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Revision 1.119 by root, Sun Dec 2 20:54:33 2007 UTC vs.
Revision 1.184 by root, Mon Nov 1 22:03:43 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 = '2.6'; 173 our $VERSION = '3.7';
200 174
201 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
202 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
203 aio_readlink aio_sync 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
204 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
205 aio_chown 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);
184
206 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block)); 185 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
207 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 186 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
208 min_parallel max_parallel max_idle 187 min_parallel max_parallel max_idle
209 nreqs nready npending nthreads 188 nreqs nready npending nthreads
210 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
211 194
212 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 195 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
213 196
214 require XSLoader; 197 require XSLoader;
215 XSLoader::load ("IO::AIO", $VERSION); 198 XSLoader::load ("IO::AIO", $VERSION);
216} 199}
217 200
218=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, $length = undef
273 IO::AIO::munlockall
219 274
220=head2 AIO REQUEST FUNCTIONS 275=head2 AIO REQUEST FUNCTIONS
221 276
222All the C<aio_*> calls are more or less thin wrappers around the syscall 277All the C<aio_*> calls are more or less thin wrappers around the syscall
223with the same name (sans C<aio_>). The arguments are similar or identical, 278with the same name (sans C<aio_>). The arguments are similar or identical,
224and they all accept an additional (and optional) C<$callback> argument 279and they all accept an additional (and optional) C<$callback> argument
225which 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
226the 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
227perl, which usually delivers "false") as it's sole argument when the given 282perl, which usually delivers "false") as its sole argument after the given
228syscall has been executed asynchronously. 283syscall has been executed asynchronously.
229 284
230All functions expecting a filehandle keep a copy of the filehandle 285All functions expecting a filehandle keep a copy of the filehandle
231internally until the request has finished. 286internally until the request has finished.
232 287
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246your 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
247environment, d) use Glib::filename_from_unicode on unicode filenames or e) 302environment, d) use Glib::filename_from_unicode on unicode filenames or e)
248use something else to ensure your scalar has the correct contents. 303use something else to ensure your scalar has the correct contents.
249 304
250This 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
251handles correctly wether it is set or not. 306handles correctly whether it is set or not.
252 307
253=over 4 308=over 4
254 309
255=item $prev_pri = aioreq_pri [$pri] 310=item $prev_pri = aioreq_pri [$pri]
256 311
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303by 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
304change the umask. 359change the umask.
305 360
306Example: 361Example:
307 362
308 aio_open "/etc/passwd", O_RDONLY, 0, sub { 363 aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
309 if ($_[0]) { 364 if ($_[0]) {
310 print "open successful, fh is $_[0]\n"; 365 print "open successful, fh is $_[0]\n";
311 ... 366 ...
312 } else { 367 } else {
313 die "open failed: $!\n"; 368 die "open failed: $!\n";
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319 374
320Asynchronously close a file and call the callback with the result 375Asynchronously close a file and call the callback with the result
321code. 376code.
322 377
323Unfortunately, you can't do this to perl. Perl I<insists> very strongly on 378Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
324closing the file descriptor associated with the filehandle itself. Here is 379closing the file descriptor associated with the filehandle itself.
325what aio_close will try:
326 380
327 1. dup()licate the fd 381Therefore, C<aio_close> will not close the filehandle - instead it will
328 2. asynchronously close() the duplicated fd 382use dup2 to overwrite the file descriptor with the write-end of a pipe
329 3. dup()licate the fd once more 383(the pipe fd will be created on demand and will be cached).
330 4. let perl close() the filehandle
331 5. asynchronously close the duplicated fd
332 384
333The idea is that the first close() flushes stuff to disk that closing an 385Or in other words: the file descriptor will be closed, but it will not be
334fd will flush, so when perl closes the fd, nothing much will need to be 386free for reuse until the perl filehandle is closed.
335flushed. The second async. close() will then flush stuff to disk that
336closing the last fd to the file will flush.
337
338Just FYI, SuSv3 has this to say on close:
339
340 All outstanding record locks owned by the process on the file
341 associated with the file descriptor shall be removed.
342
343 If fildes refers to a socket, close() shall cause the socket to be
344 destroyed. ... close() shall block for up to the current linger
345 interval until all data is transmitted.
346 [this actually sounds like a specification bug, but who knows]
347
348And at least Linux additionally actually flushes stuff on every close,
349even when the file itself is still open.
350
351Sounds enourmously inefficient and complicated? Yes... please show me how
352to nuke perl's fd out of existence...
353 387
354=cut 388=cut
355 389
356sub aio_close($;$) {
357 aio_block {
358 my ($fh, $cb) = @_;
359
360 my $pri = aioreq_pri;
361 my $grp = aio_group $cb;
362
363 my $fd = fileno $fh;
364
365 defined $fd or Carp::croak "aio_close called with fd-less filehandle";
366
367 # if the dups fail we will simply get EBADF
368 my $fd2 = _dup $fd;
369 aioreq_pri $pri;
370 add $grp _aio_close $fd2, sub {
371 my $fd2 = _dup $fd;
372 close $fh;
373 aioreq_pri $pri;
374 add $grp _aio_close $fd2, sub {
375 $grp->result ($_[0]);
376 };
377 };
378
379 $grp
380 }
381}
382
383
384=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 390=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
385 391
386=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 392=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
387 393
388Reads 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<$fh> and
389into the scalar given by C<$data> and offset C<$dataoffset> and calls the 395C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
390callback 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
391like the syscall). 397error, just like the syscall).
398
399C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
400offset plus the actual number of bytes read.
392 401
393If C<$offset> is undefined, then the current file descriptor offset will 402If C<$offset> is undefined, then the current file descriptor offset will
394be used (and updated), otherwise the file descriptor offset will not be 403be used (and updated), otherwise the file descriptor offset will not be
395changed by these calls. 404changed by these calls.
396 405
397If C<$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<$data>.
398 408
399If C<$dataoffset> is less than zero, it will be counted from the end of 409If C<$dataoffset> is less than zero, it will be counted from the end of
400C<$data>. 410C<$data>.
401 411
402The C<$data> scalar I<MUST NOT> be modified in any way while the request 412The C<$data> scalar I<MUST NOT> be modified in any way while the request
… …
420than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each 430than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
421other. 431other.
422 432
423This call tries to make use of a native C<sendfile> syscall to provide 433This call tries to make use of a native C<sendfile> syscall to provide
424zero-copy operation. For this to work, C<$out_fh> should refer to a 434zero-copy operation. For this to work, C<$out_fh> should refer to a
425socket, and C<$in_fh> should refer to mmap'able file. 435socket, and C<$in_fh> should refer to an mmap'able file.
426 436
427If the native sendfile call fails or is not implemented, it will be 437If a native sendfile cannot be found or it fails with C<ENOSYS>,
438C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
428emulated, so you can call C<aio_sendfile> on any type of filehandle 439it will be emulated, so you can call C<aio_sendfile> on any type of
429regardless of the limitations of the operating system. 440filehandle regardless of the limitations of the operating system.
430 441
431Please note, however, that C<aio_sendfile> can read more bytes from 442Please note, however, that C<aio_sendfile> can read more bytes from
432C<$in_fh> than are written, and there is no way to find out how many 443C<$in_fh> than are written, and there is no way to find out how many
433bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only 444bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
434provides the number of bytes written to C<$out_fh>. Only if the result 445provides the number of bytes written to C<$out_fh>. Only if the result
… …
472 $_[0] and die "stat failed: $!"; 483 $_[0] and die "stat failed: $!";
473 print "size is ", -s _, "\n"; 484 print "size is ", -s _, "\n";
474 }; 485 };
475 486
476 487
488=item aio_statvfs $fh_or_path, $callback->($statvfs)
489
490Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
491whether a file handle or path was passed.
492
493On success, the callback is passed a hash reference with the following
494members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
495C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
496is passed.
497
498The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
499C<ST_NOSUID>.
500
501The following non-POSIX IO::AIO::ST_* flag masks are defined to
502their correct value when available, or to C<0> on systems that do
503not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
504C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
505C<ST_NODIRATIME> and C<ST_RELATIME>.
506
507Example: stat C</wd> and dump out the data if successful.
508
509 aio_statvfs "/wd", sub {
510 my $f = $_[0]
511 or die "statvfs: $!";
512
513 use Data::Dumper;
514 say Dumper $f;
515 };
516
517 # result:
518 {
519 bsize => 1024,
520 bfree => 4333064312,
521 blocks => 10253828096,
522 files => 2050765568,
523 flag => 4096,
524 favail => 2042092649,
525 bavail => 4333064312,
526 ffree => 2042092649,
527 namemax => 255,
528 frsize => 1024,
529 fsid => 1810
530 }
531
532
477=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 533=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
478 534
479Works like perl's C<utime> function (including the special case of $atime 535Works like perl's C<utime> function (including the special case of $atime
480and $mtime being undef). Fractional times are supported if the underlying 536and $mtime being undef). Fractional times are supported if the underlying
481syscalls support them. 537syscalls support them.
… …
574 630
575Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 631Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
576directory (i.e. opendir + readdir + closedir). The entries will not be 632directory (i.e. opendir + readdir + closedir). The entries will not be
577sorted, and will B<NOT> include the C<.> and C<..> entries. 633sorted, and will B<NOT> include the C<.> and C<..> entries.
578 634
579The callback a single argument which is either C<undef> or an array-ref 635The callback is passed a single argument which is either C<undef> or an
580with the filenames. 636array-ref with the filenames.
637
638
639=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
640
641Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
642behaviour and output format. In case of an error, C<$entries> will be
643C<undef>.
644
645The flags are a combination of the following constants, ORed together (the
646flags will also be passed to the callback, possibly modified):
647
648=over 4
649
650=item IO::AIO::READDIR_DENTS
651
652When this flag is off, then the callback gets an arrayref with of names
653only (as with C<aio_readdir>), otherwise it gets an arrayref with
654C<[$name, $type, $inode]> arrayrefs, each describing a single directory
655entry in more detail.
656
657C<$name> is the name of the entry.
658
659C<$type> is one of the C<IO::AIO::DT_xxx> constants:
660
661C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
662C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
663C<IO::AIO::DT_WHT>.
664
665C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
666know, you have to run stat yourself. Also, for speed reasons, the C<$type>
667scalars are read-only: you can not modify them.
668
669C<$inode> is the inode number (which might not be exact on systems with 64
670bit inode numbers and 32 bit perls). This field has unspecified content on
671systems that do not deliver the inode information.
672
673=item IO::AIO::READDIR_DIRS_FIRST
674
675When this flag is set, then the names will be returned in an order where
676likely directories come first. This is useful when you need to quickly
677find directories, or you want to find all directories while avoiding to
678stat() each entry.
679
680If the system returns type information in readdir, then this is used
681to find directories directly. Otherwise, likely directories are files
682beginning with ".", or otherwise files with no dots, of which files with
683short names are tried first.
684
685=item IO::AIO::READDIR_STAT_ORDER
686
687When this flag is set, then the names will be returned in an order
688suitable for stat()'ing each one. That is, when you plan to stat()
689all files in the given directory, then the returned order will likely
690be fastest.
691
692If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
693the likely dirs come first, resulting in a less optimal stat order.
694
695=item IO::AIO::READDIR_FOUND_UNKNOWN
696
697This flag should not be set when calling C<aio_readdirx>. Instead, it
698is being set by C<aio_readdirx>, when any of the C<$type>'s found were
699C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
700C<$type>'s are known, which can be used to speed up some algorithms.
701
702=back
581 703
582 704
583=item aio_load $path, $data, $callback->($status) 705=item aio_load $path, $data, $callback->($status)
584 706
585This is a composite request that tries to fully load the given file into 707This is a composite request that tries to fully load the given file into
586memory. Status is the same as with aio_read. 708memory. Status is the same as with aio_read.
587 709
588=cut 710=cut
589 711
590sub aio_load($$;$) { 712sub aio_load($$;$) {
591 aio_block {
592 my ($path, undef, $cb) = @_; 713 my ($path, undef, $cb) = @_;
593 my $data = \$_[1]; 714 my $data = \$_[1];
594 715
595 my $pri = aioreq_pri; 716 my $pri = aioreq_pri;
596 my $grp = aio_group $cb; 717 my $grp = aio_group $cb;
718
719 aioreq_pri $pri;
720 add $grp aio_open $path, O_RDONLY, 0, sub {
721 my $fh = shift
722 or return $grp->result (-1);
597 723
598 aioreq_pri $pri; 724 aioreq_pri $pri;
599 add $grp aio_open $path, O_RDONLY, 0, sub {
600 my $fh = shift
601 or return $grp->result (-1);
602
603 aioreq_pri $pri;
604 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub { 725 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
605 $grp->result ($_[0]); 726 $grp->result ($_[0]);
606 };
607 }; 727 };
608
609 $grp
610 } 728 };
729
730 $grp
611} 731}
612 732
613=item aio_copy $srcpath, $dstpath, $callback->($status) 733=item aio_copy $srcpath, $dstpath, $callback->($status)
614 734
615Try to copy the I<file> (directories not supported as either source or 735Try to copy the I<file> (directories not supported as either source or
616destination) from C<$srcpath> to C<$dstpath> and call the callback with 736destination) from C<$srcpath> to C<$dstpath> and call the callback with
617the C<0> (error) or C<-1> ok. 737a status of C<0> (ok) or C<-1> (error, see C<$!>).
618 738
619This is a composite request that it creates the destination file with 739This is a composite request that creates the destination file with
620mode 0200 and copies the contents of the source file into it using 740mode 0200 and copies the contents of the source file into it using
621C<aio_sendfile>, followed by restoring atime, mtime, access mode and 741C<aio_sendfile>, followed by restoring atime, mtime, access mode and
622uid/gid, in that order. 742uid/gid, in that order.
623 743
624If an error occurs, the partial destination file will be unlinked, if 744If an error occurs, the partial destination file will be unlinked, if
… …
626errors are being ignored. 746errors are being ignored.
627 747
628=cut 748=cut
629 749
630sub aio_copy($$;$) { 750sub aio_copy($$;$) {
631 aio_block {
632 my ($src, $dst, $cb) = @_; 751 my ($src, $dst, $cb) = @_;
633 752
634 my $pri = aioreq_pri; 753 my $pri = aioreq_pri;
635 my $grp = aio_group $cb; 754 my $grp = aio_group $cb;
636 755
637 aioreq_pri $pri; 756 aioreq_pri $pri;
638 add $grp aio_open $src, O_RDONLY, 0, sub { 757 add $grp aio_open $src, O_RDONLY, 0, sub {
639 if (my $src_fh = $_[0]) { 758 if (my $src_fh = $_[0]) {
640 my @stat = stat $src_fh; 759 my @stat = stat $src_fh; # hmm, might block over nfs?
641 760
642 aioreq_pri $pri; 761 aioreq_pri $pri;
643 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub { 762 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
644 if (my $dst_fh = $_[0]) { 763 if (my $dst_fh = $_[0]) {
645 aioreq_pri $pri; 764 aioreq_pri $pri;
646 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 765 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
647 if ($_[0] == $stat[7]) { 766 if ($_[0] == $stat[7]) {
648 $grp->result (0); 767 $grp->result (0);
649 close $src_fh; 768 close $src_fh;
650 769
651 # those should not normally block. should. should.
652 utime $stat[8], $stat[9], $dst;
653 chmod $stat[2] & 07777, $dst_fh;
654 chown $stat[4], $stat[5], $dst_fh;
655 close $dst_fh;
656 } else { 770 my $ch = sub {
657 $grp->result (-1);
658 close $src_fh;
659 close $dst_fh;
660
661 aioreq $pri; 771 aioreq_pri $pri;
772 add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
773 aioreq_pri $pri;
774 add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
775 aioreq_pri $pri;
662 add $grp aio_unlink $dst; 776 add $grp aio_close $dst_fh;
777 }
778 };
663 } 779 };
780
781 aioreq_pri $pri;
782 add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
783 if ($_[0] < 0 && $! == ENOSYS) {
784 aioreq_pri $pri;
785 add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
786 } else {
787 $ch->();
788 }
789 };
790 } else {
791 $grp->result (-1);
792 close $src_fh;
793 close $dst_fh;
794
795 aioreq $pri;
796 add $grp aio_unlink $dst;
664 }; 797 }
665 } else {
666 $grp->result (-1);
667 } 798 };
799 } else {
800 $grp->result (-1);
668 }, 801 }
669
670 } else {
671 $grp->result (-1);
672 } 802 },
803
804 } else {
805 $grp->result (-1);
673 }; 806 }
674
675 $grp
676 } 807 };
808
809 $grp
677} 810}
678 811
679=item aio_move $srcpath, $dstpath, $callback->($status) 812=item aio_move $srcpath, $dstpath, $callback->($status)
680 813
681Try to move the I<file> (directories not supported as either source or 814Try to move the I<file> (directories not supported as either source or
682destination) from C<$srcpath> to C<$dstpath> and call the callback with 815destination) from C<$srcpath> to C<$dstpath> and call the callback with
683the C<0> (error) or C<-1> ok. 816a status of C<0> (ok) or C<-1> (error, see C<$!>).
684 817
685This is a composite request that tries to rename(2) the file first. If 818This is a composite request that tries to rename(2) the file first; if
686rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if 819rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
687that is successful, unlinking the C<$srcpath>. 820that is successful, unlinks the C<$srcpath>.
688 821
689=cut 822=cut
690 823
691sub aio_move($$;$) { 824sub aio_move($$;$) {
692 aio_block {
693 my ($src, $dst, $cb) = @_; 825 my ($src, $dst, $cb) = @_;
694 826
695 my $pri = aioreq_pri; 827 my $pri = aioreq_pri;
696 my $grp = aio_group $cb; 828 my $grp = aio_group $cb;
697 829
698 aioreq_pri $pri; 830 aioreq_pri $pri;
699 add $grp aio_rename $src, $dst, sub { 831 add $grp aio_rename $src, $dst, sub {
700 if ($_[0] && $! == EXDEV) { 832 if ($_[0] && $! == EXDEV) {
701 aioreq_pri $pri; 833 aioreq_pri $pri;
702 add $grp aio_copy $src, $dst, sub { 834 add $grp aio_copy $src, $dst, sub {
703 $grp->result ($_[0]);
704
705 if (!$_[0]) {
706 aioreq_pri $pri;
707 add $grp aio_unlink $src;
708 }
709 };
710 } else {
711 $grp->result ($_[0]); 835 $grp->result ($_[0]);
836
837 if (!$_[0]) {
838 aioreq_pri $pri;
839 add $grp aio_unlink $src;
840 }
712 } 841 };
842 } else {
843 $grp->result ($_[0]);
713 }; 844 }
714
715 $grp
716 } 845 };
846
847 $grp
717} 848}
718 849
719=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 850=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
720 851
721Scans a directory (similar to C<aio_readdir>) but additionally tries to 852Scans a directory (similar to C<aio_readdir>) but additionally tries to
… …
741 872
742Implementation notes. 873Implementation notes.
743 874
744The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can. 875The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
745 876
877If readdir returns file type information, then this is used directly to
878find directories.
879
746After reading the directory, the modification time, size etc. of the 880Otherwise, after reading the directory, the modification time, size etc.
747directory before and after the readdir is checked, and if they match (and 881of the directory before and after the readdir is checked, and if they
748isn't the current time), the link count will be used to decide how many 882match (and isn't the current time), the link count will be used to decide
749entries are directories (if >= 2). Otherwise, no knowledge of the number 883how many entries are directories (if >= 2). Otherwise, no knowledge of the
750of subdirectories will be assumed. 884number of subdirectories will be assumed.
751 885
752Then entries will be sorted into likely directories (everything without 886Then entries will be sorted into likely directories a non-initial dot
753a non-initial dot currently) and likely non-directories (everything 887currently) and likely non-directories (see C<aio_readdirx>). Then every
754else). Then every entry plus an appended C</.> will be C<stat>'ed, 888entry plus an appended C</.> will be C<stat>'ed, likely directories first,
755likely directories first. If that succeeds, it assumes that the entry 889in order of their inode numbers. If that succeeds, it assumes that the
756is a directory or a symlink to directory (which will be checked 890entry is a directory or a symlink to directory (which will be checked
757seperately). This is often faster than stat'ing the entry itself because 891seperately). This is often faster than stat'ing the entry itself because
758filesystems might detect the type of the entry without reading the inode 892filesystems might detect the type of the entry without reading the inode
759data (e.g. ext2fs filetype feature). 893data (e.g. ext2fs filetype feature), even on systems that cannot return
894the filetype information on readdir.
760 895
761If the known number of directories (link count - 2) has been reached, the 896If the known number of directories (link count - 2) has been reached, the
762rest of the entries is assumed to be non-directories. 897rest of the entries is assumed to be non-directories.
763 898
764This only works with certainty on POSIX (= UNIX) filesystems, which 899This only works with certainty on POSIX (= UNIX) filesystems, which
… …
769directory counting heuristic. 904directory counting heuristic.
770 905
771=cut 906=cut
772 907
773sub aio_scandir($$;$) { 908sub aio_scandir($$;$) {
774 aio_block {
775 my ($path, $maxreq, $cb) = @_; 909 my ($path, $maxreq, $cb) = @_;
776 910
777 my $pri = aioreq_pri; 911 my $pri = aioreq_pri;
778 912
779 my $grp = aio_group $cb; 913 my $grp = aio_group $cb;
780 914
781 $maxreq = 4 if $maxreq <= 0; 915 $maxreq = 4 if $maxreq <= 0;
782 916
783 # stat once 917 # stat once
918 aioreq_pri $pri;
919 add $grp aio_stat $path, sub {
920 return $grp->result () if $_[0];
921 my $now = time;
922 my $hash1 = join ":", (stat _)[0,1,3,7,9];
923
924 # read the directory entries
784 aioreq_pri $pri; 925 aioreq_pri $pri;
785 add $grp aio_stat $path, sub { 926 add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
927 my $entries = shift
786 return $grp->result () if $_[0]; 928 or return $grp->result ();
787 my $now = time;
788 my $hash1 = join ":", (stat _)[0,1,3,7,9];
789 929
790 # read the directory entries 930 # stat the dir another time
791 aioreq_pri $pri; 931 aioreq_pri $pri;
792 add $grp aio_readdir $path, sub {
793 my $entries = shift
794 or return $grp->result ();
795
796 # stat the dir another time
797 aioreq_pri $pri;
798 add $grp aio_stat $path, sub { 932 add $grp aio_stat $path, sub {
799 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 933 my $hash2 = join ":", (stat _)[0,1,3,7,9];
800 934
801 my $ndirs; 935 my $ndirs;
802 936
803 # take the slow route if anything looks fishy 937 # take the slow route if anything looks fishy
804 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 938 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
805 $ndirs = -1; 939 $ndirs = -1;
806 } else { 940 } else {
807 # if nlink == 2, we are finished 941 # if nlink == 2, we are finished
808 # on non-posix-fs's, we rely on nlink < 2 942 # for non-posix-fs's, we rely on nlink < 2
809 $ndirs = (stat _)[3] - 2 943 $ndirs = (stat _)[3] - 2
810 or return $grp->result ([], $entries); 944 or return $grp->result ([], $entries);
811 } 945 }
812 946
813 # sort into likely dirs and likely nondirs
814 # dirs == files without ".", short entries first
815 $entries = [map $_->[0],
816 sort { $b->[1] cmp $a->[1] }
817 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
818 @$entries];
819
820 my (@dirs, @nondirs); 947 my (@dirs, @nondirs);
821 948
822 my $statgrp = add $grp aio_group sub { 949 my $statgrp = add $grp aio_group sub {
823 $grp->result (\@dirs, \@nondirs); 950 $grp->result (\@dirs, \@nondirs);
824 }; 951 };
825 952
826 limit $statgrp $maxreq; 953 limit $statgrp $maxreq;
827 feed $statgrp sub { 954 feed $statgrp sub {
828 return unless @$entries; 955 return unless @$entries;
829 my $entry = pop @$entries; 956 my $entry = shift @$entries;
830 957
831 aioreq_pri $pri; 958 aioreq_pri $pri;
832 add $statgrp aio_stat "$path/$entry/.", sub { 959 add $statgrp aio_stat "$path/$entry/.", sub {
833 if ($_[0] < 0) { 960 if ($_[0] < 0) {
834 push @nondirs, $entry; 961 push @nondirs, $entry;
835 } else { 962 } else {
836 # need to check for real directory 963 # need to check for real directory
837 aioreq_pri $pri; 964 aioreq_pri $pri;
838 add $statgrp aio_lstat "$path/$entry", sub { 965 add $statgrp aio_lstat "$path/$entry", sub {
839 if (-d _) { 966 if (-d _) {
840 push @dirs, $entry; 967 push @dirs, $entry;
841 968
842 unless (--$ndirs) { 969 unless (--$ndirs) {
843 push @nondirs, @$entries; 970 push @nondirs, @$entries;
844 feed $statgrp; 971 feed $statgrp;
845 }
846 } else {
847 push @nondirs, $entry;
848 } 972 }
973 } else {
974 push @nondirs, $entry;
849 } 975 }
850 } 976 }
851 }; 977 }
852 }; 978 };
853 }; 979 };
854 }; 980 };
855 }; 981 };
856
857 $grp
858 } 982 };
983
984 $grp
859} 985}
860 986
861=item aio_rmtree $path, $callback->($status) 987=item aio_rmtree $path, $callback->($status)
862 988
863Delete a directory tree starting (and including) C<$path>, return the 989Delete a directory tree starting (and including) C<$path>, return the
… …
867 993
868=cut 994=cut
869 995
870sub aio_rmtree; 996sub aio_rmtree;
871sub aio_rmtree($;$) { 997sub aio_rmtree($;$) {
872 aio_block {
873 my ($path, $cb) = @_; 998 my ($path, $cb) = @_;
874 999
875 my $pri = aioreq_pri; 1000 my $pri = aioreq_pri;
876 my $grp = aio_group $cb; 1001 my $grp = aio_group $cb;
877 1002
878 aioreq_pri $pri; 1003 aioreq_pri $pri;
879 add $grp aio_scandir $path, 0, sub { 1004 add $grp aio_scandir $path, 0, sub {
880 my ($dirs, $nondirs) = @_; 1005 my ($dirs, $nondirs) = @_;
881 1006
882 my $dirgrp = aio_group sub { 1007 my $dirgrp = aio_group sub {
883 add $grp aio_rmdir $path, sub { 1008 add $grp aio_rmdir $path, sub {
884 $grp->result ($_[0]); 1009 $grp->result ($_[0]);
885 };
886 }; 1010 };
887
888 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
889 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
890
891 add $grp $dirgrp;
892 }; 1011 };
893 1012
894 $grp 1013 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
1014 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
1015
1016 add $grp $dirgrp;
895 } 1017 };
1018
1019 $grp
896} 1020}
897 1021
898=item aio_sync $callback->($status) 1022=item aio_sync $callback->($status)
899 1023
900Asynchronously call sync and call the callback when finished. 1024Asynchronously call sync and call the callback when finished.
… …
909Asynchronously call fdatasync on the given filehandle and call the 1033Asynchronously call fdatasync on the given filehandle and call the
910callback with the fdatasync result code. 1034callback with the fdatasync result code.
911 1035
912If this call isn't available because your OS lacks it or it couldn't be 1036If this call isn't available because your OS lacks it or it couldn't be
913detected, it will be emulated by calling C<fsync> instead. 1037detected, it will be emulated by calling C<fsync> instead.
1038
1039=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
1040
1041Sync the data portion of the file specified by C<$offset> and C<$length>
1042to disk (but NOT the metadata), by calling the Linux-specific
1043sync_file_range call. If sync_file_range is not available or it returns
1044ENOSYS, then fdatasync or fsync is being substituted.
1045
1046C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
1047C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
1048C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
1049manpage for details.
1050
1051=item aio_pathsync $path, $callback->($status)
1052
1053This request tries to open, fsync and close the given path. This is a
1054composite request intended to sync directories after directory operations
1055(E.g. rename). This might not work on all operating systems or have any
1056specific effect, but usually it makes sure that directory changes get
1057written to disc. It works for anything that can be opened for read-only,
1058not just directories.
1059
1060Future versions of this function might fall back to other methods when
1061C<fsync> on the directory fails (such as calling C<sync>).
1062
1063Passes C<0> when everything went ok, and C<-1> on error.
1064
1065=cut
1066
1067sub aio_pathsync($;$) {
1068 my ($path, $cb) = @_;
1069
1070 my $pri = aioreq_pri;
1071 my $grp = aio_group $cb;
1072
1073 aioreq_pri $pri;
1074 add $grp aio_open $path, O_RDONLY, 0, sub {
1075 my ($fh) = @_;
1076 if ($fh) {
1077 aioreq_pri $pri;
1078 add $grp aio_fsync $fh, sub {
1079 $grp->result ($_[0]);
1080
1081 aioreq_pri $pri;
1082 add $grp aio_close $fh;
1083 };
1084 } else {
1085 $grp->result (-1);
1086 }
1087 };
1088
1089 $grp
1090}
1091
1092=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1093
1094This is a rather advanced IO::AIO call, which only works on mmap(2)ed
1095scalars (see the C<IO::AIO::mmap> function, although it also works on data
1096scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
1097scalar must only be modified in-place while an aio operation is pending on
1098it).
1099
1100It calls the C<msync> function of your OS, if available, with the memory
1101area starting at C<$offset> in the string and ending C<$length> bytes
1102later. If C<$length> is negative, counts from the end, and if C<$length>
1103is C<undef>, then it goes till the end of the string. The flags can be
1104a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
1105C<IO::AIO::MS_SYNC>.
1106
1107=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1108
1109This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1110scalars.
1111
1112It touches (reads or writes) all memory pages in the specified
1113range inside the scalar. All caveats and parameters are the same
1114as for C<aio_msync>, above, except for flags, which must be either
1115C<0> (which reads all pages and ensures they are instantiated) or
1116C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
1117writing an octet from it, which dirties the page).
1118
1119=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1120
1121This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1122scalars.
1123
1124It reads in all the pages of the underlying storage into memory (if any)
1125and locks them, so they are not getting swapped/paged out or removed.
1126
1127If C<$length> is undefined, then the scalar will be locked till the end.
1128
1129On systems that do not implement C<mlock>, this function returns C<-1>
1130and sets errno to C<ENOSYS>.
1131
1132Note that the corresponding C<munlock> is synchronous and is
1133documented under L<MISCELLANEOUS FUNCTIONS>.
1134
1135Example: open a file, mmap and mlock it - both will be undone when
1136C<$data> gets destroyed.
1137
1138 open my $fh, "<", $path or die "$path: $!";
1139 my $data;
1140 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
1141 aio_mlock $data; # mlock in background
1142
1143=item aio_mlockall $flags, $callback->($status)
1144
1145Calls the C<mlockall> function with the given C<$flags> (a combination of
1146C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).
1147
1148On systems that do not implement C<mlockall>, this function returns C<-1>
1149and sets errno to C<ENOSYS>.
1150
1151Note that the corresponding C<munlockall> is synchronous and is
1152documented under L<MISCELLANEOUS FUNCTIONS>.
1153
1154Example: asynchronously lock all current and future pages into memory.
1155
1156 aio_mlockall IO::AIO::MCL_FUTURE;
914 1157
915=item aio_group $callback->(...) 1158=item aio_group $callback->(...)
916 1159
917This is a very special aio request: Instead of doing something, it is a 1160This is a very special aio request: Instead of doing something, it is a
918container for other aio requests, which is useful if you want to bundle 1161container for other aio requests, which is useful if you want to bundle
… …
968=item cancel $req 1211=item cancel $req
969 1212
970Cancels the request, if possible. Has the effect of skipping execution 1213Cancels the request, if possible. Has the effect of skipping execution
971when entering the B<execute> state and skipping calling the callback when 1214when entering the B<execute> state and skipping calling the callback when
972entering the the B<result> state, but will leave the request otherwise 1215entering the the B<result> state, but will leave the request otherwise
973untouched. That means that requests that currently execute will not be 1216untouched (with the exception of readdir). That means that requests that
974stopped and resources held by the request will not be freed prematurely. 1217currently execute will not be stopped and resources held by the request
1218will not be freed prematurely.
975 1219
976=item cb $req $callback->(...) 1220=item cb $req $callback->(...)
977 1221
978Replace (or simply set) the callback registered to the request. 1222Replace (or simply set) the callback registered to the request.
979 1223
… …
1030Their lifetime, simplified, looks like this: when they are empty, they 1274Their lifetime, simplified, looks like this: when they are empty, they
1031will finish very quickly. If they contain only requests that are in the 1275will finish very quickly. If they contain only requests that are in the
1032C<done> state, they will also finish. Otherwise they will continue to 1276C<done> state, they will also finish. Otherwise they will continue to
1033exist. 1277exist.
1034 1278
1035That means after creating a group you have some time to add requests. And 1279That means after creating a group you have some time to add requests
1036in the callbacks of those requests, you can add further requests to the 1280(precisely before the callback has been invoked, which is only done within
1037group. And only when all those requests have finished will the the group 1281the C<poll_cb>). And in the callbacks of those requests, you can add
1038itself finish. 1282further requests to the group. And only when all those requests have
1283finished will the the group itself finish.
1039 1284
1040=over 4 1285=over 4
1041 1286
1042=item add $grp ... 1287=item add $grp ...
1043 1288
… …
1052=item $grp->cancel_subs 1297=item $grp->cancel_subs
1053 1298
1054Cancel all subrequests and clears any feeder, but not the group request 1299Cancel all subrequests and clears any feeder, but not the group request
1055itself. Useful when you queued a lot of events but got a result early. 1300itself. Useful when you queued a lot of events but got a result early.
1056 1301
1302The group request will finish normally (you cannot add requests to the
1303group).
1304
1057=item $grp->result (...) 1305=item $grp->result (...)
1058 1306
1059Set the result value(s) that will be passed to the group callback when all 1307Set the result value(s) that will be passed to the group callback when all
1060subrequests have finished and set thre groups errno to the current value 1308subrequests have finished and set the groups errno to the current value
1061of errno (just like calling C<errno> without an error number). By default, 1309of errno (just like calling C<errno> without an error number). By default,
1062no argument will be passed and errno is zero. 1310no argument will be passed and errno is zero.
1063 1311
1064=item $grp->errno ([$errno]) 1312=item $grp->errno ([$errno])
1065 1313
… …
1076=item feed $grp $callback->($grp) 1324=item feed $grp $callback->($grp)
1077 1325
1078Sets a feeder/generator on this group: every group can have an attached 1326Sets a feeder/generator on this group: every group can have an attached
1079generator that generates requests if idle. The idea behind this is that, 1327generator that generates requests if idle. The idea behind this is that,
1080although you could just queue as many requests as you want in a group, 1328although you could just queue as many requests as you want in a group,
1081this might starve other requests for a potentially long time. For 1329this might starve other requests for a potentially long time. For example,
1082example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1330C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1083requests, delaying any later requests for a long time. 1331delaying any later requests for a long time.
1084 1332
1085To avoid this, and allow incremental generation of requests, you can 1333To avoid this, and allow incremental generation of requests, you can
1086instead a group and set a feeder on it that generates those requests. The 1334instead a group and set a feeder on it that generates those requests. The
1087feed callback will be called whenever there are few enough (see C<limit>, 1335feed callback will be called whenever there are few enough (see C<limit>,
1088below) requests active in the group itself and is expected to queue more 1336below) requests active in the group itself and is expected to queue more
… …
1092not impose any limits). 1340not impose any limits).
1093 1341
1094If the feed does not queue more requests when called, it will be 1342If the feed does not queue more requests when called, it will be
1095automatically removed from the group. 1343automatically removed from the group.
1096 1344
1097If the feed limit is C<0>, it will be set to C<2> automatically. 1345If the feed limit is C<0> when this method is called, it will be set to
1346C<2> automatically.
1098 1347
1099Example: 1348Example:
1100 1349
1101 # stat all files in @files, but only ever use four aio requests concurrently: 1350 # stat all files in @files, but only ever use four aio requests concurrently:
1102 1351
… …
1114Sets the feeder limit for the group: The feeder will be called whenever 1363Sets the feeder limit for the group: The feeder will be called whenever
1115the group contains less than this many requests. 1364the group contains less than this many requests.
1116 1365
1117Setting the limit to C<0> will pause the feeding process. 1366Setting the limit to C<0> will pause the feeding process.
1118 1367
1368The default value for the limit is C<0>, but note that setting a feeder
1369automatically bumps it up to C<2>.
1370
1119=back 1371=back
1120 1372
1121=head2 SUPPORT FUNCTIONS 1373=head2 SUPPORT FUNCTIONS
1122 1374
1123=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1375=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
… …
1125=over 4 1377=over 4
1126 1378
1127=item $fileno = IO::AIO::poll_fileno 1379=item $fileno = IO::AIO::poll_fileno
1128 1380
1129Return the I<request result pipe file descriptor>. This filehandle must be 1381Return the I<request result pipe file descriptor>. This filehandle must be
1130polled for reading by some mechanism outside this module (e.g. Event or 1382polled for reading by some mechanism outside this module (e.g. EV, Glib,
1131select, see below or the SYNOPSIS). If the pipe becomes readable you have 1383select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1132to call C<poll_cb> to check the results. 1384you have to call C<poll_cb> to check the results.
1133 1385
1134See C<poll_cb> for an example. 1386See C<poll_cb> for an example.
1135 1387
1136=item IO::AIO::poll_cb 1388=item IO::AIO::poll_cb
1137 1389
1138Process some outstanding events on the result pipe. You have to call this 1390Process some outstanding events on the result pipe. You have to call this
1139regularly. Returns the number of events processed. Returns immediately 1391regularly. Returns C<0> if all events could be processed, or C<-1> if it
1392returned earlier for whatever reason. Returns immediately when no events
1140when no events are outstanding. The amount of events processed depends on 1393are outstanding. The amount of events processed depends on the settings of
1141the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>. 1394C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1142 1395
1143If not all requests were processed for whatever reason, the filehandle 1396If not all requests were processed for whatever reason, the filehandle
1144will still be ready when C<poll_cb> returns. 1397will still be ready when C<poll_cb> returns, so normally you don't have to
1398do anything special to have it called later.
1145 1399
1146Example: Install an Event watcher that automatically calls 1400Example: Install an Event watcher that automatically calls
1147IO::AIO::poll_cb with high priority: 1401IO::AIO::poll_cb with high priority (more examples can be found in the
1402SYNOPSIS section, at the top of this document):
1148 1403
1149 Event->io (fd => IO::AIO::poll_fileno, 1404 Event->io (fd => IO::AIO::poll_fileno,
1150 poll => 'r', async => 1, 1405 poll => 'r', async => 1,
1151 cb => \&IO::AIO::poll_cb); 1406 cb => \&IO::AIO::poll_cb);
1407
1408=item IO::AIO::poll_wait
1409
1410If there are any outstanding requests and none of them in the result
1411phase, wait till the result filehandle becomes ready for reading (simply
1412does a C<select> on the filehandle. This is useful if you want to
1413synchronously wait for some requests to finish).
1414
1415See C<nreqs> for an example.
1416
1417=item IO::AIO::poll
1418
1419Waits until some requests have been handled.
1420
1421Returns the number of requests processed, but is otherwise strictly
1422equivalent to:
1423
1424 IO::AIO::poll_wait, IO::AIO::poll_cb
1425
1426=item IO::AIO::flush
1427
1428Wait till all outstanding AIO requests have been handled.
1429
1430Strictly equivalent to:
1431
1432 IO::AIO::poll_wait, IO::AIO::poll_cb
1433 while IO::AIO::nreqs;
1152 1434
1153=item IO::AIO::max_poll_reqs $nreqs 1435=item IO::AIO::max_poll_reqs $nreqs
1154 1436
1155=item IO::AIO::max_poll_time $seconds 1437=item IO::AIO::max_poll_time $seconds
1156 1438
… …
1181 # use a low priority so other tasks have priority 1463 # use a low priority so other tasks have priority
1182 Event->io (fd => IO::AIO::poll_fileno, 1464 Event->io (fd => IO::AIO::poll_fileno,
1183 poll => 'r', nice => 1, 1465 poll => 'r', nice => 1,
1184 cb => &IO::AIO::poll_cb); 1466 cb => &IO::AIO::poll_cb);
1185 1467
1186=item IO::AIO::poll_wait
1187
1188If there are any outstanding requests and none of them in the result
1189phase, wait till the result filehandle becomes ready for reading (simply
1190does a C<select> on the filehandle. This is useful if you want to
1191synchronously wait for some requests to finish).
1192
1193See C<nreqs> for an example.
1194
1195=item IO::AIO::poll
1196
1197Waits until some requests have been handled.
1198
1199Returns the number of requests processed, but is otherwise strictly
1200equivalent to:
1201
1202 IO::AIO::poll_wait, IO::AIO::poll_cb
1203
1204=item IO::AIO::flush
1205
1206Wait till all outstanding AIO requests have been handled.
1207
1208Strictly equivalent to:
1209
1210 IO::AIO::poll_wait, IO::AIO::poll_cb
1211 while IO::AIO::nreqs;
1212
1213=back 1468=back
1214 1469
1215=head3 CONTROLLING THE NUMBER OF THREADS 1470=head3 CONTROLLING THE NUMBER OF THREADS
1216 1471
1217=over 1472=over
… …
1263 1518
1264The default is probably ok in most situations, especially if thread 1519The default is probably ok in most situations, especially if thread
1265creation is fast. If thread creation is very slow on your system you might 1520creation is fast. If thread creation is very slow on your system you might
1266want to use larger values. 1521want to use larger values.
1267 1522
1268=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1523=item IO::AIO::max_outstanding $maxreqs
1269 1524
1270This is a very bad function to use in interactive programs because it 1525This is a very bad function to use in interactive programs because it
1271blocks, and a bad way to reduce concurrency because it is inexact: Better 1526blocks, and a bad way to reduce concurrency because it is inexact: Better
1272use an C<aio_group> together with a feed callback. 1527use an C<aio_group> together with a feed callback.
1273 1528
… …
1278 1533
1279The default value is very large, so there is no practical limit on the 1534The default value is very large, so there is no practical limit on the
1280number of outstanding requests. 1535number of outstanding requests.
1281 1536
1282You can still queue as many requests as you want. Therefore, 1537You can still queue as many requests as you want. Therefore,
1283C<max_oustsanding> is mainly useful in simple scripts (with low values) or 1538C<max_outstanding> is mainly useful in simple scripts (with low values) or
1284as a stop gap to shield against fatal memory overflow (with large values). 1539as a stop gap to shield against fatal memory overflow (with large values).
1285 1540
1286=back 1541=back
1287 1542
1288=head3 STATISTICAL INFORMATION 1543=head3 STATISTICAL INFORMATION
… …
1309Returns the number of requests currently in the pending state (executed, 1564Returns the number of requests currently in the pending state (executed,
1310but not yet processed by poll_cb). 1565but not yet processed by poll_cb).
1311 1566
1312=back 1567=back
1313 1568
1569=head3 MISCELLANEOUS FUNCTIONS
1570
1571IO::AIO implements some functions that might be useful, but are not
1572asynchronous.
1573
1574=over 4
1575
1576=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1577
1578Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
1579but is blocking (this makes most sense if you know the input data is
1580likely cached already and the output filehandle is set to non-blocking
1581operations).
1582
1583Returns the number of bytes copied, or C<-1> on error.
1584
1585=item IO::AIO::fadvise $fh, $offset, $len, $advice
1586
1587Simply calls the C<posix_fadvise> function (see its
1588manpage for details). The following advice constants are
1589avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1590C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1591C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1592
1593On systems that do not implement C<posix_fadvise>, this function returns
1594ENOSYS, otherwise the return value of C<posix_fadvise>.
1595
1596=item IO::AIO::madvise $scalar, $offset, $len, $advice
1597
1598Simply calls the C<posix_madvise> function (see its
1599manpage for details). The following advice constants are
1600avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
1601C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.
1602
1603On systems that do not implement C<posix_madvise>, this function returns
1604ENOSYS, otherwise the return value of C<posix_madvise>.
1605
1606=item IO::AIO::mprotect $scalar, $offset, $len, $protect
1607
1608Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
1609$scalar (see its manpage for details). The following protect
1610constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
1611C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
1612
1613On systems that do not implement C<mprotect>, this function returns
1614ENOSYS, otherwise the return value of C<mprotect>.
1615
1616=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1617
1618Memory-maps a file (or anonymous memory range) and attaches it to the
1619given C<$scalar>, which will act like a string scalar.
1620
1621The only operations allowed on the scalar are C<substr>/C<vec> that don't
1622change the string length, and most read-only operations such as copying it
1623or searching it with regexes and so on.
1624
1625Anything else is unsafe and will, at best, result in memory leaks.
1626
1627The memory map associated with the C<$scalar> is automatically removed
1628when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
1629C<IO::AIO::munmap> functions are called.
1630
1631This calls the C<mmap>(2) function internally. See your system's manual
1632page for details on the C<$length>, C<$prot> and C<$flags> parameters.
1633
1634The C<$length> must be larger than zero and smaller than the actual
1635filesize.
1636
1637C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1638C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1639
1640C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
1641C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
1642not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
1643(which is set to C<MAP_ANON> if your system only provides this
1644constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
1645C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
1646C<IO::AIO::MAP_NONBLOCK>
1647
1648If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1649
1650C<$offset> is the offset from the start of the file - it generally must be
1651a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
1652
1653Example:
1654
1655 use Digest::MD5;
1656 use IO::AIO;
1657
1658 open my $fh, "<verybigfile"
1659 or die "$!";
1660
1661 IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
1662 or die "verybigfile: $!";
1663
1664 my $fast_md5 = md5 $data;
1665
1666=item IO::AIO::munmap $scalar
1667
1668Removes a previous mmap and undefines the C<$scalar>.
1669
1670=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
1671
1672Calls the C<munlock> function, undoing the effects of a previous
1673C<aio_mlock> call (see its description for details).
1674
1675=item IO::AIO::munlockall
1676
1677Calls the C<munlockall> function.
1678
1679On systems that do not implement C<munlockall>, this function returns
1680ENOSYS, otherwise the return value of C<munlockall>.
1681
1682=back
1683
1314=cut 1684=cut
1315 1685
1316min_parallel 8; 1686min_parallel 8;
1317 1687
1318END { flush } 1688END { flush }
1319 1689
13201; 16901;
1691
1692=head1 EVENT LOOP INTEGRATION
1693
1694It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
1695automatically into many event loops:
1696
1697 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
1698 use AnyEvent::AIO;
1699
1700You can also integrate IO::AIO manually into many event loops, here are
1701some examples of how to do this:
1702
1703 # EV integration
1704 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
1705
1706 # Event integration
1707 Event->io (fd => IO::AIO::poll_fileno,
1708 poll => 'r',
1709 cb => \&IO::AIO::poll_cb);
1710
1711 # Glib/Gtk2 integration
1712 add_watch Glib::IO IO::AIO::poll_fileno,
1713 in => sub { IO::AIO::poll_cb; 1 };
1714
1715 # Tk integration
1716 Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
1717 readable => \&IO::AIO::poll_cb);
1718
1719 # Danga::Socket integration
1720 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
1721 \&IO::AIO::poll_cb);
1321 1722
1322=head2 FORK BEHAVIOUR 1723=head2 FORK BEHAVIOUR
1323 1724
1324This module should do "the right thing" when the process using it forks: 1725This module should do "the right thing" when the process using it forks:
1325 1726
… …
1358 1759
1359Known bugs will be fixed in the next release. 1760Known bugs will be fixed in the next release.
1360 1761
1361=head1 SEE ALSO 1762=head1 SEE ALSO
1362 1763
1363L<Coro::AIO>. 1764L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1765more natural syntax.
1364 1766
1365=head1 AUTHOR 1767=head1 AUTHOR
1366 1768
1367 Marc Lehmann <schmorp@schmorp.de> 1769 Marc Lehmann <schmorp@schmorp.de>
1368 http://home.schmorp.de/ 1770 http://home.schmorp.de/

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