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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.200 by root, Wed Jun 29 21:45:09 2011 UTC vs.
Revision 1.230 by root, Fri Jul 27 17:24:06 2012 UTC

168use common::sense; 168use common::sense;
169 169
170use base 'Exporter'; 170use base 'Exporter';
171 171
172BEGIN { 172BEGIN {
173 our $VERSION = '3.93'; 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
200 202
201=head1 FUNCTIONS 203=head1 FUNCTIONS
202 204
203=head2 QUICK OVERVIEW 205=head2 QUICK OVERVIEW
204 206
205This section simply lists the prototypes of the most important functions 207This section simply lists the prototypes most of the functions for
206for quick reference. See the following sections for function-by-function 208quick 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)
227 aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
222 aio_unlink $pathname, $callback->($status) 228 aio_unlink $pathname, $callback->($status)
223 aio_mknod $path, $mode, $dev, $callback->($status) 229 aio_mknod $pathname, $mode, $dev, $callback->($status)
224 aio_link $srcpath, $dstpath, $callback->($status) 230 aio_link $srcpath, $dstpath, $callback->($status)
225 aio_symlink $srcpath, $dstpath, $callback->($status) 231 aio_symlink $srcpath, $dstpath, $callback->($status)
226 aio_readlink $path, $callback->($link) 232 aio_readlink $pathname, $callback->($link)
233 aio_realpath $pathname, $callback->($link)
227 aio_rename $srcpath, $dstpath, $callback->($status) 234 aio_rename $srcpath, $dstpath, $callback->($status)
228 aio_mkdir $pathname, $mode, $callback->($status) 235 aio_mkdir $pathname, $mode, $callback->($status)
229 aio_rmdir $pathname, $callback->($status) 236 aio_rmdir $pathname, $callback->($status)
230 aio_readdir $pathname, $callback->($entries) 237 aio_readdir $pathname, $callback->($entries)
231 aio_readdirx $pathname, $flags, $callback->($entries, $flags) 238 aio_readdirx $pathname, $flags, $callback->($entries, $flags)
232 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST 239 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
233 IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN 240 IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN
241 aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
234 aio_load $path, $data, $callback->($status) 242 aio_load $pathname, $data, $callback->($status)
235 aio_copy $srcpath, $dstpath, $callback->($status) 243 aio_copy $srcpath, $dstpath, $callback->($status)
236 aio_move $srcpath, $dstpath, $callback->($status) 244 aio_move $srcpath, $dstpath, $callback->($status)
237 aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
238 aio_rmtree $path, $callback->($status) 245 aio_rmtree $pathname, $callback->($status)
239 aio_sync $callback->($status) 246 aio_sync $callback->($status)
247 aio_syncfs $fh, $callback->($status)
240 aio_fsync $fh, $callback->($status) 248 aio_fsync $fh, $callback->($status)
241 aio_fdatasync $fh, $callback->($status) 249 aio_fdatasync $fh, $callback->($status)
242 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) 250 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
243 aio_pathsync $path, $callback->($status) 251 aio_pathsync $pathname, $callback->($status)
244 aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 252 aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
245 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 253 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
246 aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) 254 aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
247 aio_mlockall $flags, $callback->($status) 255 aio_mlockall $flags, $callback->($status)
248 aio_group $callback->(...) 256 aio_group $callback->(...)
266 IO::AIO::nready 274 IO::AIO::nready
267 IO::AIO::npending 275 IO::AIO::npending
268 276
269 IO::AIO::sendfile $ofh, $ifh, $offset, $count 277 IO::AIO::sendfile $ofh, $ifh, $offset, $count
270 IO::AIO::fadvise $fh, $offset, $len, $advice 278 IO::AIO::fadvise $fh, $offset, $len, $advice
279 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
280 IO::AIO::munmap $scalar
271 IO::AIO::madvise $scalar, $offset, $length, $advice 281 IO::AIO::madvise $scalar, $offset, $length, $advice
272 IO::AIO::mprotect $scalar, $offset, $length, $protect 282 IO::AIO::mprotect $scalar, $offset, $length, $protect
273 IO::AIO::munlock $scalar, $offset = 0, $length = undef 283 IO::AIO::munlock $scalar, $offset = 0, $length = undef
274 IO::AIO::munlockall 284 IO::AIO::munlockall
275 285
276=head2 AIO REQUEST FUNCTIONS 286=head2 API NOTES
277 287
278All the C<aio_*> calls are more or less thin wrappers around the syscall 288All the C<aio_*> calls are more or less thin wrappers around the syscall
279with the same name (sans C<aio_>). The arguments are similar or identical, 289with the same name (sans C<aio_>). The arguments are similar or identical,
280and they all accept an additional (and optional) C<$callback> argument 290and they all accept an additional (and optional) C<$callback> argument
281which must be a code reference. This code reference will get called with 291which must be a code reference. This code reference will be called after
282the syscall return code (e.g. most syscalls return C<-1> on error, unlike 292the syscall has been executed in an asynchronous fashion. The results
283perl, which usually delivers "false") as its sole argument after the given 293of the request will be passed as arguments to the callback (and, if an
284syscall has been executed asynchronously. 294error occured, in C<$!>) - for most requests the syscall return code (e.g.
295most syscalls return C<-1> on error, unlike perl, which usually delivers
296"false").
297
298Some requests (such as C<aio_readdir>) pass the actual results and
299communicate failures by passing C<undef>.
285 300
286All functions expecting a filehandle keep a copy of the filehandle 301All functions expecting a filehandle keep a copy of the filehandle
287internally until the request has finished. 302internally until the request has finished.
288 303
289All functions return request objects of type L<IO::AIO::REQ> that allow 304All functions return request objects of type L<IO::AIO::REQ> that allow
290further manipulation of those requests while they are in-flight. 305further manipulation of those requests while they are in-flight.
291 306
292The pathnames you pass to these routines I<must> be absolute and 307The 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 308reason for this is that at the time the request is being executed, the
294request is being executed, the current working directory could have 309current working directory could have changed. Alternatively, you can
295changed. Alternatively, you can make sure that you never change the 310make sure that you never change the current working directory anywhere
296current working directory anywhere in the program and then use relative 311in the program and then use relative paths. You can also take advantage
297paths. 312of IO::AIOs working directory abstraction, that lets you specify paths
313relative to some previously-opened "working directory object" - see the
314description of the C<IO::AIO::WD> class later in this document.
298 315
299To encode pathnames as octets, either make sure you either: a) always pass 316To encode pathnames as octets, either make sure you either: a) always pass
300in filenames you got from outside (command line, readdir etc.) without 317in 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 318tinkering, b) are in your native filesystem encoding, c) use the Encode
302your pathnames to the locale (or other) encoding in effect in the user 319module and encode your pathnames to the locale (or other) encoding in
303environment, d) use Glib::filename_from_unicode on unicode filenames or e) 320effect in the user environment, d) use Glib::filename_from_unicode on
304use something else to ensure your scalar has the correct contents. 321unicode filenames or e) use something else to ensure your scalar has the
322correct contents.
305 323
306This works, btw. independent of the internal UTF-8 bit, which IO::AIO 324This works, btw. independent of the internal UTF-8 bit, which IO::AIO
307handles correctly whether it is set or not. 325handles correctly whether it is set or not.
326
327=head2 AIO REQUEST FUNCTIONS
308 328
309=over 4 329=over 4
310 330
311=item $prev_pri = aioreq_pri [$pri] 331=item $prev_pri = aioreq_pri [$pri]
312 332
394 414
395Or in other words: the file descriptor will be closed, but it will not be 415Or in other words: the file descriptor will be closed, but it will not be
396free for reuse until the perl filehandle is closed. 416free for reuse until the perl filehandle is closed.
397 417
398=cut 418=cut
419
420=item aio_seek $fh, $offset, $whence, $callback->($offs)
421
422Seeks the filehandle to the new C<$offset>, similarly to perl's
423C<sysseek>. The C<$whence> can use the traditional values (C<0> for
424C<IO::AIO::SEEK_SET>, C<1> for C<IO::AIO::SEEK_CUR> or C<2> for
425C<IO::AIO::SEEK_END>).
426
427The resulting absolute offset will be passed to the callback, or C<-1> in
428case of an error.
429
430In theory, the C<$whence> constants could be different than the
431corresponding values from L<Fcntl>, but perl guarantees they are the same,
432so don't panic.
433
434As a GNU/Linux (and maybe Solaris) extension, also the constants
435C<IO::AIO::SEEK_DATA> and C<IO::AIO::SEEK_HOLE> are available, if they
436could be found. No guarantees about suitability for use in C<aio_seek> or
437Perl's C<sysseek> can be made though, although I would naively assume they
438"just work".
399 439
400=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 440=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
401 441
402=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 442=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
403 443
600=item aio_truncate $fh_or_path, $offset, $callback->($status) 640=item aio_truncate $fh_or_path, $offset, $callback->($status)
601 641
602Works like truncate(2) or ftruncate(2). 642Works like truncate(2) or ftruncate(2).
603 643
604 644
645=item aio_allocate $fh, $mode, $offset, $len, $callback->($status)
646
647Allocates or freed disk space according to the C<$mode> argument. See the
648linux C<fallocate> docuemntation for details.
649
650C<$mode> can currently be C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE>
651to allocate space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE |
652IO::AIO::FALLOC_FL_KEEP_SIZE>, to deallocate a file range.
653
654The file system block size used by C<fallocate> is presumably the
655C<f_bsize> returned by C<statvfs>.
656
657If C<fallocate> isn't available or cannot be emulated (currently no
658emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>.
659
660
605=item aio_chmod $fh_or_path, $mode, $callback->($status) 661=item aio_chmod $fh_or_path, $mode, $callback->($status)
606 662
607Works like perl's C<chmod> function. 663Works like perl's C<chmod> function.
608 664
609 665
611 667
612Asynchronously unlink (delete) a file and call the callback with the 668Asynchronously unlink (delete) a file and call the callback with the
613result code. 669result code.
614 670
615 671
616=item aio_mknod $path, $mode, $dev, $callback->($status) 672=item aio_mknod $pathname, $mode, $dev, $callback->($status)
617 673
618[EXPERIMENTAL] 674[EXPERIMENTAL]
619 675
620Asynchronously create a device node (or fifo). See mknod(2). 676Asynchronously create a device node (or fifo). See mknod(2).
621 677
622The only (POSIX-) portable way of calling this function is: 678The only (POSIX-) portable way of calling this function is:
623 679
624 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... 680 aio_mknod $pathname, IO::AIO::S_IFIFO | $mode, 0, sub { ...
625 681
626See C<aio_stat> for info about some potentially helpful extra constants 682See C<aio_stat> for info about some potentially helpful extra constants
627and functions. 683and functions.
628 684
629=item aio_link $srcpath, $dstpath, $callback->($status) 685=item aio_link $srcpath, $dstpath, $callback->($status)
636 692
637Asynchronously create a new symbolic link to the existing object at C<$srcpath> at 693Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
638the path C<$dstpath> and call the callback with the result code. 694the path C<$dstpath> and call the callback with the result code.
639 695
640 696
641=item aio_readlink $path, $callback->($link) 697=item aio_readlink $pathname, $callback->($link)
642 698
643Asynchronously read the symlink specified by C<$path> and pass it to 699Asynchronously read the symlink specified by C<$path> and pass it to
644the callback. If an error occurs, nothing or undef gets passed to the 700the callback. If an error occurs, nothing or undef gets passed to the
645callback. 701callback.
646 702
647 703
704=item aio_realpath $pathname, $callback->($path)
705
706Asynchronously make the path absolute and resolve any symlinks in
707C<$path>. The resulting path only consists of directories (Same as
708L<Cwd::realpath>).
709
710This request can be used to get the absolute path of the current working
711directory by passing it a path of F<.> (a single dot).
712
713
648=item aio_rename $srcpath, $dstpath, $callback->($status) 714=item aio_rename $srcpath, $dstpath, $callback->($status)
649 715
650Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as 716Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
651rename(2) and call the callback with the result code. 717rename(2) and call the callback with the result code.
652 718
674array-ref with the filenames. 740array-ref with the filenames.
675 741
676 742
677=item aio_readdirx $pathname, $flags, $callback->($entries, $flags) 743=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
678 744
679Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune 745Quite 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 746tune behaviour and output format. In case of an error, C<$entries> will be
681C<undef>. 747C<undef>.
682 748
683The flags are a combination of the following constants, ORed together (the 749The flags are a combination of the following constants, ORed together (the
684flags will also be passed to the callback, possibly modified): 750flags will also be passed to the callback, possibly modified):
685 751
732 798
733=item IO::AIO::READDIR_FOUND_UNKNOWN 799=item IO::AIO::READDIR_FOUND_UNKNOWN
734 800
735This flag should not be set when calling C<aio_readdirx>. Instead, it 801This flag should not be set when calling C<aio_readdirx>. Instead, it
736is being set by C<aio_readdirx>, when any of the C<$type>'s found were 802is being set by C<aio_readdirx>, when any of the C<$type>'s found were
737C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all 803C<IO::AIO::DT_UNKNOWN>. The absence of this flag therefore indicates that all
738C<$type>'s are known, which can be used to speed up some algorithms. 804C<$type>'s are known, which can be used to speed up some algorithms.
739 805
740=back 806=back
741 807
742 808
743=item aio_load $path, $data, $callback->($status) 809=item aio_load $pathname, $data, $callback->($status)
744 810
745This is a composite request that tries to fully load the given file into 811This is a composite request that tries to fully load the given file into
746memory. Status is the same as with aio_read. 812memory. Status is the same as with aio_read.
747 813
748=cut 814=cut
883 }; 949 };
884 950
885 $grp 951 $grp
886} 952}
887 953
888=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 954=item aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
889 955
890Scans a directory (similar to C<aio_readdir>) but additionally tries to 956Scans a directory (similar to C<aio_readdir>) but additionally tries to
891efficiently separate the entries of directory C<$path> into two sets of 957efficiently separate the entries of directory C<$path> into two sets of
892names, directories you can recurse into (directories), and ones you cannot 958names, directories you can recurse into (directories), and ones you cannot
893recurse into (everything else, including symlinks to directories). 959recurse into (everything else, including symlinks to directories).
924Then entries will be sorted into likely directories a non-initial dot 990Then entries will be sorted into likely directories a non-initial dot
925currently) and likely non-directories (see C<aio_readdirx>). Then every 991currently) and likely non-directories (see C<aio_readdirx>). Then every
926entry plus an appended C</.> will be C<stat>'ed, likely directories first, 992entry 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 993in 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 994entry is a directory or a symlink to directory (which will be checked
929seperately). This is often faster than stat'ing the entry itself because 995separately). This is often faster than stat'ing the entry itself because
930filesystems might detect the type of the entry without reading the inode 996filesystems might detect the type of the entry without reading the inode
931data (e.g. ext2fs filetype feature), even on systems that cannot return 997data (e.g. ext2fs filetype feature), even on systems that cannot return
932the filetype information on readdir. 998the filetype information on readdir.
933 999
934If the known number of directories (link count - 2) has been reached, the 1000If the known number of directories (link count - 2) has been reached, the
950 1016
951 my $grp = aio_group $cb; 1017 my $grp = aio_group $cb;
952 1018
953 $maxreq = 4 if $maxreq <= 0; 1019 $maxreq = 4 if $maxreq <= 0;
954 1020
955 # stat once 1021 # get a wd object
956 aioreq_pri $pri; 1022 aioreq_pri $pri;
957 add $grp aio_stat $path, sub { 1023 add $grp aio_wd $path, sub {
1024 $_[0]
958 return $grp->result () if $_[0]; 1025 or return $grp->result ();
959 my $now = time;
960 my $hash1 = join ":", (stat _)[0,1,3,7,9];
961 1026
962 # read the directory entries 1027 my $wd = [shift, "."];
1028
1029 # stat once
963 aioreq_pri $pri; 1030 aioreq_pri $pri;
964 add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub { 1031 add $grp aio_stat $wd, sub {
965 my $entries = shift
966 or return $grp->result (); 1032 return $grp->result () if $_[0];
1033 my $now = time;
1034 my $hash1 = join ":", (stat _)[0,1,3,7,9];
967 1035
968 # stat the dir another time 1036 # read the directory entries
969 aioreq_pri $pri; 1037 aioreq_pri $pri;
1038 add $grp aio_readdirx $wd, READDIR_DIRS_FIRST, sub {
1039 my $entries = shift
1040 or return $grp->result ();
1041
1042 # stat the dir another time
1043 aioreq_pri $pri;
970 add $grp aio_stat $path, sub { 1044 add $grp aio_stat $wd, sub {
971 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 1045 my $hash2 = join ":", (stat _)[0,1,3,7,9];
972 1046
973 my $ndirs; 1047 my $ndirs;
974 1048
975 # take the slow route if anything looks fishy 1049 # take the slow route if anything looks fishy
976 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 1050 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
977 $ndirs = -1; 1051 $ndirs = -1;
978 } else { 1052 } else {
979 # if nlink == 2, we are finished 1053 # if nlink == 2, we are finished
980 # for non-posix-fs's, we rely on nlink < 2 1054 # for non-posix-fs's, we rely on nlink < 2
981 $ndirs = (stat _)[3] - 2 1055 $ndirs = (stat _)[3] - 2
982 or return $grp->result ([], $entries); 1056 or return $grp->result ([], $entries);
983 } 1057 }
984 1058
985 my (@dirs, @nondirs); 1059 my (@dirs, @nondirs);
986 1060
987 my $statgrp = add $grp aio_group sub { 1061 my $statgrp = add $grp aio_group sub {
988 $grp->result (\@dirs, \@nondirs); 1062 $grp->result (\@dirs, \@nondirs);
989 }; 1063 };
990 1064
991 limit $statgrp $maxreq; 1065 limit $statgrp $maxreq;
992 feed $statgrp sub { 1066 feed $statgrp sub {
993 return unless @$entries; 1067 return unless @$entries;
994 my $entry = shift @$entries; 1068 my $entry = shift @$entries;
995 1069
996 aioreq_pri $pri; 1070 aioreq_pri $pri;
1071 $wd->[1] = "$entry/.";
997 add $statgrp aio_stat "$path/$entry/.", sub { 1072 add $statgrp aio_stat $wd, sub {
998 if ($_[0] < 0) { 1073 if ($_[0] < 0) {
999 push @nondirs, $entry; 1074 push @nondirs, $entry;
1000 } else { 1075 } else {
1001 # need to check for real directory 1076 # need to check for real directory
1002 aioreq_pri $pri; 1077 aioreq_pri $pri;
1078 $wd->[1] = $entry;
1003 add $statgrp aio_lstat "$path/$entry", sub { 1079 add $statgrp aio_lstat $wd, sub {
1004 if (-d _) { 1080 if (-d _) {
1005 push @dirs, $entry; 1081 push @dirs, $entry;
1006 1082
1007 unless (--$ndirs) { 1083 unless (--$ndirs) {
1008 push @nondirs, @$entries; 1084 push @nondirs, @$entries;
1009 feed $statgrp; 1085 feed $statgrp;
1086 }
1087 } else {
1088 push @nondirs, $entry;
1010 } 1089 }
1011 } else {
1012 push @nondirs, $entry;
1013 } 1090 }
1014 } 1091 }
1015 } 1092 };
1016 }; 1093 };
1017 }; 1094 };
1018 }; 1095 };
1019 }; 1096 };
1020 }; 1097 };
1021 1098
1022 $grp 1099 $grp
1023} 1100}
1024 1101
1025=item aio_rmtree $path, $callback->($status) 1102=item aio_rmtree $pathname, $callback->($status)
1026 1103
1027Delete a directory tree starting (and including) C<$path>, return the 1104Delete a directory tree starting (and including) C<$path>, return the
1028status of the final C<rmdir> only. This is a composite request that 1105status of the final C<rmdir> only. This is a composite request that
1029uses C<aio_scandir> to recurse into and rmdir directories, and unlink 1106uses C<aio_scandir> to recurse into and rmdir directories, and unlink
1030everything else. 1107everything else.
1072callback with the fdatasync result code. 1149callback with the fdatasync result code.
1073 1150
1074If this call isn't available because your OS lacks it or it couldn't be 1151If 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. 1152detected, it will be emulated by calling C<fsync> instead.
1076 1153
1154=item aio_syncfs $fh, $callback->($status)
1155
1156Asynchronously call the syncfs syscall to sync the filesystem associated
1157to the given filehandle and call the callback with the syncfs result
1158code. If syncfs is not available, calls sync(), but returns C<-1> and sets
1159errno to C<ENOSYS> nevertheless.
1160
1077=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) 1161=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
1078 1162
1079Sync the data portion of the file specified by C<$offset> and C<$length> 1163Sync the data portion of the file specified by C<$offset> and C<$length>
1080to disk (but NOT the metadata), by calling the Linux-specific 1164to disk (but NOT the metadata), by calling the Linux-specific
1081sync_file_range call. If sync_file_range is not available or it returns 1165sync_file_range call. If sync_file_range is not available or it returns
1084C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>, 1168C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
1085C<IO::AIO::SYNC_FILE_RANGE_WRITE> and 1169C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
1086C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range 1170C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
1087manpage for details. 1171manpage for details.
1088 1172
1089=item aio_pathsync $path, $callback->($status) 1173=item aio_pathsync $pathname, $callback->($status)
1090 1174
1091This request tries to open, fsync and close the given path. This is a 1175This request tries to open, fsync and close the given path. This is a
1092composite request intended to sync directories after directory operations 1176composite request intended to sync directories after directory operations
1093(E.g. rename). This might not work on all operating systems or have any 1177(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 1178specific effect, but usually it makes sure that directory changes get
1191 1275
1192Example: asynchronously lock all current and future pages into memory. 1276Example: asynchronously lock all current and future pages into memory.
1193 1277
1194 aio_mlockall IO::AIO::MCL_FUTURE; 1278 aio_mlockall IO::AIO::MCL_FUTURE;
1195 1279
1280=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
1281
1282Queries the extents of the given file (by calling the Linux FIEMAP ioctl,
1283see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If the
1284C<ioctl> is not available on your OS, then this request will fail with
1285C<ENOSYS>.
1286
1287C<$start> is the starting offset to query extents for, C<$length> is the
1288size of the range to query - if it is C<undef>, then the whole file will
1289be queried.
1290
1291C<$flags> is a combination of flags (C<IO::AIO::FIEMAP_FLAG_SYNC> or
1292C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also
1293exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query
1294the data portion.
1295
1296C<$count> is the maximum number of extent records to return. If it is
1297C<undef>, then IO::AIO queries all extents of the file. As a very special
1298case, if it is C<0>, then the callback receives the number of extents
1299instead of the extents themselves.
1300
1301If an error occurs, the callback receives no arguments. The special
1302C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.
1303
1304Otherwise, the callback receives an array reference with extent
1305structures. Each extent structure is an array reference itself, with the
1306following members:
1307
1308 [$logical, $physical, $length, $flags]
1309
1310Flags is any combination of the following flag values (typically either C<0>
1311or C<IO::AIO::FIEMAP_EXTENT_LAST>):
1312
1313C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,
1314C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,
1315C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
1316C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
1317C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
1318C<IO::AIO::FIEMAP_EXTENT_SHARED>.
1319
1196=item aio_group $callback->(...) 1320=item aio_group $callback->(...)
1197 1321
1198This is a very special aio request: Instead of doing something, it is a 1322This 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 1323container for other aio requests, which is useful if you want to bundle
1200many requests into a single, composite, request with a definite callback 1324many requests into a single, composite, request with a definite callback
1236like sleep and file handle readable/writable, the overhead this creates is 1360like 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 1361immense (it blocks a thread for a long time) so do not use this function
1238except to put your application under artificial I/O pressure. 1362except to put your application under artificial I/O pressure.
1239 1363
1240=back 1364=back
1365
1366
1367=head2 IO::AIO::WD - multiple working directories
1368
1369Your process only has one current working directory, which is used by all
1370threads. This makes it hard to use relative paths (some other component
1371could call C<chdir> at any time, and it is hard to control when the path
1372will be used by IO::AIO).
1373
1374One solution for this is to always use absolute paths. This usually works,
1375but can be quite slow (the kernel has to walk the whole path on every
1376access), and can also be a hassle to implement.
1377
1378Newer POSIX systems have a number of functions (openat, fdopendir,
1379futimensat and so on) that make it possible to specify working directories
1380per operation.
1381
1382For portability, and because the clowns who "designed", or shall I write,
1383perpetrated this new interface were obviously half-drunk, this abstraction
1384cannot be perfect, though.
1385
1386IO::AIO allows you to convert directory paths into a so-called IO::AIO::WD
1387object. This object stores the canonicalised, absolute version of the
1388path, and on systems that allow it, also a directory file descriptor.
1389
1390Everywhere where a pathname is accepted by IO::AIO (e.g. in C<aio_stat>
1391or C<aio_unlink>), one can specify an array reference with an IO::AIO::WD
1392object and a pathname instead (or the IO::AIO::WD object alone, which
1393gets interpreted as C<[$wd, "."]>). If the pathname is absolute, the
1394IO::AIO::WD object is ignored, otherwise the pathname is resolved relative
1395to that IO::AIO::WD object.
1396
1397For example, to get a wd object for F</etc> and then stat F<passwd>
1398inside, you would write:
1399
1400 aio_wd "/etc", sub {
1401 my $etcdir = shift;
1402
1403 # although $etcdir can be undef on error, there is generally no reason
1404 # to check for errors here, as aio_stat will fail with ENOENT
1405 # when $etcdir is undef.
1406
1407 aio_stat [$etcdir, "passwd"], sub {
1408 # yay
1409 };
1410 };
1411
1412That C<aio_wd> is a request and not a normal function shows that creating
1413an IO::AIO::WD object is itself a potentially blocking operation, which is
1414why it is done asynchronously.
1415
1416To stat the directory obtained with C<aio_wd> above, one could write
1417either of the following three request calls:
1418
1419 aio_lstat "/etc" , sub { ... # pathname as normal string
1420 aio_lstat [$wd, "."], sub { ... # "." relative to $wd (i.e. $wd itself)
1421 aio_lstat $wd , sub { ... # shorthand for the previous
1422
1423As with normal pathnames, IO::AIO keeps a copy of the working directory
1424object and the pathname string, so you could write the following without
1425causing any issues due to C<$path> getting reused:
1426
1427 my $path = [$wd, undef];
1428
1429 for my $name (qw(abc def ghi)) {
1430 $path->[1] = $name;
1431 aio_stat $path, sub {
1432 # ...
1433 };
1434 }
1435
1436There are some caveats: when directories get renamed (or deleted), the
1437pathname string doesn't change, so will point to the new directory (or
1438nowhere at all), while the directory fd, if available on the system,
1439will still point to the original directory. Most functions accepting a
1440pathname will use the directory fd on newer systems, and the string on
1441older systems. Some functions (such as realpath) will always rely on the
1442string form of the pathname.
1443
1444So this fucntionality is mainly useful to get some protection against
1445C<chdir>, to easily get an absolute path out of a relative path for future
1446reference, and to speed up doing many operations in the same directory
1447(e.g. when stat'ing all files in a directory).
1448
1449The following functions implement this working directory abstraction:
1450
1451=over 4
1452
1453=item aio_wd $pathname, $callback->($wd)
1454
1455Asynchonously canonicalise the given pathname and convert it to an
1456IO::AIO::WD object representing it. If possible and supported on the
1457system, also open a directory fd to speed up pathname resolution relative
1458to this working directory.
1459
1460If something goes wrong, then C<undef> is passwd to the callback instead
1461of a working directory object and C<$!> is set appropriately. Since
1462passing C<undef> as working directory component of a pathname fails the
1463request with C<ENOENT>, there is often no need for error checking in the
1464C<aio_wd> callback, as future requests using the value will fail in the
1465expected way.
1466
1467If this call isn't available because your OS lacks it or it couldn't be
1468detected, it will be emulated by calling C<fsync> instead.
1469
1470=item IO::AIO::CWD
1471
1472This is a compiletime constant (object) that represents the process
1473current working directory.
1474
1475Specifying this object as working directory object for a pathname is as
1476if the pathname would be specified directly, without a directory object,
1477e.g., these calls are functionally identical:
1478
1479 aio_stat "somefile", sub { ... };
1480 aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
1481
1482=back
1483
1241 1484
1242=head2 IO::AIO::REQ CLASS 1485=head2 IO::AIO::REQ CLASS
1243 1486
1244All non-aggregate C<aio_*> functions return an object of this class when 1487All non-aggregate C<aio_*> functions return an object of this class when
1245called in non-void context. 1488called in non-void context.
1363 1606
1364Sets a feeder/generator on this group: every group can have an attached 1607Sets a feeder/generator on this group: every group can have an attached
1365generator that generates requests if idle. The idea behind this is that, 1608generator 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, 1609although 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, 1610this might starve other requests for a potentially long time. For example,
1368C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests, 1611C<aio_scandir> might generate hundreds of thousands of C<aio_stat>
1369delaying any later requests for a long time. 1612requests, delaying any later requests for a long time.
1370 1613
1371To avoid this, and allow incremental generation of requests, you can 1614To avoid this, and allow incremental generation of requests, you can
1372instead a group and set a feeder on it that generates those requests. The 1615instead 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>, 1616feed 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 1617below) requests active in the group itself and is expected to queue more
1653 1896
1654=item IO::AIO::fadvise $fh, $offset, $len, $advice 1897=item IO::AIO::fadvise $fh, $offset, $len, $advice
1655 1898
1656Simply calls the C<posix_fadvise> function (see its 1899Simply calls the C<posix_fadvise> function (see its
1657manpage for details). The following advice constants are 1900manpage for details). The following advice constants are
1658avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>, 1901available: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1659C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>, 1902C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1660C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>. 1903C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1661 1904
1662On systems that do not implement C<posix_fadvise>, this function returns 1905On systems that do not implement C<posix_fadvise>, this function returns
1663ENOSYS, otherwise the return value of C<posix_fadvise>. 1906ENOSYS, otherwise the return value of C<posix_fadvise>.
1664 1907
1665=item IO::AIO::madvise $scalar, $offset, $len, $advice 1908=item IO::AIO::madvise $scalar, $offset, $len, $advice
1666 1909
1667Simply calls the C<posix_madvise> function (see its 1910Simply calls the C<posix_madvise> function (see its
1668manpage for details). The following advice constants are 1911manpage for details). The following advice constants are
1669avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>, 1912available: 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>. 1913C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.
1671 1914
1672On systems that do not implement C<posix_madvise>, this function returns 1915On systems that do not implement C<posix_madvise>, this function returns
1673ENOSYS, otherwise the return value of C<posix_madvise>. 1916ENOSYS, otherwise the return value of C<posix_madvise>.
1674 1917
1675=item IO::AIO::mprotect $scalar, $offset, $len, $protect 1918=item IO::AIO::mprotect $scalar, $offset, $len, $protect
1676 1919
1677Simply calls the C<mprotect> function on the preferably AIO::mmap'ed 1920Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
1678$scalar (see its manpage for details). The following protect 1921$scalar (see its manpage for details). The following protect
1679constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>, 1922constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
1680C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>. 1923C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
1681 1924
1682On systems that do not implement C<mprotect>, this function returns 1925On systems that do not implement C<mprotect>, this function returns
1683ENOSYS, otherwise the return value of C<mprotect>. 1926ENOSYS, otherwise the return value of C<mprotect>.
1684 1927
1685=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] 1928=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1686 1929
1687Memory-maps a file (or anonymous memory range) and attaches it to the 1930Memory-maps a file (or anonymous memory range) and attaches it to the
1688given C<$scalar>, which will act like a string scalar. 1931given C<$scalar>, which will act like a string scalar. Returns true on
1932success, and false otherwise.
1689 1933
1690The only operations allowed on the scalar are C<substr>/C<vec> that don't 1934The 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 1935change the string length, and most read-only operations such as copying it
1692or searching it with regexes and so on. 1936or searching it with regexes and so on.
1693 1937
1746Calls the C<munlockall> function. 1990Calls the C<munlockall> function.
1747 1991
1748On systems that do not implement C<munlockall>, this function returns 1992On systems that do not implement C<munlockall>, this function returns
1749ENOSYS, otherwise the return value of C<munlockall>. 1993ENOSYS, otherwise the return value of C<munlockall>.
1750 1994
1995=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
1996
1997Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or
1998C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
1999should be the file offset.
2000
2001C<$r_fh> and C<$w_fh> should not refer to the same file, as splice might
2002silently corrupt the data in this case.
2003
2004The following symbol flag values are available: C<IO::AIO::SPLICE_F_MOVE>,
2005C<IO::AIO::SPLICE_F_NONBLOCK>, C<IO::AIO::SPLICE_F_MORE> and
2006C<IO::AIO::SPLICE_F_GIFT>.
2007
2008See the C<splice(2)> manpage for details.
2009
2010=item IO::AIO::tee $r_fh, $w_fh, $length, $flags
2011
2012Calls the GNU/Linux C<tee(2)> syscall, see it's manpage and the
2013description for C<IO::AIO::splice> above for details.
2014
1751=back 2015=back
1752 2016
1753=cut 2017=cut
1754 2018
1755min_parallel 8; 2019min_parallel 8;
1792=head2 FORK BEHAVIOUR 2056=head2 FORK BEHAVIOUR
1793 2057
1794Usage of pthreads in a program changes the semantics of fork 2058Usage of pthreads in a program changes the semantics of fork
1795considerably. Specifically, only async-safe functions can be called after 2059considerably. Specifically, only async-safe functions can be called after
1796fork. Perl doesn't know about this, so in general, you cannot call fork 2060fork. 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, 2061with defined behaviour in perl if pthreads are involved. IO::AIO uses
1798but many other extensions and (for inexplicable reasons) perl itself often 2062pthreads, so this applies, but many other extensions and (for inexplicable
1799is linked against pthreads, so this limitation applies. 2063reasons) perl itself often is linked against pthreads, so this limitation
2064applies to quite a lot of perls.
1800 2065
1801Some operating systems have extensions that allow safe use of fork, and 2066This 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 2067only works in the process that loaded it. Forking is fully supported, but
1803the time of this writing (2011) only GNU/Linux supports these extensions 2068using IO::AIO in the child is not.
1804to POSIX. 2069
2070You might get around by not I<using> IO::AIO before (or after)
2071forking. You could also try to call the L<IO::AIO::reinit> function in the
2072child:
2073
2074=over 4
2075
2076=item IO::AIO::reinit
2077
2078Abandons all current requests and I/O threads and simply reinitialises all
2079data structures. This is not an operation supported by any standards, but
2080happens to work on GNU/Linux and some newer BSD systems.
2081
2082The only reasonable use for this function is to call it after forking, if
2083C<IO::AIO> was used in the parent. Calling it while IO::AIO is active in
2084the process will result in undefined behaviour. Calling it at any time
2085will also result in any undefined (by POSIX) behaviour.
2086
2087=back
1805 2088
1806=head2 MEMORY USAGE 2089=head2 MEMORY USAGE
1807 2090
1808Per-request usage: 2091Per-request usage:
1809 2092

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