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Revision 1.88 by root, Sun Oct 29 01:50:29 2006 UTC vs.
Revision 1.143 by root, Thu Nov 20 09:01:40 2008 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
182 185
183=cut 186=cut
184 187
185package IO::AIO; 188package IO::AIO;
186 189
190use Carp ();
191
187no warnings; 192no warnings;
188use strict 'vars'; 193use strict 'vars';
189 194
190use base 'Exporter'; 195use base 'Exporter';
191 196
192BEGIN { 197BEGIN {
193 our $VERSION = '2.1'; 198 our $VERSION = '3.17';
194 199
195 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
196 aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink 201 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir
197 aio_fsync aio_fdatasync aio_readahead aio_rename aio_link aio_move 202 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
198 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
199 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); 208 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
200 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 209 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
201 min_parallel max_parallel max_idle 210 min_parallel max_parallel max_idle
202 nreqs nready npending nthreads 211 nreqs nready npending nthreads
203 max_poll_time max_poll_reqs); 212 max_poll_time max_poll_reqs);
204 213
214 push @AIO_REQ, qw(aio_busy); # not exported
215
205 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 216 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
206 217
207 require XSLoader; 218 require XSLoader;
208 XSLoader::load ("IO::AIO", $VERSION); 219 XSLoader::load ("IO::AIO", $VERSION);
209} 220}
215All the C<aio_*> calls are more or less thin wrappers around the syscall 226All the C<aio_*> calls are more or less thin wrappers around the syscall
216with the same name (sans C<aio_>). The arguments are similar or identical, 227with the same name (sans C<aio_>). The arguments are similar or identical,
217and they all accept an additional (and optional) C<$callback> argument 228and they all accept an additional (and optional) C<$callback> argument
218which 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
219the 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
220perl, which usually delivers "false") as it's sole argument when the given 231perl, which usually delivers "false") as its sole argument after the given
221syscall has been executed asynchronously. 232syscall has been executed asynchronously.
222 233
223All functions expecting a filehandle keep a copy of the filehandle 234All functions expecting a filehandle keep a copy of the filehandle
224internally until the request has finished. 235internally until the request has finished.
225 236
239your 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
240environment, d) use Glib::filename_from_unicode on unicode filenames or e) 251environment, d) use Glib::filename_from_unicode on unicode filenames or e)
241use something else to ensure your scalar has the correct contents. 252use something else to ensure your scalar has the correct contents.
242 253
243This 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
244handles correctly wether it is set or not. 255handles correctly whether it is set or not.
245 256
246=over 4 257=over 4
247 258
248=item $prev_pri = aioreq_pri [$pri] 259=item $prev_pri = aioreq_pri [$pri]
249 260
269 aio_read $_[0], ..., sub { 280 aio_read $_[0], ..., sub {
270 ... 281 ...
271 }; 282 };
272 }; 283 };
273 284
285
274=item aioreq_nice $pri_adjust 286=item aioreq_nice $pri_adjust
275 287
276Similar 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
277priority, so the effect is cumulative. 289priority, so the effect is cumulative.
290
278 291
279=item aio_open $pathname, $flags, $mode, $callback->($fh) 292=item aio_open $pathname, $flags, $mode, $callback->($fh)
280 293
281Asynchronously 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
282created filehandle for the file. 295created filehandle for the file.
288list. They are the same as used by C<sysopen>. 301list. They are the same as used by C<sysopen>.
289 302
290Likewise, 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
291didn'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>,
292except 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,
293and C<0666> or C<0777> if you do). 306and C<0666> or C<0777> if you do). Note that the C<$mode> will be modified
307by the umask in effect then the request is being executed, so better never
308change the umask.
294 309
295Example: 310Example:
296 311
297 aio_open "/etc/passwd", O_RDONLY, 0, sub { 312 aio_open "/etc/passwd", O_RDONLY, 0, sub {
298 if ($_[0]) { 313 if ($_[0]) {
301 } else { 316 } else {
302 die "open failed: $!\n"; 317 die "open failed: $!\n";
303 } 318 }
304 }; 319 };
305 320
321
306=item aio_close $fh, $callback->($status) 322=item aio_close $fh, $callback->($status)
307 323
308Asynchronously close a file and call the callback with the result 324Asynchronously close a file and call the callback with the result
309code. I<WARNING:> although accepted, you should not pass in a perl 325code.
310filehandle here, as perl will likely close the file descriptor another
311time when the filehandle is destroyed. Normally, you can safely call perls
312C<close> or just let filehandles go out of scope.
313 326
314This 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
315therefore 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
316 338
317=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 339=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
318 340
319=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 341=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
320 342
321Reads or writes C<length> bytes from the specified C<fh> and C<offset> 343Reads or writes C<$length> bytes from the specified C<$fh> and C<$offset>
322into the scalar given by C<data> and offset C<dataoffset> and calls the 344into the scalar given by C<$data> and offset C<$dataoffset> and calls the
323callback without the actual number of bytes read (or -1 on error, just 345callback without the actual number of bytes read (or -1 on error, just
324like the syscall). 346like the syscall).
325 347
348If C<$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<$length> is undefined in C<aio_write>, use the remaining length of C<$data>.
353
354If C<$dataoffset> is less than zero, it will be counted from the end of
355C<$data>.
356
326The C<$data> scalar I<MUST NOT> be modified in any way while the request 357The C<$data> scalar I<MUST NOT> be modified in any way while the request
327is outstanding. Modifying it can result in segfaults or WW3 (if the 358is outstanding. Modifying it can result in segfaults or World War III (if
328necessary/optional hardware is installed). 359the necessary/optional hardware is installed).
329 360
330Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at 361Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
331offset C<0> within the scalar: 362offset C<0> within the scalar:
332 363
333 aio_read $fh, 7, 15, $buffer, 0, sub { 364 aio_read $fh, 7, 15, $buffer, 0, sub {
334 $_[0] > 0 or die "read error: $!"; 365 $_[0] > 0 or die "read error: $!";
335 print "read $_[0] bytes: <$buffer>\n"; 366 print "read $_[0] bytes: <$buffer>\n";
336 }; 367 };
368
337 369
338=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) 370=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
339 371
340Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts 372Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
341reading at byte offset C<$in_offset>, and starts writing at the current 373reading at byte offset C<$in_offset>, and starts writing at the current
355C<$in_fh> than are written, and there is no way to find out how many 387C<$in_fh> than are written, and there is no way to find out how many
356bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only 388bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
357provides the number of bytes written to C<$out_fh>. Only if the result 389provides the number of bytes written to C<$out_fh>. Only if the result
358value equals C<$length> one can assume that C<$length> bytes have been 390value equals C<$length> one can assume that C<$length> bytes have been
359read. 391read.
392
360 393
361=item aio_readahead $fh,$offset,$length, $callback->($retval) 394=item aio_readahead $fh,$offset,$length, $callback->($retval)
362 395
363C<aio_readahead> populates the page cache with data from a file so that 396C<aio_readahead> populates the page cache with data from a file so that
364subsequent reads from that file will not block on disk I/O. The C<$offset> 397subsequent reads from that file will not block on disk I/O. The C<$offset>
370file. The current file offset of the file is left unchanged. 403file. The current file offset of the file is left unchanged.
371 404
372If that syscall doesn't exist (likely if your OS isn't Linux) it will be 405If that syscall doesn't exist (likely if your OS isn't Linux) it will be
373emulated by simply reading the data, which would have a similar effect. 406emulated by simply reading the data, which would have a similar effect.
374 407
408
375=item aio_stat $fh_or_path, $callback->($status) 409=item aio_stat $fh_or_path, $callback->($status)
376 410
377=item aio_lstat $fh, $callback->($status) 411=item aio_lstat $fh, $callback->($status)
378 412
379Works like perl's C<stat> or C<lstat> in void context. The callback will 413Works like perl's C<stat> or C<lstat> in void context. The callback will
392 aio_stat "/etc/passwd", sub { 426 aio_stat "/etc/passwd", sub {
393 $_[0] and die "stat failed: $!"; 427 $_[0] and die "stat failed: $!";
394 print "size is ", -s _, "\n"; 428 print "size is ", -s _, "\n";
395 }; 429 };
396 430
431
432=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
433
434Works like perl's C<utime> function (including the special case of $atime
435and $mtime being undef). Fractional times are supported if the underlying
436syscalls support them.
437
438When called with a pathname, uses utimes(2) if available, otherwise
439utime(2). If called on a file descriptor, uses futimes(2) if available,
440otherwise returns ENOSYS, so this is not portable.
441
442Examples:
443
444 # set atime and mtime to current time (basically touch(1)):
445 aio_utime "path", undef, undef;
446 # set atime to current time and mtime to beginning of the epoch:
447 aio_utime "path", time, undef; # undef==0
448
449
450=item aio_chown $fh_or_path, $uid, $gid, $callback->($status)
451
452Works like perl's C<chown> function, except that C<undef> for either $uid
453or $gid is being interpreted as "do not change" (but -1 can also be used).
454
455Examples:
456
457 # same as "chown root path" in the shell:
458 aio_chown "path", 0, -1;
459 # same as above:
460 aio_chown "path", 0, undef;
461
462
463=item aio_truncate $fh_or_path, $offset, $callback->($status)
464
465Works like truncate(2) or ftruncate(2).
466
467
468=item aio_chmod $fh_or_path, $mode, $callback->($status)
469
470Works like perl's C<chmod> function.
471
472
397=item aio_unlink $pathname, $callback->($status) 473=item aio_unlink $pathname, $callback->($status)
398 474
399Asynchronously unlink (delete) a file and call the callback with the 475Asynchronously unlink (delete) a file and call the callback with the
400result code. 476result code.
401 477
478
402=item aio_mknod $path, $mode, $dev, $callback->($status) 479=item aio_mknod $path, $mode, $dev, $callback->($status)
403 480
404[EXPERIMENTAL] 481[EXPERIMENTAL]
405 482
406Asynchronously create a device node (or fifo). See mknod(2). 483Asynchronously create a device node (or fifo). See mknod(2).
407 484
408The only (POSIX-) portable way of calling this function is: 485The only (POSIX-) portable way of calling this function is:
409 486
410 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... 487 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...
488
411 489
412=item aio_link $srcpath, $dstpath, $callback->($status) 490=item aio_link $srcpath, $dstpath, $callback->($status)
413 491
414Asynchronously create a new link to the existing object at C<$srcpath> at 492Asynchronously create a new link to the existing object at C<$srcpath> at
415the path C<$dstpath> and call the callback with the result code. 493the path C<$dstpath> and call the callback with the result code.
416 494
495
417=item aio_symlink $srcpath, $dstpath, $callback->($status) 496=item aio_symlink $srcpath, $dstpath, $callback->($status)
418 497
419Asynchronously create a new symbolic link to the existing object at C<$srcpath> at 498Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
420the path C<$dstpath> and call the callback with the result code. 499the path C<$dstpath> and call the callback with the result code.
421 500
501
502=item aio_readlink $path, $callback->($link)
503
504Asynchronously read the symlink specified by C<$path> and pass it to
505the callback. If an error occurs, nothing or undef gets passed to the
506callback.
507
508
422=item aio_rename $srcpath, $dstpath, $callback->($status) 509=item aio_rename $srcpath, $dstpath, $callback->($status)
423 510
424Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as 511Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
425rename(2) and call the callback with the result code. 512rename(2) and call the callback with the result code.
426 513
514
515=item aio_mkdir $pathname, $mode, $callback->($status)
516
517Asynchronously mkdir (create) a directory and call the callback with
518the result code. C<$mode> will be modified by the umask at the time the
519request is executed, so do not change your umask.
520
521
427=item aio_rmdir $pathname, $callback->($status) 522=item aio_rmdir $pathname, $callback->($status)
428 523
429Asynchronously rmdir (delete) a directory and call the callback with the 524Asynchronously rmdir (delete) a directory and call the callback with the
430result code. 525result code.
526
431 527
432=item aio_readdir $pathname, $callback->($entries) 528=item aio_readdir $pathname, $callback->($entries)
433 529
434Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 530Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
435directory (i.e. opendir + readdir + closedir). The entries will not be 531directory (i.e. opendir + readdir + closedir). The entries will not be
436sorted, and will B<NOT> include the C<.> and C<..> entries. 532sorted, and will B<NOT> include the C<.> and C<..> entries.
437 533
438The callback a single argument which is either C<undef> or an array-ref 534The callback a single argument which is either C<undef> or an array-ref
439with the filenames. 535with the filenames.
440 536
537
538=item aio_load $path, $data, $callback->($status)
539
540This is a composite request that tries to fully load the given file into
541memory. Status is the same as with aio_read.
542
543=cut
544
545sub aio_load($$;$) {
546 my ($path, undef, $cb) = @_;
547 my $data = \$_[1];
548
549 my $pri = aioreq_pri;
550 my $grp = aio_group $cb;
551
552 aioreq_pri $pri;
553 add $grp aio_open $path, O_RDONLY, 0, sub {
554 my $fh = shift
555 or return $grp->result (-1);
556
557 aioreq_pri $pri;
558 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
559 $grp->result ($_[0]);
560 };
561 };
562
563 $grp
564}
565
441=item aio_copy $srcpath, $dstpath, $callback->($status) 566=item aio_copy $srcpath, $dstpath, $callback->($status)
442 567
443Try to copy the I<file> (directories not supported as either source or 568Try to copy the I<file> (directories not supported as either source or
444destination) from C<$srcpath> to C<$dstpath> and call the callback with 569destination) from C<$srcpath> to C<$dstpath> and call the callback with
445the C<0> (error) or C<-1> ok. 570the C<0> (error) or C<-1> ok.
446 571
447This is a composite request that it creates the destination file with 572This is a composite request that creates the destination file with
448mode 0200 and copies the contents of the source file into it using 573mode 0200 and copies the contents of the source file into it using
449C<aio_sendfile>, followed by restoring atime, mtime, access mode and 574C<aio_sendfile>, followed by restoring atime, mtime, access mode and
450uid/gid, in that order. 575uid/gid, in that order.
451 576
452If an error occurs, the partial destination file will be unlinked, if 577If an error occurs, the partial destination file will be unlinked, if
477 602
478 # those should not normally block. should. should. 603 # those should not normally block. should. should.
479 utime $stat[8], $stat[9], $dst; 604 utime $stat[8], $stat[9], $dst;
480 chmod $stat[2] & 07777, $dst_fh; 605 chmod $stat[2] & 07777, $dst_fh;
481 chown $stat[4], $stat[5], $dst_fh; 606 chown $stat[4], $stat[5], $dst_fh;
607
608 aioreq_pri $pri;
482 close $dst_fh; 609 add $grp aio_close $dst_fh;
483 } else { 610 } else {
484 $grp->result (-1); 611 $grp->result (-1);
485 close $src_fh; 612 close $src_fh;
486 close $dst_fh; 613 close $dst_fh;
487 614
506 633
507Try to move the I<file> (directories not supported as either source or 634Try to move the I<file> (directories not supported as either source or
508destination) from C<$srcpath> to C<$dstpath> and call the callback with 635destination) from C<$srcpath> to C<$dstpath> and call the callback with
509the C<0> (error) or C<-1> ok. 636the C<0> (error) or C<-1> ok.
510 637
511This is a composite request that tries to rename(2) the file first. If 638This is a composite request that tries to rename(2) the file first; if
512rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if 639rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
513that is successful, unlinking the C<$srcpath>. 640that is successful, unlinks the C<$srcpath>.
514 641
515=cut 642=cut
516 643
517sub aio_move($$;$) { 644sub aio_move($$;$) {
518 my ($src, $dst, $cb) = @_; 645 my ($src, $dst, $cb) = @_;
592as those tend to return 0 or 1 as link counts, which disables the 719as those tend to return 0 or 1 as link counts, which disables the
593directory counting heuristic. 720directory counting heuristic.
594 721
595=cut 722=cut
596 723
597sub aio_scandir($$$) { 724sub aio_scandir($$;$) {
598 my ($path, $maxreq, $cb) = @_; 725 my ($path, $maxreq, $cb) = @_;
599 726
600 my $pri = aioreq_pri; 727 my $pri = aioreq_pri;
601 728
602 my $grp = aio_group $cb; 729 my $grp = aio_group $cb;
678 }; 805 };
679 806
680 $grp 807 $grp
681} 808}
682 809
810=item aio_rmtree $path, $callback->($status)
811
812Delete a directory tree starting (and including) C<$path>, return the
813status of the final C<rmdir> only. This is a composite request that
814uses C<aio_scandir> to recurse into and rmdir directories, and unlink
815everything else.
816
817=cut
818
819sub aio_rmtree;
820sub aio_rmtree($;$) {
821 my ($path, $cb) = @_;
822
823 my $pri = aioreq_pri;
824 my $grp = aio_group $cb;
825
826 aioreq_pri $pri;
827 add $grp aio_scandir $path, 0, sub {
828 my ($dirs, $nondirs) = @_;
829
830 my $dirgrp = aio_group sub {
831 add $grp aio_rmdir $path, sub {
832 $grp->result ($_[0]);
833 };
834 };
835
836 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
837 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
838
839 add $grp $dirgrp;
840 };
841
842 $grp
843}
844
845=item aio_sync $callback->($status)
846
847Asynchronously call sync and call the callback when finished.
848
683=item aio_fsync $fh, $callback->($status) 849=item aio_fsync $fh, $callback->($status)
684 850
685Asynchronously call fsync on the given filehandle and call the callback 851Asynchronously call fsync on the given filehandle and call the callback
686with the fsync result code. 852with the fsync result code.
687 853
690Asynchronously call fdatasync on the given filehandle and call the 856Asynchronously call fdatasync on the given filehandle and call the
691callback with the fdatasync result code. 857callback with the fdatasync result code.
692 858
693If this call isn't available because your OS lacks it or it couldn't be 859If this call isn't available because your OS lacks it or it couldn't be
694detected, it will be emulated by calling C<fsync> instead. 860detected, it will be emulated by calling C<fsync> instead.
861
862=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
863
864Sync the data portion of the file specified by C<$offset> and C<$length>
865to disk (but NOT the metadata), by calling the Linux-specific
866sync_file_range call. If sync_file_range is not available or it returns
867ENOSYS, then fdatasync or fsync is being substituted.
868
869C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
870C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
871C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
872manpage for details.
873
874=item aio_pathsync $path, $callback->($status)
875
876This request tries to open, fsync and close the given path. This is a
877composite request intended to sync directories after directory operations
878(E.g. rename). This might not work on all operating systems or have any
879specific effect, but usually it makes sure that directory changes get
880written to disc. It works for anything that can be opened for read-only,
881not just directories.
882
883Passes C<0> when everything went ok, and C<-1> on error.
884
885=cut
886
887sub aio_pathsync($;$) {
888 my ($path, $cb) = @_;
889
890 my $pri = aioreq_pri;
891 my $grp = aio_group $cb;
892
893 aioreq_pri $pri;
894 add $grp aio_open $path, O_RDONLY, 0, sub {
895 my ($fh) = @_;
896 if ($fh) {
897 aioreq_pri $pri;
898 add $grp aio_fsync $fh, sub {
899 $grp->result ($_[0]);
900
901 aioreq_pri $pri;
902 add $grp aio_close $fh;
903 };
904 } else {
905 $grp->result (-1);
906 }
907 };
908
909 $grp
910}
695 911
696=item aio_group $callback->(...) 912=item aio_group $callback->(...)
697 913
698This is a very special aio request: Instead of doing something, it is a 914This is a very special aio request: Instead of doing something, it is a
699container for other aio requests, which is useful if you want to bundle 915container for other aio requests, which is useful if you want to bundle
811Their lifetime, simplified, looks like this: when they are empty, they 1027Their lifetime, simplified, looks like this: when they are empty, they
812will finish very quickly. If they contain only requests that are in the 1028will finish very quickly. If they contain only requests that are in the
813C<done> state, they will also finish. Otherwise they will continue to 1029C<done> state, they will also finish. Otherwise they will continue to
814exist. 1030exist.
815 1031
816That means after creating a group you have some time to add requests. And 1032That means after creating a group you have some time to add requests
817in the callbacks of those requests, you can add further requests to the 1033(precisely before the callback has been invoked, which is only done within
818group. And only when all those requests have finished will the the group 1034the C<poll_cb>). And in the callbacks of those requests, you can add
819itself finish. 1035further requests to the group. And only when all those requests have
1036finished will the the group itself finish.
820 1037
821=over 4 1038=over 4
822 1039
823=item add $grp ... 1040=item add $grp ...
824 1041
836itself. Useful when you queued a lot of events but got a result early. 1053itself. Useful when you queued a lot of events but got a result early.
837 1054
838=item $grp->result (...) 1055=item $grp->result (...)
839 1056
840Set the result value(s) that will be passed to the group callback when all 1057Set the result value(s) that will be passed to the group callback when all
841subrequests have finished and set thre groups errno to the current value 1058subrequests have finished and set the groups errno to the current value
842of errno (just like calling C<errno> without an error number). By default, 1059of errno (just like calling C<errno> without an error number). By default,
843no argument will be passed and errno is zero. 1060no argument will be passed and errno is zero.
844 1061
845=item $grp->errno ([$errno]) 1062=item $grp->errno ([$errno])
846 1063
857=item feed $grp $callback->($grp) 1074=item feed $grp $callback->($grp)
858 1075
859Sets a feeder/generator on this group: every group can have an attached 1076Sets a feeder/generator on this group: every group can have an attached
860generator that generates requests if idle. The idea behind this is that, 1077generator that generates requests if idle. The idea behind this is that,
861although you could just queue as many requests as you want in a group, 1078although you could just queue as many requests as you want in a group,
862this might starve other requests for a potentially long time. For 1079this might starve other requests for a potentially long time. For example,
863example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1080C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
864requests, delaying any later requests for a long time. 1081delaying any later requests for a long time.
865 1082
866To avoid this, and allow incremental generation of requests, you can 1083To avoid this, and allow incremental generation of requests, you can
867instead a group and set a feeder on it that generates those requests. The 1084instead a group and set a feeder on it that generates those requests. The
868feed callback will be called whenever there are few enough (see C<limit>, 1085feed callback will be called whenever there are few enough (see C<limit>,
869below) requests active in the group itself and is expected to queue more 1086below) requests active in the group itself and is expected to queue more
873not impose any limits). 1090not impose any limits).
874 1091
875If the feed does not queue more requests when called, it will be 1092If the feed does not queue more requests when called, it will be
876automatically removed from the group. 1093automatically removed from the group.
877 1094
878If the feed limit is C<0>, it will be set to C<2> automatically. 1095If the feed limit is C<0> when this method is called, it will be set to
1096C<2> automatically.
879 1097
880Example: 1098Example:
881 1099
882 # stat all files in @files, but only ever use four aio requests concurrently: 1100 # stat all files in @files, but only ever use four aio requests concurrently:
883 1101
895Sets the feeder limit for the group: The feeder will be called whenever 1113Sets the feeder limit for the group: The feeder will be called whenever
896the group contains less than this many requests. 1114the group contains less than this many requests.
897 1115
898Setting the limit to C<0> will pause the feeding process. 1116Setting the limit to C<0> will pause the feeding process.
899 1117
1118The default value for the limit is C<0>, but note that setting a feeder
1119automatically bumps it up to C<2>.
1120
900=back 1121=back
901 1122
902=head2 SUPPORT FUNCTIONS 1123=head2 SUPPORT FUNCTIONS
903 1124
904=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1125=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
915See C<poll_cb> for an example. 1136See C<poll_cb> for an example.
916 1137
917=item IO::AIO::poll_cb 1138=item IO::AIO::poll_cb
918 1139
919Process some outstanding events on the result pipe. You have to call this 1140Process some outstanding events on the result pipe. You have to call this
920regularly. Returns the number of events processed. Returns immediately 1141regularly. Returns C<0> if all events could be processed, or C<-1> if it
1142returned earlier for whatever reason. Returns immediately when no events
921when no events are outstanding. The amount of events processed depends on 1143are outstanding. The amount of events processed depends on the settings of
922the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>. 1144C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
923 1145
924If not all requests were processed for whatever reason, the filehandle 1146If not all requests were processed for whatever reason, the filehandle
925will still be ready when C<poll_cb> returns. 1147will still be ready when C<poll_cb> returns, so normally you don't have to
1148do anything special to have it called later.
926 1149
927Example: Install an Event watcher that automatically calls 1150Example: Install an Event watcher that automatically calls
928IO::AIO::poll_cb with high priority: 1151IO::AIO::poll_cb with high priority:
929 1152
930 Event->io (fd => IO::AIO::poll_fileno, 1153 Event->io (fd => IO::AIO::poll_fileno,
939that are being processed by C<IO::AIO::poll_cb> in one call, respectively 1162that are being processed by C<IO::AIO::poll_cb> in one call, respectively
940the maximum amount of time (default C<0>, meaning infinity) spent in 1163the maximum amount of time (default C<0>, meaning infinity) spent in
941C<IO::AIO::poll_cb> to process requests (more correctly the mininum amount 1164C<IO::AIO::poll_cb> to process requests (more correctly the mininum amount
942of time C<poll_cb> is allowed to use). 1165of time C<poll_cb> is allowed to use).
943 1166
1167Setting C<max_poll_time> to a non-zero value creates an overhead of one
1168syscall per request processed, which is not normally a problem unless your
1169callbacks are really really fast or your OS is really really slow (I am
1170not mentioning Solaris here). Using C<max_poll_reqs> incurs no overhead.
1171
944Setting these is useful if you want to ensure some level of 1172Setting these is useful if you want to ensure some level of
945interactiveness when perl is not fast enough to process all requests in 1173interactiveness when perl is not fast enough to process all requests in
946time. 1174time.
947 1175
948For interactive programs, values such as C<0.01> to C<0.1> should be fine. 1176For interactive programs, values such as C<0.01> to C<0.1> should be fine.
949 1177
950Example: Install an Event watcher that automatically calls 1178Example: Install an Event watcher that automatically calls
951IO::AIO::poll_some with low priority, to ensure that other parts of the 1179IO::AIO::poll_cb with low priority, to ensure that other parts of the
952program get the CPU sometimes even under high AIO load. 1180program get the CPU sometimes even under high AIO load.
953 1181
954 # try not to spend much more than 0.1s in poll_cb 1182 # try not to spend much more than 0.1s in poll_cb
955 IO::AIO::max_poll_time 0.1; 1183 IO::AIO::max_poll_time 0.1;
956 1184
959 poll => 'r', nice => 1, 1187 poll => 'r', nice => 1,
960 cb => &IO::AIO::poll_cb); 1188 cb => &IO::AIO::poll_cb);
961 1189
962=item IO::AIO::poll_wait 1190=item IO::AIO::poll_wait
963 1191
1192If there are any outstanding requests and none of them in the result
964Wait till the result filehandle becomes ready for reading (simply does a 1193phase, wait till the result filehandle becomes ready for reading (simply
965C<select> on the filehandle. This is useful if you want to synchronously 1194does a C<select> on the filehandle. This is useful if you want to
966wait for some requests to finish). 1195synchronously wait for some requests to finish).
967 1196
968See C<nreqs> for an example. 1197See C<nreqs> for an example.
969 1198
970=item IO::AIO::poll 1199=item IO::AIO::poll
971 1200
972Waits until some requests have been handled. 1201Waits until some requests have been handled.
973 1202
1203Returns the number of requests processed, but is otherwise strictly
974Strictly equivalent to: 1204equivalent to:
975 1205
976 IO::AIO::poll_wait, IO::AIO::poll_cb 1206 IO::AIO::poll_wait, IO::AIO::poll_cb
977 if IO::AIO::nreqs;
978 1207
979=item IO::AIO::flush 1208=item IO::AIO::flush
980 1209
981Wait till all outstanding AIO requests have been handled. 1210Wait till all outstanding AIO requests have been handled.
982 1211
983Strictly equivalent to: 1212Strictly equivalent to:
984 1213
985 IO::AIO::poll_wait, IO::AIO::poll_cb 1214 IO::AIO::poll_wait, IO::AIO::poll_cb
986 while IO::AIO::nreqs; 1215 while IO::AIO::nreqs;
987 1216
1217=back
1218
988=head3 CONTROLLING THE NUMBER OF THREADS 1219=head3 CONTROLLING THE NUMBER OF THREADS
1220
1221=over
989 1222
990=item IO::AIO::min_parallel $nthreads 1223=item IO::AIO::min_parallel $nthreads
991 1224
992Set the minimum number of AIO threads to C<$nthreads>. The current 1225Set the minimum number of AIO threads to C<$nthreads>. The current
993default is C<8>, which means eight asynchronous operations can execute 1226default is C<8>, which means eight asynchronous operations can execute
1034 1267
1035The default is probably ok in most situations, especially if thread 1268The default is probably ok in most situations, especially if thread
1036creation is fast. If thread creation is very slow on your system you might 1269creation is fast. If thread creation is very slow on your system you might
1037want to use larger values. 1270want to use larger values.
1038 1271
1039=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1272=item IO::AIO::max_outstanding $maxreqs
1040 1273
1041This is a very bad function to use in interactive programs because it 1274This is a very bad function to use in interactive programs because it
1042blocks, and a bad way to reduce concurrency because it is inexact: Better 1275blocks, and a bad way to reduce concurrency because it is inexact: Better
1043use an C<aio_group> together with a feed callback. 1276use an C<aio_group> together with a feed callback.
1044 1277
1045Sets the maximum number of outstanding requests to C<$nreqs>. If you 1278Sets the maximum number of outstanding requests to C<$nreqs>. If you
1046to queue up more than this number of requests, the next call to the 1279do queue up more than this number of requests, the next call to the
1047C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>) 1280C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
1048function will block until the limit is no longer exceeded. 1281function will block until the limit is no longer exceeded.
1049 1282
1050The default value is very large, so there is no practical limit on the 1283The default value is very large, so there is no practical limit on the
1051number of outstanding requests. 1284number of outstanding requests.
1052 1285
1053You can still queue as many requests as you want. Therefore, 1286You can still queue as many requests as you want. Therefore,
1054C<max_oustsanding> is mainly useful in simple scripts (with low values) or 1287C<max_outstanding> is mainly useful in simple scripts (with low values) or
1055as a stop gap to shield against fatal memory overflow (with large values). 1288as a stop gap to shield against fatal memory overflow (with large values).
1056 1289
1290=back
1291
1057=head3 STATISTICAL INFORMATION 1292=head3 STATISTICAL INFORMATION
1293
1294=over
1058 1295
1059=item IO::AIO::nreqs 1296=item IO::AIO::nreqs
1060 1297
1061Returns the number of requests currently in the ready, execute or pending 1298Returns the number of requests currently in the ready, execute or pending
1062states (i.e. for which their callback has not been invoked yet). 1299states (i.e. for which their callback has not been invoked yet).
1078 1315
1079=back 1316=back
1080 1317
1081=cut 1318=cut
1082 1319
1083# support function to convert a fd into a perl filehandle
1084sub _fd2fh {
1085 return undef if $_[0] < 0;
1086
1087 # try to generate nice filehandles
1088 my $sym = "IO::AIO::fd#$_[0]";
1089 local *$sym;
1090
1091 open *$sym, "+<&=$_[0]" # usually works under any unix
1092 or open *$sym, "<&=$_[0]" # cygwin needs this
1093 or open *$sym, ">&=$_[0]" # or this
1094 or return undef;
1095
1096 *$sym
1097}
1098
1099min_parallel 8; 1320min_parallel 8;
1100 1321
1101END { 1322END { flush }
1102 min_parallel 1;
1103 flush;
1104};
1105 1323
11061; 13241;
1107 1325
1108=head2 FORK BEHAVIOUR 1326=head2 FORK BEHAVIOUR
1109 1327
1129bytes of memory. In addition, stat requests need a stat buffer (possibly 1347bytes of memory. In addition, stat requests need a stat buffer (possibly
1130a few hundred bytes), readdir requires a result buffer and so on. Perl 1348a few hundred bytes), readdir requires a result buffer and so on. Perl
1131scalars and other data passed into aio requests will also be locked and 1349scalars and other data passed into aio requests will also be locked and
1132will consume memory till the request has entered the done state. 1350will consume memory till the request has entered the done state.
1133 1351
1134This is now awfully much, so queuing lots of requests is not usually a 1352This is not awfully much, so queuing lots of requests is not usually a
1135problem. 1353problem.
1136 1354
1137Per-thread usage: 1355Per-thread usage:
1138 1356
1139In the execution phase, some aio requests require more memory for 1357In the execution phase, some aio requests require more memory for
1144 1362
1145Known bugs will be fixed in the next release. 1363Known bugs will be fixed in the next release.
1146 1364
1147=head1 SEE ALSO 1365=head1 SEE ALSO
1148 1366
1149L<Coro::AIO>. 1367L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1368more natural syntax.
1150 1369
1151=head1 AUTHOR 1370=head1 AUTHOR
1152 1371
1153 Marc Lehmann <schmorp@schmorp.de> 1372 Marc Lehmann <schmorp@schmorp.de>
1154 http://home.schmorp.de/ 1373 http://home.schmorp.de/

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