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Revision 1.91 by root, Mon Oct 30 23:30:29 2006 UTC vs.
Revision 1.143 by root, Thu Nov 20 09:01:40 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 = '3.17';
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_sync_file_range 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);
205 213
214 push @AIO_REQ, qw(aio_busy); # not exported
215
206 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 216 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
207 217
208 require XSLoader; 218 require XSLoader;
209 XSLoader::load ("IO::AIO", $VERSION); 219 XSLoader::load ("IO::AIO", $VERSION);
210} 220}
216All the C<aio_*> calls are more or less thin wrappers around the syscall 226All the C<aio_*> calls are more or less thin wrappers around the syscall
217with the same name (sans C<aio_>). The arguments are similar or identical, 227with the same name (sans C<aio_>). The arguments are similar or identical,
218and they all accept an additional (and optional) C<$callback> argument 228and they all accept an additional (and optional) C<$callback> argument
219which must be a code reference. This code reference will get called with 229which 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 230the 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 231perl, which usually delivers "false") as its sole argument after the given
222syscall has been executed asynchronously. 232syscall has been executed asynchronously.
223 233
224All functions expecting a filehandle keep a copy of the filehandle 234All functions expecting a filehandle keep a copy of the filehandle
225internally until the request has finished. 235internally until the request has finished.
226 236
240your pathnames to the locale (or other) encoding in effect in the user 250your pathnames to the locale (or other) encoding in effect in the user
241environment, d) use Glib::filename_from_unicode on unicode filenames or e) 251environment, d) use Glib::filename_from_unicode on unicode filenames or e)
242use something else to ensure your scalar has the correct contents. 252use something else to ensure your scalar has the correct contents.
243 253
244This works, btw. independent of the internal UTF-8 bit, which IO::AIO 254This works, btw. independent of the internal UTF-8 bit, which IO::AIO
245handles correctly wether it is set or not. 255handles correctly whether it is set or not.
246 256
247=over 4 257=over 4
248 258
249=item $prev_pri = aioreq_pri [$pri] 259=item $prev_pri = aioreq_pri [$pri]
250 260
270 aio_read $_[0], ..., sub { 280 aio_read $_[0], ..., sub {
271 ... 281 ...
272 }; 282 };
273 }; 283 };
274 284
285
275=item aioreq_nice $pri_adjust 286=item aioreq_nice $pri_adjust
276 287
277Similar to C<aioreq_pri>, but subtracts the given value from the current 288Similar to C<aioreq_pri>, but subtracts the given value from the current
278priority, so the effect is cumulative. 289priority, so the effect is cumulative.
290
279 291
280=item aio_open $pathname, $flags, $mode, $callback->($fh) 292=item aio_open $pathname, $flags, $mode, $callback->($fh)
281 293
282Asynchronously open or create a file and call the callback with a newly 294Asynchronously open or create a file and call the callback with a newly
283created filehandle for the file. 295created filehandle for the file.
289list. They are the same as used by C<sysopen>. 301list. They are the same as used by C<sysopen>.
290 302
291Likewise, C<$mode> specifies the mode of the newly created file, if it 303Likewise, C<$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>, 304didn'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, 305except 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). 306and C<0666> or C<0777> if you do). Note that the C<$mode> will be modified
307by the umask in effect then the request is being executed, so better never
308change the umask.
295 309
296Example: 310Example:
297 311
298 aio_open "/etc/passwd", O_RDONLY, 0, sub { 312 aio_open "/etc/passwd", O_RDONLY, 0, sub {
299 if ($_[0]) { 313 if ($_[0]) {
302 } else { 316 } else {
303 die "open failed: $!\n"; 317 die "open failed: $!\n";
304 } 318 }
305 }; 319 };
306 320
321
307=item aio_close $fh, $callback->($status) 322=item aio_close $fh, $callback->($status)
308 323
309Asynchronously close a file and call the callback with the result 324Asynchronously close a file and call the callback with the result
310code. I<WARNING:> although accepted, you should not pass in a perl 325code.
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.
314 326
315This is supposed to be a bug in the API, so that might change. It's 327Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
316therefore best to avoid this function. 328closing the file descriptor associated with the filehandle itself.
329
330Therefore, C<aio_close> will not close the filehandle - instead it will
331use dup2 to overwrite the file descriptor with the write-end of a pipe
332(the pipe fd will be created on demand and will be cached).
333
334Or in other words: the file descriptor will be closed, but it will not be
335free for reuse until the perl filehandle is closed.
336
337=cut
317 338
318=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 339=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
319 340
320=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 341=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
321 342
322Reads or writes C<length> bytes from the specified C<fh> and C<offset> 343Reads or writes C<$length> bytes from the specified C<$fh> and C<$offset>
323into the scalar given by C<data> and offset C<dataoffset> and calls the 344into the scalar given by C<$data> and offset C<$dataoffset> and calls the
324callback without the actual number of bytes read (or -1 on error, just 345callback without the actual number of bytes read (or -1 on error, just
325like the syscall). 346like the syscall).
326 347
348If C<$offset> is undefined, then the current file descriptor offset will
349be used (and updated), otherwise the file descriptor offset will not be
350changed by these calls.
351
352If C<$length> is undefined in C<aio_write>, use the remaining length of C<$data>.
353
354If C<$dataoffset> is less than zero, it will be counted from the end of
355C<$data>.
356
327The C<$data> scalar I<MUST NOT> be modified in any way while the request 357The C<$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 358is outstanding. Modifying it can result in segfaults or World War III (if
329necessary/optional hardware is installed). 359the necessary/optional hardware is installed).
330 360
331Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at 361Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
332offset C<0> within the scalar: 362offset C<0> within the scalar:
333 363
334 aio_read $fh, 7, 15, $buffer, 0, sub { 364 aio_read $fh, 7, 15, $buffer, 0, sub {
335 $_[0] > 0 or die "read error: $!"; 365 $_[0] > 0 or die "read error: $!";
336 print "read $_[0] bytes: <$buffer>\n"; 366 print "read $_[0] bytes: <$buffer>\n";
337 }; 367 };
368
338 369
339=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) 370=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
340 371
341Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts 372Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
342reading at byte offset C<$in_offset>, and starts writing at the current 373reading at byte offset C<$in_offset>, and starts writing at the current
356C<$in_fh> than are written, and there is no way to find out how many 387C<$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 388bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
358provides the number of bytes written to C<$out_fh>. Only if the result 389provides the number of bytes written to C<$out_fh>. Only if the result
359value equals C<$length> one can assume that C<$length> bytes have been 390value equals C<$length> one can assume that C<$length> bytes have been
360read. 391read.
392
361 393
362=item aio_readahead $fh,$offset,$length, $callback->($retval) 394=item aio_readahead $fh,$offset,$length, $callback->($retval)
363 395
364C<aio_readahead> populates the page cache with data from a file so that 396C<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<$offset> 397subsequent reads from that file will not block on disk I/O. The C<$offset>
371file. The current file offset of the file is left unchanged. 403file. The current file offset of the file is left unchanged.
372 404
373If that syscall doesn't exist (likely if your OS isn't Linux) it will be 405If 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. 406emulated by simply reading the data, which would have a similar effect.
375 407
408
376=item aio_stat $fh_or_path, $callback->($status) 409=item aio_stat $fh_or_path, $callback->($status)
377 410
378=item aio_lstat $fh, $callback->($status) 411=item aio_lstat $fh, $callback->($status)
379 412
380Works like perl's C<stat> or C<lstat> in void context. The callback will 413Works like perl's C<stat> or C<lstat> in void context. The callback will
393 aio_stat "/etc/passwd", sub { 426 aio_stat "/etc/passwd", sub {
394 $_[0] and die "stat failed: $!"; 427 $_[0] and die "stat failed: $!";
395 print "size is ", -s _, "\n"; 428 print "size is ", -s _, "\n";
396 }; 429 };
397 430
431
432=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
433
434Works like perl's C<utime> function (including the special case of $atime
435and $mtime being undef). Fractional times are supported if the underlying
436syscalls support them.
437
438When called with a pathname, uses utimes(2) if available, otherwise
439utime(2). If called on a file descriptor, uses futimes(2) if available,
440otherwise returns ENOSYS, so this is not portable.
441
442Examples:
443
444 # set atime and mtime to current time (basically touch(1)):
445 aio_utime "path", undef, undef;
446 # set atime to current time and mtime to beginning of the epoch:
447 aio_utime "path", time, undef; # undef==0
448
449
450=item aio_chown $fh_or_path, $uid, $gid, $callback->($status)
451
452Works like perl's C<chown> function, except that C<undef> for either $uid
453or $gid is being interpreted as "do not change" (but -1 can also be used).
454
455Examples:
456
457 # same as "chown root path" in the shell:
458 aio_chown "path", 0, -1;
459 # same as above:
460 aio_chown "path", 0, undef;
461
462
463=item aio_truncate $fh_or_path, $offset, $callback->($status)
464
465Works like truncate(2) or ftruncate(2).
466
467
468=item aio_chmod $fh_or_path, $mode, $callback->($status)
469
470Works like perl's C<chmod> function.
471
472
398=item aio_unlink $pathname, $callback->($status) 473=item aio_unlink $pathname, $callback->($status)
399 474
400Asynchronously unlink (delete) a file and call the callback with the 475Asynchronously unlink (delete) a file and call the callback with the
401result code. 476result code.
402 477
478
403=item aio_mknod $path, $mode, $dev, $callback->($status) 479=item aio_mknod $path, $mode, $dev, $callback->($status)
404 480
405[EXPERIMENTAL] 481[EXPERIMENTAL]
406 482
407Asynchronously create a device node (or fifo). See mknod(2). 483Asynchronously create a device node (or fifo). See mknod(2).
408 484
409The only (POSIX-) portable way of calling this function is: 485The only (POSIX-) portable way of calling this function is:
410 486
411 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... 487 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...
488
412 489
413=item aio_link $srcpath, $dstpath, $callback->($status) 490=item aio_link $srcpath, $dstpath, $callback->($status)
414 491
415Asynchronously create a new link to the existing object at C<$srcpath> at 492Asynchronously create a new link to the existing object at C<$srcpath> at
416the path C<$dstpath> and call the callback with the result code. 493the path C<$dstpath> and call the callback with the result code.
417 494
495
418=item aio_symlink $srcpath, $dstpath, $callback->($status) 496=item aio_symlink $srcpath, $dstpath, $callback->($status)
419 497
420Asynchronously create a new symbolic link to the existing object at C<$srcpath> at 498Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
421the path C<$dstpath> and call the callback with the result code. 499the path C<$dstpath> and call the callback with the result code.
500
422 501
423=item aio_readlink $path, $callback->($link) 502=item aio_readlink $path, $callback->($link)
424 503
425Asynchronously read the symlink specified by C<$path> and pass it to 504Asynchronously read the symlink specified by C<$path> and pass it to
426the callback. If an error occurs, nothing or undef gets passed to the 505the callback. If an error occurs, nothing or undef gets passed to the
427callback. 506callback.
428 507
508
429=item aio_rename $srcpath, $dstpath, $callback->($status) 509=item aio_rename $srcpath, $dstpath, $callback->($status)
430 510
431Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as 511Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
432rename(2) and call the callback with the result code. 512rename(2) and call the callback with the result code.
433 513
514
515=item aio_mkdir $pathname, $mode, $callback->($status)
516
517Asynchronously mkdir (create) a directory and call the callback with
518the result code. C<$mode> will be modified by the umask at the time the
519request is executed, so do not change your umask.
520
521
434=item aio_rmdir $pathname, $callback->($status) 522=item aio_rmdir $pathname, $callback->($status)
435 523
436Asynchronously rmdir (delete) a directory and call the callback with the 524Asynchronously rmdir (delete) a directory and call the callback with the
437result code. 525result code.
526
438 527
439=item aio_readdir $pathname, $callback->($entries) 528=item aio_readdir $pathname, $callback->($entries)
440 529
441Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 530Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
442directory (i.e. opendir + readdir + closedir). The entries will not be 531directory (i.e. opendir + readdir + closedir). The entries will not be
443sorted, and will B<NOT> include the C<.> and C<..> entries. 532sorted, and will B<NOT> include the C<.> and C<..> entries.
444 533
445The callback a single argument which is either C<undef> or an array-ref 534The callback a single argument which is either C<undef> or an array-ref
446with the filenames. 535with the filenames.
447 536
537
538=item aio_load $path, $data, $callback->($status)
539
540This is a composite request that tries to fully load the given file into
541memory. Status is the same as with aio_read.
542
543=cut
544
545sub aio_load($$;$) {
546 my ($path, undef, $cb) = @_;
547 my $data = \$_[1];
548
549 my $pri = aioreq_pri;
550 my $grp = aio_group $cb;
551
552 aioreq_pri $pri;
553 add $grp aio_open $path, O_RDONLY, 0, sub {
554 my $fh = shift
555 or return $grp->result (-1);
556
557 aioreq_pri $pri;
558 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
559 $grp->result ($_[0]);
560 };
561 };
562
563 $grp
564}
565
448=item aio_copy $srcpath, $dstpath, $callback->($status) 566=item aio_copy $srcpath, $dstpath, $callback->($status)
449 567
450Try to copy the I<file> (directories not supported as either source or 568Try to copy the I<file> (directories not supported as either source or
451destination) from C<$srcpath> to C<$dstpath> and call the callback with 569destination) from C<$srcpath> to C<$dstpath> and call the callback with
452the C<0> (error) or C<-1> ok. 570the C<0> (error) or C<-1> ok.
453 571
454This is a composite request that it creates the destination file with 572This is a composite request that creates the destination file with
455mode 0200 and copies the contents of the source file into it using 573mode 0200 and copies the contents of the source file into it using
456C<aio_sendfile>, followed by restoring atime, mtime, access mode and 574C<aio_sendfile>, followed by restoring atime, mtime, access mode and
457uid/gid, in that order. 575uid/gid, in that order.
458 576
459If an error occurs, the partial destination file will be unlinked, if 577If an error occurs, the partial destination file will be unlinked, if
484 602
485 # those should not normally block. should. should. 603 # those should not normally block. should. should.
486 utime $stat[8], $stat[9], $dst; 604 utime $stat[8], $stat[9], $dst;
487 chmod $stat[2] & 07777, $dst_fh; 605 chmod $stat[2] & 07777, $dst_fh;
488 chown $stat[4], $stat[5], $dst_fh; 606 chown $stat[4], $stat[5], $dst_fh;
607
608 aioreq_pri $pri;
489 close $dst_fh; 609 add $grp aio_close $dst_fh;
490 } else { 610 } else {
491 $grp->result (-1); 611 $grp->result (-1);
492 close $src_fh; 612 close $src_fh;
493 close $dst_fh; 613 close $dst_fh;
494 614
513 633
514Try to move the I<file> (directories not supported as either source or 634Try to move the I<file> (directories not supported as either source or
515destination) from C<$srcpath> to C<$dstpath> and call the callback with 635destination) from C<$srcpath> to C<$dstpath> and call the callback with
516the C<0> (error) or C<-1> ok. 636the C<0> (error) or C<-1> ok.
517 637
518This is a composite request that tries to rename(2) the file first. If 638This is a composite request that tries to rename(2) the file first; if
519rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if 639rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
520that is successful, unlinking the C<$srcpath>. 640that is successful, unlinks the C<$srcpath>.
521 641
522=cut 642=cut
523 643
524sub aio_move($$;$) { 644sub aio_move($$;$) {
525 my ($src, $dst, $cb) = @_; 645 my ($src, $dst, $cb) = @_;
599as those tend to return 0 or 1 as link counts, which disables the 719as those tend to return 0 or 1 as link counts, which disables the
600directory counting heuristic. 720directory counting heuristic.
601 721
602=cut 722=cut
603 723
604sub aio_scandir($$$) { 724sub aio_scandir($$;$) {
605 my ($path, $maxreq, $cb) = @_; 725 my ($path, $maxreq, $cb) = @_;
606 726
607 my $pri = aioreq_pri; 727 my $pri = aioreq_pri;
608 728
609 my $grp = aio_group $cb; 729 my $grp = aio_group $cb;
685 }; 805 };
686 806
687 $grp 807 $grp
688} 808}
689 809
810=item aio_rmtree $path, $callback->($status)
811
812Delete a directory tree starting (and including) C<$path>, return the
813status of the final C<rmdir> only. This is a composite request that
814uses C<aio_scandir> to recurse into and rmdir directories, and unlink
815everything else.
816
817=cut
818
819sub aio_rmtree;
820sub aio_rmtree($;$) {
821 my ($path, $cb) = @_;
822
823 my $pri = aioreq_pri;
824 my $grp = aio_group $cb;
825
826 aioreq_pri $pri;
827 add $grp aio_scandir $path, 0, sub {
828 my ($dirs, $nondirs) = @_;
829
830 my $dirgrp = aio_group sub {
831 add $grp aio_rmdir $path, sub {
832 $grp->result ($_[0]);
833 };
834 };
835
836 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
837 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
838
839 add $grp $dirgrp;
840 };
841
842 $grp
843}
844
845=item aio_sync $callback->($status)
846
847Asynchronously call sync and call the callback when finished.
848
690=item aio_fsync $fh, $callback->($status) 849=item aio_fsync $fh, $callback->($status)
691 850
692Asynchronously call fsync on the given filehandle and call the callback 851Asynchronously call fsync on the given filehandle and call the callback
693with the fsync result code. 852with the fsync result code.
694 853
697Asynchronously call fdatasync on the given filehandle and call the 856Asynchronously call fdatasync on the given filehandle and call the
698callback with the fdatasync result code. 857callback with the fdatasync result code.
699 858
700If this call isn't available because your OS lacks it or it couldn't be 859If 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. 860detected, it will be emulated by calling C<fsync> instead.
861
862=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
863
864Sync the data portion of the file specified by C<$offset> and C<$length>
865to disk (but NOT the metadata), by calling the Linux-specific
866sync_file_range call. If sync_file_range is not available or it returns
867ENOSYS, then fdatasync or fsync is being substituted.
868
869C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
870C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
871C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
872manpage for details.
873
874=item aio_pathsync $path, $callback->($status)
875
876This request tries to open, fsync and close the given path. This is a
877composite request intended to sync directories after directory operations
878(E.g. rename). This might not work on all operating systems or have any
879specific effect, but usually it makes sure that directory changes get
880written to disc. It works for anything that can be opened for read-only,
881not just directories.
882
883Passes C<0> when everything went ok, and C<-1> on error.
884
885=cut
886
887sub aio_pathsync($;$) {
888 my ($path, $cb) = @_;
889
890 my $pri = aioreq_pri;
891 my $grp = aio_group $cb;
892
893 aioreq_pri $pri;
894 add $grp aio_open $path, O_RDONLY, 0, sub {
895 my ($fh) = @_;
896 if ($fh) {
897 aioreq_pri $pri;
898 add $grp aio_fsync $fh, sub {
899 $grp->result ($_[0]);
900
901 aioreq_pri $pri;
902 add $grp aio_close $fh;
903 };
904 } else {
905 $grp->result (-1);
906 }
907 };
908
909 $grp
910}
702 911
703=item aio_group $callback->(...) 912=item aio_group $callback->(...)
704 913
705This is a very special aio request: Instead of doing something, it is a 914This 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 915container for other aio requests, which is useful if you want to bundle
818Their lifetime, simplified, looks like this: when they are empty, they 1027Their lifetime, simplified, looks like this: when they are empty, they
819will finish very quickly. If they contain only requests that are in the 1028will finish very quickly. If they contain only requests that are in the
820C<done> state, they will also finish. Otherwise they will continue to 1029C<done> state, they will also finish. Otherwise they will continue to
821exist. 1030exist.
822 1031
823That means after creating a group you have some time to add requests. And 1032That 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 1033(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 1034the C<poll_cb>). And in the callbacks of those requests, you can add
826itself finish. 1035further requests to the group. And only when all those requests have
1036finished will the the group itself finish.
827 1037
828=over 4 1038=over 4
829 1039
830=item add $grp ... 1040=item add $grp ...
831 1041
843itself. Useful when you queued a lot of events but got a result early. 1053itself. Useful when you queued a lot of events but got a result early.
844 1054
845=item $grp->result (...) 1055=item $grp->result (...)
846 1056
847Set the result value(s) that will be passed to the group callback when all 1057Set 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 1058subrequests have finished and set the groups errno to the current value
849of errno (just like calling C<errno> without an error number). By default, 1059of errno (just like calling C<errno> without an error number). By default,
850no argument will be passed and errno is zero. 1060no argument will be passed and errno is zero.
851 1061
852=item $grp->errno ([$errno]) 1062=item $grp->errno ([$errno])
853 1063
864=item feed $grp $callback->($grp) 1074=item feed $grp $callback->($grp)
865 1075
866Sets a feeder/generator on this group: every group can have an attached 1076Sets a feeder/generator on this group: every group can have an attached
867generator that generates requests if idle. The idea behind this is that, 1077generator 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, 1078although you could just queue as many requests as you want in a group,
869this might starve other requests for a potentially long time. For 1079this might starve other requests for a potentially long time. For example,
870example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1080C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
871requests, delaying any later requests for a long time. 1081delaying any later requests for a long time.
872 1082
873To avoid this, and allow incremental generation of requests, you can 1083To avoid this, and allow incremental generation of requests, you can
874instead a group and set a feeder on it that generates those requests. The 1084instead 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>, 1085feed 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 1086below) requests active in the group itself and is expected to queue more
880not impose any limits). 1090not impose any limits).
881 1091
882If the feed does not queue more requests when called, it will be 1092If the feed does not queue more requests when called, it will be
883automatically removed from the group. 1093automatically removed from the group.
884 1094
885If the feed limit is C<0>, it will be set to C<2> automatically. 1095If the feed limit is C<0> when this method is called, it will be set to
1096C<2> automatically.
886 1097
887Example: 1098Example:
888 1099
889 # stat all files in @files, but only ever use four aio requests concurrently: 1100 # stat all files in @files, but only ever use four aio requests concurrently:
890 1101
902Sets the feeder limit for the group: The feeder will be called whenever 1113Sets the feeder limit for the group: The feeder will be called whenever
903the group contains less than this many requests. 1114the group contains less than this many requests.
904 1115
905Setting the limit to C<0> will pause the feeding process. 1116Setting the limit to C<0> will pause the feeding process.
906 1117
1118The default value for the limit is C<0>, but note that setting a feeder
1119automatically bumps it up to C<2>.
1120
907=back 1121=back
908 1122
909=head2 SUPPORT FUNCTIONS 1123=head2 SUPPORT FUNCTIONS
910 1124
911=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1125=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
922See C<poll_cb> for an example. 1136See C<poll_cb> for an example.
923 1137
924=item IO::AIO::poll_cb 1138=item IO::AIO::poll_cb
925 1139
926Process some outstanding events on the result pipe. You have to call this 1140Process some outstanding events on the result pipe. You have to call this
927regularly. Returns the number of events processed. Returns immediately 1141regularly. Returns C<0> if all events could be processed, or C<-1> if it
1142returned earlier for whatever reason. Returns immediately when no events
928when no events are outstanding. The amount of events processed depends on 1143are 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>. 1144C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
930 1145
931If not all requests were processed for whatever reason, the filehandle 1146If not all requests were processed for whatever reason, the filehandle
932will still be ready when C<poll_cb> returns. 1147will still be ready when C<poll_cb> returns, so normally you don't have to
1148do anything special to have it called later.
933 1149
934Example: Install an Event watcher that automatically calls 1150Example: Install an Event watcher that automatically calls
935IO::AIO::poll_cb with high priority: 1151IO::AIO::poll_cb with high priority:
936 1152
937 Event->io (fd => IO::AIO::poll_fileno, 1153 Event->io (fd => IO::AIO::poll_fileno,
971 poll => 'r', nice => 1, 1187 poll => 'r', nice => 1,
972 cb => &IO::AIO::poll_cb); 1188 cb => &IO::AIO::poll_cb);
973 1189
974=item IO::AIO::poll_wait 1190=item IO::AIO::poll_wait
975 1191
1192If there are any outstanding requests and none of them in the result
976Wait till the result filehandle becomes ready for reading (simply does a 1193phase, wait till the result filehandle becomes ready for reading (simply
977C<select> on the filehandle. This is useful if you want to synchronously 1194does a C<select> on the filehandle. This is useful if you want to
978wait for some requests to finish). 1195synchronously wait for some requests to finish).
979 1196
980See C<nreqs> for an example. 1197See C<nreqs> for an example.
981 1198
982=item IO::AIO::poll 1199=item IO::AIO::poll
983 1200
984Waits until some requests have been handled. 1201Waits until some requests have been handled.
985 1202
1203Returns the number of requests processed, but is otherwise strictly
986Strictly equivalent to: 1204equivalent to:
987 1205
988 IO::AIO::poll_wait, IO::AIO::poll_cb 1206 IO::AIO::poll_wait, IO::AIO::poll_cb
989 if IO::AIO::nreqs;
990 1207
991=item IO::AIO::flush 1208=item IO::AIO::flush
992 1209
993Wait till all outstanding AIO requests have been handled. 1210Wait till all outstanding AIO requests have been handled.
994 1211
995Strictly equivalent to: 1212Strictly equivalent to:
996 1213
997 IO::AIO::poll_wait, IO::AIO::poll_cb 1214 IO::AIO::poll_wait, IO::AIO::poll_cb
998 while IO::AIO::nreqs; 1215 while IO::AIO::nreqs;
999 1216
1217=back
1218
1000=head3 CONTROLLING THE NUMBER OF THREADS 1219=head3 CONTROLLING THE NUMBER OF THREADS
1220
1221=over
1001 1222
1002=item IO::AIO::min_parallel $nthreads 1223=item IO::AIO::min_parallel $nthreads
1003 1224
1004Set the minimum number of AIO threads to C<$nthreads>. The current 1225Set the minimum number of AIO threads to C<$nthreads>. The current
1005default is C<8>, which means eight asynchronous operations can execute 1226default is C<8>, which means eight asynchronous operations can execute
1046 1267
1047The default is probably ok in most situations, especially if thread 1268The default is probably ok in most situations, especially if thread
1048creation is fast. If thread creation is very slow on your system you might 1269creation is fast. If thread creation is very slow on your system you might
1049want to use larger values. 1270want to use larger values.
1050 1271
1051=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1272=item IO::AIO::max_outstanding $maxreqs
1052 1273
1053This is a very bad function to use in interactive programs because it 1274This is a very bad function to use in interactive programs because it
1054blocks, and a bad way to reduce concurrency because it is inexact: Better 1275blocks, and a bad way to reduce concurrency because it is inexact: Better
1055use an C<aio_group> together with a feed callback. 1276use an C<aio_group> together with a feed callback.
1056 1277
1057Sets the maximum number of outstanding requests to C<$nreqs>. If you 1278Sets 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 1279do 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>) 1280C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
1060function will block until the limit is no longer exceeded. 1281function will block until the limit is no longer exceeded.
1061 1282
1062The default value is very large, so there is no practical limit on the 1283The default value is very large, so there is no practical limit on the
1063number of outstanding requests. 1284number of outstanding requests.
1064 1285
1065You can still queue as many requests as you want. Therefore, 1286You can still queue as many requests as you want. Therefore,
1066C<max_oustsanding> is mainly useful in simple scripts (with low values) or 1287C<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). 1288as a stop gap to shield against fatal memory overflow (with large values).
1068 1289
1290=back
1291
1069=head3 STATISTICAL INFORMATION 1292=head3 STATISTICAL INFORMATION
1293
1294=over
1070 1295
1071=item IO::AIO::nreqs 1296=item IO::AIO::nreqs
1072 1297
1073Returns the number of requests currently in the ready, execute or pending 1298Returns the number of requests currently in the ready, execute or pending
1074states (i.e. for which their callback has not been invoked yet). 1299states (i.e. for which their callback has not been invoked yet).
1090 1315
1091=back 1316=back
1092 1317
1093=cut 1318=cut
1094 1319
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; 1320min_parallel 8;
1112 1321
1113END { 1322END { flush }
1114 min_parallel 1;
1115 flush;
1116};
1117 1323
11181; 13241;
1119 1325
1120=head2 FORK BEHAVIOUR 1326=head2 FORK BEHAVIOUR
1121 1327
1141bytes of memory. In addition, stat requests need a stat buffer (possibly 1347bytes of memory. In addition, stat requests need a stat buffer (possibly
1142a few hundred bytes), readdir requires a result buffer and so on. Perl 1348a 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 1349scalars and other data passed into aio requests will also be locked and
1144will consume memory till the request has entered the done state. 1350will consume memory till the request has entered the done state.
1145 1351
1146This is now awfully much, so queuing lots of requests is not usually a 1352This is not awfully much, so queuing lots of requests is not usually a
1147problem. 1353problem.
1148 1354
1149Per-thread usage: 1355Per-thread usage:
1150 1356
1151In the execution phase, some aio requests require more memory for 1357In the execution phase, some aio requests require more memory for
1156 1362
1157Known bugs will be fixed in the next release. 1363Known bugs will be fixed in the next release.
1158 1364
1159=head1 SEE ALSO 1365=head1 SEE ALSO
1160 1366
1161L<Coro::AIO>. 1367L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1368more natural syntax.
1162 1369
1163=head1 AUTHOR 1370=head1 AUTHOR
1164 1371
1165 Marc Lehmann <schmorp@schmorp.de> 1372 Marc Lehmann <schmorp@schmorp.de>
1166 http://home.schmorp.de/ 1373 http://home.schmorp.de/

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