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Revision 1.117 by root, Sat Oct 6 14:05:19 2007 UTC vs.
Revision 1.177 by root, Sun Jan 10 23:08:55 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
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 # Event integration
36 Event->io (fd => IO::AIO::poll_fileno,
37 poll => 'r',
38 cb => \&IO::AIO::poll_cb);
39
40 # Glib/Gtk2 integration
41 add_watch Glib::IO IO::AIO::poll_fileno,
42 in => sub { IO::AIO::poll_cb; 1 };
43
44 # Tk integration
45 Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
46 readable => \&IO::AIO::poll_cb);
47
48 # Danga::Socket integration
49 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
50 \&IO::AIO::poll_cb);
51
52=head1 DESCRIPTION 31=head1 DESCRIPTION
53 32
54This module implements asynchronous I/O using whatever means your 33This module implements asynchronous I/O using whatever means your
55operating system supports. 34operating system supports. It is implemented as an interface to C<libeio>
35(L<http://software.schmorp.de/pkg/libeio.html>).
56 36
57Asynchronous means that operations that can normally block your program 37Asynchronous means that operations that can normally block your program
58(e.g. reading from disk) will be done asynchronously: the operation 38(e.g. reading from disk) will be done asynchronously: the operation
59will 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
60is 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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64on 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
65concurrently. 45concurrently.
66 46
67While most of this works on all types of file descriptors (for 47While most of this works on all types of file descriptors (for
68example sockets), using these functions on file descriptors that 48example sockets), using these functions on file descriptors that
69support nonblocking operation (again, sockets, pipes etc.) is very 49support nonblocking operation (again, sockets, pipes etc.) is
70inefficient. 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>
71module): IO::AIO will naturally fit into such an event loop itself. 51module): IO::AIO will naturally fit into such an event loop itself.
72 52
73In this version, a number of threads are started that execute your 53In this version, a number of threads are started that execute your
74requests and signal their completion. You don't need thread support 54requests and signal their completion. You don't need thread support
75in 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
… …
85yourself, 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
86call C<poll_cb> (or other C<aio_> functions) recursively. 66call C<poll_cb> (or other C<aio_> functions) recursively.
87 67
88=head2 EXAMPLE 68=head2 EXAMPLE
89 69
90This is a simple example that uses the Event module and loads 70This is a simple example that uses the EV module and loads
91F</etc/passwd> asynchronously: 71F</etc/passwd> asynchronously:
92 72
93 use Fcntl; 73 use Fcntl;
94 use Event; 74 use EV;
95 use IO::AIO; 75 use IO::AIO;
96 76
97 # register the IO::AIO callback with Event 77 # register the IO::AIO callback with EV
98 Event->io (fd => IO::AIO::poll_fileno, 78 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
99 poll => 'r',
100 cb => \&IO::AIO::poll_cb);
101 79
102 # queue the request to open /etc/passwd 80 # queue the request to open /etc/passwd
103 aio_open "/etc/passwd", O_RDONLY, 0, sub { 81 aio_open "/etc/passwd", O_RDONLY, 0, sub {
104 my $fh = shift 82 my $fh = shift
105 or die "error while opening: $!"; 83 or die "error while opening: $!";
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117 95
118 # file contents now in $contents 96 # file contents now in $contents
119 print $contents; 97 print $contents;
120 98
121 # exit event loop and program 99 # exit event loop and program
122 Event::unloop; 100 EV::unloop;
123 }; 101 };
124 }; 102 };
125 103
126 # possibly queue up other requests, or open GUI windows, 104 # possibly queue up other requests, or open GUI windows,
127 # check for sockets etc. etc. 105 # check for sockets etc. etc.
128 106
129 # process events as long as there are some: 107 # process events as long as there are some:
130 Event::loop; 108 EV::loop;
131 109
132=head1 REQUEST ANATOMY AND LIFETIME 110=head1 REQUEST ANATOMY AND LIFETIME
133 111
134Every 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
135directly visible to Perl. 113directly visible to Perl.
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185 163
186package IO::AIO; 164package IO::AIO;
187 165
188use Carp (); 166use Carp ();
189 167
190no warnings; 168use common::sense;
191use strict 'vars';
192 169
193use base 'Exporter'; 170use base 'Exporter';
194 171
195BEGIN { 172BEGIN {
196 our $VERSION = '2.51'; 173 our $VERSION = '3.5';
197 174
198 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat 175 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close
199 aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink 176 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
200 aio_readlink aio_fsync aio_fdatasync aio_readahead aio_rename aio_link 177 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
178 aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
179 aio_rename aio_link aio_move aio_copy aio_group
201 aio_move aio_copy aio_group aio_nop aio_mknod aio_load aio_rmtree aio_mkdir 180 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
202 aio_chown aio_chmod aio_utime aio_truncate); 181 aio_chmod aio_utime aio_truncate
182 aio_msync aio_mtouch aio_statvfs);
183
203 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block)); 184 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
204 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 185 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
205 min_parallel max_parallel max_idle 186 min_parallel max_parallel max_idle
206 nreqs nready npending nthreads 187 nreqs nready npending nthreads
207 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
208 192
209 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 193 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
210 194
211 require XSLoader; 195 require XSLoader;
212 XSLoader::load ("IO::AIO", $VERSION); 196 XSLoader::load ("IO::AIO", $VERSION);
213} 197}
214 198
215=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 $flags
267 IO::AIO::munlockall
216 268
217=head2 AIO REQUEST FUNCTIONS 269=head2 AIO REQUEST FUNCTIONS
218 270
219All the C<aio_*> calls are more or less thin wrappers around the syscall 271All the C<aio_*> calls are more or less thin wrappers around the syscall
220with the same name (sans C<aio_>). The arguments are similar or identical, 272with the same name (sans C<aio_>). The arguments are similar or identical,
221and they all accept an additional (and optional) C<$callback> argument 273and they all accept an additional (and optional) C<$callback> argument
222which 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
223the 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
224perl, which usually delivers "false") as it's sole argument when the given 276perl, which usually delivers "false") as its sole argument after the given
225syscall has been executed asynchronously. 277syscall has been executed asynchronously.
226 278
227All functions expecting a filehandle keep a copy of the filehandle 279All functions expecting a filehandle keep a copy of the filehandle
228internally until the request has finished. 280internally until the request has finished.
229 281
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243your 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
244environment, d) use Glib::filename_from_unicode on unicode filenames or e) 296environment, d) use Glib::filename_from_unicode on unicode filenames or e)
245use something else to ensure your scalar has the correct contents. 297use something else to ensure your scalar has the correct contents.
246 298
247This 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
248handles correctly wether it is set or not. 300handles correctly whether it is set or not.
249 301
250=over 4 302=over 4
251 303
252=item $prev_pri = aioreq_pri [$pri] 304=item $prev_pri = aioreq_pri [$pri]
253 305
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316 368
317Asynchronously close a file and call the callback with the result 369Asynchronously close a file and call the callback with the result
318code. 370code.
319 371
320Unfortunately, you can't do this to perl. Perl I<insists> very strongly on 372Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
321closing the file descriptor associated with the filehandle itself. Here is 373closing the file descriptor associated with the filehandle itself.
322what aio_close will try:
323 374
324 1. dup()licate the fd 375Therefore, C<aio_close> will not close the filehandle - instead it will
325 2. asynchronously close() the duplicated fd 376use dup2 to overwrite the file descriptor with the write-end of a pipe
326 3. dup()licate the fd once more 377(the pipe fd will be created on demand and will be cached).
327 4. let perl close() the filehandle
328 5. asynchronously close the duplicated fd
329 378
330The idea is that the first close() flushes stuff to disk that closing an 379Or in other words: the file descriptor will be closed, but it will not be
331fd will flush, so when perl closes the fd, nothing much will need to be 380free for reuse until the perl filehandle is closed.
332flushed. The second async. close() will then flush stuff to disk that
333closing the last fd to the file will flush.
334
335Just FYI, SuSv3 has this to say on close:
336
337 All outstanding record locks owned by the process on the file
338 associated with the file descriptor shall be removed.
339
340 If fildes refers to a socket, close() shall cause the socket to be
341 destroyed. ... close() shall block for up to the current linger
342 interval until all data is transmitted.
343 [this actually sounds like a specification bug, but who knows]
344
345And at least Linux additionally actually flushes stuff on every close,
346even when the file itself is still open.
347
348Sounds enourmously inefficient and complicated? Yes... please show me how
349to nuke perl's fd out of existence...
350 381
351=cut 382=cut
352 383
353sub aio_close($;$) {
354 aio_block {
355 my ($fh, $cb) = @_;
356
357 my $pri = aioreq_pri;
358 my $grp = aio_group $cb;
359
360 my $fd = fileno $fh;
361
362 defined $fd or Carp::croak "aio_close called with fd-less filehandle";
363
364 # if the dups fail we will simply get EBADF
365 my $fd2 = _dup $fd;
366 aioreq_pri $pri;
367 add $grp _aio_close $fd2, sub {
368 my $fd2 = _dup $fd;
369 close $fh;
370 aioreq_pri $pri;
371 add $grp _aio_close $fd2, sub {
372 $grp->result ($_[0]);
373 };
374 };
375
376 $grp
377 }
378}
379
380
381=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 384=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
382 385
383=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 386=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
384 387
385Reads 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<$fh> and
386into the scalar given by C<$data> and offset C<$dataoffset> and calls the 389C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
387callback 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
388like the syscall). 391error, just like the syscall).
392
393C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
394offset plus the actual number of bytes read.
389 395
390If C<$offset> is undefined, then the current file descriptor offset will 396If C<$offset> is undefined, then the current file descriptor offset will
391be used (and updated), otherwise the file descriptor offset will not be 397be used (and updated), otherwise the file descriptor offset will not be
392changed by these calls. 398changed by these calls.
393 399
394If C<$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<$data>.
395 402
396If C<$dataoffset> is less than zero, it will be counted from the end of 403If C<$dataoffset> is less than zero, it will be counted from the end of
397C<$data>. 404C<$data>.
398 405
399The C<$data> scalar I<MUST NOT> be modified in any way while the request 406The C<$data> scalar I<MUST NOT> be modified in any way while the request
… …
417than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each 424than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
418other. 425other.
419 426
420This call tries to make use of a native C<sendfile> syscall to provide 427This call tries to make use of a native C<sendfile> syscall to provide
421zero-copy operation. For this to work, C<$out_fh> should refer to a 428zero-copy operation. For this to work, C<$out_fh> should refer to a
422socket, and C<$in_fh> should refer to mmap'able file. 429socket, and C<$in_fh> should refer to an mmap'able file.
423 430
424If the native sendfile call fails or is not implemented, it will be 431If a native sendfile cannot be found or it fails with C<ENOSYS>,
432C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
425emulated, so you can call C<aio_sendfile> on any type of filehandle 433it will be emulated, so you can call C<aio_sendfile> on any type of
426regardless of the limitations of the operating system. 434filehandle regardless of the limitations of the operating system.
427 435
428Please note, however, that C<aio_sendfile> can read more bytes from 436Please note, however, that C<aio_sendfile> can read more bytes from
429C<$in_fh> than are written, and there is no way to find out how many 437C<$in_fh> than are written, and there is no way to find out how many
430bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only 438bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
431provides the number of bytes written to C<$out_fh>. Only if the result 439provides the number of bytes written to C<$out_fh>. Only if the result
… …
469 $_[0] and die "stat failed: $!"; 477 $_[0] and die "stat failed: $!";
470 print "size is ", -s _, "\n"; 478 print "size is ", -s _, "\n";
471 }; 479 };
472 480
473 481
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
474=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 527=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
475 528
476Works 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
477and $mtime being undef). Fractional times are supported if the underlying 530and $mtime being undef). Fractional times are supported if the underlying
478syscalls support them. 531syscalls support them.
… …
571 624
572Unlike 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
573directory (i.e. opendir + readdir + closedir). The entries will not be 626directory (i.e. opendir + readdir + closedir). The entries will not be
574sorted, and will B<NOT> include the C<.> and C<..> entries. 627sorted, and will B<NOT> include the C<.> and C<..> entries.
575 628
576The 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
577with 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
578 697
579 698
580=item aio_load $path, $data, $callback->($status) 699=item aio_load $path, $data, $callback->($status)
581 700
582This 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
583memory. Status is the same as with aio_read. 702memory. Status is the same as with aio_read.
584 703
585=cut 704=cut
586 705
587sub aio_load($$;$) { 706sub aio_load($$;$) {
588 aio_block {
589 my ($path, undef, $cb) = @_; 707 my ($path, undef, $cb) = @_;
590 my $data = \$_[1]; 708 my $data = \$_[1];
591 709
592 my $pri = aioreq_pri; 710 my $pri = aioreq_pri;
593 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);
594 717
595 aioreq_pri $pri; 718 aioreq_pri $pri;
596 add $grp aio_open $path, O_RDONLY, 0, sub {
597 my $fh = shift
598 or return $grp->result (-1);
599
600 aioreq_pri $pri;
601 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub { 719 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
602 $grp->result ($_[0]); 720 $grp->result ($_[0]);
603 };
604 }; 721 };
605
606 $grp
607 } 722 };
723
724 $grp
608} 725}
609 726
610=item aio_copy $srcpath, $dstpath, $callback->($status) 727=item aio_copy $srcpath, $dstpath, $callback->($status)
611 728
612Try 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
613destination) from C<$srcpath> to C<$dstpath> and call the callback with 730destination) from C<$srcpath> to C<$dstpath> and call the callback with
614the C<0> (error) or C<-1> ok. 731a status of C<0> (ok) or C<-1> (error, see C<$!>).
615 732
616This is a composite request that it creates the destination file with 733This is a composite request that creates the destination file with
617mode 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
618C<aio_sendfile>, followed by restoring atime, mtime, access mode and 735C<aio_sendfile>, followed by restoring atime, mtime, access mode and
619uid/gid, in that order. 736uid/gid, in that order.
620 737
621If an error occurs, the partial destination file will be unlinked, if 738If an error occurs, the partial destination file will be unlinked, if
… …
623errors are being ignored. 740errors are being ignored.
624 741
625=cut 742=cut
626 743
627sub aio_copy($$;$) { 744sub aio_copy($$;$) {
628 aio_block {
629 my ($src, $dst, $cb) = @_; 745 my ($src, $dst, $cb) = @_;
630 746
631 my $pri = aioreq_pri; 747 my $pri = aioreq_pri;
632 my $grp = aio_group $cb; 748 my $grp = aio_group $cb;
633 749
634 aioreq_pri $pri; 750 aioreq_pri $pri;
635 add $grp aio_open $src, O_RDONLY, 0, sub { 751 add $grp aio_open $src, O_RDONLY, 0, sub {
636 if (my $src_fh = $_[0]) { 752 if (my $src_fh = $_[0]) {
637 my @stat = stat $src_fh; 753 my @stat = stat $src_fh; # hmm, might block over nfs?
638 754
639 aioreq_pri $pri; 755 aioreq_pri $pri;
640 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 {
641 if (my $dst_fh = $_[0]) { 757 if (my $dst_fh = $_[0]) {
642 aioreq_pri $pri; 758 aioreq_pri $pri;
643 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 759 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
644 if ($_[0] == $stat[7]) { 760 if ($_[0] == $stat[7]) {
645 $grp->result (0); 761 $grp->result (0);
646 close $src_fh; 762 close $src_fh;
647 763
648 # those should not normally block. should. should.
649 utime $stat[8], $stat[9], $dst;
650 chmod $stat[2] & 07777, $dst_fh;
651 chown $stat[4], $stat[5], $dst_fh;
652 close $dst_fh;
653 } else { 764 my $ch = sub {
654 $grp->result (-1);
655 close $src_fh;
656 close $dst_fh;
657
658 aioreq $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;
659 add $grp aio_unlink $dst; 770 add $grp aio_close $dst_fh;
771 }
772 };
660 } 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;
661 }; 791 }
662 } else {
663 $grp->result (-1);
664 } 792 };
793 } else {
794 $grp->result (-1);
665 }, 795 }
666
667 } else {
668 $grp->result (-1);
669 } 796 },
797
798 } else {
799 $grp->result (-1);
670 }; 800 }
671
672 $grp
673 } 801 };
802
803 $grp
674} 804}
675 805
676=item aio_move $srcpath, $dstpath, $callback->($status) 806=item aio_move $srcpath, $dstpath, $callback->($status)
677 807
678Try 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
679destination) from C<$srcpath> to C<$dstpath> and call the callback with 809destination) from C<$srcpath> to C<$dstpath> and call the callback with
680the C<0> (error) or C<-1> ok. 810a status of C<0> (ok) or C<-1> (error, see C<$!>).
681 811
682This is a composite request that tries to rename(2) the file first. If 812This is a composite request that tries to rename(2) the file first; if
683rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if 813rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
684that is successful, unlinking the C<$srcpath>. 814that is successful, unlinks the C<$srcpath>.
685 815
686=cut 816=cut
687 817
688sub aio_move($$;$) { 818sub aio_move($$;$) {
689 aio_block {
690 my ($src, $dst, $cb) = @_; 819 my ($src, $dst, $cb) = @_;
691 820
692 my $pri = aioreq_pri; 821 my $pri = aioreq_pri;
693 my $grp = aio_group $cb; 822 my $grp = aio_group $cb;
694 823
695 aioreq_pri $pri; 824 aioreq_pri $pri;
696 add $grp aio_rename $src, $dst, sub { 825 add $grp aio_rename $src, $dst, sub {
697 if ($_[0] && $! == EXDEV) { 826 if ($_[0] && $! == EXDEV) {
698 aioreq_pri $pri; 827 aioreq_pri $pri;
699 add $grp aio_copy $src, $dst, sub { 828 add $grp aio_copy $src, $dst, sub {
700 $grp->result ($_[0]);
701
702 if (!$_[0]) {
703 aioreq_pri $pri;
704 add $grp aio_unlink $src;
705 }
706 };
707 } else {
708 $grp->result ($_[0]); 829 $grp->result ($_[0]);
830
831 if (!$_[0]) {
832 aioreq_pri $pri;
833 add $grp aio_unlink $src;
834 }
709 } 835 };
836 } else {
837 $grp->result ($_[0]);
710 }; 838 }
711
712 $grp
713 } 839 };
840
841 $grp
714} 842}
715 843
716=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 844=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
717 845
718Scans a directory (similar to C<aio_readdir>) but additionally tries to 846Scans a directory (similar to C<aio_readdir>) but additionally tries to
… …
738 866
739Implementation notes. 867Implementation notes.
740 868
741The 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.
742 870
871If readdir returns file type information, then this is used directly to
872find directories.
873
743After reading the directory, the modification time, size etc. of the 874Otherwise, after reading the directory, the modification time, size etc.
744directory 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
745isn'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
746entries are directories (if >= 2). Otherwise, no knowledge of the number 877how many entries are directories (if >= 2). Otherwise, no knowledge of the
747of subdirectories will be assumed. 878number of subdirectories will be assumed.
748 879
749Then entries will be sorted into likely directories (everything without 880Then entries will be sorted into likely directories a non-initial dot
750a non-initial dot currently) and likely non-directories (everything 881currently) and likely non-directories (see C<aio_readdirx>). Then every
751else). 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,
752likely directories first. If that succeeds, it assumes that the entry 883in order of their inode numbers. If that succeeds, it assumes that the
753is a directory or a symlink to directory (which will be checked 884entry is a directory or a symlink to directory (which will be checked
754seperately). This is often faster than stat'ing the entry itself because 885seperately). This is often faster than stat'ing the entry itself because
755filesystems might detect the type of the entry without reading the inode 886filesystems might detect the type of the entry without reading the inode
756data (e.g. ext2fs filetype feature). 887data (e.g. ext2fs filetype feature), even on systems that cannot return
888the filetype information on readdir.
757 889
758If 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
759rest of the entries is assumed to be non-directories. 891rest of the entries is assumed to be non-directories.
760 892
761This only works with certainty on POSIX (= UNIX) filesystems, which 893This only works with certainty on POSIX (= UNIX) filesystems, which
… …
766directory counting heuristic. 898directory counting heuristic.
767 899
768=cut 900=cut
769 901
770sub aio_scandir($$;$) { 902sub aio_scandir($$;$) {
771 aio_block {
772 my ($path, $maxreq, $cb) = @_; 903 my ($path, $maxreq, $cb) = @_;
773 904
774 my $pri = aioreq_pri; 905 my $pri = aioreq_pri;
775 906
776 my $grp = aio_group $cb; 907 my $grp = aio_group $cb;
777 908
778 $maxreq = 4 if $maxreq <= 0; 909 $maxreq = 4 if $maxreq <= 0;
779 910
780 # 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
781 aioreq_pri $pri; 919 aioreq_pri $pri;
782 add $grp aio_stat $path, sub { 920 add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
921 my $entries = shift
783 return $grp->result () if $_[0]; 922 or return $grp->result ();
784 my $now = time;
785 my $hash1 = join ":", (stat _)[0,1,3,7,9];
786 923
787 # read the directory entries 924 # stat the dir another time
788 aioreq_pri $pri; 925 aioreq_pri $pri;
789 add $grp aio_readdir $path, sub {
790 my $entries = shift
791 or return $grp->result ();
792
793 # stat the dir another time
794 aioreq_pri $pri;
795 add $grp aio_stat $path, sub { 926 add $grp aio_stat $path, sub {
796 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 927 my $hash2 = join ":", (stat _)[0,1,3,7,9];
797 928
798 my $ndirs; 929 my $ndirs;
799 930
800 # take the slow route if anything looks fishy 931 # take the slow route if anything looks fishy
801 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 932 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
802 $ndirs = -1; 933 $ndirs = -1;
803 } else { 934 } else {
804 # if nlink == 2, we are finished 935 # if nlink == 2, we are finished
805 # on non-posix-fs's, we rely on nlink < 2 936 # for non-posix-fs's, we rely on nlink < 2
806 $ndirs = (stat _)[3] - 2 937 $ndirs = (stat _)[3] - 2
807 or return $grp->result ([], $entries); 938 or return $grp->result ([], $entries);
808 } 939 }
809 940
810 # sort into likely dirs and likely nondirs
811 # dirs == files without ".", short entries first
812 $entries = [map $_->[0],
813 sort { $b->[1] cmp $a->[1] }
814 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
815 @$entries];
816
817 my (@dirs, @nondirs); 941 my (@dirs, @nondirs);
818 942
819 my $statgrp = add $grp aio_group sub { 943 my $statgrp = add $grp aio_group sub {
820 $grp->result (\@dirs, \@nondirs); 944 $grp->result (\@dirs, \@nondirs);
821 }; 945 };
822 946
823 limit $statgrp $maxreq; 947 limit $statgrp $maxreq;
824 feed $statgrp sub { 948 feed $statgrp sub {
825 return unless @$entries; 949 return unless @$entries;
826 my $entry = pop @$entries; 950 my $entry = shift @$entries;
827 951
828 aioreq_pri $pri; 952 aioreq_pri $pri;
829 add $statgrp aio_stat "$path/$entry/.", sub { 953 add $statgrp aio_stat "$path/$entry/.", sub {
830 if ($_[0] < 0) { 954 if ($_[0] < 0) {
831 push @nondirs, $entry; 955 push @nondirs, $entry;
832 } else { 956 } else {
833 # need to check for real directory 957 # need to check for real directory
834 aioreq_pri $pri; 958 aioreq_pri $pri;
835 add $statgrp aio_lstat "$path/$entry", sub { 959 add $statgrp aio_lstat "$path/$entry", sub {
836 if (-d _) { 960 if (-d _) {
837 push @dirs, $entry; 961 push @dirs, $entry;
838 962
839 unless (--$ndirs) { 963 unless (--$ndirs) {
840 push @nondirs, @$entries; 964 push @nondirs, @$entries;
841 feed $statgrp; 965 feed $statgrp;
842 }
843 } else {
844 push @nondirs, $entry;
845 } 966 }
967 } else {
968 push @nondirs, $entry;
846 } 969 }
847 } 970 }
848 }; 971 }
849 }; 972 };
850 }; 973 };
851 }; 974 };
852 }; 975 };
853
854 $grp
855 } 976 };
977
978 $grp
856} 979}
857 980
858=item aio_rmtree $path, $callback->($status) 981=item aio_rmtree $path, $callback->($status)
859 982
860Delete a directory tree starting (and including) C<$path>, return the 983Delete a directory tree starting (and including) C<$path>, return the
… …
864 987
865=cut 988=cut
866 989
867sub aio_rmtree; 990sub aio_rmtree;
868sub aio_rmtree($;$) { 991sub aio_rmtree($;$) {
869 aio_block {
870 my ($path, $cb) = @_; 992 my ($path, $cb) = @_;
871 993
872 my $pri = aioreq_pri; 994 my $pri = aioreq_pri;
873 my $grp = aio_group $cb; 995 my $grp = aio_group $cb;
874 996
875 aioreq_pri $pri; 997 aioreq_pri $pri;
876 add $grp aio_scandir $path, 0, sub { 998 add $grp aio_scandir $path, 0, sub {
877 my ($dirs, $nondirs) = @_; 999 my ($dirs, $nondirs) = @_;
878 1000
879 my $dirgrp = aio_group sub { 1001 my $dirgrp = aio_group sub {
880 add $grp aio_rmdir $path, sub { 1002 add $grp aio_rmdir $path, sub {
881 $grp->result ($_[0]); 1003 $grp->result ($_[0]);
882 };
883 }; 1004 };
884
885 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
886 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
887
888 add $grp $dirgrp;
889 }; 1005 };
890 1006
891 $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;
892 } 1011 };
1012
1013 $grp
893} 1014}
1015
1016=item aio_sync $callback->($status)
1017
1018Asynchronously call sync and call the callback when finished.
894 1019
895=item aio_fsync $fh, $callback->($status) 1020=item aio_fsync $fh, $callback->($status)
896 1021
897Asynchronously call fsync on the given filehandle and call the callback 1022Asynchronously call fsync on the given filehandle and call the callback
898with the fsync result code. 1023with the fsync result code.
… …
902Asynchronously call fdatasync on the given filehandle and call the 1027Asynchronously call fdatasync on the given filehandle and call the
903callback with the fdatasync result code. 1028callback with the fdatasync result code.
904 1029
905If 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
906detected, it will be emulated by calling C<fsync> instead. 1031detected, it will be emulated by calling C<fsync> instead.
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
1045=item aio_pathsync $path, $callback->($status)
1046
1047This request tries to open, fsync and close the given path. This is a
1048composite request intended to sync directories after directory operations
1049(E.g. rename). This might not work on all operating systems or have any
1050specific effect, but usually it makes sure that directory changes get
1051written to disc. It works for anything that can be opened for read-only,
1052not just directories.
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
1057Passes C<0> when everything went ok, and C<-1> on error.
1058
1059=cut
1060
1061sub aio_pathsync($;$) {
1062 my ($path, $cb) = @_;
1063
1064 my $pri = aioreq_pri;
1065 my $grp = aio_group $cb;
1066
1067 aioreq_pri $pri;
1068 add $grp aio_open $path, O_RDONLY, 0, sub {
1069 my ($fh) = @_;
1070 if ($fh) {
1071 aioreq_pri $pri;
1072 add $grp aio_fsync $fh, sub {
1073 $grp->result ($_[0]);
1074
1075 aioreq_pri $pri;
1076 add $grp aio_close $fh;
1077 };
1078 } else {
1079 $grp->result (-1);
1080 }
1081 };
1082
1083 $grp
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 C<IO::AIO::mmap> function, although it also works on data
1090scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
1091scalar must only be modified in-place while an aio operation is pending on
1092it).
1093
1094It calls the C<msync> function of your OS, if available, with the memory
1095area starting at C<$offset> in the string and ending C<$length> bytes
1096later. If C<$length> is negative, counts from the end, and if C<$length>
1097is C<undef>, then it goes till the end of the string. The flags can be
1098a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
1099C<IO::AIO::MS_SYNC>.
1100
1101=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1102
1103This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1104scalars.
1105
1106It touches (reads or writes) all memory pages in the specified
1107range inside the scalar. All caveats and parameters are the same
1108as for C<aio_msync>, above, except for flags, which must be either
1109C<0> (which reads all pages and ensures they are instantiated) or
1110C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
1111writing an octet from it, which dirties the page).
907 1112
908=item aio_group $callback->(...) 1113=item aio_group $callback->(...)
909 1114
910This is a very special aio request: Instead of doing something, it is a 1115This is a very special aio request: Instead of doing something, it is a
911container for other aio requests, which is useful if you want to bundle 1116container for other aio requests, which is useful if you want to bundle
… …
961=item cancel $req 1166=item cancel $req
962 1167
963Cancels the request, if possible. Has the effect of skipping execution 1168Cancels the request, if possible. Has the effect of skipping execution
964when entering the B<execute> state and skipping calling the callback when 1169when entering the B<execute> state and skipping calling the callback when
965entering the the B<result> state, but will leave the request otherwise 1170entering the the B<result> state, but will leave the request otherwise
966untouched. That means that requests that currently execute will not be 1171untouched (with the exception of readdir). That means that requests that
967stopped and resources held by the request will not be freed prematurely. 1172currently execute will not be stopped and resources held by the request
1173will not be freed prematurely.
968 1174
969=item cb $req $callback->(...) 1175=item cb $req $callback->(...)
970 1176
971Replace (or simply set) the callback registered to the request. 1177Replace (or simply set) the callback registered to the request.
972 1178
… …
1023Their lifetime, simplified, looks like this: when they are empty, they 1229Their lifetime, simplified, looks like this: when they are empty, they
1024will finish very quickly. If they contain only requests that are in the 1230will finish very quickly. If they contain only requests that are in the
1025C<done> state, they will also finish. Otherwise they will continue to 1231C<done> state, they will also finish. Otherwise they will continue to
1026exist. 1232exist.
1027 1233
1028That means after creating a group you have some time to add requests. And 1234That means after creating a group you have some time to add requests
1029in the callbacks of those requests, you can add further requests to the 1235(precisely before the callback has been invoked, which is only done within
1030group. And only when all those requests have finished will the the group 1236the C<poll_cb>). And in the callbacks of those requests, you can add
1031itself finish. 1237further requests to the group. And only when all those requests have
1238finished will the the group itself finish.
1032 1239
1033=over 4 1240=over 4
1034 1241
1035=item add $grp ... 1242=item add $grp ...
1036 1243
… …
1045=item $grp->cancel_subs 1252=item $grp->cancel_subs
1046 1253
1047Cancel all subrequests and clears any feeder, but not the group request 1254Cancel all subrequests and clears any feeder, but not the group request
1048itself. Useful when you queued a lot of events but got a result early. 1255itself. Useful when you queued a lot of events but got a result early.
1049 1256
1257The group request will finish normally (you cannot add requests to the
1258group).
1259
1050=item $grp->result (...) 1260=item $grp->result (...)
1051 1261
1052Set the result value(s) that will be passed to the group callback when all 1262Set the result value(s) that will be passed to the group callback when all
1053subrequests have finished and set thre groups errno to the current value 1263subrequests have finished and set the groups errno to the current value
1054of errno (just like calling C<errno> without an error number). By default, 1264of errno (just like calling C<errno> without an error number). By default,
1055no argument will be passed and errno is zero. 1265no argument will be passed and errno is zero.
1056 1266
1057=item $grp->errno ([$errno]) 1267=item $grp->errno ([$errno])
1058 1268
… …
1069=item feed $grp $callback->($grp) 1279=item feed $grp $callback->($grp)
1070 1280
1071Sets a feeder/generator on this group: every group can have an attached 1281Sets a feeder/generator on this group: every group can have an attached
1072generator that generates requests if idle. The idea behind this is that, 1282generator that generates requests if idle. The idea behind this is that,
1073although you could just queue as many requests as you want in a group, 1283although you could just queue as many requests as you want in a group,
1074this might starve other requests for a potentially long time. For 1284this might starve other requests for a potentially long time. For example,
1075example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1285C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1076requests, delaying any later requests for a long time. 1286delaying any later requests for a long time.
1077 1287
1078To avoid this, and allow incremental generation of requests, you can 1288To avoid this, and allow incremental generation of requests, you can
1079instead a group and set a feeder on it that generates those requests. The 1289instead a group and set a feeder on it that generates those requests. The
1080feed callback will be called whenever there are few enough (see C<limit>, 1290feed callback will be called whenever there are few enough (see C<limit>,
1081below) requests active in the group itself and is expected to queue more 1291below) requests active in the group itself and is expected to queue more
… …
1085not impose any limits). 1295not impose any limits).
1086 1296
1087If the feed does not queue more requests when called, it will be 1297If the feed does not queue more requests when called, it will be
1088automatically removed from the group. 1298automatically removed from the group.
1089 1299
1090If the feed limit is C<0>, it will be set to C<2> automatically. 1300If the feed limit is C<0> when this method is called, it will be set to
1301C<2> automatically.
1091 1302
1092Example: 1303Example:
1093 1304
1094 # stat all files in @files, but only ever use four aio requests concurrently: 1305 # stat all files in @files, but only ever use four aio requests concurrently:
1095 1306
… …
1107Sets the feeder limit for the group: The feeder will be called whenever 1318Sets the feeder limit for the group: The feeder will be called whenever
1108the group contains less than this many requests. 1319the group contains less than this many requests.
1109 1320
1110Setting the limit to C<0> will pause the feeding process. 1321Setting the limit to C<0> will pause the feeding process.
1111 1322
1323The default value for the limit is C<0>, but note that setting a feeder
1324automatically bumps it up to C<2>.
1325
1112=back 1326=back
1113 1327
1114=head2 SUPPORT FUNCTIONS 1328=head2 SUPPORT FUNCTIONS
1115 1329
1116=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1330=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
… …
1118=over 4 1332=over 4
1119 1333
1120=item $fileno = IO::AIO::poll_fileno 1334=item $fileno = IO::AIO::poll_fileno
1121 1335
1122Return the I<request result pipe file descriptor>. This filehandle must be 1336Return the I<request result pipe file descriptor>. This filehandle must be
1123polled for reading by some mechanism outside this module (e.g. Event or 1337polled for reading by some mechanism outside this module (e.g. EV, Glib,
1124select, see below or the SYNOPSIS). If the pipe becomes readable you have 1338select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1125to call C<poll_cb> to check the results. 1339you have to call C<poll_cb> to check the results.
1126 1340
1127See C<poll_cb> for an example. 1341See C<poll_cb> for an example.
1128 1342
1129=item IO::AIO::poll_cb 1343=item IO::AIO::poll_cb
1130 1344
1131Process some outstanding events on the result pipe. You have to call this 1345Process some outstanding events on the result pipe. You have to call this
1132regularly. Returns the number of events processed. Returns immediately 1346regularly. Returns C<0> if all events could be processed, or C<-1> if it
1347returned earlier for whatever reason. Returns immediately when no events
1133when no events are outstanding. The amount of events processed depends on 1348are outstanding. The amount of events processed depends on the settings of
1134the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>. 1349C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1135 1350
1136If not all requests were processed for whatever reason, the filehandle 1351If not all requests were processed for whatever reason, the filehandle
1137will still be ready when C<poll_cb> returns. 1352will still be ready when C<poll_cb> returns, so normally you don't have to
1353do anything special to have it called later.
1138 1354
1139Example: Install an Event watcher that automatically calls 1355Example: Install an Event watcher that automatically calls
1140IO::AIO::poll_cb with high priority: 1356IO::AIO::poll_cb with high priority (more examples can be found in the
1357SYNOPSIS section, at the top of this document):
1141 1358
1142 Event->io (fd => IO::AIO::poll_fileno, 1359 Event->io (fd => IO::AIO::poll_fileno,
1143 poll => 'r', async => 1, 1360 poll => 'r', async => 1,
1144 cb => \&IO::AIO::poll_cb); 1361 cb => \&IO::AIO::poll_cb);
1362
1363=item IO::AIO::poll_wait
1364
1365If there are any outstanding requests and none of them in the result
1366phase, wait till the result filehandle becomes ready for reading (simply
1367does a C<select> on the filehandle. This is useful if you want to
1368synchronously wait for some requests to finish).
1369
1370See C<nreqs> for an example.
1371
1372=item IO::AIO::poll
1373
1374Waits until some requests have been handled.
1375
1376Returns the number of requests processed, but is otherwise strictly
1377equivalent to:
1378
1379 IO::AIO::poll_wait, IO::AIO::poll_cb
1380
1381=item IO::AIO::flush
1382
1383Wait till all outstanding AIO requests have been handled.
1384
1385Strictly equivalent to:
1386
1387 IO::AIO::poll_wait, IO::AIO::poll_cb
1388 while IO::AIO::nreqs;
1145 1389
1146=item IO::AIO::max_poll_reqs $nreqs 1390=item IO::AIO::max_poll_reqs $nreqs
1147 1391
1148=item IO::AIO::max_poll_time $seconds 1392=item IO::AIO::max_poll_time $seconds
1149 1393
… …
1174 # use a low priority so other tasks have priority 1418 # use a low priority so other tasks have priority
1175 Event->io (fd => IO::AIO::poll_fileno, 1419 Event->io (fd => IO::AIO::poll_fileno,
1176 poll => 'r', nice => 1, 1420 poll => 'r', nice => 1,
1177 cb => &IO::AIO::poll_cb); 1421 cb => &IO::AIO::poll_cb);
1178 1422
1179=item IO::AIO::poll_wait
1180
1181If there are any outstanding requests and none of them in the result
1182phase, wait till the result filehandle becomes ready for reading (simply
1183does a C<select> on the filehandle. This is useful if you want to
1184synchronously wait for some requests to finish).
1185
1186See C<nreqs> for an example.
1187
1188=item IO::AIO::poll
1189
1190Waits until some requests have been handled.
1191
1192Returns the number of requests processed, but is otherwise strictly
1193equivalent to:
1194
1195 IO::AIO::poll_wait, IO::AIO::poll_cb
1196
1197=item IO::AIO::flush
1198
1199Wait till all outstanding AIO requests have been handled.
1200
1201Strictly equivalent to:
1202
1203 IO::AIO::poll_wait, IO::AIO::poll_cb
1204 while IO::AIO::nreqs;
1205
1206=back 1423=back
1207 1424
1208=head3 CONTROLLING THE NUMBER OF THREADS 1425=head3 CONTROLLING THE NUMBER OF THREADS
1209 1426
1210=over 1427=over
… …
1256 1473
1257The default is probably ok in most situations, especially if thread 1474The default is probably ok in most situations, especially if thread
1258creation is fast. If thread creation is very slow on your system you might 1475creation is fast. If thread creation is very slow on your system you might
1259want to use larger values. 1476want to use larger values.
1260 1477
1261=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1478=item IO::AIO::max_outstanding $maxreqs
1262 1479
1263This is a very bad function to use in interactive programs because it 1480This is a very bad function to use in interactive programs because it
1264blocks, and a bad way to reduce concurrency because it is inexact: Better 1481blocks, and a bad way to reduce concurrency because it is inexact: Better
1265use an C<aio_group> together with a feed callback. 1482use an C<aio_group> together with a feed callback.
1266 1483
… …
1271 1488
1272The default value is very large, so there is no practical limit on the 1489The default value is very large, so there is no practical limit on the
1273number of outstanding requests. 1490number of outstanding requests.
1274 1491
1275You can still queue as many requests as you want. Therefore, 1492You can still queue as many requests as you want. Therefore,
1276C<max_oustsanding> is mainly useful in simple scripts (with low values) or 1493C<max_outstanding> is mainly useful in simple scripts (with low values) or
1277as a stop gap to shield against fatal memory overflow (with large values). 1494as a stop gap to shield against fatal memory overflow (with large values).
1278 1495
1279=back 1496=back
1280 1497
1281=head3 STATISTICAL INFORMATION 1498=head3 STATISTICAL INFORMATION
… …
1302Returns the number of requests currently in the pending state (executed, 1519Returns the number of requests currently in the pending state (executed,
1303but not yet processed by poll_cb). 1520but not yet processed by poll_cb).
1304 1521
1305=back 1522=back
1306 1523
1524=head3 MISCELLANEOUS FUNCTIONS
1525
1526IO::AIO implements some functions that might be useful, but are not
1527asynchronous.
1528
1529=over 4
1530
1531=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1532
1533Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
1534but is blocking (this makes most sense if you know the input data is
1535likely cached already and the output filehandle is set to non-blocking
1536operations).
1537
1538Returns the number of bytes copied, or C<-1> on error.
1539
1540=item IO::AIO::fadvise $fh, $offset, $len, $advice
1541
1542Simply calls the C<posix_fadvise> function (see it's
1543manpage for details). The following advice constants are
1544avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1545C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1546C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1547
1548On systems that do not implement C<posix_fadvise>, this function returns
1549ENOSYS, otherwise the return value of C<posix_fadvise>.
1550
1551=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1552
1553Memory-maps a file (or anonymous memory range) and attaches it to the
1554given C<$scalar>, which will act like a string scalar.
1555
1556The only operations allowed on the scalar are C<substr>/C<vec> that don't
1557change the string length, and most read-only operations such as copying it
1558or searching it with regexes and so on.
1559
1560Anything else is unsafe and will, at best, result in memory leaks.
1561
1562The memory map associated with the C<$scalar> is automatically removed
1563when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
1564C<IO::AIO::munmap> functions are called.
1565
1566This calls the C<mmap>(2) function internally. See your system's manual
1567page for details on the C<$length>, C<$prot> and C<$flags> parameters.
1568
1569The C<$length> must be larger than zero and smaller than the actual
1570filesize.
1571
1572C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1573C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1574
1575C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
1576C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
1577not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
1578(which is set to C<MAP_ANON> if your system only provides this
1579constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
1580C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
1581C<IO::AIO::MAP_NONBLOCK>
1582
1583If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1584
1585Example:
1586
1587 use Digest::MD5;
1588 use IO::AIO;
1589
1590 open my $fh, "<verybigfile"
1591 or die "$!";
1592
1593 IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
1594 or die "verybigfile: $!";
1595
1596 my $fast_md5 = md5 $data;
1597
1598=item IO::AIO::munmap $scalar
1599
1600Removes a previous mmap and undefines the C<$scalar>.
1601
1602=item IO::AIO::mlockall $flags
1603
1604Calls the C<mlockall> function with the given C<$flags> (a combination of
1605C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL__FUTURE>).
1606
1607On systems that do not implement C<mlockall>, this function returns
1608ENOSYS, otherwise the return value of C<mlockall>.
1609
1610=item IO::AIO::munlockall
1611
1612Calls the C<munlockall> function.
1613
1614On systems that do not implement C<munlockall>, this function returns
1615ENOSYS, otherwise the return value of C<munlockall>.
1616
1617=back
1618
1307=cut 1619=cut
1308 1620
1309min_parallel 8; 1621min_parallel 8;
1310 1622
1311END { flush } 1623END { flush }
1312 1624
13131; 16251;
1626
1627=head1 EVENT LOOP INTEGRATION
1628
1629It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
1630automatically into many event loops:
1631
1632 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
1633 use AnyEvent::AIO;
1634
1635You can also integrate IO::AIO manually into many event loops, here are
1636some examples of how to do this:
1637
1638 # EV integration
1639 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
1640
1641 # Event integration
1642 Event->io (fd => IO::AIO::poll_fileno,
1643 poll => 'r',
1644 cb => \&IO::AIO::poll_cb);
1645
1646 # Glib/Gtk2 integration
1647 add_watch Glib::IO IO::AIO::poll_fileno,
1648 in => sub { IO::AIO::poll_cb; 1 };
1649
1650 # Tk integration
1651 Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
1652 readable => \&IO::AIO::poll_cb);
1653
1654 # Danga::Socket integration
1655 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
1656 \&IO::AIO::poll_cb);
1314 1657
1315=head2 FORK BEHAVIOUR 1658=head2 FORK BEHAVIOUR
1316 1659
1317This module should do "the right thing" when the process using it forks: 1660This module should do "the right thing" when the process using it forks:
1318 1661
… …
1351 1694
1352Known bugs will be fixed in the next release. 1695Known bugs will be fixed in the next release.
1353 1696
1354=head1 SEE ALSO 1697=head1 SEE ALSO
1355 1698
1356L<Coro::AIO>. 1699L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1700more natural syntax.
1357 1701
1358=head1 AUTHOR 1702=head1 AUTHOR
1359 1703
1360 Marc Lehmann <schmorp@schmorp.de> 1704 Marc Lehmann <schmorp@schmorp.de>
1361 http://home.schmorp.de/ 1705 http://home.schmorp.de/

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