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Revision 1.91 by root, Mon Oct 30 23:30:29 2006 UTC vs.
Revision 1.183 by root, Sun Sep 12 03:40:05 2010 UTC

4 4
5=head1 SYNOPSIS 5=head1 SYNOPSIS
6 6
7 use IO::AIO; 7 use IO::AIO;
8 8
9 aio_open "/etc/passwd", O_RDONLY, 0, sub { 9 aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
10 my ($fh) = @_; 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", IO::AIO::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 = '2.2'; 173 our $VERSION = '3.65';
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_mlock aio_mlockall
183 aio_statvfs);
184
200 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); 185 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
201 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 186 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
202 min_parallel max_parallel max_idle 187 min_parallel max_parallel max_idle
203 nreqs nready npending nthreads 188 nreqs nready npending nthreads
204 max_poll_time max_poll_reqs); 189 max_poll_time max_poll_reqs
190 sendfile fadvise madvise
191 mmap munmap munlock munlockall);
192
193 push @AIO_REQ, qw(aio_busy); # not exported
205 194
206 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 195 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
207 196
208 require XSLoader; 197 require XSLoader;
209 XSLoader::load ("IO::AIO", $VERSION); 198 XSLoader::load ("IO::AIO", $VERSION);
210} 199}
211 200
212=head1 FUNCTIONS 201=head1 FUNCTIONS
202
203=head2 QUICK OVERVIEW
204
205This section simply lists the prototypes of the most important functions
206for quick reference. See the following sections for function-by-function
207documentation.
208
209 aio_open $pathname, $flags, $mode, $callback->($fh)
210 aio_close $fh, $callback->($status)
211 aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
212 aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
213 aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
214 aio_readahead $fh,$offset,$length, $callback->($retval)
215 aio_stat $fh_or_path, $callback->($status)
216 aio_lstat $fh, $callback->($status)
217 aio_statvfs $fh_or_path, $callback->($statvfs)
218 aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
219 aio_chown $fh_or_path, $uid, $gid, $callback->($status)
220 aio_truncate $fh_or_path, $offset, $callback->($status)
221 aio_chmod $fh_or_path, $mode, $callback->($status)
222 aio_unlink $pathname, $callback->($status)
223 aio_mknod $path, $mode, $dev, $callback->($status)
224 aio_link $srcpath, $dstpath, $callback->($status)
225 aio_symlink $srcpath, $dstpath, $callback->($status)
226 aio_readlink $path, $callback->($link)
227 aio_rename $srcpath, $dstpath, $callback->($status)
228 aio_mkdir $pathname, $mode, $callback->($status)
229 aio_rmdir $pathname, $callback->($status)
230 aio_readdir $pathname, $callback->($entries)
231 aio_readdirx $pathname, $flags, $callback->($entries, $flags)
232 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
233 IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN
234 aio_load $path, $data, $callback->($status)
235 aio_copy $srcpath, $dstpath, $callback->($status)
236 aio_move $srcpath, $dstpath, $callback->($status)
237 aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
238 aio_rmtree $path, $callback->($status)
239 aio_sync $callback->($status)
240 aio_fsync $fh, $callback->($status)
241 aio_fdatasync $fh, $callback->($status)
242 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
243 aio_pathsync $path, $callback->($status)
244 aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
245 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
246 aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
247 aio_mlockall $flags, $callback->($status)
248 aio_group $callback->(...)
249 aio_nop $callback->()
250
251 $prev_pri = aioreq_pri [$pri]
252 aioreq_nice $pri_adjust
253
254 IO::AIO::poll_wait
255 IO::AIO::poll_cb
256 IO::AIO::poll
257 IO::AIO::flush
258 IO::AIO::max_poll_reqs $nreqs
259 IO::AIO::max_poll_time $seconds
260 IO::AIO::min_parallel $nthreads
261 IO::AIO::max_parallel $nthreads
262 IO::AIO::max_idle $nthreads
263 IO::AIO::max_outstanding $maxreqs
264 IO::AIO::nreqs
265 IO::AIO::nready
266 IO::AIO::npending
267
268 IO::AIO::sendfile $ofh, $ifh, $offset, $count
269 IO::AIO::fadvise $fh, $offset, $len, $advice
270 IO::AIO::munlock $scalar, $offset = 0, $length = undef
271 IO::AIO::munlockall
213 272
214=head2 AIO REQUEST FUNCTIONS 273=head2 AIO REQUEST FUNCTIONS
215 274
216All the C<aio_*> calls are more or less thin wrappers around the syscall 275All the C<aio_*> calls are more or less thin wrappers around the syscall
217with the same name (sans C<aio_>). The arguments are similar or identical, 276with the same name (sans C<aio_>). The arguments are similar or identical,
218and they all accept an additional (and optional) C<$callback> argument 277and they all accept an additional (and optional) C<$callback> argument
219which must be a code reference. This code reference will get called with 278which 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 279the 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 280perl, which usually delivers "false") as its sole argument after the given
222syscall has been executed asynchronously. 281syscall has been executed asynchronously.
223 282
224All functions expecting a filehandle keep a copy of the filehandle 283All functions expecting a filehandle keep a copy of the filehandle
225internally until the request has finished. 284internally until the request has finished.
226 285
240your pathnames to the locale (or other) encoding in effect in the user 299your pathnames to the locale (or other) encoding in effect in the user
241environment, d) use Glib::filename_from_unicode on unicode filenames or e) 300environment, d) use Glib::filename_from_unicode on unicode filenames or e)
242use something else to ensure your scalar has the correct contents. 301use something else to ensure your scalar has the correct contents.
243 302
244This works, btw. independent of the internal UTF-8 bit, which IO::AIO 303This works, btw. independent of the internal UTF-8 bit, which IO::AIO
245handles correctly wether it is set or not. 304handles correctly whether it is set or not.
246 305
247=over 4 306=over 4
248 307
249=item $prev_pri = aioreq_pri [$pri] 308=item $prev_pri = aioreq_pri [$pri]
250 309
270 aio_read $_[0], ..., sub { 329 aio_read $_[0], ..., sub {
271 ... 330 ...
272 }; 331 };
273 }; 332 };
274 333
334
275=item aioreq_nice $pri_adjust 335=item aioreq_nice $pri_adjust
276 336
277Similar to C<aioreq_pri>, but subtracts the given value from the current 337Similar to C<aioreq_pri>, but subtracts the given value from the current
278priority, so the effect is cumulative. 338priority, so the effect is cumulative.
339
279 340
280=item aio_open $pathname, $flags, $mode, $callback->($fh) 341=item aio_open $pathname, $flags, $mode, $callback->($fh)
281 342
282Asynchronously open or create a file and call the callback with a newly 343Asynchronously open or create a file and call the callback with a newly
283created filehandle for the file. 344created filehandle for the file.
289list. They are the same as used by C<sysopen>. 350list. They are the same as used by C<sysopen>.
290 351
291Likewise, C<$mode> specifies the mode of the newly created file, if it 352Likewise, C<$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>, 353didn'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, 354except 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). 355and C<0666> or C<0777> if you do). Note that the C<$mode> will be modified
356by the umask in effect then the request is being executed, so better never
357change the umask.
295 358
296Example: 359Example:
297 360
298 aio_open "/etc/passwd", O_RDONLY, 0, sub { 361 aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
299 if ($_[0]) { 362 if ($_[0]) {
300 print "open successful, fh is $_[0]\n"; 363 print "open successful, fh is $_[0]\n";
301 ... 364 ...
302 } else { 365 } else {
303 die "open failed: $!\n"; 366 die "open failed: $!\n";
304 } 367 }
305 }; 368 };
306 369
370
307=item aio_close $fh, $callback->($status) 371=item aio_close $fh, $callback->($status)
308 372
309Asynchronously close a file and call the callback with the result 373Asynchronously close a file and call the callback with the result
310code. I<WARNING:> although accepted, you should not pass in a perl 374code.
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.
314 375
315This is supposed to be a bug in the API, so that might change. It's 376Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
316therefore best to avoid this function. 377closing the file descriptor associated with the filehandle itself.
378
379Therefore, C<aio_close> will not close the filehandle - instead it will
380use dup2 to overwrite the file descriptor with the write-end of a pipe
381(the pipe fd will be created on demand and will be cached).
382
383Or in other words: the file descriptor will be closed, but it will not be
384free for reuse until the perl filehandle is closed.
385
386=cut
317 387
318=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 388=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
319 389
320=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 390=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
321 391
322Reads or writes C<length> bytes from the specified C<fh> and C<offset> 392Reads 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 393C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
324callback without the actual number of bytes read (or -1 on error, just 394and calls the callback without the actual number of bytes read (or -1 on
325like the syscall). 395error, just like the syscall).
396
397C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
398offset plus the actual number of bytes read.
399
400If C<$offset> is undefined, then the current file descriptor offset will
401be used (and updated), otherwise the file descriptor offset will not be
402changed by these calls.
403
404If C<$length> is undefined in C<aio_write>, use the remaining length of
405C<$data>.
406
407If C<$dataoffset> is less than zero, it will be counted from the end of
408C<$data>.
326 409
327The C<$data> scalar I<MUST NOT> be modified in any way while the request 410The C<$data> scalar I<MUST NOT> be modified in any way while the request
328is outstanding. Modifying it can result in segfaults or WW3 (if the 411is outstanding. Modifying it can result in segfaults or World War III (if
329necessary/optional hardware is installed). 412the necessary/optional hardware is installed).
330 413
331Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at 414Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
332offset C<0> within the scalar: 415offset C<0> within the scalar:
333 416
334 aio_read $fh, 7, 15, $buffer, 0, sub { 417 aio_read $fh, 7, 15, $buffer, 0, sub {
335 $_[0] > 0 or die "read error: $!"; 418 $_[0] > 0 or die "read error: $!";
336 print "read $_[0] bytes: <$buffer>\n"; 419 print "read $_[0] bytes: <$buffer>\n";
337 }; 420 };
421
338 422
339=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) 423=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
340 424
341Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts 425Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
342reading at byte offset C<$in_offset>, and starts writing at the current 426reading at byte offset C<$in_offset>, and starts writing at the current
344than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each 428than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
345other. 429other.
346 430
347This call tries to make use of a native C<sendfile> syscall to provide 431This call tries to make use of a native C<sendfile> syscall to provide
348zero-copy operation. For this to work, C<$out_fh> should refer to a 432zero-copy operation. For this to work, C<$out_fh> should refer to a
349socket, and C<$in_fh> should refer to mmap'able file. 433socket, and C<$in_fh> should refer to an mmap'able file.
350 434
351If the native sendfile call fails or is not implemented, it will be 435If a native sendfile cannot be found or it fails with C<ENOSYS>,
436C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
352emulated, so you can call C<aio_sendfile> on any type of filehandle 437it will be emulated, so you can call C<aio_sendfile> on any type of
353regardless of the limitations of the operating system. 438filehandle regardless of the limitations of the operating system.
354 439
355Please note, however, that C<aio_sendfile> can read more bytes from 440Please note, however, that C<aio_sendfile> can read more bytes from
356C<$in_fh> than are written, and there is no way to find out how many 441C<$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 442bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
358provides the number of bytes written to C<$out_fh>. Only if the result 443provides the number of bytes written to C<$out_fh>. Only if the result
359value equals C<$length> one can assume that C<$length> bytes have been 444value equals C<$length> one can assume that C<$length> bytes have been
360read. 445read.
446
361 447
362=item aio_readahead $fh,$offset,$length, $callback->($retval) 448=item aio_readahead $fh,$offset,$length, $callback->($retval)
363 449
364C<aio_readahead> populates the page cache with data from a file so that 450C<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<$offset> 451subsequent reads from that file will not block on disk I/O. The C<$offset>
371file. The current file offset of the file is left unchanged. 457file. The current file offset of the file is left unchanged.
372 458
373If that syscall doesn't exist (likely if your OS isn't Linux) it will be 459If 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. 460emulated by simply reading the data, which would have a similar effect.
375 461
462
376=item aio_stat $fh_or_path, $callback->($status) 463=item aio_stat $fh_or_path, $callback->($status)
377 464
378=item aio_lstat $fh, $callback->($status) 465=item aio_lstat $fh, $callback->($status)
379 466
380Works like perl's C<stat> or C<lstat> in void context. The callback will 467Works like perl's C<stat> or C<lstat> in void context. The callback will
393 aio_stat "/etc/passwd", sub { 480 aio_stat "/etc/passwd", sub {
394 $_[0] and die "stat failed: $!"; 481 $_[0] and die "stat failed: $!";
395 print "size is ", -s _, "\n"; 482 print "size is ", -s _, "\n";
396 }; 483 };
397 484
485
486=item aio_statvfs $fh_or_path, $callback->($statvfs)
487
488Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
489whether a file handle or path was passed.
490
491On success, the callback is passed a hash reference with the following
492members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
493C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
494is passed.
495
496The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
497C<ST_NOSUID>.
498
499The following non-POSIX IO::AIO::ST_* flag masks are defined to
500their correct value when available, or to C<0> on systems that do
501not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
502C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
503C<ST_NODIRATIME> and C<ST_RELATIME>.
504
505Example: stat C</wd> and dump out the data if successful.
506
507 aio_statvfs "/wd", sub {
508 my $f = $_[0]
509 or die "statvfs: $!";
510
511 use Data::Dumper;
512 say Dumper $f;
513 };
514
515 # result:
516 {
517 bsize => 1024,
518 bfree => 4333064312,
519 blocks => 10253828096,
520 files => 2050765568,
521 flag => 4096,
522 favail => 2042092649,
523 bavail => 4333064312,
524 ffree => 2042092649,
525 namemax => 255,
526 frsize => 1024,
527 fsid => 1810
528 }
529
530
531=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
532
533Works like perl's C<utime> function (including the special case of $atime
534and $mtime being undef). Fractional times are supported if the underlying
535syscalls support them.
536
537When called with a pathname, uses utimes(2) if available, otherwise
538utime(2). If called on a file descriptor, uses futimes(2) if available,
539otherwise returns ENOSYS, so this is not portable.
540
541Examples:
542
543 # set atime and mtime to current time (basically touch(1)):
544 aio_utime "path", undef, undef;
545 # set atime to current time and mtime to beginning of the epoch:
546 aio_utime "path", time, undef; # undef==0
547
548
549=item aio_chown $fh_or_path, $uid, $gid, $callback->($status)
550
551Works like perl's C<chown> function, except that C<undef> for either $uid
552or $gid is being interpreted as "do not change" (but -1 can also be used).
553
554Examples:
555
556 # same as "chown root path" in the shell:
557 aio_chown "path", 0, -1;
558 # same as above:
559 aio_chown "path", 0, undef;
560
561
562=item aio_truncate $fh_or_path, $offset, $callback->($status)
563
564Works like truncate(2) or ftruncate(2).
565
566
567=item aio_chmod $fh_or_path, $mode, $callback->($status)
568
569Works like perl's C<chmod> function.
570
571
398=item aio_unlink $pathname, $callback->($status) 572=item aio_unlink $pathname, $callback->($status)
399 573
400Asynchronously unlink (delete) a file and call the callback with the 574Asynchronously unlink (delete) a file and call the callback with the
401result code. 575result code.
402 576
577
403=item aio_mknod $path, $mode, $dev, $callback->($status) 578=item aio_mknod $path, $mode, $dev, $callback->($status)
404 579
405[EXPERIMENTAL] 580[EXPERIMENTAL]
406 581
407Asynchronously create a device node (or fifo). See mknod(2). 582Asynchronously create a device node (or fifo). See mknod(2).
408 583
409The only (POSIX-) portable way of calling this function is: 584The only (POSIX-) portable way of calling this function is:
410 585
411 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... 586 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...
587
412 588
413=item aio_link $srcpath, $dstpath, $callback->($status) 589=item aio_link $srcpath, $dstpath, $callback->($status)
414 590
415Asynchronously create a new link to the existing object at C<$srcpath> at 591Asynchronously create a new link to the existing object at C<$srcpath> at
416the path C<$dstpath> and call the callback with the result code. 592the path C<$dstpath> and call the callback with the result code.
417 593
594
418=item aio_symlink $srcpath, $dstpath, $callback->($status) 595=item aio_symlink $srcpath, $dstpath, $callback->($status)
419 596
420Asynchronously create a new symbolic link to the existing object at C<$srcpath> at 597Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
421the path C<$dstpath> and call the callback with the result code. 598the path C<$dstpath> and call the callback with the result code.
599
422 600
423=item aio_readlink $path, $callback->($link) 601=item aio_readlink $path, $callback->($link)
424 602
425Asynchronously read the symlink specified by C<$path> and pass it to 603Asynchronously read the symlink specified by C<$path> and pass it to
426the callback. If an error occurs, nothing or undef gets passed to the 604the callback. If an error occurs, nothing or undef gets passed to the
427callback. 605callback.
428 606
607
429=item aio_rename $srcpath, $dstpath, $callback->($status) 608=item aio_rename $srcpath, $dstpath, $callback->($status)
430 609
431Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as 610Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
432rename(2) and call the callback with the result code. 611rename(2) and call the callback with the result code.
433 612
613
614=item aio_mkdir $pathname, $mode, $callback->($status)
615
616Asynchronously mkdir (create) a directory and call the callback with
617the result code. C<$mode> will be modified by the umask at the time the
618request is executed, so do not change your umask.
619
620
434=item aio_rmdir $pathname, $callback->($status) 621=item aio_rmdir $pathname, $callback->($status)
435 622
436Asynchronously rmdir (delete) a directory and call the callback with the 623Asynchronously rmdir (delete) a directory and call the callback with the
437result code. 624result code.
625
438 626
439=item aio_readdir $pathname, $callback->($entries) 627=item aio_readdir $pathname, $callback->($entries)
440 628
441Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 629Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
442directory (i.e. opendir + readdir + closedir). The entries will not be 630directory (i.e. opendir + readdir + closedir). The entries will not be
443sorted, and will B<NOT> include the C<.> and C<..> entries. 631sorted, and will B<NOT> include the C<.> and C<..> entries.
444 632
445The callback a single argument which is either C<undef> or an array-ref 633The callback is passed a single argument which is either C<undef> or an
446with the filenames. 634array-ref with the filenames.
635
636
637=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
638
639Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
640behaviour and output format. In case of an error, C<$entries> will be
641C<undef>.
642
643The flags are a combination of the following constants, ORed together (the
644flags will also be passed to the callback, possibly modified):
645
646=over 4
647
648=item IO::AIO::READDIR_DENTS
649
650When this flag is off, then the callback gets an arrayref with of names
651only (as with C<aio_readdir>), otherwise it gets an arrayref with
652C<[$name, $type, $inode]> arrayrefs, each describing a single directory
653entry in more detail.
654
655C<$name> is the name of the entry.
656
657C<$type> is one of the C<IO::AIO::DT_xxx> constants:
658
659C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
660C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
661C<IO::AIO::DT_WHT>.
662
663C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
664know, you have to run stat yourself. Also, for speed reasons, the C<$type>
665scalars are read-only: you can not modify them.
666
667C<$inode> is the inode number (which might not be exact on systems with 64
668bit inode numbers and 32 bit perls). This field has unspecified content on
669systems that do not deliver the inode information.
670
671=item IO::AIO::READDIR_DIRS_FIRST
672
673When this flag is set, then the names will be returned in an order where
674likely directories come first. This is useful when you need to quickly
675find directories, or you want to find all directories while avoiding to
676stat() each entry.
677
678If the system returns type information in readdir, then this is used
679to find directories directly. Otherwise, likely directories are files
680beginning with ".", or otherwise files with no dots, of which files with
681short names are tried first.
682
683=item IO::AIO::READDIR_STAT_ORDER
684
685When this flag is set, then the names will be returned in an order
686suitable for stat()'ing each one. That is, when you plan to stat()
687all files in the given directory, then the returned order will likely
688be fastest.
689
690If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
691the likely dirs come first, resulting in a less optimal stat order.
692
693=item IO::AIO::READDIR_FOUND_UNKNOWN
694
695This flag should not be set when calling C<aio_readdirx>. Instead, it
696is being set by C<aio_readdirx>, when any of the C<$type>'s found were
697C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
698C<$type>'s are known, which can be used to speed up some algorithms.
699
700=back
701
702
703=item aio_load $path, $data, $callback->($status)
704
705This is a composite request that tries to fully load the given file into
706memory. Status is the same as with aio_read.
707
708=cut
709
710sub aio_load($$;$) {
711 my ($path, undef, $cb) = @_;
712 my $data = \$_[1];
713
714 my $pri = aioreq_pri;
715 my $grp = aio_group $cb;
716
717 aioreq_pri $pri;
718 add $grp aio_open $path, O_RDONLY, 0, sub {
719 my $fh = shift
720 or return $grp->result (-1);
721
722 aioreq_pri $pri;
723 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
724 $grp->result ($_[0]);
725 };
726 };
727
728 $grp
729}
447 730
448=item aio_copy $srcpath, $dstpath, $callback->($status) 731=item aio_copy $srcpath, $dstpath, $callback->($status)
449 732
450Try to copy the I<file> (directories not supported as either source or 733Try to copy the I<file> (directories not supported as either source or
451destination) from C<$srcpath> to C<$dstpath> and call the callback with 734destination) from C<$srcpath> to C<$dstpath> and call the callback with
452the C<0> (error) or C<-1> ok. 735a status of C<0> (ok) or C<-1> (error, see C<$!>).
453 736
454This is a composite request that it creates the destination file with 737This is a composite request that creates the destination file with
455mode 0200 and copies the contents of the source file into it using 738mode 0200 and copies the contents of the source file into it using
456C<aio_sendfile>, followed by restoring atime, mtime, access mode and 739C<aio_sendfile>, followed by restoring atime, mtime, access mode and
457uid/gid, in that order. 740uid/gid, in that order.
458 741
459If an error occurs, the partial destination file will be unlinked, if 742If an error occurs, the partial destination file will be unlinked, if
469 my $grp = aio_group $cb; 752 my $grp = aio_group $cb;
470 753
471 aioreq_pri $pri; 754 aioreq_pri $pri;
472 add $grp aio_open $src, O_RDONLY, 0, sub { 755 add $grp aio_open $src, O_RDONLY, 0, sub {
473 if (my $src_fh = $_[0]) { 756 if (my $src_fh = $_[0]) {
474 my @stat = stat $src_fh; 757 my @stat = stat $src_fh; # hmm, might block over nfs?
475 758
476 aioreq_pri $pri; 759 aioreq_pri $pri;
477 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub { 760 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
478 if (my $dst_fh = $_[0]) { 761 if (my $dst_fh = $_[0]) {
479 aioreq_pri $pri; 762 aioreq_pri $pri;
480 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 763 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
481 if ($_[0] == $stat[7]) { 764 if ($_[0] == $stat[7]) {
482 $grp->result (0); 765 $grp->result (0);
483 close $src_fh; 766 close $src_fh;
484 767
485 # those should not normally block. should. should. 768 my $ch = sub {
769 aioreq_pri $pri;
770 add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
771 aioreq_pri $pri;
772 add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
773 aioreq_pri $pri;
774 add $grp aio_close $dst_fh;
775 }
776 };
777 };
778
779 aioreq_pri $pri;
780 add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
781 if ($_[0] < 0 && $! == ENOSYS) {
782 aioreq_pri $pri;
486 utime $stat[8], $stat[9], $dst; 783 add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
487 chmod $stat[2] & 07777, $dst_fh; 784 } else {
488 chown $stat[4], $stat[5], $dst_fh; 785 $ch->();
786 }
489 close $dst_fh; 787 };
490 } else { 788 } else {
491 $grp->result (-1); 789 $grp->result (-1);
492 close $src_fh; 790 close $src_fh;
493 close $dst_fh; 791 close $dst_fh;
494 792
511 809
512=item aio_move $srcpath, $dstpath, $callback->($status) 810=item aio_move $srcpath, $dstpath, $callback->($status)
513 811
514Try to move the I<file> (directories not supported as either source or 812Try to move the I<file> (directories not supported as either source or
515destination) from C<$srcpath> to C<$dstpath> and call the callback with 813destination) from C<$srcpath> to C<$dstpath> and call the callback with
516the C<0> (error) or C<-1> ok. 814a status of C<0> (ok) or C<-1> (error, see C<$!>).
517 815
518This is a composite request that tries to rename(2) the file first. If 816This is a composite request that tries to rename(2) the file first; if
519rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if 817rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
520that is successful, unlinking the C<$srcpath>. 818that is successful, unlinks the C<$srcpath>.
521 819
522=cut 820=cut
523 821
524sub aio_move($$;$) { 822sub aio_move($$;$) {
525 my ($src, $dst, $cb) = @_; 823 my ($src, $dst, $cb) = @_;
572 870
573Implementation notes. 871Implementation notes.
574 872
575The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can. 873The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
576 874
875If readdir returns file type information, then this is used directly to
876find directories.
877
577After reading the directory, the modification time, size etc. of the 878Otherwise, after reading the directory, the modification time, size etc.
578directory before and after the readdir is checked, and if they match (and 879of 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 880match (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 881how many entries are directories (if >= 2). Otherwise, no knowledge of the
581of subdirectories will be assumed. 882number of subdirectories will be assumed.
582 883
583Then entries will be sorted into likely directories (everything without 884Then entries will be sorted into likely directories a non-initial dot
584a non-initial dot currently) and likely non-directories (everything 885currently) and likely non-directories (see C<aio_readdirx>). Then every
585else). Then every entry plus an appended C</.> will be C<stat>'ed, 886entry plus an appended C</.> will be C<stat>'ed, likely directories first,
586likely directories first. If that succeeds, it assumes that the entry 887in order of their inode numbers. If that succeeds, it assumes that the
587is a directory or a symlink to directory (which will be checked 888entry is a directory or a symlink to directory (which will be checked
588seperately). This is often faster than stat'ing the entry itself because 889seperately). This is often faster than stat'ing the entry itself because
589filesystems might detect the type of the entry without reading the inode 890filesystems might detect the type of the entry without reading the inode
590data (e.g. ext2fs filetype feature). 891data (e.g. ext2fs filetype feature), even on systems that cannot return
892the filetype information on readdir.
591 893
592If the known number of directories (link count - 2) has been reached, the 894If the known number of directories (link count - 2) has been reached, the
593rest of the entries is assumed to be non-directories. 895rest of the entries is assumed to be non-directories.
594 896
595This only works with certainty on POSIX (= UNIX) filesystems, which 897This only works with certainty on POSIX (= UNIX) filesystems, which
599as those tend to return 0 or 1 as link counts, which disables the 901as those tend to return 0 or 1 as link counts, which disables the
600directory counting heuristic. 902directory counting heuristic.
601 903
602=cut 904=cut
603 905
604sub aio_scandir($$$) { 906sub aio_scandir($$;$) {
605 my ($path, $maxreq, $cb) = @_; 907 my ($path, $maxreq, $cb) = @_;
606 908
607 my $pri = aioreq_pri; 909 my $pri = aioreq_pri;
608 910
609 my $grp = aio_group $cb; 911 my $grp = aio_group $cb;
617 my $now = time; 919 my $now = time;
618 my $hash1 = join ":", (stat _)[0,1,3,7,9]; 920 my $hash1 = join ":", (stat _)[0,1,3,7,9];
619 921
620 # read the directory entries 922 # read the directory entries
621 aioreq_pri $pri; 923 aioreq_pri $pri;
622 add $grp aio_readdir $path, sub { 924 add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
623 my $entries = shift 925 my $entries = shift
624 or return $grp->result (); 926 or return $grp->result ();
625 927
626 # stat the dir another time 928 # stat the dir another time
627 aioreq_pri $pri; 929 aioreq_pri $pri;
633 # take the slow route if anything looks fishy 935 # take the slow route if anything looks fishy
634 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 936 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
635 $ndirs = -1; 937 $ndirs = -1;
636 } else { 938 } else {
637 # if nlink == 2, we are finished 939 # if nlink == 2, we are finished
638 # on non-posix-fs's, we rely on nlink < 2 940 # for non-posix-fs's, we rely on nlink < 2
639 $ndirs = (stat _)[3] - 2 941 $ndirs = (stat _)[3] - 2
640 or return $grp->result ([], $entries); 942 or return $grp->result ([], $entries);
641 } 943 }
642 944
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); 945 my (@dirs, @nondirs);
651 946
652 my $statgrp = add $grp aio_group sub { 947 my $statgrp = add $grp aio_group sub {
653 $grp->result (\@dirs, \@nondirs); 948 $grp->result (\@dirs, \@nondirs);
654 }; 949 };
655 950
656 limit $statgrp $maxreq; 951 limit $statgrp $maxreq;
657 feed $statgrp sub { 952 feed $statgrp sub {
658 return unless @$entries; 953 return unless @$entries;
659 my $entry = pop @$entries; 954 my $entry = shift @$entries;
660 955
661 aioreq_pri $pri; 956 aioreq_pri $pri;
662 add $statgrp aio_stat "$path/$entry/.", sub { 957 add $statgrp aio_stat "$path/$entry/.", sub {
663 if ($_[0] < 0) { 958 if ($_[0] < 0) {
664 push @nondirs, $entry; 959 push @nondirs, $entry;
685 }; 980 };
686 981
687 $grp 982 $grp
688} 983}
689 984
985=item aio_rmtree $path, $callback->($status)
986
987Delete a directory tree starting (and including) C<$path>, return the
988status of the final C<rmdir> only. This is a composite request that
989uses C<aio_scandir> to recurse into and rmdir directories, and unlink
990everything else.
991
992=cut
993
994sub aio_rmtree;
995sub aio_rmtree($;$) {
996 my ($path, $cb) = @_;
997
998 my $pri = aioreq_pri;
999 my $grp = aio_group $cb;
1000
1001 aioreq_pri $pri;
1002 add $grp aio_scandir $path, 0, sub {
1003 my ($dirs, $nondirs) = @_;
1004
1005 my $dirgrp = aio_group sub {
1006 add $grp aio_rmdir $path, sub {
1007 $grp->result ($_[0]);
1008 };
1009 };
1010
1011 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
1012 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
1013
1014 add $grp $dirgrp;
1015 };
1016
1017 $grp
1018}
1019
1020=item aio_sync $callback->($status)
1021
1022Asynchronously call sync and call the callback when finished.
1023
690=item aio_fsync $fh, $callback->($status) 1024=item aio_fsync $fh, $callback->($status)
691 1025
692Asynchronously call fsync on the given filehandle and call the callback 1026Asynchronously call fsync on the given filehandle and call the callback
693with the fsync result code. 1027with the fsync result code.
694 1028
697Asynchronously call fdatasync on the given filehandle and call the 1031Asynchronously call fdatasync on the given filehandle and call the
698callback with the fdatasync result code. 1032callback with the fdatasync result code.
699 1033
700If this call isn't available because your OS lacks it or it couldn't be 1034If 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. 1035detected, it will be emulated by calling C<fsync> instead.
1036
1037=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
1038
1039Sync the data portion of the file specified by C<$offset> and C<$length>
1040to disk (but NOT the metadata), by calling the Linux-specific
1041sync_file_range call. If sync_file_range is not available or it returns
1042ENOSYS, then fdatasync or fsync is being substituted.
1043
1044C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
1045C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
1046C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
1047manpage for details.
1048
1049=item aio_pathsync $path, $callback->($status)
1050
1051This request tries to open, fsync and close the given path. This is a
1052composite request intended to sync directories after directory operations
1053(E.g. rename). This might not work on all operating systems or have any
1054specific effect, but usually it makes sure that directory changes get
1055written to disc. It works for anything that can be opened for read-only,
1056not just directories.
1057
1058Future versions of this function might fall back to other methods when
1059C<fsync> on the directory fails (such as calling C<sync>).
1060
1061Passes C<0> when everything went ok, and C<-1> on error.
1062
1063=cut
1064
1065sub aio_pathsync($;$) {
1066 my ($path, $cb) = @_;
1067
1068 my $pri = aioreq_pri;
1069 my $grp = aio_group $cb;
1070
1071 aioreq_pri $pri;
1072 add $grp aio_open $path, O_RDONLY, 0, sub {
1073 my ($fh) = @_;
1074 if ($fh) {
1075 aioreq_pri $pri;
1076 add $grp aio_fsync $fh, sub {
1077 $grp->result ($_[0]);
1078
1079 aioreq_pri $pri;
1080 add $grp aio_close $fh;
1081 };
1082 } else {
1083 $grp->result (-1);
1084 }
1085 };
1086
1087 $grp
1088}
1089
1090=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1091
1092This is a rather advanced IO::AIO call, which only works on mmap(2)ed
1093scalars (see the C<IO::AIO::mmap> function, although it also works on data
1094scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
1095scalar must only be modified in-place while an aio operation is pending on
1096it).
1097
1098It calls the C<msync> function of your OS, if available, with the memory
1099area starting at C<$offset> in the string and ending C<$length> bytes
1100later. If C<$length> is negative, counts from the end, and if C<$length>
1101is C<undef>, then it goes till the end of the string. The flags can be
1102a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
1103C<IO::AIO::MS_SYNC>.
1104
1105=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1106
1107This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1108scalars.
1109
1110It touches (reads or writes) all memory pages in the specified
1111range inside the scalar. All caveats and parameters are the same
1112as for C<aio_msync>, above, except for flags, which must be either
1113C<0> (which reads all pages and ensures they are instantiated) or
1114C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
1115writing an octet from it, which dirties the page).
1116
1117=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1118
1119This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1120scalars.
1121
1122It reads in all the pages of the underlying storage into memory (if any)
1123and locks them, so they are not getting swapped/paged out or removed.
1124
1125If C<$length> is undefined, then the scalar will be locked till the end.
1126
1127On systems that do not implement C<mlock>, this function returns C<-1>
1128and sets errno to C<ENOSYS>.
1129
1130Note that the corresponding C<munlock> is synchronous and is
1131documented under L<MISCELLANEOUS FUNCTIONS>.
1132
1133Example: open a file, mmap and mlock it - both will be undone when
1134C<$data> gets destroyed.
1135
1136 open my $fh, "<", $path or die "$path: $!";
1137 my $data;
1138 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
1139 aio_mlock $data; # mlock in background
1140
1141=item aio_mlockall $flags, $callback->($status)
1142
1143Calls the C<mlockall> function with the given C<$flags> (a combination of
1144C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).
1145
1146On systems that do not implement C<mlockall>, this function returns C<-1>
1147and sets errno to C<ENOSYS>.
1148
1149Note that the corresponding C<munlockall> is synchronous and is
1150documented under L<MISCELLANEOUS FUNCTIONS>.
1151
1152Example: asynchronously lock all current and future pages into memory.
1153
1154 aio_mlockall IO::AIO::MCL_FUTURE;
702 1155
703=item aio_group $callback->(...) 1156=item aio_group $callback->(...)
704 1157
705This is a very special aio request: Instead of doing something, it is a 1158This 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 1159container for other aio requests, which is useful if you want to bundle
756=item cancel $req 1209=item cancel $req
757 1210
758Cancels the request, if possible. Has the effect of skipping execution 1211Cancels the request, if possible. Has the effect of skipping execution
759when entering the B<execute> state and skipping calling the callback when 1212when entering the B<execute> state and skipping calling the callback when
760entering the the B<result> state, but will leave the request otherwise 1213entering the the B<result> state, but will leave the request otherwise
761untouched. That means that requests that currently execute will not be 1214untouched (with the exception of readdir). That means that requests that
762stopped and resources held by the request will not be freed prematurely. 1215currently execute will not be stopped and resources held by the request
1216will not be freed prematurely.
763 1217
764=item cb $req $callback->(...) 1218=item cb $req $callback->(...)
765 1219
766Replace (or simply set) the callback registered to the request. 1220Replace (or simply set) the callback registered to the request.
767 1221
818Their lifetime, simplified, looks like this: when they are empty, they 1272Their lifetime, simplified, looks like this: when they are empty, they
819will finish very quickly. If they contain only requests that are in the 1273will finish very quickly. If they contain only requests that are in the
820C<done> state, they will also finish. Otherwise they will continue to 1274C<done> state, they will also finish. Otherwise they will continue to
821exist. 1275exist.
822 1276
823That means after creating a group you have some time to add requests. And 1277That 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 1278(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 1279the C<poll_cb>). And in the callbacks of those requests, you can add
826itself finish. 1280further requests to the group. And only when all those requests have
1281finished will the the group itself finish.
827 1282
828=over 4 1283=over 4
829 1284
830=item add $grp ... 1285=item add $grp ...
831 1286
840=item $grp->cancel_subs 1295=item $grp->cancel_subs
841 1296
842Cancel all subrequests and clears any feeder, but not the group request 1297Cancel 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. 1298itself. Useful when you queued a lot of events but got a result early.
844 1299
1300The group request will finish normally (you cannot add requests to the
1301group).
1302
845=item $grp->result (...) 1303=item $grp->result (...)
846 1304
847Set the result value(s) that will be passed to the group callback when all 1305Set 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 1306subrequests have finished and set the groups errno to the current value
849of errno (just like calling C<errno> without an error number). By default, 1307of errno (just like calling C<errno> without an error number). By default,
850no argument will be passed and errno is zero. 1308no argument will be passed and errno is zero.
851 1309
852=item $grp->errno ([$errno]) 1310=item $grp->errno ([$errno])
853 1311
864=item feed $grp $callback->($grp) 1322=item feed $grp $callback->($grp)
865 1323
866Sets a feeder/generator on this group: every group can have an attached 1324Sets a feeder/generator on this group: every group can have an attached
867generator that generates requests if idle. The idea behind this is that, 1325generator 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, 1326although you could just queue as many requests as you want in a group,
869this might starve other requests for a potentially long time. For 1327this might starve other requests for a potentially long time. For example,
870example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1328C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
871requests, delaying any later requests for a long time. 1329delaying any later requests for a long time.
872 1330
873To avoid this, and allow incremental generation of requests, you can 1331To avoid this, and allow incremental generation of requests, you can
874instead a group and set a feeder on it that generates those requests. The 1332instead 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>, 1333feed 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 1334below) requests active in the group itself and is expected to queue more
880not impose any limits). 1338not impose any limits).
881 1339
882If the feed does not queue more requests when called, it will be 1340If the feed does not queue more requests when called, it will be
883automatically removed from the group. 1341automatically removed from the group.
884 1342
885If the feed limit is C<0>, it will be set to C<2> automatically. 1343If the feed limit is C<0> when this method is called, it will be set to
1344C<2> automatically.
886 1345
887Example: 1346Example:
888 1347
889 # stat all files in @files, but only ever use four aio requests concurrently: 1348 # stat all files in @files, but only ever use four aio requests concurrently:
890 1349
902Sets the feeder limit for the group: The feeder will be called whenever 1361Sets the feeder limit for the group: The feeder will be called whenever
903the group contains less than this many requests. 1362the group contains less than this many requests.
904 1363
905Setting the limit to C<0> will pause the feeding process. 1364Setting the limit to C<0> will pause the feeding process.
906 1365
1366The default value for the limit is C<0>, but note that setting a feeder
1367automatically bumps it up to C<2>.
1368
907=back 1369=back
908 1370
909=head2 SUPPORT FUNCTIONS 1371=head2 SUPPORT FUNCTIONS
910 1372
911=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1373=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
913=over 4 1375=over 4
914 1376
915=item $fileno = IO::AIO::poll_fileno 1377=item $fileno = IO::AIO::poll_fileno
916 1378
917Return the I<request result pipe file descriptor>. This filehandle must be 1379Return the I<request result pipe file descriptor>. This filehandle must be
918polled for reading by some mechanism outside this module (e.g. Event or 1380polled 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 1381select and so on, see below or the SYNOPSIS). If the pipe becomes readable
920to call C<poll_cb> to check the results. 1382you have to call C<poll_cb> to check the results.
921 1383
922See C<poll_cb> for an example. 1384See C<poll_cb> for an example.
923 1385
924=item IO::AIO::poll_cb 1386=item IO::AIO::poll_cb
925 1387
926Process some outstanding events on the result pipe. You have to call this 1388Process some outstanding events on the result pipe. You have to call this
927regularly. Returns the number of events processed. Returns immediately 1389regularly. Returns C<0> if all events could be processed, or C<-1> if it
1390returned earlier for whatever reason. Returns immediately when no events
928when no events are outstanding. The amount of events processed depends on 1391are 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>. 1392C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
930 1393
931If not all requests were processed for whatever reason, the filehandle 1394If not all requests were processed for whatever reason, the filehandle
932will still be ready when C<poll_cb> returns. 1395will still be ready when C<poll_cb> returns, so normally you don't have to
1396do anything special to have it called later.
933 1397
934Example: Install an Event watcher that automatically calls 1398Example: Install an Event watcher that automatically calls
935IO::AIO::poll_cb with high priority: 1399IO::AIO::poll_cb with high priority (more examples can be found in the
1400SYNOPSIS section, at the top of this document):
936 1401
937 Event->io (fd => IO::AIO::poll_fileno, 1402 Event->io (fd => IO::AIO::poll_fileno,
938 poll => 'r', async => 1, 1403 poll => 'r', async => 1,
939 cb => \&IO::AIO::poll_cb); 1404 cb => \&IO::AIO::poll_cb);
1405
1406=item IO::AIO::poll_wait
1407
1408If there are any outstanding requests and none of them in the result
1409phase, wait till the result filehandle becomes ready for reading (simply
1410does a C<select> on the filehandle. This is useful if you want to
1411synchronously wait for some requests to finish).
1412
1413See C<nreqs> for an example.
1414
1415=item IO::AIO::poll
1416
1417Waits until some requests have been handled.
1418
1419Returns the number of requests processed, but is otherwise strictly
1420equivalent to:
1421
1422 IO::AIO::poll_wait, IO::AIO::poll_cb
1423
1424=item IO::AIO::flush
1425
1426Wait till all outstanding AIO requests have been handled.
1427
1428Strictly equivalent to:
1429
1430 IO::AIO::poll_wait, IO::AIO::poll_cb
1431 while IO::AIO::nreqs;
940 1432
941=item IO::AIO::max_poll_reqs $nreqs 1433=item IO::AIO::max_poll_reqs $nreqs
942 1434
943=item IO::AIO::max_poll_time $seconds 1435=item IO::AIO::max_poll_time $seconds
944 1436
969 # use a low priority so other tasks have priority 1461 # use a low priority so other tasks have priority
970 Event->io (fd => IO::AIO::poll_fileno, 1462 Event->io (fd => IO::AIO::poll_fileno,
971 poll => 'r', nice => 1, 1463 poll => 'r', nice => 1,
972 cb => &IO::AIO::poll_cb); 1464 cb => &IO::AIO::poll_cb);
973 1465
974=item IO::AIO::poll_wait 1466=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 1467
1000=head3 CONTROLLING THE NUMBER OF THREADS 1468=head3 CONTROLLING THE NUMBER OF THREADS
1469
1470=over
1001 1471
1002=item IO::AIO::min_parallel $nthreads 1472=item IO::AIO::min_parallel $nthreads
1003 1473
1004Set the minimum number of AIO threads to C<$nthreads>. The current 1474Set the minimum number of AIO threads to C<$nthreads>. The current
1005default is C<8>, which means eight asynchronous operations can execute 1475default is C<8>, which means eight asynchronous operations can execute
1046 1516
1047The default is probably ok in most situations, especially if thread 1517The default is probably ok in most situations, especially if thread
1048creation is fast. If thread creation is very slow on your system you might 1518creation is fast. If thread creation is very slow on your system you might
1049want to use larger values. 1519want to use larger values.
1050 1520
1051=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1521=item IO::AIO::max_outstanding $maxreqs
1052 1522
1053This is a very bad function to use in interactive programs because it 1523This is a very bad function to use in interactive programs because it
1054blocks, and a bad way to reduce concurrency because it is inexact: Better 1524blocks, and a bad way to reduce concurrency because it is inexact: Better
1055use an C<aio_group> together with a feed callback. 1525use an C<aio_group> together with a feed callback.
1056 1526
1057Sets the maximum number of outstanding requests to C<$nreqs>. If you 1527Sets 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 1528do 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>) 1529C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
1060function will block until the limit is no longer exceeded. 1530function will block until the limit is no longer exceeded.
1061 1531
1062The default value is very large, so there is no practical limit on the 1532The default value is very large, so there is no practical limit on the
1063number of outstanding requests. 1533number of outstanding requests.
1064 1534
1065You can still queue as many requests as you want. Therefore, 1535You can still queue as many requests as you want. Therefore,
1066C<max_oustsanding> is mainly useful in simple scripts (with low values) or 1536C<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). 1537as a stop gap to shield against fatal memory overflow (with large values).
1068 1538
1539=back
1540
1069=head3 STATISTICAL INFORMATION 1541=head3 STATISTICAL INFORMATION
1542
1543=over
1070 1544
1071=item IO::AIO::nreqs 1545=item IO::AIO::nreqs
1072 1546
1073Returns the number of requests currently in the ready, execute or pending 1547Returns the number of requests currently in the ready, execute or pending
1074states (i.e. for which their callback has not been invoked yet). 1548states (i.e. for which their callback has not been invoked yet).
1088Returns the number of requests currently in the pending state (executed, 1562Returns the number of requests currently in the pending state (executed,
1089but not yet processed by poll_cb). 1563but not yet processed by poll_cb).
1090 1564
1091=back 1565=back
1092 1566
1567=head3 MISCELLANEOUS FUNCTIONS
1568
1569IO::AIO implements some functions that might be useful, but are not
1570asynchronous.
1571
1572=over 4
1573
1574=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1575
1576Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
1577but is blocking (this makes most sense if you know the input data is
1578likely cached already and the output filehandle is set to non-blocking
1579operations).
1580
1581Returns the number of bytes copied, or C<-1> on error.
1582
1583=item IO::AIO::fadvise $fh, $offset, $len, $advice
1584
1585Simply calls the C<posix_fadvise> function (see it's
1586manpage for details). The following advice constants are
1587avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1588C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1589C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1590
1591On systems that do not implement C<posix_fadvise>, this function returns
1592ENOSYS, otherwise the return value of C<posix_fadvise>.
1593
1594=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1595
1596Memory-maps a file (or anonymous memory range) and attaches it to the
1597given C<$scalar>, which will act like a string scalar.
1598
1599The only operations allowed on the scalar are C<substr>/C<vec> that don't
1600change the string length, and most read-only operations such as copying it
1601or searching it with regexes and so on.
1602
1603Anything else is unsafe and will, at best, result in memory leaks.
1604
1605The memory map associated with the C<$scalar> is automatically removed
1606when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
1607C<IO::AIO::munmap> functions are called.
1608
1609This calls the C<mmap>(2) function internally. See your system's manual
1610page for details on the C<$length>, C<$prot> and C<$flags> parameters.
1611
1612The C<$length> must be larger than zero and smaller than the actual
1613filesize.
1614
1615C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1616C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1617
1618C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
1619C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
1620not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
1621(which is set to C<MAP_ANON> if your system only provides this
1622constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
1623C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
1624C<IO::AIO::MAP_NONBLOCK>
1625
1626If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1627
1628C<$offset> is the offset from the start of the file - it generally must be
1629a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
1630
1631Example:
1632
1633 use Digest::MD5;
1634 use IO::AIO;
1635
1636 open my $fh, "<verybigfile"
1637 or die "$!";
1638
1639 IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
1640 or die "verybigfile: $!";
1641
1642 my $fast_md5 = md5 $data;
1643
1644=item IO::AIO::munmap $scalar
1645
1646Removes a previous mmap and undefines the C<$scalar>.
1647
1648=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
1649
1650Calls the C<munlock> function, undoing the effects of a previous
1651C<aio_mlock> call (see its description for details).
1652
1653=item IO::AIO::munlockall
1654
1655Calls the C<munlockall> function.
1656
1657On systems that do not implement C<munlockall>, this function returns
1658ENOSYS, otherwise the return value of C<munlockall>.
1659
1660=back
1661
1093=cut 1662=cut
1094 1663
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; 1664min_parallel 8;
1112 1665
1113END { 1666END { flush }
1114 min_parallel 1;
1115 flush;
1116};
1117 1667
11181; 16681;
1669
1670=head1 EVENT LOOP INTEGRATION
1671
1672It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
1673automatically into many event loops:
1674
1675 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
1676 use AnyEvent::AIO;
1677
1678You can also integrate IO::AIO manually into many event loops, here are
1679some examples of how to do this:
1680
1681 # EV integration
1682 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
1683
1684 # Event integration
1685 Event->io (fd => IO::AIO::poll_fileno,
1686 poll => 'r',
1687 cb => \&IO::AIO::poll_cb);
1688
1689 # Glib/Gtk2 integration
1690 add_watch Glib::IO IO::AIO::poll_fileno,
1691 in => sub { IO::AIO::poll_cb; 1 };
1692
1693 # Tk integration
1694 Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
1695 readable => \&IO::AIO::poll_cb);
1696
1697 # Danga::Socket integration
1698 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
1699 \&IO::AIO::poll_cb);
1119 1700
1120=head2 FORK BEHAVIOUR 1701=head2 FORK BEHAVIOUR
1121 1702
1122This module should do "the right thing" when the process using it forks: 1703This module should do "the right thing" when the process using it forks:
1123 1704
1141bytes of memory. In addition, stat requests need a stat buffer (possibly 1722bytes of memory. In addition, stat requests need a stat buffer (possibly
1142a few hundred bytes), readdir requires a result buffer and so on. Perl 1723a 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 1724scalars and other data passed into aio requests will also be locked and
1144will consume memory till the request has entered the done state. 1725will consume memory till the request has entered the done state.
1145 1726
1146This is now awfully much, so queuing lots of requests is not usually a 1727This is not awfully much, so queuing lots of requests is not usually a
1147problem. 1728problem.
1148 1729
1149Per-thread usage: 1730Per-thread usage:
1150 1731
1151In the execution phase, some aio requests require more memory for 1732In the execution phase, some aio requests require more memory for
1156 1737
1157Known bugs will be fixed in the next release. 1738Known bugs will be fixed in the next release.
1158 1739
1159=head1 SEE ALSO 1740=head1 SEE ALSO
1160 1741
1161L<Coro::AIO>. 1742L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1743more natural syntax.
1162 1744
1163=head1 AUTHOR 1745=head1 AUTHOR
1164 1746
1165 Marc Lehmann <schmorp@schmorp.de> 1747 Marc Lehmann <schmorp@schmorp.de>
1166 http://home.schmorp.de/ 1748 http://home.schmorp.de/

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