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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.268 by root, Tue May 30 22:45:52 2017 UTC vs.
Revision 1.281 by root, Tue Feb 20 04:32:59 2018 UTC

171use common::sense; 171use common::sense;
172 172
173use base 'Exporter'; 173use base 'Exporter';
174 174
175BEGIN { 175BEGIN {
176 our $VERSION = 4.35; 176 our $VERSION = 4.4;
177 177
178 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
179 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
180 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
181 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
182 aio_pathsync aio_readahead aio_fiemap aio_allocate 182 aio_pathsync aio_readahead aio_fiemap aio_allocate
183 aio_rename aio_link aio_move aio_copy aio_group 183 aio_rename aio_rename2 aio_link aio_move aio_copy aio_group
184 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
185 aio_chmod aio_utime aio_truncate 185 aio_chmod aio_utime aio_truncate
186 aio_msync aio_mtouch aio_mlock aio_mlockall 186 aio_msync aio_mtouch aio_mlock aio_mlockall
187 aio_statvfs 187 aio_statvfs
188 aio_slurp
188 aio_wd); 189 aio_wd);
189 190
190 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); 191 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
191 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 192 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
192 min_parallel max_parallel max_idle idle_timeout 193 min_parallel max_parallel max_idle idle_timeout
233 aio_link $srcpath, $dstpath, $callback->($status) 234 aio_link $srcpath, $dstpath, $callback->($status)
234 aio_symlink $srcpath, $dstpath, $callback->($status) 235 aio_symlink $srcpath, $dstpath, $callback->($status)
235 aio_readlink $pathname, $callback->($link) 236 aio_readlink $pathname, $callback->($link)
236 aio_realpath $pathname, $callback->($path) 237 aio_realpath $pathname, $callback->($path)
237 aio_rename $srcpath, $dstpath, $callback->($status) 238 aio_rename $srcpath, $dstpath, $callback->($status)
239 aio_rename2 $srcpath, $dstpath, $flags, $callback->($status)
238 aio_mkdir $pathname, $mode, $callback->($status) 240 aio_mkdir $pathname, $mode, $callback->($status)
239 aio_rmdir $pathname, $callback->($status) 241 aio_rmdir $pathname, $callback->($status)
240 aio_readdir $pathname, $callback->($entries) 242 aio_readdir $pathname, $callback->($entries)
241 aio_readdirx $pathname, $flags, $callback->($entries, $flags) 243 aio_readdirx $pathname, $flags, $callback->($entries, $flags)
242 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST 244 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
276 IO::AIO::idle_timeout $seconds 278 IO::AIO::idle_timeout $seconds
277 IO::AIO::max_outstanding $maxreqs 279 IO::AIO::max_outstanding $maxreqs
278 IO::AIO::nreqs 280 IO::AIO::nreqs
279 IO::AIO::nready 281 IO::AIO::nready
280 IO::AIO::npending 282 IO::AIO::npending
283 $nfd = IO::AIO::get_fdlimit [EXPERIMENTAL]
284 IO::AIO::min_fdlimit $nfd [EXPERIMENTAL]
281 285
282 IO::AIO::sendfile $ofh, $ifh, $offset, $count 286 IO::AIO::sendfile $ofh, $ifh, $offset, $count
283 IO::AIO::fadvise $fh, $offset, $len, $advice 287 IO::AIO::fadvise $fh, $offset, $len, $advice
284 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]] 288 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
285 IO::AIO::munmap $scalar 289 IO::AIO::munmap $scalar
608 namemax => 255, 612 namemax => 255,
609 frsize => 1024, 613 frsize => 1024,
610 fsid => 1810 614 fsid => 1810
611 } 615 }
612 616
613Here is a (likely partial - send me updates!) list of fsid values used by
614Linux - it is safe to hardcode these when C<$^O> is C<linux>:
615
616 0x0000adf5 adfs
617 0x0000adff affs
618 0x5346414f afs
619 0x09041934 anon-inode filesystem
620 0x00000187 autofs
621 0x42465331 befs
622 0x1badface bfs
623 0x42494e4d binfmt_misc
624 0x9123683e btrfs
625 0x0027e0eb cgroupfs
626 0xff534d42 cifs
627 0x73757245 coda
628 0x012ff7b7 coh
629 0x28cd3d45 cramfs
630 0x453dcd28 cramfs-wend (wrong endianness)
631 0x64626720 debugfs
632 0x00001373 devfs
633 0x00001cd1 devpts
634 0x0000f15f ecryptfs
635 0x00414a53 efs
636 0x0000137d ext
637 0x0000ef53 ext2/ext3/ext4
638 0x0000ef51 ext2
639 0xf2f52010 f2fs
640 0x00004006 fat
641 0x65735546 fuseblk
642 0x65735543 fusectl
643 0x0bad1dea futexfs
644 0x01161970 gfs2
645 0x47504653 gpfs
646 0x00004244 hfs
647 0xf995e849 hpfs
648 0x00c0ffee hostfs
649 0x958458f6 hugetlbfs
650 0x2bad1dea inotifyfs
651 0x00009660 isofs
652 0x000072b6 jffs2
653 0x3153464a jfs
654 0x6b414653 k-afs
655 0x0bd00bd0 lustre
656 0x0000137f minix
657 0x0000138f minix 30 char names
658 0x00002468 minix v2
659 0x00002478 minix v2 30 char names
660 0x00004d5a minix v3
661 0x19800202 mqueue
662 0x00004d44 msdos
663 0x0000564c novell
664 0x00006969 nfs
665 0x6e667364 nfsd
666 0x00003434 nilfs
667 0x5346544e ntfs
668 0x00009fa1 openprom
669 0x7461636F ocfs2
670 0x00009fa0 proc
671 0x6165676c pstorefs
672 0x0000002f qnx4
673 0x68191122 qnx6
674 0x858458f6 ramfs
675 0x52654973 reiserfs
676 0x00007275 romfs
677 0x67596969 rpc_pipefs
678 0x73636673 securityfs
679 0xf97cff8c selinux
680 0x0000517b smb
681 0x534f434b sockfs
682 0x73717368 squashfs
683 0x62656572 sysfs
684 0x012ff7b6 sysv2
685 0x012ff7b5 sysv4
686 0x01021994 tmpfs
687 0x15013346 udf
688 0x00011954 ufs
689 0x54190100 ufs byteswapped
690 0x00009fa2 usbdevfs
691 0x01021997 v9fs
692 0xa501fcf5 vxfs
693 0xabba1974 xenfs
694 0x012ff7b4 xenix
695 0x58465342 xfs
696 0x012fd16d xia
697
698=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 617=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
699 618
700Works like perl's C<utime> function (including the special case of $atime 619Works like perl's C<utime> function (including the special case of $atime
701and $mtime being undef). Fractional times are supported if the underlying 620and $mtime being undef). Fractional times are supported if the underlying
702syscalls support them. 621syscalls support them.
739C<$mode> is usually C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> to allocate 658C<$mode> is usually C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> to allocate
740space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE | IO::AIO::FALLOC_FL_KEEP_SIZE>, 659space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE | IO::AIO::FALLOC_FL_KEEP_SIZE>,
741to deallocate a file range. 660to deallocate a file range.
742 661
743IO::AIO also supports C<FALLOC_FL_COLLAPSE_RANGE>, to remove a range 662IO::AIO also supports C<FALLOC_FL_COLLAPSE_RANGE>, to remove a range
744(without leaving a hole) and C<FALLOC_FL_ZERO_RANGE>, to zero a range (see 663(without leaving a hole), C<FALLOC_FL_ZERO_RANGE>, to zero a range,
745your L<fallocate(2)> manpage). 664C<FALLOC_FL_INSERT_RANGE> to insert a range and C<FALLOC_FL_UNSHARE_RANGE>
665to unshare shared blocks (see your L<fallocate(2)> manpage).
746 666
747The file system block size used by C<fallocate> is presumably the 667The file system block size used by C<fallocate> is presumably the
748C<f_bsize> returned by C<statvfs>. 668C<f_bsize> returned by C<statvfs>, but different filesystems and filetypes
669can dictate other limitations.
749 670
750If C<fallocate> isn't available or cannot be emulated (currently no 671If C<fallocate> isn't available or cannot be emulated (currently no
751emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>. 672emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>.
752 673
753 674
810rename(2) and call the callback with the result code. 731rename(2) and call the callback with the result code.
811 732
812On systems that support the AIO::WD working directory abstraction 733On systems that support the AIO::WD working directory abstraction
813natively, the case C<[$wd, "."]> as C<$srcpath> is specialcased - instead 734natively, the case C<[$wd, "."]> as C<$srcpath> is specialcased - instead
814of failing, C<rename> is called on the absolute path of C<$wd>. 735of failing, C<rename> is called on the absolute path of C<$wd>.
736
737
738=item aio_rename2 $srcpath, $dstpath, $flags, $callback->($status)
739
740Basically a version of C<aio_rename> with an additional C<$flags>
741argument. Calling this with C<$flags=0> is the same as calling
742C<aio_rename>.
743
744Non-zero flags are currently only supported on GNU/Linux systems that
745support renameat2. Other systems fail with C<ENOSYS> in this case.
746
747The following constants are available (missing ones are, as usual C<0>),
748see renameat2(2) for details:
749
750C<IO::AIO::RENAME_NOREPLACE>, C<IO::AIO::RENAME_EXCHANGE>
751and C<IO::AIO::RENAME_WHITEOUT>.
815 752
816 753
817=item aio_mkdir $pathname, $mode, $callback->($status) 754=item aio_mkdir $pathname, $mode, $callback->($status)
818 755
819Asynchronously mkdir (create) a directory and call the callback with 756Asynchronously mkdir (create) a directory and call the callback with
905C<$type>'s are known, which can be used to speed up some algorithms. 842C<$type>'s are known, which can be used to speed up some algorithms.
906 843
907=back 844=back
908 845
909 846
847=item aio_slurp $pathname, $offset, $length, $data, $callback->($status)
848
849Opens, reads and closes the given file. The data is put into C<$data>,
850which is resized as required.
851
852If C<$offset> is negative, then it is counted from the end of the file.
853
854If C<$length> is zero, then the remaining length of the file is
855used. Also, in this case, the same limitations to modifying C<$data> apply
856as when IO::AIO::mmap is used, i.e. it must only be modified in-place
857with C<substr>. If the size of the file is known, specifying a non-zero
858C<$length> results in a performance advantage.
859
860This request is similar to the older C<aio_load> request, but since it is
861a single request, it might be more efficient to use.
862
863Example: load F</etc/passwd> into C<$passwd>.
864
865 my $passwd;
866 aio_slurp "/etc/passwd", 0, 0, $passwd, sub {
867 $_[0] >= 0
868 or die "/etc/passwd: $!\n";
869
870 printf "/etc/passwd is %d bytes long, and contains:\n", length $passwd;
871 print $passwd;
872 };
873 IO::AIO::flush;
874
875
910=item aio_load $pathname, $data, $callback->($status) 876=item aio_load $pathname, $data, $callback->($status)
911 877
912This is a composite request that tries to fully load the given file into 878This is a composite request that tries to fully load the given file into
913memory. Status is the same as with aio_read. 879memory. Status is the same as with aio_read.
880
881Using C<aio_slurp> might be more efficient, as it is a single request.
914 882
915=cut 883=cut
916 884
917sub aio_load($$;$) { 885sub aio_load($$;$) {
918 my ($path, undef, $cb) = @_; 886 my ($path, undef, $cb) = @_;
938=item aio_copy $srcpath, $dstpath, $callback->($status) 906=item aio_copy $srcpath, $dstpath, $callback->($status)
939 907
940Try to copy the I<file> (directories not supported as either source or 908Try to copy the I<file> (directories not supported as either source or
941destination) from C<$srcpath> to C<$dstpath> and call the callback with 909destination) from C<$srcpath> to C<$dstpath> and call the callback with
942a status of C<0> (ok) or C<-1> (error, see C<$!>). 910a status of C<0> (ok) or C<-1> (error, see C<$!>).
911
912Existing destination files will be truncated.
943 913
944This is a composite request that creates the destination file with 914This is a composite request that creates the destination file with
945mode 0200 and copies the contents of the source file into it using 915mode 0200 and copies the contents of the source file into it using
946C<aio_sendfile>, followed by restoring atime, mtime, access mode and 916C<aio_sendfile>, followed by restoring atime, mtime, access mode and
947uid/gid, in that order. 917uid/gid, in that order.
1057Scans a directory (similar to C<aio_readdir>) but additionally tries to 1027Scans a directory (similar to C<aio_readdir>) but additionally tries to
1058efficiently separate the entries of directory C<$path> into two sets of 1028efficiently separate the entries of directory C<$path> into two sets of
1059names, directories you can recurse into (directories), and ones you cannot 1029names, directories you can recurse into (directories), and ones you cannot
1060recurse into (everything else, including symlinks to directories). 1030recurse into (everything else, including symlinks to directories).
1061 1031
1062C<aio_scandir> is a composite request that creates of many sub requests_ 1032C<aio_scandir> is a composite request that generates many sub requests.
1063C<$maxreq> specifies the maximum number of outstanding aio requests that 1033C<$maxreq> specifies the maximum number of outstanding aio requests that
1064this function generates. If it is C<< <= 0 >>, then a suitable default 1034this function generates. If it is C<< <= 0 >>, then a suitable default
1065will be chosen (currently 4). 1035will be chosen (currently 4).
1066 1036
1067On error, the callback is called without arguments, otherwise it receives 1037On error, the callback is called without arguments, otherwise it receives
1254other processes), although if you are careful and know what you are doing, 1224other processes), although if you are careful and know what you are doing,
1255you still can. 1225you still can.
1256 1226
1257The following constants are available (missing ones are, as usual C<0>): 1227The following constants are available (missing ones are, as usual C<0>):
1258 1228
1229C<F_DUPFD_CLOEXEC>,
1230
1231C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>,
1232
1259C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>. 1233C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>.
1260 1234
1261C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>, 1235C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>,
1262C<FS_IOC_FIEMAP>. 1236C<FS_IOC_FIEMAP>.
1263 1237
1456C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>, 1430C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
1457C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>, 1431C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
1458C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or 1432C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
1459C<IO::AIO::FIEMAP_EXTENT_SHARED>. 1433C<IO::AIO::FIEMAP_EXTENT_SHARED>.
1460 1434
1461At the time of this writing (Linux 3.2), this requets is unreliable unless 1435At the time of this writing (Linux 3.2), this request is unreliable unless
1462C<$count> is C<undef>, as the kernel has all sorts of bugs preventing 1436C<$count> is C<undef>, as the kernel has all sorts of bugs preventing
1463it to return all extents of a range for files with large number of 1437it to return all extents of a range for files with a large number of
1464extents. The code works around all these issues if C<$count> is undef. 1438extents. The code (only) works around all these issues if C<$count> is
1439C<undef>.
1465 1440
1466=item aio_group $callback->(...) 1441=item aio_group $callback->(...)
1467 1442
1468This is a very special aio request: Instead of doing something, it is a 1443This is a very special aio request: Instead of doing something, it is a
1469container for other aio requests, which is useful if you want to bundle 1444container for other aio requests, which is useful if you want to bundle
1582There are some caveats: when directories get renamed (or deleted), the 1557There are some caveats: when directories get renamed (or deleted), the
1583pathname string doesn't change, so will point to the new directory (or 1558pathname string doesn't change, so will point to the new directory (or
1584nowhere at all), while the directory fd, if available on the system, 1559nowhere at all), while the directory fd, if available on the system,
1585will still point to the original directory. Most functions accepting a 1560will still point to the original directory. Most functions accepting a
1586pathname will use the directory fd on newer systems, and the string on 1561pathname will use the directory fd on newer systems, and the string on
1587older systems. Some functions (such as realpath) will always rely on the 1562older systems. Some functions (such as C<aio_realpath>) will always rely on
1588string form of the pathname. 1563the string form of the pathname.
1589 1564
1590So this functionality is mainly useful to get some protection against 1565So this functionality is mainly useful to get some protection against
1591C<chdir>, to easily get an absolute path out of a relative path for future 1566C<chdir>, to easily get an absolute path out of a relative path for future
1592reference, and to speed up doing many operations in the same directory 1567reference, and to speed up doing many operations in the same directory
1593(e.g. when stat'ing all files in a directory). 1568(e.g. when stat'ing all files in a directory).
1985This is a very bad function to use in interactive programs because it 1960This is a very bad function to use in interactive programs because it
1986blocks, and a bad way to reduce concurrency because it is inexact: Better 1961blocks, and a bad way to reduce concurrency because it is inexact: Better
1987use an C<aio_group> together with a feed callback. 1962use an C<aio_group> together with a feed callback.
1988 1963
1989Its main use is in scripts without an event loop - when you want to stat 1964Its main use is in scripts without an event loop - when you want to stat
1990a lot of files, you can write somehting like this: 1965a lot of files, you can write something like this:
1991 1966
1992 IO::AIO::max_outstanding 32; 1967 IO::AIO::max_outstanding 32;
1993 1968
1994 for my $path (...) { 1969 for my $path (...) {
1995 aio_stat $path , ...; 1970 aio_stat $path , ...;
2040some "Advanced I/O" function not available to in Perl, without going the 2015some "Advanced I/O" function not available to in Perl, without going the
2041"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*> 2016"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*>
2042counterpart. 2017counterpart.
2043 2018
2044=over 4 2019=over 4
2020
2021=item $numfd = IO::AIO::get_fdlimit
2022
2023This function is I<EXPERIMENTAL> and subject to change.
2024
2025Tries to find the current file descriptor limit and returns it, or
2026C<undef> and sets C<$!> in case of an error. The limit is one larger than
2027the highest valid file descriptor number.
2028
2029=item IO::AIO::min_fdlimit [$numfd]
2030
2031This function is I<EXPERIMENTAL> and subject to change.
2032
2033Try to increase the current file descriptor limit(s) to at least C<$numfd>
2034by changing the soft or hard file descriptor resource limit. If C<$numfd>
2035is missing, it will try to set a very high limit, although this is not
2036recommended when you know the actual minimum that you require.
2037
2038If the limit cannot be raised enough, the function makes a best-effort
2039attempt to increase the limit as much as possible, using various
2040tricks, while still failing. You can query the resulting limit using
2041C<IO::AIO::get_fdlimit>.
2042
2043If an error occurs, returns C<undef> and sets C<$!>, otherwise returns
2044true.
2045 2045
2046=item IO::AIO::sendfile $ofh, $ifh, $offset, $count 2046=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
2047 2047
2048Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>, 2048Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
2049but is blocking (this makes most sense if you know the input data is 2049but is blocking (this makes most sense if you know the input data is
2066=item IO::AIO::madvise $scalar, $offset, $len, $advice 2066=item IO::AIO::madvise $scalar, $offset, $len, $advice
2067 2067
2068Simply calls the C<posix_madvise> function (see its 2068Simply calls the C<posix_madvise> function (see its
2069manpage for details). The following advice constants are 2069manpage for details). The following advice constants are
2070available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>, 2070available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
2071C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>, 2071C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>,
2072C<IO::AIO::MADV_FREE>. 2072C<IO::AIO::MADV_DONTNEED>.
2073
2074If C<$offset> is negative, counts from the end. If C<$length> is negative,
2075the remaining length of the C<$scalar> is used. If possible, C<$length>
2076will be reduced to fit into the C<$scalar>.
2073 2077
2074On systems that do not implement C<posix_madvise>, this function returns 2078On systems that do not implement C<posix_madvise>, this function returns
2075ENOSYS, otherwise the return value of C<posix_madvise>. 2079ENOSYS, otherwise the return value of C<posix_madvise>.
2076 2080
2077=item IO::AIO::mprotect $scalar, $offset, $len, $protect 2081=item IO::AIO::mprotect $scalar, $offset, $len, $protect
2078 2082
2079Simply calls the C<mprotect> function on the preferably AIO::mmap'ed 2083Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
2080$scalar (see its manpage for details). The following protect 2084$scalar (see its manpage for details). The following protect
2081constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>, 2085constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
2082C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>. 2086C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
2087
2088If C<$offset> is negative, counts from the end. If C<$length> is negative,
2089the remaining length of the C<$scalar> is used. If possible, C<$length>
2090will be reduced to fit into the C<$scalar>.
2083 2091
2084On systems that do not implement C<mprotect>, this function returns 2092On systems that do not implement C<mprotect>, this function returns
2085ENOSYS, otherwise the return value of C<mprotect>. 2093ENOSYS, otherwise the return value of C<mprotect>.
2086 2094
2087=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] 2095=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
2207 2215
2208Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the 2216Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the
2209time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and 2217time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and
2210C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported. 2218C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported.
2211 2219
2220Example: create a pipe race-free w.r.t. threads and fork:
2221
2222 my ($rfh, $wfh) = IO::AIO::pipe2 IO::AIO::O_CLOEXEC
2223 or die "pipe2: $!\n";
2224
2225=item $fh = IO::AIO::eventfd ([$initval, [$flags]])
2226
2227This is a direct interface to the Linux L<eventfd(2)> system call. The
2228(unhelpful) defaults for C<$initval> and C<$flags> are C<0> for both.
2229
2230On success, the new eventfd filehandle is returned, otherwise returns
2231C<undef>. If the eventfd syscall is missing, fails with C<ENOSYS>.
2232
2233Please refer to L<eventfd(2)> for more info on this call.
2234
2235The following symbol flag values are available: C<IO::AIO::EFD_CLOEXEC>,
2236C<IO::AIO::EFD_NONBLOCK> and C<IO::AIO::EFD_SEMAPHORE> (Linux 2.6.30).
2237
2212=back 2238=back
2213 2239
2214=cut 2240=cut
2215 2241
2216min_parallel 8; 2242min_parallel 8;

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