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Revision 1.117 by root, Sat Oct 6 14:05:19 2007 UTC vs.
Revision 1.183 by root, Sun Sep 12 03:40:05 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
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
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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", IO::AIO::O_RDONLY, 0, sub {
104 my $fh = shift 82 my $fh = shift
105 or die "error while opening: $!"; 83 or die "error while opening: $!";
106 84
107 # stat'ing filehandles is generally non-blocking 85 # stat'ing filehandles is generally non-blocking
108 my $size = -s $fh; 86 my $size = -s $fh;
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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 = '3.65';
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_mlock aio_mlockall
183 aio_statvfs);
184
203 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block)); 185 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
204 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 186 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
205 min_parallel max_parallel max_idle 187 min_parallel max_parallel max_idle
206 nreqs nready npending nthreads 188 nreqs nready npending nthreads
207 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
208 194
209 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 195 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
210 196
211 require XSLoader; 197 require XSLoader;
212 XSLoader::load ("IO::AIO", $VERSION); 198 XSLoader::load ("IO::AIO", $VERSION);
213} 199}
214 200
215=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::munlock $scalar, $offset = 0, $length = undef
271 IO::AIO::munlockall
216 272
217=head2 AIO REQUEST FUNCTIONS 273=head2 AIO REQUEST FUNCTIONS
218 274
219All the C<aio_*> calls are more or less thin wrappers around the syscall 275All the C<aio_*> calls are more or less thin wrappers around the syscall
220with the same name (sans C<aio_>). The arguments are similar or identical, 276with the same name (sans C<aio_>). The arguments are similar or identical,
221and they all accept an additional (and optional) C<$callback> argument 277and they all accept an additional (and optional) C<$callback> argument
222which must be a code reference. This code reference will get called with 278which 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 279the 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 280perl, which usually delivers "false") as its sole argument after the given
225syscall has been executed asynchronously. 281syscall has been executed asynchronously.
226 282
227All functions expecting a filehandle keep a copy of the filehandle 283All functions expecting a filehandle keep a copy of the filehandle
228internally until the request has finished. 284internally until the request has finished.
229 285
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243your pathnames to the locale (or other) encoding in effect in the user 299your pathnames to the locale (or other) encoding in effect in the user
244environment, d) use Glib::filename_from_unicode on unicode filenames or e) 300environment, d) use Glib::filename_from_unicode on unicode filenames or e)
245use something else to ensure your scalar has the correct contents. 301use something else to ensure your scalar has the correct contents.
246 302
247This works, btw. independent of the internal UTF-8 bit, which IO::AIO 303This works, btw. independent of the internal UTF-8 bit, which IO::AIO
248handles correctly wether it is set or not. 304handles correctly whether it is set or not.
249 305
250=over 4 306=over 4
251 307
252=item $prev_pri = aioreq_pri [$pri] 308=item $prev_pri = aioreq_pri [$pri]
253 309
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300by the umask in effect then the request is being executed, so better never 356by the umask in effect then the request is being executed, so better never
301change the umask. 357change the umask.
302 358
303Example: 359Example:
304 360
305 aio_open "/etc/passwd", O_RDONLY, 0, sub { 361 aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
306 if ($_[0]) { 362 if ($_[0]) {
307 print "open successful, fh is $_[0]\n"; 363 print "open successful, fh is $_[0]\n";
308 ... 364 ...
309 } else { 365 } else {
310 die "open failed: $!\n"; 366 die "open failed: $!\n";
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316 372
317Asynchronously close a file and call the callback with the result 373Asynchronously close a file and call the callback with the result
318code. 374code.
319 375
320Unfortunately, you can't do this to perl. Perl I<insists> very strongly on 376Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
321closing the file descriptor associated with the filehandle itself. Here is 377closing the file descriptor associated with the filehandle itself.
322what aio_close will try:
323 378
324 1. dup()licate the fd 379Therefore, C<aio_close> will not close the filehandle - instead it will
325 2. asynchronously close() the duplicated fd 380use dup2 to overwrite the file descriptor with the write-end of a pipe
326 3. dup()licate the fd once more 381(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
329 382
330The idea is that the first close() flushes stuff to disk that closing an 383Or 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 384free 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...
350 385
351=cut 386=cut
352 387
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) 388=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
382 389
383=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 390=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
384 391
385Reads or writes C<$length> bytes from the specified C<$fh> and C<$offset> 392Reads or writes C<$length> bytes from or to the specified C<$fh> and
386into the scalar given by C<$data> and offset C<$dataoffset> and calls the 393C<$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 394and calls the callback without the actual number of bytes read (or -1 on
388like the syscall). 395error, just like the syscall).
396
397C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
398offset plus the actual number of bytes read.
389 399
390If C<$offset> is undefined, then the current file descriptor offset will 400If C<$offset> is undefined, then the current file descriptor offset will
391be used (and updated), otherwise the file descriptor offset will not be 401be used (and updated), otherwise the file descriptor offset will not be
392changed by these calls. 402changed by these calls.
393 403
394If C<$length> is undefined in C<aio_write>, use the remaining length of C<$data>. 404If C<$length> is undefined in C<aio_write>, use the remaining length of
405C<$data>.
395 406
396If C<$dataoffset> is less than zero, it will be counted from the end of 407If C<$dataoffset> is less than zero, it will be counted from the end of
397C<$data>. 408C<$data>.
398 409
399The C<$data> scalar I<MUST NOT> be modified in any way while the request 410The C<$data> scalar I<MUST NOT> be modified in any way while the request
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417than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each 428than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
418other. 429other.
419 430
420This call tries to make use of a native C<sendfile> syscall to provide 431This call tries to make use of a native C<sendfile> syscall to provide
421zero-copy operation. For this to work, C<$out_fh> should refer to a 432zero-copy operation. For this to work, C<$out_fh> should refer to a
422socket, and C<$in_fh> should refer to mmap'able file. 433socket, and C<$in_fh> should refer to an mmap'able file.
423 434
424If the native sendfile call fails or is not implemented, it will be 435If a native sendfile cannot be found or it fails with C<ENOSYS>,
436C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
425emulated, so you can call C<aio_sendfile> on any type of filehandle 437it will be emulated, so you can call C<aio_sendfile> on any type of
426regardless of the limitations of the operating system. 438filehandle regardless of the limitations of the operating system.
427 439
428Please note, however, that C<aio_sendfile> can read more bytes from 440Please note, however, that C<aio_sendfile> can read more bytes from
429C<$in_fh> than are written, and there is no way to find out how many 441C<$in_fh> than are written, and there is no way to find out how many
430bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only 442bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
431provides the number of bytes written to C<$out_fh>. Only if the result 443provides the number of bytes written to C<$out_fh>. Only if the result
… …
469 $_[0] and die "stat failed: $!"; 481 $_[0] and die "stat failed: $!";
470 print "size is ", -s _, "\n"; 482 print "size is ", -s _, "\n";
471 }; 483 };
472 484
473 485
486=item aio_statvfs $fh_or_path, $callback->($statvfs)
487
488Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
489whether a file handle or path was passed.
490
491On success, the callback is passed a hash reference with the following
492members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
493C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
494is passed.
495
496The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
497C<ST_NOSUID>.
498
499The following non-POSIX IO::AIO::ST_* flag masks are defined to
500their correct value when available, or to C<0> on systems that do
501not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
502C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
503C<ST_NODIRATIME> and C<ST_RELATIME>.
504
505Example: stat C</wd> and dump out the data if successful.
506
507 aio_statvfs "/wd", sub {
508 my $f = $_[0]
509 or die "statvfs: $!";
510
511 use Data::Dumper;
512 say Dumper $f;
513 };
514
515 # result:
516 {
517 bsize => 1024,
518 bfree => 4333064312,
519 blocks => 10253828096,
520 files => 2050765568,
521 flag => 4096,
522 favail => 2042092649,
523 bavail => 4333064312,
524 ffree => 2042092649,
525 namemax => 255,
526 frsize => 1024,
527 fsid => 1810
528 }
529
530
474=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 531=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
475 532
476Works like perl's C<utime> function (including the special case of $atime 533Works like perl's C<utime> function (including the special case of $atime
477and $mtime being undef). Fractional times are supported if the underlying 534and $mtime being undef). Fractional times are supported if the underlying
478syscalls support them. 535syscalls support them.
… …
571 628
572Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 629Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
573directory (i.e. opendir + readdir + closedir). The entries will not be 630directory (i.e. opendir + readdir + closedir). The entries will not be
574sorted, and will B<NOT> include the C<.> and C<..> entries. 631sorted, and will B<NOT> include the C<.> and C<..> entries.
575 632
576The callback a single argument which is either C<undef> or an array-ref 633The callback is passed a single argument which is either C<undef> or an
577with the filenames. 634array-ref with the filenames.
635
636
637=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
638
639Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
640behaviour and output format. In case of an error, C<$entries> will be
641C<undef>.
642
643The flags are a combination of the following constants, ORed together (the
644flags will also be passed to the callback, possibly modified):
645
646=over 4
647
648=item IO::AIO::READDIR_DENTS
649
650When this flag is off, then the callback gets an arrayref with of names
651only (as with C<aio_readdir>), otherwise it gets an arrayref with
652C<[$name, $type, $inode]> arrayrefs, each describing a single directory
653entry in more detail.
654
655C<$name> is the name of the entry.
656
657C<$type> is one of the C<IO::AIO::DT_xxx> constants:
658
659C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
660C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
661C<IO::AIO::DT_WHT>.
662
663C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
664know, you have to run stat yourself. Also, for speed reasons, the C<$type>
665scalars are read-only: you can not modify them.
666
667C<$inode> is the inode number (which might not be exact on systems with 64
668bit inode numbers and 32 bit perls). This field has unspecified content on
669systems that do not deliver the inode information.
670
671=item IO::AIO::READDIR_DIRS_FIRST
672
673When this flag is set, then the names will be returned in an order where
674likely directories come first. This is useful when you need to quickly
675find directories, or you want to find all directories while avoiding to
676stat() each entry.
677
678If the system returns type information in readdir, then this is used
679to find directories directly. Otherwise, likely directories are files
680beginning with ".", or otherwise files with no dots, of which files with
681short names are tried first.
682
683=item IO::AIO::READDIR_STAT_ORDER
684
685When this flag is set, then the names will be returned in an order
686suitable for stat()'ing each one. That is, when you plan to stat()
687all files in the given directory, then the returned order will likely
688be fastest.
689
690If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
691the likely dirs come first, resulting in a less optimal stat order.
692
693=item IO::AIO::READDIR_FOUND_UNKNOWN
694
695This flag should not be set when calling C<aio_readdirx>. Instead, it
696is being set by C<aio_readdirx>, when any of the C<$type>'s found were
697C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
698C<$type>'s are known, which can be used to speed up some algorithms.
699
700=back
578 701
579 702
580=item aio_load $path, $data, $callback->($status) 703=item aio_load $path, $data, $callback->($status)
581 704
582This is a composite request that tries to fully load the given file into 705This is a composite request that tries to fully load the given file into
583memory. Status is the same as with aio_read. 706memory. Status is the same as with aio_read.
584 707
585=cut 708=cut
586 709
587sub aio_load($$;$) { 710sub aio_load($$;$) {
588 aio_block {
589 my ($path, undef, $cb) = @_; 711 my ($path, undef, $cb) = @_;
590 my $data = \$_[1]; 712 my $data = \$_[1];
591 713
592 my $pri = aioreq_pri; 714 my $pri = aioreq_pri;
593 my $grp = aio_group $cb; 715 my $grp = aio_group $cb;
716
717 aioreq_pri $pri;
718 add $grp aio_open $path, O_RDONLY, 0, sub {
719 my $fh = shift
720 or return $grp->result (-1);
594 721
595 aioreq_pri $pri; 722 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), $$data, 0, sub { 723 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
602 $grp->result ($_[0]); 724 $grp->result ($_[0]);
603 };
604 }; 725 };
605
606 $grp
607 } 726 };
727
728 $grp
608} 729}
609 730
610=item aio_copy $srcpath, $dstpath, $callback->($status) 731=item aio_copy $srcpath, $dstpath, $callback->($status)
611 732
612Try to copy the I<file> (directories not supported as either source or 733Try to copy the I<file> (directories not supported as either source or
613destination) from C<$srcpath> to C<$dstpath> and call the callback with 734destination) from C<$srcpath> to C<$dstpath> and call the callback with
614the C<0> (error) or C<-1> ok. 735a status of C<0> (ok) or C<-1> (error, see C<$!>).
615 736
616This is a composite request that it creates the destination file with 737This is a composite request that creates the destination file with
617mode 0200 and copies the contents of the source file into it using 738mode 0200 and copies the contents of the source file into it using
618C<aio_sendfile>, followed by restoring atime, mtime, access mode and 739C<aio_sendfile>, followed by restoring atime, mtime, access mode and
619uid/gid, in that order. 740uid/gid, in that order.
620 741
621If an error occurs, the partial destination file will be unlinked, if 742If an error occurs, the partial destination file will be unlinked, if
… …
623errors are being ignored. 744errors are being ignored.
624 745
625=cut 746=cut
626 747
627sub aio_copy($$;$) { 748sub aio_copy($$;$) {
628 aio_block {
629 my ($src, $dst, $cb) = @_; 749 my ($src, $dst, $cb) = @_;
630 750
631 my $pri = aioreq_pri; 751 my $pri = aioreq_pri;
632 my $grp = aio_group $cb; 752 my $grp = aio_group $cb;
633 753
634 aioreq_pri $pri; 754 aioreq_pri $pri;
635 add $grp aio_open $src, O_RDONLY, 0, sub { 755 add $grp aio_open $src, O_RDONLY, 0, sub {
636 if (my $src_fh = $_[0]) { 756 if (my $src_fh = $_[0]) {
637 my @stat = stat $src_fh; 757 my @stat = stat $src_fh; # hmm, might block over nfs?
638 758
639 aioreq_pri $pri; 759 aioreq_pri $pri;
640 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub { 760 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
641 if (my $dst_fh = $_[0]) { 761 if (my $dst_fh = $_[0]) {
642 aioreq_pri $pri; 762 aioreq_pri $pri;
643 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 763 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
644 if ($_[0] == $stat[7]) { 764 if ($_[0] == $stat[7]) {
645 $grp->result (0); 765 $grp->result (0);
646 close $src_fh; 766 close $src_fh;
647 767
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 { 768 my $ch = sub {
654 $grp->result (-1);
655 close $src_fh;
656 close $dst_fh;
657
658 aioreq $pri; 769 aioreq_pri $pri;
770 add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
771 aioreq_pri $pri;
772 add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
773 aioreq_pri $pri;
659 add $grp aio_unlink $dst; 774 add $grp aio_close $dst_fh;
775 }
776 };
660 } 777 };
778
779 aioreq_pri $pri;
780 add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
781 if ($_[0] < 0 && $! == ENOSYS) {
782 aioreq_pri $pri;
783 add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
784 } else {
785 $ch->();
786 }
787 };
788 } else {
789 $grp->result (-1);
790 close $src_fh;
791 close $dst_fh;
792
793 aioreq $pri;
794 add $grp aio_unlink $dst;
661 }; 795 }
662 } else {
663 $grp->result (-1);
664 } 796 };
797 } else {
798 $grp->result (-1);
665 }, 799 }
666
667 } else {
668 $grp->result (-1);
669 } 800 },
801
802 } else {
803 $grp->result (-1);
670 }; 804 }
671
672 $grp
673 } 805 };
806
807 $grp
674} 808}
675 809
676=item aio_move $srcpath, $dstpath, $callback->($status) 810=item aio_move $srcpath, $dstpath, $callback->($status)
677 811
678Try to move the I<file> (directories not supported as either source or 812Try to move the I<file> (directories not supported as either source or
679destination) from C<$srcpath> to C<$dstpath> and call the callback with 813destination) from C<$srcpath> to C<$dstpath> and call the callback with
680the C<0> (error) or C<-1> ok. 814a status of C<0> (ok) or C<-1> (error, see C<$!>).
681 815
682This is a composite request that tries to rename(2) the file first. If 816This is a composite request that tries to rename(2) the file first; if
683rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if 817rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
684that is successful, unlinking the C<$srcpath>. 818that is successful, unlinks the C<$srcpath>.
685 819
686=cut 820=cut
687 821
688sub aio_move($$;$) { 822sub aio_move($$;$) {
689 aio_block {
690 my ($src, $dst, $cb) = @_; 823 my ($src, $dst, $cb) = @_;
691 824
692 my $pri = aioreq_pri; 825 my $pri = aioreq_pri;
693 my $grp = aio_group $cb; 826 my $grp = aio_group $cb;
694 827
695 aioreq_pri $pri; 828 aioreq_pri $pri;
696 add $grp aio_rename $src, $dst, sub { 829 add $grp aio_rename $src, $dst, sub {
697 if ($_[0] && $! == EXDEV) { 830 if ($_[0] && $! == EXDEV) {
698 aioreq_pri $pri; 831 aioreq_pri $pri;
699 add $grp aio_copy $src, $dst, sub { 832 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]); 833 $grp->result ($_[0]);
834
835 if (!$_[0]) {
836 aioreq_pri $pri;
837 add $grp aio_unlink $src;
838 }
709 } 839 };
840 } else {
841 $grp->result ($_[0]);
710 }; 842 }
711
712 $grp
713 } 843 };
844
845 $grp
714} 846}
715 847
716=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 848=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
717 849
718Scans a directory (similar to C<aio_readdir>) but additionally tries to 850Scans a directory (similar to C<aio_readdir>) but additionally tries to
… …
738 870
739Implementation notes. 871Implementation notes.
740 872
741The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can. 873The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
742 874
875If readdir returns file type information, then this is used directly to
876find directories.
877
743After reading the directory, the modification time, size etc. of the 878Otherwise, after reading the directory, the modification time, size etc.
744directory before and after the readdir is checked, and if they match (and 879of 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 880match (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 881how many entries are directories (if >= 2). Otherwise, no knowledge of the
747of subdirectories will be assumed. 882number of subdirectories will be assumed.
748 883
749Then entries will be sorted into likely directories (everything without 884Then entries will be sorted into likely directories a non-initial dot
750a non-initial dot currently) and likely non-directories (everything 885currently) and likely non-directories (see C<aio_readdirx>). Then every
751else). Then every entry plus an appended C</.> will be C<stat>'ed, 886entry plus an appended C</.> will be C<stat>'ed, likely directories first,
752likely directories first. If that succeeds, it assumes that the entry 887in order of their inode numbers. If that succeeds, it assumes that the
753is a directory or a symlink to directory (which will be checked 888entry is a directory or a symlink to directory (which will be checked
754seperately). This is often faster than stat'ing the entry itself because 889seperately). This is often faster than stat'ing the entry itself because
755filesystems might detect the type of the entry without reading the inode 890filesystems might detect the type of the entry without reading the inode
756data (e.g. ext2fs filetype feature). 891data (e.g. ext2fs filetype feature), even on systems that cannot return
892the filetype information on readdir.
757 893
758If the known number of directories (link count - 2) has been reached, the 894If the known number of directories (link count - 2) has been reached, the
759rest of the entries is assumed to be non-directories. 895rest of the entries is assumed to be non-directories.
760 896
761This only works with certainty on POSIX (= UNIX) filesystems, which 897This only works with certainty on POSIX (= UNIX) filesystems, which
… …
766directory counting heuristic. 902directory counting heuristic.
767 903
768=cut 904=cut
769 905
770sub aio_scandir($$;$) { 906sub aio_scandir($$;$) {
771 aio_block {
772 my ($path, $maxreq, $cb) = @_; 907 my ($path, $maxreq, $cb) = @_;
773 908
774 my $pri = aioreq_pri; 909 my $pri = aioreq_pri;
775 910
776 my $grp = aio_group $cb; 911 my $grp = aio_group $cb;
777 912
778 $maxreq = 4 if $maxreq <= 0; 913 $maxreq = 4 if $maxreq <= 0;
779 914
780 # stat once 915 # stat once
916 aioreq_pri $pri;
917 add $grp aio_stat $path, sub {
918 return $grp->result () if $_[0];
919 my $now = time;
920 my $hash1 = join ":", (stat _)[0,1,3,7,9];
921
922 # read the directory entries
781 aioreq_pri $pri; 923 aioreq_pri $pri;
782 add $grp aio_stat $path, sub { 924 add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
925 my $entries = shift
783 return $grp->result () if $_[0]; 926 or return $grp->result ();
784 my $now = time;
785 my $hash1 = join ":", (stat _)[0,1,3,7,9];
786 927
787 # read the directory entries 928 # stat the dir another time
788 aioreq_pri $pri; 929 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 { 930 add $grp aio_stat $path, sub {
796 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 931 my $hash2 = join ":", (stat _)[0,1,3,7,9];
797 932
798 my $ndirs; 933 my $ndirs;
799 934
800 # take the slow route if anything looks fishy 935 # take the slow route if anything looks fishy
801 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 936 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
802 $ndirs = -1; 937 $ndirs = -1;
803 } else { 938 } else {
804 # if nlink == 2, we are finished 939 # if nlink == 2, we are finished
805 # on non-posix-fs's, we rely on nlink < 2 940 # for non-posix-fs's, we rely on nlink < 2
806 $ndirs = (stat _)[3] - 2 941 $ndirs = (stat _)[3] - 2
807 or return $grp->result ([], $entries); 942 or return $grp->result ([], $entries);
808 } 943 }
809 944
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); 945 my (@dirs, @nondirs);
818 946
819 my $statgrp = add $grp aio_group sub { 947 my $statgrp = add $grp aio_group sub {
820 $grp->result (\@dirs, \@nondirs); 948 $grp->result (\@dirs, \@nondirs);
821 }; 949 };
822 950
823 limit $statgrp $maxreq; 951 limit $statgrp $maxreq;
824 feed $statgrp sub { 952 feed $statgrp sub {
825 return unless @$entries; 953 return unless @$entries;
826 my $entry = pop @$entries; 954 my $entry = shift @$entries;
827 955
828 aioreq_pri $pri; 956 aioreq_pri $pri;
829 add $statgrp aio_stat "$path/$entry/.", sub { 957 add $statgrp aio_stat "$path/$entry/.", sub {
830 if ($_[0] < 0) { 958 if ($_[0] < 0) {
831 push @nondirs, $entry; 959 push @nondirs, $entry;
832 } else { 960 } else {
833 # need to check for real directory 961 # need to check for real directory
834 aioreq_pri $pri; 962 aioreq_pri $pri;
835 add $statgrp aio_lstat "$path/$entry", sub { 963 add $statgrp aio_lstat "$path/$entry", sub {
836 if (-d _) { 964 if (-d _) {
837 push @dirs, $entry; 965 push @dirs, $entry;
838 966
839 unless (--$ndirs) { 967 unless (--$ndirs) {
840 push @nondirs, @$entries; 968 push @nondirs, @$entries;
841 feed $statgrp; 969 feed $statgrp;
842 }
843 } else {
844 push @nondirs, $entry;
845 } 970 }
971 } else {
972 push @nondirs, $entry;
846 } 973 }
847 } 974 }
848 }; 975 }
849 }; 976 };
850 }; 977 };
851 }; 978 };
852 }; 979 };
853
854 $grp
855 } 980 };
981
982 $grp
856} 983}
857 984
858=item aio_rmtree $path, $callback->($status) 985=item aio_rmtree $path, $callback->($status)
859 986
860Delete a directory tree starting (and including) C<$path>, return the 987Delete a directory tree starting (and including) C<$path>, return the
… …
864 991
865=cut 992=cut
866 993
867sub aio_rmtree; 994sub aio_rmtree;
868sub aio_rmtree($;$) { 995sub aio_rmtree($;$) {
869 aio_block {
870 my ($path, $cb) = @_; 996 my ($path, $cb) = @_;
871 997
872 my $pri = aioreq_pri; 998 my $pri = aioreq_pri;
873 my $grp = aio_group $cb; 999 my $grp = aio_group $cb;
874 1000
875 aioreq_pri $pri; 1001 aioreq_pri $pri;
876 add $grp aio_scandir $path, 0, sub { 1002 add $grp aio_scandir $path, 0, sub {
877 my ($dirs, $nondirs) = @_; 1003 my ($dirs, $nondirs) = @_;
878 1004
879 my $dirgrp = aio_group sub { 1005 my $dirgrp = aio_group sub {
880 add $grp aio_rmdir $path, sub { 1006 add $grp aio_rmdir $path, sub {
881 $grp->result ($_[0]); 1007 $grp->result ($_[0]);
882 };
883 }; 1008 };
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 }; 1009 };
890 1010
891 $grp 1011 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
1012 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
1013
1014 add $grp $dirgrp;
892 } 1015 };
1016
1017 $grp
893} 1018}
1019
1020=item aio_sync $callback->($status)
1021
1022Asynchronously call sync and call the callback when finished.
894 1023
895=item aio_fsync $fh, $callback->($status) 1024=item aio_fsync $fh, $callback->($status)
896 1025
897Asynchronously call fsync on the given filehandle and call the callback 1026Asynchronously call fsync on the given filehandle and call the callback
898with the fsync result code. 1027with the fsync result code.
… …
902Asynchronously call fdatasync on the given filehandle and call the 1031Asynchronously call fdatasync on the given filehandle and call the
903callback with the fdatasync result code. 1032callback with the fdatasync result code.
904 1033
905If this call isn't available because your OS lacks it or it couldn't be 1034If 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. 1035detected, it will be emulated by calling C<fsync> instead.
1036
1037=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
1038
1039Sync the data portion of the file specified by C<$offset> and C<$length>
1040to disk (but NOT the metadata), by calling the Linux-specific
1041sync_file_range call. If sync_file_range is not available or it returns
1042ENOSYS, then fdatasync or fsync is being substituted.
1043
1044C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
1045C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
1046C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
1047manpage for details.
1048
1049=item aio_pathsync $path, $callback->($status)
1050
1051This request tries to open, fsync and close the given path. This is a
1052composite request intended to sync directories after directory operations
1053(E.g. rename). This might not work on all operating systems or have any
1054specific effect, but usually it makes sure that directory changes get
1055written to disc. It works for anything that can be opened for read-only,
1056not just directories.
1057
1058Future versions of this function might fall back to other methods when
1059C<fsync> on the directory fails (such as calling C<sync>).
1060
1061Passes C<0> when everything went ok, and C<-1> on error.
1062
1063=cut
1064
1065sub aio_pathsync($;$) {
1066 my ($path, $cb) = @_;
1067
1068 my $pri = aioreq_pri;
1069 my $grp = aio_group $cb;
1070
1071 aioreq_pri $pri;
1072 add $grp aio_open $path, O_RDONLY, 0, sub {
1073 my ($fh) = @_;
1074 if ($fh) {
1075 aioreq_pri $pri;
1076 add $grp aio_fsync $fh, sub {
1077 $grp->result ($_[0]);
1078
1079 aioreq_pri $pri;
1080 add $grp aio_close $fh;
1081 };
1082 } else {
1083 $grp->result (-1);
1084 }
1085 };
1086
1087 $grp
1088}
1089
1090=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1091
1092This is a rather advanced IO::AIO call, which only works on mmap(2)ed
1093scalars (see the C<IO::AIO::mmap> function, although it also works on data
1094scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
1095scalar must only be modified in-place while an aio operation is pending on
1096it).
1097
1098It calls the C<msync> function of your OS, if available, with the memory
1099area starting at C<$offset> in the string and ending C<$length> bytes
1100later. If C<$length> is negative, counts from the end, and if C<$length>
1101is C<undef>, then it goes till the end of the string. The flags can be
1102a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
1103C<IO::AIO::MS_SYNC>.
1104
1105=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1106
1107This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1108scalars.
1109
1110It touches (reads or writes) all memory pages in the specified
1111range inside the scalar. All caveats and parameters are the same
1112as for C<aio_msync>, above, except for flags, which must be either
1113C<0> (which reads all pages and ensures they are instantiated) or
1114C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
1115writing an octet from it, which dirties the page).
1116
1117=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1118
1119This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1120scalars.
1121
1122It reads in all the pages of the underlying storage into memory (if any)
1123and locks them, so they are not getting swapped/paged out or removed.
1124
1125If C<$length> is undefined, then the scalar will be locked till the end.
1126
1127On systems that do not implement C<mlock>, this function returns C<-1>
1128and sets errno to C<ENOSYS>.
1129
1130Note that the corresponding C<munlock> is synchronous and is
1131documented under L<MISCELLANEOUS FUNCTIONS>.
1132
1133Example: open a file, mmap and mlock it - both will be undone when
1134C<$data> gets destroyed.
1135
1136 open my $fh, "<", $path or die "$path: $!";
1137 my $data;
1138 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
1139 aio_mlock $data; # mlock in background
1140
1141=item aio_mlockall $flags, $callback->($status)
1142
1143Calls the C<mlockall> function with the given C<$flags> (a combination of
1144C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).
1145
1146On systems that do not implement C<mlockall>, this function returns C<-1>
1147and sets errno to C<ENOSYS>.
1148
1149Note that the corresponding C<munlockall> is synchronous and is
1150documented under L<MISCELLANEOUS FUNCTIONS>.
1151
1152Example: asynchronously lock all current and future pages into memory.
1153
1154 aio_mlockall IO::AIO::MCL_FUTURE;
907 1155
908=item aio_group $callback->(...) 1156=item aio_group $callback->(...)
909 1157
910This is a very special aio request: Instead of doing something, it is a 1158This 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 1159container for other aio requests, which is useful if you want to bundle
… …
961=item cancel $req 1209=item cancel $req
962 1210
963Cancels the request, if possible. Has the effect of skipping execution 1211Cancels the request, if possible. Has the effect of skipping execution
964when entering the B<execute> state and skipping calling the callback when 1212when entering the B<execute> state and skipping calling the callback when
965entering the the B<result> state, but will leave the request otherwise 1213entering the the B<result> state, but will leave the request otherwise
966untouched. That means that requests that currently execute will not be 1214untouched (with the exception of readdir). That means that requests that
967stopped and resources held by the request will not be freed prematurely. 1215currently execute will not be stopped and resources held by the request
1216will not be freed prematurely.
968 1217
969=item cb $req $callback->(...) 1218=item cb $req $callback->(...)
970 1219
971Replace (or simply set) the callback registered to the request. 1220Replace (or simply set) the callback registered to the request.
972 1221
… …
1023Their lifetime, simplified, looks like this: when they are empty, they 1272Their lifetime, simplified, looks like this: when they are empty, they
1024will finish very quickly. If they contain only requests that are in the 1273will finish very quickly. If they contain only requests that are in the
1025C<done> state, they will also finish. Otherwise they will continue to 1274C<done> state, they will also finish. Otherwise they will continue to
1026exist. 1275exist.
1027 1276
1028That means after creating a group you have some time to add requests. And 1277That 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 1278(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 1279the C<poll_cb>). And in the callbacks of those requests, you can add
1031itself finish. 1280further requests to the group. And only when all those requests have
1281finished will the the group itself finish.
1032 1282
1033=over 4 1283=over 4
1034 1284
1035=item add $grp ... 1285=item add $grp ...
1036 1286
… …
1045=item $grp->cancel_subs 1295=item $grp->cancel_subs
1046 1296
1047Cancel all subrequests and clears any feeder, but not the group request 1297Cancel 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. 1298itself. Useful when you queued a lot of events but got a result early.
1049 1299
1300The group request will finish normally (you cannot add requests to the
1301group).
1302
1050=item $grp->result (...) 1303=item $grp->result (...)
1051 1304
1052Set the result value(s) that will be passed to the group callback when all 1305Set 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 1306subrequests have finished and set the groups errno to the current value
1054of errno (just like calling C<errno> without an error number). By default, 1307of errno (just like calling C<errno> without an error number). By default,
1055no argument will be passed and errno is zero. 1308no argument will be passed and errno is zero.
1056 1309
1057=item $grp->errno ([$errno]) 1310=item $grp->errno ([$errno])
1058 1311
… …
1069=item feed $grp $callback->($grp) 1322=item feed $grp $callback->($grp)
1070 1323
1071Sets a feeder/generator on this group: every group can have an attached 1324Sets a feeder/generator on this group: every group can have an attached
1072generator that generates requests if idle. The idea behind this is that, 1325generator 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, 1326although you could just queue as many requests as you want in a group,
1074this might starve other requests for a potentially long time. For 1327this might starve other requests for a potentially long time. For example,
1075example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1328C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1076requests, delaying any later requests for a long time. 1329delaying any later requests for a long time.
1077 1330
1078To avoid this, and allow incremental generation of requests, you can 1331To avoid this, and allow incremental generation of requests, you can
1079instead a group and set a feeder on it that generates those requests. The 1332instead 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>, 1333feed 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 1334below) requests active in the group itself and is expected to queue more
… …
1085not impose any limits). 1338not impose any limits).
1086 1339
1087If the feed does not queue more requests when called, it will be 1340If the feed does not queue more requests when called, it will be
1088automatically removed from the group. 1341automatically removed from the group.
1089 1342
1090If the feed limit is C<0>, it will be set to C<2> automatically. 1343If the feed limit is C<0> when this method is called, it will be set to
1344C<2> automatically.
1091 1345
1092Example: 1346Example:
1093 1347
1094 # stat all files in @files, but only ever use four aio requests concurrently: 1348 # stat all files in @files, but only ever use four aio requests concurrently:
1095 1349
… …
1107Sets the feeder limit for the group: The feeder will be called whenever 1361Sets the feeder limit for the group: The feeder will be called whenever
1108the group contains less than this many requests. 1362the group contains less than this many requests.
1109 1363
1110Setting the limit to C<0> will pause the feeding process. 1364Setting the limit to C<0> will pause the feeding process.
1111 1365
1366The default value for the limit is C<0>, but note that setting a feeder
1367automatically bumps it up to C<2>.
1368
1112=back 1369=back
1113 1370
1114=head2 SUPPORT FUNCTIONS 1371=head2 SUPPORT FUNCTIONS
1115 1372
1116=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1373=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
… …
1118=over 4 1375=over 4
1119 1376
1120=item $fileno = IO::AIO::poll_fileno 1377=item $fileno = IO::AIO::poll_fileno
1121 1378
1122Return the I<request result pipe file descriptor>. This filehandle must be 1379Return the I<request result pipe file descriptor>. This filehandle must be
1123polled for reading by some mechanism outside this module (e.g. Event or 1380polled 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 1381select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1125to call C<poll_cb> to check the results. 1382you have to call C<poll_cb> to check the results.
1126 1383
1127See C<poll_cb> for an example. 1384See C<poll_cb> for an example.
1128 1385
1129=item IO::AIO::poll_cb 1386=item IO::AIO::poll_cb
1130 1387
1131Process some outstanding events on the result pipe. You have to call this 1388Process some outstanding events on the result pipe. You have to call this
1132regularly. Returns the number of events processed. Returns immediately 1389regularly. Returns C<0> if all events could be processed, or C<-1> if it
1390returned earlier for whatever reason. Returns immediately when no events
1133when no events are outstanding. The amount of events processed depends on 1391are 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>. 1392C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1135 1393
1136If not all requests were processed for whatever reason, the filehandle 1394If not all requests were processed for whatever reason, the filehandle
1137will still be ready when C<poll_cb> returns. 1395will still be ready when C<poll_cb> returns, so normally you don't have to
1396do anything special to have it called later.
1138 1397
1139Example: Install an Event watcher that automatically calls 1398Example: Install an Event watcher that automatically calls
1140IO::AIO::poll_cb with high priority: 1399IO::AIO::poll_cb with high priority (more examples can be found in the
1400SYNOPSIS section, at the top of this document):
1141 1401
1142 Event->io (fd => IO::AIO::poll_fileno, 1402 Event->io (fd => IO::AIO::poll_fileno,
1143 poll => 'r', async => 1, 1403 poll => 'r', async => 1,
1144 cb => \&IO::AIO::poll_cb); 1404 cb => \&IO::AIO::poll_cb);
1405
1406=item IO::AIO::poll_wait
1407
1408If there are any outstanding requests and none of them in the result
1409phase, wait till the result filehandle becomes ready for reading (simply
1410does a C<select> on the filehandle. This is useful if you want to
1411synchronously wait for some requests to finish).
1412
1413See C<nreqs> for an example.
1414
1415=item IO::AIO::poll
1416
1417Waits until some requests have been handled.
1418
1419Returns the number of requests processed, but is otherwise strictly
1420equivalent to:
1421
1422 IO::AIO::poll_wait, IO::AIO::poll_cb
1423
1424=item IO::AIO::flush
1425
1426Wait till all outstanding AIO requests have been handled.
1427
1428Strictly equivalent to:
1429
1430 IO::AIO::poll_wait, IO::AIO::poll_cb
1431 while IO::AIO::nreqs;
1145 1432
1146=item IO::AIO::max_poll_reqs $nreqs 1433=item IO::AIO::max_poll_reqs $nreqs
1147 1434
1148=item IO::AIO::max_poll_time $seconds 1435=item IO::AIO::max_poll_time $seconds
1149 1436
… …
1174 # use a low priority so other tasks have priority 1461 # use a low priority so other tasks have priority
1175 Event->io (fd => IO::AIO::poll_fileno, 1462 Event->io (fd => IO::AIO::poll_fileno,
1176 poll => 'r', nice => 1, 1463 poll => 'r', nice => 1,
1177 cb => &IO::AIO::poll_cb); 1464 cb => &IO::AIO::poll_cb);
1178 1465
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 1466=back
1207 1467
1208=head3 CONTROLLING THE NUMBER OF THREADS 1468=head3 CONTROLLING THE NUMBER OF THREADS
1209 1469
1210=over 1470=over
… …
1256 1516
1257The default is probably ok in most situations, especially if thread 1517The default is probably ok in most situations, especially if thread
1258creation is fast. If thread creation is very slow on your system you might 1518creation is fast. If thread creation is very slow on your system you might
1259want to use larger values. 1519want to use larger values.
1260 1520
1261=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1521=item IO::AIO::max_outstanding $maxreqs
1262 1522
1263This is a very bad function to use in interactive programs because it 1523This 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 1524blocks, and a bad way to reduce concurrency because it is inexact: Better
1265use an C<aio_group> together with a feed callback. 1525use an C<aio_group> together with a feed callback.
1266 1526
… …
1271 1531
1272The default value is very large, so there is no practical limit on the 1532The default value is very large, so there is no practical limit on the
1273number of outstanding requests. 1533number of outstanding requests.
1274 1534
1275You can still queue as many requests as you want. Therefore, 1535You can still queue as many requests as you want. Therefore,
1276C<max_oustsanding> is mainly useful in simple scripts (with low values) or 1536C<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). 1537as a stop gap to shield against fatal memory overflow (with large values).
1278 1538
1279=back 1539=back
1280 1540
1281=head3 STATISTICAL INFORMATION 1541=head3 STATISTICAL INFORMATION
… …
1302Returns the number of requests currently in the pending state (executed, 1562Returns the number of requests currently in the pending state (executed,
1303but not yet processed by poll_cb). 1563but not yet processed by poll_cb).
1304 1564
1305=back 1565=back
1306 1566
1567=head3 MISCELLANEOUS FUNCTIONS
1568
1569IO::AIO implements some functions that might be useful, but are not
1570asynchronous.
1571
1572=over 4
1573
1574=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1575
1576Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
1577but is blocking (this makes most sense if you know the input data is
1578likely cached already and the output filehandle is set to non-blocking
1579operations).
1580
1581Returns the number of bytes copied, or C<-1> on error.
1582
1583=item IO::AIO::fadvise $fh, $offset, $len, $advice
1584
1585Simply calls the C<posix_fadvise> function (see it's
1586manpage for details). The following advice constants are
1587avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1588C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1589C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1590
1591On systems that do not implement C<posix_fadvise>, this function returns
1592ENOSYS, otherwise the return value of C<posix_fadvise>.
1593
1594=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1595
1596Memory-maps a file (or anonymous memory range) and attaches it to the
1597given C<$scalar>, which will act like a string scalar.
1598
1599The only operations allowed on the scalar are C<substr>/C<vec> that don't
1600change the string length, and most read-only operations such as copying it
1601or searching it with regexes and so on.
1602
1603Anything else is unsafe and will, at best, result in memory leaks.
1604
1605The memory map associated with the C<$scalar> is automatically removed
1606when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
1607C<IO::AIO::munmap> functions are called.
1608
1609This calls the C<mmap>(2) function internally. See your system's manual
1610page for details on the C<$length>, C<$prot> and C<$flags> parameters.
1611
1612The C<$length> must be larger than zero and smaller than the actual
1613filesize.
1614
1615C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1616C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1617
1618C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
1619C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
1620not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
1621(which is set to C<MAP_ANON> if your system only provides this
1622constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
1623C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
1624C<IO::AIO::MAP_NONBLOCK>
1625
1626If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1627
1628C<$offset> is the offset from the start of the file - it generally must be
1629a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
1630
1631Example:
1632
1633 use Digest::MD5;
1634 use IO::AIO;
1635
1636 open my $fh, "<verybigfile"
1637 or die "$!";
1638
1639 IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
1640 or die "verybigfile: $!";
1641
1642 my $fast_md5 = md5 $data;
1643
1644=item IO::AIO::munmap $scalar
1645
1646Removes a previous mmap and undefines the C<$scalar>.
1647
1648=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
1649
1650Calls the C<munlock> function, undoing the effects of a previous
1651C<aio_mlock> call (see its description for details).
1652
1653=item IO::AIO::munlockall
1654
1655Calls the C<munlockall> function.
1656
1657On systems that do not implement C<munlockall>, this function returns
1658ENOSYS, otherwise the return value of C<munlockall>.
1659
1660=back
1661
1307=cut 1662=cut
1308 1663
1309min_parallel 8; 1664min_parallel 8;
1310 1665
1311END { flush } 1666END { flush }
1312 1667
13131; 16681;
1669
1670=head1 EVENT LOOP INTEGRATION
1671
1672It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
1673automatically into many event loops:
1674
1675 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
1676 use AnyEvent::AIO;
1677
1678You can also integrate IO::AIO manually into many event loops, here are
1679some examples of how to do this:
1680
1681 # EV integration
1682 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
1683
1684 # Event integration
1685 Event->io (fd => IO::AIO::poll_fileno,
1686 poll => 'r',
1687 cb => \&IO::AIO::poll_cb);
1688
1689 # Glib/Gtk2 integration
1690 add_watch Glib::IO IO::AIO::poll_fileno,
1691 in => sub { IO::AIO::poll_cb; 1 };
1692
1693 # Tk integration
1694 Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
1695 readable => \&IO::AIO::poll_cb);
1696
1697 # Danga::Socket integration
1698 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
1699 \&IO::AIO::poll_cb);
1314 1700
1315=head2 FORK BEHAVIOUR 1701=head2 FORK BEHAVIOUR
1316 1702
1317This module should do "the right thing" when the process using it forks: 1703This module should do "the right thing" when the process using it forks:
1318 1704
… …
1351 1737
1352Known bugs will be fixed in the next release. 1738Known bugs will be fixed in the next release.
1353 1739
1354=head1 SEE ALSO 1740=head1 SEE ALSO
1355 1741
1356L<Coro::AIO>. 1742L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1743more natural syntax.
1357 1744
1358=head1 AUTHOR 1745=head1 AUTHOR
1359 1746
1360 Marc Lehmann <schmorp@schmorp.de> 1747 Marc Lehmann <schmorp@schmorp.de>
1361 http://home.schmorp.de/ 1748 http://home.schmorp.de/

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