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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.199 by root, Wed Jun 29 12:46:36 2011 UTC vs.
Revision 1.229 by root, Wed Jul 25 16:32:30 2012 UTC

168use common::sense; 168use common::sense;
169 169
170use base 'Exporter'; 170use base 'Exporter';
171 171
172BEGIN { 172BEGIN {
173 our $VERSION = '3.92'; 173 our $VERSION = '4.15';
174 174
175 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close 175 our @AIO_REQ = qw(aio_sendfile aio_seek aio_read aio_write aio_open aio_close
176 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
177 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync 177 aio_scandir aio_symlink aio_readlink aio_realpath aio_sync
178 aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead 178 aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range aio_fallocate
179 aio_pathsync aio_readahead aio_fiemap
179 aio_rename aio_link aio_move aio_copy aio_group 180 aio_rename aio_link aio_move aio_copy aio_group
180 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown 181 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
181 aio_chmod aio_utime aio_truncate 182 aio_chmod aio_utime aio_truncate
182 aio_msync aio_mtouch aio_mlock aio_mlockall 183 aio_msync aio_mtouch aio_mlock aio_mlockall
183 aio_statvfs); 184 aio_statvfs
185 aio_wd);
184 186
185 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); 187 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
186 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 188 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
187 min_parallel max_parallel max_idle idle_timeout 189 min_parallel max_parallel max_idle idle_timeout
188 nreqs nready npending nthreads 190 nreqs nready npending nthreads
204 206
205This section simply lists the prototypes of the most important functions 207This section simply lists the prototypes of the most important functions
206for quick reference. See the following sections for function-by-function 208for quick reference. See the following sections for function-by-function
207documentation. 209documentation.
208 210
211 aio_wd $pathname, $callback->($wd)
209 aio_open $pathname, $flags, $mode, $callback->($fh) 212 aio_open $pathname, $flags, $mode, $callback->($fh)
210 aio_close $fh, $callback->($status) 213 aio_close $fh, $callback->($status)
214 aio_seek $fh,$offset,$whence, $callback->($offs)
211 aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 215 aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
212 aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 216 aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
213 aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) 217 aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
214 aio_readahead $fh,$offset,$length, $callback->($retval) 218 aio_readahead $fh,$offset,$length, $callback->($retval)
215 aio_stat $fh_or_path, $callback->($status) 219 aio_stat $fh_or_path, $callback->($status)
216 aio_lstat $fh, $callback->($status) 220 aio_lstat $fh, $callback->($status)
217 aio_statvfs $fh_or_path, $callback->($statvfs) 221 aio_statvfs $fh_or_path, $callback->($statvfs)
218 aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 222 aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
219 aio_chown $fh_or_path, $uid, $gid, $callback->($status) 223 aio_chown $fh_or_path, $uid, $gid, $callback->($status)
224 aio_chmod $fh_or_path, $mode, $callback->($status)
220 aio_truncate $fh_or_path, $offset, $callback->($status) 225 aio_truncate $fh_or_path, $offset, $callback->($status)
221 aio_chmod $fh_or_path, $mode, $callback->($status) 226 aio_allocate $fh, $mode, $offset, $len, $callback->($status)
222 aio_unlink $pathname, $callback->($status) 227 aio_unlink $pathname, $callback->($status)
223 aio_mknod $path, $mode, $dev, $callback->($status) 228 aio_mknod $pathname, $mode, $dev, $callback->($status)
224 aio_link $srcpath, $dstpath, $callback->($status) 229 aio_link $srcpath, $dstpath, $callback->($status)
225 aio_symlink $srcpath, $dstpath, $callback->($status) 230 aio_symlink $srcpath, $dstpath, $callback->($status)
226 aio_readlink $path, $callback->($link) 231 aio_readlink $pathname, $callback->($link)
232 aio_realpath $pathname, $callback->($link)
227 aio_rename $srcpath, $dstpath, $callback->($status) 233 aio_rename $srcpath, $dstpath, $callback->($status)
228 aio_mkdir $pathname, $mode, $callback->($status) 234 aio_mkdir $pathname, $mode, $callback->($status)
229 aio_rmdir $pathname, $callback->($status) 235 aio_rmdir $pathname, $callback->($status)
230 aio_readdir $pathname, $callback->($entries) 236 aio_readdir $pathname, $callback->($entries)
231 aio_readdirx $pathname, $flags, $callback->($entries, $flags) 237 aio_readdirx $pathname, $flags, $callback->($entries, $flags)
232 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST 238 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
233 IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN 239 IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN
240 aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
234 aio_load $path, $data, $callback->($status) 241 aio_load $pathname, $data, $callback->($status)
235 aio_copy $srcpath, $dstpath, $callback->($status) 242 aio_copy $srcpath, $dstpath, $callback->($status)
236 aio_move $srcpath, $dstpath, $callback->($status) 243 aio_move $srcpath, $dstpath, $callback->($status)
237 aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
238 aio_rmtree $path, $callback->($status) 244 aio_rmtree $pathname, $callback->($status)
239 aio_sync $callback->($status) 245 aio_sync $callback->($status)
246 aio_syncfs $fh, $callback->($status)
240 aio_fsync $fh, $callback->($status) 247 aio_fsync $fh, $callback->($status)
241 aio_fdatasync $fh, $callback->($status) 248 aio_fdatasync $fh, $callback->($status)
242 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) 249 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
243 aio_pathsync $path, $callback->($status) 250 aio_pathsync $pathname, $callback->($status)
244 aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 251 aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
245 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 252 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
246 aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) 253 aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
247 aio_mlockall $flags, $callback->($status) 254 aio_mlockall $flags, $callback->($status)
248 aio_group $callback->(...) 255 aio_group $callback->(...)
266 IO::AIO::nready 273 IO::AIO::nready
267 IO::AIO::npending 274 IO::AIO::npending
268 275
269 IO::AIO::sendfile $ofh, $ifh, $offset, $count 276 IO::AIO::sendfile $ofh, $ifh, $offset, $count
270 IO::AIO::fadvise $fh, $offset, $len, $advice 277 IO::AIO::fadvise $fh, $offset, $len, $advice
278 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
279 IO::AIO::munmap $scalar
271 IO::AIO::madvise $scalar, $offset, $length, $advice 280 IO::AIO::madvise $scalar, $offset, $length, $advice
272 IO::AIO::mprotect $scalar, $offset, $length, $protect 281 IO::AIO::mprotect $scalar, $offset, $length, $protect
273 IO::AIO::munlock $scalar, $offset = 0, $length = undef 282 IO::AIO::munlock $scalar, $offset = 0, $length = undef
274 IO::AIO::munlockall 283 IO::AIO::munlockall
275 284
276=head2 AIO REQUEST FUNCTIONS 285=head2 API NOTES
277 286
278All the C<aio_*> calls are more or less thin wrappers around the syscall 287All the C<aio_*> calls are more or less thin wrappers around the syscall
279with the same name (sans C<aio_>). The arguments are similar or identical, 288with the same name (sans C<aio_>). The arguments are similar or identical,
280and they all accept an additional (and optional) C<$callback> argument 289and they all accept an additional (and optional) C<$callback> argument
281which must be a code reference. This code reference will get called with 290which must be a code reference. This code reference will be called after
282the syscall return code (e.g. most syscalls return C<-1> on error, unlike 291the syscall has been executed in an asynchronous fashion. The results
283perl, which usually delivers "false") as its sole argument after the given 292of the request will be passed as arguments to the callback (and, if an
284syscall has been executed asynchronously. 293error occured, in C<$!>) - for most requests the syscall return code (e.g.
294most syscalls return C<-1> on error, unlike perl, which usually delivers
295"false").
296
297Some requests (such as C<aio_readdir>) pass the actual results and
298communicate failures by passing C<undef>.
285 299
286All functions expecting a filehandle keep a copy of the filehandle 300All functions expecting a filehandle keep a copy of the filehandle
287internally until the request has finished. 301internally until the request has finished.
288 302
289All functions return request objects of type L<IO::AIO::REQ> that allow 303All functions return request objects of type L<IO::AIO::REQ> that allow
290further manipulation of those requests while they are in-flight. 304further manipulation of those requests while they are in-flight.
291 305
292The pathnames you pass to these routines I<must> be absolute and 306The pathnames you pass to these routines I<should> be absolute. The
293encoded as octets. The reason for the former is that at the time the 307reason for this is that at the time the request is being executed, the
294request is being executed, the current working directory could have 308current working directory could have changed. Alternatively, you can
295changed. Alternatively, you can make sure that you never change the 309make sure that you never change the current working directory anywhere
296current working directory anywhere in the program and then use relative 310in the program and then use relative paths. You can also take advantage
297paths. 311of IO::AIOs working directory abstraction, that lets you specify paths
312relative to some previously-opened "working directory object" - see the
313description of the C<IO::AIO::WD> class later in this document.
298 314
299To encode pathnames as octets, either make sure you either: a) always pass 315To encode pathnames as octets, either make sure you either: a) always pass
300in filenames you got from outside (command line, readdir etc.) without 316in filenames you got from outside (command line, readdir etc.) without
301tinkering, b) are ASCII or ISO 8859-1, c) use the Encode module and encode 317tinkering, b) are in your native filesystem encoding, c) use the Encode
302your pathnames to the locale (or other) encoding in effect in the user 318module and encode your pathnames to the locale (or other) encoding in
303environment, d) use Glib::filename_from_unicode on unicode filenames or e) 319effect in the user environment, d) use Glib::filename_from_unicode on
304use something else to ensure your scalar has the correct contents. 320unicode filenames or e) use something else to ensure your scalar has the
321correct contents.
305 322
306This works, btw. independent of the internal UTF-8 bit, which IO::AIO 323This works, btw. independent of the internal UTF-8 bit, which IO::AIO
307handles correctly whether it is set or not. 324handles correctly whether it is set or not.
325
326=head2 AIO REQUEST FUNCTIONS
308 327
309=over 4 328=over 4
310 329
311=item $prev_pri = aioreq_pri [$pri] 330=item $prev_pri = aioreq_pri [$pri]
312 331
394 413
395Or in other words: the file descriptor will be closed, but it will not be 414Or in other words: the file descriptor will be closed, but it will not be
396free for reuse until the perl filehandle is closed. 415free for reuse until the perl filehandle is closed.
397 416
398=cut 417=cut
418
419=item aio_seek $fh, $offset, $whence, $callback->($offs)
420
421Seeks the filehandle to the new C<$offset>, similarly to perl's
422C<sysseek>. The C<$whence> can use the traditional values (C<0> for
423C<IO::AIO::SEEK_SET>, C<1> for C<IO::AIO::SEEK_CUR> or C<2> for
424C<IO::AIO::SEEK_END>).
425
426The resulting absolute offset will be passed to the callback, or C<-1> in
427case of an error.
428
429In theory, the C<$whence> constants could be different than the
430corresponding values from L<Fcntl>, but perl guarantees they are the same,
431so don't panic.
432
433As a GNU/Linux (and maybe Solaris) extension, also the constants
434C<IO::AIO::SEEK_DATA> and C<IO::AIO::SEEK_HOLE> are available, if they
435could be found. No guarantees about suitability for use in C<aio_seek> or
436Perl's C<sysseek> can be made though, although I would naively assume they
437"just work".
399 438
400=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 439=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
401 440
402=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 441=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
403 442
600=item aio_truncate $fh_or_path, $offset, $callback->($status) 639=item aio_truncate $fh_or_path, $offset, $callback->($status)
601 640
602Works like truncate(2) or ftruncate(2). 641Works like truncate(2) or ftruncate(2).
603 642
604 643
644=item aio_allocate $fh, $mode, $offset, $len, $callback->($status)
645
646Allocates or freed disk space according to the C<$mode> argument. See the
647linux C<fallocate> docuemntation for details.
648
649C<$mode> can currently be C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE>
650to allocate space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE |
651IO::AIO::FALLOC_FL_KEEP_SIZE>, to deallocate a file range.
652
653The file system block size used by C<fallocate> is presumably the
654C<f_bsize> returned by C<statvfs>.
655
656If C<fallocate> isn't available or cannot be emulated (currently no
657emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>.
658
659
605=item aio_chmod $fh_or_path, $mode, $callback->($status) 660=item aio_chmod $fh_or_path, $mode, $callback->($status)
606 661
607Works like perl's C<chmod> function. 662Works like perl's C<chmod> function.
608 663
609 664
611 666
612Asynchronously unlink (delete) a file and call the callback with the 667Asynchronously unlink (delete) a file and call the callback with the
613result code. 668result code.
614 669
615 670
616=item aio_mknod $path, $mode, $dev, $callback->($status) 671=item aio_mknod $pathname, $mode, $dev, $callback->($status)
617 672
618[EXPERIMENTAL] 673[EXPERIMENTAL]
619 674
620Asynchronously create a device node (or fifo). See mknod(2). 675Asynchronously create a device node (or fifo). See mknod(2).
621 676
622The only (POSIX-) portable way of calling this function is: 677The only (POSIX-) portable way of calling this function is:
623 678
624 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... 679 aio_mknod $pathname, IO::AIO::S_IFIFO | $mode, 0, sub { ...
625 680
626See C<aio_stat> for info about some potentially helpful extra constants 681See C<aio_stat> for info about some potentially helpful extra constants
627and functions. 682and functions.
628 683
629=item aio_link $srcpath, $dstpath, $callback->($status) 684=item aio_link $srcpath, $dstpath, $callback->($status)
636 691
637Asynchronously create a new symbolic link to the existing object at C<$srcpath> at 692Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
638the path C<$dstpath> and call the callback with the result code. 693the path C<$dstpath> and call the callback with the result code.
639 694
640 695
641=item aio_readlink $path, $callback->($link) 696=item aio_readlink $pathname, $callback->($link)
642 697
643Asynchronously read the symlink specified by C<$path> and pass it to 698Asynchronously read the symlink specified by C<$path> and pass it to
644the callback. If an error occurs, nothing or undef gets passed to the 699the callback. If an error occurs, nothing or undef gets passed to the
645callback. 700callback.
646 701
647 702
703=item aio_realpath $pathname, $callback->($path)
704
705Asynchronously make the path absolute and resolve any symlinks in
706C<$path>. The resulting path only consists of directories (Same as
707L<Cwd::realpath>).
708
709This request can be used to get the absolute path of the current working
710directory by passing it a path of F<.> (a single dot).
711
712
648=item aio_rename $srcpath, $dstpath, $callback->($status) 713=item aio_rename $srcpath, $dstpath, $callback->($status)
649 714
650Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as 715Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
651rename(2) and call the callback with the result code. 716rename(2) and call the callback with the result code.
652 717
674array-ref with the filenames. 739array-ref with the filenames.
675 740
676 741
677=item aio_readdirx $pathname, $flags, $callback->($entries, $flags) 742=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
678 743
679Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune 744Quite similar to C<aio_readdir>, but the C<$flags> argument allows one to
680behaviour and output format. In case of an error, C<$entries> will be 745tune behaviour and output format. In case of an error, C<$entries> will be
681C<undef>. 746C<undef>.
682 747
683The flags are a combination of the following constants, ORed together (the 748The flags are a combination of the following constants, ORed together (the
684flags will also be passed to the callback, possibly modified): 749flags will also be passed to the callback, possibly modified):
685 750
732 797
733=item IO::AIO::READDIR_FOUND_UNKNOWN 798=item IO::AIO::READDIR_FOUND_UNKNOWN
734 799
735This flag should not be set when calling C<aio_readdirx>. Instead, it 800This flag should not be set when calling C<aio_readdirx>. Instead, it
736is being set by C<aio_readdirx>, when any of the C<$type>'s found were 801is being set by C<aio_readdirx>, when any of the C<$type>'s found were
737C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all 802C<IO::AIO::DT_UNKNOWN>. The absence of this flag therefore indicates that all
738C<$type>'s are known, which can be used to speed up some algorithms. 803C<$type>'s are known, which can be used to speed up some algorithms.
739 804
740=back 805=back
741 806
742 807
743=item aio_load $path, $data, $callback->($status) 808=item aio_load $pathname, $data, $callback->($status)
744 809
745This is a composite request that tries to fully load the given file into 810This is a composite request that tries to fully load the given file into
746memory. Status is the same as with aio_read. 811memory. Status is the same as with aio_read.
747 812
748=cut 813=cut
883 }; 948 };
884 949
885 $grp 950 $grp
886} 951}
887 952
888=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 953=item aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
889 954
890Scans a directory (similar to C<aio_readdir>) but additionally tries to 955Scans a directory (similar to C<aio_readdir>) but additionally tries to
891efficiently separate the entries of directory C<$path> into two sets of 956efficiently separate the entries of directory C<$path> into two sets of
892names, directories you can recurse into (directories), and ones you cannot 957names, directories you can recurse into (directories), and ones you cannot
893recurse into (everything else, including symlinks to directories). 958recurse into (everything else, including symlinks to directories).
924Then entries will be sorted into likely directories a non-initial dot 989Then entries will be sorted into likely directories a non-initial dot
925currently) and likely non-directories (see C<aio_readdirx>). Then every 990currently) and likely non-directories (see C<aio_readdirx>). Then every
926entry plus an appended C</.> will be C<stat>'ed, likely directories first, 991entry plus an appended C</.> will be C<stat>'ed, likely directories first,
927in order of their inode numbers. If that succeeds, it assumes that the 992in order of their inode numbers. If that succeeds, it assumes that the
928entry is a directory or a symlink to directory (which will be checked 993entry is a directory or a symlink to directory (which will be checked
929seperately). This is often faster than stat'ing the entry itself because 994separately). This is often faster than stat'ing the entry itself because
930filesystems might detect the type of the entry without reading the inode 995filesystems might detect the type of the entry without reading the inode
931data (e.g. ext2fs filetype feature), even on systems that cannot return 996data (e.g. ext2fs filetype feature), even on systems that cannot return
932the filetype information on readdir. 997the filetype information on readdir.
933 998
934If the known number of directories (link count - 2) has been reached, the 999If the known number of directories (link count - 2) has been reached, the
950 1015
951 my $grp = aio_group $cb; 1016 my $grp = aio_group $cb;
952 1017
953 $maxreq = 4 if $maxreq <= 0; 1018 $maxreq = 4 if $maxreq <= 0;
954 1019
955 # stat once 1020 # get a wd object
956 aioreq_pri $pri; 1021 aioreq_pri $pri;
957 add $grp aio_stat $path, sub { 1022 add $grp aio_wd $path, sub {
1023 $_[0]
958 return $grp->result () if $_[0]; 1024 or return $grp->result ();
959 my $now = time;
960 my $hash1 = join ":", (stat _)[0,1,3,7,9];
961 1025
962 # read the directory entries 1026 my $wd = [shift, "."];
1027
1028 # stat once
963 aioreq_pri $pri; 1029 aioreq_pri $pri;
964 add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub { 1030 add $grp aio_stat $wd, sub {
965 my $entries = shift
966 or return $grp->result (); 1031 return $grp->result () if $_[0];
1032 my $now = time;
1033 my $hash1 = join ":", (stat _)[0,1,3,7,9];
967 1034
968 # stat the dir another time 1035 # read the directory entries
969 aioreq_pri $pri; 1036 aioreq_pri $pri;
1037 add $grp aio_readdirx $wd, READDIR_DIRS_FIRST, sub {
1038 my $entries = shift
1039 or return $grp->result ();
1040
1041 # stat the dir another time
1042 aioreq_pri $pri;
970 add $grp aio_stat $path, sub { 1043 add $grp aio_stat $wd, sub {
971 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 1044 my $hash2 = join ":", (stat _)[0,1,3,7,9];
972 1045
973 my $ndirs; 1046 my $ndirs;
974 1047
975 # take the slow route if anything looks fishy 1048 # take the slow route if anything looks fishy
976 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 1049 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
977 $ndirs = -1; 1050 $ndirs = -1;
978 } else { 1051 } else {
979 # if nlink == 2, we are finished 1052 # if nlink == 2, we are finished
980 # for non-posix-fs's, we rely on nlink < 2 1053 # for non-posix-fs's, we rely on nlink < 2
981 $ndirs = (stat _)[3] - 2 1054 $ndirs = (stat _)[3] - 2
982 or return $grp->result ([], $entries); 1055 or return $grp->result ([], $entries);
983 } 1056 }
984 1057
985 my (@dirs, @nondirs); 1058 my (@dirs, @nondirs);
986 1059
987 my $statgrp = add $grp aio_group sub { 1060 my $statgrp = add $grp aio_group sub {
988 $grp->result (\@dirs, \@nondirs); 1061 $grp->result (\@dirs, \@nondirs);
989 }; 1062 };
990 1063
991 limit $statgrp $maxreq; 1064 limit $statgrp $maxreq;
992 feed $statgrp sub { 1065 feed $statgrp sub {
993 return unless @$entries; 1066 return unless @$entries;
994 my $entry = shift @$entries; 1067 my $entry = shift @$entries;
995 1068
996 aioreq_pri $pri; 1069 aioreq_pri $pri;
1070 $wd->[1] = "$entry/.";
997 add $statgrp aio_stat "$path/$entry/.", sub { 1071 add $statgrp aio_stat $wd, sub {
998 if ($_[0] < 0) { 1072 if ($_[0] < 0) {
999 push @nondirs, $entry; 1073 push @nondirs, $entry;
1000 } else { 1074 } else {
1001 # need to check for real directory 1075 # need to check for real directory
1002 aioreq_pri $pri; 1076 aioreq_pri $pri;
1077 $wd->[1] = $entry;
1003 add $statgrp aio_lstat "$path/$entry", sub { 1078 add $statgrp aio_lstat $wd, sub {
1004 if (-d _) { 1079 if (-d _) {
1005 push @dirs, $entry; 1080 push @dirs, $entry;
1006 1081
1007 unless (--$ndirs) { 1082 unless (--$ndirs) {
1008 push @nondirs, @$entries; 1083 push @nondirs, @$entries;
1009 feed $statgrp; 1084 feed $statgrp;
1085 }
1086 } else {
1087 push @nondirs, $entry;
1010 } 1088 }
1011 } else {
1012 push @nondirs, $entry;
1013 } 1089 }
1014 } 1090 }
1015 } 1091 };
1016 }; 1092 };
1017 }; 1093 };
1018 }; 1094 };
1019 }; 1095 };
1020 }; 1096 };
1021 1097
1022 $grp 1098 $grp
1023} 1099}
1024 1100
1025=item aio_rmtree $path, $callback->($status) 1101=item aio_rmtree $pathname, $callback->($status)
1026 1102
1027Delete a directory tree starting (and including) C<$path>, return the 1103Delete a directory tree starting (and including) C<$path>, return the
1028status of the final C<rmdir> only. This is a composite request that 1104status of the final C<rmdir> only. This is a composite request that
1029uses C<aio_scandir> to recurse into and rmdir directories, and unlink 1105uses C<aio_scandir> to recurse into and rmdir directories, and unlink
1030everything else. 1106everything else.
1072callback with the fdatasync result code. 1148callback with the fdatasync result code.
1073 1149
1074If this call isn't available because your OS lacks it or it couldn't be 1150If this call isn't available because your OS lacks it or it couldn't be
1075detected, it will be emulated by calling C<fsync> instead. 1151detected, it will be emulated by calling C<fsync> instead.
1076 1152
1153=item aio_syncfs $fh, $callback->($status)
1154
1155Asynchronously call the syncfs syscall to sync the filesystem associated
1156to the given filehandle and call the callback with the syncfs result
1157code. If syncfs is not available, calls sync(), but returns C<-1> and sets
1158errno to C<ENOSYS> nevertheless.
1159
1077=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) 1160=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
1078 1161
1079Sync the data portion of the file specified by C<$offset> and C<$length> 1162Sync the data portion of the file specified by C<$offset> and C<$length>
1080to disk (but NOT the metadata), by calling the Linux-specific 1163to disk (but NOT the metadata), by calling the Linux-specific
1081sync_file_range call. If sync_file_range is not available or it returns 1164sync_file_range call. If sync_file_range is not available or it returns
1084C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>, 1167C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
1085C<IO::AIO::SYNC_FILE_RANGE_WRITE> and 1168C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
1086C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range 1169C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
1087manpage for details. 1170manpage for details.
1088 1171
1089=item aio_pathsync $path, $callback->($status) 1172=item aio_pathsync $pathname, $callback->($status)
1090 1173
1091This request tries to open, fsync and close the given path. This is a 1174This request tries to open, fsync and close the given path. This is a
1092composite request intended to sync directories after directory operations 1175composite request intended to sync directories after directory operations
1093(E.g. rename). This might not work on all operating systems or have any 1176(E.g. rename). This might not work on all operating systems or have any
1094specific effect, but usually it makes sure that directory changes get 1177specific effect, but usually it makes sure that directory changes get
1191 1274
1192Example: asynchronously lock all current and future pages into memory. 1275Example: asynchronously lock all current and future pages into memory.
1193 1276
1194 aio_mlockall IO::AIO::MCL_FUTURE; 1277 aio_mlockall IO::AIO::MCL_FUTURE;
1195 1278
1279=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
1280
1281Queries the extents of the given file (by calling the Linux FIEMAP ioctl,
1282see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If the
1283C<ioctl> is not available on your OS, then this rquiest will fail with
1284C<ENOSYS>.
1285
1286C<$start> is the starting offset to query extents for, C<$length> is the
1287size of the range to query - if it is C<undef>, then the whole file will
1288be queried.
1289
1290C<$flags> is a combination of flags (C<IO::AIO::FIEMAP_FLAG_SYNC> or
1291C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also
1292exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query
1293the data portion.
1294
1295C<$count> is the maximum number of extent records to return. If it is
1296C<undef>, then IO::AIO queries all extents of the file. As a very special
1297case, if it is C<0>, then the callback receives the number of extents
1298instead of the extents themselves.
1299
1300If an error occurs, the callback receives no arguments. The special
1301C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.
1302
1303Otherwise, the callback receives an array reference with extent
1304structures. Each extent structure is an array reference itself, with the
1305following members:
1306
1307 [$logical, $physical, $length, $flags]
1308
1309Flags is any combination of the following flag values (typically either C<0>
1310or C<IO::AIO::FIEMAP_EXTENT_LAST>):
1311
1312C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,
1313C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,
1314C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
1315C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
1316C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
1317C<IO::AIO::FIEMAP_EXTENT_SHARED>.
1318
1196=item aio_group $callback->(...) 1319=item aio_group $callback->(...)
1197 1320
1198This is a very special aio request: Instead of doing something, it is a 1321This is a very special aio request: Instead of doing something, it is a
1199container for other aio requests, which is useful if you want to bundle 1322container for other aio requests, which is useful if you want to bundle
1200many requests into a single, composite, request with a definite callback 1323many requests into a single, composite, request with a definite callback
1236like sleep and file handle readable/writable, the overhead this creates is 1359like sleep and file handle readable/writable, the overhead this creates is
1237immense (it blocks a thread for a long time) so do not use this function 1360immense (it blocks a thread for a long time) so do not use this function
1238except to put your application under artificial I/O pressure. 1361except to put your application under artificial I/O pressure.
1239 1362
1240=back 1363=back
1364
1365
1366=head2 IO::AIO::WD - multiple working directories
1367
1368Your process only has one current working directory, which is used by all
1369threads. This makes it hard to use relative paths (some other component
1370could call C<chdir> at any time, and it is hard to control when the path
1371will be used by IO::AIO).
1372
1373One solution for this is to always use absolute paths. This usually works,
1374but can be quite slow (the kernel has to walk the whole path on every
1375access), and can also be a hassle to implement.
1376
1377Newer POSIX systems have a number of functions (openat, fdopendir,
1378futimensat and so on) that make it possible to specify working directories
1379per operation.
1380
1381For portability, and because the clowns who "designed", or shall I write,
1382perpetrated this new interface were obviously half-drunk, this abstraction
1383cannot be perfect, though.
1384
1385IO::AIO allows you to convert directory paths into a so-called IO::AIO::WD
1386object. This object stores the canonicalised, absolute version of the
1387path, and on systems that allow it, also a directory file descriptor.
1388
1389Everywhere where a pathname is accepted by IO::AIO (e.g. in C<aio_stat>
1390or C<aio_unlink>), one can specify an array reference with an IO::AIO::WD
1391object and a pathname instead (or the IO::AIO::WD object alone, which
1392gets interpreted as C<[$wd, "."]>). If the pathname is absolute, the
1393IO::AIO::WD object is ignored, otherwise the pathname is resolved relative
1394to that IO::AIO::WD object.
1395
1396For example, to get a wd object for F</etc> and then stat F<passwd>
1397inside, you would write:
1398
1399 aio_wd "/etc", sub {
1400 my $etcdir = shift;
1401
1402 # although $etcdir can be undef on error, there is generally no reason
1403 # to check for errors here, as aio_stat will fail with ENOENT
1404 # when $etcdir is undef.
1405
1406 aio_stat [$etcdir, "passwd"], sub {
1407 # yay
1408 };
1409 };
1410
1411That C<aio_wd> is a request and not a normal function shows that creating
1412an IO::AIO::WD object is itself a potentially blocking operation, which is
1413why it is done asynchronously.
1414
1415To stat the directory obtained with C<aio_wd> above, one could write
1416either of the following three request calls:
1417
1418 aio_lstat "/etc" , sub { ... # pathname as normal string
1419 aio_lstat [$wd, "."], sub { ... # "." relative to $wd (i.e. $wd itself)
1420 aio_lstat $wd , sub { ... # shorthand for the previous
1421
1422As with normal pathnames, IO::AIO keeps a copy of the working directory
1423object and the pathname string, so you could write the following without
1424causing any issues due to C<$path> getting reused:
1425
1426 my $path = [$wd, undef];
1427
1428 for my $name (qw(abc def ghi)) {
1429 $path->[1] = $name;
1430 aio_stat $path, sub {
1431 # ...
1432 };
1433 }
1434
1435There are some caveats: when directories get renamed (or deleted), the
1436pathname string doesn't change, so will point to the new directory (or
1437nowhere at all), while the directory fd, if available on the system,
1438will still point to the original directory. Most functions accepting a
1439pathname will use the directory fd on newer systems, and the string on
1440older systems. Some functions (such as realpath) will always rely on the
1441string form of the pathname.
1442
1443So this fucntionality is mainly useful to get some protection against
1444C<chdir>, to easily get an absolute path out of a relative path for future
1445reference, and to speed up doing many operations in the same directory
1446(e.g. when stat'ing all files in a directory).
1447
1448The following functions implement this working directory abstraction:
1449
1450=over 4
1451
1452=item aio_wd $pathname, $callback->($wd)
1453
1454Asynchonously canonicalise the given pathname and convert it to an
1455IO::AIO::WD object representing it. If possible and supported on the
1456system, also open a directory fd to speed up pathname resolution relative
1457to this working directory.
1458
1459If something goes wrong, then C<undef> is passwd to the callback instead
1460of a working directory object and C<$!> is set appropriately. Since
1461passing C<undef> as working directory component of a pathname fails the
1462request with C<ENOENT>, there is often no need for error checking in the
1463C<aio_wd> callback, as future requests using the value will fail in the
1464expected way.
1465
1466If this call isn't available because your OS lacks it or it couldn't be
1467detected, it will be emulated by calling C<fsync> instead.
1468
1469=item IO::AIO::CWD
1470
1471This is a compiletime constant (object) that represents the process
1472current working directory.
1473
1474Specifying this object as working directory object for a pathname is as
1475if the pathname would be specified directly, without a directory object,
1476e.g., these calls are functionally identical:
1477
1478 aio_stat "somefile", sub { ... };
1479 aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
1480
1481=back
1482
1241 1483
1242=head2 IO::AIO::REQ CLASS 1484=head2 IO::AIO::REQ CLASS
1243 1485
1244All non-aggregate C<aio_*> functions return an object of this class when 1486All non-aggregate C<aio_*> functions return an object of this class when
1245called in non-void context. 1487called in non-void context.
1363 1605
1364Sets a feeder/generator on this group: every group can have an attached 1606Sets a feeder/generator on this group: every group can have an attached
1365generator that generates requests if idle. The idea behind this is that, 1607generator that generates requests if idle. The idea behind this is that,
1366although you could just queue as many requests as you want in a group, 1608although you could just queue as many requests as you want in a group,
1367this might starve other requests for a potentially long time. For example, 1609this might starve other requests for a potentially long time. For example,
1368C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests, 1610C<aio_scandir> might generate hundreds of thousands of C<aio_stat>
1369delaying any later requests for a long time. 1611requests, delaying any later requests for a long time.
1370 1612
1371To avoid this, and allow incremental generation of requests, you can 1613To avoid this, and allow incremental generation of requests, you can
1372instead a group and set a feeder on it that generates those requests. The 1614instead a group and set a feeder on it that generates those requests. The
1373feed callback will be called whenever there are few enough (see C<limit>, 1615feed callback will be called whenever there are few enough (see C<limit>,
1374below) requests active in the group itself and is expected to queue more 1616below) requests active in the group itself and is expected to queue more
1653 1895
1654=item IO::AIO::fadvise $fh, $offset, $len, $advice 1896=item IO::AIO::fadvise $fh, $offset, $len, $advice
1655 1897
1656Simply calls the C<posix_fadvise> function (see its 1898Simply calls the C<posix_fadvise> function (see its
1657manpage for details). The following advice constants are 1899manpage for details). The following advice constants are
1658avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>, 1900available: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1659C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>, 1901C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1660C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>. 1902C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1661 1903
1662On systems that do not implement C<posix_fadvise>, this function returns 1904On systems that do not implement C<posix_fadvise>, this function returns
1663ENOSYS, otherwise the return value of C<posix_fadvise>. 1905ENOSYS, otherwise the return value of C<posix_fadvise>.
1664 1906
1665=item IO::AIO::madvise $scalar, $offset, $len, $advice 1907=item IO::AIO::madvise $scalar, $offset, $len, $advice
1666 1908
1667Simply calls the C<posix_madvise> function (see its 1909Simply calls the C<posix_madvise> function (see its
1668manpage for details). The following advice constants are 1910manpage for details). The following advice constants are
1669avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>, 1911available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
1670C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>. 1912C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.
1671 1913
1672On systems that do not implement C<posix_madvise>, this function returns 1914On systems that do not implement C<posix_madvise>, this function returns
1673ENOSYS, otherwise the return value of C<posix_madvise>. 1915ENOSYS, otherwise the return value of C<posix_madvise>.
1674 1916
1675=item IO::AIO::mprotect $scalar, $offset, $len, $protect 1917=item IO::AIO::mprotect $scalar, $offset, $len, $protect
1676 1918
1677Simply calls the C<mprotect> function on the preferably AIO::mmap'ed 1919Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
1678$scalar (see its manpage for details). The following protect 1920$scalar (see its manpage for details). The following protect
1679constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>, 1921constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
1680C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>. 1922C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
1681 1923
1682On systems that do not implement C<mprotect>, this function returns 1924On systems that do not implement C<mprotect>, this function returns
1683ENOSYS, otherwise the return value of C<mprotect>. 1925ENOSYS, otherwise the return value of C<mprotect>.
1684 1926
1685=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] 1927=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1686 1928
1687Memory-maps a file (or anonymous memory range) and attaches it to the 1929Memory-maps a file (or anonymous memory range) and attaches it to the
1688given C<$scalar>, which will act like a string scalar. 1930given C<$scalar>, which will act like a string scalar. Returns true on
1931success, and false otherwise.
1689 1932
1690The only operations allowed on the scalar are C<substr>/C<vec> that don't 1933The only operations allowed on the scalar are C<substr>/C<vec> that don't
1691change the string length, and most read-only operations such as copying it 1934change the string length, and most read-only operations such as copying it
1692or searching it with regexes and so on. 1935or searching it with regexes and so on.
1693 1936
1746Calls the C<munlockall> function. 1989Calls the C<munlockall> function.
1747 1990
1748On systems that do not implement C<munlockall>, this function returns 1991On systems that do not implement C<munlockall>, this function returns
1749ENOSYS, otherwise the return value of C<munlockall>. 1992ENOSYS, otherwise the return value of C<munlockall>.
1750 1993
1994=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
1995
1996Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or
1997C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
1998should be the file offset.
1999
2000C<$r_fh> and C<$w_fh> should not refer to the same file, as splice might
2001silently corrupt the data in this case.
2002
2003The following symbol flag values are available: C<IO::AIO::SPLICE_F_MOVE>,
2004C<IO::AIO::SPLICE_F_NONBLOCK>, C<IO::AIO::SPLICE_F_MORE> and
2005C<IO::AIO::SPLICE_F_GIFT>.
2006
2007See the C<splice(2)> manpage for details.
2008
2009=item IO::AIO::tee $r_fh, $w_fh, $length, $flags
2010
2011Calls the GNU/Linux C<tee(2)> syscall, see it's manpage and the
2012description for C<IO::AIO::splice> above for details.
2013
1751=back 2014=back
1752 2015
1753=cut 2016=cut
1754 2017
1755min_parallel 8; 2018min_parallel 8;
1792=head2 FORK BEHAVIOUR 2055=head2 FORK BEHAVIOUR
1793 2056
1794Usage of pthreads in a program changes the semantics of fork 2057Usage of pthreads in a program changes the semantics of fork
1795considerably. Specifically, only async-safe functions can be called after 2058considerably. Specifically, only async-safe functions can be called after
1796fork. Perl doesn't know about this, so in general, you cannot call fork 2059fork. Perl doesn't know about this, so in general, you cannot call fork
1797with defined behaviour in perl. IO::AIO uses pthreads, so this applies, 2060with defined behaviour in perl if pthreads are involved. IO::AIO uses
1798but many other extensions and (for inexplicable reasons) perl itself often 2061pthreads, so this applies, but many other extensions and (for inexplicable
1799is linked against pthreads, so this limitation applies. 2062reasons) perl itself often is linked against pthreads, so this limitation
2063applies to quite a lot of perls.
1800 2064
1801Some operating systems have extensions that allow safe use of fork, and 2065This module no longer tries to fight your OS, or POSIX. That means IO::AIO
1802this module should do "the right thing" on those, and tries on others. At 2066only works in the process that loaded it. Forking is fully supported, but
1803the time of this writing (2011) only GNU/Linux supports these extensions 2067using IO::AIO in the child is not.
1804to POSIX. 2068
2069You might get around by not I<using> IO::AIO before (or after)
2070forking. You could also try to call the L<IO::AIO::reinit> function in the
2071child:
2072
2073=over 4
2074
2075=item IO::AIO::reinit
2076
2077Abandons all current requests and I/O threads and simply reinitialises all
2078data structures. This is not an operation supported by any standards, but
2079happens to work on GNU/Linux and some newer BSD systems.
2080
2081The only reasonable use for this function is to call it after forking, if
2082C<IO::AIO> was used in the parent. Calling it while IO::AIO is active in
2083the process will result in undefined behaviour. Calling it at any time
2084will also result in any undefined (by POSIX) behaviour.
2085
2086=back
1805 2087
1806=head2 MEMORY USAGE 2088=head2 MEMORY USAGE
1807 2089
1808Per-request usage: 2090Per-request usage:
1809 2091

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