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Revision 1.85 by root, Sat Oct 28 01:40:30 2006 UTC vs.
Revision 1.110 by root, Sun Jul 8 09:09:34 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
67using these functions on file descriptors that support nonblocking 68example sockets), using these functions on file descriptors that
68operation (again, sockets, pipes etc.) is very inefficient. Use an event 69support nonblocking operation (again, sockets, pipes etc.) is very
69loop for that (such as the L<Event|Event> module): IO::AIO will naturally 70inefficient. Use an event loop for that (such as the L<Event|Event>
70fit into such an event loop itself. 71module): IO::AIO will naturally fit into such an event loop itself.
71 72
72In this version, a number of threads are started that execute your 73In this version, a number of threads are started that execute your
73requests and signal their completion. You don't need thread support 74requests and signal their completion. You don't need thread support
74in perl, and the threads created by this module will not be visible 75in 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 76to perl. In the future, this module might make use of the native aio
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77not well-supported or restricted (GNU/Linux doesn't allow them on normal 78not well-supported or restricted (GNU/Linux doesn't allow them on normal
78files currently, for example), and they would only support aio_read and 79files currently, for example), and they would only support aio_read and
79aio_write, so the remaining functionality would have to be implemented 80aio_write, so the remaining functionality would have to be implemented
80using threads anyway. 81using threads anyway.
81 82
82Although the module will work with in the presence of other (Perl-) 83Although the module will work in the presence of other (Perl-) threads,
83threads, it is currently not reentrant in any way, so use appropriate 84it is currently not reentrant in any way, so use appropriate locking
84locking yourself, always call C<poll_cb> from within the same thread, or 85yourself, always call C<poll_cb> from within the same thread, or never
85never call C<poll_cb> (or other C<aio_> functions) recursively. 86call C<poll_cb> (or other C<aio_> functions) recursively.
87
88=head2 EXAMPLE
89
90This is a simple example that uses the Event module and loads
91F</etc/passwd> asynchronously:
92
93 use Fcntl;
94 use Event;
95 use IO::AIO;
96
97 # register the IO::AIO callback with Event
98 Event->io (fd => IO::AIO::poll_fileno,
99 poll => 'r',
100 cb => \&IO::AIO::poll_cb);
101
102 # queue the request to open /etc/passwd
103 aio_open "/etc/passwd", O_RDONLY, 0, sub {
104 my $fh = shift
105 or die "error while opening: $!";
106
107 # stat'ing filehandles is generally non-blocking
108 my $size = -s $fh;
109
110 # queue a request to read the file
111 my $contents;
112 aio_read $fh, 0, $size, $contents, 0, sub {
113 $_[0] == $size
114 or die "short read: $!";
115
116 close $fh;
117
118 # file contents now in $contents
119 print $contents;
120
121 # exit event loop and program
122 Event::unloop;
123 };
124 };
125
126 # possibly queue up other requests, or open GUI windows,
127 # check for sockets etc. etc.
128
129 # process events as long as there are some:
130 Event::loop;
86 131
87=head1 REQUEST ANATOMY AND LIFETIME 132=head1 REQUEST ANATOMY AND LIFETIME
88 133
89Every C<aio_*> function creates a request. which is a C data structure not 134Every C<aio_*> function creates a request. which is a C data structure not
90directly visible to Perl. 135directly visible to Perl.
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132Request has reached the end of its lifetime and holds no resources anymore 177Request 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 178(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 179aio request is severed and calling its methods will either do nothing or
135result in a runtime error). 180result in a runtime error).
136 181
182=back
183
137=cut 184=cut
138 185
139package IO::AIO; 186package IO::AIO;
140 187
141no warnings; 188no warnings;
142use strict 'vars'; 189use strict 'vars';
143 190
144use base 'Exporter'; 191use base 'Exporter';
145 192
146BEGIN { 193BEGIN {
147 our $VERSION = '2.0'; 194 our $VERSION = '2.4';
148 195
149 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat 196 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 197 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 198 aio_readlink aio_fsync aio_fdatasync aio_readahead aio_rename aio_link
152 aio_copy aio_group aio_nop aio_mknod); 199 aio_move aio_copy aio_group aio_nop aio_mknod aio_load aio_rmtree aio_mkdir
200 aio_chown aio_chmod aio_utime aio_truncate);
153 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); 201 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block));
154 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 202 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
155 min_parallel max_parallel nreqs nready npending); 203 min_parallel max_parallel max_idle
204 nreqs nready npending nthreads
205 max_poll_time max_poll_reqs);
156 206
157 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 207 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
158 208
159 require XSLoader; 209 require XSLoader;
160 XSLoader::load ("IO::AIO", $VERSION); 210 XSLoader::load ("IO::AIO", $VERSION);
161} 211}
162 212
163=head1 FUNCTIONS 213=head1 FUNCTIONS
164 214
165=head2 AIO FUNCTIONS 215=head2 AIO REQUEST FUNCTIONS
166 216
167All the C<aio_*> calls are more or less thin wrappers around the syscall 217All the C<aio_*> calls are more or less thin wrappers around the syscall
168with the same name (sans C<aio_>). The arguments are similar or identical, 218with the same name (sans C<aio_>). The arguments are similar or identical,
169and they all accept an additional (and optional) C<$callback> argument 219and they all accept an additional (and optional) C<$callback> argument
170which must be a code reference. This code reference will get called with 220which must be a code reference. This code reference will get called with
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173syscall has been executed asynchronously. 223syscall has been executed asynchronously.
174 224
175All functions expecting a filehandle keep a copy of the filehandle 225All functions expecting a filehandle keep a copy of the filehandle
176internally until the request has finished. 226internally until the request has finished.
177 227
178All requests return objects of type L<IO::AIO::REQ> that allow further 228All functions return request objects of type L<IO::AIO::REQ> that allow
179manipulation of those requests while they are in-flight. 229further manipulation of those requests while they are in-flight.
180 230
181The pathnames you pass to these routines I<must> be absolute and 231The pathnames you pass to these routines I<must> be absolute and
182encoded in byte form. The reason for the former is that at the time the 232encoded as octets. The reason for the former is that at the time the
183request is being executed, the current working directory could have 233request is being executed, the current working directory could have
184changed. Alternatively, you can make sure that you never change the 234changed. Alternatively, you can make sure that you never change the
185current working directory. 235current working directory anywhere in the program and then use relative
236paths.
186 237
187To encode pathnames to byte form, either make sure you either: a) 238To encode pathnames as octets, either make sure you either: a) always pass
188always pass in filenames you got from outside (command line, readdir 239in filenames you got from outside (command line, readdir etc.) without
189etc.), b) are ASCII or ISO 8859-1, c) use the Encode module and encode 240tinkering, b) are ASCII or ISO 8859-1, c) use the Encode module and encode
190your pathnames to the locale (or other) encoding in effect in the user 241your pathnames to the locale (or other) encoding in effect in the user
191environment, d) use Glib::filename_from_unicode on unicode filenames or e) 242environment, d) use Glib::filename_from_unicode on unicode filenames or e)
192use something else. 243use something else to ensure your scalar has the correct contents.
244
245This works, btw. independent of the internal UTF-8 bit, which IO::AIO
246handles correctly wether it is set or not.
193 247
194=over 4 248=over 4
195 249
196=item $prev_pri = aioreq_pri [$pri] 250=item $prev_pri = aioreq_pri [$pri]
197 251
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217 aio_read $_[0], ..., sub { 271 aio_read $_[0], ..., sub {
218 ... 272 ...
219 }; 273 };
220 }; 274 };
221 275
276
222=item aioreq_nice $pri_adjust 277=item aioreq_nice $pri_adjust
223 278
224Similar to C<aioreq_pri>, but subtracts the given value from the current 279Similar to C<aioreq_pri>, but subtracts the given value from the current
225priority, so effects are cumulative. 280priority, so the effect is cumulative.
281
226 282
227=item aio_open $pathname, $flags, $mode, $callback->($fh) 283=item aio_open $pathname, $flags, $mode, $callback->($fh)
228 284
229Asynchronously open or create a file and call the callback with a newly 285Asynchronously open or create a file and call the callback with a newly
230created filehandle for the file. 286created filehandle for the file.
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236list. They are the same as used by C<sysopen>. 292list. They are the same as used by C<sysopen>.
237 293
238Likewise, C<$mode> specifies the mode of the newly created file, if it 294Likewise, C<$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>, 295didn'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, 296except 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). 297and C<0666> or C<0777> if you do). Note that the C<$mode> will be modified
298by the umask in effect then the request is being executed, so better never
299change the umask.
242 300
243Example: 301Example:
244 302
245 aio_open "/etc/passwd", O_RDONLY, 0, sub { 303 aio_open "/etc/passwd", O_RDONLY, 0, sub {
246 if ($_[0]) { 304 if ($_[0]) {
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249 } else { 307 } else {
250 die "open failed: $!\n"; 308 die "open failed: $!\n";
251 } 309 }
252 }; 310 };
253 311
312
254=item aio_close $fh, $callback->($status) 313=item aio_close $fh, $callback->($status)
255 314
256Asynchronously close a file and call the callback with the result 315Asynchronously close a file and call the callback with the result
257code. I<WARNING:> although accepted, you should not pass in a perl 316code. I<WARNING:> although accepted, you should not pass in a perl
258filehandle here, as perl will likely close the file descriptor another 317filehandle here, as perl will likely close the file descriptor another
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260C<close> or just let filehandles go out of scope. 319C<close> or just let filehandles go out of scope.
261 320
262This is supposed to be a bug in the API, so that might change. It's 321This is supposed to be a bug in the API, so that might change. It's
263therefore best to avoid this function. 322therefore best to avoid this function.
264 323
324
265=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 325=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
266 326
267=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 327=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
268 328
269Reads or writes C<length> bytes from the specified C<fh> and C<offset> 329Reads or writes C<$length> bytes from the specified C<$fh> and C<$offset>
270into the scalar given by C<data> and offset C<dataoffset> and calls the 330into the scalar given by C<$data> and offset C<$dataoffset> and calls the
271callback without the actual number of bytes read (or -1 on error, just 331callback without the actual number of bytes read (or -1 on error, just
272like the syscall). 332like the syscall).
273 333
334If C<$offset> is undefined, then the current file offset will be used (and
335updated), otherwise the file offset will not be changed by these calls.
336
337If C<$length> is undefined in C<aio_write>, use the remaining length of C<$data>.
338
339If C<$dataoffset> is less than zero, it will be counted from the end of
340C<$data>.
341
274The C<$data> scalar I<MUST NOT> be modified in any way while the request 342The C<$data> scalar I<MUST NOT> be modified in any way while the request
275is outstanding. Modifying it can result in segfaults or WW3 (if the 343is outstanding. Modifying it can result in segfaults or World War III (if
276necessary/optional hardware is installed). 344the necessary/optional hardware is installed).
277 345
278Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at 346Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
279offset C<0> within the scalar: 347offset C<0> within the scalar:
280 348
281 aio_read $fh, 7, 15, $buffer, 0, sub { 349 aio_read $fh, 7, 15, $buffer, 0, sub {
282 $_[0] > 0 or die "read error: $!"; 350 $_[0] > 0 or die "read error: $!";
283 print "read $_[0] bytes: <$buffer>\n"; 351 print "read $_[0] bytes: <$buffer>\n";
284 }; 352 };
353
285 354
286=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) 355=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
287 356
288Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts 357Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
289reading at byte offset C<$in_offset>, and starts writing at the current 358reading at byte offset C<$in_offset>, and starts writing at the current
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303C<$in_fh> than are written, and there is no way to find out how many 372C<$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 373bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
305provides the number of bytes written to C<$out_fh>. Only if the result 374provides the number of bytes written to C<$out_fh>. Only if the result
306value equals C<$length> one can assume that C<$length> bytes have been 375value equals C<$length> one can assume that C<$length> bytes have been
307read. 376read.
377
308 378
309=item aio_readahead $fh,$offset,$length, $callback->($retval) 379=item aio_readahead $fh,$offset,$length, $callback->($retval)
310 380
311C<aio_readahead> populates the page cache with data from a file so that 381C<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<$offset> 382subsequent reads from that file will not block on disk I/O. The C<$offset>
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318file. The current file offset of the file is left unchanged. 388file. The current file offset of the file is left unchanged.
319 389
320If that syscall doesn't exist (likely if your OS isn't Linux) it will be 390If 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. 391emulated by simply reading the data, which would have a similar effect.
322 392
393
323=item aio_stat $fh_or_path, $callback->($status) 394=item aio_stat $fh_or_path, $callback->($status)
324 395
325=item aio_lstat $fh, $callback->($status) 396=item aio_lstat $fh, $callback->($status)
326 397
327Works like perl's C<stat> or C<lstat> in void context. The callback will 398Works like perl's C<stat> or C<lstat> in void context. The callback will
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340 aio_stat "/etc/passwd", sub { 411 aio_stat "/etc/passwd", sub {
341 $_[0] and die "stat failed: $!"; 412 $_[0] and die "stat failed: $!";
342 print "size is ", -s _, "\n"; 413 print "size is ", -s _, "\n";
343 }; 414 };
344 415
416
417=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
418
419Works like perl's C<utime> function (including the special case of $atime
420and $mtime being undef). Fractional times are supported if the underlying
421syscalls support them.
422
423When called with a pathname, uses utimes(2) if available, otherwise
424utime(2). If called on a file descriptor, uses futimes(2) if available,
425otherwise returns ENOSYS, so this is not portable.
426
427Examples:
428
429 # set atime and mtime to current time (basically touch(1)):
430 aio_utime "path", undef, undef;
431 # set atime to current time and mtime to beginning of the epoch:
432 aio_utime "path", time, undef; # undef==0
433
434
435=item aio_chown $fh_or_path, $uid, $gid, $callback->($status)
436
437Works like perl's C<chown> function, except that C<undef> for either $uid
438or $gid is being interpreted as "do not change" (but -1 can also be used).
439
440Examples:
441
442 # same as "chown root path" in the shell:
443 aio_chown "path", 0, -1;
444 # same as above:
445 aio_chown "path", 0, undef;
446
447
448=item aio_truncate $fh_or_path, $offset, $callback->($status)
449
450Works like truncate(2) or ftruncate(2).
451
452
453=item aio_chmod $fh_or_path, $mode, $callback->($status)
454
455Works like perl's C<chmod> function.
456
457
345=item aio_unlink $pathname, $callback->($status) 458=item aio_unlink $pathname, $callback->($status)
346 459
347Asynchronously unlink (delete) a file and call the callback with the 460Asynchronously unlink (delete) a file and call the callback with the
348result code. 461result code.
349 462
463
350=item aio_mknod $path, $mode, $dev, $callback->($status) 464=item aio_mknod $path, $mode, $dev, $callback->($status)
351 465
466[EXPERIMENTAL]
467
352Asynchronously create a device node (or fifo). See mknod(2). 468Asynchronously create a device node (or fifo). See mknod(2).
353 469
354The only portable (POSIX) way of calling this function is: 470The only (POSIX-) portable way of calling this function is:
355 471
356 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... 472 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...
473
357 474
358=item aio_link $srcpath, $dstpath, $callback->($status) 475=item aio_link $srcpath, $dstpath, $callback->($status)
359 476
360Asynchronously create a new link to the existing object at C<$srcpath> at 477Asynchronously create a new link to the existing object at C<$srcpath> at
361the path C<$dstpath> and call the callback with the result code. 478the path C<$dstpath> and call the callback with the result code.
362 479
480
363=item aio_symlink $srcpath, $dstpath, $callback->($status) 481=item aio_symlink $srcpath, $dstpath, $callback->($status)
364 482
365Asynchronously create a new symbolic link to the existing object at C<$srcpath> at 483Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
366the path C<$dstpath> and call the callback with the result code. 484the path C<$dstpath> and call the callback with the result code.
367 485
486
487=item aio_readlink $path, $callback->($link)
488
489Asynchronously read the symlink specified by C<$path> and pass it to
490the callback. If an error occurs, nothing or undef gets passed to the
491callback.
492
493
368=item aio_rename $srcpath, $dstpath, $callback->($status) 494=item aio_rename $srcpath, $dstpath, $callback->($status)
369 495
370Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as 496Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
371rename(2) and call the callback with the result code. 497rename(2) and call the callback with the result code.
372 498
499
500=item aio_mkdir $pathname, $mode, $callback->($status)
501
502Asynchronously mkdir (create) a directory and call the callback with
503the result code. C<$mode> will be modified by the umask at the time the
504request is executed, so do not change your umask.
505
506
373=item aio_rmdir $pathname, $callback->($status) 507=item aio_rmdir $pathname, $callback->($status)
374 508
375Asynchronously rmdir (delete) a directory and call the callback with the 509Asynchronously rmdir (delete) a directory and call the callback with the
376result code. 510result code.
511
377 512
378=item aio_readdir $pathname, $callback->($entries) 513=item aio_readdir $pathname, $callback->($entries)
379 514
380Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 515Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
381directory (i.e. opendir + readdir + closedir). The entries will not be 516directory (i.e. opendir + readdir + closedir). The entries will not be
382sorted, and will B<NOT> include the C<.> and C<..> entries. 517sorted, and will B<NOT> include the C<.> and C<..> entries.
383 518
384The callback a single argument which is either C<undef> or an array-ref 519The callback a single argument which is either C<undef> or an array-ref
385with the filenames. 520with the filenames.
521
522
523=item aio_load $path, $data, $callback->($status)
524
525This is a composite request that tries to fully load the given file into
526memory. Status is the same as with aio_read.
527
528=cut
529
530sub aio_load($$;$) {
531 aio_block {
532 my ($path, undef, $cb) = @_;
533 my $data = \$_[1];
534
535 my $pri = aioreq_pri;
536 my $grp = aio_group $cb;
537
538 aioreq_pri $pri;
539 add $grp aio_open $path, O_RDONLY, 0, sub {
540 my $fh = shift
541 or return $grp->result (-1);
542
543 aioreq_pri $pri;
544 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
545 $grp->result ($_[0]);
546 };
547 };
548
549 $grp
550 }
551}
386 552
387=item aio_copy $srcpath, $dstpath, $callback->($status) 553=item aio_copy $srcpath, $dstpath, $callback->($status)
388 554
389Try to copy the I<file> (directories not supported as either source or 555Try to copy the I<file> (directories not supported as either source or
390destination) from C<$srcpath> to C<$dstpath> and call the callback with 556destination) from C<$srcpath> to C<$dstpath> and call the callback with
… …
400errors are being ignored. 566errors are being ignored.
401 567
402=cut 568=cut
403 569
404sub aio_copy($$;$) { 570sub aio_copy($$;$) {
571 aio_block {
405 my ($src, $dst, $cb) = @_; 572 my ($src, $dst, $cb) = @_;
406 573
407 my $pri = aioreq_pri; 574 my $pri = aioreq_pri;
408 my $grp = aio_group $cb; 575 my $grp = aio_group $cb;
409 576
410 aioreq_pri $pri; 577 aioreq_pri $pri;
411 add $grp aio_open $src, O_RDONLY, 0, sub { 578 add $grp aio_open $src, O_RDONLY, 0, sub {
412 if (my $src_fh = $_[0]) { 579 if (my $src_fh = $_[0]) {
413 my @stat = stat $src_fh; 580 my @stat = stat $src_fh;
414 581
415 aioreq_pri $pri; 582 aioreq_pri $pri;
416 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub { 583 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
417 if (my $dst_fh = $_[0]) { 584 if (my $dst_fh = $_[0]) {
418 aioreq_pri $pri; 585 aioreq_pri $pri;
419 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 586 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
420 if ($_[0] == $stat[7]) { 587 if ($_[0] == $stat[7]) {
421 $grp->result (0); 588 $grp->result (0);
422 close $src_fh; 589 close $src_fh;
423 590
424 # those should not normally block. should. should. 591 # those should not normally block. should. should.
425 utime $stat[8], $stat[9], $dst; 592 utime $stat[8], $stat[9], $dst;
426 chmod $stat[2] & 07777, $dst_fh; 593 chmod $stat[2] & 07777, $dst_fh;
427 chown $stat[4], $stat[5], $dst_fh; 594 chown $stat[4], $stat[5], $dst_fh;
428 close $dst_fh; 595 close $dst_fh;
429 } else { 596 } else {
430 $grp->result (-1); 597 $grp->result (-1);
431 close $src_fh; 598 close $src_fh;
432 close $dst_fh; 599 close $dst_fh;
433 600
434 aioreq $pri; 601 aioreq $pri;
435 add $grp aio_unlink $dst; 602 add $grp aio_unlink $dst;
603 }
436 } 604 };
605 } else {
606 $grp->result (-1);
437 }; 607 }
438 } else {
439 $grp->result (-1);
440 } 608 },
609
610 } else {
611 $grp->result (-1);
441 }, 612 }
442
443 } else {
444 $grp->result (-1);
445 } 613 };
614
615 $grp
446 }; 616 }
447
448 $grp
449} 617}
450 618
451=item aio_move $srcpath, $dstpath, $callback->($status) 619=item aio_move $srcpath, $dstpath, $callback->($status)
452 620
453Try to move the I<file> (directories not supported as either source or 621Try to move the I<file> (directories not supported as either source or
… …
459that is successful, unlinking the C<$srcpath>. 627that is successful, unlinking the C<$srcpath>.
460 628
461=cut 629=cut
462 630
463sub aio_move($$;$) { 631sub aio_move($$;$) {
632 aio_block {
464 my ($src, $dst, $cb) = @_; 633 my ($src, $dst, $cb) = @_;
465 634
466 my $pri = aioreq_pri; 635 my $pri = aioreq_pri;
467 my $grp = aio_group $cb; 636 my $grp = aio_group $cb;
468 637
469 aioreq_pri $pri; 638 aioreq_pri $pri;
470 add $grp aio_rename $src, $dst, sub { 639 add $grp aio_rename $src, $dst, sub {
471 if ($_[0] && $! == EXDEV) { 640 if ($_[0] && $! == EXDEV) {
472 aioreq_pri $pri; 641 aioreq_pri $pri;
473 add $grp aio_copy $src, $dst, sub { 642 add $grp aio_copy $src, $dst, sub {
643 $grp->result ($_[0]);
644
645 if (!$_[0]) {
646 aioreq_pri $pri;
647 add $grp aio_unlink $src;
648 }
649 };
650 } else {
474 $grp->result ($_[0]); 651 $grp->result ($_[0]);
475
476 if (!$_[0]) {
477 aioreq_pri $pri;
478 add $grp aio_unlink $src;
479 }
480 }; 652 }
481 } else {
482 $grp->result ($_[0]);
483 } 653 };
654
655 $grp
484 }; 656 }
485
486 $grp
487} 657}
488 658
489=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 659=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
490 660
491Scans a directory (similar to C<aio_readdir>) but additionally tries to 661Scans 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 708as those tend to return 0 or 1 as link counts, which disables the
539directory counting heuristic. 709directory counting heuristic.
540 710
541=cut 711=cut
542 712
543sub aio_scandir($$$) { 713sub aio_scandir($$;$) {
714 aio_block {
544 my ($path, $maxreq, $cb) = @_; 715 my ($path, $maxreq, $cb) = @_;
545 716
546 my $pri = aioreq_pri; 717 my $pri = aioreq_pri;
547 718
548 my $grp = aio_group $cb; 719 my $grp = aio_group $cb;
549 720
550 $maxreq = 4 if $maxreq <= 0; 721 $maxreq = 4 if $maxreq <= 0;
551 722
552 # stat once 723 # 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; 724 aioreq_pri $pri;
561 add $grp aio_readdir $path, sub { 725 add $grp aio_stat $path, sub {
562 my $entries = shift
563 or return $grp->result (); 726 return $grp->result () if $_[0];
727 my $now = time;
728 my $hash1 = join ":", (stat _)[0,1,3,7,9];
564 729
565 # stat the dir another time 730 # read the directory entries
566 aioreq_pri $pri; 731 aioreq_pri $pri;
732 add $grp aio_readdir $path, sub {
733 my $entries = shift
734 or return $grp->result ();
735
736 # stat the dir another time
737 aioreq_pri $pri;
567 add $grp aio_stat $path, sub { 738 add $grp aio_stat $path, sub {
568 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 739 my $hash2 = join ":", (stat _)[0,1,3,7,9];
569 740
570 my $ndirs; 741 my $ndirs;
571 742
572 # take the slow route if anything looks fishy 743 # take the slow route if anything looks fishy
573 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 744 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
574 $ndirs = -1; 745 $ndirs = -1;
575 } else { 746 } else {
576 # if nlink == 2, we are finished 747 # if nlink == 2, we are finished
577 # on non-posix-fs's, we rely on nlink < 2 748 # on non-posix-fs's, we rely on nlink < 2
578 $ndirs = (stat _)[3] - 2 749 $ndirs = (stat _)[3] - 2
579 or return $grp->result ([], $entries); 750 or return $grp->result ([], $entries);
580 } 751 }
581 752
582 # sort into likely dirs and likely nondirs 753 # sort into likely dirs and likely nondirs
583 # dirs == files without ".", short entries first 754 # dirs == files without ".", short entries first
584 $entries = [map $_->[0], 755 $entries = [map $_->[0],
585 sort { $b->[1] cmp $a->[1] } 756 sort { $b->[1] cmp $a->[1] }
586 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length], 757 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
587 @$entries]; 758 @$entries];
588 759
589 my (@dirs, @nondirs); 760 my (@dirs, @nondirs);
590 761
591 my $statgrp = add $grp aio_group sub { 762 my $statgrp = add $grp aio_group sub {
592 $grp->result (\@dirs, \@nondirs); 763 $grp->result (\@dirs, \@nondirs);
593 }; 764 };
594 765
595 limit $statgrp $maxreq; 766 limit $statgrp $maxreq;
596 feed $statgrp sub { 767 feed $statgrp sub {
597 return unless @$entries; 768 return unless @$entries;
598 my $entry = pop @$entries; 769 my $entry = pop @$entries;
599 770
600 aioreq_pri $pri; 771 aioreq_pri $pri;
601 add $statgrp aio_stat "$path/$entry/.", sub { 772 add $statgrp aio_stat "$path/$entry/.", sub {
602 if ($_[0] < 0) { 773 if ($_[0] < 0) {
603 push @nondirs, $entry; 774 push @nondirs, $entry;
604 } else { 775 } else {
605 # need to check for real directory 776 # need to check for real directory
606 aioreq_pri $pri; 777 aioreq_pri $pri;
607 add $statgrp aio_lstat "$path/$entry", sub { 778 add $statgrp aio_lstat "$path/$entry", sub {
608 if (-d _) { 779 if (-d _) {
609 push @dirs, $entry; 780 push @dirs, $entry;
610 781
611 unless (--$ndirs) { 782 unless (--$ndirs) {
612 push @nondirs, @$entries; 783 push @nondirs, @$entries;
613 feed $statgrp; 784 feed $statgrp;
785 }
786 } else {
787 push @nondirs, $entry;
614 } 788 }
615 } else {
616 push @nondirs, $entry;
617 } 789 }
618 } 790 }
619 } 791 };
620 }; 792 };
621 }; 793 };
622 }; 794 };
623 }; 795 };
796
797 $grp
624 }; 798 }
799}
625 800
801=item aio_rmtree $path, $callback->($status)
802
803Delete a directory tree starting (and including) C<$path>, return the
804status of the final C<rmdir> only. This is a composite request that
805uses C<aio_scandir> to recurse into and rmdir directories, and unlink
806everything else.
807
808=cut
809
810sub aio_rmtree;
811sub aio_rmtree($;$) {
812 aio_block {
813 my ($path, $cb) = @_;
814
815 my $pri = aioreq_pri;
816 my $grp = aio_group $cb;
817
818 aioreq_pri $pri;
819 add $grp aio_scandir $path, 0, sub {
820 my ($dirs, $nondirs) = @_;
821
822 my $dirgrp = aio_group sub {
823 add $grp aio_rmdir $path, sub {
824 $grp->result ($_[0]);
825 };
826 };
827
828 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
829 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
830
831 add $grp $dirgrp;
832 };
833
626 $grp 834 $grp
835 }
627} 836}
628 837
629=item aio_fsync $fh, $callback->($status) 838=item aio_fsync $fh, $callback->($status)
630 839
631Asynchronously call fsync on the given filehandle and call the callback 840Asynchronously call fsync on the given filehandle and call the callback
… …
845 1054
846=back 1055=back
847 1056
848=head2 SUPPORT FUNCTIONS 1057=head2 SUPPORT FUNCTIONS
849 1058
1059=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
1060
850=over 4 1061=over 4
851 1062
852=item $fileno = IO::AIO::poll_fileno 1063=item $fileno = IO::AIO::poll_fileno
853 1064
854Return the I<request result pipe file descriptor>. This filehandle must be 1065Return the I<request result pipe file descriptor>. This filehandle must be
… …
858 1069
859See C<poll_cb> for an example. 1070See C<poll_cb> for an example.
860 1071
861=item IO::AIO::poll_cb 1072=item IO::AIO::poll_cb
862 1073
863Process all outstanding events on the result pipe. You have to call this 1074Process some outstanding events on the result pipe. You have to call this
864regularly. Returns the number of events processed. Returns immediately 1075regularly. Returns the number of events processed. Returns immediately
865when no events are outstanding. 1076when no events are outstanding. The amount of events processed depends on
1077the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
866 1078
867If not all requests were processed for whatever reason, the filehandle 1079If not all requests were processed for whatever reason, the filehandle
868will still be ready when C<poll_cb> returns. 1080will still be ready when C<poll_cb> returns.
869 1081
870Example: Install an Event watcher that automatically calls 1082Example: Install an Event watcher that automatically calls
… …
872 1084
873 Event->io (fd => IO::AIO::poll_fileno, 1085 Event->io (fd => IO::AIO::poll_fileno,
874 poll => 'r', async => 1, 1086 poll => 'r', async => 1,
875 cb => \&IO::AIO::poll_cb); 1087 cb => \&IO::AIO::poll_cb);
876 1088
877=item IO::AIO::poll_some $max_requests 1089=item IO::AIO::max_poll_reqs $nreqs
878 1090
879Similar to C<poll_cb>, but only processes up to C<$max_requests> requests 1091=item IO::AIO::max_poll_time $seconds
880at a time.
881 1092
882Useful if you want to ensure some level of interactiveness when perl is 1093These set the maximum number of requests (default C<0>, meaning infinity)
883not fast enough to process all requests in time. 1094that are being processed by C<IO::AIO::poll_cb> in one call, respectively
1095the maximum amount of time (default C<0>, meaning infinity) spent in
1096C<IO::AIO::poll_cb> to process requests (more correctly the mininum amount
1097of time C<poll_cb> is allowed to use).
1098
1099Setting C<max_poll_time> to a non-zero value creates an overhead of one
1100syscall per request processed, which is not normally a problem unless your
1101callbacks are really really fast or your OS is really really slow (I am
1102not mentioning Solaris here). Using C<max_poll_reqs> incurs no overhead.
1103
1104Setting these is useful if you want to ensure some level of
1105interactiveness when perl is not fast enough to process all requests in
1106time.
1107
1108For interactive programs, values such as C<0.01> to C<0.1> should be fine.
884 1109
885Example: Install an Event watcher that automatically calls 1110Example: Install an Event watcher that automatically calls
886IO::AIO::poll_some with low priority, to ensure that other parts of the 1111IO::AIO::poll_cb with low priority, to ensure that other parts of the
887program get the CPU sometimes even under high AIO load. 1112program get the CPU sometimes even under high AIO load.
888 1113
1114 # try not to spend much more than 0.1s in poll_cb
1115 IO::AIO::max_poll_time 0.1;
1116
1117 # use a low priority so other tasks have priority
889 Event->io (fd => IO::AIO::poll_fileno, 1118 Event->io (fd => IO::AIO::poll_fileno,
890 poll => 'r', nice => 1, 1119 poll => 'r', nice => 1,
891 cb => sub { IO::AIO::poll_some 256 }); 1120 cb => &IO::AIO::poll_cb);
892 1121
893=item IO::AIO::poll_wait 1122=item IO::AIO::poll_wait
894 1123
1124If there are any outstanding requests and none of them in the result
895Wait till the result filehandle becomes ready for reading (simply does a 1125phase, wait till the result filehandle becomes ready for reading (simply
896C<select> on the filehandle. This is useful if you want to synchronously wait 1126does a C<select> on the filehandle. This is useful if you want to
897for some requests to finish). 1127synchronously wait for some requests to finish).
898 1128
899See C<nreqs> for an example. 1129See C<nreqs> for an example.
900 1130
1131=item IO::AIO::poll
1132
1133Waits until some requests have been handled.
1134
1135Returns the number of requests processed, but is otherwise strictly
1136equivalent to:
1137
1138 IO::AIO::poll_wait, IO::AIO::poll_cb
1139
901=item IO::AIO::nreqs 1140=item IO::AIO::flush
902 1141
903Returns the number of requests currently in the ready, execute or pending 1142Wait till all outstanding AIO requests have been handled.
904states (i.e. for which their callback has not been invoked yet).
905 1143
906Example: wait till there are no outstanding requests anymore: 1144Strictly equivalent to:
907 1145
908 IO::AIO::poll_wait, IO::AIO::poll_cb 1146 IO::AIO::poll_wait, IO::AIO::poll_cb
909 while IO::AIO::nreqs; 1147 while IO::AIO::nreqs;
910 1148
911=item IO::AIO::nready 1149=back
912 1150
913Returns the number of requests currently in the ready state (not yet 1151=head3 CONTROLLING THE NUMBER OF THREADS
914executed).
915 1152
916=item IO::AIO::npending 1153=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 1154
939=item IO::AIO::min_parallel $nthreads 1155=item IO::AIO::min_parallel $nthreads
940 1156
941Set the minimum number of AIO threads to C<$nthreads>. The current 1157Set the minimum number of AIO threads to C<$nthreads>. The current
942default is C<8>, which means eight asynchronous operations can execute 1158default is C<8>, which means eight asynchronous operations can execute
943concurrently at any one time (the number of outstanding requests, 1159concurrently at any one time (the number of outstanding requests,
944however, is unlimited). 1160however, is unlimited).
945 1161
946IO::AIO starts threads only on demand, when an AIO request is queued and 1162IO::AIO starts threads only on demand, when an AIO request is queued and
947no free thread exists. 1163no free thread exists. Please note that queueing up a hundred requests can
1164create demand for a hundred threads, even if it turns out that everything
1165is in the cache and could have been processed faster by a single thread.
948 1166
949It is recommended to keep the number of threads relatively low, as some 1167It is recommended to keep the number of threads relatively low, as some
950Linux kernel versions will scale negatively with the number of threads 1168Linux kernel versions will scale negatively with the number of threads
951(higher parallelity => MUCH higher latency). With current Linux 2.6 1169(higher parallelity => MUCH higher latency). With current Linux 2.6
952versions, 4-32 threads should be fine. 1170versions, 4-32 threads should be fine.
… …
966This module automatically runs C<max_parallel 0> at program end, to ensure 1184This module automatically runs C<max_parallel 0> at program end, to ensure
967that all threads are killed and that there are no outstanding requests. 1185that all threads are killed and that there are no outstanding requests.
968 1186
969Under normal circumstances you don't need to call this function. 1187Under normal circumstances you don't need to call this function.
970 1188
1189=item IO::AIO::max_idle $nthreads
1190
1191Limit the number of threads (default: 4) that are allowed to idle (i.e.,
1192threads that did not get a request to process within 10 seconds). That
1193means if a thread becomes idle while C<$nthreads> other threads are also
1194idle, it will free its resources and exit.
1195
1196This is useful when you allow a large number of threads (e.g. 100 or 1000)
1197to allow for extremely high load situations, but want to free resources
1198under normal circumstances (1000 threads can easily consume 30MB of RAM).
1199
1200The default is probably ok in most situations, especially if thread
1201creation is fast. If thread creation is very slow on your system you might
1202want to use larger values.
1203
971=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1204=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs
972 1205
973This is a very bad function to use in interactive programs because it 1206This 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 1207blocks, and a bad way to reduce concurrency because it is inexact: Better
975use an C<aio_group> together with a feed callback. 1208use an C<aio_group> together with a feed callback.
… …
986C<max_oustsanding> is mainly useful in simple scripts (with low values) or 1219C<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). 1220as a stop gap to shield against fatal memory overflow (with large values).
988 1221
989=back 1222=back
990 1223
1224=head3 STATISTICAL INFORMATION
1225
1226=over
1227
1228=item IO::AIO::nreqs
1229
1230Returns the number of requests currently in the ready, execute or pending
1231states (i.e. for which their callback has not been invoked yet).
1232
1233Example: wait till there are no outstanding requests anymore:
1234
1235 IO::AIO::poll_wait, IO::AIO::poll_cb
1236 while IO::AIO::nreqs;
1237
1238=item IO::AIO::nready
1239
1240Returns the number of requests currently in the ready state (not yet
1241executed).
1242
1243=item IO::AIO::npending
1244
1245Returns the number of requests currently in the pending state (executed,
1246but not yet processed by poll_cb).
1247
1248=back
1249
991=cut 1250=cut
992 1251
993# support function to convert a fd into a perl filehandle 1252# support function to convert a fd into a perl filehandle
994sub _fd2fh { 1253sub _fd2fh {
995 return undef if $_[0] < 0; 1254 return undef if $_[0] < 0;
… …
1006 *$sym 1265 *$sym
1007} 1266}
1008 1267
1009min_parallel 8; 1268min_parallel 8;
1010 1269
1011END { 1270END { flush }
1012 min_parallel 1;
1013 flush;
1014};
1015 1271
10161; 12721;
1017 1273
1018=head2 FORK BEHAVIOUR 1274=head2 FORK BEHAVIOUR
1019 1275

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