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Revision 1.122 by root, Sat Apr 26 12:00:23 2008 UTC vs.
Revision 1.186 by root, Thu Dec 30 07:19:31 2010 UTC

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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
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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", IO::AIO::O_RDONLY, 0, sub {
107 my $fh = shift 82 my $fh = shift
108 or die "error while opening: $!"; 83 or die "error while opening: $!";
109 84
110 # stat'ing filehandles is generally non-blocking 85 # stat'ing filehandles is generally non-blocking
111 my $size = -s $fh; 86 my $size = -s $fh;
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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 = '2.62'; 173 our $VERSION = '3.71';
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_mlock aio_mlockall
183 aio_statvfs);
208 184
209 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block)); 185 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
210 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 186 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
211 min_parallel max_parallel max_idle 187 min_parallel max_parallel max_idle
212 nreqs nready npending nthreads 188 nreqs nready npending nthreads
213 max_poll_time max_poll_reqs); 189 max_poll_time max_poll_reqs
190 sendfile fadvise madvise
191 mmap munmap munlock munlockall);
192
193 push @AIO_REQ, qw(aio_busy); # not exported
214 194
215 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 195 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
216 196
217 require XSLoader; 197 require XSLoader;
218 XSLoader::load ("IO::AIO", $VERSION); 198 XSLoader::load ("IO::AIO", $VERSION);
219} 199}
220 200
221=head1 FUNCTIONS 201=head1 FUNCTIONS
202
203=head2 QUICK OVERVIEW
204
205This section simply lists the prototypes of the most important functions
206for quick reference. See the following sections for function-by-function
207documentation.
208
209 aio_open $pathname, $flags, $mode, $callback->($fh)
210 aio_close $fh, $callback->($status)
211 aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
212 aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
213 aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
214 aio_readahead $fh,$offset,$length, $callback->($retval)
215 aio_stat $fh_or_path, $callback->($status)
216 aio_lstat $fh, $callback->($status)
217 aio_statvfs $fh_or_path, $callback->($statvfs)
218 aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
219 aio_chown $fh_or_path, $uid, $gid, $callback->($status)
220 aio_truncate $fh_or_path, $offset, $callback->($status)
221 aio_chmod $fh_or_path, $mode, $callback->($status)
222 aio_unlink $pathname, $callback->($status)
223 aio_mknod $path, $mode, $dev, $callback->($status)
224 aio_link $srcpath, $dstpath, $callback->($status)
225 aio_symlink $srcpath, $dstpath, $callback->($status)
226 aio_readlink $path, $callback->($link)
227 aio_rename $srcpath, $dstpath, $callback->($status)
228 aio_mkdir $pathname, $mode, $callback->($status)
229 aio_rmdir $pathname, $callback->($status)
230 aio_readdir $pathname, $callback->($entries)
231 aio_readdirx $pathname, $flags, $callback->($entries, $flags)
232 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
233 IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN
234 aio_load $path, $data, $callback->($status)
235 aio_copy $srcpath, $dstpath, $callback->($status)
236 aio_move $srcpath, $dstpath, $callback->($status)
237 aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
238 aio_rmtree $path, $callback->($status)
239 aio_sync $callback->($status)
240 aio_fsync $fh, $callback->($status)
241 aio_fdatasync $fh, $callback->($status)
242 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
243 aio_pathsync $path, $callback->($status)
244 aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
245 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
246 aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
247 aio_mlockall $flags, $callback->($status)
248 aio_group $callback->(...)
249 aio_nop $callback->()
250
251 $prev_pri = aioreq_pri [$pri]
252 aioreq_nice $pri_adjust
253
254 IO::AIO::poll_wait
255 IO::AIO::poll_cb
256 IO::AIO::poll
257 IO::AIO::flush
258 IO::AIO::max_poll_reqs $nreqs
259 IO::AIO::max_poll_time $seconds
260 IO::AIO::min_parallel $nthreads
261 IO::AIO::max_parallel $nthreads
262 IO::AIO::max_idle $nthreads
263 IO::AIO::max_outstanding $maxreqs
264 IO::AIO::nreqs
265 IO::AIO::nready
266 IO::AIO::npending
267
268 IO::AIO::sendfile $ofh, $ifh, $offset, $count
269 IO::AIO::fadvise $fh, $offset, $len, $advice
270 IO::AIO::madvise $scalar, $offset, $length, $advice
271 IO::AIO::mprotect $scalar, $offset, $length, $protect
272 IO::AIO::munlock $scalar, $offset = 0, $length = undef
273 IO::AIO::munlockall
222 274
223=head2 AIO REQUEST FUNCTIONS 275=head2 AIO REQUEST FUNCTIONS
224 276
225All the C<aio_*> calls are more or less thin wrappers around the syscall 277All the C<aio_*> calls are more or less thin wrappers around the syscall
226with the same name (sans C<aio_>). The arguments are similar or identical, 278with the same name (sans C<aio_>). The arguments are similar or identical,
227and they all accept an additional (and optional) C<$callback> argument 279and they all accept an additional (and optional) C<$callback> argument
228which must be a code reference. This code reference will get called with 280which 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 281the 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 282perl, which usually delivers "false") as its sole argument after the given
231syscall has been executed asynchronously. 283syscall has been executed asynchronously.
232 284
233All functions expecting a filehandle keep a copy of the filehandle 285All functions expecting a filehandle keep a copy of the filehandle
234internally until the request has finished. 286internally until the request has finished.
235 287
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249your pathnames to the locale (or other) encoding in effect in the user 301your pathnames to the locale (or other) encoding in effect in the user
250environment, d) use Glib::filename_from_unicode on unicode filenames or e) 302environment, d) use Glib::filename_from_unicode on unicode filenames or e)
251use something else to ensure your scalar has the correct contents. 303use something else to ensure your scalar has the correct contents.
252 304
253This works, btw. independent of the internal UTF-8 bit, which IO::AIO 305This works, btw. independent of the internal UTF-8 bit, which IO::AIO
254handles correctly wether it is set or not. 306handles correctly whether it is set or not.
255 307
256=over 4 308=over 4
257 309
258=item $prev_pri = aioreq_pri [$pri] 310=item $prev_pri = aioreq_pri [$pri]
259 311
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306by the umask in effect then the request is being executed, so better never 358by the umask in effect then the request is being executed, so better never
307change the umask. 359change the umask.
308 360
309Example: 361Example:
310 362
311 aio_open "/etc/passwd", O_RDONLY, 0, sub { 363 aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
312 if ($_[0]) { 364 if ($_[0]) {
313 print "open successful, fh is $_[0]\n"; 365 print "open successful, fh is $_[0]\n";
314 ... 366 ...
315 } else { 367 } else {
316 die "open failed: $!\n"; 368 die "open failed: $!\n";
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337 389
338=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 390=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
339 391
340=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 392=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
341 393
342Reads or writes C<$length> bytes from the specified C<$fh> and C<$offset> 394Reads or writes C<$length> bytes from or to the specified C<$fh> and
343into the scalar given by C<$data> and offset C<$dataoffset> and calls the 395C<$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 396and calls the callback without the actual number of bytes read (or -1 on
345like the syscall). 397error, just like the syscall).
398
399C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
400offset plus the actual number of bytes read.
346 401
347If C<$offset> is undefined, then the current file descriptor offset will 402If C<$offset> is undefined, then the current file descriptor offset will
348be used (and updated), otherwise the file descriptor offset will not be 403be used (and updated), otherwise the file descriptor offset will not be
349changed by these calls. 404changed by these calls.
350 405
351If C<$length> is undefined in C<aio_write>, use the remaining length of C<$data>. 406If C<$length> is undefined in C<aio_write>, use the remaining length of
407C<$data>.
352 408
353If C<$dataoffset> is less than zero, it will be counted from the end of 409If C<$dataoffset> is less than zero, it will be counted from the end of
354C<$data>. 410C<$data>.
355 411
356The C<$data> scalar I<MUST NOT> be modified in any way while the request 412The C<$data> scalar I<MUST NOT> be modified in any way while the request
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372reading at byte offset C<$in_offset>, and starts writing at the current 428reading at byte offset C<$in_offset>, and starts writing at the current
373file offset of C<$out_fh>. Because of that, it is not safe to issue more 429file offset of C<$out_fh>. Because of that, it is not safe to issue more
374than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each 430than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
375other. 431other.
376 432
433Please note that C<aio_sendfile> can read more bytes from C<$in_fh> than
434are written, and there is no way to find out how many bytes have been read
435from C<aio_sendfile> alone, as C<aio_sendfile> only provides the number of
436bytes written to C<$out_fh>. Only if the result value equals C<$length>
437one can assume that C<$length> bytes have been read.
438
439Unlike with other C<aio_> functions, it makes a lot of sense to use
440C<aio_sendfile> on non-blocking sockets, as long as one end (typically
441the C<$in_fh>) is a file - the file I/O will then be asynchronous, while
442the socket I/O will be non-blocking. Note, however, that you can run into
443a trap where C<aio_sendfile> reads some data with readahead, then fails
444to write all data, and when the socket is ready the next time, the data
445in the cache is already lost, forcing C<aio_sendfile> to again hit the
446disk. Explicit C<aio_read> + C<aio_write> let's you control resource usage
447much better.
448
377This call tries to make use of a native C<sendfile> syscall to provide 449This call tries to make use of a native C<sendfile> syscall to provide
378zero-copy operation. For this to work, C<$out_fh> should refer to a 450zero-copy operation. For this to work, C<$out_fh> should refer to a
379socket, and C<$in_fh> should refer to mmap'able file. 451socket, and C<$in_fh> should refer to an mmap'able file.
380 452
381If the native sendfile call fails or is not implemented, it will be 453If a native sendfile cannot be found or it fails with C<ENOSYS>,
454C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
382emulated, so you can call C<aio_sendfile> on any type of filehandle 455it will be emulated, so you can call C<aio_sendfile> on any type of
383regardless of the limitations of the operating system. 456filehandle regardless of the limitations of the operating system.
384
385Please note, however, that C<aio_sendfile> can read more bytes from
386C<$in_fh> than are written, and there is no way to find out how many
387bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
388provides the number of bytes written to C<$out_fh>. Only if the result
389value equals C<$length> one can assume that C<$length> bytes have been
390read.
391 457
392 458
393=item aio_readahead $fh,$offset,$length, $callback->($retval) 459=item aio_readahead $fh,$offset,$length, $callback->($retval)
394 460
395C<aio_readahead> populates the page cache with data from a file so that 461C<aio_readahead> populates the page cache with data from a file so that
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426 $_[0] and die "stat failed: $!"; 492 $_[0] and die "stat failed: $!";
427 print "size is ", -s _, "\n"; 493 print "size is ", -s _, "\n";
428 }; 494 };
429 495
430 496
497=item aio_statvfs $fh_or_path, $callback->($statvfs)
498
499Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
500whether a file handle or path was passed.
501
502On success, the callback is passed a hash reference with the following
503members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
504C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
505is passed.
506
507The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
508C<ST_NOSUID>.
509
510The following non-POSIX IO::AIO::ST_* flag masks are defined to
511their correct value when available, or to C<0> on systems that do
512not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
513C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
514C<ST_NODIRATIME> and C<ST_RELATIME>.
515
516Example: stat C</wd> and dump out the data if successful.
517
518 aio_statvfs "/wd", sub {
519 my $f = $_[0]
520 or die "statvfs: $!";
521
522 use Data::Dumper;
523 say Dumper $f;
524 };
525
526 # result:
527 {
528 bsize => 1024,
529 bfree => 4333064312,
530 blocks => 10253828096,
531 files => 2050765568,
532 flag => 4096,
533 favail => 2042092649,
534 bavail => 4333064312,
535 ffree => 2042092649,
536 namemax => 255,
537 frsize => 1024,
538 fsid => 1810
539 }
540
541
431=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 542=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
432 543
433Works like perl's C<utime> function (including the special case of $atime 544Works like perl's C<utime> function (including the special case of $atime
434and $mtime being undef). Fractional times are supported if the underlying 545and $mtime being undef). Fractional times are supported if the underlying
435syscalls support them. 546syscalls support them.
… …
528 639
529Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 640Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
530directory (i.e. opendir + readdir + closedir). The entries will not be 641directory (i.e. opendir + readdir + closedir). The entries will not be
531sorted, and will B<NOT> include the C<.> and C<..> entries. 642sorted, and will B<NOT> include the C<.> and C<..> entries.
532 643
533The callback a single argument which is either C<undef> or an array-ref 644The callback is passed a single argument which is either C<undef> or an
534with the filenames. 645array-ref with the filenames.
646
647
648=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
649
650Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
651behaviour and output format. In case of an error, C<$entries> will be
652C<undef>.
653
654The flags are a combination of the following constants, ORed together (the
655flags will also be passed to the callback, possibly modified):
656
657=over 4
658
659=item IO::AIO::READDIR_DENTS
660
661When this flag is off, then the callback gets an arrayref with of names
662only (as with C<aio_readdir>), otherwise it gets an arrayref with
663C<[$name, $type, $inode]> arrayrefs, each describing a single directory
664entry in more detail.
665
666C<$name> is the name of the entry.
667
668C<$type> is one of the C<IO::AIO::DT_xxx> constants:
669
670C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
671C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
672C<IO::AIO::DT_WHT>.
673
674C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
675know, you have to run stat yourself. Also, for speed reasons, the C<$type>
676scalars are read-only: you can not modify them.
677
678C<$inode> is the inode number (which might not be exact on systems with 64
679bit inode numbers and 32 bit perls). This field has unspecified content on
680systems that do not deliver the inode information.
681
682=item IO::AIO::READDIR_DIRS_FIRST
683
684When this flag is set, then the names will be returned in an order where
685likely directories come first. This is useful when you need to quickly
686find directories, or you want to find all directories while avoiding to
687stat() each entry.
688
689If the system returns type information in readdir, then this is used
690to find directories directly. Otherwise, likely directories are files
691beginning with ".", or otherwise files with no dots, of which files with
692short names are tried first.
693
694=item IO::AIO::READDIR_STAT_ORDER
695
696When this flag is set, then the names will be returned in an order
697suitable for stat()'ing each one. That is, when you plan to stat()
698all files in the given directory, then the returned order will likely
699be fastest.
700
701If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
702the likely dirs come first, resulting in a less optimal stat order.
703
704=item IO::AIO::READDIR_FOUND_UNKNOWN
705
706This flag should not be set when calling C<aio_readdirx>. Instead, it
707is being set by C<aio_readdirx>, when any of the C<$type>'s found were
708C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
709C<$type>'s are known, which can be used to speed up some algorithms.
710
711=back
535 712
536 713
537=item aio_load $path, $data, $callback->($status) 714=item aio_load $path, $data, $callback->($status)
538 715
539This is a composite request that tries to fully load the given file into 716This is a composite request that tries to fully load the given file into
540memory. Status is the same as with aio_read. 717memory. Status is the same as with aio_read.
541 718
542=cut 719=cut
543 720
544sub aio_load($$;$) { 721sub aio_load($$;$) {
545 aio_block {
546 my ($path, undef, $cb) = @_; 722 my ($path, undef, $cb) = @_;
547 my $data = \$_[1]; 723 my $data = \$_[1];
548 724
549 my $pri = aioreq_pri; 725 my $pri = aioreq_pri;
550 my $grp = aio_group $cb; 726 my $grp = aio_group $cb;
727
728 aioreq_pri $pri;
729 add $grp aio_open $path, O_RDONLY, 0, sub {
730 my $fh = shift
731 or return $grp->result (-1);
551 732
552 aioreq_pri $pri; 733 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), $$data, 0, sub { 734 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
559 $grp->result ($_[0]); 735 $grp->result ($_[0]);
560 };
561 }; 736 };
562
563 $grp
564 } 737 };
738
739 $grp
565} 740}
566 741
567=item aio_copy $srcpath, $dstpath, $callback->($status) 742=item aio_copy $srcpath, $dstpath, $callback->($status)
568 743
569Try to copy the I<file> (directories not supported as either source or 744Try to copy the I<file> (directories not supported as either source or
570destination) from C<$srcpath> to C<$dstpath> and call the callback with 745destination) from C<$srcpath> to C<$dstpath> and call the callback with
571the C<0> (error) or C<-1> ok. 746a status of C<0> (ok) or C<-1> (error, see C<$!>).
572 747
573This is a composite request that it creates the destination file with 748This is a composite request that creates the destination file with
574mode 0200 and copies the contents of the source file into it using 749mode 0200 and copies the contents of the source file into it using
575C<aio_sendfile>, followed by restoring atime, mtime, access mode and 750C<aio_sendfile>, followed by restoring atime, mtime, access mode and
576uid/gid, in that order. 751uid/gid, in that order.
577 752
578If an error occurs, the partial destination file will be unlinked, if 753If an error occurs, the partial destination file will be unlinked, if
… …
580errors are being ignored. 755errors are being ignored.
581 756
582=cut 757=cut
583 758
584sub aio_copy($$;$) { 759sub aio_copy($$;$) {
585 aio_block {
586 my ($src, $dst, $cb) = @_; 760 my ($src, $dst, $cb) = @_;
587 761
588 my $pri = aioreq_pri; 762 my $pri = aioreq_pri;
589 my $grp = aio_group $cb; 763 my $grp = aio_group $cb;
590 764
591 aioreq_pri $pri; 765 aioreq_pri $pri;
592 add $grp aio_open $src, O_RDONLY, 0, sub { 766 add $grp aio_open $src, O_RDONLY, 0, sub {
593 if (my $src_fh = $_[0]) { 767 if (my $src_fh = $_[0]) {
594 my @stat = stat $src_fh; 768 my @stat = stat $src_fh; # hmm, might block over nfs?
595 769
596 aioreq_pri $pri; 770 aioreq_pri $pri;
597 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub { 771 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
598 if (my $dst_fh = $_[0]) { 772 if (my $dst_fh = $_[0]) {
599 aioreq_pri $pri; 773 aioreq_pri $pri;
600 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 774 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
601 if ($_[0] == $stat[7]) { 775 if ($_[0] == $stat[7]) {
602 $grp->result (0); 776 $grp->result (0);
603 close $src_fh; 777 close $src_fh;
604 778
605 # those should not normally block. should. should. 779 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; 780 aioreq_pri $pri;
781 add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
782 aioreq_pri $pri;
783 add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
784 aioreq_pri $pri;
611 add $grp aio_close $dst_fh; 785 add $grp aio_close $dst_fh;
612 } else { 786 }
613 $grp->result (-1);
614 close $src_fh;
615 close $dst_fh;
616
617 aioreq $pri; 787 };
618 add $grp aio_unlink $dst;
619 } 788 };
789
790 aioreq_pri $pri;
791 add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
792 if ($_[0] < 0 && $! == ENOSYS) {
793 aioreq_pri $pri;
794 add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
795 } else {
796 $ch->();
797 }
798 };
799 } else {
800 $grp->result (-1);
801 close $src_fh;
802 close $dst_fh;
803
804 aioreq $pri;
805 add $grp aio_unlink $dst;
620 }; 806 }
621 } else {
622 $grp->result (-1);
623 } 807 };
808 } else {
809 $grp->result (-1);
624 }, 810 }
625
626 } else {
627 $grp->result (-1);
628 } 811 },
812
813 } else {
814 $grp->result (-1);
629 }; 815 }
630
631 $grp
632 } 816 };
817
818 $grp
633} 819}
634 820
635=item aio_move $srcpath, $dstpath, $callback->($status) 821=item aio_move $srcpath, $dstpath, $callback->($status)
636 822
637Try to move the I<file> (directories not supported as either source or 823Try to move the I<file> (directories not supported as either source or
638destination) from C<$srcpath> to C<$dstpath> and call the callback with 824destination) from C<$srcpath> to C<$dstpath> and call the callback with
639the C<0> (error) or C<-1> ok. 825a status of C<0> (ok) or C<-1> (error, see C<$!>).
640 826
641This is a composite request that tries to rename(2) the file first. If 827This is a composite request that tries to rename(2) the file first; if
642rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if 828rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
643that is successful, unlinking the C<$srcpath>. 829that is successful, unlinks the C<$srcpath>.
644 830
645=cut 831=cut
646 832
647sub aio_move($$;$) { 833sub aio_move($$;$) {
648 aio_block {
649 my ($src, $dst, $cb) = @_; 834 my ($src, $dst, $cb) = @_;
650 835
651 my $pri = aioreq_pri; 836 my $pri = aioreq_pri;
652 my $grp = aio_group $cb; 837 my $grp = aio_group $cb;
653 838
654 aioreq_pri $pri; 839 aioreq_pri $pri;
655 add $grp aio_rename $src, $dst, sub { 840 add $grp aio_rename $src, $dst, sub {
656 if ($_[0] && $! == EXDEV) { 841 if ($_[0] && $! == EXDEV) {
657 aioreq_pri $pri; 842 aioreq_pri $pri;
658 add $grp aio_copy $src, $dst, sub { 843 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]); 844 $grp->result ($_[0]);
845
846 if (!$_[0]) {
847 aioreq_pri $pri;
848 add $grp aio_unlink $src;
849 }
668 } 850 };
851 } else {
852 $grp->result ($_[0]);
669 }; 853 }
670
671 $grp
672 } 854 };
855
856 $grp
673} 857}
674 858
675=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 859=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
676 860
677Scans a directory (similar to C<aio_readdir>) but additionally tries to 861Scans a directory (similar to C<aio_readdir>) but additionally tries to
… …
697 881
698Implementation notes. 882Implementation notes.
699 883
700The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can. 884The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
701 885
886If readdir returns file type information, then this is used directly to
887find directories.
888
702After reading the directory, the modification time, size etc. of the 889Otherwise, after reading the directory, the modification time, size etc.
703directory before and after the readdir is checked, and if they match (and 890of 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 891match (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 892how many entries are directories (if >= 2). Otherwise, no knowledge of the
706of subdirectories will be assumed. 893number of subdirectories will be assumed.
707 894
708Then entries will be sorted into likely directories (everything without 895Then entries will be sorted into likely directories a non-initial dot
709a non-initial dot currently) and likely non-directories (everything 896currently) and likely non-directories (see C<aio_readdirx>). Then every
710else). Then every entry plus an appended C</.> will be C<stat>'ed, 897entry plus an appended C</.> will be C<stat>'ed, likely directories first,
711likely directories first. If that succeeds, it assumes that the entry 898in order of their inode numbers. If that succeeds, it assumes that the
712is a directory or a symlink to directory (which will be checked 899entry is a directory or a symlink to directory (which will be checked
713seperately). This is often faster than stat'ing the entry itself because 900seperately). This is often faster than stat'ing the entry itself because
714filesystems might detect the type of the entry without reading the inode 901filesystems might detect the type of the entry without reading the inode
715data (e.g. ext2fs filetype feature). 902data (e.g. ext2fs filetype feature), even on systems that cannot return
903the filetype information on readdir.
716 904
717If the known number of directories (link count - 2) has been reached, the 905If the known number of directories (link count - 2) has been reached, the
718rest of the entries is assumed to be non-directories. 906rest of the entries is assumed to be non-directories.
719 907
720This only works with certainty on POSIX (= UNIX) filesystems, which 908This only works with certainty on POSIX (= UNIX) filesystems, which
… …
725directory counting heuristic. 913directory counting heuristic.
726 914
727=cut 915=cut
728 916
729sub aio_scandir($$;$) { 917sub aio_scandir($$;$) {
730 aio_block {
731 my ($path, $maxreq, $cb) = @_; 918 my ($path, $maxreq, $cb) = @_;
732 919
733 my $pri = aioreq_pri; 920 my $pri = aioreq_pri;
734 921
735 my $grp = aio_group $cb; 922 my $grp = aio_group $cb;
736 923
737 $maxreq = 4 if $maxreq <= 0; 924 $maxreq = 4 if $maxreq <= 0;
738 925
739 # stat once 926 # stat once
927 aioreq_pri $pri;
928 add $grp aio_stat $path, sub {
929 return $grp->result () if $_[0];
930 my $now = time;
931 my $hash1 = join ":", (stat _)[0,1,3,7,9];
932
933 # read the directory entries
740 aioreq_pri $pri; 934 aioreq_pri $pri;
741 add $grp aio_stat $path, sub { 935 add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
936 my $entries = shift
742 return $grp->result () if $_[0]; 937 or return $grp->result ();
743 my $now = time;
744 my $hash1 = join ":", (stat _)[0,1,3,7,9];
745 938
746 # read the directory entries 939 # stat the dir another time
747 aioreq_pri $pri; 940 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 { 941 add $grp aio_stat $path, sub {
755 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 942 my $hash2 = join ":", (stat _)[0,1,3,7,9];
756 943
757 my $ndirs; 944 my $ndirs;
758 945
759 # take the slow route if anything looks fishy 946 # take the slow route if anything looks fishy
760 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 947 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
761 $ndirs = -1; 948 $ndirs = -1;
762 } else { 949 } else {
763 # if nlink == 2, we are finished 950 # if nlink == 2, we are finished
764 # on non-posix-fs's, we rely on nlink < 2 951 # for non-posix-fs's, we rely on nlink < 2
765 $ndirs = (stat _)[3] - 2 952 $ndirs = (stat _)[3] - 2
766 or return $grp->result ([], $entries); 953 or return $grp->result ([], $entries);
767 } 954 }
768 955
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); 956 my (@dirs, @nondirs);
777 957
778 my $statgrp = add $grp aio_group sub { 958 my $statgrp = add $grp aio_group sub {
779 $grp->result (\@dirs, \@nondirs); 959 $grp->result (\@dirs, \@nondirs);
780 }; 960 };
781 961
782 limit $statgrp $maxreq; 962 limit $statgrp $maxreq;
783 feed $statgrp sub { 963 feed $statgrp sub {
784 return unless @$entries; 964 return unless @$entries;
785 my $entry = pop @$entries; 965 my $entry = shift @$entries;
786 966
787 aioreq_pri $pri; 967 aioreq_pri $pri;
788 add $statgrp aio_stat "$path/$entry/.", sub { 968 add $statgrp aio_stat "$path/$entry/.", sub {
789 if ($_[0] < 0) { 969 if ($_[0] < 0) {
790 push @nondirs, $entry; 970 push @nondirs, $entry;
791 } else { 971 } else {
792 # need to check for real directory 972 # need to check for real directory
793 aioreq_pri $pri; 973 aioreq_pri $pri;
794 add $statgrp aio_lstat "$path/$entry", sub { 974 add $statgrp aio_lstat "$path/$entry", sub {
795 if (-d _) { 975 if (-d _) {
796 push @dirs, $entry; 976 push @dirs, $entry;
797 977
798 unless (--$ndirs) { 978 unless (--$ndirs) {
799 push @nondirs, @$entries; 979 push @nondirs, @$entries;
800 feed $statgrp; 980 feed $statgrp;
801 }
802 } else {
803 push @nondirs, $entry;
804 } 981 }
982 } else {
983 push @nondirs, $entry;
805 } 984 }
806 } 985 }
807 }; 986 }
808 }; 987 };
809 }; 988 };
810 }; 989 };
811 }; 990 };
812
813 $grp
814 } 991 };
992
993 $grp
815} 994}
816 995
817=item aio_rmtree $path, $callback->($status) 996=item aio_rmtree $path, $callback->($status)
818 997
819Delete a directory tree starting (and including) C<$path>, return the 998Delete a directory tree starting (and including) C<$path>, return the
… …
823 1002
824=cut 1003=cut
825 1004
826sub aio_rmtree; 1005sub aio_rmtree;
827sub aio_rmtree($;$) { 1006sub aio_rmtree($;$) {
828 aio_block {
829 my ($path, $cb) = @_; 1007 my ($path, $cb) = @_;
830 1008
831 my $pri = aioreq_pri; 1009 my $pri = aioreq_pri;
832 my $grp = aio_group $cb; 1010 my $grp = aio_group $cb;
833 1011
834 aioreq_pri $pri; 1012 aioreq_pri $pri;
835 add $grp aio_scandir $path, 0, sub { 1013 add $grp aio_scandir $path, 0, sub {
836 my ($dirs, $nondirs) = @_; 1014 my ($dirs, $nondirs) = @_;
837 1015
838 my $dirgrp = aio_group sub { 1016 my $dirgrp = aio_group sub {
839 add $grp aio_rmdir $path, sub { 1017 add $grp aio_rmdir $path, sub {
840 $grp->result ($_[0]); 1018 $grp->result ($_[0]);
841 };
842 }; 1019 };
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 }; 1020 };
849 1021
850 $grp 1022 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
1023 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
1024
1025 add $grp $dirgrp;
851 } 1026 };
1027
1028 $grp
852} 1029}
853 1030
854=item aio_sync $callback->($status) 1031=item aio_sync $callback->($status)
855 1032
856Asynchronously call sync and call the callback when finished. 1033Asynchronously call sync and call the callback when finished.
… …
866callback with the fdatasync result code. 1043callback with the fdatasync result code.
867 1044
868If this call isn't available because your OS lacks it or it couldn't be 1045If 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. 1046detected, it will be emulated by calling C<fsync> instead.
870 1047
1048=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
1049
1050Sync the data portion of the file specified by C<$offset> and C<$length>
1051to disk (but NOT the metadata), by calling the Linux-specific
1052sync_file_range call. If sync_file_range is not available or it returns
1053ENOSYS, then fdatasync or fsync is being substituted.
1054
1055C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
1056C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
1057C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
1058manpage for details.
1059
871=item aio_pathsync $path, $callback->($status) 1060=item aio_pathsync $path, $callback->($status)
872 1061
873This request tries to open, fsync and close the given path. This is a 1062This request tries to open, fsync and close the given path. This is a
874composite request intended tosync directories after directory operations 1063composite request intended to sync directories after directory operations
875(E.g. rename). This might not work on all operating systems or have any 1064(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 1065specific effect, but usually it makes sure that directory changes get
877written to disc. It works for anything that can be opened for read-only, 1066written to disc. It works for anything that can be opened for read-only,
878not just directories. 1067not just directories.
879 1068
1069Future versions of this function might fall back to other methods when
1070C<fsync> on the directory fails (such as calling C<sync>).
1071
880Passes C<0> when everything went ok, and C<-1> on error. 1072Passes C<0> when everything went ok, and C<-1> on error.
881 1073
882=cut 1074=cut
883 1075
884sub aio_pathsync($;$) { 1076sub aio_pathsync($;$) {
885 aio_block {
886 my ($path, $cb) = @_; 1077 my ($path, $cb) = @_;
887 1078
888 my $pri = aioreq_pri; 1079 my $pri = aioreq_pri;
889 my $grp = aio_group $cb; 1080 my $grp = aio_group $cb;
890 1081
891 aioreq_pri $pri; 1082 aioreq_pri $pri;
892 add $grp aio_open $path, O_RDONLY, 0, sub { 1083 add $grp aio_open $path, O_RDONLY, 0, sub {
893 my ($fh) = @_; 1084 my ($fh) = @_;
894 if ($fh) { 1085 if ($fh) {
1086 aioreq_pri $pri;
1087 add $grp aio_fsync $fh, sub {
1088 $grp->result ($_[0]);
1089
895 aioreq_pri $pri; 1090 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; 1091 add $grp aio_close $fh;
901 };
902 } else {
903 $grp->result (-1);
904 } 1092 };
1093 } else {
1094 $grp->result (-1);
905 }; 1095 }
906
907 $grp
908 } 1096 };
1097
1098 $grp
909} 1099}
1100
1101=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1102
1103This is a rather advanced IO::AIO call, which only works on mmap(2)ed
1104scalars (see the C<IO::AIO::mmap> function, although it also works on data
1105scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
1106scalar must only be modified in-place while an aio operation is pending on
1107it).
1108
1109It calls the C<msync> function of your OS, if available, with the memory
1110area starting at C<$offset> in the string and ending C<$length> bytes
1111later. If C<$length> is negative, counts from the end, and if C<$length>
1112is C<undef>, then it goes till the end of the string. The flags can be
1113a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
1114C<IO::AIO::MS_SYNC>.
1115
1116=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1117
1118This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1119scalars.
1120
1121It touches (reads or writes) all memory pages in the specified
1122range inside the scalar. All caveats and parameters are the same
1123as for C<aio_msync>, above, except for flags, which must be either
1124C<0> (which reads all pages and ensures they are instantiated) or
1125C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
1126writing an octet from it, which dirties the page).
1127
1128=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1129
1130This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1131scalars.
1132
1133It reads in all the pages of the underlying storage into memory (if any)
1134and locks them, so they are not getting swapped/paged out or removed.
1135
1136If C<$length> is undefined, then the scalar will be locked till the end.
1137
1138On systems that do not implement C<mlock>, this function returns C<-1>
1139and sets errno to C<ENOSYS>.
1140
1141Note that the corresponding C<munlock> is synchronous and is
1142documented under L<MISCELLANEOUS FUNCTIONS>.
1143
1144Example: open a file, mmap and mlock it - both will be undone when
1145C<$data> gets destroyed.
1146
1147 open my $fh, "<", $path or die "$path: $!";
1148 my $data;
1149 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
1150 aio_mlock $data; # mlock in background
1151
1152=item aio_mlockall $flags, $callback->($status)
1153
1154Calls the C<mlockall> function with the given C<$flags> (a combination of
1155C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).
1156
1157On systems that do not implement C<mlockall>, this function returns C<-1>
1158and sets errno to C<ENOSYS>.
1159
1160Note that the corresponding C<munlockall> is synchronous and is
1161documented under L<MISCELLANEOUS FUNCTIONS>.
1162
1163Example: asynchronously lock all current and future pages into memory.
1164
1165 aio_mlockall IO::AIO::MCL_FUTURE;
910 1166
911=item aio_group $callback->(...) 1167=item aio_group $callback->(...)
912 1168
913This is a very special aio request: Instead of doing something, it is a 1169This 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 1170container for other aio requests, which is useful if you want to bundle
… …
964=item cancel $req 1220=item cancel $req
965 1221
966Cancels the request, if possible. Has the effect of skipping execution 1222Cancels the request, if possible. Has the effect of skipping execution
967when entering the B<execute> state and skipping calling the callback when 1223when entering the B<execute> state and skipping calling the callback when
968entering the the B<result> state, but will leave the request otherwise 1224entering the the B<result> state, but will leave the request otherwise
969untouched. That means that requests that currently execute will not be 1225untouched (with the exception of readdir). That means that requests that
970stopped and resources held by the request will not be freed prematurely. 1226currently execute will not be stopped and resources held by the request
1227will not be freed prematurely.
971 1228
972=item cb $req $callback->(...) 1229=item cb $req $callback->(...)
973 1230
974Replace (or simply set) the callback registered to the request. 1231Replace (or simply set) the callback registered to the request.
975 1232
… …
1026Their lifetime, simplified, looks like this: when they are empty, they 1283Their lifetime, simplified, looks like this: when they are empty, they
1027will finish very quickly. If they contain only requests that are in the 1284will finish very quickly. If they contain only requests that are in the
1028C<done> state, they will also finish. Otherwise they will continue to 1285C<done> state, they will also finish. Otherwise they will continue to
1029exist. 1286exist.
1030 1287
1031That means after creating a group you have some time to add requests. And 1288That 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 1289(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 1290the C<poll_cb>). And in the callbacks of those requests, you can add
1034itself finish. 1291further requests to the group. And only when all those requests have
1292finished will the the group itself finish.
1035 1293
1036=over 4 1294=over 4
1037 1295
1038=item add $grp ... 1296=item add $grp ...
1039 1297
… …
1047 1305
1048=item $grp->cancel_subs 1306=item $grp->cancel_subs
1049 1307
1050Cancel all subrequests and clears any feeder, but not the group request 1308Cancel 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. 1309itself. Useful when you queued a lot of events but got a result early.
1310
1311The group request will finish normally (you cannot add requests to the
1312group).
1052 1313
1053=item $grp->result (...) 1314=item $grp->result (...)
1054 1315
1055Set the result value(s) that will be passed to the group callback when all 1316Set 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 1317subrequests have finished and set the groups errno to the current value
… …
1072=item feed $grp $callback->($grp) 1333=item feed $grp $callback->($grp)
1073 1334
1074Sets a feeder/generator on this group: every group can have an attached 1335Sets a feeder/generator on this group: every group can have an attached
1075generator that generates requests if idle. The idea behind this is that, 1336generator 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, 1337although you could just queue as many requests as you want in a group,
1077this might starve other requests for a potentially long time. For 1338this might starve other requests for a potentially long time. For example,
1078example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1339C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1079requests, delaying any later requests for a long time. 1340delaying any later requests for a long time.
1080 1341
1081To avoid this, and allow incremental generation of requests, you can 1342To avoid this, and allow incremental generation of requests, you can
1082instead a group and set a feeder on it that generates those requests. The 1343instead 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>, 1344feed 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 1345below) requests active in the group itself and is expected to queue more
… …
1088not impose any limits). 1349not impose any limits).
1089 1350
1090If the feed does not queue more requests when called, it will be 1351If the feed does not queue more requests when called, it will be
1091automatically removed from the group. 1352automatically removed from the group.
1092 1353
1093If the feed limit is C<0>, it will be set to C<2> automatically. 1354If the feed limit is C<0> when this method is called, it will be set to
1355C<2> automatically.
1094 1356
1095Example: 1357Example:
1096 1358
1097 # stat all files in @files, but only ever use four aio requests concurrently: 1359 # stat all files in @files, but only ever use four aio requests concurrently:
1098 1360
… …
1110Sets the feeder limit for the group: The feeder will be called whenever 1372Sets the feeder limit for the group: The feeder will be called whenever
1111the group contains less than this many requests. 1373the group contains less than this many requests.
1112 1374
1113Setting the limit to C<0> will pause the feeding process. 1375Setting the limit to C<0> will pause the feeding process.
1114 1376
1377The default value for the limit is C<0>, but note that setting a feeder
1378automatically bumps it up to C<2>.
1379
1115=back 1380=back
1116 1381
1117=head2 SUPPORT FUNCTIONS 1382=head2 SUPPORT FUNCTIONS
1118 1383
1119=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1384=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
… …
1121=over 4 1386=over 4
1122 1387
1123=item $fileno = IO::AIO::poll_fileno 1388=item $fileno = IO::AIO::poll_fileno
1124 1389
1125Return the I<request result pipe file descriptor>. This filehandle must be 1390Return the I<request result pipe file descriptor>. This filehandle must be
1126polled for reading by some mechanism outside this module (e.g. Event or 1391polled 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 1392select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1128to call C<poll_cb> to check the results. 1393you have to call C<poll_cb> to check the results.
1129 1394
1130See C<poll_cb> for an example. 1395See C<poll_cb> for an example.
1131 1396
1132=item IO::AIO::poll_cb 1397=item IO::AIO::poll_cb
1133 1398
1134Process some outstanding events on the result pipe. You have to call this 1399Process some outstanding events on the result pipe. You have to call this
1135regularly. Returns the number of events processed. Returns immediately 1400regularly. Returns C<0> if all events could be processed, or C<-1> if it
1401returned earlier for whatever reason. Returns immediately when no events
1136when no events are outstanding. The amount of events processed depends on 1402are 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>. 1403C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1138 1404
1139If not all requests were processed for whatever reason, the filehandle 1405If not all requests were processed for whatever reason, the filehandle
1140will still be ready when C<poll_cb> returns. 1406will still be ready when C<poll_cb> returns, so normally you don't have to
1407do anything special to have it called later.
1141 1408
1142Example: Install an Event watcher that automatically calls 1409Example: Install an Event watcher that automatically calls
1143IO::AIO::poll_cb with high priority: 1410IO::AIO::poll_cb with high priority (more examples can be found in the
1411SYNOPSIS section, at the top of this document):
1144 1412
1145 Event->io (fd => IO::AIO::poll_fileno, 1413 Event->io (fd => IO::AIO::poll_fileno,
1146 poll => 'r', async => 1, 1414 poll => 'r', async => 1,
1147 cb => \&IO::AIO::poll_cb); 1415 cb => \&IO::AIO::poll_cb);
1416
1417=item IO::AIO::poll_wait
1418
1419If there are any outstanding requests and none of them in the result
1420phase, wait till the result filehandle becomes ready for reading (simply
1421does a C<select> on the filehandle. This is useful if you want to
1422synchronously wait for some requests to finish).
1423
1424See C<nreqs> for an example.
1425
1426=item IO::AIO::poll
1427
1428Waits until some requests have been handled.
1429
1430Returns the number of requests processed, but is otherwise strictly
1431equivalent to:
1432
1433 IO::AIO::poll_wait, IO::AIO::poll_cb
1434
1435=item IO::AIO::flush
1436
1437Wait till all outstanding AIO requests have been handled.
1438
1439Strictly equivalent to:
1440
1441 IO::AIO::poll_wait, IO::AIO::poll_cb
1442 while IO::AIO::nreqs;
1148 1443
1149=item IO::AIO::max_poll_reqs $nreqs 1444=item IO::AIO::max_poll_reqs $nreqs
1150 1445
1151=item IO::AIO::max_poll_time $seconds 1446=item IO::AIO::max_poll_time $seconds
1152 1447
… …
1177 # use a low priority so other tasks have priority 1472 # use a low priority so other tasks have priority
1178 Event->io (fd => IO::AIO::poll_fileno, 1473 Event->io (fd => IO::AIO::poll_fileno,
1179 poll => 'r', nice => 1, 1474 poll => 'r', nice => 1,
1180 cb => &IO::AIO::poll_cb); 1475 cb => &IO::AIO::poll_cb);
1181 1476
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 1477=back
1210 1478
1211=head3 CONTROLLING THE NUMBER OF THREADS 1479=head3 CONTROLLING THE NUMBER OF THREADS
1212 1480
1213=over 1481=over
… …
1259 1527
1260The default is probably ok in most situations, especially if thread 1528The default is probably ok in most situations, especially if thread
1261creation is fast. If thread creation is very slow on your system you might 1529creation is fast. If thread creation is very slow on your system you might
1262want to use larger values. 1530want to use larger values.
1263 1531
1264=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1532=item IO::AIO::max_outstanding $maxreqs
1265 1533
1266This is a very bad function to use in interactive programs because it 1534This 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 1535blocks, and a bad way to reduce concurrency because it is inexact: Better
1268use an C<aio_group> together with a feed callback. 1536use an C<aio_group> together with a feed callback.
1269 1537
… …
1274 1542
1275The default value is very large, so there is no practical limit on the 1543The default value is very large, so there is no practical limit on the
1276number of outstanding requests. 1544number of outstanding requests.
1277 1545
1278You can still queue as many requests as you want. Therefore, 1546You can still queue as many requests as you want. Therefore,
1279C<max_oustsanding> is mainly useful in simple scripts (with low values) or 1547C<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). 1548as a stop gap to shield against fatal memory overflow (with large values).
1281 1549
1282=back 1550=back
1283 1551
1284=head3 STATISTICAL INFORMATION 1552=head3 STATISTICAL INFORMATION
… …
1305Returns the number of requests currently in the pending state (executed, 1573Returns the number of requests currently in the pending state (executed,
1306but not yet processed by poll_cb). 1574but not yet processed by poll_cb).
1307 1575
1308=back 1576=back
1309 1577
1578=head3 MISCELLANEOUS FUNCTIONS
1579
1580IO::AIO implements some functions that might be useful, but are not
1581asynchronous.
1582
1583=over 4
1584
1585=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1586
1587Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
1588but is blocking (this makes most sense if you know the input data is
1589likely cached already and the output filehandle is set to non-blocking
1590operations).
1591
1592Returns the number of bytes copied, or C<-1> on error.
1593
1594=item IO::AIO::fadvise $fh, $offset, $len, $advice
1595
1596Simply calls the C<posix_fadvise> function (see its
1597manpage for details). The following advice constants are
1598avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1599C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1600C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1601
1602On systems that do not implement C<posix_fadvise>, this function returns
1603ENOSYS, otherwise the return value of C<posix_fadvise>.
1604
1605=item IO::AIO::madvise $scalar, $offset, $len, $advice
1606
1607Simply calls the C<posix_madvise> function (see its
1608manpage for details). The following advice constants are
1609avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
1610C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.
1611
1612On systems that do not implement C<posix_madvise>, this function returns
1613ENOSYS, otherwise the return value of C<posix_madvise>.
1614
1615=item IO::AIO::mprotect $scalar, $offset, $len, $protect
1616
1617Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
1618$scalar (see its manpage for details). The following protect
1619constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
1620C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
1621
1622On systems that do not implement C<mprotect>, this function returns
1623ENOSYS, otherwise the return value of C<mprotect>.
1624
1625=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1626
1627Memory-maps a file (or anonymous memory range) and attaches it to the
1628given C<$scalar>, which will act like a string scalar.
1629
1630The only operations allowed on the scalar are C<substr>/C<vec> that don't
1631change the string length, and most read-only operations such as copying it
1632or searching it with regexes and so on.
1633
1634Anything else is unsafe and will, at best, result in memory leaks.
1635
1636The memory map associated with the C<$scalar> is automatically removed
1637when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
1638C<IO::AIO::munmap> functions are called.
1639
1640This calls the C<mmap>(2) function internally. See your system's manual
1641page for details on the C<$length>, C<$prot> and C<$flags> parameters.
1642
1643The C<$length> must be larger than zero and smaller than the actual
1644filesize.
1645
1646C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1647C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1648
1649C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
1650C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
1651not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
1652(which is set to C<MAP_ANON> if your system only provides this
1653constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
1654C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
1655C<IO::AIO::MAP_NONBLOCK>
1656
1657If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1658
1659C<$offset> is the offset from the start of the file - it generally must be
1660a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
1661
1662Example:
1663
1664 use Digest::MD5;
1665 use IO::AIO;
1666
1667 open my $fh, "<verybigfile"
1668 or die "$!";
1669
1670 IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
1671 or die "verybigfile: $!";
1672
1673 my $fast_md5 = md5 $data;
1674
1675=item IO::AIO::munmap $scalar
1676
1677Removes a previous mmap and undefines the C<$scalar>.
1678
1679=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
1680
1681Calls the C<munlock> function, undoing the effects of a previous
1682C<aio_mlock> call (see its description for details).
1683
1684=item IO::AIO::munlockall
1685
1686Calls the C<munlockall> function.
1687
1688On systems that do not implement C<munlockall>, this function returns
1689ENOSYS, otherwise the return value of C<munlockall>.
1690
1691=back
1692
1310=cut 1693=cut
1311 1694
1312min_parallel 8; 1695min_parallel 8;
1313 1696
1314END { flush } 1697END { flush }
1315 1698
13161; 16991;
1700
1701=head1 EVENT LOOP INTEGRATION
1702
1703It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
1704automatically into many event loops:
1705
1706 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
1707 use AnyEvent::AIO;
1708
1709You can also integrate IO::AIO manually into many event loops, here are
1710some examples of how to do this:
1711
1712 # EV integration
1713 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
1714
1715 # Event integration
1716 Event->io (fd => IO::AIO::poll_fileno,
1717 poll => 'r',
1718 cb => \&IO::AIO::poll_cb);
1719
1720 # Glib/Gtk2 integration
1721 add_watch Glib::IO IO::AIO::poll_fileno,
1722 in => sub { IO::AIO::poll_cb; 1 };
1723
1724 # Tk integration
1725 Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
1726 readable => \&IO::AIO::poll_cb);
1727
1728 # Danga::Socket integration
1729 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
1730 \&IO::AIO::poll_cb);
1317 1731
1318=head2 FORK BEHAVIOUR 1732=head2 FORK BEHAVIOUR
1319 1733
1320This module should do "the right thing" when the process using it forks: 1734This module should do "the right thing" when the process using it forks:
1321 1735
… …
1354 1768
1355Known bugs will be fixed in the next release. 1769Known bugs will be fixed in the next release.
1356 1770
1357=head1 SEE ALSO 1771=head1 SEE ALSO
1358 1772
1359L<Coro::AIO>. 1773L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1774more natural syntax.
1360 1775
1361=head1 AUTHOR 1776=head1 AUTHOR
1362 1777
1363 Marc Lehmann <schmorp@schmorp.de> 1778 Marc Lehmann <schmorp@schmorp.de>
1364 http://home.schmorp.de/ 1779 http://home.schmorp.de/

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