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Revision 1.121 by root, Wed Apr 16 16:45:18 2008 UTC vs.
Revision 1.174 by root, Sun Jan 10 20:28:43 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 = '2.61'; 196 our $VERSION = '3.5';
200 197
201 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close 198 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close
202 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir 199 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
203 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync 200 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
204 aio_fdatasync aio_pathsync aio_readahead 201 aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
205 aio_rename aio_link aio_move aio_copy aio_group 202 aio_rename aio_link aio_move aio_copy aio_group
206 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown 203 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
207 aio_chmod aio_utime aio_truncate); 204 aio_chmod aio_utime aio_truncate
205 aio_msync aio_mtouch aio_statvfs);
208 206
209 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block)); 207 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
210 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 208 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
211 min_parallel max_parallel max_idle 209 min_parallel max_parallel max_idle
212 nreqs nready npending nthreads 210 nreqs nready npending nthreads
213 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
214 215
215 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 216 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
216 217
217 require XSLoader; 218 require XSLoader;
218 XSLoader::load ("IO::AIO", $VERSION); 219 XSLoader::load ("IO::AIO", $VERSION);
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225All the C<aio_*> calls are more or less thin wrappers around the syscall 226All the C<aio_*> calls are more or less thin wrappers around the syscall
226with the same name (sans C<aio_>). The arguments are similar or identical, 227with the same name (sans C<aio_>). The arguments are similar or identical,
227and they all accept an additional (and optional) C<$callback> argument 228and they all accept an additional (and optional) C<$callback> argument
228which 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
229the 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
230perl, which usually delivers "false") as it's sole argument when the given 231perl, which usually delivers "false") as its sole argument after the given
231syscall has been executed asynchronously. 232syscall has been executed asynchronously.
232 233
233All functions expecting a filehandle keep a copy of the filehandle 234All functions expecting a filehandle keep a copy of the filehandle
234internally until the request has finished. 235internally until the request has finished.
235 236
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249your 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
250environment, d) use Glib::filename_from_unicode on unicode filenames or e) 251environment, d) use Glib::filename_from_unicode on unicode filenames or e)
251use something else to ensure your scalar has the correct contents. 252use something else to ensure your scalar has the correct contents.
252 253
253This 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
254handles correctly wether it is set or not. 255handles correctly whether it is set or not.
255 256
256=over 4 257=over 4
257 258
258=item $prev_pri = aioreq_pri [$pri] 259=item $prev_pri = aioreq_pri [$pri]
259 260
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337 338
338=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 339=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
339 340
340=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 341=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
341 342
342Reads 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<$fh> and
343into the scalar given by C<$data> and offset C<$dataoffset> and calls the 344C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
344callback 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
345like the syscall). 346error, just like the syscall).
347
348C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
349offset plus the actual number of bytes read.
346 350
347If C<$offset> is undefined, then the current file descriptor offset will 351If C<$offset> is undefined, then the current file descriptor offset will
348be used (and updated), otherwise the file descriptor offset will not be 352be used (and updated), otherwise the file descriptor offset will not be
349changed by these calls. 353changed by these calls.
350 354
351If C<$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<$data>.
352 357
353If C<$dataoffset> is less than zero, it will be counted from the end of 358If C<$dataoffset> is less than zero, it will be counted from the end of
354C<$data>. 359C<$data>.
355 360
356The C<$data> scalar I<MUST NOT> be modified in any way while the request 361The C<$data> scalar I<MUST NOT> be modified in any way while the request
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376 381
377This call tries to make use of a native C<sendfile> syscall to provide 382This call tries to make use of a native C<sendfile> syscall to provide
378zero-copy operation. For this to work, C<$out_fh> should refer to a 383zero-copy operation. For this to work, C<$out_fh> should refer to a
379socket, and C<$in_fh> should refer to mmap'able file. 384socket, and C<$in_fh> should refer to mmap'able file.
380 385
381If the native sendfile call fails or is not implemented, it will be 386If a native sendfile cannot be found or it fails with C<ENOSYS>,
387C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
382emulated, so you can call C<aio_sendfile> on any type of filehandle 388it will be emulated, so you can call C<aio_sendfile> on any type of
383regardless of the limitations of the operating system. 389filehandle regardless of the limitations of the operating system.
384 390
385Please note, however, that C<aio_sendfile> can read more bytes from 391Please note, however, that C<aio_sendfile> can read more bytes from
386C<$in_fh> than are written, and there is no way to find out how many 392C<$in_fh> than are written, and there is no way to find out how many
387bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only 393bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
388provides the number of bytes written to C<$out_fh>. Only if the result 394provides the number of bytes written to C<$out_fh>. Only if the result
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426 $_[0] and die "stat failed: $!"; 432 $_[0] and die "stat failed: $!";
427 print "size is ", -s _, "\n"; 433 print "size is ", -s _, "\n";
428 }; 434 };
429 435
430 436
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
431=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 482=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
432 483
433Works 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
434and $mtime being undef). Fractional times are supported if the underlying 485and $mtime being undef). Fractional times are supported if the underlying
435syscalls support them. 486syscalls support them.
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528 579
529Unlike 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
530directory (i.e. opendir + readdir + closedir). The entries will not be 581directory (i.e. opendir + readdir + closedir). The entries will not be
531sorted, and will B<NOT> include the C<.> and C<..> entries. 582sorted, and will B<NOT> include the C<.> and C<..> entries.
532 583
533The 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
534with 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
535 652
536 653
537=item aio_load $path, $data, $callback->($status) 654=item aio_load $path, $data, $callback->($status)
538 655
539This 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
540memory. Status is the same as with aio_read. 657memory. Status is the same as with aio_read.
541 658
542=cut 659=cut
543 660
544sub aio_load($$;$) { 661sub aio_load($$;$) {
545 aio_block {
546 my ($path, undef, $cb) = @_; 662 my ($path, undef, $cb) = @_;
547 my $data = \$_[1]; 663 my $data = \$_[1];
548 664
549 my $pri = aioreq_pri; 665 my $pri = aioreq_pri;
550 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);
551 672
552 aioreq_pri $pri; 673 aioreq_pri $pri;
553 add $grp aio_open $path, O_RDONLY, 0, sub {
554 my $fh = shift
555 or return $grp->result (-1);
556
557 aioreq_pri $pri;
558 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub { 674 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
559 $grp->result ($_[0]); 675 $grp->result ($_[0]);
560 };
561 }; 676 };
562
563 $grp
564 } 677 };
678
679 $grp
565} 680}
566 681
567=item aio_copy $srcpath, $dstpath, $callback->($status) 682=item aio_copy $srcpath, $dstpath, $callback->($status)
568 683
569Try 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
570destination) from C<$srcpath> to C<$dstpath> and call the callback with 685destination) from C<$srcpath> to C<$dstpath> and call the callback with
571the C<0> (error) or C<-1> ok. 686a status of C<0> (ok) or C<-1> (error, see C<$!>).
572 687
573This is a composite request that it creates the destination file with 688This is a composite request that creates the destination file with
574mode 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
575C<aio_sendfile>, followed by restoring atime, mtime, access mode and 690C<aio_sendfile>, followed by restoring atime, mtime, access mode and
576uid/gid, in that order. 691uid/gid, in that order.
577 692
578If an error occurs, the partial destination file will be unlinked, if 693If an error occurs, the partial destination file will be unlinked, if
… …
580errors are being ignored. 695errors are being ignored.
581 696
582=cut 697=cut
583 698
584sub aio_copy($$;$) { 699sub aio_copy($$;$) {
585 aio_block {
586 my ($src, $dst, $cb) = @_; 700 my ($src, $dst, $cb) = @_;
587 701
588 my $pri = aioreq_pri; 702 my $pri = aioreq_pri;
589 my $grp = aio_group $cb; 703 my $grp = aio_group $cb;
590 704
591 aioreq_pri $pri; 705 aioreq_pri $pri;
592 add $grp aio_open $src, O_RDONLY, 0, sub { 706 add $grp aio_open $src, O_RDONLY, 0, sub {
593 if (my $src_fh = $_[0]) { 707 if (my $src_fh = $_[0]) {
594 my @stat = stat $src_fh; 708 my @stat = stat $src_fh; # hmm, might block over nfs?
595 709
596 aioreq_pri $pri; 710 aioreq_pri $pri;
597 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 {
598 if (my $dst_fh = $_[0]) { 712 if (my $dst_fh = $_[0]) {
599 aioreq_pri $pri; 713 aioreq_pri $pri;
600 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 714 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
601 if ($_[0] == $stat[7]) { 715 if ($_[0] == $stat[7]) {
602 $grp->result (0); 716 $grp->result (0);
603 close $src_fh; 717 close $src_fh;
604 718
605 # those should not normally block. should. should. 719 my $ch = sub {
606 utime $stat[8], $stat[9], $dst;
607 chmod $stat[2] & 07777, $dst_fh;
608 chown $stat[4], $stat[5], $dst_fh;
609
610 aioreq_pri $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;
611 add $grp aio_close $dst_fh; 725 add $grp aio_close $dst_fh;
612 } else { 726 }
613 $grp->result (-1);
614 close $src_fh;
615 close $dst_fh;
616
617 aioreq $pri; 727 };
618 add $grp aio_unlink $dst;
619 } 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;
620 }; 746 }
621 } else {
622 $grp->result (-1);
623 } 747 };
748 } else {
749 $grp->result (-1);
624 }, 750 }
625
626 } else {
627 $grp->result (-1);
628 } 751 },
752
753 } else {
754 $grp->result (-1);
629 }; 755 }
630
631 $grp
632 } 756 };
757
758 $grp
633} 759}
634 760
635=item aio_move $srcpath, $dstpath, $callback->($status) 761=item aio_move $srcpath, $dstpath, $callback->($status)
636 762
637Try 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
638destination) from C<$srcpath> to C<$dstpath> and call the callback with 764destination) from C<$srcpath> to C<$dstpath> and call the callback with
639the C<0> (error) or C<-1> ok. 765a status of C<0> (ok) or C<-1> (error, see C<$!>).
640 766
641This is a composite request that tries to rename(2) the file first. If 767This is a composite request that tries to rename(2) the file first; if
642rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if 768rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
643that is successful, unlinking the C<$srcpath>. 769that is successful, unlinks the C<$srcpath>.
644 770
645=cut 771=cut
646 772
647sub aio_move($$;$) { 773sub aio_move($$;$) {
648 aio_block {
649 my ($src, $dst, $cb) = @_; 774 my ($src, $dst, $cb) = @_;
650 775
651 my $pri = aioreq_pri; 776 my $pri = aioreq_pri;
652 my $grp = aio_group $cb; 777 my $grp = aio_group $cb;
653 778
654 aioreq_pri $pri; 779 aioreq_pri $pri;
655 add $grp aio_rename $src, $dst, sub { 780 add $grp aio_rename $src, $dst, sub {
656 if ($_[0] && $! == EXDEV) { 781 if ($_[0] && $! == EXDEV) {
657 aioreq_pri $pri; 782 aioreq_pri $pri;
658 add $grp aio_copy $src, $dst, sub { 783 add $grp aio_copy $src, $dst, sub {
659 $grp->result ($_[0]);
660
661 if (!$_[0]) {
662 aioreq_pri $pri;
663 add $grp aio_unlink $src;
664 }
665 };
666 } else {
667 $grp->result ($_[0]); 784 $grp->result ($_[0]);
785
786 if (!$_[0]) {
787 aioreq_pri $pri;
788 add $grp aio_unlink $src;
789 }
668 } 790 };
791 } else {
792 $grp->result ($_[0]);
669 }; 793 }
670
671 $grp
672 } 794 };
795
796 $grp
673} 797}
674 798
675=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 799=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
676 800
677Scans a directory (similar to C<aio_readdir>) but additionally tries to 801Scans a directory (similar to C<aio_readdir>) but additionally tries to
… …
697 821
698Implementation notes. 822Implementation notes.
699 823
700The 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.
701 825
826If readdir returns file type information, then this is used directly to
827find directories.
828
702After reading the directory, the modification time, size etc. of the 829Otherwise, after reading the directory, the modification time, size etc.
703directory 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
704isn'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
705entries are directories (if >= 2). Otherwise, no knowledge of the number 832how many entries are directories (if >= 2). Otherwise, no knowledge of the
706of subdirectories will be assumed. 833number of subdirectories will be assumed.
707 834
708Then entries will be sorted into likely directories (everything without 835Then entries will be sorted into likely directories a non-initial dot
709a non-initial dot currently) and likely non-directories (everything 836currently) and likely non-directories (see C<aio_readdirx>). Then every
710else). 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,
711likely directories first. If that succeeds, it assumes that the entry 838in order of their inode numbers. If that succeeds, it assumes that the
712is a directory or a symlink to directory (which will be checked 839entry is a directory or a symlink to directory (which will be checked
713seperately). This is often faster than stat'ing the entry itself because 840seperately). This is often faster than stat'ing the entry itself because
714filesystems might detect the type of the entry without reading the inode 841filesystems might detect the type of the entry without reading the inode
715data (e.g. ext2fs filetype feature). 842data (e.g. ext2fs filetype feature), even on systems that cannot return
843the filetype information on readdir.
716 844
717If 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
718rest of the entries is assumed to be non-directories. 846rest of the entries is assumed to be non-directories.
719 847
720This only works with certainty on POSIX (= UNIX) filesystems, which 848This only works with certainty on POSIX (= UNIX) filesystems, which
… …
725directory counting heuristic. 853directory counting heuristic.
726 854
727=cut 855=cut
728 856
729sub aio_scandir($$;$) { 857sub aio_scandir($$;$) {
730 aio_block {
731 my ($path, $maxreq, $cb) = @_; 858 my ($path, $maxreq, $cb) = @_;
732 859
733 my $pri = aioreq_pri; 860 my $pri = aioreq_pri;
734 861
735 my $grp = aio_group $cb; 862 my $grp = aio_group $cb;
736 863
737 $maxreq = 4 if $maxreq <= 0; 864 $maxreq = 4 if $maxreq <= 0;
738 865
739 # 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
740 aioreq_pri $pri; 874 aioreq_pri $pri;
741 add $grp aio_stat $path, sub { 875 add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
876 my $entries = shift
742 return $grp->result () if $_[0]; 877 or return $grp->result ();
743 my $now = time;
744 my $hash1 = join ":", (stat _)[0,1,3,7,9];
745 878
746 # read the directory entries 879 # stat the dir another time
747 aioreq_pri $pri; 880 aioreq_pri $pri;
748 add $grp aio_readdir $path, sub {
749 my $entries = shift
750 or return $grp->result ();
751
752 # stat the dir another time
753 aioreq_pri $pri;
754 add $grp aio_stat $path, sub { 881 add $grp aio_stat $path, sub {
755 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 882 my $hash2 = join ":", (stat _)[0,1,3,7,9];
756 883
757 my $ndirs; 884 my $ndirs;
758 885
759 # take the slow route if anything looks fishy 886 # take the slow route if anything looks fishy
760 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 887 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
761 $ndirs = -1; 888 $ndirs = -1;
762 } else { 889 } else {
763 # if nlink == 2, we are finished 890 # if nlink == 2, we are finished
764 # on non-posix-fs's, we rely on nlink < 2 891 # for non-posix-fs's, we rely on nlink < 2
765 $ndirs = (stat _)[3] - 2 892 $ndirs = (stat _)[3] - 2
766 or return $grp->result ([], $entries); 893 or return $grp->result ([], $entries);
767 } 894 }
768 895
769 # sort into likely dirs and likely nondirs
770 # dirs == files without ".", short entries first
771 $entries = [map $_->[0],
772 sort { $b->[1] cmp $a->[1] }
773 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
774 @$entries];
775
776 my (@dirs, @nondirs); 896 my (@dirs, @nondirs);
777 897
778 my $statgrp = add $grp aio_group sub { 898 my $statgrp = add $grp aio_group sub {
779 $grp->result (\@dirs, \@nondirs); 899 $grp->result (\@dirs, \@nondirs);
780 }; 900 };
781 901
782 limit $statgrp $maxreq; 902 limit $statgrp $maxreq;
783 feed $statgrp sub { 903 feed $statgrp sub {
784 return unless @$entries; 904 return unless @$entries;
785 my $entry = pop @$entries; 905 my $entry = shift @$entries;
786 906
787 aioreq_pri $pri; 907 aioreq_pri $pri;
788 add $statgrp aio_stat "$path/$entry/.", sub { 908 add $statgrp aio_stat "$path/$entry/.", sub {
789 if ($_[0] < 0) { 909 if ($_[0] < 0) {
790 push @nondirs, $entry; 910 push @nondirs, $entry;
791 } else { 911 } else {
792 # need to check for real directory 912 # need to check for real directory
793 aioreq_pri $pri; 913 aioreq_pri $pri;
794 add $statgrp aio_lstat "$path/$entry", sub { 914 add $statgrp aio_lstat "$path/$entry", sub {
795 if (-d _) { 915 if (-d _) {
796 push @dirs, $entry; 916 push @dirs, $entry;
797 917
798 unless (--$ndirs) { 918 unless (--$ndirs) {
799 push @nondirs, @$entries; 919 push @nondirs, @$entries;
800 feed $statgrp; 920 feed $statgrp;
801 }
802 } else {
803 push @nondirs, $entry;
804 } 921 }
922 } else {
923 push @nondirs, $entry;
805 } 924 }
806 } 925 }
807 }; 926 }
808 }; 927 };
809 }; 928 };
810 }; 929 };
811 }; 930 };
812
813 $grp
814 } 931 };
932
933 $grp
815} 934}
816 935
817=item aio_rmtree $path, $callback->($status) 936=item aio_rmtree $path, $callback->($status)
818 937
819Delete a directory tree starting (and including) C<$path>, return the 938Delete a directory tree starting (and including) C<$path>, return the
… …
823 942
824=cut 943=cut
825 944
826sub aio_rmtree; 945sub aio_rmtree;
827sub aio_rmtree($;$) { 946sub aio_rmtree($;$) {
828 aio_block {
829 my ($path, $cb) = @_; 947 my ($path, $cb) = @_;
830 948
831 my $pri = aioreq_pri; 949 my $pri = aioreq_pri;
832 my $grp = aio_group $cb; 950 my $grp = aio_group $cb;
833 951
834 aioreq_pri $pri; 952 aioreq_pri $pri;
835 add $grp aio_scandir $path, 0, sub { 953 add $grp aio_scandir $path, 0, sub {
836 my ($dirs, $nondirs) = @_; 954 my ($dirs, $nondirs) = @_;
837 955
838 my $dirgrp = aio_group sub { 956 my $dirgrp = aio_group sub {
839 add $grp aio_rmdir $path, sub { 957 add $grp aio_rmdir $path, sub {
840 $grp->result ($_[0]); 958 $grp->result ($_[0]);
841 };
842 }; 959 };
843
844 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
845 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
846
847 add $grp $dirgrp;
848 }; 960 };
849 961
850 $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;
851 } 966 };
967
968 $grp
852} 969}
853 970
854=item aio_sync $callback->($status) 971=item aio_sync $callback->($status)
855 972
856Asynchronously call sync and call the callback when finished. 973Asynchronously call sync and call the callback when finished.
… …
866callback with the fdatasync result code. 983callback with the fdatasync result code.
867 984
868If 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
869detected, it will be emulated by calling C<fsync> instead. 986detected, it will be emulated by calling C<fsync> instead.
870 987
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
871=item aio_pathsync $path, $callback->($status) 1000=item aio_pathsync $path, $callback->($status)
872 1001
873This request tries to open, fsync and close the given path. This is a 1002This request tries to open, fsync and close the given path. This is a
874composite request intended tosync directories after directory operations 1003composite request intended to sync directories after directory operations
875(E.g. rename). This might not work on all operating systems or have any 1004(E.g. rename). This might not work on all operating systems or have any
876specific effect, but usually it makes sure that directory changes get 1005specific effect, but usually it makes sure that directory changes get
877written to disc. It works for anything that can be opened for read-only, 1006written to disc. It works for anything that can be opened for read-only,
878not just directories. 1007not just directories.
879 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
880Passes C<0> when everything went ok, and C<-1> on error. 1012Passes C<0> when everything went ok, and C<-1> on error.
881 1013
882=cut 1014=cut
883 1015
884sub aio_pathsync($;$) { 1016sub aio_pathsync($;$) {
885 aio_block {
886 my ($path, $cb) = @_; 1017 my ($path, $cb) = @_;
887 1018
888 my $pri = aioreq_pri; 1019 my $pri = aioreq_pri;
889 my $grp = aio_group $cb; 1020 my $grp = aio_group $cb;
890 1021
891 aioreq_pri $pri; 1022 aioreq_pri $pri;
892 add $grp aio_open $path, O_RDONLY, 0, sub { 1023 add $grp aio_open $path, O_RDONLY, 0, sub {
893 my ($fh) = @_; 1024 my ($fh) = @_;
894 if ($fh) { 1025 if ($fh) {
1026 aioreq_pri $pri;
1027 add $grp aio_fsync $fh, sub {
1028 $grp->result ($_[0]);
1029
895 aioreq_pri $pri; 1030 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; 1031 add $grp aio_close $fh;
901 };
902 } else {
903 $grp->result (-1);
904 } 1032 };
1033 } else {
1034 $grp->result (-1);
905 }; 1035 }
906
907 $grp
908 } 1036 };
1037
1038 $grp
909} 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).
910 1066
911=item aio_group $callback->(...) 1067=item aio_group $callback->(...)
912 1068
913This 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
914container 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
… …
964=item cancel $req 1120=item cancel $req
965 1121
966Cancels the request, if possible. Has the effect of skipping execution 1122Cancels the request, if possible. Has the effect of skipping execution
967when entering the B<execute> state and skipping calling the callback when 1123when entering the B<execute> state and skipping calling the callback when
968entering the the B<result> state, but will leave the request otherwise 1124entering the the B<result> state, but will leave the request otherwise
969untouched. That means that requests that currently execute will not be 1125untouched (with the exception of readdir). That means that requests that
970stopped 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.
971 1128
972=item cb $req $callback->(...) 1129=item cb $req $callback->(...)
973 1130
974Replace (or simply set) the callback registered to the request. 1131Replace (or simply set) the callback registered to the request.
975 1132
… …
1026Their lifetime, simplified, looks like this: when they are empty, they 1183Their lifetime, simplified, looks like this: when they are empty, they
1027will 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
1028C<done> state, they will also finish. Otherwise they will continue to 1185C<done> state, they will also finish. Otherwise they will continue to
1029exist. 1186exist.
1030 1187
1031That 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
1032in 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
1033group. 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
1034itself finish. 1191further requests to the group. And only when all those requests have
1192finished will the the group itself finish.
1035 1193
1036=over 4 1194=over 4
1037 1195
1038=item add $grp ... 1196=item add $grp ...
1039 1197
… …
1047 1205
1048=item $grp->cancel_subs 1206=item $grp->cancel_subs
1049 1207
1050Cancel all subrequests and clears any feeder, but not the group request 1208Cancel all subrequests and clears any feeder, but not the group request
1051itself. 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.
1210
1211The group request will finish normally (you cannot add requests to the
1212group).
1052 1213
1053=item $grp->result (...) 1214=item $grp->result (...)
1054 1215
1055Set 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
1056subrequests have finished and set the groups errno to the current value 1217subrequests have finished and set the groups errno to the current value
… …
1072=item feed $grp $callback->($grp) 1233=item feed $grp $callback->($grp)
1073 1234
1074Sets 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
1075generator that generates requests if idle. The idea behind this is that, 1236generator that generates requests if idle. The idea behind this is that,
1076although 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,
1077this might starve other requests for a potentially long time. For 1238this might starve other requests for a potentially long time. For example,
1078example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1239C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1079requests, delaying any later requests for a long time. 1240delaying any later requests for a long time.
1080 1241
1081To avoid this, and allow incremental generation of requests, you can 1242To avoid this, and allow incremental generation of requests, you can
1082instead 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
1083feed 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>,
1084below) 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
… …
1088not impose any limits). 1249not impose any limits).
1089 1250
1090If 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
1091automatically removed from the group. 1252automatically removed from the group.
1092 1253
1093If 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.
1094 1256
1095Example: 1257Example:
1096 1258
1097 # 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:
1098 1260
… …
1110Sets 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
1111the group contains less than this many requests. 1273the group contains less than this many requests.
1112 1274
1113Setting the limit to C<0> will pause the feeding process. 1275Setting the limit to C<0> will pause the feeding process.
1114 1276
1277The default value for the limit is C<0>, but note that setting a feeder
1278automatically bumps it up to C<2>.
1279
1115=back 1280=back
1116 1281
1117=head2 SUPPORT FUNCTIONS 1282=head2 SUPPORT FUNCTIONS
1118 1283
1119=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1284=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
… …
1121=over 4 1286=over 4
1122 1287
1123=item $fileno = IO::AIO::poll_fileno 1288=item $fileno = IO::AIO::poll_fileno
1124 1289
1125Return the I<request result pipe file descriptor>. This filehandle must be 1290Return the I<request result pipe file descriptor>. This filehandle must be
1126polled 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,
1127select, 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
1128to call C<poll_cb> to check the results. 1293you have to call C<poll_cb> to check the results.
1129 1294
1130See C<poll_cb> for an example. 1295See C<poll_cb> for an example.
1131 1296
1132=item IO::AIO::poll_cb 1297=item IO::AIO::poll_cb
1133 1298
1134Process 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
1135regularly. 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
1136when no events are outstanding. The amount of events processed depends on 1302are outstanding. The amount of events processed depends on the settings of
1137the 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>.
1138 1304
1139If not all requests were processed for whatever reason, the filehandle 1305If not all requests were processed for whatever reason, the filehandle
1140will 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.
1141 1308
1142Example: Install an Event watcher that automatically calls 1309Example: Install an Event watcher that automatically calls
1143IO::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):
1144 1312
1145 Event->io (fd => IO::AIO::poll_fileno, 1313 Event->io (fd => IO::AIO::poll_fileno,
1146 poll => 'r', async => 1, 1314 poll => 'r', async => 1,
1147 cb => \&IO::AIO::poll_cb); 1315 cb => \&IO::AIO::poll_cb);
1148 1316
… …
1259 1427
1260The default is probably ok in most situations, especially if thread 1428The default is probably ok in most situations, especially if thread
1261creation 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
1262want to use larger values. 1430want to use larger values.
1263 1431
1264=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1432=item IO::AIO::max_outstanding $maxreqs
1265 1433
1266This 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
1267blocks, 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
1268use an C<aio_group> together with a feed callback. 1436use an C<aio_group> together with a feed callback.
1269 1437
… …
1274 1442
1275The 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
1276number of outstanding requests. 1444number of outstanding requests.
1277 1445
1278You can still queue as many requests as you want. Therefore, 1446You can still queue as many requests as you want. Therefore,
1279C<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
1280as 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).
1281 1449
1282=back 1450=back
1283 1451
1284=head3 STATISTICAL INFORMATION 1452=head3 STATISTICAL INFORMATION
… …
1302 1470
1303=item IO::AIO::npending 1471=item IO::AIO::npending
1304 1472
1305Returns the number of requests currently in the pending state (executed, 1473Returns the number of requests currently in the pending state (executed,
1306but 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>.
1504
1505=item IO::AIO::mlockall $flags
1506
1507Calls the C<mlockall> function with the given C<$flags> (a combination of
1508C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL__FUTURE>).
1509
1510On systems that do not implement C<mlockall>, this function returns
1511ENOSYS, otherwise the return value of C<mlockall>.
1512
1513=item IO::AIO::munlockall
1514
1515Calls the C<munlockall> function.
1516
1517On systems that do not implement C<munlockall>, this function returns
1518ENOSYS, otherwise the return value of C<munlockall>.
1307 1519
1308=back 1520=back
1309 1521
1310=cut 1522=cut
1311 1523
… …
1354 1566
1355Known bugs will be fixed in the next release. 1567Known bugs will be fixed in the next release.
1356 1568
1357=head1 SEE ALSO 1569=head1 SEE ALSO
1358 1570
1359L<Coro::AIO>. 1571L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1572more natural syntax.
1360 1573
1361=head1 AUTHOR 1574=head1 AUTHOR
1362 1575
1363 Marc Lehmann <schmorp@schmorp.de> 1576 Marc Lehmann <schmorp@schmorp.de>
1364 http://home.schmorp.de/ 1577 http://home.schmorp.de/

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