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Revision 1.39 by root, Sun Aug 28 11:05:50 2005 UTC vs.
Revision 1.54 by root, Sun Oct 22 00:19:05 2006 UTC

14 aio_unlink "/tmp/file", sub { }; 14 aio_unlink "/tmp/file", sub { };
15 15
16 aio_read $fh, 30000, 1024, $buffer, 0, sub { 16 aio_read $fh, 30000, 1024, $buffer, 0, sub {
17 $_[0] > 0 or die "read error: $!"; 17 $_[0] > 0 or die "read error: $!";
18 }; 18 };
19
20 use IO::AIO 2; # version has aio objects
21
22 my $req = aio_unlink "/tmp/file", sub { };
23 $req->cancel; # cancel request if still in queue
24
25 # AnyEvent
26 open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!";
27 my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });
19 28
20 # Event 29 # Event
21 Event->io (fd => IO::AIO::poll_fileno, 30 Event->io (fd => IO::AIO::poll_fileno,
22 poll => 'r', 31 poll => 'r',
23 cb => \&IO::AIO::poll_cb); 32 cb => \&IO::AIO::poll_cb);
57=cut 66=cut
58 67
59package IO::AIO; 68package IO::AIO;
60 69
61no warnings; 70no warnings;
71use strict 'vars';
62 72
63use base 'Exporter'; 73use base 'Exporter';
64 74
65use Fcntl ();
66
67BEGIN { 75BEGIN {
68 $VERSION = 1.6; 76 our $VERSION = '1.99';
69 77
70 @EXPORT = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat 78 our @EXPORT = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat
71 aio_lstat aio_unlink aio_rmdir aio_readdir aio_symlink 79 aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink
72 aio_fsync aio_fdatasync aio_readahead); 80 aio_fsync aio_fdatasync aio_readahead aio_rename aio_link aio_move
81 aio_group);
73 @EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel 82 our @EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel max_outstanding nreqs);
74 max_outstanding nreqs); 83
84 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
75 85
76 require XSLoader; 86 require XSLoader;
77 XSLoader::load IO::AIO, $VERSION; 87 XSLoader::load ("IO::AIO", $VERSION);
78} 88}
79 89
80=head1 FUNCTIONS 90=head1 FUNCTIONS
81 91
82=head2 AIO FUNCTIONS 92=head2 AIO FUNCTIONS
90syscall has been executed asynchronously. 100syscall has been executed asynchronously.
91 101
92All functions expecting a filehandle keep a copy of the filehandle 102All functions expecting a filehandle keep a copy of the filehandle
93internally until the request has finished. 103internally until the request has finished.
94 104
105All non-composite requests (requests that are not broken down into
106multiple requests) return objects of type L<IO::AIO::REQ> that allow
107further manipulation of running requests.
108
95The pathnames you pass to these routines I<must> be absolute and 109The pathnames you pass to these routines I<must> be absolute and
96encoded in byte form. The reason for the former is that at the time the 110encoded in byte form. The reason for the former is that at the time the
97request is being executed, the current working directory could have 111request is being executed, the current working directory could have
98changed. Alternatively, you can make sure that you never change the 112changed. Alternatively, you can make sure that you never change the
99current working directory. 113current working directory.
105environment, d) use Glib::filename_from_unicode on unicode filenames or e) 119environment, d) use Glib::filename_from_unicode on unicode filenames or e)
106use something else. 120use something else.
107 121
108=over 4 122=over 4
109 123
110=item aio_open $pathname, $flags, $mode, $callback 124=item aio_open $pathname, $flags, $mode, $callback->($fh)
111 125
112Asynchronously open or create a file and call the callback with a newly 126Asynchronously open or create a file and call the callback with a newly
113created filehandle for the file. 127created filehandle for the file.
114 128
115The pathname passed to C<aio_open> must be absolute. See API NOTES, above, 129The pathname passed to C<aio_open> must be absolute. See API NOTES, above,
132 } else { 146 } else {
133 die "open failed: $!\n"; 147 die "open failed: $!\n";
134 } 148 }
135 }; 149 };
136 150
137=item aio_close $fh, $callback 151=item aio_close $fh, $callback->($status)
138 152
139Asynchronously close a file and call the callback with the result 153Asynchronously close a file and call the callback with the result
140code. I<WARNING:> although accepted, you should not pass in a perl 154code. I<WARNING:> although accepted, you should not pass in a perl
141filehandle here, as perl will likely close the file descriptor another 155filehandle here, as perl will likely close the file descriptor another
142time when the filehandle is destroyed. Normally, you can safely call perls 156time when the filehandle is destroyed. Normally, you can safely call perls
143C<close> or just let filehandles go out of scope. 157C<close> or just let filehandles go out of scope.
144 158
145This is supposed to be a bug in the API, so that might change. It's 159This is supposed to be a bug in the API, so that might change. It's
146therefore best to avoid this function. 160therefore best to avoid this function.
147 161
148=item aio_read $fh,$offset,$length, $data,$dataoffset,$callback 162=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
149 163
150=item aio_write $fh,$offset,$length, $data,$dataoffset,$callback 164=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
151 165
152Reads or writes C<length> bytes from the specified C<fh> and C<offset> 166Reads or writes C<length> bytes from the specified C<fh> and C<offset>
153into the scalar given by C<data> and offset C<dataoffset> and calls the 167into the scalar given by C<data> and offset C<dataoffset> and calls the
154callback without the actual number of bytes read (or -1 on error, just 168callback without the actual number of bytes read (or -1 on error, just
155like the syscall). 169like the syscall).
164 aio_read $fh, 7, 15, $buffer, 0, sub { 178 aio_read $fh, 7, 15, $buffer, 0, sub {
165 $_[0] > 0 or die "read error: $!"; 179 $_[0] > 0 or die "read error: $!";
166 print "read $_[0] bytes: <$buffer>\n"; 180 print "read $_[0] bytes: <$buffer>\n";
167 }; 181 };
168 182
183=item aio_move $srcpath, $dstpath, $callback->($status)
184
185Try to move the I<file> (directories not supported as either source or
186destination) from C<$srcpath> to C<$dstpath> and call the callback with
187the C<0> (error) or C<-1> ok.
188
189This is a composite request that tries to rename(2) the file first. If
190rename files with C<EXDEV>, it creates the destination file with mode 0200
191and copies the contents of the source file into it using C<aio_sendfile>,
192followed by restoring atime, mtime, access mode and uid/gid, in that
193order, and unlinking the C<$srcpath>.
194
195If an error occurs, the partial destination file will be unlinked, if
196possible, except when setting atime, mtime, access mode and uid/gid, where
197errors are being ignored.
198
199=cut
200
201sub aio_move($$$) {
202 my ($src, $dst, $cb) = @_;
203
204 aio_rename $src, $dst, sub {
205 if ($_[0] && $! == EXDEV) {
206 aio_open $src, O_RDONLY, 0, sub {
207 if (my $src_fh = $_[0]) {
208 my @stat = stat $src_fh;
209
210 aio_open $dst, O_WRONLY, 0200, sub {
211 if (my $dst_fh = $_[0]) {
212 aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
213 close $src_fh;
214
215 if ($_[0] == $stat[7]) {
216 utime $stat[8], $stat[9], $dst;
217 chmod $stat[2] & 07777, $dst_fh;
218 chown $stat[4], $stat[5], $dst_fh;
219 close $dst_fh;
220
221 aio_unlink $src, sub {
222 $cb->($_[0]);
223 };
224 } else {
225 my $errno = $!;
226 aio_unlink $dst, sub {
227 $! = $errno;
228 $cb->(-1);
229 };
230 }
231 };
232 } else {
233 $cb->(-1);
234 }
235 },
236
237 } else {
238 $cb->(-1);
239 }
240 };
241 } else {
242 $cb->($_[0]);
243 }
244 };
245}
246
169=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback 247=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
170 248
171Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts 249Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
172reading at byte offset C<$in_offset>, and starts writing at the current 250reading at byte offset C<$in_offset>, and starts writing at the current
173file offset of C<$out_fh>. Because of that, it is not safe to issue more 251file offset of C<$out_fh>. Because of that, it is not safe to issue more
174than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each 252than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
187bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only 265bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
188provides the number of bytes written to C<$out_fh>. Only if the result 266provides the number of bytes written to C<$out_fh>. Only if the result
189value equals C<$length> one can assume that C<$length> bytes have been 267value equals C<$length> one can assume that C<$length> bytes have been
190read. 268read.
191 269
192=item aio_readahead $fh,$offset,$length, $callback 270=item aio_readahead $fh,$offset,$length, $callback->($retval)
193 271
194C<aio_readahead> populates the page cache with data from a file so that 272C<aio_readahead> populates the page cache with data from a file so that
195subsequent reads from that file will not block on disk I/O. The C<$offset> 273subsequent reads from that file will not block on disk I/O. The C<$offset>
196argument specifies the starting point from which data is to be read and 274argument specifies the starting point from which data is to be read and
197C<$length> specifies the number of bytes to be read. I/O is performed in 275C<$length> specifies the number of bytes to be read. I/O is performed in
201file. The current file offset of the file is left unchanged. 279file. The current file offset of the file is left unchanged.
202 280
203If that syscall doesn't exist (likely if your OS isn't Linux) it will be 281If that syscall doesn't exist (likely if your OS isn't Linux) it will be
204emulated by simply reading the data, which would have a similar effect. 282emulated by simply reading the data, which would have a similar effect.
205 283
206=item aio_stat $fh_or_path, $callback 284=item aio_stat $fh_or_path, $callback->($status)
207 285
208=item aio_lstat $fh, $callback 286=item aio_lstat $fh, $callback->($status)
209 287
210Works like perl's C<stat> or C<lstat> in void context. The callback will 288Works like perl's C<stat> or C<lstat> in void context. The callback will
211be called after the stat and the results will be available using C<stat _> 289be called after the stat and the results will be available using C<stat _>
212or C<-s _> etc... 290or C<-s _> etc...
213 291
223 aio_stat "/etc/passwd", sub { 301 aio_stat "/etc/passwd", sub {
224 $_[0] and die "stat failed: $!"; 302 $_[0] and die "stat failed: $!";
225 print "size is ", -s _, "\n"; 303 print "size is ", -s _, "\n";
226 }; 304 };
227 305
228=item aio_unlink $pathname, $callback 306=item aio_unlink $pathname, $callback->($status)
229 307
230Asynchronously unlink (delete) a file and call the callback with the 308Asynchronously unlink (delete) a file and call the callback with the
231result code. 309result code.
232 310
311=item aio_link $srcpath, $dstpath, $callback->($status)
312
313Asynchronously create a new link to the existing object at C<$srcpath> at
314the path C<$dstpath> and call the callback with the result code.
315
316=item aio_symlink $srcpath, $dstpath, $callback->($status)
317
318Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
319the path C<$dstpath> and call the callback with the result code.
320
321=item aio_rename $srcpath, $dstpath, $callback->($status)
322
323Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
324rename(2) and call the callback with the result code.
325
233=item aio_rmdir $pathname, $callback 326=item aio_rmdir $pathname, $callback->($status)
234 327
235Asynchronously rmdir (delete) a directory and call the callback with the 328Asynchronously rmdir (delete) a directory and call the callback with the
236result code. 329result code.
237 330
238=item aio_readdir $pathname $callback 331=item aio_readdir $pathname, $callback->($entries)
239 332
240Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 333Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
241directory (i.e. opendir + readdir + closedir). The entries will not be 334directory (i.e. opendir + readdir + closedir). The entries will not be
242sorted, and will B<NOT> include the C<.> and C<..> entries. 335sorted, and will B<NOT> include the C<.> and C<..> entries.
243 336
244The callback a single argument which is either C<undef> or an array-ref 337The callback a single argument which is either C<undef> or an array-ref
245with the filenames. 338with the filenames.
246 339
340=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
341
342Scans a directory (similar to C<aio_readdir>) but additionally tries to
343separate the entries of directory C<$path> into two sets of names, ones
344you can recurse into (directories or links to them), and ones you cannot
345recurse into (everything else).
346
347C<aio_scandir> is a composite request that consists of many sub
348requests. C<$maxreq> specifies the maximum number of outstanding aio
349requests that this function generates. If it is C<< <= 0 >>, then a
350suitable default will be chosen (currently 8).
351
352On error, the callback is called without arguments, otherwise it receives
353two array-refs with path-relative entry names.
354
355Example:
356
357 aio_scandir $dir, 0, sub {
358 my ($dirs, $nondirs) = @_;
359 print "real directories: @$dirs\n";
360 print "everything else: @$nondirs\n";
361 };
362
363Implementation notes.
364
365The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
366
367After reading the directory, the modification time, size etc. of the
368directory before and after the readdir is checked, and if they match (and
369isn't the current time), the link count will be used to decide how many
370entries are directories (if >= 2). Otherwise, no knowledge of the number
371of subdirectories will be assumed.
372
373Then entries will be sorted into likely directories (everything without
374a non-initial dot currently) and likely non-directories (everything
375else). Then every entry plus an appended C</.> will be C<stat>'ed,
376likely directories first. If that succeeds, it assumes that the entry
377is a directory or a symlink to directory (which will be checked
378seperately). This is often faster than stat'ing the entry itself because
379filesystems might detect the type of the entry without reading the inode
380data (e.g. ext2fs filetype feature).
381
382If the known number of directories (link count - 2) has been reached, the
383rest of the entries is assumed to be non-directories.
384
385This only works with certainty on POSIX (= UNIX) filesystems, which
386fortunately are the vast majority of filesystems around.
387
388It will also likely work on non-POSIX filesystems with reduced efficiency
389as those tend to return 0 or 1 as link counts, which disables the
390directory counting heuristic.
391
392=cut
393
394sub aio_scandir($$$) {
395 my ($path, $maxreq, $cb) = @_;
396
397 $maxreq = 8 if $maxreq <= 0;
398
399 # stat once
400 aio_stat $path, sub {
401 return $cb->() if $_[0];
402 my $now = time;
403 my $hash1 = join ":", (stat _)[0,1,3,7,9];
404
405 # read the directory entries
406 aio_readdir $path, sub {
407 my $entries = shift
408 or return $cb->();
409
410 # stat the dir another time
411 aio_stat $path, sub {
412 my $hash2 = join ":", (stat _)[0,1,3,7,9];
413
414 my $ndirs;
415
416 # take the slow route if anything looks fishy
417 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
418 $ndirs = -1;
419 } else {
420 # if nlink == 2, we are finished
421 # on non-posix-fs's, we rely on nlink < 2
422 $ndirs = (stat _)[3] - 2
423 or return $cb->([], $entries);
424 }
425
426 # sort into likely dirs and likely nondirs
427 # dirs == files without ".", short entries first
428 $entries = [map $_->[0],
429 sort { $b->[1] cmp $a->[1] }
430 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
431 @$entries];
432
433 my (@dirs, @nondirs);
434
435 my ($statcb, $schedcb);
436 my $nreq = 0;
437
438 $schedcb = sub {
439 if (@$entries) {
440 if ($nreq < $maxreq) {
441 my $ent = pop @$entries;
442 $nreq++;
443 aio_stat "$path/$ent/.", sub { $statcb->($_[0], $ent) };
444 }
445 } elsif (!$nreq) {
446 # finished
447 undef $statcb;
448 undef $schedcb;
449 $cb->(\@dirs, \@nondirs) if $cb;
450 undef $cb;
451 }
452 };
453 $statcb = sub {
454 my ($status, $entry) = @_;
455
456 if ($status < 0) {
457 $nreq--;
458 push @nondirs, $entry;
459 &$schedcb;
460 } else {
461 # need to check for real directory
462 aio_lstat "$path/$entry", sub {
463 $nreq--;
464
465 if (-d _) {
466 push @dirs, $entry;
467
468 if (!--$ndirs) {
469 push @nondirs, @$entries;
470 $entries = [];
471 }
472 } else {
473 push @nondirs, $entry;
474 }
475
476 &$schedcb;
477 }
478 }
479 };
480
481 &$schedcb while @$entries && $nreq < $maxreq;
482 };
483 };
484 };
485}
486
247=item aio_fsync $fh, $callback 487=item aio_fsync $fh, $callback->($status)
248 488
249Asynchronously call fsync on the given filehandle and call the callback 489Asynchronously call fsync on the given filehandle and call the callback
250with the fsync result code. 490with the fsync result code.
251 491
252=item aio_fdatasync $fh, $callback 492=item aio_fdatasync $fh, $callback->($status)
253 493
254Asynchronously call fdatasync on the given filehandle and call the 494Asynchronously call fdatasync on the given filehandle and call the
255callback with the fdatasync result code. 495callback with the fdatasync result code.
256 496
257If this call isn't available because your OS lacks it or it couldn't be 497If this call isn't available because your OS lacks it or it couldn't be
258detected, it will be emulated by calling C<fsync> instead. 498detected, it will be emulated by calling C<fsync> instead.
499
500=item aio_group $callback->()
501
502=item aio_sleep $fractional_seconds, $callback->() *NOT EXPORTED*
503
504Mainly used for debugging and benchmarking, this aio request puts one of
505the request workers to sleep for the given time.
506
507=back
508
509=head2 IO::AIO::REQ CLASS
510
511All non-aggregate C<aio_*> functions return an object of this class when
512called in non-void context.
513
514A request always moves through the following five states in its lifetime,
515in order: B<ready> (request has been created, but has not been executed
516yet), B<execute> (request is currently being executed), B<pending>
517(request has been executed but callback has not been called yet),
518B<result> (results are being processed synchronously, includes calling the
519callback) and B<done> (request has reached the end of its lifetime and
520holds no resources anymore).
521
522=over 4
523
524=item $req->cancel
525
526Cancels the request, if possible. Has the effect of skipping execution
527when entering the B<execute> state and skipping calling the callback when
528entering the the B<result> state, but will leave the request otherwise
529untouched. That means that requests that currently execute will not be
530stopped and resources held by the request will not be freed prematurely.
259 531
260=back 532=back
261 533
262=head2 SUPPORT FUNCTIONS 534=head2 SUPPORT FUNCTIONS
263 535
391} 663}
392 664
3931; 6651;
394 666
395=head2 FORK BEHAVIOUR 667=head2 FORK BEHAVIOUR
668
669This module should do "the right thing" when the process using it forks:
396 670
397Before the fork, IO::AIO enters a quiescent state where no requests 671Before the fork, IO::AIO enters a quiescent state where no requests
398can be added in other threads and no results will be processed. After 672can be added in other threads and no results will be processed. After
399the fork the parent simply leaves the quiescent state and continues 673the fork the parent simply leaves the quiescent state and continues
400request/result processing, while the child clears the request/result 674request/result processing, while the child clears the request/result
401queue (so the requests started before the fork will only be handled in 675queue (so the requests started before the fork will only be handled in
402the parent). Threats will be started on demand until the limit ste in the 676the parent). Threads will be started on demand until the limit ste in the
403parent process has been reached again. 677parent process has been reached again.
404 678
679In short: the parent will, after a short pause, continue as if fork had
680not been called, while the child will act as if IO::AIO has not been used
681yet.
682
405=head1 SEE ALSO 683=head1 SEE ALSO
406 684
407L<Coro>, L<Linux::AIO>. 685L<Coro>, L<Linux::AIO> (obsolete).
408 686
409=head1 AUTHOR 687=head1 AUTHOR
410 688
411 Marc Lehmann <schmorp@schmorp.de> 689 Marc Lehmann <schmorp@schmorp.de>
412 http://home.schmorp.de/ 690 http://home.schmorp.de/

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