ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/IO-AIO/AIO.pm
(Generate patch)

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.89 by root, Sun Oct 29 11:03:18 2006 UTC vs.
Revision 1.142 by root, Wed Oct 22 18:15:36 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 this works on all types of file descriptors (for example sockets), 69While most of this works on all types of file descriptors (for
67using these functions on file descriptors that support nonblocking 70example sockets), using these functions on file descriptors that
68operation (again, sockets, pipes etc.) is very inefficient. Use an event 71support nonblocking operation (again, sockets, pipes etc.) is very
69loop for that (such as the L<Event|Event> module): IO::AIO will naturally 72inefficient. Use an event loop for that (such as the L<Event|Event>
70fit into such an event loop itself. 73module): IO::AIO will naturally fit into such an event loop itself.
71 74
72In this version, a number of threads are started that execute your 75In this version, a number of threads are started that execute your
73requests and signal their completion. You don't need thread support 76requests and signal their completion. You don't need thread support
74in 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
75to 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
77not 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
78files currently, for example), and they would only support aio_read and 81files currently, for example), and they would only support aio_read and
79aio_write, so the remaining functionality would have to be implemented 82aio_write, so the remaining functionality would have to be implemented
80using threads anyway. 83using threads anyway.
81 84
82Although the module will work with in the presence of other (Perl-) 85Although the module will work in the presence of other (Perl-) threads,
83threads, it is currently not reentrant in any way, so use appropriate 86it is currently not reentrant in any way, so use appropriate locking
84locking 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
85never call C<poll_cb> (or other C<aio_> functions) recursively. 88call C<poll_cb> (or other C<aio_> functions) recursively.
86 89
87=head2 EXAMPLE 90=head2 EXAMPLE
88 91
89This is a simple example that uses the Event module and loads 92This is a simple example that uses the Event module and loads
90F</etc/passwd> asynchronously: 93F</etc/passwd> asynchronously:
98 poll => 'r', 101 poll => 'r',
99 cb => \&IO::AIO::poll_cb); 102 cb => \&IO::AIO::poll_cb);
100 103
101 # queue the request to open /etc/passwd 104 # queue the request to open /etc/passwd
102 aio_open "/etc/passwd", O_RDONLY, 0, sub { 105 aio_open "/etc/passwd", O_RDONLY, 0, sub {
103 my $fh = $_[0] 106 my $fh = shift
104 or die "error while opening: $!"; 107 or die "error while opening: $!";
105 108
106 # stat'ing filehandles is generally non-blocking 109 # stat'ing filehandles is generally non-blocking
107 my $size = -s $fh; 110 my $size = -s $fh;
108 111
182 185
183=cut 186=cut
184 187
185package IO::AIO; 188package IO::AIO;
186 189
190use Carp ();
191
187no warnings; 192no warnings;
188use strict 'vars'; 193use strict 'vars';
189 194
190use base 'Exporter'; 195use base 'Exporter';
191 196
192BEGIN { 197BEGIN {
193 our $VERSION = '2.1'; 198 our $VERSION = '3.16';
194 199
195 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat 200 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close
196 aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink 201 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir
197 aio_fsync aio_fdatasync aio_readahead aio_rename aio_link aio_move 202 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
198 aio_copy aio_group aio_nop aio_mknod); 203 aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
204 aio_rename aio_link aio_move aio_copy aio_group
205 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
206 aio_chmod aio_utime aio_truncate);
207
199 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); 208 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
200 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 209 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
201 min_parallel max_parallel max_idle 210 min_parallel max_parallel max_idle
202 nreqs nready npending nthreads 211 nreqs nready npending nthreads
203 max_poll_time max_poll_reqs); 212 max_poll_time max_poll_reqs);
215All the C<aio_*> calls are more or less thin wrappers around the syscall 224All the C<aio_*> calls are more or less thin wrappers around the syscall
216with the same name (sans C<aio_>). The arguments are similar or identical, 225with the same name (sans C<aio_>). The arguments are similar or identical,
217and they all accept an additional (and optional) C<$callback> argument 226and they all accept an additional (and optional) C<$callback> argument
218which 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
219the 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
220perl, which usually delivers "false") as it's sole argument when the given 229perl, which usually delivers "false") as its sole argument after the given
221syscall has been executed asynchronously. 230syscall has been executed asynchronously.
222 231
223All functions expecting a filehandle keep a copy of the filehandle 232All functions expecting a filehandle keep a copy of the filehandle
224internally until the request has finished. 233internally until the request has finished.
225 234
239your 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
240environment, d) use Glib::filename_from_unicode on unicode filenames or e) 249environment, d) use Glib::filename_from_unicode on unicode filenames or e)
241use something else to ensure your scalar has the correct contents. 250use something else to ensure your scalar has the correct contents.
242 251
243This 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
244handles correctly wether it is set or not. 253handles correctly whether it is set or not.
245 254
246=over 4 255=over 4
247 256
248=item $prev_pri = aioreq_pri [$pri] 257=item $prev_pri = aioreq_pri [$pri]
249 258
269 aio_read $_[0], ..., sub { 278 aio_read $_[0], ..., sub {
270 ... 279 ...
271 }; 280 };
272 }; 281 };
273 282
283
274=item aioreq_nice $pri_adjust 284=item aioreq_nice $pri_adjust
275 285
276Similar 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
277priority, so the effect is cumulative. 287priority, so the effect is cumulative.
288
278 289
279=item aio_open $pathname, $flags, $mode, $callback->($fh) 290=item aio_open $pathname, $flags, $mode, $callback->($fh)
280 291
281Asynchronously 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
282created filehandle for the file. 293created filehandle for the file.
288list. They are the same as used by C<sysopen>. 299list. They are the same as used by C<sysopen>.
289 300
290Likewise, 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
291didn'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>,
292except 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,
293and C<0666> or C<0777> if you do). 304and C<0666> or C<0777> if you do). Note that the C<$mode> will be modified
305by the umask in effect then the request is being executed, so better never
306change the umask.
294 307
295Example: 308Example:
296 309
297 aio_open "/etc/passwd", O_RDONLY, 0, sub { 310 aio_open "/etc/passwd", O_RDONLY, 0, sub {
298 if ($_[0]) { 311 if ($_[0]) {
301 } else { 314 } else {
302 die "open failed: $!\n"; 315 die "open failed: $!\n";
303 } 316 }
304 }; 317 };
305 318
319
306=item aio_close $fh, $callback->($status) 320=item aio_close $fh, $callback->($status)
307 321
308Asynchronously close a file and call the callback with the result 322Asynchronously close a file and call the callback with the result
309code. I<WARNING:> although accepted, you should not pass in a perl 323code.
310filehandle here, as perl will likely close the file descriptor another
311time when the filehandle is destroyed. Normally, you can safely call perls
312C<close> or just let filehandles go out of scope.
313 324
314This 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
315therefore 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
316 336
317=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 337=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
318 338
319=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 339=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
320 340
321Reads 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<$offset>
322into the scalar given by C<data> and offset C<dataoffset> and calls the 342into the scalar given by C<$data> and offset C<$dataoffset> and calls the
323callback without the actual number of bytes read (or -1 on error, just 343callback without the actual number of bytes read (or -1 on error, just
324like the syscall). 344like the syscall).
325 345
346If C<$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
326The 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
327is outstanding. Modifying it can result in segfaults or WW3 (if the 356is outstanding. Modifying it can result in segfaults or World War III (if
328necessary/optional hardware is installed). 357the necessary/optional hardware is installed).
329 358
330Example: 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
331offset C<0> within the scalar: 360offset C<0> within the scalar:
332 361
333 aio_read $fh, 7, 15, $buffer, 0, sub { 362 aio_read $fh, 7, 15, $buffer, 0, sub {
334 $_[0] > 0 or die "read error: $!"; 363 $_[0] > 0 or die "read error: $!";
335 print "read $_[0] bytes: <$buffer>\n"; 364 print "read $_[0] bytes: <$buffer>\n";
336 }; 365 };
366
337 367
338=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)
339 369
340Tries 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
341reading 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
355C<$in_fh> than are written, and there is no way to find out how many 385C<$in_fh> than are written, and there is no way to find out how many
356bytes 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
357provides 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
358value 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
359read. 389read.
390
360 391
361=item aio_readahead $fh,$offset,$length, $callback->($retval) 392=item aio_readahead $fh,$offset,$length, $callback->($retval)
362 393
363C<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
364subsequent 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>
370file. The current file offset of the file is left unchanged. 401file. The current file offset of the file is left unchanged.
371 402
372If 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
373emulated by simply reading the data, which would have a similar effect. 404emulated by simply reading the data, which would have a similar effect.
374 405
406
375=item aio_stat $fh_or_path, $callback->($status) 407=item aio_stat $fh_or_path, $callback->($status)
376 408
377=item aio_lstat $fh, $callback->($status) 409=item aio_lstat $fh, $callback->($status)
378 410
379Works 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
392 aio_stat "/etc/passwd", sub { 424 aio_stat "/etc/passwd", sub {
393 $_[0] and die "stat failed: $!"; 425 $_[0] and die "stat failed: $!";
394 print "size is ", -s _, "\n"; 426 print "size is ", -s _, "\n";
395 }; 427 };
396 428
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
397=item aio_unlink $pathname, $callback->($status) 471=item aio_unlink $pathname, $callback->($status)
398 472
399Asynchronously unlink (delete) a file and call the callback with the 473Asynchronously unlink (delete) a file and call the callback with the
400result code. 474result code.
401 475
476
402=item aio_mknod $path, $mode, $dev, $callback->($status) 477=item aio_mknod $path, $mode, $dev, $callback->($status)
403 478
404[EXPERIMENTAL] 479[EXPERIMENTAL]
405 480
406Asynchronously create a device node (or fifo). See mknod(2). 481Asynchronously create a device node (or fifo). See mknod(2).
407 482
408The only (POSIX-) portable way of calling this function is: 483The only (POSIX-) portable way of calling this function is:
409 484
410 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... 485 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...
486
411 487
412=item aio_link $srcpath, $dstpath, $callback->($status) 488=item aio_link $srcpath, $dstpath, $callback->($status)
413 489
414Asynchronously 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
415the path C<$dstpath> and call the callback with the result code. 491the path C<$dstpath> and call the callback with the result code.
416 492
493
417=item aio_symlink $srcpath, $dstpath, $callback->($status) 494=item aio_symlink $srcpath, $dstpath, $callback->($status)
418 495
419Asynchronously 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
420the path C<$dstpath> and call the callback with the result code. 497the path C<$dstpath> and call the callback with the result code.
421 498
499
500=item aio_readlink $path, $callback->($link)
501
502Asynchronously read the symlink specified by C<$path> and pass it to
503the callback. If an error occurs, nothing or undef gets passed to the
504callback.
505
506
422=item aio_rename $srcpath, $dstpath, $callback->($status) 507=item aio_rename $srcpath, $dstpath, $callback->($status)
423 508
424Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as 509Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
425rename(2) and call the callback with the result code. 510rename(2) and call the callback with the result code.
426 511
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
427=item aio_rmdir $pathname, $callback->($status) 520=item aio_rmdir $pathname, $callback->($status)
428 521
429Asynchronously rmdir (delete) a directory and call the callback with the 522Asynchronously rmdir (delete) a directory and call the callback with the
430result code. 523result code.
524
431 525
432=item aio_readdir $pathname, $callback->($entries) 526=item aio_readdir $pathname, $callback->($entries)
433 527
434Unlike 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
435directory (i.e. opendir + readdir + closedir). The entries will not be 529directory (i.e. opendir + readdir + closedir). The entries will not be
436sorted, and will B<NOT> include the C<.> and C<..> entries. 530sorted, and will B<NOT> include the C<.> and C<..> entries.
437 531
438The 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
439with the filenames. 533with the filenames.
440 534
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
441=item aio_copy $srcpath, $dstpath, $callback->($status) 564=item aio_copy $srcpath, $dstpath, $callback->($status)
442 565
443Try 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
444destination) from C<$srcpath> to C<$dstpath> and call the callback with 567destination) from C<$srcpath> to C<$dstpath> and call the callback with
445the C<0> (error) or C<-1> ok. 568the C<0> (error) or C<-1> ok.
446 569
447This is a composite request that it creates the destination file with 570This is a composite request that creates the destination file with
448mode 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
449C<aio_sendfile>, followed by restoring atime, mtime, access mode and 572C<aio_sendfile>, followed by restoring atime, mtime, access mode and
450uid/gid, in that order. 573uid/gid, in that order.
451 574
452If an error occurs, the partial destination file will be unlinked, if 575If an error occurs, the partial destination file will be unlinked, if
477 600
478 # those should not normally block. should. should. 601 # those should not normally block. should. should.
479 utime $stat[8], $stat[9], $dst; 602 utime $stat[8], $stat[9], $dst;
480 chmod $stat[2] & 07777, $dst_fh; 603 chmod $stat[2] & 07777, $dst_fh;
481 chown $stat[4], $stat[5], $dst_fh; 604 chown $stat[4], $stat[5], $dst_fh;
605
606 aioreq_pri $pri;
482 close $dst_fh; 607 add $grp aio_close $dst_fh;
483 } else { 608 } else {
484 $grp->result (-1); 609 $grp->result (-1);
485 close $src_fh; 610 close $src_fh;
486 close $dst_fh; 611 close $dst_fh;
487 612
506 631
507Try to move the I<file> (directories not supported as either source or 632Try to move the I<file> (directories not supported as either source or
508destination) from C<$srcpath> to C<$dstpath> and call the callback with 633destination) from C<$srcpath> to C<$dstpath> and call the callback with
509the C<0> (error) or C<-1> ok. 634the C<0> (error) or C<-1> ok.
510 635
511This is a composite request that tries to rename(2) the file first. If 636This is a composite request that tries to rename(2) the file first; if
512rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if 637rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
513that is successful, unlinking the C<$srcpath>. 638that is successful, unlinks the C<$srcpath>.
514 639
515=cut 640=cut
516 641
517sub aio_move($$;$) { 642sub aio_move($$;$) {
518 my ($src, $dst, $cb) = @_; 643 my ($src, $dst, $cb) = @_;
592as 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
593directory counting heuristic. 718directory counting heuristic.
594 719
595=cut 720=cut
596 721
597sub aio_scandir($$$) { 722sub aio_scandir($$;$) {
598 my ($path, $maxreq, $cb) = @_; 723 my ($path, $maxreq, $cb) = @_;
599 724
600 my $pri = aioreq_pri; 725 my $pri = aioreq_pri;
601 726
602 my $grp = aio_group $cb; 727 my $grp = aio_group $cb;
678 }; 803 };
679 804
680 $grp 805 $grp
681} 806}
682 807
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
683=item aio_fsync $fh, $callback->($status) 847=item aio_fsync $fh, $callback->($status)
684 848
685Asynchronously call fsync on the given filehandle and call the callback 849Asynchronously call fsync on the given filehandle and call the callback
686with the fsync result code. 850with the fsync result code.
687 851
690Asynchronously call fdatasync on the given filehandle and call the 854Asynchronously call fdatasync on the given filehandle and call the
691callback with the fdatasync result code. 855callback with the fdatasync result code.
692 856
693If 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
694detected, it will be emulated by calling C<fsync> instead. 858detected, it will be emulated by calling C<fsync> instead.
859
860=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
861
862Sync the data portion of the file specified by C<$offset> and C<$length>
863to disk (but NOT the metadata), by calling the Linux-specific
864sync_file_range call. If sync_file_range is not available or it returns
865ENOSYS, then fdatasync or fsync is being substituted.
866
867C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
868C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
869C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
870manpage for details.
871
872=item aio_pathsync $path, $callback->($status)
873
874This request tries to open, fsync and close the given path. This is a
875composite request intended to sync directories after directory operations
876(E.g. rename). This might not work on all operating systems or have any
877specific effect, but usually it makes sure that directory changes get
878written to disc. It works for anything that can be opened for read-only,
879not just directories.
880
881Passes C<0> when everything went ok, and C<-1> on error.
882
883=cut
884
885sub aio_pathsync($;$) {
886 my ($path, $cb) = @_;
887
888 my $pri = aioreq_pri;
889 my $grp = aio_group $cb;
890
891 aioreq_pri $pri;
892 add $grp aio_open $path, O_RDONLY, 0, sub {
893 my ($fh) = @_;
894 if ($fh) {
895 aioreq_pri $pri;
896 add $grp aio_fsync $fh, sub {
897 $grp->result ($_[0]);
898
899 aioreq_pri $pri;
900 add $grp aio_close $fh;
901 };
902 } else {
903 $grp->result (-1);
904 }
905 };
906
907 $grp
908}
695 909
696=item aio_group $callback->(...) 910=item aio_group $callback->(...)
697 911
698This is a very special aio request: Instead of doing something, it is a 912This is a very special aio request: Instead of doing something, it is a
699container for other aio requests, which is useful if you want to bundle 913container for other aio requests, which is useful if you want to bundle
811Their lifetime, simplified, looks like this: when they are empty, they 1025Their lifetime, simplified, looks like this: when they are empty, they
812will finish very quickly. If they contain only requests that are in the 1026will finish very quickly. If they contain only requests that are in the
813C<done> state, they will also finish. Otherwise they will continue to 1027C<done> state, they will also finish. Otherwise they will continue to
814exist. 1028exist.
815 1029
816That means after creating a group you have some time to add requests. And 1030That means after creating a group you have some time to add requests
817in the callbacks of those requests, you can add further requests to the 1031(precisely before the callback has been invoked, which is only done within
818group. And only when all those requests have finished will the the group 1032the C<poll_cb>). And in the callbacks of those requests, you can add
819itself finish. 1033further requests to the group. And only when all those requests have
1034finished will the the group itself finish.
820 1035
821=over 4 1036=over 4
822 1037
823=item add $grp ... 1038=item add $grp ...
824 1039
836itself. Useful when you queued a lot of events but got a result early. 1051itself. Useful when you queued a lot of events but got a result early.
837 1052
838=item $grp->result (...) 1053=item $grp->result (...)
839 1054
840Set the result value(s) that will be passed to the group callback when all 1055Set the result value(s) that will be passed to the group callback when all
841subrequests have finished and set thre groups errno to the current value 1056subrequests have finished and set the groups errno to the current value
842of errno (just like calling C<errno> without an error number). By default, 1057of errno (just like calling C<errno> without an error number). By default,
843no argument will be passed and errno is zero. 1058no argument will be passed and errno is zero.
844 1059
845=item $grp->errno ([$errno]) 1060=item $grp->errno ([$errno])
846 1061
857=item feed $grp $callback->($grp) 1072=item feed $grp $callback->($grp)
858 1073
859Sets a feeder/generator on this group: every group can have an attached 1074Sets a feeder/generator on this group: every group can have an attached
860generator that generates requests if idle. The idea behind this is that, 1075generator that generates requests if idle. The idea behind this is that,
861although you could just queue as many requests as you want in a group, 1076although you could just queue as many requests as you want in a group,
862this might starve other requests for a potentially long time. For 1077this might starve other requests for a potentially long time. For example,
863example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1078C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
864requests, delaying any later requests for a long time. 1079delaying any later requests for a long time.
865 1080
866To avoid this, and allow incremental generation of requests, you can 1081To avoid this, and allow incremental generation of requests, you can
867instead a group and set a feeder on it that generates those requests. The 1082instead a group and set a feeder on it that generates those requests. The
868feed callback will be called whenever there are few enough (see C<limit>, 1083feed callback will be called whenever there are few enough (see C<limit>,
869below) requests active in the group itself and is expected to queue more 1084below) requests active in the group itself and is expected to queue more
873not impose any limits). 1088not impose any limits).
874 1089
875If the feed does not queue more requests when called, it will be 1090If the feed does not queue more requests when called, it will be
876automatically removed from the group. 1091automatically removed from the group.
877 1092
878If the feed limit is C<0>, it will be set to C<2> automatically. 1093If the feed limit is C<0> when this method is called, it will be set to
1094C<2> automatically.
879 1095
880Example: 1096Example:
881 1097
882 # stat all files in @files, but only ever use four aio requests concurrently: 1098 # stat all files in @files, but only ever use four aio requests concurrently:
883 1099
895Sets the feeder limit for the group: The feeder will be called whenever 1111Sets the feeder limit for the group: The feeder will be called whenever
896the group contains less than this many requests. 1112the group contains less than this many requests.
897 1113
898Setting the limit to C<0> will pause the feeding process. 1114Setting the limit to C<0> will pause the feeding process.
899 1115
1116The default value for the limit is C<0>, but note that setting a feeder
1117automatically bumps it up to C<2>.
1118
900=back 1119=back
901 1120
902=head2 SUPPORT FUNCTIONS 1121=head2 SUPPORT FUNCTIONS
903 1122
904=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1123=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
915See C<poll_cb> for an example. 1134See C<poll_cb> for an example.
916 1135
917=item IO::AIO::poll_cb 1136=item IO::AIO::poll_cb
918 1137
919Process some outstanding events on the result pipe. You have to call this 1138Process some outstanding events on the result pipe. You have to call this
920regularly. Returns the number of events processed. Returns immediately 1139regularly. Returns C<0> if all events could be processed, or C<-1> if it
1140returned earlier for whatever reason. Returns immediately when no events
921when no events are outstanding. The amount of events processed depends on 1141are outstanding. The amount of events processed depends on the settings of
922the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>. 1142C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
923 1143
924If not all requests were processed for whatever reason, the filehandle 1144If not all requests were processed for whatever reason, the filehandle
925will still be ready when C<poll_cb> returns. 1145will still be ready when C<poll_cb> returns, so normally you don't have to
1146do anything special to have it called later.
926 1147
927Example: Install an Event watcher that automatically calls 1148Example: Install an Event watcher that automatically calls
928IO::AIO::poll_cb with high priority: 1149IO::AIO::poll_cb with high priority:
929 1150
930 Event->io (fd => IO::AIO::poll_fileno, 1151 Event->io (fd => IO::AIO::poll_fileno,
964 poll => 'r', nice => 1, 1185 poll => 'r', nice => 1,
965 cb => &IO::AIO::poll_cb); 1186 cb => &IO::AIO::poll_cb);
966 1187
967=item IO::AIO::poll_wait 1188=item IO::AIO::poll_wait
968 1189
1190If there are any outstanding requests and none of them in the result
969Wait till the result filehandle becomes ready for reading (simply does a 1191phase, wait till the result filehandle becomes ready for reading (simply
970C<select> on the filehandle. This is useful if you want to synchronously 1192does a C<select> on the filehandle. This is useful if you want to
971wait for some requests to finish). 1193synchronously wait for some requests to finish).
972 1194
973See C<nreqs> for an example. 1195See C<nreqs> for an example.
974 1196
975=item IO::AIO::poll 1197=item IO::AIO::poll
976 1198
977Waits until some requests have been handled. 1199Waits until some requests have been handled.
978 1200
1201Returns the number of requests processed, but is otherwise strictly
979Strictly equivalent to: 1202equivalent to:
980 1203
981 IO::AIO::poll_wait, IO::AIO::poll_cb 1204 IO::AIO::poll_wait, IO::AIO::poll_cb
982 if IO::AIO::nreqs;
983 1205
984=item IO::AIO::flush 1206=item IO::AIO::flush
985 1207
986Wait till all outstanding AIO requests have been handled. 1208Wait till all outstanding AIO requests have been handled.
987 1209
988Strictly equivalent to: 1210Strictly equivalent to:
989 1211
990 IO::AIO::poll_wait, IO::AIO::poll_cb 1212 IO::AIO::poll_wait, IO::AIO::poll_cb
991 while IO::AIO::nreqs; 1213 while IO::AIO::nreqs;
992 1214
1215=back
1216
993=head3 CONTROLLING THE NUMBER OF THREADS 1217=head3 CONTROLLING THE NUMBER OF THREADS
1218
1219=over
994 1220
995=item IO::AIO::min_parallel $nthreads 1221=item IO::AIO::min_parallel $nthreads
996 1222
997Set the minimum number of AIO threads to C<$nthreads>. The current 1223Set the minimum number of AIO threads to C<$nthreads>. The current
998default is C<8>, which means eight asynchronous operations can execute 1224default is C<8>, which means eight asynchronous operations can execute
1039 1265
1040The default is probably ok in most situations, especially if thread 1266The default is probably ok in most situations, especially if thread
1041creation is fast. If thread creation is very slow on your system you might 1267creation is fast. If thread creation is very slow on your system you might
1042want to use larger values. 1268want to use larger values.
1043 1269
1044=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1270=item IO::AIO::max_outstanding $maxreqs
1045 1271
1046This is a very bad function to use in interactive programs because it 1272This is a very bad function to use in interactive programs because it
1047blocks, and a bad way to reduce concurrency because it is inexact: Better 1273blocks, and a bad way to reduce concurrency because it is inexact: Better
1048use an C<aio_group> together with a feed callback. 1274use an C<aio_group> together with a feed callback.
1049 1275
1050Sets the maximum number of outstanding requests to C<$nreqs>. If you 1276Sets the maximum number of outstanding requests to C<$nreqs>. If you
1051to queue up more than this number of requests, the next call to the 1277do queue up more than this number of requests, the next call to the
1052C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>) 1278C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
1053function will block until the limit is no longer exceeded. 1279function will block until the limit is no longer exceeded.
1054 1280
1055The default value is very large, so there is no practical limit on the 1281The default value is very large, so there is no practical limit on the
1056number of outstanding requests. 1282number of outstanding requests.
1057 1283
1058You can still queue as many requests as you want. Therefore, 1284You can still queue as many requests as you want. Therefore,
1059C<max_oustsanding> is mainly useful in simple scripts (with low values) or 1285C<max_outstanding> is mainly useful in simple scripts (with low values) or
1060as a stop gap to shield against fatal memory overflow (with large values). 1286as a stop gap to shield against fatal memory overflow (with large values).
1061 1287
1288=back
1289
1062=head3 STATISTICAL INFORMATION 1290=head3 STATISTICAL INFORMATION
1291
1292=over
1063 1293
1064=item IO::AIO::nreqs 1294=item IO::AIO::nreqs
1065 1295
1066Returns the number of requests currently in the ready, execute or pending 1296Returns the number of requests currently in the ready, execute or pending
1067states (i.e. for which their callback has not been invoked yet). 1297states (i.e. for which their callback has not been invoked yet).
1083 1313
1084=back 1314=back
1085 1315
1086=cut 1316=cut
1087 1317
1088# support function to convert a fd into a perl filehandle
1089sub _fd2fh {
1090 return undef if $_[0] < 0;
1091
1092 # try to generate nice filehandles
1093 my $sym = "IO::AIO::fd#$_[0]";
1094 local *$sym;
1095
1096 open *$sym, "+<&=$_[0]" # usually works under any unix
1097 or open *$sym, "<&=$_[0]" # cygwin needs this
1098 or open *$sym, ">&=$_[0]" # or this
1099 or return undef;
1100
1101 *$sym
1102}
1103
1104min_parallel 8; 1318min_parallel 8;
1105 1319
1106END { 1320END { flush }
1107 min_parallel 1;
1108 flush;
1109};
1110 1321
11111; 13221;
1112 1323
1113=head2 FORK BEHAVIOUR 1324=head2 FORK BEHAVIOUR
1114 1325
1134bytes of memory. In addition, stat requests need a stat buffer (possibly 1345bytes of memory. In addition, stat requests need a stat buffer (possibly
1135a few hundred bytes), readdir requires a result buffer and so on. Perl 1346a few hundred bytes), readdir requires a result buffer and so on. Perl
1136scalars and other data passed into aio requests will also be locked and 1347scalars and other data passed into aio requests will also be locked and
1137will consume memory till the request has entered the done state. 1348will consume memory till the request has entered the done state.
1138 1349
1139This is now awfully much, so queuing lots of requests is not usually a 1350This is not awfully much, so queuing lots of requests is not usually a
1140problem. 1351problem.
1141 1352
1142Per-thread usage: 1353Per-thread usage:
1143 1354
1144In the execution phase, some aio requests require more memory for 1355In the execution phase, some aio requests require more memory for
1149 1360
1150Known bugs will be fixed in the next release. 1361Known bugs will be fixed in the next release.
1151 1362
1152=head1 SEE ALSO 1363=head1 SEE ALSO
1153 1364
1154L<Coro::AIO>. 1365L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1366more natural syntax.
1155 1367
1156=head1 AUTHOR 1368=head1 AUTHOR
1157 1369
1158 Marc Lehmann <schmorp@schmorp.de> 1370 Marc Lehmann <schmorp@schmorp.de>
1159 http://home.schmorp.de/ 1371 http://home.schmorp.de/

Diff Legend

Removed lines
+ Added lines
< Changed lines
> Changed lines