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Revision 1.96 by root, Fri Dec 22 04:05:50 2006 UTC vs.
Revision 1.175 by root, Sun Jan 10 20:37:33 2010 UTC

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
62etc.), but can also be used to easily do operations in parallel that are 42etc.), but can also be used to easily do operations in parallel that are
63normally done sequentially, e.g. stat'ing many files, which is much faster 43normally done sequentially, e.g. stat'ing many files, which is much faster
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 example 47While most of this works on all types of file descriptors (for
68sockets), using these functions on file descriptors that support 48example sockets), using these functions on file descriptors that
69nonblocking operation (again, sockets, pipes etc.) is very inefficient or 49support nonblocking operation (again, sockets, pipes etc.) is
70might not work (aio_read fails on sockets/pipes/fifos). Use an event loop 50very inefficient. Use an event loop for that (such as the L<EV>
71for that (such as the L<Event|Event> module): IO::AIO will naturally fit 51module): IO::AIO will naturally fit into such an event loop itself.
72into such an event loop itself.
73 52
74In this version, a number of threads are started that execute your 53In this version, a number of threads are started that execute your
75requests and signal their completion. You don't need thread support 54requests and signal their completion. You don't need thread support
76in 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
77to perl. In the future, this module might make use of the native aio 56to perl. In the future, this module might make use of the native aio
79not well-supported or restricted (GNU/Linux doesn't allow them on normal 58not well-supported or restricted (GNU/Linux doesn't allow them on normal
80files currently, for example), and they would only support aio_read and 59files currently, for example), and they would only support aio_read and
81aio_write, so the remaining functionality would have to be implemented 60aio_write, so the remaining functionality would have to be implemented
82using threads anyway. 61using threads anyway.
83 62
84Although the module will work with in the presence of other (Perl-) 63Although the module will work in the presence of other (Perl-) threads,
85threads, it is currently not reentrant in any way, so use appropriate 64it is currently not reentrant in any way, so use appropriate locking
86locking yourself, always call C<poll_cb> from within the same thread, or 65yourself, always call C<poll_cb> from within the same thread, or never
87never call C<poll_cb> (or other C<aio_> functions) recursively. 66call C<poll_cb> (or other C<aio_> functions) recursively.
88 67
89=head2 EXAMPLE 68=head2 EXAMPLE
90 69
91This is a simple example that uses the Event module and loads 70This is a simple example that uses the EV module and loads
92F</etc/passwd> asynchronously: 71F</etc/passwd> asynchronously:
93 72
94 use Fcntl; 73 use Fcntl;
95 use Event; 74 use EV;
96 use IO::AIO; 75 use IO::AIO;
97 76
98 # register the IO::AIO callback with Event 77 # register the IO::AIO callback with EV
99 Event->io (fd => IO::AIO::poll_fileno, 78 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
100 poll => 'r',
101 cb => \&IO::AIO::poll_cb);
102 79
103 # queue the request to open /etc/passwd 80 # queue the request to open /etc/passwd
104 aio_open "/etc/passwd", O_RDONLY, 0, sub { 81 aio_open "/etc/passwd", O_RDONLY, 0, sub {
105 my $fh = shift 82 my $fh = shift
106 or die "error while opening: $!"; 83 or die "error while opening: $!";
118 95
119 # file contents now in $contents 96 # file contents now in $contents
120 print $contents; 97 print $contents;
121 98
122 # exit event loop and program 99 # exit event loop and program
123 Event::unloop; 100 EV::unloop;
124 }; 101 };
125 }; 102 };
126 103
127 # possibly queue up other requests, or open GUI windows, 104 # possibly queue up other requests, or open GUI windows,
128 # check for sockets etc. etc. 105 # check for sockets etc. etc.
129 106
130 # process events as long as there are some: 107 # process events as long as there are some:
131 Event::loop; 108 EV::loop;
132 109
133=head1 REQUEST ANATOMY AND LIFETIME 110=head1 REQUEST ANATOMY AND LIFETIME
134 111
135Every 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
136directly visible to Perl. 113directly visible to Perl.
184 161
185=cut 162=cut
186 163
187package IO::AIO; 164package IO::AIO;
188 165
189no warnings; 166use Carp ();
190use strict 'vars'; 167
168use common::sense;
191 169
192use base 'Exporter'; 170use base 'Exporter';
193 171
194BEGIN { 172BEGIN {
195 our $VERSION = '2.21'; 173 our $VERSION = '3.5';
196 174
197 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
198 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
199 aio_readlink aio_fsync aio_fdatasync aio_readahead aio_rename aio_link 177 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
200 aio_move aio_copy aio_group aio_nop aio_mknod); 178 aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
179 aio_rename aio_link aio_move aio_copy aio_group
180 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
181 aio_chmod aio_utime aio_truncate
182 aio_msync aio_mtouch aio_statvfs);
183
201 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block)); 184 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
202 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 185 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
203 min_parallel max_parallel max_idle 186 min_parallel max_parallel max_idle
204 nreqs nready npending nthreads 187 nreqs nready npending nthreads
205 max_poll_time max_poll_reqs); 188 max_poll_time max_poll_reqs
189 sendfile fadvise);
190
191 push @AIO_REQ, qw(aio_busy); # not exported
206 192
207 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 193 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
208 194
209 require XSLoader; 195 require XSLoader;
210 XSLoader::load ("IO::AIO", $VERSION); 196 XSLoader::load ("IO::AIO", $VERSION);
211} 197}
212 198
213=head1 FUNCTIONS 199=head1 FUNCTIONS
200
201=head2 QUICK OVERVIEW
202
203This section simply lists the prototypes of the most important functions
204for quick reference. See the following sections for function-by-function
205documentation.
206
207 aio_open $pathname, $flags, $mode, $callback->($fh)
208 aio_close $fh, $callback->($status)
209 aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
210 aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
211 aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
212 aio_readahead $fh,$offset,$length, $callback->($retval)
213 aio_stat $fh_or_path, $callback->($status)
214 aio_lstat $fh, $callback->($status)
215 aio_statvfs $fh_or_path, $callback->($statvfs)
216 aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
217 aio_chown $fh_or_path, $uid, $gid, $callback->($status)
218 aio_truncate $fh_or_path, $offset, $callback->($status)
219 aio_chmod $fh_or_path, $mode, $callback->($status)
220 aio_unlink $pathname, $callback->($status)
221 aio_mknod $path, $mode, $dev, $callback->($status)
222 aio_link $srcpath, $dstpath, $callback->($status)
223 aio_symlink $srcpath, $dstpath, $callback->($status)
224 aio_readlink $path, $callback->($link)
225 aio_rename $srcpath, $dstpath, $callback->($status)
226 aio_mkdir $pathname, $mode, $callback->($status)
227 aio_rmdir $pathname, $callback->($status)
228 aio_readdir $pathname, $callback->($entries)
229 aio_readdirx $pathname, $flags, $callback->($entries, $flags)
230 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
231 IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN
232 aio_load $path, $data, $callback->($status)
233 aio_copy $srcpath, $dstpath, $callback->($status)
234 aio_move $srcpath, $dstpath, $callback->($status)
235 aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
236 aio_rmtree $path, $callback->($status)
237 aio_sync $callback->($status)
238 aio_fsync $fh, $callback->($status)
239 aio_fdatasync $fh, $callback->($status)
240 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
241 aio_pathsync $path, $callback->($status)
242 aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
243 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
244 aio_group $callback->(...)
245 aio_nop $callback->()
246
247 $prev_pri = aioreq_pri [$pri]
248 aioreq_nice $pri_adjust
249
250 IO::AIO::poll_wait
251 IO::AIO::poll_cb
252 IO::AIO::poll
253 IO::AIO::flush
254 IO::AIO::max_poll_reqs $nreqs
255 IO::AIO::max_poll_time $seconds
256 IO::AIO::min_parallel $nthreads
257 IO::AIO::max_parallel $nthreads
258 IO::AIO::max_idle $nthreads
259 IO::AIO::max_outstanding $maxreqs
260 IO::AIO::nreqs
261 IO::AIO::nready
262 IO::AIO::npending
263
264 IO::AIO::sendfile $ofh, $ifh, $offset, $count
265 IO::AIO::fadvise $fh, $offset, $len, $advice
266 IO::AIO::mlockall $flags
267 IO::AIO::munlockall
214 268
215=head2 AIO REQUEST FUNCTIONS 269=head2 AIO REQUEST FUNCTIONS
216 270
217All the C<aio_*> calls are more or less thin wrappers around the syscall 271All the C<aio_*> calls are more or less thin wrappers around the syscall
218with the same name (sans C<aio_>). The arguments are similar or identical, 272with the same name (sans C<aio_>). The arguments are similar or identical,
219and they all accept an additional (and optional) C<$callback> argument 273and they all accept an additional (and optional) C<$callback> argument
220which must be a code reference. This code reference will get called with 274which 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 275the 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 276perl, which usually delivers "false") as its sole argument after the given
223syscall has been executed asynchronously. 277syscall has been executed asynchronously.
224 278
225All functions expecting a filehandle keep a copy of the filehandle 279All functions expecting a filehandle keep a copy of the filehandle
226internally until the request has finished. 280internally until the request has finished.
227 281
241your pathnames to the locale (or other) encoding in effect in the user 295your pathnames to the locale (or other) encoding in effect in the user
242environment, d) use Glib::filename_from_unicode on unicode filenames or e) 296environment, d) use Glib::filename_from_unicode on unicode filenames or e)
243use something else to ensure your scalar has the correct contents. 297use something else to ensure your scalar has the correct contents.
244 298
245This works, btw. independent of the internal UTF-8 bit, which IO::AIO 299This works, btw. independent of the internal UTF-8 bit, which IO::AIO
246handles correctly wether it is set or not. 300handles correctly whether it is set or not.
247 301
248=over 4 302=over 4
249 303
250=item $prev_pri = aioreq_pri [$pri] 304=item $prev_pri = aioreq_pri [$pri]
251 305
271 aio_read $_[0], ..., sub { 325 aio_read $_[0], ..., sub {
272 ... 326 ...
273 }; 327 };
274 }; 328 };
275 329
330
276=item aioreq_nice $pri_adjust 331=item aioreq_nice $pri_adjust
277 332
278Similar to C<aioreq_pri>, but subtracts the given value from the current 333Similar to C<aioreq_pri>, but subtracts the given value from the current
279priority, so the effect is cumulative. 334priority, so the effect is cumulative.
335
280 336
281=item aio_open $pathname, $flags, $mode, $callback->($fh) 337=item aio_open $pathname, $flags, $mode, $callback->($fh)
282 338
283Asynchronously open or create a file and call the callback with a newly 339Asynchronously open or create a file and call the callback with a newly
284created filehandle for the file. 340created filehandle for the file.
290list. They are the same as used by C<sysopen>. 346list. They are the same as used by C<sysopen>.
291 347
292Likewise, C<$mode> specifies the mode of the newly created file, if it 348Likewise, C<$mode> specifies the mode of the newly created file, if it
293didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>, 349didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>,
294except that it is mandatory (i.e. use C<0> if you don't create new files, 350except that it is mandatory (i.e. use C<0> if you don't create new files,
295and C<0666> or C<0777> if you do). 351and C<0666> or C<0777> if you do). Note that the C<$mode> will be modified
352by the umask in effect then the request is being executed, so better never
353change the umask.
296 354
297Example: 355Example:
298 356
299 aio_open "/etc/passwd", O_RDONLY, 0, sub { 357 aio_open "/etc/passwd", O_RDONLY, 0, sub {
300 if ($_[0]) { 358 if ($_[0]) {
303 } else { 361 } else {
304 die "open failed: $!\n"; 362 die "open failed: $!\n";
305 } 363 }
306 }; 364 };
307 365
366
308=item aio_close $fh, $callback->($status) 367=item aio_close $fh, $callback->($status)
309 368
310Asynchronously close a file and call the callback with the result 369Asynchronously close a file and call the callback with the result
311code. I<WARNING:> although accepted, you should not pass in a perl 370code.
312filehandle here, as perl will likely close the file descriptor another
313time when the filehandle is destroyed. Normally, you can safely call perls
314C<close> or just let filehandles go out of scope.
315 371
316This is supposed to be a bug in the API, so that might change. It's 372Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
317therefore best to avoid this function. 373closing the file descriptor associated with the filehandle itself.
374
375Therefore, C<aio_close> will not close the filehandle - instead it will
376use dup2 to overwrite the file descriptor with the write-end of a pipe
377(the pipe fd will be created on demand and will be cached).
378
379Or in other words: the file descriptor will be closed, but it will not be
380free for reuse until the perl filehandle is closed.
381
382=cut
318 383
319=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 384=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
320 385
321=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 386=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
322 387
323Reads or writes C<length> bytes from the specified C<fh> and C<offset> 388Reads or writes C<$length> bytes from or to the specified C<$fh> and
324into the scalar given by C<data> and offset C<dataoffset> and calls the 389C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
325callback without the actual number of bytes read (or -1 on error, just 390and calls the callback without the actual number of bytes read (or -1 on
326like the syscall). 391error, just like the syscall).
392
393C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
394offset plus the actual number of bytes read.
395
396If C<$offset> is undefined, then the current file descriptor offset will
397be used (and updated), otherwise the file descriptor offset will not be
398changed by these calls.
399
400If C<$length> is undefined in C<aio_write>, use the remaining length of
401C<$data>.
402
403If C<$dataoffset> is less than zero, it will be counted from the end of
404C<$data>.
327 405
328The C<$data> scalar I<MUST NOT> be modified in any way while the request 406The C<$data> scalar I<MUST NOT> be modified in any way while the request
329is outstanding. Modifying it can result in segfaults or WW3 (if the 407is outstanding. Modifying it can result in segfaults or World War III (if
330necessary/optional hardware is installed). 408the necessary/optional hardware is installed).
331 409
332Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at 410Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
333offset C<0> within the scalar: 411offset C<0> within the scalar:
334 412
335 aio_read $fh, 7, 15, $buffer, 0, sub { 413 aio_read $fh, 7, 15, $buffer, 0, sub {
336 $_[0] > 0 or die "read error: $!"; 414 $_[0] > 0 or die "read error: $!";
337 print "read $_[0] bytes: <$buffer>\n"; 415 print "read $_[0] bytes: <$buffer>\n";
338 }; 416 };
417
339 418
340=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) 419=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
341 420
342Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts 421Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
343reading at byte offset C<$in_offset>, and starts writing at the current 422reading at byte offset C<$in_offset>, and starts writing at the current
347 426
348This call tries to make use of a native C<sendfile> syscall to provide 427This call tries to make use of a native C<sendfile> syscall to provide
349zero-copy operation. For this to work, C<$out_fh> should refer to a 428zero-copy operation. For this to work, C<$out_fh> should refer to a
350socket, and C<$in_fh> should refer to mmap'able file. 429socket, and C<$in_fh> should refer to mmap'able file.
351 430
352If the native sendfile call fails or is not implemented, it will be 431If a native sendfile cannot be found or it fails with C<ENOSYS>,
432C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
353emulated, so you can call C<aio_sendfile> on any type of filehandle 433it will be emulated, so you can call C<aio_sendfile> on any type of
354regardless of the limitations of the operating system. 434filehandle regardless of the limitations of the operating system.
355 435
356Please note, however, that C<aio_sendfile> can read more bytes from 436Please note, however, that C<aio_sendfile> can read more bytes from
357C<$in_fh> than are written, and there is no way to find out how many 437C<$in_fh> than are written, and there is no way to find out how many
358bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only 438bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
359provides the number of bytes written to C<$out_fh>. Only if the result 439provides the number of bytes written to C<$out_fh>. Only if the result
360value equals C<$length> one can assume that C<$length> bytes have been 440value equals C<$length> one can assume that C<$length> bytes have been
361read. 441read.
442
362 443
363=item aio_readahead $fh,$offset,$length, $callback->($retval) 444=item aio_readahead $fh,$offset,$length, $callback->($retval)
364 445
365C<aio_readahead> populates the page cache with data from a file so that 446C<aio_readahead> populates the page cache with data from a file so that
366subsequent reads from that file will not block on disk I/O. The C<$offset> 447subsequent reads from that file will not block on disk I/O. The C<$offset>
372file. The current file offset of the file is left unchanged. 453file. The current file offset of the file is left unchanged.
373 454
374If that syscall doesn't exist (likely if your OS isn't Linux) it will be 455If that syscall doesn't exist (likely if your OS isn't Linux) it will be
375emulated by simply reading the data, which would have a similar effect. 456emulated by simply reading the data, which would have a similar effect.
376 457
458
377=item aio_stat $fh_or_path, $callback->($status) 459=item aio_stat $fh_or_path, $callback->($status)
378 460
379=item aio_lstat $fh, $callback->($status) 461=item aio_lstat $fh, $callback->($status)
380 462
381Works like perl's C<stat> or C<lstat> in void context. The callback will 463Works like perl's C<stat> or C<lstat> in void context. The callback will
394 aio_stat "/etc/passwd", sub { 476 aio_stat "/etc/passwd", sub {
395 $_[0] and die "stat failed: $!"; 477 $_[0] and die "stat failed: $!";
396 print "size is ", -s _, "\n"; 478 print "size is ", -s _, "\n";
397 }; 479 };
398 480
481
482=item aio_statvfs $fh_or_path, $callback->($statvfs)
483
484Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
485whether a file handle or path was passed.
486
487On success, the callback is passed a hash reference with the following
488members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
489C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
490is passed.
491
492The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
493C<ST_NOSUID>.
494
495The following non-POSIX IO::AIO::ST_* flag masks are defined to
496their correct value when available, or to C<0> on systems that do
497not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
498C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
499C<ST_NODIRATIME> and C<ST_RELATIME>.
500
501Example: stat C</wd> and dump out the data if successful.
502
503 aio_statvfs "/wd", sub {
504 my $f = $_[0]
505 or die "statvfs: $!";
506
507 use Data::Dumper;
508 say Dumper $f;
509 };
510
511 # result:
512 {
513 bsize => 1024,
514 bfree => 4333064312,
515 blocks => 10253828096,
516 files => 2050765568,
517 flag => 4096,
518 favail => 2042092649,
519 bavail => 4333064312,
520 ffree => 2042092649,
521 namemax => 255,
522 frsize => 1024,
523 fsid => 1810
524 }
525
526
527=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
528
529Works like perl's C<utime> function (including the special case of $atime
530and $mtime being undef). Fractional times are supported if the underlying
531syscalls support them.
532
533When called with a pathname, uses utimes(2) if available, otherwise
534utime(2). If called on a file descriptor, uses futimes(2) if available,
535otherwise returns ENOSYS, so this is not portable.
536
537Examples:
538
539 # set atime and mtime to current time (basically touch(1)):
540 aio_utime "path", undef, undef;
541 # set atime to current time and mtime to beginning of the epoch:
542 aio_utime "path", time, undef; # undef==0
543
544
545=item aio_chown $fh_or_path, $uid, $gid, $callback->($status)
546
547Works like perl's C<chown> function, except that C<undef> for either $uid
548or $gid is being interpreted as "do not change" (but -1 can also be used).
549
550Examples:
551
552 # same as "chown root path" in the shell:
553 aio_chown "path", 0, -1;
554 # same as above:
555 aio_chown "path", 0, undef;
556
557
558=item aio_truncate $fh_or_path, $offset, $callback->($status)
559
560Works like truncate(2) or ftruncate(2).
561
562
563=item aio_chmod $fh_or_path, $mode, $callback->($status)
564
565Works like perl's C<chmod> function.
566
567
399=item aio_unlink $pathname, $callback->($status) 568=item aio_unlink $pathname, $callback->($status)
400 569
401Asynchronously unlink (delete) a file and call the callback with the 570Asynchronously unlink (delete) a file and call the callback with the
402result code. 571result code.
403 572
573
404=item aio_mknod $path, $mode, $dev, $callback->($status) 574=item aio_mknod $path, $mode, $dev, $callback->($status)
405 575
406[EXPERIMENTAL] 576[EXPERIMENTAL]
407 577
408Asynchronously create a device node (or fifo). See mknod(2). 578Asynchronously create a device node (or fifo). See mknod(2).
409 579
410The only (POSIX-) portable way of calling this function is: 580The only (POSIX-) portable way of calling this function is:
411 581
412 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... 582 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...
583
413 584
414=item aio_link $srcpath, $dstpath, $callback->($status) 585=item aio_link $srcpath, $dstpath, $callback->($status)
415 586
416Asynchronously create a new link to the existing object at C<$srcpath> at 587Asynchronously create a new link to the existing object at C<$srcpath> at
417the path C<$dstpath> and call the callback with the result code. 588the path C<$dstpath> and call the callback with the result code.
418 589
590
419=item aio_symlink $srcpath, $dstpath, $callback->($status) 591=item aio_symlink $srcpath, $dstpath, $callback->($status)
420 592
421Asynchronously create a new symbolic link to the existing object at C<$srcpath> at 593Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
422the path C<$dstpath> and call the callback with the result code. 594the path C<$dstpath> and call the callback with the result code.
595
423 596
424=item aio_readlink $path, $callback->($link) 597=item aio_readlink $path, $callback->($link)
425 598
426Asynchronously read the symlink specified by C<$path> and pass it to 599Asynchronously read the symlink specified by C<$path> and pass it to
427the callback. If an error occurs, nothing or undef gets passed to the 600the callback. If an error occurs, nothing or undef gets passed to the
428callback. 601callback.
429 602
603
430=item aio_rename $srcpath, $dstpath, $callback->($status) 604=item aio_rename $srcpath, $dstpath, $callback->($status)
431 605
432Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as 606Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
433rename(2) and call the callback with the result code. 607rename(2) and call the callback with the result code.
434 608
609
610=item aio_mkdir $pathname, $mode, $callback->($status)
611
612Asynchronously mkdir (create) a directory and call the callback with
613the result code. C<$mode> will be modified by the umask at the time the
614request is executed, so do not change your umask.
615
616
435=item aio_rmdir $pathname, $callback->($status) 617=item aio_rmdir $pathname, $callback->($status)
436 618
437Asynchronously rmdir (delete) a directory and call the callback with the 619Asynchronously rmdir (delete) a directory and call the callback with the
438result code. 620result code.
621
439 622
440=item aio_readdir $pathname, $callback->($entries) 623=item aio_readdir $pathname, $callback->($entries)
441 624
442Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 625Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
443directory (i.e. opendir + readdir + closedir). The entries will not be 626directory (i.e. opendir + readdir + closedir). The entries will not be
444sorted, and will B<NOT> include the C<.> and C<..> entries. 627sorted, and will B<NOT> include the C<.> and C<..> entries.
445 628
446The callback a single argument which is either C<undef> or an array-ref 629The callback is passed a single argument which is either C<undef> or an
447with the filenames. 630array-ref with the filenames.
631
632
633=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
634
635Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
636behaviour and output format. In case of an error, C<$entries> will be
637C<undef>.
638
639The flags are a combination of the following constants, ORed together (the
640flags will also be passed to the callback, possibly modified):
641
642=over 4
643
644=item IO::AIO::READDIR_DENTS
645
646When this flag is off, then the callback gets an arrayref with of names
647only (as with C<aio_readdir>), otherwise it gets an arrayref with
648C<[$name, $type, $inode]> arrayrefs, each describing a single directory
649entry in more detail.
650
651C<$name> is the name of the entry.
652
653C<$type> is one of the C<IO::AIO::DT_xxx> constants:
654
655C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
656C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
657C<IO::AIO::DT_WHT>.
658
659C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
660know, you have to run stat yourself. Also, for speed reasons, the C<$type>
661scalars are read-only: you can not modify them.
662
663C<$inode> is the inode number (which might not be exact on systems with 64
664bit inode numbers and 32 bit perls). This field has unspecified content on
665systems that do not deliver the inode information.
666
667=item IO::AIO::READDIR_DIRS_FIRST
668
669When this flag is set, then the names will be returned in an order where
670likely directories come first. This is useful when you need to quickly
671find directories, or you want to find all directories while avoiding to
672stat() each entry.
673
674If the system returns type information in readdir, then this is used
675to find directories directly. Otherwise, likely directories are files
676beginning with ".", or otherwise files with no dots, of which files with
677short names are tried first.
678
679=item IO::AIO::READDIR_STAT_ORDER
680
681When this flag is set, then the names will be returned in an order
682suitable for stat()'ing each one. That is, when you plan to stat()
683all files in the given directory, then the returned order will likely
684be fastest.
685
686If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
687the likely dirs come first, resulting in a less optimal stat order.
688
689=item IO::AIO::READDIR_FOUND_UNKNOWN
690
691This flag should not be set when calling C<aio_readdirx>. Instead, it
692is being set by C<aio_readdirx>, when any of the C<$type>'s found were
693C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
694C<$type>'s are known, which can be used to speed up some algorithms.
695
696=back
697
698
699=item aio_load $path, $data, $callback->($status)
700
701This is a composite request that tries to fully load the given file into
702memory. Status is the same as with aio_read.
703
704=cut
705
706sub aio_load($$;$) {
707 my ($path, undef, $cb) = @_;
708 my $data = \$_[1];
709
710 my $pri = aioreq_pri;
711 my $grp = aio_group $cb;
712
713 aioreq_pri $pri;
714 add $grp aio_open $path, O_RDONLY, 0, sub {
715 my $fh = shift
716 or return $grp->result (-1);
717
718 aioreq_pri $pri;
719 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
720 $grp->result ($_[0]);
721 };
722 };
723
724 $grp
725}
448 726
449=item aio_copy $srcpath, $dstpath, $callback->($status) 727=item aio_copy $srcpath, $dstpath, $callback->($status)
450 728
451Try to copy the I<file> (directories not supported as either source or 729Try to copy the I<file> (directories not supported as either source or
452destination) from C<$srcpath> to C<$dstpath> and call the callback with 730destination) from C<$srcpath> to C<$dstpath> and call the callback with
453the C<0> (error) or C<-1> ok. 731a status of C<0> (ok) or C<-1> (error, see C<$!>).
454 732
455This is a composite request that it creates the destination file with 733This is a composite request that creates the destination file with
456mode 0200 and copies the contents of the source file into it using 734mode 0200 and copies the contents of the source file into it using
457C<aio_sendfile>, followed by restoring atime, mtime, access mode and 735C<aio_sendfile>, followed by restoring atime, mtime, access mode and
458uid/gid, in that order. 736uid/gid, in that order.
459 737
460If an error occurs, the partial destination file will be unlinked, if 738If an error occurs, the partial destination file will be unlinked, if
462errors are being ignored. 740errors are being ignored.
463 741
464=cut 742=cut
465 743
466sub aio_copy($$;$) { 744sub aio_copy($$;$) {
467 aio_block {
468 my ($src, $dst, $cb) = @_; 745 my ($src, $dst, $cb) = @_;
469 746
470 my $pri = aioreq_pri; 747 my $pri = aioreq_pri;
471 my $grp = aio_group $cb; 748 my $grp = aio_group $cb;
472 749
473 aioreq_pri $pri; 750 aioreq_pri $pri;
474 add $grp aio_open $src, O_RDONLY, 0, sub { 751 add $grp aio_open $src, O_RDONLY, 0, sub {
475 if (my $src_fh = $_[0]) { 752 if (my $src_fh = $_[0]) {
476 my @stat = stat $src_fh; 753 my @stat = stat $src_fh; # hmm, might block over nfs?
477 754
478 aioreq_pri $pri; 755 aioreq_pri $pri;
479 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub { 756 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
480 if (my $dst_fh = $_[0]) { 757 if (my $dst_fh = $_[0]) {
481 aioreq_pri $pri; 758 aioreq_pri $pri;
482 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 759 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
483 if ($_[0] == $stat[7]) { 760 if ($_[0] == $stat[7]) {
484 $grp->result (0); 761 $grp->result (0);
485 close $src_fh; 762 close $src_fh;
486 763
487 # those should not normally block. should. should.
488 utime $stat[8], $stat[9], $dst;
489 chmod $stat[2] & 07777, $dst_fh;
490 chown $stat[4], $stat[5], $dst_fh;
491 close $dst_fh;
492 } else { 764 my $ch = sub {
493 $grp->result (-1);
494 close $src_fh;
495 close $dst_fh;
496
497 aioreq $pri; 765 aioreq_pri $pri;
766 add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
767 aioreq_pri $pri;
768 add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
769 aioreq_pri $pri;
498 add $grp aio_unlink $dst; 770 add $grp aio_close $dst_fh;
771 }
772 };
499 } 773 };
774
775 aioreq_pri $pri;
776 add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
777 if ($_[0] < 0 && $! == ENOSYS) {
778 aioreq_pri $pri;
779 add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
780 } else {
781 $ch->();
782 }
783 };
784 } else {
785 $grp->result (-1);
786 close $src_fh;
787 close $dst_fh;
788
789 aioreq $pri;
790 add $grp aio_unlink $dst;
500 }; 791 }
501 } else {
502 $grp->result (-1);
503 } 792 };
793 } else {
794 $grp->result (-1);
504 }, 795 }
505
506 } else {
507 $grp->result (-1);
508 } 796 },
797
798 } else {
799 $grp->result (-1);
509 }; 800 }
510
511 $grp
512 } 801 };
802
803 $grp
513} 804}
514 805
515=item aio_move $srcpath, $dstpath, $callback->($status) 806=item aio_move $srcpath, $dstpath, $callback->($status)
516 807
517Try to move the I<file> (directories not supported as either source or 808Try to move the I<file> (directories not supported as either source or
518destination) from C<$srcpath> to C<$dstpath> and call the callback with 809destination) from C<$srcpath> to C<$dstpath> and call the callback with
519the C<0> (error) or C<-1> ok. 810a status of C<0> (ok) or C<-1> (error, see C<$!>).
520 811
521This is a composite request that tries to rename(2) the file first. If 812This is a composite request that tries to rename(2) the file first; if
522rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if 813rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
523that is successful, unlinking the C<$srcpath>. 814that is successful, unlinks the C<$srcpath>.
524 815
525=cut 816=cut
526 817
527sub aio_move($$;$) { 818sub aio_move($$;$) {
528 aio_block {
529 my ($src, $dst, $cb) = @_; 819 my ($src, $dst, $cb) = @_;
530 820
531 my $pri = aioreq_pri; 821 my $pri = aioreq_pri;
532 my $grp = aio_group $cb; 822 my $grp = aio_group $cb;
533 823
534 aioreq_pri $pri; 824 aioreq_pri $pri;
535 add $grp aio_rename $src, $dst, sub { 825 add $grp aio_rename $src, $dst, sub {
536 if ($_[0] && $! == EXDEV) { 826 if ($_[0] && $! == EXDEV) {
537 aioreq_pri $pri; 827 aioreq_pri $pri;
538 add $grp aio_copy $src, $dst, sub { 828 add $grp aio_copy $src, $dst, sub {
539 $grp->result ($_[0]);
540
541 if (!$_[0]) {
542 aioreq_pri $pri;
543 add $grp aio_unlink $src;
544 }
545 };
546 } else {
547 $grp->result ($_[0]); 829 $grp->result ($_[0]);
830
831 if (!$_[0]) {
832 aioreq_pri $pri;
833 add $grp aio_unlink $src;
834 }
548 } 835 };
836 } else {
837 $grp->result ($_[0]);
549 }; 838 }
550
551 $grp
552 } 839 };
840
841 $grp
553} 842}
554 843
555=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 844=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
556 845
557Scans a directory (similar to C<aio_readdir>) but additionally tries to 846Scans a directory (similar to C<aio_readdir>) but additionally tries to
577 866
578Implementation notes. 867Implementation notes.
579 868
580The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can. 869The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
581 870
871If readdir returns file type information, then this is used directly to
872find directories.
873
582After reading the directory, the modification time, size etc. of the 874Otherwise, after reading the directory, the modification time, size etc.
583directory before and after the readdir is checked, and if they match (and 875of the directory before and after the readdir is checked, and if they
584isn't the current time), the link count will be used to decide how many 876match (and isn't the current time), the link count will be used to decide
585entries are directories (if >= 2). Otherwise, no knowledge of the number 877how many entries are directories (if >= 2). Otherwise, no knowledge of the
586of subdirectories will be assumed. 878number of subdirectories will be assumed.
587 879
588Then entries will be sorted into likely directories (everything without 880Then entries will be sorted into likely directories a non-initial dot
589a non-initial dot currently) and likely non-directories (everything 881currently) and likely non-directories (see C<aio_readdirx>). Then every
590else). Then every entry plus an appended C</.> will be C<stat>'ed, 882entry plus an appended C</.> will be C<stat>'ed, likely directories first,
591likely directories first. If that succeeds, it assumes that the entry 883in order of their inode numbers. If that succeeds, it assumes that the
592is a directory or a symlink to directory (which will be checked 884entry is a directory or a symlink to directory (which will be checked
593seperately). This is often faster than stat'ing the entry itself because 885seperately). This is often faster than stat'ing the entry itself because
594filesystems might detect the type of the entry without reading the inode 886filesystems might detect the type of the entry without reading the inode
595data (e.g. ext2fs filetype feature). 887data (e.g. ext2fs filetype feature), even on systems that cannot return
888the filetype information on readdir.
596 889
597If the known number of directories (link count - 2) has been reached, the 890If the known number of directories (link count - 2) has been reached, the
598rest of the entries is assumed to be non-directories. 891rest of the entries is assumed to be non-directories.
599 892
600This only works with certainty on POSIX (= UNIX) filesystems, which 893This only works with certainty on POSIX (= UNIX) filesystems, which
604as those tend to return 0 or 1 as link counts, which disables the 897as those tend to return 0 or 1 as link counts, which disables the
605directory counting heuristic. 898directory counting heuristic.
606 899
607=cut 900=cut
608 901
609sub aio_scandir($$$) { 902sub aio_scandir($$;$) {
610 aio_block {
611 my ($path, $maxreq, $cb) = @_; 903 my ($path, $maxreq, $cb) = @_;
612 904
613 my $pri = aioreq_pri; 905 my $pri = aioreq_pri;
614 906
615 my $grp = aio_group $cb; 907 my $grp = aio_group $cb;
616 908
617 $maxreq = 4 if $maxreq <= 0; 909 $maxreq = 4 if $maxreq <= 0;
618 910
619 # stat once 911 # stat once
912 aioreq_pri $pri;
913 add $grp aio_stat $path, sub {
914 return $grp->result () if $_[0];
915 my $now = time;
916 my $hash1 = join ":", (stat _)[0,1,3,7,9];
917
918 # read the directory entries
620 aioreq_pri $pri; 919 aioreq_pri $pri;
621 add $grp aio_stat $path, sub { 920 add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
921 my $entries = shift
622 return $grp->result () if $_[0]; 922 or return $grp->result ();
623 my $now = time;
624 my $hash1 = join ":", (stat _)[0,1,3,7,9];
625 923
626 # read the directory entries 924 # stat the dir another time
627 aioreq_pri $pri; 925 aioreq_pri $pri;
628 add $grp aio_readdir $path, sub {
629 my $entries = shift
630 or return $grp->result ();
631
632 # stat the dir another time
633 aioreq_pri $pri;
634 add $grp aio_stat $path, sub { 926 add $grp aio_stat $path, sub {
635 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 927 my $hash2 = join ":", (stat _)[0,1,3,7,9];
636 928
637 my $ndirs; 929 my $ndirs;
638 930
639 # take the slow route if anything looks fishy 931 # take the slow route if anything looks fishy
640 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 932 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
641 $ndirs = -1; 933 $ndirs = -1;
642 } else { 934 } else {
643 # if nlink == 2, we are finished 935 # if nlink == 2, we are finished
644 # on non-posix-fs's, we rely on nlink < 2 936 # for non-posix-fs's, we rely on nlink < 2
645 $ndirs = (stat _)[3] - 2 937 $ndirs = (stat _)[3] - 2
646 or return $grp->result ([], $entries); 938 or return $grp->result ([], $entries);
647 } 939 }
648 940
649 # sort into likely dirs and likely nondirs
650 # dirs == files without ".", short entries first
651 $entries = [map $_->[0],
652 sort { $b->[1] cmp $a->[1] }
653 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
654 @$entries];
655
656 my (@dirs, @nondirs); 941 my (@dirs, @nondirs);
657 942
658 my $statgrp = add $grp aio_group sub { 943 my $statgrp = add $grp aio_group sub {
659 $grp->result (\@dirs, \@nondirs); 944 $grp->result (\@dirs, \@nondirs);
660 }; 945 };
661 946
662 limit $statgrp $maxreq; 947 limit $statgrp $maxreq;
663 feed $statgrp sub { 948 feed $statgrp sub {
664 return unless @$entries; 949 return unless @$entries;
665 my $entry = pop @$entries; 950 my $entry = shift @$entries;
666 951
667 aioreq_pri $pri; 952 aioreq_pri $pri;
668 add $statgrp aio_stat "$path/$entry/.", sub { 953 add $statgrp aio_stat "$path/$entry/.", sub {
669 if ($_[0] < 0) { 954 if ($_[0] < 0) {
670 push @nondirs, $entry; 955 push @nondirs, $entry;
671 } else { 956 } else {
672 # need to check for real directory 957 # need to check for real directory
673 aioreq_pri $pri; 958 aioreq_pri $pri;
674 add $statgrp aio_lstat "$path/$entry", sub { 959 add $statgrp aio_lstat "$path/$entry", sub {
675 if (-d _) { 960 if (-d _) {
676 push @dirs, $entry; 961 push @dirs, $entry;
677 962
678 unless (--$ndirs) { 963 unless (--$ndirs) {
679 push @nondirs, @$entries; 964 push @nondirs, @$entries;
680 feed $statgrp; 965 feed $statgrp;
681 }
682 } else {
683 push @nondirs, $entry;
684 } 966 }
967 } else {
968 push @nondirs, $entry;
685 } 969 }
686 } 970 }
687 }; 971 }
688 }; 972 };
689 }; 973 };
690 }; 974 };
691 }; 975 };
692
693 $grp
694 } 976 };
977
978 $grp
695} 979}
980
981=item aio_rmtree $path, $callback->($status)
982
983Delete a directory tree starting (and including) C<$path>, return the
984status of the final C<rmdir> only. This is a composite request that
985uses C<aio_scandir> to recurse into and rmdir directories, and unlink
986everything else.
987
988=cut
989
990sub aio_rmtree;
991sub aio_rmtree($;$) {
992 my ($path, $cb) = @_;
993
994 my $pri = aioreq_pri;
995 my $grp = aio_group $cb;
996
997 aioreq_pri $pri;
998 add $grp aio_scandir $path, 0, sub {
999 my ($dirs, $nondirs) = @_;
1000
1001 my $dirgrp = aio_group sub {
1002 add $grp aio_rmdir $path, sub {
1003 $grp->result ($_[0]);
1004 };
1005 };
1006
1007 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
1008 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
1009
1010 add $grp $dirgrp;
1011 };
1012
1013 $grp
1014}
1015
1016=item aio_sync $callback->($status)
1017
1018Asynchronously call sync and call the callback when finished.
696 1019
697=item aio_fsync $fh, $callback->($status) 1020=item aio_fsync $fh, $callback->($status)
698 1021
699Asynchronously call fsync on the given filehandle and call the callback 1022Asynchronously call fsync on the given filehandle and call the callback
700with the fsync result code. 1023with the fsync result code.
704Asynchronously call fdatasync on the given filehandle and call the 1027Asynchronously call fdatasync on the given filehandle and call the
705callback with the fdatasync result code. 1028callback with the fdatasync result code.
706 1029
707If this call isn't available because your OS lacks it or it couldn't be 1030If this call isn't available because your OS lacks it or it couldn't be
708detected, it will be emulated by calling C<fsync> instead. 1031detected, it will be emulated by calling C<fsync> instead.
1032
1033=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
1034
1035Sync the data portion of the file specified by C<$offset> and C<$length>
1036to disk (but NOT the metadata), by calling the Linux-specific
1037sync_file_range call. If sync_file_range is not available or it returns
1038ENOSYS, then fdatasync or fsync is being substituted.
1039
1040C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
1041C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
1042C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
1043manpage for details.
1044
1045=item aio_pathsync $path, $callback->($status)
1046
1047This request tries to open, fsync and close the given path. This is a
1048composite request intended to sync directories after directory operations
1049(E.g. rename). This might not work on all operating systems or have any
1050specific effect, but usually it makes sure that directory changes get
1051written to disc. It works for anything that can be opened for read-only,
1052not just directories.
1053
1054Future versions of this function might fall back to other methods when
1055C<fsync> on the directory fails (such as calling C<sync>).
1056
1057Passes C<0> when everything went ok, and C<-1> on error.
1058
1059=cut
1060
1061sub aio_pathsync($;$) {
1062 my ($path, $cb) = @_;
1063
1064 my $pri = aioreq_pri;
1065 my $grp = aio_group $cb;
1066
1067 aioreq_pri $pri;
1068 add $grp aio_open $path, O_RDONLY, 0, sub {
1069 my ($fh) = @_;
1070 if ($fh) {
1071 aioreq_pri $pri;
1072 add $grp aio_fsync $fh, sub {
1073 $grp->result ($_[0]);
1074
1075 aioreq_pri $pri;
1076 add $grp aio_close $fh;
1077 };
1078 } else {
1079 $grp->result (-1);
1080 }
1081 };
1082
1083 $grp
1084}
1085
1086=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1087
1088This is a rather advanced IO::AIO call, which only works on mmap(2)ed
1089scalars (see the L<Sys::Mmap> or L<Mmap> modules for details on this, note
1090that the scalar must only be modified in-place while an aio operation is
1091pending on it).
1092
1093It calls the C<msync> function of your OS, if available, with the memory
1094area starting at C<$offset> in the string and ending C<$length> bytes
1095later. If C<$length> is negative, counts from the end, and if C<$length>
1096is C<undef>, then it goes till the end of the string. The flags can be
1097a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
1098C<IO::AIO::MS_SYNC>.
1099
1100=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1101
1102This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1103scalars.
1104
1105It touches (reads or writes) all memory pages in the specified
1106range inside the scalar. All caveats and parameters are the same
1107as for C<aio_msync>, above, except for flags, which must be either
1108C<0> (which reads all pages and ensures they are instantiated) or
1109C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
1110writing an octet from it, which dirties the page).
709 1111
710=item aio_group $callback->(...) 1112=item aio_group $callback->(...)
711 1113
712This is a very special aio request: Instead of doing something, it is a 1114This is a very special aio request: Instead of doing something, it is a
713container for other aio requests, which is useful if you want to bundle 1115container for other aio requests, which is useful if you want to bundle
763=item cancel $req 1165=item cancel $req
764 1166
765Cancels the request, if possible. Has the effect of skipping execution 1167Cancels the request, if possible. Has the effect of skipping execution
766when entering the B<execute> state and skipping calling the callback when 1168when entering the B<execute> state and skipping calling the callback when
767entering the the B<result> state, but will leave the request otherwise 1169entering the the B<result> state, but will leave the request otherwise
768untouched. That means that requests that currently execute will not be 1170untouched (with the exception of readdir). That means that requests that
769stopped and resources held by the request will not be freed prematurely. 1171currently execute will not be stopped and resources held by the request
1172will not be freed prematurely.
770 1173
771=item cb $req $callback->(...) 1174=item cb $req $callback->(...)
772 1175
773Replace (or simply set) the callback registered to the request. 1176Replace (or simply set) the callback registered to the request.
774 1177
825Their lifetime, simplified, looks like this: when they are empty, they 1228Their lifetime, simplified, looks like this: when they are empty, they
826will finish very quickly. If they contain only requests that are in the 1229will finish very quickly. If they contain only requests that are in the
827C<done> state, they will also finish. Otherwise they will continue to 1230C<done> state, they will also finish. Otherwise they will continue to
828exist. 1231exist.
829 1232
830That means after creating a group you have some time to add requests. And 1233That means after creating a group you have some time to add requests
831in the callbacks of those requests, you can add further requests to the 1234(precisely before the callback has been invoked, which is only done within
832group. And only when all those requests have finished will the the group 1235the C<poll_cb>). And in the callbacks of those requests, you can add
833itself finish. 1236further requests to the group. And only when all those requests have
1237finished will the the group itself finish.
834 1238
835=over 4 1239=over 4
836 1240
837=item add $grp ... 1241=item add $grp ...
838 1242
847=item $grp->cancel_subs 1251=item $grp->cancel_subs
848 1252
849Cancel all subrequests and clears any feeder, but not the group request 1253Cancel all subrequests and clears any feeder, but not the group request
850itself. Useful when you queued a lot of events but got a result early. 1254itself. Useful when you queued a lot of events but got a result early.
851 1255
1256The group request will finish normally (you cannot add requests to the
1257group).
1258
852=item $grp->result (...) 1259=item $grp->result (...)
853 1260
854Set the result value(s) that will be passed to the group callback when all 1261Set the result value(s) that will be passed to the group callback when all
855subrequests have finished and set thre groups errno to the current value 1262subrequests have finished and set the groups errno to the current value
856of errno (just like calling C<errno> without an error number). By default, 1263of errno (just like calling C<errno> without an error number). By default,
857no argument will be passed and errno is zero. 1264no argument will be passed and errno is zero.
858 1265
859=item $grp->errno ([$errno]) 1266=item $grp->errno ([$errno])
860 1267
871=item feed $grp $callback->($grp) 1278=item feed $grp $callback->($grp)
872 1279
873Sets a feeder/generator on this group: every group can have an attached 1280Sets a feeder/generator on this group: every group can have an attached
874generator that generates requests if idle. The idea behind this is that, 1281generator that generates requests if idle. The idea behind this is that,
875although you could just queue as many requests as you want in a group, 1282although you could just queue as many requests as you want in a group,
876this might starve other requests for a potentially long time. For 1283this might starve other requests for a potentially long time. For example,
877example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1284C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
878requests, delaying any later requests for a long time. 1285delaying any later requests for a long time.
879 1286
880To avoid this, and allow incremental generation of requests, you can 1287To avoid this, and allow incremental generation of requests, you can
881instead a group and set a feeder on it that generates those requests. The 1288instead a group and set a feeder on it that generates those requests. The
882feed callback will be called whenever there are few enough (see C<limit>, 1289feed callback will be called whenever there are few enough (see C<limit>,
883below) requests active in the group itself and is expected to queue more 1290below) requests active in the group itself and is expected to queue more
887not impose any limits). 1294not impose any limits).
888 1295
889If the feed does not queue more requests when called, it will be 1296If the feed does not queue more requests when called, it will be
890automatically removed from the group. 1297automatically removed from the group.
891 1298
892If the feed limit is C<0>, it will be set to C<2> automatically. 1299If the feed limit is C<0> when this method is called, it will be set to
1300C<2> automatically.
893 1301
894Example: 1302Example:
895 1303
896 # stat all files in @files, but only ever use four aio requests concurrently: 1304 # stat all files in @files, but only ever use four aio requests concurrently:
897 1305
909Sets the feeder limit for the group: The feeder will be called whenever 1317Sets the feeder limit for the group: The feeder will be called whenever
910the group contains less than this many requests. 1318the group contains less than this many requests.
911 1319
912Setting the limit to C<0> will pause the feeding process. 1320Setting the limit to C<0> will pause the feeding process.
913 1321
1322The default value for the limit is C<0>, but note that setting a feeder
1323automatically bumps it up to C<2>.
1324
914=back 1325=back
915 1326
916=head2 SUPPORT FUNCTIONS 1327=head2 SUPPORT FUNCTIONS
917 1328
918=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1329=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
920=over 4 1331=over 4
921 1332
922=item $fileno = IO::AIO::poll_fileno 1333=item $fileno = IO::AIO::poll_fileno
923 1334
924Return the I<request result pipe file descriptor>. This filehandle must be 1335Return the I<request result pipe file descriptor>. This filehandle must be
925polled for reading by some mechanism outside this module (e.g. Event or 1336polled for reading by some mechanism outside this module (e.g. EV, Glib,
926select, see below or the SYNOPSIS). If the pipe becomes readable you have 1337select and so on, see below or the SYNOPSIS). If the pipe becomes readable
927to call C<poll_cb> to check the results. 1338you have to call C<poll_cb> to check the results.
928 1339
929See C<poll_cb> for an example. 1340See C<poll_cb> for an example.
930 1341
931=item IO::AIO::poll_cb 1342=item IO::AIO::poll_cb
932 1343
933Process some outstanding events on the result pipe. You have to call this 1344Process some outstanding events on the result pipe. You have to call this
934regularly. Returns the number of events processed. Returns immediately 1345regularly. Returns C<0> if all events could be processed, or C<-1> if it
1346returned earlier for whatever reason. Returns immediately when no events
935when no events are outstanding. The amount of events processed depends on 1347are outstanding. The amount of events processed depends on the settings of
936the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>. 1348C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
937 1349
938If not all requests were processed for whatever reason, the filehandle 1350If not all requests were processed for whatever reason, the filehandle
939will still be ready when C<poll_cb> returns. 1351will still be ready when C<poll_cb> returns, so normally you don't have to
1352do anything special to have it called later.
940 1353
941Example: Install an Event watcher that automatically calls 1354Example: Install an Event watcher that automatically calls
942IO::AIO::poll_cb with high priority: 1355IO::AIO::poll_cb with high priority (more examples can be found in the
1356SYNOPSIS section, at the top of this document):
943 1357
944 Event->io (fd => IO::AIO::poll_fileno, 1358 Event->io (fd => IO::AIO::poll_fileno,
945 poll => 'r', async => 1, 1359 poll => 'r', async => 1,
946 cb => \&IO::AIO::poll_cb); 1360 cb => \&IO::AIO::poll_cb);
1361
1362=item IO::AIO::poll_wait
1363
1364If there are any outstanding requests and none of them in the result
1365phase, wait till the result filehandle becomes ready for reading (simply
1366does a C<select> on the filehandle. This is useful if you want to
1367synchronously wait for some requests to finish).
1368
1369See C<nreqs> for an example.
1370
1371=item IO::AIO::poll
1372
1373Waits until some requests have been handled.
1374
1375Returns the number of requests processed, but is otherwise strictly
1376equivalent to:
1377
1378 IO::AIO::poll_wait, IO::AIO::poll_cb
1379
1380=item IO::AIO::flush
1381
1382Wait till all outstanding AIO requests have been handled.
1383
1384Strictly equivalent to:
1385
1386 IO::AIO::poll_wait, IO::AIO::poll_cb
1387 while IO::AIO::nreqs;
947 1388
948=item IO::AIO::max_poll_reqs $nreqs 1389=item IO::AIO::max_poll_reqs $nreqs
949 1390
950=item IO::AIO::max_poll_time $seconds 1391=item IO::AIO::max_poll_time $seconds
951 1392
976 # use a low priority so other tasks have priority 1417 # use a low priority so other tasks have priority
977 Event->io (fd => IO::AIO::poll_fileno, 1418 Event->io (fd => IO::AIO::poll_fileno,
978 poll => 'r', nice => 1, 1419 poll => 'r', nice => 1,
979 cb => &IO::AIO::poll_cb); 1420 cb => &IO::AIO::poll_cb);
980 1421
981=item IO::AIO::poll_wait 1422=back
982
983If there are any outstanding requests and none of them in the result
984phase, wait till the result filehandle becomes ready for reading (simply
985does a C<select> on the filehandle. This is useful if you want to
986synchronously wait for some requests to finish).
987
988See C<nreqs> for an example.
989
990=item IO::AIO::poll
991
992Waits until some requests have been handled.
993
994Returns the number of requests processed, but is otherwise strictly
995equivalent to:
996
997 IO::AIO::poll_wait, IO::AIO::poll_cb
998
999=item IO::AIO::flush
1000
1001Wait till all outstanding AIO requests have been handled.
1002
1003Strictly equivalent to:
1004
1005 IO::AIO::poll_wait, IO::AIO::poll_cb
1006 while IO::AIO::nreqs;
1007 1423
1008=head3 CONTROLLING THE NUMBER OF THREADS 1424=head3 CONTROLLING THE NUMBER OF THREADS
1425
1426=over
1009 1427
1010=item IO::AIO::min_parallel $nthreads 1428=item IO::AIO::min_parallel $nthreads
1011 1429
1012Set the minimum number of AIO threads to C<$nthreads>. The current 1430Set the minimum number of AIO threads to C<$nthreads>. The current
1013default is C<8>, which means eight asynchronous operations can execute 1431default is C<8>, which means eight asynchronous operations can execute
1054 1472
1055The default is probably ok in most situations, especially if thread 1473The default is probably ok in most situations, especially if thread
1056creation is fast. If thread creation is very slow on your system you might 1474creation is fast. If thread creation is very slow on your system you might
1057want to use larger values. 1475want to use larger values.
1058 1476
1059=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1477=item IO::AIO::max_outstanding $maxreqs
1060 1478
1061This is a very bad function to use in interactive programs because it 1479This is a very bad function to use in interactive programs because it
1062blocks, and a bad way to reduce concurrency because it is inexact: Better 1480blocks, and a bad way to reduce concurrency because it is inexact: Better
1063use an C<aio_group> together with a feed callback. 1481use an C<aio_group> together with a feed callback.
1064 1482
1065Sets the maximum number of outstanding requests to C<$nreqs>. If you 1483Sets the maximum number of outstanding requests to C<$nreqs>. If you
1066to queue up more than this number of requests, the next call to the 1484do queue up more than this number of requests, the next call to the
1067C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>) 1485C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
1068function will block until the limit is no longer exceeded. 1486function will block until the limit is no longer exceeded.
1069 1487
1070The default value is very large, so there is no practical limit on the 1488The default value is very large, so there is no practical limit on the
1071number of outstanding requests. 1489number of outstanding requests.
1072 1490
1073You can still queue as many requests as you want. Therefore, 1491You can still queue as many requests as you want. Therefore,
1074C<max_oustsanding> is mainly useful in simple scripts (with low values) or 1492C<max_outstanding> is mainly useful in simple scripts (with low values) or
1075as a stop gap to shield against fatal memory overflow (with large values). 1493as a stop gap to shield against fatal memory overflow (with large values).
1076 1494
1495=back
1496
1077=head3 STATISTICAL INFORMATION 1497=head3 STATISTICAL INFORMATION
1498
1499=over
1078 1500
1079=item IO::AIO::nreqs 1501=item IO::AIO::nreqs
1080 1502
1081Returns the number of requests currently in the ready, execute or pending 1503Returns the number of requests currently in the ready, execute or pending
1082states (i.e. for which their callback has not been invoked yet). 1504states (i.e. for which their callback has not been invoked yet).
1096Returns the number of requests currently in the pending state (executed, 1518Returns the number of requests currently in the pending state (executed,
1097but not yet processed by poll_cb). 1519but not yet processed by poll_cb).
1098 1520
1099=back 1521=back
1100 1522
1523=head3 MISCELLANEOUS FUNCTIONS
1524
1525IO::AIO implements some functions that might be useful, but are not
1526asynchronous.
1527
1528=over 4
1529
1530=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1531
1532Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
1533but is blocking (this makes most sense if you know the input data is
1534likely cached already and the output filehandle is set to non-blocking
1535operations).
1536
1537Returns the number of bytes copied, or C<-1> on error.
1538
1539=item IO::AIO::fadvise $fh, $offset, $len, $advice
1540
1541Simply calls the C<posix_fadvise> function (see it's
1542manpage for details). The following advice constants are
1543avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1544C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1545C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1546
1547On systems that do not implement C<posix_fadvise>, this function returns
1548ENOSYS, otherwise the return value of C<posix_fadvise>.
1549
1550=item IO::AIO::mlockall $flags
1551
1552Calls the C<mlockall> function with the given C<$flags> (a combination of
1553C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL__FUTURE>).
1554
1555On systems that do not implement C<mlockall>, this function returns
1556ENOSYS, otherwise the return value of C<mlockall>.
1557
1558=item IO::AIO::munlockall
1559
1560Calls the C<munlockall> function.
1561
1562On systems that do not implement C<munlockall>, this function returns
1563ENOSYS, otherwise the return value of C<munlockall>.
1564
1565=back
1566
1101=cut 1567=cut
1102 1568
1103# support function to convert a fd into a perl filehandle
1104sub _fd2fh {
1105 return undef if $_[0] < 0;
1106
1107 # try to generate nice filehandles
1108 my $sym = "IO::AIO::fd#$_[0]";
1109 local *$sym;
1110
1111 open *$sym, "+<&=$_[0]" # usually works under any unix
1112 or open *$sym, "<&=$_[0]" # cygwin needs this
1113 or open *$sym, ">&=$_[0]" # or this
1114 or return undef;
1115
1116 *$sym
1117}
1118
1119min_parallel 8; 1569min_parallel 8;
1120 1570
1121END { flush } 1571END { flush }
1122 1572
11231; 15731;
1574
1575=head1 EVENT LOOP INTEGRATION
1576
1577It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
1578automatically into many event loops:
1579
1580 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
1581 use AnyEvent::AIO;
1582
1583You can also integrate IO::AIO manually into many event loops, here are
1584some examples of how to do this:
1585
1586 # EV integration
1587 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
1588
1589 # Event integration
1590 Event->io (fd => IO::AIO::poll_fileno,
1591 poll => 'r',
1592 cb => \&IO::AIO::poll_cb);
1593
1594 # Glib/Gtk2 integration
1595 add_watch Glib::IO IO::AIO::poll_fileno,
1596 in => sub { IO::AIO::poll_cb; 1 };
1597
1598 # Tk integration
1599 Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
1600 readable => \&IO::AIO::poll_cb);
1601
1602 # Danga::Socket integration
1603 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
1604 \&IO::AIO::poll_cb);
1124 1605
1125=head2 FORK BEHAVIOUR 1606=head2 FORK BEHAVIOUR
1126 1607
1127This module should do "the right thing" when the process using it forks: 1608This module should do "the right thing" when the process using it forks:
1128 1609
1146bytes of memory. In addition, stat requests need a stat buffer (possibly 1627bytes of memory. In addition, stat requests need a stat buffer (possibly
1147a few hundred bytes), readdir requires a result buffer and so on. Perl 1628a few hundred bytes), readdir requires a result buffer and so on. Perl
1148scalars and other data passed into aio requests will also be locked and 1629scalars and other data passed into aio requests will also be locked and
1149will consume memory till the request has entered the done state. 1630will consume memory till the request has entered the done state.
1150 1631
1151This is now awfully much, so queuing lots of requests is not usually a 1632This is not awfully much, so queuing lots of requests is not usually a
1152problem. 1633problem.
1153 1634
1154Per-thread usage: 1635Per-thread usage:
1155 1636
1156In the execution phase, some aio requests require more memory for 1637In the execution phase, some aio requests require more memory for
1161 1642
1162Known bugs will be fixed in the next release. 1643Known bugs will be fixed in the next release.
1163 1644
1164=head1 SEE ALSO 1645=head1 SEE ALSO
1165 1646
1166L<Coro::AIO>. 1647L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1648more natural syntax.
1167 1649
1168=head1 AUTHOR 1650=head1 AUTHOR
1169 1651
1170 Marc Lehmann <schmorp@schmorp.de> 1652 Marc Lehmann <schmorp@schmorp.de>
1171 http://home.schmorp.de/ 1653 http://home.schmorp.de/

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