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Revision 1.119 by root, Sun Dec 2 20:54:33 2007 UTC vs.
Revision 1.172 by root, Thu Jan 7 18:08:21 2010 UTC

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26 $req->cancel; # cancel request if still in queue 26 $req->cancel; # cancel request if still in queue
27 27
28 my $grp = aio_group sub { print "all stats done\n" }; 28 my $grp = aio_group sub { print "all stats done\n" };
29 add $grp aio_stat "..." for ...; 29 add $grp aio_stat "..." for ...;
30 30
31 # AnyEvent integration (EV, Event, Glib, Tk, urxvt, pureperl...) 31 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
32 open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!"; 32 use AnyEvent::AIO;
33 my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });
34 33
35 # EV integration 34 # EV integration
36 my $w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; 35 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
37 36
38 # Event integration 37 # Event integration
39 Event->io (fd => IO::AIO::poll_fileno, 38 Event->io (fd => IO::AIO::poll_fileno,
40 poll => 'r', 39 poll => 'r',
41 cb => \&IO::AIO::poll_cb); 40 cb => \&IO::AIO::poll_cb);
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53 \&IO::AIO::poll_cb); 52 \&IO::AIO::poll_cb);
54 53
55=head1 DESCRIPTION 54=head1 DESCRIPTION
56 55
57This module implements asynchronous I/O using whatever means your 56This module implements asynchronous I/O using whatever means your
58operating system supports. 57operating system supports. It is implemented as an interface to C<libeio>
58(L<http://software.schmorp.de/pkg/libeio.html>).
59 59
60Asynchronous means that operations that can normally block your program 60Asynchronous means that operations that can normally block your program
61(e.g. reading from disk) will be done asynchronously: the operation 61(e.g. reading from disk) will be done asynchronously: the operation
62will still block, but you can do something else in the meantime. This 62will still block, but you can do something else in the meantime. This
63is extremely useful for programs that need to stay interactive even 63is extremely useful for programs that need to stay interactive even
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67on a RAID volume or over NFS when you do a number of stat operations 67on a RAID volume or over NFS when you do a number of stat operations
68concurrently. 68concurrently.
69 69
70While most of this works on all types of file descriptors (for 70While most of this works on all types of file descriptors (for
71example sockets), using these functions on file descriptors that 71example sockets), using these functions on file descriptors that
72support nonblocking operation (again, sockets, pipes etc.) is very 72support nonblocking operation (again, sockets, pipes etc.) is
73inefficient. Use an event loop for that (such as the L<Event|Event> 73very inefficient. Use an event loop for that (such as the L<EV>
74module): IO::AIO will naturally fit into such an event loop itself. 74module): IO::AIO will naturally fit into such an event loop itself.
75 75
76In this version, a number of threads are started that execute your 76In this version, a number of threads are started that execute your
77requests and signal their completion. You don't need thread support 77requests and signal their completion. You don't need thread support
78in perl, and the threads created by this module will not be visible 78in perl, and the threads created by this module will not be visible
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88yourself, always call C<poll_cb> from within the same thread, or never 88yourself, always call C<poll_cb> from within the same thread, or never
89call C<poll_cb> (or other C<aio_> functions) recursively. 89call C<poll_cb> (or other C<aio_> functions) recursively.
90 90
91=head2 EXAMPLE 91=head2 EXAMPLE
92 92
93This is a simple example that uses the Event module and loads 93This is a simple example that uses the EV module and loads
94F</etc/passwd> asynchronously: 94F</etc/passwd> asynchronously:
95 95
96 use Fcntl; 96 use Fcntl;
97 use Event; 97 use EV;
98 use IO::AIO; 98 use IO::AIO;
99 99
100 # register the IO::AIO callback with Event 100 # register the IO::AIO callback with EV
101 Event->io (fd => IO::AIO::poll_fileno, 101 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
102 poll => 'r',
103 cb => \&IO::AIO::poll_cb);
104 102
105 # queue the request to open /etc/passwd 103 # queue the request to open /etc/passwd
106 aio_open "/etc/passwd", O_RDONLY, 0, sub { 104 aio_open "/etc/passwd", O_RDONLY, 0, sub {
107 my $fh = shift 105 my $fh = shift
108 or die "error while opening: $!"; 106 or die "error while opening: $!";
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120 118
121 # file contents now in $contents 119 # file contents now in $contents
122 print $contents; 120 print $contents;
123 121
124 # exit event loop and program 122 # exit event loop and program
125 Event::unloop; 123 EV::unloop;
126 }; 124 };
127 }; 125 };
128 126
129 # possibly queue up other requests, or open GUI windows, 127 # possibly queue up other requests, or open GUI windows,
130 # check for sockets etc. etc. 128 # check for sockets etc. etc.
131 129
132 # process events as long as there are some: 130 # process events as long as there are some:
133 Event::loop; 131 EV::loop;
134 132
135=head1 REQUEST ANATOMY AND LIFETIME 133=head1 REQUEST ANATOMY AND LIFETIME
136 134
137Every C<aio_*> function creates a request. which is a C data structure not 135Every C<aio_*> function creates a request. which is a C data structure not
138directly visible to Perl. 136directly visible to Perl.
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188 186
189package IO::AIO; 187package IO::AIO;
190 188
191use Carp (); 189use Carp ();
192 190
193no warnings; 191use common::sense;
194use strict 'vars';
195 192
196use base 'Exporter'; 193use base 'Exporter';
197 194
198BEGIN { 195BEGIN {
199 our $VERSION = '2.6'; 196 our $VERSION = '3.4';
200 197
201 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat 198 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close
202 aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink 199 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
203 aio_readlink aio_sync aio_fsync aio_fdatasync aio_readahead aio_rename aio_link 200 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
201 aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
202 aio_rename aio_link aio_move aio_copy aio_group
204 aio_move aio_copy aio_group aio_nop aio_mknod aio_load aio_rmtree aio_mkdir 203 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
205 aio_chown aio_chmod aio_utime aio_truncate); 204 aio_chmod aio_utime aio_truncate
205 aio_msync aio_mtouch aio_statvfs);
206
206 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block)); 207 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
207 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 208 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
208 min_parallel max_parallel max_idle 209 min_parallel max_parallel max_idle
209 nreqs nready npending nthreads 210 nreqs nready npending nthreads
210 max_poll_time max_poll_reqs); 211 max_poll_time max_poll_reqs
212 sendfile fadvise);
213
214 push @AIO_REQ, qw(aio_busy); # not exported
211 215
212 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 216 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
213 217
214 require XSLoader; 218 require XSLoader;
215 XSLoader::load ("IO::AIO", $VERSION); 219 XSLoader::load ("IO::AIO", $VERSION);
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222All the C<aio_*> calls are more or less thin wrappers around the syscall 226All the C<aio_*> calls are more or less thin wrappers around the syscall
223with the same name (sans C<aio_>). The arguments are similar or identical, 227with the same name (sans C<aio_>). The arguments are similar or identical,
224and they all accept an additional (and optional) C<$callback> argument 228and they all accept an additional (and optional) C<$callback> argument
225which 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
226the 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
227perl, which usually delivers "false") as it's sole argument when the given 231perl, which usually delivers "false") as its sole argument after the given
228syscall has been executed asynchronously. 232syscall has been executed asynchronously.
229 233
230All functions expecting a filehandle keep a copy of the filehandle 234All functions expecting a filehandle keep a copy of the filehandle
231internally until the request has finished. 235internally until the request has finished.
232 236
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246your 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
247environment, d) use Glib::filename_from_unicode on unicode filenames or e) 251environment, d) use Glib::filename_from_unicode on unicode filenames or e)
248use something else to ensure your scalar has the correct contents. 252use something else to ensure your scalar has the correct contents.
249 253
250This 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
251handles correctly wether it is set or not. 255handles correctly whether it is set or not.
252 256
253=over 4 257=over 4
254 258
255=item $prev_pri = aioreq_pri [$pri] 259=item $prev_pri = aioreq_pri [$pri]
256 260
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319 323
320Asynchronously close a file and call the callback with the result 324Asynchronously close a file and call the callback with the result
321code. 325code.
322 326
323Unfortunately, you can't do this to perl. Perl I<insists> very strongly on 327Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
324closing the file descriptor associated with the filehandle itself. Here is 328closing the file descriptor associated with the filehandle itself.
325what aio_close will try:
326 329
327 1. dup()licate the fd 330Therefore, C<aio_close> will not close the filehandle - instead it will
328 2. asynchronously close() the duplicated fd 331use dup2 to overwrite the file descriptor with the write-end of a pipe
329 3. dup()licate the fd once more 332(the pipe fd will be created on demand and will be cached).
330 4. let perl close() the filehandle
331 5. asynchronously close the duplicated fd
332 333
333The idea is that the first close() flushes stuff to disk that closing an 334Or in other words: the file descriptor will be closed, but it will not be
334fd will flush, so when perl closes the fd, nothing much will need to be 335free for reuse until the perl filehandle is closed.
335flushed. The second async. close() will then flush stuff to disk that
336closing the last fd to the file will flush.
337
338Just FYI, SuSv3 has this to say on close:
339
340 All outstanding record locks owned by the process on the file
341 associated with the file descriptor shall be removed.
342
343 If fildes refers to a socket, close() shall cause the socket to be
344 destroyed. ... close() shall block for up to the current linger
345 interval until all data is transmitted.
346 [this actually sounds like a specification bug, but who knows]
347
348And at least Linux additionally actually flushes stuff on every close,
349even when the file itself is still open.
350
351Sounds enourmously inefficient and complicated? Yes... please show me how
352to nuke perl's fd out of existence...
353 336
354=cut 337=cut
355 338
356sub aio_close($;$) {
357 aio_block {
358 my ($fh, $cb) = @_;
359
360 my $pri = aioreq_pri;
361 my $grp = aio_group $cb;
362
363 my $fd = fileno $fh;
364
365 defined $fd or Carp::croak "aio_close called with fd-less filehandle";
366
367 # if the dups fail we will simply get EBADF
368 my $fd2 = _dup $fd;
369 aioreq_pri $pri;
370 add $grp _aio_close $fd2, sub {
371 my $fd2 = _dup $fd;
372 close $fh;
373 aioreq_pri $pri;
374 add $grp _aio_close $fd2, sub {
375 $grp->result ($_[0]);
376 };
377 };
378
379 $grp
380 }
381}
382
383
384=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 339=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
385 340
386=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 341=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
387 342
388Reads or writes C<$length> bytes from the specified C<$fh> and C<$offset> 343Reads or writes C<$length> bytes from or to the specified C<$fh> and
389into the scalar given by C<$data> and offset C<$dataoffset> and calls the 344C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
390callback without the actual number of bytes read (or -1 on error, just 345and calls the callback without the actual number of bytes read (or -1 on
391like the syscall). 346error, just like the syscall).
347
348C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
349offset plus the actual number of bytes read.
392 350
393If C<$offset> is undefined, then the current file descriptor offset will 351If C<$offset> is undefined, then the current file descriptor offset will
394be used (and updated), otherwise the file descriptor offset will not be 352be used (and updated), otherwise the file descriptor offset will not be
395changed by these calls. 353changed by these calls.
396 354
397If C<$length> is undefined in C<aio_write>, use the remaining length of C<$data>. 355If C<$length> is undefined in C<aio_write>, use the remaining length of
356C<$data>.
398 357
399If C<$dataoffset> is less than zero, it will be counted from the end of 358If C<$dataoffset> is less than zero, it will be counted from the end of
400C<$data>. 359C<$data>.
401 360
402The C<$data> scalar I<MUST NOT> be modified in any way while the request 361The C<$data> scalar I<MUST NOT> be modified in any way while the request
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422 381
423This call tries to make use of a native C<sendfile> syscall to provide 382This call tries to make use of a native C<sendfile> syscall to provide
424zero-copy operation. For this to work, C<$out_fh> should refer to a 383zero-copy operation. For this to work, C<$out_fh> should refer to a
425socket, and C<$in_fh> should refer to mmap'able file. 384socket, and C<$in_fh> should refer to mmap'able file.
426 385
427If the native sendfile call fails or is not implemented, it will be 386If a native sendfile cannot be found or it fails with C<ENOSYS>,
387C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
428emulated, so you can call C<aio_sendfile> on any type of filehandle 388it will be emulated, so you can call C<aio_sendfile> on any type of
429regardless of the limitations of the operating system. 389filehandle regardless of the limitations of the operating system.
430 390
431Please note, however, that C<aio_sendfile> can read more bytes from 391Please note, however, that C<aio_sendfile> can read more bytes from
432C<$in_fh> than are written, and there is no way to find out how many 392C<$in_fh> than are written, and there is no way to find out how many
433bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only 393bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
434provides the number of bytes written to C<$out_fh>. Only if the result 394provides the number of bytes written to C<$out_fh>. Only if the result
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472 $_[0] and die "stat failed: $!"; 432 $_[0] and die "stat failed: $!";
473 print "size is ", -s _, "\n"; 433 print "size is ", -s _, "\n";
474 }; 434 };
475 435
476 436
437=item aio_statvfs $fh_or_path, $callback->($statvfs)
438
439Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
440whether a file handle or path was passed.
441
442On success, the callback is passed a hash reference with the following
443members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
444C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
445is passed.
446
447The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
448C<ST_NOSUID>.
449
450The following non-POSIX IO::AIO::ST_* flag masks are defined to
451their correct value when available, or to C<0> on systems that do
452not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
453C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
454C<ST_NODIRATIME> and C<ST_RELATIME>.
455
456Example: stat C</wd> and dump out the data if successful.
457
458 aio_statvfs "/wd", sub {
459 my $f = $_[0]
460 or die "statvfs: $!";
461
462 use Data::Dumper;
463 say Dumper $f;
464 };
465
466 # result:
467 {
468 bsize => 1024,
469 bfree => 4333064312,
470 blocks => 10253828096,
471 files => 2050765568,
472 flag => 4096,
473 favail => 2042092649,
474 bavail => 4333064312,
475 ffree => 2042092649,
476 namemax => 255,
477 frsize => 1024,
478 fsid => 1810
479 }
480
481
477=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 482=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
478 483
479Works like perl's C<utime> function (including the special case of $atime 484Works like perl's C<utime> function (including the special case of $atime
480and $mtime being undef). Fractional times are supported if the underlying 485and $mtime being undef). Fractional times are supported if the underlying
481syscalls support them. 486syscalls support them.
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574 579
575Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 580Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
576directory (i.e. opendir + readdir + closedir). The entries will not be 581directory (i.e. opendir + readdir + closedir). The entries will not be
577sorted, and will B<NOT> include the C<.> and C<..> entries. 582sorted, and will B<NOT> include the C<.> and C<..> entries.
578 583
579The callback a single argument which is either C<undef> or an array-ref 584The callback is passed a single argument which is either C<undef> or an
580with the filenames. 585array-ref with the filenames.
586
587
588=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
589
590Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
591behaviour and output format. In case of an error, C<$entries> will be
592C<undef>.
593
594The flags are a combination of the following constants, ORed together (the
595flags will also be passed to the callback, possibly modified):
596
597=over 4
598
599=item IO::AIO::READDIR_DENTS
600
601When this flag is off, then the callback gets an arrayref with of names
602only (as with C<aio_readdir>), otherwise it gets an arrayref with
603C<[$name, $type, $inode]> arrayrefs, each describing a single directory
604entry in more detail.
605
606C<$name> is the name of the entry.
607
608C<$type> is one of the C<IO::AIO::DT_xxx> constants:
609
610C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
611C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
612C<IO::AIO::DT_WHT>.
613
614C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
615know, you have to run stat yourself. Also, for speed reasons, the C<$type>
616scalars are read-only: you can not modify them.
617
618C<$inode> is the inode number (which might not be exact on systems with 64
619bit inode numbers and 32 bit perls). This field has unspecified content on
620systems that do not deliver the inode information.
621
622=item IO::AIO::READDIR_DIRS_FIRST
623
624When this flag is set, then the names will be returned in an order where
625likely directories come first. This is useful when you need to quickly
626find directories, or you want to find all directories while avoiding to
627stat() each entry.
628
629If the system returns type information in readdir, then this is used
630to find directories directly. Otherwise, likely directories are files
631beginning with ".", or otherwise files with no dots, of which files with
632short names are tried first.
633
634=item IO::AIO::READDIR_STAT_ORDER
635
636When this flag is set, then the names will be returned in an order
637suitable for stat()'ing each one. That is, when you plan to stat()
638all files in the given directory, then the returned order will likely
639be fastest.
640
641If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
642the likely dirs come first, resulting in a less optimal stat order.
643
644=item IO::AIO::READDIR_FOUND_UNKNOWN
645
646This flag should not be set when calling C<aio_readdirx>. Instead, it
647is being set by C<aio_readdirx>, when any of the C<$type>'s found were
648C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
649C<$type>'s are known, which can be used to speed up some algorithms.
650
651=back
581 652
582 653
583=item aio_load $path, $data, $callback->($status) 654=item aio_load $path, $data, $callback->($status)
584 655
585This is a composite request that tries to fully load the given file into 656This is a composite request that tries to fully load the given file into
586memory. Status is the same as with aio_read. 657memory. Status is the same as with aio_read.
587 658
588=cut 659=cut
589 660
590sub aio_load($$;$) { 661sub aio_load($$;$) {
591 aio_block {
592 my ($path, undef, $cb) = @_; 662 my ($path, undef, $cb) = @_;
593 my $data = \$_[1]; 663 my $data = \$_[1];
594 664
595 my $pri = aioreq_pri; 665 my $pri = aioreq_pri;
596 my $grp = aio_group $cb; 666 my $grp = aio_group $cb;
667
668 aioreq_pri $pri;
669 add $grp aio_open $path, O_RDONLY, 0, sub {
670 my $fh = shift
671 or return $grp->result (-1);
597 672
598 aioreq_pri $pri; 673 aioreq_pri $pri;
599 add $grp aio_open $path, O_RDONLY, 0, sub {
600 my $fh = shift
601 or return $grp->result (-1);
602
603 aioreq_pri $pri;
604 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub { 674 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
605 $grp->result ($_[0]); 675 $grp->result ($_[0]);
606 };
607 }; 676 };
608
609 $grp
610 } 677 };
678
679 $grp
611} 680}
612 681
613=item aio_copy $srcpath, $dstpath, $callback->($status) 682=item aio_copy $srcpath, $dstpath, $callback->($status)
614 683
615Try to copy the I<file> (directories not supported as either source or 684Try to copy the I<file> (directories not supported as either source or
616destination) from C<$srcpath> to C<$dstpath> and call the callback with 685destination) from C<$srcpath> to C<$dstpath> and call the callback with
617the C<0> (error) or C<-1> ok. 686a status of C<0> (ok) or C<-1> (error, see C<$!>).
618 687
619This is a composite request that it creates the destination file with 688This is a composite request that creates the destination file with
620mode 0200 and copies the contents of the source file into it using 689mode 0200 and copies the contents of the source file into it using
621C<aio_sendfile>, followed by restoring atime, mtime, access mode and 690C<aio_sendfile>, followed by restoring atime, mtime, access mode and
622uid/gid, in that order. 691uid/gid, in that order.
623 692
624If an error occurs, the partial destination file will be unlinked, if 693If an error occurs, the partial destination file will be unlinked, if
… …
626errors are being ignored. 695errors are being ignored.
627 696
628=cut 697=cut
629 698
630sub aio_copy($$;$) { 699sub aio_copy($$;$) {
631 aio_block {
632 my ($src, $dst, $cb) = @_; 700 my ($src, $dst, $cb) = @_;
633 701
634 my $pri = aioreq_pri; 702 my $pri = aioreq_pri;
635 my $grp = aio_group $cb; 703 my $grp = aio_group $cb;
636 704
637 aioreq_pri $pri; 705 aioreq_pri $pri;
638 add $grp aio_open $src, O_RDONLY, 0, sub { 706 add $grp aio_open $src, O_RDONLY, 0, sub {
639 if (my $src_fh = $_[0]) { 707 if (my $src_fh = $_[0]) {
640 my @stat = stat $src_fh; 708 my @stat = stat $src_fh; # hmm, might block over nfs?
641 709
642 aioreq_pri $pri; 710 aioreq_pri $pri;
643 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub { 711 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
644 if (my $dst_fh = $_[0]) { 712 if (my $dst_fh = $_[0]) {
645 aioreq_pri $pri; 713 aioreq_pri $pri;
646 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 714 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
647 if ($_[0] == $stat[7]) { 715 if ($_[0] == $stat[7]) {
648 $grp->result (0); 716 $grp->result (0);
649 close $src_fh; 717 close $src_fh;
650 718
651 # those should not normally block. should. should.
652 utime $stat[8], $stat[9], $dst;
653 chmod $stat[2] & 07777, $dst_fh;
654 chown $stat[4], $stat[5], $dst_fh;
655 close $dst_fh;
656 } else { 719 my $ch = sub {
657 $grp->result (-1);
658 close $src_fh;
659 close $dst_fh;
660
661 aioreq $pri; 720 aioreq_pri $pri;
721 add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
722 aioreq_pri $pri;
723 add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
724 aioreq_pri $pri;
662 add $grp aio_unlink $dst; 725 add $grp aio_close $dst_fh;
726 }
727 };
663 } 728 };
729
730 aioreq_pri $pri;
731 add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
732 if ($_[0] < 0 && $! == ENOSYS) {
733 aioreq_pri $pri;
734 add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
735 } else {
736 $ch->();
737 }
738 };
739 } else {
740 $grp->result (-1);
741 close $src_fh;
742 close $dst_fh;
743
744 aioreq $pri;
745 add $grp aio_unlink $dst;
664 }; 746 }
665 } else {
666 $grp->result (-1);
667 } 747 };
748 } else {
749 $grp->result (-1);
668 }, 750 }
669
670 } else {
671 $grp->result (-1);
672 } 751 },
752
753 } else {
754 $grp->result (-1);
673 }; 755 }
674
675 $grp
676 } 756 };
757
758 $grp
677} 759}
678 760
679=item aio_move $srcpath, $dstpath, $callback->($status) 761=item aio_move $srcpath, $dstpath, $callback->($status)
680 762
681Try to move the I<file> (directories not supported as either source or 763Try to move the I<file> (directories not supported as either source or
682destination) from C<$srcpath> to C<$dstpath> and call the callback with 764destination) from C<$srcpath> to C<$dstpath> and call the callback with
683the C<0> (error) or C<-1> ok. 765a status of C<0> (ok) or C<-1> (error, see C<$!>).
684 766
685This is a composite request that tries to rename(2) the file first. If 767This is a composite request that tries to rename(2) the file first; if
686rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if 768rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
687that is successful, unlinking the C<$srcpath>. 769that is successful, unlinks the C<$srcpath>.
688 770
689=cut 771=cut
690 772
691sub aio_move($$;$) { 773sub aio_move($$;$) {
692 aio_block {
693 my ($src, $dst, $cb) = @_; 774 my ($src, $dst, $cb) = @_;
694 775
695 my $pri = aioreq_pri; 776 my $pri = aioreq_pri;
696 my $grp = aio_group $cb; 777 my $grp = aio_group $cb;
697 778
698 aioreq_pri $pri; 779 aioreq_pri $pri;
699 add $grp aio_rename $src, $dst, sub { 780 add $grp aio_rename $src, $dst, sub {
700 if ($_[0] && $! == EXDEV) { 781 if ($_[0] && $! == EXDEV) {
701 aioreq_pri $pri; 782 aioreq_pri $pri;
702 add $grp aio_copy $src, $dst, sub { 783 add $grp aio_copy $src, $dst, sub {
703 $grp->result ($_[0]);
704
705 if (!$_[0]) {
706 aioreq_pri $pri;
707 add $grp aio_unlink $src;
708 }
709 };
710 } else {
711 $grp->result ($_[0]); 784 $grp->result ($_[0]);
785
786 if (!$_[0]) {
787 aioreq_pri $pri;
788 add $grp aio_unlink $src;
789 }
712 } 790 };
791 } else {
792 $grp->result ($_[0]);
713 }; 793 }
714
715 $grp
716 } 794 };
795
796 $grp
717} 797}
718 798
719=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 799=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
720 800
721Scans a directory (similar to C<aio_readdir>) but additionally tries to 801Scans a directory (similar to C<aio_readdir>) but additionally tries to
… …
741 821
742Implementation notes. 822Implementation notes.
743 823
744The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can. 824The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
745 825
826If readdir returns file type information, then this is used directly to
827find directories.
828
746After reading the directory, the modification time, size etc. of the 829Otherwise, after reading the directory, the modification time, size etc.
747directory before and after the readdir is checked, and if they match (and 830of the directory before and after the readdir is checked, and if they
748isn't the current time), the link count will be used to decide how many 831match (and isn't the current time), the link count will be used to decide
749entries are directories (if >= 2). Otherwise, no knowledge of the number 832how many entries are directories (if >= 2). Otherwise, no knowledge of the
750of subdirectories will be assumed. 833number of subdirectories will be assumed.
751 834
752Then entries will be sorted into likely directories (everything without 835Then entries will be sorted into likely directories a non-initial dot
753a non-initial dot currently) and likely non-directories (everything 836currently) and likely non-directories (see C<aio_readdirx>). Then every
754else). Then every entry plus an appended C</.> will be C<stat>'ed, 837entry plus an appended C</.> will be C<stat>'ed, likely directories first,
755likely directories first. If that succeeds, it assumes that the entry 838in order of their inode numbers. If that succeeds, it assumes that the
756is a directory or a symlink to directory (which will be checked 839entry is a directory or a symlink to directory (which will be checked
757seperately). This is often faster than stat'ing the entry itself because 840seperately). This is often faster than stat'ing the entry itself because
758filesystems might detect the type of the entry without reading the inode 841filesystems might detect the type of the entry without reading the inode
759data (e.g. ext2fs filetype feature). 842data (e.g. ext2fs filetype feature), even on systems that cannot return
843the filetype information on readdir.
760 844
761If the known number of directories (link count - 2) has been reached, the 845If the known number of directories (link count - 2) has been reached, the
762rest of the entries is assumed to be non-directories. 846rest of the entries is assumed to be non-directories.
763 847
764This only works with certainty on POSIX (= UNIX) filesystems, which 848This only works with certainty on POSIX (= UNIX) filesystems, which
… …
769directory counting heuristic. 853directory counting heuristic.
770 854
771=cut 855=cut
772 856
773sub aio_scandir($$;$) { 857sub aio_scandir($$;$) {
774 aio_block {
775 my ($path, $maxreq, $cb) = @_; 858 my ($path, $maxreq, $cb) = @_;
776 859
777 my $pri = aioreq_pri; 860 my $pri = aioreq_pri;
778 861
779 my $grp = aio_group $cb; 862 my $grp = aio_group $cb;
780 863
781 $maxreq = 4 if $maxreq <= 0; 864 $maxreq = 4 if $maxreq <= 0;
782 865
783 # stat once 866 # stat once
867 aioreq_pri $pri;
868 add $grp aio_stat $path, sub {
869 return $grp->result () if $_[0];
870 my $now = time;
871 my $hash1 = join ":", (stat _)[0,1,3,7,9];
872
873 # read the directory entries
784 aioreq_pri $pri; 874 aioreq_pri $pri;
785 add $grp aio_stat $path, sub { 875 add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
876 my $entries = shift
786 return $grp->result () if $_[0]; 877 or return $grp->result ();
787 my $now = time;
788 my $hash1 = join ":", (stat _)[0,1,3,7,9];
789 878
790 # read the directory entries 879 # stat the dir another time
791 aioreq_pri $pri; 880 aioreq_pri $pri;
792 add $grp aio_readdir $path, sub {
793 my $entries = shift
794 or return $grp->result ();
795
796 # stat the dir another time
797 aioreq_pri $pri;
798 add $grp aio_stat $path, sub { 881 add $grp aio_stat $path, sub {
799 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 882 my $hash2 = join ":", (stat _)[0,1,3,7,9];
800 883
801 my $ndirs; 884 my $ndirs;
802 885
803 # take the slow route if anything looks fishy 886 # take the slow route if anything looks fishy
804 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 887 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
805 $ndirs = -1; 888 $ndirs = -1;
806 } else { 889 } else {
807 # if nlink == 2, we are finished 890 # if nlink == 2, we are finished
808 # on non-posix-fs's, we rely on nlink < 2 891 # for non-posix-fs's, we rely on nlink < 2
809 $ndirs = (stat _)[3] - 2 892 $ndirs = (stat _)[3] - 2
810 or return $grp->result ([], $entries); 893 or return $grp->result ([], $entries);
811 } 894 }
812 895
813 # sort into likely dirs and likely nondirs
814 # dirs == files without ".", short entries first
815 $entries = [map $_->[0],
816 sort { $b->[1] cmp $a->[1] }
817 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
818 @$entries];
819
820 my (@dirs, @nondirs); 896 my (@dirs, @nondirs);
821 897
822 my $statgrp = add $grp aio_group sub { 898 my $statgrp = add $grp aio_group sub {
823 $grp->result (\@dirs, \@nondirs); 899 $grp->result (\@dirs, \@nondirs);
824 }; 900 };
825 901
826 limit $statgrp $maxreq; 902 limit $statgrp $maxreq;
827 feed $statgrp sub { 903 feed $statgrp sub {
828 return unless @$entries; 904 return unless @$entries;
829 my $entry = pop @$entries; 905 my $entry = shift @$entries;
830 906
831 aioreq_pri $pri; 907 aioreq_pri $pri;
832 add $statgrp aio_stat "$path/$entry/.", sub { 908 add $statgrp aio_stat "$path/$entry/.", sub {
833 if ($_[0] < 0) { 909 if ($_[0] < 0) {
834 push @nondirs, $entry; 910 push @nondirs, $entry;
835 } else { 911 } else {
836 # need to check for real directory 912 # need to check for real directory
837 aioreq_pri $pri; 913 aioreq_pri $pri;
838 add $statgrp aio_lstat "$path/$entry", sub { 914 add $statgrp aio_lstat "$path/$entry", sub {
839 if (-d _) { 915 if (-d _) {
840 push @dirs, $entry; 916 push @dirs, $entry;
841 917
842 unless (--$ndirs) { 918 unless (--$ndirs) {
843 push @nondirs, @$entries; 919 push @nondirs, @$entries;
844 feed $statgrp; 920 feed $statgrp;
845 }
846 } else {
847 push @nondirs, $entry;
848 } 921 }
922 } else {
923 push @nondirs, $entry;
849 } 924 }
850 } 925 }
851 }; 926 }
852 }; 927 };
853 }; 928 };
854 }; 929 };
855 }; 930 };
856
857 $grp
858 } 931 };
932
933 $grp
859} 934}
860 935
861=item aio_rmtree $path, $callback->($status) 936=item aio_rmtree $path, $callback->($status)
862 937
863Delete a directory tree starting (and including) C<$path>, return the 938Delete a directory tree starting (and including) C<$path>, return the
… …
867 942
868=cut 943=cut
869 944
870sub aio_rmtree; 945sub aio_rmtree;
871sub aio_rmtree($;$) { 946sub aio_rmtree($;$) {
872 aio_block {
873 my ($path, $cb) = @_; 947 my ($path, $cb) = @_;
874 948
875 my $pri = aioreq_pri; 949 my $pri = aioreq_pri;
876 my $grp = aio_group $cb; 950 my $grp = aio_group $cb;
877 951
878 aioreq_pri $pri; 952 aioreq_pri $pri;
879 add $grp aio_scandir $path, 0, sub { 953 add $grp aio_scandir $path, 0, sub {
880 my ($dirs, $nondirs) = @_; 954 my ($dirs, $nondirs) = @_;
881 955
882 my $dirgrp = aio_group sub { 956 my $dirgrp = aio_group sub {
883 add $grp aio_rmdir $path, sub { 957 add $grp aio_rmdir $path, sub {
884 $grp->result ($_[0]); 958 $grp->result ($_[0]);
885 };
886 }; 959 };
887
888 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
889 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
890
891 add $grp $dirgrp;
892 }; 960 };
893 961
894 $grp 962 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
963 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
964
965 add $grp $dirgrp;
895 } 966 };
967
968 $grp
896} 969}
897 970
898=item aio_sync $callback->($status) 971=item aio_sync $callback->($status)
899 972
900Asynchronously call sync and call the callback when finished. 973Asynchronously call sync and call the callback when finished.
… …
909Asynchronously call fdatasync on the given filehandle and call the 982Asynchronously call fdatasync on the given filehandle and call the
910callback with the fdatasync result code. 983callback with the fdatasync result code.
911 984
912If this call isn't available because your OS lacks it or it couldn't be 985If this call isn't available because your OS lacks it or it couldn't be
913detected, it will be emulated by calling C<fsync> instead. 986detected, it will be emulated by calling C<fsync> instead.
987
988=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
989
990Sync the data portion of the file specified by C<$offset> and C<$length>
991to disk (but NOT the metadata), by calling the Linux-specific
992sync_file_range call. If sync_file_range is not available or it returns
993ENOSYS, then fdatasync or fsync is being substituted.
994
995C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
996C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
997C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
998manpage for details.
999
1000=item aio_pathsync $path, $callback->($status)
1001
1002This request tries to open, fsync and close the given path. This is a
1003composite request intended to sync directories after directory operations
1004(E.g. rename). This might not work on all operating systems or have any
1005specific effect, but usually it makes sure that directory changes get
1006written to disc. It works for anything that can be opened for read-only,
1007not just directories.
1008
1009Future versions of this function might fall back to other methods when
1010C<fsync> on the directory fails (such as calling C<sync>).
1011
1012Passes C<0> when everything went ok, and C<-1> on error.
1013
1014=cut
1015
1016sub aio_pathsync($;$) {
1017 my ($path, $cb) = @_;
1018
1019 my $pri = aioreq_pri;
1020 my $grp = aio_group $cb;
1021
1022 aioreq_pri $pri;
1023 add $grp aio_open $path, O_RDONLY, 0, sub {
1024 my ($fh) = @_;
1025 if ($fh) {
1026 aioreq_pri $pri;
1027 add $grp aio_fsync $fh, sub {
1028 $grp->result ($_[0]);
1029
1030 aioreq_pri $pri;
1031 add $grp aio_close $fh;
1032 };
1033 } else {
1034 $grp->result (-1);
1035 }
1036 };
1037
1038 $grp
1039}
1040
1041=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1042
1043This is a rather advanced IO::AIO call, which only works on mmap(2)ed
1044scalars (see the L<Sys::Mmap> or L<Mmap> modules for details on this, note
1045that the scalar must only be modified in-place while an aio operation is
1046pending on it).
1047
1048It calls the C<msync> function of your OS, if available, with the memory
1049area starting at C<$offset> in the string and ending C<$length> bytes
1050later. If C<$length> is negative, counts from the end, and if C<$length>
1051is C<undef>, then it goes till the end of the string. The flags can be
1052a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
1053C<IO::AIO::MS_SYNC>.
1054
1055=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1056
1057This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1058scalars.
1059
1060It touches (reads or writes) all memory pages in the specified
1061range inside the scalar. All caveats and parameters are the same
1062as for C<aio_msync>, above, except for flags, which must be either
1063C<0> (which reads all pages and ensures they are instantiated) or
1064C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
1065writing an octet from it, which dirties the page).
914 1066
915=item aio_group $callback->(...) 1067=item aio_group $callback->(...)
916 1068
917This is a very special aio request: Instead of doing something, it is a 1069This is a very special aio request: Instead of doing something, it is a
918container for other aio requests, which is useful if you want to bundle 1070container for other aio requests, which is useful if you want to bundle
… …
968=item cancel $req 1120=item cancel $req
969 1121
970Cancels the request, if possible. Has the effect of skipping execution 1122Cancels the request, if possible. Has the effect of skipping execution
971when entering the B<execute> state and skipping calling the callback when 1123when entering the B<execute> state and skipping calling the callback when
972entering the the B<result> state, but will leave the request otherwise 1124entering the the B<result> state, but will leave the request otherwise
973untouched. That means that requests that currently execute will not be 1125untouched (with the exception of readdir). That means that requests that
974stopped and resources held by the request will not be freed prematurely. 1126currently execute will not be stopped and resources held by the request
1127will not be freed prematurely.
975 1128
976=item cb $req $callback->(...) 1129=item cb $req $callback->(...)
977 1130
978Replace (or simply set) the callback registered to the request. 1131Replace (or simply set) the callback registered to the request.
979 1132
… …
1030Their lifetime, simplified, looks like this: when they are empty, they 1183Their lifetime, simplified, looks like this: when they are empty, they
1031will finish very quickly. If they contain only requests that are in the 1184will finish very quickly. If they contain only requests that are in the
1032C<done> state, they will also finish. Otherwise they will continue to 1185C<done> state, they will also finish. Otherwise they will continue to
1033exist. 1186exist.
1034 1187
1035That means after creating a group you have some time to add requests. And 1188That means after creating a group you have some time to add requests
1036in the callbacks of those requests, you can add further requests to the 1189(precisely before the callback has been invoked, which is only done within
1037group. And only when all those requests have finished will the the group 1190the C<poll_cb>). And in the callbacks of those requests, you can add
1038itself finish. 1191further requests to the group. And only when all those requests have
1192finished will the the group itself finish.
1039 1193
1040=over 4 1194=over 4
1041 1195
1042=item add $grp ... 1196=item add $grp ...
1043 1197
… …
1052=item $grp->cancel_subs 1206=item $grp->cancel_subs
1053 1207
1054Cancel all subrequests and clears any feeder, but not the group request 1208Cancel all subrequests and clears any feeder, but not the group request
1055itself. Useful when you queued a lot of events but got a result early. 1209itself. Useful when you queued a lot of events but got a result early.
1056 1210
1211The group request will finish normally (you cannot add requests to the
1212group).
1213
1057=item $grp->result (...) 1214=item $grp->result (...)
1058 1215
1059Set the result value(s) that will be passed to the group callback when all 1216Set the result value(s) that will be passed to the group callback when all
1060subrequests have finished and set thre groups errno to the current value 1217subrequests have finished and set the groups errno to the current value
1061of errno (just like calling C<errno> without an error number). By default, 1218of errno (just like calling C<errno> without an error number). By default,
1062no argument will be passed and errno is zero. 1219no argument will be passed and errno is zero.
1063 1220
1064=item $grp->errno ([$errno]) 1221=item $grp->errno ([$errno])
1065 1222
… …
1076=item feed $grp $callback->($grp) 1233=item feed $grp $callback->($grp)
1077 1234
1078Sets a feeder/generator on this group: every group can have an attached 1235Sets a feeder/generator on this group: every group can have an attached
1079generator that generates requests if idle. The idea behind this is that, 1236generator that generates requests if idle. The idea behind this is that,
1080although you could just queue as many requests as you want in a group, 1237although you could just queue as many requests as you want in a group,
1081this might starve other requests for a potentially long time. For 1238this might starve other requests for a potentially long time. For example,
1082example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1239C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1083requests, delaying any later requests for a long time. 1240delaying any later requests for a long time.
1084 1241
1085To avoid this, and allow incremental generation of requests, you can 1242To avoid this, and allow incremental generation of requests, you can
1086instead a group and set a feeder on it that generates those requests. The 1243instead a group and set a feeder on it that generates those requests. The
1087feed callback will be called whenever there are few enough (see C<limit>, 1244feed callback will be called whenever there are few enough (see C<limit>,
1088below) requests active in the group itself and is expected to queue more 1245below) requests active in the group itself and is expected to queue more
… …
1092not impose any limits). 1249not impose any limits).
1093 1250
1094If the feed does not queue more requests when called, it will be 1251If the feed does not queue more requests when called, it will be
1095automatically removed from the group. 1252automatically removed from the group.
1096 1253
1097If the feed limit is C<0>, it will be set to C<2> automatically. 1254If the feed limit is C<0> when this method is called, it will be set to
1255C<2> automatically.
1098 1256
1099Example: 1257Example:
1100 1258
1101 # stat all files in @files, but only ever use four aio requests concurrently: 1259 # stat all files in @files, but only ever use four aio requests concurrently:
1102 1260
… …
1114Sets the feeder limit for the group: The feeder will be called whenever 1272Sets the feeder limit for the group: The feeder will be called whenever
1115the group contains less than this many requests. 1273the group contains less than this many requests.
1116 1274
1117Setting the limit to C<0> will pause the feeding process. 1275Setting the limit to C<0> will pause the feeding process.
1118 1276
1277The default value for the limit is C<0>, but note that setting a feeder
1278automatically bumps it up to C<2>.
1279
1119=back 1280=back
1120 1281
1121=head2 SUPPORT FUNCTIONS 1282=head2 SUPPORT FUNCTIONS
1122 1283
1123=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1284=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
… …
1125=over 4 1286=over 4
1126 1287
1127=item $fileno = IO::AIO::poll_fileno 1288=item $fileno = IO::AIO::poll_fileno
1128 1289
1129Return the I<request result pipe file descriptor>. This filehandle must be 1290Return the I<request result pipe file descriptor>. This filehandle must be
1130polled for reading by some mechanism outside this module (e.g. Event or 1291polled for reading by some mechanism outside this module (e.g. EV, Glib,
1131select, see below or the SYNOPSIS). If the pipe becomes readable you have 1292select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1132to call C<poll_cb> to check the results. 1293you have to call C<poll_cb> to check the results.
1133 1294
1134See C<poll_cb> for an example. 1295See C<poll_cb> for an example.
1135 1296
1136=item IO::AIO::poll_cb 1297=item IO::AIO::poll_cb
1137 1298
1138Process some outstanding events on the result pipe. You have to call this 1299Process some outstanding events on the result pipe. You have to call this
1139regularly. Returns the number of events processed. Returns immediately 1300regularly. Returns C<0> if all events could be processed, or C<-1> if it
1301returned earlier for whatever reason. Returns immediately when no events
1140when no events are outstanding. The amount of events processed depends on 1302are outstanding. The amount of events processed depends on the settings of
1141the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>. 1303C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1142 1304
1143If not all requests were processed for whatever reason, the filehandle 1305If not all requests were processed for whatever reason, the filehandle
1144will still be ready when C<poll_cb> returns. 1306will still be ready when C<poll_cb> returns, so normally you don't have to
1307do anything special to have it called later.
1145 1308
1146Example: Install an Event watcher that automatically calls 1309Example: Install an Event watcher that automatically calls
1147IO::AIO::poll_cb with high priority: 1310IO::AIO::poll_cb with high priority (more examples can be found in the
1311SYNOPSIS section, at the top of this document):
1148 1312
1149 Event->io (fd => IO::AIO::poll_fileno, 1313 Event->io (fd => IO::AIO::poll_fileno,
1150 poll => 'r', async => 1, 1314 poll => 'r', async => 1,
1151 cb => \&IO::AIO::poll_cb); 1315 cb => \&IO::AIO::poll_cb);
1152 1316
… …
1263 1427
1264The default is probably ok in most situations, especially if thread 1428The default is probably ok in most situations, especially if thread
1265creation is fast. If thread creation is very slow on your system you might 1429creation is fast. If thread creation is very slow on your system you might
1266want to use larger values. 1430want to use larger values.
1267 1431
1268=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1432=item IO::AIO::max_outstanding $maxreqs
1269 1433
1270This is a very bad function to use in interactive programs because it 1434This is a very bad function to use in interactive programs because it
1271blocks, and a bad way to reduce concurrency because it is inexact: Better 1435blocks, and a bad way to reduce concurrency because it is inexact: Better
1272use an C<aio_group> together with a feed callback. 1436use an C<aio_group> together with a feed callback.
1273 1437
… …
1278 1442
1279The default value is very large, so there is no practical limit on the 1443The default value is very large, so there is no practical limit on the
1280number of outstanding requests. 1444number of outstanding requests.
1281 1445
1282You can still queue as many requests as you want. Therefore, 1446You can still queue as many requests as you want. Therefore,
1283C<max_oustsanding> is mainly useful in simple scripts (with low values) or 1447C<max_outstanding> is mainly useful in simple scripts (with low values) or
1284as a stop gap to shield against fatal memory overflow (with large values). 1448as a stop gap to shield against fatal memory overflow (with large values).
1285 1449
1286=back 1450=back
1287 1451
1288=head3 STATISTICAL INFORMATION 1452=head3 STATISTICAL INFORMATION
… …
1306 1470
1307=item IO::AIO::npending 1471=item IO::AIO::npending
1308 1472
1309Returns the number of requests currently in the pending state (executed, 1473Returns the number of requests currently in the pending state (executed,
1310but not yet processed by poll_cb). 1474but not yet processed by poll_cb).
1475
1476=back
1477
1478=head3 MISCELLANEOUS FUNCTIONS
1479
1480IO::AIO implements some functions that might be useful, but are not
1481asynchronous.
1482
1483=over 4
1484
1485=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1486
1487Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
1488but is blocking (this makes most sense if you know the input data is
1489likely cached already and the output filehandle is set to non-blocking
1490operations).
1491
1492Returns the number of bytes copied, or C<-1> on error.
1493
1494=item IO::AIO::fadvise $fh, $offset, $len, $advice
1495
1496Simply calls the C<posix_fadvise> function (see it's
1497manpage for details). The following advice constants are
1498avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1499C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1500C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1501
1502On systems that do not implement C<posix_fadvise>, this function returns
1503ENOSYS, otherwise the return value of C<posix_fadvise>.
1311 1504
1312=back 1505=back
1313 1506
1314=cut 1507=cut
1315 1508
… …
1358 1551
1359Known bugs will be fixed in the next release. 1552Known bugs will be fixed in the next release.
1360 1553
1361=head1 SEE ALSO 1554=head1 SEE ALSO
1362 1555
1363L<Coro::AIO>. 1556L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1557more natural syntax.
1364 1558
1365=head1 AUTHOR 1559=head1 AUTHOR
1366 1560
1367 Marc Lehmann <schmorp@schmorp.de> 1561 Marc Lehmann <schmorp@schmorp.de>
1368 http://home.schmorp.de/ 1562 http://home.schmorp.de/

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