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Revision 1.119 by root, Sun Dec 2 20:54:33 2007 UTC vs.
Revision 1.182 by root, Sun Sep 12 03:36:27 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 = '3.65';
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::munlock $scalar, $offset = 0, $length = undef
271 IO::AIO::munlockall
219 272
220=head2 AIO REQUEST FUNCTIONS 273=head2 AIO REQUEST FUNCTIONS
221 274
222All the C<aio_*> calls are more or less thin wrappers around the syscall 275All the C<aio_*> calls are more or less thin wrappers around the syscall
223with the same name (sans C<aio_>). The arguments are similar or identical, 276with the same name (sans C<aio_>). The arguments are similar or identical,
224and they all accept an additional (and optional) C<$callback> argument 277and they all accept an additional (and optional) C<$callback> argument
225which 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
226the 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
227perl, which usually delivers "false") as it's sole argument when the given 280perl, which usually delivers "false") as its sole argument after the given
228syscall has been executed asynchronously. 281syscall has been executed asynchronously.
229 282
230All functions expecting a filehandle keep a copy of the filehandle 283All functions expecting a filehandle keep a copy of the filehandle
231internally until the request has finished. 284internally until the request has finished.
232 285
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246your 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
247environment, d) use Glib::filename_from_unicode on unicode filenames or e) 300environment, d) use Glib::filename_from_unicode on unicode filenames or e)
248use something else to ensure your scalar has the correct contents. 301use something else to ensure your scalar has the correct contents.
249 302
250This 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
251handles correctly wether it is set or not. 304handles correctly whether it is set or not.
252 305
253=over 4 306=over 4
254 307
255=item $prev_pri = aioreq_pri [$pri] 308=item $prev_pri = aioreq_pri [$pri]
256 309
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303by 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
304change the umask. 357change the umask.
305 358
306Example: 359Example:
307 360
308 aio_open "/etc/passwd", O_RDONLY, 0, sub { 361 aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
309 if ($_[0]) { 362 if ($_[0]) {
310 print "open successful, fh is $_[0]\n"; 363 print "open successful, fh is $_[0]\n";
311 ... 364 ...
312 } else { 365 } else {
313 die "open failed: $!\n"; 366 die "open failed: $!\n";
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319 372
320Asynchronously close a file and call the callback with the result 373Asynchronously close a file and call the callback with the result
321code. 374code.
322 375
323Unfortunately, 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
324closing the file descriptor associated with the filehandle itself. Here is 377closing the file descriptor associated with the filehandle itself.
325what aio_close will try:
326 378
327 1. dup()licate the fd 379Therefore, C<aio_close> will not close the filehandle - instead it will
328 2. asynchronously close() the duplicated fd 380use dup2 to overwrite the file descriptor with the write-end of a pipe
329 3. dup()licate the fd once more 381(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
332 382
333The 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
334fd will flush, so when perl closes the fd, nothing much will need to be 384free 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...
353 385
354=cut 386=cut
355 387
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) 388=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
385 389
386=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 390=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
387 391
388Reads 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<$fh> and
389into the scalar given by C<$data> and offset C<$dataoffset> and calls the 393C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
390callback 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
391like the syscall). 395error, just like the syscall).
396
397C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
398offset plus the actual number of bytes read.
392 399
393If C<$offset> is undefined, then the current file descriptor offset will 400If C<$offset> is undefined, then the current file descriptor offset will
394be used (and updated), otherwise the file descriptor offset will not be 401be used (and updated), otherwise the file descriptor offset will not be
395changed by these calls. 402changed by these calls.
396 403
397If C<$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<$data>.
398 406
399If C<$dataoffset> is less than zero, it will be counted from the end of 407If C<$dataoffset> is less than zero, it will be counted from the end of
400C<$data>. 408C<$data>.
401 409
402The C<$data> scalar I<MUST NOT> be modified in any way while the request 410The C<$data> scalar I<MUST NOT> be modified in any way while the request
… …
420than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each 428than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
421other. 429other.
422 430
423This call tries to make use of a native C<sendfile> syscall to provide 431This call tries to make use of a native C<sendfile> syscall to provide
424zero-copy operation. For this to work, C<$out_fh> should refer to a 432zero-copy operation. For this to work, C<$out_fh> should refer to a
425socket, and C<$in_fh> should refer to mmap'able file. 433socket, and C<$in_fh> should refer to an mmap'able file.
426 434
427If the native sendfile call fails or is not implemented, it will be 435If a native sendfile cannot be found or it fails with C<ENOSYS>,
436C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
428emulated, so you can call C<aio_sendfile> on any type of filehandle 437it will be emulated, so you can call C<aio_sendfile> on any type of
429regardless of the limitations of the operating system. 438filehandle regardless of the limitations of the operating system.
430 439
431Please note, however, that C<aio_sendfile> can read more bytes from 440Please note, however, that C<aio_sendfile> can read more bytes from
432C<$in_fh> than are written, and there is no way to find out how many 441C<$in_fh> than are written, and there is no way to find out how many
433bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only 442bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
434provides the number of bytes written to C<$out_fh>. Only if the result 443provides the number of bytes written to C<$out_fh>. Only if the result
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472 $_[0] and die "stat failed: $!"; 481 $_[0] and die "stat failed: $!";
473 print "size is ", -s _, "\n"; 482 print "size is ", -s _, "\n";
474 }; 483 };
475 484
476 485
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
477=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 531=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
478 532
479Works 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
480and $mtime being undef). Fractional times are supported if the underlying 534and $mtime being undef). Fractional times are supported if the underlying
481syscalls support them. 535syscalls support them.
… …
574 628
575Unlike 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
576directory (i.e. opendir + readdir + closedir). The entries will not be 630directory (i.e. opendir + readdir + closedir). The entries will not be
577sorted, and will B<NOT> include the C<.> and C<..> entries. 631sorted, and will B<NOT> include the C<.> and C<..> entries.
578 632
579The 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
580with 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
581 701
582 702
583=item aio_load $path, $data, $callback->($status) 703=item aio_load $path, $data, $callback->($status)
584 704
585This 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
586memory. Status is the same as with aio_read. 706memory. Status is the same as with aio_read.
587 707
588=cut 708=cut
589 709
590sub aio_load($$;$) { 710sub aio_load($$;$) {
591 aio_block {
592 my ($path, undef, $cb) = @_; 711 my ($path, undef, $cb) = @_;
593 my $data = \$_[1]; 712 my $data = \$_[1];
594 713
595 my $pri = aioreq_pri; 714 my $pri = aioreq_pri;
596 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);
597 721
598 aioreq_pri $pri; 722 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), $$data, 0, sub { 723 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
605 $grp->result ($_[0]); 724 $grp->result ($_[0]);
606 };
607 }; 725 };
608
609 $grp
610 } 726 };
727
728 $grp
611} 729}
612 730
613=item aio_copy $srcpath, $dstpath, $callback->($status) 731=item aio_copy $srcpath, $dstpath, $callback->($status)
614 732
615Try 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
616destination) from C<$srcpath> to C<$dstpath> and call the callback with 734destination) from C<$srcpath> to C<$dstpath> and call the callback with
617the C<0> (error) or C<-1> ok. 735a status of C<0> (ok) or C<-1> (error, see C<$!>).
618 736
619This is a composite request that it creates the destination file with 737This is a composite request that creates the destination file with
620mode 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
621C<aio_sendfile>, followed by restoring atime, mtime, access mode and 739C<aio_sendfile>, followed by restoring atime, mtime, access mode and
622uid/gid, in that order. 740uid/gid, in that order.
623 741
624If an error occurs, the partial destination file will be unlinked, if 742If an error occurs, the partial destination file will be unlinked, if
… …
626errors are being ignored. 744errors are being ignored.
627 745
628=cut 746=cut
629 747
630sub aio_copy($$;$) { 748sub aio_copy($$;$) {
631 aio_block {
632 my ($src, $dst, $cb) = @_; 749 my ($src, $dst, $cb) = @_;
633 750
634 my $pri = aioreq_pri; 751 my $pri = aioreq_pri;
635 my $grp = aio_group $cb; 752 my $grp = aio_group $cb;
636 753
637 aioreq_pri $pri; 754 aioreq_pri $pri;
638 add $grp aio_open $src, O_RDONLY, 0, sub { 755 add $grp aio_open $src, O_RDONLY, 0, sub {
639 if (my $src_fh = $_[0]) { 756 if (my $src_fh = $_[0]) {
640 my @stat = stat $src_fh; 757 my @stat = stat $src_fh; # hmm, might block over nfs?
641 758
642 aioreq_pri $pri; 759 aioreq_pri $pri;
643 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 {
644 if (my $dst_fh = $_[0]) { 761 if (my $dst_fh = $_[0]) {
645 aioreq_pri $pri; 762 aioreq_pri $pri;
646 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 763 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
647 if ($_[0] == $stat[7]) { 764 if ($_[0] == $stat[7]) {
648 $grp->result (0); 765 $grp->result (0);
649 close $src_fh; 766 close $src_fh;
650 767
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 { 768 my $ch = sub {
657 $grp->result (-1);
658 close $src_fh;
659 close $dst_fh;
660
661 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;
662 add $grp aio_unlink $dst; 774 add $grp aio_close $dst_fh;
775 }
776 };
663 } 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;
664 }; 795 }
665 } else {
666 $grp->result (-1);
667 } 796 };
797 } else {
798 $grp->result (-1);
668 }, 799 }
669
670 } else {
671 $grp->result (-1);
672 } 800 },
801
802 } else {
803 $grp->result (-1);
673 }; 804 }
674
675 $grp
676 } 805 };
806
807 $grp
677} 808}
678 809
679=item aio_move $srcpath, $dstpath, $callback->($status) 810=item aio_move $srcpath, $dstpath, $callback->($status)
680 811
681Try 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
682destination) from C<$srcpath> to C<$dstpath> and call the callback with 813destination) from C<$srcpath> to C<$dstpath> and call the callback with
683the C<0> (error) or C<-1> ok. 814a status of C<0> (ok) or C<-1> (error, see C<$!>).
684 815
685This is a composite request that tries to rename(2) the file first. If 816This is a composite request that tries to rename(2) the file first; if
686rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if 817rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
687that is successful, unlinking the C<$srcpath>. 818that is successful, unlinks the C<$srcpath>.
688 819
689=cut 820=cut
690 821
691sub aio_move($$;$) { 822sub aio_move($$;$) {
692 aio_block {
693 my ($src, $dst, $cb) = @_; 823 my ($src, $dst, $cb) = @_;
694 824
695 my $pri = aioreq_pri; 825 my $pri = aioreq_pri;
696 my $grp = aio_group $cb; 826 my $grp = aio_group $cb;
697 827
698 aioreq_pri $pri; 828 aioreq_pri $pri;
699 add $grp aio_rename $src, $dst, sub { 829 add $grp aio_rename $src, $dst, sub {
700 if ($_[0] && $! == EXDEV) { 830 if ($_[0] && $! == EXDEV) {
701 aioreq_pri $pri; 831 aioreq_pri $pri;
702 add $grp aio_copy $src, $dst, sub { 832 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]); 833 $grp->result ($_[0]);
834
835 if (!$_[0]) {
836 aioreq_pri $pri;
837 add $grp aio_unlink $src;
838 }
712 } 839 };
840 } else {
841 $grp->result ($_[0]);
713 }; 842 }
714
715 $grp
716 } 843 };
844
845 $grp
717} 846}
718 847
719=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 848=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
720 849
721Scans a directory (similar to C<aio_readdir>) but additionally tries to 850Scans a directory (similar to C<aio_readdir>) but additionally tries to
… …
741 870
742Implementation notes. 871Implementation notes.
743 872
744The 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.
745 874
875If readdir returns file type information, then this is used directly to
876find directories.
877
746After reading the directory, the modification time, size etc. of the 878Otherwise, after reading the directory, the modification time, size etc.
747directory 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
748isn'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
749entries are directories (if >= 2). Otherwise, no knowledge of the number 881how many entries are directories (if >= 2). Otherwise, no knowledge of the
750of subdirectories will be assumed. 882number of subdirectories will be assumed.
751 883
752Then entries will be sorted into likely directories (everything without 884Then entries will be sorted into likely directories a non-initial dot
753a non-initial dot currently) and likely non-directories (everything 885currently) and likely non-directories (see C<aio_readdirx>). Then every
754else). 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,
755likely directories first. If that succeeds, it assumes that the entry 887in order of their inode numbers. If that succeeds, it assumes that the
756is a directory or a symlink to directory (which will be checked 888entry is a directory or a symlink to directory (which will be checked
757seperately). This is often faster than stat'ing the entry itself because 889seperately). This is often faster than stat'ing the entry itself because
758filesystems might detect the type of the entry without reading the inode 890filesystems might detect the type of the entry without reading the inode
759data (e.g. ext2fs filetype feature). 891data (e.g. ext2fs filetype feature), even on systems that cannot return
892the filetype information on readdir.
760 893
761If 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
762rest of the entries is assumed to be non-directories. 895rest of the entries is assumed to be non-directories.
763 896
764This only works with certainty on POSIX (= UNIX) filesystems, which 897This only works with certainty on POSIX (= UNIX) filesystems, which
… …
769directory counting heuristic. 902directory counting heuristic.
770 903
771=cut 904=cut
772 905
773sub aio_scandir($$;$) { 906sub aio_scandir($$;$) {
774 aio_block {
775 my ($path, $maxreq, $cb) = @_; 907 my ($path, $maxreq, $cb) = @_;
776 908
777 my $pri = aioreq_pri; 909 my $pri = aioreq_pri;
778 910
779 my $grp = aio_group $cb; 911 my $grp = aio_group $cb;
780 912
781 $maxreq = 4 if $maxreq <= 0; 913 $maxreq = 4 if $maxreq <= 0;
782 914
783 # 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
784 aioreq_pri $pri; 923 aioreq_pri $pri;
785 add $grp aio_stat $path, sub { 924 add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
925 my $entries = shift
786 return $grp->result () if $_[0]; 926 or return $grp->result ();
787 my $now = time;
788 my $hash1 = join ":", (stat _)[0,1,3,7,9];
789 927
790 # read the directory entries 928 # stat the dir another time
791 aioreq_pri $pri; 929 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 { 930 add $grp aio_stat $path, sub {
799 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 931 my $hash2 = join ":", (stat _)[0,1,3,7,9];
800 932
801 my $ndirs; 933 my $ndirs;
802 934
803 # take the slow route if anything looks fishy 935 # take the slow route if anything looks fishy
804 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 936 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
805 $ndirs = -1; 937 $ndirs = -1;
806 } else { 938 } else {
807 # if nlink == 2, we are finished 939 # if nlink == 2, we are finished
808 # on non-posix-fs's, we rely on nlink < 2 940 # for non-posix-fs's, we rely on nlink < 2
809 $ndirs = (stat _)[3] - 2 941 $ndirs = (stat _)[3] - 2
810 or return $grp->result ([], $entries); 942 or return $grp->result ([], $entries);
811 } 943 }
812 944
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); 945 my (@dirs, @nondirs);
821 946
822 my $statgrp = add $grp aio_group sub { 947 my $statgrp = add $grp aio_group sub {
823 $grp->result (\@dirs, \@nondirs); 948 $grp->result (\@dirs, \@nondirs);
824 }; 949 };
825 950
826 limit $statgrp $maxreq; 951 limit $statgrp $maxreq;
827 feed $statgrp sub { 952 feed $statgrp sub {
828 return unless @$entries; 953 return unless @$entries;
829 my $entry = pop @$entries; 954 my $entry = shift @$entries;
830 955
831 aioreq_pri $pri; 956 aioreq_pri $pri;
832 add $statgrp aio_stat "$path/$entry/.", sub { 957 add $statgrp aio_stat "$path/$entry/.", sub {
833 if ($_[0] < 0) { 958 if ($_[0] < 0) {
834 push @nondirs, $entry; 959 push @nondirs, $entry;
835 } else { 960 } else {
836 # need to check for real directory 961 # need to check for real directory
837 aioreq_pri $pri; 962 aioreq_pri $pri;
838 add $statgrp aio_lstat "$path/$entry", sub { 963 add $statgrp aio_lstat "$path/$entry", sub {
839 if (-d _) { 964 if (-d _) {
840 push @dirs, $entry; 965 push @dirs, $entry;
841 966
842 unless (--$ndirs) { 967 unless (--$ndirs) {
843 push @nondirs, @$entries; 968 push @nondirs, @$entries;
844 feed $statgrp; 969 feed $statgrp;
845 }
846 } else {
847 push @nondirs, $entry;
848 } 970 }
971 } else {
972 push @nondirs, $entry;
849 } 973 }
850 } 974 }
851 }; 975 }
852 }; 976 };
853 }; 977 };
854 }; 978 };
855 }; 979 };
856
857 $grp
858 } 980 };
981
982 $grp
859} 983}
860 984
861=item aio_rmtree $path, $callback->($status) 985=item aio_rmtree $path, $callback->($status)
862 986
863Delete a directory tree starting (and including) C<$path>, return the 987Delete a directory tree starting (and including) C<$path>, return the
… …
867 991
868=cut 992=cut
869 993
870sub aio_rmtree; 994sub aio_rmtree;
871sub aio_rmtree($;$) { 995sub aio_rmtree($;$) {
872 aio_block {
873 my ($path, $cb) = @_; 996 my ($path, $cb) = @_;
874 997
875 my $pri = aioreq_pri; 998 my $pri = aioreq_pri;
876 my $grp = aio_group $cb; 999 my $grp = aio_group $cb;
877 1000
878 aioreq_pri $pri; 1001 aioreq_pri $pri;
879 add $grp aio_scandir $path, 0, sub { 1002 add $grp aio_scandir $path, 0, sub {
880 my ($dirs, $nondirs) = @_; 1003 my ($dirs, $nondirs) = @_;
881 1004
882 my $dirgrp = aio_group sub { 1005 my $dirgrp = aio_group sub {
883 add $grp aio_rmdir $path, sub { 1006 add $grp aio_rmdir $path, sub {
884 $grp->result ($_[0]); 1007 $grp->result ($_[0]);
885 };
886 }; 1008 };
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 }; 1009 };
893 1010
894 $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;
895 } 1015 };
1016
1017 $grp
896} 1018}
897 1019
898=item aio_sync $callback->($status) 1020=item aio_sync $callback->($status)
899 1021
900Asynchronously call sync and call the callback when finished. 1022Asynchronously call sync and call the callback when finished.
… …
909Asynchronously call fdatasync on the given filehandle and call the 1031Asynchronously call fdatasync on the given filehandle and call the
910callback with the fdatasync result code. 1032callback with the fdatasync result code.
911 1033
912If 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
913detected, 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
1133=item aio_mlockall $flags, $callback->($status)
1134
1135Calls the C<mlockall> function with the given C<$flags> (a combination of
1136C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).
1137
1138On systems that do not implement C<mlockall>, this function returns C<-1>
1139and sets errno to C<ENOSYS>.
1140
1141Note that the corresponding C<munlockall> is synchronous and is
1142documented under L<MISCELLANEOUS FUNCTIONS>.
914 1143
915=item aio_group $callback->(...) 1144=item aio_group $callback->(...)
916 1145
917This is a very special aio request: Instead of doing something, it is a 1146This 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 1147container for other aio requests, which is useful if you want to bundle
… …
968=item cancel $req 1197=item cancel $req
969 1198
970Cancels the request, if possible. Has the effect of skipping execution 1199Cancels the request, if possible. Has the effect of skipping execution
971when entering the B<execute> state and skipping calling the callback when 1200when entering the B<execute> state and skipping calling the callback when
972entering the the B<result> state, but will leave the request otherwise 1201entering the the B<result> state, but will leave the request otherwise
973untouched. That means that requests that currently execute will not be 1202untouched (with the exception of readdir). That means that requests that
974stopped and resources held by the request will not be freed prematurely. 1203currently execute will not be stopped and resources held by the request
1204will not be freed prematurely.
975 1205
976=item cb $req $callback->(...) 1206=item cb $req $callback->(...)
977 1207
978Replace (or simply set) the callback registered to the request. 1208Replace (or simply set) the callback registered to the request.
979 1209
… …
1030Their lifetime, simplified, looks like this: when they are empty, they 1260Their lifetime, simplified, looks like this: when they are empty, they
1031will finish very quickly. If they contain only requests that are in the 1261will finish very quickly. If they contain only requests that are in the
1032C<done> state, they will also finish. Otherwise they will continue to 1262C<done> state, they will also finish. Otherwise they will continue to
1033exist. 1263exist.
1034 1264
1035That means after creating a group you have some time to add requests. And 1265That 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 1266(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 1267the C<poll_cb>). And in the callbacks of those requests, you can add
1038itself finish. 1268further requests to the group. And only when all those requests have
1269finished will the the group itself finish.
1039 1270
1040=over 4 1271=over 4
1041 1272
1042=item add $grp ... 1273=item add $grp ...
1043 1274
… …
1052=item $grp->cancel_subs 1283=item $grp->cancel_subs
1053 1284
1054Cancel all subrequests and clears any feeder, but not the group request 1285Cancel 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. 1286itself. Useful when you queued a lot of events but got a result early.
1056 1287
1288The group request will finish normally (you cannot add requests to the
1289group).
1290
1057=item $grp->result (...) 1291=item $grp->result (...)
1058 1292
1059Set the result value(s) that will be passed to the group callback when all 1293Set 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 1294subrequests have finished and set the groups errno to the current value
1061of errno (just like calling C<errno> without an error number). By default, 1295of errno (just like calling C<errno> without an error number). By default,
1062no argument will be passed and errno is zero. 1296no argument will be passed and errno is zero.
1063 1297
1064=item $grp->errno ([$errno]) 1298=item $grp->errno ([$errno])
1065 1299
… …
1076=item feed $grp $callback->($grp) 1310=item feed $grp $callback->($grp)
1077 1311
1078Sets a feeder/generator on this group: every group can have an attached 1312Sets a feeder/generator on this group: every group can have an attached
1079generator that generates requests if idle. The idea behind this is that, 1313generator 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, 1314although you could just queue as many requests as you want in a group,
1081this might starve other requests for a potentially long time. For 1315this might starve other requests for a potentially long time. For example,
1082example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1316C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1083requests, delaying any later requests for a long time. 1317delaying any later requests for a long time.
1084 1318
1085To avoid this, and allow incremental generation of requests, you can 1319To avoid this, and allow incremental generation of requests, you can
1086instead a group and set a feeder on it that generates those requests. The 1320instead 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>, 1321feed 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 1322below) requests active in the group itself and is expected to queue more
… …
1092not impose any limits). 1326not impose any limits).
1093 1327
1094If the feed does not queue more requests when called, it will be 1328If the feed does not queue more requests when called, it will be
1095automatically removed from the group. 1329automatically removed from the group.
1096 1330
1097If the feed limit is C<0>, it will be set to C<2> automatically. 1331If the feed limit is C<0> when this method is called, it will be set to
1332C<2> automatically.
1098 1333
1099Example: 1334Example:
1100 1335
1101 # stat all files in @files, but only ever use four aio requests concurrently: 1336 # stat all files in @files, but only ever use four aio requests concurrently:
1102 1337
… …
1114Sets the feeder limit for the group: The feeder will be called whenever 1349Sets the feeder limit for the group: The feeder will be called whenever
1115the group contains less than this many requests. 1350the group contains less than this many requests.
1116 1351
1117Setting the limit to C<0> will pause the feeding process. 1352Setting the limit to C<0> will pause the feeding process.
1118 1353
1354The default value for the limit is C<0>, but note that setting a feeder
1355automatically bumps it up to C<2>.
1356
1119=back 1357=back
1120 1358
1121=head2 SUPPORT FUNCTIONS 1359=head2 SUPPORT FUNCTIONS
1122 1360
1123=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1361=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
… …
1125=over 4 1363=over 4
1126 1364
1127=item $fileno = IO::AIO::poll_fileno 1365=item $fileno = IO::AIO::poll_fileno
1128 1366
1129Return the I<request result pipe file descriptor>. This filehandle must be 1367Return the I<request result pipe file descriptor>. This filehandle must be
1130polled for reading by some mechanism outside this module (e.g. Event or 1368polled 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 1369select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1132to call C<poll_cb> to check the results. 1370you have to call C<poll_cb> to check the results.
1133 1371
1134See C<poll_cb> for an example. 1372See C<poll_cb> for an example.
1135 1373
1136=item IO::AIO::poll_cb 1374=item IO::AIO::poll_cb
1137 1375
1138Process some outstanding events on the result pipe. You have to call this 1376Process some outstanding events on the result pipe. You have to call this
1139regularly. Returns the number of events processed. Returns immediately 1377regularly. Returns C<0> if all events could be processed, or C<-1> if it
1378returned earlier for whatever reason. Returns immediately when no events
1140when no events are outstanding. The amount of events processed depends on 1379are 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>. 1380C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1142 1381
1143If not all requests were processed for whatever reason, the filehandle 1382If not all requests were processed for whatever reason, the filehandle
1144will still be ready when C<poll_cb> returns. 1383will still be ready when C<poll_cb> returns, so normally you don't have to
1384do anything special to have it called later.
1145 1385
1146Example: Install an Event watcher that automatically calls 1386Example: Install an Event watcher that automatically calls
1147IO::AIO::poll_cb with high priority: 1387IO::AIO::poll_cb with high priority (more examples can be found in the
1388SYNOPSIS section, at the top of this document):
1148 1389
1149 Event->io (fd => IO::AIO::poll_fileno, 1390 Event->io (fd => IO::AIO::poll_fileno,
1150 poll => 'r', async => 1, 1391 poll => 'r', async => 1,
1151 cb => \&IO::AIO::poll_cb); 1392 cb => \&IO::AIO::poll_cb);
1393
1394=item IO::AIO::poll_wait
1395
1396If there are any outstanding requests and none of them in the result
1397phase, wait till the result filehandle becomes ready for reading (simply
1398does a C<select> on the filehandle. This is useful if you want to
1399synchronously wait for some requests to finish).
1400
1401See C<nreqs> for an example.
1402
1403=item IO::AIO::poll
1404
1405Waits until some requests have been handled.
1406
1407Returns the number of requests processed, but is otherwise strictly
1408equivalent to:
1409
1410 IO::AIO::poll_wait, IO::AIO::poll_cb
1411
1412=item IO::AIO::flush
1413
1414Wait till all outstanding AIO requests have been handled.
1415
1416Strictly equivalent to:
1417
1418 IO::AIO::poll_wait, IO::AIO::poll_cb
1419 while IO::AIO::nreqs;
1152 1420
1153=item IO::AIO::max_poll_reqs $nreqs 1421=item IO::AIO::max_poll_reqs $nreqs
1154 1422
1155=item IO::AIO::max_poll_time $seconds 1423=item IO::AIO::max_poll_time $seconds
1156 1424
… …
1181 # use a low priority so other tasks have priority 1449 # use a low priority so other tasks have priority
1182 Event->io (fd => IO::AIO::poll_fileno, 1450 Event->io (fd => IO::AIO::poll_fileno,
1183 poll => 'r', nice => 1, 1451 poll => 'r', nice => 1,
1184 cb => &IO::AIO::poll_cb); 1452 cb => &IO::AIO::poll_cb);
1185 1453
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 1454=back
1214 1455
1215=head3 CONTROLLING THE NUMBER OF THREADS 1456=head3 CONTROLLING THE NUMBER OF THREADS
1216 1457
1217=over 1458=over
… …
1263 1504
1264The default is probably ok in most situations, especially if thread 1505The default is probably ok in most situations, especially if thread
1265creation is fast. If thread creation is very slow on your system you might 1506creation is fast. If thread creation is very slow on your system you might
1266want to use larger values. 1507want to use larger values.
1267 1508
1268=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1509=item IO::AIO::max_outstanding $maxreqs
1269 1510
1270This is a very bad function to use in interactive programs because it 1511This 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 1512blocks, and a bad way to reduce concurrency because it is inexact: Better
1272use an C<aio_group> together with a feed callback. 1513use an C<aio_group> together with a feed callback.
1273 1514
… …
1278 1519
1279The default value is very large, so there is no practical limit on the 1520The default value is very large, so there is no practical limit on the
1280number of outstanding requests. 1521number of outstanding requests.
1281 1522
1282You can still queue as many requests as you want. Therefore, 1523You can still queue as many requests as you want. Therefore,
1283C<max_oustsanding> is mainly useful in simple scripts (with low values) or 1524C<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). 1525as a stop gap to shield against fatal memory overflow (with large values).
1285 1526
1286=back 1527=back
1287 1528
1288=head3 STATISTICAL INFORMATION 1529=head3 STATISTICAL INFORMATION
… …
1309Returns the number of requests currently in the pending state (executed, 1550Returns the number of requests currently in the pending state (executed,
1310but not yet processed by poll_cb). 1551but not yet processed by poll_cb).
1311 1552
1312=back 1553=back
1313 1554
1555=head3 MISCELLANEOUS FUNCTIONS
1556
1557IO::AIO implements some functions that might be useful, but are not
1558asynchronous.
1559
1560=over 4
1561
1562=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1563
1564Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
1565but is blocking (this makes most sense if you know the input data is
1566likely cached already and the output filehandle is set to non-blocking
1567operations).
1568
1569Returns the number of bytes copied, or C<-1> on error.
1570
1571=item IO::AIO::fadvise $fh, $offset, $len, $advice
1572
1573Simply calls the C<posix_fadvise> function (see it's
1574manpage for details). The following advice constants are
1575avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1576C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1577C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1578
1579On systems that do not implement C<posix_fadvise>, this function returns
1580ENOSYS, otherwise the return value of C<posix_fadvise>.
1581
1582=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1583
1584Memory-maps a file (or anonymous memory range) and attaches it to the
1585given C<$scalar>, which will act like a string scalar.
1586
1587The only operations allowed on the scalar are C<substr>/C<vec> that don't
1588change the string length, and most read-only operations such as copying it
1589or searching it with regexes and so on.
1590
1591Anything else is unsafe and will, at best, result in memory leaks.
1592
1593The memory map associated with the C<$scalar> is automatically removed
1594when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
1595C<IO::AIO::munmap> functions are called.
1596
1597This calls the C<mmap>(2) function internally. See your system's manual
1598page for details on the C<$length>, C<$prot> and C<$flags> parameters.
1599
1600The C<$length> must be larger than zero and smaller than the actual
1601filesize.
1602
1603C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1604C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1605
1606C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
1607C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
1608not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
1609(which is set to C<MAP_ANON> if your system only provides this
1610constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
1611C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
1612C<IO::AIO::MAP_NONBLOCK>
1613
1614If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1615
1616C<$offset> is the offset from the start of the file - it generally must be
1617a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
1618
1619Example:
1620
1621 use Digest::MD5;
1622 use IO::AIO;
1623
1624 open my $fh, "<verybigfile"
1625 or die "$!";
1626
1627 IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
1628 or die "verybigfile: $!";
1629
1630 my $fast_md5 = md5 $data;
1631
1632=item IO::AIO::munmap $scalar
1633
1634Removes a previous mmap and undefines the C<$scalar>.
1635
1636=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
1637
1638Calls the C<munlock> function, undoing the effects of a previous
1639C<aio_mlock> call (see its description for details).
1640
1641=item IO::AIO::munlockall
1642
1643Calls the C<munlockall> function.
1644
1645On systems that do not implement C<munlockall>, this function returns
1646ENOSYS, otherwise the return value of C<munlockall>.
1647
1648=back
1649
1314=cut 1650=cut
1315 1651
1316min_parallel 8; 1652min_parallel 8;
1317 1653
1318END { flush } 1654END { flush }
1319 1655
13201; 16561;
1657
1658=head1 EVENT LOOP INTEGRATION
1659
1660It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
1661automatically into many event loops:
1662
1663 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
1664 use AnyEvent::AIO;
1665
1666You can also integrate IO::AIO manually into many event loops, here are
1667some examples of how to do this:
1668
1669 # EV integration
1670 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
1671
1672 # Event integration
1673 Event->io (fd => IO::AIO::poll_fileno,
1674 poll => 'r',
1675 cb => \&IO::AIO::poll_cb);
1676
1677 # Glib/Gtk2 integration
1678 add_watch Glib::IO IO::AIO::poll_fileno,
1679 in => sub { IO::AIO::poll_cb; 1 };
1680
1681 # Tk integration
1682 Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
1683 readable => \&IO::AIO::poll_cb);
1684
1685 # Danga::Socket integration
1686 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
1687 \&IO::AIO::poll_cb);
1321 1688
1322=head2 FORK BEHAVIOUR 1689=head2 FORK BEHAVIOUR
1323 1690
1324This module should do "the right thing" when the process using it forks: 1691This module should do "the right thing" when the process using it forks:
1325 1692
… …
1358 1725
1359Known bugs will be fixed in the next release. 1726Known bugs will be fixed in the next release.
1360 1727
1361=head1 SEE ALSO 1728=head1 SEE ALSO
1362 1729
1363L<Coro::AIO>. 1730L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1731more natural syntax.
1364 1732
1365=head1 AUTHOR 1733=head1 AUTHOR
1366 1734
1367 Marc Lehmann <schmorp@schmorp.de> 1735 Marc Lehmann <schmorp@schmorp.de>
1368 http://home.schmorp.de/ 1736 http://home.schmorp.de/

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