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Revision 1.86 by root, Sat Oct 28 23:32:29 2006 UTC vs.
Revision 1.119 by root, Sun Dec 2 20:54:33 2007 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 # AnyEvent integration (EV, Event, Glib, Tk, urxvt, pureperl...)
31 open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!"; 32 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 my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });
34
35 # EV integration
36 my $w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
33 37
34 # Event integration 38 # Event integration
35 Event->io (fd => IO::AIO::poll_fileno, 39 Event->io (fd => IO::AIO::poll_fileno,
36 poll => 'r', 40 poll => 'r',
37 cb => \&IO::AIO::poll_cb); 41 cb => \&IO::AIO::poll_cb);
61etc.), but can also be used to easily do operations in parallel that are 65etc.), 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 66normally 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 67on a RAID volume or over NFS when you do a number of stat operations
64concurrently. 68concurrently.
65 69
66While this works on all types of file descriptors (for example sockets), 70While most of this works on all types of file descriptors (for
67using these functions on file descriptors that support nonblocking 71example sockets), using these functions on file descriptors that
68operation (again, sockets, pipes etc.) is very inefficient. Use an event 72support nonblocking operation (again, sockets, pipes etc.) is very
69loop for that (such as the L<Event|Event> module): IO::AIO will naturally 73inefficient. Use an event loop for that (such as the L<Event|Event>
70fit into such an event loop itself. 74module): IO::AIO will naturally fit into such an event loop itself.
71 75
72In this version, a number of threads are started that execute your 76In this version, a number of threads are started that execute your
73requests and signal their completion. You don't need thread support 77requests and signal their completion. You don't need thread support
74in perl, and the threads created by this module will not be visible 78in perl, and the threads created by this module will not be visible
75to perl. In the future, this module might make use of the native aio 79to perl. In the future, this module might make use of the native aio
77not well-supported or restricted (GNU/Linux doesn't allow them on normal 81not well-supported or restricted (GNU/Linux doesn't allow them on normal
78files currently, for example), and they would only support aio_read and 82files currently, for example), and they would only support aio_read and
79aio_write, so the remaining functionality would have to be implemented 83aio_write, so the remaining functionality would have to be implemented
80using threads anyway. 84using threads anyway.
81 85
82Although the module will work with in the presence of other (Perl-) 86Although the module will work in the presence of other (Perl-) threads,
83threads, it is currently not reentrant in any way, so use appropriate 87it is currently not reentrant in any way, so use appropriate locking
84locking yourself, always call C<poll_cb> from within the same thread, or 88yourself, always call C<poll_cb> from within the same thread, or never
85never call C<poll_cb> (or other C<aio_> functions) recursively. 89call C<poll_cb> (or other C<aio_> functions) recursively.
86 90
87=head2 EXAMPLE 91=head2 EXAMPLE
88 92
89This is a simple example that uses the Event module and loads 93This is a simple example that uses the Event module and loads
90F</etc/passwd> asynchronously: 94F</etc/passwd> asynchronously:
98 poll => 'r', 102 poll => 'r',
99 cb => \&IO::AIO::poll_cb); 103 cb => \&IO::AIO::poll_cb);
100 104
101 # queue the request to open /etc/passwd 105 # queue the request to open /etc/passwd
102 aio_open "/etc/passwd", O_RDONLY, 0, sub { 106 aio_open "/etc/passwd", O_RDONLY, 0, sub {
103 my $fh = $_[0] 107 my $fh = shift
104 or die "error while opening: $!"; 108 or die "error while opening: $!";
105 109
106 # stat'ing filehandles is generally non-blocking 110 # stat'ing filehandles is generally non-blocking
107 my $size = -s $fh; 111 my $size = -s $fh;
108 112
176Request has reached the end of its lifetime and holds no resources anymore 180Request has reached the end of its lifetime and holds no resources anymore
177(except possibly for the Perl object, but its connection to the actual 181(except possibly for the Perl object, but its connection to the actual
178aio request is severed and calling its methods will either do nothing or 182aio request is severed and calling its methods will either do nothing or
179result in a runtime error). 183result in a runtime error).
180 184
185=back
186
181=cut 187=cut
182 188
183package IO::AIO; 189package IO::AIO;
190
191use Carp ();
184 192
185no warnings; 193no warnings;
186use strict 'vars'; 194use strict 'vars';
187 195
188use base 'Exporter'; 196use base 'Exporter';
189 197
190BEGIN { 198BEGIN {
191 our $VERSION = '2.1'; 199 our $VERSION = '2.6';
192 200
193 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat 201 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat
194 aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink 202 aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink
195 aio_fsync aio_fdatasync aio_readahead aio_rename aio_link aio_move 203 aio_readlink aio_sync aio_fsync aio_fdatasync aio_readahead aio_rename aio_link
196 aio_copy aio_group aio_nop aio_mknod); 204 aio_move aio_copy aio_group aio_nop aio_mknod aio_load aio_rmtree aio_mkdir
205 aio_chown aio_chmod aio_utime aio_truncate);
197 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); 206 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block));
198 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 207 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
199 min_parallel max_parallel max_idle 208 min_parallel max_parallel max_idle
200 nreqs nready npending nthreads 209 nreqs nready npending nthreads
201 max_poll_time max_poll_reqs); 210 max_poll_time max_poll_reqs);
202 211
206 XSLoader::load ("IO::AIO", $VERSION); 215 XSLoader::load ("IO::AIO", $VERSION);
207} 216}
208 217
209=head1 FUNCTIONS 218=head1 FUNCTIONS
210 219
211=head2 AIO FUNCTIONS 220=head2 AIO REQUEST FUNCTIONS
212 221
213All the C<aio_*> calls are more or less thin wrappers around the syscall 222All the C<aio_*> calls are more or less thin wrappers around the syscall
214with the same name (sans C<aio_>). The arguments are similar or identical, 223with the same name (sans C<aio_>). The arguments are similar or identical,
215and they all accept an additional (and optional) C<$callback> argument 224and they all accept an additional (and optional) C<$callback> argument
216which must be a code reference. This code reference will get called with 225which must be a code reference. This code reference will get called with
219syscall has been executed asynchronously. 228syscall has been executed asynchronously.
220 229
221All functions expecting a filehandle keep a copy of the filehandle 230All functions expecting a filehandle keep a copy of the filehandle
222internally until the request has finished. 231internally until the request has finished.
223 232
224All requests return objects of type L<IO::AIO::REQ> that allow further 233All functions return request objects of type L<IO::AIO::REQ> that allow
225manipulation of those requests while they are in-flight. 234further manipulation of those requests while they are in-flight.
226 235
227The pathnames you pass to these routines I<must> be absolute and 236The pathnames you pass to these routines I<must> be absolute and
228encoded in byte form. The reason for the former is that at the time the 237encoded as octets. The reason for the former is that at the time the
229request is being executed, the current working directory could have 238request is being executed, the current working directory could have
230changed. Alternatively, you can make sure that you never change the 239changed. Alternatively, you can make sure that you never change the
231current working directory. 240current working directory anywhere in the program and then use relative
241paths.
232 242
233To encode pathnames to byte form, either make sure you either: a) 243To encode pathnames as octets, either make sure you either: a) always pass
234always pass in filenames you got from outside (command line, readdir 244in filenames you got from outside (command line, readdir etc.) without
235etc.), b) are ASCII or ISO 8859-1, c) use the Encode module and encode 245tinkering, b) are ASCII or ISO 8859-1, c) use the Encode module and encode
236your pathnames to the locale (or other) encoding in effect in the user 246your pathnames to the locale (or other) encoding in effect in the user
237environment, d) use Glib::filename_from_unicode on unicode filenames or e) 247environment, d) use Glib::filename_from_unicode on unicode filenames or e)
238use something else. 248use something else to ensure your scalar has the correct contents.
249
250This works, btw. independent of the internal UTF-8 bit, which IO::AIO
251handles correctly wether it is set or not.
239 252
240=over 4 253=over 4
241 254
242=item $prev_pri = aioreq_pri [$pri] 255=item $prev_pri = aioreq_pri [$pri]
243 256
263 aio_read $_[0], ..., sub { 276 aio_read $_[0], ..., sub {
264 ... 277 ...
265 }; 278 };
266 }; 279 };
267 280
281
268=item aioreq_nice $pri_adjust 282=item aioreq_nice $pri_adjust
269 283
270Similar to C<aioreq_pri>, but subtracts the given value from the current 284Similar to C<aioreq_pri>, but subtracts the given value from the current
271priority, so effects are cumulative. 285priority, so the effect is cumulative.
286
272 287
273=item aio_open $pathname, $flags, $mode, $callback->($fh) 288=item aio_open $pathname, $flags, $mode, $callback->($fh)
274 289
275Asynchronously open or create a file and call the callback with a newly 290Asynchronously open or create a file and call the callback with a newly
276created filehandle for the file. 291created filehandle for the file.
282list. They are the same as used by C<sysopen>. 297list. They are the same as used by C<sysopen>.
283 298
284Likewise, C<$mode> specifies the mode of the newly created file, if it 299Likewise, C<$mode> specifies the mode of the newly created file, if it
285didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>, 300didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>,
286except that it is mandatory (i.e. use C<0> if you don't create new files, 301except that it is mandatory (i.e. use C<0> if you don't create new files,
287and C<0666> or C<0777> if you do). 302and C<0666> or C<0777> if you do). Note that the C<$mode> will be modified
303by the umask in effect then the request is being executed, so better never
304change the umask.
288 305
289Example: 306Example:
290 307
291 aio_open "/etc/passwd", O_RDONLY, 0, sub { 308 aio_open "/etc/passwd", O_RDONLY, 0, sub {
292 if ($_[0]) { 309 if ($_[0]) {
295 } else { 312 } else {
296 die "open failed: $!\n"; 313 die "open failed: $!\n";
297 } 314 }
298 }; 315 };
299 316
317
300=item aio_close $fh, $callback->($status) 318=item aio_close $fh, $callback->($status)
301 319
302Asynchronously close a file and call the callback with the result 320Asynchronously close a file and call the callback with the result
303code. I<WARNING:> although accepted, you should not pass in a perl 321code.
304filehandle here, as perl will likely close the file descriptor another
305time when the filehandle is destroyed. Normally, you can safely call perls
306C<close> or just let filehandles go out of scope.
307 322
308This is supposed to be a bug in the API, so that might change. It's 323Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
309therefore best to avoid this function. 324closing the file descriptor associated with the filehandle itself. Here is
325what aio_close will try:
326
327 1. dup()licate the fd
328 2. asynchronously close() the duplicated fd
329 3. dup()licate the fd once more
330 4. let perl close() the filehandle
331 5. asynchronously close the duplicated fd
332
333The idea is that the first close() flushes stuff to disk that closing an
334fd will flush, so when perl closes the fd, nothing much will need to be
335flushed. The second async. close() will then flush stuff to disk that
336closing the last fd to the file will flush.
337
338Just FYI, SuSv3 has this to say on close:
339
340 All outstanding record locks owned by the process on the file
341 associated with the file descriptor shall be removed.
342
343 If fildes refers to a socket, close() shall cause the socket to be
344 destroyed. ... close() shall block for up to the current linger
345 interval until all data is transmitted.
346 [this actually sounds like a specification bug, but who knows]
347
348And at least Linux additionally actually flushes stuff on every close,
349even when the file itself is still open.
350
351Sounds enourmously inefficient and complicated? Yes... please show me how
352to nuke perl's fd out of existence...
353
354=cut
355
356sub aio_close($;$) {
357 aio_block {
358 my ($fh, $cb) = @_;
359
360 my $pri = aioreq_pri;
361 my $grp = aio_group $cb;
362
363 my $fd = fileno $fh;
364
365 defined $fd or Carp::croak "aio_close called with fd-less filehandle";
366
367 # if the dups fail we will simply get EBADF
368 my $fd2 = _dup $fd;
369 aioreq_pri $pri;
370 add $grp _aio_close $fd2, sub {
371 my $fd2 = _dup $fd;
372 close $fh;
373 aioreq_pri $pri;
374 add $grp _aio_close $fd2, sub {
375 $grp->result ($_[0]);
376 };
377 };
378
379 $grp
380 }
381}
382
310 383
311=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 384=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
312 385
313=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 386=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
314 387
315Reads or writes C<length> bytes from the specified C<fh> and C<offset> 388Reads or writes C<$length> bytes from the specified C<$fh> and C<$offset>
316into the scalar given by C<data> and offset C<dataoffset> and calls the 389into the scalar given by C<$data> and offset C<$dataoffset> and calls the
317callback without the actual number of bytes read (or -1 on error, just 390callback without the actual number of bytes read (or -1 on error, just
318like the syscall). 391like the syscall).
319 392
393If C<$offset> is undefined, then the current file descriptor offset will
394be used (and updated), otherwise the file descriptor offset will not be
395changed by these calls.
396
397If C<$length> is undefined in C<aio_write>, use the remaining length of C<$data>.
398
399If C<$dataoffset> is less than zero, it will be counted from the end of
400C<$data>.
401
320The C<$data> scalar I<MUST NOT> be modified in any way while the request 402The C<$data> scalar I<MUST NOT> be modified in any way while the request
321is outstanding. Modifying it can result in segfaults or WW3 (if the 403is outstanding. Modifying it can result in segfaults or World War III (if
322necessary/optional hardware is installed). 404the necessary/optional hardware is installed).
323 405
324Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at 406Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
325offset C<0> within the scalar: 407offset C<0> within the scalar:
326 408
327 aio_read $fh, 7, 15, $buffer, 0, sub { 409 aio_read $fh, 7, 15, $buffer, 0, sub {
328 $_[0] > 0 or die "read error: $!"; 410 $_[0] > 0 or die "read error: $!";
329 print "read $_[0] bytes: <$buffer>\n"; 411 print "read $_[0] bytes: <$buffer>\n";
330 }; 412 };
413
331 414
332=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) 415=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
333 416
334Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts 417Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
335reading at byte offset C<$in_offset>, and starts writing at the current 418reading at byte offset C<$in_offset>, and starts writing at the current
349C<$in_fh> than are written, and there is no way to find out how many 432C<$in_fh> than are written, and there is no way to find out how many
350bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only 433bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
351provides the number of bytes written to C<$out_fh>. Only if the result 434provides the number of bytes written to C<$out_fh>. Only if the result
352value equals C<$length> one can assume that C<$length> bytes have been 435value equals C<$length> one can assume that C<$length> bytes have been
353read. 436read.
437
354 438
355=item aio_readahead $fh,$offset,$length, $callback->($retval) 439=item aio_readahead $fh,$offset,$length, $callback->($retval)
356 440
357C<aio_readahead> populates the page cache with data from a file so that 441C<aio_readahead> populates the page cache with data from a file so that
358subsequent reads from that file will not block on disk I/O. The C<$offset> 442subsequent reads from that file will not block on disk I/O. The C<$offset>
364file. The current file offset of the file is left unchanged. 448file. The current file offset of the file is left unchanged.
365 449
366If that syscall doesn't exist (likely if your OS isn't Linux) it will be 450If that syscall doesn't exist (likely if your OS isn't Linux) it will be
367emulated by simply reading the data, which would have a similar effect. 451emulated by simply reading the data, which would have a similar effect.
368 452
453
369=item aio_stat $fh_or_path, $callback->($status) 454=item aio_stat $fh_or_path, $callback->($status)
370 455
371=item aio_lstat $fh, $callback->($status) 456=item aio_lstat $fh, $callback->($status)
372 457
373Works like perl's C<stat> or C<lstat> in void context. The callback will 458Works like perl's C<stat> or C<lstat> in void context. The callback will
386 aio_stat "/etc/passwd", sub { 471 aio_stat "/etc/passwd", sub {
387 $_[0] and die "stat failed: $!"; 472 $_[0] and die "stat failed: $!";
388 print "size is ", -s _, "\n"; 473 print "size is ", -s _, "\n";
389 }; 474 };
390 475
476
477=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
478
479Works like perl's C<utime> function (including the special case of $atime
480and $mtime being undef). Fractional times are supported if the underlying
481syscalls support them.
482
483When called with a pathname, uses utimes(2) if available, otherwise
484utime(2). If called on a file descriptor, uses futimes(2) if available,
485otherwise returns ENOSYS, so this is not portable.
486
487Examples:
488
489 # set atime and mtime to current time (basically touch(1)):
490 aio_utime "path", undef, undef;
491 # set atime to current time and mtime to beginning of the epoch:
492 aio_utime "path", time, undef; # undef==0
493
494
495=item aio_chown $fh_or_path, $uid, $gid, $callback->($status)
496
497Works like perl's C<chown> function, except that C<undef> for either $uid
498or $gid is being interpreted as "do not change" (but -1 can also be used).
499
500Examples:
501
502 # same as "chown root path" in the shell:
503 aio_chown "path", 0, -1;
504 # same as above:
505 aio_chown "path", 0, undef;
506
507
508=item aio_truncate $fh_or_path, $offset, $callback->($status)
509
510Works like truncate(2) or ftruncate(2).
511
512
513=item aio_chmod $fh_or_path, $mode, $callback->($status)
514
515Works like perl's C<chmod> function.
516
517
391=item aio_unlink $pathname, $callback->($status) 518=item aio_unlink $pathname, $callback->($status)
392 519
393Asynchronously unlink (delete) a file and call the callback with the 520Asynchronously unlink (delete) a file and call the callback with the
394result code. 521result code.
395 522
523
396=item aio_mknod $path, $mode, $dev, $callback->($status) 524=item aio_mknod $path, $mode, $dev, $callback->($status)
397 525
398[EXPERIMENTAL] 526[EXPERIMENTAL]
399 527
400Asynchronously create a device node (or fifo). See mknod(2). 528Asynchronously create a device node (or fifo). See mknod(2).
401 529
402The only (POSIX-) portable way of calling this function is: 530The only (POSIX-) portable way of calling this function is:
403 531
404 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... 532 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...
533
405 534
406=item aio_link $srcpath, $dstpath, $callback->($status) 535=item aio_link $srcpath, $dstpath, $callback->($status)
407 536
408Asynchronously create a new link to the existing object at C<$srcpath> at 537Asynchronously create a new link to the existing object at C<$srcpath> at
409the path C<$dstpath> and call the callback with the result code. 538the path C<$dstpath> and call the callback with the result code.
410 539
540
411=item aio_symlink $srcpath, $dstpath, $callback->($status) 541=item aio_symlink $srcpath, $dstpath, $callback->($status)
412 542
413Asynchronously create a new symbolic link to the existing object at C<$srcpath> at 543Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
414the path C<$dstpath> and call the callback with the result code. 544the path C<$dstpath> and call the callback with the result code.
415 545
546
547=item aio_readlink $path, $callback->($link)
548
549Asynchronously read the symlink specified by C<$path> and pass it to
550the callback. If an error occurs, nothing or undef gets passed to the
551callback.
552
553
416=item aio_rename $srcpath, $dstpath, $callback->($status) 554=item aio_rename $srcpath, $dstpath, $callback->($status)
417 555
418Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as 556Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
419rename(2) and call the callback with the result code. 557rename(2) and call the callback with the result code.
420 558
559
560=item aio_mkdir $pathname, $mode, $callback->($status)
561
562Asynchronously mkdir (create) a directory and call the callback with
563the result code. C<$mode> will be modified by the umask at the time the
564request is executed, so do not change your umask.
565
566
421=item aio_rmdir $pathname, $callback->($status) 567=item aio_rmdir $pathname, $callback->($status)
422 568
423Asynchronously rmdir (delete) a directory and call the callback with the 569Asynchronously rmdir (delete) a directory and call the callback with the
424result code. 570result code.
571
425 572
426=item aio_readdir $pathname, $callback->($entries) 573=item aio_readdir $pathname, $callback->($entries)
427 574
428Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 575Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
429directory (i.e. opendir + readdir + closedir). The entries will not be 576directory (i.e. opendir + readdir + closedir). The entries will not be
430sorted, and will B<NOT> include the C<.> and C<..> entries. 577sorted, and will B<NOT> include the C<.> and C<..> entries.
431 578
432The callback a single argument which is either C<undef> or an array-ref 579The callback a single argument which is either C<undef> or an array-ref
433with the filenames. 580with the filenames.
581
582
583=item aio_load $path, $data, $callback->($status)
584
585This is a composite request that tries to fully load the given file into
586memory. Status is the same as with aio_read.
587
588=cut
589
590sub aio_load($$;$) {
591 aio_block {
592 my ($path, undef, $cb) = @_;
593 my $data = \$_[1];
594
595 my $pri = aioreq_pri;
596 my $grp = aio_group $cb;
597
598 aioreq_pri $pri;
599 add $grp aio_open $path, O_RDONLY, 0, sub {
600 my $fh = shift
601 or return $grp->result (-1);
602
603 aioreq_pri $pri;
604 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
605 $grp->result ($_[0]);
606 };
607 };
608
609 $grp
610 }
611}
434 612
435=item aio_copy $srcpath, $dstpath, $callback->($status) 613=item aio_copy $srcpath, $dstpath, $callback->($status)
436 614
437Try to copy the I<file> (directories not supported as either source or 615Try to copy the I<file> (directories not supported as either source or
438destination) from C<$srcpath> to C<$dstpath> and call the callback with 616destination) from C<$srcpath> to C<$dstpath> and call the callback with
448errors are being ignored. 626errors are being ignored.
449 627
450=cut 628=cut
451 629
452sub aio_copy($$;$) { 630sub aio_copy($$;$) {
631 aio_block {
453 my ($src, $dst, $cb) = @_; 632 my ($src, $dst, $cb) = @_;
454 633
455 my $pri = aioreq_pri; 634 my $pri = aioreq_pri;
456 my $grp = aio_group $cb; 635 my $grp = aio_group $cb;
457 636
458 aioreq_pri $pri; 637 aioreq_pri $pri;
459 add $grp aio_open $src, O_RDONLY, 0, sub { 638 add $grp aio_open $src, O_RDONLY, 0, sub {
460 if (my $src_fh = $_[0]) { 639 if (my $src_fh = $_[0]) {
461 my @stat = stat $src_fh; 640 my @stat = stat $src_fh;
462 641
463 aioreq_pri $pri; 642 aioreq_pri $pri;
464 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub { 643 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
465 if (my $dst_fh = $_[0]) { 644 if (my $dst_fh = $_[0]) {
466 aioreq_pri $pri; 645 aioreq_pri $pri;
467 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 646 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
468 if ($_[0] == $stat[7]) { 647 if ($_[0] == $stat[7]) {
469 $grp->result (0); 648 $grp->result (0);
470 close $src_fh; 649 close $src_fh;
471 650
472 # those should not normally block. should. should. 651 # those should not normally block. should. should.
473 utime $stat[8], $stat[9], $dst; 652 utime $stat[8], $stat[9], $dst;
474 chmod $stat[2] & 07777, $dst_fh; 653 chmod $stat[2] & 07777, $dst_fh;
475 chown $stat[4], $stat[5], $dst_fh; 654 chown $stat[4], $stat[5], $dst_fh;
476 close $dst_fh; 655 close $dst_fh;
477 } else { 656 } else {
478 $grp->result (-1); 657 $grp->result (-1);
479 close $src_fh; 658 close $src_fh;
480 close $dst_fh; 659 close $dst_fh;
481 660
482 aioreq $pri; 661 aioreq $pri;
483 add $grp aio_unlink $dst; 662 add $grp aio_unlink $dst;
663 }
484 } 664 };
665 } else {
666 $grp->result (-1);
485 }; 667 }
486 } else {
487 $grp->result (-1);
488 } 668 },
669
670 } else {
671 $grp->result (-1);
489 }, 672 }
490
491 } else {
492 $grp->result (-1);
493 } 673 };
674
675 $grp
494 }; 676 }
495
496 $grp
497} 677}
498 678
499=item aio_move $srcpath, $dstpath, $callback->($status) 679=item aio_move $srcpath, $dstpath, $callback->($status)
500 680
501Try to move the I<file> (directories not supported as either source or 681Try to move the I<file> (directories not supported as either source or
507that is successful, unlinking the C<$srcpath>. 687that is successful, unlinking the C<$srcpath>.
508 688
509=cut 689=cut
510 690
511sub aio_move($$;$) { 691sub aio_move($$;$) {
692 aio_block {
512 my ($src, $dst, $cb) = @_; 693 my ($src, $dst, $cb) = @_;
513 694
514 my $pri = aioreq_pri; 695 my $pri = aioreq_pri;
515 my $grp = aio_group $cb; 696 my $grp = aio_group $cb;
516 697
517 aioreq_pri $pri; 698 aioreq_pri $pri;
518 add $grp aio_rename $src, $dst, sub { 699 add $grp aio_rename $src, $dst, sub {
519 if ($_[0] && $! == EXDEV) { 700 if ($_[0] && $! == EXDEV) {
520 aioreq_pri $pri; 701 aioreq_pri $pri;
521 add $grp aio_copy $src, $dst, sub { 702 add $grp aio_copy $src, $dst, sub {
703 $grp->result ($_[0]);
704
705 if (!$_[0]) {
706 aioreq_pri $pri;
707 add $grp aio_unlink $src;
708 }
709 };
710 } else {
522 $grp->result ($_[0]); 711 $grp->result ($_[0]);
523
524 if (!$_[0]) {
525 aioreq_pri $pri;
526 add $grp aio_unlink $src;
527 }
528 }; 712 }
529 } else {
530 $grp->result ($_[0]);
531 } 713 };
714
715 $grp
532 }; 716 }
533
534 $grp
535} 717}
536 718
537=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 719=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
538 720
539Scans a directory (similar to C<aio_readdir>) but additionally tries to 721Scans a directory (similar to C<aio_readdir>) but additionally tries to
586as those tend to return 0 or 1 as link counts, which disables the 768as those tend to return 0 or 1 as link counts, which disables the
587directory counting heuristic. 769directory counting heuristic.
588 770
589=cut 771=cut
590 772
591sub aio_scandir($$$) { 773sub aio_scandir($$;$) {
774 aio_block {
592 my ($path, $maxreq, $cb) = @_; 775 my ($path, $maxreq, $cb) = @_;
593 776
594 my $pri = aioreq_pri; 777 my $pri = aioreq_pri;
595 778
596 my $grp = aio_group $cb; 779 my $grp = aio_group $cb;
597 780
598 $maxreq = 4 if $maxreq <= 0; 781 $maxreq = 4 if $maxreq <= 0;
599 782
600 # stat once 783 # stat once
601 aioreq_pri $pri;
602 add $grp aio_stat $path, sub {
603 return $grp->result () if $_[0];
604 my $now = time;
605 my $hash1 = join ":", (stat _)[0,1,3,7,9];
606
607 # read the directory entries
608 aioreq_pri $pri; 784 aioreq_pri $pri;
609 add $grp aio_readdir $path, sub { 785 add $grp aio_stat $path, sub {
610 my $entries = shift
611 or return $grp->result (); 786 return $grp->result () if $_[0];
787 my $now = time;
788 my $hash1 = join ":", (stat _)[0,1,3,7,9];
612 789
613 # stat the dir another time 790 # read the directory entries
614 aioreq_pri $pri; 791 aioreq_pri $pri;
792 add $grp aio_readdir $path, sub {
793 my $entries = shift
794 or return $grp->result ();
795
796 # stat the dir another time
797 aioreq_pri $pri;
615 add $grp aio_stat $path, sub { 798 add $grp aio_stat $path, sub {
616 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 799 my $hash2 = join ":", (stat _)[0,1,3,7,9];
617 800
618 my $ndirs; 801 my $ndirs;
619 802
620 # take the slow route if anything looks fishy 803 # take the slow route if anything looks fishy
621 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 804 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
622 $ndirs = -1; 805 $ndirs = -1;
623 } else { 806 } else {
624 # if nlink == 2, we are finished 807 # if nlink == 2, we are finished
625 # on non-posix-fs's, we rely on nlink < 2 808 # on non-posix-fs's, we rely on nlink < 2
626 $ndirs = (stat _)[3] - 2 809 $ndirs = (stat _)[3] - 2
627 or return $grp->result ([], $entries); 810 or return $grp->result ([], $entries);
628 } 811 }
629 812
630 # sort into likely dirs and likely nondirs 813 # sort into likely dirs and likely nondirs
631 # dirs == files without ".", short entries first 814 # dirs == files without ".", short entries first
632 $entries = [map $_->[0], 815 $entries = [map $_->[0],
633 sort { $b->[1] cmp $a->[1] } 816 sort { $b->[1] cmp $a->[1] }
634 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length], 817 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
635 @$entries]; 818 @$entries];
636 819
637 my (@dirs, @nondirs); 820 my (@dirs, @nondirs);
638 821
639 my $statgrp = add $grp aio_group sub { 822 my $statgrp = add $grp aio_group sub {
640 $grp->result (\@dirs, \@nondirs); 823 $grp->result (\@dirs, \@nondirs);
641 }; 824 };
642 825
643 limit $statgrp $maxreq; 826 limit $statgrp $maxreq;
644 feed $statgrp sub { 827 feed $statgrp sub {
645 return unless @$entries; 828 return unless @$entries;
646 my $entry = pop @$entries; 829 my $entry = pop @$entries;
647 830
648 aioreq_pri $pri; 831 aioreq_pri $pri;
649 add $statgrp aio_stat "$path/$entry/.", sub { 832 add $statgrp aio_stat "$path/$entry/.", sub {
650 if ($_[0] < 0) { 833 if ($_[0] < 0) {
651 push @nondirs, $entry; 834 push @nondirs, $entry;
652 } else { 835 } else {
653 # need to check for real directory 836 # need to check for real directory
654 aioreq_pri $pri; 837 aioreq_pri $pri;
655 add $statgrp aio_lstat "$path/$entry", sub { 838 add $statgrp aio_lstat "$path/$entry", sub {
656 if (-d _) { 839 if (-d _) {
657 push @dirs, $entry; 840 push @dirs, $entry;
658 841
659 unless (--$ndirs) { 842 unless (--$ndirs) {
660 push @nondirs, @$entries; 843 push @nondirs, @$entries;
661 feed $statgrp; 844 feed $statgrp;
845 }
846 } else {
847 push @nondirs, $entry;
662 } 848 }
663 } else {
664 push @nondirs, $entry;
665 } 849 }
666 } 850 }
667 } 851 };
668 }; 852 };
669 }; 853 };
670 }; 854 };
671 }; 855 };
856
857 $grp
672 }; 858 }
673
674 $grp
675} 859}
860
861=item aio_rmtree $path, $callback->($status)
862
863Delete a directory tree starting (and including) C<$path>, return the
864status of the final C<rmdir> only. This is a composite request that
865uses C<aio_scandir> to recurse into and rmdir directories, and unlink
866everything else.
867
868=cut
869
870sub aio_rmtree;
871sub aio_rmtree($;$) {
872 aio_block {
873 my ($path, $cb) = @_;
874
875 my $pri = aioreq_pri;
876 my $grp = aio_group $cb;
877
878 aioreq_pri $pri;
879 add $grp aio_scandir $path, 0, sub {
880 my ($dirs, $nondirs) = @_;
881
882 my $dirgrp = aio_group sub {
883 add $grp aio_rmdir $path, sub {
884 $grp->result ($_[0]);
885 };
886 };
887
888 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
889 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
890
891 add $grp $dirgrp;
892 };
893
894 $grp
895 }
896}
897
898=item aio_sync $callback->($status)
899
900Asynchronously call sync and call the callback when finished.
676 901
677=item aio_fsync $fh, $callback->($status) 902=item aio_fsync $fh, $callback->($status)
678 903
679Asynchronously call fsync on the given filehandle and call the callback 904Asynchronously call fsync on the given filehandle and call the callback
680with the fsync result code. 905with the fsync result code.
933that are being processed by C<IO::AIO::poll_cb> in one call, respectively 1158that are being processed by C<IO::AIO::poll_cb> in one call, respectively
934the maximum amount of time (default C<0>, meaning infinity) spent in 1159the maximum amount of time (default C<0>, meaning infinity) spent in
935C<IO::AIO::poll_cb> to process requests (more correctly the mininum amount 1160C<IO::AIO::poll_cb> to process requests (more correctly the mininum amount
936of time C<poll_cb> is allowed to use). 1161of time C<poll_cb> is allowed to use).
937 1162
1163Setting C<max_poll_time> to a non-zero value creates an overhead of one
1164syscall per request processed, which is not normally a problem unless your
1165callbacks are really really fast or your OS is really really slow (I am
1166not mentioning Solaris here). Using C<max_poll_reqs> incurs no overhead.
1167
938Setting these is useful if you want to ensure some level of 1168Setting these is useful if you want to ensure some level of
939interactiveness when perl is not fast enough to process all requests in 1169interactiveness when perl is not fast enough to process all requests in
940time. 1170time.
941 1171
942For interactive programs, values such as C<0.01> to C<0.1> should be fine. 1172For interactive programs, values such as C<0.01> to C<0.1> should be fine.
943 1173
944Example: Install an Event watcher that automatically calls 1174Example: Install an Event watcher that automatically calls
945IO::AIO::poll_some with low priority, to ensure that other parts of the 1175IO::AIO::poll_cb with low priority, to ensure that other parts of the
946program get the CPU sometimes even under high AIO load. 1176program get the CPU sometimes even under high AIO load.
947 1177
948 # try not to spend much more than 0.1s in poll_cb 1178 # try not to spend much more than 0.1s in poll_cb
949 IO::AIO::max_poll_time 0.1; 1179 IO::AIO::max_poll_time 0.1;
950 1180
953 poll => 'r', nice => 1, 1183 poll => 'r', nice => 1,
954 cb => &IO::AIO::poll_cb); 1184 cb => &IO::AIO::poll_cb);
955 1185
956=item IO::AIO::poll_wait 1186=item IO::AIO::poll_wait
957 1187
1188If there are any outstanding requests and none of them in the result
958Wait till the result filehandle becomes ready for reading (simply does a 1189phase, wait till the result filehandle becomes ready for reading (simply
959C<select> on the filehandle. This is useful if you want to synchronously 1190does a C<select> on the filehandle. This is useful if you want to
960wait for some requests to finish). 1191synchronously wait for some requests to finish).
961 1192
962See C<nreqs> for an example. 1193See C<nreqs> for an example.
963 1194
964=item IO::AIO::poll 1195=item IO::AIO::poll
965 1196
966Waits until some requests have been handled. 1197Waits until some requests have been handled.
967 1198
1199Returns the number of requests processed, but is otherwise strictly
968Strictly equivalent to: 1200equivalent to:
969 1201
970 IO::AIO::poll_wait, IO::AIO::poll_cb 1202 IO::AIO::poll_wait, IO::AIO::poll_cb
971 if IO::AIO::nreqs;
972 1203
973=item IO::AIO::flush 1204=item IO::AIO::flush
974 1205
975Wait till all outstanding AIO requests have been handled. 1206Wait till all outstanding AIO requests have been handled.
976 1207
977Strictly equivalent to: 1208Strictly equivalent to:
978 1209
979 IO::AIO::poll_wait, IO::AIO::poll_cb 1210 IO::AIO::poll_wait, IO::AIO::poll_cb
980 while IO::AIO::nreqs; 1211 while IO::AIO::nreqs;
981 1212
1213=back
1214
982=head3 CONTROLLING THE NUMBER OF THREADS 1215=head3 CONTROLLING THE NUMBER OF THREADS
1216
1217=over
983 1218
984=item IO::AIO::min_parallel $nthreads 1219=item IO::AIO::min_parallel $nthreads
985 1220
986Set the minimum number of AIO threads to C<$nthreads>. The current 1221Set the minimum number of AIO threads to C<$nthreads>. The current
987default is C<8>, which means eight asynchronous operations can execute 1222default is C<8>, which means eight asynchronous operations can execute
1035This is a very bad function to use in interactive programs because it 1270This is a very bad function to use in interactive programs because it
1036blocks, and a bad way to reduce concurrency because it is inexact: Better 1271blocks, and a bad way to reduce concurrency because it is inexact: Better
1037use an C<aio_group> together with a feed callback. 1272use an C<aio_group> together with a feed callback.
1038 1273
1039Sets the maximum number of outstanding requests to C<$nreqs>. If you 1274Sets the maximum number of outstanding requests to C<$nreqs>. If you
1040to queue up more than this number of requests, the next call to the 1275do queue up more than this number of requests, the next call to the
1041C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>) 1276C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
1042function will block until the limit is no longer exceeded. 1277function will block until the limit is no longer exceeded.
1043 1278
1044The default value is very large, so there is no practical limit on the 1279The default value is very large, so there is no practical limit on the
1045number of outstanding requests. 1280number of outstanding requests.
1046 1281
1047You can still queue as many requests as you want. Therefore, 1282You can still queue as many requests as you want. Therefore,
1048C<max_oustsanding> is mainly useful in simple scripts (with low values) or 1283C<max_oustsanding> is mainly useful in simple scripts (with low values) or
1049as a stop gap to shield against fatal memory overflow (with large values). 1284as a stop gap to shield against fatal memory overflow (with large values).
1050 1285
1286=back
1287
1051=head3 STATISTICAL INFORMATION 1288=head3 STATISTICAL INFORMATION
1289
1290=over
1052 1291
1053=item IO::AIO::nreqs 1292=item IO::AIO::nreqs
1054 1293
1055Returns the number of requests currently in the ready, execute or pending 1294Returns the number of requests currently in the ready, execute or pending
1056states (i.e. for which their callback has not been invoked yet). 1295states (i.e. for which their callback has not been invoked yet).
1072 1311
1073=back 1312=back
1074 1313
1075=cut 1314=cut
1076 1315
1077# support function to convert a fd into a perl filehandle
1078sub _fd2fh {
1079 return undef if $_[0] < 0;
1080
1081 # try to generate nice filehandles
1082 my $sym = "IO::AIO::fd#$_[0]";
1083 local *$sym;
1084
1085 open *$sym, "+<&=$_[0]" # usually works under any unix
1086 or open *$sym, "<&=$_[0]" # cygwin needs this
1087 or open *$sym, ">&=$_[0]" # or this
1088 or return undef;
1089
1090 *$sym
1091}
1092
1093min_parallel 8; 1316min_parallel 8;
1094 1317
1095END { 1318END { flush }
1096 min_parallel 1;
1097 flush;
1098};
1099 1319
11001; 13201;
1101 1321
1102=head2 FORK BEHAVIOUR 1322=head2 FORK BEHAVIOUR
1103 1323
1123bytes of memory. In addition, stat requests need a stat buffer (possibly 1343bytes of memory. In addition, stat requests need a stat buffer (possibly
1124a few hundred bytes), readdir requires a result buffer and so on. Perl 1344a few hundred bytes), readdir requires a result buffer and so on. Perl
1125scalars and other data passed into aio requests will also be locked and 1345scalars and other data passed into aio requests will also be locked and
1126will consume memory till the request has entered the done state. 1346will consume memory till the request has entered the done state.
1127 1347
1128This is now awfully much, so queuing lots of requests is not usually a 1348This is not awfully much, so queuing lots of requests is not usually a
1129problem. 1349problem.
1130 1350
1131Per-thread usage: 1351Per-thread usage:
1132 1352
1133In the execution phase, some aio requests require more memory for 1353In the execution phase, some aio requests require more memory for

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