ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/IO-AIO/AIO.pm
(Generate patch)

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.123 by root, Sat May 10 18:06:41 2008 UTC vs.
Revision 1.193 by root, Thu May 26 04:15:37 2011 UTC

… …
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
… …
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
… …
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
… …
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;
… …
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.
… …
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 = '2.62'; 173 our $VERSION = '3.8';
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 idle_timeout
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::idle_timeout $seconds
264 IO::AIO::max_outstanding $maxreqs
265 IO::AIO::nreqs
266 IO::AIO::nready
267 IO::AIO::npending
268
269 IO::AIO::sendfile $ofh, $ifh, $offset, $count
270 IO::AIO::fadvise $fh, $offset, $len, $advice
271 IO::AIO::madvise $scalar, $offset, $length, $advice
272 IO::AIO::mprotect $scalar, $offset, $length, $protect
273 IO::AIO::munlock $scalar, $offset = 0, $length = undef
274 IO::AIO::munlockall
222 275
223=head2 AIO REQUEST FUNCTIONS 276=head2 AIO REQUEST FUNCTIONS
224 277
225All the C<aio_*> calls are more or less thin wrappers around the syscall 278All the C<aio_*> calls are more or less thin wrappers around the syscall
226with the same name (sans C<aio_>). The arguments are similar or identical, 279with the same name (sans C<aio_>). The arguments are similar or identical,
227and they all accept an additional (and optional) C<$callback> argument 280and they all accept an additional (and optional) C<$callback> argument
228which must be a code reference. This code reference will get called with 281which 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 282the 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 283perl, which usually delivers "false") as its sole argument after the given
231syscall has been executed asynchronously. 284syscall has been executed asynchronously.
232 285
233All functions expecting a filehandle keep a copy of the filehandle 286All functions expecting a filehandle keep a copy of the filehandle
234internally until the request has finished. 287internally until the request has finished.
235 288
… …
249your pathnames to the locale (or other) encoding in effect in the user 302your pathnames to the locale (or other) encoding in effect in the user
250environment, d) use Glib::filename_from_unicode on unicode filenames or e) 303environment, d) use Glib::filename_from_unicode on unicode filenames or e)
251use something else to ensure your scalar has the correct contents. 304use something else to ensure your scalar has the correct contents.
252 305
253This works, btw. independent of the internal UTF-8 bit, which IO::AIO 306This works, btw. independent of the internal UTF-8 bit, which IO::AIO
254handles correctly wether it is set or not. 307handles correctly whether it is set or not.
255 308
256=over 4 309=over 4
257 310
258=item $prev_pri = aioreq_pri [$pri] 311=item $prev_pri = aioreq_pri [$pri]
259 312
… …
306by the umask in effect then the request is being executed, so better never 359by the umask in effect then the request is being executed, so better never
307change the umask. 360change the umask.
308 361
309Example: 362Example:
310 363
311 aio_open "/etc/passwd", O_RDONLY, 0, sub { 364 aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
312 if ($_[0]) { 365 if ($_[0]) {
313 print "open successful, fh is $_[0]\n"; 366 print "open successful, fh is $_[0]\n";
314 ... 367 ...
315 } else { 368 } else {
316 die "open failed: $!\n"; 369 die "open failed: $!\n";
… …
337 390
338=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 391=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
339 392
340=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 393=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
341 394
342Reads or writes C<$length> bytes from the specified C<$fh> and C<$offset> 395Reads or writes C<$length> bytes from or to the specified C<$fh> and
343into the scalar given by C<$data> and offset C<$dataoffset> and calls the 396C<$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 397and calls the callback without the actual number of bytes read (or -1 on
345like the syscall). 398error, just like the syscall).
399
400C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
401offset plus the actual number of bytes read.
346 402
347If C<$offset> is undefined, then the current file descriptor offset will 403If C<$offset> is undefined, then the current file descriptor offset will
348be used (and updated), otherwise the file descriptor offset will not be 404be used (and updated), otherwise the file descriptor offset will not be
349changed by these calls. 405changed by these calls.
350 406
351If C<$length> is undefined in C<aio_write>, use the remaining length of C<$data>. 407If C<$length> is undefined in C<aio_write>, use the remaining length of
408C<$data>.
352 409
353If C<$dataoffset> is less than zero, it will be counted from the end of 410If C<$dataoffset> is less than zero, it will be counted from the end of
354C<$data>. 411C<$data>.
355 412
356The C<$data> scalar I<MUST NOT> be modified in any way while the request 413The C<$data> scalar I<MUST NOT> be modified in any way while the request
… …
372reading at byte offset C<$in_offset>, and starts writing at the current 429reading at byte offset C<$in_offset>, and starts writing at the current
373file offset of C<$out_fh>. Because of that, it is not safe to issue more 430file offset of C<$out_fh>. Because of that, it is not safe to issue more
374than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each 431than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
375other. 432other.
376 433
434Please note that C<aio_sendfile> can read more bytes from C<$in_fh> than
435are written, and there is no way to find out how many bytes have been read
436from C<aio_sendfile> alone, as C<aio_sendfile> only provides the number of
437bytes written to C<$out_fh>. Only if the result value equals C<$length>
438one can assume that C<$length> bytes have been read.
439
440Unlike with other C<aio_> functions, it makes a lot of sense to use
441C<aio_sendfile> on non-blocking sockets, as long as one end (typically
442the C<$in_fh>) is a file - the file I/O will then be asynchronous, while
443the socket I/O will be non-blocking. Note, however, that you can run into
444a trap where C<aio_sendfile> reads some data with readahead, then fails
445to write all data, and when the socket is ready the next time, the data
446in the cache is already lost, forcing C<aio_sendfile> to again hit the
447disk. Explicit C<aio_read> + C<aio_write> let's you control resource usage
448much better.
449
377This call tries to make use of a native C<sendfile> syscall to provide 450This call tries to make use of a native C<sendfile> syscall to provide
378zero-copy operation. For this to work, C<$out_fh> should refer to a 451zero-copy operation. For this to work, C<$out_fh> should refer to a
379socket, and C<$in_fh> should refer to mmap'able file. 452socket, and C<$in_fh> should refer to an mmap'able file.
380 453
381If the native sendfile call fails or is not implemented, it will be 454If a native sendfile cannot be found or it fails with C<ENOSYS>,
455C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
382emulated, so you can call C<aio_sendfile> on any type of filehandle 456it will be emulated, so you can call C<aio_sendfile> on any type of
383regardless of the limitations of the operating system. 457filehandle regardless of the limitations of the operating system.
384
385Please note, however, that C<aio_sendfile> can read more bytes from
386C<$in_fh> than are written, and there is no way to find out how many
387bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
388provides the number of bytes written to C<$out_fh>. Only if the result
389value equals C<$length> one can assume that C<$length> bytes have been
390read.
391 458
392 459
393=item aio_readahead $fh,$offset,$length, $callback->($retval) 460=item aio_readahead $fh,$offset,$length, $callback->($retval)
394 461
395C<aio_readahead> populates the page cache with data from a file so that 462C<aio_readahead> populates the page cache with data from a file so that
… …
418 485
419Currently, the stats are always 64-bit-stats, i.e. instead of returning an 486Currently, the stats are always 64-bit-stats, i.e. instead of returning an
420error when stat'ing a large file, the results will be silently truncated 487error when stat'ing a large file, the results will be silently truncated
421unless perl itself is compiled with large file support. 488unless perl itself is compiled with large file support.
422 489
490To help interpret the mode and dev/rdev stat values, IO::AIO offers the
491following constants and functions (if not implemented, the constants will
492be C<0> and the functions will either C<croak> or fall back on traditional
493behaviour).
494
495C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>,
496C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>,
497C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>.
498
423Example: Print the length of F</etc/passwd>: 499Example: Print the length of F</etc/passwd>:
424 500
425 aio_stat "/etc/passwd", sub { 501 aio_stat "/etc/passwd", sub {
426 $_[0] and die "stat failed: $!"; 502 $_[0] and die "stat failed: $!";
427 print "size is ", -s _, "\n"; 503 print "size is ", -s _, "\n";
428 }; 504 };
429 505
430 506
507=item aio_statvfs $fh_or_path, $callback->($statvfs)
508
509Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
510whether a file handle or path was passed.
511
512On success, the callback is passed a hash reference with the following
513members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
514C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
515is passed.
516
517The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
518C<ST_NOSUID>.
519
520The following non-POSIX IO::AIO::ST_* flag masks are defined to
521their correct value when available, or to C<0> on systems that do
522not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
523C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
524C<ST_NODIRATIME> and C<ST_RELATIME>.
525
526Example: stat C</wd> and dump out the data if successful.
527
528 aio_statvfs "/wd", sub {
529 my $f = $_[0]
530 or die "statvfs: $!";
531
532 use Data::Dumper;
533 say Dumper $f;
534 };
535
536 # result:
537 {
538 bsize => 1024,
539 bfree => 4333064312,
540 blocks => 10253828096,
541 files => 2050765568,
542 flag => 4096,
543 favail => 2042092649,
544 bavail => 4333064312,
545 ffree => 2042092649,
546 namemax => 255,
547 frsize => 1024,
548 fsid => 1810
549 }
550
551
431=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 552=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
432 553
433Works like perl's C<utime> function (including the special case of $atime 554Works like perl's C<utime> function (including the special case of $atime
434and $mtime being undef). Fractional times are supported if the underlying 555and $mtime being undef). Fractional times are supported if the underlying
435syscalls support them. 556syscalls support them.
… …
483 604
484The only (POSIX-) portable way of calling this function is: 605The only (POSIX-) portable way of calling this function is:
485 606
486 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... 607 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...
487 608
609See C<aio_stat> for info about some potentially helpful extra constants
610and functions.
488 611
489=item aio_link $srcpath, $dstpath, $callback->($status) 612=item aio_link $srcpath, $dstpath, $callback->($status)
490 613
491Asynchronously create a new link to the existing object at C<$srcpath> at 614Asynchronously create a new link to the existing object at C<$srcpath> at
492the path C<$dstpath> and call the callback with the result code. 615the path C<$dstpath> and call the callback with the result code.
… …
528 651
529Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 652Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
530directory (i.e. opendir + readdir + closedir). The entries will not be 653directory (i.e. opendir + readdir + closedir). The entries will not be
531sorted, and will B<NOT> include the C<.> and C<..> entries. 654sorted, and will B<NOT> include the C<.> and C<..> entries.
532 655
533The callback a single argument which is either C<undef> or an array-ref 656The callback is passed a single argument which is either C<undef> or an
534with the filenames. 657array-ref with the filenames.
658
659
660=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
661
662Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
663behaviour and output format. In case of an error, C<$entries> will be
664C<undef>.
665
666The flags are a combination of the following constants, ORed together (the
667flags will also be passed to the callback, possibly modified):
668
669=over 4
670
671=item IO::AIO::READDIR_DENTS
672
673When this flag is off, then the callback gets an arrayref consisting of
674names only (as with C<aio_readdir>), otherwise it gets an arrayref with
675C<[$name, $type, $inode]> arrayrefs, each describing a single directory
676entry in more detail.
677
678C<$name> is the name of the entry.
679
680C<$type> is one of the C<IO::AIO::DT_xxx> constants:
681
682C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
683C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
684C<IO::AIO::DT_WHT>.
685
686C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
687know, you have to run stat yourself. Also, for speed reasons, the C<$type>
688scalars are read-only: you can not modify them.
689
690C<$inode> is the inode number (which might not be exact on systems with 64
691bit inode numbers and 32 bit perls). This field has unspecified content on
692systems that do not deliver the inode information.
693
694=item IO::AIO::READDIR_DIRS_FIRST
695
696When this flag is set, then the names will be returned in an order where
697likely directories come first, in optimal stat order. This is useful when
698you need to quickly find directories, or you want to find all directories
699while avoiding to stat() each entry.
700
701If the system returns type information in readdir, then this is used
702to find directories directly. Otherwise, likely directories are names
703beginning with ".", or otherwise names with no dots, of which names with
704short names are tried first.
705
706=item IO::AIO::READDIR_STAT_ORDER
707
708When this flag is set, then the names will be returned in an order
709suitable for stat()'ing each one. That is, when you plan to stat()
710all files in the given directory, then the returned order will likely
711be fastest.
712
713If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
714the likely dirs come first, resulting in a less optimal stat order.
715
716=item IO::AIO::READDIR_FOUND_UNKNOWN
717
718This flag should not be set when calling C<aio_readdirx>. Instead, it
719is being set by C<aio_readdirx>, when any of the C<$type>'s found were
720C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
721C<$type>'s are known, which can be used to speed up some algorithms.
722
723=back
535 724
536 725
537=item aio_load $path, $data, $callback->($status) 726=item aio_load $path, $data, $callback->($status)
538 727
539This is a composite request that tries to fully load the given file into 728This is a composite request that tries to fully load the given file into
… …
564 753
565=item aio_copy $srcpath, $dstpath, $callback->($status) 754=item aio_copy $srcpath, $dstpath, $callback->($status)
566 755
567Try to copy the I<file> (directories not supported as either source or 756Try to copy the I<file> (directories not supported as either source or
568destination) from C<$srcpath> to C<$dstpath> and call the callback with 757destination) from C<$srcpath> to C<$dstpath> and call the callback with
569the C<0> (error) or C<-1> ok. 758a status of C<0> (ok) or C<-1> (error, see C<$!>).
570 759
571This is a composite request that it creates the destination file with 760This is a composite request that creates the destination file with
572mode 0200 and copies the contents of the source file into it using 761mode 0200 and copies the contents of the source file into it using
573C<aio_sendfile>, followed by restoring atime, mtime, access mode and 762C<aio_sendfile>, followed by restoring atime, mtime, access mode and
574uid/gid, in that order. 763uid/gid, in that order.
575 764
576If an error occurs, the partial destination file will be unlinked, if 765If an error occurs, the partial destination file will be unlinked, if
… …
586 my $grp = aio_group $cb; 775 my $grp = aio_group $cb;
587 776
588 aioreq_pri $pri; 777 aioreq_pri $pri;
589 add $grp aio_open $src, O_RDONLY, 0, sub { 778 add $grp aio_open $src, O_RDONLY, 0, sub {
590 if (my $src_fh = $_[0]) { 779 if (my $src_fh = $_[0]) {
591 my @stat = stat $src_fh; 780 my @stat = stat $src_fh; # hmm, might block over nfs?
592 781
593 aioreq_pri $pri; 782 aioreq_pri $pri;
594 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub { 783 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
595 if (my $dst_fh = $_[0]) { 784 if (my $dst_fh = $_[0]) {
596 aioreq_pri $pri; 785 aioreq_pri $pri;
597 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 786 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
598 if ($_[0] == $stat[7]) { 787 if ($_[0] == $stat[7]) {
599 $grp->result (0); 788 $grp->result (0);
600 close $src_fh; 789 close $src_fh;
601 790
602 # those should not normally block. should. should. 791 my $ch = sub {
603 utime $stat[8], $stat[9], $dst; 792 aioreq_pri $pri;
604 chmod $stat[2] & 07777, $dst_fh; 793 add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
605 chown $stat[4], $stat[5], $dst_fh; 794 aioreq_pri $pri;
795 add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
796 aioreq_pri $pri;
797 add $grp aio_close $dst_fh;
798 }
799 };
800 };
606 801
607 aioreq_pri $pri; 802 aioreq_pri $pri;
608 add $grp aio_close $dst_fh; 803 add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
804 if ($_[0] < 0 && $! == ENOSYS) {
805 aioreq_pri $pri;
806 add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
807 } else {
808 $ch->();
809 }
810 };
609 } else { 811 } else {
610 $grp->result (-1); 812 $grp->result (-1);
611 close $src_fh; 813 close $src_fh;
612 close $dst_fh; 814 close $dst_fh;
613 815
… …
630 832
631=item aio_move $srcpath, $dstpath, $callback->($status) 833=item aio_move $srcpath, $dstpath, $callback->($status)
632 834
633Try to move the I<file> (directories not supported as either source or 835Try to move the I<file> (directories not supported as either source or
634destination) from C<$srcpath> to C<$dstpath> and call the callback with 836destination) from C<$srcpath> to C<$dstpath> and call the callback with
635the C<0> (error) or C<-1> ok. 837a status of C<0> (ok) or C<-1> (error, see C<$!>).
636 838
637This is a composite request that tries to rename(2) the file first. If 839This is a composite request that tries to rename(2) the file first; if
638rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if 840rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
639that is successful, unlinking the C<$srcpath>. 841that is successful, unlinks the C<$srcpath>.
640 842
641=cut 843=cut
642 844
643sub aio_move($$;$) { 845sub aio_move($$;$) {
644 my ($src, $dst, $cb) = @_; 846 my ($src, $dst, $cb) = @_;
… …
691 893
692Implementation notes. 894Implementation notes.
693 895
694The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can. 896The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
695 897
898If readdir returns file type information, then this is used directly to
899find directories.
900
696After reading the directory, the modification time, size etc. of the 901Otherwise, after reading the directory, the modification time, size etc.
697directory before and after the readdir is checked, and if they match (and 902of 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 903match (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 904how many entries are directories (if >= 2). Otherwise, no knowledge of the
700of subdirectories will be assumed. 905number of subdirectories will be assumed.
701 906
702Then entries will be sorted into likely directories (everything without 907Then entries will be sorted into likely directories a non-initial dot
703a non-initial dot currently) and likely non-directories (everything 908currently) and likely non-directories (see C<aio_readdirx>). Then every
704else). Then every entry plus an appended C</.> will be C<stat>'ed, 909entry plus an appended C</.> will be C<stat>'ed, likely directories first,
705likely directories first. If that succeeds, it assumes that the entry 910in order of their inode numbers. If that succeeds, it assumes that the
706is a directory or a symlink to directory (which will be checked 911entry is a directory or a symlink to directory (which will be checked
707seperately). This is often faster than stat'ing the entry itself because 912seperately). This is often faster than stat'ing the entry itself because
708filesystems might detect the type of the entry without reading the inode 913filesystems might detect the type of the entry without reading the inode
709data (e.g. ext2fs filetype feature). 914data (e.g. ext2fs filetype feature), even on systems that cannot return
915the filetype information on readdir.
710 916
711If the known number of directories (link count - 2) has been reached, the 917If the known number of directories (link count - 2) has been reached, the
712rest of the entries is assumed to be non-directories. 918rest of the entries is assumed to be non-directories.
713 919
714This only works with certainty on POSIX (= UNIX) filesystems, which 920This only works with certainty on POSIX (= UNIX) filesystems, which
… …
736 my $now = time; 942 my $now = time;
737 my $hash1 = join ":", (stat _)[0,1,3,7,9]; 943 my $hash1 = join ":", (stat _)[0,1,3,7,9];
738 944
739 # read the directory entries 945 # read the directory entries
740 aioreq_pri $pri; 946 aioreq_pri $pri;
741 add $grp aio_readdir $path, sub { 947 add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
742 my $entries = shift 948 my $entries = shift
743 or return $grp->result (); 949 or return $grp->result ();
744 950
745 # stat the dir another time 951 # stat the dir another time
746 aioreq_pri $pri; 952 aioreq_pri $pri;
… …
752 # take the slow route if anything looks fishy 958 # take the slow route if anything looks fishy
753 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 959 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
754 $ndirs = -1; 960 $ndirs = -1;
755 } else { 961 } else {
756 # if nlink == 2, we are finished 962 # if nlink == 2, we are finished
757 # on non-posix-fs's, we rely on nlink < 2 963 # for non-posix-fs's, we rely on nlink < 2
758 $ndirs = (stat _)[3] - 2 964 $ndirs = (stat _)[3] - 2
759 or return $grp->result ([], $entries); 965 or return $grp->result ([], $entries);
760 } 966 }
761 967
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); 968 my (@dirs, @nondirs);
770 969
771 my $statgrp = add $grp aio_group sub { 970 my $statgrp = add $grp aio_group sub {
772 $grp->result (\@dirs, \@nondirs); 971 $grp->result (\@dirs, \@nondirs);
773 }; 972 };
774 973
775 limit $statgrp $maxreq; 974 limit $statgrp $maxreq;
776 feed $statgrp sub { 975 feed $statgrp sub {
777 return unless @$entries; 976 return unless @$entries;
778 my $entry = pop @$entries; 977 my $entry = shift @$entries;
779 978
780 aioreq_pri $pri; 979 aioreq_pri $pri;
781 add $statgrp aio_stat "$path/$entry/.", sub { 980 add $statgrp aio_stat "$path/$entry/.", sub {
782 if ($_[0] < 0) { 981 if ($_[0] < 0) {
783 push @nondirs, $entry; 982 push @nondirs, $entry;
… …
856callback with the fdatasync result code. 1055callback with the fdatasync result code.
857 1056
858If this call isn't available because your OS lacks it or it couldn't be 1057If 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. 1058detected, it will be emulated by calling C<fsync> instead.
860 1059
1060=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
1061
1062Sync the data portion of the file specified by C<$offset> and C<$length>
1063to disk (but NOT the metadata), by calling the Linux-specific
1064sync_file_range call. If sync_file_range is not available or it returns
1065ENOSYS, then fdatasync or fsync is being substituted.
1066
1067C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
1068C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
1069C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
1070manpage for details.
1071
861=item aio_pathsync $path, $callback->($status) 1072=item aio_pathsync $path, $callback->($status)
862 1073
863This request tries to open, fsync and close the given path. This is a 1074This request tries to open, fsync and close the given path. This is a
864composite request intended tosync directories after directory operations 1075composite request intended to sync directories after directory operations
865(E.g. rename). This might not work on all operating systems or have any 1076(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 1077specific effect, but usually it makes sure that directory changes get
867written to disc. It works for anything that can be opened for read-only, 1078written to disc. It works for anything that can be opened for read-only,
868not just directories. 1079not just directories.
1080
1081Future versions of this function might fall back to other methods when
1082C<fsync> on the directory fails (such as calling C<sync>).
869 1083
870Passes C<0> when everything went ok, and C<-1> on error. 1084Passes C<0> when everything went ok, and C<-1> on error.
871 1085
872=cut 1086=cut
873 1087
… …
894 }; 1108 };
895 1109
896 $grp 1110 $grp
897} 1111}
898 1112
1113=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1114
1115This is a rather advanced IO::AIO call, which only works on mmap(2)ed
1116scalars (see the C<IO::AIO::mmap> function, although it also works on data
1117scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
1118scalar must only be modified in-place while an aio operation is pending on
1119it).
1120
1121It calls the C<msync> function of your OS, if available, with the memory
1122area starting at C<$offset> in the string and ending C<$length> bytes
1123later. If C<$length> is negative, counts from the end, and if C<$length>
1124is C<undef>, then it goes till the end of the string. The flags can be
1125a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
1126C<IO::AIO::MS_SYNC>.
1127
1128=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1129
1130This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1131scalars.
1132
1133It touches (reads or writes) all memory pages in the specified
1134range inside the scalar. All caveats and parameters are the same
1135as for C<aio_msync>, above, except for flags, which must be either
1136C<0> (which reads all pages and ensures they are instantiated) or
1137C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
1138writing an octet from it, which dirties the page).
1139
1140=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1141
1142This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1143scalars.
1144
1145It reads in all the pages of the underlying storage into memory (if any)
1146and locks them, so they are not getting swapped/paged out or removed.
1147
1148If C<$length> is undefined, then the scalar will be locked till the end.
1149
1150On systems that do not implement C<mlock>, this function returns C<-1>
1151and sets errno to C<ENOSYS>.
1152
1153Note that the corresponding C<munlock> is synchronous and is
1154documented under L<MISCELLANEOUS FUNCTIONS>.
1155
1156Example: open a file, mmap and mlock it - both will be undone when
1157C<$data> gets destroyed.
1158
1159 open my $fh, "<", $path or die "$path: $!";
1160 my $data;
1161 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
1162 aio_mlock $data; # mlock in background
1163
1164=item aio_mlockall $flags, $callback->($status)
1165
1166Calls the C<mlockall> function with the given C<$flags> (a combination of
1167C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).
1168
1169On systems that do not implement C<mlockall>, this function returns C<-1>
1170and sets errno to C<ENOSYS>.
1171
1172Note that the corresponding C<munlockall> is synchronous and is
1173documented under L<MISCELLANEOUS FUNCTIONS>.
1174
1175Example: asynchronously lock all current and future pages into memory.
1176
1177 aio_mlockall IO::AIO::MCL_FUTURE;
1178
899=item aio_group $callback->(...) 1179=item aio_group $callback->(...)
900 1180
901This is a very special aio request: Instead of doing something, it is a 1181This 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 1182container for other aio requests, which is useful if you want to bundle
903many requests into a single, composite, request with a definite callback 1183many requests into a single, composite, request with a definite callback
… …
952=item cancel $req 1232=item cancel $req
953 1233
954Cancels the request, if possible. Has the effect of skipping execution 1234Cancels the request, if possible. Has the effect of skipping execution
955when entering the B<execute> state and skipping calling the callback when 1235when entering the B<execute> state and skipping calling the callback when
956entering the the B<result> state, but will leave the request otherwise 1236entering the the B<result> state, but will leave the request otherwise
957untouched. That means that requests that currently execute will not be 1237untouched (with the exception of readdir). That means that requests that
958stopped and resources held by the request will not be freed prematurely. 1238currently execute will not be stopped and resources held by the request
1239will not be freed prematurely.
959 1240
960=item cb $req $callback->(...) 1241=item cb $req $callback->(...)
961 1242
962Replace (or simply set) the callback registered to the request. 1243Replace (or simply set) the callback registered to the request.
963 1244
… …
1014Their lifetime, simplified, looks like this: when they are empty, they 1295Their lifetime, simplified, looks like this: when they are empty, they
1015will finish very quickly. If they contain only requests that are in the 1296will finish very quickly. If they contain only requests that are in the
1016C<done> state, they will also finish. Otherwise they will continue to 1297C<done> state, they will also finish. Otherwise they will continue to
1017exist. 1298exist.
1018 1299
1019That means after creating a group you have some time to add requests. And 1300That 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 1301(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 1302the C<poll_cb>). And in the callbacks of those requests, you can add
1022itself finish. 1303further requests to the group. And only when all those requests have
1304finished will the the group itself finish.
1023 1305
1024=over 4 1306=over 4
1025 1307
1026=item add $grp ... 1308=item add $grp ...
1027 1309
… …
1035 1317
1036=item $grp->cancel_subs 1318=item $grp->cancel_subs
1037 1319
1038Cancel all subrequests and clears any feeder, but not the group request 1320Cancel 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. 1321itself. Useful when you queued a lot of events but got a result early.
1322
1323The group request will finish normally (you cannot add requests to the
1324group).
1040 1325
1041=item $grp->result (...) 1326=item $grp->result (...)
1042 1327
1043Set the result value(s) that will be passed to the group callback when all 1328Set 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 1329subrequests have finished and set the groups errno to the current value
… …
1060=item feed $grp $callback->($grp) 1345=item feed $grp $callback->($grp)
1061 1346
1062Sets a feeder/generator on this group: every group can have an attached 1347Sets a feeder/generator on this group: every group can have an attached
1063generator that generates requests if idle. The idea behind this is that, 1348generator 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, 1349although you could just queue as many requests as you want in a group,
1065this might starve other requests for a potentially long time. For 1350this might starve other requests for a potentially long time. For example,
1066example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1351C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1067requests, delaying any later requests for a long time. 1352delaying any later requests for a long time.
1068 1353
1069To avoid this, and allow incremental generation of requests, you can 1354To avoid this, and allow incremental generation of requests, you can
1070instead a group and set a feeder on it that generates those requests. The 1355instead 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>, 1356feed 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 1357below) requests active in the group itself and is expected to queue more
… …
1076not impose any limits). 1361not impose any limits).
1077 1362
1078If the feed does not queue more requests when called, it will be 1363If the feed does not queue more requests when called, it will be
1079automatically removed from the group. 1364automatically removed from the group.
1080 1365
1081If the feed limit is C<0>, it will be set to C<2> automatically. 1366If the feed limit is C<0> when this method is called, it will be set to
1367C<2> automatically.
1082 1368
1083Example: 1369Example:
1084 1370
1085 # stat all files in @files, but only ever use four aio requests concurrently: 1371 # stat all files in @files, but only ever use four aio requests concurrently:
1086 1372
… …
1098Sets the feeder limit for the group: The feeder will be called whenever 1384Sets the feeder limit for the group: The feeder will be called whenever
1099the group contains less than this many requests. 1385the group contains less than this many requests.
1100 1386
1101Setting the limit to C<0> will pause the feeding process. 1387Setting the limit to C<0> will pause the feeding process.
1102 1388
1389The default value for the limit is C<0>, but note that setting a feeder
1390automatically bumps it up to C<2>.
1391
1103=back 1392=back
1104 1393
1105=head2 SUPPORT FUNCTIONS 1394=head2 SUPPORT FUNCTIONS
1106 1395
1107=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1396=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
… …
1109=over 4 1398=over 4
1110 1399
1111=item $fileno = IO::AIO::poll_fileno 1400=item $fileno = IO::AIO::poll_fileno
1112 1401
1113Return the I<request result pipe file descriptor>. This filehandle must be 1402Return the I<request result pipe file descriptor>. This filehandle must be
1114polled for reading by some mechanism outside this module (e.g. Event or 1403polled 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 1404select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1116to call C<poll_cb> to check the results. 1405you have to call C<poll_cb> to check the results.
1117 1406
1118See C<poll_cb> for an example. 1407See C<poll_cb> for an example.
1119 1408
1120=item IO::AIO::poll_cb 1409=item IO::AIO::poll_cb
1121 1410
1122Process some outstanding events on the result pipe. You have to call this 1411Process some outstanding events on the result pipe. You have to call
1123regularly. Returns the number of events processed. Returns immediately 1412this regularly. Returns C<0> if all events could be processed (or there
1124when no events are outstanding. The amount of events processed depends on 1413were no events to process), or C<-1> if it returned earlier for whatever
1125the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>. 1414reason. Returns immediately when no events are outstanding. The amount of
1415events processed depends on the settings of C<IO::AIO::max_poll_req> and
1416C<IO::AIO::max_poll_time>.
1126 1417
1127If not all requests were processed for whatever reason, the filehandle 1418If not all requests were processed for whatever reason, the filehandle
1128will still be ready when C<poll_cb> returns. 1419will still be ready when C<poll_cb> returns, so normally you don't have to
1420do anything special to have it called later.
1421
1422Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes
1423ready, it can be beneficial to call this function from loops which submit
1424a lot of requests, to make sure the results get processed when they become
1425available and not just when the loop is finished and the event loop takes
1426over again. This function returns very fast when there are no outstanding
1427requests.
1129 1428
1130Example: Install an Event watcher that automatically calls 1429Example: Install an Event watcher that automatically calls
1131IO::AIO::poll_cb with high priority: 1430IO::AIO::poll_cb with high priority (more examples can be found in the
1431SYNOPSIS section, at the top of this document):
1132 1432
1133 Event->io (fd => IO::AIO::poll_fileno, 1433 Event->io (fd => IO::AIO::poll_fileno,
1134 poll => 'r', async => 1, 1434 poll => 'r', async => 1,
1135 cb => \&IO::AIO::poll_cb); 1435 cb => \&IO::AIO::poll_cb);
1436
1437=item IO::AIO::poll_wait
1438
1439If there are any outstanding requests and none of them in the result
1440phase, wait till the result filehandle becomes ready for reading (simply
1441does a C<select> on the filehandle. This is useful if you want to
1442synchronously wait for some requests to finish).
1443
1444See C<nreqs> for an example.
1445
1446=item IO::AIO::poll
1447
1448Waits until some requests have been handled.
1449
1450Returns the number of requests processed, but is otherwise strictly
1451equivalent to:
1452
1453 IO::AIO::poll_wait, IO::AIO::poll_cb
1454
1455=item IO::AIO::flush
1456
1457Wait till all outstanding AIO requests have been handled.
1458
1459Strictly equivalent to:
1460
1461 IO::AIO::poll_wait, IO::AIO::poll_cb
1462 while IO::AIO::nreqs;
1136 1463
1137=item IO::AIO::max_poll_reqs $nreqs 1464=item IO::AIO::max_poll_reqs $nreqs
1138 1465
1139=item IO::AIO::max_poll_time $seconds 1466=item IO::AIO::max_poll_time $seconds
1140 1467
… …
1165 # use a low priority so other tasks have priority 1492 # use a low priority so other tasks have priority
1166 Event->io (fd => IO::AIO::poll_fileno, 1493 Event->io (fd => IO::AIO::poll_fileno,
1167 poll => 'r', nice => 1, 1494 poll => 'r', nice => 1,
1168 cb => &IO::AIO::poll_cb); 1495 cb => &IO::AIO::poll_cb);
1169 1496
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 1497=back
1198 1498
1199=head3 CONTROLLING THE NUMBER OF THREADS 1499=head3 CONTROLLING THE NUMBER OF THREADS
1200 1500
1201=over 1501=over
… …
1234 1534
1235Under normal circumstances you don't need to call this function. 1535Under normal circumstances you don't need to call this function.
1236 1536
1237=item IO::AIO::max_idle $nthreads 1537=item IO::AIO::max_idle $nthreads
1238 1538
1239Limit the number of threads (default: 4) that are allowed to idle (i.e., 1539Limit the number of threads (default: 4) that are allowed to idle
1240threads that did not get a request to process within 10 seconds). That 1540(i.e., threads that did not get a request to process within the idle
1241means if a thread becomes idle while C<$nthreads> other threads are also 1541timeout (default: 10 seconds). That means if a thread becomes idle while
1242idle, it will free its resources and exit. 1542C<$nthreads> other threads are also idle, it will free its resources and
1543exit.
1243 1544
1244This is useful when you allow a large number of threads (e.g. 100 or 1000) 1545This is useful when you allow a large number of threads (e.g. 100 or 1000)
1245to allow for extremely high load situations, but want to free resources 1546to allow for extremely high load situations, but want to free resources
1246under normal circumstances (1000 threads can easily consume 30MB of RAM). 1547under normal circumstances (1000 threads can easily consume 30MB of RAM).
1247 1548
1248The default is probably ok in most situations, especially if thread 1549The default is probably ok in most situations, especially if thread
1249creation is fast. If thread creation is very slow on your system you might 1550creation is fast. If thread creation is very slow on your system you might
1250want to use larger values. 1551want to use larger values.
1552
1553=item IO::AIO::idle_timeout $seconds
1554
1555Sets the minimum idle timeout (default 10) after which worker threads are
1556allowed to exit. SEe C<IO::AIO::max_idle>.
1251 1557
1252=item IO::AIO::max_outstanding $maxreqs 1558=item IO::AIO::max_outstanding $maxreqs
1253 1559
1254This is a very bad function to use in interactive programs because it 1560This is a very bad function to use in interactive programs because it
1255blocks, and a bad way to reduce concurrency because it is inexact: Better 1561blocks, and a bad way to reduce concurrency because it is inexact: Better
… …
1293Returns the number of requests currently in the pending state (executed, 1599Returns the number of requests currently in the pending state (executed,
1294but not yet processed by poll_cb). 1600but not yet processed by poll_cb).
1295 1601
1296=back 1602=back
1297 1603
1604=head3 MISCELLANEOUS FUNCTIONS
1605
1606IO::AIO implements some functions that might be useful, but are not
1607asynchronous.
1608
1609=over 4
1610
1611=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1612
1613Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
1614but is blocking (this makes most sense if you know the input data is
1615likely cached already and the output filehandle is set to non-blocking
1616operations).
1617
1618Returns the number of bytes copied, or C<-1> on error.
1619
1620=item IO::AIO::fadvise $fh, $offset, $len, $advice
1621
1622Simply calls the C<posix_fadvise> function (see its
1623manpage for details). The following advice constants are
1624avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1625C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1626C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1627
1628On systems that do not implement C<posix_fadvise>, this function returns
1629ENOSYS, otherwise the return value of C<posix_fadvise>.
1630
1631=item IO::AIO::madvise $scalar, $offset, $len, $advice
1632
1633Simply calls the C<posix_madvise> function (see its
1634manpage for details). The following advice constants are
1635avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
1636C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.
1637
1638On systems that do not implement C<posix_madvise>, this function returns
1639ENOSYS, otherwise the return value of C<posix_madvise>.
1640
1641=item IO::AIO::mprotect $scalar, $offset, $len, $protect
1642
1643Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
1644$scalar (see its manpage for details). The following protect
1645constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
1646C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
1647
1648On systems that do not implement C<mprotect>, this function returns
1649ENOSYS, otherwise the return value of C<mprotect>.
1650
1651=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1652
1653Memory-maps a file (or anonymous memory range) and attaches it to the
1654given C<$scalar>, which will act like a string scalar.
1655
1656The only operations allowed on the scalar are C<substr>/C<vec> that don't
1657change the string length, and most read-only operations such as copying it
1658or searching it with regexes and so on.
1659
1660Anything else is unsafe and will, at best, result in memory leaks.
1661
1662The memory map associated with the C<$scalar> is automatically removed
1663when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
1664C<IO::AIO::munmap> functions are called.
1665
1666This calls the C<mmap>(2) function internally. See your system's manual
1667page for details on the C<$length>, C<$prot> and C<$flags> parameters.
1668
1669The C<$length> must be larger than zero and smaller than the actual
1670filesize.
1671
1672C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1673C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1674
1675C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
1676C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
1677not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
1678(which is set to C<MAP_ANON> if your system only provides this
1679constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
1680C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
1681C<IO::AIO::MAP_NONBLOCK>
1682
1683If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1684
1685C<$offset> is the offset from the start of the file - it generally must be
1686a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
1687
1688Example:
1689
1690 use Digest::MD5;
1691 use IO::AIO;
1692
1693 open my $fh, "<verybigfile"
1694 or die "$!";
1695
1696 IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
1697 or die "verybigfile: $!";
1698
1699 my $fast_md5 = md5 $data;
1700
1701=item IO::AIO::munmap $scalar
1702
1703Removes a previous mmap and undefines the C<$scalar>.
1704
1705=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
1706
1707Calls the C<munlock> function, undoing the effects of a previous
1708C<aio_mlock> call (see its description for details).
1709
1710=item IO::AIO::munlockall
1711
1712Calls the C<munlockall> function.
1713
1714On systems that do not implement C<munlockall>, this function returns
1715ENOSYS, otherwise the return value of C<munlockall>.
1716
1717=back
1718
1298=cut 1719=cut
1299 1720
1300min_parallel 8; 1721min_parallel 8;
1301 1722
1302END { flush } 1723END { flush }
1303 1724
13041; 17251;
1726
1727=head1 EVENT LOOP INTEGRATION
1728
1729It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
1730automatically into many event loops:
1731
1732 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
1733 use AnyEvent::AIO;
1734
1735You can also integrate IO::AIO manually into many event loops, here are
1736some examples of how to do this:
1737
1738 # EV integration
1739 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
1740
1741 # Event integration
1742 Event->io (fd => IO::AIO::poll_fileno,
1743 poll => 'r',
1744 cb => \&IO::AIO::poll_cb);
1745
1746 # Glib/Gtk2 integration
1747 add_watch Glib::IO IO::AIO::poll_fileno,
1748 in => sub { IO::AIO::poll_cb; 1 };
1749
1750 # Tk integration
1751 Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
1752 readable => \&IO::AIO::poll_cb);
1753
1754 # Danga::Socket integration
1755 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
1756 \&IO::AIO::poll_cb);
1305 1757
1306=head2 FORK BEHAVIOUR 1758=head2 FORK BEHAVIOUR
1307 1759
1308This module should do "the right thing" when the process using it forks: 1760This module should do "the right thing" when the process using it forks:
1309 1761
… …
1342 1794
1343Known bugs will be fixed in the next release. 1795Known bugs will be fixed in the next release.
1344 1796
1345=head1 SEE ALSO 1797=head1 SEE ALSO
1346 1798
1347L<Coro::AIO>. 1799L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1800more natural syntax.
1348 1801
1349=head1 AUTHOR 1802=head1 AUTHOR
1350 1803
1351 Marc Lehmann <schmorp@schmorp.de> 1804 Marc Lehmann <schmorp@schmorp.de>
1352 http://home.schmorp.de/ 1805 http://home.schmorp.de/

Diff Legend

– Removed lines
+ Added lines
< Changed lines
> Changed lines