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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.278 by root, Sun Oct 1 07:24:34 2017 UTC vs.
Revision 1.318 by root, Sat Apr 1 02:14:05 2023 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 = 4.80;
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
198
199 accept4 tee splice pipe2 pipesize
200 fexecve mount umount memfd_create eventfd
201 timerfd_create timerfd_settime timerfd_gettime
202 pidfd_open pidfd_send_signal pidfd_getfd);
197 203
198 push @AIO_REQ, qw(aio_busy); # not exported 204 push @AIO_REQ, qw(aio_busy); # not exported
199 205
200 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 206 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
201 207
277 IO::AIO::idle_timeout $seconds 283 IO::AIO::idle_timeout $seconds
278 IO::AIO::max_outstanding $maxreqs 284 IO::AIO::max_outstanding $maxreqs
279 IO::AIO::nreqs 285 IO::AIO::nreqs
280 IO::AIO::nready 286 IO::AIO::nready
281 IO::AIO::npending 287 IO::AIO::npending
288 IO::AIO::reinit
289
282 $nfd = IO::AIO::get_fdlimit [EXPERIMENTAL] 290 $nfd = IO::AIO::get_fdlimit
283 IO::AIO::min_fdlimit $nfd [EXPERIMENTAL] 291 IO::AIO::min_fdlimit $nfd
284 292
285 IO::AIO::sendfile $ofh, $ifh, $offset, $count 293 IO::AIO::sendfile $ofh, $ifh, $offset, $count
286 IO::AIO::fadvise $fh, $offset, $len, $advice 294 IO::AIO::fadvise $fh, $offset, $len, $advice
295 IO::AIO::fexecve $fh, $argv, $envp
296
287 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]] 297 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
288 IO::AIO::munmap $scalar 298 IO::AIO::munmap $scalar
299 IO::AIO::mremap $scalar, $new_length, $flags[, $new_address]
289 IO::AIO::madvise $scalar, $offset, $length, $advice 300 IO::AIO::madvise $scalar, $offset, $length, $advice
290 IO::AIO::mprotect $scalar, $offset, $length, $protect 301 IO::AIO::mprotect $scalar, $offset, $length, $protect
291 IO::AIO::munlock $scalar, $offset = 0, $length = undef 302 IO::AIO::munlock $scalar, $offset = 0, $length = undef
292 IO::AIO::munlockall 303 IO::AIO::munlockall
304
305 # stat extensions
306 $counter = IO::AIO::st_gen
307 $seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime, IO::AIO::st_btime
308 ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtime
309 $nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec, IO::AIO::st_ctimensec, IO::AIO::st_btimensec
310 $seconds = IO::AIO::st_btimesec
311 ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtimensec
312
313 # very much unportable syscalls
314 IO::AIO::accept4 $r_fh, $sockaddr, $sockaddr_len, $flags
315 IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
316 IO::AIO::tee $r_fh, $w_fh, $length, $flags
317
318 $actual_size = IO::AIO::pipesize $r_fh[, $new_size]
319 ($rfh, $wfh) = IO::AIO::pipe2 [$flags]
320
321 $fh = IO::AIO::eventfd [$initval, [$flags]]
322 $fh = IO::AIO::memfd_create $pathname[, $flags]
323
324 $fh = IO::AIO::timerfd_create $clockid[, $flags]
325 ($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags, $new_interval, $nbw_value
326 ($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh
327
328 $fh = IO::AIO::pidfd_open $pid[, $flags]
329 $status = IO::AIO::pidfd_send_signal $pidfh, $signal[, $siginfo[, $flags]]
330 $fh = IO::AIO::pidfd_getfd $pidfh, $targetfd[, $flags]
331
332 $retval = IO::AIO::mount $special, $path, $fstype, $flags = 0, $data = undef
333 $retval = IO::AIO::umount $path, $flags = 0
293 334
294=head2 API NOTES 335=head2 API NOTES
295 336
296All the C<aio_*> calls are more or less thin wrappers around the syscall 337All the C<aio_*> calls are more or less thin wrappers around the syscall
297with the same name (sans C<aio_>). The arguments are similar or identical, 338with the same name (sans C<aio_>). The arguments are similar or identical,
372=item aio_open $pathname, $flags, $mode, $callback->($fh) 413=item aio_open $pathname, $flags, $mode, $callback->($fh)
373 414
374Asynchronously open or create a file and call the callback with a newly 415Asynchronously open or create a file and call the callback with a newly
375created filehandle for the file (or C<undef> in case of an error). 416created filehandle for the file (or C<undef> in case of an error).
376 417
377The pathname passed to C<aio_open> must be absolute. See API NOTES, above,
378for an explanation.
379
380The C<$flags> argument is a bitmask. See the C<Fcntl> module for a 418The C<$flags> argument is a bitmask. See the C<Fcntl> module for a
381list. They are the same as used by C<sysopen>. 419list. They are the same as used by C<sysopen>.
382 420
383Likewise, C<$mode> specifies the mode of the newly created file, if it 421Likewise, C<$mode> specifies the mode of the newly created file, if it
384didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>, 422didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>,
403following POSIX and non-POSIX constants are available (missing ones on 441following POSIX and non-POSIX constants are available (missing ones on
404your system are, as usual, C<0>): 442your system are, as usual, C<0>):
405 443
406C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>, 444C<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>, 445C<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>. 446C<O_RSYNC>, C<O_SYNC>, C<O_PATH>, C<O_TMPFILE>, C<O_TTY_INIT> and C<O_ACCMODE>.
409 447
410 448
411=item aio_close $fh, $callback->($status) 449=item aio_close $fh, $callback->($status)
412 450
413Asynchronously close a file and call the callback with the result 451Asynchronously close a file and call the callback with the result
539 577
540=item aio_stat $fh_or_path, $callback->($status) 578=item aio_stat $fh_or_path, $callback->($status)
541 579
542=item aio_lstat $fh, $callback->($status) 580=item aio_lstat $fh, $callback->($status)
543 581
544Works like perl's C<stat> or C<lstat> in void context. The callback will 582Works 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 _> 583callback will be called after the stat and the results will be available
546or C<-s _> etc... 584using C<stat _> or C<-s _> and other tests (with the exception of C<-B>
547 585and C<-T>).
548The pathname passed to C<aio_stat> must be absolute. See API NOTES, above,
549for an explanation.
550 586
551Currently, the stats are always 64-bit-stats, i.e. instead of returning an 587Currently, the stats are always 64-bit-stats, i.e. instead of returning an
552error when stat'ing a large file, the results will be silently truncated 588error when stat'ing a large file, the results will be silently truncated
553unless perl itself is compiled with large file support. 589unless perl itself is compiled with large file support.
554 590
558behaviour). 594behaviour).
559 595
560C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>, 596C<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>, 597C<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>. 598C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>.
599
600To access higher resolution stat timestamps, see L<SUBSECOND STAT TIME
601ACCESS>.
563 602
564Example: Print the length of F</etc/passwd>: 603Example: Print the length of F</etc/passwd>:
565 604
566 aio_stat "/etc/passwd", sub { 605 aio_stat "/etc/passwd", sub {
567 $_[0] and die "stat failed: $!"; 606 $_[0] and die "stat failed: $!";
611 namemax => 255, 650 namemax => 255,
612 frsize => 1024, 651 frsize => 1024,
613 fsid => 1810 652 fsid => 1810
614 } 653 }
615 654
616Here is a (likely partial - send me updates!) list of fsid values used by
617Linux - it is safe to hardcode these when C<$^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) 655=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
702 656
703Works like perl's C<utime> function (including the special case of $atime 657Works like perl's C<utime> function (including the special case of $atime
704and $mtime being undef). Fractional times are supported if the underlying 658and $mtime being undef). Fractional times are supported if the underlying
705syscalls support them. 659syscalls support them.
706 660
707When called with a pathname, uses utimes(2) if available, otherwise 661When called with a pathname, uses utimensat(2) or utimes(2) if available,
708utime(2). If called on a file descriptor, uses futimes(2) if available, 662otherwise utime(2). If called on a file descriptor, uses futimens(2)
709otherwise returns ENOSYS, so this is not portable. 663or futimes(2) if available, otherwise returns ENOSYS, so this is not
664portable.
710 665
711Examples: 666Examples:
712 667
713 # set atime and mtime to current time (basically touch(1)): 668 # set atime and mtime to current time (basically touch(1)):
714 aio_utime "path", undef, undef; 669 aio_utime "path", undef, undef;
873 828
874=over 4 829=over 4
875 830
876=item IO::AIO::READDIR_DENTS 831=item IO::AIO::READDIR_DENTS
877 832
878When this flag is off, then the callback gets an arrayref consisting of 833Normally the callback gets an arrayref consisting of names only (as
879names only (as with C<aio_readdir>), otherwise it gets an arrayref with 834with C<aio_readdir>). If this flag is set, then the callback gets an
880C<[$name, $type, $inode]> arrayrefs, each describing a single directory 835arrayref with C<[$name, $type, $inode]> arrayrefs, each describing a
881entry in more detail. 836single directory entry in more detail:
882 837
883C<$name> is the name of the entry. 838C<$name> is the name of the entry.
884 839
885C<$type> is one of the C<IO::AIO::DT_xxx> constants: 840C<$type> is one of the C<IO::AIO::DT_xxx> constants:
886 841
887C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>, 842C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
888C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>, 843C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
889C<IO::AIO::DT_WHT>. 844C<IO::AIO::DT_WHT>.
890 845
891C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to 846C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need
892know, you have to run stat yourself. Also, for speed reasons, the C<$type> 847to know, you have to run stat yourself. Also, for speed/memory reasons,
893scalars are read-only: you can not modify them. 848the C<$type> scalars are read-only: you must not modify them.
894 849
895C<$inode> is the inode number (which might not be exact on systems with 64 850C<$inode> is the inode number (which might not be exact on systems with 64
896bit inode numbers and 32 bit perls). This field has unspecified content on 851bit inode numbers and 32 bit perls). This field has unspecified content on
897systems that do not deliver the inode information. 852systems that do not deliver the inode information.
898 853
909short names are tried first. 864short names are tried first.
910 865
911=item IO::AIO::READDIR_STAT_ORDER 866=item IO::AIO::READDIR_STAT_ORDER
912 867
913When this flag is set, then the names will be returned in an order 868When this flag is set, then the names will be returned in an order
914suitable for stat()'ing each one. That is, when you plan to stat() 869suitable for stat()'ing each one. That is, when you plan to stat() most or
915all files in the given directory, then the returned order will likely 870all files in the given directory, then the returned order will likely be
916be fastest. 871faster.
917 872
918If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then 873If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified,
919the likely dirs come first, resulting in a less optimal stat order. 874then the likely dirs come first, resulting in a less optimal stat order
875for stat'ing all entries, but likely a more optimal order for finding
876subdirectories.
920 877
921=item IO::AIO::READDIR_FOUND_UNKNOWN 878=item IO::AIO::READDIR_FOUND_UNKNOWN
922 879
923This flag should not be set when calling C<aio_readdirx>. Instead, it 880This flag should not be set when calling C<aio_readdirx>. Instead, it
924is being set by C<aio_readdirx>, when any of the C<$type>'s found were 881is 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. 883C<$type>'s are known, which can be used to speed up some algorithms.
927 884
928=back 885=back
929 886
930 887
888=item aio_slurp $pathname, $offset, $length, $data, $callback->($status)
889
890Opens, reads and closes the given file. The data is put into C<$data>,
891which is resized as required.
892
893If C<$offset> is negative, then it is counted from the end of the file.
894
895If C<$length> is zero, then the remaining length of the file is
896used. Also, in this case, the same limitations to modifying C<$data> apply
897as when IO::AIO::mmap is used, i.e. it must only be modified in-place
898with C<substr>. If the size of the file is known, specifying a non-zero
899C<$length> results in a performance advantage.
900
901This request is similar to the older C<aio_load> request, but since it is
902a single request, it might be more efficient to use.
903
904Example: load F</etc/passwd> into C<$passwd>.
905
906 my $passwd;
907 aio_slurp "/etc/passwd", 0, 0, $passwd, sub {
908 $_[0] >= 0
909 or die "/etc/passwd: $!\n";
910
911 printf "/etc/passwd is %d bytes long, and contains:\n", length $passwd;
912 print $passwd;
913 };
914 IO::AIO::flush;
915
916
931=item aio_load $pathname, $data, $callback->($status) 917=item aio_load $pathname, $data, $callback->($status)
932 918
933This is a composite request that tries to fully load the given file into 919This is a composite request that tries to fully load the given file into
934memory. Status is the same as with aio_read. 920memory. Status is the same as with aio_read.
921
922Using C<aio_slurp> might be more efficient, as it is a single request.
935 923
936=cut 924=cut
937 925
938sub aio_load($$;$) { 926sub aio_load($$;$) {
939 my ($path, undef, $cb) = @_; 927 my ($path, undef, $cb) = @_;
1154 aioreq_pri $pri; 1142 aioreq_pri $pri;
1155 add $grp aio_stat $wd, sub { 1143 add $grp aio_stat $wd, sub {
1156 return $grp->result () if $_[0]; 1144 return $grp->result () if $_[0];
1157 my $now = time; 1145 my $now = time;
1158 my $hash1 = join ":", (stat _)[0,1,3,7,9]; 1146 my $hash1 = join ":", (stat _)[0,1,3,7,9];
1147 my $rdxflags = READDIR_DIRS_FIRST;
1148
1149 if ((stat _)[3] < 2) {
1150 # at least one non-POSIX filesystem exists
1151 # that returns useful DT_type values: btrfs,
1152 # so optimise for this here by requesting dents
1153 $rdxflags |= READDIR_DENTS;
1154 }
1159 1155
1160 # read the directory entries 1156 # read the directory entries
1161 aioreq_pri $pri; 1157 aioreq_pri $pri;
1162 add $grp aio_readdirx $wd, READDIR_DIRS_FIRST, sub { 1158 add $grp aio_readdirx $wd, $rdxflags, sub {
1163 my $entries = shift 1159 my ($entries, $flags) = @_
1164 or return $grp->result (); 1160 or return $grp->result ();
1161
1162 if ($rdxflags & READDIR_DENTS) {
1163 # if we requested type values, see if we can use them directly.
1164
1165 # if there were any DT_UNKNOWN entries then we assume we
1166 # don't know. alternatively, we could assume that if we get
1167 # one DT_DIR, then all directories are indeed marked with
1168 # DT_DIR, but this seems not required for btrfs, and this
1169 # is basically the "btrfs can't get it's act together" code
1170 # branch.
1171 unless ($flags & READDIR_FOUND_UNKNOWN) {
1172 # now we have valid DT_ information for all entries,
1173 # so use it as an optimisation without further stat's.
1174 # they must also all be at the beginning of @$entries
1175 # by now.
1176
1177 my $dirs;
1178
1179 if (@$entries) {
1180 for (0 .. $#$entries) {
1181 if ($entries->[$_][1] != DT_DIR) {
1182 # splice out directories
1183 $dirs = [splice @$entries, 0, $_];
1184 last;
1185 }
1186 }
1187
1188 # if we didn't find any non-dir, then all entries are dirs
1189 unless ($dirs) {
1190 ($dirs, $entries) = ($entries, []);
1191 }
1192 } else {
1193 # directory is empty, so there are no sbdirs
1194 $dirs = [];
1195 }
1196
1197 # either splice'd the directories out or the dir was empty.
1198 # convert dents to filenames
1199 $_ = $_->[0] for @$dirs;
1200 $_ = $_->[0] for @$entries;
1201
1202 return $grp->result ($dirs, $entries);
1203 }
1204
1205 # cannot use, so return to our old ways
1206 # by pretending we only scanned for names.
1207 $_ = $_->[0] for @$entries;
1208 }
1165 1209
1166 # stat the dir another time 1210 # stat the dir another time
1167 aioreq_pri $pri; 1211 aioreq_pri $pri;
1168 add $grp aio_stat $wd, sub { 1212 add $grp aio_stat $wd, sub {
1169 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 1213 my $hash2 = join ":", (stat _)[0,1,3,7,9];
1275So in general, you should only use these calls for things that do 1319So in general, you should only use these calls for things that do
1276(filesystem) I/O, not for things that wait for other events (network, 1320(filesystem) I/O, not for things that wait for other events (network,
1277other processes), although if you are careful and know what you are doing, 1321other processes), although if you are careful and know what you are doing,
1278you still can. 1322you still can.
1279 1323
1280The following constants are available (missing ones are, as usual C<0>): 1324The following constants are available and can be used for normal C<ioctl>
1325and C<fcntl> as well (missing ones are, as usual C<0>):
1281 1326
1282C<F_DUPFD_CLOEXEC>, 1327C<F_DUPFD_CLOEXEC>,
1283 1328
1284C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>, 1329C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>,
1285 1330
1286C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>. 1331C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>.
1332
1333C<F_ADD_SEALS>, C<F_GET_SEALS>, C<F_SEAL_SEAL>, C<F_SEAL_SHRINK>, C<F_SEAL_GROW> and
1334C<F_SEAL_WRITE>.
1287 1335
1288C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>, 1336C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>,
1289C<FS_IOC_FIEMAP>. 1337C<FS_IOC_FIEMAP>.
1290 1338
1291C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>, 1339C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>,
1299 1347
1300C<FS_XFLAG_REALTIME>, C<FS_XFLAG_PREALLOC>, C<FS_XFLAG_IMMUTABLE>, C<FS_XFLAG_APPEND>, 1348C<FS_XFLAG_REALTIME>, C<FS_XFLAG_PREALLOC>, C<FS_XFLAG_IMMUTABLE>, C<FS_XFLAG_APPEND>,
1301C<FS_XFLAG_SYNC>, C<FS_XFLAG_NOATIME>, C<FS_XFLAG_NODUMP>, C<FS_XFLAG_RTINHERIT>, 1349C<FS_XFLAG_SYNC>, C<FS_XFLAG_NOATIME>, C<FS_XFLAG_NODUMP>, C<FS_XFLAG_RTINHERIT>,
1302C<FS_XFLAG_PROJINHERIT>, C<FS_XFLAG_NOSYMLINKS>, C<FS_XFLAG_EXTSIZE>, C<FS_XFLAG_EXTSZINHERIT>, 1350C<FS_XFLAG_PROJINHERIT>, C<FS_XFLAG_NOSYMLINKS>, C<FS_XFLAG_EXTSIZE>, C<FS_XFLAG_EXTSZINHERIT>,
1303C<FS_XFLAG_NODEFRAG>, C<FS_XFLAG_FILESTREAM>, C<FS_XFLAG_DAX>, C<FS_XFLAG_HASATTR>, 1351C<FS_XFLAG_NODEFRAG>, C<FS_XFLAG_FILESTREAM>, C<FS_XFLAG_DAX>, C<FS_XFLAG_HASATTR>,
1352
1353C<BLKROSET>, C<BLKROGET>, C<BLKRRPART>, C<BLKGETSIZE>, C<BLKFLSBUF>, C<BLKRASET>,
1354C<BLKRAGET>, C<BLKFRASET>, C<BLKFRAGET>, C<BLKSECTSET>, C<BLKSECTGET>, C<BLKSSZGET>,
1355C<BLKBSZGET>, C<BLKBSZSET>, C<BLKGETSIZE64>,
1356
1304 1357
1305=item aio_sync $callback->($status) 1358=item aio_sync $callback->($status)
1306 1359
1307Asynchronously call sync and call the callback when finished. 1360Asynchronously call sync and call the callback when finished.
1308 1361
1430 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh; 1483 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
1431 aio_mlock $data; # mlock in background 1484 aio_mlock $data; # mlock in background
1432 1485
1433=item aio_mlockall $flags, $callback->($status) 1486=item aio_mlockall $flags, $callback->($status)
1434 1487
1435Calls the C<mlockall> function with the given C<$flags> (a combination of 1488Calls the C<mlockall> function with the given C<$flags> (a
1436C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>). 1489combination of C<IO::AIO::MCL_CURRENT>, C<IO::AIO::MCL_FUTURE> and
1490C<IO::AIO::MCL_ONFAULT>).
1437 1491
1438On systems that do not implement C<mlockall>, this function returns C<-1> 1492On systems that do not implement C<mlockall>, this function returns C<-1>
1439and sets errno to C<ENOSYS>. 1493and sets errno to C<ENOSYS>. Similarly, flag combinations not supported
1494by the system result in a return value of C<-1> with errno being set to
1495C<EINVAL>.
1440 1496
1441Note that the corresponding C<munlockall> is synchronous and is 1497Note that the corresponding C<munlockall> is synchronous and is
1442documented under L<MISCELLANEOUS FUNCTIONS>. 1498documented under L<MISCELLANEOUS FUNCTIONS>.
1443 1499
1444Example: asynchronously lock all current and future pages into memory. 1500Example: asynchronously lock all current and future pages into memory.
1638C<aio_wd> callback, as future requests using the value will fail in the 1694C<aio_wd> callback, as future requests using the value will fail in the
1639expected way. 1695expected way.
1640 1696
1641=item IO::AIO::CWD 1697=item IO::AIO::CWD
1642 1698
1643This is a compiletime constant (object) that represents the process 1699This is a compile time constant (object) that represents the process
1644current working directory. 1700current working directory.
1645 1701
1646Specifying this object as working directory object for a pathname is as if 1702Specifying this object as working directory object for a pathname is as if
1647the pathname would be specified directly, without a directory object. For 1703the pathname would be specified directly, without a directory object. For
1648example, these calls are functionally identical: 1704example, these calls are functionally identical:
1829The default value for the limit is C<0>, but note that setting a feeder 1885The default value for the limit is C<0>, but note that setting a feeder
1830automatically bumps it up to C<2>. 1886automatically bumps it up to C<2>.
1831 1887
1832=back 1888=back
1833 1889
1890
1834=head2 SUPPORT FUNCTIONS 1891=head2 SUPPORT FUNCTIONS
1835 1892
1836=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1893=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
1837 1894
1838=over 4 1895=over 4
1903Strictly equivalent to: 1960Strictly equivalent to:
1904 1961
1905 IO::AIO::poll_wait, IO::AIO::poll_cb 1962 IO::AIO::poll_wait, IO::AIO::poll_cb
1906 while IO::AIO::nreqs; 1963 while IO::AIO::nreqs;
1907 1964
1965This function can be useful at program aborts, to make sure outstanding
1966I/O has been done (C<IO::AIO> uses an C<END> block which already calls
1967this function on normal exits), or when you are merely using C<IO::AIO>
1968for its more advanced functions, rather than for async I/O, e.g.:
1969
1970 my ($dirs, $nondirs);
1971 IO::AIO::aio_scandir "/tmp", 0, sub { ($dirs, $nondirs) = @_ };
1972 IO::AIO::flush;
1973 # $dirs, $nondirs are now set
1974
1908=item IO::AIO::max_poll_reqs $nreqs 1975=item IO::AIO::max_poll_reqs $nreqs
1909 1976
1910=item IO::AIO::max_poll_time $seconds 1977=item IO::AIO::max_poll_time $seconds
1911 1978
1912These set the maximum number of requests (default C<0>, meaning infinity) 1979These set the maximum number of requests (default C<0>, meaning infinity)
1938 poll => 'r', nice => 1, 2005 poll => 'r', nice => 1,
1939 cb => &IO::AIO::poll_cb); 2006 cb => &IO::AIO::poll_cb);
1940 2007
1941=back 2008=back
1942 2009
2010
1943=head3 CONTROLLING THE NUMBER OF THREADS 2011=head3 CONTROLLING THE NUMBER OF THREADS
1944 2012
1945=over 2013=over
1946 2014
1947=item IO::AIO::min_parallel $nthreads 2015=item IO::AIO::min_parallel $nthreads
2008longer exceeded. 2076longer exceeded.
2009 2077
2010In other words, this setting does not enforce a queue limit, but can be 2078In other words, this setting does not enforce a queue limit, but can be
2011used to make poll functions block if the limit is exceeded. 2079used to make poll functions block if the limit is exceeded.
2012 2080
2013This is a very bad function to use in interactive programs because it 2081This is a bad function to use in interactive programs because it blocks,
2014blocks, and a bad way to reduce concurrency because it is inexact: Better 2082and a bad way to reduce concurrency because it is inexact. If you need to
2083issue many requests without being able to call a poll function on demand,
2015use an C<aio_group> together with a feed callback. 2084it is better to use an C<aio_group> together with a feed callback.
2016 2085
2017Its main use is in scripts without an event loop - when you want to stat 2086Its main use is in scripts without an event loop - when you want to stat a
2018a lot of files, you can write something like this: 2087lot of files, you can write something like this:
2019 2088
2020 IO::AIO::max_outstanding 32; 2089 IO::AIO::max_outstanding 32;
2021 2090
2022 for my $path (...) { 2091 for my $path (...) {
2023 aio_stat $path , ...; 2092 aio_stat $path , ...;
2024 IO::AIO::poll_cb; 2093 IO::AIO::poll_cb;
2025 } 2094 }
2026 2095
2027 IO::AIO::flush; 2096 IO::AIO::flush;
2028 2097
2029The call to C<poll_cb> inside the loop will normally return instantly, but 2098The call to C<poll_cb> inside the loop will normally return instantly,
2030as soon as more thna C<32> reqeusts are in-flight, it will block until 2099allowing the loop to progress, but as soon as more than C<32> requests
2031some requests have been handled. This keeps the loop from pushing a large 2100are in-flight, it will block until some requests have been handled. This
2032number of C<aio_stat> requests onto the queue. 2101keeps the loop from pushing a large number of C<aio_stat> requests onto
2102the queue (which, with many paths to stat, can use up a lot of memory).
2033 2103
2034The default value for C<max_outstanding> is very large, so there is no 2104The default value for C<max_outstanding> is very large, so there is no
2035practical limit on the number of outstanding requests. 2105practical limit on the number of outstanding requests.
2036 2106
2037=back 2107=back
2038 2108
2109
2039=head3 STATISTICAL INFORMATION 2110=head3 STATISTICAL INFORMATION
2040 2111
2041=over 2112=over
2042 2113
2043=item IO::AIO::nreqs 2114=item IO::AIO::nreqs
2059 2130
2060Returns the number of requests currently in the pending state (executed, 2131Returns the number of requests currently in the pending state (executed,
2061but not yet processed by poll_cb). 2132but not yet processed by poll_cb).
2062 2133
2063=back 2134=back
2135
2136
2137=head3 SUBSECOND STAT TIME ACCESS
2138
2139Both C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> functions can
2140generally find access/modification and change times with subsecond time
2141accuracy of the system supports it, but perl's built-in functions only
2142return the integer part.
2143
2144The following functions return the timestamps of the most recent
2145stat with subsecond precision on most systems and work both after
2146C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> calls. Their return
2147value is only meaningful after a successful C<stat>/C<lstat> call, or
2148during/after a successful C<aio_stat>/C<aio_lstat> callback.
2149
2150This is similar to the L<Time::HiRes> C<stat> functions, but can return
2151full resolution without rounding and work with standard perl C<stat>,
2152alleviating the need to call the special C<Time::HiRes> functions, which
2153do not act like their perl counterparts.
2154
2155On operating systems or file systems where subsecond time resolution is
2156not supported or could not be detected, a fractional part of C<0> is
2157returned, so it is always safe to call these functions.
2158
2159=over 4
2160
2161=item $seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime, IO::AIO::st_btime
2162
2163Return the access, modication, change or birth time, respectively,
2164including fractional part. Due to the limited precision of floating point,
2165the accuracy on most platforms is only a bit better than milliseconds
2166for times around now - see the I<nsec> function family, below, for full
2167accuracy.
2168
2169File birth time is only available when the OS and perl support it (on
2170FreeBSD and NetBSD at the time of this writing, although support is
2171adaptive, so if your OS/perl gains support, IO::AIO can take advantage of
2172it). On systems where it isn't available, C<0> is currently returned, but
2173this might change to C<undef> in a future version.
2174
2175=item ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtime
2176
2177Returns access, modification, change and birth time all in one go, and
2178maybe more times in the future version.
2179
2180=item $nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec, IO::AIO::st_ctimensec, IO::AIO::st_btimensec
2181
2182Return the fractional access, modifcation, change or birth time, in nanoseconds,
2183as an integer in the range C<0> to C<999999999>.
2184
2185Note that no accessors are provided for access, modification and
2186change times - you need to get those from C<stat _> if required (C<int
2187IO::AIO::st_atime> and so on will I<not> generally give you the correct
2188value).
2189
2190=item $seconds = IO::AIO::st_btimesec
2191
2192The (integral) seconds part of the file birth time, if available.
2193
2194=item ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtimensec
2195
2196Like the functions above, but returns all four times in one go (and maybe
2197more in future versions).
2198
2199=item $counter = IO::AIO::st_gen
2200
2201Returns the generation counter (in practice this is just a random number)
2202of the file. This is only available on platforms which have this member in
2203their C<struct stat> (most BSDs at the time of this writing) and generally
2204only to the root usert. If unsupported, C<0> is returned, but this might
2205change to C<undef> in a future version.
2206
2207=back
2208
2209Example: print the high resolution modification time of F</etc>, using
2210C<stat>, and C<IO::AIO::aio_stat>.
2211
2212 if (stat "/etc") {
2213 printf "stat(/etc) mtime: %f\n", IO::AIO::st_mtime;
2214 }
2215
2216 IO::AIO::aio_stat "/etc", sub {
2217 $_[0]
2218 and return;
2219
2220 printf "aio_stat(/etc) mtime: %d.%09d\n", (stat _)[9], IO::AIO::st_mtimensec;
2221 };
2222
2223 IO::AIO::flush;
2224
2225Output of the awbove on my system, showing reduced and full accuracy:
2226
2227 stat(/etc) mtime: 1534043702.020808
2228 aio_stat(/etc) mtime: 1534043702.020807792
2229
2064 2230
2065=head3 MISCELLANEOUS FUNCTIONS 2231=head3 MISCELLANEOUS FUNCTIONS
2066 2232
2067IO::AIO implements some functions that are useful when you want to use 2233IO::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 2234some "Advanced I/O" function not available to in Perl, without going the
2069"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*> 2235"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*>
2070counterpart. 2236counterpart.
2071 2237
2072=over 4 2238=over 4
2073 2239
2240=item $retval = IO::AIO::fexecve $fh, $argv, $envp
2241
2242A more-or-less direct equivalent to the POSIX C<fexecve> functions, which
2243allows you to specify the program to be executed via a file descriptor (or
2244handle). Returns C<-1> and sets errno to C<ENOSYS> if not available.
2245
2246=item $retval = IO::AIO::mount $special, $path, $fstype, $flags = 0, $data = undef
2247
2248Calls the GNU/Linux mount syscall with the given arguments. All except
2249C<$flags> are strings, and if C<$data> is C<undef>, a C<NULL> will be
2250passed.
2251
2252The following values for C<$flags> are available:
2253
2254C<IO::AIO::MS_RDONLY>, C<IO::AIO::MS_NOSUID>, C<IO::AIO::MS_NODEV>, C<IO::AIO::MS_NOEXEC>, C<IO::AIO::MS_SYNCHRONOUS>,
2255C<IO::AIO::MS_REMOUNT>, C<IO::AIO::MS_MANDLOCK>, C<IO::AIO::MS_DIRSYNC>, C<IO::AIO::MS_NOATIME>,
2256C<IO::AIO::MS_NODIRATIME>, C<IO::AIO::MS_BIND>, C<IO::AIO::MS_MOVE>, C<IO::AIO::MS_REC>, C<IO::AIO::MS_SILENT>,
2257C<IO::AIO::MS_POSIXACL>, C<IO::AIO::MS_UNBINDABLE>, C<IO::AIO::MS_PRIVATE>, C<IO::AIO::MS_SLAVE>, C<IO::AIO::MS_SHARED>,
2258C<IO::AIO::MS_RELATIME>, C<IO::AIO::MS_KERNMOUNT>, C<IO::AIO::MS_I_VERSION>, C<IO::AIO::MS_STRICTATIME>,
2259C<IO::AIO::MS_LAZYTIME>, C<IO::AIO::MS_ACTIVE>, C<IO::AIO::MS_NOUSER>, C<IO::AIO::MS_RMT_MASK>, C<IO::AIO::MS_MGC_VAL> and
2260C<IO::AIO::MS_MGC_MSK>.
2261
2262=item $retval = IO::AIO::umount $path, $flags = 0
2263
2264Invokes the GNU/Linux C<umount> or C<umount2> syscalls. Always calls
2265C<umount> if C<$flags> is C<0>, otherwqise always tries to call
2266C<umount2>.
2267
2268The following C<$flags> are available:
2269
2270C<IO::AIO::MNT_FORCE>, C<IO::AIO::MNT_DETACH>, C<IO::AIO::MNT_EXPIRE> and C<IO::AIO::UMOUNT_NOFOLLOW>.
2271
2074=item $numfd = IO::AIO::get_fdlimit 2272=item $numfd = IO::AIO::get_fdlimit
2075
2076This function is I<EXPERIMENTAL> and subject to change.
2077 2273
2078Tries to find the current file descriptor limit and returns it, or 2274Tries to find the current file descriptor limit and returns it, or
2079C<undef> and sets C<$!> in case of an error. The limit is one larger than 2275C<undef> and sets C<$!> in case of an error. The limit is one larger than
2080the highest valid file descriptor number. 2276the highest valid file descriptor number.
2081 2277
2082=item IO::AIO::min_fdlimit [$numfd] 2278=item IO::AIO::min_fdlimit [$numfd]
2083
2084This function is I<EXPERIMENTAL> and subject to change.
2085 2279
2086Try to increase the current file descriptor limit(s) to at least C<$numfd> 2280Try to increase the current file descriptor limit(s) to at least C<$numfd>
2087by changing the soft or hard file descriptor resource limit. If C<$numfd> 2281by changing the soft or hard file descriptor resource limit. If C<$numfd>
2088is missing, it will try to set a very high limit, although this is not 2282is missing, it will try to set a very high limit, although this is not
2089recommended when you know the actual minimum that you require. 2283recommended when you know the actual minimum that you require.
2184C<IO::AIO::MAP_POPULATE>, 2378C<IO::AIO::MAP_POPULATE>,
2185C<IO::AIO::MAP_NONBLOCK>, 2379C<IO::AIO::MAP_NONBLOCK>,
2186C<IO::AIO::MAP_FIXED>, 2380C<IO::AIO::MAP_FIXED>,
2187C<IO::AIO::MAP_GROWSDOWN>, 2381C<IO::AIO::MAP_GROWSDOWN>,
2188C<IO::AIO::MAP_32BIT>, 2382C<IO::AIO::MAP_32BIT>,
2189C<IO::AIO::MAP_HUGETLB> or 2383C<IO::AIO::MAP_HUGETLB>,
2190C<IO::AIO::MAP_STACK>. 2384C<IO::AIO::MAP_STACK>,
2385C<IO::AIO::MAP_FIXED_NOREPLACE>,
2386C<IO::AIO::MAP_SHARED_VALIDATE>,
2387C<IO::AIO::MAP_SYNC> or
2388C<IO::AIO::MAP_UNINITIALIZED>.
2191 2389
2192If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed. 2390If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
2193 2391
2194C<$offset> is the offset from the start of the file - it generally must be 2392C<$offset> is the offset from the start of the file - it generally must be
2195a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>. 2393a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
2209 2407
2210=item IO::AIO::munmap $scalar 2408=item IO::AIO::munmap $scalar
2211 2409
2212Removes a previous mmap and undefines the C<$scalar>. 2410Removes a previous mmap and undefines the C<$scalar>.
2213 2411
2412=item IO::AIO::mremap $scalar, $new_length, $flags = MREMAP_MAYMOVE[, $new_address = 0]
2413
2414Calls the Linux-specific mremap(2) system call. The C<$scalar> must have
2415been mapped by C<IO::AIO::mmap>, and C<$flags> must currently either be
2416C<0> or C<IO::AIO::MREMAP_MAYMOVE>.
2417
2418Returns true if successful, and false otherwise. If the underlying mmapped
2419region has changed address, then the true value has the numerical value
2420C<1>, otherwise it has the numerical value C<0>:
2421
2422 my $success = IO::AIO::mremap $mmapped, 8192, IO::AIO::MREMAP_MAYMOVE
2423 or die "mremap: $!";
2424
2425 if ($success*1) {
2426 warn "scalar has chanegd address in memory\n";
2427 }
2428
2429C<IO::AIO::MREMAP_FIXED> and the C<$new_address> argument are currently
2430implemented, but not supported and might go away in a future version.
2431
2432On systems where this call is not supported or is not emulated, this call
2433returns falls and sets C<$!> to C<ENOSYS>.
2434
2435=item IO::AIO::mlockall $flags
2436
2437Calls the C<eio_mlockall_sync> function, which is like C<aio_mlockall>,
2438but is blocking.
2439
2214=item IO::AIO::munlock $scalar, $offset = 0, $length = undef 2440=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
2215 2441
2216Calls the C<munlock> function, undoing the effects of a previous 2442Calls the C<munlock> function, undoing the effects of a previous
2217C<aio_mlock> call (see its description for details). 2443C<aio_mlock> call (see its description for details).
2218 2444
2220 2446
2221Calls the C<munlockall> function. 2447Calls the C<munlockall> function.
2222 2448
2223On systems that do not implement C<munlockall>, this function returns 2449On systems that do not implement C<munlockall>, this function returns
2224ENOSYS, otherwise the return value of C<munlockall>. 2450ENOSYS, otherwise the return value of C<munlockall>.
2451
2452=item $fh = IO::AIO::accept4 $r_fh, $sockaddr, $sockaddr_maxlen, $flags
2453
2454Uses the GNU/Linux C<accept4(2)> syscall, if available, to accept a socket
2455and return the new file handle on success, or sets C<$!> and returns
2456C<undef> on error.
2457
2458The remote name of the new socket will be stored in C<$sockaddr>, which
2459will be extended to allow for at least C<$sockaddr_maxlen> octets. If the
2460socket name does not fit into C<$sockaddr_maxlen> octets, this is signaled
2461by returning a longer string in C<$sockaddr>, which might or might not be
2462truncated.
2463
2464To accept name-less sockets, use C<undef> for C<$sockaddr> and C<0> for
2465C<$sockaddr_maxlen>.
2466
2467The main reasons to use this syscall rather than portable C<accept(2)>
2468are that you can specify C<SOCK_NONBLOCK> and/or C<SOCK_CLOEXEC>
2469flags and you can accept name-less sockets by specifying C<0> for
2470C<$sockaddr_maxlen>, which is sadly not possible with perl's interface to
2471C<accept>.
2225 2472
2226=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags 2473=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
2227 2474
2228Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or 2475Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or
2229C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they 2476C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
2267C<$flags> is non-zero, fails with C<ENOSYS>. 2514C<$flags> is non-zero, fails with C<ENOSYS>.
2268 2515
2269Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the 2516Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the
2270time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and 2517time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and
2271C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported. 2518C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported.
2519
2520Example: create a pipe race-free w.r.t. threads and fork:
2521
2522 my ($rfh, $wfh) = IO::AIO::pipe2 IO::AIO::O_CLOEXEC
2523 or die "pipe2: $!\n";
2524
2525=item $fh = IO::AIO::memfd_create $pathname[, $flags]
2526
2527This is a direct interface to the Linux L<memfd_create(2)> system
2528call. The (unhelpful) default for C<$flags> is C<0>, but your default
2529should be C<IO::AIO::MFD_CLOEXEC>.
2530
2531On success, the new memfd filehandle is returned, otherwise returns
2532C<undef>. If the memfd_create syscall is missing, fails with C<ENOSYS>.
2533
2534Please refer to L<memfd_create(2)> for more info on this call.
2535
2536The following C<$flags> values are available: C<IO::AIO::MFD_CLOEXEC>,
2537C<IO::AIO::MFD_ALLOW_SEALING>, C<IO::AIO::MFD_HUGETLB>,
2538C<IO::AIO::MFD_HUGETLB_2MB> and C<IO::AIO::MFD_HUGETLB_1GB>.
2539
2540Example: create a new memfd.
2541
2542 my $fh = IO::AIO::memfd_create "somenameforprocfd", IO::AIO::MFD_CLOEXEC
2543 or die "memfd_create: $!\n";
2544
2545=item $fh = IO::AIO::pidfd_open $pid[, $flags]
2546
2547This is an interface to the Linux L<pidfd_open(2)> system call. The
2548default for C<$flags> is C<0>.
2549
2550On success, a new pidfd filehandle is returned (that is already set to
2551close-on-exec), otherwise returns C<undef>. If the syscall is missing,
2552fails with C<ENOSYS>.
2553
2554Example: open pid 6341 as pidfd.
2555
2556 my $fh = IO::AIO::pidfd_open 6341
2557 or die "pidfd_open: $!\n";
2558
2559=item $status = IO::AIO::pidfd_send_signal $pidfh, $signal[, $siginfo[, $flags]]
2560
2561This is an interface to the Linux L<pidfd_send_signal> system call. The
2562default for C<$siginfo> is C<undef> and the default for C<$flags> is C<0>.
2563
2564Returns the system call status. If the syscall is missing, fails with
2565C<ENOSYS>.
2566
2567When specified, C<$siginfo> must be a reference to a hash with one or more
2568of the following members:
2569
2570=over
2571
2572=item code - the C<si_code> member
2573
2574=item pid - the C<si_pid> member
2575
2576=item uid - the C<si_uid> member
2577
2578=item value_int - the C<si_value.sival_int> member
2579
2580=item value_ptr - the C<si_value.sival_ptr> member, specified as an integer
2581
2582=back
2583
2584Example: send a SIGKILL to the specified process.
2585
2586 my $status = IO::AIO::pidfd_send_signal $pidfh, 9, undef
2587 and die "pidfd_send_signal: $!\n";
2588
2589Example: send a SIGKILL to the specified process with extra data.
2590
2591 my $status = IO::AIO::pidfd_send_signal $pidfh, 9, { code => -1, value_int => 7 }
2592 and die "pidfd_send_signal: $!\n";
2593
2594=item $fh = IO::AIO::pidfd_getfd $pidfh, $targetfd[, $flags]
2595
2596This is an interface to the Linux L<pidfd_getfd> system call. The default
2597for C<$flags> is C<0>.
2598
2599On success, returns a dup'ed copy of the target file descriptor (specified
2600as an integer) returned (that is already set to close-on-exec), otherwise
2601returns C<undef>. If the syscall is missing, fails with C<ENOSYS>.
2602
2603Example: get a copy of standard error of another process and print soemthing to it.
2604
2605 my $errfh = IO::AIO::pidfd_getfd $pidfh, 2
2606 or die "pidfd_getfd: $!\n";
2607 print $errfh "stderr\n";
2608
2609=item $fh = IO::AIO::eventfd [$initval, [$flags]]
2610
2611This is a direct interface to the Linux L<eventfd(2)> system call. The
2612(unhelpful) defaults for C<$initval> and C<$flags> are C<0> for both.
2613
2614On success, the new eventfd filehandle is returned, otherwise returns
2615C<undef>. If the eventfd syscall is missing, fails with C<ENOSYS>.
2616
2617Please refer to L<eventfd(2)> for more info on this call.
2618
2619The following symbol flag values are available: C<IO::AIO::EFD_CLOEXEC>,
2620C<IO::AIO::EFD_NONBLOCK> and C<IO::AIO::EFD_SEMAPHORE> (Linux 2.6.30).
2621
2622Example: create a new eventfd filehandle:
2623
2624 $fh = IO::AIO::eventfd 0, IO::AIO::EFD_CLOEXEC
2625 or die "eventfd: $!\n";
2626
2627=item $fh = IO::AIO::timerfd_create $clockid[, $flags]
2628
2629This is a direct interface to the Linux L<timerfd_create(2)> system
2630call. The (unhelpful) default for C<$flags> is C<0>, but your default
2631should be C<IO::AIO::TFD_CLOEXEC>.
2632
2633On success, the new timerfd filehandle is returned, otherwise returns
2634C<undef>. If the timerfd_create syscall is missing, fails with C<ENOSYS>.
2635
2636Please refer to L<timerfd_create(2)> for more info on this call.
2637
2638The following C<$clockid> values are
2639available: C<IO::AIO::CLOCK_REALTIME>, C<IO::AIO::CLOCK_MONOTONIC>
2640C<IO::AIO::CLOCK_CLOCK_BOOTTIME> (Linux 3.15)
2641C<IO::AIO::CLOCK_CLOCK_REALTIME_ALARM> (Linux 3.11) and
2642C<IO::AIO::CLOCK_CLOCK_BOOTTIME_ALARM> (Linux 3.11).
2643
2644The following C<$flags> values are available (Linux
26452.6.27): C<IO::AIO::TFD_NONBLOCK> and C<IO::AIO::TFD_CLOEXEC>.
2646
2647Example: create a new timerfd and set it to one-second repeated alarms,
2648then wait for two alarms:
2649
2650 my $fh = IO::AIO::timerfd_create IO::AIO::CLOCK_BOOTTIME, IO::AIO::TFD_CLOEXEC
2651 or die "timerfd_create: $!\n";
2652
2653 defined IO::AIO::timerfd_settime $fh, 0, 1, 1
2654 or die "timerfd_settime: $!\n";
2655
2656 for (1..2) {
2657 8 == sysread $fh, my $buf, 8
2658 or die "timerfd read failure\n";
2659
2660 printf "number of expirations (likely 1): %d\n",
2661 unpack "Q", $buf;
2662 }
2663
2664=item ($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags, $new_interval, $nbw_value
2665
2666This is a direct interface to the Linux L<timerfd_settime(2)> system
2667call. Please refer to its manpage for more info on this call.
2668
2669The new itimerspec is specified using two (possibly fractional) second
2670values, C<$new_interval> and C<$new_value>).
2671
2672On success, the current interval and value are returned (as per
2673C<timerfd_gettime>). On failure, the empty list is returned.
2674
2675The following C<$flags> values are
2676available: C<IO::AIO::TFD_TIMER_ABSTIME> and
2677C<IO::AIO::TFD_TIMER_CANCEL_ON_SET>.
2678
2679See C<IO::AIO::timerfd_create> for a full example.
2680
2681=item ($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh
2682
2683This is a direct interface to the Linux L<timerfd_gettime(2)> system
2684call. Please refer to its manpage for more info on this call.
2685
2686On success, returns the current values of interval and value for the given
2687timerfd (as potentially fractional second values). On failure, the empty
2688list is returned.
2272 2689
2273=back 2690=back
2274 2691
2275=cut 2692=cut
2276 2693
2342the process will result in undefined behaviour. Calling it at any time 2759the process will result in undefined behaviour. Calling it at any time
2343will also result in any undefined (by POSIX) behaviour. 2760will also result in any undefined (by POSIX) behaviour.
2344 2761
2345=back 2762=back
2346 2763
2764=head2 LINUX-SPECIFIC CALLS
2765
2766When a call is documented as "linux-specific" then this means it
2767originated on GNU/Linux. C<IO::AIO> will usually try to autodetect the
2768availability and compatibility of such calls regardless of the platform
2769it is compiled on, so platforms such as FreeBSD which often implement
2770these calls will work. When in doubt, call them and see if they fail wth
2771C<ENOSYS>.
2772
2347=head2 MEMORY USAGE 2773=head2 MEMORY USAGE
2348 2774
2349Per-request usage: 2775Per-request usage:
2350 2776
2351Each aio request uses - depending on your architecture - around 100-200 2777Each aio request uses - depending on your architecture - around 100-200
2363temporary buffers, and each thread requires a stack and other data 2789temporary buffers, and each thread requires a stack and other data
2364structures (usually around 16k-128k, depending on the OS). 2790structures (usually around 16k-128k, depending on the OS).
2365 2791
2366=head1 KNOWN BUGS 2792=head1 KNOWN BUGS
2367 2793
2368Known bugs will be fixed in the next release. 2794Known bugs will be fixed in the next release :)
2795
2796=head1 KNOWN ISSUES
2797
2798Calls that try to "import" foreign memory areas (such as C<IO::AIO::mmap>
2799or C<IO::AIO::aio_slurp>) do not work with generic lvalues, such as
2800non-created hash slots or other scalars I didn't think of. It's best to
2801avoid such and either use scalar variables or making sure that the scalar
2802exists (e.g. by storing C<undef>) and isn't "funny" (e.g. tied).
2803
2804I am not sure anything can be done about this, so this is considered a
2805known issue, rather than a bug.
2369 2806
2370=head1 SEE ALSO 2807=head1 SEE ALSO
2371 2808
2372L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a 2809L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
2373more natural syntax. 2810more natural syntax and L<IO::FDPass> for file descriptor passing.
2374 2811
2375=head1 AUTHOR 2812=head1 AUTHOR
2376 2813
2377 Marc Lehmann <schmorp@schmorp.de> 2814 Marc Lehmann <schmorp@schmorp.de>
2378 http://home.schmorp.de/ 2815 http://home.schmorp.de/

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