67While most of this works on all types of file descriptors (for example
67using these functions on file descriptors that support nonblocking 68sockets), using these functions on file descriptors that support
68operation (again, sockets, pipes etc.) is very inefficient. Use an event 69nonblocking operation (again, sockets, pipes etc.) is very inefficient or
70might not work (aio_read fails on sockets/pipes/fifos). Use an event loop
69loop for that (such as the L<Event|Event> module): IO::AIO will naturally 71for that (such as the L<Event|Event> module): IO::AIO will naturally fit
70fit into such an event loop itself. 72into such an event loop itself.
71 73
72In this version, a number of threads are started that execute your 74In this version, a number of threads are started that execute your
73requests and signal their completion. You don't need thread support 75requests and signal their completion. You don't need thread support
74in 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
75to 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
… …
82Although the module will work with in the presence of other (Perl-) 84Although the module will work with in the presence of other (Perl-)
83threads, it is currently not reentrant in any way, so use appropriate 85threads, it is currently not reentrant in any way, so use appropriate
84locking 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
85never call C<poll_cb> (or other C<aio_> functions) recursively. 87never call C<poll_cb> (or other C<aio_> functions) recursively.
86 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
87=head1 REQUEST ANATOMY AND LIFETIME 133=head1 REQUEST ANATOMY AND LIFETIME
88 134
89Every 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
90directly visible to Perl. 136directly visible to Perl.
91 137
… …
132Request 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
133(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
134aio 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
135result in a runtime error). 181result in a runtime error).
136 182
183=back
184
137=cut 185=cut
138 186
139package IO::AIO; 187package IO::AIO;
140 188
141no warnings; 189no warnings;
142use strict 'vars'; 190use strict 'vars';
143 191
144use base 'Exporter'; 192use base 'Exporter';
145 193
146BEGIN { 194BEGIN {
147 our $VERSION = '2.0'; 195 our $VERSION = '2.33';
148 196
149 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
150 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
151 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
152 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);
153 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); 201 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block));
154 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 202 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
155 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);
156 206
157 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 207 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
158 208
159 require XSLoader; 209 require XSLoader;
160 XSLoader::load ("IO::AIO", $VERSION); 210 XSLoader::load ("IO::AIO", $VERSION);
161} 211}
162 212
163=head1 FUNCTIONS 213=head1 FUNCTIONS
164 214
165=head2 AIO FUNCTIONS 215=head2 AIO REQUEST FUNCTIONS
166 216
167All the C<aio_*> calls are more or less thin wrappers around the syscall 217All the C<aio_*> calls are more or less thin wrappers around the syscall
168with the same name (sans C<aio_>). The arguments are similar or identical, 218with the same name (sans C<aio_>). The arguments are similar or identical,
169and they all accept an additional (and optional) C<$callback> argument 219and they all accept an additional (and optional) C<$callback> argument
170which 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
… …
173syscall has been executed asynchronously. 223syscall has been executed asynchronously.
174 224
175All functions expecting a filehandle keep a copy of the filehandle 225All functions expecting a filehandle keep a copy of the filehandle
176internally until the request has finished. 226internally until the request has finished.
177 227
178All 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
179manipulation of those requests while they are in-flight. 229further manipulation of those requests while they are in-flight.
180 230
181The pathnames you pass to these routines I<must> be absolute and 231The pathnames you pass to these routines I<must> be absolute and
182encoded 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
183request is being executed, the current working directory could have 233request is being executed, the current working directory could have
184changed. Alternatively, you can make sure that you never change the 234changed. Alternatively, you can make sure that you never change the
185current working directory. 235current working directory anywhere in the program and then use relative
236paths.
186 237
187To encode pathnames to byte form, either make sure you either: a) 238To encode pathnames as octets, either make sure you either: a) always pass
188always pass in filenames you got from outside (command line, readdir 239in filenames you got from outside (command line, readdir etc.) without
189etc.), 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
190your 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
191environment, d) use Glib::filename_from_unicode on unicode filenames or e) 242environment, d) use Glib::filename_from_unicode on unicode filenames or e)
192use 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.
193 247
194=over 4 248=over 4
195 249
196=item $prev_pri = aioreq_pri [$pri] 250=item $prev_pri = aioreq_pri [$pri]
197 251
… …
220 }; 274 };
221 275
222=item aioreq_nice $pri_adjust 276=item aioreq_nice $pri_adjust
223 277
224Similar 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
225priority, so effects are cumulative. 279priority, so the effect is cumulative.
226 280
227=item aio_open $pathname, $flags, $mode, $callback->($fh) 281=item aio_open $pathname, $flags, $mode, $callback->($fh)
228 282
229Asynchronously 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
230created filehandle for the file. 284created filehandle for the file.
… …
236list. They are the same as used by C<sysopen>. 290list. They are the same as used by C<sysopen>.
237 291
238Likewise, 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
239didn'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>,
240except 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,
241and C<0666> or C<0777> if you do). 295and C<0666> or C<0777> if you do). Note that the C<$mode> will be modified
296by the umask in effect then the request is being executed, so better never
297change the umask.
242 298
243Example: 299Example:
244 300
245 aio_open "/etc/passwd", O_RDONLY, 0, sub { 301 aio_open "/etc/passwd", O_RDONLY, 0, sub {
246 if ($_[0]) { 302 if ($_[0]) {
… …
347Asynchronously unlink (delete) a file and call the callback with the 403Asynchronously unlink (delete) a file and call the callback with the
348result code. 404result code.
349 405
350=item aio_mknod $path, $mode, $dev, $callback->($status) 406=item aio_mknod $path, $mode, $dev, $callback->($status)
351 407
408[EXPERIMENTAL]
409
352Asynchronously create a device node (or fifo). See mknod(2). 410Asynchronously create a device node (or fifo). See mknod(2).
353 411
354The only portable (POSIX) way of calling this function is: 412The only (POSIX-) portable way of calling this function is:
355 413
356 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... 414 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...
357 415
358=item aio_link $srcpath, $dstpath, $callback->($status) 416=item aio_link $srcpath, $dstpath, $callback->($status)
359 417
… …
363=item aio_symlink $srcpath, $dstpath, $callback->($status) 421=item aio_symlink $srcpath, $dstpath, $callback->($status)
364 422
365Asynchronously 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
366the path C<$dstpath> and call the callback with the result code. 424the path C<$dstpath> and call the callback with the result code.
367 425
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
368=item aio_rename $srcpath, $dstpath, $callback->($status) 432=item aio_rename $srcpath, $dstpath, $callback->($status)
369 433
370Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as 434Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
371rename(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.
372 442
373=item aio_rmdir $pathname, $callback->($status) 443=item aio_rmdir $pathname, $callback->($status)
374 444
375Asynchronously rmdir (delete) a directory and call the callback with the 445Asynchronously rmdir (delete) a directory and call the callback with the
376result code. 446result code.
… …
381directory (i.e. opendir + readdir + closedir). The entries will not be 451directory (i.e. opendir + readdir + closedir). The entries will not be
382sorted, and will B<NOT> include the C<.> and C<..> entries. 452sorted, and will B<NOT> include the C<.> and C<..> entries.
383 453
384The 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
385with 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}
386 486
387=item aio_copy $srcpath, $dstpath, $callback->($status) 487=item aio_copy $srcpath, $dstpath, $callback->($status)
388 488
389Try 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
390destination) from C<$srcpath> to C<$dstpath> and call the callback with 490destination) from C<$srcpath> to C<$dstpath> and call the callback with
… …
400errors are being ignored. 500errors are being ignored.
401 501
402=cut 502=cut
403 503
404sub aio_copy($$;$) { 504sub aio_copy($$;$) {
505 aio_block {
405 my ($src, $dst, $cb) = @_; 506 my ($src, $dst, $cb) = @_;
406 507
407 my $pri = aioreq_pri; 508 my $pri = aioreq_pri;
408 my $grp = aio_group $cb; 509 my $grp = aio_group $cb;
409 510
410 aioreq_pri $pri; 511 aioreq_pri $pri;
411 add $grp aio_open $src, O_RDONLY, 0, sub { 512 add $grp aio_open $src, O_RDONLY, 0, sub {
412 if (my $src_fh = $_[0]) { 513 if (my $src_fh = $_[0]) {
413 my @stat = stat $src_fh; 514 my @stat = stat $src_fh;
414 515
415 aioreq_pri $pri; 516 aioreq_pri $pri;
416 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 {
417 if (my $dst_fh = $_[0]) { 518 if (my $dst_fh = $_[0]) {
418 aioreq_pri $pri; 519 aioreq_pri $pri;
419 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 520 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
420 if ($_[0] == $stat[7]) { 521 if ($_[0] == $stat[7]) {
421 $grp->result (0); 522 $grp->result (0);
422 close $src_fh; 523 close $src_fh;
423 524
424 # those should not normally block. should. should. 525 # those should not normally block. should. should.
425 utime $stat[8], $stat[9], $dst; 526 utime $stat[8], $stat[9], $dst;
426 chmod $stat[2] & 07777, $dst_fh; 527 chmod $stat[2] & 07777, $dst_fh;
427 chown $stat[4], $stat[5], $dst_fh; 528 chown $stat[4], $stat[5], $dst_fh;
428 close $dst_fh; 529 close $dst_fh;
429 } else { 530 } else {
430 $grp->result (-1); 531 $grp->result (-1);
431 close $src_fh; 532 close $src_fh;
432 close $dst_fh; 533 close $dst_fh;
433 534
434 aioreq $pri; 535 aioreq $pri;
435 add $grp aio_unlink $dst; 536 add $grp aio_unlink $dst;
537 }
436 } 538 };
539 } else {
540 $grp->result (-1);
437 }; 541 }
438 } else {
439 $grp->result (-1);
440 } 542 },
543
544 } else {
545 $grp->result (-1);
441 }, 546 }
442
443 } else {
444 $grp->result (-1);
445 } 547 };
548
549 $grp
446 }; 550 }
447
448 $grp
449} 551}
450 552
451=item aio_move $srcpath, $dstpath, $callback->($status) 553=item aio_move $srcpath, $dstpath, $callback->($status)
452 554
453Try 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
… …
459that is successful, unlinking the C<$srcpath>. 561that is successful, unlinking the C<$srcpath>.
460 562
461=cut 563=cut
462 564
463sub aio_move($$;$) { 565sub aio_move($$;$) {
566 aio_block {
464 my ($src, $dst, $cb) = @_; 567 my ($src, $dst, $cb) = @_;
465 568
466 my $pri = aioreq_pri; 569 my $pri = aioreq_pri;
467 my $grp = aio_group $cb; 570 my $grp = aio_group $cb;
468 571
469 aioreq_pri $pri; 572 aioreq_pri $pri;
470 add $grp aio_rename $src, $dst, sub { 573 add $grp aio_rename $src, $dst, sub {
471 if ($_[0] && $! == EXDEV) { 574 if ($_[0] && $! == EXDEV) {
472 aioreq_pri $pri; 575 aioreq_pri $pri;
473 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 {
474 $grp->result ($_[0]); 585 $grp->result ($_[0]);
475
476 if (!$_[0]) {
477 aioreq_pri $pri;
478 add $grp aio_unlink $src;
479 }
480 }; 586 }
481 } else {
482 $grp->result ($_[0]);
483 } 587 };
588
589 $grp
484 }; 590 }
485
486 $grp
487} 591}
488 592
489=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 593=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
490 594
491Scans a directory (similar to C<aio_readdir>) but additionally tries to 595Scans a directory (similar to C<aio_readdir>) but additionally tries to
… …
538as 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
539directory counting heuristic. 643directory counting heuristic.
540 644
541=cut 645=cut
542 646
543sub aio_scandir($$$) { 647sub aio_scandir($$;$) {
648 aio_block {
544 my ($path, $maxreq, $cb) = @_; 649 my ($path, $maxreq, $cb) = @_;
545 650
546 my $pri = aioreq_pri; 651 my $pri = aioreq_pri;
547 652
548 my $grp = aio_group $cb; 653 my $grp = aio_group $cb;
549 654
550 $maxreq = 4 if $maxreq <= 0; 655 $maxreq = 4 if $maxreq <= 0;
551 656
552 # stat once 657 # stat once
553 aioreq_pri $pri;
554 add $grp aio_stat $path, sub {
555 return $grp->result () if $_[0];
556 my $now = time;
557 my $hash1 = join ":", (stat _)[0,1,3,7,9];
558
559 # read the directory entries
560 aioreq_pri $pri; 658 aioreq_pri $pri;
561 add $grp aio_readdir $path, sub { 659 add $grp aio_stat $path, sub {
562 my $entries = shift
563 or return $grp->result (); 660 return $grp->result () if $_[0];
661 my $now = time;
662 my $hash1 = join ":", (stat _)[0,1,3,7,9];
564 663
565 # stat the dir another time 664 # read the directory entries
566 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;
567 add $grp aio_stat $path, sub { 672 add $grp aio_stat $path, sub {
568 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 673 my $hash2 = join ":", (stat _)[0,1,3,7,9];
569 674
570 my $ndirs; 675 my $ndirs;
571 676
572 # take the slow route if anything looks fishy 677 # take the slow route if anything looks fishy
573 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 678 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
574 $ndirs = -1; 679 $ndirs = -1;
575 } else { 680 } else {
576 # if nlink == 2, we are finished 681 # if nlink == 2, we are finished
577 # on non-posix-fs's, we rely on nlink < 2 682 # on non-posix-fs's, we rely on nlink < 2
578 $ndirs = (stat _)[3] - 2 683 $ndirs = (stat _)[3] - 2
579 or return $grp->result ([], $entries); 684 or return $grp->result ([], $entries);
580 } 685 }
581 686
582 # sort into likely dirs and likely nondirs 687 # sort into likely dirs and likely nondirs
583 # dirs == files without ".", short entries first 688 # dirs == files without ".", short entries first
584 $entries = [map $_->[0], 689 $entries = [map $_->[0],
585 sort { $b->[1] cmp $a->[1] } 690 sort { $b->[1] cmp $a->[1] }
586 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length], 691 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
587 @$entries]; 692 @$entries];
588 693
589 my (@dirs, @nondirs); 694 my (@dirs, @nondirs);
590 695
591 my $statgrp = add $grp aio_group sub { 696 my $statgrp = add $grp aio_group sub {
592 $grp->result (\@dirs, \@nondirs); 697 $grp->result (\@dirs, \@nondirs);
593 }; 698 };
594 699
595 limit $statgrp $maxreq; 700 limit $statgrp $maxreq;
596 feed $statgrp sub { 701 feed $statgrp sub {
597 return unless @$entries; 702 return unless @$entries;
598 my $entry = pop @$entries; 703 my $entry = pop @$entries;
599 704
600 aioreq_pri $pri; 705 aioreq_pri $pri;
601 add $statgrp aio_stat "$path/$entry/.", sub { 706 add $statgrp aio_stat "$path/$entry/.", sub {
602 if ($_[0] < 0) { 707 if ($_[0] < 0) {
603 push @nondirs, $entry; 708 push @nondirs, $entry;
604 } else { 709 } else {
605 # need to check for real directory 710 # need to check for real directory
606 aioreq_pri $pri; 711 aioreq_pri $pri;
607 add $statgrp aio_lstat "$path/$entry", sub { 712 add $statgrp aio_lstat "$path/$entry", sub {
608 if (-d _) { 713 if (-d _) {
609 push @dirs, $entry; 714 push @dirs, $entry;
610 715
611 unless (--$ndirs) { 716 unless (--$ndirs) {
612 push @nondirs, @$entries; 717 push @nondirs, @$entries;
613 feed $statgrp; 718 feed $statgrp;
719 }
720 } else {
721 push @nondirs, $entry;
614 } 722 }
615 } else {
616 push @nondirs, $entry;
617 } 723 }
618 } 724 }
619 } 725 };
620 }; 726 };
621 }; 727 };
622 }; 728 };
623 }; 729 };
730
731 $grp
624 }; 732 }
733}
625 734
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
626 $grp 768 $grp
769 }
627} 770}
628 771
629=item aio_fsync $fh, $callback->($status) 772=item aio_fsync $fh, $callback->($status)
630 773
631Asynchronously call fsync on the given filehandle and call the callback 774Asynchronously call fsync on the given filehandle and call the callback
… …
845 988
846=back 989=back
847 990
848=head2 SUPPORT FUNCTIONS 991=head2 SUPPORT FUNCTIONS
849 992
993=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
994
850=over 4 995=over 4
851 996
852=item $fileno = IO::AIO::poll_fileno 997=item $fileno = IO::AIO::poll_fileno
853 998
854Return the I<request result pipe file descriptor>. This filehandle must be 999Return the I<request result pipe file descriptor>. This filehandle must be
… …
858 1003
859See C<poll_cb> for an example. 1004See C<poll_cb> for an example.
860 1005
861=item IO::AIO::poll_cb 1006=item IO::AIO::poll_cb
862 1007
863Process 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
864regularly. Returns the number of events processed. Returns immediately 1009regularly. Returns the number of events processed. Returns immediately
865when 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>.
866 1012
867If not all requests were processed for whatever reason, the filehandle 1013If not all requests were processed for whatever reason, the filehandle
868will still be ready when C<poll_cb> returns. 1014will still be ready when C<poll_cb> returns.
869 1015
870Example: Install an Event watcher that automatically calls 1016Example: Install an Event watcher that automatically calls
… …
872 1018
873 Event->io (fd => IO::AIO::poll_fileno, 1019 Event->io (fd => IO::AIO::poll_fileno,
874 poll => 'r', async => 1, 1020 poll => 'r', async => 1,
875 cb => \&IO::AIO::poll_cb); 1021 cb => \&IO::AIO::poll_cb);
876 1022
877=item IO::AIO::poll_some $max_requests 1023=item IO::AIO::max_poll_reqs $nreqs
878 1024
879Similar to C<poll_cb>, but only processes up to C<$max_requests> requests 1025=item IO::AIO::max_poll_time $seconds
880at a time.
881 1026
882Useful if you want to ensure some level of interactiveness when perl is 1027These set the maximum number of requests (default C<0>, meaning infinity)
883not 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.
884 1043
885Example: Install an Event watcher that automatically calls 1044Example: Install an Event watcher that automatically calls
886IO::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
887program get the CPU sometimes even under high AIO load. 1046program get the CPU sometimes even under high AIO load.
888 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
889 Event->io (fd => IO::AIO::poll_fileno, 1052 Event->io (fd => IO::AIO::poll_fileno,
890 poll => 'r', nice => 1, 1053 poll => 'r', nice => 1,
891 cb => sub { IO::AIO::poll_some 256 }); 1054 cb => &IO::AIO::poll_cb);
892 1055
893=item IO::AIO::poll_wait 1056=item IO::AIO::poll_wait
894 1057
1058If there are any outstanding requests and none of them in the result
895Wait till the result filehandle becomes ready for reading (simply does a 1059phase, wait till the result filehandle becomes ready for reading (simply
896C<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
897for some requests to finish). 1061synchronously wait for some requests to finish).
898 1062
899See C<nreqs> for an example. 1063See C<nreqs> for an example.
900 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
901=item IO::AIO::nreqs 1074=item IO::AIO::flush
902 1075
903Returns the number of requests currently in the ready, execute or pending 1076Wait till all outstanding AIO requests have been handled.
904states (i.e. for which their callback has not been invoked yet).
905 1077
906Example: wait till there are no outstanding requests anymore: 1078Strictly equivalent to:
907 1079
908 IO::AIO::poll_wait, IO::AIO::poll_cb 1080 IO::AIO::poll_wait, IO::AIO::poll_cb
909 while IO::AIO::nreqs; 1081 while IO::AIO::nreqs;
910 1082
911=item IO::AIO::nready 1083=back
912 1084
913Returns the number of requests currently in the ready state (not yet 1085=head3 CONTROLLING THE NUMBER OF THREADS
914executed).
915
916=item IO::AIO::npending
917
918Returns the number of requests currently in the pending state (executed,
919but not yet processed by poll_cb).
920
921=item IO::AIO::flush
922
923Wait till all outstanding AIO requests have been handled.
924
925Strictly equivalent to:
926
927 IO::AIO::poll_wait, IO::AIO::poll_cb
928 while IO::AIO::nreqs;
929
930=item IO::AIO::poll
931
932Waits until some requests have been handled.
933
934Strictly equivalent to:
935
936 IO::AIO::poll_wait, IO::AIO::poll_cb
937 if IO::AIO::nreqs;
938 1086
939=item IO::AIO::min_parallel $nthreads 1087=item IO::AIO::min_parallel $nthreads
940 1088
941Set the minimum number of AIO threads to C<$nthreads>. The current 1089Set the minimum number of AIO threads to C<$nthreads>. The current
942default is C<8>, which means eight asynchronous operations can execute 1090default is C<8>, which means eight asynchronous operations can execute
943concurrently at any one time (the number of outstanding requests, 1091concurrently at any one time (the number of outstanding requests,
944however, is unlimited). 1092however, is unlimited).
945 1093
946IO::AIO starts threads only on demand, when an AIO request is queued and 1094IO::AIO starts threads only on demand, when an AIO request is queued and
947no free thread exists. 1095no free thread exists. Please note that queueing up a hundred requests can
1096create demand for a hundred threads, even if it turns out that everything
1097is in the cache and could have been processed faster by a single thread.
948 1098
949It is recommended to keep the number of threads relatively low, as some 1099It is recommended to keep the number of threads relatively low, as some
950Linux kernel versions will scale negatively with the number of threads 1100Linux kernel versions will scale negatively with the number of threads
951(higher parallelity => MUCH higher latency). With current Linux 2.6 1101(higher parallelity => MUCH higher latency). With current Linux 2.6
952versions, 4-32 threads should be fine. 1102versions, 4-32 threads should be fine.
… …
966This module automatically runs C<max_parallel 0> at program end, to ensure 1116This module automatically runs C<max_parallel 0> at program end, to ensure
967that all threads are killed and that there are no outstanding requests. 1117that all threads are killed and that there are no outstanding requests.
968 1118
969Under normal circumstances you don't need to call this function. 1119Under normal circumstances you don't need to call this function.
970 1120
1121=item IO::AIO::max_idle $nthreads
1122
1123Limit the number of threads (default: 4) that are allowed to idle (i.e.,
1124threads that did not get a request to process within 10 seconds). That
1125means if a thread becomes idle while C<$nthreads> other threads are also
1126idle, it will free its resources and exit.
1127
1128This is useful when you allow a large number of threads (e.g. 100 or 1000)
1129to allow for extremely high load situations, but want to free resources
1130under normal circumstances (1000 threads can easily consume 30MB of RAM).
1131
1132The default is probably ok in most situations, especially if thread
1133creation is fast. If thread creation is very slow on your system you might
1134want to use larger values.
1135
971=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1136=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs
972 1137
973This is a very bad function to use in interactive programs because it 1138This is a very bad function to use in interactive programs because it
974blocks, and a bad way to reduce concurrency because it is inexact: Better 1139blocks, and a bad way to reduce concurrency because it is inexact: Better
975use an C<aio_group> together with a feed callback. 1140use an C<aio_group> together with a feed callback.
… …
986C<max_oustsanding> is mainly useful in simple scripts (with low values) or 1151C<max_oustsanding> is mainly useful in simple scripts (with low values) or
987as a stop gap to shield against fatal memory overflow (with large values). 1152as a stop gap to shield against fatal memory overflow (with large values).
988 1153
989=back 1154=back
990 1155
1156=head3 STATISTICAL INFORMATION
1157
1158=over
1159
1160=item IO::AIO::nreqs
1161
1162Returns the number of requests currently in the ready, execute or pending
1163states (i.e. for which their callback has not been invoked yet).
1164
1165Example: wait till there are no outstanding requests anymore:
1166
1167 IO::AIO::poll_wait, IO::AIO::poll_cb
1168 while IO::AIO::nreqs;
1169
1170=item IO::AIO::nready
1171
1172Returns the number of requests currently in the ready state (not yet
1173executed).
1174
1175=item IO::AIO::npending
1176
1177Returns the number of requests currently in the pending state (executed,
1178but not yet processed by poll_cb).
1179
1180=back
1181
991=cut 1182=cut
992 1183
993# support function to convert a fd into a perl filehandle 1184# support function to convert a fd into a perl filehandle
994sub _fd2fh { 1185sub _fd2fh {
995 return undef if $_[0] < 0; 1186 return undef if $_[0] < 0;
… …
1006 *$sym 1197 *$sym
1007} 1198}
1008 1199
1009min_parallel 8; 1200min_parallel 8;
1010 1201
1011END { 1202END { flush }
1012 min_parallel 1;
1013 flush;
1014};
1015 1203
10161; 12041;
1017 1205
1018=head2 FORK BEHAVIOUR 1206=head2 FORK BEHAVIOUR
1019 1207

Diff Legend

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