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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.202 by root, Tue Jul 5 14:02:15 2011 UTC vs.
Revision 1.233 by root, Mon Aug 13 01:01:04 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_realpath 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)
227 aio_realpath $path, $callback->($link) 233 aio_realpath $pathname, $callback->($link)
228 aio_rename $srcpath, $dstpath, $callback->($status) 234 aio_rename $srcpath, $dstpath, $callback->($status)
229 aio_mkdir $pathname, $mode, $callback->($status) 235 aio_mkdir $pathname, $mode, $callback->($status)
230 aio_rmdir $pathname, $callback->($status) 236 aio_rmdir $pathname, $callback->($status)
231 aio_readdir $pathname, $callback->($entries) 237 aio_readdir $pathname, $callback->($entries)
232 aio_readdirx $pathname, $flags, $callback->($entries, $flags) 238 aio_readdirx $pathname, $flags, $callback->($entries, $flags)
233 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST 239 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
234 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)
235 aio_load $path, $data, $callback->($status) 242 aio_load $pathname, $data, $callback->($status)
236 aio_copy $srcpath, $dstpath, $callback->($status) 243 aio_copy $srcpath, $dstpath, $callback->($status)
237 aio_move $srcpath, $dstpath, $callback->($status) 244 aio_move $srcpath, $dstpath, $callback->($status)
238 aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
239 aio_rmtree $path, $callback->($status) 245 aio_rmtree $pathname, $callback->($status)
240 aio_sync $callback->($status) 246 aio_sync $callback->($status)
247 aio_syncfs $fh, $callback->($status)
241 aio_fsync $fh, $callback->($status) 248 aio_fsync $fh, $callback->($status)
242 aio_fdatasync $fh, $callback->($status) 249 aio_fdatasync $fh, $callback->($status)
243 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) 250 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
244 aio_pathsync $path, $callback->($status) 251 aio_pathsync $pathname, $callback->($status)
245 aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 252 aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
246 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 253 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
247 aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) 254 aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
248 aio_mlockall $flags, $callback->($status) 255 aio_mlockall $flags, $callback->($status)
249 aio_group $callback->(...) 256 aio_group $callback->(...)
267 IO::AIO::nready 274 IO::AIO::nready
268 IO::AIO::npending 275 IO::AIO::npending
269 276
270 IO::AIO::sendfile $ofh, $ifh, $offset, $count 277 IO::AIO::sendfile $ofh, $ifh, $offset, $count
271 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
272 IO::AIO::madvise $scalar, $offset, $length, $advice 281 IO::AIO::madvise $scalar, $offset, $length, $advice
273 IO::AIO::mprotect $scalar, $offset, $length, $protect 282 IO::AIO::mprotect $scalar, $offset, $length, $protect
274 IO::AIO::munlock $scalar, $offset = 0, $length = undef 283 IO::AIO::munlock $scalar, $offset = 0, $length = undef
275 IO::AIO::munlockall 284 IO::AIO::munlockall
276 285
277=head2 AIO REQUEST FUNCTIONS 286=head2 API NOTES
278 287
279All the C<aio_*> calls are more or less thin wrappers around the syscall 288All the C<aio_*> calls are more or less thin wrappers around the syscall
280with the same name (sans C<aio_>). The arguments are similar or identical, 289with the same name (sans C<aio_>). The arguments are similar or identical,
281and they all accept an additional (and optional) C<$callback> argument 290and they all accept an additional (and optional) C<$callback> argument
282which must be a code reference. This code reference will get called with 291which must be a code reference. This code reference will be called after
283the syscall return code (e.g. most syscalls return C<-1> on error, unlike 292the syscall has been executed in an asynchronous fashion. The results
284perl, which usually delivers "false") as its sole argument after the given 293of the request will be passed as arguments to the callback (and, if an
285syscall has been executed asynchronously. 294error occured, in C<$!>) - 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>.
286 300
287All functions expecting a filehandle keep a copy of the filehandle 301All functions expecting a filehandle keep a copy of the filehandle
288internally until the request has finished. 302internally until the request has finished.
289 303
290All 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
291further manipulation of those requests while they are in-flight. 305further manipulation of those requests while they are in-flight.
292 306
293The pathnames you pass to these routines I<must> be absolute and 307The pathnames you pass to these routines I<should> be absolute. The
294encoded 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
295request is being executed, the current working directory could have 309current working directory could have changed. Alternatively, you can
296changed. Alternatively, you can make sure that you never change the 310make sure that you never change the current working directory anywhere
297current working directory anywhere in the program and then use relative 311in the program and then use relative paths. You can also take advantage
298paths. 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.
299 315
300To 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
301in filenames you got from outside (command line, readdir etc.) without 317in filenames you got from outside (command line, readdir etc.) without
302tinkering, 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
303your pathnames to the locale (or other) encoding in effect in the user 319module and encode your pathnames to the locale (or other) encoding in
304environment, d) use Glib::filename_from_unicode on unicode filenames or e) 320effect in the user environment, d) use Glib::filename_from_unicode on
305use 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.
306 323
307This 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
308handles correctly whether it is set or not. 325handles correctly whether it is set or not.
326
327=head2 AIO REQUEST FUNCTIONS
309 328
310=over 4 329=over 4
311 330
312=item $prev_pri = aioreq_pri [$pri] 331=item $prev_pri = aioreq_pri [$pri]
313 332
343 362
344 363
345=item aio_open $pathname, $flags, $mode, $callback->($fh) 364=item aio_open $pathname, $flags, $mode, $callback->($fh)
346 365
347Asynchronously open or create a file and call the callback with a newly 366Asynchronously open or create a file and call the callback with a newly
348created filehandle for the file. 367created filehandle for the file (or C<undef> in case of an error).
349 368
350The pathname passed to C<aio_open> must be absolute. See API NOTES, above, 369The pathname passed to C<aio_open> must be absolute. See API NOTES, above,
351for an explanation. 370for an explanation.
352 371
353The C<$flags> argument is a bitmask. See the C<Fcntl> module for a 372The C<$flags> argument is a bitmask. See the C<Fcntl> module for a
395 414
396Or 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
397free for reuse until the perl filehandle is closed. 416free for reuse until the perl filehandle is closed.
398 417
399=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".
400 439
401=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 440=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
402 441
403=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 442=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
404 443
601=item aio_truncate $fh_or_path, $offset, $callback->($status) 640=item aio_truncate $fh_or_path, $offset, $callback->($status)
602 641
603Works like truncate(2) or ftruncate(2). 642Works like truncate(2) or ftruncate(2).
604 643
605 644
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
606=item aio_chmod $fh_or_path, $mode, $callback->($status) 661=item aio_chmod $fh_or_path, $mode, $callback->($status)
607 662
608Works like perl's C<chmod> function. 663Works like perl's C<chmod> function.
609 664
610 665
612 667
613Asynchronously unlink (delete) a file and call the callback with the 668Asynchronously unlink (delete) a file and call the callback with the
614result code. 669result code.
615 670
616 671
617=item aio_mknod $path, $mode, $dev, $callback->($status) 672=item aio_mknod $pathname, $mode, $dev, $callback->($status)
618 673
619[EXPERIMENTAL] 674[EXPERIMENTAL]
620 675
621Asynchronously create a device node (or fifo). See mknod(2). 676Asynchronously create a device node (or fifo). See mknod(2).
622 677
623The only (POSIX-) portable way of calling this function is: 678The only (POSIX-) portable way of calling this function is:
624 679
625 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... 680 aio_mknod $pathname, IO::AIO::S_IFIFO | $mode, 0, sub { ...
626 681
627See C<aio_stat> for info about some potentially helpful extra constants 682See C<aio_stat> for info about some potentially helpful extra constants
628and functions. 683and functions.
629 684
630=item aio_link $srcpath, $dstpath, $callback->($status) 685=item aio_link $srcpath, $dstpath, $callback->($status)
637 692
638Asynchronously 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
639the path C<$dstpath> and call the callback with the result code. 694the path C<$dstpath> and call the callback with the result code.
640 695
641 696
642=item aio_readlink $path, $callback->($link) 697=item aio_readlink $pathname, $callback->($link)
643 698
644Asynchronously read the symlink specified by C<$path> and pass it to 699Asynchronously read the symlink specified by C<$path> and pass it to
645the 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
646callback. 701callback.
647 702
648 703
649=item aio_realpath $path, $callback->($path) 704=item aio_realpath $pathname, $callback->($path)
650 705
651Asynchronously make the path absolute and resolve any symlinks in 706Asynchronously make the path absolute and resolve any symlinks in
652C<$path>. The resulting path only consists of directories (Same as 707C<$path>. The resulting path only consists of directories (Same as
653L<Cwd::realpath>). 708L<Cwd::realpath>).
654 709
685array-ref with the filenames. 740array-ref with the filenames.
686 741
687 742
688=item aio_readdirx $pathname, $flags, $callback->($entries, $flags) 743=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
689 744
690Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune 745Quite similar to C<aio_readdir>, but the C<$flags> argument allows one to
691behaviour and output format. In case of an error, C<$entries> will be 746tune behaviour and output format. In case of an error, C<$entries> will be
692C<undef>. 747C<undef>.
693 748
694The flags are a combination of the following constants, ORed together (the 749The flags are a combination of the following constants, ORed together (the
695flags will also be passed to the callback, possibly modified): 750flags will also be passed to the callback, possibly modified):
696 751
743 798
744=item IO::AIO::READDIR_FOUND_UNKNOWN 799=item IO::AIO::READDIR_FOUND_UNKNOWN
745 800
746This flag should not be set when calling C<aio_readdirx>. Instead, it 801This flag should not be set when calling C<aio_readdirx>. Instead, it
747is being set by C<aio_readdirx>, when any of the C<$type>'s found were 802is being set by C<aio_readdirx>, when any of the C<$type>'s found were
748C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all 803C<IO::AIO::DT_UNKNOWN>. The absence of this flag therefore indicates that all
749C<$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.
750 805
751=back 806=back
752 807
753 808
754=item aio_load $path, $data, $callback->($status) 809=item aio_load $pathname, $data, $callback->($status)
755 810
756This 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
757memory. Status is the same as with aio_read. 812memory. Status is the same as with aio_read.
758 813
759=cut 814=cut
894 }; 949 };
895 950
896 $grp 951 $grp
897} 952}
898 953
899=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 954=item aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
900 955
901Scans a directory (similar to C<aio_readdir>) but additionally tries to 956Scans a directory (similar to C<aio_readdir>) but additionally tries to
902efficiently separate the entries of directory C<$path> into two sets of 957efficiently separate the entries of directory C<$path> into two sets of
903names, directories you can recurse into (directories), and ones you cannot 958names, directories you can recurse into (directories), and ones you cannot
904recurse into (everything else, including symlinks to directories). 959recurse into (everything else, including symlinks to directories).
935Then entries will be sorted into likely directories a non-initial dot 990Then entries will be sorted into likely directories a non-initial dot
936currently) and likely non-directories (see C<aio_readdirx>). Then every 991currently) and likely non-directories (see C<aio_readdirx>). Then every
937entry 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,
938in 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
939entry 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
940seperately). This is often faster than stat'ing the entry itself because 995separately). This is often faster than stat'ing the entry itself because
941filesystems might detect the type of the entry without reading the inode 996filesystems might detect the type of the entry without reading the inode
942data (e.g. ext2fs filetype feature), even on systems that cannot return 997data (e.g. ext2fs filetype feature), even on systems that cannot return
943the filetype information on readdir. 998the filetype information on readdir.
944 999
945If 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
961 1016
962 my $grp = aio_group $cb; 1017 my $grp = aio_group $cb;
963 1018
964 $maxreq = 4 if $maxreq <= 0; 1019 $maxreq = 4 if $maxreq <= 0;
965 1020
966 # stat once 1021 # get a wd object
967 aioreq_pri $pri; 1022 aioreq_pri $pri;
968 add $grp aio_stat $path, sub { 1023 add $grp aio_wd $path, sub {
1024 $_[0]
969 return $grp->result () if $_[0]; 1025 or return $grp->result ();
970 my $now = time;
971 my $hash1 = join ":", (stat _)[0,1,3,7,9];
972 1026
973 # read the directory entries 1027 my $wd = [shift, "."];
1028
1029 # stat once
974 aioreq_pri $pri; 1030 aioreq_pri $pri;
975 add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub { 1031 add $grp aio_stat $wd, sub {
976 my $entries = shift
977 or return $grp->result (); 1032 return $grp->result () if $_[0];
1033 my $now = time;
1034 my $hash1 = join ":", (stat _)[0,1,3,7,9];
978 1035
979 # stat the dir another time 1036 # read the directory entries
980 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;
981 add $grp aio_stat $path, sub { 1044 add $grp aio_stat $wd, sub {
982 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 1045 my $hash2 = join ":", (stat _)[0,1,3,7,9];
983 1046
984 my $ndirs; 1047 my $ndirs;
985 1048
986 # take the slow route if anything looks fishy 1049 # take the slow route if anything looks fishy
987 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 1050 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
988 $ndirs = -1; 1051 $ndirs = -1;
989 } else { 1052 } else {
990 # if nlink == 2, we are finished 1053 # if nlink == 2, we are finished
991 # for non-posix-fs's, we rely on nlink < 2 1054 # for non-posix-fs's, we rely on nlink < 2
992 $ndirs = (stat _)[3] - 2 1055 $ndirs = (stat _)[3] - 2
993 or return $grp->result ([], $entries); 1056 or return $grp->result ([], $entries);
994 } 1057 }
995 1058
996 my (@dirs, @nondirs); 1059 my (@dirs, @nondirs);
997 1060
998 my $statgrp = add $grp aio_group sub { 1061 my $statgrp = add $grp aio_group sub {
999 $grp->result (\@dirs, \@nondirs); 1062 $grp->result (\@dirs, \@nondirs);
1000 }; 1063 };
1001 1064
1002 limit $statgrp $maxreq; 1065 limit $statgrp $maxreq;
1003 feed $statgrp sub { 1066 feed $statgrp sub {
1004 return unless @$entries; 1067 return unless @$entries;
1005 my $entry = shift @$entries; 1068 my $entry = shift @$entries;
1006 1069
1007 aioreq_pri $pri; 1070 aioreq_pri $pri;
1071 $wd->[1] = "$entry/.";
1008 add $statgrp aio_stat "$path/$entry/.", sub { 1072 add $statgrp aio_stat $wd, sub {
1009 if ($_[0] < 0) { 1073 if ($_[0] < 0) {
1010 push @nondirs, $entry; 1074 push @nondirs, $entry;
1011 } else { 1075 } else {
1012 # need to check for real directory 1076 # need to check for real directory
1013 aioreq_pri $pri; 1077 aioreq_pri $pri;
1078 $wd->[1] = $entry;
1014 add $statgrp aio_lstat "$path/$entry", sub { 1079 add $statgrp aio_lstat $wd, sub {
1015 if (-d _) { 1080 if (-d _) {
1016 push @dirs, $entry; 1081 push @dirs, $entry;
1017 1082
1018 unless (--$ndirs) { 1083 unless (--$ndirs) {
1019 push @nondirs, @$entries; 1084 push @nondirs, @$entries;
1020 feed $statgrp; 1085 feed $statgrp;
1086 }
1087 } else {
1088 push @nondirs, $entry;
1021 } 1089 }
1022 } else {
1023 push @nondirs, $entry;
1024 } 1090 }
1025 } 1091 }
1026 } 1092 };
1027 }; 1093 };
1028 }; 1094 };
1029 }; 1095 };
1030 }; 1096 };
1031 }; 1097 };
1032 1098
1033 $grp 1099 $grp
1034} 1100}
1035 1101
1036=item aio_rmtree $path, $callback->($status) 1102=item aio_rmtree $pathname, $callback->($status)
1037 1103
1038Delete a directory tree starting (and including) C<$path>, return the 1104Delete a directory tree starting (and including) C<$path>, return the
1039status 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
1040uses C<aio_scandir> to recurse into and rmdir directories, and unlink 1106uses C<aio_scandir> to recurse into and rmdir directories, and unlink
1041everything else. 1107everything else.
1083callback with the fdatasync result code. 1149callback with the fdatasync result code.
1084 1150
1085If 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
1086detected, it will be emulated by calling C<fsync> instead. 1152detected, it will be emulated by calling C<fsync> instead.
1087 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
1088=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) 1161=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
1089 1162
1090Sync 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>
1091to disk (but NOT the metadata), by calling the Linux-specific 1164to disk (but NOT the metadata), by calling the Linux-specific
1092sync_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
1095C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>, 1168C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
1096C<IO::AIO::SYNC_FILE_RANGE_WRITE> and 1169C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
1097C<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
1098manpage for details. 1171manpage for details.
1099 1172
1100=item aio_pathsync $path, $callback->($status) 1173=item aio_pathsync $pathname, $callback->($status)
1101 1174
1102This 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
1103composite request intended to sync directories after directory operations 1176composite request intended to sync directories after directory operations
1104(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
1105specific effect, but usually it makes sure that directory changes get 1178specific effect, but usually it makes sure that directory changes get
1202 1275
1203Example: asynchronously lock all current and future pages into memory. 1276Example: asynchronously lock all current and future pages into memory.
1204 1277
1205 aio_mlockall IO::AIO::MCL_FUTURE; 1278 aio_mlockall IO::AIO::MCL_FUTURE;
1206 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<$count> is the maximum number of extent records to return. If it is
1297C<undef>, then IO::AIO queries all extents of the range. As a very special
1298case, if it is C<0>, then the callback receives the number of extents
1299instead of the extents themselves (which is unreliable, see below).
1300
1301If an error occurs, the callback receives no arguments. The special
1302C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.
1303
1304Otherwise, the callback receives an array reference with extent
1305structures. Each extent structure is an array reference itself, with the
1306following members:
1307
1308 [$logical, $physical, $length, $flags]
1309
1310Flags is any combination of the following flag values (typically either C<0>
1311or C<IO::AIO::FIEMAP_EXTENT_LAST> (1)):
1312
1313C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,
1314C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,
1315C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
1316C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
1317C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
1318C<IO::AIO::FIEMAP_EXTENT_SHARED>.
1319
1320At the time of this writing (Linux 3.2), this requets is unreliable unless
1321C<$count> is C<undef>, as the kernel has all sorts of bugs preventing
1322it to return all extents of a range for files with large number of
1323extents. The code works around all these issues if C<$count> is undef.
1324
1207=item aio_group $callback->(...) 1325=item aio_group $callback->(...)
1208 1326
1209This is a very special aio request: Instead of doing something, it is a 1327This is a very special aio request: Instead of doing something, it is a
1210container for other aio requests, which is useful if you want to bundle 1328container for other aio requests, which is useful if you want to bundle
1211many requests into a single, composite, request with a definite callback 1329many requests into a single, composite, request with a definite callback
1247like sleep and file handle readable/writable, the overhead this creates is 1365like sleep and file handle readable/writable, the overhead this creates is
1248immense (it blocks a thread for a long time) so do not use this function 1366immense (it blocks a thread for a long time) so do not use this function
1249except to put your application under artificial I/O pressure. 1367except to put your application under artificial I/O pressure.
1250 1368
1251=back 1369=back
1370
1371
1372=head2 IO::AIO::WD - multiple working directories
1373
1374Your process only has one current working directory, which is used by all
1375threads. This makes it hard to use relative paths (some other component
1376could call C<chdir> at any time, and it is hard to control when the path
1377will be used by IO::AIO).
1378
1379One solution for this is to always use absolute paths. This usually works,
1380but can be quite slow (the kernel has to walk the whole path on every
1381access), and can also be a hassle to implement.
1382
1383Newer POSIX systems have a number of functions (openat, fdopendir,
1384futimensat and so on) that make it possible to specify working directories
1385per operation.
1386
1387For portability, and because the clowns who "designed", or shall I write,
1388perpetrated this new interface were obviously half-drunk, this abstraction
1389cannot be perfect, though.
1390
1391IO::AIO allows you to convert directory paths into a so-called IO::AIO::WD
1392object. This object stores the canonicalised, absolute version of the
1393path, and on systems that allow it, also a directory file descriptor.
1394
1395Everywhere where a pathname is accepted by IO::AIO (e.g. in C<aio_stat>
1396or C<aio_unlink>), one can specify an array reference with an IO::AIO::WD
1397object and a pathname instead (or the IO::AIO::WD object alone, which
1398gets interpreted as C<[$wd, "."]>). If the pathname is absolute, the
1399IO::AIO::WD object is ignored, otherwise the pathname is resolved relative
1400to that IO::AIO::WD object.
1401
1402For example, to get a wd object for F</etc> and then stat F<passwd>
1403inside, you would write:
1404
1405 aio_wd "/etc", sub {
1406 my $etcdir = shift;
1407
1408 # although $etcdir can be undef on error, there is generally no reason
1409 # to check for errors here, as aio_stat will fail with ENOENT
1410 # when $etcdir is undef.
1411
1412 aio_stat [$etcdir, "passwd"], sub {
1413 # yay
1414 };
1415 };
1416
1417That C<aio_wd> is a request and not a normal function shows that creating
1418an IO::AIO::WD object is itself a potentially blocking operation, which is
1419why it is done asynchronously.
1420
1421To stat the directory obtained with C<aio_wd> above, one could write
1422either of the following three request calls:
1423
1424 aio_lstat "/etc" , sub { ... # pathname as normal string
1425 aio_lstat [$wd, "."], sub { ... # "." relative to $wd (i.e. $wd itself)
1426 aio_lstat $wd , sub { ... # shorthand for the previous
1427
1428As with normal pathnames, IO::AIO keeps a copy of the working directory
1429object and the pathname string, so you could write the following without
1430causing any issues due to C<$path> getting reused:
1431
1432 my $path = [$wd, undef];
1433
1434 for my $name (qw(abc def ghi)) {
1435 $path->[1] = $name;
1436 aio_stat $path, sub {
1437 # ...
1438 };
1439 }
1440
1441There are some caveats: when directories get renamed (or deleted), the
1442pathname string doesn't change, so will point to the new directory (or
1443nowhere at all), while the directory fd, if available on the system,
1444will still point to the original directory. Most functions accepting a
1445pathname will use the directory fd on newer systems, and the string on
1446older systems. Some functions (such as realpath) will always rely on the
1447string form of the pathname.
1448
1449So this fucntionality is mainly useful to get some protection against
1450C<chdir>, to easily get an absolute path out of a relative path for future
1451reference, and to speed up doing many operations in the same directory
1452(e.g. when stat'ing all files in a directory).
1453
1454The following functions implement this working directory abstraction:
1455
1456=over 4
1457
1458=item aio_wd $pathname, $callback->($wd)
1459
1460Asynchonously canonicalise the given pathname and convert it to an
1461IO::AIO::WD object representing it. If possible and supported on the
1462system, also open a directory fd to speed up pathname resolution relative
1463to this working directory.
1464
1465If something goes wrong, then C<undef> is passwd to the callback instead
1466of a working directory object and C<$!> is set appropriately. Since
1467passing C<undef> as working directory component of a pathname fails the
1468request with C<ENOENT>, there is often no need for error checking in the
1469C<aio_wd> callback, as future requests using the value will fail in the
1470expected way.
1471
1472If this call isn't available because your OS lacks it or it couldn't be
1473detected, it will be emulated by calling C<fsync> instead.
1474
1475=item IO::AIO::CWD
1476
1477This is a compiletime constant (object) that represents the process
1478current working directory.
1479
1480Specifying this object as working directory object for a pathname is as
1481if the pathname would be specified directly, without a directory object,
1482e.g., these calls are functionally identical:
1483
1484 aio_stat "somefile", sub { ... };
1485 aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
1486
1487=back
1488
1252 1489
1253=head2 IO::AIO::REQ CLASS 1490=head2 IO::AIO::REQ CLASS
1254 1491
1255All non-aggregate C<aio_*> functions return an object of this class when 1492All non-aggregate C<aio_*> functions return an object of this class when
1256called in non-void context. 1493called in non-void context.
1374 1611
1375Sets a feeder/generator on this group: every group can have an attached 1612Sets a feeder/generator on this group: every group can have an attached
1376generator that generates requests if idle. The idea behind this is that, 1613generator that generates requests if idle. The idea behind this is that,
1377although you could just queue as many requests as you want in a group, 1614although you could just queue as many requests as you want in a group,
1378this might starve other requests for a potentially long time. For example, 1615this might starve other requests for a potentially long time. For example,
1379C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests, 1616C<aio_scandir> might generate hundreds of thousands of C<aio_stat>
1380delaying any later requests for a long time. 1617requests, delaying any later requests for a long time.
1381 1618
1382To avoid this, and allow incremental generation of requests, you can 1619To avoid this, and allow incremental generation of requests, you can
1383instead a group and set a feeder on it that generates those requests. The 1620instead a group and set a feeder on it that generates those requests. The
1384feed callback will be called whenever there are few enough (see C<limit>, 1621feed callback will be called whenever there are few enough (see C<limit>,
1385below) requests active in the group itself and is expected to queue more 1622below) requests active in the group itself and is expected to queue more
1664 1901
1665=item IO::AIO::fadvise $fh, $offset, $len, $advice 1902=item IO::AIO::fadvise $fh, $offset, $len, $advice
1666 1903
1667Simply calls the C<posix_fadvise> function (see its 1904Simply calls the C<posix_fadvise> function (see its
1668manpage for details). The following advice constants are 1905manpage for details). The following advice constants are
1669avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>, 1906available: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1670C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>, 1907C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1671C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>. 1908C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1672 1909
1673On systems that do not implement C<posix_fadvise>, this function returns 1910On systems that do not implement C<posix_fadvise>, this function returns
1674ENOSYS, otherwise the return value of C<posix_fadvise>. 1911ENOSYS, otherwise the return value of C<posix_fadvise>.
1675 1912
1676=item IO::AIO::madvise $scalar, $offset, $len, $advice 1913=item IO::AIO::madvise $scalar, $offset, $len, $advice
1677 1914
1678Simply calls the C<posix_madvise> function (see its 1915Simply calls the C<posix_madvise> function (see its
1679manpage for details). The following advice constants are 1916manpage for details). The following advice constants are
1680avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>, 1917available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
1681C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>. 1918C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.
1682 1919
1683On systems that do not implement C<posix_madvise>, this function returns 1920On systems that do not implement C<posix_madvise>, this function returns
1684ENOSYS, otherwise the return value of C<posix_madvise>. 1921ENOSYS, otherwise the return value of C<posix_madvise>.
1685 1922
1686=item IO::AIO::mprotect $scalar, $offset, $len, $protect 1923=item IO::AIO::mprotect $scalar, $offset, $len, $protect
1687 1924
1688Simply calls the C<mprotect> function on the preferably AIO::mmap'ed 1925Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
1689$scalar (see its manpage for details). The following protect 1926$scalar (see its manpage for details). The following protect
1690constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>, 1927constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
1691C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>. 1928C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
1692 1929
1693On systems that do not implement C<mprotect>, this function returns 1930On systems that do not implement C<mprotect>, this function returns
1694ENOSYS, otherwise the return value of C<mprotect>. 1931ENOSYS, otherwise the return value of C<mprotect>.
1695 1932
1696=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] 1933=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1697 1934
1698Memory-maps a file (or anonymous memory range) and attaches it to the 1935Memory-maps a file (or anonymous memory range) and attaches it to the
1699given C<$scalar>, which will act like a string scalar. 1936given C<$scalar>, which will act like a string scalar. Returns true on
1937success, and false otherwise.
1700 1938
1701The only operations allowed on the scalar are C<substr>/C<vec> that don't 1939The only operations allowed on the scalar are C<substr>/C<vec> that don't
1702change the string length, and most read-only operations such as copying it 1940change the string length, and most read-only operations such as copying it
1703or searching it with regexes and so on. 1941or searching it with regexes and so on.
1704 1942
1757Calls the C<munlockall> function. 1995Calls the C<munlockall> function.
1758 1996
1759On systems that do not implement C<munlockall>, this function returns 1997On systems that do not implement C<munlockall>, this function returns
1760ENOSYS, otherwise the return value of C<munlockall>. 1998ENOSYS, otherwise the return value of C<munlockall>.
1761 1999
2000=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
2001
2002Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or
2003C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
2004should be the file offset.
2005
2006C<$r_fh> and C<$w_fh> should not refer to the same file, as splice might
2007silently corrupt the data in this case.
2008
2009The following symbol flag values are available: C<IO::AIO::SPLICE_F_MOVE>,
2010C<IO::AIO::SPLICE_F_NONBLOCK>, C<IO::AIO::SPLICE_F_MORE> and
2011C<IO::AIO::SPLICE_F_GIFT>.
2012
2013See the C<splice(2)> manpage for details.
2014
2015=item IO::AIO::tee $r_fh, $w_fh, $length, $flags
2016
2017Calls the GNU/Linux C<tee(2)> syscall, see it's manpage and the
2018description for C<IO::AIO::splice> above for details.
2019
1762=back 2020=back
1763 2021
1764=cut 2022=cut
1765 2023
1766min_parallel 8; 2024min_parallel 8;
1803=head2 FORK BEHAVIOUR 2061=head2 FORK BEHAVIOUR
1804 2062
1805Usage of pthreads in a program changes the semantics of fork 2063Usage of pthreads in a program changes the semantics of fork
1806considerably. Specifically, only async-safe functions can be called after 2064considerably. Specifically, only async-safe functions can be called after
1807fork. Perl doesn't know about this, so in general, you cannot call fork 2065fork. Perl doesn't know about this, so in general, you cannot call fork
1808with defined behaviour in perl. IO::AIO uses pthreads, so this applies, 2066with defined behaviour in perl if pthreads are involved. IO::AIO uses
1809but many other extensions and (for inexplicable reasons) perl itself often 2067pthreads, so this applies, but many other extensions and (for inexplicable
1810is linked against pthreads, so this limitation applies. 2068reasons) perl itself often is linked against pthreads, so this limitation
2069applies to quite a lot of perls.
1811 2070
1812Some operating systems have extensions that allow safe use of fork, and 2071This module no longer tries to fight your OS, or POSIX. That means IO::AIO
1813this module should do "the right thing" on those, and tries on others. At 2072only works in the process that loaded it. Forking is fully supported, but
1814the time of this writing (2011) only GNU/Linux supports these extensions 2073using IO::AIO in the child is not.
1815to POSIX. 2074
2075You might get around by not I<using> IO::AIO before (or after)
2076forking. You could also try to call the L<IO::AIO::reinit> function in the
2077child:
2078
2079=over 4
2080
2081=item IO::AIO::reinit
2082
2083Abandons all current requests and I/O threads and simply reinitialises all
2084data structures. This is not an operation supported by any standards, but
2085happens to work on GNU/Linux and some newer BSD systems.
2086
2087The only reasonable use for this function is to call it after forking, if
2088C<IO::AIO> was used in the parent. Calling it while IO::AIO is active in
2089the process will result in undefined behaviour. Calling it at any time
2090will also result in any undefined (by POSIX) behaviour.
2091
2092=back
1816 2093
1817=head2 MEMORY USAGE 2094=head2 MEMORY USAGE
1818 2095
1819Per-request usage: 2096Per-request usage:
1820 2097

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