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Revision 1.87 by root, Sun Oct 29 00:52:02 2006 UTC vs.
Revision 1.145 by root, Sun Apr 19 19:20:10 2009 UTC

5=head1 SYNOPSIS 5=head1 SYNOPSIS
6 6
7 use IO::AIO; 7 use IO::AIO;
8 8
9 aio_open "/etc/passwd", O_RDONLY, 0, sub { 9 aio_open "/etc/passwd", O_RDONLY, 0, sub {
10 my ($fh) = @_; 10 my $fh = shift
11 or die "/etc/passwd: $!";
11 ... 12 ...
12 }; 13 };
13 14
14 aio_unlink "/tmp/file", sub { }; 15 aio_unlink "/tmp/file", sub { };
15 16
25 $req->cancel; # cancel request if still in queue 26 $req->cancel; # cancel request if still in queue
26 27
27 my $grp = aio_group sub { print "all stats done\n" }; 28 my $grp = aio_group sub { print "all stats done\n" };
28 add $grp aio_stat "..." for ...; 29 add $grp aio_stat "..." for ...;
29 30
31 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
32 use AnyEvent::AIO;
33
30 # AnyEvent integration 34 # EV integration
31 open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!"; 35 my $w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
32 my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });
33 36
34 # Event integration 37 # Event integration
35 Event->io (fd => IO::AIO::poll_fileno, 38 Event->io (fd => IO::AIO::poll_fileno,
36 poll => 'r', 39 poll => 'r',
37 cb => \&IO::AIO::poll_cb); 40 cb => \&IO::AIO::poll_cb);
61etc.), but can also be used to easily do operations in parallel that are 64etc.), 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 65normally 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 66on a RAID volume or over NFS when you do a number of stat operations
64concurrently. 67concurrently.
65 68
66While this works on all types of file descriptors (for example sockets), 69While most of this works on all types of file descriptors (for
67using these functions on file descriptors that support nonblocking 70example sockets), using these functions on file descriptors that
68operation (again, sockets, pipes etc.) is very inefficient. Use an event 71support nonblocking operation (again, sockets, pipes etc.) is very
69loop for that (such as the L<Event|Event> module): IO::AIO will naturally 72inefficient. Use an event loop for that (such as the L<Event|Event>
70fit into such an event loop itself. 73module): IO::AIO will naturally fit into such an event loop itself.
71 74
72In this version, a number of threads are started that execute your 75In this version, a number of threads are started that execute your
73requests and signal their completion. You don't need thread support 76requests and signal their completion. You don't need thread support
74in perl, and the threads created by this module will not be visible 77in 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 78to perl. In the future, this module might make use of the native aio
77not well-supported or restricted (GNU/Linux doesn't allow them on normal 80not well-supported or restricted (GNU/Linux doesn't allow them on normal
78files currently, for example), and they would only support aio_read and 81files currently, for example), and they would only support aio_read and
79aio_write, so the remaining functionality would have to be implemented 82aio_write, so the remaining functionality would have to be implemented
80using threads anyway. 83using threads anyway.
81 84
82Although the module will work with in the presence of other (Perl-) 85Although the module will work in the presence of other (Perl-) threads,
83threads, it is currently not reentrant in any way, so use appropriate 86it is currently not reentrant in any way, so use appropriate locking
84locking yourself, always call C<poll_cb> from within the same thread, or 87yourself, always call C<poll_cb> from within the same thread, or never
85never call C<poll_cb> (or other C<aio_> functions) recursively. 88call C<poll_cb> (or other C<aio_> functions) recursively.
86 89
87=head2 EXAMPLE 90=head2 EXAMPLE
88 91
89This is a simple example that uses the Event module and loads 92This is a simple example that uses the Event module and loads
90F</etc/passwd> asynchronously: 93F</etc/passwd> asynchronously:
98 poll => 'r', 101 poll => 'r',
99 cb => \&IO::AIO::poll_cb); 102 cb => \&IO::AIO::poll_cb);
100 103
101 # queue the request to open /etc/passwd 104 # queue the request to open /etc/passwd
102 aio_open "/etc/passwd", O_RDONLY, 0, sub { 105 aio_open "/etc/passwd", O_RDONLY, 0, sub {
103 my $fh = $_[0] 106 my $fh = shift
104 or die "error while opening: $!"; 107 or die "error while opening: $!";
105 108
106 # stat'ing filehandles is generally non-blocking 109 # stat'ing filehandles is generally non-blocking
107 my $size = -s $fh; 110 my $size = -s $fh;
108 111
176Request has reached the end of its lifetime and holds no resources anymore 179Request has reached the end of its lifetime and holds no resources anymore
177(except possibly for the Perl object, but its connection to the actual 180(except possibly for the Perl object, but its connection to the actual
178aio request is severed and calling its methods will either do nothing or 181aio request is severed and calling its methods will either do nothing or
179result in a runtime error). 182result in a runtime error).
180 183
184=back
185
181=cut 186=cut
182 187
183package IO::AIO; 188package IO::AIO;
189
190use Carp ();
184 191
185no warnings; 192no warnings;
186use strict 'vars'; 193use strict 'vars';
187 194
188use base 'Exporter'; 195use base 'Exporter';
189 196
190BEGIN { 197BEGIN {
191 our $VERSION = '2.1'; 198 our $VERSION = '3.18';
192 199
193 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat 200 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close
194 aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink 201 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir
195 aio_fsync aio_fdatasync aio_readahead aio_rename aio_link aio_move 202 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
196 aio_copy aio_group aio_nop aio_mknod); 203 aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
204 aio_rename aio_link aio_move aio_copy aio_group
205 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
206 aio_chmod aio_utime aio_truncate);
207
197 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); 208 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
198 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 209 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
199 min_parallel max_parallel max_idle 210 min_parallel max_parallel max_idle
200 nreqs nready npending nthreads 211 nreqs nready npending nthreads
201 max_poll_time max_poll_reqs); 212 max_poll_time max_poll_reqs);
202 213
214 push @AIO_REQ, qw(aio_busy); # not exported
215
203 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 216 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
204 217
205 require XSLoader; 218 require XSLoader;
206 XSLoader::load ("IO::AIO", $VERSION); 219 XSLoader::load ("IO::AIO", $VERSION);
207} 220}
213All the C<aio_*> calls are more or less thin wrappers around the syscall 226All the C<aio_*> calls are more or less thin wrappers around the syscall
214with the same name (sans C<aio_>). The arguments are similar or identical, 227with the same name (sans C<aio_>). The arguments are similar or identical,
215and they all accept an additional (and optional) C<$callback> argument 228and they all accept an additional (and optional) C<$callback> argument
216which must be a code reference. This code reference will get called with 229which must be a code reference. This code reference will get called with
217the syscall return code (e.g. most syscalls return C<-1> on error, unlike 230the syscall return code (e.g. most syscalls return C<-1> on error, unlike
218perl, which usually delivers "false") as it's sole argument when the given 231perl, which usually delivers "false") as its sole argument after the given
219syscall has been executed asynchronously. 232syscall has been executed asynchronously.
220 233
221All functions expecting a filehandle keep a copy of the filehandle 234All functions expecting a filehandle keep a copy of the filehandle
222internally until the request has finished. 235internally until the request has finished.
223 236
237your pathnames to the locale (or other) encoding in effect in the user 250your pathnames to the locale (or other) encoding in effect in the user
238environment, d) use Glib::filename_from_unicode on unicode filenames or e) 251environment, d) use Glib::filename_from_unicode on unicode filenames or e)
239use something else to ensure your scalar has the correct contents. 252use something else to ensure your scalar has the correct contents.
240 253
241This works, btw. independent of the internal UTF-8 bit, which IO::AIO 254This works, btw. independent of the internal UTF-8 bit, which IO::AIO
242handles correctly wether it is set or not. 255handles correctly whether it is set or not.
243 256
244=over 4 257=over 4
245 258
246=item $prev_pri = aioreq_pri [$pri] 259=item $prev_pri = aioreq_pri [$pri]
247 260
267 aio_read $_[0], ..., sub { 280 aio_read $_[0], ..., sub {
268 ... 281 ...
269 }; 282 };
270 }; 283 };
271 284
285
272=item aioreq_nice $pri_adjust 286=item aioreq_nice $pri_adjust
273 287
274Similar to C<aioreq_pri>, but subtracts the given value from the current 288Similar to C<aioreq_pri>, but subtracts the given value from the current
275priority, so the effect is cumulative. 289priority, so the effect is cumulative.
290
276 291
277=item aio_open $pathname, $flags, $mode, $callback->($fh) 292=item aio_open $pathname, $flags, $mode, $callback->($fh)
278 293
279Asynchronously open or create a file and call the callback with a newly 294Asynchronously open or create a file and call the callback with a newly
280created filehandle for the file. 295created filehandle for the file.
286list. They are the same as used by C<sysopen>. 301list. They are the same as used by C<sysopen>.
287 302
288Likewise, C<$mode> specifies the mode of the newly created file, if it 303Likewise, C<$mode> specifies the mode of the newly created file, if it
289didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>, 304didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>,
290except that it is mandatory (i.e. use C<0> if you don't create new files, 305except that it is mandatory (i.e. use C<0> if you don't create new files,
291and C<0666> or C<0777> if you do). 306and C<0666> or C<0777> if you do). Note that the C<$mode> will be modified
307by the umask in effect then the request is being executed, so better never
308change the umask.
292 309
293Example: 310Example:
294 311
295 aio_open "/etc/passwd", O_RDONLY, 0, sub { 312 aio_open "/etc/passwd", O_RDONLY, 0, sub {
296 if ($_[0]) { 313 if ($_[0]) {
299 } else { 316 } else {
300 die "open failed: $!\n"; 317 die "open failed: $!\n";
301 } 318 }
302 }; 319 };
303 320
321
304=item aio_close $fh, $callback->($status) 322=item aio_close $fh, $callback->($status)
305 323
306Asynchronously close a file and call the callback with the result 324Asynchronously close a file and call the callback with the result
307code. I<WARNING:> although accepted, you should not pass in a perl 325code.
308filehandle here, as perl will likely close the file descriptor another
309time when the filehandle is destroyed. Normally, you can safely call perls
310C<close> or just let filehandles go out of scope.
311 326
312This is supposed to be a bug in the API, so that might change. It's 327Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
313therefore best to avoid this function. 328closing the file descriptor associated with the filehandle itself.
329
330Therefore, C<aio_close> will not close the filehandle - instead it will
331use dup2 to overwrite the file descriptor with the write-end of a pipe
332(the pipe fd will be created on demand and will be cached).
333
334Or in other words: the file descriptor will be closed, but it will not be
335free for reuse until the perl filehandle is closed.
336
337=cut
314 338
315=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 339=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
316 340
317=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 341=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
318 342
319Reads or writes C<length> bytes from the specified C<fh> and C<offset> 343Reads or writes C<$length> bytes from or to the specified C<$fh> and
320into the scalar given by C<data> and offset C<dataoffset> and calls the 344C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
321callback without the actual number of bytes read (or -1 on error, just 345and calls the callback without the actual number of bytes read (or -1 on
322like the syscall). 346error, just like the syscall).
347
348If C<$offset> is undefined, then the current file descriptor offset will
349be used (and updated), otherwise the file descriptor offset will not be
350changed by these calls.
351
352If C<$length> is undefined in C<aio_write>, use the remaining length of
353C<$data>.
354
355If C<$dataoffset> is less than zero, it will be counted from the end of
356C<$data>.
323 357
324The C<$data> scalar I<MUST NOT> be modified in any way while the request 358The C<$data> scalar I<MUST NOT> be modified in any way while the request
325is outstanding. Modifying it can result in segfaults or WW3 (if the 359is outstanding. Modifying it can result in segfaults or World War III (if
326necessary/optional hardware is installed). 360the necessary/optional hardware is installed).
327 361
328Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at 362Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
329offset C<0> within the scalar: 363offset C<0> within the scalar:
330 364
331 aio_read $fh, 7, 15, $buffer, 0, sub { 365 aio_read $fh, 7, 15, $buffer, 0, sub {
332 $_[0] > 0 or die "read error: $!"; 366 $_[0] > 0 or die "read error: $!";
333 print "read $_[0] bytes: <$buffer>\n"; 367 print "read $_[0] bytes: <$buffer>\n";
334 }; 368 };
369
335 370
336=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) 371=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
337 372
338Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts 373Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
339reading at byte offset C<$in_offset>, and starts writing at the current 374reading at byte offset C<$in_offset>, and starts writing at the current
353C<$in_fh> than are written, and there is no way to find out how many 388C<$in_fh> than are written, and there is no way to find out how many
354bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only 389bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
355provides the number of bytes written to C<$out_fh>. Only if the result 390provides the number of bytes written to C<$out_fh>. Only if the result
356value equals C<$length> one can assume that C<$length> bytes have been 391value equals C<$length> one can assume that C<$length> bytes have been
357read. 392read.
393
358 394
359=item aio_readahead $fh,$offset,$length, $callback->($retval) 395=item aio_readahead $fh,$offset,$length, $callback->($retval)
360 396
361C<aio_readahead> populates the page cache with data from a file so that 397C<aio_readahead> populates the page cache with data from a file so that
362subsequent reads from that file will not block on disk I/O. The C<$offset> 398subsequent reads from that file will not block on disk I/O. The C<$offset>
368file. The current file offset of the file is left unchanged. 404file. The current file offset of the file is left unchanged.
369 405
370If that syscall doesn't exist (likely if your OS isn't Linux) it will be 406If that syscall doesn't exist (likely if your OS isn't Linux) it will be
371emulated by simply reading the data, which would have a similar effect. 407emulated by simply reading the data, which would have a similar effect.
372 408
409
373=item aio_stat $fh_or_path, $callback->($status) 410=item aio_stat $fh_or_path, $callback->($status)
374 411
375=item aio_lstat $fh, $callback->($status) 412=item aio_lstat $fh, $callback->($status)
376 413
377Works like perl's C<stat> or C<lstat> in void context. The callback will 414Works like perl's C<stat> or C<lstat> in void context. The callback will
390 aio_stat "/etc/passwd", sub { 427 aio_stat "/etc/passwd", sub {
391 $_[0] and die "stat failed: $!"; 428 $_[0] and die "stat failed: $!";
392 print "size is ", -s _, "\n"; 429 print "size is ", -s _, "\n";
393 }; 430 };
394 431
432
433=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
434
435Works like perl's C<utime> function (including the special case of $atime
436and $mtime being undef). Fractional times are supported if the underlying
437syscalls support them.
438
439When called with a pathname, uses utimes(2) if available, otherwise
440utime(2). If called on a file descriptor, uses futimes(2) if available,
441otherwise returns ENOSYS, so this is not portable.
442
443Examples:
444
445 # set atime and mtime to current time (basically touch(1)):
446 aio_utime "path", undef, undef;
447 # set atime to current time and mtime to beginning of the epoch:
448 aio_utime "path", time, undef; # undef==0
449
450
451=item aio_chown $fh_or_path, $uid, $gid, $callback->($status)
452
453Works like perl's C<chown> function, except that C<undef> for either $uid
454or $gid is being interpreted as "do not change" (but -1 can also be used).
455
456Examples:
457
458 # same as "chown root path" in the shell:
459 aio_chown "path", 0, -1;
460 # same as above:
461 aio_chown "path", 0, undef;
462
463
464=item aio_truncate $fh_or_path, $offset, $callback->($status)
465
466Works like truncate(2) or ftruncate(2).
467
468
469=item aio_chmod $fh_or_path, $mode, $callback->($status)
470
471Works like perl's C<chmod> function.
472
473
395=item aio_unlink $pathname, $callback->($status) 474=item aio_unlink $pathname, $callback->($status)
396 475
397Asynchronously unlink (delete) a file and call the callback with the 476Asynchronously unlink (delete) a file and call the callback with the
398result code. 477result code.
399 478
479
400=item aio_mknod $path, $mode, $dev, $callback->($status) 480=item aio_mknod $path, $mode, $dev, $callback->($status)
401 481
402[EXPERIMENTAL] 482[EXPERIMENTAL]
403 483
404Asynchronously create a device node (or fifo). See mknod(2). 484Asynchronously create a device node (or fifo). See mknod(2).
405 485
406The only (POSIX-) portable way of calling this function is: 486The only (POSIX-) portable way of calling this function is:
407 487
408 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... 488 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...
489
409 490
410=item aio_link $srcpath, $dstpath, $callback->($status) 491=item aio_link $srcpath, $dstpath, $callback->($status)
411 492
412Asynchronously create a new link to the existing object at C<$srcpath> at 493Asynchronously create a new link to the existing object at C<$srcpath> at
413the path C<$dstpath> and call the callback with the result code. 494the path C<$dstpath> and call the callback with the result code.
414 495
496
415=item aio_symlink $srcpath, $dstpath, $callback->($status) 497=item aio_symlink $srcpath, $dstpath, $callback->($status)
416 498
417Asynchronously create a new symbolic link to the existing object at C<$srcpath> at 499Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
418the path C<$dstpath> and call the callback with the result code. 500the path C<$dstpath> and call the callback with the result code.
419 501
502
503=item aio_readlink $path, $callback->($link)
504
505Asynchronously read the symlink specified by C<$path> and pass it to
506the callback. If an error occurs, nothing or undef gets passed to the
507callback.
508
509
420=item aio_rename $srcpath, $dstpath, $callback->($status) 510=item aio_rename $srcpath, $dstpath, $callback->($status)
421 511
422Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as 512Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
423rename(2) and call the callback with the result code. 513rename(2) and call the callback with the result code.
424 514
515
516=item aio_mkdir $pathname, $mode, $callback->($status)
517
518Asynchronously mkdir (create) a directory and call the callback with
519the result code. C<$mode> will be modified by the umask at the time the
520request is executed, so do not change your umask.
521
522
425=item aio_rmdir $pathname, $callback->($status) 523=item aio_rmdir $pathname, $callback->($status)
426 524
427Asynchronously rmdir (delete) a directory and call the callback with the 525Asynchronously rmdir (delete) a directory and call the callback with the
428result code. 526result code.
527
429 528
430=item aio_readdir $pathname, $callback->($entries) 529=item aio_readdir $pathname, $callback->($entries)
431 530
432Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 531Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
433directory (i.e. opendir + readdir + closedir). The entries will not be 532directory (i.e. opendir + readdir + closedir). The entries will not be
434sorted, and will B<NOT> include the C<.> and C<..> entries. 533sorted, and will B<NOT> include the C<.> and C<..> entries.
435 534
436The callback a single argument which is either C<undef> or an array-ref 535The callback a single argument which is either C<undef> or an array-ref
437with the filenames. 536with the filenames.
438 537
538
539=item aio_load $path, $data, $callback->($status)
540
541This is a composite request that tries to fully load the given file into
542memory. Status is the same as with aio_read.
543
544=cut
545
546sub aio_load($$;$) {
547 my ($path, undef, $cb) = @_;
548 my $data = \$_[1];
549
550 my $pri = aioreq_pri;
551 my $grp = aio_group $cb;
552
553 aioreq_pri $pri;
554 add $grp aio_open $path, O_RDONLY, 0, sub {
555 my $fh = shift
556 or return $grp->result (-1);
557
558 aioreq_pri $pri;
559 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
560 $grp->result ($_[0]);
561 };
562 };
563
564 $grp
565}
566
439=item aio_copy $srcpath, $dstpath, $callback->($status) 567=item aio_copy $srcpath, $dstpath, $callback->($status)
440 568
441Try to copy the I<file> (directories not supported as either source or 569Try to copy the I<file> (directories not supported as either source or
442destination) from C<$srcpath> to C<$dstpath> and call the callback with 570destination) from C<$srcpath> to C<$dstpath> and call the callback with
443the C<0> (error) or C<-1> ok. 571the C<0> (error) or C<-1> ok.
444 572
445This is a composite request that it creates the destination file with 573This is a composite request that creates the destination file with
446mode 0200 and copies the contents of the source file into it using 574mode 0200 and copies the contents of the source file into it using
447C<aio_sendfile>, followed by restoring atime, mtime, access mode and 575C<aio_sendfile>, followed by restoring atime, mtime, access mode and
448uid/gid, in that order. 576uid/gid, in that order.
449 577
450If an error occurs, the partial destination file will be unlinked, if 578If an error occurs, the partial destination file will be unlinked, if
475 603
476 # those should not normally block. should. should. 604 # those should not normally block. should. should.
477 utime $stat[8], $stat[9], $dst; 605 utime $stat[8], $stat[9], $dst;
478 chmod $stat[2] & 07777, $dst_fh; 606 chmod $stat[2] & 07777, $dst_fh;
479 chown $stat[4], $stat[5], $dst_fh; 607 chown $stat[4], $stat[5], $dst_fh;
608
609 aioreq_pri $pri;
480 close $dst_fh; 610 add $grp aio_close $dst_fh;
481 } else { 611 } else {
482 $grp->result (-1); 612 $grp->result (-1);
483 close $src_fh; 613 close $src_fh;
484 close $dst_fh; 614 close $dst_fh;
485 615
504 634
505Try to move the I<file> (directories not supported as either source or 635Try to move the I<file> (directories not supported as either source or
506destination) from C<$srcpath> to C<$dstpath> and call the callback with 636destination) from C<$srcpath> to C<$dstpath> and call the callback with
507the C<0> (error) or C<-1> ok. 637the C<0> (error) or C<-1> ok.
508 638
509This is a composite request that tries to rename(2) the file first. If 639This is a composite request that tries to rename(2) the file first; if
510rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if 640rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
511that is successful, unlinking the C<$srcpath>. 641that is successful, unlinks the C<$srcpath>.
512 642
513=cut 643=cut
514 644
515sub aio_move($$;$) { 645sub aio_move($$;$) {
516 my ($src, $dst, $cb) = @_; 646 my ($src, $dst, $cb) = @_;
590as those tend to return 0 or 1 as link counts, which disables the 720as those tend to return 0 or 1 as link counts, which disables the
591directory counting heuristic. 721directory counting heuristic.
592 722
593=cut 723=cut
594 724
595sub aio_scandir($$$) { 725sub aio_scandir($$;$) {
596 my ($path, $maxreq, $cb) = @_; 726 my ($path, $maxreq, $cb) = @_;
597 727
598 my $pri = aioreq_pri; 728 my $pri = aioreq_pri;
599 729
600 my $grp = aio_group $cb; 730 my $grp = aio_group $cb;
676 }; 806 };
677 807
678 $grp 808 $grp
679} 809}
680 810
811=item aio_rmtree $path, $callback->($status)
812
813Delete a directory tree starting (and including) C<$path>, return the
814status of the final C<rmdir> only. This is a composite request that
815uses C<aio_scandir> to recurse into and rmdir directories, and unlink
816everything else.
817
818=cut
819
820sub aio_rmtree;
821sub aio_rmtree($;$) {
822 my ($path, $cb) = @_;
823
824 my $pri = aioreq_pri;
825 my $grp = aio_group $cb;
826
827 aioreq_pri $pri;
828 add $grp aio_scandir $path, 0, sub {
829 my ($dirs, $nondirs) = @_;
830
831 my $dirgrp = aio_group sub {
832 add $grp aio_rmdir $path, sub {
833 $grp->result ($_[0]);
834 };
835 };
836
837 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
838 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
839
840 add $grp $dirgrp;
841 };
842
843 $grp
844}
845
846=item aio_sync $callback->($status)
847
848Asynchronously call sync and call the callback when finished.
849
681=item aio_fsync $fh, $callback->($status) 850=item aio_fsync $fh, $callback->($status)
682 851
683Asynchronously call fsync on the given filehandle and call the callback 852Asynchronously call fsync on the given filehandle and call the callback
684with the fsync result code. 853with the fsync result code.
685 854
688Asynchronously call fdatasync on the given filehandle and call the 857Asynchronously call fdatasync on the given filehandle and call the
689callback with the fdatasync result code. 858callback with the fdatasync result code.
690 859
691If this call isn't available because your OS lacks it or it couldn't be 860If this call isn't available because your OS lacks it or it couldn't be
692detected, it will be emulated by calling C<fsync> instead. 861detected, it will be emulated by calling C<fsync> instead.
862
863=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
864
865Sync the data portion of the file specified by C<$offset> and C<$length>
866to disk (but NOT the metadata), by calling the Linux-specific
867sync_file_range call. If sync_file_range is not available or it returns
868ENOSYS, then fdatasync or fsync is being substituted.
869
870C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
871C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
872C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
873manpage for details.
874
875=item aio_pathsync $path, $callback->($status)
876
877This request tries to open, fsync and close the given path. This is a
878composite request intended to sync directories after directory operations
879(E.g. rename). This might not work on all operating systems or have any
880specific effect, but usually it makes sure that directory changes get
881written to disc. It works for anything that can be opened for read-only,
882not just directories.
883
884Passes C<0> when everything went ok, and C<-1> on error.
885
886=cut
887
888sub aio_pathsync($;$) {
889 my ($path, $cb) = @_;
890
891 my $pri = aioreq_pri;
892 my $grp = aio_group $cb;
893
894 aioreq_pri $pri;
895 add $grp aio_open $path, O_RDONLY, 0, sub {
896 my ($fh) = @_;
897 if ($fh) {
898 aioreq_pri $pri;
899 add $grp aio_fsync $fh, sub {
900 $grp->result ($_[0]);
901
902 aioreq_pri $pri;
903 add $grp aio_close $fh;
904 };
905 } else {
906 $grp->result (-1);
907 }
908 };
909
910 $grp
911}
693 912
694=item aio_group $callback->(...) 913=item aio_group $callback->(...)
695 914
696This is a very special aio request: Instead of doing something, it is a 915This is a very special aio request: Instead of doing something, it is a
697container for other aio requests, which is useful if you want to bundle 916container for other aio requests, which is useful if you want to bundle
809Their lifetime, simplified, looks like this: when they are empty, they 1028Their lifetime, simplified, looks like this: when they are empty, they
810will finish very quickly. If they contain only requests that are in the 1029will finish very quickly. If they contain only requests that are in the
811C<done> state, they will also finish. Otherwise they will continue to 1030C<done> state, they will also finish. Otherwise they will continue to
812exist. 1031exist.
813 1032
814That means after creating a group you have some time to add requests. And 1033That means after creating a group you have some time to add requests
815in the callbacks of those requests, you can add further requests to the 1034(precisely before the callback has been invoked, which is only done within
816group. And only when all those requests have finished will the the group 1035the C<poll_cb>). And in the callbacks of those requests, you can add
817itself finish. 1036further requests to the group. And only when all those requests have
1037finished will the the group itself finish.
818 1038
819=over 4 1039=over 4
820 1040
821=item add $grp ... 1041=item add $grp ...
822 1042
834itself. Useful when you queued a lot of events but got a result early. 1054itself. Useful when you queued a lot of events but got a result early.
835 1055
836=item $grp->result (...) 1056=item $grp->result (...)
837 1057
838Set the result value(s) that will be passed to the group callback when all 1058Set the result value(s) that will be passed to the group callback when all
839subrequests have finished and set thre groups errno to the current value 1059subrequests have finished and set the groups errno to the current value
840of errno (just like calling C<errno> without an error number). By default, 1060of errno (just like calling C<errno> without an error number). By default,
841no argument will be passed and errno is zero. 1061no argument will be passed and errno is zero.
842 1062
843=item $grp->errno ([$errno]) 1063=item $grp->errno ([$errno])
844 1064
855=item feed $grp $callback->($grp) 1075=item feed $grp $callback->($grp)
856 1076
857Sets a feeder/generator on this group: every group can have an attached 1077Sets a feeder/generator on this group: every group can have an attached
858generator that generates requests if idle. The idea behind this is that, 1078generator that generates requests if idle. The idea behind this is that,
859although you could just queue as many requests as you want in a group, 1079although you could just queue as many requests as you want in a group,
860this might starve other requests for a potentially long time. For 1080this might starve other requests for a potentially long time. For example,
861example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1081C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
862requests, delaying any later requests for a long time. 1082delaying any later requests for a long time.
863 1083
864To avoid this, and allow incremental generation of requests, you can 1084To avoid this, and allow incremental generation of requests, you can
865instead a group and set a feeder on it that generates those requests. The 1085instead a group and set a feeder on it that generates those requests. The
866feed callback will be called whenever there are few enough (see C<limit>, 1086feed callback will be called whenever there are few enough (see C<limit>,
867below) requests active in the group itself and is expected to queue more 1087below) requests active in the group itself and is expected to queue more
871not impose any limits). 1091not impose any limits).
872 1092
873If the feed does not queue more requests when called, it will be 1093If the feed does not queue more requests when called, it will be
874automatically removed from the group. 1094automatically removed from the group.
875 1095
876If the feed limit is C<0>, it will be set to C<2> automatically. 1096If the feed limit is C<0> when this method is called, it will be set to
1097C<2> automatically.
877 1098
878Example: 1099Example:
879 1100
880 # stat all files in @files, but only ever use four aio requests concurrently: 1101 # stat all files in @files, but only ever use four aio requests concurrently:
881 1102
893Sets the feeder limit for the group: The feeder will be called whenever 1114Sets the feeder limit for the group: The feeder will be called whenever
894the group contains less than this many requests. 1115the group contains less than this many requests.
895 1116
896Setting the limit to C<0> will pause the feeding process. 1117Setting the limit to C<0> will pause the feeding process.
897 1118
1119The default value for the limit is C<0>, but note that setting a feeder
1120automatically bumps it up to C<2>.
1121
898=back 1122=back
899 1123
900=head2 SUPPORT FUNCTIONS 1124=head2 SUPPORT FUNCTIONS
901 1125
902=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1126=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
913See C<poll_cb> for an example. 1137See C<poll_cb> for an example.
914 1138
915=item IO::AIO::poll_cb 1139=item IO::AIO::poll_cb
916 1140
917Process some outstanding events on the result pipe. You have to call this 1141Process some outstanding events on the result pipe. You have to call this
918regularly. Returns the number of events processed. Returns immediately 1142regularly. Returns C<0> if all events could be processed, or C<-1> if it
1143returned earlier for whatever reason. Returns immediately when no events
919when no events are outstanding. The amount of events processed depends on 1144are outstanding. The amount of events processed depends on the settings of
920the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>. 1145C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
921 1146
922If not all requests were processed for whatever reason, the filehandle 1147If not all requests were processed for whatever reason, the filehandle
923will still be ready when C<poll_cb> returns. 1148will still be ready when C<poll_cb> returns, so normally you don't have to
1149do anything special to have it called later.
924 1150
925Example: Install an Event watcher that automatically calls 1151Example: Install an Event watcher that automatically calls
926IO::AIO::poll_cb with high priority: 1152IO::AIO::poll_cb with high priority:
927 1153
928 Event->io (fd => IO::AIO::poll_fileno, 1154 Event->io (fd => IO::AIO::poll_fileno,
937that are being processed by C<IO::AIO::poll_cb> in one call, respectively 1163that are being processed by C<IO::AIO::poll_cb> in one call, respectively
938the maximum amount of time (default C<0>, meaning infinity) spent in 1164the maximum amount of time (default C<0>, meaning infinity) spent in
939C<IO::AIO::poll_cb> to process requests (more correctly the mininum amount 1165C<IO::AIO::poll_cb> to process requests (more correctly the mininum amount
940of time C<poll_cb> is allowed to use). 1166of time C<poll_cb> is allowed to use).
941 1167
1168Setting C<max_poll_time> to a non-zero value creates an overhead of one
1169syscall per request processed, which is not normally a problem unless your
1170callbacks are really really fast or your OS is really really slow (I am
1171not mentioning Solaris here). Using C<max_poll_reqs> incurs no overhead.
1172
942Setting these is useful if you want to ensure some level of 1173Setting these is useful if you want to ensure some level of
943interactiveness when perl is not fast enough to process all requests in 1174interactiveness when perl is not fast enough to process all requests in
944time. 1175time.
945 1176
946For interactive programs, values such as C<0.01> to C<0.1> should be fine. 1177For interactive programs, values such as C<0.01> to C<0.1> should be fine.
947 1178
948Example: Install an Event watcher that automatically calls 1179Example: Install an Event watcher that automatically calls
949IO::AIO::poll_some with low priority, to ensure that other parts of the 1180IO::AIO::poll_cb with low priority, to ensure that other parts of the
950program get the CPU sometimes even under high AIO load. 1181program get the CPU sometimes even under high AIO load.
951 1182
952 # try not to spend much more than 0.1s in poll_cb 1183 # try not to spend much more than 0.1s in poll_cb
953 IO::AIO::max_poll_time 0.1; 1184 IO::AIO::max_poll_time 0.1;
954 1185
957 poll => 'r', nice => 1, 1188 poll => 'r', nice => 1,
958 cb => &IO::AIO::poll_cb); 1189 cb => &IO::AIO::poll_cb);
959 1190
960=item IO::AIO::poll_wait 1191=item IO::AIO::poll_wait
961 1192
1193If there are any outstanding requests and none of them in the result
962Wait till the result filehandle becomes ready for reading (simply does a 1194phase, wait till the result filehandle becomes ready for reading (simply
963C<select> on the filehandle. This is useful if you want to synchronously 1195does a C<select> on the filehandle. This is useful if you want to
964wait for some requests to finish). 1196synchronously wait for some requests to finish).
965 1197
966See C<nreqs> for an example. 1198See C<nreqs> for an example.
967 1199
968=item IO::AIO::poll 1200=item IO::AIO::poll
969 1201
970Waits until some requests have been handled. 1202Waits until some requests have been handled.
971 1203
1204Returns the number of requests processed, but is otherwise strictly
972Strictly equivalent to: 1205equivalent to:
973 1206
974 IO::AIO::poll_wait, IO::AIO::poll_cb 1207 IO::AIO::poll_wait, IO::AIO::poll_cb
975 if IO::AIO::nreqs;
976 1208
977=item IO::AIO::flush 1209=item IO::AIO::flush
978 1210
979Wait till all outstanding AIO requests have been handled. 1211Wait till all outstanding AIO requests have been handled.
980 1212
981Strictly equivalent to: 1213Strictly equivalent to:
982 1214
983 IO::AIO::poll_wait, IO::AIO::poll_cb 1215 IO::AIO::poll_wait, IO::AIO::poll_cb
984 while IO::AIO::nreqs; 1216 while IO::AIO::nreqs;
985 1217
1218=back
1219
986=head3 CONTROLLING THE NUMBER OF THREADS 1220=head3 CONTROLLING THE NUMBER OF THREADS
1221
1222=over
987 1223
988=item IO::AIO::min_parallel $nthreads 1224=item IO::AIO::min_parallel $nthreads
989 1225
990Set the minimum number of AIO threads to C<$nthreads>. The current 1226Set the minimum number of AIO threads to C<$nthreads>. The current
991default is C<8>, which means eight asynchronous operations can execute 1227default is C<8>, which means eight asynchronous operations can execute
1032 1268
1033The default is probably ok in most situations, especially if thread 1269The default is probably ok in most situations, especially if thread
1034creation is fast. If thread creation is very slow on your system you might 1270creation is fast. If thread creation is very slow on your system you might
1035want to use larger values. 1271want to use larger values.
1036 1272
1037=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1273=item IO::AIO::max_outstanding $maxreqs
1038 1274
1039This is a very bad function to use in interactive programs because it 1275This is a very bad function to use in interactive programs because it
1040blocks, and a bad way to reduce concurrency because it is inexact: Better 1276blocks, and a bad way to reduce concurrency because it is inexact: Better
1041use an C<aio_group> together with a feed callback. 1277use an C<aio_group> together with a feed callback.
1042 1278
1043Sets the maximum number of outstanding requests to C<$nreqs>. If you 1279Sets the maximum number of outstanding requests to C<$nreqs>. If you
1044to queue up more than this number of requests, the next call to the 1280do queue up more than this number of requests, the next call to the
1045C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>) 1281C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
1046function will block until the limit is no longer exceeded. 1282function will block until the limit is no longer exceeded.
1047 1283
1048The default value is very large, so there is no practical limit on the 1284The default value is very large, so there is no practical limit on the
1049number of outstanding requests. 1285number of outstanding requests.
1050 1286
1051You can still queue as many requests as you want. Therefore, 1287You can still queue as many requests as you want. Therefore,
1052C<max_oustsanding> is mainly useful in simple scripts (with low values) or 1288C<max_outstanding> is mainly useful in simple scripts (with low values) or
1053as a stop gap to shield against fatal memory overflow (with large values). 1289as a stop gap to shield against fatal memory overflow (with large values).
1054 1290
1291=back
1292
1055=head3 STATISTICAL INFORMATION 1293=head3 STATISTICAL INFORMATION
1294
1295=over
1056 1296
1057=item IO::AIO::nreqs 1297=item IO::AIO::nreqs
1058 1298
1059Returns the number of requests currently in the ready, execute or pending 1299Returns the number of requests currently in the ready, execute or pending
1060states (i.e. for which their callback has not been invoked yet). 1300states (i.e. for which their callback has not been invoked yet).
1076 1316
1077=back 1317=back
1078 1318
1079=cut 1319=cut
1080 1320
1081# support function to convert a fd into a perl filehandle
1082sub _fd2fh {
1083 return undef if $_[0] < 0;
1084
1085 # try to generate nice filehandles
1086 my $sym = "IO::AIO::fd#$_[0]";
1087 local *$sym;
1088
1089 open *$sym, "+<&=$_[0]" # usually works under any unix
1090 or open *$sym, "<&=$_[0]" # cygwin needs this
1091 or open *$sym, ">&=$_[0]" # or this
1092 or return undef;
1093
1094 *$sym
1095}
1096
1097min_parallel 8; 1321min_parallel 8;
1098 1322
1099END { 1323END { flush }
1100 min_parallel 1;
1101 flush;
1102};
1103 1324
11041; 13251;
1105 1326
1106=head2 FORK BEHAVIOUR 1327=head2 FORK BEHAVIOUR
1107 1328
1127bytes of memory. In addition, stat requests need a stat buffer (possibly 1348bytes of memory. In addition, stat requests need a stat buffer (possibly
1128a few hundred bytes), readdir requires a result buffer and so on. Perl 1349a few hundred bytes), readdir requires a result buffer and so on. Perl
1129scalars and other data passed into aio requests will also be locked and 1350scalars and other data passed into aio requests will also be locked and
1130will consume memory till the request has entered the done state. 1351will consume memory till the request has entered the done state.
1131 1352
1132This is now awfully much, so queuing lots of requests is not usually a 1353This is not awfully much, so queuing lots of requests is not usually a
1133problem. 1354problem.
1134 1355
1135Per-thread usage: 1356Per-thread usage:
1136 1357
1137In the execution phase, some aio requests require more memory for 1358In the execution phase, some aio requests require more memory for
1142 1363
1143Known bugs will be fixed in the next release. 1364Known bugs will be fixed in the next release.
1144 1365
1145=head1 SEE ALSO 1366=head1 SEE ALSO
1146 1367
1147L<Coro::AIO>. 1368L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1369more natural syntax.
1148 1370
1149=head1 AUTHOR 1371=head1 AUTHOR
1150 1372
1151 Marc Lehmann <schmorp@schmorp.de> 1373 Marc Lehmann <schmorp@schmorp.de>
1152 http://home.schmorp.de/ 1374 http://home.schmorp.de/

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