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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.45 by root, Mon Dec 26 19:20:26 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
19 24
20 # AnyEvent 25 # AnyEvent
21 open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!"; 26 open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!";
22 my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb }); 27 my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });
23 28
61=cut 66=cut
62 67
63package IO::AIO; 68package IO::AIO;
64 69
65no warnings; 70no warnings;
71use strict 'vars';
66 72
67use base 'Exporter'; 73use base 'Exporter';
68 74
69use Fcntl ();
70
71BEGIN { 75BEGIN {
72 $VERSION = '1.71'; 76 our $VERSION = '1.99';
73 77
74 @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
75 aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink 79 aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink
76 aio_fsync aio_fdatasync aio_readahead); 80 aio_fsync aio_fdatasync aio_readahead aio_rename aio_link aio_move
81 aio_group);
77 @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);
78 max_outstanding nreqs); 83
84 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
79 85
80 require XSLoader; 86 require XSLoader;
81 XSLoader::load IO::AIO, $VERSION; 87 XSLoader::load ("IO::AIO", $VERSION);
82} 88}
83 89
84=head1 FUNCTIONS 90=head1 FUNCTIONS
85 91
86=head2 AIO FUNCTIONS 92=head2 AIO FUNCTIONS
93perl, which usually delivers "false") as it's sole argument when the given 99perl, which usually delivers "false") as it's sole argument when the given
94syscall has been executed asynchronously. 100syscall has been executed asynchronously.
95 101
96All functions expecting a filehandle keep a copy of the filehandle 102All functions expecting a filehandle keep a copy of the filehandle
97internally until the request has finished. 103internally until the request has finished.
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.
98 108
99The pathnames you pass to these routines I<must> be absolute and 109The pathnames you pass to these routines I<must> be absolute and
100encoded 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
101request is being executed, the current working directory could have 111request is being executed, the current working directory could have
102changed. Alternatively, you can make sure that you never change the 112changed. Alternatively, you can make sure that you never change the
168 aio_read $fh, 7, 15, $buffer, 0, sub { 178 aio_read $fh, 7, 15, $buffer, 0, sub {
169 $_[0] > 0 or die "read error: $!"; 179 $_[0] > 0 or die "read error: $!";
170 print "read $_[0] bytes: <$buffer>\n"; 180 print "read $_[0] bytes: <$buffer>\n";
171 }; 181 };
172 182
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
173=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) 247=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
174 248
175Tries 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
176reading 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
177file 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
232=item aio_unlink $pathname, $callback->($status) 306=item aio_unlink $pathname, $callback->($status)
233 307
234Asynchronously unlink (delete) a file and call the callback with the 308Asynchronously unlink (delete) a file and call the callback with the
235result code. 309result code.
236 310
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
237=item aio_rmdir $pathname, $callback->($status) 326=item aio_rmdir $pathname, $callback->($status)
238 327
239Asynchronously rmdir (delete) a directory and call the callback with the 328Asynchronously rmdir (delete) a directory and call the callback with the
240result code. 329result code.
241 330
242=item aio_readdir $pathname $callback->($entries) 331=item aio_readdir $pathname, $callback->($entries)
243 332
244Unlike 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
245directory (i.e. opendir + readdir + closedir). The entries will not be 334directory (i.e. opendir + readdir + closedir). The entries will not be
246sorted, and will B<NOT> include the C<.> and C<..> entries. 335sorted, and will B<NOT> include the C<.> and C<..> entries.
247 336
248The 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
249with the filenames. 338with the filenames.
250 339
251=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 340=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
252 341
253Scans a directory (similar to C<aio_readdir>) and tries to separate the 342Scans a directory (similar to C<aio_readdir>) but additionally tries to
254entries of directory C<$path> into two sets of names, ones you can recurse 343separate the entries of directory C<$path> into two sets of names, ones
255into (directories), and ones you cannot recurse into (everything else). 344you can recurse into (directories or links to them), and ones you cannot
345recurse into (everything else).
256 346
257C<aio_scandir> is a composite request that consists of many 347C<aio_scandir> is a composite request that consists of many sub
258aio-primitives. C<$maxreq> specifies the maximum number of outstanding 348requests. C<$maxreq> specifies the maximum number of outstanding aio
259aio requests that this function generates. If it is C<< <= 0 >>, then a 349requests that this function generates. If it is C<< <= 0 >>, then a
260suitable default will be chosen (currently 8). 350suitable default will be chosen (currently 8).
261 351
262On error, the callback is called without arguments, otherwise it receives 352On error, the callback is called without arguments, otherwise it receives
263two array-refs with path-relative entry names. 353two array-refs with path-relative entry names.
264 354
273Implementation notes. 363Implementation notes.
274 364
275The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can. 365The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
276 366
277After reading the directory, the modification time, size etc. of the 367After reading the directory, the modification time, size etc. of the
278directory before and after the readdir is checked, and if they match, the 368directory before and after the readdir is checked, and if they match (and
279link count will be used to decide how many entries are directories (if 369isn't the current time), the link count will be used to decide how many
280>= 2). Otherwise, no knowledge of the number of subdirectories will be 370entries are directories (if >= 2). Otherwise, no knowledge of the number
281assumed. 371of subdirectories will be assumed.
282 372
283Then entires will be sorted into likely directories (everything without a 373Then entries will be sorted into likely directories (everything without
284non-initial dot) and likely non-directories (everything else). Then every 374a non-initial dot currently) and likely non-directories (everything
285entry + C</.> will be C<stat>'ed, likely directories first. This is often 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
286faster because filesystems might detect the type of the entry without 379filesystems might detect the type of the entry without reading the inode
287reading the inode data (e.g. ext2s filetype feature). If that succeeds, 380data (e.g. ext2fs filetype feature).
288it assumes that the entry is a directory or a symlink to directory (which
289will be checked seperately).
290 381
291If the known number of directories has been reached, the rest of the 382If the known number of directories (link count - 2) has been reached, the
292entries is assumed to be non-directories. 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.
293 391
294=cut 392=cut
295 393
296sub aio_scandir($$$) { 394sub aio_scandir($$$) {
297 my ($path, $maxreq, $cb) = @_; 395 my ($path, $maxreq, $cb) = @_;
298 396
299 $maxreq = 8 if $maxreq <= 0; 397 $maxreq = 8 if $maxreq <= 0;
300 398
301 # stat once 399 # stat once
302 aio_stat $path, sub { 400 aio_stat $path, sub {
303 $cb->() if $_[0]; 401 return $cb->() if $_[0];
402 my $now = time;
304 my $hash1 = join ":", (stat _)[0,1,3,7,9]; 403 my $hash1 = join ":", (stat _)[0,1,3,7,9];
305 404
306 # read the directory entries 405 # read the directory entries
307 aio_readdir $path, sub { 406 aio_readdir $path, sub {
308 my $entries = shift 407 my $entries = shift
313 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 412 my $hash2 = join ":", (stat _)[0,1,3,7,9];
314 413
315 my $ndirs; 414 my $ndirs;
316 415
317 # take the slow route if anything looks fishy 416 # take the slow route if anything looks fishy
318 if ($hash1 ne $hash2) { 417 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
319 $ndirs = -1; 418 $ndirs = -1;
320 } else { 419 } else {
321 # if nlink == 2, we are finished 420 # if nlink == 2, we are finished
322 # on non-posix-fs's, we rely on nlink < 2 421 # on non-posix-fs's, we rely on nlink < 2
323 $ndirs = (stat _)[3] - 2 422 $ndirs = (stat _)[3] - 2
396callback with the fdatasync result code. 495callback with the fdatasync result code.
397 496
398If 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
399detected, it will be emulated by calling C<fsync> instead. 498detected, it will be emulated by calling C<fsync> instead.
400 499
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.
531
401=back 532=back
402 533
403=head2 SUPPORT FUNCTIONS 534=head2 SUPPORT FUNCTIONS
404 535
405=over 4 536=over 4
532} 663}
533 664
5341; 6651;
535 666
536=head2 FORK BEHAVIOUR 667=head2 FORK BEHAVIOUR
668
669This module should do "the right thing" when the process using it forks:
537 670
538Before the fork, IO::AIO enters a quiescent state where no requests 671Before the fork, IO::AIO enters a quiescent state where no requests
539can 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
540the fork the parent simply leaves the quiescent state and continues 673the fork the parent simply leaves the quiescent state and continues
541request/result processing, while the child clears the request/result 674request/result processing, while the child clears the request/result
542queue (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
543the 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
544parent process has been reached again. 677parent process has been reached again.
545 678
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
546=head1 SEE ALSO 683=head1 SEE ALSO
547 684
548L<Coro>, L<Linux::AIO>. 685L<Coro>, L<Linux::AIO> (obsolete).
549 686
550=head1 AUTHOR 687=head1 AUTHOR
551 688
552 Marc Lehmann <schmorp@schmorp.de> 689 Marc Lehmann <schmorp@schmorp.de>
553 http://home.schmorp.de/ 690 http://home.schmorp.de/

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