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Revision 1.115 by root, Mon Sep 24 18:14:00 2007 UTC vs.
Revision 1.187 by root, Fri Feb 11 00:05:17 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 = '2.41'; 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
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::max_outstanding $maxreqs
264 IO::AIO::nreqs
265 IO::AIO::nready
266 IO::AIO::npending
267
268 IO::AIO::sendfile $ofh, $ifh, $offset, $count
269 IO::AIO::fadvise $fh, $offset, $len, $advice
270 IO::AIO::madvise $scalar, $offset, $length, $advice
271 IO::AIO::mprotect $scalar, $offset, $length, $protect
272 IO::AIO::munlock $scalar, $offset = 0, $length = undef
273 IO::AIO::munlockall
214 274
215=head2 AIO REQUEST FUNCTIONS 275=head2 AIO REQUEST FUNCTIONS
216 276
217All the C<aio_*> calls are more or less thin wrappers around the syscall 277All the C<aio_*> calls are more or less thin wrappers around the syscall
218with the same name (sans C<aio_>). The arguments are similar or identical, 278with the same name (sans C<aio_>). The arguments are similar or identical,
219and they all accept an additional (and optional) C<$callback> argument 279and they all accept an additional (and optional) C<$callback> argument
220which must be a code reference. This code reference will get called with 280which must be a code reference. This code reference will get called with
221the syscall return code (e.g. most syscalls return C<-1> on error, unlike 281the syscall return code (e.g. most syscalls return C<-1> on error, unlike
222perl, which usually delivers "false") as it's sole argument when the given 282perl, which usually delivers "false") as its sole argument after the given
223syscall has been executed asynchronously. 283syscall has been executed asynchronously.
224 284
225All functions expecting a filehandle keep a copy of the filehandle 285All functions expecting a filehandle keep a copy of the filehandle
226internally until the request has finished. 286internally until the request has finished.
227 287
241your pathnames to the locale (or other) encoding in effect in the user 301your pathnames to the locale (or other) encoding in effect in the user
242environment, d) use Glib::filename_from_unicode on unicode filenames or e) 302environment, d) use Glib::filename_from_unicode on unicode filenames or e)
243use something else to ensure your scalar has the correct contents. 303use something else to ensure your scalar has the correct contents.
244 304
245This works, btw. independent of the internal UTF-8 bit, which IO::AIO 305This works, btw. independent of the internal UTF-8 bit, which IO::AIO
246handles correctly wether it is set or not. 306handles correctly whether it is set or not.
247 307
248=over 4 308=over 4
249 309
250=item $prev_pri = aioreq_pri [$pri] 310=item $prev_pri = aioreq_pri [$pri]
251 311
298by the umask in effect then the request is being executed, so better never 358by the umask in effect then the request is being executed, so better never
299change the umask. 359change the umask.
300 360
301Example: 361Example:
302 362
303 aio_open "/etc/passwd", O_RDONLY, 0, sub { 363 aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
304 if ($_[0]) { 364 if ($_[0]) {
305 print "open successful, fh is $_[0]\n"; 365 print "open successful, fh is $_[0]\n";
306 ... 366 ...
307 } else { 367 } else {
308 die "open failed: $!\n"; 368 die "open failed: $!\n";
311 371
312 372
313=item aio_close $fh, $callback->($status) 373=item aio_close $fh, $callback->($status)
314 374
315Asynchronously close a file and call the callback with the result 375Asynchronously close a file and call the callback with the result
316code. I<WARNING:> although accepted, you should not pass in a perl 376code.
317filehandle here, as perl will likely close the file descriptor another
318time when the filehandle is destroyed. Normally, you can safely call perls
319C<close> or just let filehandles go out of scope.
320 377
321This is supposed to be a bug in the API, so that might change. It's 378Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
322therefore best to avoid this function. 379closing the file descriptor associated with the filehandle itself.
323 380
381Therefore, C<aio_close> will not close the filehandle - instead it will
382use dup2 to overwrite the file descriptor with the write-end of a pipe
383(the pipe fd will be created on demand and will be cached).
384
385Or in other words: the file descriptor will be closed, but it will not be
386free for reuse until the perl filehandle is closed.
387
388=cut
324 389
325=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 390=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
326 391
327=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 392=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
328 393
329Reads or writes C<$length> bytes from the specified C<$fh> and C<$offset> 394Reads or writes C<$length> bytes from or to the specified C<$fh> and
330into the scalar given by C<$data> and offset C<$dataoffset> and calls the 395C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
331callback without the actual number of bytes read (or -1 on error, just 396and calls the callback without the actual number of bytes read (or -1 on
332like the syscall). 397error, just like the syscall).
398
399C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
400offset plus the actual number of bytes read.
333 401
334If C<$offset> is undefined, then the current file descriptor offset will 402If C<$offset> is undefined, then the current file descriptor offset will
335be used (and updated), otherwise the file descriptor offset will not be 403be used (and updated), otherwise the file descriptor offset will not be
336changed by these calls. 404changed by these calls.
337 405
338If C<$length> is undefined in C<aio_write>, use the remaining length of C<$data>. 406If C<$length> is undefined in C<aio_write>, use the remaining length of
407C<$data>.
339 408
340If C<$dataoffset> is less than zero, it will be counted from the end of 409If C<$dataoffset> is less than zero, it will be counted from the end of
341C<$data>. 410C<$data>.
342 411
343The C<$data> scalar I<MUST NOT> be modified in any way while the request 412The C<$data> scalar I<MUST NOT> be modified in any way while the request
359reading at byte offset C<$in_offset>, and starts writing at the current 428reading at byte offset C<$in_offset>, and starts writing at the current
360file offset of C<$out_fh>. Because of that, it is not safe to issue more 429file offset of C<$out_fh>. Because of that, it is not safe to issue more
361than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each 430than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
362other. 431other.
363 432
433Please note that C<aio_sendfile> can read more bytes from C<$in_fh> than
434are written, and there is no way to find out how many bytes have been read
435from C<aio_sendfile> alone, as C<aio_sendfile> only provides the number of
436bytes written to C<$out_fh>. Only if the result value equals C<$length>
437one can assume that C<$length> bytes have been read.
438
439Unlike with other C<aio_> functions, it makes a lot of sense to use
440C<aio_sendfile> on non-blocking sockets, as long as one end (typically
441the C<$in_fh>) is a file - the file I/O will then be asynchronous, while
442the socket I/O will be non-blocking. Note, however, that you can run into
443a trap where C<aio_sendfile> reads some data with readahead, then fails
444to write all data, and when the socket is ready the next time, the data
445in the cache is already lost, forcing C<aio_sendfile> to again hit the
446disk. Explicit C<aio_read> + C<aio_write> let's you control resource usage
447much better.
448
364This call tries to make use of a native C<sendfile> syscall to provide 449This call tries to make use of a native C<sendfile> syscall to provide
365zero-copy operation. For this to work, C<$out_fh> should refer to a 450zero-copy operation. For this to work, C<$out_fh> should refer to a
366socket, and C<$in_fh> should refer to mmap'able file. 451socket, and C<$in_fh> should refer to an mmap'able file.
367 452
368If the native sendfile call fails or is not implemented, it will be 453If a native sendfile cannot be found or it fails with C<ENOSYS>,
454C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
369emulated, so you can call C<aio_sendfile> on any type of filehandle 455it will be emulated, so you can call C<aio_sendfile> on any type of
370regardless of the limitations of the operating system. 456filehandle regardless of the limitations of the operating system.
371
372Please note, however, that C<aio_sendfile> can read more bytes from
373C<$in_fh> than are written, and there is no way to find out how many
374bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
375provides the number of bytes written to C<$out_fh>. Only if the result
376value equals C<$length> one can assume that C<$length> bytes have been
377read.
378 457
379 458
380=item aio_readahead $fh,$offset,$length, $callback->($retval) 459=item aio_readahead $fh,$offset,$length, $callback->($retval)
381 460
382C<aio_readahead> populates the page cache with data from a file so that 461C<aio_readahead> populates the page cache with data from a file so that
405 484
406Currently, the stats are always 64-bit-stats, i.e. instead of returning an 485Currently, the stats are always 64-bit-stats, i.e. instead of returning an
407error when stat'ing a large file, the results will be silently truncated 486error when stat'ing a large file, the results will be silently truncated
408unless perl itself is compiled with large file support. 487unless perl itself is compiled with large file support.
409 488
489To help interpret the mode and dev/rdev stat values, IO::AIO offers the
490following constants and functions (if not implemented, the constants will
491be C<0> and the functions will either C<croak> or fall back on traditional
492behaviour).
493
494C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>,
495C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>,
496C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>.
497
410Example: Print the length of F</etc/passwd>: 498Example: Print the length of F</etc/passwd>:
411 499
412 aio_stat "/etc/passwd", sub { 500 aio_stat "/etc/passwd", sub {
413 $_[0] and die "stat failed: $!"; 501 $_[0] and die "stat failed: $!";
414 print "size is ", -s _, "\n"; 502 print "size is ", -s _, "\n";
415 }; 503 };
416 504
417 505
506=item aio_statvfs $fh_or_path, $callback->($statvfs)
507
508Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
509whether a file handle or path was passed.
510
511On success, the callback is passed a hash reference with the following
512members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
513C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
514is passed.
515
516The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
517C<ST_NOSUID>.
518
519The following non-POSIX IO::AIO::ST_* flag masks are defined to
520their correct value when available, or to C<0> on systems that do
521not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
522C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
523C<ST_NODIRATIME> and C<ST_RELATIME>.
524
525Example: stat C</wd> and dump out the data if successful.
526
527 aio_statvfs "/wd", sub {
528 my $f = $_[0]
529 or die "statvfs: $!";
530
531 use Data::Dumper;
532 say Dumper $f;
533 };
534
535 # result:
536 {
537 bsize => 1024,
538 bfree => 4333064312,
539 blocks => 10253828096,
540 files => 2050765568,
541 flag => 4096,
542 favail => 2042092649,
543 bavail => 4333064312,
544 ffree => 2042092649,
545 namemax => 255,
546 frsize => 1024,
547 fsid => 1810
548 }
549
550
418=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 551=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
419 552
420Works like perl's C<utime> function (including the special case of $atime 553Works like perl's C<utime> function (including the special case of $atime
421and $mtime being undef). Fractional times are supported if the underlying 554and $mtime being undef). Fractional times are supported if the underlying
422syscalls support them. 555syscalls support them.
470 603
471The only (POSIX-) portable way of calling this function is: 604The only (POSIX-) portable way of calling this function is:
472 605
473 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... 606 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...
474 607
608See C<aio_stat> for info about some potentially helpful extra constants
609and functions.
475 610
476=item aio_link $srcpath, $dstpath, $callback->($status) 611=item aio_link $srcpath, $dstpath, $callback->($status)
477 612
478Asynchronously create a new link to the existing object at C<$srcpath> at 613Asynchronously create a new link to the existing object at C<$srcpath> at
479the path C<$dstpath> and call the callback with the result code. 614the path C<$dstpath> and call the callback with the result code.
515 650
516Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 651Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
517directory (i.e. opendir + readdir + closedir). The entries will not be 652directory (i.e. opendir + readdir + closedir). The entries will not be
518sorted, and will B<NOT> include the C<.> and C<..> entries. 653sorted, and will B<NOT> include the C<.> and C<..> entries.
519 654
520The callback a single argument which is either C<undef> or an array-ref 655The callback is passed a single argument which is either C<undef> or an
521with the filenames. 656array-ref with the filenames.
657
658
659=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
660
661Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
662behaviour and output format. In case of an error, C<$entries> will be
663C<undef>.
664
665The flags are a combination of the following constants, ORed together (the
666flags will also be passed to the callback, possibly modified):
667
668=over 4
669
670=item IO::AIO::READDIR_DENTS
671
672When this flag is off, then the callback gets an arrayref with of names
673only (as with C<aio_readdir>), otherwise it gets an arrayref with
674C<[$name, $type, $inode]> arrayrefs, each describing a single directory
675entry in more detail.
676
677C<$name> is the name of the entry.
678
679C<$type> is one of the C<IO::AIO::DT_xxx> constants:
680
681C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
682C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
683C<IO::AIO::DT_WHT>.
684
685C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
686know, you have to run stat yourself. Also, for speed reasons, the C<$type>
687scalars are read-only: you can not modify them.
688
689C<$inode> is the inode number (which might not be exact on systems with 64
690bit inode numbers and 32 bit perls). This field has unspecified content on
691systems that do not deliver the inode information.
692
693=item IO::AIO::READDIR_DIRS_FIRST
694
695When this flag is set, then the names will be returned in an order where
696likely directories come first. This is useful when you need to quickly
697find directories, or you want to find all directories while avoiding to
698stat() each entry.
699
700If the system returns type information in readdir, then this is used
701to find directories directly. Otherwise, likely directories are files
702beginning with ".", or otherwise files with no dots, of which files with
703short names are tried first.
704
705=item IO::AIO::READDIR_STAT_ORDER
706
707When this flag is set, then the names will be returned in an order
708suitable for stat()'ing each one. That is, when you plan to stat()
709all files in the given directory, then the returned order will likely
710be fastest.
711
712If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
713the likely dirs come first, resulting in a less optimal stat order.
714
715=item IO::AIO::READDIR_FOUND_UNKNOWN
716
717This flag should not be set when calling C<aio_readdirx>. Instead, it
718is being set by C<aio_readdirx>, when any of the C<$type>'s found were
719C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
720C<$type>'s are known, which can be used to speed up some algorithms.
721
722=back
522 723
523 724
524=item aio_load $path, $data, $callback->($status) 725=item aio_load $path, $data, $callback->($status)
525 726
526This is a composite request that tries to fully load the given file into 727This is a composite request that tries to fully load the given file into
527memory. Status is the same as with aio_read. 728memory. Status is the same as with aio_read.
528 729
529=cut 730=cut
530 731
531sub aio_load($$;$) { 732sub aio_load($$;$) {
532 aio_block {
533 my ($path, undef, $cb) = @_; 733 my ($path, undef, $cb) = @_;
534 my $data = \$_[1]; 734 my $data = \$_[1];
535 735
536 my $pri = aioreq_pri; 736 my $pri = aioreq_pri;
537 my $grp = aio_group $cb; 737 my $grp = aio_group $cb;
738
739 aioreq_pri $pri;
740 add $grp aio_open $path, O_RDONLY, 0, sub {
741 my $fh = shift
742 or return $grp->result (-1);
538 743
539 aioreq_pri $pri; 744 aioreq_pri $pri;
540 add $grp aio_open $path, O_RDONLY, 0, sub {
541 my $fh = shift
542 or return $grp->result (-1);
543
544 aioreq_pri $pri;
545 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub { 745 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
546 $grp->result ($_[0]); 746 $grp->result ($_[0]);
547 };
548 }; 747 };
549
550 $grp
551 } 748 };
749
750 $grp
552} 751}
553 752
554=item aio_copy $srcpath, $dstpath, $callback->($status) 753=item aio_copy $srcpath, $dstpath, $callback->($status)
555 754
556Try to copy the I<file> (directories not supported as either source or 755Try to copy the I<file> (directories not supported as either source or
557destination) from C<$srcpath> to C<$dstpath> and call the callback with 756destination) from C<$srcpath> to C<$dstpath> and call the callback with
558the C<0> (error) or C<-1> ok. 757a status of C<0> (ok) or C<-1> (error, see C<$!>).
559 758
560This is a composite request that it creates the destination file with 759This is a composite request that creates the destination file with
561mode 0200 and copies the contents of the source file into it using 760mode 0200 and copies the contents of the source file into it using
562C<aio_sendfile>, followed by restoring atime, mtime, access mode and 761C<aio_sendfile>, followed by restoring atime, mtime, access mode and
563uid/gid, in that order. 762uid/gid, in that order.
564 763
565If an error occurs, the partial destination file will be unlinked, if 764If an error occurs, the partial destination file will be unlinked, if
567errors are being ignored. 766errors are being ignored.
568 767
569=cut 768=cut
570 769
571sub aio_copy($$;$) { 770sub aio_copy($$;$) {
572 aio_block {
573 my ($src, $dst, $cb) = @_; 771 my ($src, $dst, $cb) = @_;
574 772
575 my $pri = aioreq_pri; 773 my $pri = aioreq_pri;
576 my $grp = aio_group $cb; 774 my $grp = aio_group $cb;
577 775
578 aioreq_pri $pri; 776 aioreq_pri $pri;
579 add $grp aio_open $src, O_RDONLY, 0, sub { 777 add $grp aio_open $src, O_RDONLY, 0, sub {
580 if (my $src_fh = $_[0]) { 778 if (my $src_fh = $_[0]) {
581 my @stat = stat $src_fh; 779 my @stat = stat $src_fh; # hmm, might block over nfs?
582 780
583 aioreq_pri $pri; 781 aioreq_pri $pri;
584 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub { 782 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
585 if (my $dst_fh = $_[0]) { 783 if (my $dst_fh = $_[0]) {
586 aioreq_pri $pri; 784 aioreq_pri $pri;
587 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 785 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
588 if ($_[0] == $stat[7]) { 786 if ($_[0] == $stat[7]) {
589 $grp->result (0); 787 $grp->result (0);
590 close $src_fh; 788 close $src_fh;
591 789
592 # those should not normally block. should. should.
593 utime $stat[8], $stat[9], $dst;
594 chmod $stat[2] & 07777, $dst_fh;
595 chown $stat[4], $stat[5], $dst_fh;
596 close $dst_fh;
597 } else { 790 my $ch = sub {
598 $grp->result (-1);
599 close $src_fh;
600 close $dst_fh;
601
602 aioreq $pri; 791 aioreq_pri $pri;
792 add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
793 aioreq_pri $pri;
794 add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
795 aioreq_pri $pri;
603 add $grp aio_unlink $dst; 796 add $grp aio_close $dst_fh;
797 }
798 };
604 } 799 };
800
801 aioreq_pri $pri;
802 add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
803 if ($_[0] < 0 && $! == ENOSYS) {
804 aioreq_pri $pri;
805 add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
806 } else {
807 $ch->();
808 }
809 };
810 } else {
811 $grp->result (-1);
812 close $src_fh;
813 close $dst_fh;
814
815 aioreq $pri;
816 add $grp aio_unlink $dst;
605 }; 817 }
606 } else {
607 $grp->result (-1);
608 } 818 };
819 } else {
820 $grp->result (-1);
609 }, 821 }
610
611 } else {
612 $grp->result (-1);
613 } 822 },
823
824 } else {
825 $grp->result (-1);
614 }; 826 }
615
616 $grp
617 } 827 };
828
829 $grp
618} 830}
619 831
620=item aio_move $srcpath, $dstpath, $callback->($status) 832=item aio_move $srcpath, $dstpath, $callback->($status)
621 833
622Try to move the I<file> (directories not supported as either source or 834Try to move the I<file> (directories not supported as either source or
623destination) from C<$srcpath> to C<$dstpath> and call the callback with 835destination) from C<$srcpath> to C<$dstpath> and call the callback with
624the C<0> (error) or C<-1> ok. 836a status of C<0> (ok) or C<-1> (error, see C<$!>).
625 837
626This is a composite request that tries to rename(2) the file first. If 838This is a composite request that tries to rename(2) the file first; if
627rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if 839rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
628that is successful, unlinking the C<$srcpath>. 840that is successful, unlinks the C<$srcpath>.
629 841
630=cut 842=cut
631 843
632sub aio_move($$;$) { 844sub aio_move($$;$) {
633 aio_block {
634 my ($src, $dst, $cb) = @_; 845 my ($src, $dst, $cb) = @_;
635 846
636 my $pri = aioreq_pri; 847 my $pri = aioreq_pri;
637 my $grp = aio_group $cb; 848 my $grp = aio_group $cb;
638 849
639 aioreq_pri $pri; 850 aioreq_pri $pri;
640 add $grp aio_rename $src, $dst, sub { 851 add $grp aio_rename $src, $dst, sub {
641 if ($_[0] && $! == EXDEV) { 852 if ($_[0] && $! == EXDEV) {
642 aioreq_pri $pri; 853 aioreq_pri $pri;
643 add $grp aio_copy $src, $dst, sub { 854 add $grp aio_copy $src, $dst, sub {
644 $grp->result ($_[0]);
645
646 if (!$_[0]) {
647 aioreq_pri $pri;
648 add $grp aio_unlink $src;
649 }
650 };
651 } else {
652 $grp->result ($_[0]); 855 $grp->result ($_[0]);
856
857 if (!$_[0]) {
858 aioreq_pri $pri;
859 add $grp aio_unlink $src;
860 }
653 } 861 };
862 } else {
863 $grp->result ($_[0]);
654 }; 864 }
655
656 $grp
657 } 865 };
866
867 $grp
658} 868}
659 869
660=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 870=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
661 871
662Scans a directory (similar to C<aio_readdir>) but additionally tries to 872Scans a directory (similar to C<aio_readdir>) but additionally tries to
682 892
683Implementation notes. 893Implementation notes.
684 894
685The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can. 895The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
686 896
897If readdir returns file type information, then this is used directly to
898find directories.
899
687After reading the directory, the modification time, size etc. of the 900Otherwise, after reading the directory, the modification time, size etc.
688directory before and after the readdir is checked, and if they match (and 901of the directory before and after the readdir is checked, and if they
689isn't the current time), the link count will be used to decide how many 902match (and isn't the current time), the link count will be used to decide
690entries are directories (if >= 2). Otherwise, no knowledge of the number 903how many entries are directories (if >= 2). Otherwise, no knowledge of the
691of subdirectories will be assumed. 904number of subdirectories will be assumed.
692 905
693Then entries will be sorted into likely directories (everything without 906Then entries will be sorted into likely directories a non-initial dot
694a non-initial dot currently) and likely non-directories (everything 907currently) and likely non-directories (see C<aio_readdirx>). Then every
695else). Then every entry plus an appended C</.> will be C<stat>'ed, 908entry plus an appended C</.> will be C<stat>'ed, likely directories first,
696likely directories first. If that succeeds, it assumes that the entry 909in order of their inode numbers. If that succeeds, it assumes that the
697is a directory or a symlink to directory (which will be checked 910entry is a directory or a symlink to directory (which will be checked
698seperately). This is often faster than stat'ing the entry itself because 911seperately). This is often faster than stat'ing the entry itself because
699filesystems might detect the type of the entry without reading the inode 912filesystems might detect the type of the entry without reading the inode
700data (e.g. ext2fs filetype feature). 913data (e.g. ext2fs filetype feature), even on systems that cannot return
914the filetype information on readdir.
701 915
702If the known number of directories (link count - 2) has been reached, the 916If the known number of directories (link count - 2) has been reached, the
703rest of the entries is assumed to be non-directories. 917rest of the entries is assumed to be non-directories.
704 918
705This only works with certainty on POSIX (= UNIX) filesystems, which 919This only works with certainty on POSIX (= UNIX) filesystems, which
710directory counting heuristic. 924directory counting heuristic.
711 925
712=cut 926=cut
713 927
714sub aio_scandir($$;$) { 928sub aio_scandir($$;$) {
715 aio_block {
716 my ($path, $maxreq, $cb) = @_; 929 my ($path, $maxreq, $cb) = @_;
717 930
718 my $pri = aioreq_pri; 931 my $pri = aioreq_pri;
719 932
720 my $grp = aio_group $cb; 933 my $grp = aio_group $cb;
721 934
722 $maxreq = 4 if $maxreq <= 0; 935 $maxreq = 4 if $maxreq <= 0;
723 936
724 # stat once 937 # stat once
938 aioreq_pri $pri;
939 add $grp aio_stat $path, sub {
940 return $grp->result () if $_[0];
941 my $now = time;
942 my $hash1 = join ":", (stat _)[0,1,3,7,9];
943
944 # read the directory entries
725 aioreq_pri $pri; 945 aioreq_pri $pri;
726 add $grp aio_stat $path, sub { 946 add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
947 my $entries = shift
727 return $grp->result () if $_[0]; 948 or return $grp->result ();
728 my $now = time;
729 my $hash1 = join ":", (stat _)[0,1,3,7,9];
730 949
731 # read the directory entries 950 # stat the dir another time
732 aioreq_pri $pri; 951 aioreq_pri $pri;
733 add $grp aio_readdir $path, sub {
734 my $entries = shift
735 or return $grp->result ();
736
737 # stat the dir another time
738 aioreq_pri $pri;
739 add $grp aio_stat $path, sub { 952 add $grp aio_stat $path, sub {
740 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 953 my $hash2 = join ":", (stat _)[0,1,3,7,9];
741 954
742 my $ndirs; 955 my $ndirs;
743 956
744 # take the slow route if anything looks fishy 957 # take the slow route if anything looks fishy
745 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 958 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
746 $ndirs = -1; 959 $ndirs = -1;
747 } else { 960 } else {
748 # if nlink == 2, we are finished 961 # if nlink == 2, we are finished
749 # on non-posix-fs's, we rely on nlink < 2 962 # for non-posix-fs's, we rely on nlink < 2
750 $ndirs = (stat _)[3] - 2 963 $ndirs = (stat _)[3] - 2
751 or return $grp->result ([], $entries); 964 or return $grp->result ([], $entries);
752 } 965 }
753 966
754 # sort into likely dirs and likely nondirs
755 # dirs == files without ".", short entries first
756 $entries = [map $_->[0],
757 sort { $b->[1] cmp $a->[1] }
758 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
759 @$entries];
760
761 my (@dirs, @nondirs); 967 my (@dirs, @nondirs);
762 968
763 my $statgrp = add $grp aio_group sub { 969 my $statgrp = add $grp aio_group sub {
764 $grp->result (\@dirs, \@nondirs); 970 $grp->result (\@dirs, \@nondirs);
765 }; 971 };
766 972
767 limit $statgrp $maxreq; 973 limit $statgrp $maxreq;
768 feed $statgrp sub { 974 feed $statgrp sub {
769 return unless @$entries; 975 return unless @$entries;
770 my $entry = pop @$entries; 976 my $entry = shift @$entries;
771 977
772 aioreq_pri $pri; 978 aioreq_pri $pri;
773 add $statgrp aio_stat "$path/$entry/.", sub { 979 add $statgrp aio_stat "$path/$entry/.", sub {
774 if ($_[0] < 0) { 980 if ($_[0] < 0) {
775 push @nondirs, $entry; 981 push @nondirs, $entry;
776 } else { 982 } else {
777 # need to check for real directory 983 # need to check for real directory
778 aioreq_pri $pri; 984 aioreq_pri $pri;
779 add $statgrp aio_lstat "$path/$entry", sub { 985 add $statgrp aio_lstat "$path/$entry", sub {
780 if (-d _) { 986 if (-d _) {
781 push @dirs, $entry; 987 push @dirs, $entry;
782 988
783 unless (--$ndirs) { 989 unless (--$ndirs) {
784 push @nondirs, @$entries; 990 push @nondirs, @$entries;
785 feed $statgrp; 991 feed $statgrp;
786 }
787 } else {
788 push @nondirs, $entry;
789 } 992 }
993 } else {
994 push @nondirs, $entry;
790 } 995 }
791 } 996 }
792 }; 997 }
793 }; 998 };
794 }; 999 };
795 }; 1000 };
796 }; 1001 };
797
798 $grp
799 } 1002 };
1003
1004 $grp
800} 1005}
801 1006
802=item aio_rmtree $path, $callback->($status) 1007=item aio_rmtree $path, $callback->($status)
803 1008
804Delete a directory tree starting (and including) C<$path>, return the 1009Delete a directory tree starting (and including) C<$path>, return the
808 1013
809=cut 1014=cut
810 1015
811sub aio_rmtree; 1016sub aio_rmtree;
812sub aio_rmtree($;$) { 1017sub aio_rmtree($;$) {
813 aio_block {
814 my ($path, $cb) = @_; 1018 my ($path, $cb) = @_;
815 1019
816 my $pri = aioreq_pri; 1020 my $pri = aioreq_pri;
817 my $grp = aio_group $cb; 1021 my $grp = aio_group $cb;
818 1022
819 aioreq_pri $pri; 1023 aioreq_pri $pri;
820 add $grp aio_scandir $path, 0, sub { 1024 add $grp aio_scandir $path, 0, sub {
821 my ($dirs, $nondirs) = @_; 1025 my ($dirs, $nondirs) = @_;
822 1026
823 my $dirgrp = aio_group sub { 1027 my $dirgrp = aio_group sub {
824 add $grp aio_rmdir $path, sub { 1028 add $grp aio_rmdir $path, sub {
825 $grp->result ($_[0]); 1029 $grp->result ($_[0]);
826 };
827 }; 1030 };
828
829 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
830 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
831
832 add $grp $dirgrp;
833 }; 1031 };
834 1032
835 $grp 1033 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
1034 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
1035
1036 add $grp $dirgrp;
836 } 1037 };
1038
1039 $grp
837} 1040}
1041
1042=item aio_sync $callback->($status)
1043
1044Asynchronously call sync and call the callback when finished.
838 1045
839=item aio_fsync $fh, $callback->($status) 1046=item aio_fsync $fh, $callback->($status)
840 1047
841Asynchronously call fsync on the given filehandle and call the callback 1048Asynchronously call fsync on the given filehandle and call the callback
842with the fsync result code. 1049with the fsync result code.
846Asynchronously call fdatasync on the given filehandle and call the 1053Asynchronously call fdatasync on the given filehandle and call the
847callback with the fdatasync result code. 1054callback with the fdatasync result code.
848 1055
849If this call isn't available because your OS lacks it or it couldn't be 1056If this call isn't available because your OS lacks it or it couldn't be
850detected, it will be emulated by calling C<fsync> instead. 1057detected, it will be emulated by calling C<fsync> instead.
1058
1059=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
1060
1061Sync the data portion of the file specified by C<$offset> and C<$length>
1062to disk (but NOT the metadata), by calling the Linux-specific
1063sync_file_range call. If sync_file_range is not available or it returns
1064ENOSYS, then fdatasync or fsync is being substituted.
1065
1066C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
1067C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
1068C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
1069manpage for details.
1070
1071=item aio_pathsync $path, $callback->($status)
1072
1073This request tries to open, fsync and close the given path. This is a
1074composite request intended to sync directories after directory operations
1075(E.g. rename). This might not work on all operating systems or have any
1076specific effect, but usually it makes sure that directory changes get
1077written to disc. It works for anything that can be opened for read-only,
1078not just directories.
1079
1080Future versions of this function might fall back to other methods when
1081C<fsync> on the directory fails (such as calling C<sync>).
1082
1083Passes C<0> when everything went ok, and C<-1> on error.
1084
1085=cut
1086
1087sub aio_pathsync($;$) {
1088 my ($path, $cb) = @_;
1089
1090 my $pri = aioreq_pri;
1091 my $grp = aio_group $cb;
1092
1093 aioreq_pri $pri;
1094 add $grp aio_open $path, O_RDONLY, 0, sub {
1095 my ($fh) = @_;
1096 if ($fh) {
1097 aioreq_pri $pri;
1098 add $grp aio_fsync $fh, sub {
1099 $grp->result ($_[0]);
1100
1101 aioreq_pri $pri;
1102 add $grp aio_close $fh;
1103 };
1104 } else {
1105 $grp->result (-1);
1106 }
1107 };
1108
1109 $grp
1110}
1111
1112=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1113
1114This is a rather advanced IO::AIO call, which only works on mmap(2)ed
1115scalars (see the C<IO::AIO::mmap> function, although it also works on data
1116scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
1117scalar must only be modified in-place while an aio operation is pending on
1118it).
1119
1120It calls the C<msync> function of your OS, if available, with the memory
1121area starting at C<$offset> in the string and ending C<$length> bytes
1122later. If C<$length> is negative, counts from the end, and if C<$length>
1123is C<undef>, then it goes till the end of the string. The flags can be
1124a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
1125C<IO::AIO::MS_SYNC>.
1126
1127=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1128
1129This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1130scalars.
1131
1132It touches (reads or writes) all memory pages in the specified
1133range inside the scalar. All caveats and parameters are the same
1134as for C<aio_msync>, above, except for flags, which must be either
1135C<0> (which reads all pages and ensures they are instantiated) or
1136C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
1137writing an octet from it, which dirties the page).
1138
1139=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1140
1141This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1142scalars.
1143
1144It reads in all the pages of the underlying storage into memory (if any)
1145and locks them, so they are not getting swapped/paged out or removed.
1146
1147If C<$length> is undefined, then the scalar will be locked till the end.
1148
1149On systems that do not implement C<mlock>, this function returns C<-1>
1150and sets errno to C<ENOSYS>.
1151
1152Note that the corresponding C<munlock> is synchronous and is
1153documented under L<MISCELLANEOUS FUNCTIONS>.
1154
1155Example: open a file, mmap and mlock it - both will be undone when
1156C<$data> gets destroyed.
1157
1158 open my $fh, "<", $path or die "$path: $!";
1159 my $data;
1160 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
1161 aio_mlock $data; # mlock in background
1162
1163=item aio_mlockall $flags, $callback->($status)
1164
1165Calls the C<mlockall> function with the given C<$flags> (a combination of
1166C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).
1167
1168On systems that do not implement C<mlockall>, this function returns C<-1>
1169and sets errno to C<ENOSYS>.
1170
1171Note that the corresponding C<munlockall> is synchronous and is
1172documented under L<MISCELLANEOUS FUNCTIONS>.
1173
1174Example: asynchronously lock all current and future pages into memory.
1175
1176 aio_mlockall IO::AIO::MCL_FUTURE;
851 1177
852=item aio_group $callback->(...) 1178=item aio_group $callback->(...)
853 1179
854This is a very special aio request: Instead of doing something, it is a 1180This is a very special aio request: Instead of doing something, it is a
855container for other aio requests, which is useful if you want to bundle 1181container for other aio requests, which is useful if you want to bundle
905=item cancel $req 1231=item cancel $req
906 1232
907Cancels the request, if possible. Has the effect of skipping execution 1233Cancels the request, if possible. Has the effect of skipping execution
908when entering the B<execute> state and skipping calling the callback when 1234when entering the B<execute> state and skipping calling the callback when
909entering the the B<result> state, but will leave the request otherwise 1235entering the the B<result> state, but will leave the request otherwise
910untouched. That means that requests that currently execute will not be 1236untouched (with the exception of readdir). That means that requests that
911stopped and resources held by the request will not be freed prematurely. 1237currently execute will not be stopped and resources held by the request
1238will not be freed prematurely.
912 1239
913=item cb $req $callback->(...) 1240=item cb $req $callback->(...)
914 1241
915Replace (or simply set) the callback registered to the request. 1242Replace (or simply set) the callback registered to the request.
916 1243
967Their lifetime, simplified, looks like this: when they are empty, they 1294Their lifetime, simplified, looks like this: when they are empty, they
968will finish very quickly. If they contain only requests that are in the 1295will finish very quickly. If they contain only requests that are in the
969C<done> state, they will also finish. Otherwise they will continue to 1296C<done> state, they will also finish. Otherwise they will continue to
970exist. 1297exist.
971 1298
972That means after creating a group you have some time to add requests. And 1299That means after creating a group you have some time to add requests
973in the callbacks of those requests, you can add further requests to the 1300(precisely before the callback has been invoked, which is only done within
974group. And only when all those requests have finished will the the group 1301the C<poll_cb>). And in the callbacks of those requests, you can add
975itself finish. 1302further requests to the group. And only when all those requests have
1303finished will the the group itself finish.
976 1304
977=over 4 1305=over 4
978 1306
979=item add $grp ... 1307=item add $grp ...
980 1308
989=item $grp->cancel_subs 1317=item $grp->cancel_subs
990 1318
991Cancel all subrequests and clears any feeder, but not the group request 1319Cancel all subrequests and clears any feeder, but not the group request
992itself. Useful when you queued a lot of events but got a result early. 1320itself. Useful when you queued a lot of events but got a result early.
993 1321
1322The group request will finish normally (you cannot add requests to the
1323group).
1324
994=item $grp->result (...) 1325=item $grp->result (...)
995 1326
996Set the result value(s) that will be passed to the group callback when all 1327Set the result value(s) that will be passed to the group callback when all
997subrequests have finished and set thre groups errno to the current value 1328subrequests have finished and set the groups errno to the current value
998of errno (just like calling C<errno> without an error number). By default, 1329of errno (just like calling C<errno> without an error number). By default,
999no argument will be passed and errno is zero. 1330no argument will be passed and errno is zero.
1000 1331
1001=item $grp->errno ([$errno]) 1332=item $grp->errno ([$errno])
1002 1333
1013=item feed $grp $callback->($grp) 1344=item feed $grp $callback->($grp)
1014 1345
1015Sets a feeder/generator on this group: every group can have an attached 1346Sets a feeder/generator on this group: every group can have an attached
1016generator that generates requests if idle. The idea behind this is that, 1347generator that generates requests if idle. The idea behind this is that,
1017although you could just queue as many requests as you want in a group, 1348although you could just queue as many requests as you want in a group,
1018this might starve other requests for a potentially long time. For 1349this might starve other requests for a potentially long time. For example,
1019example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1350C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1020requests, delaying any later requests for a long time. 1351delaying any later requests for a long time.
1021 1352
1022To avoid this, and allow incremental generation of requests, you can 1353To avoid this, and allow incremental generation of requests, you can
1023instead a group and set a feeder on it that generates those requests. The 1354instead a group and set a feeder on it that generates those requests. The
1024feed callback will be called whenever there are few enough (see C<limit>, 1355feed callback will be called whenever there are few enough (see C<limit>,
1025below) requests active in the group itself and is expected to queue more 1356below) requests active in the group itself and is expected to queue more
1029not impose any limits). 1360not impose any limits).
1030 1361
1031If the feed does not queue more requests when called, it will be 1362If the feed does not queue more requests when called, it will be
1032automatically removed from the group. 1363automatically removed from the group.
1033 1364
1034If the feed limit is C<0>, it will be set to C<2> automatically. 1365If the feed limit is C<0> when this method is called, it will be set to
1366C<2> automatically.
1035 1367
1036Example: 1368Example:
1037 1369
1038 # stat all files in @files, but only ever use four aio requests concurrently: 1370 # stat all files in @files, but only ever use four aio requests concurrently:
1039 1371
1051Sets the feeder limit for the group: The feeder will be called whenever 1383Sets the feeder limit for the group: The feeder will be called whenever
1052the group contains less than this many requests. 1384the group contains less than this many requests.
1053 1385
1054Setting the limit to C<0> will pause the feeding process. 1386Setting the limit to C<0> will pause the feeding process.
1055 1387
1388The default value for the limit is C<0>, but note that setting a feeder
1389automatically bumps it up to C<2>.
1390
1056=back 1391=back
1057 1392
1058=head2 SUPPORT FUNCTIONS 1393=head2 SUPPORT FUNCTIONS
1059 1394
1060=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1395=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
1062=over 4 1397=over 4
1063 1398
1064=item $fileno = IO::AIO::poll_fileno 1399=item $fileno = IO::AIO::poll_fileno
1065 1400
1066Return the I<request result pipe file descriptor>. This filehandle must be 1401Return the I<request result pipe file descriptor>. This filehandle must be
1067polled for reading by some mechanism outside this module (e.g. Event or 1402polled for reading by some mechanism outside this module (e.g. EV, Glib,
1068select, see below or the SYNOPSIS). If the pipe becomes readable you have 1403select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1069to call C<poll_cb> to check the results. 1404you have to call C<poll_cb> to check the results.
1070 1405
1071See C<poll_cb> for an example. 1406See C<poll_cb> for an example.
1072 1407
1073=item IO::AIO::poll_cb 1408=item IO::AIO::poll_cb
1074 1409
1075Process some outstanding events on the result pipe. You have to call this 1410Process some outstanding events on the result pipe. You have to call this
1076regularly. Returns the number of events processed. Returns immediately 1411regularly. Returns C<0> if all events could be processed, or C<-1> if it
1412returned earlier for whatever reason. Returns immediately when no events
1077when no events are outstanding. The amount of events processed depends on 1413are outstanding. The amount of events processed depends on the settings of
1078the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>. 1414C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1079 1415
1080If not all requests were processed for whatever reason, the filehandle 1416If not all requests were processed for whatever reason, the filehandle
1081will still be ready when C<poll_cb> returns. 1417will still be ready when C<poll_cb> returns, so normally you don't have to
1418do anything special to have it called later.
1082 1419
1083Example: Install an Event watcher that automatically calls 1420Example: Install an Event watcher that automatically calls
1084IO::AIO::poll_cb with high priority: 1421IO::AIO::poll_cb with high priority (more examples can be found in the
1422SYNOPSIS section, at the top of this document):
1085 1423
1086 Event->io (fd => IO::AIO::poll_fileno, 1424 Event->io (fd => IO::AIO::poll_fileno,
1087 poll => 'r', async => 1, 1425 poll => 'r', async => 1,
1088 cb => \&IO::AIO::poll_cb); 1426 cb => \&IO::AIO::poll_cb);
1427
1428=item IO::AIO::poll_wait
1429
1430If there are any outstanding requests and none of them in the result
1431phase, wait till the result filehandle becomes ready for reading (simply
1432does a C<select> on the filehandle. This is useful if you want to
1433synchronously wait for some requests to finish).
1434
1435See C<nreqs> for an example.
1436
1437=item IO::AIO::poll
1438
1439Waits until some requests have been handled.
1440
1441Returns the number of requests processed, but is otherwise strictly
1442equivalent to:
1443
1444 IO::AIO::poll_wait, IO::AIO::poll_cb
1445
1446=item IO::AIO::flush
1447
1448Wait till all outstanding AIO requests have been handled.
1449
1450Strictly equivalent to:
1451
1452 IO::AIO::poll_wait, IO::AIO::poll_cb
1453 while IO::AIO::nreqs;
1089 1454
1090=item IO::AIO::max_poll_reqs $nreqs 1455=item IO::AIO::max_poll_reqs $nreqs
1091 1456
1092=item IO::AIO::max_poll_time $seconds 1457=item IO::AIO::max_poll_time $seconds
1093 1458
1118 # use a low priority so other tasks have priority 1483 # use a low priority so other tasks have priority
1119 Event->io (fd => IO::AIO::poll_fileno, 1484 Event->io (fd => IO::AIO::poll_fileno,
1120 poll => 'r', nice => 1, 1485 poll => 'r', nice => 1,
1121 cb => &IO::AIO::poll_cb); 1486 cb => &IO::AIO::poll_cb);
1122 1487
1123=item IO::AIO::poll_wait
1124
1125If there are any outstanding requests and none of them in the result
1126phase, wait till the result filehandle becomes ready for reading (simply
1127does a C<select> on the filehandle. This is useful if you want to
1128synchronously wait for some requests to finish).
1129
1130See C<nreqs> for an example.
1131
1132=item IO::AIO::poll
1133
1134Waits until some requests have been handled.
1135
1136Returns the number of requests processed, but is otherwise strictly
1137equivalent to:
1138
1139 IO::AIO::poll_wait, IO::AIO::poll_cb
1140
1141=item IO::AIO::flush
1142
1143Wait till all outstanding AIO requests have been handled.
1144
1145Strictly equivalent to:
1146
1147 IO::AIO::poll_wait, IO::AIO::poll_cb
1148 while IO::AIO::nreqs;
1149
1150=back 1488=back
1151 1489
1152=head3 CONTROLLING THE NUMBER OF THREADS 1490=head3 CONTROLLING THE NUMBER OF THREADS
1153 1491
1154=over 1492=over
1200 1538
1201The default is probably ok in most situations, especially if thread 1539The default is probably ok in most situations, especially if thread
1202creation is fast. If thread creation is very slow on your system you might 1540creation is fast. If thread creation is very slow on your system you might
1203want to use larger values. 1541want to use larger values.
1204 1542
1205=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1543=item IO::AIO::max_outstanding $maxreqs
1206 1544
1207This is a very bad function to use in interactive programs because it 1545This is a very bad function to use in interactive programs because it
1208blocks, and a bad way to reduce concurrency because it is inexact: Better 1546blocks, and a bad way to reduce concurrency because it is inexact: Better
1209use an C<aio_group> together with a feed callback. 1547use an C<aio_group> together with a feed callback.
1210 1548
1215 1553
1216The default value is very large, so there is no practical limit on the 1554The default value is very large, so there is no practical limit on the
1217number of outstanding requests. 1555number of outstanding requests.
1218 1556
1219You can still queue as many requests as you want. Therefore, 1557You can still queue as many requests as you want. Therefore,
1220C<max_oustsanding> is mainly useful in simple scripts (with low values) or 1558C<max_outstanding> is mainly useful in simple scripts (with low values) or
1221as a stop gap to shield against fatal memory overflow (with large values). 1559as a stop gap to shield against fatal memory overflow (with large values).
1222 1560
1223=back 1561=back
1224 1562
1225=head3 STATISTICAL INFORMATION 1563=head3 STATISTICAL INFORMATION
1246Returns the number of requests currently in the pending state (executed, 1584Returns the number of requests currently in the pending state (executed,
1247but not yet processed by poll_cb). 1585but not yet processed by poll_cb).
1248 1586
1249=back 1587=back
1250 1588
1589=head3 MISCELLANEOUS FUNCTIONS
1590
1591IO::AIO implements some functions that might be useful, but are not
1592asynchronous.
1593
1594=over 4
1595
1596=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1597
1598Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
1599but is blocking (this makes most sense if you know the input data is
1600likely cached already and the output filehandle is set to non-blocking
1601operations).
1602
1603Returns the number of bytes copied, or C<-1> on error.
1604
1605=item IO::AIO::fadvise $fh, $offset, $len, $advice
1606
1607Simply calls the C<posix_fadvise> function (see its
1608manpage for details). The following advice constants are
1609avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1610C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1611C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1612
1613On systems that do not implement C<posix_fadvise>, this function returns
1614ENOSYS, otherwise the return value of C<posix_fadvise>.
1615
1616=item IO::AIO::madvise $scalar, $offset, $len, $advice
1617
1618Simply calls the C<posix_madvise> function (see its
1619manpage for details). The following advice constants are
1620avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
1621C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.
1622
1623On systems that do not implement C<posix_madvise>, this function returns
1624ENOSYS, otherwise the return value of C<posix_madvise>.
1625
1626=item IO::AIO::mprotect $scalar, $offset, $len, $protect
1627
1628Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
1629$scalar (see its manpage for details). The following protect
1630constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
1631C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
1632
1633On systems that do not implement C<mprotect>, this function returns
1634ENOSYS, otherwise the return value of C<mprotect>.
1635
1636=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1637
1638Memory-maps a file (or anonymous memory range) and attaches it to the
1639given C<$scalar>, which will act like a string scalar.
1640
1641The only operations allowed on the scalar are C<substr>/C<vec> that don't
1642change the string length, and most read-only operations such as copying it
1643or searching it with regexes and so on.
1644
1645Anything else is unsafe and will, at best, result in memory leaks.
1646
1647The memory map associated with the C<$scalar> is automatically removed
1648when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
1649C<IO::AIO::munmap> functions are called.
1650
1651This calls the C<mmap>(2) function internally. See your system's manual
1652page for details on the C<$length>, C<$prot> and C<$flags> parameters.
1653
1654The C<$length> must be larger than zero and smaller than the actual
1655filesize.
1656
1657C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1658C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1659
1660C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
1661C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
1662not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
1663(which is set to C<MAP_ANON> if your system only provides this
1664constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
1665C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
1666C<IO::AIO::MAP_NONBLOCK>
1667
1668If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1669
1670C<$offset> is the offset from the start of the file - it generally must be
1671a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
1672
1673Example:
1674
1675 use Digest::MD5;
1676 use IO::AIO;
1677
1678 open my $fh, "<verybigfile"
1679 or die "$!";
1680
1681 IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
1682 or die "verybigfile: $!";
1683
1684 my $fast_md5 = md5 $data;
1685
1686=item IO::AIO::munmap $scalar
1687
1688Removes a previous mmap and undefines the C<$scalar>.
1689
1690=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
1691
1692Calls the C<munlock> function, undoing the effects of a previous
1693C<aio_mlock> call (see its description for details).
1694
1695=item IO::AIO::munlockall
1696
1697Calls the C<munlockall> function.
1698
1699On systems that do not implement C<munlockall>, this function returns
1700ENOSYS, otherwise the return value of C<munlockall>.
1701
1702=back
1703
1251=cut 1704=cut
1252 1705
1253# support function to convert a fd into a perl filehandle
1254sub _fd2fh {
1255 return undef if $_[0] < 0;
1256
1257 # try to generate nice filehandles
1258 my $sym = "IO::AIO::fd#$_[0]";
1259 local *$sym;
1260
1261 open *$sym, "+<&=$_[0]" # usually works under any unix
1262 or open *$sym, "<&=$_[0]" # cygwin needs this
1263 or open *$sym, ">&=$_[0]" # or this
1264 or return undef;
1265
1266 *$sym
1267}
1268
1269min_parallel 8; 1706min_parallel 8;
1270 1707
1271END { flush } 1708END { flush }
1272 1709
12731; 17101;
1711
1712=head1 EVENT LOOP INTEGRATION
1713
1714It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
1715automatically into many event loops:
1716
1717 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
1718 use AnyEvent::AIO;
1719
1720You can also integrate IO::AIO manually into many event loops, here are
1721some examples of how to do this:
1722
1723 # EV integration
1724 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
1725
1726 # Event integration
1727 Event->io (fd => IO::AIO::poll_fileno,
1728 poll => 'r',
1729 cb => \&IO::AIO::poll_cb);
1730
1731 # Glib/Gtk2 integration
1732 add_watch Glib::IO IO::AIO::poll_fileno,
1733 in => sub { IO::AIO::poll_cb; 1 };
1734
1735 # Tk integration
1736 Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
1737 readable => \&IO::AIO::poll_cb);
1738
1739 # Danga::Socket integration
1740 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
1741 \&IO::AIO::poll_cb);
1274 1742
1275=head2 FORK BEHAVIOUR 1743=head2 FORK BEHAVIOUR
1276 1744
1277This module should do "the right thing" when the process using it forks: 1745This module should do "the right thing" when the process using it forks:
1278 1746
1311 1779
1312Known bugs will be fixed in the next release. 1780Known bugs will be fixed in the next release.
1313 1781
1314=head1 SEE ALSO 1782=head1 SEE ALSO
1315 1783
1316L<Coro::AIO>. 1784L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1785more natural syntax.
1317 1786
1318=head1 AUTHOR 1787=head1 AUTHOR
1319 1788
1320 Marc Lehmann <schmorp@schmorp.de> 1789 Marc Lehmann <schmorp@schmorp.de>
1321 http://home.schmorp.de/ 1790 http://home.schmorp.de/

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