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Revision 1.169 by root, Sat Jan 2 13:02:20 2010 UTC vs.
Revision 1.208 by root, Mon Sep 26 20:19:08 2011 UTC

4 4
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", IO::AIO::O_RDONLY, 0, sub {
10 my $fh = shift 10 my $fh = shift
11 or die "/etc/passwd: $!"; 11 or die "/etc/passwd: $!";
12 ... 12 ...
13 }; 13 };
14 14
25 my $req = aio_unlink "/tmp/file", sub { }; 25 my $req = aio_unlink "/tmp/file", sub { };
26 $req->cancel; # cancel request if still in queue 26 $req->cancel; # cancel request if still in queue
27 27
28 my $grp = aio_group sub { print "all stats done\n" }; 28 my $grp = aio_group sub { print "all stats done\n" };
29 add $grp aio_stat "..." for ...; 29 add $grp aio_stat "..." for ...;
30
31 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
32 use AnyEvent::AIO;
33
34 # EV integration
35 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
36
37 # Event integration
38 Event->io (fd => IO::AIO::poll_fileno,
39 poll => 'r',
40 cb => \&IO::AIO::poll_cb);
41
42 # Glib/Gtk2 integration
43 add_watch Glib::IO IO::AIO::poll_fileno,
44 in => sub { IO::AIO::poll_cb; 1 };
45
46 # Tk integration
47 Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
48 readable => \&IO::AIO::poll_cb);
49
50 # Danga::Socket integration
51 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
52 \&IO::AIO::poll_cb);
53 30
54=head1 DESCRIPTION 31=head1 DESCRIPTION
55 32
56This module implements asynchronous I/O using whatever means your 33This module implements asynchronous I/O using whatever means your
57operating system supports. It is implemented as an interface to C<libeio> 34operating system supports. It is implemented as an interface to C<libeio>
99 76
100 # register the IO::AIO callback with EV 77 # register the IO::AIO callback with EV
101 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; 78 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
102 79
103 # queue the request to open /etc/passwd 80 # queue the request to open /etc/passwd
104 aio_open "/etc/passwd", O_RDONLY, 0, sub { 81 aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
105 my $fh = shift 82 my $fh = shift
106 or die "error while opening: $!"; 83 or die "error while opening: $!";
107 84
108 # stat'ing filehandles is generally non-blocking 85 # stat'ing filehandles is generally non-blocking
109 my $size = -s $fh; 86 my $size = -s $fh;
191use common::sense; 168use common::sense;
192 169
193use base 'Exporter'; 170use base 'Exporter';
194 171
195BEGIN { 172BEGIN {
196 our $VERSION = '3.31'; 173 our $VERSION = '4.0';
197 174
198 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close 175 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close
199 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx 176 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
200 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync 177 aio_scandir aio_symlink aio_readlink aio_realpath aio_sync
201 aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead 178 aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range aio_fallocate
179 aio_pathsync aio_readahead
202 aio_rename aio_link aio_move aio_copy aio_group 180 aio_rename aio_link aio_move aio_copy aio_group
203 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown 181 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
204 aio_chmod aio_utime aio_truncate); 182 aio_chmod aio_utime aio_truncate
183 aio_msync aio_mtouch aio_mlock aio_mlockall
184 aio_statvfs
185 aio_wd);
205 186
206 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); 187 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
207 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 188 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
208 min_parallel max_parallel max_idle 189 min_parallel max_parallel max_idle idle_timeout
209 nreqs nready npending nthreads 190 nreqs nready npending nthreads
210 max_poll_time max_poll_reqs 191 max_poll_time max_poll_reqs
211 sendfile fadvise); 192 sendfile fadvise madvise
193 mmap munmap munlock munlockall);
212 194
213 push @AIO_REQ, qw(aio_busy); # not exported 195 push @AIO_REQ, qw(aio_busy); # not exported
214 196
215 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 197 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
216 198
217 require XSLoader; 199 require XSLoader;
218 XSLoader::load ("IO::AIO", $VERSION); 200 XSLoader::load ("IO::AIO", $VERSION);
219} 201}
220 202
221=head1 FUNCTIONS 203=head1 FUNCTIONS
204
205=head2 QUICK OVERVIEW
206
207This section simply lists the prototypes of the most important functions
208for quick reference. See the following sections for function-by-function
209documentation.
210
211 aio_wd $pathname, $callback->($wd)
212 aio_open $pathname, $flags, $mode, $callback->($fh)
213 aio_close $fh, $callback->($status)
214 aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
215 aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
216 aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
217 aio_readahead $fh,$offset,$length, $callback->($retval)
218 aio_stat $fh_or_path, $callback->($status)
219 aio_lstat $fh, $callback->($status)
220 aio_statvfs $fh_or_path, $callback->($statvfs)
221 aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
222 aio_chown $fh_or_path, $uid, $gid, $callback->($status)
223 aio_truncate $fh_or_path, $offset, $callback->($status)
224 aio_chmod $fh_or_path, $mode, $callback->($status)
225 aio_unlink $pathname, $callback->($status)
226 aio_mknod $path, $mode, $dev, $callback->($status)
227 aio_link $srcpath, $dstpath, $callback->($status)
228 aio_symlink $srcpath, $dstpath, $callback->($status)
229 aio_readlink $path, $callback->($link)
230 aio_realpath $path, $callback->($link)
231 aio_rename $srcpath, $dstpath, $callback->($status)
232 aio_mkdir $pathname, $mode, $callback->($status)
233 aio_rmdir $pathname, $callback->($status)
234 aio_readdir $pathname, $callback->($entries)
235 aio_readdirx $pathname, $flags, $callback->($entries, $flags)
236 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
237 IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN
238 aio_load $path, $data, $callback->($status)
239 aio_copy $srcpath, $dstpath, $callback->($status)
240 aio_move $srcpath, $dstpath, $callback->($status)
241 aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
242 aio_rmtree $path, $callback->($status)
243 aio_sync $callback->($status)
244 aio_syncfs $fh, $callback->($status)
245 aio_fsync $fh, $callback->($status)
246 aio_fdatasync $fh, $callback->($status)
247 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
248 aio_pathsync $path, $callback->($status)
249 aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
250 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
251 aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
252 aio_mlockall $flags, $callback->($status)
253 aio_group $callback->(...)
254 aio_nop $callback->()
255
256 $prev_pri = aioreq_pri [$pri]
257 aioreq_nice $pri_adjust
258
259 IO::AIO::poll_wait
260 IO::AIO::poll_cb
261 IO::AIO::poll
262 IO::AIO::flush
263 IO::AIO::max_poll_reqs $nreqs
264 IO::AIO::max_poll_time $seconds
265 IO::AIO::min_parallel $nthreads
266 IO::AIO::max_parallel $nthreads
267 IO::AIO::max_idle $nthreads
268 IO::AIO::idle_timeout $seconds
269 IO::AIO::max_outstanding $maxreqs
270 IO::AIO::nreqs
271 IO::AIO::nready
272 IO::AIO::npending
273
274 IO::AIO::sendfile $ofh, $ifh, $offset, $count
275 IO::AIO::fadvise $fh, $offset, $len, $advice
276 IO::AIO::madvise $scalar, $offset, $length, $advice
277 IO::AIO::mprotect $scalar, $offset, $length, $protect
278 IO::AIO::munlock $scalar, $offset = 0, $length = undef
279 IO::AIO::munlockall
222 280
223=head2 AIO REQUEST FUNCTIONS 281=head2 AIO REQUEST FUNCTIONS
224 282
225All the C<aio_*> calls are more or less thin wrappers around the syscall 283All the C<aio_*> calls are more or less thin wrappers around the syscall
226with the same name (sans C<aio_>). The arguments are similar or identical, 284with the same name (sans C<aio_>). The arguments are similar or identical,
306by the umask in effect then the request is being executed, so better never 364by the umask in effect then the request is being executed, so better never
307change the umask. 365change the umask.
308 366
309Example: 367Example:
310 368
311 aio_open "/etc/passwd", O_RDONLY, 0, sub { 369 aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
312 if ($_[0]) { 370 if ($_[0]) {
313 print "open successful, fh is $_[0]\n"; 371 print "open successful, fh is $_[0]\n";
314 ... 372 ...
315 } else { 373 } else {
316 die "open failed: $!\n"; 374 die "open failed: $!\n";
317 } 375 }
318 }; 376 };
319 377
378In addition to all the common open modes/flags (C<O_RDONLY>, C<O_WRONLY>,
379C<O_RDWR>, C<O_CREAT>, C<O_TRUNC>, C<O_EXCL> and C<O_APPEND>), the
380following POSIX and non-POSIX constants are available (missing ones on
381your system are, as usual, C<0>):
382
383C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,
384C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,
385C<O_RSYNC>, C<O_SYNC> and C<O_TTY_INIT>.
386
320 387
321=item aio_close $fh, $callback->($status) 388=item aio_close $fh, $callback->($status)
322 389
323Asynchronously close a file and call the callback with the result 390Asynchronously close a file and call the callback with the result
324code. 391code.
374 441
375Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts 442Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
376reading at byte offset C<$in_offset>, and starts writing at the current 443reading at byte offset C<$in_offset>, and starts writing at the current
377file offset of C<$out_fh>. Because of that, it is not safe to issue more 444file offset of C<$out_fh>. Because of that, it is not safe to issue more
378than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each 445than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
379other. 446other. The same C<$in_fh> works fine though, as this function does not
447move or use the file offset of C<$in_fh>.
380 448
449Please note that C<aio_sendfile> can read more bytes from C<$in_fh> than
450are written, and there is no way to find out how many more bytes have been
451read from C<aio_sendfile> alone, as C<aio_sendfile> only provides the
452number of bytes written to C<$out_fh>. Only if the result value equals
453C<$length> one can assume that C<$length> bytes have been read.
454
455Unlike with other C<aio_> functions, it makes a lot of sense to use
456C<aio_sendfile> on non-blocking sockets, as long as one end (typically
457the C<$in_fh>) is a file - the file I/O will then be asynchronous, while
458the socket I/O will be non-blocking. Note, however, that you can run
459into a trap where C<aio_sendfile> reads some data with readahead, then
460fails to write all data, and when the socket is ready the next time, the
461data in the cache is already lost, forcing C<aio_sendfile> to again hit
462the disk. Explicit C<aio_read> + C<aio_write> let's you better control
463resource usage.
464
381This call tries to make use of a native C<sendfile> syscall to provide 465This call tries to make use of a native C<sendfile>-like syscall to
382zero-copy operation. For this to work, C<$out_fh> should refer to a 466provide zero-copy operation. For this to work, C<$out_fh> should refer to
383socket, and C<$in_fh> should refer to mmap'able file. 467a socket, and C<$in_fh> should refer to an mmap'able file.
384 468
385If the native sendfile call fails with C<ENOSYS>, C<ENOTSUP>, 469If a native sendfile cannot be found or it fails with C<ENOSYS>,
386C<EOPNOTSUPP> or C<ENOTSOCK>, or is not implemented, it will be emulated, 470C<EINVAL>, C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or
387so you can call C<aio_sendfile> on any type of filehandle regardless of 471C<ENOTSOCK>, it will be emulated, so you can call C<aio_sendfile> on any
388the limitations of the operating system. 472type of filehandle regardless of the limitations of the operating system.
389 473
390Please note, however, that C<aio_sendfile> can read more bytes from 474As native sendfile syscalls (as practically any non-POSIX interface hacked
391C<$in_fh> than are written, and there is no way to find out how many 475together in a hurry to improve benchmark numbers) tend to be rather buggy
392bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only 476on many systems, this implementation tries to work around some known bugs
393provides the number of bytes written to C<$out_fh>. Only if the result 477in Linux and FreeBSD kernels (probably others, too), but that might fail,
394value equals C<$length> one can assume that C<$length> bytes have been 478so you really really should check the return value of C<aio_sendfile> -
395read. 479fewre bytes than expected might have been transferred.
396 480
397 481
398=item aio_readahead $fh,$offset,$length, $callback->($retval) 482=item aio_readahead $fh,$offset,$length, $callback->($retval)
399 483
400C<aio_readahead> populates the page cache with data from a file so that 484C<aio_readahead> populates the page cache with data from a file so that
423 507
424Currently, the stats are always 64-bit-stats, i.e. instead of returning an 508Currently, the stats are always 64-bit-stats, i.e. instead of returning an
425error when stat'ing a large file, the results will be silently truncated 509error when stat'ing a large file, the results will be silently truncated
426unless perl itself is compiled with large file support. 510unless perl itself is compiled with large file support.
427 511
512To help interpret the mode and dev/rdev stat values, IO::AIO offers the
513following constants and functions (if not implemented, the constants will
514be C<0> and the functions will either C<croak> or fall back on traditional
515behaviour).
516
517C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>,
518C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>,
519C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>.
520
428Example: Print the length of F</etc/passwd>: 521Example: Print the length of F</etc/passwd>:
429 522
430 aio_stat "/etc/passwd", sub { 523 aio_stat "/etc/passwd", sub {
431 $_[0] and die "stat failed: $!"; 524 $_[0] and die "stat failed: $!";
432 print "size is ", -s _, "\n"; 525 print "size is ", -s _, "\n";
433 }; 526 };
434 527
435 528
529=item aio_statvfs $fh_or_path, $callback->($statvfs)
530
531Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
532whether a file handle or path was passed.
533
534On success, the callback is passed a hash reference with the following
535members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
536C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
537is passed.
538
539The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
540C<ST_NOSUID>.
541
542The following non-POSIX IO::AIO::ST_* flag masks are defined to
543their correct value when available, or to C<0> on systems that do
544not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
545C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
546C<ST_NODIRATIME> and C<ST_RELATIME>.
547
548Example: stat C</wd> and dump out the data if successful.
549
550 aio_statvfs "/wd", sub {
551 my $f = $_[0]
552 or die "statvfs: $!";
553
554 use Data::Dumper;
555 say Dumper $f;
556 };
557
558 # result:
559 {
560 bsize => 1024,
561 bfree => 4333064312,
562 blocks => 10253828096,
563 files => 2050765568,
564 flag => 4096,
565 favail => 2042092649,
566 bavail => 4333064312,
567 ffree => 2042092649,
568 namemax => 255,
569 frsize => 1024,
570 fsid => 1810
571 }
572
573
436=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 574=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
437 575
438Works like perl's C<utime> function (including the special case of $atime 576Works like perl's C<utime> function (including the special case of $atime
439and $mtime being undef). Fractional times are supported if the underlying 577and $mtime being undef). Fractional times are supported if the underlying
440syscalls support them. 578syscalls support them.
488 626
489The only (POSIX-) portable way of calling this function is: 627The only (POSIX-) portable way of calling this function is:
490 628
491 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... 629 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...
492 630
631See C<aio_stat> for info about some potentially helpful extra constants
632and functions.
493 633
494=item aio_link $srcpath, $dstpath, $callback->($status) 634=item aio_link $srcpath, $dstpath, $callback->($status)
495 635
496Asynchronously create a new link to the existing object at C<$srcpath> at 636Asynchronously create a new link to the existing object at C<$srcpath> at
497the path C<$dstpath> and call the callback with the result code. 637the path C<$dstpath> and call the callback with the result code.
508Asynchronously read the symlink specified by C<$path> and pass it to 648Asynchronously read the symlink specified by C<$path> and pass it to
509the callback. If an error occurs, nothing or undef gets passed to the 649the callback. If an error occurs, nothing or undef gets passed to the
510callback. 650callback.
511 651
512 652
653=item aio_realpath $path, $callback->($path)
654
655Asynchronously make the path absolute and resolve any symlinks in
656C<$path>. The resulting path only consists of directories (Same as
657L<Cwd::realpath>).
658
659This request can be used to get the absolute path of the current working
660directory by passing it a path of F<.> (a single dot).
661
662
513=item aio_rename $srcpath, $dstpath, $callback->($status) 663=item aio_rename $srcpath, $dstpath, $callback->($status)
514 664
515Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as 665Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
516rename(2) and call the callback with the result code. 666rename(2) and call the callback with the result code.
517 667
539array-ref with the filenames. 689array-ref with the filenames.
540 690
541 691
542=item aio_readdirx $pathname, $flags, $callback->($entries, $flags) 692=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
543 693
544Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune 694Quite similar to C<aio_readdir>, but the C<$flags> argument allows one to
545behaviour and output format. In case of an error, C<$entries> will be 695tune behaviour and output format. In case of an error, C<$entries> will be
546C<undef>. 696C<undef>.
547 697
548The flags are a combination of the following constants, ORed together (the 698The flags are a combination of the following constants, ORed together (the
549flags will also be passed to the callback, possibly modified): 699flags will also be passed to the callback, possibly modified):
550 700
551=over 4 701=over 4
552 702
553=item IO::AIO::READDIR_DENTS 703=item IO::AIO::READDIR_DENTS
554 704
555When this flag is off, then the callback gets an arrayref with of names 705When this flag is off, then the callback gets an arrayref consisting of
556only (as with C<aio_readdir>), otherwise it gets an arrayref with 706names only (as with C<aio_readdir>), otherwise it gets an arrayref with
557C<[$name, $type, $inode]> arrayrefs, each describing a single directory 707C<[$name, $type, $inode]> arrayrefs, each describing a single directory
558entry in more detail. 708entry in more detail.
559 709
560C<$name> is the name of the entry. 710C<$name> is the name of the entry.
561 711
574systems that do not deliver the inode information. 724systems that do not deliver the inode information.
575 725
576=item IO::AIO::READDIR_DIRS_FIRST 726=item IO::AIO::READDIR_DIRS_FIRST
577 727
578When this flag is set, then the names will be returned in an order where 728When this flag is set, then the names will be returned in an order where
579likely directories come first. This is useful when you need to quickly 729likely directories come first, in optimal stat order. This is useful when
580find directories, or you want to find all directories while avoiding to 730you need to quickly find directories, or you want to find all directories
581stat() each entry. 731while avoiding to stat() each entry.
582 732
583If the system returns type information in readdir, then this is used 733If the system returns type information in readdir, then this is used
584to find directories directly. Otherwise, likely directories are files 734to find directories directly. Otherwise, likely directories are names
585beginning with ".", or otherwise files with no dots, of which files with 735beginning with ".", or otherwise names with no dots, of which names with
586short names are tried first. 736short names are tried first.
587 737
588=item IO::AIO::READDIR_STAT_ORDER 738=item IO::AIO::READDIR_STAT_ORDER
589 739
590When this flag is set, then the names will be returned in an order 740When this flag is set, then the names will be returned in an order
597 747
598=item IO::AIO::READDIR_FOUND_UNKNOWN 748=item IO::AIO::READDIR_FOUND_UNKNOWN
599 749
600This flag should not be set when calling C<aio_readdirx>. Instead, it 750This flag should not be set when calling C<aio_readdirx>. Instead, it
601is being set by C<aio_readdirx>, when any of the C<$type>'s found were 751is being set by C<aio_readdirx>, when any of the C<$type>'s found were
602C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all 752C<IO::AIO::DT_UNKNOWN>. The absence of this flag therefore indicates that all
603C<$type>'s are known, which can be used to speed up some algorithms. 753C<$type>'s are known, which can be used to speed up some algorithms.
604 754
605=back 755=back
606 756
607 757
735 if ($_[0] && $! == EXDEV) { 885 if ($_[0] && $! == EXDEV) {
736 aioreq_pri $pri; 886 aioreq_pri $pri;
737 add $grp aio_copy $src, $dst, sub { 887 add $grp aio_copy $src, $dst, sub {
738 $grp->result ($_[0]); 888 $grp->result ($_[0]);
739 889
740 if (!$_[0]) { 890 unless ($_[0]) {
741 aioreq_pri $pri; 891 aioreq_pri $pri;
742 add $grp aio_unlink $src; 892 add $grp aio_unlink $src;
743 } 893 }
744 }; 894 };
745 } else { 895 } else {
789Then entries will be sorted into likely directories a non-initial dot 939Then entries will be sorted into likely directories a non-initial dot
790currently) and likely non-directories (see C<aio_readdirx>). Then every 940currently) and likely non-directories (see C<aio_readdirx>). Then every
791entry plus an appended C</.> will be C<stat>'ed, likely directories first, 941entry plus an appended C</.> will be C<stat>'ed, likely directories first,
792in order of their inode numbers. If that succeeds, it assumes that the 942in order of their inode numbers. If that succeeds, it assumes that the
793entry is a directory or a symlink to directory (which will be checked 943entry is a directory or a symlink to directory (which will be checked
794seperately). This is often faster than stat'ing the entry itself because 944separately). This is often faster than stat'ing the entry itself because
795filesystems might detect the type of the entry without reading the inode 945filesystems might detect the type of the entry without reading the inode
796data (e.g. ext2fs filetype feature), even on systems that cannot return 946data (e.g. ext2fs filetype feature), even on systems that cannot return
797the filetype information on readdir. 947the filetype information on readdir.
798 948
799If the known number of directories (link count - 2) has been reached, the 949If the known number of directories (link count - 2) has been reached, the
937callback with the fdatasync result code. 1087callback with the fdatasync result code.
938 1088
939If this call isn't available because your OS lacks it or it couldn't be 1089If this call isn't available because your OS lacks it or it couldn't be
940detected, it will be emulated by calling C<fsync> instead. 1090detected, it will be emulated by calling C<fsync> instead.
941 1091
1092=item aio_syncfs $fh, $callback->($status)
1093
1094Asynchronously call the syncfs syscall to sync the filesystem associated
1095to the given filehandle and call the callback with the syncfs result
1096code. If syncfs is not available, calls sync(), but returns C<-1> and sets
1097errno to C<ENOSYS> nevertheless.
1098
942=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) 1099=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
943 1100
944Sync the data portion of the file specified by C<$offset> and C<$length> 1101Sync the data portion of the file specified by C<$offset> and C<$length>
945to disk (but NOT the metadata), by calling the Linux-specific 1102to disk (but NOT the metadata), by calling the Linux-specific
946sync_file_range call. If sync_file_range is not available or it returns 1103sync_file_range call. If sync_file_range is not available or it returns
990 }; 1147 };
991 1148
992 $grp 1149 $grp
993} 1150}
994 1151
1152=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1153
1154This is a rather advanced IO::AIO call, which only works on mmap(2)ed
1155scalars (see the C<IO::AIO::mmap> function, although it also works on data
1156scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
1157scalar must only be modified in-place while an aio operation is pending on
1158it).
1159
1160It calls the C<msync> function of your OS, if available, with the memory
1161area starting at C<$offset> in the string and ending C<$length> bytes
1162later. If C<$length> is negative, counts from the end, and if C<$length>
1163is C<undef>, then it goes till the end of the string. The flags can be
1164a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
1165C<IO::AIO::MS_SYNC>.
1166
1167=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1168
1169This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1170scalars.
1171
1172It touches (reads or writes) all memory pages in the specified
1173range inside the scalar. All caveats and parameters are the same
1174as for C<aio_msync>, above, except for flags, which must be either
1175C<0> (which reads all pages and ensures they are instantiated) or
1176C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
1177writing an octet from it, which dirties the page).
1178
1179=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1180
1181This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1182scalars.
1183
1184It reads in all the pages of the underlying storage into memory (if any)
1185and locks them, so they are not getting swapped/paged out or removed.
1186
1187If C<$length> is undefined, then the scalar will be locked till the end.
1188
1189On systems that do not implement C<mlock>, this function returns C<-1>
1190and sets errno to C<ENOSYS>.
1191
1192Note that the corresponding C<munlock> is synchronous and is
1193documented under L<MISCELLANEOUS FUNCTIONS>.
1194
1195Example: open a file, mmap and mlock it - both will be undone when
1196C<$data> gets destroyed.
1197
1198 open my $fh, "<", $path or die "$path: $!";
1199 my $data;
1200 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
1201 aio_mlock $data; # mlock in background
1202
1203=item aio_mlockall $flags, $callback->($status)
1204
1205Calls the C<mlockall> function with the given C<$flags> (a combination of
1206C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).
1207
1208On systems that do not implement C<mlockall>, this function returns C<-1>
1209and sets errno to C<ENOSYS>.
1210
1211Note that the corresponding C<munlockall> is synchronous and is
1212documented under L<MISCELLANEOUS FUNCTIONS>.
1213
1214Example: asynchronously lock all current and future pages into memory.
1215
1216 aio_mlockall IO::AIO::MCL_FUTURE;
1217
995=item aio_group $callback->(...) 1218=item aio_group $callback->(...)
996 1219
997This is a very special aio request: Instead of doing something, it is a 1220This is a very special aio request: Instead of doing something, it is a
998container for other aio requests, which is useful if you want to bundle 1221container for other aio requests, which is useful if you want to bundle
999many requests into a single, composite, request with a definite callback 1222many requests into a single, composite, request with a definite callback
1222 1445
1223See C<poll_cb> for an example. 1446See C<poll_cb> for an example.
1224 1447
1225=item IO::AIO::poll_cb 1448=item IO::AIO::poll_cb
1226 1449
1227Process some outstanding events on the result pipe. You have to call this 1450Process some outstanding events on the result pipe. You have to call
1228regularly. Returns C<0> if all events could be processed, or C<-1> if it 1451this regularly. Returns C<0> if all events could be processed (or there
1229returned earlier for whatever reason. Returns immediately when no events 1452were no events to process), or C<-1> if it returned earlier for whatever
1230are outstanding. The amount of events processed depends on the settings of 1453reason. Returns immediately when no events are outstanding. The amount of
1231C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>. 1454events processed depends on the settings of C<IO::AIO::max_poll_req> and
1455C<IO::AIO::max_poll_time>.
1232 1456
1233If not all requests were processed for whatever reason, the filehandle 1457If not all requests were processed for whatever reason, the filehandle
1234will still be ready when C<poll_cb> returns, so normally you don't have to 1458will still be ready when C<poll_cb> returns, so normally you don't have to
1235do anything special to have it called later. 1459do anything special to have it called later.
1236 1460
1461Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes
1462ready, it can be beneficial to call this function from loops which submit
1463a lot of requests, to make sure the results get processed when they become
1464available and not just when the loop is finished and the event loop takes
1465over again. This function returns very fast when there are no outstanding
1466requests.
1467
1237Example: Install an Event watcher that automatically calls 1468Example: Install an Event watcher that automatically calls
1238IO::AIO::poll_cb with high priority (more examples can be found in the 1469IO::AIO::poll_cb with high priority (more examples can be found in the
1239SYNOPSIS section, at the top of this document): 1470SYNOPSIS section, at the top of this document):
1240 1471
1241 Event->io (fd => IO::AIO::poll_fileno, 1472 Event->io (fd => IO::AIO::poll_fileno,
1242 poll => 'r', async => 1, 1473 poll => 'r', async => 1,
1243 cb => \&IO::AIO::poll_cb); 1474 cb => \&IO::AIO::poll_cb);
1475
1476=item IO::AIO::poll_wait
1477
1478If there are any outstanding requests and none of them in the result
1479phase, wait till the result filehandle becomes ready for reading (simply
1480does a C<select> on the filehandle. This is useful if you want to
1481synchronously wait for some requests to finish).
1482
1483See C<nreqs> for an example.
1484
1485=item IO::AIO::poll
1486
1487Waits until some requests have been handled.
1488
1489Returns the number of requests processed, but is otherwise strictly
1490equivalent to:
1491
1492 IO::AIO::poll_wait, IO::AIO::poll_cb
1493
1494=item IO::AIO::flush
1495
1496Wait till all outstanding AIO requests have been handled.
1497
1498Strictly equivalent to:
1499
1500 IO::AIO::poll_wait, IO::AIO::poll_cb
1501 while IO::AIO::nreqs;
1244 1502
1245=item IO::AIO::max_poll_reqs $nreqs 1503=item IO::AIO::max_poll_reqs $nreqs
1246 1504
1247=item IO::AIO::max_poll_time $seconds 1505=item IO::AIO::max_poll_time $seconds
1248 1506
1273 # use a low priority so other tasks have priority 1531 # use a low priority so other tasks have priority
1274 Event->io (fd => IO::AIO::poll_fileno, 1532 Event->io (fd => IO::AIO::poll_fileno,
1275 poll => 'r', nice => 1, 1533 poll => 'r', nice => 1,
1276 cb => &IO::AIO::poll_cb); 1534 cb => &IO::AIO::poll_cb);
1277 1535
1278=item IO::AIO::poll_wait
1279
1280If there are any outstanding requests and none of them in the result
1281phase, wait till the result filehandle becomes ready for reading (simply
1282does a C<select> on the filehandle. This is useful if you want to
1283synchronously wait for some requests to finish).
1284
1285See C<nreqs> for an example.
1286
1287=item IO::AIO::poll
1288
1289Waits until some requests have been handled.
1290
1291Returns the number of requests processed, but is otherwise strictly
1292equivalent to:
1293
1294 IO::AIO::poll_wait, IO::AIO::poll_cb
1295
1296=item IO::AIO::flush
1297
1298Wait till all outstanding AIO requests have been handled.
1299
1300Strictly equivalent to:
1301
1302 IO::AIO::poll_wait, IO::AIO::poll_cb
1303 while IO::AIO::nreqs;
1304
1305=back 1536=back
1306 1537
1307=head3 CONTROLLING THE NUMBER OF THREADS 1538=head3 CONTROLLING THE NUMBER OF THREADS
1308 1539
1309=over 1540=over
1342 1573
1343Under normal circumstances you don't need to call this function. 1574Under normal circumstances you don't need to call this function.
1344 1575
1345=item IO::AIO::max_idle $nthreads 1576=item IO::AIO::max_idle $nthreads
1346 1577
1347Limit the number of threads (default: 4) that are allowed to idle (i.e., 1578Limit the number of threads (default: 4) that are allowed to idle
1348threads that did not get a request to process within 10 seconds). That 1579(i.e., threads that did not get a request to process within the idle
1349means if a thread becomes idle while C<$nthreads> other threads are also 1580timeout (default: 10 seconds). That means if a thread becomes idle while
1350idle, it will free its resources and exit. 1581C<$nthreads> other threads are also idle, it will free its resources and
1582exit.
1351 1583
1352This is useful when you allow a large number of threads (e.g. 100 or 1000) 1584This is useful when you allow a large number of threads (e.g. 100 or 1000)
1353to allow for extremely high load situations, but want to free resources 1585to allow for extremely high load situations, but want to free resources
1354under normal circumstances (1000 threads can easily consume 30MB of RAM). 1586under normal circumstances (1000 threads can easily consume 30MB of RAM).
1355 1587
1356The default is probably ok in most situations, especially if thread 1588The default is probably ok in most situations, especially if thread
1357creation is fast. If thread creation is very slow on your system you might 1589creation is fast. If thread creation is very slow on your system you might
1358want to use larger values. 1590want to use larger values.
1359 1591
1592=item IO::AIO::idle_timeout $seconds
1593
1594Sets the minimum idle timeout (default 10) after which worker threads are
1595allowed to exit. SEe C<IO::AIO::max_idle>.
1596
1360=item IO::AIO::max_outstanding $maxreqs 1597=item IO::AIO::max_outstanding $maxreqs
1598
1599Sets the maximum number of outstanding requests to C<$nreqs>. If
1600you do queue up more than this number of requests, the next call to
1601C<IO::AIO::poll_cb> (and other functions calling C<poll_cb>, such as
1602C<IO::AIO::flush> or C<IO::AIO::poll>) will block until the limit is no
1603longer exceeded.
1604
1605In other words, this setting does not enforce a queue limit, but can be
1606used to make poll functions block if the limit is exceeded.
1361 1607
1362This is a very bad function to use in interactive programs because it 1608This is a very bad function to use in interactive programs because it
1363blocks, and a bad way to reduce concurrency because it is inexact: Better 1609blocks, and a bad way to reduce concurrency because it is inexact: Better
1364use an C<aio_group> together with a feed callback. 1610use an C<aio_group> together with a feed callback.
1365 1611
1366Sets the maximum number of outstanding requests to C<$nreqs>. If you 1612It's main use is in scripts without an event loop - when you want to stat
1367do queue up more than this number of requests, the next call to the 1613a lot of files, you can write somehting like this:
1368C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
1369function will block until the limit is no longer exceeded.
1370 1614
1371The default value is very large, so there is no practical limit on the 1615 IO::AIO::max_outstanding 32;
1372number of outstanding requests.
1373 1616
1374You can still queue as many requests as you want. Therefore, 1617 for my $path (...) {
1375C<max_outstanding> is mainly useful in simple scripts (with low values) or 1618 aio_stat $path , ...;
1376as a stop gap to shield against fatal memory overflow (with large values). 1619 IO::AIO::poll_cb;
1620 }
1621
1622 IO::AIO::flush;
1623
1624The call to C<poll_cb> inside the loop will normally return instantly, but
1625as soon as more thna C<32> reqeusts are in-flight, it will block until
1626some requests have been handled. This keeps the loop from pushing a large
1627number of C<aio_stat> requests onto the queue.
1628
1629The default value for C<max_outstanding> is very large, so there is no
1630practical limit on the number of outstanding requests.
1377 1631
1378=back 1632=back
1379 1633
1380=head3 STATISTICAL INFORMATION 1634=head3 STATISTICAL INFORMATION
1381 1635
1419 1673
1420Returns the number of bytes copied, or C<-1> on error. 1674Returns the number of bytes copied, or C<-1> on error.
1421 1675
1422=item IO::AIO::fadvise $fh, $offset, $len, $advice 1676=item IO::AIO::fadvise $fh, $offset, $len, $advice
1423 1677
1424Simply calls the C<posix_fadvise> function (see it's 1678Simply calls the C<posix_fadvise> function (see its
1425manpage for details). The following advice constants are 1679manpage for details). The following advice constants are
1426avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>, 1680available: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1427C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>, 1681C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1428C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>. 1682C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1429 1683
1430On systems that do not implement C<posix_fadvise>, this function returns 1684On systems that do not implement C<posix_fadvise>, this function returns
1431ENOSYS, otherwise the return value of C<posix_fadvise>. 1685ENOSYS, otherwise the return value of C<posix_fadvise>.
1432 1686
1687=item IO::AIO::madvise $scalar, $offset, $len, $advice
1688
1689Simply calls the C<posix_madvise> function (see its
1690manpage for details). The following advice constants are
1691available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
1692C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.
1693
1694On systems that do not implement C<posix_madvise>, this function returns
1695ENOSYS, otherwise the return value of C<posix_madvise>.
1696
1697=item IO::AIO::mprotect $scalar, $offset, $len, $protect
1698
1699Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
1700$scalar (see its manpage for details). The following protect
1701constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
1702C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
1703
1704On systems that do not implement C<mprotect>, this function returns
1705ENOSYS, otherwise the return value of C<mprotect>.
1706
1707=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1708
1709Memory-maps a file (or anonymous memory range) and attaches it to the
1710given C<$scalar>, which will act like a string scalar.
1711
1712The only operations allowed on the scalar are C<substr>/C<vec> that don't
1713change the string length, and most read-only operations such as copying it
1714or searching it with regexes and so on.
1715
1716Anything else is unsafe and will, at best, result in memory leaks.
1717
1718The memory map associated with the C<$scalar> is automatically removed
1719when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
1720C<IO::AIO::munmap> functions are called.
1721
1722This calls the C<mmap>(2) function internally. See your system's manual
1723page for details on the C<$length>, C<$prot> and C<$flags> parameters.
1724
1725The C<$length> must be larger than zero and smaller than the actual
1726filesize.
1727
1728C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1729C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1730
1731C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
1732C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
1733not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
1734(which is set to C<MAP_ANON> if your system only provides this
1735constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
1736C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
1737C<IO::AIO::MAP_NONBLOCK>
1738
1739If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1740
1741C<$offset> is the offset from the start of the file - it generally must be
1742a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
1743
1744Example:
1745
1746 use Digest::MD5;
1747 use IO::AIO;
1748
1749 open my $fh, "<verybigfile"
1750 or die "$!";
1751
1752 IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
1753 or die "verybigfile: $!";
1754
1755 my $fast_md5 = md5 $data;
1756
1757=item IO::AIO::munmap $scalar
1758
1759Removes a previous mmap and undefines the C<$scalar>.
1760
1761=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
1762
1763Calls the C<munlock> function, undoing the effects of a previous
1764C<aio_mlock> call (see its description for details).
1765
1766=item IO::AIO::munlockall
1767
1768Calls the C<munlockall> function.
1769
1770On systems that do not implement C<munlockall>, this function returns
1771ENOSYS, otherwise the return value of C<munlockall>.
1772
1433=back 1773=back
1434 1774
1435=cut 1775=cut
1436 1776
1437min_parallel 8; 1777min_parallel 8;
1438 1778
1439END { flush } 1779END { flush }
1440 1780
14411; 17811;
1442 1782
1783=head1 EVENT LOOP INTEGRATION
1784
1785It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
1786automatically into many event loops:
1787
1788 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
1789 use AnyEvent::AIO;
1790
1791You can also integrate IO::AIO manually into many event loops, here are
1792some examples of how to do this:
1793
1794 # EV integration
1795 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
1796
1797 # Event integration
1798 Event->io (fd => IO::AIO::poll_fileno,
1799 poll => 'r',
1800 cb => \&IO::AIO::poll_cb);
1801
1802 # Glib/Gtk2 integration
1803 add_watch Glib::IO IO::AIO::poll_fileno,
1804 in => sub { IO::AIO::poll_cb; 1 };
1805
1806 # Tk integration
1807 Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
1808 readable => \&IO::AIO::poll_cb);
1809
1810 # Danga::Socket integration
1811 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
1812 \&IO::AIO::poll_cb);
1813
1443=head2 FORK BEHAVIOUR 1814=head2 FORK BEHAVIOUR
1444 1815
1445This module should do "the right thing" when the process using it forks: 1816Usage of pthreads in a program changes the semantics of fork
1817considerably. Specifically, only async-safe functions can be called after
1818fork. Perl doesn't know about this, so in general, you cannot call fork
1819with defined behaviour in perl if pthreads are involved. IO::AIO uses
1820pthreads, so this applies, but many other extensions and (for inexplicable
1821reasons) perl itself often is linked against pthreads, so this limitation
1822applies to quite a lot of perls.
1446 1823
1447Before the fork, IO::AIO enters a quiescent state where no requests 1824This module no longer tries to fight your OS, or POSIX. That means IO::AIO
1448can be added in other threads and no results will be processed. After 1825only works in the process that loaded it. Forking is fully supported, but
1449the fork the parent simply leaves the quiescent state and continues 1826using IO::AIO in the child is not.
1450request/result processing, while the child frees the request/result queue
1451(so that the requests started before the fork will only be handled in the
1452parent). Threads will be started on demand until the limit set in the
1453parent process has been reached again.
1454 1827
1455In short: the parent will, after a short pause, continue as if fork had 1828You might get around by not I<using> IO::AIO before (or after)
1456not been called, while the child will act as if IO::AIO has not been used 1829forking. You could also try to call the L<IO::AIO::reinit> function in the
1457yet. 1830child:
1831
1832=over 4
1833
1834=item IO::AIO::reinit
1835
1836Abandons all current requests and I/O threads and simply reinitialises all
1837data structures. This is not an operation supported by any standards, but
1838happens to work on GNU/Linux and some newer BSD systems.
1839
1840The only reasonable use for this function is to call it after forking, if
1841C<IO::AIO> was used in the parent. Calling it while IO::AIO is active in
1842the process will result in undefined behaviour. Calling it at any time
1843will also result in any undefined (by POSIX) behaviour.
1844
1845=back
1458 1846
1459=head2 MEMORY USAGE 1847=head2 MEMORY USAGE
1460 1848
1461Per-request usage: 1849Per-request usage:
1462 1850

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