ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/IO-AIO/AIO.pm
(Generate patch)

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.278 by root, Sun Oct 1 07:24:34 2017 UTC vs.
Revision 1.298 by root, Thu Nov 29 21:48:44 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 = 4.6;
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
284 285
285 IO::AIO::sendfile $ofh, $ifh, $offset, $count 286 IO::AIO::sendfile $ofh, $ifh, $offset, $count
286 IO::AIO::fadvise $fh, $offset, $len, $advice 287 IO::AIO::fadvise $fh, $offset, $len, $advice
287 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]] 288 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
288 IO::AIO::munmap $scalar 289 IO::AIO::munmap $scalar
290 IO::AIO::mremap $scalar, $new_length, $flags[, $new_address]
289 IO::AIO::madvise $scalar, $offset, $length, $advice 291 IO::AIO::madvise $scalar, $offset, $length, $advice
290 IO::AIO::mprotect $scalar, $offset, $length, $protect 292 IO::AIO::mprotect $scalar, $offset, $length, $protect
291 IO::AIO::munlock $scalar, $offset = 0, $length = undef 293 IO::AIO::munlock $scalar, $offset = 0, $length = undef
292 IO::AIO::munlockall 294 IO::AIO::munlockall
293 295
403following POSIX and non-POSIX constants are available (missing ones on 405following POSIX and non-POSIX constants are available (missing ones on
404your system are, as usual, C<0>): 406your system are, as usual, C<0>):
405 407
406C<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>,
407C<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>,
408C<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>.
409 411
410 412
411=item aio_close $fh, $callback->($status) 413=item aio_close $fh, $callback->($status)
412 414
413Asynchronously close a file and call the callback with the result 415Asynchronously close a file and call the callback with the result
539 541
540=item aio_stat $fh_or_path, $callback->($status) 542=item aio_stat $fh_or_path, $callback->($status)
541 543
542=item aio_lstat $fh, $callback->($status) 544=item aio_lstat $fh, $callback->($status)
543 545
544Works like perl's C<stat> or C<lstat> in void context. The callback will 546Works almost exactly like perl's C<stat> or C<lstat> in void context. The
545be called after the stat and the results will be available using C<stat _> 547callback will be called after the stat and the results will be available
546or C<-s _> etc... 548using C<stat _> or C<-s _> and other tests (with the exception of C<-B>
549and C<-T>).
547 550
548The pathname passed to C<aio_stat> must be absolute. See API NOTES, above, 551The pathname passed to C<aio_stat> must be absolute. See API NOTES, above,
549for an explanation. 552for an explanation.
550 553
551Currently, the stats are always 64-bit-stats, i.e. instead of returning an 554Currently, the stats are always 64-bit-stats, i.e. instead of returning an
558behaviour). 561behaviour).
559 562
560C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>, 563C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>,
561C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>, 564C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>,
562C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>. 565C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>.
566
567To access higher resolution stat timestamps, see L<SUBSECOND STAT TIME
568ACCESS>.
563 569
564Example: Print the length of F</etc/passwd>: 570Example: Print the length of F</etc/passwd>:
565 571
566 aio_stat "/etc/passwd", sub { 572 aio_stat "/etc/passwd", sub {
567 $_[0] and die "stat failed: $!"; 573 $_[0] and die "stat failed: $!";
611 namemax => 255, 617 namemax => 255,
612 frsize => 1024, 618 frsize => 1024,
613 fsid => 1810 619 fsid => 1810
614 } 620 }
615 621
616Here is a (likely partial - send me updates!) list of fsid values used by
617Linux - it is safe to hardcode these when C<$^O> is C<linux>:
618
619 0x0000adf5 adfs
620 0x0000adff affs
621 0x5346414f afs
622 0x09041934 anon-inode filesystem
623 0x00000187 autofs
624 0x42465331 befs
625 0x1badface bfs
626 0x42494e4d binfmt_misc
627 0x9123683e btrfs
628 0x0027e0eb cgroupfs
629 0xff534d42 cifs
630 0x73757245 coda
631 0x012ff7b7 coh
632 0x28cd3d45 cramfs
633 0x453dcd28 cramfs-wend (wrong endianness)
634 0x64626720 debugfs
635 0x00001373 devfs
636 0x00001cd1 devpts
637 0x0000f15f ecryptfs
638 0x00414a53 efs
639 0x0000137d ext
640 0x0000ef53 ext2/ext3/ext4
641 0x0000ef51 ext2
642 0xf2f52010 f2fs
643 0x00004006 fat
644 0x65735546 fuseblk
645 0x65735543 fusectl
646 0x0bad1dea futexfs
647 0x01161970 gfs2
648 0x47504653 gpfs
649 0x00004244 hfs
650 0xf995e849 hpfs
651 0x00c0ffee hostfs
652 0x958458f6 hugetlbfs
653 0x2bad1dea inotifyfs
654 0x00009660 isofs
655 0x000072b6 jffs2
656 0x3153464a jfs
657 0x6b414653 k-afs
658 0x0bd00bd0 lustre
659 0x0000137f minix
660 0x0000138f minix 30 char names
661 0x00002468 minix v2
662 0x00002478 minix v2 30 char names
663 0x00004d5a minix v3
664 0x19800202 mqueue
665 0x00004d44 msdos
666 0x0000564c novell
667 0x00006969 nfs
668 0x6e667364 nfsd
669 0x00003434 nilfs
670 0x5346544e ntfs
671 0x00009fa1 openprom
672 0x7461636F ocfs2
673 0x00009fa0 proc
674 0x6165676c pstorefs
675 0x0000002f qnx4
676 0x68191122 qnx6
677 0x858458f6 ramfs
678 0x52654973 reiserfs
679 0x00007275 romfs
680 0x67596969 rpc_pipefs
681 0x73636673 securityfs
682 0xf97cff8c selinux
683 0x0000517b smb
684 0x534f434b sockfs
685 0x73717368 squashfs
686 0x62656572 sysfs
687 0x012ff7b6 sysv2
688 0x012ff7b5 sysv4
689 0x01021994 tmpfs
690 0x15013346 udf
691 0x00011954 ufs
692 0x54190100 ufs byteswapped
693 0x00009fa2 usbdevfs
694 0x01021997 v9fs
695 0xa501fcf5 vxfs
696 0xabba1974 xenfs
697 0x012ff7b4 xenix
698 0x58465342 xfs
699 0x012fd16d xia
700
701=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 622=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
702 623
703Works like perl's C<utime> function (including the special case of $atime 624Works like perl's C<utime> function (including the special case of $atime
704and $mtime being undef). Fractional times are supported if the underlying 625and $mtime being undef). Fractional times are supported if the underlying
705syscalls support them. 626syscalls support them.
706 627
707When called with a pathname, uses utimes(2) if available, otherwise 628When called with a pathname, uses utimensat(2) or utimes(2) if available,
708utime(2). If called on a file descriptor, uses futimes(2) if available, 629otherwise utime(2). If called on a file descriptor, uses futimens(2)
709otherwise returns ENOSYS, so this is not portable. 630or futimes(2) if available, otherwise returns ENOSYS, so this is not
631portable.
710 632
711Examples: 633Examples:
712 634
713 # set atime and mtime to current time (basically touch(1)): 635 # set atime and mtime to current time (basically touch(1)):
714 aio_utime "path", undef, undef; 636 aio_utime "path", undef, undef;
873 795
874=over 4 796=over 4
875 797
876=item IO::AIO::READDIR_DENTS 798=item IO::AIO::READDIR_DENTS
877 799
878When this flag is off, then the callback gets an arrayref consisting of 800Normally the callback gets an arrayref consisting of names only (as
879names only (as with C<aio_readdir>), otherwise it gets an arrayref with 801with C<aio_readdir>). If this flag is set, then the callback gets an
880C<[$name, $type, $inode]> arrayrefs, each describing a single directory 802arrayref with C<[$name, $type, $inode]> arrayrefs, each describing a
881entry in more detail. 803single directory entry in more detail:
882 804
883C<$name> is the name of the entry. 805C<$name> is the name of the entry.
884 806
885C<$type> is one of the C<IO::AIO::DT_xxx> constants: 807C<$type> is one of the C<IO::AIO::DT_xxx> constants:
886 808
887C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>, 809C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
888C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>, 810C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
889C<IO::AIO::DT_WHT>. 811C<IO::AIO::DT_WHT>.
890 812
891C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to 813C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need
892know, you have to run stat yourself. Also, for speed reasons, the C<$type> 814to know, you have to run stat yourself. Also, for speed/memory reasons,
893scalars are read-only: you can not modify them. 815the C<$type> scalars are read-only: you must not modify them.
894 816
895C<$inode> is the inode number (which might not be exact on systems with 64 817C<$inode> is the inode number (which might not be exact on systems with 64
896bit inode numbers and 32 bit perls). This field has unspecified content on 818bit inode numbers and 32 bit perls). This field has unspecified content on
897systems that do not deliver the inode information. 819systems that do not deliver the inode information.
898 820
909short names are tried first. 831short names are tried first.
910 832
911=item IO::AIO::READDIR_STAT_ORDER 833=item IO::AIO::READDIR_STAT_ORDER
912 834
913When this flag is set, then the names will be returned in an order 835When this flag is set, then the names will be returned in an order
914suitable for stat()'ing each one. That is, when you plan to stat() 836suitable for stat()'ing each one. That is, when you plan to stat() most or
915all files in the given directory, then the returned order will likely 837all files in the given directory, then the returned order will likely be
916be fastest. 838faster.
917 839
918If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then 840If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified,
919the likely dirs come first, resulting in a less optimal stat order. 841then the likely dirs come first, resulting in a less optimal stat order
842for stat'ing all entries, but likely a more optimal order for finding
843subdirectories.
920 844
921=item IO::AIO::READDIR_FOUND_UNKNOWN 845=item IO::AIO::READDIR_FOUND_UNKNOWN
922 846
923This flag should not be set when calling C<aio_readdirx>. Instead, it 847This flag should not be set when calling C<aio_readdirx>. Instead, it
924is being set by C<aio_readdirx>, when any of the C<$type>'s found were 848is being set by C<aio_readdirx>, when any of the C<$type>'s found were
926C<$type>'s are known, which can be used to speed up some algorithms. 850C<$type>'s are known, which can be used to speed up some algorithms.
927 851
928=back 852=back
929 853
930 854
855=item aio_slurp $pathname, $offset, $length, $data, $callback->($status)
856
857Opens, reads and closes the given file. The data is put into C<$data>,
858which is resized as required.
859
860If C<$offset> is negative, then it is counted from the end of the file.
861
862If C<$length> is zero, then the remaining length of the file is
863used. Also, in this case, the same limitations to modifying C<$data> apply
864as when IO::AIO::mmap is used, i.e. it must only be modified in-place
865with C<substr>. If the size of the file is known, specifying a non-zero
866C<$length> results in a performance advantage.
867
868This request is similar to the older C<aio_load> request, but since it is
869a single request, it might be more efficient to use.
870
871Example: load F</etc/passwd> into C<$passwd>.
872
873 my $passwd;
874 aio_slurp "/etc/passwd", 0, 0, $passwd, sub {
875 $_[0] >= 0
876 or die "/etc/passwd: $!\n";
877
878 printf "/etc/passwd is %d bytes long, and contains:\n", length $passwd;
879 print $passwd;
880 };
881 IO::AIO::flush;
882
883
931=item aio_load $pathname, $data, $callback->($status) 884=item aio_load $pathname, $data, $callback->($status)
932 885
933This is a composite request that tries to fully load the given file into 886This is a composite request that tries to fully load the given file into
934memory. Status is the same as with aio_read. 887memory. Status is the same as with aio_read.
888
889Using C<aio_slurp> might be more efficient, as it is a single request.
935 890
936=cut 891=cut
937 892
938sub aio_load($$;$) { 893sub aio_load($$;$) {
939 my ($path, undef, $cb) = @_; 894 my ($path, undef, $cb) = @_;
1430 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh; 1385 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
1431 aio_mlock $data; # mlock in background 1386 aio_mlock $data; # mlock in background
1432 1387
1433=item aio_mlockall $flags, $callback->($status) 1388=item aio_mlockall $flags, $callback->($status)
1434 1389
1435Calls the C<mlockall> function with the given C<$flags> (a combination of 1390Calls the C<mlockall> function with the given C<$flags> (a
1436C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>). 1391combination of C<IO::AIO::MCL_CURRENT>, C<IO::AIO::MCL_FUTURE> and
1392C<IO::AIO::MCL_ONFAULT>).
1437 1393
1438On systems that do not implement C<mlockall>, this function returns C<-1> 1394On systems that do not implement C<mlockall>, this function returns C<-1>
1439and sets errno to C<ENOSYS>. 1395and sets errno to C<ENOSYS>. Similarly, flag combinations not supported
1396by the system result in a return value of C<-1> with errno being set to
1397C<EINVAL>.
1440 1398
1441Note that the corresponding C<munlockall> is synchronous and is 1399Note that the corresponding C<munlockall> is synchronous and is
1442documented under L<MISCELLANEOUS FUNCTIONS>. 1400documented under L<MISCELLANEOUS FUNCTIONS>.
1443 1401
1444Example: asynchronously lock all current and future pages into memory. 1402Example: asynchronously lock all current and future pages into memory.
1829The default value for the limit is C<0>, but note that setting a feeder 1787The default value for the limit is C<0>, but note that setting a feeder
1830automatically bumps it up to C<2>. 1788automatically bumps it up to C<2>.
1831 1789
1832=back 1790=back
1833 1791
1792
1834=head2 SUPPORT FUNCTIONS 1793=head2 SUPPORT FUNCTIONS
1835 1794
1836=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1795=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
1837 1796
1838=over 4 1797=over 4
1903Strictly equivalent to: 1862Strictly equivalent to:
1904 1863
1905 IO::AIO::poll_wait, IO::AIO::poll_cb 1864 IO::AIO::poll_wait, IO::AIO::poll_cb
1906 while IO::AIO::nreqs; 1865 while IO::AIO::nreqs;
1907 1866
1867This function can be useful at program aborts, to make sure outstanding
1868I/O has been done (C<IO::AIO> uses an C<END> block which already calls
1869this function on normal exits), or when you are merely using C<IO::AIO>
1870for its more advanced functions, rather than for async I/O, e.g.:
1871
1872 my ($dirs, $nondirs);
1873 IO::AIO::aio_scandir "/tmp", 0, sub { ($dirs, $nondirs) = @_ };
1874 IO::AIO::flush;
1875 # $dirs, $nondirs are now set
1876
1908=item IO::AIO::max_poll_reqs $nreqs 1877=item IO::AIO::max_poll_reqs $nreqs
1909 1878
1910=item IO::AIO::max_poll_time $seconds 1879=item IO::AIO::max_poll_time $seconds
1911 1880
1912These set the maximum number of requests (default C<0>, meaning infinity) 1881These set the maximum number of requests (default C<0>, meaning infinity)
1938 poll => 'r', nice => 1, 1907 poll => 'r', nice => 1,
1939 cb => &IO::AIO::poll_cb); 1908 cb => &IO::AIO::poll_cb);
1940 1909
1941=back 1910=back
1942 1911
1912
1943=head3 CONTROLLING THE NUMBER OF THREADS 1913=head3 CONTROLLING THE NUMBER OF THREADS
1944 1914
1945=over 1915=over
1946 1916
1947=item IO::AIO::min_parallel $nthreads 1917=item IO::AIO::min_parallel $nthreads
2034The default value for C<max_outstanding> is very large, so there is no 2004The default value for C<max_outstanding> is very large, so there is no
2035practical limit on the number of outstanding requests. 2005practical limit on the number of outstanding requests.
2036 2006
2037=back 2007=back
2038 2008
2009
2039=head3 STATISTICAL INFORMATION 2010=head3 STATISTICAL INFORMATION
2040 2011
2041=over 2012=over
2042 2013
2043=item IO::AIO::nreqs 2014=item IO::AIO::nreqs
2059 2030
2060Returns the number of requests currently in the pending state (executed, 2031Returns the number of requests currently in the pending state (executed,
2061but not yet processed by poll_cb). 2032but not yet processed by poll_cb).
2062 2033
2063=back 2034=back
2035
2036
2037=head3 SUBSECOND STAT TIME ACCESS
2038
2039Both C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> functions can
2040generally find access/modification and change times with subsecond time
2041accuracy of the system supports it, but perl's built-in functions only
2042return the integer part.
2043
2044The following functions return the timestamps of the most recent
2045stat with subsecond precision on most systems and work both after
2046C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> calls. Their return
2047value is only meaningful after a successful C<stat>/C<lstat> call, or
2048during/after a successful C<aio_stat>/C<aio_lstat> callback.
2049
2050This is similar to the L<Time::HiRes> C<stat> functions, but can return
2051full resolution without rounding and work with standard perl C<stat>,
2052alleviating the need to call the special C<Time::HiRes> functions, which
2053do not act like their perl counterparts.
2054
2055On operating systems or file systems where subsecond time resolution is
2056not supported or could not be detected, a fractional part of C<0> is
2057returned, so it is always safe to call these functions.
2058
2059=over 4
2060
2061=item $seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime, IO::AIO::st_btime
2062
2063Return the access, modication, change or birth time, respectively,
2064including fractional part. Due to the limited precision of floating point,
2065the accuracy on most platforms is only a bit better than milliseconds
2066for times around now - see the I<nsec> function family, below, for full
2067accuracy.
2068
2069File birth time is only available when the OS and perl support it (on
2070FreeBSD and NetBSD at the time of this writing, although support is
2071adaptive, so if your OS/perl gains support, IO::AIO can take avdantage of
2072it). On systems where it isn't available, C<0> is currently returned, but
2073this might change to C<undef> in a future version.
2074
2075=item ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtime
2076
2077Returns access, modification, change and birth time all in one go, and
2078maybe more times in the future version.
2079
2080=item $nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec, IO::AIO::st_ctimensec, IO::AIO::st_btimensec
2081
2082Return the fractional access, modifcation, change or birth time, in nanoseconds,
2083as an integer in the range C<0> to C<999999999>.
2084
2085Note that no accessors are provided for access, modification and
2086change times - you need to get those from C<stat _> if required (C<int
2087IO::AIO::st_atime> and so on will I<not> generally give you the correct
2088value).
2089
2090=item $seconds = IO::AIO::st_btimesec
2091
2092The (integral) seconds part of the file birth time, if available.
2093
2094=item ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtimensec
2095
2096Like the functions above, but returns all four times in one go (and maybe
2097more in future versions).
2098
2099=item $counter = IO::AIO::st_gen
2100
2101Returns the generation counter (in practice this is just a random number)
2102of the file. This is only available on platforms which have this member in
2103their C<struct stat> (most BSDs at the time of this writing) and generally
2104only to the root usert. If unsupported, C<0> is returned, but this might
2105change to C<undef> in a future version.
2106
2107=back
2108
2109Example: print the high resolution modification time of F</etc>, using
2110C<stat>, and C<IO::AIO::aio_stat>.
2111
2112 if (stat "/etc") {
2113 printf "stat(/etc) mtime: %f\n", IO::AIO::st_mtime;
2114 }
2115
2116 IO::AIO::aio_stat "/etc", sub {
2117 $_[0]
2118 and return;
2119
2120 printf "aio_stat(/etc) mtime: %d.%09d\n", (stat _)[9], IO::AIO::st_mtimensec;
2121 };
2122
2123 IO::AIO::flush;
2124
2125Output of the awbove on my system, showing reduced and full accuracy:
2126
2127 stat(/etc) mtime: 1534043702.020808
2128 aio_stat(/etc) mtime: 1534043702.020807792
2129
2064 2130
2065=head3 MISCELLANEOUS FUNCTIONS 2131=head3 MISCELLANEOUS FUNCTIONS
2066 2132
2067IO::AIO implements some functions that are useful when you want to use 2133IO::AIO implements some functions that are useful when you want to use
2068some "Advanced I/O" function not available to in Perl, without going the 2134some "Advanced I/O" function not available to in Perl, without going the
2209 2275
2210=item IO::AIO::munmap $scalar 2276=item IO::AIO::munmap $scalar
2211 2277
2212Removes a previous mmap and undefines the C<$scalar>. 2278Removes a previous mmap and undefines the C<$scalar>.
2213 2279
2280=item IO::AIO::mremap $scalar, $new_length, $flags = MREMAP_MAYMOVE[, $new_address = 0]
2281
2282Calls the Linux-specific mremap(2) system call. The C<$scalar> must have
2283been mapped by C<IO::AIO::mmap>, and C<$flags> must currently either be
2284C<0> or C<IO::AIO::MREMAP_MAYMOVE>.
2285
2286Returns true if successful, and false otherwise. If the underlying mmapped
2287region has changed address, then the true value has the numerical value
2288C<1>, otherwise it has the numerical value C<0>:
2289
2290 my $success = IO::AIO::mremap $mmapped, 8192, IO::AIO::MREMAP_MAYMOVE
2291 or die "mremap: $!";
2292
2293 if ($success*1) {
2294 warn "scalar has chanegd address in memory\n";
2295 }
2296
2297C<IO::AIO::MREMAP_FIXED> and the C<$new_address> argument are currently
2298implemented, but not supported and might go away in a future version.
2299
2300On systems where this call is not supported or is not emulated, this call
2301returns falls and sets C<$!> to C<ENOSYS>.
2302
2303=item IO::AIO::mlockall $flags
2304
2305Calls the C<eio_mlockall_sync> function, which is like C<aio_mlockall>,
2306but is blocking.
2307
2214=item IO::AIO::munlock $scalar, $offset = 0, $length = undef 2308=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
2215 2309
2216Calls the C<munlock> function, undoing the effects of a previous 2310Calls the C<munlock> function, undoing the effects of a previous
2217C<aio_mlock> call (see its description for details). 2311C<aio_mlock> call (see its description for details).
2218 2312
2267C<$flags> is non-zero, fails with C<ENOSYS>. 2361C<$flags> is non-zero, fails with C<ENOSYS>.
2268 2362
2269Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the 2363Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the
2270time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and 2364time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and
2271C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported. 2365C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported.
2366
2367Example: create a pipe race-free w.r.t. threads and fork:
2368
2369 my ($rfh, $wfh) = IO::AIO::pipe2 IO::AIO::O_CLOEXEC
2370 or die "pipe2: $!\n";
2371
2372=item $fh = IO::AIO::eventfd [$initval, [$flags]]
2373
2374This is a direct interface to the Linux L<eventfd(2)> system call. The
2375(unhelpful) defaults for C<$initval> and C<$flags> are C<0> for both.
2376
2377On success, the new eventfd filehandle is returned, otherwise returns
2378C<undef>. If the eventfd syscall is missing, fails with C<ENOSYS>.
2379
2380Please refer to L<eventfd(2)> for more info on this call.
2381
2382The following symbol flag values are available: C<IO::AIO::EFD_CLOEXEC>,
2383C<IO::AIO::EFD_NONBLOCK> and C<IO::AIO::EFD_SEMAPHORE> (Linux 2.6.30).
2384
2385Example: create a new eventfd filehandle:
2386
2387 $fh = IO::AIO::eventfd 0, IO::AIO::O_CLOEXEC
2388 or die "eventfd: $!\n";
2389
2390=item $fh = IO::AIO::timerfd_create $clockid[, $flags]
2391
2392This is a direct interface to the Linux L<timerfd_create(2)> system call. The
2393(unhelpful) default for C<$flags> is C<0>.
2394
2395On success, the new timerfd filehandle is returned, otherwise returns
2396C<undef>. If the eventfd syscall is missing, fails with C<ENOSYS>.
2397
2398Please refer to L<timerfd_create(2)> for more info on this call.
2399
2400The following C<$clockid> values are
2401available: C<IO::AIO::CLOCK_REALTIME>, C<IO::AIO::CLOCK_MONOTONIC>
2402C<IO::AIO::CLOCK_CLOCK_BOOTTIME> (Linux 3.15)
2403C<IO::AIO::CLOCK_CLOCK_REALTIME_ALARM> (Linux 3.11) and
2404C<IO::AIO::CLOCK_CLOCK_BOOTTIME_ALARM> (Linux 3.11).
2405
2406The following C<$flags> values are available (Linux
24072.6.27): C<IO::AIO::TFD_NONBLOCK> and C<IO::AIO::TFD_CLOEXEC>.
2408
2409Example: create a new timerfd and set it to one-second repeated alarms,
2410then wait for two alarms:
2411
2412 my $fh = IO::AIO::timerfd_create IO::AIO::CLOCK_BOOTTIME, IO::AIO::TFD_CLOEXEC
2413 or die "timerfd_create: $!\n";
2414
2415 defined IO::AIO::timerfd_settime $fh, 0, 1, 1
2416 or die "timerfd_settime: $!\n";
2417
2418 for (1..2) {
2419 8 == sysread $fh, my $buf, 8
2420 or die "timerfd read failure\n";
2421
2422 printf "number of expirations (likely 1): %d\n",
2423 unpack "Q", $buf;
2424 }
2425
2426=item ($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags, $new_interval, $nbw_value
2427
2428This is a direct interface to the Linux L<timerfd_settime(2)> system
2429call. Please refer to its manpage for more info on this call.
2430
2431The new itimerspec is specified using two (possibly fractional) second
2432values, C<$new_interval> and C<$new_value>).
2433
2434On success, the current interval and value are returned (as per
2435C<timerfd_gettime>). On failure, the empty list is returned.
2436
2437The following C<$flags> values are
2438available: C<IO::AIO::TFD_TIMER_ABSTIME> and
2439C<IO::AIO::TFD_TIMER_CANCEL_ON_SET>.
2440
2441See C<IO::AIO::timerfd_create> for a full example.
2442
2443=item ($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh
2444
2445This is a direct interface to the Linux L<timerfd_gettime(2)> system
2446call. Please refer to its manpage for more info on this call.
2447
2448On success, returns the current values of interval and value for the given
2449timerfd (as potentially fractional second values). On failure, the empty
2450list is returned.
2272 2451
2273=back 2452=back
2274 2453
2275=cut 2454=cut
2276 2455
2342the process will result in undefined behaviour. Calling it at any time 2521the process will result in undefined behaviour. Calling it at any time
2343will also result in any undefined (by POSIX) behaviour. 2522will also result in any undefined (by POSIX) behaviour.
2344 2523
2345=back 2524=back
2346 2525
2526=head2 LINUX-SPECIFIC CALLS
2527
2528When a call is documented as "linux-specific" then this means it
2529originated on GNU/Linux. C<IO::AIO> will usually try to autodetect the
2530availability and compatibility of such calls regardless of the platform
2531it is compiled on, so platforms such as FreeBSD which often implement
2532these calls will work. When in doubt, call them and see if they fail wth
2533C<ENOSYS>.
2534
2347=head2 MEMORY USAGE 2535=head2 MEMORY USAGE
2348 2536
2349Per-request usage: 2537Per-request usage:
2350 2538
2351Each aio request uses - depending on your architecture - around 100-200 2539Each aio request uses - depending on your architecture - around 100-200
2363temporary buffers, and each thread requires a stack and other data 2551temporary buffers, and each thread requires a stack and other data
2364structures (usually around 16k-128k, depending on the OS). 2552structures (usually around 16k-128k, depending on the OS).
2365 2553
2366=head1 KNOWN BUGS 2554=head1 KNOWN BUGS
2367 2555
2368Known bugs will be fixed in the next release. 2556Known bugs will be fixed in the next release :)
2557
2558=head1 KNOWN ISSUES
2559
2560Calls that try to "import" foreign memory areas (such as C<IO::AIO::mmap>
2561or C<IO::AIO::aio_slurp>) do not work with generic lvalues, such as
2562non-created hash slots or other scalars I didn't think of. It's best to
2563avoid such and either use scalar variables or making sure that the scalar
2564exists (e.g. by storing C<undef>) and isn't "funny" (e.g. tied).
2565
2566I am not sure anything can be done about this, so this is considered a
2567known issue, rather than a bug.
2369 2568
2370=head1 SEE ALSO 2569=head1 SEE ALSO
2371 2570
2372L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a 2571L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
2373more natural syntax. 2572more natural syntax.

Diff Legend

Removed lines
+ Added lines
< Changed lines
> Changed lines