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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.258 by root, Thu Jan 21 23:04:46 2016 UTC vs.
Revision 1.267 by root, Tue Aug 9 11:39:17 2016 UTC

1=head1 NAME 1=head1 NAME
2 2
3IO::AIO - Asynchronous Input/Output 3IO::AIO - Asynchronous/Advanced Input/Output
4 4
5=head1 SYNOPSIS 5=head1 SYNOPSIS
6 6
7 use IO::AIO; 7 use IO::AIO;
8 8
58not well-supported or restricted (GNU/Linux doesn't allow them on normal 58not well-supported or restricted (GNU/Linux doesn't allow them on normal
59files currently, for example), and they would only support aio_read and 59files currently, for example), and they would only support aio_read and
60aio_write, so the remaining functionality would have to be implemented 60aio_write, so the remaining functionality would have to be implemented
61using threads anyway. 61using threads anyway.
62 62
63In addition to asynchronous I/O, this module also exports some rather
64arcane interfaces, such as C<madvise> or linux's C<splice> system call,
65which is why the C<A> in C<AIO> can also mean I<advanced>.
66
63Although the module will work in the presence of other (Perl-) threads, 67Although the module will work in the presence of other (Perl-) threads,
64it is currently not reentrant in any way, so use appropriate locking 68it is currently not reentrant in any way, so use appropriate locking
65yourself, always call C<poll_cb> from within the same thread, or never 69yourself, always call C<poll_cb> from within the same thread, or never
66call C<poll_cb> (or other C<aio_> functions) recursively. 70call C<poll_cb> (or other C<aio_> functions) recursively.
67 71
167use common::sense; 171use common::sense;
168 172
169use base 'Exporter'; 173use base 'Exporter';
170 174
171BEGIN { 175BEGIN {
172 our $VERSION = 4.33; 176 our $VERSION = 4.34;
173 177
174 our @AIO_REQ = qw(aio_sendfile aio_seek aio_read aio_write aio_open aio_close 178 our @AIO_REQ = qw(aio_sendfile aio_seek aio_read aio_write aio_open aio_close
175 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx 179 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
176 aio_scandir aio_symlink aio_readlink aio_realpath aio_sync 180 aio_scandir aio_symlink aio_readlink aio_realpath aio_fcntl aio_ioctl
177 aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range aio_allocate 181 aio_sync aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range
178 aio_pathsync aio_readahead aio_fiemap 182 aio_pathsync aio_readahead aio_fiemap aio_allocate
179 aio_rename aio_link aio_move aio_copy aio_group 183 aio_rename aio_link aio_move aio_copy aio_group
180 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown 184 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
181 aio_chmod aio_utime aio_truncate 185 aio_chmod aio_utime aio_truncate
182 aio_msync aio_mtouch aio_mlock aio_mlockall 186 aio_msync aio_mtouch aio_mlock aio_mlockall
183 aio_statvfs 187 aio_statvfs
240 aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) 244 aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
241 aio_load $pathname, $data, $callback->($status) 245 aio_load $pathname, $data, $callback->($status)
242 aio_copy $srcpath, $dstpath, $callback->($status) 246 aio_copy $srcpath, $dstpath, $callback->($status)
243 aio_move $srcpath, $dstpath, $callback->($status) 247 aio_move $srcpath, $dstpath, $callback->($status)
244 aio_rmtree $pathname, $callback->($status) 248 aio_rmtree $pathname, $callback->($status)
249 aio_fcntl $fh, $cmd, $arg, $callback->($status)
250 aio_ioctl $fh, $request, $buf, $callback->($status)
245 aio_sync $callback->($status) 251 aio_sync $callback->($status)
246 aio_syncfs $fh, $callback->($status) 252 aio_syncfs $fh, $callback->($status)
247 aio_fsync $fh, $callback->($status) 253 aio_fsync $fh, $callback->($status)
248 aio_fdatasync $fh, $callback->($status) 254 aio_fdatasync $fh, $callback->($status)
249 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) 255 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
439=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 445=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
440 446
441=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 447=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
442 448
443Reads or writes C<$length> bytes from or to the specified C<$fh> and 449Reads or writes C<$length> bytes from or to the specified C<$fh> and
444C<$offset> into the scalar given by C<$data> and offset C<$dataoffset> 450C<$offset> into the scalar given by C<$data> and offset C<$dataoffset> and
445and calls the callback without the actual number of bytes read (or -1 on 451calls the callback with the actual number of bytes transferred (or -1 on
446error, just like the syscall). 452error, just like the syscall).
447 453
448C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to 454C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
449offset plus the actual number of bytes read. 455offset plus the actual number of bytes read.
450 456
508As native sendfile syscalls (as practically any non-POSIX interface hacked 514As native sendfile syscalls (as practically any non-POSIX interface hacked
509together in a hurry to improve benchmark numbers) tend to be rather buggy 515together in a hurry to improve benchmark numbers) tend to be rather buggy
510on many systems, this implementation tries to work around some known bugs 516on many systems, this implementation tries to work around some known bugs
511in Linux and FreeBSD kernels (probably others, too), but that might fail, 517in Linux and FreeBSD kernels (probably others, too), but that might fail,
512so you really really should check the return value of C<aio_sendfile> - 518so you really really should check the return value of C<aio_sendfile> -
513fewre bytes than expected might have been transferred. 519fewer bytes than expected might have been transferred.
514 520
515 521
516=item aio_readahead $fh,$offset,$length, $callback->($retval) 522=item aio_readahead $fh,$offset,$length, $callback->($retval)
517 523
518C<aio_readahead> populates the page cache with data from a file so that 524C<aio_readahead> populates the page cache with data from a file so that
522whole pages, so that offset is effectively rounded down to a page boundary 528whole pages, so that offset is effectively rounded down to a page boundary
523and bytes are read up to the next page boundary greater than or equal to 529and bytes are read up to the next page boundary greater than or equal to
524(off-set+length). C<aio_readahead> does not read beyond the end of the 530(off-set+length). C<aio_readahead> does not read beyond the end of the
525file. The current file offset of the file is left unchanged. 531file. The current file offset of the file is left unchanged.
526 532
527If that syscall doesn't exist (likely if your OS isn't Linux) it will be 533If that syscall doesn't exist (likely if your kernel isn't Linux) it will
528emulated by simply reading the data, which would have a similar effect. 534be emulated by simply reading the data, which would have a similar effect.
529 535
530 536
531=item aio_stat $fh_or_path, $callback->($status) 537=item aio_stat $fh_or_path, $callback->($status)
532 538
533=item aio_lstat $fh, $callback->($status) 539=item aio_lstat $fh, $callback->($status)
1227 }; 1233 };
1228 1234
1229 $grp 1235 $grp
1230} 1236}
1231 1237
1238=item aio_fcntl $fh, $cmd, $arg, $callback->($status)
1239
1240=item aio_ioctl $fh, $request, $buf, $callback->($status)
1241
1242These work just like the C<fcntl> and C<ioctl> built-in functions, except
1243they execute asynchronously and pass the return value to the callback.
1244
1245Both calls can be used for a lot of things, some of which make more sense
1246to run asynchronously in their own thread, while some others make less
1247sense. For example, calls that block waiting for external events, such
1248as locking, will also lock down an I/O thread while it is waiting, which
1249can deadlock the whole I/O system. At the same time, there might be no
1250alternative to using a thread to wait.
1251
1252So in general, you should only use these calls for things that do
1253(filesystem) I/O, not for things that wait for other events (network,
1254other processes), although if you are careful and know what you are doing,
1255you still can.
1256
1257The following constants are available (missing ones are, as usual C<0>):
1258
1259C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>.
1260
1261C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>,
1262C<FS_IOC_FIEMAP>.
1263
1264C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>,
1265C<FS_IOC_GET_ENCRYPTION_PWSALT>, C<FS_IOC_GET_ENCRYPTION_POLICY>, C<FS_KEY_DESCRIPTOR_SIZE>.
1266
1267C<FS_SECRM_FL>, C<FS_UNRM_FL>, C<FS_COMPR_FL>, C<FS_SYNC_FL>, C<FS_IMMUTABLE_FL>,
1268C<FS_APPEND_FL>, C<FS_NODUMP_FL>, C<FS_NOATIME_FL>, C<FS_DIRTY_FL>,
1269C<FS_COMPRBLK_FL>, C<FS_NOCOMP_FL>, C<FS_ENCRYPT_FL>, C<FS_BTREE_FL>,
1270C<FS_INDEX_FL>, C<FS_JOURNAL_DATA_FL>, C<FS_NOTAIL_FL>, C<FS_DIRSYNC_FL>, C<FS_TOPDIR_FL>,
1271C<FS_FL_USER_MODIFIABLE>.
1272
1273C<FS_XFLAG_REALTIME>, C<FS_XFLAG_PREALLOC>, C<FS_XFLAG_IMMUTABLE>, C<FS_XFLAG_APPEND>,
1274C<FS_XFLAG_SYNC>, C<FS_XFLAG_NOATIME>, C<FS_XFLAG_NODUMP>, C<FS_XFLAG_RTINHERIT>,
1275C<FS_XFLAG_PROJINHERIT>, C<FS_XFLAG_NOSYMLINKS>, C<FS_XFLAG_EXTSIZE>, C<FS_XFLAG_EXTSZINHERIT>,
1276C<FS_XFLAG_NODEFRAG>, C<FS_XFLAG_FILESTREAM>, C<FS_XFLAG_DAX>, C<FS_XFLAG_HASATTR>,
1277
1232=item aio_sync $callback->($status) 1278=item aio_sync $callback->($status)
1233 1279
1234Asynchronously call sync and call the callback when finished. 1280Asynchronously call sync and call the callback when finished.
1235 1281
1236=item aio_fsync $fh, $callback->($status) 1282=item aio_fsync $fh, $callback->($status)
2020=item IO::AIO::madvise $scalar, $offset, $len, $advice 2066=item IO::AIO::madvise $scalar, $offset, $len, $advice
2021 2067
2022Simply calls the C<posix_madvise> function (see its 2068Simply calls the C<posix_madvise> function (see its
2023manpage for details). The following advice constants are 2069manpage for details). The following advice constants are
2024available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>, 2070available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
2025C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>. 2071C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>,
2072C<IO::AIO::MADV_FREE>.
2026 2073
2027On systems that do not implement C<posix_madvise>, this function returns 2074On systems that do not implement C<posix_madvise>, this function returns
2028ENOSYS, otherwise the return value of C<posix_madvise>. 2075ENOSYS, otherwise the return value of C<posix_madvise>.
2029 2076
2030=item IO::AIO::mprotect $scalar, $offset, $len, $protect 2077=item IO::AIO::mprotect $scalar, $offset, $len, $protect

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