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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.261 by root, Sat May 21 04:43:31 2016 UTC vs.
Revision 1.268 by root, Tue May 30 22:45:52 2017 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 = 4.34; 176 our $VERSION = 4.35;
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_fcntl aio_ioctl 180 aio_scandir aio_symlink aio_readlink aio_realpath aio_fcntl aio_ioctl
177 aio_sync aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range 181 aio_sync aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range
248 aio_syncfs $fh, $callback->($status) 252 aio_syncfs $fh, $callback->($status)
249 aio_fsync $fh, $callback->($status) 253 aio_fsync $fh, $callback->($status)
250 aio_fdatasync $fh, $callback->($status) 254 aio_fdatasync $fh, $callback->($status)
251 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) 255 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
252 aio_pathsync $pathname, $callback->($status) 256 aio_pathsync $pathname, $callback->($status)
253 aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 257 aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status)
254 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 258 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
255 aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) 259 aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
256 aio_mlockall $flags, $callback->($status) 260 aio_mlockall $flags, $callback->($status)
257 aio_group $callback->(...) 261 aio_group $callback->(...)
258 aio_nop $callback->() 262 aio_nop $callback->()
441=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 445=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
442 446
443=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 447=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
444 448
445Reads 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
446C<$offset> into the scalar given by C<$data> and offset C<$dataoffset> 450C<$offset> into the scalar given by C<$data> and offset C<$dataoffset> and
447and 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
448error, just like the syscall). 452error, just like the syscall).
449 453
450C<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
451offset plus the actual number of bytes read. 455offset plus the actual number of bytes read.
452 456
510As native sendfile syscalls (as practically any non-POSIX interface hacked 514As native sendfile syscalls (as practically any non-POSIX interface hacked
511together 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
512on many systems, this implementation tries to work around some known bugs 516on many systems, this implementation tries to work around some known bugs
513in Linux and FreeBSD kernels (probably others, too), but that might fail, 517in Linux and FreeBSD kernels (probably others, too), but that might fail,
514so 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> -
515fewre bytes than expected might have been transferred. 519fewer bytes than expected might have been transferred.
516 520
517 521
518=item aio_readahead $fh,$offset,$length, $callback->($retval) 522=item aio_readahead $fh,$offset,$length, $callback->($retval)
519 523
520C<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
1248So in general, you should only use these calls for things that do 1252So in general, you should only use these calls for things that do
1249(filesystem) I/O, not for things that wait for other events (network, 1253(filesystem) I/O, not for things that wait for other events (network,
1250other processes), although if you are careful and know what you are doing, 1254other processes), although if you are careful and know what you are doing,
1251you still can. 1255you still can.
1252 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
1253=item aio_sync $callback->($status) 1278=item aio_sync $callback->($status)
1254 1279
1255Asynchronously call sync and call the callback when finished. 1280Asynchronously call sync and call the callback when finished.
1256 1281
1257=item aio_fsync $fh, $callback->($status) 1282=item aio_fsync $fh, $callback->($status)
1325 }; 1350 };
1326 1351
1327 $grp 1352 $grp
1328} 1353}
1329 1354
1330=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 1355=item aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status)
1331 1356
1332This is a rather advanced IO::AIO call, which only works on mmap(2)ed 1357This is a rather advanced IO::AIO call, which only works on mmap(2)ed
1333scalars (see the C<IO::AIO::mmap> function, although it also works on data 1358scalars (see the C<IO::AIO::mmap> function, although it also works on data
1334scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the 1359scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
1335scalar must only be modified in-place while an aio operation is pending on 1360scalar must only be modified in-place while an aio operation is pending on
1337 1362
1338It calls the C<msync> function of your OS, if available, with the memory 1363It calls the C<msync> function of your OS, if available, with the memory
1339area starting at C<$offset> in the string and ending C<$length> bytes 1364area starting at C<$offset> in the string and ending C<$length> bytes
1340later. If C<$length> is negative, counts from the end, and if C<$length> 1365later. If C<$length> is negative, counts from the end, and if C<$length>
1341is C<undef>, then it goes till the end of the string. The flags can be 1366is C<undef>, then it goes till the end of the string. The flags can be
1342a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and 1367either C<IO::AIO::MS_ASYNC> or C<IO::AIO::MS_SYNC>, plus an optional
1343C<IO::AIO::MS_SYNC>. 1368C<IO::AIO::MS_INVALIDATE>.
1344 1369
1345=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 1370=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1346 1371
1347This is a rather advanced IO::AIO call, which works best on mmap(2)ed 1372This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1348scalars. 1373scalars.
2041=item IO::AIO::madvise $scalar, $offset, $len, $advice 2066=item IO::AIO::madvise $scalar, $offset, $len, $advice
2042 2067
2043Simply calls the C<posix_madvise> function (see its 2068Simply calls the C<posix_madvise> function (see its
2044manpage for details). The following advice constants are 2069manpage for details). The following advice constants are
2045available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>, 2070available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
2046C<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>.
2047 2073
2048On systems that do not implement C<posix_madvise>, this function returns 2074On systems that do not implement C<posix_madvise>, this function returns
2049ENOSYS, otherwise the return value of C<posix_madvise>. 2075ENOSYS, otherwise the return value of C<posix_madvise>.
2050 2076
2051=item IO::AIO::mprotect $scalar, $offset, $len, $protect 2077=item IO::AIO::mprotect $scalar, $offset, $len, $protect
2062 2088
2063Memory-maps a file (or anonymous memory range) and attaches it to the 2089Memory-maps a file (or anonymous memory range) and attaches it to the
2064given C<$scalar>, which will act like a string scalar. Returns true on 2090given C<$scalar>, which will act like a string scalar. Returns true on
2065success, and false otherwise. 2091success, and false otherwise.
2066 2092
2093The scalar must exist, but its contents do not matter - this means you
2094cannot use a nonexistant array or hash element. When in doubt, C<undef>
2095the scalar first.
2096
2067The only operations allowed on the scalar are C<substr>/C<vec> that don't 2097The only operations allowed on the mmapped scalar are C<substr>/C<vec>,
2068change the string length, and most read-only operations such as copying it 2098which don't change the string length, and most read-only operations such
2069or searching it with regexes and so on. 2099as copying it or searching it with regexes and so on.
2070 2100
2071Anything else is unsafe and will, at best, result in memory leaks. 2101Anything else is unsafe and will, at best, result in memory leaks.
2072 2102
2073The memory map associated with the C<$scalar> is automatically removed 2103The memory map associated with the C<$scalar> is automatically removed
2074when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or 2104when the C<$scalar> is undef'd or destroyed, or when the C<IO::AIO::mmap>
2075C<IO::AIO::munmap> functions are called. 2105or C<IO::AIO::munmap> functions are called on it.
2076 2106
2077This calls the C<mmap>(2) function internally. See your system's manual 2107This calls the C<mmap>(2) function internally. See your system's manual
2078page for details on the C<$length>, C<$prot> and C<$flags> parameters. 2108page for details on the C<$length>, C<$prot> and C<$flags> parameters.
2079 2109
2080The C<$length> must be larger than zero and smaller than the actual 2110The C<$length> must be larger than zero and smaller than the actual

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