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Revision 1.90 by root, Mon Oct 30 23:30:00 2006 UTC vs.
Revision 1.176 by root, Sun Jan 10 23:05:11 2010 UTC

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", O_RDONLY, 0, sub {
10 my ($fh) = @_; 10 my $fh = shift
11 or die "/etc/passwd: $!";
11 ... 12 ...
12 }; 13 };
13 14
14 aio_unlink "/tmp/file", sub { }; 15 aio_unlink "/tmp/file", sub { };
15 16
25 $req->cancel; # cancel request if still in queue 26 $req->cancel; # cancel request if still in queue
26 27
27 my $grp = aio_group sub { print "all stats done\n" }; 28 my $grp = aio_group sub { print "all stats done\n" };
28 add $grp aio_stat "..." for ...; 29 add $grp aio_stat "..." for ...;
29 30
30 # AnyEvent integration
31 open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!";
32 my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });
33
34 # Event integration
35 Event->io (fd => IO::AIO::poll_fileno,
36 poll => 'r',
37 cb => \&IO::AIO::poll_cb);
38
39 # Glib/Gtk2 integration
40 add_watch Glib::IO IO::AIO::poll_fileno,
41 in => sub { IO::AIO::poll_cb; 1 };
42
43 # Tk integration
44 Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
45 readable => \&IO::AIO::poll_cb);
46
47 # Danga::Socket integration
48 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
49 \&IO::AIO::poll_cb);
50
51=head1 DESCRIPTION 31=head1 DESCRIPTION
52 32
53This module implements asynchronous I/O using whatever means your 33This module implements asynchronous I/O using whatever means your
54operating system supports. 34operating system supports. It is implemented as an interface to C<libeio>
35(L<http://software.schmorp.de/pkg/libeio.html>).
55 36
56Asynchronous means that operations that can normally block your program 37Asynchronous means that operations that can normally block your program
57(e.g. reading from disk) will be done asynchronously: the operation 38(e.g. reading from disk) will be done asynchronously: the operation
58will 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
59is extremely useful for programs that need to stay interactive even 40is extremely useful for programs that need to stay interactive even
61etc.), 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
62normally 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
63on 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
64concurrently. 45concurrently.
65 46
66While most of this works on all types of file descriptors (for example 47While most of this works on all types of file descriptors (for
67sockets), using these functions on file descriptors that support 48example sockets), using these functions on file descriptors that
68nonblocking operation (again, sockets, pipes etc.) is very inefficient or 49support nonblocking operation (again, sockets, pipes etc.) is
69might 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>
70for 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.
71into 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
76to 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
78not 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
79files currently, for example), and they would only support aio_read and 59files currently, for example), and they would only support aio_read and
80aio_write, so the remaining functionality would have to be implemented 60aio_write, so the remaining functionality would have to be implemented
81using threads anyway. 61using threads anyway.
82 62
83Although the module will work with in the presence of other (Perl-) 63Although the module will work in the presence of other (Perl-) threads,
84threads, it is currently not reentrant in any way, so use appropriate 64it is currently not reentrant in any way, so use appropriate locking
85locking 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
86never call 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", O_RDONLY, 0, sub {
104 my $fh = $_[0] 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;
109 87
117 95
118 # file contents now in $contents 96 # file contents now in $contents
119 print $contents; 97 print $contents;
120 98
121 # exit event loop and program 99 # exit event loop and program
122 Event::unloop; 100 EV::unloop;
123 }; 101 };
124 }; 102 };
125 103
126 # possibly queue up other requests, or open GUI windows, 104 # possibly queue up other requests, or open GUI windows,
127 # check for sockets etc. etc. 105 # check for sockets etc. etc.
128 106
129 # process events as long as there are some: 107 # process events as long as there are some:
130 Event::loop; 108 EV::loop;
131 109
132=head1 REQUEST ANATOMY AND LIFETIME 110=head1 REQUEST ANATOMY AND LIFETIME
133 111
134Every C<aio_*> function creates a request. which is a C data structure not 112Every C<aio_*> function creates a request. which is a C data structure not
135directly visible to Perl. 113directly visible to Perl.
183 161
184=cut 162=cut
185 163
186package IO::AIO; 164package IO::AIO;
187 165
188no warnings; 166use Carp ();
189use strict 'vars'; 167
168use common::sense;
190 169
191use base 'Exporter'; 170use base 'Exporter';
192 171
193BEGIN { 172BEGIN {
194 our $VERSION = '2.1'; 173 our $VERSION = '3.5';
195 174
196 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat 175 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close
197 aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink 176 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
198 aio_readlink aio_fsync aio_fdatasync aio_readahead aio_rename aio_link 177 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
199 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
200 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); 184 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
201 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 185 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
202 min_parallel max_parallel max_idle 186 min_parallel max_parallel max_idle
203 nreqs nready npending nthreads 187 nreqs nready npending nthreads
204 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
205 192
206 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 193 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
207 194
208 require XSLoader; 195 require XSLoader;
209 XSLoader::load ("IO::AIO", $VERSION); 196 XSLoader::load ("IO::AIO", $VERSION);
210} 197}
211 198
212=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 $flags
267 IO::AIO::munlockall
213 268
214=head2 AIO REQUEST FUNCTIONS 269=head2 AIO REQUEST FUNCTIONS
215 270
216All the C<aio_*> calls are more or less thin wrappers around the syscall 271All the C<aio_*> calls are more or less thin wrappers around the syscall
217with the same name (sans C<aio_>). The arguments are similar or identical, 272with the same name (sans C<aio_>). The arguments are similar or identical,
218and they all accept an additional (and optional) C<$callback> argument 273and they all accept an additional (and optional) C<$callback> argument
219which 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
220the 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
221perl, which usually delivers "false") as it's sole argument when the given 276perl, which usually delivers "false") as its sole argument after the given
222syscall has been executed asynchronously. 277syscall has been executed asynchronously.
223 278
224All functions expecting a filehandle keep a copy of the filehandle 279All functions expecting a filehandle keep a copy of the filehandle
225internally until the request has finished. 280internally until the request has finished.
226 281
240your 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
241environment, d) use Glib::filename_from_unicode on unicode filenames or e) 296environment, d) use Glib::filename_from_unicode on unicode filenames or e)
242use something else to ensure your scalar has the correct contents. 297use something else to ensure your scalar has the correct contents.
243 298
244This 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
245handles correctly wether it is set or not. 300handles correctly whether it is set or not.
246 301
247=over 4 302=over 4
248 303
249=item $prev_pri = aioreq_pri [$pri] 304=item $prev_pri = aioreq_pri [$pri]
250 305
270 aio_read $_[0], ..., sub { 325 aio_read $_[0], ..., sub {
271 ... 326 ...
272 }; 327 };
273 }; 328 };
274 329
330
275=item aioreq_nice $pri_adjust 331=item aioreq_nice $pri_adjust
276 332
277Similar 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
278priority, so the effect is cumulative. 334priority, so the effect is cumulative.
335
279 336
280=item aio_open $pathname, $flags, $mode, $callback->($fh) 337=item aio_open $pathname, $flags, $mode, $callback->($fh)
281 338
282Asynchronously 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
283created filehandle for the file. 340created filehandle for the file.
289list. They are the same as used by C<sysopen>. 346list. They are the same as used by C<sysopen>.
290 347
291Likewise, 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
292didn'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>,
293except 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,
294and C<0666> or C<0777> if you do). 351and C<0666> or C<0777> if you do). Note that the C<$mode> will be modified
352by the umask in effect then the request is being executed, so better never
353change the umask.
295 354
296Example: 355Example:
297 356
298 aio_open "/etc/passwd", O_RDONLY, 0, sub { 357 aio_open "/etc/passwd", O_RDONLY, 0, sub {
299 if ($_[0]) { 358 if ($_[0]) {
302 } else { 361 } else {
303 die "open failed: $!\n"; 362 die "open failed: $!\n";
304 } 363 }
305 }; 364 };
306 365
366
307=item aio_close $fh, $callback->($status) 367=item aio_close $fh, $callback->($status)
308 368
309Asynchronously close a file and call the callback with the result 369Asynchronously close a file and call the callback with the result
310code. I<WARNING:> although accepted, you should not pass in a perl 370code.
311filehandle here, as perl will likely close the file descriptor another
312time when the filehandle is destroyed. Normally, you can safely call perls
313C<close> or just let filehandles go out of scope.
314 371
315This 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
316therefore 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
317 383
318=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 384=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
319 385
320=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 386=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
321 387
322Reads 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
323into 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<$dataoffset>
324callback without the actual number of bytes read (or -1 on error, just 390and calls the callback without the actual number of bytes read (or -1 on
325like the syscall). 391error, just like the syscall).
392
393C<aio_read> will, like C<sysread>, shrink or grow the C<$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<$data>.
326 405
327The C<$data> scalar I<MUST NOT> be modified in any way while the request 406The C<$data> scalar I<MUST NOT> be modified in any way while the request
328is outstanding. Modifying it can result in segfaults or WW3 (if the 407is outstanding. Modifying it can result in segfaults or World War III (if
329necessary/optional hardware is installed). 408the necessary/optional hardware is installed).
330 409
331Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at 410Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
332offset C<0> within the scalar: 411offset C<0> within the scalar:
333 412
334 aio_read $fh, 7, 15, $buffer, 0, sub { 413 aio_read $fh, 7, 15, $buffer, 0, sub {
335 $_[0] > 0 or die "read error: $!"; 414 $_[0] > 0 or die "read error: $!";
336 print "read $_[0] bytes: <$buffer>\n"; 415 print "read $_[0] bytes: <$buffer>\n";
337 }; 416 };
417
338 418
339=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)
340 420
341Tries 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
342reading 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
344than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each 424than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
345other. 425other.
346 426
347This 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
348zero-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
349socket, and C<$in_fh> should refer to mmap'able file. 429socket, and C<$in_fh> should refer to an mmap'able file.
350 430
351If 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>,
352emulated, 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
353regardless of the limitations of the operating system. 434filehandle regardless of the limitations of the operating system.
354 435
355Please note, however, that C<aio_sendfile> can read more bytes from 436Please note, however, that C<aio_sendfile> can read more bytes from
356C<$in_fh> than are written, and there is no way to find out how many 437C<$in_fh> than are written, and there is no way to find out how many
357bytes 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
358provides 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
359value 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
360read. 441read.
442
361 443
362=item aio_readahead $fh,$offset,$length, $callback->($retval) 444=item aio_readahead $fh,$offset,$length, $callback->($retval)
363 445
364C<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
365subsequent 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>
371file. The current file offset of the file is left unchanged. 453file. The current file offset of the file is left unchanged.
372 454
373If 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
374emulated by simply reading the data, which would have a similar effect. 456emulated by simply reading the data, which would have a similar effect.
375 457
458
376=item aio_stat $fh_or_path, $callback->($status) 459=item aio_stat $fh_or_path, $callback->($status)
377 460
378=item aio_lstat $fh, $callback->($status) 461=item aio_lstat $fh, $callback->($status)
379 462
380Works 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
393 aio_stat "/etc/passwd", sub { 476 aio_stat "/etc/passwd", sub {
394 $_[0] and die "stat failed: $!"; 477 $_[0] and die "stat failed: $!";
395 print "size is ", -s _, "\n"; 478 print "size is ", -s _, "\n";
396 }; 479 };
397 480
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
398=item aio_unlink $pathname, $callback->($status) 568=item aio_unlink $pathname, $callback->($status)
399 569
400Asynchronously unlink (delete) a file and call the callback with the 570Asynchronously unlink (delete) a file and call the callback with the
401result code. 571result code.
402 572
573
403=item aio_mknod $path, $mode, $dev, $callback->($status) 574=item aio_mknod $path, $mode, $dev, $callback->($status)
404 575
405[EXPERIMENTAL] 576[EXPERIMENTAL]
406 577
407Asynchronously create a device node (or fifo). See mknod(2). 578Asynchronously create a device node (or fifo). See mknod(2).
408 579
409The only (POSIX-) portable way of calling this function is: 580The only (POSIX-) portable way of calling this function is:
410 581
411 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... 582 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...
583
412 584
413=item aio_link $srcpath, $dstpath, $callback->($status) 585=item aio_link $srcpath, $dstpath, $callback->($status)
414 586
415Asynchronously 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
416the path C<$dstpath> and call the callback with the result code. 588the path C<$dstpath> and call the callback with the result code.
417 589
590
418=item aio_symlink $srcpath, $dstpath, $callback->($status) 591=item aio_symlink $srcpath, $dstpath, $callback->($status)
419 592
420Asynchronously 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
421the path C<$dstpath> and call the callback with the result code. 594the path C<$dstpath> and call the callback with the result code.
595
422 596
423=item aio_readlink $path, $callback->($link) 597=item aio_readlink $path, $callback->($link)
424 598
425Asynchronously read the symlink specified by C<$path> and pass it to 599Asynchronously read the symlink specified by C<$path> and pass it to
426the 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
427callback. 601callback.
428 602
603
429=item aio_rename $srcpath, $dstpath, $callback->($status) 604=item aio_rename $srcpath, $dstpath, $callback->($status)
430 605
431Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as 606Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
432rename(2) and call the callback with the result code. 607rename(2) and call the callback with the result code.
433 608
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
434=item aio_rmdir $pathname, $callback->($status) 617=item aio_rmdir $pathname, $callback->($status)
435 618
436Asynchronously rmdir (delete) a directory and call the callback with the 619Asynchronously rmdir (delete) a directory and call the callback with the
437result code. 620result code.
621
438 622
439=item aio_readdir $pathname, $callback->($entries) 623=item aio_readdir $pathname, $callback->($entries)
440 624
441Unlike 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
442directory (i.e. opendir + readdir + closedir). The entries will not be 626directory (i.e. opendir + readdir + closedir). The entries will not be
443sorted, and will B<NOT> include the C<.> and C<..> entries. 627sorted, and will B<NOT> include the C<.> and C<..> entries.
444 628
445The 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
446with 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}
447 726
448=item aio_copy $srcpath, $dstpath, $callback->($status) 727=item aio_copy $srcpath, $dstpath, $callback->($status)
449 728
450Try 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
451destination) from C<$srcpath> to C<$dstpath> and call the callback with 730destination) from C<$srcpath> to C<$dstpath> and call the callback with
452the C<0> (error) or C<-1> ok. 731a status of C<0> (ok) or C<-1> (error, see C<$!>).
453 732
454This is a composite request that it creates the destination file with 733This is a composite request that creates the destination file with
455mode 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
456C<aio_sendfile>, followed by restoring atime, mtime, access mode and 735C<aio_sendfile>, followed by restoring atime, mtime, access mode and
457uid/gid, in that order. 736uid/gid, in that order.
458 737
459If an error occurs, the partial destination file will be unlinked, if 738If an error occurs, the partial destination file will be unlinked, if
469 my $grp = aio_group $cb; 748 my $grp = aio_group $cb;
470 749
471 aioreq_pri $pri; 750 aioreq_pri $pri;
472 add $grp aio_open $src, O_RDONLY, 0, sub { 751 add $grp aio_open $src, O_RDONLY, 0, sub {
473 if (my $src_fh = $_[0]) { 752 if (my $src_fh = $_[0]) {
474 my @stat = stat $src_fh; 753 my @stat = stat $src_fh; # hmm, might block over nfs?
475 754
476 aioreq_pri $pri; 755 aioreq_pri $pri;
477 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 {
478 if (my $dst_fh = $_[0]) { 757 if (my $dst_fh = $_[0]) {
479 aioreq_pri $pri; 758 aioreq_pri $pri;
480 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 759 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
481 if ($_[0] == $stat[7]) { 760 if ($_[0] == $stat[7]) {
482 $grp->result (0); 761 $grp->result (0);
483 close $src_fh; 762 close $src_fh;
484 763
485 # those should not normally block. should. should. 764 my $ch = sub {
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;
770 add $grp aio_close $dst_fh;
771 }
772 };
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;
486 utime $stat[8], $stat[9], $dst; 779 add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
487 chmod $stat[2] & 07777, $dst_fh; 780 } else {
488 chown $stat[4], $stat[5], $dst_fh; 781 $ch->();
782 }
489 close $dst_fh; 783 };
490 } else { 784 } else {
491 $grp->result (-1); 785 $grp->result (-1);
492 close $src_fh; 786 close $src_fh;
493 close $dst_fh; 787 close $dst_fh;
494 788
511 805
512=item aio_move $srcpath, $dstpath, $callback->($status) 806=item aio_move $srcpath, $dstpath, $callback->($status)
513 807
514Try 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
515destination) from C<$srcpath> to C<$dstpath> and call the callback with 809destination) from C<$srcpath> to C<$dstpath> and call the callback with
516the C<0> (error) or C<-1> ok. 810a status of C<0> (ok) or C<-1> (error, see C<$!>).
517 811
518This is a composite request that tries to rename(2) the file first. If 812This is a composite request that tries to rename(2) the file first; if
519rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if 813rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
520that is successful, unlinking the C<$srcpath>. 814that is successful, unlinks the C<$srcpath>.
521 815
522=cut 816=cut
523 817
524sub aio_move($$;$) { 818sub aio_move($$;$) {
525 my ($src, $dst, $cb) = @_; 819 my ($src, $dst, $cb) = @_;
572 866
573Implementation notes. 867Implementation notes.
574 868
575The 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.
576 870
871If readdir returns file type information, then this is used directly to
872find directories.
873
577After reading the directory, the modification time, size etc. of the 874Otherwise, after reading the directory, the modification time, size etc.
578directory 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
579isn'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
580entries are directories (if >= 2). Otherwise, no knowledge of the number 877how many entries are directories (if >= 2). Otherwise, no knowledge of the
581of subdirectories will be assumed. 878number of subdirectories will be assumed.
582 879
583Then entries will be sorted into likely directories (everything without 880Then entries will be sorted into likely directories a non-initial dot
584a non-initial dot currently) and likely non-directories (everything 881currently) and likely non-directories (see C<aio_readdirx>). Then every
585else). 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,
586likely directories first. If that succeeds, it assumes that the entry 883in order of their inode numbers. If that succeeds, it assumes that the
587is a directory or a symlink to directory (which will be checked 884entry is a directory or a symlink to directory (which will be checked
588seperately). This is often faster than stat'ing the entry itself because 885seperately). This is often faster than stat'ing the entry itself because
589filesystems might detect the type of the entry without reading the inode 886filesystems might detect the type of the entry without reading the inode
590data (e.g. ext2fs filetype feature). 887data (e.g. ext2fs filetype feature), even on systems that cannot return
888the filetype information on readdir.
591 889
592If 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
593rest of the entries is assumed to be non-directories. 891rest of the entries is assumed to be non-directories.
594 892
595This only works with certainty on POSIX (= UNIX) filesystems, which 893This only works with certainty on POSIX (= UNIX) filesystems, which
599as 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
600directory counting heuristic. 898directory counting heuristic.
601 899
602=cut 900=cut
603 901
604sub aio_scandir($$$) { 902sub aio_scandir($$;$) {
605 my ($path, $maxreq, $cb) = @_; 903 my ($path, $maxreq, $cb) = @_;
606 904
607 my $pri = aioreq_pri; 905 my $pri = aioreq_pri;
608 906
609 my $grp = aio_group $cb; 907 my $grp = aio_group $cb;
617 my $now = time; 915 my $now = time;
618 my $hash1 = join ":", (stat _)[0,1,3,7,9]; 916 my $hash1 = join ":", (stat _)[0,1,3,7,9];
619 917
620 # read the directory entries 918 # read the directory entries
621 aioreq_pri $pri; 919 aioreq_pri $pri;
622 add $grp aio_readdir $path, sub { 920 add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
623 my $entries = shift 921 my $entries = shift
624 or return $grp->result (); 922 or return $grp->result ();
625 923
626 # stat the dir another time 924 # stat the dir another time
627 aioreq_pri $pri; 925 aioreq_pri $pri;
633 # take the slow route if anything looks fishy 931 # take the slow route if anything looks fishy
634 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 932 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
635 $ndirs = -1; 933 $ndirs = -1;
636 } else { 934 } else {
637 # if nlink == 2, we are finished 935 # if nlink == 2, we are finished
638 # on non-posix-fs's, we rely on nlink < 2 936 # for non-posix-fs's, we rely on nlink < 2
639 $ndirs = (stat _)[3] - 2 937 $ndirs = (stat _)[3] - 2
640 or return $grp->result ([], $entries); 938 or return $grp->result ([], $entries);
641 } 939 }
642 940
643 # sort into likely dirs and likely nondirs
644 # dirs == files without ".", short entries first
645 $entries = [map $_->[0],
646 sort { $b->[1] cmp $a->[1] }
647 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
648 @$entries];
649
650 my (@dirs, @nondirs); 941 my (@dirs, @nondirs);
651 942
652 my $statgrp = add $grp aio_group sub { 943 my $statgrp = add $grp aio_group sub {
653 $grp->result (\@dirs, \@nondirs); 944 $grp->result (\@dirs, \@nondirs);
654 }; 945 };
655 946
656 limit $statgrp $maxreq; 947 limit $statgrp $maxreq;
657 feed $statgrp sub { 948 feed $statgrp sub {
658 return unless @$entries; 949 return unless @$entries;
659 my $entry = pop @$entries; 950 my $entry = shift @$entries;
660 951
661 aioreq_pri $pri; 952 aioreq_pri $pri;
662 add $statgrp aio_stat "$path/$entry/.", sub { 953 add $statgrp aio_stat "$path/$entry/.", sub {
663 if ($_[0] < 0) { 954 if ($_[0] < 0) {
664 push @nondirs, $entry; 955 push @nondirs, $entry;
685 }; 976 };
686 977
687 $grp 978 $grp
688} 979}
689 980
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.
1019
690=item aio_fsync $fh, $callback->($status) 1020=item aio_fsync $fh, $callback->($status)
691 1021
692Asynchronously call fsync on the given filehandle and call the callback 1022Asynchronously call fsync on the given filehandle and call the callback
693with the fsync result code. 1023with the fsync result code.
694 1024
697Asynchronously call fdatasync on the given filehandle and call the 1027Asynchronously call fdatasync on the given filehandle and call the
698callback with the fdatasync result code. 1028callback with the fdatasync result code.
699 1029
700If 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
701detected, 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 C<IO::AIO::mmap> function, although it also works on data
1090scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
1091scalar must only be modified in-place while an aio operation is pending on
1092it).
1093
1094It calls the C<msync> function of your OS, if available, with the memory
1095area starting at C<$offset> in the string and ending C<$length> bytes
1096later. If C<$length> is negative, counts from the end, and if C<$length>
1097is C<undef>, then it goes till the end of the string. The flags can be
1098a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
1099C<IO::AIO::MS_SYNC>.
1100
1101=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1102
1103This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1104scalars.
1105
1106It touches (reads or writes) all memory pages in the specified
1107range inside the scalar. All caveats and parameters are the same
1108as for C<aio_msync>, above, except for flags, which must be either
1109C<0> (which reads all pages and ensures they are instantiated) or
1110C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
1111writing an octet from it, which dirties the page).
702 1112
703=item aio_group $callback->(...) 1113=item aio_group $callback->(...)
704 1114
705This is a very special aio request: Instead of doing something, it is a 1115This is a very special aio request: Instead of doing something, it is a
706container for other aio requests, which is useful if you want to bundle 1116container for other aio requests, which is useful if you want to bundle
756=item cancel $req 1166=item cancel $req
757 1167
758Cancels the request, if possible. Has the effect of skipping execution 1168Cancels the request, if possible. Has the effect of skipping execution
759when entering the B<execute> state and skipping calling the callback when 1169when entering the B<execute> state and skipping calling the callback when
760entering the the B<result> state, but will leave the request otherwise 1170entering the the B<result> state, but will leave the request otherwise
761untouched. That means that requests that currently execute will not be 1171untouched (with the exception of readdir). That means that requests that
762stopped and resources held by the request will not be freed prematurely. 1172currently execute will not be stopped and resources held by the request
1173will not be freed prematurely.
763 1174
764=item cb $req $callback->(...) 1175=item cb $req $callback->(...)
765 1176
766Replace (or simply set) the callback registered to the request. 1177Replace (or simply set) the callback registered to the request.
767 1178
818Their lifetime, simplified, looks like this: when they are empty, they 1229Their lifetime, simplified, looks like this: when they are empty, they
819will finish very quickly. If they contain only requests that are in the 1230will finish very quickly. If they contain only requests that are in the
820C<done> state, they will also finish. Otherwise they will continue to 1231C<done> state, they will also finish. Otherwise they will continue to
821exist. 1232exist.
822 1233
823That means after creating a group you have some time to add requests. And 1234That means after creating a group you have some time to add requests
824in the callbacks of those requests, you can add further requests to the 1235(precisely before the callback has been invoked, which is only done within
825group. And only when all those requests have finished will the the group 1236the C<poll_cb>). And in the callbacks of those requests, you can add
826itself finish. 1237further requests to the group. And only when all those requests have
1238finished will the the group itself finish.
827 1239
828=over 4 1240=over 4
829 1241
830=item add $grp ... 1242=item add $grp ...
831 1243
840=item $grp->cancel_subs 1252=item $grp->cancel_subs
841 1253
842Cancel all subrequests and clears any feeder, but not the group request 1254Cancel all subrequests and clears any feeder, but not the group request
843itself. Useful when you queued a lot of events but got a result early. 1255itself. Useful when you queued a lot of events but got a result early.
844 1256
1257The group request will finish normally (you cannot add requests to the
1258group).
1259
845=item $grp->result (...) 1260=item $grp->result (...)
846 1261
847Set the result value(s) that will be passed to the group callback when all 1262Set the result value(s) that will be passed to the group callback when all
848subrequests have finished and set thre groups errno to the current value 1263subrequests have finished and set the groups errno to the current value
849of errno (just like calling C<errno> without an error number). By default, 1264of errno (just like calling C<errno> without an error number). By default,
850no argument will be passed and errno is zero. 1265no argument will be passed and errno is zero.
851 1266
852=item $grp->errno ([$errno]) 1267=item $grp->errno ([$errno])
853 1268
864=item feed $grp $callback->($grp) 1279=item feed $grp $callback->($grp)
865 1280
866Sets a feeder/generator on this group: every group can have an attached 1281Sets a feeder/generator on this group: every group can have an attached
867generator that generates requests if idle. The idea behind this is that, 1282generator that generates requests if idle. The idea behind this is that,
868although you could just queue as many requests as you want in a group, 1283although you could just queue as many requests as you want in a group,
869this might starve other requests for a potentially long time. For 1284this might starve other requests for a potentially long time. For example,
870example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1285C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
871requests, delaying any later requests for a long time. 1286delaying any later requests for a long time.
872 1287
873To avoid this, and allow incremental generation of requests, you can 1288To avoid this, and allow incremental generation of requests, you can
874instead a group and set a feeder on it that generates those requests. The 1289instead a group and set a feeder on it that generates those requests. The
875feed callback will be called whenever there are few enough (see C<limit>, 1290feed callback will be called whenever there are few enough (see C<limit>,
876below) requests active in the group itself and is expected to queue more 1291below) requests active in the group itself and is expected to queue more
880not impose any limits). 1295not impose any limits).
881 1296
882If the feed does not queue more requests when called, it will be 1297If the feed does not queue more requests when called, it will be
883automatically removed from the group. 1298automatically removed from the group.
884 1299
885If the feed limit is C<0>, it will be set to C<2> automatically. 1300If the feed limit is C<0> when this method is called, it will be set to
1301C<2> automatically.
886 1302
887Example: 1303Example:
888 1304
889 # stat all files in @files, but only ever use four aio requests concurrently: 1305 # stat all files in @files, but only ever use four aio requests concurrently:
890 1306
902Sets the feeder limit for the group: The feeder will be called whenever 1318Sets the feeder limit for the group: The feeder will be called whenever
903the group contains less than this many requests. 1319the group contains less than this many requests.
904 1320
905Setting the limit to C<0> will pause the feeding process. 1321Setting the limit to C<0> will pause the feeding process.
906 1322
1323The default value for the limit is C<0>, but note that setting a feeder
1324automatically bumps it up to C<2>.
1325
907=back 1326=back
908 1327
909=head2 SUPPORT FUNCTIONS 1328=head2 SUPPORT FUNCTIONS
910 1329
911=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1330=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
913=over 4 1332=over 4
914 1333
915=item $fileno = IO::AIO::poll_fileno 1334=item $fileno = IO::AIO::poll_fileno
916 1335
917Return the I<request result pipe file descriptor>. This filehandle must be 1336Return the I<request result pipe file descriptor>. This filehandle must be
918polled for reading by some mechanism outside this module (e.g. Event or 1337polled for reading by some mechanism outside this module (e.g. EV, Glib,
919select, see below or the SYNOPSIS). If the pipe becomes readable you have 1338select and so on, see below or the SYNOPSIS). If the pipe becomes readable
920to call C<poll_cb> to check the results. 1339you have to call C<poll_cb> to check the results.
921 1340
922See C<poll_cb> for an example. 1341See C<poll_cb> for an example.
923 1342
924=item IO::AIO::poll_cb 1343=item IO::AIO::poll_cb
925 1344
926Process some outstanding events on the result pipe. You have to call this 1345Process some outstanding events on the result pipe. You have to call this
927regularly. Returns the number of events processed. Returns immediately 1346regularly. Returns C<0> if all events could be processed, or C<-1> if it
1347returned earlier for whatever reason. Returns immediately when no events
928when no events are outstanding. The amount of events processed depends on 1348are outstanding. The amount of events processed depends on the settings of
929the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>. 1349C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
930 1350
931If not all requests were processed for whatever reason, the filehandle 1351If not all requests were processed for whatever reason, the filehandle
932will still be ready when C<poll_cb> returns. 1352will still be ready when C<poll_cb> returns, so normally you don't have to
1353do anything special to have it called later.
933 1354
934Example: Install an Event watcher that automatically calls 1355Example: Install an Event watcher that automatically calls
935IO::AIO::poll_cb with high priority: 1356IO::AIO::poll_cb with high priority (more examples can be found in the
1357SYNOPSIS section, at the top of this document):
936 1358
937 Event->io (fd => IO::AIO::poll_fileno, 1359 Event->io (fd => IO::AIO::poll_fileno,
938 poll => 'r', async => 1, 1360 poll => 'r', async => 1,
939 cb => \&IO::AIO::poll_cb); 1361 cb => \&IO::AIO::poll_cb);
1362
1363=item IO::AIO::poll_wait
1364
1365If there are any outstanding requests and none of them in the result
1366phase, wait till the result filehandle becomes ready for reading (simply
1367does a C<select> on the filehandle. This is useful if you want to
1368synchronously wait for some requests to finish).
1369
1370See C<nreqs> for an example.
1371
1372=item IO::AIO::poll
1373
1374Waits until some requests have been handled.
1375
1376Returns the number of requests processed, but is otherwise strictly
1377equivalent to:
1378
1379 IO::AIO::poll_wait, IO::AIO::poll_cb
1380
1381=item IO::AIO::flush
1382
1383Wait till all outstanding AIO requests have been handled.
1384
1385Strictly equivalent to:
1386
1387 IO::AIO::poll_wait, IO::AIO::poll_cb
1388 while IO::AIO::nreqs;
940 1389
941=item IO::AIO::max_poll_reqs $nreqs 1390=item IO::AIO::max_poll_reqs $nreqs
942 1391
943=item IO::AIO::max_poll_time $seconds 1392=item IO::AIO::max_poll_time $seconds
944 1393
969 # use a low priority so other tasks have priority 1418 # use a low priority so other tasks have priority
970 Event->io (fd => IO::AIO::poll_fileno, 1419 Event->io (fd => IO::AIO::poll_fileno,
971 poll => 'r', nice => 1, 1420 poll => 'r', nice => 1,
972 cb => &IO::AIO::poll_cb); 1421 cb => &IO::AIO::poll_cb);
973 1422
974=item IO::AIO::poll_wait 1423=back
975
976Wait till the result filehandle becomes ready for reading (simply does a
977C<select> on the filehandle. This is useful if you want to synchronously
978wait for some requests to finish).
979
980See C<nreqs> for an example.
981
982=item IO::AIO::poll
983
984Waits until some requests have been handled.
985
986Strictly equivalent to:
987
988 IO::AIO::poll_wait, IO::AIO::poll_cb
989 if IO::AIO::nreqs;
990
991=item IO::AIO::flush
992
993Wait till all outstanding AIO requests have been handled.
994
995Strictly equivalent to:
996
997 IO::AIO::poll_wait, IO::AIO::poll_cb
998 while IO::AIO::nreqs;
999 1424
1000=head3 CONTROLLING THE NUMBER OF THREADS 1425=head3 CONTROLLING THE NUMBER OF THREADS
1426
1427=over
1001 1428
1002=item IO::AIO::min_parallel $nthreads 1429=item IO::AIO::min_parallel $nthreads
1003 1430
1004Set the minimum number of AIO threads to C<$nthreads>. The current 1431Set the minimum number of AIO threads to C<$nthreads>. The current
1005default is C<8>, which means eight asynchronous operations can execute 1432default is C<8>, which means eight asynchronous operations can execute
1046 1473
1047The default is probably ok in most situations, especially if thread 1474The default is probably ok in most situations, especially if thread
1048creation is fast. If thread creation is very slow on your system you might 1475creation is fast. If thread creation is very slow on your system you might
1049want to use larger values. 1476want to use larger values.
1050 1477
1051=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1478=item IO::AIO::max_outstanding $maxreqs
1052 1479
1053This is a very bad function to use in interactive programs because it 1480This is a very bad function to use in interactive programs because it
1054blocks, and a bad way to reduce concurrency because it is inexact: Better 1481blocks, and a bad way to reduce concurrency because it is inexact: Better
1055use an C<aio_group> together with a feed callback. 1482use an C<aio_group> together with a feed callback.
1056 1483
1057Sets the maximum number of outstanding requests to C<$nreqs>. If you 1484Sets the maximum number of outstanding requests to C<$nreqs>. If you
1058to queue up more than this number of requests, the next call to the 1485do queue up more than this number of requests, the next call to the
1059C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>) 1486C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
1060function will block until the limit is no longer exceeded. 1487function will block until the limit is no longer exceeded.
1061 1488
1062The default value is very large, so there is no practical limit on the 1489The default value is very large, so there is no practical limit on the
1063number of outstanding requests. 1490number of outstanding requests.
1064 1491
1065You can still queue as many requests as you want. Therefore, 1492You can still queue as many requests as you want. Therefore,
1066C<max_oustsanding> is mainly useful in simple scripts (with low values) or 1493C<max_outstanding> is mainly useful in simple scripts (with low values) or
1067as a stop gap to shield against fatal memory overflow (with large values). 1494as a stop gap to shield against fatal memory overflow (with large values).
1068 1495
1496=back
1497
1069=head3 STATISTICAL INFORMATION 1498=head3 STATISTICAL INFORMATION
1499
1500=over
1070 1501
1071=item IO::AIO::nreqs 1502=item IO::AIO::nreqs
1072 1503
1073Returns the number of requests currently in the ready, execute or pending 1504Returns the number of requests currently in the ready, execute or pending
1074states (i.e. for which their callback has not been invoked yet). 1505states (i.e. for which their callback has not been invoked yet).
1088Returns the number of requests currently in the pending state (executed, 1519Returns the number of requests currently in the pending state (executed,
1089but not yet processed by poll_cb). 1520but not yet processed by poll_cb).
1090 1521
1091=back 1522=back
1092 1523
1524=head3 MISCELLANEOUS FUNCTIONS
1525
1526IO::AIO implements some functions that might be useful, but are not
1527asynchronous.
1528
1529=over 4
1530
1531=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1532
1533Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
1534but is blocking (this makes most sense if you know the input data is
1535likely cached already and the output filehandle is set to non-blocking
1536operations).
1537
1538Returns the number of bytes copied, or C<-1> on error.
1539
1540=item IO::AIO::fadvise $fh, $offset, $len, $advice
1541
1542Simply calls the C<posix_fadvise> function (see it's
1543manpage for details). The following advice constants are
1544avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1545C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1546C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1547
1548On systems that do not implement C<posix_fadvise>, this function returns
1549ENOSYS, otherwise the return value of C<posix_fadvise>.
1550
1551=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1552
1553Memory-maps a file (or anonymous memory range) and attaches it to the
1554given C<$scalar>, which will act like a string scalar.
1555
1556The only operations allowed on the scalar are C<substr>/C<vec> that don't
1557change the string length, and most read-only operations such as copying it
1558or searching it with regexes and so on.
1559
1560Anything else is unsafe and will, at best, result in memory leaks.
1561
1562The memory map associated with the C<$scalar> is automatically removed
1563when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
1564C<IO::AIO::munmap> functions are called.
1565
1566This calls the C<mmap>(2) function internally. See your system's manual
1567page for details on the C<$length>, C<$prot> and C<$flags> parameters.
1568
1569The C<$length> must be larger than zero and smaller than the actual
1570filesize.
1571
1572C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1573C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1574
1575C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
1576C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
1577not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
1578(which is set to C<MAP_ANON> if your system only provides this
1579constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
1580C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
1581C<IO::AIO::MAP_NONBLOCK>
1582
1583If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1584
1585=item IO::AIO::munmap $scalar
1586
1587Removes a previous mmap and undefines the C<$scalar>.
1588
1589=item IO::AIO::mlockall $flags
1590
1591Calls the C<mlockall> function with the given C<$flags> (a combination of
1592C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL__FUTURE>).
1593
1594On systems that do not implement C<mlockall>, this function returns
1595ENOSYS, otherwise the return value of C<mlockall>.
1596
1597=item IO::AIO::munlockall
1598
1599Calls the C<munlockall> function.
1600
1601On systems that do not implement C<munlockall>, this function returns
1602ENOSYS, otherwise the return value of C<munlockall>.
1603
1604=back
1605
1093=cut 1606=cut
1094 1607
1095# support function to convert a fd into a perl filehandle
1096sub _fd2fh {
1097 return undef if $_[0] < 0;
1098
1099 # try to generate nice filehandles
1100 my $sym = "IO::AIO::fd#$_[0]";
1101 local *$sym;
1102
1103 open *$sym, "+<&=$_[0]" # usually works under any unix
1104 or open *$sym, "<&=$_[0]" # cygwin needs this
1105 or open *$sym, ">&=$_[0]" # or this
1106 or return undef;
1107
1108 *$sym
1109}
1110
1111min_parallel 8; 1608min_parallel 8;
1112 1609
1113END { 1610END { flush }
1114 min_parallel 1;
1115 flush;
1116};
1117 1611
11181; 16121;
1613
1614=head1 EVENT LOOP INTEGRATION
1615
1616It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
1617automatically into many event loops:
1618
1619 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
1620 use AnyEvent::AIO;
1621
1622You can also integrate IO::AIO manually into many event loops, here are
1623some examples of how to do this:
1624
1625 # EV integration
1626 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
1627
1628 # Event integration
1629 Event->io (fd => IO::AIO::poll_fileno,
1630 poll => 'r',
1631 cb => \&IO::AIO::poll_cb);
1632
1633 # Glib/Gtk2 integration
1634 add_watch Glib::IO IO::AIO::poll_fileno,
1635 in => sub { IO::AIO::poll_cb; 1 };
1636
1637 # Tk integration
1638 Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
1639 readable => \&IO::AIO::poll_cb);
1640
1641 # Danga::Socket integration
1642 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
1643 \&IO::AIO::poll_cb);
1119 1644
1120=head2 FORK BEHAVIOUR 1645=head2 FORK BEHAVIOUR
1121 1646
1122This module should do "the right thing" when the process using it forks: 1647This module should do "the right thing" when the process using it forks:
1123 1648
1141bytes of memory. In addition, stat requests need a stat buffer (possibly 1666bytes of memory. In addition, stat requests need a stat buffer (possibly
1142a few hundred bytes), readdir requires a result buffer and so on. Perl 1667a few hundred bytes), readdir requires a result buffer and so on. Perl
1143scalars and other data passed into aio requests will also be locked and 1668scalars and other data passed into aio requests will also be locked and
1144will consume memory till the request has entered the done state. 1669will consume memory till the request has entered the done state.
1145 1670
1146This is now awfully much, so queuing lots of requests is not usually a 1671This is not awfully much, so queuing lots of requests is not usually a
1147problem. 1672problem.
1148 1673
1149Per-thread usage: 1674Per-thread usage:
1150 1675
1151In the execution phase, some aio requests require more memory for 1676In the execution phase, some aio requests require more memory for
1156 1681
1157Known bugs will be fixed in the next release. 1682Known bugs will be fixed in the next release.
1158 1683
1159=head1 SEE ALSO 1684=head1 SEE ALSO
1160 1685
1161L<Coro::AIO>. 1686L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1687more natural syntax.
1162 1688
1163=head1 AUTHOR 1689=head1 AUTHOR
1164 1690
1165 Marc Lehmann <schmorp@schmorp.de> 1691 Marc Lehmann <schmorp@schmorp.de>
1166 http://home.schmorp.de/ 1692 http://home.schmorp.de/

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