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30 30
31 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...) 31 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
32 use AnyEvent::AIO; 32 use AnyEvent::AIO;
33 33
34 # EV integration 34 # EV integration
35 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;
36 36
37 # Event integration 37 # Event integration
38 Event->io (fd => IO::AIO::poll_fileno, 38 Event->io (fd => IO::AIO::poll_fileno,
39 poll => 'r', 39 poll => 'r',
40 cb => \&IO::AIO::poll_cb); 40 cb => \&IO::AIO::poll_cb);
52 \&IO::AIO::poll_cb); 52 \&IO::AIO::poll_cb);
53 53
54=head1 DESCRIPTION 54=head1 DESCRIPTION
55 55
56This module implements asynchronous I/O using whatever means your 56This module implements asynchronous I/O using whatever means your
57operating system supports. 57operating system supports. It is implemented as an interface to C<libeio>
58(L<http://software.schmorp.de/pkg/libeio.html>).
58 59
59Asynchronous means that operations that can normally block your program 60Asynchronous means that operations that can normally block your program
60(e.g. reading from disk) will be done asynchronously: the operation 61(e.g. reading from disk) will be done asynchronously: the operation
61will 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
62is extremely useful for programs that need to stay interactive even 63is extremely useful for programs that need to stay interactive even
66on 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
67concurrently. 68concurrently.
68 69
69While most of this works on all types of file descriptors (for 70While most of this works on all types of file descriptors (for
70example sockets), using these functions on file descriptors that 71example sockets), using these functions on file descriptors that
71support nonblocking operation (again, sockets, pipes etc.) is very 72support nonblocking operation (again, sockets, pipes etc.) is
72inefficient. 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>
73module): IO::AIO will naturally fit into such an event loop itself. 74module): IO::AIO will naturally fit into such an event loop itself.
74 75
75In this version, a number of threads are started that execute your 76In this version, a number of threads are started that execute your
76requests and signal their completion. You don't need thread support 77requests and signal their completion. You don't need thread support
77in 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
87yourself, 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
88call C<poll_cb> (or other C<aio_> functions) recursively. 89call C<poll_cb> (or other C<aio_> functions) recursively.
89 90
90=head2 EXAMPLE 91=head2 EXAMPLE
91 92
92This is a simple example that uses the Event module and loads 93This is a simple example that uses the EV module and loads
93F</etc/passwd> asynchronously: 94F</etc/passwd> asynchronously:
94 95
95 use Fcntl; 96 use Fcntl;
96 use Event; 97 use EV;
97 use IO::AIO; 98 use IO::AIO;
98 99
99 # register the IO::AIO callback with Event 100 # register the IO::AIO callback with EV
100 Event->io (fd => IO::AIO::poll_fileno, 101 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
101 poll => 'r',
102 cb => \&IO::AIO::poll_cb);
103 102
104 # queue the request to open /etc/passwd 103 # queue the request to open /etc/passwd
105 aio_open "/etc/passwd", O_RDONLY, 0, sub { 104 aio_open "/etc/passwd", O_RDONLY, 0, sub {
106 my $fh = shift 105 my $fh = shift
107 or die "error while opening: $!"; 106 or die "error while opening: $!";
119 118
120 # file contents now in $contents 119 # file contents now in $contents
121 print $contents; 120 print $contents;
122 121
123 # exit event loop and program 122 # exit event loop and program
124 Event::unloop; 123 EV::unloop;
125 }; 124 };
126 }; 125 };
127 126
128 # possibly queue up other requests, or open GUI windows, 127 # possibly queue up other requests, or open GUI windows,
129 # check for sockets etc. etc. 128 # check for sockets etc. etc.
130 129
131 # process events as long as there are some: 130 # process events as long as there are some:
132 Event::loop; 131 EV::loop;
133 132
134=head1 REQUEST ANATOMY AND LIFETIME 133=head1 REQUEST ANATOMY AND LIFETIME
135 134
136Every 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
137directly visible to Perl. 136directly visible to Perl.
187 186
188package IO::AIO; 187package IO::AIO;
189 188
190use Carp (); 189use Carp ();
191 190
192no warnings; 191use common::sense;
193use strict 'vars';
194 192
195use base 'Exporter'; 193use base 'Exporter';
196 194
197BEGIN { 195BEGIN {
198 our $VERSION = '3.1'; 196 our $VERSION = '3.4';
199 197
200 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
201 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir 199 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
202 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync 200 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
203 aio_fdatasync aio_pathsync aio_readahead 201 aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
204 aio_rename aio_link aio_move aio_copy aio_group 202 aio_rename aio_link aio_move aio_copy aio_group
205 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
206 aio_chmod aio_utime aio_truncate); 204 aio_chmod aio_utime aio_truncate
205 aio_msync aio_mtouch aio_statvfs);
207 206
208 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); 207 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
209 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 208 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
210 min_parallel max_parallel max_idle 209 min_parallel max_parallel max_idle
211 nreqs nready npending nthreads 210 nreqs nready npending nthreads
212 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
213 215
214 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 216 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
215 217
216 require XSLoader; 218 require XSLoader;
217 XSLoader::load ("IO::AIO", $VERSION); 219 XSLoader::load ("IO::AIO", $VERSION);
336 338
337=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 339=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
338 340
339=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 341=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
340 342
341Reads 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<$fh> and
342into the scalar given by C<$data> and offset C<$dataoffset> and calls the 344C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
343callback 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
344like the syscall). 346error, just like the syscall).
347
348C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
349offset plus the actual number of bytes read.
345 350
346If C<$offset> is undefined, then the current file descriptor offset will 351If C<$offset> is undefined, then the current file descriptor offset will
347be used (and updated), otherwise the file descriptor offset will not be 352be used (and updated), otherwise the file descriptor offset will not be
348changed by these calls. 353changed by these calls.
349 354
350If C<$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<$data>.
351 357
352If C<$dataoffset> is less than zero, it will be counted from the end of 358If C<$dataoffset> is less than zero, it will be counted from the end of
353C<$data>. 359C<$data>.
354 360
355The C<$data> scalar I<MUST NOT> be modified in any way while the request 361The C<$data> scalar I<MUST NOT> be modified in any way while the request
375 381
376This call tries to make use of a native C<sendfile> syscall to provide 382This call tries to make use of a native C<sendfile> syscall to provide
377zero-copy operation. For this to work, C<$out_fh> should refer to a 383zero-copy operation. For this to work, C<$out_fh> should refer to a
378socket, and C<$in_fh> should refer to mmap'able file. 384socket, and C<$in_fh> should refer to mmap'able file.
379 385
380If the native sendfile call fails or is not implemented, it will be 386If a native sendfile cannot be found or it fails with C<ENOSYS>,
387C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
381emulated, so you can call C<aio_sendfile> on any type of filehandle 388it will be emulated, so you can call C<aio_sendfile> on any type of
382regardless of the limitations of the operating system. 389filehandle regardless of the limitations of the operating system.
383 390
384Please note, however, that C<aio_sendfile> can read more bytes from 391Please note, however, that C<aio_sendfile> can read more bytes from
385C<$in_fh> than are written, and there is no way to find out how many 392C<$in_fh> than are written, and there is no way to find out how many
386bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only 393bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
387provides the number of bytes written to C<$out_fh>. Only if the result 394provides the number of bytes written to C<$out_fh>. Only if the result
425 $_[0] and die "stat failed: $!"; 432 $_[0] and die "stat failed: $!";
426 print "size is ", -s _, "\n"; 433 print "size is ", -s _, "\n";
427 }; 434 };
428 435
429 436
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
430=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 482=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
431 483
432Works 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
433and $mtime being undef). Fractional times are supported if the underlying 485and $mtime being undef). Fractional times are supported if the underlying
434syscalls support them. 486syscalls support them.
527 579
528Unlike 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
529directory (i.e. opendir + readdir + closedir). The entries will not be 581directory (i.e. opendir + readdir + closedir). The entries will not be
530sorted, and will B<NOT> include the C<.> and C<..> entries. 582sorted, and will B<NOT> include the C<.> and C<..> entries.
531 583
532The 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
533with 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
534 652
535 653
536=item aio_load $path, $data, $callback->($status) 654=item aio_load $path, $data, $callback->($status)
537 655
538This 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
563 681
564=item aio_copy $srcpath, $dstpath, $callback->($status) 682=item aio_copy $srcpath, $dstpath, $callback->($status)
565 683
566Try 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
567destination) from C<$srcpath> to C<$dstpath> and call the callback with 685destination) from C<$srcpath> to C<$dstpath> and call the callback with
568the C<0> (error) or C<-1> ok. 686a status of C<0> (ok) or C<-1> (error, see C<$!>).
569 687
570This is a composite request that creates the destination file with 688This is a composite request that creates the destination file with
571mode 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
572C<aio_sendfile>, followed by restoring atime, mtime, access mode and 690C<aio_sendfile>, followed by restoring atime, mtime, access mode and
573uid/gid, in that order. 691uid/gid, in that order.
585 my $grp = aio_group $cb; 703 my $grp = aio_group $cb;
586 704
587 aioreq_pri $pri; 705 aioreq_pri $pri;
588 add $grp aio_open $src, O_RDONLY, 0, sub { 706 add $grp aio_open $src, O_RDONLY, 0, sub {
589 if (my $src_fh = $_[0]) { 707 if (my $src_fh = $_[0]) {
590 my @stat = stat $src_fh; 708 my @stat = stat $src_fh; # hmm, might block over nfs?
591 709
592 aioreq_pri $pri; 710 aioreq_pri $pri;
593 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 {
594 if (my $dst_fh = $_[0]) { 712 if (my $dst_fh = $_[0]) {
595 aioreq_pri $pri; 713 aioreq_pri $pri;
596 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 714 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
597 if ($_[0] == $stat[7]) { 715 if ($_[0] == $stat[7]) {
598 $grp->result (0); 716 $grp->result (0);
599 close $src_fh; 717 close $src_fh;
600 718
601 # those should not normally block. should. should. 719 my $ch = sub {
602 utime $stat[8], $stat[9], $dst; 720 aioreq_pri $pri;
603 chmod $stat[2] & 07777, $dst_fh; 721 add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
604 chown $stat[4], $stat[5], $dst_fh; 722 aioreq_pri $pri;
723 add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
724 aioreq_pri $pri;
725 add $grp aio_close $dst_fh;
726 }
727 };
728 };
605 729
606 aioreq_pri $pri; 730 aioreq_pri $pri;
607 add $grp aio_close $dst_fh; 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 };
608 } else { 739 } else {
609 $grp->result (-1); 740 $grp->result (-1);
610 close $src_fh; 741 close $src_fh;
611 close $dst_fh; 742 close $dst_fh;
612 743
629 760
630=item aio_move $srcpath, $dstpath, $callback->($status) 761=item aio_move $srcpath, $dstpath, $callback->($status)
631 762
632Try 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
633destination) from C<$srcpath> to C<$dstpath> and call the callback with 764destination) from C<$srcpath> to C<$dstpath> and call the callback with
634the C<0> (error) or C<-1> ok. 765a status of C<0> (ok) or C<-1> (error, see C<$!>).
635 766
636This is a composite request that tries to rename(2) the file first; if 767This is a composite request that tries to rename(2) the file first; if
637rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if 768rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
638that is successful, unlinks the C<$srcpath>. 769that is successful, unlinks the C<$srcpath>.
639 770
690 821
691Implementation notes. 822Implementation notes.
692 823
693The 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.
694 825
826If readdir returns file type information, then this is used directly to
827find directories.
828
695After reading the directory, the modification time, size etc. of the 829Otherwise, after reading the directory, the modification time, size etc.
696directory 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
697isn'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
698entries are directories (if >= 2). Otherwise, no knowledge of the number 832how many entries are directories (if >= 2). Otherwise, no knowledge of the
699of subdirectories will be assumed. 833number of subdirectories will be assumed.
700 834
701Then entries will be sorted into likely directories (everything without 835Then entries will be sorted into likely directories a non-initial dot
702a non-initial dot currently) and likely non-directories (everything 836currently) and likely non-directories (see C<aio_readdirx>). Then every
703else). 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,
704likely directories first. If that succeeds, it assumes that the entry 838in order of their inode numbers. If that succeeds, it assumes that the
705is a directory or a symlink to directory (which will be checked 839entry is a directory or a symlink to directory (which will be checked
706seperately). This is often faster than stat'ing the entry itself because 840seperately). This is often faster than stat'ing the entry itself because
707filesystems might detect the type of the entry without reading the inode 841filesystems might detect the type of the entry without reading the inode
708data (e.g. ext2fs filetype feature). 842data (e.g. ext2fs filetype feature), even on systems that cannot return
843the filetype information on readdir.
709 844
710If 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
711rest of the entries is assumed to be non-directories. 846rest of the entries is assumed to be non-directories.
712 847
713This only works with certainty on POSIX (= UNIX) filesystems, which 848This only works with certainty on POSIX (= UNIX) filesystems, which
735 my $now = time; 870 my $now = time;
736 my $hash1 = join ":", (stat _)[0,1,3,7,9]; 871 my $hash1 = join ":", (stat _)[0,1,3,7,9];
737 872
738 # read the directory entries 873 # read the directory entries
739 aioreq_pri $pri; 874 aioreq_pri $pri;
740 add $grp aio_readdir $path, sub { 875 add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
741 my $entries = shift 876 my $entries = shift
742 or return $grp->result (); 877 or return $grp->result ();
743 878
744 # stat the dir another time 879 # stat the dir another time
745 aioreq_pri $pri; 880 aioreq_pri $pri;
751 # take the slow route if anything looks fishy 886 # take the slow route if anything looks fishy
752 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 887 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
753 $ndirs = -1; 888 $ndirs = -1;
754 } else { 889 } else {
755 # if nlink == 2, we are finished 890 # if nlink == 2, we are finished
756 # on non-posix-fs's, we rely on nlink < 2 891 # for non-posix-fs's, we rely on nlink < 2
757 $ndirs = (stat _)[3] - 2 892 $ndirs = (stat _)[3] - 2
758 or return $grp->result ([], $entries); 893 or return $grp->result ([], $entries);
759 } 894 }
760 895
761 # sort into likely dirs and likely nondirs
762 # dirs == files without ".", short entries first
763 $entries = [map $_->[0],
764 sort { $b->[1] cmp $a->[1] }
765 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
766 @$entries];
767
768 my (@dirs, @nondirs); 896 my (@dirs, @nondirs);
769 897
770 my $statgrp = add $grp aio_group sub { 898 my $statgrp = add $grp aio_group sub {
771 $grp->result (\@dirs, \@nondirs); 899 $grp->result (\@dirs, \@nondirs);
772 }; 900 };
773 901
774 limit $statgrp $maxreq; 902 limit $statgrp $maxreq;
775 feed $statgrp sub { 903 feed $statgrp sub {
776 return unless @$entries; 904 return unless @$entries;
777 my $entry = pop @$entries; 905 my $entry = shift @$entries;
778 906
779 aioreq_pri $pri; 907 aioreq_pri $pri;
780 add $statgrp aio_stat "$path/$entry/.", sub { 908 add $statgrp aio_stat "$path/$entry/.", sub {
781 if ($_[0] < 0) { 909 if ($_[0] < 0) {
782 push @nondirs, $entry; 910 push @nondirs, $entry;
855callback with the fdatasync result code. 983callback with the fdatasync result code.
856 984
857If 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
858detected, it will be emulated by calling C<fsync> instead. 986detected, it will be emulated by calling C<fsync> instead.
859 987
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
860=item aio_pathsync $path, $callback->($status) 1000=item aio_pathsync $path, $callback->($status)
861 1001
862This 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
863composite request intended to sync directories after directory operations 1003composite request intended to sync directories after directory operations
864(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
865specific effect, but usually it makes sure that directory changes get 1005specific effect, but usually it makes sure that directory changes get
866written 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,
867not just directories. 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>).
868 1011
869Passes C<0> when everything went ok, and C<-1> on error. 1012Passes C<0> when everything went ok, and C<-1> on error.
870 1013
871=cut 1014=cut
872 1015
893 }; 1036 };
894 1037
895 $grp 1038 $grp
896} 1039}
897 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).
1066
898=item aio_group $callback->(...) 1067=item aio_group $callback->(...)
899 1068
900This 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
901container 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
902many requests into a single, composite, request with a definite callback 1071many requests into a single, composite, request with a definite callback
951=item cancel $req 1120=item cancel $req
952 1121
953Cancels the request, if possible. Has the effect of skipping execution 1122Cancels the request, if possible. Has the effect of skipping execution
954when entering the B<execute> state and skipping calling the callback when 1123when entering the B<execute> state and skipping calling the callback when
955entering the the B<result> state, but will leave the request otherwise 1124entering the the B<result> state, but will leave the request otherwise
956untouched. That means that requests that currently execute will not be 1125untouched (with the exception of readdir). That means that requests that
957stopped 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.
958 1128
959=item cb $req $callback->(...) 1129=item cb $req $callback->(...)
960 1130
961Replace (or simply set) the callback registered to the request. 1131Replace (or simply set) the callback registered to the request.
962 1132
1036=item $grp->cancel_subs 1206=item $grp->cancel_subs
1037 1207
1038Cancel all subrequests and clears any feeder, but not the group request 1208Cancel all subrequests and clears any feeder, but not the group request
1039itself. 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.
1040 1210
1211The group request will finish normally (you cannot add requests to the
1212group).
1213
1041=item $grp->result (...) 1214=item $grp->result (...)
1042 1215
1043Set 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
1044subrequests have finished and set the groups errno to the current value 1217subrequests have finished and set the groups errno to the current value
1045of 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,
1060=item feed $grp $callback->($grp) 1233=item feed $grp $callback->($grp)
1061 1234
1062Sets 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
1063generator that generates requests if idle. The idea behind this is that, 1236generator that generates requests if idle. The idea behind this is that,
1064although 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,
1065this might starve other requests for a potentially long time. For 1238this might starve other requests for a potentially long time. For example,
1066example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1239C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1067requests, delaying any later requests for a long time. 1240delaying any later requests for a long time.
1068 1241
1069To avoid this, and allow incremental generation of requests, you can 1242To avoid this, and allow incremental generation of requests, you can
1070instead 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
1071feed 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>,
1072below) 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
1113=over 4 1286=over 4
1114 1287
1115=item $fileno = IO::AIO::poll_fileno 1288=item $fileno = IO::AIO::poll_fileno
1116 1289
1117Return the I<request result pipe file descriptor>. This filehandle must be 1290Return the I<request result pipe file descriptor>. This filehandle must be
1118polled 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,
1119select, 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
1120to call C<poll_cb> to check the results. 1293you have to call C<poll_cb> to check the results.
1121 1294
1122See C<poll_cb> for an example. 1295See C<poll_cb> for an example.
1123 1296
1124=item IO::AIO::poll_cb 1297=item IO::AIO::poll_cb
1125 1298
1132If not all requests were processed for whatever reason, the filehandle 1305If not all requests were processed for whatever reason, the filehandle
1133will still be ready when C<poll_cb> returns, so normally you don't have to 1306will still be ready when C<poll_cb> returns, so normally you don't have to
1134do anything special to have it called later. 1307do anything special to have it called later.
1135 1308
1136Example: Install an Event watcher that automatically calls 1309Example: Install an Event watcher that automatically calls
1137IO::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):
1138 1312
1139 Event->io (fd => IO::AIO::poll_fileno, 1313 Event->io (fd => IO::AIO::poll_fileno,
1140 poll => 'r', async => 1, 1314 poll => 'r', async => 1,
1141 cb => \&IO::AIO::poll_cb); 1315 cb => \&IO::AIO::poll_cb);
1142 1316
1296 1470
1297=item IO::AIO::npending 1471=item IO::AIO::npending
1298 1472
1299Returns the number of requests currently in the pending state (executed, 1473Returns the number of requests currently in the pending state (executed,
1300but 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>.
1301 1504
1302=back 1505=back
1303 1506
1304=cut 1507=cut
1305 1508

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