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Revision 1.117 by root, Sat Oct 6 14:05:19 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.
185 163
186package IO::AIO; 164package IO::AIO;
187 165
188use Carp (); 166use Carp ();
189 167
190no warnings; 168use common::sense;
191use strict 'vars';
192 169
193use base 'Exporter'; 170use base 'Exporter';
194 171
195BEGIN { 172BEGIN {
196 our $VERSION = '2.51'; 173 our $VERSION = '3.72';
197 174
198 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat 175 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close
199 aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink 176 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
200 aio_readlink aio_fsync aio_fdatasync aio_readahead aio_rename aio_link 177 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
178 aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
179 aio_rename aio_link aio_move aio_copy aio_group
201 aio_move aio_copy aio_group aio_nop aio_mknod aio_load aio_rmtree aio_mkdir 180 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
202 aio_chown aio_chmod aio_utime aio_truncate); 181 aio_chmod aio_utime aio_truncate
182 aio_msync aio_mtouch aio_mlock aio_mlockall
183 aio_statvfs);
184
203 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block)); 185 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
204 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 186 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
205 min_parallel max_parallel max_idle 187 min_parallel max_parallel max_idle
206 nreqs nready npending nthreads 188 nreqs nready npending nthreads
207 max_poll_time max_poll_reqs); 189 max_poll_time max_poll_reqs
190 sendfile fadvise madvise
191 mmap munmap munlock munlockall);
192
193 push @AIO_REQ, qw(aio_busy); # not exported
208 194
209 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 195 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
210 196
211 require XSLoader; 197 require XSLoader;
212 XSLoader::load ("IO::AIO", $VERSION); 198 XSLoader::load ("IO::AIO", $VERSION);
213} 199}
214 200
215=head1 FUNCTIONS 201=head1 FUNCTIONS
202
203=head2 QUICK OVERVIEW
204
205This section simply lists the prototypes of the most important functions
206for quick reference. See the following sections for function-by-function
207documentation.
208
209 aio_open $pathname, $flags, $mode, $callback->($fh)
210 aio_close $fh, $callback->($status)
211 aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
212 aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
213 aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
214 aio_readahead $fh,$offset,$length, $callback->($retval)
215 aio_stat $fh_or_path, $callback->($status)
216 aio_lstat $fh, $callback->($status)
217 aio_statvfs $fh_or_path, $callback->($statvfs)
218 aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
219 aio_chown $fh_or_path, $uid, $gid, $callback->($status)
220 aio_truncate $fh_or_path, $offset, $callback->($status)
221 aio_chmod $fh_or_path, $mode, $callback->($status)
222 aio_unlink $pathname, $callback->($status)
223 aio_mknod $path, $mode, $dev, $callback->($status)
224 aio_link $srcpath, $dstpath, $callback->($status)
225 aio_symlink $srcpath, $dstpath, $callback->($status)
226 aio_readlink $path, $callback->($link)
227 aio_rename $srcpath, $dstpath, $callback->($status)
228 aio_mkdir $pathname, $mode, $callback->($status)
229 aio_rmdir $pathname, $callback->($status)
230 aio_readdir $pathname, $callback->($entries)
231 aio_readdirx $pathname, $flags, $callback->($entries, $flags)
232 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
233 IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN
234 aio_load $path, $data, $callback->($status)
235 aio_copy $srcpath, $dstpath, $callback->($status)
236 aio_move $srcpath, $dstpath, $callback->($status)
237 aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
238 aio_rmtree $path, $callback->($status)
239 aio_sync $callback->($status)
240 aio_fsync $fh, $callback->($status)
241 aio_fdatasync $fh, $callback->($status)
242 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
243 aio_pathsync $path, $callback->($status)
244 aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
245 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
246 aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
247 aio_mlockall $flags, $callback->($status)
248 aio_group $callback->(...)
249 aio_nop $callback->()
250
251 $prev_pri = aioreq_pri [$pri]
252 aioreq_nice $pri_adjust
253
254 IO::AIO::poll_wait
255 IO::AIO::poll_cb
256 IO::AIO::poll
257 IO::AIO::flush
258 IO::AIO::max_poll_reqs $nreqs
259 IO::AIO::max_poll_time $seconds
260 IO::AIO::min_parallel $nthreads
261 IO::AIO::max_parallel $nthreads
262 IO::AIO::max_idle $nthreads
263 IO::AIO::max_outstanding $maxreqs
264 IO::AIO::nreqs
265 IO::AIO::nready
266 IO::AIO::npending
267
268 IO::AIO::sendfile $ofh, $ifh, $offset, $count
269 IO::AIO::fadvise $fh, $offset, $len, $advice
270 IO::AIO::madvise $scalar, $offset, $length, $advice
271 IO::AIO::mprotect $scalar, $offset, $length, $protect
272 IO::AIO::munlock $scalar, $offset = 0, $length = undef
273 IO::AIO::munlockall
216 274
217=head2 AIO REQUEST FUNCTIONS 275=head2 AIO REQUEST FUNCTIONS
218 276
219All the C<aio_*> calls are more or less thin wrappers around the syscall 277All the C<aio_*> calls are more or less thin wrappers around the syscall
220with the same name (sans C<aio_>). The arguments are similar or identical, 278with the same name (sans C<aio_>). The arguments are similar or identical,
221and they all accept an additional (and optional) C<$callback> argument 279and they all accept an additional (and optional) C<$callback> argument
222which 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
223the 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
224perl, which usually delivers "false") as it's sole argument when the given 282perl, which usually delivers "false") as its sole argument after the given
225syscall has been executed asynchronously. 283syscall has been executed asynchronously.
226 284
227All functions expecting a filehandle keep a copy of the filehandle 285All functions expecting a filehandle keep a copy of the filehandle
228internally until the request has finished. 286internally until the request has finished.
229 287
243your 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
244environment, d) use Glib::filename_from_unicode on unicode filenames or e) 302environment, d) use Glib::filename_from_unicode on unicode filenames or e)
245use something else to ensure your scalar has the correct contents. 303use something else to ensure your scalar has the correct contents.
246 304
247This 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
248handles correctly wether it is set or not. 306handles correctly whether it is set or not.
249 307
250=over 4 308=over 4
251 309
252=item $prev_pri = aioreq_pri [$pri] 310=item $prev_pri = aioreq_pri [$pri]
253 311
300by 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
301change the umask. 359change the umask.
302 360
303Example: 361Example:
304 362
305 aio_open "/etc/passwd", O_RDONLY, 0, sub { 363 aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
306 if ($_[0]) { 364 if ($_[0]) {
307 print "open successful, fh is $_[0]\n"; 365 print "open successful, fh is $_[0]\n";
308 ... 366 ...
309 } else { 367 } else {
310 die "open failed: $!\n"; 368 die "open failed: $!\n";
316 374
317Asynchronously close a file and call the callback with the result 375Asynchronously close a file and call the callback with the result
318code. 376code.
319 377
320Unfortunately, you can't do this to perl. Perl I<insists> very strongly on 378Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
321closing the file descriptor associated with the filehandle itself. Here is 379closing the file descriptor associated with the filehandle itself.
322what aio_close will try:
323 380
324 1. dup()licate the fd 381Therefore, C<aio_close> will not close the filehandle - instead it will
325 2. asynchronously close() the duplicated fd 382use dup2 to overwrite the file descriptor with the write-end of a pipe
326 3. dup()licate the fd once more 383(the pipe fd will be created on demand and will be cached).
327 4. let perl close() the filehandle
328 5. asynchronously close the duplicated fd
329 384
330The idea is that the first close() flushes stuff to disk that closing an 385Or in other words: the file descriptor will be closed, but it will not be
331fd will flush, so when perl closes the fd, nothing much will need to be 386free for reuse until the perl filehandle is closed.
332flushed. The second async. close() will then flush stuff to disk that
333closing the last fd to the file will flush.
334
335Just FYI, SuSv3 has this to say on close:
336
337 All outstanding record locks owned by the process on the file
338 associated with the file descriptor shall be removed.
339
340 If fildes refers to a socket, close() shall cause the socket to be
341 destroyed. ... close() shall block for up to the current linger
342 interval until all data is transmitted.
343 [this actually sounds like a specification bug, but who knows]
344
345And at least Linux additionally actually flushes stuff on every close,
346even when the file itself is still open.
347
348Sounds enourmously inefficient and complicated? Yes... please show me how
349to nuke perl's fd out of existence...
350 387
351=cut 388=cut
352 389
353sub aio_close($;$) {
354 aio_block {
355 my ($fh, $cb) = @_;
356
357 my $pri = aioreq_pri;
358 my $grp = aio_group $cb;
359
360 my $fd = fileno $fh;
361
362 defined $fd or Carp::croak "aio_close called with fd-less filehandle";
363
364 # if the dups fail we will simply get EBADF
365 my $fd2 = _dup $fd;
366 aioreq_pri $pri;
367 add $grp _aio_close $fd2, sub {
368 my $fd2 = _dup $fd;
369 close $fh;
370 aioreq_pri $pri;
371 add $grp _aio_close $fd2, sub {
372 $grp->result ($_[0]);
373 };
374 };
375
376 $grp
377 }
378}
379
380
381=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 390=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
382 391
383=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 392=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
384 393
385Reads 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<$fh> and
386into the scalar given by C<$data> and offset C<$dataoffset> and calls the 395C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
387callback 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
388like the syscall). 397error, just like the syscall).
398
399C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
400offset plus the actual number of bytes read.
389 401
390If C<$offset> is undefined, then the current file descriptor offset will 402If C<$offset> is undefined, then the current file descriptor offset will
391be used (and updated), otherwise the file descriptor offset will not be 403be used (and updated), otherwise the file descriptor offset will not be
392changed by these calls. 404changed by these calls.
393 405
394If C<$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<$data>.
395 408
396If C<$dataoffset> is less than zero, it will be counted from the end of 409If C<$dataoffset> is less than zero, it will be counted from the end of
397C<$data>. 410C<$data>.
398 411
399The C<$data> scalar I<MUST NOT> be modified in any way while the request 412The C<$data> scalar I<MUST NOT> be modified in any way while the request
415reading at byte offset C<$in_offset>, and starts writing at the current 428reading at byte offset C<$in_offset>, and starts writing at the current
416file offset of C<$out_fh>. Because of that, it is not safe to issue more 429file offset of C<$out_fh>. Because of that, it is not safe to issue more
417than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each 430than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
418other. 431other.
419 432
433Please note that C<aio_sendfile> can read more bytes from C<$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
420This 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
421zero-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
422socket, and C<$in_fh> should refer to mmap'able file. 451socket, and C<$in_fh> should refer to an mmap'able file.
423 452
424If 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>,
425emulated, 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
426regardless of the limitations of the operating system. 456filehandle regardless of the limitations of the operating system.
427
428Please note, however, that C<aio_sendfile> can read more bytes from
429C<$in_fh> than are written, and there is no way to find out how many
430bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
431provides the number of bytes written to C<$out_fh>. Only if the result
432value equals C<$length> one can assume that C<$length> bytes have been
433read.
434 457
435 458
436=item aio_readahead $fh,$offset,$length, $callback->($retval) 459=item aio_readahead $fh,$offset,$length, $callback->($retval)
437 460
438C<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
461 484
462Currently, 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
463error 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
464unless perl itself is compiled with large file support. 487unless perl itself is compiled with large file support.
465 488
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
466Example: Print the length of F</etc/passwd>: 498Example: Print the length of F</etc/passwd>:
467 499
468 aio_stat "/etc/passwd", sub { 500 aio_stat "/etc/passwd", sub {
469 $_[0] and die "stat failed: $!"; 501 $_[0] and die "stat failed: $!";
470 print "size is ", -s _, "\n"; 502 print "size is ", -s _, "\n";
471 }; 503 };
472 504
473 505
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
474=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 551=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
475 552
476Works 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
477and $mtime being undef). Fractional times are supported if the underlying 554and $mtime being undef). Fractional times are supported if the underlying
478syscalls support them. 555syscalls support them.
526 603
527The only (POSIX-) portable way of calling this function is: 604The only (POSIX-) portable way of calling this function is:
528 605
529 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... 606 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...
530 607
608See C<aio_stat> for info about some potentially helpful extra constants
609and functions.
531 610
532=item aio_link $srcpath, $dstpath, $callback->($status) 611=item aio_link $srcpath, $dstpath, $callback->($status)
533 612
534Asynchronously 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
535the path C<$dstpath> and call the callback with the result code. 614the path C<$dstpath> and call the callback with the result code.
571 650
572Unlike 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
573directory (i.e. opendir + readdir + closedir). The entries will not be 652directory (i.e. opendir + readdir + closedir). The entries will not be
574sorted, and will B<NOT> include the C<.> and C<..> entries. 653sorted, and will B<NOT> include the C<.> and C<..> entries.
575 654
576The 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
577with 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
578 723
579 724
580=item aio_load $path, $data, $callback->($status) 725=item aio_load $path, $data, $callback->($status)
581 726
582This 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
583memory. Status is the same as with aio_read. 728memory. Status is the same as with aio_read.
584 729
585=cut 730=cut
586 731
587sub aio_load($$;$) { 732sub aio_load($$;$) {
588 aio_block {
589 my ($path, undef, $cb) = @_; 733 my ($path, undef, $cb) = @_;
590 my $data = \$_[1]; 734 my $data = \$_[1];
591 735
592 my $pri = aioreq_pri; 736 my $pri = aioreq_pri;
593 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);
594 743
595 aioreq_pri $pri; 744 aioreq_pri $pri;
596 add $grp aio_open $path, O_RDONLY, 0, sub {
597 my $fh = shift
598 or return $grp->result (-1);
599
600 aioreq_pri $pri;
601 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub { 745 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
602 $grp->result ($_[0]); 746 $grp->result ($_[0]);
603 };
604 }; 747 };
605
606 $grp
607 } 748 };
749
750 $grp
608} 751}
609 752
610=item aio_copy $srcpath, $dstpath, $callback->($status) 753=item aio_copy $srcpath, $dstpath, $callback->($status)
611 754
612Try 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
613destination) from C<$srcpath> to C<$dstpath> and call the callback with 756destination) from C<$srcpath> to C<$dstpath> and call the callback with
614the C<0> (error) or C<-1> ok. 757a status of C<0> (ok) or C<-1> (error, see C<$!>).
615 758
616This is a composite request that it creates the destination file with 759This is a composite request that creates the destination file with
617mode 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
618C<aio_sendfile>, followed by restoring atime, mtime, access mode and 761C<aio_sendfile>, followed by restoring atime, mtime, access mode and
619uid/gid, in that order. 762uid/gid, in that order.
620 763
621If an error occurs, the partial destination file will be unlinked, if 764If an error occurs, the partial destination file will be unlinked, if
623errors are being ignored. 766errors are being ignored.
624 767
625=cut 768=cut
626 769
627sub aio_copy($$;$) { 770sub aio_copy($$;$) {
628 aio_block {
629 my ($src, $dst, $cb) = @_; 771 my ($src, $dst, $cb) = @_;
630 772
631 my $pri = aioreq_pri; 773 my $pri = aioreq_pri;
632 my $grp = aio_group $cb; 774 my $grp = aio_group $cb;
633 775
634 aioreq_pri $pri; 776 aioreq_pri $pri;
635 add $grp aio_open $src, O_RDONLY, 0, sub { 777 add $grp aio_open $src, O_RDONLY, 0, sub {
636 if (my $src_fh = $_[0]) { 778 if (my $src_fh = $_[0]) {
637 my @stat = stat $src_fh; 779 my @stat = stat $src_fh; # hmm, might block over nfs?
638 780
639 aioreq_pri $pri; 781 aioreq_pri $pri;
640 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 {
641 if (my $dst_fh = $_[0]) { 783 if (my $dst_fh = $_[0]) {
642 aioreq_pri $pri; 784 aioreq_pri $pri;
643 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 785 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
644 if ($_[0] == $stat[7]) { 786 if ($_[0] == $stat[7]) {
645 $grp->result (0); 787 $grp->result (0);
646 close $src_fh; 788 close $src_fh;
647 789
648 # those should not normally block. should. should.
649 utime $stat[8], $stat[9], $dst;
650 chmod $stat[2] & 07777, $dst_fh;
651 chown $stat[4], $stat[5], $dst_fh;
652 close $dst_fh;
653 } else { 790 my $ch = sub {
654 $grp->result (-1);
655 close $src_fh;
656 close $dst_fh;
657
658 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;
659 add $grp aio_unlink $dst; 796 add $grp aio_close $dst_fh;
797 }
798 };
660 } 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;
661 }; 817 }
662 } else {
663 $grp->result (-1);
664 } 818 };
819 } else {
820 $grp->result (-1);
665 }, 821 }
666
667 } else {
668 $grp->result (-1);
669 } 822 },
823
824 } else {
825 $grp->result (-1);
670 }; 826 }
671
672 $grp
673 } 827 };
828
829 $grp
674} 830}
675 831
676=item aio_move $srcpath, $dstpath, $callback->($status) 832=item aio_move $srcpath, $dstpath, $callback->($status)
677 833
678Try 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
679destination) from C<$srcpath> to C<$dstpath> and call the callback with 835destination) from C<$srcpath> to C<$dstpath> and call the callback with
680the C<0> (error) or C<-1> ok. 836a status of C<0> (ok) or C<-1> (error, see C<$!>).
681 837
682This is a composite request that tries to rename(2) the file first. If 838This is a composite request that tries to rename(2) the file first; if
683rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if 839rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
684that is successful, unlinking the C<$srcpath>. 840that is successful, unlinks the C<$srcpath>.
685 841
686=cut 842=cut
687 843
688sub aio_move($$;$) { 844sub aio_move($$;$) {
689 aio_block {
690 my ($src, $dst, $cb) = @_; 845 my ($src, $dst, $cb) = @_;
691 846
692 my $pri = aioreq_pri; 847 my $pri = aioreq_pri;
693 my $grp = aio_group $cb; 848 my $grp = aio_group $cb;
694 849
695 aioreq_pri $pri; 850 aioreq_pri $pri;
696 add $grp aio_rename $src, $dst, sub { 851 add $grp aio_rename $src, $dst, sub {
697 if ($_[0] && $! == EXDEV) { 852 if ($_[0] && $! == EXDEV) {
698 aioreq_pri $pri; 853 aioreq_pri $pri;
699 add $grp aio_copy $src, $dst, sub { 854 add $grp aio_copy $src, $dst, sub {
700 $grp->result ($_[0]);
701
702 if (!$_[0]) {
703 aioreq_pri $pri;
704 add $grp aio_unlink $src;
705 }
706 };
707 } else {
708 $grp->result ($_[0]); 855 $grp->result ($_[0]);
856
857 if (!$_[0]) {
858 aioreq_pri $pri;
859 add $grp aio_unlink $src;
860 }
709 } 861 };
862 } else {
863 $grp->result ($_[0]);
710 }; 864 }
711
712 $grp
713 } 865 };
866
867 $grp
714} 868}
715 869
716=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 870=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
717 871
718Scans a directory (similar to C<aio_readdir>) but additionally tries to 872Scans a directory (similar to C<aio_readdir>) but additionally tries to
738 892
739Implementation notes. 893Implementation notes.
740 894
741The 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.
742 896
897If readdir returns file type information, then this is used directly to
898find directories.
899
743After reading the directory, the modification time, size etc. of the 900Otherwise, after reading the directory, the modification time, size etc.
744directory 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
745isn'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
746entries are directories (if >= 2). Otherwise, no knowledge of the number 903how many entries are directories (if >= 2). Otherwise, no knowledge of the
747of subdirectories will be assumed. 904number of subdirectories will be assumed.
748 905
749Then entries will be sorted into likely directories (everything without 906Then entries will be sorted into likely directories a non-initial dot
750a non-initial dot currently) and likely non-directories (everything 907currently) and likely non-directories (see C<aio_readdirx>). Then every
751else). 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,
752likely directories first. If that succeeds, it assumes that the entry 909in order of their inode numbers. If that succeeds, it assumes that the
753is a directory or a symlink to directory (which will be checked 910entry is a directory or a symlink to directory (which will be checked
754seperately). This is often faster than stat'ing the entry itself because 911seperately). This is often faster than stat'ing the entry itself because
755filesystems might detect the type of the entry without reading the inode 912filesystems might detect the type of the entry without reading the inode
756data (e.g. ext2fs filetype feature). 913data (e.g. ext2fs filetype feature), even on systems that cannot return
914the filetype information on readdir.
757 915
758If 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
759rest of the entries is assumed to be non-directories. 917rest of the entries is assumed to be non-directories.
760 918
761This only works with certainty on POSIX (= UNIX) filesystems, which 919This only works with certainty on POSIX (= UNIX) filesystems, which
766directory counting heuristic. 924directory counting heuristic.
767 925
768=cut 926=cut
769 927
770sub aio_scandir($$;$) { 928sub aio_scandir($$;$) {
771 aio_block {
772 my ($path, $maxreq, $cb) = @_; 929 my ($path, $maxreq, $cb) = @_;
773 930
774 my $pri = aioreq_pri; 931 my $pri = aioreq_pri;
775 932
776 my $grp = aio_group $cb; 933 my $grp = aio_group $cb;
777 934
778 $maxreq = 4 if $maxreq <= 0; 935 $maxreq = 4 if $maxreq <= 0;
779 936
780 # 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
781 aioreq_pri $pri; 945 aioreq_pri $pri;
782 add $grp aio_stat $path, sub { 946 add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
947 my $entries = shift
783 return $grp->result () if $_[0]; 948 or return $grp->result ();
784 my $now = time;
785 my $hash1 = join ":", (stat _)[0,1,3,7,9];
786 949
787 # read the directory entries 950 # stat the dir another time
788 aioreq_pri $pri; 951 aioreq_pri $pri;
789 add $grp aio_readdir $path, sub {
790 my $entries = shift
791 or return $grp->result ();
792
793 # stat the dir another time
794 aioreq_pri $pri;
795 add $grp aio_stat $path, sub { 952 add $grp aio_stat $path, sub {
796 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 953 my $hash2 = join ":", (stat _)[0,1,3,7,9];
797 954
798 my $ndirs; 955 my $ndirs;
799 956
800 # take the slow route if anything looks fishy 957 # take the slow route if anything looks fishy
801 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 958 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
802 $ndirs = -1; 959 $ndirs = -1;
803 } else { 960 } else {
804 # if nlink == 2, we are finished 961 # if nlink == 2, we are finished
805 # on non-posix-fs's, we rely on nlink < 2 962 # for non-posix-fs's, we rely on nlink < 2
806 $ndirs = (stat _)[3] - 2 963 $ndirs = (stat _)[3] - 2
807 or return $grp->result ([], $entries); 964 or return $grp->result ([], $entries);
808 } 965 }
809 966
810 # sort into likely dirs and likely nondirs
811 # dirs == files without ".", short entries first
812 $entries = [map $_->[0],
813 sort { $b->[1] cmp $a->[1] }
814 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
815 @$entries];
816
817 my (@dirs, @nondirs); 967 my (@dirs, @nondirs);
818 968
819 my $statgrp = add $grp aio_group sub { 969 my $statgrp = add $grp aio_group sub {
820 $grp->result (\@dirs, \@nondirs); 970 $grp->result (\@dirs, \@nondirs);
821 }; 971 };
822 972
823 limit $statgrp $maxreq; 973 limit $statgrp $maxreq;
824 feed $statgrp sub { 974 feed $statgrp sub {
825 return unless @$entries; 975 return unless @$entries;
826 my $entry = pop @$entries; 976 my $entry = shift @$entries;
827 977
828 aioreq_pri $pri; 978 aioreq_pri $pri;
829 add $statgrp aio_stat "$path/$entry/.", sub { 979 add $statgrp aio_stat "$path/$entry/.", sub {
830 if ($_[0] < 0) { 980 if ($_[0] < 0) {
831 push @nondirs, $entry; 981 push @nondirs, $entry;
832 } else { 982 } else {
833 # need to check for real directory 983 # need to check for real directory
834 aioreq_pri $pri; 984 aioreq_pri $pri;
835 add $statgrp aio_lstat "$path/$entry", sub { 985 add $statgrp aio_lstat "$path/$entry", sub {
836 if (-d _) { 986 if (-d _) {
837 push @dirs, $entry; 987 push @dirs, $entry;
838 988
839 unless (--$ndirs) { 989 unless (--$ndirs) {
840 push @nondirs, @$entries; 990 push @nondirs, @$entries;
841 feed $statgrp; 991 feed $statgrp;
842 }
843 } else {
844 push @nondirs, $entry;
845 } 992 }
993 } else {
994 push @nondirs, $entry;
846 } 995 }
847 } 996 }
848 }; 997 }
849 }; 998 };
850 }; 999 };
851 }; 1000 };
852 }; 1001 };
853
854 $grp
855 } 1002 };
1003
1004 $grp
856} 1005}
857 1006
858=item aio_rmtree $path, $callback->($status) 1007=item aio_rmtree $path, $callback->($status)
859 1008
860Delete a directory tree starting (and including) C<$path>, return the 1009Delete a directory tree starting (and including) C<$path>, return the
864 1013
865=cut 1014=cut
866 1015
867sub aio_rmtree; 1016sub aio_rmtree;
868sub aio_rmtree($;$) { 1017sub aio_rmtree($;$) {
869 aio_block {
870 my ($path, $cb) = @_; 1018 my ($path, $cb) = @_;
871 1019
872 my $pri = aioreq_pri; 1020 my $pri = aioreq_pri;
873 my $grp = aio_group $cb; 1021 my $grp = aio_group $cb;
874 1022
875 aioreq_pri $pri; 1023 aioreq_pri $pri;
876 add $grp aio_scandir $path, 0, sub { 1024 add $grp aio_scandir $path, 0, sub {
877 my ($dirs, $nondirs) = @_; 1025 my ($dirs, $nondirs) = @_;
878 1026
879 my $dirgrp = aio_group sub { 1027 my $dirgrp = aio_group sub {
880 add $grp aio_rmdir $path, sub { 1028 add $grp aio_rmdir $path, sub {
881 $grp->result ($_[0]); 1029 $grp->result ($_[0]);
882 };
883 }; 1030 };
884
885 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
886 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
887
888 add $grp $dirgrp;
889 }; 1031 };
890 1032
891 $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;
892 } 1037 };
1038
1039 $grp
893} 1040}
1041
1042=item aio_sync $callback->($status)
1043
1044Asynchronously call sync and call the callback when finished.
894 1045
895=item aio_fsync $fh, $callback->($status) 1046=item aio_fsync $fh, $callback->($status)
896 1047
897Asynchronously call fsync on the given filehandle and call the callback 1048Asynchronously call fsync on the given filehandle and call the callback
898with the fsync result code. 1049with the fsync result code.
902Asynchronously call fdatasync on the given filehandle and call the 1053Asynchronously call fdatasync on the given filehandle and call the
903callback with the fdatasync result code. 1054callback with the fdatasync result code.
904 1055
905If 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
906detected, 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;
907 1177
908=item aio_group $callback->(...) 1178=item aio_group $callback->(...)
909 1179
910This 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
911container 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
961=item cancel $req 1231=item cancel $req
962 1232
963Cancels the request, if possible. Has the effect of skipping execution 1233Cancels the request, if possible. Has the effect of skipping execution
964when entering the B<execute> state and skipping calling the callback when 1234when entering the B<execute> state and skipping calling the callback when
965entering the the B<result> state, but will leave the request otherwise 1235entering the the B<result> state, but will leave the request otherwise
966untouched. That means that requests that currently execute will not be 1236untouched (with the exception of readdir). That means that requests that
967stopped 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.
968 1239
969=item cb $req $callback->(...) 1240=item cb $req $callback->(...)
970 1241
971Replace (or simply set) the callback registered to the request. 1242Replace (or simply set) the callback registered to the request.
972 1243
1023Their lifetime, simplified, looks like this: when they are empty, they 1294Their lifetime, simplified, looks like this: when they are empty, they
1024will 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
1025C<done> state, they will also finish. Otherwise they will continue to 1296C<done> state, they will also finish. Otherwise they will continue to
1026exist. 1297exist.
1027 1298
1028That 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
1029in 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
1030group. 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
1031itself finish. 1302further requests to the group. And only when all those requests have
1303finished will the the group itself finish.
1032 1304
1033=over 4 1305=over 4
1034 1306
1035=item add $grp ... 1307=item add $grp ...
1036 1308
1045=item $grp->cancel_subs 1317=item $grp->cancel_subs
1046 1318
1047Cancel all subrequests and clears any feeder, but not the group request 1319Cancel all subrequests and clears any feeder, but not the group request
1048itself. Useful when you queued a lot of events but got a result early. 1320itself. Useful when you queued a lot of events but got a result early.
1049 1321
1322The group request will finish normally (you cannot add requests to the
1323group).
1324
1050=item $grp->result (...) 1325=item $grp->result (...)
1051 1326
1052Set 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
1053subrequests have finished and set thre groups errno to the current value 1328subrequests have finished and set the groups errno to the current value
1054of 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,
1055no argument will be passed and errno is zero. 1330no argument will be passed and errno is zero.
1056 1331
1057=item $grp->errno ([$errno]) 1332=item $grp->errno ([$errno])
1058 1333
1069=item feed $grp $callback->($grp) 1344=item feed $grp $callback->($grp)
1070 1345
1071Sets 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
1072generator that generates requests if idle. The idea behind this is that, 1347generator that generates requests if idle. The idea behind this is that,
1073although you could just queue as many requests as you want in a group, 1348although you could just queue as many requests as you want in a group,
1074this might starve other requests for a potentially long time. For 1349this might starve other requests for a potentially long time. For example,
1075example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1350C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1076requests, delaying any later requests for a long time. 1351delaying any later requests for a long time.
1077 1352
1078To avoid this, and allow incremental generation of requests, you can 1353To avoid this, and allow incremental generation of requests, you can
1079instead 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
1080feed 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>,
1081below) 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
1085not impose any limits). 1360not impose any limits).
1086 1361
1087If 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
1088automatically removed from the group. 1363automatically removed from the group.
1089 1364
1090If 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.
1091 1367
1092Example: 1368Example:
1093 1369
1094 # 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:
1095 1371
1107Sets 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
1108the group contains less than this many requests. 1384the group contains less than this many requests.
1109 1385
1110Setting the limit to C<0> will pause the feeding process. 1386Setting the limit to C<0> will pause the feeding process.
1111 1387
1388The default value for the limit is C<0>, but note that setting a feeder
1389automatically bumps it up to C<2>.
1390
1112=back 1391=back
1113 1392
1114=head2 SUPPORT FUNCTIONS 1393=head2 SUPPORT FUNCTIONS
1115 1394
1116=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1395=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
1118=over 4 1397=over 4
1119 1398
1120=item $fileno = IO::AIO::poll_fileno 1399=item $fileno = IO::AIO::poll_fileno
1121 1400
1122Return the I<request result pipe file descriptor>. This filehandle must be 1401Return the I<request result pipe file descriptor>. This filehandle must be
1123polled 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,
1124select, 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
1125to call C<poll_cb> to check the results. 1404you have to call C<poll_cb> to check the results.
1126 1405
1127See C<poll_cb> for an example. 1406See C<poll_cb> for an example.
1128 1407
1129=item IO::AIO::poll_cb 1408=item IO::AIO::poll_cb
1130 1409
1131Process 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
1132regularly. 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
1133when no events are outstanding. The amount of events processed depends on 1413are outstanding. The amount of events processed depends on the settings of
1134the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>. 1414C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1135 1415
1136If not all requests were processed for whatever reason, the filehandle 1416If not all requests were processed for whatever reason, the filehandle
1137will 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.
1138 1419
1139Example: Install an Event watcher that automatically calls 1420Example: Install an Event watcher that automatically calls
1140IO::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):
1141 1423
1142 Event->io (fd => IO::AIO::poll_fileno, 1424 Event->io (fd => IO::AIO::poll_fileno,
1143 poll => 'r', async => 1, 1425 poll => 'r', async => 1,
1144 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;
1145 1454
1146=item IO::AIO::max_poll_reqs $nreqs 1455=item IO::AIO::max_poll_reqs $nreqs
1147 1456
1148=item IO::AIO::max_poll_time $seconds 1457=item IO::AIO::max_poll_time $seconds
1149 1458
1174 # use a low priority so other tasks have priority 1483 # use a low priority so other tasks have priority
1175 Event->io (fd => IO::AIO::poll_fileno, 1484 Event->io (fd => IO::AIO::poll_fileno,
1176 poll => 'r', nice => 1, 1485 poll => 'r', nice => 1,
1177 cb => &IO::AIO::poll_cb); 1486 cb => &IO::AIO::poll_cb);
1178 1487
1179=item IO::AIO::poll_wait
1180
1181If there are any outstanding requests and none of them in the result
1182phase, wait till the result filehandle becomes ready for reading (simply
1183does a C<select> on the filehandle. This is useful if you want to
1184synchronously wait for some requests to finish).
1185
1186See C<nreqs> for an example.
1187
1188=item IO::AIO::poll
1189
1190Waits until some requests have been handled.
1191
1192Returns the number of requests processed, but is otherwise strictly
1193equivalent to:
1194
1195 IO::AIO::poll_wait, IO::AIO::poll_cb
1196
1197=item IO::AIO::flush
1198
1199Wait till all outstanding AIO requests have been handled.
1200
1201Strictly equivalent to:
1202
1203 IO::AIO::poll_wait, IO::AIO::poll_cb
1204 while IO::AIO::nreqs;
1205
1206=back 1488=back
1207 1489
1208=head3 CONTROLLING THE NUMBER OF THREADS 1490=head3 CONTROLLING THE NUMBER OF THREADS
1209 1491
1210=over 1492=over
1256 1538
1257The default is probably ok in most situations, especially if thread 1539The default is probably ok in most situations, especially if thread
1258creation 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
1259want to use larger values. 1541want to use larger values.
1260 1542
1261=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1543=item IO::AIO::max_outstanding $maxreqs
1262 1544
1263This 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
1264blocks, 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
1265use an C<aio_group> together with a feed callback. 1547use an C<aio_group> together with a feed callback.
1266 1548
1271 1553
1272The 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
1273number of outstanding requests. 1555number of outstanding requests.
1274 1556
1275You can still queue as many requests as you want. Therefore, 1557You can still queue as many requests as you want. Therefore,
1276C<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
1277as 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).
1278 1560
1279=back 1561=back
1280 1562
1281=head3 STATISTICAL INFORMATION 1563=head3 STATISTICAL INFORMATION
1302Returns the number of requests currently in the pending state (executed, 1584Returns the number of requests currently in the pending state (executed,
1303but not yet processed by poll_cb). 1585but not yet processed by poll_cb).
1304 1586
1305=back 1587=back
1306 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
1307=cut 1704=cut
1308 1705
1309min_parallel 8; 1706min_parallel 8;
1310 1707
1311END { flush } 1708END { flush }
1312 1709
13131; 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);
1314 1742
1315=head2 FORK BEHAVIOUR 1743=head2 FORK BEHAVIOUR
1316 1744
1317This 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:
1318 1746
1351 1779
1352Known bugs will be fixed in the next release. 1780Known bugs will be fixed in the next release.
1353 1781
1354=head1 SEE ALSO 1782=head1 SEE ALSO
1355 1783
1356L<Coro::AIO>. 1784L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1785more natural syntax.
1357 1786
1358=head1 AUTHOR 1787=head1 AUTHOR
1359 1788
1360 Marc Lehmann <schmorp@schmorp.de> 1789 Marc Lehmann <schmorp@schmorp.de>
1361 http://home.schmorp.de/ 1790 http://home.schmorp.de/

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