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Revision 1.136 by root, Tue Sep 30 14:07:59 2008 UTC vs.
Revision 1.184 by root, Mon Nov 1 22:03:43 2010 UTC

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4 4
5=head1 SYNOPSIS 5=head1 SYNOPSIS
6 6
7 use IO::AIO; 7 use IO::AIO;
8 8
9 aio_open "/etc/passwd", O_RDONLY, 0, sub { 9 aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
10 my $fh = shift 10 my $fh = shift
11 or die "/etc/passwd: $!"; 11 or die "/etc/passwd: $!";
12 ... 12 ...
13 }; 13 };
14 14
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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, POE, urxvt, pureperl...)
32 use AnyEvent::AIO;
33
34 # EV integration
35 my $w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
36
37 # Event integration
38 Event->io (fd => IO::AIO::poll_fileno,
39 poll => 'r',
40 cb => \&IO::AIO::poll_cb);
41
42 # Glib/Gtk2 integration
43 add_watch Glib::IO IO::AIO::poll_fileno,
44 in => sub { IO::AIO::poll_cb; 1 };
45
46 # Tk integration
47 Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
48 readable => \&IO::AIO::poll_cb);
49
50 # Danga::Socket integration
51 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
52 \&IO::AIO::poll_cb);
53
54=head1 DESCRIPTION 31=head1 DESCRIPTION
55 32
56This module implements asynchronous I/O using whatever means your 33This module implements asynchronous I/O using whatever means your
57operating system supports. 34operating system supports. It is implemented as an interface to C<libeio>
35(L<http://software.schmorp.de/pkg/libeio.html>).
58 36
59Asynchronous means that operations that can normally block your program 37Asynchronous means that operations that can normally block your program
60(e.g. reading from disk) will be done asynchronously: the operation 38(e.g. reading from disk) will be done asynchronously: the operation
61will still block, but you can do something else in the meantime. This 39will still block, but you can do something else in the meantime. This
62is extremely useful for programs that need to stay interactive even 40is extremely useful for programs that need to stay interactive even
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66on a RAID volume or over NFS when you do a number of stat operations 44on a RAID volume or over NFS when you do a number of stat operations
67concurrently. 45concurrently.
68 46
69While most of this works on all types of file descriptors (for 47While most of this works on all types of file descriptors (for
70example sockets), using these functions on file descriptors that 48example sockets), using these functions on file descriptors that
71support nonblocking operation (again, sockets, pipes etc.) is very 49support nonblocking operation (again, sockets, pipes etc.) is
72inefficient. Use an event loop for that (such as the L<Event|Event> 50very inefficient. Use an event loop for that (such as the L<EV>
73module): IO::AIO will naturally fit into such an event loop itself. 51module): IO::AIO will naturally fit into such an event loop itself.
74 52
75In this version, a number of threads are started that execute your 53In this version, a number of threads are started that execute your
76requests and signal their completion. You don't need thread support 54requests and signal their completion. You don't need thread support
77in perl, and the threads created by this module will not be visible 55in perl, and the threads created by this module will not be visible
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87yourself, always call C<poll_cb> from within the same thread, or never 65yourself, always call C<poll_cb> from within the same thread, or never
88call C<poll_cb> (or other C<aio_> functions) recursively. 66call C<poll_cb> (or other C<aio_> functions) recursively.
89 67
90=head2 EXAMPLE 68=head2 EXAMPLE
91 69
92This is a simple example that uses the Event module and loads 70This is a simple example that uses the EV module and loads
93F</etc/passwd> asynchronously: 71F</etc/passwd> asynchronously:
94 72
95 use Fcntl; 73 use Fcntl;
96 use Event; 74 use EV;
97 use IO::AIO; 75 use IO::AIO;
98 76
99 # register the IO::AIO callback with Event 77 # register the IO::AIO callback with EV
100 Event->io (fd => IO::AIO::poll_fileno, 78 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 79
104 # queue the request to open /etc/passwd 80 # queue the request to open /etc/passwd
105 aio_open "/etc/passwd", O_RDONLY, 0, sub { 81 aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
106 my $fh = shift 82 my $fh = shift
107 or die "error while opening: $!"; 83 or die "error while opening: $!";
108 84
109 # stat'ing filehandles is generally non-blocking 85 # stat'ing filehandles is generally non-blocking
110 my $size = -s $fh; 86 my $size = -s $fh;
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119 95
120 # file contents now in $contents 96 # file contents now in $contents
121 print $contents; 97 print $contents;
122 98
123 # exit event loop and program 99 # exit event loop and program
124 Event::unloop; 100 EV::unloop;
125 }; 101 };
126 }; 102 };
127 103
128 # possibly queue up other requests, or open GUI windows, 104 # possibly queue up other requests, or open GUI windows,
129 # check for sockets etc. etc. 105 # check for sockets etc. etc.
130 106
131 # process events as long as there are some: 107 # process events as long as there are some:
132 Event::loop; 108 EV::loop;
133 109
134=head1 REQUEST ANATOMY AND LIFETIME 110=head1 REQUEST ANATOMY AND LIFETIME
135 111
136Every C<aio_*> function creates a request. which is a C data structure not 112Every C<aio_*> function creates a request. which is a C data structure not
137directly visible to Perl. 113directly visible to Perl.
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187 163
188package IO::AIO; 164package IO::AIO;
189 165
190use Carp (); 166use Carp ();
191 167
192no warnings; 168use common::sense;
193use strict 'vars';
194 169
195use base 'Exporter'; 170use base 'Exporter';
196 171
197BEGIN { 172BEGIN {
198 our $VERSION = '3.1'; 173 our $VERSION = '3.7';
199 174
200 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close 175 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 176 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
202 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync 177 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
203 aio_fdatasync aio_pathsync aio_readahead 178 aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
204 aio_rename aio_link aio_move aio_copy aio_group 179 aio_rename aio_link aio_move aio_copy aio_group
205 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown 180 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
206 aio_chmod aio_utime aio_truncate); 181 aio_chmod aio_utime aio_truncate
182 aio_msync aio_mtouch aio_mlock aio_mlockall
183 aio_statvfs);
207 184
208 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); 185 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
209 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 186 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
210 min_parallel max_parallel max_idle 187 min_parallel max_parallel max_idle
211 nreqs nready npending nthreads 188 nreqs nready npending nthreads
212 max_poll_time max_poll_reqs); 189 max_poll_time max_poll_reqs
190 sendfile fadvise madvise
191 mmap munmap munlock munlockall);
192
193 push @AIO_REQ, qw(aio_busy); # not exported
213 194
214 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 195 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
215 196
216 require XSLoader; 197 require XSLoader;
217 XSLoader::load ("IO::AIO", $VERSION); 198 XSLoader::load ("IO::AIO", $VERSION);
218} 199}
219 200
220=head1 FUNCTIONS 201=head1 FUNCTIONS
202
203=head2 QUICK OVERVIEW
204
205This section simply lists the prototypes of the most important functions
206for quick reference. See the following sections for function-by-function
207documentation.
208
209 aio_open $pathname, $flags, $mode, $callback->($fh)
210 aio_close $fh, $callback->($status)
211 aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
212 aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
213 aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
214 aio_readahead $fh,$offset,$length, $callback->($retval)
215 aio_stat $fh_or_path, $callback->($status)
216 aio_lstat $fh, $callback->($status)
217 aio_statvfs $fh_or_path, $callback->($statvfs)
218 aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
219 aio_chown $fh_or_path, $uid, $gid, $callback->($status)
220 aio_truncate $fh_or_path, $offset, $callback->($status)
221 aio_chmod $fh_or_path, $mode, $callback->($status)
222 aio_unlink $pathname, $callback->($status)
223 aio_mknod $path, $mode, $dev, $callback->($status)
224 aio_link $srcpath, $dstpath, $callback->($status)
225 aio_symlink $srcpath, $dstpath, $callback->($status)
226 aio_readlink $path, $callback->($link)
227 aio_rename $srcpath, $dstpath, $callback->($status)
228 aio_mkdir $pathname, $mode, $callback->($status)
229 aio_rmdir $pathname, $callback->($status)
230 aio_readdir $pathname, $callback->($entries)
231 aio_readdirx $pathname, $flags, $callback->($entries, $flags)
232 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
233 IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN
234 aio_load $path, $data, $callback->($status)
235 aio_copy $srcpath, $dstpath, $callback->($status)
236 aio_move $srcpath, $dstpath, $callback->($status)
237 aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
238 aio_rmtree $path, $callback->($status)
239 aio_sync $callback->($status)
240 aio_fsync $fh, $callback->($status)
241 aio_fdatasync $fh, $callback->($status)
242 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
243 aio_pathsync $path, $callback->($status)
244 aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
245 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
246 aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
247 aio_mlockall $flags, $callback->($status)
248 aio_group $callback->(...)
249 aio_nop $callback->()
250
251 $prev_pri = aioreq_pri [$pri]
252 aioreq_nice $pri_adjust
253
254 IO::AIO::poll_wait
255 IO::AIO::poll_cb
256 IO::AIO::poll
257 IO::AIO::flush
258 IO::AIO::max_poll_reqs $nreqs
259 IO::AIO::max_poll_time $seconds
260 IO::AIO::min_parallel $nthreads
261 IO::AIO::max_parallel $nthreads
262 IO::AIO::max_idle $nthreads
263 IO::AIO::max_outstanding $maxreqs
264 IO::AIO::nreqs
265 IO::AIO::nready
266 IO::AIO::npending
267
268 IO::AIO::sendfile $ofh, $ifh, $offset, $count
269 IO::AIO::fadvise $fh, $offset, $len, $advice
270 IO::AIO::madvise $scalar, $offset, $length, $advice
271 IO::AIO::mprotect $scalar, $offset, $length, $protect
272 IO::AIO::munlock $scalar, $offset = 0, $length = undef
273 IO::AIO::munlockall
221 274
222=head2 AIO REQUEST FUNCTIONS 275=head2 AIO REQUEST FUNCTIONS
223 276
224All the C<aio_*> calls are more or less thin wrappers around the syscall 277All the C<aio_*> calls are more or less thin wrappers around the syscall
225with the same name (sans C<aio_>). The arguments are similar or identical, 278with the same name (sans C<aio_>). The arguments are similar or identical,
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305by the umask in effect then the request is being executed, so better never 358by the umask in effect then the request is being executed, so better never
306change the umask. 359change the umask.
307 360
308Example: 361Example:
309 362
310 aio_open "/etc/passwd", O_RDONLY, 0, sub { 363 aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
311 if ($_[0]) { 364 if ($_[0]) {
312 print "open successful, fh is $_[0]\n"; 365 print "open successful, fh is $_[0]\n";
313 ... 366 ...
314 } else { 367 } else {
315 die "open failed: $!\n"; 368 die "open failed: $!\n";
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336 389
337=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 390=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
338 391
339=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 392=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
340 393
341Reads or writes C<$length> bytes from the specified C<$fh> and C<$offset> 394Reads or writes C<$length> bytes from or to the specified C<$fh> and
342into the scalar given by C<$data> and offset C<$dataoffset> and calls the 395C<$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 396and calls the callback without the actual number of bytes read (or -1 on
344like the syscall). 397error, just like the syscall).
398
399C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
400offset plus the actual number of bytes read.
345 401
346If C<$offset> is undefined, then the current file descriptor offset will 402If C<$offset> is undefined, then the current file descriptor offset will
347be used (and updated), otherwise the file descriptor offset will not be 403be used (and updated), otherwise the file descriptor offset will not be
348changed by these calls. 404changed by these calls.
349 405
350If C<$length> is undefined in C<aio_write>, use the remaining length of C<$data>. 406If C<$length> is undefined in C<aio_write>, use the remaining length of
407C<$data>.
351 408
352If C<$dataoffset> is less than zero, it will be counted from the end of 409If C<$dataoffset> is less than zero, it will be counted from the end of
353C<$data>. 410C<$data>.
354 411
355The C<$data> scalar I<MUST NOT> be modified in any way while the request 412The C<$data> scalar I<MUST NOT> be modified in any way while the request
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373than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each 430than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
374other. 431other.
375 432
376This call tries to make use of a native C<sendfile> syscall to provide 433This call tries to make use of a native C<sendfile> syscall to provide
377zero-copy operation. For this to work, C<$out_fh> should refer to a 434zero-copy operation. For this to work, C<$out_fh> should refer to a
378socket, and C<$in_fh> should refer to mmap'able file. 435socket, and C<$in_fh> should refer to an mmap'able file.
379 436
380If the native sendfile call fails or is not implemented, it will be 437If a native sendfile cannot be found or it fails with C<ENOSYS>,
438C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
381emulated, so you can call C<aio_sendfile> on any type of filehandle 439it will be emulated, so you can call C<aio_sendfile> on any type of
382regardless of the limitations of the operating system. 440filehandle regardless of the limitations of the operating system.
383 441
384Please note, however, that C<aio_sendfile> can read more bytes from 442Please note, however, that C<aio_sendfile> can read more bytes from
385C<$in_fh> than are written, and there is no way to find out how many 443C<$in_fh> than are written, and there is no way to find out how many
386bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only 444bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
387provides the number of bytes written to C<$out_fh>. Only if the result 445provides the number of bytes written to C<$out_fh>. Only if the result
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425 $_[0] and die "stat failed: $!"; 483 $_[0] and die "stat failed: $!";
426 print "size is ", -s _, "\n"; 484 print "size is ", -s _, "\n";
427 }; 485 };
428 486
429 487
488=item aio_statvfs $fh_or_path, $callback->($statvfs)
489
490Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
491whether a file handle or path was passed.
492
493On success, the callback is passed a hash reference with the following
494members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
495C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
496is passed.
497
498The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
499C<ST_NOSUID>.
500
501The following non-POSIX IO::AIO::ST_* flag masks are defined to
502their correct value when available, or to C<0> on systems that do
503not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
504C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
505C<ST_NODIRATIME> and C<ST_RELATIME>.
506
507Example: stat C</wd> and dump out the data if successful.
508
509 aio_statvfs "/wd", sub {
510 my $f = $_[0]
511 or die "statvfs: $!";
512
513 use Data::Dumper;
514 say Dumper $f;
515 };
516
517 # result:
518 {
519 bsize => 1024,
520 bfree => 4333064312,
521 blocks => 10253828096,
522 files => 2050765568,
523 flag => 4096,
524 favail => 2042092649,
525 bavail => 4333064312,
526 ffree => 2042092649,
527 namemax => 255,
528 frsize => 1024,
529 fsid => 1810
530 }
531
532
430=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 533=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
431 534
432Works like perl's C<utime> function (including the special case of $atime 535Works like perl's C<utime> function (including the special case of $atime
433and $mtime being undef). Fractional times are supported if the underlying 536and $mtime being undef). Fractional times are supported if the underlying
434syscalls support them. 537syscalls support them.
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527 630
528Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 631Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
529directory (i.e. opendir + readdir + closedir). The entries will not be 632directory (i.e. opendir + readdir + closedir). The entries will not be
530sorted, and will B<NOT> include the C<.> and C<..> entries. 633sorted, and will B<NOT> include the C<.> and C<..> entries.
531 634
532The callback a single argument which is either C<undef> or an array-ref 635The callback is passed a single argument which is either C<undef> or an
533with the filenames. 636array-ref with the filenames.
637
638
639=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
640
641Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
642behaviour and output format. In case of an error, C<$entries> will be
643C<undef>.
644
645The flags are a combination of the following constants, ORed together (the
646flags will also be passed to the callback, possibly modified):
647
648=over 4
649
650=item IO::AIO::READDIR_DENTS
651
652When this flag is off, then the callback gets an arrayref with of names
653only (as with C<aio_readdir>), otherwise it gets an arrayref with
654C<[$name, $type, $inode]> arrayrefs, each describing a single directory
655entry in more detail.
656
657C<$name> is the name of the entry.
658
659C<$type> is one of the C<IO::AIO::DT_xxx> constants:
660
661C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
662C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
663C<IO::AIO::DT_WHT>.
664
665C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
666know, you have to run stat yourself. Also, for speed reasons, the C<$type>
667scalars are read-only: you can not modify them.
668
669C<$inode> is the inode number (which might not be exact on systems with 64
670bit inode numbers and 32 bit perls). This field has unspecified content on
671systems that do not deliver the inode information.
672
673=item IO::AIO::READDIR_DIRS_FIRST
674
675When this flag is set, then the names will be returned in an order where
676likely directories come first. This is useful when you need to quickly
677find directories, or you want to find all directories while avoiding to
678stat() each entry.
679
680If the system returns type information in readdir, then this is used
681to find directories directly. Otherwise, likely directories are files
682beginning with ".", or otherwise files with no dots, of which files with
683short names are tried first.
684
685=item IO::AIO::READDIR_STAT_ORDER
686
687When this flag is set, then the names will be returned in an order
688suitable for stat()'ing each one. That is, when you plan to stat()
689all files in the given directory, then the returned order will likely
690be fastest.
691
692If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
693the likely dirs come first, resulting in a less optimal stat order.
694
695=item IO::AIO::READDIR_FOUND_UNKNOWN
696
697This flag should not be set when calling C<aio_readdirx>. Instead, it
698is being set by C<aio_readdirx>, when any of the C<$type>'s found were
699C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
700C<$type>'s are known, which can be used to speed up some algorithms.
701
702=back
534 703
535 704
536=item aio_load $path, $data, $callback->($status) 705=item aio_load $path, $data, $callback->($status)
537 706
538This is a composite request that tries to fully load the given file into 707This is a composite request that tries to fully load the given file into
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563 732
564=item aio_copy $srcpath, $dstpath, $callback->($status) 733=item aio_copy $srcpath, $dstpath, $callback->($status)
565 734
566Try to copy the I<file> (directories not supported as either source or 735Try to copy the I<file> (directories not supported as either source or
567destination) from C<$srcpath> to C<$dstpath> and call the callback with 736destination) from C<$srcpath> to C<$dstpath> and call the callback with
568the C<0> (error) or C<-1> ok. 737a status of C<0> (ok) or C<-1> (error, see C<$!>).
569 738
570This is a composite request that creates the destination file with 739This is a composite request that creates the destination file with
571mode 0200 and copies the contents of the source file into it using 740mode 0200 and copies the contents of the source file into it using
572C<aio_sendfile>, followed by restoring atime, mtime, access mode and 741C<aio_sendfile>, followed by restoring atime, mtime, access mode and
573uid/gid, in that order. 742uid/gid, in that order.
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585 my $grp = aio_group $cb; 754 my $grp = aio_group $cb;
586 755
587 aioreq_pri $pri; 756 aioreq_pri $pri;
588 add $grp aio_open $src, O_RDONLY, 0, sub { 757 add $grp aio_open $src, O_RDONLY, 0, sub {
589 if (my $src_fh = $_[0]) { 758 if (my $src_fh = $_[0]) {
590 my @stat = stat $src_fh; 759 my @stat = stat $src_fh; # hmm, might block over nfs?
591 760
592 aioreq_pri $pri; 761 aioreq_pri $pri;
593 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub { 762 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
594 if (my $dst_fh = $_[0]) { 763 if (my $dst_fh = $_[0]) {
595 aioreq_pri $pri; 764 aioreq_pri $pri;
596 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 765 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
597 if ($_[0] == $stat[7]) { 766 if ($_[0] == $stat[7]) {
598 $grp->result (0); 767 $grp->result (0);
599 close $src_fh; 768 close $src_fh;
600 769
601 # those should not normally block. should. should. 770 my $ch = sub {
602 utime $stat[8], $stat[9], $dst; 771 aioreq_pri $pri;
603 chmod $stat[2] & 07777, $dst_fh; 772 add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
604 chown $stat[4], $stat[5], $dst_fh; 773 aioreq_pri $pri;
774 add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
775 aioreq_pri $pri;
776 add $grp aio_close $dst_fh;
777 }
778 };
779 };
605 780
606 aioreq_pri $pri; 781 aioreq_pri $pri;
607 add $grp aio_close $dst_fh; 782 add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
783 if ($_[0] < 0 && $! == ENOSYS) {
784 aioreq_pri $pri;
785 add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
786 } else {
787 $ch->();
788 }
789 };
608 } else { 790 } else {
609 $grp->result (-1); 791 $grp->result (-1);
610 close $src_fh; 792 close $src_fh;
611 close $dst_fh; 793 close $dst_fh;
612 794
… …
629 811
630=item aio_move $srcpath, $dstpath, $callback->($status) 812=item aio_move $srcpath, $dstpath, $callback->($status)
631 813
632Try to move the I<file> (directories not supported as either source or 814Try to move the I<file> (directories not supported as either source or
633destination) from C<$srcpath> to C<$dstpath> and call the callback with 815destination) from C<$srcpath> to C<$dstpath> and call the callback with
634the C<0> (error) or C<-1> ok. 816a status of C<0> (ok) or C<-1> (error, see C<$!>).
635 817
636This is a composite request that tries to rename(2) the file first. If 818This is a composite request that tries to rename(2) the file first; if
637rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if 819rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
638that is successful, unlinking the C<$srcpath>. 820that is successful, unlinks the C<$srcpath>.
639 821
640=cut 822=cut
641 823
642sub aio_move($$;$) { 824sub aio_move($$;$) {
643 my ($src, $dst, $cb) = @_; 825 my ($src, $dst, $cb) = @_;
… …
690 872
691Implementation notes. 873Implementation notes.
692 874
693The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can. 875The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
694 876
877If readdir returns file type information, then this is used directly to
878find directories.
879
695After reading the directory, the modification time, size etc. of the 880Otherwise, after reading the directory, the modification time, size etc.
696directory before and after the readdir is checked, and if they match (and 881of 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 882match (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 883how many entries are directories (if >= 2). Otherwise, no knowledge of the
699of subdirectories will be assumed. 884number of subdirectories will be assumed.
700 885
701Then entries will be sorted into likely directories (everything without 886Then entries will be sorted into likely directories a non-initial dot
702a non-initial dot currently) and likely non-directories (everything 887currently) and likely non-directories (see C<aio_readdirx>). Then every
703else). Then every entry plus an appended C</.> will be C<stat>'ed, 888entry plus an appended C</.> will be C<stat>'ed, likely directories first,
704likely directories first. If that succeeds, it assumes that the entry 889in order of their inode numbers. If that succeeds, it assumes that the
705is a directory or a symlink to directory (which will be checked 890entry is a directory or a symlink to directory (which will be checked
706seperately). This is often faster than stat'ing the entry itself because 891seperately). This is often faster than stat'ing the entry itself because
707filesystems might detect the type of the entry without reading the inode 892filesystems might detect the type of the entry without reading the inode
708data (e.g. ext2fs filetype feature). 893data (e.g. ext2fs filetype feature), even on systems that cannot return
894the filetype information on readdir.
709 895
710If the known number of directories (link count - 2) has been reached, the 896If the known number of directories (link count - 2) has been reached, the
711rest of the entries is assumed to be non-directories. 897rest of the entries is assumed to be non-directories.
712 898
713This only works with certainty on POSIX (= UNIX) filesystems, which 899This only works with certainty on POSIX (= UNIX) filesystems, which
… …
735 my $now = time; 921 my $now = time;
736 my $hash1 = join ":", (stat _)[0,1,3,7,9]; 922 my $hash1 = join ":", (stat _)[0,1,3,7,9];
737 923
738 # read the directory entries 924 # read the directory entries
739 aioreq_pri $pri; 925 aioreq_pri $pri;
740 add $grp aio_readdir $path, sub { 926 add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
741 my $entries = shift 927 my $entries = shift
742 or return $grp->result (); 928 or return $grp->result ();
743 929
744 # stat the dir another time 930 # stat the dir another time
745 aioreq_pri $pri; 931 aioreq_pri $pri;
… …
751 # take the slow route if anything looks fishy 937 # take the slow route if anything looks fishy
752 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 938 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
753 $ndirs = -1; 939 $ndirs = -1;
754 } else { 940 } else {
755 # if nlink == 2, we are finished 941 # if nlink == 2, we are finished
756 # on non-posix-fs's, we rely on nlink < 2 942 # for non-posix-fs's, we rely on nlink < 2
757 $ndirs = (stat _)[3] - 2 943 $ndirs = (stat _)[3] - 2
758 or return $grp->result ([], $entries); 944 or return $grp->result ([], $entries);
759 } 945 }
760 946
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); 947 my (@dirs, @nondirs);
769 948
770 my $statgrp = add $grp aio_group sub { 949 my $statgrp = add $grp aio_group sub {
771 $grp->result (\@dirs, \@nondirs); 950 $grp->result (\@dirs, \@nondirs);
772 }; 951 };
773 952
774 limit $statgrp $maxreq; 953 limit $statgrp $maxreq;
775 feed $statgrp sub { 954 feed $statgrp sub {
776 return unless @$entries; 955 return unless @$entries;
777 my $entry = pop @$entries; 956 my $entry = shift @$entries;
778 957
779 aioreq_pri $pri; 958 aioreq_pri $pri;
780 add $statgrp aio_stat "$path/$entry/.", sub { 959 add $statgrp aio_stat "$path/$entry/.", sub {
781 if ($_[0] < 0) { 960 if ($_[0] < 0) {
782 push @nondirs, $entry; 961 push @nondirs, $entry;
… …
855callback with the fdatasync result code. 1034callback with the fdatasync result code.
856 1035
857If this call isn't available because your OS lacks it or it couldn't be 1036If 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. 1037detected, it will be emulated by calling C<fsync> instead.
859 1038
1039=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
1040
1041Sync the data portion of the file specified by C<$offset> and C<$length>
1042to disk (but NOT the metadata), by calling the Linux-specific
1043sync_file_range call. If sync_file_range is not available or it returns
1044ENOSYS, then fdatasync or fsync is being substituted.
1045
1046C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
1047C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
1048C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
1049manpage for details.
1050
860=item aio_pathsync $path, $callback->($status) 1051=item aio_pathsync $path, $callback->($status)
861 1052
862This request tries to open, fsync and close the given path. This is a 1053This request tries to open, fsync and close the given path. This is a
863composite request intended to sync directories after directory operations 1054composite request intended to sync directories after directory operations
864(E.g. rename). This might not work on all operating systems or have any 1055(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 1056specific effect, but usually it makes sure that directory changes get
866written to disc. It works for anything that can be opened for read-only, 1057written to disc. It works for anything that can be opened for read-only,
867not just directories. 1058not just directories.
1059
1060Future versions of this function might fall back to other methods when
1061C<fsync> on the directory fails (such as calling C<sync>).
868 1062
869Passes C<0> when everything went ok, and C<-1> on error. 1063Passes C<0> when everything went ok, and C<-1> on error.
870 1064
871=cut 1065=cut
872 1066
… …
893 }; 1087 };
894 1088
895 $grp 1089 $grp
896} 1090}
897 1091
1092=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1093
1094This is a rather advanced IO::AIO call, which only works on mmap(2)ed
1095scalars (see the C<IO::AIO::mmap> function, although it also works on data
1096scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
1097scalar must only be modified in-place while an aio operation is pending on
1098it).
1099
1100It calls the C<msync> function of your OS, if available, with the memory
1101area starting at C<$offset> in the string and ending C<$length> bytes
1102later. If C<$length> is negative, counts from the end, and if C<$length>
1103is C<undef>, then it goes till the end of the string. The flags can be
1104a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
1105C<IO::AIO::MS_SYNC>.
1106
1107=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1108
1109This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1110scalars.
1111
1112It touches (reads or writes) all memory pages in the specified
1113range inside the scalar. All caveats and parameters are the same
1114as for C<aio_msync>, above, except for flags, which must be either
1115C<0> (which reads all pages and ensures they are instantiated) or
1116C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
1117writing an octet from it, which dirties the page).
1118
1119=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1120
1121This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1122scalars.
1123
1124It reads in all the pages of the underlying storage into memory (if any)
1125and locks them, so they are not getting swapped/paged out or removed.
1126
1127If C<$length> is undefined, then the scalar will be locked till the end.
1128
1129On systems that do not implement C<mlock>, this function returns C<-1>
1130and sets errno to C<ENOSYS>.
1131
1132Note that the corresponding C<munlock> is synchronous and is
1133documented under L<MISCELLANEOUS FUNCTIONS>.
1134
1135Example: open a file, mmap and mlock it - both will be undone when
1136C<$data> gets destroyed.
1137
1138 open my $fh, "<", $path or die "$path: $!";
1139 my $data;
1140 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
1141 aio_mlock $data; # mlock in background
1142
1143=item aio_mlockall $flags, $callback->($status)
1144
1145Calls the C<mlockall> function with the given C<$flags> (a combination of
1146C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).
1147
1148On systems that do not implement C<mlockall>, this function returns C<-1>
1149and sets errno to C<ENOSYS>.
1150
1151Note that the corresponding C<munlockall> is synchronous and is
1152documented under L<MISCELLANEOUS FUNCTIONS>.
1153
1154Example: asynchronously lock all current and future pages into memory.
1155
1156 aio_mlockall IO::AIO::MCL_FUTURE;
1157
898=item aio_group $callback->(...) 1158=item aio_group $callback->(...)
899 1159
900This is a very special aio request: Instead of doing something, it is a 1160This 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 1161container for other aio requests, which is useful if you want to bundle
902many requests into a single, composite, request with a definite callback 1162many requests into a single, composite, request with a definite callback
… …
951=item cancel $req 1211=item cancel $req
952 1212
953Cancels the request, if possible. Has the effect of skipping execution 1213Cancels the request, if possible. Has the effect of skipping execution
954when entering the B<execute> state and skipping calling the callback when 1214when entering the B<execute> state and skipping calling the callback when
955entering the the B<result> state, but will leave the request otherwise 1215entering the the B<result> state, but will leave the request otherwise
956untouched. That means that requests that currently execute will not be 1216untouched (with the exception of readdir). That means that requests that
957stopped and resources held by the request will not be freed prematurely. 1217currently execute will not be stopped and resources held by the request
1218will not be freed prematurely.
958 1219
959=item cb $req $callback->(...) 1220=item cb $req $callback->(...)
960 1221
961Replace (or simply set) the callback registered to the request. 1222Replace (or simply set) the callback registered to the request.
962 1223
… …
1036=item $grp->cancel_subs 1297=item $grp->cancel_subs
1037 1298
1038Cancel all subrequests and clears any feeder, but not the group request 1299Cancel 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. 1300itself. Useful when you queued a lot of events but got a result early.
1040 1301
1302The group request will finish normally (you cannot add requests to the
1303group).
1304
1041=item $grp->result (...) 1305=item $grp->result (...)
1042 1306
1043Set the result value(s) that will be passed to the group callback when all 1307Set 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 1308subrequests have finished and set the groups errno to the current value
1045of errno (just like calling C<errno> without an error number). By default, 1309of errno (just like calling C<errno> without an error number). By default,
… …
1060=item feed $grp $callback->($grp) 1324=item feed $grp $callback->($grp)
1061 1325
1062Sets a feeder/generator on this group: every group can have an attached 1326Sets a feeder/generator on this group: every group can have an attached
1063generator that generates requests if idle. The idea behind this is that, 1327generator 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, 1328although you could just queue as many requests as you want in a group,
1065this might starve other requests for a potentially long time. For 1329this might starve other requests for a potentially long time. For example,
1066example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1330C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1067requests, delaying any later requests for a long time. 1331delaying any later requests for a long time.
1068 1332
1069To avoid this, and allow incremental generation of requests, you can 1333To avoid this, and allow incremental generation of requests, you can
1070instead a group and set a feeder on it that generates those requests. The 1334instead 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>, 1335feed 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 1336below) requests active in the group itself and is expected to queue more
… …
1076not impose any limits). 1340not impose any limits).
1077 1341
1078If the feed does not queue more requests when called, it will be 1342If the feed does not queue more requests when called, it will be
1079automatically removed from the group. 1343automatically removed from the group.
1080 1344
1081If the feed limit is C<0>, it will be set to C<2> automatically. 1345If the feed limit is C<0> when this method is called, it will be set to
1346C<2> automatically.
1082 1347
1083Example: 1348Example:
1084 1349
1085 # stat all files in @files, but only ever use four aio requests concurrently: 1350 # stat all files in @files, but only ever use four aio requests concurrently:
1086 1351
… …
1098Sets the feeder limit for the group: The feeder will be called whenever 1363Sets the feeder limit for the group: The feeder will be called whenever
1099the group contains less than this many requests. 1364the group contains less than this many requests.
1100 1365
1101Setting the limit to C<0> will pause the feeding process. 1366Setting the limit to C<0> will pause the feeding process.
1102 1367
1368The default value for the limit is C<0>, but note that setting a feeder
1369automatically bumps it up to C<2>.
1370
1103=back 1371=back
1104 1372
1105=head2 SUPPORT FUNCTIONS 1373=head2 SUPPORT FUNCTIONS
1106 1374
1107=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1375=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
… …
1109=over 4 1377=over 4
1110 1378
1111=item $fileno = IO::AIO::poll_fileno 1379=item $fileno = IO::AIO::poll_fileno
1112 1380
1113Return the I<request result pipe file descriptor>. This filehandle must be 1381Return the I<request result pipe file descriptor>. This filehandle must be
1114polled for reading by some mechanism outside this module (e.g. Event or 1382polled for reading by some mechanism outside this module (e.g. EV, Glib,
1115select, see below or the SYNOPSIS). If the pipe becomes readable you have 1383select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1116to call C<poll_cb> to check the results. 1384you have to call C<poll_cb> to check the results.
1117 1385
1118See C<poll_cb> for an example. 1386See C<poll_cb> for an example.
1119 1387
1120=item IO::AIO::poll_cb 1388=item IO::AIO::poll_cb
1121 1389
… …
1128If not all requests were processed for whatever reason, the filehandle 1396If not all requests were processed for whatever reason, the filehandle
1129will still be ready when C<poll_cb> returns, so normally you don't have to 1397will still be ready when C<poll_cb> returns, so normally you don't have to
1130do anything special to have it called later. 1398do anything special to have it called later.
1131 1399
1132Example: Install an Event watcher that automatically calls 1400Example: Install an Event watcher that automatically calls
1133IO::AIO::poll_cb with high priority: 1401IO::AIO::poll_cb with high priority (more examples can be found in the
1402SYNOPSIS section, at the top of this document):
1134 1403
1135 Event->io (fd => IO::AIO::poll_fileno, 1404 Event->io (fd => IO::AIO::poll_fileno,
1136 poll => 'r', async => 1, 1405 poll => 'r', async => 1,
1137 cb => \&IO::AIO::poll_cb); 1406 cb => \&IO::AIO::poll_cb);
1407
1408=item IO::AIO::poll_wait
1409
1410If there are any outstanding requests and none of them in the result
1411phase, wait till the result filehandle becomes ready for reading (simply
1412does a C<select> on the filehandle. This is useful if you want to
1413synchronously wait for some requests to finish).
1414
1415See C<nreqs> for an example.
1416
1417=item IO::AIO::poll
1418
1419Waits until some requests have been handled.
1420
1421Returns the number of requests processed, but is otherwise strictly
1422equivalent to:
1423
1424 IO::AIO::poll_wait, IO::AIO::poll_cb
1425
1426=item IO::AIO::flush
1427
1428Wait till all outstanding AIO requests have been handled.
1429
1430Strictly equivalent to:
1431
1432 IO::AIO::poll_wait, IO::AIO::poll_cb
1433 while IO::AIO::nreqs;
1138 1434
1139=item IO::AIO::max_poll_reqs $nreqs 1435=item IO::AIO::max_poll_reqs $nreqs
1140 1436
1141=item IO::AIO::max_poll_time $seconds 1437=item IO::AIO::max_poll_time $seconds
1142 1438
… …
1167 # use a low priority so other tasks have priority 1463 # use a low priority so other tasks have priority
1168 Event->io (fd => IO::AIO::poll_fileno, 1464 Event->io (fd => IO::AIO::poll_fileno,
1169 poll => 'r', nice => 1, 1465 poll => 'r', nice => 1,
1170 cb => &IO::AIO::poll_cb); 1466 cb => &IO::AIO::poll_cb);
1171 1467
1172=item IO::AIO::poll_wait
1173
1174If there are any outstanding requests and none of them in the result
1175phase, wait till the result filehandle becomes ready for reading (simply
1176does a C<select> on the filehandle. This is useful if you want to
1177synchronously wait for some requests to finish).
1178
1179See C<nreqs> for an example.
1180
1181=item IO::AIO::poll
1182
1183Waits until some requests have been handled.
1184
1185Returns the number of requests processed, but is otherwise strictly
1186equivalent to:
1187
1188 IO::AIO::poll_wait, IO::AIO::poll_cb
1189
1190=item IO::AIO::flush
1191
1192Wait till all outstanding AIO requests have been handled.
1193
1194Strictly equivalent to:
1195
1196 IO::AIO::poll_wait, IO::AIO::poll_cb
1197 while IO::AIO::nreqs;
1198
1199=back 1468=back
1200 1469
1201=head3 CONTROLLING THE NUMBER OF THREADS 1470=head3 CONTROLLING THE NUMBER OF THREADS
1202 1471
1203=over 1472=over
… …
1295Returns the number of requests currently in the pending state (executed, 1564Returns the number of requests currently in the pending state (executed,
1296but not yet processed by poll_cb). 1565but not yet processed by poll_cb).
1297 1566
1298=back 1567=back
1299 1568
1569=head3 MISCELLANEOUS FUNCTIONS
1570
1571IO::AIO implements some functions that might be useful, but are not
1572asynchronous.
1573
1574=over 4
1575
1576=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1577
1578Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
1579but is blocking (this makes most sense if you know the input data is
1580likely cached already and the output filehandle is set to non-blocking
1581operations).
1582
1583Returns the number of bytes copied, or C<-1> on error.
1584
1585=item IO::AIO::fadvise $fh, $offset, $len, $advice
1586
1587Simply calls the C<posix_fadvise> function (see its
1588manpage for details). The following advice constants are
1589avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1590C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1591C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1592
1593On systems that do not implement C<posix_fadvise>, this function returns
1594ENOSYS, otherwise the return value of C<posix_fadvise>.
1595
1596=item IO::AIO::madvise $scalar, $offset, $len, $advice
1597
1598Simply calls the C<posix_madvise> function (see its
1599manpage for details). The following advice constants are
1600avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
1601C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.
1602
1603On systems that do not implement C<posix_madvise>, this function returns
1604ENOSYS, otherwise the return value of C<posix_madvise>.
1605
1606=item IO::AIO::mprotect $scalar, $offset, $len, $protect
1607
1608Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
1609$scalar (see its manpage for details). The following protect
1610constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
1611C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
1612
1613On systems that do not implement C<mprotect>, this function returns
1614ENOSYS, otherwise the return value of C<mprotect>.
1615
1616=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1617
1618Memory-maps a file (or anonymous memory range) and attaches it to the
1619given C<$scalar>, which will act like a string scalar.
1620
1621The only operations allowed on the scalar are C<substr>/C<vec> that don't
1622change the string length, and most read-only operations such as copying it
1623or searching it with regexes and so on.
1624
1625Anything else is unsafe and will, at best, result in memory leaks.
1626
1627The memory map associated with the C<$scalar> is automatically removed
1628when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
1629C<IO::AIO::munmap> functions are called.
1630
1631This calls the C<mmap>(2) function internally. See your system's manual
1632page for details on the C<$length>, C<$prot> and C<$flags> parameters.
1633
1634The C<$length> must be larger than zero and smaller than the actual
1635filesize.
1636
1637C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1638C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1639
1640C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
1641C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
1642not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
1643(which is set to C<MAP_ANON> if your system only provides this
1644constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
1645C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
1646C<IO::AIO::MAP_NONBLOCK>
1647
1648If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1649
1650C<$offset> is the offset from the start of the file - it generally must be
1651a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
1652
1653Example:
1654
1655 use Digest::MD5;
1656 use IO::AIO;
1657
1658 open my $fh, "<verybigfile"
1659 or die "$!";
1660
1661 IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
1662 or die "verybigfile: $!";
1663
1664 my $fast_md5 = md5 $data;
1665
1666=item IO::AIO::munmap $scalar
1667
1668Removes a previous mmap and undefines the C<$scalar>.
1669
1670=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
1671
1672Calls the C<munlock> function, undoing the effects of a previous
1673C<aio_mlock> call (see its description for details).
1674
1675=item IO::AIO::munlockall
1676
1677Calls the C<munlockall> function.
1678
1679On systems that do not implement C<munlockall>, this function returns
1680ENOSYS, otherwise the return value of C<munlockall>.
1681
1682=back
1683
1300=cut 1684=cut
1301 1685
1302min_parallel 8; 1686min_parallel 8;
1303 1687
1304END { flush } 1688END { flush }
1305 1689
13061; 16901;
1691
1692=head1 EVENT LOOP INTEGRATION
1693
1694It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
1695automatically into many event loops:
1696
1697 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
1698 use AnyEvent::AIO;
1699
1700You can also integrate IO::AIO manually into many event loops, here are
1701some examples of how to do this:
1702
1703 # EV integration
1704 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
1705
1706 # Event integration
1707 Event->io (fd => IO::AIO::poll_fileno,
1708 poll => 'r',
1709 cb => \&IO::AIO::poll_cb);
1710
1711 # Glib/Gtk2 integration
1712 add_watch Glib::IO IO::AIO::poll_fileno,
1713 in => sub { IO::AIO::poll_cb; 1 };
1714
1715 # Tk integration
1716 Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
1717 readable => \&IO::AIO::poll_cb);
1718
1719 # Danga::Socket integration
1720 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
1721 \&IO::AIO::poll_cb);
1307 1722
1308=head2 FORK BEHAVIOUR 1723=head2 FORK BEHAVIOUR
1309 1724
1310This module should do "the right thing" when the process using it forks: 1725This module should do "the right thing" when the process using it forks:
1311 1726

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