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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.275 by root, Fri Sep 22 05:20:39 2017 UTC vs.
Revision 1.289 by root, Sun Aug 12 05:21:35 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 = 4.5;
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
183 aio_rename aio_rename2 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
193 nreqs nready npending nthreads 194 nreqs nready npending nthreads
194 max_poll_time max_poll_reqs 195 max_poll_time max_poll_reqs
195 sendfile fadvise madvise 196 sendfile fadvise madvise
196 mmap munmap munlock munlockall); 197 mmap munmap mremap munlock munlockall);
197 198
198 push @AIO_REQ, qw(aio_busy); # not exported 199 push @AIO_REQ, qw(aio_busy); # not exported
199 200
200 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 201 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
201 202
277 IO::AIO::idle_timeout $seconds 278 IO::AIO::idle_timeout $seconds
278 IO::AIO::max_outstanding $maxreqs 279 IO::AIO::max_outstanding $maxreqs
279 IO::AIO::nreqs 280 IO::AIO::nreqs
280 IO::AIO::nready 281 IO::AIO::nready
281 IO::AIO::npending 282 IO::AIO::npending
283 $nfd = IO::AIO::get_fdlimit [EXPERIMENTAL]
282 IO::AIO::min_fdlimit $nfd; 284 IO::AIO::min_fdlimit $nfd [EXPERIMENTAL]
283 285
284 IO::AIO::sendfile $ofh, $ifh, $offset, $count 286 IO::AIO::sendfile $ofh, $ifh, $offset, $count
285 IO::AIO::fadvise $fh, $offset, $len, $advice 287 IO::AIO::fadvise $fh, $offset, $len, $advice
286 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]] 288 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
287 IO::AIO::munmap $scalar 289 IO::AIO::munmap $scalar
290 IO::AIO::mremap $scalar, $new_length, $flags[, $new_address]
288 IO::AIO::madvise $scalar, $offset, $length, $advice 291 IO::AIO::madvise $scalar, $offset, $length, $advice
289 IO::AIO::mprotect $scalar, $offset, $length, $protect 292 IO::AIO::mprotect $scalar, $offset, $length, $protect
290 IO::AIO::munlock $scalar, $offset = 0, $length = undef 293 IO::AIO::munlock $scalar, $offset = 0, $length = undef
291 IO::AIO::munlockall 294 IO::AIO::munlockall
292 295
402following POSIX and non-POSIX constants are available (missing ones on 405following POSIX and non-POSIX constants are available (missing ones on
403your system are, as usual, C<0>): 406your system are, as usual, C<0>):
404 407
405C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>, 408C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,
406C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>, 409C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,
407C<O_RSYNC>, C<O_SYNC>, C<O_PATH>, C<O_TMPFILE>, and C<O_TTY_INIT>. 410C<O_RSYNC>, C<O_SYNC>, C<O_PATH>, C<O_TMPFILE>, C<O_TTY_INIT> and C<O_ACCMODE>.
408 411
409 412
410=item aio_close $fh, $callback->($status) 413=item aio_close $fh, $callback->($status)
411 414
412Asynchronously close a file and call the callback with the result 415Asynchronously close a file and call the callback with the result
557behaviour). 560behaviour).
558 561
559C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>, 562C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>,
560C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>, 563C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>,
561C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>. 564C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>.
565
566To access higher resolution stat timestamps, see L<SUBSECOND STAT TIME
567ACCESS>.
562 568
563Example: Print the length of F</etc/passwd>: 569Example: Print the length of F</etc/passwd>:
564 570
565 aio_stat "/etc/passwd", sub { 571 aio_stat "/etc/passwd", sub {
566 $_[0] and die "stat failed: $!"; 572 $_[0] and die "stat failed: $!";
610 namemax => 255, 616 namemax => 255,
611 frsize => 1024, 617 frsize => 1024,
612 fsid => 1810 618 fsid => 1810
613 } 619 }
614 620
615Here is a (likely partial - send me updates!) list of fsid values used by
616Linux - it is safe to hardcode these when C<$^O> is C<linux>:
617
618 0x0000adf5 adfs
619 0x0000adff affs
620 0x5346414f afs
621 0x09041934 anon-inode filesystem
622 0x00000187 autofs
623 0x42465331 befs
624 0x1badface bfs
625 0x42494e4d binfmt_misc
626 0x9123683e btrfs
627 0x0027e0eb cgroupfs
628 0xff534d42 cifs
629 0x73757245 coda
630 0x012ff7b7 coh
631 0x28cd3d45 cramfs
632 0x453dcd28 cramfs-wend (wrong endianness)
633 0x64626720 debugfs
634 0x00001373 devfs
635 0x00001cd1 devpts
636 0x0000f15f ecryptfs
637 0x00414a53 efs
638 0x0000137d ext
639 0x0000ef53 ext2/ext3/ext4
640 0x0000ef51 ext2
641 0xf2f52010 f2fs
642 0x00004006 fat
643 0x65735546 fuseblk
644 0x65735543 fusectl
645 0x0bad1dea futexfs
646 0x01161970 gfs2
647 0x47504653 gpfs
648 0x00004244 hfs
649 0xf995e849 hpfs
650 0x00c0ffee hostfs
651 0x958458f6 hugetlbfs
652 0x2bad1dea inotifyfs
653 0x00009660 isofs
654 0x000072b6 jffs2
655 0x3153464a jfs
656 0x6b414653 k-afs
657 0x0bd00bd0 lustre
658 0x0000137f minix
659 0x0000138f minix 30 char names
660 0x00002468 minix v2
661 0x00002478 minix v2 30 char names
662 0x00004d5a minix v3
663 0x19800202 mqueue
664 0x00004d44 msdos
665 0x0000564c novell
666 0x00006969 nfs
667 0x6e667364 nfsd
668 0x00003434 nilfs
669 0x5346544e ntfs
670 0x00009fa1 openprom
671 0x7461636F ocfs2
672 0x00009fa0 proc
673 0x6165676c pstorefs
674 0x0000002f qnx4
675 0x68191122 qnx6
676 0x858458f6 ramfs
677 0x52654973 reiserfs
678 0x00007275 romfs
679 0x67596969 rpc_pipefs
680 0x73636673 securityfs
681 0xf97cff8c selinux
682 0x0000517b smb
683 0x534f434b sockfs
684 0x73717368 squashfs
685 0x62656572 sysfs
686 0x012ff7b6 sysv2
687 0x012ff7b5 sysv4
688 0x01021994 tmpfs
689 0x15013346 udf
690 0x00011954 ufs
691 0x54190100 ufs byteswapped
692 0x00009fa2 usbdevfs
693 0x01021997 v9fs
694 0xa501fcf5 vxfs
695 0xabba1974 xenfs
696 0x012ff7b4 xenix
697 0x58465342 xfs
698 0x012fd16d xia
699
700=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 621=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
701 622
702Works like perl's C<utime> function (including the special case of $atime 623Works like perl's C<utime> function (including the special case of $atime
703and $mtime being undef). Fractional times are supported if the underlying 624and $mtime being undef). Fractional times are supported if the underlying
704syscalls support them. 625syscalls support them.
872 793
873=over 4 794=over 4
874 795
875=item IO::AIO::READDIR_DENTS 796=item IO::AIO::READDIR_DENTS
876 797
877When this flag is off, then the callback gets an arrayref consisting of 798Normally the callback gets an arrayref consisting of names only (as
878names only (as with C<aio_readdir>), otherwise it gets an arrayref with 799with C<aio_readdir>). If this flag is set, then the callback gets an
879C<[$name, $type, $inode]> arrayrefs, each describing a single directory 800arrayref with C<[$name, $type, $inode]> arrayrefs, each describing a
880entry in more detail. 801single directory entry in more detail:
881 802
882C<$name> is the name of the entry. 803C<$name> is the name of the entry.
883 804
884C<$type> is one of the C<IO::AIO::DT_xxx> constants: 805C<$type> is one of the C<IO::AIO::DT_xxx> constants:
885 806
886C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>, 807C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
887C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>, 808C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
888C<IO::AIO::DT_WHT>. 809C<IO::AIO::DT_WHT>.
889 810
890C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to 811C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need
891know, you have to run stat yourself. Also, for speed reasons, the C<$type> 812to know, you have to run stat yourself. Also, for speed/memory reasons,
892scalars are read-only: you can not modify them. 813the C<$type> scalars are read-only: you must not modify them.
893 814
894C<$inode> is the inode number (which might not be exact on systems with 64 815C<$inode> is the inode number (which might not be exact on systems with 64
895bit inode numbers and 32 bit perls). This field has unspecified content on 816bit inode numbers and 32 bit perls). This field has unspecified content on
896systems that do not deliver the inode information. 817systems that do not deliver the inode information.
897 818
908short names are tried first. 829short names are tried first.
909 830
910=item IO::AIO::READDIR_STAT_ORDER 831=item IO::AIO::READDIR_STAT_ORDER
911 832
912When this flag is set, then the names will be returned in an order 833When this flag is set, then the names will be returned in an order
913suitable for stat()'ing each one. That is, when you plan to stat() 834suitable for stat()'ing each one. That is, when you plan to stat() most or
914all files in the given directory, then the returned order will likely 835all files in the given directory, then the returned order will likely be
915be fastest. 836faster.
916 837
917If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then 838If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified,
918the likely dirs come first, resulting in a less optimal stat order. 839then the likely dirs come first, resulting in a less optimal stat order
840for stat'ing all entries, but likely a more optimal order for finding
841subdirectories.
919 842
920=item IO::AIO::READDIR_FOUND_UNKNOWN 843=item IO::AIO::READDIR_FOUND_UNKNOWN
921 844
922This flag should not be set when calling C<aio_readdirx>. Instead, it 845This flag should not be set when calling C<aio_readdirx>. Instead, it
923is being set by C<aio_readdirx>, when any of the C<$type>'s found were 846is being set by C<aio_readdirx>, when any of the C<$type>'s found were
925C<$type>'s are known, which can be used to speed up some algorithms. 848C<$type>'s are known, which can be used to speed up some algorithms.
926 849
927=back 850=back
928 851
929 852
853=item aio_slurp $pathname, $offset, $length, $data, $callback->($status)
854
855Opens, reads and closes the given file. The data is put into C<$data>,
856which is resized as required.
857
858If C<$offset> is negative, then it is counted from the end of the file.
859
860If C<$length> is zero, then the remaining length of the file is
861used. Also, in this case, the same limitations to modifying C<$data> apply
862as when IO::AIO::mmap is used, i.e. it must only be modified in-place
863with C<substr>. If the size of the file is known, specifying a non-zero
864C<$length> results in a performance advantage.
865
866This request is similar to the older C<aio_load> request, but since it is
867a single request, it might be more efficient to use.
868
869Example: load F</etc/passwd> into C<$passwd>.
870
871 my $passwd;
872 aio_slurp "/etc/passwd", 0, 0, $passwd, sub {
873 $_[0] >= 0
874 or die "/etc/passwd: $!\n";
875
876 printf "/etc/passwd is %d bytes long, and contains:\n", length $passwd;
877 print $passwd;
878 };
879 IO::AIO::flush;
880
881
930=item aio_load $pathname, $data, $callback->($status) 882=item aio_load $pathname, $data, $callback->($status)
931 883
932This is a composite request that tries to fully load the given file into 884This is a composite request that tries to fully load the given file into
933memory. Status is the same as with aio_read. 885memory. Status is the same as with aio_read.
886
887Using C<aio_slurp> might be more efficient, as it is a single request.
934 888
935=cut 889=cut
936 890
937sub aio_load($$;$) { 891sub aio_load($$;$) {
938 my ($path, undef, $cb) = @_; 892 my ($path, undef, $cb) = @_;
1079Scans a directory (similar to C<aio_readdir>) but additionally tries to 1033Scans a directory (similar to C<aio_readdir>) but additionally tries to
1080efficiently separate the entries of directory C<$path> into two sets of 1034efficiently separate the entries of directory C<$path> into two sets of
1081names, directories you can recurse into (directories), and ones you cannot 1035names, directories you can recurse into (directories), and ones you cannot
1082recurse into (everything else, including symlinks to directories). 1036recurse into (everything else, including symlinks to directories).
1083 1037
1084C<aio_scandir> is a composite request that creates of many sub requests_ 1038C<aio_scandir> is a composite request that generates many sub requests.
1085C<$maxreq> specifies the maximum number of outstanding aio requests that 1039C<$maxreq> specifies the maximum number of outstanding aio requests that
1086this function generates. If it is C<< <= 0 >>, then a suitable default 1040this function generates. If it is C<< <= 0 >>, then a suitable default
1087will be chosen (currently 4). 1041will be chosen (currently 4).
1088 1042
1089On error, the callback is called without arguments, otherwise it receives 1043On error, the callback is called without arguments, otherwise it receives
1482C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>, 1436C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
1483C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>, 1437C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
1484C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or 1438C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
1485C<IO::AIO::FIEMAP_EXTENT_SHARED>. 1439C<IO::AIO::FIEMAP_EXTENT_SHARED>.
1486 1440
1487At the time of this writing (Linux 3.2), this requets is unreliable unless 1441At the time of this writing (Linux 3.2), this request is unreliable unless
1488C<$count> is C<undef>, as the kernel has all sorts of bugs preventing 1442C<$count> is C<undef>, as the kernel has all sorts of bugs preventing
1489it to return all extents of a range for files with large number of 1443it to return all extents of a range for files with a large number of
1490extents. The code works around all these issues if C<$count> is undef. 1444extents. The code (only) works around all these issues if C<$count> is
1445C<undef>.
1491 1446
1492=item aio_group $callback->(...) 1447=item aio_group $callback->(...)
1493 1448
1494This is a very special aio request: Instead of doing something, it is a 1449This is a very special aio request: Instead of doing something, it is a
1495container for other aio requests, which is useful if you want to bundle 1450container for other aio requests, which is useful if you want to bundle
1608There are some caveats: when directories get renamed (or deleted), the 1563There are some caveats: when directories get renamed (or deleted), the
1609pathname string doesn't change, so will point to the new directory (or 1564pathname string doesn't change, so will point to the new directory (or
1610nowhere at all), while the directory fd, if available on the system, 1565nowhere at all), while the directory fd, if available on the system,
1611will still point to the original directory. Most functions accepting a 1566will still point to the original directory. Most functions accepting a
1612pathname will use the directory fd on newer systems, and the string on 1567pathname will use the directory fd on newer systems, and the string on
1613older systems. Some functions (such as realpath) will always rely on the 1568older systems. Some functions (such as C<aio_realpath>) will always rely on
1614string form of the pathname. 1569the string form of the pathname.
1615 1570
1616So this functionality is mainly useful to get some protection against 1571So this functionality is mainly useful to get some protection against
1617C<chdir>, to easily get an absolute path out of a relative path for future 1572C<chdir>, to easily get an absolute path out of a relative path for future
1618reference, and to speed up doing many operations in the same directory 1573reference, and to speed up doing many operations in the same directory
1619(e.g. when stat'ing all files in a directory). 1574(e.g. when stat'ing all files in a directory).
2058Returns the number of requests currently in the pending state (executed, 2013Returns the number of requests currently in the pending state (executed,
2059but not yet processed by poll_cb). 2014but not yet processed by poll_cb).
2060 2015
2061=back 2016=back
2062 2017
2018=head3 SUBSECOND STAT TIME ACCESS
2019
2020Both C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> functions can
2021generally find access/modification and change times with subsecond time
2022accuracy of the system supports it, but perl's built-in functions only
2023return the integer part.
2024
2025The following functions return the timestamps of the most recent
2026stat with subsecond precision on most systems and work both after
2027C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> calls. Their return
2028value is only meaningful after a successful C<stat>/C<lstat> call, or
2029during/after a successful C<aio_stat>/C<aio_lstat> callback.
2030
2031This is similar to the L<Time::HiRes> C<stat> functions, but can return
2032full resolution without rounding and work with standard perl C<stat>,
2033alleviating the need to call the special C<Time::HiRes> functions, which
2034do not act like their perl counterparts.
2035
2036On operating systems or file systems where subsecond time resolution is
2037not supported or could not be detected, a fractional part of C<0> is
2038returned, so it is always safe to call these functions.
2039
2040=over 4
2041
2042=item IO::AIO::stat_atime, IO::AIO::stat_mtime, IO::AIO::stat_ctime
2043
2044Return the access, modication or change time, respectively, including
2045fractional part. Due to the limited precision of floating point, the
2046accuracy on most platforms is only a bit better than milliseconds for
2047times around now - see the I<nsec> function family, below, for full
2048accuracy.
2049
2050=item ($atime, $mtime, $ctime, ...) = IO::AIO::stat_xtime
2051
2052Returns access, modification and change time all in one go, and maybe more
2053times in the future version.
2054
2055=item IO::AIO::stat_atimensec, IO::AIO::stat_mtimensec, IO::AIO::stat_ctimensec
2056
2057Return the fractional access, modifcation or change time, in nanoseconds,
2058as an integer in the range C<0> to C<999999999>.
2059
2060=back
2061
2062Example: print the high resolution modification time of F</etc>, using
2063C<stat>, and C<IO::AIO::aio_stat>.
2064
2065 if (stat "/etc") {
2066 printf "stat(/etc) mtime: %f\n", IO::AIO::stat_mtime;
2067 }
2068
2069 IO::AIO::aio_stat "/etc", sub {
2070 $_[0]
2071 and return;
2072
2073 printf "aio_stat(/etc) mtime: %d.%09d\n", (stat _)[9], IO::AIO::stat_mtimensec;
2074 };
2075
2076 IO::AIO::flush;
2077
2078Output of the awbove on my system, showing reduced and full accuracy:
2079
2080 stat(/etc) mtime: 1534043702.020808
2081 aio_stat(/etc) mtime: 1534043702.020807792
2082
2063=head3 MISCELLANEOUS FUNCTIONS 2083=head3 MISCELLANEOUS FUNCTIONS
2064 2084
2065IO::AIO implements some functions that are useful when you want to use 2085IO::AIO implements some functions that are useful when you want to use
2066some "Advanced I/O" function not available to in Perl, without going the 2086some "Advanced I/O" function not available to in Perl, without going the
2067"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*> 2087"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*>
2069 2089
2070=over 4 2090=over 4
2071 2091
2072=item $numfd = IO::AIO::get_fdlimit 2092=item $numfd = IO::AIO::get_fdlimit
2073 2093
2094This function is I<EXPERIMENTAL> and subject to change.
2095
2074Tries to find the current file descriptor limit and returns it, or 2096Tries to find the current file descriptor limit and returns it, or
2075C<undef> and sets C<$!> in case of an error. The limit is one larger than 2097C<undef> and sets C<$!> in case of an error. The limit is one larger than
2076the highest valid file descriptor number. 2098the highest valid file descriptor number.
2077 2099
2078=item IO::AIO::min_fdlimit [$numfd] 2100=item IO::AIO::min_fdlimit [$numfd]
2101
2102This function is I<EXPERIMENTAL> and subject to change.
2079 2103
2080Try to increase the current file descriptor limit(s) to at least C<$numfd> 2104Try to increase the current file descriptor limit(s) to at least C<$numfd>
2081by changing the soft or hard file descriptor resource limit. If C<$numfd> 2105by changing the soft or hard file descriptor resource limit. If C<$numfd>
2082is missing, it will try to set a very high limit, although this is not 2106is missing, it will try to set a very high limit, although this is not
2083recommended when you know the actual minimum that you require. 2107recommended when you know the actual minimum that you require.
2085If the limit cannot be raised enough, the function makes a best-effort 2109If the limit cannot be raised enough, the function makes a best-effort
2086attempt to increase the limit as much as possible, using various 2110attempt to increase the limit as much as possible, using various
2087tricks, while still failing. You can query the resulting limit using 2111tricks, while still failing. You can query the resulting limit using
2088C<IO::AIO::get_fdlimit>. 2112C<IO::AIO::get_fdlimit>.
2089 2113
2090If an error occurs, returns C<undef> and sets C<$!>. 2114If an error occurs, returns C<undef> and sets C<$!>, otherwise returns
2115true.
2091 2116
2092=item IO::AIO::sendfile $ofh, $ifh, $offset, $count 2117=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
2093 2118
2094Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>, 2119Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
2095but is blocking (this makes most sense if you know the input data is 2120but is blocking (this makes most sense if you know the input data is
2202 2227
2203=item IO::AIO::munmap $scalar 2228=item IO::AIO::munmap $scalar
2204 2229
2205Removes a previous mmap and undefines the C<$scalar>. 2230Removes a previous mmap and undefines the C<$scalar>.
2206 2231
2232=item IO::AIO::mremap $scalar, $new_length, $flags = MREMAP_MAYMOVE[, $new_address = 0]
2233
2234Calls the Linux-specific mremap(2) system call. The C<$scalar> must have
2235been mapped by C<IO::AIO::mmap>, and C<$flags> must currently either be
2236C<0> or C<IO::AIO::MREMAP_MAYMOVE>.
2237
2238Returns true if successful, and false otherwise. If the underlying mmapped
2239region has changed address, then the true value has the numerical value
2240C<1>, otherwise it has the numerical value C<0>:
2241
2242 my $success = IO::AIO::mremap $mmapped, 8192, IO::AIO::MREMAP_MAYMOVE
2243 or die "mremap: $!";
2244
2245 if ($success*1) {
2246 warn "scalar has chanegd address in memory\n";
2247 }
2248
2249C<IO::AIO::MREMAP_FIXED> and the C<$new_address> argument are currently
2250implemented, but not supported and might go away in a future version.
2251
2252On systems where this call is not supported or is not emulated, this call
2253returns falls and sets C<$!> to C<ENOSYS>.
2254
2207=item IO::AIO::munlock $scalar, $offset = 0, $length = undef 2255=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
2208 2256
2209Calls the C<munlock> function, undoing the effects of a previous 2257Calls the C<munlock> function, undoing the effects of a previous
2210C<aio_mlock> call (see its description for details). 2258C<aio_mlock> call (see its description for details).
2211 2259
2260C<$flags> is non-zero, fails with C<ENOSYS>. 2308C<$flags> is non-zero, fails with C<ENOSYS>.
2261 2309
2262Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the 2310Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the
2263time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and 2311time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and
2264C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported. 2312C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported.
2313
2314Example: create a pipe race-free w.r.t. threads and fork:
2315
2316 my ($rfh, $wfh) = IO::AIO::pipe2 IO::AIO::O_CLOEXEC
2317 or die "pipe2: $!\n";
2318
2319=item $fh = IO::AIO::eventfd [$initval, [$flags]]
2320
2321This is a direct interface to the Linux L<eventfd(2)> system call. The
2322(unhelpful) defaults for C<$initval> and C<$flags> are C<0> for both.
2323
2324On success, the new eventfd filehandle is returned, otherwise returns
2325C<undef>. If the eventfd syscall is missing, fails with C<ENOSYS>.
2326
2327Please refer to L<eventfd(2)> for more info on this call.
2328
2329The following symbol flag values are available: C<IO::AIO::EFD_CLOEXEC>,
2330C<IO::AIO::EFD_NONBLOCK> and C<IO::AIO::EFD_SEMAPHORE> (Linux 2.6.30).
2331
2332Example: create a new eventfd filehandle:
2333
2334 $fh = IO::AIO::eventfd 0, IO::AIO::O_CLOEXEC
2335 or die "eventfd: $!\n";
2336
2337=item $fh = IO::AIO::timerfd_create $clockid[, $flags]
2338
2339This is a direct interface to the Linux L<timerfd_create(2)> system call. The
2340(unhelpful) default for C<$flags> is C<0>.
2341
2342On success, the new timerfd filehandle is returned, otherwise returns
2343C<undef>. If the eventfd syscall is missing, fails with C<ENOSYS>.
2344
2345Please refer to L<timerfd_create(2)> for more info on this call.
2346
2347The following C<$clockid> values are
2348available: C<IO::AIO::CLOCK_REALTIME>, C<IO::AIO::CLOCK_MONOTONIC>
2349C<IO::AIO::CLOCK_CLOCK_BOOTTIME> (Linux 3.15)
2350C<IO::AIO::CLOCK_CLOCK_REALTIME_ALARM> (Linux 3.11) and
2351C<IO::AIO::CLOCK_CLOCK_BOOTTIME_ALARM> (Linux 3.11).
2352
2353The following C<$flags> values are available (Linux
23542.6.27): C<IO::AIO::TFD_NONBLOCK> and C<IO::AIO::TFD_CLOEXEC>.
2355
2356Example: create a new timerfd and set it to one-second repeated alarms,
2357then wait for two alarms:
2358
2359 my $fh = IO::AIO::timerfd_create IO::AIO::CLOCK_BOOTTIME, IO::AIO::TFD_CLOEXEC
2360 or die "timerfd_create: $!\n";
2361
2362 defined IO::AIO::timerfd_settime $fh, 0, 1, 1
2363 or die "timerfd_settime: $!\n";
2364
2365 for (1..2) {
2366 8 == sysread $fh, my $buf, 8
2367 or die "timerfd read failure\n";
2368
2369 printf "number of expirations (likely 1): %d\n",
2370 unpack "Q", $buf;
2371 }
2372
2373=item ($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags, $new_interval, $nbw_value
2374
2375This is a direct interface to the Linux L<timerfd_settime(2)> system
2376call. Please refer to its manpage for more info on this call.
2377
2378The new itimerspec is specified using two (possibly fractional) second
2379values, C<$new_interval> and C<$new_value>).
2380
2381On success, the current interval and value are returned (as per
2382C<timerfd_gettime>). On failure, the empty list is returned.
2383
2384The following C<$flags> values are
2385available: C<IO::AIO::TFD_TIMER_ABSTIME> and
2386C<IO::AIO::TFD_TIMER_CANCEL_ON_SET>.
2387
2388See C<IO::AIO::timerfd_create> for a full example.
2389
2390=item ($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh
2391
2392This is a direct interface to the Linux L<timerfd_gettime(2)> system
2393call. Please refer to its manpage for more info on this call.
2394
2395On success, returns the current values of interval and value for the given
2396timerfd (as potentially fractional second values). On failure, the empty
2397list is returned.
2265 2398
2266=back 2399=back
2267 2400
2268=cut 2401=cut
2269 2402
2335the process will result in undefined behaviour. Calling it at any time 2468the process will result in undefined behaviour. Calling it at any time
2336will also result in any undefined (by POSIX) behaviour. 2469will also result in any undefined (by POSIX) behaviour.
2337 2470
2338=back 2471=back
2339 2472
2473=head2 LINUX-SPECIFIC CALLS
2474
2475When a call is documented as "linux-specific" then this means it
2476originated on GNU/Linux. C<IO::AIO> will usually try to autodetect the
2477availability and compatibility of such calls regardless of the platform
2478it is compiled on, so platforms such as FreeBSD which often implement
2479these calls will work. When in doubt, call them and see if they fail wth
2480C<ENOSYS>.
2481
2340=head2 MEMORY USAGE 2482=head2 MEMORY USAGE
2341 2483
2342Per-request usage: 2484Per-request usage:
2343 2485
2344Each aio request uses - depending on your architecture - around 100-200 2486Each aio request uses - depending on your architecture - around 100-200
2356temporary buffers, and each thread requires a stack and other data 2498temporary buffers, and each thread requires a stack and other data
2357structures (usually around 16k-128k, depending on the OS). 2499structures (usually around 16k-128k, depending on the OS).
2358 2500
2359=head1 KNOWN BUGS 2501=head1 KNOWN BUGS
2360 2502
2361Known bugs will be fixed in the next release. 2503Known bugs will be fixed in the next release :)
2504
2505=head1 KNOWN ISSUES
2506
2507Calls that try to "import" foreign memory areas (such as C<IO::AIO::mmap>
2508or C<IO::AIO::aio_slurp>) do not work with generic lvalues, such as
2509non-created hash slots or other scalars I didn't think of. It's best to
2510avoid such and either use scalar variables or making sure that the scalar
2511exists (e.g. by storing C<undef>) and isn't "funny" (e.g. tied).
2512
2513I am not sure anything can be done about this, so this is considered a
2514known issue, rather than a bug.
2362 2515
2363=head1 SEE ALSO 2516=head1 SEE ALSO
2364 2517
2365L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a 2518L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
2366more natural syntax. 2519more natural syntax.

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