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Revision 1.91 by root, Mon Oct 30 23:30:29 2006 UTC vs.
Revision 1.139 by root, Sun Oct 12 22:30:33 2008 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
31 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
32 use AnyEvent::AIO;
33
30 # AnyEvent integration 34 # EV integration
31 open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!"; 35 my $w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
32 my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });
33 36
34 # Event integration 37 # Event integration
35 Event->io (fd => IO::AIO::poll_fileno, 38 Event->io (fd => IO::AIO::poll_fileno,
36 poll => 'r', 39 poll => 'r',
37 cb => \&IO::AIO::poll_cb); 40 cb => \&IO::AIO::poll_cb);
61etc.), but can also be used to easily do operations in parallel that are 64etc.), 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 65normally 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 66on a RAID volume or over NFS when you do a number of stat operations
64concurrently. 67concurrently.
65 68
66While most of this works on all types of file descriptors (for example 69While most of this works on all types of file descriptors (for
67sockets), using these functions on file descriptors that support 70example sockets), using these functions on file descriptors that
68nonblocking operation (again, sockets, pipes etc.) is very inefficient or 71support nonblocking operation (again, sockets, pipes etc.) is very
69might not work (aio_read fails on sockets/pipes/fifos). Use an event loop 72inefficient. Use an event loop for that (such as the L<Event|Event>
70for that (such as the L<Event|Event> module): IO::AIO will naturally fit 73module): IO::AIO will naturally fit into such an event loop itself.
71into such an event loop itself.
72 74
73In this version, a number of threads are started that execute your 75In this version, a number of threads are started that execute your
74requests and signal their completion. You don't need thread support 76requests and signal their completion. You don't need thread support
75in perl, and the threads created by this module will not be visible 77in 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 78to 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 80not well-supported or restricted (GNU/Linux doesn't allow them on normal
79files currently, for example), and they would only support aio_read and 81files currently, for example), and they would only support aio_read and
80aio_write, so the remaining functionality would have to be implemented 82aio_write, so the remaining functionality would have to be implemented
81using threads anyway. 83using threads anyway.
82 84
83Although the module will work with in the presence of other (Perl-) 85Although the module will work in the presence of other (Perl-) threads,
84threads, it is currently not reentrant in any way, so use appropriate 86it is currently not reentrant in any way, so use appropriate locking
85locking yourself, always call C<poll_cb> from within the same thread, or 87yourself, always call C<poll_cb> from within the same thread, or never
86never call C<poll_cb> (or other C<aio_> functions) recursively. 88call C<poll_cb> (or other C<aio_> functions) recursively.
87 89
88=head2 EXAMPLE 90=head2 EXAMPLE
89 91
90This is a simple example that uses the Event module and loads 92This is a simple example that uses the Event module and loads
91F</etc/passwd> asynchronously: 93F</etc/passwd> asynchronously:
99 poll => 'r', 101 poll => 'r',
100 cb => \&IO::AIO::poll_cb); 102 cb => \&IO::AIO::poll_cb);
101 103
102 # queue the request to open /etc/passwd 104 # queue the request to open /etc/passwd
103 aio_open "/etc/passwd", O_RDONLY, 0, sub { 105 aio_open "/etc/passwd", O_RDONLY, 0, sub {
104 my $fh = $_[0] 106 my $fh = shift
105 or die "error while opening: $!"; 107 or die "error while opening: $!";
106 108
107 # stat'ing filehandles is generally non-blocking 109 # stat'ing filehandles is generally non-blocking
108 my $size = -s $fh; 110 my $size = -s $fh;
109 111
183 185
184=cut 186=cut
185 187
186package IO::AIO; 188package IO::AIO;
187 189
190use Carp ();
191
188no warnings; 192no warnings;
189use strict 'vars'; 193use strict 'vars';
190 194
191use base 'Exporter'; 195use base 'Exporter';
192 196
193BEGIN { 197BEGIN {
194 our $VERSION = '2.2'; 198 our $VERSION = '3.1';
195 199
196 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat 200 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close
197 aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink 201 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir
198 aio_readlink aio_fsync aio_fdatasync aio_readahead aio_rename aio_link 202 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
199 aio_move aio_copy aio_group aio_nop aio_mknod); 203 aio_fdatasync aio_pathsync aio_readahead
204 aio_rename aio_link aio_move aio_copy aio_group
205 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
206 aio_chmod aio_utime aio_truncate);
207
200 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); 208 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
201 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 209 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
202 min_parallel max_parallel max_idle 210 min_parallel max_parallel max_idle
203 nreqs nready npending nthreads 211 nreqs nready npending nthreads
204 max_poll_time max_poll_reqs); 212 max_poll_time max_poll_reqs);
216All the C<aio_*> calls are more or less thin wrappers around the syscall 224All the C<aio_*> calls are more or less thin wrappers around the syscall
217with the same name (sans C<aio_>). The arguments are similar or identical, 225with the same name (sans C<aio_>). The arguments are similar or identical,
218and they all accept an additional (and optional) C<$callback> argument 226and they all accept an additional (and optional) C<$callback> argument
219which must be a code reference. This code reference will get called with 227which 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 228the 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 229perl, which usually delivers "false") as its sole argument after the given
222syscall has been executed asynchronously. 230syscall has been executed asynchronously.
223 231
224All functions expecting a filehandle keep a copy of the filehandle 232All functions expecting a filehandle keep a copy of the filehandle
225internally until the request has finished. 233internally until the request has finished.
226 234
240your pathnames to the locale (or other) encoding in effect in the user 248your pathnames to the locale (or other) encoding in effect in the user
241environment, d) use Glib::filename_from_unicode on unicode filenames or e) 249environment, d) use Glib::filename_from_unicode on unicode filenames or e)
242use something else to ensure your scalar has the correct contents. 250use something else to ensure your scalar has the correct contents.
243 251
244This works, btw. independent of the internal UTF-8 bit, which IO::AIO 252This works, btw. independent of the internal UTF-8 bit, which IO::AIO
245handles correctly wether it is set or not. 253handles correctly whether it is set or not.
246 254
247=over 4 255=over 4
248 256
249=item $prev_pri = aioreq_pri [$pri] 257=item $prev_pri = aioreq_pri [$pri]
250 258
270 aio_read $_[0], ..., sub { 278 aio_read $_[0], ..., sub {
271 ... 279 ...
272 }; 280 };
273 }; 281 };
274 282
283
275=item aioreq_nice $pri_adjust 284=item aioreq_nice $pri_adjust
276 285
277Similar to C<aioreq_pri>, but subtracts the given value from the current 286Similar to C<aioreq_pri>, but subtracts the given value from the current
278priority, so the effect is cumulative. 287priority, so the effect is cumulative.
288
279 289
280=item aio_open $pathname, $flags, $mode, $callback->($fh) 290=item aio_open $pathname, $flags, $mode, $callback->($fh)
281 291
282Asynchronously open or create a file and call the callback with a newly 292Asynchronously open or create a file and call the callback with a newly
283created filehandle for the file. 293created filehandle for the file.
289list. They are the same as used by C<sysopen>. 299list. They are the same as used by C<sysopen>.
290 300
291Likewise, C<$mode> specifies the mode of the newly created file, if it 301Likewise, C<$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>, 302didn'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, 303except 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). 304and C<0666> or C<0777> if you do). Note that the C<$mode> will be modified
305by the umask in effect then the request is being executed, so better never
306change the umask.
295 307
296Example: 308Example:
297 309
298 aio_open "/etc/passwd", O_RDONLY, 0, sub { 310 aio_open "/etc/passwd", O_RDONLY, 0, sub {
299 if ($_[0]) { 311 if ($_[0]) {
302 } else { 314 } else {
303 die "open failed: $!\n"; 315 die "open failed: $!\n";
304 } 316 }
305 }; 317 };
306 318
319
307=item aio_close $fh, $callback->($status) 320=item aio_close $fh, $callback->($status)
308 321
309Asynchronously close a file and call the callback with the result 322Asynchronously close a file and call the callback with the result
310code. I<WARNING:> although accepted, you should not pass in a perl 323code.
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.
314 324
315This is supposed to be a bug in the API, so that might change. It's 325Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
316therefore best to avoid this function. 326closing the file descriptor associated with the filehandle itself.
327
328Therefore, C<aio_close> will not close the filehandle - instead it will
329use dup2 to overwrite the file descriptor with the write-end of a pipe
330(the pipe fd will be created on demand and will be cached).
331
332Or in other words: the file descriptor will be closed, but it will not be
333free for reuse until the perl filehandle is closed.
334
335=cut
317 336
318=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 337=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
319 338
320=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 339=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
321 340
322Reads or writes C<length> bytes from the specified C<fh> and C<offset> 341Reads or writes C<$length> bytes from the specified C<$fh> and C<$offset>
323into the scalar given by C<data> and offset C<dataoffset> and calls the 342into the scalar given by C<$data> and offset C<$dataoffset> and calls the
324callback without the actual number of bytes read (or -1 on error, just 343callback without the actual number of bytes read (or -1 on error, just
325like the syscall). 344like the syscall).
326 345
346If C<$offset> is undefined, then the current file descriptor offset will
347be used (and updated), otherwise the file descriptor offset will not be
348changed by these calls.
349
350If C<$length> is undefined in C<aio_write>, use the remaining length of C<$data>.
351
352If C<$dataoffset> is less than zero, it will be counted from the end of
353C<$data>.
354
327The C<$data> scalar I<MUST NOT> be modified in any way while the request 355The C<$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 356is outstanding. Modifying it can result in segfaults or World War III (if
329necessary/optional hardware is installed). 357the necessary/optional hardware is installed).
330 358
331Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at 359Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
332offset C<0> within the scalar: 360offset C<0> within the scalar:
333 361
334 aio_read $fh, 7, 15, $buffer, 0, sub { 362 aio_read $fh, 7, 15, $buffer, 0, sub {
335 $_[0] > 0 or die "read error: $!"; 363 $_[0] > 0 or die "read error: $!";
336 print "read $_[0] bytes: <$buffer>\n"; 364 print "read $_[0] bytes: <$buffer>\n";
337 }; 365 };
366
338 367
339=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) 368=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
340 369
341Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts 370Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
342reading at byte offset C<$in_offset>, and starts writing at the current 371reading at byte offset C<$in_offset>, and starts writing at the current
356C<$in_fh> than are written, and there is no way to find out how many 385C<$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 386bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
358provides the number of bytes written to C<$out_fh>. Only if the result 387provides the number of bytes written to C<$out_fh>. Only if the result
359value equals C<$length> one can assume that C<$length> bytes have been 388value equals C<$length> one can assume that C<$length> bytes have been
360read. 389read.
390
361 391
362=item aio_readahead $fh,$offset,$length, $callback->($retval) 392=item aio_readahead $fh,$offset,$length, $callback->($retval)
363 393
364C<aio_readahead> populates the page cache with data from a file so that 394C<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<$offset> 395subsequent reads from that file will not block on disk I/O. The C<$offset>
371file. The current file offset of the file is left unchanged. 401file. The current file offset of the file is left unchanged.
372 402
373If that syscall doesn't exist (likely if your OS isn't Linux) it will be 403If 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. 404emulated by simply reading the data, which would have a similar effect.
375 405
406
376=item aio_stat $fh_or_path, $callback->($status) 407=item aio_stat $fh_or_path, $callback->($status)
377 408
378=item aio_lstat $fh, $callback->($status) 409=item aio_lstat $fh, $callback->($status)
379 410
380Works like perl's C<stat> or C<lstat> in void context. The callback will 411Works like perl's C<stat> or C<lstat> in void context. The callback will
393 aio_stat "/etc/passwd", sub { 424 aio_stat "/etc/passwd", sub {
394 $_[0] and die "stat failed: $!"; 425 $_[0] and die "stat failed: $!";
395 print "size is ", -s _, "\n"; 426 print "size is ", -s _, "\n";
396 }; 427 };
397 428
429
430=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
431
432Works like perl's C<utime> function (including the special case of $atime
433and $mtime being undef). Fractional times are supported if the underlying
434syscalls support them.
435
436When called with a pathname, uses utimes(2) if available, otherwise
437utime(2). If called on a file descriptor, uses futimes(2) if available,
438otherwise returns ENOSYS, so this is not portable.
439
440Examples:
441
442 # set atime and mtime to current time (basically touch(1)):
443 aio_utime "path", undef, undef;
444 # set atime to current time and mtime to beginning of the epoch:
445 aio_utime "path", time, undef; # undef==0
446
447
448=item aio_chown $fh_or_path, $uid, $gid, $callback->($status)
449
450Works like perl's C<chown> function, except that C<undef> for either $uid
451or $gid is being interpreted as "do not change" (but -1 can also be used).
452
453Examples:
454
455 # same as "chown root path" in the shell:
456 aio_chown "path", 0, -1;
457 # same as above:
458 aio_chown "path", 0, undef;
459
460
461=item aio_truncate $fh_or_path, $offset, $callback->($status)
462
463Works like truncate(2) or ftruncate(2).
464
465
466=item aio_chmod $fh_or_path, $mode, $callback->($status)
467
468Works like perl's C<chmod> function.
469
470
398=item aio_unlink $pathname, $callback->($status) 471=item aio_unlink $pathname, $callback->($status)
399 472
400Asynchronously unlink (delete) a file and call the callback with the 473Asynchronously unlink (delete) a file and call the callback with the
401result code. 474result code.
402 475
476
403=item aio_mknod $path, $mode, $dev, $callback->($status) 477=item aio_mknod $path, $mode, $dev, $callback->($status)
404 478
405[EXPERIMENTAL] 479[EXPERIMENTAL]
406 480
407Asynchronously create a device node (or fifo). See mknod(2). 481Asynchronously create a device node (or fifo). See mknod(2).
408 482
409The only (POSIX-) portable way of calling this function is: 483The only (POSIX-) portable way of calling this function is:
410 484
411 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... 485 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...
486
412 487
413=item aio_link $srcpath, $dstpath, $callback->($status) 488=item aio_link $srcpath, $dstpath, $callback->($status)
414 489
415Asynchronously create a new link to the existing object at C<$srcpath> at 490Asynchronously create a new link to the existing object at C<$srcpath> at
416the path C<$dstpath> and call the callback with the result code. 491the path C<$dstpath> and call the callback with the result code.
417 492
493
418=item aio_symlink $srcpath, $dstpath, $callback->($status) 494=item aio_symlink $srcpath, $dstpath, $callback->($status)
419 495
420Asynchronously create a new symbolic link to the existing object at C<$srcpath> at 496Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
421the path C<$dstpath> and call the callback with the result code. 497the path C<$dstpath> and call the callback with the result code.
498
422 499
423=item aio_readlink $path, $callback->($link) 500=item aio_readlink $path, $callback->($link)
424 501
425Asynchronously read the symlink specified by C<$path> and pass it to 502Asynchronously read the symlink specified by C<$path> and pass it to
426the callback. If an error occurs, nothing or undef gets passed to the 503the callback. If an error occurs, nothing or undef gets passed to the
427callback. 504callback.
428 505
506
429=item aio_rename $srcpath, $dstpath, $callback->($status) 507=item aio_rename $srcpath, $dstpath, $callback->($status)
430 508
431Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as 509Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
432rename(2) and call the callback with the result code. 510rename(2) and call the callback with the result code.
433 511
512
513=item aio_mkdir $pathname, $mode, $callback->($status)
514
515Asynchronously mkdir (create) a directory and call the callback with
516the result code. C<$mode> will be modified by the umask at the time the
517request is executed, so do not change your umask.
518
519
434=item aio_rmdir $pathname, $callback->($status) 520=item aio_rmdir $pathname, $callback->($status)
435 521
436Asynchronously rmdir (delete) a directory and call the callback with the 522Asynchronously rmdir (delete) a directory and call the callback with the
437result code. 523result code.
524
438 525
439=item aio_readdir $pathname, $callback->($entries) 526=item aio_readdir $pathname, $callback->($entries)
440 527
441Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 528Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
442directory (i.e. opendir + readdir + closedir). The entries will not be 529directory (i.e. opendir + readdir + closedir). The entries will not be
443sorted, and will B<NOT> include the C<.> and C<..> entries. 530sorted, and will B<NOT> include the C<.> and C<..> entries.
444 531
445The callback a single argument which is either C<undef> or an array-ref 532The callback a single argument which is either C<undef> or an array-ref
446with the filenames. 533with the filenames.
447 534
535
536=item aio_load $path, $data, $callback->($status)
537
538This is a composite request that tries to fully load the given file into
539memory. Status is the same as with aio_read.
540
541=cut
542
543sub aio_load($$;$) {
544 my ($path, undef, $cb) = @_;
545 my $data = \$_[1];
546
547 my $pri = aioreq_pri;
548 my $grp = aio_group $cb;
549
550 aioreq_pri $pri;
551 add $grp aio_open $path, O_RDONLY, 0, sub {
552 my $fh = shift
553 or return $grp->result (-1);
554
555 aioreq_pri $pri;
556 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
557 $grp->result ($_[0]);
558 };
559 };
560
561 $grp
562}
563
448=item aio_copy $srcpath, $dstpath, $callback->($status) 564=item aio_copy $srcpath, $dstpath, $callback->($status)
449 565
450Try to copy the I<file> (directories not supported as either source or 566Try to copy the I<file> (directories not supported as either source or
451destination) from C<$srcpath> to C<$dstpath> and call the callback with 567destination) from C<$srcpath> to C<$dstpath> and call the callback with
452the C<0> (error) or C<-1> ok. 568the C<0> (error) or C<-1> ok.
453 569
454This is a composite request that it creates the destination file with 570This is a composite request that creates the destination file with
455mode 0200 and copies the contents of the source file into it using 571mode 0200 and copies the contents of the source file into it using
456C<aio_sendfile>, followed by restoring atime, mtime, access mode and 572C<aio_sendfile>, followed by restoring atime, mtime, access mode and
457uid/gid, in that order. 573uid/gid, in that order.
458 574
459If an error occurs, the partial destination file will be unlinked, if 575If an error occurs, the partial destination file will be unlinked, if
484 600
485 # those should not normally block. should. should. 601 # those should not normally block. should. should.
486 utime $stat[8], $stat[9], $dst; 602 utime $stat[8], $stat[9], $dst;
487 chmod $stat[2] & 07777, $dst_fh; 603 chmod $stat[2] & 07777, $dst_fh;
488 chown $stat[4], $stat[5], $dst_fh; 604 chown $stat[4], $stat[5], $dst_fh;
605
606 aioreq_pri $pri;
489 close $dst_fh; 607 add $grp aio_close $dst_fh;
490 } else { 608 } else {
491 $grp->result (-1); 609 $grp->result (-1);
492 close $src_fh; 610 close $src_fh;
493 close $dst_fh; 611 close $dst_fh;
494 612
513 631
514Try to move the I<file> (directories not supported as either source or 632Try to move the I<file> (directories not supported as either source or
515destination) from C<$srcpath> to C<$dstpath> and call the callback with 633destination) from C<$srcpath> to C<$dstpath> and call the callback with
516the C<0> (error) or C<-1> ok. 634the C<0> (error) or C<-1> ok.
517 635
518This is a composite request that tries to rename(2) the file first. If 636This is a composite request that tries to rename(2) the file first; if
519rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if 637rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
520that is successful, unlinking the C<$srcpath>. 638that is successful, unlinks the C<$srcpath>.
521 639
522=cut 640=cut
523 641
524sub aio_move($$;$) { 642sub aio_move($$;$) {
525 my ($src, $dst, $cb) = @_; 643 my ($src, $dst, $cb) = @_;
599as those tend to return 0 or 1 as link counts, which disables the 717as those tend to return 0 or 1 as link counts, which disables the
600directory counting heuristic. 718directory counting heuristic.
601 719
602=cut 720=cut
603 721
604sub aio_scandir($$$) { 722sub aio_scandir($$;$) {
605 my ($path, $maxreq, $cb) = @_; 723 my ($path, $maxreq, $cb) = @_;
606 724
607 my $pri = aioreq_pri; 725 my $pri = aioreq_pri;
608 726
609 my $grp = aio_group $cb; 727 my $grp = aio_group $cb;
685 }; 803 };
686 804
687 $grp 805 $grp
688} 806}
689 807
808=item aio_rmtree $path, $callback->($status)
809
810Delete a directory tree starting (and including) C<$path>, return the
811status of the final C<rmdir> only. This is a composite request that
812uses C<aio_scandir> to recurse into and rmdir directories, and unlink
813everything else.
814
815=cut
816
817sub aio_rmtree;
818sub aio_rmtree($;$) {
819 my ($path, $cb) = @_;
820
821 my $pri = aioreq_pri;
822 my $grp = aio_group $cb;
823
824 aioreq_pri $pri;
825 add $grp aio_scandir $path, 0, sub {
826 my ($dirs, $nondirs) = @_;
827
828 my $dirgrp = aio_group sub {
829 add $grp aio_rmdir $path, sub {
830 $grp->result ($_[0]);
831 };
832 };
833
834 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
835 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
836
837 add $grp $dirgrp;
838 };
839
840 $grp
841}
842
843=item aio_sync $callback->($status)
844
845Asynchronously call sync and call the callback when finished.
846
690=item aio_fsync $fh, $callback->($status) 847=item aio_fsync $fh, $callback->($status)
691 848
692Asynchronously call fsync on the given filehandle and call the callback 849Asynchronously call fsync on the given filehandle and call the callback
693with the fsync result code. 850with the fsync result code.
694 851
697Asynchronously call fdatasync on the given filehandle and call the 854Asynchronously call fdatasync on the given filehandle and call the
698callback with the fdatasync result code. 855callback with the fdatasync result code.
699 856
700If this call isn't available because your OS lacks it or it couldn't be 857If 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. 858detected, it will be emulated by calling C<fsync> instead.
859
860=item aio_pathsync $path, $callback->($status)
861
862This request tries to open, fsync and close the given path. This is a
863composite request intended to sync directories after directory operations
864(E.g. rename). This might not work on all operating systems or have any
865specific effect, but usually it makes sure that directory changes get
866written to disc. It works for anything that can be opened for read-only,
867not just directories.
868
869Passes C<0> when everything went ok, and C<-1> on error.
870
871=cut
872
873sub aio_pathsync($;$) {
874 my ($path, $cb) = @_;
875
876 my $pri = aioreq_pri;
877 my $grp = aio_group $cb;
878
879 aioreq_pri $pri;
880 add $grp aio_open $path, O_RDONLY, 0, sub {
881 my ($fh) = @_;
882 if ($fh) {
883 aioreq_pri $pri;
884 add $grp aio_fsync $fh, sub {
885 $grp->result ($_[0]);
886
887 aioreq_pri $pri;
888 add $grp aio_close $fh;
889 };
890 } else {
891 $grp->result (-1);
892 }
893 };
894
895 $grp
896}
702 897
703=item aio_group $callback->(...) 898=item aio_group $callback->(...)
704 899
705This is a very special aio request: Instead of doing something, it is a 900This 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 901container for other aio requests, which is useful if you want to bundle
818Their lifetime, simplified, looks like this: when they are empty, they 1013Their lifetime, simplified, looks like this: when they are empty, they
819will finish very quickly. If they contain only requests that are in the 1014will finish very quickly. If they contain only requests that are in the
820C<done> state, they will also finish. Otherwise they will continue to 1015C<done> state, they will also finish. Otherwise they will continue to
821exist. 1016exist.
822 1017
823That means after creating a group you have some time to add requests. And 1018That 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 1019(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 1020the C<poll_cb>). And in the callbacks of those requests, you can add
826itself finish. 1021further requests to the group. And only when all those requests have
1022finished will the the group itself finish.
827 1023
828=over 4 1024=over 4
829 1025
830=item add $grp ... 1026=item add $grp ...
831 1027
843itself. Useful when you queued a lot of events but got a result early. 1039itself. Useful when you queued a lot of events but got a result early.
844 1040
845=item $grp->result (...) 1041=item $grp->result (...)
846 1042
847Set the result value(s) that will be passed to the group callback when all 1043Set 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 1044subrequests have finished and set the groups errno to the current value
849of errno (just like calling C<errno> without an error number). By default, 1045of errno (just like calling C<errno> without an error number). By default,
850no argument will be passed and errno is zero. 1046no argument will be passed and errno is zero.
851 1047
852=item $grp->errno ([$errno]) 1048=item $grp->errno ([$errno])
853 1049
864=item feed $grp $callback->($grp) 1060=item feed $grp $callback->($grp)
865 1061
866Sets a feeder/generator on this group: every group can have an attached 1062Sets a feeder/generator on this group: every group can have an attached
867generator that generates requests if idle. The idea behind this is that, 1063generator 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, 1064although you could just queue as many requests as you want in a group,
869this might starve other requests for a potentially long time. For 1065this might starve other requests for a potentially long time. For example,
870example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1066C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
871requests, delaying any later requests for a long time. 1067delaying any later requests for a long time.
872 1068
873To avoid this, and allow incremental generation of requests, you can 1069To avoid this, and allow incremental generation of requests, you can
874instead a group and set a feeder on it that generates those requests. The 1070instead 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>, 1071feed 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 1072below) requests active in the group itself and is expected to queue more
880not impose any limits). 1076not impose any limits).
881 1077
882If the feed does not queue more requests when called, it will be 1078If the feed does not queue more requests when called, it will be
883automatically removed from the group. 1079automatically removed from the group.
884 1080
885If the feed limit is C<0>, it will be set to C<2> automatically. 1081If the feed limit is C<0> when this method is called, it will be set to
1082C<2> automatically.
886 1083
887Example: 1084Example:
888 1085
889 # stat all files in @files, but only ever use four aio requests concurrently: 1086 # stat all files in @files, but only ever use four aio requests concurrently:
890 1087
902Sets the feeder limit for the group: The feeder will be called whenever 1099Sets the feeder limit for the group: The feeder will be called whenever
903the group contains less than this many requests. 1100the group contains less than this many requests.
904 1101
905Setting the limit to C<0> will pause the feeding process. 1102Setting the limit to C<0> will pause the feeding process.
906 1103
1104The default value for the limit is C<0>, but note that setting a feeder
1105automatically bumps it up to C<2>.
1106
907=back 1107=back
908 1108
909=head2 SUPPORT FUNCTIONS 1109=head2 SUPPORT FUNCTIONS
910 1110
911=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1111=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
922See C<poll_cb> for an example. 1122See C<poll_cb> for an example.
923 1123
924=item IO::AIO::poll_cb 1124=item IO::AIO::poll_cb
925 1125
926Process some outstanding events on the result pipe. You have to call this 1126Process some outstanding events on the result pipe. You have to call this
927regularly. Returns the number of events processed. Returns immediately 1127regularly. Returns C<0> if all events could be processed, or C<-1> if it
1128returned earlier for whatever reason. Returns immediately when no events
928when no events are outstanding. The amount of events processed depends on 1129are 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>. 1130C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
930 1131
931If not all requests were processed for whatever reason, the filehandle 1132If not all requests were processed for whatever reason, the filehandle
932will still be ready when C<poll_cb> returns. 1133will still be ready when C<poll_cb> returns, so normally you don't have to
1134do anything special to have it called later.
933 1135
934Example: Install an Event watcher that automatically calls 1136Example: Install an Event watcher that automatically calls
935IO::AIO::poll_cb with high priority: 1137IO::AIO::poll_cb with high priority:
936 1138
937 Event->io (fd => IO::AIO::poll_fileno, 1139 Event->io (fd => IO::AIO::poll_fileno,
971 poll => 'r', nice => 1, 1173 poll => 'r', nice => 1,
972 cb => &IO::AIO::poll_cb); 1174 cb => &IO::AIO::poll_cb);
973 1175
974=item IO::AIO::poll_wait 1176=item IO::AIO::poll_wait
975 1177
1178If there are any outstanding requests and none of them in the result
976Wait till the result filehandle becomes ready for reading (simply does a 1179phase, wait till the result filehandle becomes ready for reading (simply
977C<select> on the filehandle. This is useful if you want to synchronously 1180does a C<select> on the filehandle. This is useful if you want to
978wait for some requests to finish). 1181synchronously wait for some requests to finish).
979 1182
980See C<nreqs> for an example. 1183See C<nreqs> for an example.
981 1184
982=item IO::AIO::poll 1185=item IO::AIO::poll
983 1186
984Waits until some requests have been handled. 1187Waits until some requests have been handled.
985 1188
1189Returns the number of requests processed, but is otherwise strictly
986Strictly equivalent to: 1190equivalent to:
987 1191
988 IO::AIO::poll_wait, IO::AIO::poll_cb 1192 IO::AIO::poll_wait, IO::AIO::poll_cb
989 if IO::AIO::nreqs;
990 1193
991=item IO::AIO::flush 1194=item IO::AIO::flush
992 1195
993Wait till all outstanding AIO requests have been handled. 1196Wait till all outstanding AIO requests have been handled.
994 1197
995Strictly equivalent to: 1198Strictly equivalent to:
996 1199
997 IO::AIO::poll_wait, IO::AIO::poll_cb 1200 IO::AIO::poll_wait, IO::AIO::poll_cb
998 while IO::AIO::nreqs; 1201 while IO::AIO::nreqs;
999 1202
1203=back
1204
1000=head3 CONTROLLING THE NUMBER OF THREADS 1205=head3 CONTROLLING THE NUMBER OF THREADS
1206
1207=over
1001 1208
1002=item IO::AIO::min_parallel $nthreads 1209=item IO::AIO::min_parallel $nthreads
1003 1210
1004Set the minimum number of AIO threads to C<$nthreads>. The current 1211Set the minimum number of AIO threads to C<$nthreads>. The current
1005default is C<8>, which means eight asynchronous operations can execute 1212default is C<8>, which means eight asynchronous operations can execute
1046 1253
1047The default is probably ok in most situations, especially if thread 1254The default is probably ok in most situations, especially if thread
1048creation is fast. If thread creation is very slow on your system you might 1255creation is fast. If thread creation is very slow on your system you might
1049want to use larger values. 1256want to use larger values.
1050 1257
1051=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1258=item IO::AIO::max_outstanding $maxreqs
1052 1259
1053This is a very bad function to use in interactive programs because it 1260This is a very bad function to use in interactive programs because it
1054blocks, and a bad way to reduce concurrency because it is inexact: Better 1261blocks, and a bad way to reduce concurrency because it is inexact: Better
1055use an C<aio_group> together with a feed callback. 1262use an C<aio_group> together with a feed callback.
1056 1263
1057Sets the maximum number of outstanding requests to C<$nreqs>. If you 1264Sets 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 1265do 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>) 1266C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
1060function will block until the limit is no longer exceeded. 1267function will block until the limit is no longer exceeded.
1061 1268
1062The default value is very large, so there is no practical limit on the 1269The default value is very large, so there is no practical limit on the
1063number of outstanding requests. 1270number of outstanding requests.
1064 1271
1065You can still queue as many requests as you want. Therefore, 1272You can still queue as many requests as you want. Therefore,
1066C<max_oustsanding> is mainly useful in simple scripts (with low values) or 1273C<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). 1274as a stop gap to shield against fatal memory overflow (with large values).
1068 1275
1276=back
1277
1069=head3 STATISTICAL INFORMATION 1278=head3 STATISTICAL INFORMATION
1279
1280=over
1070 1281
1071=item IO::AIO::nreqs 1282=item IO::AIO::nreqs
1072 1283
1073Returns the number of requests currently in the ready, execute or pending 1284Returns the number of requests currently in the ready, execute or pending
1074states (i.e. for which their callback has not been invoked yet). 1285states (i.e. for which their callback has not been invoked yet).
1090 1301
1091=back 1302=back
1092 1303
1093=cut 1304=cut
1094 1305
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; 1306min_parallel 8;
1112 1307
1113END { 1308END { flush }
1114 min_parallel 1;
1115 flush;
1116};
1117 1309
11181; 13101;
1119 1311
1120=head2 FORK BEHAVIOUR 1312=head2 FORK BEHAVIOUR
1121 1313
1141bytes of memory. In addition, stat requests need a stat buffer (possibly 1333bytes of memory. In addition, stat requests need a stat buffer (possibly
1142a few hundred bytes), readdir requires a result buffer and so on. Perl 1334a 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 1335scalars and other data passed into aio requests will also be locked and
1144will consume memory till the request has entered the done state. 1336will consume memory till the request has entered the done state.
1145 1337
1146This is now awfully much, so queuing lots of requests is not usually a 1338This is not awfully much, so queuing lots of requests is not usually a
1147problem. 1339problem.
1148 1340
1149Per-thread usage: 1341Per-thread usage:
1150 1342
1151In the execution phase, some aio requests require more memory for 1343In the execution phase, some aio requests require more memory for
1156 1348
1157Known bugs will be fixed in the next release. 1349Known bugs will be fixed in the next release.
1158 1350
1159=head1 SEE ALSO 1351=head1 SEE ALSO
1160 1352
1161L<Coro::AIO>. 1353L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1354more natural syntax.
1162 1355
1163=head1 AUTHOR 1356=head1 AUTHOR
1164 1357
1165 Marc Lehmann <schmorp@schmorp.de> 1358 Marc Lehmann <schmorp@schmorp.de>
1166 http://home.schmorp.de/ 1359 http://home.schmorp.de/

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