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Revision 1.124 by root, Sat May 10 19:25:33 2008 UTC vs.
Revision 1.183 by root, Sun Sep 12 03:40:05 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, urxvt, pureperl...)
32 open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!";
33 my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });
34
35 # EV integration
36 my $w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
37
38 # Event integration
39 Event->io (fd => IO::AIO::poll_fileno,
40 poll => 'r',
41 cb => \&IO::AIO::poll_cb);
42
43 # Glib/Gtk2 integration
44 add_watch Glib::IO IO::AIO::poll_fileno,
45 in => sub { IO::AIO::poll_cb; 1 };
46
47 # Tk integration
48 Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
49 readable => \&IO::AIO::poll_cb);
50
51 # Danga::Socket integration
52 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
53 \&IO::AIO::poll_cb);
54
55=head1 DESCRIPTION 31=head1 DESCRIPTION
56 32
57This module implements asynchronous I/O using whatever means your 33This module implements asynchronous I/O using whatever means your
58operating system supports. 34operating system supports. It is implemented as an interface to C<libeio>
35(L<http://software.schmorp.de/pkg/libeio.html>).
59 36
60Asynchronous means that operations that can normally block your program 37Asynchronous means that operations that can normally block your program
61(e.g. reading from disk) will be done asynchronously: the operation 38(e.g. reading from disk) will be done asynchronously: the operation
62will 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
63is 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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67on 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
68concurrently. 45concurrently.
69 46
70While most of this works on all types of file descriptors (for 47While most of this works on all types of file descriptors (for
71example sockets), using these functions on file descriptors that 48example sockets), using these functions on file descriptors that
72support nonblocking operation (again, sockets, pipes etc.) is very 49support nonblocking operation (again, sockets, pipes etc.) is
73inefficient. 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>
74module): IO::AIO will naturally fit into such an event loop itself. 51module): IO::AIO will naturally fit into such an event loop itself.
75 52
76In this version, a number of threads are started that execute your 53In this version, a number of threads are started that execute your
77requests and signal their completion. You don't need thread support 54requests and signal their completion. You don't need thread support
78in 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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88yourself, 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
89call C<poll_cb> (or other C<aio_> functions) recursively. 66call C<poll_cb> (or other C<aio_> functions) recursively.
90 67
91=head2 EXAMPLE 68=head2 EXAMPLE
92 69
93This is a simple example that uses the Event module and loads 70This is a simple example that uses the EV module and loads
94F</etc/passwd> asynchronously: 71F</etc/passwd> asynchronously:
95 72
96 use Fcntl; 73 use Fcntl;
97 use Event; 74 use EV;
98 use IO::AIO; 75 use IO::AIO;
99 76
100 # register the IO::AIO callback with Event 77 # register the IO::AIO callback with EV
101 Event->io (fd => IO::AIO::poll_fileno, 78 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 79
105 # queue the request to open /etc/passwd 80 # queue the request to open /etc/passwd
106 aio_open "/etc/passwd", O_RDONLY, 0, sub { 81 aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
107 my $fh = shift 82 my $fh = shift
108 or die "error while opening: $!"; 83 or die "error while opening: $!";
109 84
110 # stat'ing filehandles is generally non-blocking 85 # stat'ing filehandles is generally non-blocking
111 my $size = -s $fh; 86 my $size = -s $fh;
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120 95
121 # file contents now in $contents 96 # file contents now in $contents
122 print $contents; 97 print $contents;
123 98
124 # exit event loop and program 99 # exit event loop and program
125 Event::unloop; 100 EV::unloop;
126 }; 101 };
127 }; 102 };
128 103
129 # possibly queue up other requests, or open GUI windows, 104 # possibly queue up other requests, or open GUI windows,
130 # check for sockets etc. etc. 105 # check for sockets etc. etc.
131 106
132 # process events as long as there are some: 107 # process events as long as there are some:
133 Event::loop; 108 EV::loop;
134 109
135=head1 REQUEST ANATOMY AND LIFETIME 110=head1 REQUEST ANATOMY AND LIFETIME
136 111
137Every 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
138directly visible to Perl. 113directly visible to Perl.
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188 163
189package IO::AIO; 164package IO::AIO;
190 165
191use Carp (); 166use Carp ();
192 167
193no warnings; 168use common::sense;
194use strict 'vars';
195 169
196use base 'Exporter'; 170use base 'Exporter';
197 171
198BEGIN { 172BEGIN {
199 our $VERSION = '3.0'; 173 our $VERSION = '3.65';
200 174
201 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
202 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir 176 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
203 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync 177 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
204 aio_fdatasync aio_pathsync aio_readahead 178 aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
205 aio_rename aio_link aio_move aio_copy aio_group 179 aio_rename aio_link aio_move aio_copy aio_group
206 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
207 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);
208 184
209 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); 185 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
210 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 186 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
211 min_parallel max_parallel max_idle 187 min_parallel max_parallel max_idle
212 nreqs nready npending nthreads 188 nreqs nready npending nthreads
213 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
214 194
215 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 195 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
216 196
217 require XSLoader; 197 require XSLoader;
218 XSLoader::load ("IO::AIO", $VERSION); 198 XSLoader::load ("IO::AIO", $VERSION);
219} 199}
220 200
221=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::munlock $scalar, $offset = 0, $length = undef
271 IO::AIO::munlockall
222 272
223=head2 AIO REQUEST FUNCTIONS 273=head2 AIO REQUEST FUNCTIONS
224 274
225All the C<aio_*> calls are more or less thin wrappers around the syscall 275All the C<aio_*> calls are more or less thin wrappers around the syscall
226with the same name (sans C<aio_>). The arguments are similar or identical, 276with the same name (sans C<aio_>). The arguments are similar or identical,
227and they all accept an additional (and optional) C<$callback> argument 277and they all accept an additional (and optional) C<$callback> argument
228which must be a code reference. This code reference will get called with 278which 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 279the 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 280perl, which usually delivers "false") as its sole argument after the given
231syscall has been executed asynchronously. 281syscall has been executed asynchronously.
232 282
233All functions expecting a filehandle keep a copy of the filehandle 283All functions expecting a filehandle keep a copy of the filehandle
234internally until the request has finished. 284internally until the request has finished.
235 285
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249your pathnames to the locale (or other) encoding in effect in the user 299your pathnames to the locale (or other) encoding in effect in the user
250environment, d) use Glib::filename_from_unicode on unicode filenames or e) 300environment, d) use Glib::filename_from_unicode on unicode filenames or e)
251use something else to ensure your scalar has the correct contents. 301use something else to ensure your scalar has the correct contents.
252 302
253This works, btw. independent of the internal UTF-8 bit, which IO::AIO 303This works, btw. independent of the internal UTF-8 bit, which IO::AIO
254handles correctly wether it is set or not. 304handles correctly whether it is set or not.
255 305
256=over 4 306=over 4
257 307
258=item $prev_pri = aioreq_pri [$pri] 308=item $prev_pri = aioreq_pri [$pri]
259 309
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306by the umask in effect then the request is being executed, so better never 356by the umask in effect then the request is being executed, so better never
307change the umask. 357change the umask.
308 358
309Example: 359Example:
310 360
311 aio_open "/etc/passwd", O_RDONLY, 0, sub { 361 aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
312 if ($_[0]) { 362 if ($_[0]) {
313 print "open successful, fh is $_[0]\n"; 363 print "open successful, fh is $_[0]\n";
314 ... 364 ...
315 } else { 365 } else {
316 die "open failed: $!\n"; 366 die "open failed: $!\n";
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337 387
338=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 388=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
339 389
340=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 390=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
341 391
342Reads or writes C<$length> bytes from the specified C<$fh> and C<$offset> 392Reads or writes C<$length> bytes from or to the specified C<$fh> and
343into the scalar given by C<$data> and offset C<$dataoffset> and calls the 393C<$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 394and calls the callback without the actual number of bytes read (or -1 on
345like the syscall). 395error, just like the syscall).
396
397C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
398offset plus the actual number of bytes read.
346 399
347If C<$offset> is undefined, then the current file descriptor offset will 400If C<$offset> is undefined, then the current file descriptor offset will
348be used (and updated), otherwise the file descriptor offset will not be 401be used (and updated), otherwise the file descriptor offset will not be
349changed by these calls. 402changed by these calls.
350 403
351If C<$length> is undefined in C<aio_write>, use the remaining length of C<$data>. 404If C<$length> is undefined in C<aio_write>, use the remaining length of
405C<$data>.
352 406
353If C<$dataoffset> is less than zero, it will be counted from the end of 407If C<$dataoffset> is less than zero, it will be counted from the end of
354C<$data>. 408C<$data>.
355 409
356The C<$data> scalar I<MUST NOT> be modified in any way while the request 410The C<$data> scalar I<MUST NOT> be modified in any way while the request
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374than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each 428than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
375other. 429other.
376 430
377This call tries to make use of a native C<sendfile> syscall to provide 431This call tries to make use of a native C<sendfile> syscall to provide
378zero-copy operation. For this to work, C<$out_fh> should refer to a 432zero-copy operation. For this to work, C<$out_fh> should refer to a
379socket, and C<$in_fh> should refer to mmap'able file. 433socket, and C<$in_fh> should refer to an mmap'able file.
380 434
381If the native sendfile call fails or is not implemented, it will be 435If a native sendfile cannot be found or it fails with C<ENOSYS>,
436C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
382emulated, so you can call C<aio_sendfile> on any type of filehandle 437it will be emulated, so you can call C<aio_sendfile> on any type of
383regardless of the limitations of the operating system. 438filehandle regardless of the limitations of the operating system.
384 439
385Please note, however, that C<aio_sendfile> can read more bytes from 440Please note, however, that C<aio_sendfile> can read more bytes from
386C<$in_fh> than are written, and there is no way to find out how many 441C<$in_fh> than are written, and there is no way to find out how many
387bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only 442bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
388provides the number of bytes written to C<$out_fh>. Only if the result 443provides the number of bytes written to C<$out_fh>. Only if the result
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426 $_[0] and die "stat failed: $!"; 481 $_[0] and die "stat failed: $!";
427 print "size is ", -s _, "\n"; 482 print "size is ", -s _, "\n";
428 }; 483 };
429 484
430 485
486=item aio_statvfs $fh_or_path, $callback->($statvfs)
487
488Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
489whether a file handle or path was passed.
490
491On success, the callback is passed a hash reference with the following
492members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
493C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
494is passed.
495
496The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
497C<ST_NOSUID>.
498
499The following non-POSIX IO::AIO::ST_* flag masks are defined to
500their correct value when available, or to C<0> on systems that do
501not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
502C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
503C<ST_NODIRATIME> and C<ST_RELATIME>.
504
505Example: stat C</wd> and dump out the data if successful.
506
507 aio_statvfs "/wd", sub {
508 my $f = $_[0]
509 or die "statvfs: $!";
510
511 use Data::Dumper;
512 say Dumper $f;
513 };
514
515 # result:
516 {
517 bsize => 1024,
518 bfree => 4333064312,
519 blocks => 10253828096,
520 files => 2050765568,
521 flag => 4096,
522 favail => 2042092649,
523 bavail => 4333064312,
524 ffree => 2042092649,
525 namemax => 255,
526 frsize => 1024,
527 fsid => 1810
528 }
529
530
431=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 531=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
432 532
433Works like perl's C<utime> function (including the special case of $atime 533Works like perl's C<utime> function (including the special case of $atime
434and $mtime being undef). Fractional times are supported if the underlying 534and $mtime being undef). Fractional times are supported if the underlying
435syscalls support them. 535syscalls support them.
… …
528 628
529Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 629Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
530directory (i.e. opendir + readdir + closedir). The entries will not be 630directory (i.e. opendir + readdir + closedir). The entries will not be
531sorted, and will B<NOT> include the C<.> and C<..> entries. 631sorted, and will B<NOT> include the C<.> and C<..> entries.
532 632
533The callback a single argument which is either C<undef> or an array-ref 633The callback is passed a single argument which is either C<undef> or an
534with the filenames. 634array-ref with the filenames.
635
636
637=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
638
639Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
640behaviour and output format. In case of an error, C<$entries> will be
641C<undef>.
642
643The flags are a combination of the following constants, ORed together (the
644flags will also be passed to the callback, possibly modified):
645
646=over 4
647
648=item IO::AIO::READDIR_DENTS
649
650When this flag is off, then the callback gets an arrayref with of names
651only (as with C<aio_readdir>), otherwise it gets an arrayref with
652C<[$name, $type, $inode]> arrayrefs, each describing a single directory
653entry in more detail.
654
655C<$name> is the name of the entry.
656
657C<$type> is one of the C<IO::AIO::DT_xxx> constants:
658
659C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
660C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
661C<IO::AIO::DT_WHT>.
662
663C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
664know, you have to run stat yourself. Also, for speed reasons, the C<$type>
665scalars are read-only: you can not modify them.
666
667C<$inode> is the inode number (which might not be exact on systems with 64
668bit inode numbers and 32 bit perls). This field has unspecified content on
669systems that do not deliver the inode information.
670
671=item IO::AIO::READDIR_DIRS_FIRST
672
673When this flag is set, then the names will be returned in an order where
674likely directories come first. This is useful when you need to quickly
675find directories, or you want to find all directories while avoiding to
676stat() each entry.
677
678If the system returns type information in readdir, then this is used
679to find directories directly. Otherwise, likely directories are files
680beginning with ".", or otherwise files with no dots, of which files with
681short names are tried first.
682
683=item IO::AIO::READDIR_STAT_ORDER
684
685When this flag is set, then the names will be returned in an order
686suitable for stat()'ing each one. That is, when you plan to stat()
687all files in the given directory, then the returned order will likely
688be fastest.
689
690If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
691the likely dirs come first, resulting in a less optimal stat order.
692
693=item IO::AIO::READDIR_FOUND_UNKNOWN
694
695This flag should not be set when calling C<aio_readdirx>. Instead, it
696is being set by C<aio_readdirx>, when any of the C<$type>'s found were
697C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
698C<$type>'s are known, which can be used to speed up some algorithms.
699
700=back
535 701
536 702
537=item aio_load $path, $data, $callback->($status) 703=item aio_load $path, $data, $callback->($status)
538 704
539This is a composite request that tries to fully load the given file into 705This is a composite request that tries to fully load the given file into
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564 730
565=item aio_copy $srcpath, $dstpath, $callback->($status) 731=item aio_copy $srcpath, $dstpath, $callback->($status)
566 732
567Try to copy the I<file> (directories not supported as either source or 733Try to copy the I<file> (directories not supported as either source or
568destination) from C<$srcpath> to C<$dstpath> and call the callback with 734destination) from C<$srcpath> to C<$dstpath> and call the callback with
569the C<0> (error) or C<-1> ok. 735a status of C<0> (ok) or C<-1> (error, see C<$!>).
570 736
571This is a composite request that it creates the destination file with 737This is a composite request that creates the destination file with
572mode 0200 and copies the contents of the source file into it using 738mode 0200 and copies the contents of the source file into it using
573C<aio_sendfile>, followed by restoring atime, mtime, access mode and 739C<aio_sendfile>, followed by restoring atime, mtime, access mode and
574uid/gid, in that order. 740uid/gid, in that order.
575 741
576If an error occurs, the partial destination file will be unlinked, if 742If an error occurs, the partial destination file will be unlinked, if
… …
586 my $grp = aio_group $cb; 752 my $grp = aio_group $cb;
587 753
588 aioreq_pri $pri; 754 aioreq_pri $pri;
589 add $grp aio_open $src, O_RDONLY, 0, sub { 755 add $grp aio_open $src, O_RDONLY, 0, sub {
590 if (my $src_fh = $_[0]) { 756 if (my $src_fh = $_[0]) {
591 my @stat = stat $src_fh; 757 my @stat = stat $src_fh; # hmm, might block over nfs?
592 758
593 aioreq_pri $pri; 759 aioreq_pri $pri;
594 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub { 760 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
595 if (my $dst_fh = $_[0]) { 761 if (my $dst_fh = $_[0]) {
596 aioreq_pri $pri; 762 aioreq_pri $pri;
597 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 763 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
598 if ($_[0] == $stat[7]) { 764 if ($_[0] == $stat[7]) {
599 $grp->result (0); 765 $grp->result (0);
600 close $src_fh; 766 close $src_fh;
601 767
602 # those should not normally block. should. should. 768 my $ch = sub {
603 utime $stat[8], $stat[9], $dst; 769 aioreq_pri $pri;
604 chmod $stat[2] & 07777, $dst_fh; 770 add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
605 chown $stat[4], $stat[5], $dst_fh; 771 aioreq_pri $pri;
772 add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
773 aioreq_pri $pri;
774 add $grp aio_close $dst_fh;
775 }
776 };
777 };
606 778
607 aioreq_pri $pri; 779 aioreq_pri $pri;
608 add $grp aio_close $dst_fh; 780 add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
781 if ($_[0] < 0 && $! == ENOSYS) {
782 aioreq_pri $pri;
783 add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
784 } else {
785 $ch->();
786 }
787 };
609 } else { 788 } else {
610 $grp->result (-1); 789 $grp->result (-1);
611 close $src_fh; 790 close $src_fh;
612 close $dst_fh; 791 close $dst_fh;
613 792
… …
630 809
631=item aio_move $srcpath, $dstpath, $callback->($status) 810=item aio_move $srcpath, $dstpath, $callback->($status)
632 811
633Try to move the I<file> (directories not supported as either source or 812Try to move the I<file> (directories not supported as either source or
634destination) from C<$srcpath> to C<$dstpath> and call the callback with 813destination) from C<$srcpath> to C<$dstpath> and call the callback with
635the C<0> (error) or C<-1> ok. 814a status of C<0> (ok) or C<-1> (error, see C<$!>).
636 815
637This is a composite request that tries to rename(2) the file first. If 816This is a composite request that tries to rename(2) the file first; if
638rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if 817rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
639that is successful, unlinking the C<$srcpath>. 818that is successful, unlinks the C<$srcpath>.
640 819
641=cut 820=cut
642 821
643sub aio_move($$;$) { 822sub aio_move($$;$) {
644 my ($src, $dst, $cb) = @_; 823 my ($src, $dst, $cb) = @_;
… …
691 870
692Implementation notes. 871Implementation notes.
693 872
694The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can. 873The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
695 874
875If readdir returns file type information, then this is used directly to
876find directories.
877
696After reading the directory, the modification time, size etc. of the 878Otherwise, after reading the directory, the modification time, size etc.
697directory before and after the readdir is checked, and if they match (and 879of the directory before and after the readdir is checked, and if they
698isn't the current time), the link count will be used to decide how many 880match (and isn't the current time), the link count will be used to decide
699entries are directories (if >= 2). Otherwise, no knowledge of the number 881how many entries are directories (if >= 2). Otherwise, no knowledge of the
700of subdirectories will be assumed. 882number of subdirectories will be assumed.
701 883
702Then entries will be sorted into likely directories (everything without 884Then entries will be sorted into likely directories a non-initial dot
703a non-initial dot currently) and likely non-directories (everything 885currently) and likely non-directories (see C<aio_readdirx>). Then every
704else). Then every entry plus an appended C</.> will be C<stat>'ed, 886entry plus an appended C</.> will be C<stat>'ed, likely directories first,
705likely directories first. If that succeeds, it assumes that the entry 887in order of their inode numbers. If that succeeds, it assumes that the
706is a directory or a symlink to directory (which will be checked 888entry is a directory or a symlink to directory (which will be checked
707seperately). This is often faster than stat'ing the entry itself because 889seperately). This is often faster than stat'ing the entry itself because
708filesystems might detect the type of the entry without reading the inode 890filesystems might detect the type of the entry without reading the inode
709data (e.g. ext2fs filetype feature). 891data (e.g. ext2fs filetype feature), even on systems that cannot return
892the filetype information on readdir.
710 893
711If the known number of directories (link count - 2) has been reached, the 894If the known number of directories (link count - 2) has been reached, the
712rest of the entries is assumed to be non-directories. 895rest of the entries is assumed to be non-directories.
713 896
714This only works with certainty on POSIX (= UNIX) filesystems, which 897This only works with certainty on POSIX (= UNIX) filesystems, which
… …
736 my $now = time; 919 my $now = time;
737 my $hash1 = join ":", (stat _)[0,1,3,7,9]; 920 my $hash1 = join ":", (stat _)[0,1,3,7,9];
738 921
739 # read the directory entries 922 # read the directory entries
740 aioreq_pri $pri; 923 aioreq_pri $pri;
741 add $grp aio_readdir $path, sub { 924 add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
742 my $entries = shift 925 my $entries = shift
743 or return $grp->result (); 926 or return $grp->result ();
744 927
745 # stat the dir another time 928 # stat the dir another time
746 aioreq_pri $pri; 929 aioreq_pri $pri;
… …
752 # take the slow route if anything looks fishy 935 # take the slow route if anything looks fishy
753 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 936 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
754 $ndirs = -1; 937 $ndirs = -1;
755 } else { 938 } else {
756 # if nlink == 2, we are finished 939 # if nlink == 2, we are finished
757 # on non-posix-fs's, we rely on nlink < 2 940 # for non-posix-fs's, we rely on nlink < 2
758 $ndirs = (stat _)[3] - 2 941 $ndirs = (stat _)[3] - 2
759 or return $grp->result ([], $entries); 942 or return $grp->result ([], $entries);
760 } 943 }
761 944
762 # sort into likely dirs and likely nondirs
763 # dirs == files without ".", short entries first
764 $entries = [map $_->[0],
765 sort { $b->[1] cmp $a->[1] }
766 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
767 @$entries];
768
769 my (@dirs, @nondirs); 945 my (@dirs, @nondirs);
770 946
771 my $statgrp = add $grp aio_group sub { 947 my $statgrp = add $grp aio_group sub {
772 $grp->result (\@dirs, \@nondirs); 948 $grp->result (\@dirs, \@nondirs);
773 }; 949 };
774 950
775 limit $statgrp $maxreq; 951 limit $statgrp $maxreq;
776 feed $statgrp sub { 952 feed $statgrp sub {
777 return unless @$entries; 953 return unless @$entries;
778 my $entry = pop @$entries; 954 my $entry = shift @$entries;
779 955
780 aioreq_pri $pri; 956 aioreq_pri $pri;
781 add $statgrp aio_stat "$path/$entry/.", sub { 957 add $statgrp aio_stat "$path/$entry/.", sub {
782 if ($_[0] < 0) { 958 if ($_[0] < 0) {
783 push @nondirs, $entry; 959 push @nondirs, $entry;
… …
856callback with the fdatasync result code. 1032callback with the fdatasync result code.
857 1033
858If this call isn't available because your OS lacks it or it couldn't be 1034If this call isn't available because your OS lacks it or it couldn't be
859detected, it will be emulated by calling C<fsync> instead. 1035detected, it will be emulated by calling C<fsync> instead.
860 1036
1037=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
1038
1039Sync the data portion of the file specified by C<$offset> and C<$length>
1040to disk (but NOT the metadata), by calling the Linux-specific
1041sync_file_range call. If sync_file_range is not available or it returns
1042ENOSYS, then fdatasync or fsync is being substituted.
1043
1044C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
1045C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
1046C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
1047manpage for details.
1048
861=item aio_pathsync $path, $callback->($status) 1049=item aio_pathsync $path, $callback->($status)
862 1050
863This request tries to open, fsync and close the given path. This is a 1051This request tries to open, fsync and close the given path. This is a
864composite request intended tosync directories after directory operations 1052composite request intended to sync directories after directory operations
865(E.g. rename). This might not work on all operating systems or have any 1053(E.g. rename). This might not work on all operating systems or have any
866specific effect, but usually it makes sure that directory changes get 1054specific effect, but usually it makes sure that directory changes get
867written to disc. It works for anything that can be opened for read-only, 1055written to disc. It works for anything that can be opened for read-only,
868not just directories. 1056not just directories.
1057
1058Future versions of this function might fall back to other methods when
1059C<fsync> on the directory fails (such as calling C<sync>).
869 1060
870Passes C<0> when everything went ok, and C<-1> on error. 1061Passes C<0> when everything went ok, and C<-1> on error.
871 1062
872=cut 1063=cut
873 1064
… …
894 }; 1085 };
895 1086
896 $grp 1087 $grp
897} 1088}
898 1089
1090=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1091
1092This is a rather advanced IO::AIO call, which only works on mmap(2)ed
1093scalars (see the C<IO::AIO::mmap> function, although it also works on data
1094scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
1095scalar must only be modified in-place while an aio operation is pending on
1096it).
1097
1098It calls the C<msync> function of your OS, if available, with the memory
1099area starting at C<$offset> in the string and ending C<$length> bytes
1100later. If C<$length> is negative, counts from the end, and if C<$length>
1101is C<undef>, then it goes till the end of the string. The flags can be
1102a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
1103C<IO::AIO::MS_SYNC>.
1104
1105=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1106
1107This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1108scalars.
1109
1110It touches (reads or writes) all memory pages in the specified
1111range inside the scalar. All caveats and parameters are the same
1112as for C<aio_msync>, above, except for flags, which must be either
1113C<0> (which reads all pages and ensures they are instantiated) or
1114C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
1115writing an octet from it, which dirties the page).
1116
1117=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1118
1119This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1120scalars.
1121
1122It reads in all the pages of the underlying storage into memory (if any)
1123and locks them, so they are not getting swapped/paged out or removed.
1124
1125If C<$length> is undefined, then the scalar will be locked till the end.
1126
1127On systems that do not implement C<mlock>, this function returns C<-1>
1128and sets errno to C<ENOSYS>.
1129
1130Note that the corresponding C<munlock> is synchronous and is
1131documented under L<MISCELLANEOUS FUNCTIONS>.
1132
1133Example: open a file, mmap and mlock it - both will be undone when
1134C<$data> gets destroyed.
1135
1136 open my $fh, "<", $path or die "$path: $!";
1137 my $data;
1138 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
1139 aio_mlock $data; # mlock in background
1140
1141=item aio_mlockall $flags, $callback->($status)
1142
1143Calls the C<mlockall> function with the given C<$flags> (a combination of
1144C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).
1145
1146On systems that do not implement C<mlockall>, this function returns C<-1>
1147and sets errno to C<ENOSYS>.
1148
1149Note that the corresponding C<munlockall> is synchronous and is
1150documented under L<MISCELLANEOUS FUNCTIONS>.
1151
1152Example: asynchronously lock all current and future pages into memory.
1153
1154 aio_mlockall IO::AIO::MCL_FUTURE;
1155
899=item aio_group $callback->(...) 1156=item aio_group $callback->(...)
900 1157
901This is a very special aio request: Instead of doing something, it is a 1158This is a very special aio request: Instead of doing something, it is a
902container for other aio requests, which is useful if you want to bundle 1159container for other aio requests, which is useful if you want to bundle
903many requests into a single, composite, request with a definite callback 1160many requests into a single, composite, request with a definite callback
… …
952=item cancel $req 1209=item cancel $req
953 1210
954Cancels the request, if possible. Has the effect of skipping execution 1211Cancels the request, if possible. Has the effect of skipping execution
955when entering the B<execute> state and skipping calling the callback when 1212when entering the B<execute> state and skipping calling the callback when
956entering the the B<result> state, but will leave the request otherwise 1213entering the the B<result> state, but will leave the request otherwise
957untouched. That means that requests that currently execute will not be 1214untouched (with the exception of readdir). That means that requests that
958stopped and resources held by the request will not be freed prematurely. 1215currently execute will not be stopped and resources held by the request
1216will not be freed prematurely.
959 1217
960=item cb $req $callback->(...) 1218=item cb $req $callback->(...)
961 1219
962Replace (or simply set) the callback registered to the request. 1220Replace (or simply set) the callback registered to the request.
963 1221
… …
1014Their lifetime, simplified, looks like this: when they are empty, they 1272Their lifetime, simplified, looks like this: when they are empty, they
1015will finish very quickly. If they contain only requests that are in the 1273will finish very quickly. If they contain only requests that are in the
1016C<done> state, they will also finish. Otherwise they will continue to 1274C<done> state, they will also finish. Otherwise they will continue to
1017exist. 1275exist.
1018 1276
1019That means after creating a group you have some time to add requests. And 1277That means after creating a group you have some time to add requests
1020in the callbacks of those requests, you can add further requests to the 1278(precisely before the callback has been invoked, which is only done within
1021group. And only when all those requests have finished will the the group 1279the C<poll_cb>). And in the callbacks of those requests, you can add
1022itself finish. 1280further requests to the group. And only when all those requests have
1281finished will the the group itself finish.
1023 1282
1024=over 4 1283=over 4
1025 1284
1026=item add $grp ... 1285=item add $grp ...
1027 1286
… …
1035 1294
1036=item $grp->cancel_subs 1295=item $grp->cancel_subs
1037 1296
1038Cancel all subrequests and clears any feeder, but not the group request 1297Cancel 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. 1298itself. Useful when you queued a lot of events but got a result early.
1299
1300The group request will finish normally (you cannot add requests to the
1301group).
1040 1302
1041=item $grp->result (...) 1303=item $grp->result (...)
1042 1304
1043Set the result value(s) that will be passed to the group callback when all 1305Set 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 1306subrequests have finished and set the groups errno to the current value
… …
1060=item feed $grp $callback->($grp) 1322=item feed $grp $callback->($grp)
1061 1323
1062Sets a feeder/generator on this group: every group can have an attached 1324Sets a feeder/generator on this group: every group can have an attached
1063generator that generates requests if idle. The idea behind this is that, 1325generator 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, 1326although you could just queue as many requests as you want in a group,
1065this might starve other requests for a potentially long time. For 1327this might starve other requests for a potentially long time. For example,
1066example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1328C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1067requests, delaying any later requests for a long time. 1329delaying any later requests for a long time.
1068 1330
1069To avoid this, and allow incremental generation of requests, you can 1331To avoid this, and allow incremental generation of requests, you can
1070instead a group and set a feeder on it that generates those requests. The 1332instead 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>, 1333feed 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 1334below) requests active in the group itself and is expected to queue more
… …
1076not impose any limits). 1338not impose any limits).
1077 1339
1078If the feed does not queue more requests when called, it will be 1340If the feed does not queue more requests when called, it will be
1079automatically removed from the group. 1341automatically removed from the group.
1080 1342
1081If the feed limit is C<0>, it will be set to C<2> automatically. 1343If the feed limit is C<0> when this method is called, it will be set to
1344C<2> automatically.
1082 1345
1083Example: 1346Example:
1084 1347
1085 # stat all files in @files, but only ever use four aio requests concurrently: 1348 # stat all files in @files, but only ever use four aio requests concurrently:
1086 1349
… …
1098Sets the feeder limit for the group: The feeder will be called whenever 1361Sets the feeder limit for the group: The feeder will be called whenever
1099the group contains less than this many requests. 1362the group contains less than this many requests.
1100 1363
1101Setting the limit to C<0> will pause the feeding process. 1364Setting the limit to C<0> will pause the feeding process.
1102 1365
1366The default value for the limit is C<0>, but note that setting a feeder
1367automatically bumps it up to C<2>.
1368
1103=back 1369=back
1104 1370
1105=head2 SUPPORT FUNCTIONS 1371=head2 SUPPORT FUNCTIONS
1106 1372
1107=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1373=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
… …
1109=over 4 1375=over 4
1110 1376
1111=item $fileno = IO::AIO::poll_fileno 1377=item $fileno = IO::AIO::poll_fileno
1112 1378
1113Return the I<request result pipe file descriptor>. This filehandle must be 1379Return the I<request result pipe file descriptor>. This filehandle must be
1114polled for reading by some mechanism outside this module (e.g. Event or 1380polled 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 1381select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1116to call C<poll_cb> to check the results. 1382you have to call C<poll_cb> to check the results.
1117 1383
1118See C<poll_cb> for an example. 1384See C<poll_cb> for an example.
1119 1385
1120=item IO::AIO::poll_cb 1386=item IO::AIO::poll_cb
1121 1387
1122Process some outstanding events on the result pipe. You have to call this 1388Process some outstanding events on the result pipe. You have to call this
1123regularly. Returns the number of events processed. Returns immediately 1389regularly. Returns C<0> if all events could be processed, or C<-1> if it
1390returned earlier for whatever reason. Returns immediately when no events
1124when no events are outstanding. The amount of events processed depends on 1391are outstanding. The amount of events processed depends on the settings of
1125the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>. 1392C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1126 1393
1127If not all requests were processed for whatever reason, the filehandle 1394If not all requests were processed for whatever reason, the filehandle
1128will still be ready when C<poll_cb> returns. 1395will still be ready when C<poll_cb> returns, so normally you don't have to
1396do anything special to have it called later.
1129 1397
1130Example: Install an Event watcher that automatically calls 1398Example: Install an Event watcher that automatically calls
1131IO::AIO::poll_cb with high priority: 1399IO::AIO::poll_cb with high priority (more examples can be found in the
1400SYNOPSIS section, at the top of this document):
1132 1401
1133 Event->io (fd => IO::AIO::poll_fileno, 1402 Event->io (fd => IO::AIO::poll_fileno,
1134 poll => 'r', async => 1, 1403 poll => 'r', async => 1,
1135 cb => \&IO::AIO::poll_cb); 1404 cb => \&IO::AIO::poll_cb);
1405
1406=item IO::AIO::poll_wait
1407
1408If there are any outstanding requests and none of them in the result
1409phase, wait till the result filehandle becomes ready for reading (simply
1410does a C<select> on the filehandle. This is useful if you want to
1411synchronously wait for some requests to finish).
1412
1413See C<nreqs> for an example.
1414
1415=item IO::AIO::poll
1416
1417Waits until some requests have been handled.
1418
1419Returns the number of requests processed, but is otherwise strictly
1420equivalent to:
1421
1422 IO::AIO::poll_wait, IO::AIO::poll_cb
1423
1424=item IO::AIO::flush
1425
1426Wait till all outstanding AIO requests have been handled.
1427
1428Strictly equivalent to:
1429
1430 IO::AIO::poll_wait, IO::AIO::poll_cb
1431 while IO::AIO::nreqs;
1136 1432
1137=item IO::AIO::max_poll_reqs $nreqs 1433=item IO::AIO::max_poll_reqs $nreqs
1138 1434
1139=item IO::AIO::max_poll_time $seconds 1435=item IO::AIO::max_poll_time $seconds
1140 1436
… …
1165 # use a low priority so other tasks have priority 1461 # use a low priority so other tasks have priority
1166 Event->io (fd => IO::AIO::poll_fileno, 1462 Event->io (fd => IO::AIO::poll_fileno,
1167 poll => 'r', nice => 1, 1463 poll => 'r', nice => 1,
1168 cb => &IO::AIO::poll_cb); 1464 cb => &IO::AIO::poll_cb);
1169 1465
1170=item IO::AIO::poll_wait
1171
1172If there are any outstanding requests and none of them in the result
1173phase, wait till the result filehandle becomes ready for reading (simply
1174does a C<select> on the filehandle. This is useful if you want to
1175synchronously wait for some requests to finish).
1176
1177See C<nreqs> for an example.
1178
1179=item IO::AIO::poll
1180
1181Waits until some requests have been handled.
1182
1183Returns the number of requests processed, but is otherwise strictly
1184equivalent to:
1185
1186 IO::AIO::poll_wait, IO::AIO::poll_cb
1187
1188=item IO::AIO::flush
1189
1190Wait till all outstanding AIO requests have been handled.
1191
1192Strictly equivalent to:
1193
1194 IO::AIO::poll_wait, IO::AIO::poll_cb
1195 while IO::AIO::nreqs;
1196
1197=back 1466=back
1198 1467
1199=head3 CONTROLLING THE NUMBER OF THREADS 1468=head3 CONTROLLING THE NUMBER OF THREADS
1200 1469
1201=over 1470=over
… …
1293Returns the number of requests currently in the pending state (executed, 1562Returns the number of requests currently in the pending state (executed,
1294but not yet processed by poll_cb). 1563but not yet processed by poll_cb).
1295 1564
1296=back 1565=back
1297 1566
1567=head3 MISCELLANEOUS FUNCTIONS
1568
1569IO::AIO implements some functions that might be useful, but are not
1570asynchronous.
1571
1572=over 4
1573
1574=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1575
1576Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
1577but is blocking (this makes most sense if you know the input data is
1578likely cached already and the output filehandle is set to non-blocking
1579operations).
1580
1581Returns the number of bytes copied, or C<-1> on error.
1582
1583=item IO::AIO::fadvise $fh, $offset, $len, $advice
1584
1585Simply calls the C<posix_fadvise> function (see it's
1586manpage for details). The following advice constants are
1587avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1588C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1589C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1590
1591On systems that do not implement C<posix_fadvise>, this function returns
1592ENOSYS, otherwise the return value of C<posix_fadvise>.
1593
1594=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1595
1596Memory-maps a file (or anonymous memory range) and attaches it to the
1597given C<$scalar>, which will act like a string scalar.
1598
1599The only operations allowed on the scalar are C<substr>/C<vec> that don't
1600change the string length, and most read-only operations such as copying it
1601or searching it with regexes and so on.
1602
1603Anything else is unsafe and will, at best, result in memory leaks.
1604
1605The memory map associated with the C<$scalar> is automatically removed
1606when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
1607C<IO::AIO::munmap> functions are called.
1608
1609This calls the C<mmap>(2) function internally. See your system's manual
1610page for details on the C<$length>, C<$prot> and C<$flags> parameters.
1611
1612The C<$length> must be larger than zero and smaller than the actual
1613filesize.
1614
1615C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1616C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1617
1618C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
1619C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
1620not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
1621(which is set to C<MAP_ANON> if your system only provides this
1622constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
1623C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
1624C<IO::AIO::MAP_NONBLOCK>
1625
1626If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1627
1628C<$offset> is the offset from the start of the file - it generally must be
1629a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
1630
1631Example:
1632
1633 use Digest::MD5;
1634 use IO::AIO;
1635
1636 open my $fh, "<verybigfile"
1637 or die "$!";
1638
1639 IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
1640 or die "verybigfile: $!";
1641
1642 my $fast_md5 = md5 $data;
1643
1644=item IO::AIO::munmap $scalar
1645
1646Removes a previous mmap and undefines the C<$scalar>.
1647
1648=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
1649
1650Calls the C<munlock> function, undoing the effects of a previous
1651C<aio_mlock> call (see its description for details).
1652
1653=item IO::AIO::munlockall
1654
1655Calls the C<munlockall> function.
1656
1657On systems that do not implement C<munlockall>, this function returns
1658ENOSYS, otherwise the return value of C<munlockall>.
1659
1660=back
1661
1298=cut 1662=cut
1299 1663
1300min_parallel 8; 1664min_parallel 8;
1301 1665
1302END { flush } 1666END { flush }
1303 1667
13041; 16681;
1669
1670=head1 EVENT LOOP INTEGRATION
1671
1672It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
1673automatically into many event loops:
1674
1675 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
1676 use AnyEvent::AIO;
1677
1678You can also integrate IO::AIO manually into many event loops, here are
1679some examples of how to do this:
1680
1681 # EV integration
1682 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
1683
1684 # Event integration
1685 Event->io (fd => IO::AIO::poll_fileno,
1686 poll => 'r',
1687 cb => \&IO::AIO::poll_cb);
1688
1689 # Glib/Gtk2 integration
1690 add_watch Glib::IO IO::AIO::poll_fileno,
1691 in => sub { IO::AIO::poll_cb; 1 };
1692
1693 # Tk integration
1694 Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
1695 readable => \&IO::AIO::poll_cb);
1696
1697 # Danga::Socket integration
1698 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
1699 \&IO::AIO::poll_cb);
1305 1700
1306=head2 FORK BEHAVIOUR 1701=head2 FORK BEHAVIOUR
1307 1702
1308This module should do "the right thing" when the process using it forks: 1703This module should do "the right thing" when the process using it forks:
1309 1704
… …
1342 1737
1343Known bugs will be fixed in the next release. 1738Known bugs will be fixed in the next release.
1344 1739
1345=head1 SEE ALSO 1740=head1 SEE ALSO
1346 1741
1347L<Coro::AIO>. 1742L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1743more natural syntax.
1348 1744
1349=head1 AUTHOR 1745=head1 AUTHOR
1350 1746
1351 Marc Lehmann <schmorp@schmorp.de> 1747 Marc Lehmann <schmorp@schmorp.de>
1352 http://home.schmorp.de/ 1748 http://home.schmorp.de/

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