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Revision 1.211 by root, Tue Sep 27 12:10:29 2011 UTC vs.
Revision 1.234 by root, Mon Aug 13 01:02:30 2012 UTC

… …
168use common::sense; 168use common::sense;
169 169
170use base 'Exporter'; 170use base 'Exporter';
171 171
172BEGIN { 172BEGIN {
173 our $VERSION = '4.0'; 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 177 aio_scandir aio_symlink aio_readlink aio_realpath aio_sync
178 aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range aio_fallocate 178 aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range aio_fallocate
179 aio_pathsync aio_readahead 179 aio_pathsync aio_readahead aio_fiemap
180 aio_rename aio_link aio_move aio_copy aio_group 180 aio_rename aio_link aio_move aio_copy aio_group
181 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
182 aio_chmod aio_utime aio_truncate 182 aio_chmod aio_utime aio_truncate
183 aio_msync aio_mtouch aio_mlock aio_mlockall 183 aio_msync aio_mtouch aio_mlock aio_mlockall
184 aio_statvfs 184 aio_statvfs
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202 202
203=head1 FUNCTIONS 203=head1 FUNCTIONS
204 204
205=head2 QUICK OVERVIEW 205=head2 QUICK OVERVIEW
206 206
207This section simply lists the prototypes of the most important functions 207This section simply lists the prototypes most of the functions for
208for quick reference. See the following sections for function-by-function 208quick reference. See the following sections for function-by-function
209documentation. 209documentation.
210 210
211 aio_wd $pathname, $callback->($wd) 211 aio_wd $pathname, $callback->($wd)
212 aio_open $pathname, $flags, $mode, $callback->($fh) 212 aio_open $pathname, $flags, $mode, $callback->($fh)
213 aio_close $fh, $callback->($status) 213 aio_close $fh, $callback->($status)
214 aio_seek $fh,$offset,$whence, $callback->($offs)
214 aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 215 aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
215 aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 216 aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
216 aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) 217 aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
217 aio_readahead $fh,$offset,$length, $callback->($retval) 218 aio_readahead $fh,$offset,$length, $callback->($retval)
218 aio_stat $fh_or_path, $callback->($status) 219 aio_stat $fh_or_path, $callback->($status)
219 aio_lstat $fh, $callback->($status) 220 aio_lstat $fh, $callback->($status)
220 aio_statvfs $fh_or_path, $callback->($statvfs) 221 aio_statvfs $fh_or_path, $callback->($statvfs)
221 aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 222 aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
222 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)
223 aio_truncate $fh_or_path, $offset, $callback->($status) 225 aio_truncate $fh_or_path, $offset, $callback->($status)
224 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)
225 aio_unlink $pathname, $callback->($status) 228 aio_unlink $pathname, $callback->($status)
226 aio_mknod $pathname, $mode, $dev, $callback->($status) 229 aio_mknod $pathname, $mode, $dev, $callback->($status)
227 aio_link $srcpath, $dstpath, $callback->($status) 230 aio_link $srcpath, $dstpath, $callback->($status)
228 aio_symlink $srcpath, $dstpath, $callback->($status) 231 aio_symlink $srcpath, $dstpath, $callback->($status)
229 aio_readlink $pathname, $callback->($link) 232 aio_readlink $pathname, $callback->($link)
… …
233 aio_rmdir $pathname, $callback->($status) 236 aio_rmdir $pathname, $callback->($status)
234 aio_readdir $pathname, $callback->($entries) 237 aio_readdir $pathname, $callback->($entries)
235 aio_readdirx $pathname, $flags, $callback->($entries, $flags) 238 aio_readdirx $pathname, $flags, $callback->($entries, $flags)
236 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST 239 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
237 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)
238 aio_load $pathname, $data, $callback->($status) 242 aio_load $pathname, $data, $callback->($status)
239 aio_copy $srcpath, $dstpath, $callback->($status) 243 aio_copy $srcpath, $dstpath, $callback->($status)
240 aio_move $srcpath, $dstpath, $callback->($status) 244 aio_move $srcpath, $dstpath, $callback->($status)
241 aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
242 aio_rmtree $pathname, $callback->($status) 245 aio_rmtree $pathname, $callback->($status)
243 aio_sync $callback->($status) 246 aio_sync $callback->($status)
244 aio_syncfs $fh, $callback->($status) 247 aio_syncfs $fh, $callback->($status)
245 aio_fsync $fh, $callback->($status) 248 aio_fsync $fh, $callback->($status)
246 aio_fdatasync $fh, $callback->($status) 249 aio_fdatasync $fh, $callback->($status)
… …
271 IO::AIO::nready 274 IO::AIO::nready
272 IO::AIO::npending 275 IO::AIO::npending
273 276
274 IO::AIO::sendfile $ofh, $ifh, $offset, $count 277 IO::AIO::sendfile $ofh, $ifh, $offset, $count
275 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
276 IO::AIO::madvise $scalar, $offset, $length, $advice 281 IO::AIO::madvise $scalar, $offset, $length, $advice
277 IO::AIO::mprotect $scalar, $offset, $length, $protect 282 IO::AIO::mprotect $scalar, $offset, $length, $protect
278 IO::AIO::munlock $scalar, $offset = 0, $length = undef 283 IO::AIO::munlock $scalar, $offset = 0, $length = undef
279 IO::AIO::munlockall 284 IO::AIO::munlockall
280 285
281=head2 AIO REQUEST FUNCTIONS 286=head2 API NOTES
282 287
283All the C<aio_*> calls are more or less thin wrappers around the syscall 288All the C<aio_*> calls are more or less thin wrappers around the syscall
284with the same name (sans C<aio_>). The arguments are similar or identical, 289with the same name (sans C<aio_>). The arguments are similar or identical,
285and they all accept an additional (and optional) C<$callback> argument 290and they all accept an additional (and optional) C<$callback> argument
286which must be a code reference. This code reference will get called with 291which must be a code reference. This code reference will be called after
287the syscall return code (e.g. most syscalls return C<-1> on error, unlike 292the syscall has been executed in an asynchronous fashion. The results
288perl, which usually delivers "false") as its sole argument after the given 293of the request will be passed as arguments to the callback (and, if an
289syscall has been executed asynchronously. 294error occured, in C<$!>) - 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>.
290 300
291All functions expecting a filehandle keep a copy of the filehandle 301All functions expecting a filehandle keep a copy of the filehandle
292internally until the request has finished. 302internally until the request has finished.
293 303
294All 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
295further manipulation of those requests while they are in-flight. 305further manipulation of those requests while they are in-flight.
296 306
297The pathnames you pass to these routines I<should> be absolute. The 307The pathnames you pass to these routines I<should> be absolute. The
298reason for this is that at the time the request is being executed, the 308reason for this is that at the time the request is being executed, the
299current working directory could have changed. Alternatively, you can make 309current working directory could have changed. Alternatively, you can
300sure that you never change the current working directory anywhere in 310make sure that you never change the current working directory anywhere
301the program and then use relative paths. Lastly, you can take advantage 311in the program and then use relative paths. You can also take advantage
302of IO::AIOs working directory abstraction - see the description of the 312of IO::AIOs working directory abstraction, that lets you specify paths
313relative to some previously-opened "working directory object" - see the
303C<IO::AIO::WD> class later in this document. 314description of the C<IO::AIO::WD> class later in this document.
304 315
305To 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
306in filenames you got from outside (command line, readdir etc.) without 317in filenames you got from outside (command line, readdir etc.) without
307tinkering, 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
308your pathnames to the locale (or other) encoding in effect in the user 319module and encode your pathnames to the locale (or other) encoding in
309environment, d) use Glib::filename_from_unicode on unicode filenames or e) 320effect in the user environment, d) use Glib::filename_from_unicode on
310use 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.
311 323
312This 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
313handles correctly whether it is set or not. 325handles correctly whether it is set or not.
326
327=head2 AIO REQUEST FUNCTIONS
314 328
315=over 4 329=over 4
316 330
317=item $prev_pri = aioreq_pri [$pri] 331=item $prev_pri = aioreq_pri [$pri]
318 332
… …
348 362
349 363
350=item aio_open $pathname, $flags, $mode, $callback->($fh) 364=item aio_open $pathname, $flags, $mode, $callback->($fh)
351 365
352Asynchronously 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
353created filehandle for the file. 367created filehandle for the file (or C<undef> in case of an error).
354 368
355The 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,
356for an explanation. 370for an explanation.
357 371
358The 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
… …
400 414
401Or 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
402free for reuse until the perl filehandle is closed. 416free for reuse until the perl filehandle is closed.
403 417
404=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".
405 439
406=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 440=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
407 441
408=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 442=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
409 443
… …
606=item aio_truncate $fh_or_path, $offset, $callback->($status) 640=item aio_truncate $fh_or_path, $offset, $callback->($status)
607 641
608Works like truncate(2) or ftruncate(2). 642Works like truncate(2) or ftruncate(2).
609 643
610 644
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
611=item aio_chmod $fh_or_path, $mode, $callback->($status) 661=item aio_chmod $fh_or_path, $mode, $callback->($status)
612 662
613Works like perl's C<chmod> function. 663Works like perl's C<chmod> function.
614 664
615 665
… …
967 my $grp = aio_group $cb; 1017 my $grp = aio_group $cb;
968 1018
969 $maxreq = 4 if $maxreq <= 0; 1019 $maxreq = 4 if $maxreq <= 0;
970 1020
971 # get a wd object 1021 # get a wd object
972
973 aioreq_pri $pri; 1022 aioreq_pri $pri;
974 add $grp aio_wd $path, sub { 1023 add $grp aio_wd $path, sub {
1024 $_[0]
1025 or return $grp->result ();
1026
975 my $wd = [shift, "."]; 1027 my $wd = [shift, "."];
976 1028
977 # stat once 1029 # stat once
978 aioreq_pri $pri; 1030 aioreq_pri $pri;
979 add $grp aio_stat $wd, sub { 1031 add $grp aio_stat $wd, sub {
… …
1223 1275
1224Example: asynchronously lock all current and future pages into memory. 1276Example: asynchronously lock all current and future pages into memory.
1225 1277
1226 aio_mlockall IO::AIO::MCL_FUTURE; 1278 aio_mlockall IO::AIO::MCL_FUTURE;
1227 1279
1280=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
1281
1282Queries the extents of the given file (by calling the Linux C<FIEMAP>
1283ioctl, see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If
1284the ioctl is not available on your OS, then this request will fail with
1285C<ENOSYS>.
1286
1287C<$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
1228=item aio_group $callback->(...) 1325=item aio_group $callback->(...)
1229 1326
1230This is a very special aio request: Instead of doing something, it is a 1327This is a very special aio request: Instead of doing something, it is a
1231container for other aio requests, which is useful if you want to bundle 1328container for other aio requests, which is useful if you want to bundle
1232many requests into a single, composite, request with a definite callback 1329many requests into a single, composite, request with a definite callback
… …
1295object. This object stores the canonicalised, absolute version of the 1392object. This object stores the canonicalised, absolute version of the
1296path, and on systems that allow it, also a directory file descriptor. 1393path, and on systems that allow it, also a directory file descriptor.
1297 1394
1298Everywhere where a pathname is accepted by IO::AIO (e.g. in C<aio_stat> 1395Everywhere where a pathname is accepted by IO::AIO (e.g. in C<aio_stat>
1299or C<aio_unlink>), one can specify an array reference with an IO::AIO::WD 1396or C<aio_unlink>), one can specify an array reference with an IO::AIO::WD
1300object and a pathname instead. If the pathname is absolute, the 1397object and a pathname instead (or the IO::AIO::WD object alone, which
1398gets interpreted as C<[$wd, "."]>). If the pathname is absolute, the
1301IO::AIO::WD objetc is ignored, otherwise the pathname is resolved relative 1399IO::AIO::WD object is ignored, otherwise the pathname is resolved relative
1302to that IO::AIO::WD object. 1400to that IO::AIO::WD object.
1303 1401
1304For example, to get a wd object for F</etc> and then stat F<passwd> 1402For example, to get a wd object for F</etc> and then stat F<passwd>
1305inside, you would write: 1403inside, you would write:
1306 1404
… …
1314 aio_stat [$etcdir, "passwd"], sub { 1412 aio_stat [$etcdir, "passwd"], sub {
1315 # yay 1413 # yay
1316 }; 1414 };
1317 }; 1415 };
1318 1416
1319This shows that creating an IO::AIO::WD object is itself a potentially 1417That C<aio_wd> is a request and not a normal function shows that creating
1320blocking operation, which is why it is done asynchronously. 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 $wd , sub { ... # shorthand for the previous
1321 1427
1322As with normal pathnames, IO::AIO keeps a copy of the working directory 1428As with normal pathnames, IO::AIO keeps a copy of the working directory
1323object and the pathname string, so you could write the following without 1429object and the pathname string, so you could write the following without
1324causing any issues due to C<$path> getting reused: 1430causing any issues due to C<$path> getting reused:
1325 1431
… …
1825ENOSYS, otherwise the return value of C<mprotect>. 1931ENOSYS, otherwise the return value of C<mprotect>.
1826 1932
1827=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] 1933=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1828 1934
1829Memory-maps a file (or anonymous memory range) and attaches it to the 1935Memory-maps a file (or anonymous memory range) and attaches it to the
1830given C<$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.
1831 1938
1832The 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
1833change 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
1834or searching it with regexes and so on. 1941or searching it with regexes and so on.
1835 1942
… …
1888Calls the C<munlockall> function. 1995Calls the C<munlockall> function.
1889 1996
1890On systems that do not implement C<munlockall>, this function returns 1997On systems that do not implement C<munlockall>, this function returns
1891ENOSYS, otherwise the return value of C<munlockall>. 1998ENOSYS, otherwise the return value of C<munlockall>.
1892 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
1893=back 2020=back
1894 2021
1895=cut 2022=cut
1896 2023
1897min_parallel 8; 2024min_parallel 8;

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