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Revision 1.85 by root, Sat Oct 28 01:40:30 2006 UTC vs.
Revision 1.106 by root, Fri Jun 1 05:51:21 2007 UTC

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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
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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
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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
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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 = '2.4';
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
200 aio_move aio_copy aio_group aio_nop aio_mknod aio_load aio_rmtree aio_mkdir
152 aio_copy aio_group aio_nop aio_mknod); 201 aio_chown aio_chmod aio_utime);
153 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); 202 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block));
154 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 203 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
155 min_parallel max_parallel nreqs nready npending); 204 min_parallel max_parallel max_idle
205 nreqs nready npending nthreads
206 max_poll_time max_poll_reqs);
156 207
157 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 208 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
158 209
159 require XSLoader; 210 require XSLoader;
160 XSLoader::load ("IO::AIO", $VERSION); 211 XSLoader::load ("IO::AIO", $VERSION);
161} 212}
162 213
163=head1 FUNCTIONS 214=head1 FUNCTIONS
164 215
165=head2 AIO FUNCTIONS 216=head2 AIO REQUEST FUNCTIONS
166 217
167All the C<aio_*> calls are more or less thin wrappers around the syscall 218All the C<aio_*> calls are more or less thin wrappers around the syscall
168with the same name (sans C<aio_>). The arguments are similar or identical, 219with the same name (sans C<aio_>). The arguments are similar or identical,
169and they all accept an additional (and optional) C<$callback> argument 220and they all accept an additional (and optional) C<$callback> argument
170which must be a code reference. This code reference will get called with 221which must be a code reference. This code reference will get called with
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173syscall has been executed asynchronously. 224syscall has been executed asynchronously.
174 225
175All functions expecting a filehandle keep a copy of the filehandle 226All functions expecting a filehandle keep a copy of the filehandle
176internally until the request has finished. 227internally until the request has finished.
177 228
178All requests return objects of type L<IO::AIO::REQ> that allow further 229All functions return request objects of type L<IO::AIO::REQ> that allow
179manipulation of those requests while they are in-flight. 230further manipulation of those requests while they are in-flight.
180 231
181The pathnames you pass to these routines I<must> be absolute and 232The 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 233encoded as octets. The reason for the former is that at the time the
183request is being executed, the current working directory could have 234request is being executed, the current working directory could have
184changed. Alternatively, you can make sure that you never change the 235changed. Alternatively, you can make sure that you never change the
185current working directory. 236current working directory anywhere in the program and then use relative
237paths.
186 238
187To encode pathnames to byte form, either make sure you either: a) 239To encode pathnames as octets, either make sure you either: a) always pass
188always pass in filenames you got from outside (command line, readdir 240in 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 241tinkering, 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 242your pathnames to the locale (or other) encoding in effect in the user
191environment, d) use Glib::filename_from_unicode on unicode filenames or e) 243environment, d) use Glib::filename_from_unicode on unicode filenames or e)
192use something else. 244use something else to ensure your scalar has the correct contents.
245
246This works, btw. independent of the internal UTF-8 bit, which IO::AIO
247handles correctly wether it is set or not.
193 248
194=over 4 249=over 4
195 250
196=item $prev_pri = aioreq_pri [$pri] 251=item $prev_pri = aioreq_pri [$pri]
197 252
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217 aio_read $_[0], ..., sub { 272 aio_read $_[0], ..., sub {
218 ... 273 ...
219 }; 274 };
220 }; 275 };
221 276
277
222=item aioreq_nice $pri_adjust 278=item aioreq_nice $pri_adjust
223 279
224Similar to C<aioreq_pri>, but subtracts the given value from the current 280Similar to C<aioreq_pri>, but subtracts the given value from the current
225priority, so effects are cumulative. 281priority, so the effect is cumulative.
282
226 283
227=item aio_open $pathname, $flags, $mode, $callback->($fh) 284=item aio_open $pathname, $flags, $mode, $callback->($fh)
228 285
229Asynchronously open or create a file and call the callback with a newly 286Asynchronously open or create a file and call the callback with a newly
230created filehandle for the file. 287created filehandle for the file.
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236list. They are the same as used by C<sysopen>. 293list. They are the same as used by C<sysopen>.
237 294
238Likewise, C<$mode> specifies the mode of the newly created file, if it 295Likewise, C<$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>, 296didn'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, 297except 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). 298and C<0666> or C<0777> if you do). Note that the C<$mode> will be modified
299by the umask in effect then the request is being executed, so better never
300change the umask.
242 301
243Example: 302Example:
244 303
245 aio_open "/etc/passwd", O_RDONLY, 0, sub { 304 aio_open "/etc/passwd", O_RDONLY, 0, sub {
246 if ($_[0]) { 305 if ($_[0]) {
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249 } else { 308 } else {
250 die "open failed: $!\n"; 309 die "open failed: $!\n";
251 } 310 }
252 }; 311 };
253 312
313
254=item aio_close $fh, $callback->($status) 314=item aio_close $fh, $callback->($status)
255 315
256Asynchronously close a file and call the callback with the result 316Asynchronously close a file and call the callback with the result
257code. I<WARNING:> although accepted, you should not pass in a perl 317code. I<WARNING:> although accepted, you should not pass in a perl
258filehandle here, as perl will likely close the file descriptor another 318filehandle here, as perl will likely close the file descriptor another
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260C<close> or just let filehandles go out of scope. 320C<close> or just let filehandles go out of scope.
261 321
262This is supposed to be a bug in the API, so that might change. It's 322This is supposed to be a bug in the API, so that might change. It's
263therefore best to avoid this function. 323therefore best to avoid this function.
264 324
325
265=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 326=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
266 327
267=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 328=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
268 329
269Reads or writes C<length> bytes from the specified C<fh> and C<offset> 330Reads or writes C<length> bytes from the specified C<fh> and C<offset>
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280 341
281 aio_read $fh, 7, 15, $buffer, 0, sub { 342 aio_read $fh, 7, 15, $buffer, 0, sub {
282 $_[0] > 0 or die "read error: $!"; 343 $_[0] > 0 or die "read error: $!";
283 print "read $_[0] bytes: <$buffer>\n"; 344 print "read $_[0] bytes: <$buffer>\n";
284 }; 345 };
346
285 347
286=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) 348=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
287 349
288Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts 350Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
289reading at byte offset C<$in_offset>, and starts writing at the current 351reading at byte offset C<$in_offset>, and starts writing at the current
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303C<$in_fh> than are written, and there is no way to find out how many 365C<$in_fh> than are written, and there is no way to find out how many
304bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only 366bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
305provides the number of bytes written to C<$out_fh>. Only if the result 367provides the number of bytes written to C<$out_fh>. Only if the result
306value equals C<$length> one can assume that C<$length> bytes have been 368value equals C<$length> one can assume that C<$length> bytes have been
307read. 369read.
370
308 371
309=item aio_readahead $fh,$offset,$length, $callback->($retval) 372=item aio_readahead $fh,$offset,$length, $callback->($retval)
310 373
311C<aio_readahead> populates the page cache with data from a file so that 374C<aio_readahead> populates the page cache with data from a file so that
312subsequent reads from that file will not block on disk I/O. The C<$offset> 375subsequent reads from that file will not block on disk I/O. The C<$offset>
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318file. The current file offset of the file is left unchanged. 381file. The current file offset of the file is left unchanged.
319 382
320If that syscall doesn't exist (likely if your OS isn't Linux) it will be 383If that syscall doesn't exist (likely if your OS isn't Linux) it will be
321emulated by simply reading the data, which would have a similar effect. 384emulated by simply reading the data, which would have a similar effect.
322 385
386
323=item aio_stat $fh_or_path, $callback->($status) 387=item aio_stat $fh_or_path, $callback->($status)
324 388
325=item aio_lstat $fh, $callback->($status) 389=item aio_lstat $fh, $callback->($status)
326 390
327Works like perl's C<stat> or C<lstat> in void context. The callback will 391Works like perl's C<stat> or C<lstat> in void context. The callback will
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340 aio_stat "/etc/passwd", sub { 404 aio_stat "/etc/passwd", sub {
341 $_[0] and die "stat failed: $!"; 405 $_[0] and die "stat failed: $!";
342 print "size is ", -s _, "\n"; 406 print "size is ", -s _, "\n";
343 }; 407 };
344 408
409
410=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
411
412Works like perl's C<utime> function (including the special case of $atime
413and $mtime being undef). Fractional times are supported if the underlying
414syscalls support them.
415
416When called with a pathname, uses utimes(2) if available, otherwise
417utime(2). If called on a file descriptor, uses futimes(2) if available,
418otherwise returns ENOSYS, so this is not portable.
419
420Examples:
421
422 # set atime and mtime to current time:
423 aio_utime "path", undef, undef;
424 # set atime to current time and mtime to beginning of the epoch:
425 aio_utime "path", time, undef; # undef==0
426
427
428=item aio_chown $fh_or_path, $uid, $gid, $callback->($status)
429
430Works like perl's C<chown> function, except that C<undef> for either $uid
431or $gid is being interpreted as "do not change" (but -1 can also be used).
432
433Examples:
434
435 # same as "chown root path" in the shell:
436 aio_chown "path", 0, -1;
437 # same as above:
438 aio_chown "path", 0, undef;
439
440
441=item aio_chmod $fh_or_path, $mode, $callback->($status)
442
443Works like perl's C<chmod> function.
444
445
345=item aio_unlink $pathname, $callback->($status) 446=item aio_unlink $pathname, $callback->($status)
346 447
347Asynchronously unlink (delete) a file and call the callback with the 448Asynchronously unlink (delete) a file and call the callback with the
348result code. 449result code.
349 450
451
350=item aio_mknod $path, $mode, $dev, $callback->($status) 452=item aio_mknod $path, $mode, $dev, $callback->($status)
351 453
454[EXPERIMENTAL]
455
352Asynchronously create a device node (or fifo). See mknod(2). 456Asynchronously create a device node (or fifo). See mknod(2).
353 457
354The only portable (POSIX) way of calling this function is: 458The only (POSIX-) portable way of calling this function is:
355 459
356 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... 460 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...
461
357 462
358=item aio_link $srcpath, $dstpath, $callback->($status) 463=item aio_link $srcpath, $dstpath, $callback->($status)
359 464
360Asynchronously create a new link to the existing object at C<$srcpath> at 465Asynchronously create a new link to the existing object at C<$srcpath> at
361the path C<$dstpath> and call the callback with the result code. 466the path C<$dstpath> and call the callback with the result code.
362 467
468
363=item aio_symlink $srcpath, $dstpath, $callback->($status) 469=item aio_symlink $srcpath, $dstpath, $callback->($status)
364 470
365Asynchronously create a new symbolic link to the existing object at C<$srcpath> at 471Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
366the path C<$dstpath> and call the callback with the result code. 472the path C<$dstpath> and call the callback with the result code.
367 473
474
475=item aio_readlink $path, $callback->($link)
476
477Asynchronously read the symlink specified by C<$path> and pass it to
478the callback. If an error occurs, nothing or undef gets passed to the
479callback.
480
481
368=item aio_rename $srcpath, $dstpath, $callback->($status) 482=item aio_rename $srcpath, $dstpath, $callback->($status)
369 483
370Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as 484Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
371rename(2) and call the callback with the result code. 485rename(2) and call the callback with the result code.
372 486
487
488=item aio_mkdir $pathname, $mode, $callback->($status)
489
490Asynchronously mkdir (create) a directory and call the callback with
491the result code. C<$mode> will be modified by the umask at the time the
492request is executed, so do not change your umask.
493
494
373=item aio_rmdir $pathname, $callback->($status) 495=item aio_rmdir $pathname, $callback->($status)
374 496
375Asynchronously rmdir (delete) a directory and call the callback with the 497Asynchronously rmdir (delete) a directory and call the callback with the
376result code. 498result code.
499
377 500
378=item aio_readdir $pathname, $callback->($entries) 501=item aio_readdir $pathname, $callback->($entries)
379 502
380Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 503Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
381directory (i.e. opendir + readdir + closedir). The entries will not be 504directory (i.e. opendir + readdir + closedir). The entries will not be
382sorted, and will B<NOT> include the C<.> and C<..> entries. 505sorted, and will B<NOT> include the C<.> and C<..> entries.
383 506
384The callback a single argument which is either C<undef> or an array-ref 507The callback a single argument which is either C<undef> or an array-ref
385with the filenames. 508with the filenames.
509
510
511=item aio_load $path, $data, $callback->($status)
512
513This is a composite request that tries to fully load the given file into
514memory. Status is the same as with aio_read.
515
516=cut
517
518sub aio_load($$;$) {
519 aio_block {
520 my ($path, undef, $cb) = @_;
521 my $data = \$_[1];
522
523 my $pri = aioreq_pri;
524 my $grp = aio_group $cb;
525
526 aioreq_pri $pri;
527 add $grp aio_open $path, O_RDONLY, 0, sub {
528 my $fh = shift
529 or return $grp->result (-1);
530
531 aioreq_pri $pri;
532 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
533 $grp->result ($_[0]);
534 };
535 };
536
537 $grp
538 }
539}
386 540
387=item aio_copy $srcpath, $dstpath, $callback->($status) 541=item aio_copy $srcpath, $dstpath, $callback->($status)
388 542
389Try to copy the I<file> (directories not supported as either source or 543Try to copy the I<file> (directories not supported as either source or
390destination) from C<$srcpath> to C<$dstpath> and call the callback with 544destination) from C<$srcpath> to C<$dstpath> and call the callback with
… …
400errors are being ignored. 554errors are being ignored.
401 555
402=cut 556=cut
403 557
404sub aio_copy($$;$) { 558sub aio_copy($$;$) {
559 aio_block {
405 my ($src, $dst, $cb) = @_; 560 my ($src, $dst, $cb) = @_;
406 561
407 my $pri = aioreq_pri; 562 my $pri = aioreq_pri;
408 my $grp = aio_group $cb; 563 my $grp = aio_group $cb;
409 564
410 aioreq_pri $pri; 565 aioreq_pri $pri;
411 add $grp aio_open $src, O_RDONLY, 0, sub { 566 add $grp aio_open $src, O_RDONLY, 0, sub {
412 if (my $src_fh = $_[0]) { 567 if (my $src_fh = $_[0]) {
413 my @stat = stat $src_fh; 568 my @stat = stat $src_fh;
414 569
415 aioreq_pri $pri; 570 aioreq_pri $pri;
416 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub { 571 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
417 if (my $dst_fh = $_[0]) { 572 if (my $dst_fh = $_[0]) {
418 aioreq_pri $pri; 573 aioreq_pri $pri;
419 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 574 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
420 if ($_[0] == $stat[7]) { 575 if ($_[0] == $stat[7]) {
421 $grp->result (0); 576 $grp->result (0);
422 close $src_fh; 577 close $src_fh;
423 578
424 # those should not normally block. should. should. 579 # those should not normally block. should. should.
425 utime $stat[8], $stat[9], $dst; 580 utime $stat[8], $stat[9], $dst;
426 chmod $stat[2] & 07777, $dst_fh; 581 chmod $stat[2] & 07777, $dst_fh;
427 chown $stat[4], $stat[5], $dst_fh; 582 chown $stat[4], $stat[5], $dst_fh;
428 close $dst_fh; 583 close $dst_fh;
429 } else { 584 } else {
430 $grp->result (-1); 585 $grp->result (-1);
431 close $src_fh; 586 close $src_fh;
432 close $dst_fh; 587 close $dst_fh;
433 588
434 aioreq $pri; 589 aioreq $pri;
435 add $grp aio_unlink $dst; 590 add $grp aio_unlink $dst;
591 }
436 } 592 };
593 } else {
594 $grp->result (-1);
437 }; 595 }
438 } else {
439 $grp->result (-1);
440 } 596 },
597
598 } else {
599 $grp->result (-1);
441 }, 600 }
442
443 } else {
444 $grp->result (-1);
445 } 601 };
602
603 $grp
446 }; 604 }
447
448 $grp
449} 605}
450 606
451=item aio_move $srcpath, $dstpath, $callback->($status) 607=item aio_move $srcpath, $dstpath, $callback->($status)
452 608
453Try to move the I<file> (directories not supported as either source or 609Try to move the I<file> (directories not supported as either source or
… …
459that is successful, unlinking the C<$srcpath>. 615that is successful, unlinking the C<$srcpath>.
460 616
461=cut 617=cut
462 618
463sub aio_move($$;$) { 619sub aio_move($$;$) {
620 aio_block {
464 my ($src, $dst, $cb) = @_; 621 my ($src, $dst, $cb) = @_;
465 622
466 my $pri = aioreq_pri; 623 my $pri = aioreq_pri;
467 my $grp = aio_group $cb; 624 my $grp = aio_group $cb;
468 625
469 aioreq_pri $pri; 626 aioreq_pri $pri;
470 add $grp aio_rename $src, $dst, sub { 627 add $grp aio_rename $src, $dst, sub {
471 if ($_[0] && $! == EXDEV) { 628 if ($_[0] && $! == EXDEV) {
472 aioreq_pri $pri; 629 aioreq_pri $pri;
473 add $grp aio_copy $src, $dst, sub { 630 add $grp aio_copy $src, $dst, sub {
631 $grp->result ($_[0]);
632
633 if (!$_[0]) {
634 aioreq_pri $pri;
635 add $grp aio_unlink $src;
636 }
637 };
638 } else {
474 $grp->result ($_[0]); 639 $grp->result ($_[0]);
475
476 if (!$_[0]) {
477 aioreq_pri $pri;
478 add $grp aio_unlink $src;
479 }
480 }; 640 }
481 } else {
482 $grp->result ($_[0]);
483 } 641 };
642
643 $grp
484 }; 644 }
485
486 $grp
487} 645}
488 646
489=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 647=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
490 648
491Scans a directory (similar to C<aio_readdir>) but additionally tries to 649Scans 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 696as those tend to return 0 or 1 as link counts, which disables the
539directory counting heuristic. 697directory counting heuristic.
540 698
541=cut 699=cut
542 700
543sub aio_scandir($$$) { 701sub aio_scandir($$;$) {
702 aio_block {
544 my ($path, $maxreq, $cb) = @_; 703 my ($path, $maxreq, $cb) = @_;
545 704
546 my $pri = aioreq_pri; 705 my $pri = aioreq_pri;
547 706
548 my $grp = aio_group $cb; 707 my $grp = aio_group $cb;
549 708
550 $maxreq = 4 if $maxreq <= 0; 709 $maxreq = 4 if $maxreq <= 0;
551 710
552 # stat once 711 # 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; 712 aioreq_pri $pri;
561 add $grp aio_readdir $path, sub { 713 add $grp aio_stat $path, sub {
562 my $entries = shift
563 or return $grp->result (); 714 return $grp->result () if $_[0];
715 my $now = time;
716 my $hash1 = join ":", (stat _)[0,1,3,7,9];
564 717
565 # stat the dir another time 718 # read the directory entries
566 aioreq_pri $pri; 719 aioreq_pri $pri;
720 add $grp aio_readdir $path, sub {
721 my $entries = shift
722 or return $grp->result ();
723
724 # stat the dir another time
725 aioreq_pri $pri;
567 add $grp aio_stat $path, sub { 726 add $grp aio_stat $path, sub {
568 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 727 my $hash2 = join ":", (stat _)[0,1,3,7,9];
569 728
570 my $ndirs; 729 my $ndirs;
571 730
572 # take the slow route if anything looks fishy 731 # take the slow route if anything looks fishy
573 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 732 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
574 $ndirs = -1; 733 $ndirs = -1;
575 } else { 734 } else {
576 # if nlink == 2, we are finished 735 # if nlink == 2, we are finished
577 # on non-posix-fs's, we rely on nlink < 2 736 # on non-posix-fs's, we rely on nlink < 2
578 $ndirs = (stat _)[3] - 2 737 $ndirs = (stat _)[3] - 2
579 or return $grp->result ([], $entries); 738 or return $grp->result ([], $entries);
580 } 739 }
581 740
582 # sort into likely dirs and likely nondirs 741 # sort into likely dirs and likely nondirs
583 # dirs == files without ".", short entries first 742 # dirs == files without ".", short entries first
584 $entries = [map $_->[0], 743 $entries = [map $_->[0],
585 sort { $b->[1] cmp $a->[1] } 744 sort { $b->[1] cmp $a->[1] }
586 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length], 745 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
587 @$entries]; 746 @$entries];
588 747
589 my (@dirs, @nondirs); 748 my (@dirs, @nondirs);
590 749
591 my $statgrp = add $grp aio_group sub { 750 my $statgrp = add $grp aio_group sub {
592 $grp->result (\@dirs, \@nondirs); 751 $grp->result (\@dirs, \@nondirs);
593 }; 752 };
594 753
595 limit $statgrp $maxreq; 754 limit $statgrp $maxreq;
596 feed $statgrp sub { 755 feed $statgrp sub {
597 return unless @$entries; 756 return unless @$entries;
598 my $entry = pop @$entries; 757 my $entry = pop @$entries;
599 758
600 aioreq_pri $pri; 759 aioreq_pri $pri;
601 add $statgrp aio_stat "$path/$entry/.", sub { 760 add $statgrp aio_stat "$path/$entry/.", sub {
602 if ($_[0] < 0) { 761 if ($_[0] < 0) {
603 push @nondirs, $entry; 762 push @nondirs, $entry;
604 } else { 763 } else {
605 # need to check for real directory 764 # need to check for real directory
606 aioreq_pri $pri; 765 aioreq_pri $pri;
607 add $statgrp aio_lstat "$path/$entry", sub { 766 add $statgrp aio_lstat "$path/$entry", sub {
608 if (-d _) { 767 if (-d _) {
609 push @dirs, $entry; 768 push @dirs, $entry;
610 769
611 unless (--$ndirs) { 770 unless (--$ndirs) {
612 push @nondirs, @$entries; 771 push @nondirs, @$entries;
613 feed $statgrp; 772 feed $statgrp;
773 }
774 } else {
775 push @nondirs, $entry;
614 } 776 }
615 } else {
616 push @nondirs, $entry;
617 } 777 }
618 } 778 }
619 } 779 };
620 }; 780 };
621 }; 781 };
622 }; 782 };
623 }; 783 };
784
785 $grp
624 }; 786 }
787}
625 788
789=item aio_rmtree $path, $callback->($status)
790
791Delete a directory tree starting (and including) C<$path>, return the
792status of the final C<rmdir> only. This is a composite request that
793uses C<aio_scandir> to recurse into and rmdir directories, and unlink
794everything else.
795
796=cut
797
798sub aio_rmtree;
799sub aio_rmtree($;$) {
800 aio_block {
801 my ($path, $cb) = @_;
802
803 my $pri = aioreq_pri;
804 my $grp = aio_group $cb;
805
806 aioreq_pri $pri;
807 add $grp aio_scandir $path, 0, sub {
808 my ($dirs, $nondirs) = @_;
809
810 my $dirgrp = aio_group sub {
811 add $grp aio_rmdir $path, sub {
812 $grp->result ($_[0]);
813 };
814 };
815
816 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
817 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
818
819 add $grp $dirgrp;
820 };
821
626 $grp 822 $grp
823 }
627} 824}
628 825
629=item aio_fsync $fh, $callback->($status) 826=item aio_fsync $fh, $callback->($status)
630 827
631Asynchronously call fsync on the given filehandle and call the callback 828Asynchronously call fsync on the given filehandle and call the callback
… …
845 1042
846=back 1043=back
847 1044
848=head2 SUPPORT FUNCTIONS 1045=head2 SUPPORT FUNCTIONS
849 1046
1047=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
1048
850=over 4 1049=over 4
851 1050
852=item $fileno = IO::AIO::poll_fileno 1051=item $fileno = IO::AIO::poll_fileno
853 1052
854Return the I<request result pipe file descriptor>. This filehandle must be 1053Return the I<request result pipe file descriptor>. This filehandle must be
… …
858 1057
859See C<poll_cb> for an example. 1058See C<poll_cb> for an example.
860 1059
861=item IO::AIO::poll_cb 1060=item IO::AIO::poll_cb
862 1061
863Process all outstanding events on the result pipe. You have to call this 1062Process some outstanding events on the result pipe. You have to call this
864regularly. Returns the number of events processed. Returns immediately 1063regularly. Returns the number of events processed. Returns immediately
865when no events are outstanding. 1064when no events are outstanding. The amount of events processed depends on
1065the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
866 1066
867If not all requests were processed for whatever reason, the filehandle 1067If not all requests were processed for whatever reason, the filehandle
868will still be ready when C<poll_cb> returns. 1068will still be ready when C<poll_cb> returns.
869 1069
870Example: Install an Event watcher that automatically calls 1070Example: Install an Event watcher that automatically calls
… …
872 1072
873 Event->io (fd => IO::AIO::poll_fileno, 1073 Event->io (fd => IO::AIO::poll_fileno,
874 poll => 'r', async => 1, 1074 poll => 'r', async => 1,
875 cb => \&IO::AIO::poll_cb); 1075 cb => \&IO::AIO::poll_cb);
876 1076
877=item IO::AIO::poll_some $max_requests 1077=item IO::AIO::max_poll_reqs $nreqs
878 1078
879Similar to C<poll_cb>, but only processes up to C<$max_requests> requests 1079=item IO::AIO::max_poll_time $seconds
880at a time.
881 1080
882Useful if you want to ensure some level of interactiveness when perl is 1081These set the maximum number of requests (default C<0>, meaning infinity)
883not fast enough to process all requests in time. 1082that are being processed by C<IO::AIO::poll_cb> in one call, respectively
1083the maximum amount of time (default C<0>, meaning infinity) spent in
1084C<IO::AIO::poll_cb> to process requests (more correctly the mininum amount
1085of time C<poll_cb> is allowed to use).
1086
1087Setting C<max_poll_time> to a non-zero value creates an overhead of one
1088syscall per request processed, which is not normally a problem unless your
1089callbacks are really really fast or your OS is really really slow (I am
1090not mentioning Solaris here). Using C<max_poll_reqs> incurs no overhead.
1091
1092Setting these is useful if you want to ensure some level of
1093interactiveness when perl is not fast enough to process all requests in
1094time.
1095
1096For interactive programs, values such as C<0.01> to C<0.1> should be fine.
884 1097
885Example: Install an Event watcher that automatically calls 1098Example: Install an Event watcher that automatically calls
886IO::AIO::poll_some with low priority, to ensure that other parts of the 1099IO::AIO::poll_cb with low priority, to ensure that other parts of the
887program get the CPU sometimes even under high AIO load. 1100program get the CPU sometimes even under high AIO load.
888 1101
1102 # try not to spend much more than 0.1s in poll_cb
1103 IO::AIO::max_poll_time 0.1;
1104
1105 # use a low priority so other tasks have priority
889 Event->io (fd => IO::AIO::poll_fileno, 1106 Event->io (fd => IO::AIO::poll_fileno,
890 poll => 'r', nice => 1, 1107 poll => 'r', nice => 1,
891 cb => sub { IO::AIO::poll_some 256 }); 1108 cb => &IO::AIO::poll_cb);
892 1109
893=item IO::AIO::poll_wait 1110=item IO::AIO::poll_wait
894 1111
1112If there are any outstanding requests and none of them in the result
895Wait till the result filehandle becomes ready for reading (simply does a 1113phase, wait till the result filehandle becomes ready for reading (simply
896C<select> on the filehandle. This is useful if you want to synchronously wait 1114does a C<select> on the filehandle. This is useful if you want to
897for some requests to finish). 1115synchronously wait for some requests to finish).
898 1116
899See C<nreqs> for an example. 1117See C<nreqs> for an example.
900 1118
1119=item IO::AIO::poll
1120
1121Waits until some requests have been handled.
1122
1123Returns the number of requests processed, but is otherwise strictly
1124equivalent to:
1125
1126 IO::AIO::poll_wait, IO::AIO::poll_cb
1127
901=item IO::AIO::nreqs 1128=item IO::AIO::flush
902 1129
903Returns the number of requests currently in the ready, execute or pending 1130Wait till all outstanding AIO requests have been handled.
904states (i.e. for which their callback has not been invoked yet).
905 1131
906Example: wait till there are no outstanding requests anymore: 1132Strictly equivalent to:
907 1133
908 IO::AIO::poll_wait, IO::AIO::poll_cb 1134 IO::AIO::poll_wait, IO::AIO::poll_cb
909 while IO::AIO::nreqs; 1135 while IO::AIO::nreqs;
910 1136
911=item IO::AIO::nready 1137=back
912 1138
913Returns the number of requests currently in the ready state (not yet 1139=head3 CONTROLLING THE NUMBER OF THREADS
914executed).
915 1140
916=item IO::AIO::npending 1141=over
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 1142
939=item IO::AIO::min_parallel $nthreads 1143=item IO::AIO::min_parallel $nthreads
940 1144
941Set the minimum number of AIO threads to C<$nthreads>. The current 1145Set the minimum number of AIO threads to C<$nthreads>. The current
942default is C<8>, which means eight asynchronous operations can execute 1146default is C<8>, which means eight asynchronous operations can execute
943concurrently at any one time (the number of outstanding requests, 1147concurrently at any one time (the number of outstanding requests,
944however, is unlimited). 1148however, is unlimited).
945 1149
946IO::AIO starts threads only on demand, when an AIO request is queued and 1150IO::AIO starts threads only on demand, when an AIO request is queued and
947no free thread exists. 1151no free thread exists. Please note that queueing up a hundred requests can
1152create demand for a hundred threads, even if it turns out that everything
1153is in the cache and could have been processed faster by a single thread.
948 1154
949It is recommended to keep the number of threads relatively low, as some 1155It is recommended to keep the number of threads relatively low, as some
950Linux kernel versions will scale negatively with the number of threads 1156Linux kernel versions will scale negatively with the number of threads
951(higher parallelity => MUCH higher latency). With current Linux 2.6 1157(higher parallelity => MUCH higher latency). With current Linux 2.6
952versions, 4-32 threads should be fine. 1158versions, 4-32 threads should be fine.
… …
966This module automatically runs C<max_parallel 0> at program end, to ensure 1172This module automatically runs C<max_parallel 0> at program end, to ensure
967that all threads are killed and that there are no outstanding requests. 1173that all threads are killed and that there are no outstanding requests.
968 1174
969Under normal circumstances you don't need to call this function. 1175Under normal circumstances you don't need to call this function.
970 1176
1177=item IO::AIO::max_idle $nthreads
1178
1179Limit the number of threads (default: 4) that are allowed to idle (i.e.,
1180threads that did not get a request to process within 10 seconds). That
1181means if a thread becomes idle while C<$nthreads> other threads are also
1182idle, it will free its resources and exit.
1183
1184This is useful when you allow a large number of threads (e.g. 100 or 1000)
1185to allow for extremely high load situations, but want to free resources
1186under normal circumstances (1000 threads can easily consume 30MB of RAM).
1187
1188The default is probably ok in most situations, especially if thread
1189creation is fast. If thread creation is very slow on your system you might
1190want to use larger values.
1191
971=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1192=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs
972 1193
973This is a very bad function to use in interactive programs because it 1194This 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 1195blocks, and a bad way to reduce concurrency because it is inexact: Better
975use an C<aio_group> together with a feed callback. 1196use an C<aio_group> together with a feed callback.
… …
986C<max_oustsanding> is mainly useful in simple scripts (with low values) or 1207C<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). 1208as a stop gap to shield against fatal memory overflow (with large values).
988 1209
989=back 1210=back
990 1211
1212=head3 STATISTICAL INFORMATION
1213
1214=over
1215
1216=item IO::AIO::nreqs
1217
1218Returns the number of requests currently in the ready, execute or pending
1219states (i.e. for which their callback has not been invoked yet).
1220
1221Example: wait till there are no outstanding requests anymore:
1222
1223 IO::AIO::poll_wait, IO::AIO::poll_cb
1224 while IO::AIO::nreqs;
1225
1226=item IO::AIO::nready
1227
1228Returns the number of requests currently in the ready state (not yet
1229executed).
1230
1231=item IO::AIO::npending
1232
1233Returns the number of requests currently in the pending state (executed,
1234but not yet processed by poll_cb).
1235
1236=back
1237
991=cut 1238=cut
992 1239
993# support function to convert a fd into a perl filehandle 1240# support function to convert a fd into a perl filehandle
994sub _fd2fh { 1241sub _fd2fh {
995 return undef if $_[0] < 0; 1242 return undef if $_[0] < 0;
… …
1006 *$sym 1253 *$sym
1007} 1254}
1008 1255
1009min_parallel 8; 1256min_parallel 8;
1010 1257
1011END { 1258END { flush }
1012 min_parallel 1;
1013 flush;
1014};
1015 1259
10161; 12601;
1017 1261
1018=head2 FORK BEHAVIOUR 1262=head2 FORK BEHAVIOUR
1019 1263

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