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Revision 1.81 by root, Fri Oct 27 19:17:23 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
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_group aio_nop); 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]) {
265 aio_read $fh, 7, 15, $buffer, 0, sub { 337 aio_read $fh, 7, 15, $buffer, 0, sub {
266 $_[0] > 0 or die "read error: $!"; 338 $_[0] > 0 or die "read error: $!";
267 print "read $_[0] bytes: <$buffer>\n"; 339 print "read $_[0] bytes: <$buffer>\n";
268 }; 340 };
269 341
270=item aio_move $srcpath, $dstpath, $callback->($status)
271
272Try to move the I<file> (directories not supported as either source or
273destination) from C<$srcpath> to C<$dstpath> and call the callback with
274the C<0> (error) or C<-1> ok.
275
276This is a composite request that tries to rename(2) the file first. If
277rename files with C<EXDEV>, it creates the destination file with mode 0200
278and copies the contents of the source file into it using C<aio_sendfile>,
279followed by restoring atime, mtime, access mode and uid/gid, in that
280order, and unlinking the C<$srcpath>.
281
282If an error occurs, the partial destination file will be unlinked, if
283possible, except when setting atime, mtime, access mode and uid/gid, where
284errors are being ignored.
285
286=cut
287
288sub aio_move($$$) {
289 my ($src, $dst, $cb) = @_;
290
291 my $pri = aioreq_pri;
292 my $grp = aio_group $cb;
293
294 aioreq_pri $pri;
295 add $grp aio_rename $src, $dst, sub {
296 if ($_[0] && $! == EXDEV) {
297 aioreq_pri $pri;
298 add $grp aio_open $src, O_RDONLY, 0, sub {
299 if (my $src_fh = $_[0]) {
300 my @stat = stat $src_fh;
301
302 aioreq_pri $pri;
303 add $grp aio_open $dst, O_WRONLY, 0200, sub {
304 if (my $dst_fh = $_[0]) {
305 aioreq_pri $pri;
306 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
307 close $src_fh;
308
309 if ($_[0] == $stat[7]) {
310 utime $stat[8], $stat[9], $dst;
311 chmod $stat[2] & 07777, $dst_fh;
312 chown $stat[4], $stat[5], $dst_fh;
313 close $dst_fh;
314
315 aioreq_pri $pri;
316 add $grp aio_unlink $src, sub {
317 $grp->result ($_[0]);
318 };
319 } else {
320 my $errno = $!;
321 aioreq_pri $pri;
322 add $grp aio_unlink $dst, sub {
323 $! = $errno;
324 $grp->result (-1);
325 };
326 }
327 };
328 } else {
329 $grp->result (-1);
330 }
331 },
332
333 } else {
334 $grp->result (-1);
335 }
336 };
337 } else {
338 $grp->result ($_[0]);
339 }
340 };
341
342 $grp
343}
344
345=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) 342=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
346 343
347Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts 344Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
348reading at byte offset C<$in_offset>, and starts writing at the current 345reading at byte offset C<$in_offset>, and starts writing at the current
349file offset of C<$out_fh>. Because of that, it is not safe to issue more 346file offset of C<$out_fh>. Because of that, it is not safe to issue more
404=item aio_unlink $pathname, $callback->($status) 401=item aio_unlink $pathname, $callback->($status)
405 402
406Asynchronously unlink (delete) a file and call the callback with the 403Asynchronously unlink (delete) a file and call the callback with the
407result code. 404result code.
408 405
406=item aio_mknod $path, $mode, $dev, $callback->($status)
407
408[EXPERIMENTAL]
409
410Asynchronously create a device node (or fifo). See mknod(2).
411
412The only (POSIX-) portable way of calling this function is:
413
414 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...
415
409=item aio_link $srcpath, $dstpath, $callback->($status) 416=item aio_link $srcpath, $dstpath, $callback->($status)
410 417
411Asynchronously create a new link to the existing object at C<$srcpath> at 418Asynchronously create a new link to the existing object at C<$srcpath> at
412the path C<$dstpath> and call the callback with the result code. 419the path C<$dstpath> and call the callback with the result code.
413 420
414=item aio_symlink $srcpath, $dstpath, $callback->($status) 421=item aio_symlink $srcpath, $dstpath, $callback->($status)
415 422
416Asynchronously 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
417the path C<$dstpath> and call the callback with the result code. 424the path C<$dstpath> and call the callback with the result code.
418 425
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
419=item aio_rename $srcpath, $dstpath, $callback->($status) 432=item aio_rename $srcpath, $dstpath, $callback->($status)
420 433
421Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as 434Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
422rename(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.
423 442
424=item aio_rmdir $pathname, $callback->($status) 443=item aio_rmdir $pathname, $callback->($status)
425 444
426Asynchronously rmdir (delete) a directory and call the callback with the 445Asynchronously rmdir (delete) a directory and call the callback with the
427result code. 446result code.
432directory (i.e. opendir + readdir + closedir). The entries will not be 451directory (i.e. opendir + readdir + closedir). The entries will not be
433sorted, and will B<NOT> include the C<.> and C<..> entries. 452sorted, and will B<NOT> include the C<.> and C<..> entries.
434 453
435The 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
436with 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), $$data, 0, sub {
479 $grp->result ($_[0]);
480 };
481 };
482
483 $grp
484 }
485}
486
487=item aio_copy $srcpath, $dstpath, $callback->($status)
488
489Try to copy the I<file> (directories not supported as either source or
490destination) from C<$srcpath> to C<$dstpath> and call the callback with
491the C<0> (error) or C<-1> ok.
492
493This is a composite request that it creates the destination file with
494mode 0200 and copies the contents of the source file into it using
495C<aio_sendfile>, followed by restoring atime, mtime, access mode and
496uid/gid, in that order.
497
498If an error occurs, the partial destination file will be unlinked, if
499possible, except when setting atime, mtime, access mode and uid/gid, where
500errors are being ignored.
501
502=cut
503
504sub aio_copy($$;$) {
505 aio_block {
506 my ($src, $dst, $cb) = @_;
507
508 my $pri = aioreq_pri;
509 my $grp = aio_group $cb;
510
511 aioreq_pri $pri;
512 add $grp aio_open $src, O_RDONLY, 0, sub {
513 if (my $src_fh = $_[0]) {
514 my @stat = stat $src_fh;
515
516 aioreq_pri $pri;
517 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
518 if (my $dst_fh = $_[0]) {
519 aioreq_pri $pri;
520 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
521 if ($_[0] == $stat[7]) {
522 $grp->result (0);
523 close $src_fh;
524
525 # those should not normally block. should. should.
526 utime $stat[8], $stat[9], $dst;
527 chmod $stat[2] & 07777, $dst_fh;
528 chown $stat[4], $stat[5], $dst_fh;
529 close $dst_fh;
530 } else {
531 $grp->result (-1);
532 close $src_fh;
533 close $dst_fh;
534
535 aioreq $pri;
536 add $grp aio_unlink $dst;
537 }
538 };
539 } else {
540 $grp->result (-1);
541 }
542 },
543
544 } else {
545 $grp->result (-1);
546 }
547 };
548
549 $grp
550 }
551}
552
553=item aio_move $srcpath, $dstpath, $callback->($status)
554
555Try to move the I<file> (directories not supported as either source or
556destination) from C<$srcpath> to C<$dstpath> and call the callback with
557the C<0> (error) or C<-1> ok.
558
559This is a composite request that tries to rename(2) the file first. If
560rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if
561that is successful, unlinking the C<$srcpath>.
562
563=cut
564
565sub aio_move($$;$) {
566 aio_block {
567 my ($src, $dst, $cb) = @_;
568
569 my $pri = aioreq_pri;
570 my $grp = aio_group $cb;
571
572 aioreq_pri $pri;
573 add $grp aio_rename $src, $dst, sub {
574 if ($_[0] && $! == EXDEV) {
575 aioreq_pri $pri;
576 add $grp aio_copy $src, $dst, sub {
577 $grp->result ($_[0]);
578
579 if (!$_[0]) {
580 aioreq_pri $pri;
581 add $grp aio_unlink $src;
582 }
583 };
584 } else {
585 $grp->result ($_[0]);
586 }
587 };
588
589 $grp
590 }
591}
437 592
438=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 593=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
439 594
440Scans a directory (similar to C<aio_readdir>) but additionally tries to 595Scans a directory (similar to C<aio_readdir>) but additionally tries to
441efficiently separate the entries of directory C<$path> into two sets of 596efficiently separate the entries of directory C<$path> into two sets of
487as those tend to return 0 or 1 as link counts, which disables the 642as those tend to return 0 or 1 as link counts, which disables the
488directory counting heuristic. 643directory counting heuristic.
489 644
490=cut 645=cut
491 646
492sub aio_scandir($$$) { 647sub aio_scandir($$;$) {
648 aio_block {
493 my ($path, $maxreq, $cb) = @_; 649 my ($path, $maxreq, $cb) = @_;
494 650
495 my $pri = aioreq_pri; 651 my $pri = aioreq_pri;
496 652
497 my $grp = aio_group $cb; 653 my $grp = aio_group $cb;
498 654
499 $maxreq = 4 if $maxreq <= 0; 655 $maxreq = 4 if $maxreq <= 0;
500 656
501 # stat once 657 # stat once
502 aioreq_pri $pri;
503 add $grp aio_stat $path, sub {
504 return $grp->result () if $_[0];
505 my $now = time;
506 my $hash1 = join ":", (stat _)[0,1,3,7,9];
507
508 # read the directory entries
509 aioreq_pri $pri; 658 aioreq_pri $pri;
510 add $grp aio_readdir $path, sub { 659 add $grp aio_stat $path, sub {
511 my $entries = shift
512 or return $grp->result (); 660 return $grp->result () if $_[0];
661 my $now = time;
662 my $hash1 = join ":", (stat _)[0,1,3,7,9];
513 663
514 # stat the dir another time 664 # read the directory entries
515 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;
516 add $grp aio_stat $path, sub { 672 add $grp aio_stat $path, sub {
517 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 673 my $hash2 = join ":", (stat _)[0,1,3,7,9];
518 674
519 my $ndirs; 675 my $ndirs;
520 676
521 # take the slow route if anything looks fishy 677 # take the slow route if anything looks fishy
522 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 678 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
523 $ndirs = -1; 679 $ndirs = -1;
524 } else { 680 } else {
525 # if nlink == 2, we are finished 681 # if nlink == 2, we are finished
526 # on non-posix-fs's, we rely on nlink < 2 682 # on non-posix-fs's, we rely on nlink < 2
527 $ndirs = (stat _)[3] - 2 683 $ndirs = (stat _)[3] - 2
528 or return $grp->result ([], $entries); 684 or return $grp->result ([], $entries);
529 } 685 }
530 686
531 # sort into likely dirs and likely nondirs 687 # sort into likely dirs and likely nondirs
532 # dirs == files without ".", short entries first 688 # dirs == files without ".", short entries first
533 $entries = [map $_->[0], 689 $entries = [map $_->[0],
534 sort { $b->[1] cmp $a->[1] } 690 sort { $b->[1] cmp $a->[1] }
535 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length], 691 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
536 @$entries]; 692 @$entries];
537 693
538 my (@dirs, @nondirs); 694 my (@dirs, @nondirs);
539 695
540 my $statgrp = add $grp aio_group sub { 696 my $statgrp = add $grp aio_group sub {
541 $grp->result (\@dirs, \@nondirs); 697 $grp->result (\@dirs, \@nondirs);
542 }; 698 };
543 699
544 limit $statgrp $maxreq; 700 limit $statgrp $maxreq;
545 feed $statgrp sub { 701 feed $statgrp sub {
546 return unless @$entries; 702 return unless @$entries;
547 my $entry = pop @$entries; 703 my $entry = pop @$entries;
548 704
549 aioreq_pri $pri; 705 aioreq_pri $pri;
550 add $statgrp aio_stat "$path/$entry/.", sub { 706 add $statgrp aio_stat "$path/$entry/.", sub {
551 if ($_[0] < 0) { 707 if ($_[0] < 0) {
552 push @nondirs, $entry; 708 push @nondirs, $entry;
553 } else { 709 } else {
554 # need to check for real directory 710 # need to check for real directory
555 aioreq_pri $pri; 711 aioreq_pri $pri;
556 add $statgrp aio_lstat "$path/$entry", sub { 712 add $statgrp aio_lstat "$path/$entry", sub {
557 if (-d _) { 713 if (-d _) {
558 push @dirs, $entry; 714 push @dirs, $entry;
559 715
560 unless (--$ndirs) { 716 unless (--$ndirs) {
561 push @nondirs, @$entries; 717 push @nondirs, @$entries;
562 feed $statgrp; 718 feed $statgrp;
719 }
720 } else {
721 push @nondirs, $entry;
563 } 722 }
564 } else {
565 push @nondirs, $entry;
566 } 723 }
567 } 724 }
568 } 725 };
569 }; 726 };
570 }; 727 };
571 }; 728 };
572 }; 729 };
730
731 $grp
573 }; 732 }
733}
574 734
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
575 $grp 768 $grp
769 }
576} 770}
577 771
578=item aio_fsync $fh, $callback->($status) 772=item aio_fsync $fh, $callback->($status)
579 773
580Asynchronously call fsync on the given filehandle and call the callback 774Asynchronously call fsync on the given filehandle and call the callback
794 988
795=back 989=back
796 990
797=head2 SUPPORT FUNCTIONS 991=head2 SUPPORT FUNCTIONS
798 992
993=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
994
799=over 4 995=over 4
800 996
801=item $fileno = IO::AIO::poll_fileno 997=item $fileno = IO::AIO::poll_fileno
802 998
803Return the I<request result pipe file descriptor>. This filehandle must be 999Return the I<request result pipe file descriptor>. This filehandle must be
807 1003
808See C<poll_cb> for an example. 1004See C<poll_cb> for an example.
809 1005
810=item IO::AIO::poll_cb 1006=item IO::AIO::poll_cb
811 1007
812Process 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
813regularly. Returns the number of events processed. Returns immediately 1009regularly. Returns the number of events processed. Returns immediately
814when 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>.
815 1012
816If not all requests were processed for whatever reason, the filehandle 1013If not all requests were processed for whatever reason, the filehandle
817will still be ready when C<poll_cb> returns. 1014will still be ready when C<poll_cb> returns.
818 1015
819Example: Install an Event watcher that automatically calls 1016Example: Install an Event watcher that automatically calls
821 1018
822 Event->io (fd => IO::AIO::poll_fileno, 1019 Event->io (fd => IO::AIO::poll_fileno,
823 poll => 'r', async => 1, 1020 poll => 'r', async => 1,
824 cb => \&IO::AIO::poll_cb); 1021 cb => \&IO::AIO::poll_cb);
825 1022
826=item IO::AIO::poll_some $max_requests 1023=item IO::AIO::max_poll_reqs $nreqs
827 1024
828Similar to C<poll_cb>, but only processes up to C<$max_requests> requests 1025=item IO::AIO::max_poll_time $seconds
829at a time.
830 1026
831Useful if you want to ensure some level of interactiveness when perl is 1027These set the maximum number of requests (default C<0>, meaning infinity)
832not 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.
833 1043
834Example: Install an Event watcher that automatically calls 1044Example: Install an Event watcher that automatically calls
835IO::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
836program get the CPU sometimes even under high AIO load. 1046program get the CPU sometimes even under high AIO load.
837 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
838 Event->io (fd => IO::AIO::poll_fileno, 1052 Event->io (fd => IO::AIO::poll_fileno,
839 poll => 'r', nice => 1, 1053 poll => 'r', nice => 1,
840 cb => sub { IO::AIO::poll_some 256 }); 1054 cb => &IO::AIO::poll_cb);
841 1055
842=item IO::AIO::poll_wait 1056=item IO::AIO::poll_wait
843 1057
1058If there are any outstanding requests and none of them in the result
844Wait till the result filehandle becomes ready for reading (simply does a 1059phase, wait till the result filehandle becomes ready for reading (simply
845C<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
846for some requests to finish). 1061synchronously wait for some requests to finish).
847 1062
848See C<nreqs> for an example. 1063See C<nreqs> for an example.
849 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
850=item IO::AIO::nreqs 1074=item IO::AIO::flush
851 1075
852Returns the number of requests currently in the ready, execute or pending 1076Wait till all outstanding AIO requests have been handled.
853states (i.e. for which their callback has not been invoked yet).
854 1077
855Example: wait till there are no outstanding requests anymore: 1078Strictly equivalent to:
856 1079
857 IO::AIO::poll_wait, IO::AIO::poll_cb 1080 IO::AIO::poll_wait, IO::AIO::poll_cb
858 while IO::AIO::nreqs; 1081 while IO::AIO::nreqs;
859 1082
860=item IO::AIO::nready 1083=back
861 1084
862Returns the number of requests currently in the ready state (not yet 1085=head3 CONTROLLING THE NUMBER OF THREADS
863executed).
864
865=item IO::AIO::npending
866
867Returns the number of requests currently in the pending state (executed,
868but not yet processed by poll_cb).
869
870=item IO::AIO::flush
871
872Wait till all outstanding AIO requests have been handled.
873
874Strictly equivalent to:
875
876 IO::AIO::poll_wait, IO::AIO::poll_cb
877 while IO::AIO::nreqs;
878
879=item IO::AIO::poll
880
881Waits until some requests have been handled.
882
883Strictly equivalent to:
884
885 IO::AIO::poll_wait, IO::AIO::poll_cb
886 if IO::AIO::nreqs;
887 1086
888=item IO::AIO::min_parallel $nthreads 1087=item IO::AIO::min_parallel $nthreads
889 1088
890Set the minimum number of AIO threads to C<$nthreads>. The current 1089Set the minimum number of AIO threads to C<$nthreads>. The current
891default is C<8>, which means eight asynchronous operations can execute 1090default is C<8>, which means eight asynchronous operations can execute
892concurrently at any one time (the number of outstanding requests, 1091concurrently at any one time (the number of outstanding requests,
893however, is unlimited). 1092however, is unlimited).
894 1093
895IO::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
896no 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.
897 1098
898It 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
899Linux kernel versions will scale negatively with the number of threads 1100Linux kernel versions will scale negatively with the number of threads
900(higher parallelity => MUCH higher latency). With current Linux 2.6 1101(higher parallelity => MUCH higher latency). With current Linux 2.6
901versions, 4-32 threads should be fine. 1102versions, 4-32 threads should be fine.
915This 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
916that all threads are killed and that there are no outstanding requests. 1117that all threads are killed and that there are no outstanding requests.
917 1118
918Under normal circumstances you don't need to call this function. 1119Under normal circumstances you don't need to call this function.
919 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
920=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1136=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs
921 1137
922This 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
923blocks, 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
924use an C<aio_group> together with a feed callback. 1140use an C<aio_group> together with a feed callback.
935C<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
936as 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).
937 1153
938=back 1154=back
939 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
940=cut 1182=cut
941 1183
942# support function to convert a fd into a perl filehandle 1184# support function to convert a fd into a perl filehandle
943sub _fd2fh { 1185sub _fd2fh {
944 return undef if $_[0] < 0; 1186 return undef if $_[0] < 0;
954 1196
955 *$sym 1197 *$sym
956} 1198}
957 1199
958min_parallel 8; 1200min_parallel 8;
1201
1202END { flush }
959 1203
9601; 12041;
961 1205
962=head2 FORK BEHAVIOUR 1206=head2 FORK BEHAVIOUR
963 1207

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