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Revision 1.120 by root, Sun Dec 2 21:51:36 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 (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 175 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close
202 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir 176 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
203 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync 177 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
204 aio_fdatasync aio_pathsync aio_readahead 178 aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
205 aio_rename aio_link aio_move aio_copy aio_group 179 aio_rename aio_link aio_move aio_copy aio_group
206 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown 180 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
207 aio_chmod aio_utime aio_truncate); 181 aio_chmod aio_utime aio_truncate
182 aio_msync aio_mtouch aio_mlock aio_mlockall
183 aio_statvfs);
208 184
209 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block)); 185 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
210 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 186 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
211 min_parallel max_parallel max_idle 187 min_parallel max_parallel max_idle
212 nreqs nready npending nthreads 188 nreqs nready npending nthreads
213 max_poll_time max_poll_reqs); 189 max_poll_time max_poll_reqs
190 sendfile fadvise madvise
191 mmap munmap munlock munlockall);
192
193 push @AIO_REQ, qw(aio_busy); # not exported
214 194
215 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 195 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
216 196
217 require XSLoader; 197 require XSLoader;
218 XSLoader::load ("IO::AIO", $VERSION); 198 XSLoader::load ("IO::AIO", $VERSION);
219} 199}
220 200
221=head1 FUNCTIONS 201=head1 FUNCTIONS
202
203=head2 QUICK OVERVIEW
204
205This section simply lists the prototypes of the most important functions
206for quick reference. See the following sections for function-by-function
207documentation.
208
209 aio_open $pathname, $flags, $mode, $callback->($fh)
210 aio_close $fh, $callback->($status)
211 aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
212 aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
213 aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
214 aio_readahead $fh,$offset,$length, $callback->($retval)
215 aio_stat $fh_or_path, $callback->($status)
216 aio_lstat $fh, $callback->($status)
217 aio_statvfs $fh_or_path, $callback->($statvfs)
218 aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
219 aio_chown $fh_or_path, $uid, $gid, $callback->($status)
220 aio_truncate $fh_or_path, $offset, $callback->($status)
221 aio_chmod $fh_or_path, $mode, $callback->($status)
222 aio_unlink $pathname, $callback->($status)
223 aio_mknod $path, $mode, $dev, $callback->($status)
224 aio_link $srcpath, $dstpath, $callback->($status)
225 aio_symlink $srcpath, $dstpath, $callback->($status)
226 aio_readlink $path, $callback->($link)
227 aio_rename $srcpath, $dstpath, $callback->($status)
228 aio_mkdir $pathname, $mode, $callback->($status)
229 aio_rmdir $pathname, $callback->($status)
230 aio_readdir $pathname, $callback->($entries)
231 aio_readdirx $pathname, $flags, $callback->($entries, $flags)
232 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
233 IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN
234 aio_load $path, $data, $callback->($status)
235 aio_copy $srcpath, $dstpath, $callback->($status)
236 aio_move $srcpath, $dstpath, $callback->($status)
237 aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
238 aio_rmtree $path, $callback->($status)
239 aio_sync $callback->($status)
240 aio_fsync $fh, $callback->($status)
241 aio_fdatasync $fh, $callback->($status)
242 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
243 aio_pathsync $path, $callback->($status)
244 aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
245 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
246 aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
247 aio_mlockall $flags, $callback->($status)
248 aio_group $callback->(...)
249 aio_nop $callback->()
250
251 $prev_pri = aioreq_pri [$pri]
252 aioreq_nice $pri_adjust
253
254 IO::AIO::poll_wait
255 IO::AIO::poll_cb
256 IO::AIO::poll
257 IO::AIO::flush
258 IO::AIO::max_poll_reqs $nreqs
259 IO::AIO::max_poll_time $seconds
260 IO::AIO::min_parallel $nthreads
261 IO::AIO::max_parallel $nthreads
262 IO::AIO::max_idle $nthreads
263 IO::AIO::max_outstanding $maxreqs
264 IO::AIO::nreqs
265 IO::AIO::nready
266 IO::AIO::npending
267
268 IO::AIO::sendfile $ofh, $ifh, $offset, $count
269 IO::AIO::fadvise $fh, $offset, $len, $advice
270 IO::AIO::munlock $scalar, $offset = 0, $length = undef
271 IO::AIO::munlockall
222 272
223=head2 AIO REQUEST FUNCTIONS 273=head2 AIO REQUEST FUNCTIONS
224 274
225All the C<aio_*> calls are more or less thin wrappers around the syscall 275All the C<aio_*> calls are more or less thin wrappers around the syscall
226with the same name (sans C<aio_>). The arguments are similar or identical, 276with the same name (sans C<aio_>). The arguments are similar or identical,
227and they all accept an additional (and optional) C<$callback> argument 277and they all accept an additional (and optional) C<$callback> argument
228which 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
229the 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
230perl, which usually delivers "false") as it's sole argument when the given 280perl, which usually delivers "false") as its sole argument after the given
231syscall has been executed asynchronously. 281syscall has been executed asynchronously.
232 282
233All functions expecting a filehandle keep a copy of the filehandle 283All functions expecting a filehandle keep a copy of the filehandle
234internally until the request has finished. 284internally until the request has finished.
235 285
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249your 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
250environment, d) use Glib::filename_from_unicode on unicode filenames or e) 300environment, d) use Glib::filename_from_unicode on unicode filenames or e)
251use something else to ensure your scalar has the correct contents. 301use something else to ensure your scalar has the correct contents.
252 302
253This 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
254handles correctly wether it is set or not. 304handles correctly whether it is set or not.
255 305
256=over 4 306=over 4
257 307
258=item $prev_pri = aioreq_pri [$pri] 308=item $prev_pri = aioreq_pri [$pri]
259 309
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306by 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
307change the umask. 357change the umask.
308 358
309Example: 359Example:
310 360
311 aio_open "/etc/passwd", O_RDONLY, 0, sub { 361 aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
312 if ($_[0]) { 362 if ($_[0]) {
313 print "open successful, fh is $_[0]\n"; 363 print "open successful, fh is $_[0]\n";
314 ... 364 ...
315 } else { 365 } else {
316 die "open failed: $!\n"; 366 die "open failed: $!\n";
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322 372
323Asynchronously close a file and call the callback with the result 373Asynchronously close a file and call the callback with the result
324code. 374code.
325 375
326Unfortunately, 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
327closing the file descriptor associated with the filehandle itself. Here is 377closing the file descriptor associated with the filehandle itself.
328what aio_close will try:
329 378
330 1. dup()licate the fd 379Therefore, C<aio_close> will not close the filehandle - instead it will
331 2. asynchronously close() the duplicated fd 380use dup2 to overwrite the file descriptor with the write-end of a pipe
332 3. dup()licate the fd once more 381(the pipe fd will be created on demand and will be cached).
333 4. let perl close() the filehandle
334 5. asynchronously close the duplicated fd
335 382
336The 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
337fd will flush, so when perl closes the fd, nothing much will need to be 384free for reuse until the perl filehandle is closed.
338flushed. The second async. close() will then flush stuff to disk that
339closing the last fd to the file will flush.
340
341Just FYI, SuSv3 has this to say on close:
342
343 All outstanding record locks owned by the process on the file
344 associated with the file descriptor shall be removed.
345
346 If fildes refers to a socket, close() shall cause the socket to be
347 destroyed. ... close() shall block for up to the current linger
348 interval until all data is transmitted.
349 [this actually sounds like a specification bug, but who knows]
350
351And at least Linux additionally actually flushes stuff on every close,
352even when the file itself is still open.
353
354Sounds enourmously inefficient and complicated? Yes... please show me how
355to nuke perl's fd out of existence...
356 385
357=cut 386=cut
358 387
359sub aio_close($;$) {
360 aio_block {
361 my ($fh, $cb) = @_;
362
363 my $pri = aioreq_pri;
364 my $grp = aio_group $cb;
365
366 my $fd = fileno $fh;
367
368 defined $fd or Carp::croak "aio_close called with fd-less filehandle";
369
370 # if the dups fail we will simply get EBADF
371 my $fd2 = _dup $fd;
372 aioreq_pri $pri;
373 add $grp _aio_close $fd2, sub {
374 my $fd2 = _dup $fd;
375 close $fh;
376 aioreq_pri $pri;
377 add $grp _aio_close $fd2, sub {
378 $grp->result ($_[0]);
379 };
380 };
381
382 $grp
383 }
384}
385
386
387=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 388=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
388 389
389=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 390=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
390 391
391Reads 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<$fh> and
392into the scalar given by C<$data> and offset C<$dataoffset> and calls the 393C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
393callback 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
394like the syscall). 395error, just like the syscall).
396
397C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
398offset plus the actual number of bytes read.
395 399
396If C<$offset> is undefined, then the current file descriptor offset will 400If C<$offset> is undefined, then the current file descriptor offset will
397be used (and updated), otherwise the file descriptor offset will not be 401be used (and updated), otherwise the file descriptor offset will not be
398changed by these calls. 402changed by these calls.
399 403
400If C<$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<$data>.
401 406
402If C<$dataoffset> is less than zero, it will be counted from the end of 407If C<$dataoffset> is less than zero, it will be counted from the end of
403C<$data>. 408C<$data>.
404 409
405The C<$data> scalar I<MUST NOT> be modified in any way while the request 410The C<$data> scalar I<MUST NOT> be modified in any way while the request
… …
423than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each 428than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
424other. 429other.
425 430
426This call tries to make use of a native C<sendfile> syscall to provide 431This call tries to make use of a native C<sendfile> syscall to provide
427zero-copy operation. For this to work, C<$out_fh> should refer to a 432zero-copy operation. For this to work, C<$out_fh> should refer to a
428socket, and C<$in_fh> should refer to mmap'able file. 433socket, and C<$in_fh> should refer to an mmap'able file.
429 434
430If the native sendfile call fails or is not implemented, it will be 435If a native sendfile cannot be found or it fails with C<ENOSYS>,
436C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
431emulated, so you can call C<aio_sendfile> on any type of filehandle 437it will be emulated, so you can call C<aio_sendfile> on any type of
432regardless of the limitations of the operating system. 438filehandle regardless of the limitations of the operating system.
433 439
434Please note, however, that C<aio_sendfile> can read more bytes from 440Please note, however, that C<aio_sendfile> can read more bytes from
435C<$in_fh> than are written, and there is no way to find out how many 441C<$in_fh> than are written, and there is no way to find out how many
436bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only 442bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
437provides the number of bytes written to C<$out_fh>. Only if the result 443provides the number of bytes written to C<$out_fh>. Only if the result
… …
475 $_[0] and die "stat failed: $!"; 481 $_[0] and die "stat failed: $!";
476 print "size is ", -s _, "\n"; 482 print "size is ", -s _, "\n";
477 }; 483 };
478 484
479 485
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
480=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 531=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
481 532
482Works 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
483and $mtime being undef). Fractional times are supported if the underlying 534and $mtime being undef). Fractional times are supported if the underlying
484syscalls support them. 535syscalls support them.
… …
577 628
578Unlike 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
579directory (i.e. opendir + readdir + closedir). The entries will not be 630directory (i.e. opendir + readdir + closedir). The entries will not be
580sorted, and will B<NOT> include the C<.> and C<..> entries. 631sorted, and will B<NOT> include the C<.> and C<..> entries.
581 632
582The 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
583with 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
584 701
585 702
586=item aio_load $path, $data, $callback->($status) 703=item aio_load $path, $data, $callback->($status)
587 704
588This 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
589memory. Status is the same as with aio_read. 706memory. Status is the same as with aio_read.
590 707
591=cut 708=cut
592 709
593sub aio_load($$;$) { 710sub aio_load($$;$) {
594 aio_block {
595 my ($path, undef, $cb) = @_; 711 my ($path, undef, $cb) = @_;
596 my $data = \$_[1]; 712 my $data = \$_[1];
597 713
598 my $pri = aioreq_pri; 714 my $pri = aioreq_pri;
599 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);
600 721
601 aioreq_pri $pri; 722 aioreq_pri $pri;
602 add $grp aio_open $path, O_RDONLY, 0, sub {
603 my $fh = shift
604 or return $grp->result (-1);
605
606 aioreq_pri $pri;
607 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub { 723 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
608 $grp->result ($_[0]); 724 $grp->result ($_[0]);
609 };
610 }; 725 };
611
612 $grp
613 } 726 };
727
728 $grp
614} 729}
615 730
616=item aio_copy $srcpath, $dstpath, $callback->($status) 731=item aio_copy $srcpath, $dstpath, $callback->($status)
617 732
618Try 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
619destination) from C<$srcpath> to C<$dstpath> and call the callback with 734destination) from C<$srcpath> to C<$dstpath> and call the callback with
620the C<0> (error) or C<-1> ok. 735a status of C<0> (ok) or C<-1> (error, see C<$!>).
621 736
622This is a composite request that it creates the destination file with 737This is a composite request that creates the destination file with
623mode 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
624C<aio_sendfile>, followed by restoring atime, mtime, access mode and 739C<aio_sendfile>, followed by restoring atime, mtime, access mode and
625uid/gid, in that order. 740uid/gid, in that order.
626 741
627If an error occurs, the partial destination file will be unlinked, if 742If an error occurs, the partial destination file will be unlinked, if
… …
629errors are being ignored. 744errors are being ignored.
630 745
631=cut 746=cut
632 747
633sub aio_copy($$;$) { 748sub aio_copy($$;$) {
634 aio_block {
635 my ($src, $dst, $cb) = @_; 749 my ($src, $dst, $cb) = @_;
636 750
637 my $pri = aioreq_pri; 751 my $pri = aioreq_pri;
638 my $grp = aio_group $cb; 752 my $grp = aio_group $cb;
639 753
640 aioreq_pri $pri; 754 aioreq_pri $pri;
641 add $grp aio_open $src, O_RDONLY, 0, sub { 755 add $grp aio_open $src, O_RDONLY, 0, sub {
642 if (my $src_fh = $_[0]) { 756 if (my $src_fh = $_[0]) {
643 my @stat = stat $src_fh; 757 my @stat = stat $src_fh; # hmm, might block over nfs?
644 758
645 aioreq_pri $pri; 759 aioreq_pri $pri;
646 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 {
647 if (my $dst_fh = $_[0]) { 761 if (my $dst_fh = $_[0]) {
648 aioreq_pri $pri; 762 aioreq_pri $pri;
649 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 763 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
650 if ($_[0] == $stat[7]) { 764 if ($_[0] == $stat[7]) {
651 $grp->result (0); 765 $grp->result (0);
652 close $src_fh; 766 close $src_fh;
653 767
654 # those should not normally block. should. should. 768 my $ch = sub {
655 utime $stat[8], $stat[9], $dst;
656 chmod $stat[2] & 07777, $dst_fh;
657 chown $stat[4], $stat[5], $dst_fh;
658
659 aioreq_pri $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;
660 add $grp aio_close $dst_fh; 774 add $grp aio_close $dst_fh;
661 } else { 775 }
662 $grp->result (-1);
663 close $src_fh;
664 close $dst_fh;
665
666 aioreq $pri; 776 };
667 add $grp aio_unlink $dst;
668 } 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;
669 }; 795 }
670 } else {
671 $grp->result (-1);
672 } 796 };
797 } else {
798 $grp->result (-1);
673 }, 799 }
674
675 } else {
676 $grp->result (-1);
677 } 800 },
801
802 } else {
803 $grp->result (-1);
678 }; 804 }
679
680 $grp
681 } 805 };
806
807 $grp
682} 808}
683 809
684=item aio_move $srcpath, $dstpath, $callback->($status) 810=item aio_move $srcpath, $dstpath, $callback->($status)
685 811
686Try 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
687destination) from C<$srcpath> to C<$dstpath> and call the callback with 813destination) from C<$srcpath> to C<$dstpath> and call the callback with
688the C<0> (error) or C<-1> ok. 814a status of C<0> (ok) or C<-1> (error, see C<$!>).
689 815
690This is a composite request that tries to rename(2) the file first. If 816This is a composite request that tries to rename(2) the file first; if
691rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if 817rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
692that is successful, unlinking the C<$srcpath>. 818that is successful, unlinks the C<$srcpath>.
693 819
694=cut 820=cut
695 821
696sub aio_move($$;$) { 822sub aio_move($$;$) {
697 aio_block {
698 my ($src, $dst, $cb) = @_; 823 my ($src, $dst, $cb) = @_;
699 824
700 my $pri = aioreq_pri; 825 my $pri = aioreq_pri;
701 my $grp = aio_group $cb; 826 my $grp = aio_group $cb;
702 827
703 aioreq_pri $pri; 828 aioreq_pri $pri;
704 add $grp aio_rename $src, $dst, sub { 829 add $grp aio_rename $src, $dst, sub {
705 if ($_[0] && $! == EXDEV) { 830 if ($_[0] && $! == EXDEV) {
706 aioreq_pri $pri; 831 aioreq_pri $pri;
707 add $grp aio_copy $src, $dst, sub { 832 add $grp aio_copy $src, $dst, sub {
708 $grp->result ($_[0]);
709
710 if (!$_[0]) {
711 aioreq_pri $pri;
712 add $grp aio_unlink $src;
713 }
714 };
715 } else {
716 $grp->result ($_[0]); 833 $grp->result ($_[0]);
834
835 if (!$_[0]) {
836 aioreq_pri $pri;
837 add $grp aio_unlink $src;
838 }
717 } 839 };
840 } else {
841 $grp->result ($_[0]);
718 }; 842 }
719
720 $grp
721 } 843 };
844
845 $grp
722} 846}
723 847
724=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 848=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
725 849
726Scans a directory (similar to C<aio_readdir>) but additionally tries to 850Scans a directory (similar to C<aio_readdir>) but additionally tries to
… …
746 870
747Implementation notes. 871Implementation notes.
748 872
749The 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.
750 874
875If readdir returns file type information, then this is used directly to
876find directories.
877
751After reading the directory, the modification time, size etc. of the 878Otherwise, after reading the directory, the modification time, size etc.
752directory 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
753isn'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
754entries are directories (if >= 2). Otherwise, no knowledge of the number 881how many entries are directories (if >= 2). Otherwise, no knowledge of the
755of subdirectories will be assumed. 882number of subdirectories will be assumed.
756 883
757Then entries will be sorted into likely directories (everything without 884Then entries will be sorted into likely directories a non-initial dot
758a non-initial dot currently) and likely non-directories (everything 885currently) and likely non-directories (see C<aio_readdirx>). Then every
759else). 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,
760likely directories first. If that succeeds, it assumes that the entry 887in order of their inode numbers. If that succeeds, it assumes that the
761is a directory or a symlink to directory (which will be checked 888entry is a directory or a symlink to directory (which will be checked
762seperately). This is often faster than stat'ing the entry itself because 889seperately). This is often faster than stat'ing the entry itself because
763filesystems might detect the type of the entry without reading the inode 890filesystems might detect the type of the entry without reading the inode
764data (e.g. ext2fs filetype feature). 891data (e.g. ext2fs filetype feature), even on systems that cannot return
892the filetype information on readdir.
765 893
766If 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
767rest of the entries is assumed to be non-directories. 895rest of the entries is assumed to be non-directories.
768 896
769This only works with certainty on POSIX (= UNIX) filesystems, which 897This only works with certainty on POSIX (= UNIX) filesystems, which
… …
774directory counting heuristic. 902directory counting heuristic.
775 903
776=cut 904=cut
777 905
778sub aio_scandir($$;$) { 906sub aio_scandir($$;$) {
779 aio_block {
780 my ($path, $maxreq, $cb) = @_; 907 my ($path, $maxreq, $cb) = @_;
781 908
782 my $pri = aioreq_pri; 909 my $pri = aioreq_pri;
783 910
784 my $grp = aio_group $cb; 911 my $grp = aio_group $cb;
785 912
786 $maxreq = 4 if $maxreq <= 0; 913 $maxreq = 4 if $maxreq <= 0;
787 914
788 # 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
789 aioreq_pri $pri; 923 aioreq_pri $pri;
790 add $grp aio_stat $path, sub { 924 add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
925 my $entries = shift
791 return $grp->result () if $_[0]; 926 or return $grp->result ();
792 my $now = time;
793 my $hash1 = join ":", (stat _)[0,1,3,7,9];
794 927
795 # read the directory entries 928 # stat the dir another time
796 aioreq_pri $pri; 929 aioreq_pri $pri;
797 add $grp aio_readdir $path, sub {
798 my $entries = shift
799 or return $grp->result ();
800
801 # stat the dir another time
802 aioreq_pri $pri;
803 add $grp aio_stat $path, sub { 930 add $grp aio_stat $path, sub {
804 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 931 my $hash2 = join ":", (stat _)[0,1,3,7,9];
805 932
806 my $ndirs; 933 my $ndirs;
807 934
808 # take the slow route if anything looks fishy 935 # take the slow route if anything looks fishy
809 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 936 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
810 $ndirs = -1; 937 $ndirs = -1;
811 } else { 938 } else {
812 # if nlink == 2, we are finished 939 # if nlink == 2, we are finished
813 # on non-posix-fs's, we rely on nlink < 2 940 # for non-posix-fs's, we rely on nlink < 2
814 $ndirs = (stat _)[3] - 2 941 $ndirs = (stat _)[3] - 2
815 or return $grp->result ([], $entries); 942 or return $grp->result ([], $entries);
816 } 943 }
817 944
818 # sort into likely dirs and likely nondirs
819 # dirs == files without ".", short entries first
820 $entries = [map $_->[0],
821 sort { $b->[1] cmp $a->[1] }
822 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
823 @$entries];
824
825 my (@dirs, @nondirs); 945 my (@dirs, @nondirs);
826 946
827 my $statgrp = add $grp aio_group sub { 947 my $statgrp = add $grp aio_group sub {
828 $grp->result (\@dirs, \@nondirs); 948 $grp->result (\@dirs, \@nondirs);
829 }; 949 };
830 950
831 limit $statgrp $maxreq; 951 limit $statgrp $maxreq;
832 feed $statgrp sub { 952 feed $statgrp sub {
833 return unless @$entries; 953 return unless @$entries;
834 my $entry = pop @$entries; 954 my $entry = shift @$entries;
835 955
836 aioreq_pri $pri; 956 aioreq_pri $pri;
837 add $statgrp aio_stat "$path/$entry/.", sub { 957 add $statgrp aio_stat "$path/$entry/.", sub {
838 if ($_[0] < 0) { 958 if ($_[0] < 0) {
839 push @nondirs, $entry; 959 push @nondirs, $entry;
840 } else { 960 } else {
841 # need to check for real directory 961 # need to check for real directory
842 aioreq_pri $pri; 962 aioreq_pri $pri;
843 add $statgrp aio_lstat "$path/$entry", sub { 963 add $statgrp aio_lstat "$path/$entry", sub {
844 if (-d _) { 964 if (-d _) {
845 push @dirs, $entry; 965 push @dirs, $entry;
846 966
847 unless (--$ndirs) { 967 unless (--$ndirs) {
848 push @nondirs, @$entries; 968 push @nondirs, @$entries;
849 feed $statgrp; 969 feed $statgrp;
850 }
851 } else {
852 push @nondirs, $entry;
853 } 970 }
971 } else {
972 push @nondirs, $entry;
854 } 973 }
855 } 974 }
856 }; 975 }
857 }; 976 };
858 }; 977 };
859 }; 978 };
860 }; 979 };
861
862 $grp
863 } 980 };
981
982 $grp
864} 983}
865 984
866=item aio_rmtree $path, $callback->($status) 985=item aio_rmtree $path, $callback->($status)
867 986
868Delete a directory tree starting (and including) C<$path>, return the 987Delete a directory tree starting (and including) C<$path>, return the
… …
872 991
873=cut 992=cut
874 993
875sub aio_rmtree; 994sub aio_rmtree;
876sub aio_rmtree($;$) { 995sub aio_rmtree($;$) {
877 aio_block {
878 my ($path, $cb) = @_; 996 my ($path, $cb) = @_;
879 997
880 my $pri = aioreq_pri; 998 my $pri = aioreq_pri;
881 my $grp = aio_group $cb; 999 my $grp = aio_group $cb;
882 1000
883 aioreq_pri $pri; 1001 aioreq_pri $pri;
884 add $grp aio_scandir $path, 0, sub { 1002 add $grp aio_scandir $path, 0, sub {
885 my ($dirs, $nondirs) = @_; 1003 my ($dirs, $nondirs) = @_;
886 1004
887 my $dirgrp = aio_group sub { 1005 my $dirgrp = aio_group sub {
888 add $grp aio_rmdir $path, sub { 1006 add $grp aio_rmdir $path, sub {
889 $grp->result ($_[0]); 1007 $grp->result ($_[0]);
890 };
891 }; 1008 };
892
893 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
894 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
895
896 add $grp $dirgrp;
897 }; 1009 };
898 1010
899 $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;
900 } 1015 };
1016
1017 $grp
901} 1018}
902 1019
903=item aio_sync $callback->($status) 1020=item aio_sync $callback->($status)
904 1021
905Asynchronously call sync and call the callback when finished. 1022Asynchronously call sync and call the callback when finished.
… …
915callback with the fdatasync result code. 1032callback with the fdatasync result code.
916 1033
917If 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
918detected, it will be emulated by calling C<fsync> instead. 1035detected, it will be emulated by calling C<fsync> instead.
919 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
920=item aio_pathsync $path, $callback->($status) 1049=item aio_pathsync $path, $callback->($status)
921 1050
922This request tries to open, fsync and close the given path. This is a 1051This request tries to open, fsync and close the given path. This is a
923composite request intended tosync directories after directory operations 1052composite request intended to sync directories after directory operations
924(E.g. rename). This might not work on all operating systems or have any 1053(E.g. rename). This might not work on all operating systems or have any
925specific effect, but usually it makes sure that directory changes get 1054specific effect, but usually it makes sure that directory changes get
926written to disc. It works for anything that can be opened for read-only, 1055written to disc. It works for anything that can be opened for read-only,
927not just directories. 1056not just directories.
928 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
929Passes C<0> when everything went ok, and C<-1> on error. 1061Passes C<0> when everything went ok, and C<-1> on error.
930 1062
931=cut 1063=cut
932 1064
933sub aio_pathsync($;$) { 1065sub aio_pathsync($;$) {
934 aio_block {
935 my ($path, $cb) = @_; 1066 my ($path, $cb) = @_;
936 1067
937 my $pri = aioreq_pri; 1068 my $pri = aioreq_pri;
938 my $grp = aio_group $cb; 1069 my $grp = aio_group $cb;
939 1070
940 aioreq_pri $pri; 1071 aioreq_pri $pri;
941 add $grp aio_open $path, O_RDONLY, 0, sub { 1072 add $grp aio_open $path, O_RDONLY, 0, sub {
942 my ($fh) = @_; 1073 my ($fh) = @_;
943 if ($fh) { 1074 if ($fh) {
1075 aioreq_pri $pri;
1076 add $grp aio_fsync $fh, sub {
1077 $grp->result ($_[0]);
1078
944 aioreq_pri $pri; 1079 aioreq_pri $pri;
945 add $grp aio_fsync $fh, sub {
946 $grp->result ($_[0]);
947
948 aioreq_pri $pri;
949 add $grp aio_close $fh; 1080 add $grp aio_close $fh;
950 };
951 } else {
952 $grp->result (-1);
953 } 1081 };
1082 } else {
1083 $grp->result (-1);
954 }; 1084 }
955
956 $grp
957 } 1085 };
1086
1087 $grp
958} 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;
959 1155
960=item aio_group $callback->(...) 1156=item aio_group $callback->(...)
961 1157
962This 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
963container 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
… …
1013=item cancel $req 1209=item cancel $req
1014 1210
1015Cancels the request, if possible. Has the effect of skipping execution 1211Cancels the request, if possible. Has the effect of skipping execution
1016when entering the B<execute> state and skipping calling the callback when 1212when entering the B<execute> state and skipping calling the callback when
1017entering the the B<result> state, but will leave the request otherwise 1213entering the the B<result> state, but will leave the request otherwise
1018untouched. That means that requests that currently execute will not be 1214untouched (with the exception of readdir). That means that requests that
1019stopped 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.
1020 1217
1021=item cb $req $callback->(...) 1218=item cb $req $callback->(...)
1022 1219
1023Replace (or simply set) the callback registered to the request. 1220Replace (or simply set) the callback registered to the request.
1024 1221
… …
1075Their lifetime, simplified, looks like this: when they are empty, they 1272Their lifetime, simplified, looks like this: when they are empty, they
1076will 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
1077C<done> state, they will also finish. Otherwise they will continue to 1274C<done> state, they will also finish. Otherwise they will continue to
1078exist. 1275exist.
1079 1276
1080That 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
1081in 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
1082group. 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
1083itself finish. 1280further requests to the group. And only when all those requests have
1281finished will the the group itself finish.
1084 1282
1085=over 4 1283=over 4
1086 1284
1087=item add $grp ... 1285=item add $grp ...
1088 1286
… …
1096 1294
1097=item $grp->cancel_subs 1295=item $grp->cancel_subs
1098 1296
1099Cancel all subrequests and clears any feeder, but not the group request 1297Cancel all subrequests and clears any feeder, but not the group request
1100itself. 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.
1299
1300The group request will finish normally (you cannot add requests to the
1301group).
1101 1302
1102=item $grp->result (...) 1303=item $grp->result (...)
1103 1304
1104Set 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
1105subrequests have finished and set the groups errno to the current value 1306subrequests have finished and set the groups errno to the current value
… …
1121=item feed $grp $callback->($grp) 1322=item feed $grp $callback->($grp)
1122 1323
1123Sets 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
1124generator that generates requests if idle. The idea behind this is that, 1325generator that generates requests if idle. The idea behind this is that,
1125although 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,
1126this might starve other requests for a potentially long time. For 1327this might starve other requests for a potentially long time. For example,
1127example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1328C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1128requests, delaying any later requests for a long time. 1329delaying any later requests for a long time.
1129 1330
1130To avoid this, and allow incremental generation of requests, you can 1331To avoid this, and allow incremental generation of requests, you can
1131instead 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
1132feed 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>,
1133below) 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
… …
1137not impose any limits). 1338not impose any limits).
1138 1339
1139If 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
1140automatically removed from the group. 1341automatically removed from the group.
1141 1342
1142If 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.
1143 1345
1144Example: 1346Example:
1145 1347
1146 # 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:
1147 1349
… …
1159Sets 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
1160the group contains less than this many requests. 1362the group contains less than this many requests.
1161 1363
1162Setting the limit to C<0> will pause the feeding process. 1364Setting the limit to C<0> will pause the feeding process.
1163 1365
1366The default value for the limit is C<0>, but note that setting a feeder
1367automatically bumps it up to C<2>.
1368
1164=back 1369=back
1165 1370
1166=head2 SUPPORT FUNCTIONS 1371=head2 SUPPORT FUNCTIONS
1167 1372
1168=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1373=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
… …
1170=over 4 1375=over 4
1171 1376
1172=item $fileno = IO::AIO::poll_fileno 1377=item $fileno = IO::AIO::poll_fileno
1173 1378
1174Return the I<request result pipe file descriptor>. This filehandle must be 1379Return the I<request result pipe file descriptor>. This filehandle must be
1175polled 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,
1176select, 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
1177to call C<poll_cb> to check the results. 1382you have to call C<poll_cb> to check the results.
1178 1383
1179See C<poll_cb> for an example. 1384See C<poll_cb> for an example.
1180 1385
1181=item IO::AIO::poll_cb 1386=item IO::AIO::poll_cb
1182 1387
1183Process 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
1184regularly. 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
1185when no events are outstanding. The amount of events processed depends on 1391are outstanding. The amount of events processed depends on the settings of
1186the 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>.
1187 1393
1188If not all requests were processed for whatever reason, the filehandle 1394If not all requests were processed for whatever reason, the filehandle
1189will 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.
1190 1397
1191Example: Install an Event watcher that automatically calls 1398Example: Install an Event watcher that automatically calls
1192IO::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):
1193 1401
1194 Event->io (fd => IO::AIO::poll_fileno, 1402 Event->io (fd => IO::AIO::poll_fileno,
1195 poll => 'r', async => 1, 1403 poll => 'r', async => 1,
1196 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;
1197 1432
1198=item IO::AIO::max_poll_reqs $nreqs 1433=item IO::AIO::max_poll_reqs $nreqs
1199 1434
1200=item IO::AIO::max_poll_time $seconds 1435=item IO::AIO::max_poll_time $seconds
1201 1436
… …
1226 # use a low priority so other tasks have priority 1461 # use a low priority so other tasks have priority
1227 Event->io (fd => IO::AIO::poll_fileno, 1462 Event->io (fd => IO::AIO::poll_fileno,
1228 poll => 'r', nice => 1, 1463 poll => 'r', nice => 1,
1229 cb => &IO::AIO::poll_cb); 1464 cb => &IO::AIO::poll_cb);
1230 1465
1231=item IO::AIO::poll_wait
1232
1233If there are any outstanding requests and none of them in the result
1234phase, wait till the result filehandle becomes ready for reading (simply
1235does a C<select> on the filehandle. This is useful if you want to
1236synchronously wait for some requests to finish).
1237
1238See C<nreqs> for an example.
1239
1240=item IO::AIO::poll
1241
1242Waits until some requests have been handled.
1243
1244Returns the number of requests processed, but is otherwise strictly
1245equivalent to:
1246
1247 IO::AIO::poll_wait, IO::AIO::poll_cb
1248
1249=item IO::AIO::flush
1250
1251Wait till all outstanding AIO requests have been handled.
1252
1253Strictly equivalent to:
1254
1255 IO::AIO::poll_wait, IO::AIO::poll_cb
1256 while IO::AIO::nreqs;
1257
1258=back 1466=back
1259 1467
1260=head3 CONTROLLING THE NUMBER OF THREADS 1468=head3 CONTROLLING THE NUMBER OF THREADS
1261 1469
1262=over 1470=over
… …
1308 1516
1309The default is probably ok in most situations, especially if thread 1517The default is probably ok in most situations, especially if thread
1310creation 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
1311want to use larger values. 1519want to use larger values.
1312 1520
1313=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1521=item IO::AIO::max_outstanding $maxreqs
1314 1522
1315This 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
1316blocks, 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
1317use an C<aio_group> together with a feed callback. 1525use an C<aio_group> together with a feed callback.
1318 1526
… …
1323 1531
1324The 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
1325number of outstanding requests. 1533number of outstanding requests.
1326 1534
1327You can still queue as many requests as you want. Therefore, 1535You can still queue as many requests as you want. Therefore,
1328C<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
1329as 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).
1330 1538
1331=back 1539=back
1332 1540
1333=head3 STATISTICAL INFORMATION 1541=head3 STATISTICAL INFORMATION
… …
1354Returns the number of requests currently in the pending state (executed, 1562Returns the number of requests currently in the pending state (executed,
1355but not yet processed by poll_cb). 1563but not yet processed by poll_cb).
1356 1564
1357=back 1565=back
1358 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
1359=cut 1662=cut
1360 1663
1361min_parallel 8; 1664min_parallel 8;
1362 1665
1363END { flush } 1666END { flush }
1364 1667
13651; 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);
1366 1700
1367=head2 FORK BEHAVIOUR 1701=head2 FORK BEHAVIOUR
1368 1702
1369This 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:
1370 1704
… …
1403 1737
1404Known bugs will be fixed in the next release. 1738Known bugs will be fixed in the next release.
1405 1739
1406=head1 SEE ALSO 1740=head1 SEE ALSO
1407 1741
1408L<Coro::AIO>. 1742L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1743more natural syntax.
1409 1744
1410=head1 AUTHOR 1745=head1 AUTHOR
1411 1746
1412 Marc Lehmann <schmorp@schmorp.de> 1747 Marc Lehmann <schmorp@schmorp.de>
1413 http://home.schmorp.de/ 1748 http://home.schmorp.de/

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