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Revision 1.116 by root, Wed Oct 3 21:27:51 2007 UTC vs.
Revision 1.188 by root, Tue Feb 15 03:21:41 2011 UTC

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
26 $req->cancel; # cancel request if still in queue 26 $req->cancel; # cancel request if still in queue
27 27
28 my $grp = aio_group sub { print "all stats done\n" }; 28 my $grp = aio_group sub { print "all stats done\n" };
29 add $grp aio_stat "..." for ...; 29 add $grp aio_stat "..." for ...;
30 30
31 # AnyEvent integration
32 open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!";
33 my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });
34
35 # Event integration
36 Event->io (fd => IO::AIO::poll_fileno,
37 poll => 'r',
38 cb => \&IO::AIO::poll_cb);
39
40 # Glib/Gtk2 integration
41 add_watch Glib::IO IO::AIO::poll_fileno,
42 in => sub { IO::AIO::poll_cb; 1 };
43
44 # Tk integration
45 Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
46 readable => \&IO::AIO::poll_cb);
47
48 # Danga::Socket integration
49 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
50 \&IO::AIO::poll_cb);
51
52=head1 DESCRIPTION 31=head1 DESCRIPTION
53 32
54This module implements asynchronous I/O using whatever means your 33This module implements asynchronous I/O using whatever means your
55operating system supports. 34operating system supports. It is implemented as an interface to C<libeio>
35(L<http://software.schmorp.de/pkg/libeio.html>).
56 36
57Asynchronous means that operations that can normally block your program 37Asynchronous means that operations that can normally block your program
58(e.g. reading from disk) will be done asynchronously: the operation 38(e.g. reading from disk) will be done asynchronously: the operation
59will still block, but you can do something else in the meantime. This 39will still block, but you can do something else in the meantime. This
60is extremely useful for programs that need to stay interactive even 40is extremely useful for programs that need to stay interactive even
64on a RAID volume or over NFS when you do a number of stat operations 44on a RAID volume or over NFS when you do a number of stat operations
65concurrently. 45concurrently.
66 46
67While most of this works on all types of file descriptors (for 47While most of this works on all types of file descriptors (for
68example sockets), using these functions on file descriptors that 48example sockets), using these functions on file descriptors that
69support nonblocking operation (again, sockets, pipes etc.) is very 49support nonblocking operation (again, sockets, pipes etc.) is
70inefficient. Use an event loop for that (such as the L<Event|Event> 50very inefficient. Use an event loop for that (such as the L<EV>
71module): IO::AIO will naturally fit into such an event loop itself. 51module): IO::AIO will naturally fit into such an event loop itself.
72 52
73In this version, a number of threads are started that execute your 53In this version, a number of threads are started that execute your
74requests and signal their completion. You don't need thread support 54requests and signal their completion. You don't need thread support
75in perl, and the threads created by this module will not be visible 55in perl, and the threads created by this module will not be visible
85yourself, always call C<poll_cb> from within the same thread, or never 65yourself, always call C<poll_cb> from within the same thread, or never
86call C<poll_cb> (or other C<aio_> functions) recursively. 66call C<poll_cb> (or other C<aio_> functions) recursively.
87 67
88=head2 EXAMPLE 68=head2 EXAMPLE
89 69
90This is a simple example that uses the Event module and loads 70This is a simple example that uses the EV module and loads
91F</etc/passwd> asynchronously: 71F</etc/passwd> asynchronously:
92 72
93 use Fcntl; 73 use Fcntl;
94 use Event; 74 use EV;
95 use IO::AIO; 75 use IO::AIO;
96 76
97 # register the IO::AIO callback with Event 77 # register the IO::AIO callback with EV
98 Event->io (fd => IO::AIO::poll_fileno, 78 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
99 poll => 'r',
100 cb => \&IO::AIO::poll_cb);
101 79
102 # queue the request to open /etc/passwd 80 # queue the request to open /etc/passwd
103 aio_open "/etc/passwd", O_RDONLY, 0, sub { 81 aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
104 my $fh = shift 82 my $fh = shift
105 or die "error while opening: $!"; 83 or die "error while opening: $!";
106 84
107 # stat'ing filehandles is generally non-blocking 85 # stat'ing filehandles is generally non-blocking
108 my $size = -s $fh; 86 my $size = -s $fh;
117 95
118 # file contents now in $contents 96 # file contents now in $contents
119 print $contents; 97 print $contents;
120 98
121 # exit event loop and program 99 # exit event loop and program
122 Event::unloop; 100 EV::unloop;
123 }; 101 };
124 }; 102 };
125 103
126 # possibly queue up other requests, or open GUI windows, 104 # possibly queue up other requests, or open GUI windows,
127 # check for sockets etc. etc. 105 # check for sockets etc. etc.
128 106
129 # process events as long as there are some: 107 # process events as long as there are some:
130 Event::loop; 108 EV::loop;
131 109
132=head1 REQUEST ANATOMY AND LIFETIME 110=head1 REQUEST ANATOMY AND LIFETIME
133 111
134Every C<aio_*> function creates a request. which is a C data structure not 112Every C<aio_*> function creates a request. which is a C data structure not
135directly visible to Perl. 113directly visible to Perl.
183 161
184=cut 162=cut
185 163
186package IO::AIO; 164package IO::AIO;
187 165
188no warnings; 166use Carp ();
189use strict 'vars'; 167
168use common::sense;
190 169
191use base 'Exporter'; 170use base 'Exporter';
192 171
193BEGIN { 172BEGIN {
194 our $VERSION = '2.5'; 173 our $VERSION = '3.72';
195 174
196 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
197 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
198 aio_readlink aio_fsync aio_fdatasync aio_readahead aio_rename aio_link 177 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
178 aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
179 aio_rename aio_link aio_move aio_copy aio_group
199 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
200 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
201 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block)); 185 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
202 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 186 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
203 min_parallel max_parallel max_idle 187 min_parallel max_parallel max_idle idle_timeout
204 nreqs nready npending nthreads 188 nreqs nready npending nthreads
205 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
206 194
207 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 195 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
208 196
209 require XSLoader; 197 require XSLoader;
210 XSLoader::load ("IO::AIO", $VERSION); 198 XSLoader::load ("IO::AIO", $VERSION);
211} 199}
212 200
213=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::idle_timeout $seconds
264 IO::AIO::max_outstanding $maxreqs
265 IO::AIO::nreqs
266 IO::AIO::nready
267 IO::AIO::npending
268
269 IO::AIO::sendfile $ofh, $ifh, $offset, $count
270 IO::AIO::fadvise $fh, $offset, $len, $advice
271 IO::AIO::madvise $scalar, $offset, $length, $advice
272 IO::AIO::mprotect $scalar, $offset, $length, $protect
273 IO::AIO::munlock $scalar, $offset = 0, $length = undef
274 IO::AIO::munlockall
214 275
215=head2 AIO REQUEST FUNCTIONS 276=head2 AIO REQUEST FUNCTIONS
216 277
217All the C<aio_*> calls are more or less thin wrappers around the syscall 278All the C<aio_*> calls are more or less thin wrappers around the syscall
218with the same name (sans C<aio_>). The arguments are similar or identical, 279with the same name (sans C<aio_>). The arguments are similar or identical,
219and they all accept an additional (and optional) C<$callback> argument 280and they all accept an additional (and optional) C<$callback> argument
220which must be a code reference. This code reference will get called with 281which must be a code reference. This code reference will get called with
221the syscall return code (e.g. most syscalls return C<-1> on error, unlike 282the syscall return code (e.g. most syscalls return C<-1> on error, unlike
222perl, which usually delivers "false") as it's sole argument when the given 283perl, which usually delivers "false") as its sole argument after the given
223syscall has been executed asynchronously. 284syscall has been executed asynchronously.
224 285
225All functions expecting a filehandle keep a copy of the filehandle 286All functions expecting a filehandle keep a copy of the filehandle
226internally until the request has finished. 287internally until the request has finished.
227 288
241your pathnames to the locale (or other) encoding in effect in the user 302your pathnames to the locale (or other) encoding in effect in the user
242environment, d) use Glib::filename_from_unicode on unicode filenames or e) 303environment, d) use Glib::filename_from_unicode on unicode filenames or e)
243use something else to ensure your scalar has the correct contents. 304use something else to ensure your scalar has the correct contents.
244 305
245This works, btw. independent of the internal UTF-8 bit, which IO::AIO 306This works, btw. independent of the internal UTF-8 bit, which IO::AIO
246handles correctly wether it is set or not. 307handles correctly whether it is set or not.
247 308
248=over 4 309=over 4
249 310
250=item $prev_pri = aioreq_pri [$pri] 311=item $prev_pri = aioreq_pri [$pri]
251 312
298by the umask in effect then the request is being executed, so better never 359by the umask in effect then the request is being executed, so better never
299change the umask. 360change the umask.
300 361
301Example: 362Example:
302 363
303 aio_open "/etc/passwd", O_RDONLY, 0, sub { 364 aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
304 if ($_[0]) { 365 if ($_[0]) {
305 print "open successful, fh is $_[0]\n"; 366 print "open successful, fh is $_[0]\n";
306 ... 367 ...
307 } else { 368 } else {
308 die "open failed: $!\n"; 369 die "open failed: $!\n";
313=item aio_close $fh, $callback->($status) 374=item aio_close $fh, $callback->($status)
314 375
315Asynchronously close a file and call the callback with the result 376Asynchronously close a file and call the callback with the result
316code. 377code.
317 378
318Unlike the other functions operating on files, this function uses the 379Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
319PerlIO layer to close the filehandle. The reason is that the PerlIO API 380closing the file descriptor associated with the filehandle itself.
320insists on closing the underlying fd itself, no matter what, and doesn't
321allow modifications to the fd. Unfortunately, it is not clear that you can
322call PerlIO from different threads (actually, its quite clear that this
323won't work in some cases), so while it likely works perfectly with simple
324file handles (such as the ones created by C<aio_open>) it might fail in
325interesting ways for others.
326 381
327Having said that, aio_close tries to clean up the filehandle as much as 382Therefore, C<aio_close> will not close the filehandle - instead it will
328possible before handing it to an io thread, and generally does work. 383use dup2 to overwrite the file descriptor with the write-end of a pipe
384(the pipe fd will be created on demand and will be cached).
329 385
386Or in other words: the file descriptor will be closed, but it will not be
387free for reuse until the perl filehandle is closed.
388
389=cut
330 390
331=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 391=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
332 392
333=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 393=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
334 394
335Reads or writes C<$length> bytes from the specified C<$fh> and C<$offset> 395Reads or writes C<$length> bytes from or to the specified C<$fh> and
336into the scalar given by C<$data> and offset C<$dataoffset> and calls the 396C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
337callback without the actual number of bytes read (or -1 on error, just 397and calls the callback without the actual number of bytes read (or -1 on
338like the syscall). 398error, just like the syscall).
399
400C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
401offset plus the actual number of bytes read.
339 402
340If C<$offset> is undefined, then the current file descriptor offset will 403If C<$offset> is undefined, then the current file descriptor offset will
341be used (and updated), otherwise the file descriptor offset will not be 404be used (and updated), otherwise the file descriptor offset will not be
342changed by these calls. 405changed by these calls.
343 406
344If C<$length> is undefined in C<aio_write>, use the remaining length of C<$data>. 407If C<$length> is undefined in C<aio_write>, use the remaining length of
408C<$data>.
345 409
346If C<$dataoffset> is less than zero, it will be counted from the end of 410If C<$dataoffset> is less than zero, it will be counted from the end of
347C<$data>. 411C<$data>.
348 412
349The C<$data> scalar I<MUST NOT> be modified in any way while the request 413The C<$data> scalar I<MUST NOT> be modified in any way while the request
365reading at byte offset C<$in_offset>, and starts writing at the current 429reading at byte offset C<$in_offset>, and starts writing at the current
366file offset of C<$out_fh>. Because of that, it is not safe to issue more 430file offset of C<$out_fh>. Because of that, it is not safe to issue more
367than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each 431than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
368other. 432other.
369 433
434Please note that C<aio_sendfile> can read more bytes from C<$in_fh> than
435are written, and there is no way to find out how many bytes have been read
436from C<aio_sendfile> alone, as C<aio_sendfile> only provides the number of
437bytes written to C<$out_fh>. Only if the result value equals C<$length>
438one can assume that C<$length> bytes have been read.
439
440Unlike with other C<aio_> functions, it makes a lot of sense to use
441C<aio_sendfile> on non-blocking sockets, as long as one end (typically
442the C<$in_fh>) is a file - the file I/O will then be asynchronous, while
443the socket I/O will be non-blocking. Note, however, that you can run into
444a trap where C<aio_sendfile> reads some data with readahead, then fails
445to write all data, and when the socket is ready the next time, the data
446in the cache is already lost, forcing C<aio_sendfile> to again hit the
447disk. Explicit C<aio_read> + C<aio_write> let's you control resource usage
448much better.
449
370This call tries to make use of a native C<sendfile> syscall to provide 450This call tries to make use of a native C<sendfile> syscall to provide
371zero-copy operation. For this to work, C<$out_fh> should refer to a 451zero-copy operation. For this to work, C<$out_fh> should refer to a
372socket, and C<$in_fh> should refer to mmap'able file. 452socket, and C<$in_fh> should refer to an mmap'able file.
373 453
374If the native sendfile call fails or is not implemented, it will be 454If a native sendfile cannot be found or it fails with C<ENOSYS>,
455C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
375emulated, so you can call C<aio_sendfile> on any type of filehandle 456it will be emulated, so you can call C<aio_sendfile> on any type of
376regardless of the limitations of the operating system. 457filehandle regardless of the limitations of the operating system.
377
378Please note, however, that C<aio_sendfile> can read more bytes from
379C<$in_fh> than are written, and there is no way to find out how many
380bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
381provides the number of bytes written to C<$out_fh>. Only if the result
382value equals C<$length> one can assume that C<$length> bytes have been
383read.
384 458
385 459
386=item aio_readahead $fh,$offset,$length, $callback->($retval) 460=item aio_readahead $fh,$offset,$length, $callback->($retval)
387 461
388C<aio_readahead> populates the page cache with data from a file so that 462C<aio_readahead> populates the page cache with data from a file so that
411 485
412Currently, the stats are always 64-bit-stats, i.e. instead of returning an 486Currently, the stats are always 64-bit-stats, i.e. instead of returning an
413error when stat'ing a large file, the results will be silently truncated 487error when stat'ing a large file, the results will be silently truncated
414unless perl itself is compiled with large file support. 488unless perl itself is compiled with large file support.
415 489
490To help interpret the mode and dev/rdev stat values, IO::AIO offers the
491following constants and functions (if not implemented, the constants will
492be C<0> and the functions will either C<croak> or fall back on traditional
493behaviour).
494
495C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>,
496C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>,
497C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>.
498
416Example: Print the length of F</etc/passwd>: 499Example: Print the length of F</etc/passwd>:
417 500
418 aio_stat "/etc/passwd", sub { 501 aio_stat "/etc/passwd", sub {
419 $_[0] and die "stat failed: $!"; 502 $_[0] and die "stat failed: $!";
420 print "size is ", -s _, "\n"; 503 print "size is ", -s _, "\n";
421 }; 504 };
422 505
423 506
507=item aio_statvfs $fh_or_path, $callback->($statvfs)
508
509Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
510whether a file handle or path was passed.
511
512On success, the callback is passed a hash reference with the following
513members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
514C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
515is passed.
516
517The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
518C<ST_NOSUID>.
519
520The following non-POSIX IO::AIO::ST_* flag masks are defined to
521their correct value when available, or to C<0> on systems that do
522not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
523C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
524C<ST_NODIRATIME> and C<ST_RELATIME>.
525
526Example: stat C</wd> and dump out the data if successful.
527
528 aio_statvfs "/wd", sub {
529 my $f = $_[0]
530 or die "statvfs: $!";
531
532 use Data::Dumper;
533 say Dumper $f;
534 };
535
536 # result:
537 {
538 bsize => 1024,
539 bfree => 4333064312,
540 blocks => 10253828096,
541 files => 2050765568,
542 flag => 4096,
543 favail => 2042092649,
544 bavail => 4333064312,
545 ffree => 2042092649,
546 namemax => 255,
547 frsize => 1024,
548 fsid => 1810
549 }
550
551
424=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 552=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
425 553
426Works like perl's C<utime> function (including the special case of $atime 554Works like perl's C<utime> function (including the special case of $atime
427and $mtime being undef). Fractional times are supported if the underlying 555and $mtime being undef). Fractional times are supported if the underlying
428syscalls support them. 556syscalls support them.
476 604
477The only (POSIX-) portable way of calling this function is: 605The only (POSIX-) portable way of calling this function is:
478 606
479 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... 607 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...
480 608
609See C<aio_stat> for info about some potentially helpful extra constants
610and functions.
481 611
482=item aio_link $srcpath, $dstpath, $callback->($status) 612=item aio_link $srcpath, $dstpath, $callback->($status)
483 613
484Asynchronously create a new link to the existing object at C<$srcpath> at 614Asynchronously create a new link to the existing object at C<$srcpath> at
485the path C<$dstpath> and call the callback with the result code. 615the path C<$dstpath> and call the callback with the result code.
521 651
522Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 652Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
523directory (i.e. opendir + readdir + closedir). The entries will not be 653directory (i.e. opendir + readdir + closedir). The entries will not be
524sorted, and will B<NOT> include the C<.> and C<..> entries. 654sorted, and will B<NOT> include the C<.> and C<..> entries.
525 655
526The callback a single argument which is either C<undef> or an array-ref 656The callback is passed a single argument which is either C<undef> or an
527with the filenames. 657array-ref with the filenames.
658
659
660=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
661
662Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
663behaviour and output format. In case of an error, C<$entries> will be
664C<undef>.
665
666The flags are a combination of the following constants, ORed together (the
667flags will also be passed to the callback, possibly modified):
668
669=over 4
670
671=item IO::AIO::READDIR_DENTS
672
673When this flag is off, then the callback gets an arrayref with of names
674only (as with C<aio_readdir>), otherwise it gets an arrayref with
675C<[$name, $type, $inode]> arrayrefs, each describing a single directory
676entry in more detail.
677
678C<$name> is the name of the entry.
679
680C<$type> is one of the C<IO::AIO::DT_xxx> constants:
681
682C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
683C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
684C<IO::AIO::DT_WHT>.
685
686C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
687know, you have to run stat yourself. Also, for speed reasons, the C<$type>
688scalars are read-only: you can not modify them.
689
690C<$inode> is the inode number (which might not be exact on systems with 64
691bit inode numbers and 32 bit perls). This field has unspecified content on
692systems that do not deliver the inode information.
693
694=item IO::AIO::READDIR_DIRS_FIRST
695
696When this flag is set, then the names will be returned in an order where
697likely directories come first. This is useful when you need to quickly
698find directories, or you want to find all directories while avoiding to
699stat() each entry.
700
701If the system returns type information in readdir, then this is used
702to find directories directly. Otherwise, likely directories are files
703beginning with ".", or otherwise files with no dots, of which files with
704short names are tried first.
705
706=item IO::AIO::READDIR_STAT_ORDER
707
708When this flag is set, then the names will be returned in an order
709suitable for stat()'ing each one. That is, when you plan to stat()
710all files in the given directory, then the returned order will likely
711be fastest.
712
713If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
714the likely dirs come first, resulting in a less optimal stat order.
715
716=item IO::AIO::READDIR_FOUND_UNKNOWN
717
718This flag should not be set when calling C<aio_readdirx>. Instead, it
719is being set by C<aio_readdirx>, when any of the C<$type>'s found were
720C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
721C<$type>'s are known, which can be used to speed up some algorithms.
722
723=back
528 724
529 725
530=item aio_load $path, $data, $callback->($status) 726=item aio_load $path, $data, $callback->($status)
531 727
532This is a composite request that tries to fully load the given file into 728This is a composite request that tries to fully load the given file into
533memory. Status is the same as with aio_read. 729memory. Status is the same as with aio_read.
534 730
535=cut 731=cut
536 732
537sub aio_load($$;$) { 733sub aio_load($$;$) {
538 aio_block {
539 my ($path, undef, $cb) = @_; 734 my ($path, undef, $cb) = @_;
540 my $data = \$_[1]; 735 my $data = \$_[1];
541 736
542 my $pri = aioreq_pri; 737 my $pri = aioreq_pri;
543 my $grp = aio_group $cb; 738 my $grp = aio_group $cb;
739
740 aioreq_pri $pri;
741 add $grp aio_open $path, O_RDONLY, 0, sub {
742 my $fh = shift
743 or return $grp->result (-1);
544 744
545 aioreq_pri $pri; 745 aioreq_pri $pri;
546 add $grp aio_open $path, O_RDONLY, 0, sub {
547 my $fh = shift
548 or return $grp->result (-1);
549
550 aioreq_pri $pri;
551 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub { 746 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
552 $grp->result ($_[0]); 747 $grp->result ($_[0]);
553 };
554 }; 748 };
555
556 $grp
557 } 749 };
750
751 $grp
558} 752}
559 753
560=item aio_copy $srcpath, $dstpath, $callback->($status) 754=item aio_copy $srcpath, $dstpath, $callback->($status)
561 755
562Try to copy the I<file> (directories not supported as either source or 756Try to copy the I<file> (directories not supported as either source or
563destination) from C<$srcpath> to C<$dstpath> and call the callback with 757destination) from C<$srcpath> to C<$dstpath> and call the callback with
564the C<0> (error) or C<-1> ok. 758a status of C<0> (ok) or C<-1> (error, see C<$!>).
565 759
566This is a composite request that it creates the destination file with 760This is a composite request that creates the destination file with
567mode 0200 and copies the contents of the source file into it using 761mode 0200 and copies the contents of the source file into it using
568C<aio_sendfile>, followed by restoring atime, mtime, access mode and 762C<aio_sendfile>, followed by restoring atime, mtime, access mode and
569uid/gid, in that order. 763uid/gid, in that order.
570 764
571If an error occurs, the partial destination file will be unlinked, if 765If an error occurs, the partial destination file will be unlinked, if
573errors are being ignored. 767errors are being ignored.
574 768
575=cut 769=cut
576 770
577sub aio_copy($$;$) { 771sub aio_copy($$;$) {
578 aio_block {
579 my ($src, $dst, $cb) = @_; 772 my ($src, $dst, $cb) = @_;
580 773
581 my $pri = aioreq_pri; 774 my $pri = aioreq_pri;
582 my $grp = aio_group $cb; 775 my $grp = aio_group $cb;
583 776
584 aioreq_pri $pri; 777 aioreq_pri $pri;
585 add $grp aio_open $src, O_RDONLY, 0, sub { 778 add $grp aio_open $src, O_RDONLY, 0, sub {
586 if (my $src_fh = $_[0]) { 779 if (my $src_fh = $_[0]) {
587 my @stat = stat $src_fh; 780 my @stat = stat $src_fh; # hmm, might block over nfs?
588 781
589 aioreq_pri $pri; 782 aioreq_pri $pri;
590 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub { 783 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
591 if (my $dst_fh = $_[0]) { 784 if (my $dst_fh = $_[0]) {
592 aioreq_pri $pri; 785 aioreq_pri $pri;
593 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 786 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
594 if ($_[0] == $stat[7]) { 787 if ($_[0] == $stat[7]) {
595 $grp->result (0); 788 $grp->result (0);
596 close $src_fh; 789 close $src_fh;
597 790
598 # those should not normally block. should. should.
599 utime $stat[8], $stat[9], $dst;
600 chmod $stat[2] & 07777, $dst_fh;
601 chown $stat[4], $stat[5], $dst_fh;
602 close $dst_fh;
603 } else { 791 my $ch = sub {
604 $grp->result (-1);
605 close $src_fh;
606 close $dst_fh;
607
608 aioreq $pri; 792 aioreq_pri $pri;
793 add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
794 aioreq_pri $pri;
795 add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
796 aioreq_pri $pri;
609 add $grp aio_unlink $dst; 797 add $grp aio_close $dst_fh;
798 }
799 };
610 } 800 };
801
802 aioreq_pri $pri;
803 add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
804 if ($_[0] < 0 && $! == ENOSYS) {
805 aioreq_pri $pri;
806 add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
807 } else {
808 $ch->();
809 }
810 };
811 } else {
812 $grp->result (-1);
813 close $src_fh;
814 close $dst_fh;
815
816 aioreq $pri;
817 add $grp aio_unlink $dst;
611 }; 818 }
612 } else {
613 $grp->result (-1);
614 } 819 };
820 } else {
821 $grp->result (-1);
615 }, 822 }
616
617 } else {
618 $grp->result (-1);
619 } 823 },
824
825 } else {
826 $grp->result (-1);
620 }; 827 }
621
622 $grp
623 } 828 };
829
830 $grp
624} 831}
625 832
626=item aio_move $srcpath, $dstpath, $callback->($status) 833=item aio_move $srcpath, $dstpath, $callback->($status)
627 834
628Try to move the I<file> (directories not supported as either source or 835Try to move the I<file> (directories not supported as either source or
629destination) from C<$srcpath> to C<$dstpath> and call the callback with 836destination) from C<$srcpath> to C<$dstpath> and call the callback with
630the C<0> (error) or C<-1> ok. 837a status of C<0> (ok) or C<-1> (error, see C<$!>).
631 838
632This is a composite request that tries to rename(2) the file first. If 839This is a composite request that tries to rename(2) the file first; if
633rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if 840rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
634that is successful, unlinking the C<$srcpath>. 841that is successful, unlinks the C<$srcpath>.
635 842
636=cut 843=cut
637 844
638sub aio_move($$;$) { 845sub aio_move($$;$) {
639 aio_block {
640 my ($src, $dst, $cb) = @_; 846 my ($src, $dst, $cb) = @_;
641 847
642 my $pri = aioreq_pri; 848 my $pri = aioreq_pri;
643 my $grp = aio_group $cb; 849 my $grp = aio_group $cb;
644 850
645 aioreq_pri $pri; 851 aioreq_pri $pri;
646 add $grp aio_rename $src, $dst, sub { 852 add $grp aio_rename $src, $dst, sub {
647 if ($_[0] && $! == EXDEV) { 853 if ($_[0] && $! == EXDEV) {
648 aioreq_pri $pri; 854 aioreq_pri $pri;
649 add $grp aio_copy $src, $dst, sub { 855 add $grp aio_copy $src, $dst, sub {
650 $grp->result ($_[0]);
651
652 if (!$_[0]) {
653 aioreq_pri $pri;
654 add $grp aio_unlink $src;
655 }
656 };
657 } else {
658 $grp->result ($_[0]); 856 $grp->result ($_[0]);
857
858 if (!$_[0]) {
859 aioreq_pri $pri;
860 add $grp aio_unlink $src;
861 }
659 } 862 };
863 } else {
864 $grp->result ($_[0]);
660 }; 865 }
661
662 $grp
663 } 866 };
867
868 $grp
664} 869}
665 870
666=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 871=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
667 872
668Scans a directory (similar to C<aio_readdir>) but additionally tries to 873Scans a directory (similar to C<aio_readdir>) but additionally tries to
688 893
689Implementation notes. 894Implementation notes.
690 895
691The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can. 896The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
692 897
898If readdir returns file type information, then this is used directly to
899find directories.
900
693After reading the directory, the modification time, size etc. of the 901Otherwise, after reading the directory, the modification time, size etc.
694directory before and after the readdir is checked, and if they match (and 902of the directory before and after the readdir is checked, and if they
695isn't the current time), the link count will be used to decide how many 903match (and isn't the current time), the link count will be used to decide
696entries are directories (if >= 2). Otherwise, no knowledge of the number 904how many entries are directories (if >= 2). Otherwise, no knowledge of the
697of subdirectories will be assumed. 905number of subdirectories will be assumed.
698 906
699Then entries will be sorted into likely directories (everything without 907Then entries will be sorted into likely directories a non-initial dot
700a non-initial dot currently) and likely non-directories (everything 908currently) and likely non-directories (see C<aio_readdirx>). Then every
701else). Then every entry plus an appended C</.> will be C<stat>'ed, 909entry plus an appended C</.> will be C<stat>'ed, likely directories first,
702likely directories first. If that succeeds, it assumes that the entry 910in order of their inode numbers. If that succeeds, it assumes that the
703is a directory or a symlink to directory (which will be checked 911entry is a directory or a symlink to directory (which will be checked
704seperately). This is often faster than stat'ing the entry itself because 912seperately). This is often faster than stat'ing the entry itself because
705filesystems might detect the type of the entry without reading the inode 913filesystems might detect the type of the entry without reading the inode
706data (e.g. ext2fs filetype feature). 914data (e.g. ext2fs filetype feature), even on systems that cannot return
915the filetype information on readdir.
707 916
708If the known number of directories (link count - 2) has been reached, the 917If the known number of directories (link count - 2) has been reached, the
709rest of the entries is assumed to be non-directories. 918rest of the entries is assumed to be non-directories.
710 919
711This only works with certainty on POSIX (= UNIX) filesystems, which 920This only works with certainty on POSIX (= UNIX) filesystems, which
716directory counting heuristic. 925directory counting heuristic.
717 926
718=cut 927=cut
719 928
720sub aio_scandir($$;$) { 929sub aio_scandir($$;$) {
721 aio_block {
722 my ($path, $maxreq, $cb) = @_; 930 my ($path, $maxreq, $cb) = @_;
723 931
724 my $pri = aioreq_pri; 932 my $pri = aioreq_pri;
725 933
726 my $grp = aio_group $cb; 934 my $grp = aio_group $cb;
727 935
728 $maxreq = 4 if $maxreq <= 0; 936 $maxreq = 4 if $maxreq <= 0;
729 937
730 # stat once 938 # stat once
939 aioreq_pri $pri;
940 add $grp aio_stat $path, sub {
941 return $grp->result () if $_[0];
942 my $now = time;
943 my $hash1 = join ":", (stat _)[0,1,3,7,9];
944
945 # read the directory entries
731 aioreq_pri $pri; 946 aioreq_pri $pri;
732 add $grp aio_stat $path, sub { 947 add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
948 my $entries = shift
733 return $grp->result () if $_[0]; 949 or return $grp->result ();
734 my $now = time;
735 my $hash1 = join ":", (stat _)[0,1,3,7,9];
736 950
737 # read the directory entries 951 # stat the dir another time
738 aioreq_pri $pri; 952 aioreq_pri $pri;
739 add $grp aio_readdir $path, sub {
740 my $entries = shift
741 or return $grp->result ();
742
743 # stat the dir another time
744 aioreq_pri $pri;
745 add $grp aio_stat $path, sub { 953 add $grp aio_stat $path, sub {
746 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 954 my $hash2 = join ":", (stat _)[0,1,3,7,9];
747 955
748 my $ndirs; 956 my $ndirs;
749 957
750 # take the slow route if anything looks fishy 958 # take the slow route if anything looks fishy
751 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 959 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
752 $ndirs = -1; 960 $ndirs = -1;
753 } else { 961 } else {
754 # if nlink == 2, we are finished 962 # if nlink == 2, we are finished
755 # on non-posix-fs's, we rely on nlink < 2 963 # for non-posix-fs's, we rely on nlink < 2
756 $ndirs = (stat _)[3] - 2 964 $ndirs = (stat _)[3] - 2
757 or return $grp->result ([], $entries); 965 or return $grp->result ([], $entries);
758 } 966 }
759 967
760 # sort into likely dirs and likely nondirs
761 # dirs == files without ".", short entries first
762 $entries = [map $_->[0],
763 sort { $b->[1] cmp $a->[1] }
764 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
765 @$entries];
766
767 my (@dirs, @nondirs); 968 my (@dirs, @nondirs);
768 969
769 my $statgrp = add $grp aio_group sub { 970 my $statgrp = add $grp aio_group sub {
770 $grp->result (\@dirs, \@nondirs); 971 $grp->result (\@dirs, \@nondirs);
771 }; 972 };
772 973
773 limit $statgrp $maxreq; 974 limit $statgrp $maxreq;
774 feed $statgrp sub { 975 feed $statgrp sub {
775 return unless @$entries; 976 return unless @$entries;
776 my $entry = pop @$entries; 977 my $entry = shift @$entries;
777 978
778 aioreq_pri $pri; 979 aioreq_pri $pri;
779 add $statgrp aio_stat "$path/$entry/.", sub { 980 add $statgrp aio_stat "$path/$entry/.", sub {
780 if ($_[0] < 0) { 981 if ($_[0] < 0) {
781 push @nondirs, $entry; 982 push @nondirs, $entry;
782 } else { 983 } else {
783 # need to check for real directory 984 # need to check for real directory
784 aioreq_pri $pri; 985 aioreq_pri $pri;
785 add $statgrp aio_lstat "$path/$entry", sub { 986 add $statgrp aio_lstat "$path/$entry", sub {
786 if (-d _) { 987 if (-d _) {
787 push @dirs, $entry; 988 push @dirs, $entry;
788 989
789 unless (--$ndirs) { 990 unless (--$ndirs) {
790 push @nondirs, @$entries; 991 push @nondirs, @$entries;
791 feed $statgrp; 992 feed $statgrp;
792 }
793 } else {
794 push @nondirs, $entry;
795 } 993 }
994 } else {
995 push @nondirs, $entry;
796 } 996 }
797 } 997 }
798 }; 998 }
799 }; 999 };
800 }; 1000 };
801 }; 1001 };
802 }; 1002 };
803
804 $grp
805 } 1003 };
1004
1005 $grp
806} 1006}
807 1007
808=item aio_rmtree $path, $callback->($status) 1008=item aio_rmtree $path, $callback->($status)
809 1009
810Delete a directory tree starting (and including) C<$path>, return the 1010Delete a directory tree starting (and including) C<$path>, return the
814 1014
815=cut 1015=cut
816 1016
817sub aio_rmtree; 1017sub aio_rmtree;
818sub aio_rmtree($;$) { 1018sub aio_rmtree($;$) {
819 aio_block {
820 my ($path, $cb) = @_; 1019 my ($path, $cb) = @_;
821 1020
822 my $pri = aioreq_pri; 1021 my $pri = aioreq_pri;
823 my $grp = aio_group $cb; 1022 my $grp = aio_group $cb;
824 1023
825 aioreq_pri $pri; 1024 aioreq_pri $pri;
826 add $grp aio_scandir $path, 0, sub { 1025 add $grp aio_scandir $path, 0, sub {
827 my ($dirs, $nondirs) = @_; 1026 my ($dirs, $nondirs) = @_;
828 1027
829 my $dirgrp = aio_group sub { 1028 my $dirgrp = aio_group sub {
830 add $grp aio_rmdir $path, sub { 1029 add $grp aio_rmdir $path, sub {
831 $grp->result ($_[0]); 1030 $grp->result ($_[0]);
832 };
833 }; 1031 };
834
835 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
836 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
837
838 add $grp $dirgrp;
839 }; 1032 };
840 1033
841 $grp 1034 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
1035 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
1036
1037 add $grp $dirgrp;
842 } 1038 };
1039
1040 $grp
843} 1041}
1042
1043=item aio_sync $callback->($status)
1044
1045Asynchronously call sync and call the callback when finished.
844 1046
845=item aio_fsync $fh, $callback->($status) 1047=item aio_fsync $fh, $callback->($status)
846 1048
847Asynchronously call fsync on the given filehandle and call the callback 1049Asynchronously call fsync on the given filehandle and call the callback
848with the fsync result code. 1050with the fsync result code.
852Asynchronously call fdatasync on the given filehandle and call the 1054Asynchronously call fdatasync on the given filehandle and call the
853callback with the fdatasync result code. 1055callback with the fdatasync result code.
854 1056
855If this call isn't available because your OS lacks it or it couldn't be 1057If this call isn't available because your OS lacks it or it couldn't be
856detected, it will be emulated by calling C<fsync> instead. 1058detected, it will be emulated by calling C<fsync> instead.
1059
1060=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
1061
1062Sync the data portion of the file specified by C<$offset> and C<$length>
1063to disk (but NOT the metadata), by calling the Linux-specific
1064sync_file_range call. If sync_file_range is not available or it returns
1065ENOSYS, then fdatasync or fsync is being substituted.
1066
1067C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
1068C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
1069C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
1070manpage for details.
1071
1072=item aio_pathsync $path, $callback->($status)
1073
1074This request tries to open, fsync and close the given path. This is a
1075composite request intended to sync directories after directory operations
1076(E.g. rename). This might not work on all operating systems or have any
1077specific effect, but usually it makes sure that directory changes get
1078written to disc. It works for anything that can be opened for read-only,
1079not just directories.
1080
1081Future versions of this function might fall back to other methods when
1082C<fsync> on the directory fails (such as calling C<sync>).
1083
1084Passes C<0> when everything went ok, and C<-1> on error.
1085
1086=cut
1087
1088sub aio_pathsync($;$) {
1089 my ($path, $cb) = @_;
1090
1091 my $pri = aioreq_pri;
1092 my $grp = aio_group $cb;
1093
1094 aioreq_pri $pri;
1095 add $grp aio_open $path, O_RDONLY, 0, sub {
1096 my ($fh) = @_;
1097 if ($fh) {
1098 aioreq_pri $pri;
1099 add $grp aio_fsync $fh, sub {
1100 $grp->result ($_[0]);
1101
1102 aioreq_pri $pri;
1103 add $grp aio_close $fh;
1104 };
1105 } else {
1106 $grp->result (-1);
1107 }
1108 };
1109
1110 $grp
1111}
1112
1113=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1114
1115This is a rather advanced IO::AIO call, which only works on mmap(2)ed
1116scalars (see the C<IO::AIO::mmap> function, although it also works on data
1117scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
1118scalar must only be modified in-place while an aio operation is pending on
1119it).
1120
1121It calls the C<msync> function of your OS, if available, with the memory
1122area starting at C<$offset> in the string and ending C<$length> bytes
1123later. If C<$length> is negative, counts from the end, and if C<$length>
1124is C<undef>, then it goes till the end of the string. The flags can be
1125a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
1126C<IO::AIO::MS_SYNC>.
1127
1128=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1129
1130This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1131scalars.
1132
1133It touches (reads or writes) all memory pages in the specified
1134range inside the scalar. All caveats and parameters are the same
1135as for C<aio_msync>, above, except for flags, which must be either
1136C<0> (which reads all pages and ensures they are instantiated) or
1137C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
1138writing an octet from it, which dirties the page).
1139
1140=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1141
1142This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1143scalars.
1144
1145It reads in all the pages of the underlying storage into memory (if any)
1146and locks them, so they are not getting swapped/paged out or removed.
1147
1148If C<$length> is undefined, then the scalar will be locked till the end.
1149
1150On systems that do not implement C<mlock>, this function returns C<-1>
1151and sets errno to C<ENOSYS>.
1152
1153Note that the corresponding C<munlock> is synchronous and is
1154documented under L<MISCELLANEOUS FUNCTIONS>.
1155
1156Example: open a file, mmap and mlock it - both will be undone when
1157C<$data> gets destroyed.
1158
1159 open my $fh, "<", $path or die "$path: $!";
1160 my $data;
1161 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
1162 aio_mlock $data; # mlock in background
1163
1164=item aio_mlockall $flags, $callback->($status)
1165
1166Calls the C<mlockall> function with the given C<$flags> (a combination of
1167C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).
1168
1169On systems that do not implement C<mlockall>, this function returns C<-1>
1170and sets errno to C<ENOSYS>.
1171
1172Note that the corresponding C<munlockall> is synchronous and is
1173documented under L<MISCELLANEOUS FUNCTIONS>.
1174
1175Example: asynchronously lock all current and future pages into memory.
1176
1177 aio_mlockall IO::AIO::MCL_FUTURE;
857 1178
858=item aio_group $callback->(...) 1179=item aio_group $callback->(...)
859 1180
860This is a very special aio request: Instead of doing something, it is a 1181This is a very special aio request: Instead of doing something, it is a
861container for other aio requests, which is useful if you want to bundle 1182container for other aio requests, which is useful if you want to bundle
911=item cancel $req 1232=item cancel $req
912 1233
913Cancels the request, if possible. Has the effect of skipping execution 1234Cancels the request, if possible. Has the effect of skipping execution
914when entering the B<execute> state and skipping calling the callback when 1235when entering the B<execute> state and skipping calling the callback when
915entering the the B<result> state, but will leave the request otherwise 1236entering the the B<result> state, but will leave the request otherwise
916untouched. That means that requests that currently execute will not be 1237untouched (with the exception of readdir). That means that requests that
917stopped and resources held by the request will not be freed prematurely. 1238currently execute will not be stopped and resources held by the request
1239will not be freed prematurely.
918 1240
919=item cb $req $callback->(...) 1241=item cb $req $callback->(...)
920 1242
921Replace (or simply set) the callback registered to the request. 1243Replace (or simply set) the callback registered to the request.
922 1244
973Their lifetime, simplified, looks like this: when they are empty, they 1295Their lifetime, simplified, looks like this: when they are empty, they
974will finish very quickly. If they contain only requests that are in the 1296will finish very quickly. If they contain only requests that are in the
975C<done> state, they will also finish. Otherwise they will continue to 1297C<done> state, they will also finish. Otherwise they will continue to
976exist. 1298exist.
977 1299
978That means after creating a group you have some time to add requests. And 1300That means after creating a group you have some time to add requests
979in the callbacks of those requests, you can add further requests to the 1301(precisely before the callback has been invoked, which is only done within
980group. And only when all those requests have finished will the the group 1302the C<poll_cb>). And in the callbacks of those requests, you can add
981itself finish. 1303further requests to the group. And only when all those requests have
1304finished will the the group itself finish.
982 1305
983=over 4 1306=over 4
984 1307
985=item add $grp ... 1308=item add $grp ...
986 1309
995=item $grp->cancel_subs 1318=item $grp->cancel_subs
996 1319
997Cancel all subrequests and clears any feeder, but not the group request 1320Cancel all subrequests and clears any feeder, but not the group request
998itself. Useful when you queued a lot of events but got a result early. 1321itself. Useful when you queued a lot of events but got a result early.
999 1322
1323The group request will finish normally (you cannot add requests to the
1324group).
1325
1000=item $grp->result (...) 1326=item $grp->result (...)
1001 1327
1002Set the result value(s) that will be passed to the group callback when all 1328Set the result value(s) that will be passed to the group callback when all
1003subrequests have finished and set thre groups errno to the current value 1329subrequests have finished and set the groups errno to the current value
1004of errno (just like calling C<errno> without an error number). By default, 1330of errno (just like calling C<errno> without an error number). By default,
1005no argument will be passed and errno is zero. 1331no argument will be passed and errno is zero.
1006 1332
1007=item $grp->errno ([$errno]) 1333=item $grp->errno ([$errno])
1008 1334
1019=item feed $grp $callback->($grp) 1345=item feed $grp $callback->($grp)
1020 1346
1021Sets a feeder/generator on this group: every group can have an attached 1347Sets a feeder/generator on this group: every group can have an attached
1022generator that generates requests if idle. The idea behind this is that, 1348generator that generates requests if idle. The idea behind this is that,
1023although you could just queue as many requests as you want in a group, 1349although you could just queue as many requests as you want in a group,
1024this might starve other requests for a potentially long time. For 1350this might starve other requests for a potentially long time. For example,
1025example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1351C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1026requests, delaying any later requests for a long time. 1352delaying any later requests for a long time.
1027 1353
1028To avoid this, and allow incremental generation of requests, you can 1354To avoid this, and allow incremental generation of requests, you can
1029instead a group and set a feeder on it that generates those requests. The 1355instead a group and set a feeder on it that generates those requests. The
1030feed callback will be called whenever there are few enough (see C<limit>, 1356feed callback will be called whenever there are few enough (see C<limit>,
1031below) requests active in the group itself and is expected to queue more 1357below) requests active in the group itself and is expected to queue more
1035not impose any limits). 1361not impose any limits).
1036 1362
1037If the feed does not queue more requests when called, it will be 1363If the feed does not queue more requests when called, it will be
1038automatically removed from the group. 1364automatically removed from the group.
1039 1365
1040If the feed limit is C<0>, it will be set to C<2> automatically. 1366If the feed limit is C<0> when this method is called, it will be set to
1367C<2> automatically.
1041 1368
1042Example: 1369Example:
1043 1370
1044 # stat all files in @files, but only ever use four aio requests concurrently: 1371 # stat all files in @files, but only ever use four aio requests concurrently:
1045 1372
1057Sets the feeder limit for the group: The feeder will be called whenever 1384Sets the feeder limit for the group: The feeder will be called whenever
1058the group contains less than this many requests. 1385the group contains less than this many requests.
1059 1386
1060Setting the limit to C<0> will pause the feeding process. 1387Setting the limit to C<0> will pause the feeding process.
1061 1388
1389The default value for the limit is C<0>, but note that setting a feeder
1390automatically bumps it up to C<2>.
1391
1062=back 1392=back
1063 1393
1064=head2 SUPPORT FUNCTIONS 1394=head2 SUPPORT FUNCTIONS
1065 1395
1066=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1396=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
1068=over 4 1398=over 4
1069 1399
1070=item $fileno = IO::AIO::poll_fileno 1400=item $fileno = IO::AIO::poll_fileno
1071 1401
1072Return the I<request result pipe file descriptor>. This filehandle must be 1402Return the I<request result pipe file descriptor>. This filehandle must be
1073polled for reading by some mechanism outside this module (e.g. Event or 1403polled for reading by some mechanism outside this module (e.g. EV, Glib,
1074select, see below or the SYNOPSIS). If the pipe becomes readable you have 1404select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1075to call C<poll_cb> to check the results. 1405you have to call C<poll_cb> to check the results.
1076 1406
1077See C<poll_cb> for an example. 1407See C<poll_cb> for an example.
1078 1408
1079=item IO::AIO::poll_cb 1409=item IO::AIO::poll_cb
1080 1410
1081Process some outstanding events on the result pipe. You have to call this 1411Process some outstanding events on the result pipe. You have to call this
1082regularly. Returns the number of events processed. Returns immediately 1412regularly. Returns C<0> if all events could be processed, or C<-1> if it
1413returned earlier for whatever reason. Returns immediately when no events
1083when no events are outstanding. The amount of events processed depends on 1414are outstanding. The amount of events processed depends on the settings of
1084the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>. 1415C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1085 1416
1086If not all requests were processed for whatever reason, the filehandle 1417If not all requests were processed for whatever reason, the filehandle
1087will still be ready when C<poll_cb> returns. 1418will still be ready when C<poll_cb> returns, so normally you don't have to
1419do anything special to have it called later.
1088 1420
1089Example: Install an Event watcher that automatically calls 1421Example: Install an Event watcher that automatically calls
1090IO::AIO::poll_cb with high priority: 1422IO::AIO::poll_cb with high priority (more examples can be found in the
1423SYNOPSIS section, at the top of this document):
1091 1424
1092 Event->io (fd => IO::AIO::poll_fileno, 1425 Event->io (fd => IO::AIO::poll_fileno,
1093 poll => 'r', async => 1, 1426 poll => 'r', async => 1,
1094 cb => \&IO::AIO::poll_cb); 1427 cb => \&IO::AIO::poll_cb);
1428
1429=item IO::AIO::poll_wait
1430
1431If there are any outstanding requests and none of them in the result
1432phase, wait till the result filehandle becomes ready for reading (simply
1433does a C<select> on the filehandle. This is useful if you want to
1434synchronously wait for some requests to finish).
1435
1436See C<nreqs> for an example.
1437
1438=item IO::AIO::poll
1439
1440Waits until some requests have been handled.
1441
1442Returns the number of requests processed, but is otherwise strictly
1443equivalent to:
1444
1445 IO::AIO::poll_wait, IO::AIO::poll_cb
1446
1447=item IO::AIO::flush
1448
1449Wait till all outstanding AIO requests have been handled.
1450
1451Strictly equivalent to:
1452
1453 IO::AIO::poll_wait, IO::AIO::poll_cb
1454 while IO::AIO::nreqs;
1095 1455
1096=item IO::AIO::max_poll_reqs $nreqs 1456=item IO::AIO::max_poll_reqs $nreqs
1097 1457
1098=item IO::AIO::max_poll_time $seconds 1458=item IO::AIO::max_poll_time $seconds
1099 1459
1124 # use a low priority so other tasks have priority 1484 # use a low priority so other tasks have priority
1125 Event->io (fd => IO::AIO::poll_fileno, 1485 Event->io (fd => IO::AIO::poll_fileno,
1126 poll => 'r', nice => 1, 1486 poll => 'r', nice => 1,
1127 cb => &IO::AIO::poll_cb); 1487 cb => &IO::AIO::poll_cb);
1128 1488
1129=item IO::AIO::poll_wait
1130
1131If there are any outstanding requests and none of them in the result
1132phase, wait till the result filehandle becomes ready for reading (simply
1133does a C<select> on the filehandle. This is useful if you want to
1134synchronously wait for some requests to finish).
1135
1136See C<nreqs> for an example.
1137
1138=item IO::AIO::poll
1139
1140Waits until some requests have been handled.
1141
1142Returns the number of requests processed, but is otherwise strictly
1143equivalent to:
1144
1145 IO::AIO::poll_wait, IO::AIO::poll_cb
1146
1147=item IO::AIO::flush
1148
1149Wait till all outstanding AIO requests have been handled.
1150
1151Strictly equivalent to:
1152
1153 IO::AIO::poll_wait, IO::AIO::poll_cb
1154 while IO::AIO::nreqs;
1155
1156=back 1489=back
1157 1490
1158=head3 CONTROLLING THE NUMBER OF THREADS 1491=head3 CONTROLLING THE NUMBER OF THREADS
1159 1492
1160=over 1493=over
1193 1526
1194Under normal circumstances you don't need to call this function. 1527Under normal circumstances you don't need to call this function.
1195 1528
1196=item IO::AIO::max_idle $nthreads 1529=item IO::AIO::max_idle $nthreads
1197 1530
1198Limit the number of threads (default: 4) that are allowed to idle (i.e., 1531Limit the number of threads (default: 4) that are allowed to idle
1199threads that did not get a request to process within 10 seconds). That 1532(i.e., threads that did not get a request to process within the idle
1200means if a thread becomes idle while C<$nthreads> other threads are also 1533timeout (default: 10 seconds). That means if a thread becomes idle while
1201idle, it will free its resources and exit. 1534C<$nthreads> other threads are also idle, it will free its resources and
1535exit.
1202 1536
1203This is useful when you allow a large number of threads (e.g. 100 or 1000) 1537This is useful when you allow a large number of threads (e.g. 100 or 1000)
1204to allow for extremely high load situations, but want to free resources 1538to allow for extremely high load situations, but want to free resources
1205under normal circumstances (1000 threads can easily consume 30MB of RAM). 1539under normal circumstances (1000 threads can easily consume 30MB of RAM).
1206 1540
1207The default is probably ok in most situations, especially if thread 1541The default is probably ok in most situations, especially if thread
1208creation is fast. If thread creation is very slow on your system you might 1542creation is fast. If thread creation is very slow on your system you might
1209want to use larger values. 1543want to use larger values.
1210 1544
1545=item IO::AIO::idle_timeout $seconds
1546
1547Sets the minimum idle timeout (default 10) after which worker threads are
1548allowed to exit. SEe C<IO::AIO::max_idle>.
1549
1211=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1550=item IO::AIO::max_outstanding $maxreqs
1212 1551
1213This is a very bad function to use in interactive programs because it 1552This is a very bad function to use in interactive programs because it
1214blocks, and a bad way to reduce concurrency because it is inexact: Better 1553blocks, and a bad way to reduce concurrency because it is inexact: Better
1215use an C<aio_group> together with a feed callback. 1554use an C<aio_group> together with a feed callback.
1216 1555
1221 1560
1222The default value is very large, so there is no practical limit on the 1561The default value is very large, so there is no practical limit on the
1223number of outstanding requests. 1562number of outstanding requests.
1224 1563
1225You can still queue as many requests as you want. Therefore, 1564You can still queue as many requests as you want. Therefore,
1226C<max_oustsanding> is mainly useful in simple scripts (with low values) or 1565C<max_outstanding> is mainly useful in simple scripts (with low values) or
1227as a stop gap to shield against fatal memory overflow (with large values). 1566as a stop gap to shield against fatal memory overflow (with large values).
1228 1567
1229=back 1568=back
1230 1569
1231=head3 STATISTICAL INFORMATION 1570=head3 STATISTICAL INFORMATION
1252Returns the number of requests currently in the pending state (executed, 1591Returns the number of requests currently in the pending state (executed,
1253but not yet processed by poll_cb). 1592but not yet processed by poll_cb).
1254 1593
1255=back 1594=back
1256 1595
1596=head3 MISCELLANEOUS FUNCTIONS
1597
1598IO::AIO implements some functions that might be useful, but are not
1599asynchronous.
1600
1601=over 4
1602
1603=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1604
1605Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
1606but is blocking (this makes most sense if you know the input data is
1607likely cached already and the output filehandle is set to non-blocking
1608operations).
1609
1610Returns the number of bytes copied, or C<-1> on error.
1611
1612=item IO::AIO::fadvise $fh, $offset, $len, $advice
1613
1614Simply calls the C<posix_fadvise> function (see its
1615manpage for details). The following advice constants are
1616avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1617C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1618C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1619
1620On systems that do not implement C<posix_fadvise>, this function returns
1621ENOSYS, otherwise the return value of C<posix_fadvise>.
1622
1623=item IO::AIO::madvise $scalar, $offset, $len, $advice
1624
1625Simply calls the C<posix_madvise> function (see its
1626manpage for details). The following advice constants are
1627avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
1628C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.
1629
1630On systems that do not implement C<posix_madvise>, this function returns
1631ENOSYS, otherwise the return value of C<posix_madvise>.
1632
1633=item IO::AIO::mprotect $scalar, $offset, $len, $protect
1634
1635Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
1636$scalar (see its manpage for details). The following protect
1637constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
1638C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
1639
1640On systems that do not implement C<mprotect>, this function returns
1641ENOSYS, otherwise the return value of C<mprotect>.
1642
1643=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1644
1645Memory-maps a file (or anonymous memory range) and attaches it to the
1646given C<$scalar>, which will act like a string scalar.
1647
1648The only operations allowed on the scalar are C<substr>/C<vec> that don't
1649change the string length, and most read-only operations such as copying it
1650or searching it with regexes and so on.
1651
1652Anything else is unsafe and will, at best, result in memory leaks.
1653
1654The memory map associated with the C<$scalar> is automatically removed
1655when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
1656C<IO::AIO::munmap> functions are called.
1657
1658This calls the C<mmap>(2) function internally. See your system's manual
1659page for details on the C<$length>, C<$prot> and C<$flags> parameters.
1660
1661The C<$length> must be larger than zero and smaller than the actual
1662filesize.
1663
1664C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1665C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1666
1667C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
1668C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
1669not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
1670(which is set to C<MAP_ANON> if your system only provides this
1671constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
1672C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
1673C<IO::AIO::MAP_NONBLOCK>
1674
1675If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1676
1677C<$offset> is the offset from the start of the file - it generally must be
1678a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
1679
1680Example:
1681
1682 use Digest::MD5;
1683 use IO::AIO;
1684
1685 open my $fh, "<verybigfile"
1686 or die "$!";
1687
1688 IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
1689 or die "verybigfile: $!";
1690
1691 my $fast_md5 = md5 $data;
1692
1693=item IO::AIO::munmap $scalar
1694
1695Removes a previous mmap and undefines the C<$scalar>.
1696
1697=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
1698
1699Calls the C<munlock> function, undoing the effects of a previous
1700C<aio_mlock> call (see its description for details).
1701
1702=item IO::AIO::munlockall
1703
1704Calls the C<munlockall> function.
1705
1706On systems that do not implement C<munlockall>, this function returns
1707ENOSYS, otherwise the return value of C<munlockall>.
1708
1709=back
1710
1257=cut 1711=cut
1258 1712
1259min_parallel 8; 1713min_parallel 8;
1260 1714
1261END { flush } 1715END { flush }
1262 1716
12631; 17171;
1718
1719=head1 EVENT LOOP INTEGRATION
1720
1721It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
1722automatically into many event loops:
1723
1724 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
1725 use AnyEvent::AIO;
1726
1727You can also integrate IO::AIO manually into many event loops, here are
1728some examples of how to do this:
1729
1730 # EV integration
1731 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
1732
1733 # Event integration
1734 Event->io (fd => IO::AIO::poll_fileno,
1735 poll => 'r',
1736 cb => \&IO::AIO::poll_cb);
1737
1738 # Glib/Gtk2 integration
1739 add_watch Glib::IO IO::AIO::poll_fileno,
1740 in => sub { IO::AIO::poll_cb; 1 };
1741
1742 # Tk integration
1743 Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
1744 readable => \&IO::AIO::poll_cb);
1745
1746 # Danga::Socket integration
1747 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
1748 \&IO::AIO::poll_cb);
1264 1749
1265=head2 FORK BEHAVIOUR 1750=head2 FORK BEHAVIOUR
1266 1751
1267This module should do "the right thing" when the process using it forks: 1752This module should do "the right thing" when the process using it forks:
1268 1753
1301 1786
1302Known bugs will be fixed in the next release. 1787Known bugs will be fixed in the next release.
1303 1788
1304=head1 SEE ALSO 1789=head1 SEE ALSO
1305 1790
1306L<Coro::AIO>. 1791L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1792more natural syntax.
1307 1793
1308=head1 AUTHOR 1794=head1 AUTHOR
1309 1795
1310 Marc Lehmann <schmorp@schmorp.de> 1796 Marc Lehmann <schmorp@schmorp.de>
1311 http://home.schmorp.de/ 1797 http://home.schmorp.de/

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