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Revision 1.121 by root, Wed Apr 16 16:45:18 2008 UTC vs.
Revision 1.175 by root, Sun Jan 10 20:37:33 2010 UTC

… …
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 30
31 # AnyEvent integration (EV, Event, Glib, Tk, urxvt, pureperl...)
32 open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!";
33 my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });
34
35 # EV integration
36 my $w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
37
38 # Event integration
39 Event->io (fd => IO::AIO::poll_fileno,
40 poll => 'r',
41 cb => \&IO::AIO::poll_cb);
42
43 # Glib/Gtk2 integration
44 add_watch Glib::IO IO::AIO::poll_fileno,
45 in => sub { IO::AIO::poll_cb; 1 };
46
47 # Tk integration
48 Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
49 readable => \&IO::AIO::poll_cb);
50
51 # Danga::Socket integration
52 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
53 \&IO::AIO::poll_cb);
54
55=head1 DESCRIPTION 31=head1 DESCRIPTION
56 32
57This module implements asynchronous I/O using whatever means your 33This module implements asynchronous I/O using whatever means your
58operating system supports. 34operating system supports. It is implemented as an interface to C<libeio>
35(L<http://software.schmorp.de/pkg/libeio.html>).
59 36
60Asynchronous means that operations that can normally block your program 37Asynchronous means that operations that can normally block your program
61(e.g. reading from disk) will be done asynchronously: the operation 38(e.g. reading from disk) will be done asynchronously: the operation
62will still block, but you can do something else in the meantime. This 39will still block, but you can do something else in the meantime. This
63is extremely useful for programs that need to stay interactive even 40is extremely useful for programs that need to stay interactive even
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67on a RAID volume or over NFS when you do a number of stat operations 44on a RAID volume or over NFS when you do a number of stat operations
68concurrently. 45concurrently.
69 46
70While most of this works on all types of file descriptors (for 47While most of this works on all types of file descriptors (for
71example sockets), using these functions on file descriptors that 48example sockets), using these functions on file descriptors that
72support nonblocking operation (again, sockets, pipes etc.) is very 49support nonblocking operation (again, sockets, pipes etc.) is
73inefficient. Use an event loop for that (such as the L<Event|Event> 50very inefficient. Use an event loop for that (such as the L<EV>
74module): IO::AIO will naturally fit into such an event loop itself. 51module): IO::AIO will naturally fit into such an event loop itself.
75 52
76In this version, a number of threads are started that execute your 53In this version, a number of threads are started that execute your
77requests and signal their completion. You don't need thread support 54requests and signal their completion. You don't need thread support
78in perl, and the threads created by this module will not be visible 55in perl, and the threads created by this module will not be visible
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88yourself, always call C<poll_cb> from within the same thread, or never 65yourself, always call C<poll_cb> from within the same thread, or never
89call C<poll_cb> (or other C<aio_> functions) recursively. 66call C<poll_cb> (or other C<aio_> functions) recursively.
90 67
91=head2 EXAMPLE 68=head2 EXAMPLE
92 69
93This is a simple example that uses the Event module and loads 70This is a simple example that uses the EV module and loads
94F</etc/passwd> asynchronously: 71F</etc/passwd> asynchronously:
95 72
96 use Fcntl; 73 use Fcntl;
97 use Event; 74 use EV;
98 use IO::AIO; 75 use IO::AIO;
99 76
100 # register the IO::AIO callback with Event 77 # register the IO::AIO callback with EV
101 Event->io (fd => IO::AIO::poll_fileno, 78 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
102 poll => 'r',
103 cb => \&IO::AIO::poll_cb);
104 79
105 # queue the request to open /etc/passwd 80 # queue the request to open /etc/passwd
106 aio_open "/etc/passwd", O_RDONLY, 0, sub { 81 aio_open "/etc/passwd", O_RDONLY, 0, sub {
107 my $fh = shift 82 my $fh = shift
108 or die "error while opening: $!"; 83 or die "error while opening: $!";
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120 95
121 # file contents now in $contents 96 # file contents now in $contents
122 print $contents; 97 print $contents;
123 98
124 # exit event loop and program 99 # exit event loop and program
125 Event::unloop; 100 EV::unloop;
126 }; 101 };
127 }; 102 };
128 103
129 # possibly queue up other requests, or open GUI windows, 104 # possibly queue up other requests, or open GUI windows,
130 # check for sockets etc. etc. 105 # check for sockets etc. etc.
131 106
132 # process events as long as there are some: 107 # process events as long as there are some:
133 Event::loop; 108 EV::loop;
134 109
135=head1 REQUEST ANATOMY AND LIFETIME 110=head1 REQUEST ANATOMY AND LIFETIME
136 111
137Every C<aio_*> function creates a request. which is a C data structure not 112Every C<aio_*> function creates a request. which is a C data structure not
138directly visible to Perl. 113directly visible to Perl.
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188 163
189package IO::AIO; 164package IO::AIO;
190 165
191use Carp (); 166use Carp ();
192 167
193no warnings; 168use common::sense;
194use strict 'vars';
195 169
196use base 'Exporter'; 170use base 'Exporter';
197 171
198BEGIN { 172BEGIN {
199 our $VERSION = '2.61'; 173 our $VERSION = '3.5';
200 174
201 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
202 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir 176 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
203 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync 177 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
204 aio_fdatasync aio_pathsync aio_readahead 178 aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
205 aio_rename aio_link aio_move aio_copy aio_group 179 aio_rename aio_link aio_move aio_copy aio_group
206 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown 180 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
207 aio_chmod aio_utime aio_truncate); 181 aio_chmod aio_utime aio_truncate
182 aio_msync aio_mtouch aio_statvfs);
208 183
209 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block)); 184 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
210 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 185 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
211 min_parallel max_parallel max_idle 186 min_parallel max_parallel max_idle
212 nreqs nready npending nthreads 187 nreqs nready npending nthreads
213 max_poll_time max_poll_reqs); 188 max_poll_time max_poll_reqs
189 sendfile fadvise);
190
191 push @AIO_REQ, qw(aio_busy); # not exported
214 192
215 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 193 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
216 194
217 require XSLoader; 195 require XSLoader;
218 XSLoader::load ("IO::AIO", $VERSION); 196 XSLoader::load ("IO::AIO", $VERSION);
219} 197}
220 198
221=head1 FUNCTIONS 199=head1 FUNCTIONS
200
201=head2 QUICK OVERVIEW
202
203This section simply lists the prototypes of the most important functions
204for quick reference. See the following sections for function-by-function
205documentation.
206
207 aio_open $pathname, $flags, $mode, $callback->($fh)
208 aio_close $fh, $callback->($status)
209 aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
210 aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
211 aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
212 aio_readahead $fh,$offset,$length, $callback->($retval)
213 aio_stat $fh_or_path, $callback->($status)
214 aio_lstat $fh, $callback->($status)
215 aio_statvfs $fh_or_path, $callback->($statvfs)
216 aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
217 aio_chown $fh_or_path, $uid, $gid, $callback->($status)
218 aio_truncate $fh_or_path, $offset, $callback->($status)
219 aio_chmod $fh_or_path, $mode, $callback->($status)
220 aio_unlink $pathname, $callback->($status)
221 aio_mknod $path, $mode, $dev, $callback->($status)
222 aio_link $srcpath, $dstpath, $callback->($status)
223 aio_symlink $srcpath, $dstpath, $callback->($status)
224 aio_readlink $path, $callback->($link)
225 aio_rename $srcpath, $dstpath, $callback->($status)
226 aio_mkdir $pathname, $mode, $callback->($status)
227 aio_rmdir $pathname, $callback->($status)
228 aio_readdir $pathname, $callback->($entries)
229 aio_readdirx $pathname, $flags, $callback->($entries, $flags)
230 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
231 IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN
232 aio_load $path, $data, $callback->($status)
233 aio_copy $srcpath, $dstpath, $callback->($status)
234 aio_move $srcpath, $dstpath, $callback->($status)
235 aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
236 aio_rmtree $path, $callback->($status)
237 aio_sync $callback->($status)
238 aio_fsync $fh, $callback->($status)
239 aio_fdatasync $fh, $callback->($status)
240 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
241 aio_pathsync $path, $callback->($status)
242 aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
243 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
244 aio_group $callback->(...)
245 aio_nop $callback->()
246
247 $prev_pri = aioreq_pri [$pri]
248 aioreq_nice $pri_adjust
249
250 IO::AIO::poll_wait
251 IO::AIO::poll_cb
252 IO::AIO::poll
253 IO::AIO::flush
254 IO::AIO::max_poll_reqs $nreqs
255 IO::AIO::max_poll_time $seconds
256 IO::AIO::min_parallel $nthreads
257 IO::AIO::max_parallel $nthreads
258 IO::AIO::max_idle $nthreads
259 IO::AIO::max_outstanding $maxreqs
260 IO::AIO::nreqs
261 IO::AIO::nready
262 IO::AIO::npending
263
264 IO::AIO::sendfile $ofh, $ifh, $offset, $count
265 IO::AIO::fadvise $fh, $offset, $len, $advice
266 IO::AIO::mlockall $flags
267 IO::AIO::munlockall
222 268
223=head2 AIO REQUEST FUNCTIONS 269=head2 AIO REQUEST FUNCTIONS
224 270
225All the C<aio_*> calls are more or less thin wrappers around the syscall 271All the C<aio_*> calls are more or less thin wrappers around the syscall
226with the same name (sans C<aio_>). The arguments are similar or identical, 272with the same name (sans C<aio_>). The arguments are similar or identical,
227and they all accept an additional (and optional) C<$callback> argument 273and they all accept an additional (and optional) C<$callback> argument
228which must be a code reference. This code reference will get called with 274which must be a code reference. This code reference will get called with
229the syscall return code (e.g. most syscalls return C<-1> on error, unlike 275the syscall return code (e.g. most syscalls return C<-1> on error, unlike
230perl, which usually delivers "false") as it's sole argument when the given 276perl, which usually delivers "false") as its sole argument after the given
231syscall has been executed asynchronously. 277syscall has been executed asynchronously.
232 278
233All functions expecting a filehandle keep a copy of the filehandle 279All functions expecting a filehandle keep a copy of the filehandle
234internally until the request has finished. 280internally until the request has finished.
235 281
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249your pathnames to the locale (or other) encoding in effect in the user 295your pathnames to the locale (or other) encoding in effect in the user
250environment, d) use Glib::filename_from_unicode on unicode filenames or e) 296environment, d) use Glib::filename_from_unicode on unicode filenames or e)
251use something else to ensure your scalar has the correct contents. 297use something else to ensure your scalar has the correct contents.
252 298
253This works, btw. independent of the internal UTF-8 bit, which IO::AIO 299This works, btw. independent of the internal UTF-8 bit, which IO::AIO
254handles correctly wether it is set or not. 300handles correctly whether it is set or not.
255 301
256=over 4 302=over 4
257 303
258=item $prev_pri = aioreq_pri [$pri] 304=item $prev_pri = aioreq_pri [$pri]
259 305
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337 383
338=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 384=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
339 385
340=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 386=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
341 387
342Reads or writes C<$length> bytes from the specified C<$fh> and C<$offset> 388Reads or writes C<$length> bytes from or to the specified C<$fh> and
343into the scalar given by C<$data> and offset C<$dataoffset> and calls the 389C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
344callback without the actual number of bytes read (or -1 on error, just 390and calls the callback without the actual number of bytes read (or -1 on
345like the syscall). 391error, just like the syscall).
392
393C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
394offset plus the actual number of bytes read.
346 395
347If C<$offset> is undefined, then the current file descriptor offset will 396If C<$offset> is undefined, then the current file descriptor offset will
348be used (and updated), otherwise the file descriptor offset will not be 397be used (and updated), otherwise the file descriptor offset will not be
349changed by these calls. 398changed by these calls.
350 399
351If C<$length> is undefined in C<aio_write>, use the remaining length of C<$data>. 400If C<$length> is undefined in C<aio_write>, use the remaining length of
401C<$data>.
352 402
353If C<$dataoffset> is less than zero, it will be counted from the end of 403If C<$dataoffset> is less than zero, it will be counted from the end of
354C<$data>. 404C<$data>.
355 405
356The C<$data> scalar I<MUST NOT> be modified in any way while the request 406The C<$data> scalar I<MUST NOT> be modified in any way while the request
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376 426
377This call tries to make use of a native C<sendfile> syscall to provide 427This call tries to make use of a native C<sendfile> syscall to provide
378zero-copy operation. For this to work, C<$out_fh> should refer to a 428zero-copy operation. For this to work, C<$out_fh> should refer to a
379socket, and C<$in_fh> should refer to mmap'able file. 429socket, and C<$in_fh> should refer to mmap'able file.
380 430
381If the native sendfile call fails or is not implemented, it will be 431If a native sendfile cannot be found or it fails with C<ENOSYS>,
432C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
382emulated, so you can call C<aio_sendfile> on any type of filehandle 433it will be emulated, so you can call C<aio_sendfile> on any type of
383regardless of the limitations of the operating system. 434filehandle regardless of the limitations of the operating system.
384 435
385Please note, however, that C<aio_sendfile> can read more bytes from 436Please note, however, that C<aio_sendfile> can read more bytes from
386C<$in_fh> than are written, and there is no way to find out how many 437C<$in_fh> than are written, and there is no way to find out how many
387bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only 438bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
388provides the number of bytes written to C<$out_fh>. Only if the result 439provides the number of bytes written to C<$out_fh>. Only if the result
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426 $_[0] and die "stat failed: $!"; 477 $_[0] and die "stat failed: $!";
427 print "size is ", -s _, "\n"; 478 print "size is ", -s _, "\n";
428 }; 479 };
429 480
430 481
482=item aio_statvfs $fh_or_path, $callback->($statvfs)
483
484Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
485whether a file handle or path was passed.
486
487On success, the callback is passed a hash reference with the following
488members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
489C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
490is passed.
491
492The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
493C<ST_NOSUID>.
494
495The following non-POSIX IO::AIO::ST_* flag masks are defined to
496their correct value when available, or to C<0> on systems that do
497not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
498C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
499C<ST_NODIRATIME> and C<ST_RELATIME>.
500
501Example: stat C</wd> and dump out the data if successful.
502
503 aio_statvfs "/wd", sub {
504 my $f = $_[0]
505 or die "statvfs: $!";
506
507 use Data::Dumper;
508 say Dumper $f;
509 };
510
511 # result:
512 {
513 bsize => 1024,
514 bfree => 4333064312,
515 blocks => 10253828096,
516 files => 2050765568,
517 flag => 4096,
518 favail => 2042092649,
519 bavail => 4333064312,
520 ffree => 2042092649,
521 namemax => 255,
522 frsize => 1024,
523 fsid => 1810
524 }
525
526
431=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 527=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
432 528
433Works like perl's C<utime> function (including the special case of $atime 529Works like perl's C<utime> function (including the special case of $atime
434and $mtime being undef). Fractional times are supported if the underlying 530and $mtime being undef). Fractional times are supported if the underlying
435syscalls support them. 531syscalls support them.
… …
528 624
529Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 625Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
530directory (i.e. opendir + readdir + closedir). The entries will not be 626directory (i.e. opendir + readdir + closedir). The entries will not be
531sorted, and will B<NOT> include the C<.> and C<..> entries. 627sorted, and will B<NOT> include the C<.> and C<..> entries.
532 628
533The callback a single argument which is either C<undef> or an array-ref 629The callback is passed a single argument which is either C<undef> or an
534with the filenames. 630array-ref with the filenames.
631
632
633=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
634
635Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
636behaviour and output format. In case of an error, C<$entries> will be
637C<undef>.
638
639The flags are a combination of the following constants, ORed together (the
640flags will also be passed to the callback, possibly modified):
641
642=over 4
643
644=item IO::AIO::READDIR_DENTS
645
646When this flag is off, then the callback gets an arrayref with of names
647only (as with C<aio_readdir>), otherwise it gets an arrayref with
648C<[$name, $type, $inode]> arrayrefs, each describing a single directory
649entry in more detail.
650
651C<$name> is the name of the entry.
652
653C<$type> is one of the C<IO::AIO::DT_xxx> constants:
654
655C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
656C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
657C<IO::AIO::DT_WHT>.
658
659C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
660know, you have to run stat yourself. Also, for speed reasons, the C<$type>
661scalars are read-only: you can not modify them.
662
663C<$inode> is the inode number (which might not be exact on systems with 64
664bit inode numbers and 32 bit perls). This field has unspecified content on
665systems that do not deliver the inode information.
666
667=item IO::AIO::READDIR_DIRS_FIRST
668
669When this flag is set, then the names will be returned in an order where
670likely directories come first. This is useful when you need to quickly
671find directories, or you want to find all directories while avoiding to
672stat() each entry.
673
674If the system returns type information in readdir, then this is used
675to find directories directly. Otherwise, likely directories are files
676beginning with ".", or otherwise files with no dots, of which files with
677short names are tried first.
678
679=item IO::AIO::READDIR_STAT_ORDER
680
681When this flag is set, then the names will be returned in an order
682suitable for stat()'ing each one. That is, when you plan to stat()
683all files in the given directory, then the returned order will likely
684be fastest.
685
686If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
687the likely dirs come first, resulting in a less optimal stat order.
688
689=item IO::AIO::READDIR_FOUND_UNKNOWN
690
691This flag should not be set when calling C<aio_readdirx>. Instead, it
692is being set by C<aio_readdirx>, when any of the C<$type>'s found were
693C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
694C<$type>'s are known, which can be used to speed up some algorithms.
695
696=back
535 697
536 698
537=item aio_load $path, $data, $callback->($status) 699=item aio_load $path, $data, $callback->($status)
538 700
539This is a composite request that tries to fully load the given file into 701This is a composite request that tries to fully load the given file into
540memory. Status is the same as with aio_read. 702memory. Status is the same as with aio_read.
541 703
542=cut 704=cut
543 705
544sub aio_load($$;$) { 706sub aio_load($$;$) {
545 aio_block {
546 my ($path, undef, $cb) = @_; 707 my ($path, undef, $cb) = @_;
547 my $data = \$_[1]; 708 my $data = \$_[1];
548 709
549 my $pri = aioreq_pri; 710 my $pri = aioreq_pri;
550 my $grp = aio_group $cb; 711 my $grp = aio_group $cb;
712
713 aioreq_pri $pri;
714 add $grp aio_open $path, O_RDONLY, 0, sub {
715 my $fh = shift
716 or return $grp->result (-1);
551 717
552 aioreq_pri $pri; 718 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), $$data, 0, sub { 719 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
559 $grp->result ($_[0]); 720 $grp->result ($_[0]);
560 };
561 }; 721 };
562
563 $grp
564 } 722 };
723
724 $grp
565} 725}
566 726
567=item aio_copy $srcpath, $dstpath, $callback->($status) 727=item aio_copy $srcpath, $dstpath, $callback->($status)
568 728
569Try to copy the I<file> (directories not supported as either source or 729Try to copy the I<file> (directories not supported as either source or
570destination) from C<$srcpath> to C<$dstpath> and call the callback with 730destination) from C<$srcpath> to C<$dstpath> and call the callback with
571the C<0> (error) or C<-1> ok. 731a status of C<0> (ok) or C<-1> (error, see C<$!>).
572 732
573This is a composite request that it creates the destination file with 733This is a composite request that creates the destination file with
574mode 0200 and copies the contents of the source file into it using 734mode 0200 and copies the contents of the source file into it using
575C<aio_sendfile>, followed by restoring atime, mtime, access mode and 735C<aio_sendfile>, followed by restoring atime, mtime, access mode and
576uid/gid, in that order. 736uid/gid, in that order.
577 737
578If an error occurs, the partial destination file will be unlinked, if 738If an error occurs, the partial destination file will be unlinked, if
… …
580errors are being ignored. 740errors are being ignored.
581 741
582=cut 742=cut
583 743
584sub aio_copy($$;$) { 744sub aio_copy($$;$) {
585 aio_block {
586 my ($src, $dst, $cb) = @_; 745 my ($src, $dst, $cb) = @_;
587 746
588 my $pri = aioreq_pri; 747 my $pri = aioreq_pri;
589 my $grp = aio_group $cb; 748 my $grp = aio_group $cb;
590 749
591 aioreq_pri $pri; 750 aioreq_pri $pri;
592 add $grp aio_open $src, O_RDONLY, 0, sub { 751 add $grp aio_open $src, O_RDONLY, 0, sub {
593 if (my $src_fh = $_[0]) { 752 if (my $src_fh = $_[0]) {
594 my @stat = stat $src_fh; 753 my @stat = stat $src_fh; # hmm, might block over nfs?
595 754
596 aioreq_pri $pri; 755 aioreq_pri $pri;
597 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub { 756 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
598 if (my $dst_fh = $_[0]) { 757 if (my $dst_fh = $_[0]) {
599 aioreq_pri $pri; 758 aioreq_pri $pri;
600 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 759 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
601 if ($_[0] == $stat[7]) { 760 if ($_[0] == $stat[7]) {
602 $grp->result (0); 761 $grp->result (0);
603 close $src_fh; 762 close $src_fh;
604 763
605 # those should not normally block. should. should. 764 my $ch = sub {
606 utime $stat[8], $stat[9], $dst;
607 chmod $stat[2] & 07777, $dst_fh;
608 chown $stat[4], $stat[5], $dst_fh;
609
610 aioreq_pri $pri; 765 aioreq_pri $pri;
766 add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
767 aioreq_pri $pri;
768 add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
769 aioreq_pri $pri;
611 add $grp aio_close $dst_fh; 770 add $grp aio_close $dst_fh;
612 } else { 771 }
613 $grp->result (-1);
614 close $src_fh;
615 close $dst_fh;
616
617 aioreq $pri; 772 };
618 add $grp aio_unlink $dst;
619 } 773 };
774
775 aioreq_pri $pri;
776 add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
777 if ($_[0] < 0 && $! == ENOSYS) {
778 aioreq_pri $pri;
779 add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
780 } else {
781 $ch->();
782 }
783 };
784 } else {
785 $grp->result (-1);
786 close $src_fh;
787 close $dst_fh;
788
789 aioreq $pri;
790 add $grp aio_unlink $dst;
620 }; 791 }
621 } else {
622 $grp->result (-1);
623 } 792 };
793 } else {
794 $grp->result (-1);
624 }, 795 }
625
626 } else {
627 $grp->result (-1);
628 } 796 },
797
798 } else {
799 $grp->result (-1);
629 }; 800 }
630
631 $grp
632 } 801 };
802
803 $grp
633} 804}
634 805
635=item aio_move $srcpath, $dstpath, $callback->($status) 806=item aio_move $srcpath, $dstpath, $callback->($status)
636 807
637Try to move the I<file> (directories not supported as either source or 808Try to move the I<file> (directories not supported as either source or
638destination) from C<$srcpath> to C<$dstpath> and call the callback with 809destination) from C<$srcpath> to C<$dstpath> and call the callback with
639the C<0> (error) or C<-1> ok. 810a status of C<0> (ok) or C<-1> (error, see C<$!>).
640 811
641This is a composite request that tries to rename(2) the file first. If 812This is a composite request that tries to rename(2) the file first; if
642rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if 813rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
643that is successful, unlinking the C<$srcpath>. 814that is successful, unlinks the C<$srcpath>.
644 815
645=cut 816=cut
646 817
647sub aio_move($$;$) { 818sub aio_move($$;$) {
648 aio_block {
649 my ($src, $dst, $cb) = @_; 819 my ($src, $dst, $cb) = @_;
650 820
651 my $pri = aioreq_pri; 821 my $pri = aioreq_pri;
652 my $grp = aio_group $cb; 822 my $grp = aio_group $cb;
653 823
654 aioreq_pri $pri; 824 aioreq_pri $pri;
655 add $grp aio_rename $src, $dst, sub { 825 add $grp aio_rename $src, $dst, sub {
656 if ($_[0] && $! == EXDEV) { 826 if ($_[0] && $! == EXDEV) {
657 aioreq_pri $pri; 827 aioreq_pri $pri;
658 add $grp aio_copy $src, $dst, sub { 828 add $grp aio_copy $src, $dst, sub {
659 $grp->result ($_[0]);
660
661 if (!$_[0]) {
662 aioreq_pri $pri;
663 add $grp aio_unlink $src;
664 }
665 };
666 } else {
667 $grp->result ($_[0]); 829 $grp->result ($_[0]);
830
831 if (!$_[0]) {
832 aioreq_pri $pri;
833 add $grp aio_unlink $src;
834 }
668 } 835 };
836 } else {
837 $grp->result ($_[0]);
669 }; 838 }
670
671 $grp
672 } 839 };
840
841 $grp
673} 842}
674 843
675=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 844=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
676 845
677Scans a directory (similar to C<aio_readdir>) but additionally tries to 846Scans a directory (similar to C<aio_readdir>) but additionally tries to
… …
697 866
698Implementation notes. 867Implementation notes.
699 868
700The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can. 869The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
701 870
871If readdir returns file type information, then this is used directly to
872find directories.
873
702After reading the directory, the modification time, size etc. of the 874Otherwise, after reading the directory, the modification time, size etc.
703directory before and after the readdir is checked, and if they match (and 875of the directory before and after the readdir is checked, and if they
704isn't the current time), the link count will be used to decide how many 876match (and isn't the current time), the link count will be used to decide
705entries are directories (if >= 2). Otherwise, no knowledge of the number 877how many entries are directories (if >= 2). Otherwise, no knowledge of the
706of subdirectories will be assumed. 878number of subdirectories will be assumed.
707 879
708Then entries will be sorted into likely directories (everything without 880Then entries will be sorted into likely directories a non-initial dot
709a non-initial dot currently) and likely non-directories (everything 881currently) and likely non-directories (see C<aio_readdirx>). Then every
710else). Then every entry plus an appended C</.> will be C<stat>'ed, 882entry plus an appended C</.> will be C<stat>'ed, likely directories first,
711likely directories first. If that succeeds, it assumes that the entry 883in order of their inode numbers. If that succeeds, it assumes that the
712is a directory or a symlink to directory (which will be checked 884entry is a directory or a symlink to directory (which will be checked
713seperately). This is often faster than stat'ing the entry itself because 885seperately). This is often faster than stat'ing the entry itself because
714filesystems might detect the type of the entry without reading the inode 886filesystems might detect the type of the entry without reading the inode
715data (e.g. ext2fs filetype feature). 887data (e.g. ext2fs filetype feature), even on systems that cannot return
888the filetype information on readdir.
716 889
717If the known number of directories (link count - 2) has been reached, the 890If the known number of directories (link count - 2) has been reached, the
718rest of the entries is assumed to be non-directories. 891rest of the entries is assumed to be non-directories.
719 892
720This only works with certainty on POSIX (= UNIX) filesystems, which 893This only works with certainty on POSIX (= UNIX) filesystems, which
… …
725directory counting heuristic. 898directory counting heuristic.
726 899
727=cut 900=cut
728 901
729sub aio_scandir($$;$) { 902sub aio_scandir($$;$) {
730 aio_block {
731 my ($path, $maxreq, $cb) = @_; 903 my ($path, $maxreq, $cb) = @_;
732 904
733 my $pri = aioreq_pri; 905 my $pri = aioreq_pri;
734 906
735 my $grp = aio_group $cb; 907 my $grp = aio_group $cb;
736 908
737 $maxreq = 4 if $maxreq <= 0; 909 $maxreq = 4 if $maxreq <= 0;
738 910
739 # stat once 911 # stat once
912 aioreq_pri $pri;
913 add $grp aio_stat $path, sub {
914 return $grp->result () if $_[0];
915 my $now = time;
916 my $hash1 = join ":", (stat _)[0,1,3,7,9];
917
918 # read the directory entries
740 aioreq_pri $pri; 919 aioreq_pri $pri;
741 add $grp aio_stat $path, sub { 920 add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
921 my $entries = shift
742 return $grp->result () if $_[0]; 922 or return $grp->result ();
743 my $now = time;
744 my $hash1 = join ":", (stat _)[0,1,3,7,9];
745 923
746 # read the directory entries 924 # stat the dir another time
747 aioreq_pri $pri; 925 aioreq_pri $pri;
748 add $grp aio_readdir $path, sub {
749 my $entries = shift
750 or return $grp->result ();
751
752 # stat the dir another time
753 aioreq_pri $pri;
754 add $grp aio_stat $path, sub { 926 add $grp aio_stat $path, sub {
755 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 927 my $hash2 = join ":", (stat _)[0,1,3,7,9];
756 928
757 my $ndirs; 929 my $ndirs;
758 930
759 # take the slow route if anything looks fishy 931 # take the slow route if anything looks fishy
760 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 932 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
761 $ndirs = -1; 933 $ndirs = -1;
762 } else { 934 } else {
763 # if nlink == 2, we are finished 935 # if nlink == 2, we are finished
764 # on non-posix-fs's, we rely on nlink < 2 936 # for non-posix-fs's, we rely on nlink < 2
765 $ndirs = (stat _)[3] - 2 937 $ndirs = (stat _)[3] - 2
766 or return $grp->result ([], $entries); 938 or return $grp->result ([], $entries);
767 } 939 }
768 940
769 # sort into likely dirs and likely nondirs
770 # dirs == files without ".", short entries first
771 $entries = [map $_->[0],
772 sort { $b->[1] cmp $a->[1] }
773 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
774 @$entries];
775
776 my (@dirs, @nondirs); 941 my (@dirs, @nondirs);
777 942
778 my $statgrp = add $grp aio_group sub { 943 my $statgrp = add $grp aio_group sub {
779 $grp->result (\@dirs, \@nondirs); 944 $grp->result (\@dirs, \@nondirs);
780 }; 945 };
781 946
782 limit $statgrp $maxreq; 947 limit $statgrp $maxreq;
783 feed $statgrp sub { 948 feed $statgrp sub {
784 return unless @$entries; 949 return unless @$entries;
785 my $entry = pop @$entries; 950 my $entry = shift @$entries;
786 951
787 aioreq_pri $pri; 952 aioreq_pri $pri;
788 add $statgrp aio_stat "$path/$entry/.", sub { 953 add $statgrp aio_stat "$path/$entry/.", sub {
789 if ($_[0] < 0) { 954 if ($_[0] < 0) {
790 push @nondirs, $entry; 955 push @nondirs, $entry;
791 } else { 956 } else {
792 # need to check for real directory 957 # need to check for real directory
793 aioreq_pri $pri; 958 aioreq_pri $pri;
794 add $statgrp aio_lstat "$path/$entry", sub { 959 add $statgrp aio_lstat "$path/$entry", sub {
795 if (-d _) { 960 if (-d _) {
796 push @dirs, $entry; 961 push @dirs, $entry;
797 962
798 unless (--$ndirs) { 963 unless (--$ndirs) {
799 push @nondirs, @$entries; 964 push @nondirs, @$entries;
800 feed $statgrp; 965 feed $statgrp;
801 }
802 } else {
803 push @nondirs, $entry;
804 } 966 }
967 } else {
968 push @nondirs, $entry;
805 } 969 }
806 } 970 }
807 }; 971 }
808 }; 972 };
809 }; 973 };
810 }; 974 };
811 }; 975 };
812
813 $grp
814 } 976 };
977
978 $grp
815} 979}
816 980
817=item aio_rmtree $path, $callback->($status) 981=item aio_rmtree $path, $callback->($status)
818 982
819Delete a directory tree starting (and including) C<$path>, return the 983Delete a directory tree starting (and including) C<$path>, return the
… …
823 987
824=cut 988=cut
825 989
826sub aio_rmtree; 990sub aio_rmtree;
827sub aio_rmtree($;$) { 991sub aio_rmtree($;$) {
828 aio_block {
829 my ($path, $cb) = @_; 992 my ($path, $cb) = @_;
830 993
831 my $pri = aioreq_pri; 994 my $pri = aioreq_pri;
832 my $grp = aio_group $cb; 995 my $grp = aio_group $cb;
833 996
834 aioreq_pri $pri; 997 aioreq_pri $pri;
835 add $grp aio_scandir $path, 0, sub { 998 add $grp aio_scandir $path, 0, sub {
836 my ($dirs, $nondirs) = @_; 999 my ($dirs, $nondirs) = @_;
837 1000
838 my $dirgrp = aio_group sub { 1001 my $dirgrp = aio_group sub {
839 add $grp aio_rmdir $path, sub { 1002 add $grp aio_rmdir $path, sub {
840 $grp->result ($_[0]); 1003 $grp->result ($_[0]);
841 };
842 }; 1004 };
843
844 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
845 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
846
847 add $grp $dirgrp;
848 }; 1005 };
849 1006
850 $grp 1007 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
1008 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
1009
1010 add $grp $dirgrp;
851 } 1011 };
1012
1013 $grp
852} 1014}
853 1015
854=item aio_sync $callback->($status) 1016=item aio_sync $callback->($status)
855 1017
856Asynchronously call sync and call the callback when finished. 1018Asynchronously call sync and call the callback when finished.
… …
866callback with the fdatasync result code. 1028callback with the fdatasync result code.
867 1029
868If this call isn't available because your OS lacks it or it couldn't be 1030If this call isn't available because your OS lacks it or it couldn't be
869detected, it will be emulated by calling C<fsync> instead. 1031detected, it will be emulated by calling C<fsync> instead.
870 1032
1033=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
1034
1035Sync the data portion of the file specified by C<$offset> and C<$length>
1036to disk (but NOT the metadata), by calling the Linux-specific
1037sync_file_range call. If sync_file_range is not available or it returns
1038ENOSYS, then fdatasync or fsync is being substituted.
1039
1040C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
1041C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
1042C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
1043manpage for details.
1044
871=item aio_pathsync $path, $callback->($status) 1045=item aio_pathsync $path, $callback->($status)
872 1046
873This request tries to open, fsync and close the given path. This is a 1047This request tries to open, fsync and close the given path. This is a
874composite request intended tosync directories after directory operations 1048composite request intended to sync directories after directory operations
875(E.g. rename). This might not work on all operating systems or have any 1049(E.g. rename). This might not work on all operating systems or have any
876specific effect, but usually it makes sure that directory changes get 1050specific effect, but usually it makes sure that directory changes get
877written to disc. It works for anything that can be opened for read-only, 1051written to disc. It works for anything that can be opened for read-only,
878not just directories. 1052not just directories.
879 1053
1054Future versions of this function might fall back to other methods when
1055C<fsync> on the directory fails (such as calling C<sync>).
1056
880Passes C<0> when everything went ok, and C<-1> on error. 1057Passes C<0> when everything went ok, and C<-1> on error.
881 1058
882=cut 1059=cut
883 1060
884sub aio_pathsync($;$) { 1061sub aio_pathsync($;$) {
885 aio_block {
886 my ($path, $cb) = @_; 1062 my ($path, $cb) = @_;
887 1063
888 my $pri = aioreq_pri; 1064 my $pri = aioreq_pri;
889 my $grp = aio_group $cb; 1065 my $grp = aio_group $cb;
890 1066
891 aioreq_pri $pri; 1067 aioreq_pri $pri;
892 add $grp aio_open $path, O_RDONLY, 0, sub { 1068 add $grp aio_open $path, O_RDONLY, 0, sub {
893 my ($fh) = @_; 1069 my ($fh) = @_;
894 if ($fh) { 1070 if ($fh) {
1071 aioreq_pri $pri;
1072 add $grp aio_fsync $fh, sub {
1073 $grp->result ($_[0]);
1074
895 aioreq_pri $pri; 1075 aioreq_pri $pri;
896 add $grp aio_fsync $fh, sub {
897 $grp->result ($_[0]);
898
899 aioreq_pri $pri;
900 add $grp aio_close $fh; 1076 add $grp aio_close $fh;
901 };
902 } else {
903 $grp->result (-1);
904 } 1077 };
1078 } else {
1079 $grp->result (-1);
905 }; 1080 }
906
907 $grp
908 } 1081 };
1082
1083 $grp
909} 1084}
1085
1086=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1087
1088This is a rather advanced IO::AIO call, which only works on mmap(2)ed
1089scalars (see the L<Sys::Mmap> or L<Mmap> modules for details on this, note
1090that the scalar must only be modified in-place while an aio operation is
1091pending on it).
1092
1093It calls the C<msync> function of your OS, if available, with the memory
1094area starting at C<$offset> in the string and ending C<$length> bytes
1095later. If C<$length> is negative, counts from the end, and if C<$length>
1096is C<undef>, then it goes till the end of the string. The flags can be
1097a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
1098C<IO::AIO::MS_SYNC>.
1099
1100=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1101
1102This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1103scalars.
1104
1105It touches (reads or writes) all memory pages in the specified
1106range inside the scalar. All caveats and parameters are the same
1107as for C<aio_msync>, above, except for flags, which must be either
1108C<0> (which reads all pages and ensures they are instantiated) or
1109C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
1110writing an octet from it, which dirties the page).
910 1111
911=item aio_group $callback->(...) 1112=item aio_group $callback->(...)
912 1113
913This is a very special aio request: Instead of doing something, it is a 1114This is a very special aio request: Instead of doing something, it is a
914container for other aio requests, which is useful if you want to bundle 1115container for other aio requests, which is useful if you want to bundle
… …
964=item cancel $req 1165=item cancel $req
965 1166
966Cancels the request, if possible. Has the effect of skipping execution 1167Cancels the request, if possible. Has the effect of skipping execution
967when entering the B<execute> state and skipping calling the callback when 1168when entering the B<execute> state and skipping calling the callback when
968entering the the B<result> state, but will leave the request otherwise 1169entering the the B<result> state, but will leave the request otherwise
969untouched. That means that requests that currently execute will not be 1170untouched (with the exception of readdir). That means that requests that
970stopped and resources held by the request will not be freed prematurely. 1171currently execute will not be stopped and resources held by the request
1172will not be freed prematurely.
971 1173
972=item cb $req $callback->(...) 1174=item cb $req $callback->(...)
973 1175
974Replace (or simply set) the callback registered to the request. 1176Replace (or simply set) the callback registered to the request.
975 1177
… …
1026Their lifetime, simplified, looks like this: when they are empty, they 1228Their lifetime, simplified, looks like this: when they are empty, they
1027will finish very quickly. If they contain only requests that are in the 1229will finish very quickly. If they contain only requests that are in the
1028C<done> state, they will also finish. Otherwise they will continue to 1230C<done> state, they will also finish. Otherwise they will continue to
1029exist. 1231exist.
1030 1232
1031That means after creating a group you have some time to add requests. And 1233That means after creating a group you have some time to add requests
1032in the callbacks of those requests, you can add further requests to the 1234(precisely before the callback has been invoked, which is only done within
1033group. And only when all those requests have finished will the the group 1235the C<poll_cb>). And in the callbacks of those requests, you can add
1034itself finish. 1236further requests to the group. And only when all those requests have
1237finished will the the group itself finish.
1035 1238
1036=over 4 1239=over 4
1037 1240
1038=item add $grp ... 1241=item add $grp ...
1039 1242
… …
1047 1250
1048=item $grp->cancel_subs 1251=item $grp->cancel_subs
1049 1252
1050Cancel all subrequests and clears any feeder, but not the group request 1253Cancel all subrequests and clears any feeder, but not the group request
1051itself. Useful when you queued a lot of events but got a result early. 1254itself. Useful when you queued a lot of events but got a result early.
1255
1256The group request will finish normally (you cannot add requests to the
1257group).
1052 1258
1053=item $grp->result (...) 1259=item $grp->result (...)
1054 1260
1055Set the result value(s) that will be passed to the group callback when all 1261Set the result value(s) that will be passed to the group callback when all
1056subrequests have finished and set the groups errno to the current value 1262subrequests have finished and set the groups errno to the current value
… …
1072=item feed $grp $callback->($grp) 1278=item feed $grp $callback->($grp)
1073 1279
1074Sets a feeder/generator on this group: every group can have an attached 1280Sets a feeder/generator on this group: every group can have an attached
1075generator that generates requests if idle. The idea behind this is that, 1281generator that generates requests if idle. The idea behind this is that,
1076although you could just queue as many requests as you want in a group, 1282although you could just queue as many requests as you want in a group,
1077this might starve other requests for a potentially long time. For 1283this might starve other requests for a potentially long time. For example,
1078example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1284C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1079requests, delaying any later requests for a long time. 1285delaying any later requests for a long time.
1080 1286
1081To avoid this, and allow incremental generation of requests, you can 1287To avoid this, and allow incremental generation of requests, you can
1082instead a group and set a feeder on it that generates those requests. The 1288instead a group and set a feeder on it that generates those requests. The
1083feed callback will be called whenever there are few enough (see C<limit>, 1289feed callback will be called whenever there are few enough (see C<limit>,
1084below) requests active in the group itself and is expected to queue more 1290below) requests active in the group itself and is expected to queue more
… …
1088not impose any limits). 1294not impose any limits).
1089 1295
1090If the feed does not queue more requests when called, it will be 1296If the feed does not queue more requests when called, it will be
1091automatically removed from the group. 1297automatically removed from the group.
1092 1298
1093If the feed limit is C<0>, it will be set to C<2> automatically. 1299If the feed limit is C<0> when this method is called, it will be set to
1300C<2> automatically.
1094 1301
1095Example: 1302Example:
1096 1303
1097 # stat all files in @files, but only ever use four aio requests concurrently: 1304 # stat all files in @files, but only ever use four aio requests concurrently:
1098 1305
… …
1110Sets the feeder limit for the group: The feeder will be called whenever 1317Sets the feeder limit for the group: The feeder will be called whenever
1111the group contains less than this many requests. 1318the group contains less than this many requests.
1112 1319
1113Setting the limit to C<0> will pause the feeding process. 1320Setting the limit to C<0> will pause the feeding process.
1114 1321
1322The default value for the limit is C<0>, but note that setting a feeder
1323automatically bumps it up to C<2>.
1324
1115=back 1325=back
1116 1326
1117=head2 SUPPORT FUNCTIONS 1327=head2 SUPPORT FUNCTIONS
1118 1328
1119=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1329=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
… …
1121=over 4 1331=over 4
1122 1332
1123=item $fileno = IO::AIO::poll_fileno 1333=item $fileno = IO::AIO::poll_fileno
1124 1334
1125Return the I<request result pipe file descriptor>. This filehandle must be 1335Return the I<request result pipe file descriptor>. This filehandle must be
1126polled for reading by some mechanism outside this module (e.g. Event or 1336polled for reading by some mechanism outside this module (e.g. EV, Glib,
1127select, see below or the SYNOPSIS). If the pipe becomes readable you have 1337select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1128to call C<poll_cb> to check the results. 1338you have to call C<poll_cb> to check the results.
1129 1339
1130See C<poll_cb> for an example. 1340See C<poll_cb> for an example.
1131 1341
1132=item IO::AIO::poll_cb 1342=item IO::AIO::poll_cb
1133 1343
1134Process some outstanding events on the result pipe. You have to call this 1344Process some outstanding events on the result pipe. You have to call this
1135regularly. Returns the number of events processed. Returns immediately 1345regularly. Returns C<0> if all events could be processed, or C<-1> if it
1346returned earlier for whatever reason. Returns immediately when no events
1136when no events are outstanding. The amount of events processed depends on 1347are outstanding. The amount of events processed depends on the settings of
1137the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>. 1348C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1138 1349
1139If not all requests were processed for whatever reason, the filehandle 1350If not all requests were processed for whatever reason, the filehandle
1140will still be ready when C<poll_cb> returns. 1351will still be ready when C<poll_cb> returns, so normally you don't have to
1352do anything special to have it called later.
1141 1353
1142Example: Install an Event watcher that automatically calls 1354Example: Install an Event watcher that automatically calls
1143IO::AIO::poll_cb with high priority: 1355IO::AIO::poll_cb with high priority (more examples can be found in the
1356SYNOPSIS section, at the top of this document):
1144 1357
1145 Event->io (fd => IO::AIO::poll_fileno, 1358 Event->io (fd => IO::AIO::poll_fileno,
1146 poll => 'r', async => 1, 1359 poll => 'r', async => 1,
1147 cb => \&IO::AIO::poll_cb); 1360 cb => \&IO::AIO::poll_cb);
1361
1362=item IO::AIO::poll_wait
1363
1364If there are any outstanding requests and none of them in the result
1365phase, wait till the result filehandle becomes ready for reading (simply
1366does a C<select> on the filehandle. This is useful if you want to
1367synchronously wait for some requests to finish).
1368
1369See C<nreqs> for an example.
1370
1371=item IO::AIO::poll
1372
1373Waits until some requests have been handled.
1374
1375Returns the number of requests processed, but is otherwise strictly
1376equivalent to:
1377
1378 IO::AIO::poll_wait, IO::AIO::poll_cb
1379
1380=item IO::AIO::flush
1381
1382Wait till all outstanding AIO requests have been handled.
1383
1384Strictly equivalent to:
1385
1386 IO::AIO::poll_wait, IO::AIO::poll_cb
1387 while IO::AIO::nreqs;
1148 1388
1149=item IO::AIO::max_poll_reqs $nreqs 1389=item IO::AIO::max_poll_reqs $nreqs
1150 1390
1151=item IO::AIO::max_poll_time $seconds 1391=item IO::AIO::max_poll_time $seconds
1152 1392
… …
1177 # use a low priority so other tasks have priority 1417 # use a low priority so other tasks have priority
1178 Event->io (fd => IO::AIO::poll_fileno, 1418 Event->io (fd => IO::AIO::poll_fileno,
1179 poll => 'r', nice => 1, 1419 poll => 'r', nice => 1,
1180 cb => &IO::AIO::poll_cb); 1420 cb => &IO::AIO::poll_cb);
1181 1421
1182=item IO::AIO::poll_wait
1183
1184If there are any outstanding requests and none of them in the result
1185phase, wait till the result filehandle becomes ready for reading (simply
1186does a C<select> on the filehandle. This is useful if you want to
1187synchronously wait for some requests to finish).
1188
1189See C<nreqs> for an example.
1190
1191=item IO::AIO::poll
1192
1193Waits until some requests have been handled.
1194
1195Returns the number of requests processed, but is otherwise strictly
1196equivalent to:
1197
1198 IO::AIO::poll_wait, IO::AIO::poll_cb
1199
1200=item IO::AIO::flush
1201
1202Wait till all outstanding AIO requests have been handled.
1203
1204Strictly equivalent to:
1205
1206 IO::AIO::poll_wait, IO::AIO::poll_cb
1207 while IO::AIO::nreqs;
1208
1209=back 1422=back
1210 1423
1211=head3 CONTROLLING THE NUMBER OF THREADS 1424=head3 CONTROLLING THE NUMBER OF THREADS
1212 1425
1213=over 1426=over
… …
1259 1472
1260The default is probably ok in most situations, especially if thread 1473The default is probably ok in most situations, especially if thread
1261creation is fast. If thread creation is very slow on your system you might 1474creation is fast. If thread creation is very slow on your system you might
1262want to use larger values. 1475want to use larger values.
1263 1476
1264=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1477=item IO::AIO::max_outstanding $maxreqs
1265 1478
1266This is a very bad function to use in interactive programs because it 1479This is a very bad function to use in interactive programs because it
1267blocks, and a bad way to reduce concurrency because it is inexact: Better 1480blocks, and a bad way to reduce concurrency because it is inexact: Better
1268use an C<aio_group> together with a feed callback. 1481use an C<aio_group> together with a feed callback.
1269 1482
… …
1274 1487
1275The default value is very large, so there is no practical limit on the 1488The default value is very large, so there is no practical limit on the
1276number of outstanding requests. 1489number of outstanding requests.
1277 1490
1278You can still queue as many requests as you want. Therefore, 1491You can still queue as many requests as you want. Therefore,
1279C<max_oustsanding> is mainly useful in simple scripts (with low values) or 1492C<max_outstanding> is mainly useful in simple scripts (with low values) or
1280as a stop gap to shield against fatal memory overflow (with large values). 1493as a stop gap to shield against fatal memory overflow (with large values).
1281 1494
1282=back 1495=back
1283 1496
1284=head3 STATISTICAL INFORMATION 1497=head3 STATISTICAL INFORMATION
… …
1305Returns the number of requests currently in the pending state (executed, 1518Returns the number of requests currently in the pending state (executed,
1306but not yet processed by poll_cb). 1519but not yet processed by poll_cb).
1307 1520
1308=back 1521=back
1309 1522
1523=head3 MISCELLANEOUS FUNCTIONS
1524
1525IO::AIO implements some functions that might be useful, but are not
1526asynchronous.
1527
1528=over 4
1529
1530=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1531
1532Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
1533but is blocking (this makes most sense if you know the input data is
1534likely cached already and the output filehandle is set to non-blocking
1535operations).
1536
1537Returns the number of bytes copied, or C<-1> on error.
1538
1539=item IO::AIO::fadvise $fh, $offset, $len, $advice
1540
1541Simply calls the C<posix_fadvise> function (see it's
1542manpage for details). The following advice constants are
1543avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1544C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1545C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1546
1547On systems that do not implement C<posix_fadvise>, this function returns
1548ENOSYS, otherwise the return value of C<posix_fadvise>.
1549
1550=item IO::AIO::mlockall $flags
1551
1552Calls the C<mlockall> function with the given C<$flags> (a combination of
1553C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL__FUTURE>).
1554
1555On systems that do not implement C<mlockall>, this function returns
1556ENOSYS, otherwise the return value of C<mlockall>.
1557
1558=item IO::AIO::munlockall
1559
1560Calls the C<munlockall> function.
1561
1562On systems that do not implement C<munlockall>, this function returns
1563ENOSYS, otherwise the return value of C<munlockall>.
1564
1565=back
1566
1310=cut 1567=cut
1311 1568
1312min_parallel 8; 1569min_parallel 8;
1313 1570
1314END { flush } 1571END { flush }
1315 1572
13161; 15731;
1574
1575=head1 EVENT LOOP INTEGRATION
1576
1577It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
1578automatically into many event loops:
1579
1580 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
1581 use AnyEvent::AIO;
1582
1583You can also integrate IO::AIO manually into many event loops, here are
1584some examples of how to do this:
1585
1586 # EV integration
1587 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
1588
1589 # Event integration
1590 Event->io (fd => IO::AIO::poll_fileno,
1591 poll => 'r',
1592 cb => \&IO::AIO::poll_cb);
1593
1594 # Glib/Gtk2 integration
1595 add_watch Glib::IO IO::AIO::poll_fileno,
1596 in => sub { IO::AIO::poll_cb; 1 };
1597
1598 # Tk integration
1599 Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
1600 readable => \&IO::AIO::poll_cb);
1601
1602 # Danga::Socket integration
1603 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
1604 \&IO::AIO::poll_cb);
1317 1605
1318=head2 FORK BEHAVIOUR 1606=head2 FORK BEHAVIOUR
1319 1607
1320This module should do "the right thing" when the process using it forks: 1608This module should do "the right thing" when the process using it forks:
1321 1609
… …
1354 1642
1355Known bugs will be fixed in the next release. 1643Known bugs will be fixed in the next release.
1356 1644
1357=head1 SEE ALSO 1645=head1 SEE ALSO
1358 1646
1359L<Coro::AIO>. 1647L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1648more natural syntax.
1360 1649
1361=head1 AUTHOR 1650=head1 AUTHOR
1362 1651
1363 Marc Lehmann <schmorp@schmorp.de> 1652 Marc Lehmann <schmorp@schmorp.de>
1364 http://home.schmorp.de/ 1653 http://home.schmorp.de/

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