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Revision 1.150 by root, Sat Jun 6 19:44:17 2009 UTC vs.
Revision 1.181 by root, Tue May 4 21:14:01 2010 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, POE, urxvt, pureperl...)
32 use AnyEvent::AIO;
33
34 # EV integration
35 my $w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
36
37 # Event integration
38 Event->io (fd => IO::AIO::poll_fileno,
39 poll => 'r',
40 cb => \&IO::AIO::poll_cb);
41
42 # Glib/Gtk2 integration
43 add_watch Glib::IO IO::AIO::poll_fileno,
44 in => sub { IO::AIO::poll_cb; 1 };
45
46 # Tk integration
47 Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
48 readable => \&IO::AIO::poll_cb);
49
50 # Danga::Socket integration
51 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
52 \&IO::AIO::poll_cb);
53
54=head1 DESCRIPTION 31=head1 DESCRIPTION
55 32
56This module implements asynchronous I/O using whatever means your 33This module implements asynchronous I/O using whatever means your
57operating system supports. 34operating system supports. It is implemented as an interface to C<libeio>
35(L<http://software.schmorp.de/pkg/libeio.html>).
58 36
59Asynchronous means that operations that can normally block your program 37Asynchronous means that operations that can normally block your program
60(e.g. reading from disk) will be done asynchronously: the operation 38(e.g. reading from disk) will be done asynchronously: the operation
61will still block, but you can do something else in the meantime. This 39will still block, but you can do something else in the meantime. This
62is extremely useful for programs that need to stay interactive even 40is extremely useful for programs that need to stay interactive even
66on a RAID volume or over NFS when you do a number of stat operations 44on a RAID volume or over NFS when you do a number of stat operations
67concurrently. 45concurrently.
68 46
69While most of this works on all types of file descriptors (for 47While most of this works on all types of file descriptors (for
70example sockets), using these functions on file descriptors that 48example sockets), using these functions on file descriptors that
71support nonblocking operation (again, sockets, pipes etc.) is very 49support nonblocking operation (again, sockets, pipes etc.) is
72inefficient. Use an event loop for that (such as the L<Event|Event> 50very inefficient. Use an event loop for that (such as the L<EV>
73module): IO::AIO will naturally fit into such an event loop itself. 51module): IO::AIO will naturally fit into such an event loop itself.
74 52
75In this version, a number of threads are started that execute your 53In this version, a number of threads are started that execute your
76requests and signal their completion. You don't need thread support 54requests and signal their completion. You don't need thread support
77in perl, and the threads created by this module will not be visible 55in perl, and the threads created by this module will not be visible
87yourself, always call C<poll_cb> from within the same thread, or never 65yourself, always call C<poll_cb> from within the same thread, or never
88call C<poll_cb> (or other C<aio_> functions) recursively. 66call C<poll_cb> (or other C<aio_> functions) recursively.
89 67
90=head2 EXAMPLE 68=head2 EXAMPLE
91 69
92This is a simple example that uses the Event module and loads 70This is a simple example that uses the EV module and loads
93F</etc/passwd> asynchronously: 71F</etc/passwd> asynchronously:
94 72
95 use Fcntl; 73 use Fcntl;
96 use Event; 74 use EV;
97 use IO::AIO; 75 use IO::AIO;
98 76
99 # register the IO::AIO callback with Event 77 # register the IO::AIO callback with EV
100 Event->io (fd => IO::AIO::poll_fileno, 78 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
101 poll => 'r',
102 cb => \&IO::AIO::poll_cb);
103 79
104 # queue the request to open /etc/passwd 80 # queue the request to open /etc/passwd
105 aio_open "/etc/passwd", O_RDONLY, 0, sub { 81 aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
106 my $fh = shift 82 my $fh = shift
107 or die "error while opening: $!"; 83 or die "error while opening: $!";
108 84
109 # stat'ing filehandles is generally non-blocking 85 # stat'ing filehandles is generally non-blocking
110 my $size = -s $fh; 86 my $size = -s $fh;
119 95
120 # file contents now in $contents 96 # file contents now in $contents
121 print $contents; 97 print $contents;
122 98
123 # exit event loop and program 99 # exit event loop and program
124 Event::unloop; 100 EV::unloop;
125 }; 101 };
126 }; 102 };
127 103
128 # possibly queue up other requests, or open GUI windows, 104 # possibly queue up other requests, or open GUI windows,
129 # check for sockets etc. etc. 105 # check for sockets etc. etc.
130 106
131 # process events as long as there are some: 107 # process events as long as there are some:
132 Event::loop; 108 EV::loop;
133 109
134=head1 REQUEST ANATOMY AND LIFETIME 110=head1 REQUEST ANATOMY AND LIFETIME
135 111
136Every C<aio_*> function creates a request. which is a C data structure not 112Every C<aio_*> function creates a request. which is a C data structure not
137directly visible to Perl. 113directly visible to Perl.
187 163
188package IO::AIO; 164package IO::AIO;
189 165
190use Carp (); 166use Carp ();
191 167
192no warnings; 168use common::sense;
193use strict 'vars';
194 169
195use base 'Exporter'; 170use base 'Exporter';
196 171
197BEGIN { 172BEGIN {
198 our $VERSION = '3.2'; 173 our $VERSION = '3.65';
199 174
200 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close 175 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close
201 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx 176 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
202 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync 177 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
203 aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead 178 aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
204 aio_rename aio_link aio_move aio_copy aio_group 179 aio_rename aio_link aio_move aio_copy aio_group
205 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown 180 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
206 aio_chmod aio_utime aio_truncate); 181 aio_chmod aio_utime aio_truncate
182 aio_msync aio_mtouch aio_statvfs);
207 183
208 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); 184 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
209 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 185 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
210 min_parallel max_parallel max_idle 186 min_parallel max_parallel max_idle
211 nreqs nready npending nthreads 187 nreqs nready npending nthreads
212 max_poll_time max_poll_reqs); 188 max_poll_time max_poll_reqs
189 sendfile fadvise);
213 190
214 push @AIO_REQ, qw(aio_busy); # not exported 191 push @AIO_REQ, qw(aio_busy); # not exported
215 192
216 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 193 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
217 194
218 require XSLoader; 195 require XSLoader;
219 XSLoader::load ("IO::AIO", $VERSION); 196 XSLoader::load ("IO::AIO", $VERSION);
220} 197}
221 198
222=head1 FUNCTIONS 199=head1 FUNCTIONS
200
201=head2 QUICK OVERVIEW
202
203This section simply lists the prototypes of the most important functions
204for quick reference. See the following sections for function-by-function
205documentation.
206
207 aio_open $pathname, $flags, $mode, $callback->($fh)
208 aio_close $fh, $callback->($status)
209 aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
210 aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
211 aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
212 aio_readahead $fh,$offset,$length, $callback->($retval)
213 aio_stat $fh_or_path, $callback->($status)
214 aio_lstat $fh, $callback->($status)
215 aio_statvfs $fh_or_path, $callback->($statvfs)
216 aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
217 aio_chown $fh_or_path, $uid, $gid, $callback->($status)
218 aio_truncate $fh_or_path, $offset, $callback->($status)
219 aio_chmod $fh_or_path, $mode, $callback->($status)
220 aio_unlink $pathname, $callback->($status)
221 aio_mknod $path, $mode, $dev, $callback->($status)
222 aio_link $srcpath, $dstpath, $callback->($status)
223 aio_symlink $srcpath, $dstpath, $callback->($status)
224 aio_readlink $path, $callback->($link)
225 aio_rename $srcpath, $dstpath, $callback->($status)
226 aio_mkdir $pathname, $mode, $callback->($status)
227 aio_rmdir $pathname, $callback->($status)
228 aio_readdir $pathname, $callback->($entries)
229 aio_readdirx $pathname, $flags, $callback->($entries, $flags)
230 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
231 IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN
232 aio_load $path, $data, $callback->($status)
233 aio_copy $srcpath, $dstpath, $callback->($status)
234 aio_move $srcpath, $dstpath, $callback->($status)
235 aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
236 aio_rmtree $path, $callback->($status)
237 aio_sync $callback->($status)
238 aio_fsync $fh, $callback->($status)
239 aio_fdatasync $fh, $callback->($status)
240 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
241 aio_pathsync $path, $callback->($status)
242 aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
243 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
244 aio_group $callback->(...)
245 aio_nop $callback->()
246
247 $prev_pri = aioreq_pri [$pri]
248 aioreq_nice $pri_adjust
249
250 IO::AIO::poll_wait
251 IO::AIO::poll_cb
252 IO::AIO::poll
253 IO::AIO::flush
254 IO::AIO::max_poll_reqs $nreqs
255 IO::AIO::max_poll_time $seconds
256 IO::AIO::min_parallel $nthreads
257 IO::AIO::max_parallel $nthreads
258 IO::AIO::max_idle $nthreads
259 IO::AIO::max_outstanding $maxreqs
260 IO::AIO::nreqs
261 IO::AIO::nready
262 IO::AIO::npending
263
264 IO::AIO::sendfile $ofh, $ifh, $offset, $count
265 IO::AIO::fadvise $fh, $offset, $len, $advice
266 IO::AIO::mlockall $flags
267 IO::AIO::munlockall
223 268
224=head2 AIO REQUEST FUNCTIONS 269=head2 AIO REQUEST FUNCTIONS
225 270
226All the C<aio_*> calls are more or less thin wrappers around the syscall 271All the C<aio_*> calls are more or less thin wrappers around the syscall
227with the same name (sans C<aio_>). The arguments are similar or identical, 272with the same name (sans C<aio_>). The arguments are similar or identical,
307by the umask in effect then the request is being executed, so better never 352by the umask in effect then the request is being executed, so better never
308change the umask. 353change the umask.
309 354
310Example: 355Example:
311 356
312 aio_open "/etc/passwd", O_RDONLY, 0, sub { 357 aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
313 if ($_[0]) { 358 if ($_[0]) {
314 print "open successful, fh is $_[0]\n"; 359 print "open successful, fh is $_[0]\n";
315 ... 360 ...
316 } else { 361 } else {
317 die "open failed: $!\n"; 362 die "open failed: $!\n";
379than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each 424than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
380other. 425other.
381 426
382This call tries to make use of a native C<sendfile> syscall to provide 427This call tries to make use of a native C<sendfile> syscall to provide
383zero-copy operation. For this to work, C<$out_fh> should refer to a 428zero-copy operation. For this to work, C<$out_fh> should refer to a
384socket, and C<$in_fh> should refer to mmap'able file. 429socket, and C<$in_fh> should refer to an mmap'able file.
385 430
386If the native sendfile call fails or is not implemented, it will be 431If a native sendfile cannot be found or it fails with C<ENOSYS>,
432C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
387emulated, so you can call C<aio_sendfile> on any type of filehandle 433it will be emulated, so you can call C<aio_sendfile> on any type of
388regardless of the limitations of the operating system. 434filehandle regardless of the limitations of the operating system.
389 435
390Please note, however, that C<aio_sendfile> can read more bytes from 436Please note, however, that C<aio_sendfile> can read more bytes from
391C<$in_fh> than are written, and there is no way to find out how many 437C<$in_fh> than are written, and there is no way to find out how many
392bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only 438bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
393provides the number of bytes written to C<$out_fh>. Only if the result 439provides the number of bytes written to C<$out_fh>. Only if the result
431 $_[0] and die "stat failed: $!"; 477 $_[0] and die "stat failed: $!";
432 print "size is ", -s _, "\n"; 478 print "size is ", -s _, "\n";
433 }; 479 };
434 480
435 481
482=item aio_statvfs $fh_or_path, $callback->($statvfs)
483
484Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
485whether a file handle or path was passed.
486
487On success, the callback is passed a hash reference with the following
488members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
489C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
490is passed.
491
492The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
493C<ST_NOSUID>.
494
495The following non-POSIX IO::AIO::ST_* flag masks are defined to
496their correct value when available, or to C<0> on systems that do
497not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
498C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
499C<ST_NODIRATIME> and C<ST_RELATIME>.
500
501Example: stat C</wd> and dump out the data if successful.
502
503 aio_statvfs "/wd", sub {
504 my $f = $_[0]
505 or die "statvfs: $!";
506
507 use Data::Dumper;
508 say Dumper $f;
509 };
510
511 # result:
512 {
513 bsize => 1024,
514 bfree => 4333064312,
515 blocks => 10253828096,
516 files => 2050765568,
517 flag => 4096,
518 favail => 2042092649,
519 bavail => 4333064312,
520 ffree => 2042092649,
521 namemax => 255,
522 frsize => 1024,
523 fsid => 1810
524 }
525
526
436=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 527=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
437 528
438Works like perl's C<utime> function (including the special case of $atime 529Works like perl's C<utime> function (including the special case of $atime
439and $mtime being undef). Fractional times are supported if the underlying 530and $mtime being undef). Fractional times are supported if the underlying
440syscalls support them. 531syscalls support them.
568C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to 659C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
569know, you have to run stat yourself. Also, for speed reasons, the C<$type> 660know, you have to run stat yourself. Also, for speed reasons, the C<$type>
570scalars are read-only: you can not modify them. 661scalars are read-only: you can not modify them.
571 662
572C<$inode> is the inode number (which might not be exact on systems with 64 663C<$inode> is the inode number (which might not be exact on systems with 64
573bit inode numbers and 32 bit perls). On systems that do not deliver the 664bit inode numbers and 32 bit perls). This field has unspecified content on
574inode information, this will always be zero. 665systems that do not deliver the inode information.
575 666
576=item IO::AIO::READDIR_DIRS_FIRST 667=item IO::AIO::READDIR_DIRS_FIRST
577 668
578When this flag is set, then the names will be returned in an order where 669When this flag is set, then the names will be returned in an order where
579likely directories come first. This is useful when you need to quickly 670likely directories come first. This is useful when you need to quickly
635 726
636=item aio_copy $srcpath, $dstpath, $callback->($status) 727=item aio_copy $srcpath, $dstpath, $callback->($status)
637 728
638Try to copy the I<file> (directories not supported as either source or 729Try to copy the I<file> (directories not supported as either source or
639destination) from C<$srcpath> to C<$dstpath> and call the callback with 730destination) from C<$srcpath> to C<$dstpath> and call the callback with
640the C<0> (error) or C<-1> ok. 731a status of C<0> (ok) or C<-1> (error, see C<$!>).
641 732
642This is a composite request that creates the destination file with 733This is a composite request that creates the destination file with
643mode 0200 and copies the contents of the source file into it using 734mode 0200 and copies the contents of the source file into it using
644C<aio_sendfile>, followed by restoring atime, mtime, access mode and 735C<aio_sendfile>, followed by restoring atime, mtime, access mode and
645uid/gid, in that order. 736uid/gid, in that order.
657 my $grp = aio_group $cb; 748 my $grp = aio_group $cb;
658 749
659 aioreq_pri $pri; 750 aioreq_pri $pri;
660 add $grp aio_open $src, O_RDONLY, 0, sub { 751 add $grp aio_open $src, O_RDONLY, 0, sub {
661 if (my $src_fh = $_[0]) { 752 if (my $src_fh = $_[0]) {
662 my @stat = stat $src_fh; # hmm, might bock over nfs? 753 my @stat = stat $src_fh; # hmm, might block over nfs?
663 754
664 aioreq_pri $pri; 755 aioreq_pri $pri;
665 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub { 756 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
666 if (my $dst_fh = $_[0]) { 757 if (my $dst_fh = $_[0]) {
667 aioreq_pri $pri; 758 aioreq_pri $pri;
714 805
715=item aio_move $srcpath, $dstpath, $callback->($status) 806=item aio_move $srcpath, $dstpath, $callback->($status)
716 807
717Try to move the I<file> (directories not supported as either source or 808Try to move the I<file> (directories not supported as either source or
718destination) from C<$srcpath> to C<$dstpath> and call the callback with 809destination) from C<$srcpath> to C<$dstpath> and call the callback with
719the C<0> (error) or C<-1> ok. 810a status of C<0> (ok) or C<-1> (error, see C<$!>).
720 811
721This is a composite request that tries to rename(2) the file first; if 812This is a composite request that tries to rename(2) the file first; if
722rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if 813rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
723that is successful, unlinks the C<$srcpath>. 814that is successful, unlinks the C<$srcpath>.
724 815
958(E.g. rename). This might not work on all operating systems or have any 1049(E.g. rename). This might not work on all operating systems or have any
959specific effect, but usually it makes sure that directory changes get 1050specific effect, but usually it makes sure that directory changes get
960written to disc. It works for anything that can be opened for read-only, 1051written to disc. It works for anything that can be opened for read-only,
961not just directories. 1052not just directories.
962 1053
1054Future versions of this function might fall back to other methods when
1055C<fsync> on the directory fails (such as calling C<sync>).
1056
963Passes C<0> when everything went ok, and C<-1> on error. 1057Passes C<0> when everything went ok, and C<-1> on error.
964 1058
965=cut 1059=cut
966 1060
967sub aio_pathsync($;$) { 1061sub aio_pathsync($;$) {
987 }; 1081 };
988 1082
989 $grp 1083 $grp
990} 1084}
991 1085
1086=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1087
1088This is a rather advanced IO::AIO call, which only works on mmap(2)ed
1089scalars (see the C<IO::AIO::mmap> function, although it also works on data
1090scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
1091scalar must only be modified in-place while an aio operation is pending on
1092it).
1093
1094It calls the C<msync> function of your OS, if available, with the memory
1095area starting at C<$offset> in the string and ending C<$length> bytes
1096later. If C<$length> is negative, counts from the end, and if C<$length>
1097is C<undef>, then it goes till the end of the string. The flags can be
1098a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
1099C<IO::AIO::MS_SYNC>.
1100
1101=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1102
1103This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1104scalars.
1105
1106It touches (reads or writes) all memory pages in the specified
1107range inside the scalar. All caveats and parameters are the same
1108as for C<aio_msync>, above, except for flags, which must be either
1109C<0> (which reads all pages and ensures they are instantiated) or
1110C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
1111writing an octet from it, which dirties the page).
1112
992=item aio_group $callback->(...) 1113=item aio_group $callback->(...)
993 1114
994This is a very special aio request: Instead of doing something, it is a 1115This is a very special aio request: Instead of doing something, it is a
995container for other aio requests, which is useful if you want to bundle 1116container for other aio requests, which is useful if you want to bundle
996many requests into a single, composite, request with a definite callback 1117many requests into a single, composite, request with a definite callback
1045=item cancel $req 1166=item cancel $req
1046 1167
1047Cancels the request, if possible. Has the effect of skipping execution 1168Cancels the request, if possible. Has the effect of skipping execution
1048when entering the B<execute> state and skipping calling the callback when 1169when entering the B<execute> state and skipping calling the callback when
1049entering the the B<result> state, but will leave the request otherwise 1170entering the the B<result> state, but will leave the request otherwise
1050untouched. That means that requests that currently execute will not be 1171untouched (with the exception of readdir). That means that requests that
1051stopped and resources held by the request will not be freed prematurely. 1172currently execute will not be stopped and resources held by the request
1173will not be freed prematurely.
1052 1174
1053=item cb $req $callback->(...) 1175=item cb $req $callback->(...)
1054 1176
1055Replace (or simply set) the callback registered to the request. 1177Replace (or simply set) the callback registered to the request.
1056 1178
1129 1251
1130=item $grp->cancel_subs 1252=item $grp->cancel_subs
1131 1253
1132Cancel all subrequests and clears any feeder, but not the group request 1254Cancel all subrequests and clears any feeder, but not the group request
1133itself. Useful when you queued a lot of events but got a result early. 1255itself. Useful when you queued a lot of events but got a result early.
1256
1257The group request will finish normally (you cannot add requests to the
1258group).
1134 1259
1135=item $grp->result (...) 1260=item $grp->result (...)
1136 1261
1137Set the result value(s) that will be passed to the group callback when all 1262Set the result value(s) that will be passed to the group callback when all
1138subrequests have finished and set the groups errno to the current value 1263subrequests have finished and set the groups errno to the current value
1207=over 4 1332=over 4
1208 1333
1209=item $fileno = IO::AIO::poll_fileno 1334=item $fileno = IO::AIO::poll_fileno
1210 1335
1211Return the I<request result pipe file descriptor>. This filehandle must be 1336Return the I<request result pipe file descriptor>. This filehandle must be
1212polled for reading by some mechanism outside this module (e.g. Event or 1337polled for reading by some mechanism outside this module (e.g. EV, Glib,
1213select, see below or the SYNOPSIS). If the pipe becomes readable you have 1338select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1214to call C<poll_cb> to check the results. 1339you have to call C<poll_cb> to check the results.
1215 1340
1216See C<poll_cb> for an example. 1341See C<poll_cb> for an example.
1217 1342
1218=item IO::AIO::poll_cb 1343=item IO::AIO::poll_cb
1219 1344
1226If not all requests were processed for whatever reason, the filehandle 1351If not all requests were processed for whatever reason, the filehandle
1227will still be ready when C<poll_cb> returns, so normally you don't have to 1352will still be ready when C<poll_cb> returns, so normally you don't have to
1228do anything special to have it called later. 1353do anything special to have it called later.
1229 1354
1230Example: Install an Event watcher that automatically calls 1355Example: Install an Event watcher that automatically calls
1231IO::AIO::poll_cb with high priority: 1356IO::AIO::poll_cb with high priority (more examples can be found in the
1357SYNOPSIS section, at the top of this document):
1232 1358
1233 Event->io (fd => IO::AIO::poll_fileno, 1359 Event->io (fd => IO::AIO::poll_fileno,
1234 poll => 'r', async => 1, 1360 poll => 'r', async => 1,
1235 cb => \&IO::AIO::poll_cb); 1361 cb => \&IO::AIO::poll_cb);
1362
1363=item IO::AIO::poll_wait
1364
1365If there are any outstanding requests and none of them in the result
1366phase, wait till the result filehandle becomes ready for reading (simply
1367does a C<select> on the filehandle. This is useful if you want to
1368synchronously wait for some requests to finish).
1369
1370See C<nreqs> for an example.
1371
1372=item IO::AIO::poll
1373
1374Waits until some requests have been handled.
1375
1376Returns the number of requests processed, but is otherwise strictly
1377equivalent to:
1378
1379 IO::AIO::poll_wait, IO::AIO::poll_cb
1380
1381=item IO::AIO::flush
1382
1383Wait till all outstanding AIO requests have been handled.
1384
1385Strictly equivalent to:
1386
1387 IO::AIO::poll_wait, IO::AIO::poll_cb
1388 while IO::AIO::nreqs;
1236 1389
1237=item IO::AIO::max_poll_reqs $nreqs 1390=item IO::AIO::max_poll_reqs $nreqs
1238 1391
1239=item IO::AIO::max_poll_time $seconds 1392=item IO::AIO::max_poll_time $seconds
1240 1393
1265 # use a low priority so other tasks have priority 1418 # use a low priority so other tasks have priority
1266 Event->io (fd => IO::AIO::poll_fileno, 1419 Event->io (fd => IO::AIO::poll_fileno,
1267 poll => 'r', nice => 1, 1420 poll => 'r', nice => 1,
1268 cb => &IO::AIO::poll_cb); 1421 cb => &IO::AIO::poll_cb);
1269 1422
1270=item IO::AIO::poll_wait
1271
1272If there are any outstanding requests and none of them in the result
1273phase, wait till the result filehandle becomes ready for reading (simply
1274does a C<select> on the filehandle. This is useful if you want to
1275synchronously wait for some requests to finish).
1276
1277See C<nreqs> for an example.
1278
1279=item IO::AIO::poll
1280
1281Waits until some requests have been handled.
1282
1283Returns the number of requests processed, but is otherwise strictly
1284equivalent to:
1285
1286 IO::AIO::poll_wait, IO::AIO::poll_cb
1287
1288=item IO::AIO::flush
1289
1290Wait till all outstanding AIO requests have been handled.
1291
1292Strictly equivalent to:
1293
1294 IO::AIO::poll_wait, IO::AIO::poll_cb
1295 while IO::AIO::nreqs;
1296
1297=back 1423=back
1298 1424
1299=head3 CONTROLLING THE NUMBER OF THREADS 1425=head3 CONTROLLING THE NUMBER OF THREADS
1300 1426
1301=over 1427=over
1393Returns the number of requests currently in the pending state (executed, 1519Returns the number of requests currently in the pending state (executed,
1394but not yet processed by poll_cb). 1520but not yet processed by poll_cb).
1395 1521
1396=back 1522=back
1397 1523
1524=head3 MISCELLANEOUS FUNCTIONS
1525
1526IO::AIO implements some functions that might be useful, but are not
1527asynchronous.
1528
1529=over 4
1530
1531=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1532
1533Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
1534but is blocking (this makes most sense if you know the input data is
1535likely cached already and the output filehandle is set to non-blocking
1536operations).
1537
1538Returns the number of bytes copied, or C<-1> on error.
1539
1540=item IO::AIO::fadvise $fh, $offset, $len, $advice
1541
1542Simply calls the C<posix_fadvise> function (see it's
1543manpage for details). The following advice constants are
1544avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1545C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1546C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1547
1548On systems that do not implement C<posix_fadvise>, this function returns
1549ENOSYS, otherwise the return value of C<posix_fadvise>.
1550
1551=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1552
1553Memory-maps a file (or anonymous memory range) and attaches it to the
1554given C<$scalar>, which will act like a string scalar.
1555
1556The only operations allowed on the scalar are C<substr>/C<vec> that don't
1557change the string length, and most read-only operations such as copying it
1558or searching it with regexes and so on.
1559
1560Anything else is unsafe and will, at best, result in memory leaks.
1561
1562The memory map associated with the C<$scalar> is automatically removed
1563when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
1564C<IO::AIO::munmap> functions are called.
1565
1566This calls the C<mmap>(2) function internally. See your system's manual
1567page for details on the C<$length>, C<$prot> and C<$flags> parameters.
1568
1569The C<$length> must be larger than zero and smaller than the actual
1570filesize.
1571
1572C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1573C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1574
1575C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
1576C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
1577not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
1578(which is set to C<MAP_ANON> if your system only provides this
1579constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
1580C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
1581C<IO::AIO::MAP_NONBLOCK>
1582
1583If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1584
1585C<$offset> is the offset from the start of the file - it generally must be
1586a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
1587
1588Example:
1589
1590 use Digest::MD5;
1591 use IO::AIO;
1592
1593 open my $fh, "<verybigfile"
1594 or die "$!";
1595
1596 IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
1597 or die "verybigfile: $!";
1598
1599 my $fast_md5 = md5 $data;
1600
1601=item IO::AIO::munmap $scalar
1602
1603Removes a previous mmap and undefines the C<$scalar>.
1604
1605=item IO::AIO::mlockall $flags
1606
1607Calls the C<mlockall> function with the given C<$flags> (a combination of
1608C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL__FUTURE>).
1609
1610On systems that do not implement C<mlockall>, this function returns
1611ENOSYS, otherwise the return value of C<mlockall>.
1612
1613=item IO::AIO::munlockall
1614
1615Calls the C<munlockall> function.
1616
1617On systems that do not implement C<munlockall>, this function returns
1618ENOSYS, otherwise the return value of C<munlockall>.
1619
1620=back
1621
1398=cut 1622=cut
1399 1623
1400min_parallel 8; 1624min_parallel 8;
1401 1625
1402END { flush } 1626END { flush }
1403 1627
14041; 16281;
1629
1630=head1 EVENT LOOP INTEGRATION
1631
1632It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
1633automatically into many event loops:
1634
1635 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
1636 use AnyEvent::AIO;
1637
1638You can also integrate IO::AIO manually into many event loops, here are
1639some examples of how to do this:
1640
1641 # EV integration
1642 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
1643
1644 # Event integration
1645 Event->io (fd => IO::AIO::poll_fileno,
1646 poll => 'r',
1647 cb => \&IO::AIO::poll_cb);
1648
1649 # Glib/Gtk2 integration
1650 add_watch Glib::IO IO::AIO::poll_fileno,
1651 in => sub { IO::AIO::poll_cb; 1 };
1652
1653 # Tk integration
1654 Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
1655 readable => \&IO::AIO::poll_cb);
1656
1657 # Danga::Socket integration
1658 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
1659 \&IO::AIO::poll_cb);
1405 1660
1406=head2 FORK BEHAVIOUR 1661=head2 FORK BEHAVIOUR
1407 1662
1408This module should do "the right thing" when the process using it forks: 1663This module should do "the right thing" when the process using it forks:
1409 1664

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