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 1.276 by root, Fri Sep 22 05:24:41 2017 UTC vs.
Revision 1.315 by root, Mon Sep 5 00:03:32 2022 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 = 4.77;
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 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
290 $nfd = IO::AIO::get_fdlimit
282 IO::AIO::min_fdlimit $nfd; 291 IO::AIO::min_fdlimit $nfd
283 292
284 IO::AIO::sendfile $ofh, $ifh, $offset, $count 293 IO::AIO::sendfile $ofh, $ifh, $offset, $count
285 IO::AIO::fadvise $fh, $offset, $len, $advice 294 IO::AIO::fadvise $fh, $offset, $len, $advice
295 IO::AIO::fexecve $fh, $argv, $envp
296
286 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]] 297 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
287 IO::AIO::munmap $scalar 298 IO::AIO::munmap $scalar
299 IO::AIO::mremap $scalar, $new_length, $flags[, $new_address]
288 IO::AIO::madvise $scalar, $offset, $length, $advice 300 IO::AIO::madvise $scalar, $offset, $length, $advice
289 IO::AIO::mprotect $scalar, $offset, $length, $protect 301 IO::AIO::mprotect $scalar, $offset, $length, $protect
290 IO::AIO::munlock $scalar, $offset = 0, $length = undef 302 IO::AIO::munlock $scalar, $offset = 0, $length = undef
291 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]
292 331
293=head2 API NOTES 332=head2 API NOTES
294 333
295All the C<aio_*> calls are more or less thin wrappers around the syscall 334All the C<aio_*> calls are more or less thin wrappers around the syscall
296with the same name (sans C<aio_>). The arguments are similar or identical, 335with the same name (sans C<aio_>). The arguments are similar or identical,
402following POSIX and non-POSIX constants are available (missing ones on 441following POSIX and non-POSIX constants are available (missing ones on
403your system are, as usual, C<0>): 442your system are, as usual, C<0>):
404 443
405C<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>,
406C<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>,
407C<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>.
408 447
409 448
410=item aio_close $fh, $callback->($status) 449=item aio_close $fh, $callback->($status)
411 450
412Asynchronously close a file and call the callback with the result 451Asynchronously close a file and call the callback with the result
538 577
539=item aio_stat $fh_or_path, $callback->($status) 578=item aio_stat $fh_or_path, $callback->($status)
540 579
541=item aio_lstat $fh, $callback->($status) 580=item aio_lstat $fh, $callback->($status)
542 581
543Works 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
544be 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
545or C<-s _> etc... 584using C<stat _> or C<-s _> and other tests (with the exception of C<-B>
585and C<-T>).
546 586
547The pathname passed to C<aio_stat> must be absolute. See API NOTES, above, 587The pathname passed to C<aio_stat> must be absolute. See API NOTES, above,
548for an explanation. 588for an explanation.
549 589
550Currently, the stats are always 64-bit-stats, i.e. instead of returning an 590Currently, the stats are always 64-bit-stats, i.e. instead of returning an
557behaviour). 597behaviour).
558 598
559C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>, 599C<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>, 600C<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>. 601C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>.
602
603To access higher resolution stat timestamps, see L<SUBSECOND STAT TIME
604ACCESS>.
562 605
563Example: Print the length of F</etc/passwd>: 606Example: Print the length of F</etc/passwd>:
564 607
565 aio_stat "/etc/passwd", sub { 608 aio_stat "/etc/passwd", sub {
566 $_[0] and die "stat failed: $!"; 609 $_[0] and die "stat failed: $!";
610 namemax => 255, 653 namemax => 255,
611 frsize => 1024, 654 frsize => 1024,
612 fsid => 1810 655 fsid => 1810
613 } 656 }
614 657
615Here is a (likely partial - send me updates!) list of fsid values used by
616Linux - it is safe to hardcode these when C<$^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) 658=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
701 659
702Works like perl's C<utime> function (including the special case of $atime 660Works like perl's C<utime> function (including the special case of $atime
703and $mtime being undef). Fractional times are supported if the underlying 661and $mtime being undef). Fractional times are supported if the underlying
704syscalls support them. 662syscalls support them.
705 663
706When called with a pathname, uses utimes(2) if available, otherwise 664When called with a pathname, uses utimensat(2) or utimes(2) if available,
707utime(2). If called on a file descriptor, uses futimes(2) if available, 665otherwise utime(2). If called on a file descriptor, uses futimens(2)
708otherwise returns ENOSYS, so this is not portable. 666or futimes(2) if available, otherwise returns ENOSYS, so this is not
667portable.
709 668
710Examples: 669Examples:
711 670
712 # set atime and mtime to current time (basically touch(1)): 671 # set atime and mtime to current time (basically touch(1)):
713 aio_utime "path", undef, undef; 672 aio_utime "path", undef, undef;
872 831
873=over 4 832=over 4
874 833
875=item IO::AIO::READDIR_DENTS 834=item IO::AIO::READDIR_DENTS
876 835
877When this flag is off, then the callback gets an arrayref consisting of 836Normally the callback gets an arrayref consisting of names only (as
878names only (as with C<aio_readdir>), otherwise it gets an arrayref with 837with C<aio_readdir>). If this flag is set, then the callback gets an
879C<[$name, $type, $inode]> arrayrefs, each describing a single directory 838arrayref with C<[$name, $type, $inode]> arrayrefs, each describing a
880entry in more detail. 839single directory entry in more detail:
881 840
882C<$name> is the name of the entry. 841C<$name> is the name of the entry.
883 842
884C<$type> is one of the C<IO::AIO::DT_xxx> constants: 843C<$type> is one of the C<IO::AIO::DT_xxx> constants:
885 844
886C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>, 845C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
887C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>, 846C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
888C<IO::AIO::DT_WHT>. 847C<IO::AIO::DT_WHT>.
889 848
890C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to 849C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need
891know, you have to run stat yourself. Also, for speed reasons, the C<$type> 850to know, you have to run stat yourself. Also, for speed/memory reasons,
892scalars are read-only: you can not modify them. 851the C<$type> scalars are read-only: you must not modify them.
893 852
894C<$inode> is the inode number (which might not be exact on systems with 64 853C<$inode> is the inode number (which might not be exact on systems with 64
895bit inode numbers and 32 bit perls). This field has unspecified content on 854bit inode numbers and 32 bit perls). This field has unspecified content on
896systems that do not deliver the inode information. 855systems that do not deliver the inode information.
897 856
908short names are tried first. 867short names are tried first.
909 868
910=item IO::AIO::READDIR_STAT_ORDER 869=item IO::AIO::READDIR_STAT_ORDER
911 870
912When this flag is set, then the names will be returned in an order 871When this flag is set, then the names will be returned in an order
913suitable for stat()'ing each one. That is, when you plan to stat() 872suitable for stat()'ing each one. That is, when you plan to stat() most or
914all files in the given directory, then the returned order will likely 873all files in the given directory, then the returned order will likely be
915be fastest. 874faster.
916 875
917If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then 876If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified,
918the likely dirs come first, resulting in a less optimal stat order. 877then the likely dirs come first, resulting in a less optimal stat order
878for stat'ing all entries, but likely a more optimal order for finding
879subdirectories.
919 880
920=item IO::AIO::READDIR_FOUND_UNKNOWN 881=item IO::AIO::READDIR_FOUND_UNKNOWN
921 882
922This flag should not be set when calling C<aio_readdirx>. Instead, it 883This flag should not be set when calling C<aio_readdirx>. Instead, it
923is being set by C<aio_readdirx>, when any of the C<$type>'s found were 884is 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. 886C<$type>'s are known, which can be used to speed up some algorithms.
926 887
927=back 888=back
928 889
929 890
891=item aio_slurp $pathname, $offset, $length, $data, $callback->($status)
892
893Opens, reads and closes the given file. The data is put into C<$data>,
894which is resized as required.
895
896If C<$offset> is negative, then it is counted from the end of the file.
897
898If C<$length> is zero, then the remaining length of the file is
899used. Also, in this case, the same limitations to modifying C<$data> apply
900as when IO::AIO::mmap is used, i.e. it must only be modified in-place
901with C<substr>. If the size of the file is known, specifying a non-zero
902C<$length> results in a performance advantage.
903
904This request is similar to the older C<aio_load> request, but since it is
905a single request, it might be more efficient to use.
906
907Example: load F</etc/passwd> into C<$passwd>.
908
909 my $passwd;
910 aio_slurp "/etc/passwd", 0, 0, $passwd, sub {
911 $_[0] >= 0
912 or die "/etc/passwd: $!\n";
913
914 printf "/etc/passwd is %d bytes long, and contains:\n", length $passwd;
915 print $passwd;
916 };
917 IO::AIO::flush;
918
919
930=item aio_load $pathname, $data, $callback->($status) 920=item aio_load $pathname, $data, $callback->($status)
931 921
932This is a composite request that tries to fully load the given file into 922This is a composite request that tries to fully load the given file into
933memory. Status is the same as with aio_read. 923memory. Status is the same as with aio_read.
924
925Using C<aio_slurp> might be more efficient, as it is a single request.
934 926
935=cut 927=cut
936 928
937sub aio_load($$;$) { 929sub aio_load($$;$) {
938 my ($path, undef, $cb) = @_; 930 my ($path, undef, $cb) = @_;
1079Scans a directory (similar to C<aio_readdir>) but additionally tries to 1071Scans a directory (similar to C<aio_readdir>) but additionally tries to
1080efficiently separate the entries of directory C<$path> into two sets of 1072efficiently separate the entries of directory C<$path> into two sets of
1081names, directories you can recurse into (directories), and ones you cannot 1073names, directories you can recurse into (directories), and ones you cannot
1082recurse into (everything else, including symlinks to directories). 1074recurse into (everything else, including symlinks to directories).
1083 1075
1084C<aio_scandir> is a composite request that creates of many sub requests_ 1076C<aio_scandir> is a composite request that generates many sub requests.
1085C<$maxreq> specifies the maximum number of outstanding aio requests that 1077C<$maxreq> specifies the maximum number of outstanding aio requests that
1086this function generates. If it is C<< <= 0 >>, then a suitable default 1078this function generates. If it is C<< <= 0 >>, then a suitable default
1087will be chosen (currently 4). 1079will be chosen (currently 4).
1088 1080
1089On error, the callback is called without arguments, otherwise it receives 1081On error, the callback is called without arguments, otherwise it receives
1153 aioreq_pri $pri; 1145 aioreq_pri $pri;
1154 add $grp aio_stat $wd, sub { 1146 add $grp aio_stat $wd, sub {
1155 return $grp->result () if $_[0]; 1147 return $grp->result () if $_[0];
1156 my $now = time; 1148 my $now = time;
1157 my $hash1 = join ":", (stat _)[0,1,3,7,9]; 1149 my $hash1 = join ":", (stat _)[0,1,3,7,9];
1150 my $rdxflags = READDIR_DIRS_FIRST;
1151
1152 if ((stat _)[3] < 2) {
1153 # at least one non-POSIX filesystem exists
1154 # that returns useful DT_type values: btrfs,
1155 # so optimise for this here by requesting dents
1156 $rdxflags |= READDIR_DENTS;
1157 }
1158 1158
1159 # read the directory entries 1159 # read the directory entries
1160 aioreq_pri $pri; 1160 aioreq_pri $pri;
1161 add $grp aio_readdirx $wd, READDIR_DIRS_FIRST, sub { 1161 add $grp aio_readdirx $wd, $rdxflags, sub {
1162 my $entries = shift 1162 my ($entries, $flags) = @_
1163 or return $grp->result (); 1163 or return $grp->result ();
1164
1165 if ($rdxflags & READDIR_DENTS) {
1166 # if we requested type values, see if we can use them directly.
1167
1168 # if there were any DT_UNKNOWN entries then we assume we
1169 # don't know. alternatively, we could assume that if we get
1170 # one DT_DIR, then all directories are indeed marked with
1171 # DT_DIR, but this seems not required for btrfs, and this
1172 # is basically the "btrfs can't get it's act together" code
1173 # branch.
1174 unless ($flags & READDIR_FOUND_UNKNOWN) {
1175 # now we have valid DT_ information for all entries,
1176 # so use it as an optimisation without further stat's.
1177 # they must also all be at the beginning of @$entries
1178 # by now.
1179
1180 my $dirs;
1181
1182 if (@$entries) {
1183 for (0 .. $#$entries) {
1184 if ($entries->[$_][1] != DT_DIR) {
1185 # splice out directories
1186 $dirs = [splice @$entries, 0, $_];
1187 last;
1188 }
1189 }
1190
1191 # if we didn't find any non-dir, then all entries are dirs
1192 unless ($dirs) {
1193 ($dirs, $entries) = ($entries, []);
1194 }
1195 } else {
1196 # directory is empty, so there are no sbdirs
1197 $dirs = [];
1198 }
1199
1200 # either splice'd the directories out or the dir was empty.
1201 # convert dents to filenames
1202 $_ = $_->[0] for @$dirs;
1203 $_ = $_->[0] for @$entries;
1204
1205 return $grp->result ($dirs, $entries);
1206 }
1207
1208 # cannot use, so return to our old ways
1209 # by pretending we only scanned for names.
1210 $_ = $_->[0] for @$entries;
1211 }
1164 1212
1165 # stat the dir another time 1213 # stat the dir another time
1166 aioreq_pri $pri; 1214 aioreq_pri $pri;
1167 add $grp aio_stat $wd, sub { 1215 add $grp aio_stat $wd, sub {
1168 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 1216 my $hash2 = join ":", (stat _)[0,1,3,7,9];
1274So in general, you should only use these calls for things that do 1322So in general, you should only use these calls for things that do
1275(filesystem) I/O, not for things that wait for other events (network, 1323(filesystem) I/O, not for things that wait for other events (network,
1276other processes), although if you are careful and know what you are doing, 1324other processes), although if you are careful and know what you are doing,
1277you still can. 1325you still can.
1278 1326
1279The following constants are available (missing ones are, as usual C<0>): 1327The following constants are available and can be used for normal C<ioctl>
1328and C<fcntl> as well (missing ones are, as usual C<0>):
1280 1329
1281C<F_DUPFD_CLOEXEC>, 1330C<F_DUPFD_CLOEXEC>,
1282 1331
1283C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>, 1332C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>,
1284 1333
1285C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>. 1334C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>.
1335
1336C<F_ADD_SEALS>, C<F_GET_SEALS>, C<F_SEAL_SEAL>, C<F_SEAL_SHRINK>, C<F_SEAL_GROW> and
1337C<F_SEAL_WRITE>.
1286 1338
1287C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>, 1339C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>,
1288C<FS_IOC_FIEMAP>. 1340C<FS_IOC_FIEMAP>.
1289 1341
1290C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>, 1342C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>,
1429 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh; 1481 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
1430 aio_mlock $data; # mlock in background 1482 aio_mlock $data; # mlock in background
1431 1483
1432=item aio_mlockall $flags, $callback->($status) 1484=item aio_mlockall $flags, $callback->($status)
1433 1485
1434Calls the C<mlockall> function with the given C<$flags> (a combination of 1486Calls the C<mlockall> function with the given C<$flags> (a
1435C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>). 1487combination of C<IO::AIO::MCL_CURRENT>, C<IO::AIO::MCL_FUTURE> and
1488C<IO::AIO::MCL_ONFAULT>).
1436 1489
1437On systems that do not implement C<mlockall>, this function returns C<-1> 1490On systems that do not implement C<mlockall>, this function returns C<-1>
1438and sets errno to C<ENOSYS>. 1491and sets errno to C<ENOSYS>. Similarly, flag combinations not supported
1492by the system result in a return value of C<-1> with errno being set to
1493C<EINVAL>.
1439 1494
1440Note that the corresponding C<munlockall> is synchronous and is 1495Note that the corresponding C<munlockall> is synchronous and is
1441documented under L<MISCELLANEOUS FUNCTIONS>. 1496documented under L<MISCELLANEOUS FUNCTIONS>.
1442 1497
1443Example: asynchronously lock all current and future pages into memory. 1498Example: asynchronously lock all current and future pages into memory.
1482C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>, 1537C<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>, 1538C<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 1539C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
1485C<IO::AIO::FIEMAP_EXTENT_SHARED>. 1540C<IO::AIO::FIEMAP_EXTENT_SHARED>.
1486 1541
1487At the time of this writing (Linux 3.2), this requets is unreliable unless 1542At the time of this writing (Linux 3.2), this request is unreliable unless
1488C<$count> is C<undef>, as the kernel has all sorts of bugs preventing 1543C<$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 1544it to return all extents of a range for files with a large number of
1490extents. The code works around all these issues if C<$count> is undef. 1545extents. The code (only) works around all these issues if C<$count> is
1546C<undef>.
1491 1547
1492=item aio_group $callback->(...) 1548=item aio_group $callback->(...)
1493 1549
1494This is a very special aio request: Instead of doing something, it is a 1550This 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 1551container for other aio requests, which is useful if you want to bundle
1608There are some caveats: when directories get renamed (or deleted), the 1664There are some caveats: when directories get renamed (or deleted), the
1609pathname string doesn't change, so will point to the new directory (or 1665pathname string doesn't change, so will point to the new directory (or
1610nowhere at all), while the directory fd, if available on the system, 1666nowhere at all), while the directory fd, if available on the system,
1611will still point to the original directory. Most functions accepting a 1667will still point to the original directory. Most functions accepting a
1612pathname will use the directory fd on newer systems, and the string on 1668pathname will use the directory fd on newer systems, and the string on
1613older systems. Some functions (such as realpath) will always rely on the 1669older systems. Some functions (such as C<aio_realpath>) will always rely on
1614string form of the pathname. 1670the string form of the pathname.
1615 1671
1616So this functionality is mainly useful to get some protection against 1672So 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 1673C<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 1674reference, and to speed up doing many operations in the same directory
1619(e.g. when stat'ing all files in a directory). 1675(e.g. when stat'ing all files in a directory).
1636C<aio_wd> callback, as future requests using the value will fail in the 1692C<aio_wd> callback, as future requests using the value will fail in the
1637expected way. 1693expected way.
1638 1694
1639=item IO::AIO::CWD 1695=item IO::AIO::CWD
1640 1696
1641This is a compiletime constant (object) that represents the process 1697This is a compile time constant (object) that represents the process
1642current working directory. 1698current working directory.
1643 1699
1644Specifying this object as working directory object for a pathname is as if 1700Specifying this object as working directory object for a pathname is as if
1645the pathname would be specified directly, without a directory object. For 1701the pathname would be specified directly, without a directory object. For
1646example, these calls are functionally identical: 1702example, these calls are functionally identical:
1827The default value for the limit is C<0>, but note that setting a feeder 1883The default value for the limit is C<0>, but note that setting a feeder
1828automatically bumps it up to C<2>. 1884automatically bumps it up to C<2>.
1829 1885
1830=back 1886=back
1831 1887
1888
1832=head2 SUPPORT FUNCTIONS 1889=head2 SUPPORT FUNCTIONS
1833 1890
1834=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1891=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
1835 1892
1836=over 4 1893=over 4
1901Strictly equivalent to: 1958Strictly equivalent to:
1902 1959
1903 IO::AIO::poll_wait, IO::AIO::poll_cb 1960 IO::AIO::poll_wait, IO::AIO::poll_cb
1904 while IO::AIO::nreqs; 1961 while IO::AIO::nreqs;
1905 1962
1963This function can be useful at program aborts, to make sure outstanding
1964I/O has been done (C<IO::AIO> uses an C<END> block which already calls
1965this function on normal exits), or when you are merely using C<IO::AIO>
1966for its more advanced functions, rather than for async I/O, e.g.:
1967
1968 my ($dirs, $nondirs);
1969 IO::AIO::aio_scandir "/tmp", 0, sub { ($dirs, $nondirs) = @_ };
1970 IO::AIO::flush;
1971 # $dirs, $nondirs are now set
1972
1906=item IO::AIO::max_poll_reqs $nreqs 1973=item IO::AIO::max_poll_reqs $nreqs
1907 1974
1908=item IO::AIO::max_poll_time $seconds 1975=item IO::AIO::max_poll_time $seconds
1909 1976
1910These set the maximum number of requests (default C<0>, meaning infinity) 1977These set the maximum number of requests (default C<0>, meaning infinity)
1936 poll => 'r', nice => 1, 2003 poll => 'r', nice => 1,
1937 cb => &IO::AIO::poll_cb); 2004 cb => &IO::AIO::poll_cb);
1938 2005
1939=back 2006=back
1940 2007
2008
1941=head3 CONTROLLING THE NUMBER OF THREADS 2009=head3 CONTROLLING THE NUMBER OF THREADS
1942 2010
1943=over 2011=over
1944 2012
1945=item IO::AIO::min_parallel $nthreads 2013=item IO::AIO::min_parallel $nthreads
2006longer exceeded. 2074longer exceeded.
2007 2075
2008In other words, this setting does not enforce a queue limit, but can be 2076In other words, this setting does not enforce a queue limit, but can be
2009used to make poll functions block if the limit is exceeded. 2077used to make poll functions block if the limit is exceeded.
2010 2078
2011This is a very bad function to use in interactive programs because it 2079This is a bad function to use in interactive programs because it blocks,
2012blocks, and a bad way to reduce concurrency because it is inexact: Better 2080and a bad way to reduce concurrency because it is inexact. If you need to
2081issue many requests without being able to call a poll function on demand,
2013use an C<aio_group> together with a feed callback. 2082it is better to use an C<aio_group> together with a feed callback.
2014 2083
2015Its main use is in scripts without an event loop - when you want to stat 2084Its main use is in scripts without an event loop - when you want to stat a
2016a lot of files, you can write something like this: 2085lot of files, you can write something like this:
2017 2086
2018 IO::AIO::max_outstanding 32; 2087 IO::AIO::max_outstanding 32;
2019 2088
2020 for my $path (...) { 2089 for my $path (...) {
2021 aio_stat $path , ...; 2090 aio_stat $path , ...;
2022 IO::AIO::poll_cb; 2091 IO::AIO::poll_cb;
2023 } 2092 }
2024 2093
2025 IO::AIO::flush; 2094 IO::AIO::flush;
2026 2095
2027The call to C<poll_cb> inside the loop will normally return instantly, but 2096The call to C<poll_cb> inside the loop will normally return instantly,
2028as soon as more thna C<32> reqeusts are in-flight, it will block until 2097allowing the loop to progress, but as soon as more than C<32> requests
2029some requests have been handled. This keeps the loop from pushing a large 2098are in-flight, it will block until some requests have been handled. This
2030number of C<aio_stat> requests onto the queue. 2099keeps the loop from pushing a large number of C<aio_stat> requests onto
2100the queue (which, with many paths to stat, can use up a lot of memory).
2031 2101
2032The default value for C<max_outstanding> is very large, so there is no 2102The default value for C<max_outstanding> is very large, so there is no
2033practical limit on the number of outstanding requests. 2103practical limit on the number of outstanding requests.
2034 2104
2035=back 2105=back
2036 2106
2107
2037=head3 STATISTICAL INFORMATION 2108=head3 STATISTICAL INFORMATION
2038 2109
2039=over 2110=over
2040 2111
2041=item IO::AIO::nreqs 2112=item IO::AIO::nreqs
2057 2128
2058Returns the number of requests currently in the pending state (executed, 2129Returns the number of requests currently in the pending state (executed,
2059but not yet processed by poll_cb). 2130but not yet processed by poll_cb).
2060 2131
2061=back 2132=back
2133
2134
2135=head3 SUBSECOND STAT TIME ACCESS
2136
2137Both C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> functions can
2138generally find access/modification and change times with subsecond time
2139accuracy of the system supports it, but perl's built-in functions only
2140return the integer part.
2141
2142The following functions return the timestamps of the most recent
2143stat with subsecond precision on most systems and work both after
2144C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> calls. Their return
2145value is only meaningful after a successful C<stat>/C<lstat> call, or
2146during/after a successful C<aio_stat>/C<aio_lstat> callback.
2147
2148This is similar to the L<Time::HiRes> C<stat> functions, but can return
2149full resolution without rounding and work with standard perl C<stat>,
2150alleviating the need to call the special C<Time::HiRes> functions, which
2151do not act like their perl counterparts.
2152
2153On operating systems or file systems where subsecond time resolution is
2154not supported or could not be detected, a fractional part of C<0> is
2155returned, so it is always safe to call these functions.
2156
2157=over 4
2158
2159=item $seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime, IO::AIO::st_btime
2160
2161Return the access, modication, change or birth time, respectively,
2162including fractional part. Due to the limited precision of floating point,
2163the accuracy on most platforms is only a bit better than milliseconds
2164for times around now - see the I<nsec> function family, below, for full
2165accuracy.
2166
2167File birth time is only available when the OS and perl support it (on
2168FreeBSD and NetBSD at the time of this writing, although support is
2169adaptive, so if your OS/perl gains support, IO::AIO can take advantage of
2170it). On systems where it isn't available, C<0> is currently returned, but
2171this might change to C<undef> in a future version.
2172
2173=item ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtime
2174
2175Returns access, modification, change and birth time all in one go, and
2176maybe more times in the future version.
2177
2178=item $nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec, IO::AIO::st_ctimensec, IO::AIO::st_btimensec
2179
2180Return the fractional access, modifcation, change or birth time, in nanoseconds,
2181as an integer in the range C<0> to C<999999999>.
2182
2183Note that no accessors are provided for access, modification and
2184change times - you need to get those from C<stat _> if required (C<int
2185IO::AIO::st_atime> and so on will I<not> generally give you the correct
2186value).
2187
2188=item $seconds = IO::AIO::st_btimesec
2189
2190The (integral) seconds part of the file birth time, if available.
2191
2192=item ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtimensec
2193
2194Like the functions above, but returns all four times in one go (and maybe
2195more in future versions).
2196
2197=item $counter = IO::AIO::st_gen
2198
2199Returns the generation counter (in practice this is just a random number)
2200of the file. This is only available on platforms which have this member in
2201their C<struct stat> (most BSDs at the time of this writing) and generally
2202only to the root usert. If unsupported, C<0> is returned, but this might
2203change to C<undef> in a future version.
2204
2205=back
2206
2207Example: print the high resolution modification time of F</etc>, using
2208C<stat>, and C<IO::AIO::aio_stat>.
2209
2210 if (stat "/etc") {
2211 printf "stat(/etc) mtime: %f\n", IO::AIO::st_mtime;
2212 }
2213
2214 IO::AIO::aio_stat "/etc", sub {
2215 $_[0]
2216 and return;
2217
2218 printf "aio_stat(/etc) mtime: %d.%09d\n", (stat _)[9], IO::AIO::st_mtimensec;
2219 };
2220
2221 IO::AIO::flush;
2222
2223Output of the awbove on my system, showing reduced and full accuracy:
2224
2225 stat(/etc) mtime: 1534043702.020808
2226 aio_stat(/etc) mtime: 1534043702.020807792
2227
2062 2228
2063=head3 MISCELLANEOUS FUNCTIONS 2229=head3 MISCELLANEOUS FUNCTIONS
2064 2230
2065IO::AIO implements some functions that are useful when you want to use 2231IO::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 2232some "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_*> 2233"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*>
2068counterpart. 2234counterpart.
2069 2235
2070=over 4 2236=over 4
2237
2238=item $retval = IO::AIO::fexecve $fh, $argv, $envp
2239
2240A more-or-less direct equivalent to the POSIX C<fexecve> functions, which
2241allows you to specify the program to be executed via a file descriptor (or
2242handle). Returns C<-1> and sets errno to C<ENOSYS> if not available.
2071 2243
2072=item $numfd = IO::AIO::get_fdlimit 2244=item $numfd = IO::AIO::get_fdlimit
2073 2245
2074Tries to find the current file descriptor limit and returns it, or 2246Tries to find the current file descriptor limit and returns it, or
2075C<undef> and sets C<$!> in case of an error. The limit is one larger than 2247C<undef> and sets C<$!> in case of an error. The limit is one larger than
2178C<IO::AIO::MAP_POPULATE>, 2350C<IO::AIO::MAP_POPULATE>,
2179C<IO::AIO::MAP_NONBLOCK>, 2351C<IO::AIO::MAP_NONBLOCK>,
2180C<IO::AIO::MAP_FIXED>, 2352C<IO::AIO::MAP_FIXED>,
2181C<IO::AIO::MAP_GROWSDOWN>, 2353C<IO::AIO::MAP_GROWSDOWN>,
2182C<IO::AIO::MAP_32BIT>, 2354C<IO::AIO::MAP_32BIT>,
2183C<IO::AIO::MAP_HUGETLB> or 2355C<IO::AIO::MAP_HUGETLB>,
2184C<IO::AIO::MAP_STACK>. 2356C<IO::AIO::MAP_STACK>,
2357C<IO::AIO::MAP_FIXED_NOREPLACE>,
2358C<IO::AIO::MAP_SHARED_VALIDATE>,
2359C<IO::AIO::MAP_SYNC> or
2360C<IO::AIO::MAP_UNINITIALIZED>.
2185 2361
2186If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed. 2362If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
2187 2363
2188C<$offset> is the offset from the start of the file - it generally must be 2364C<$offset> is the offset from the start of the file - it generally must be
2189a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>. 2365a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
2203 2379
2204=item IO::AIO::munmap $scalar 2380=item IO::AIO::munmap $scalar
2205 2381
2206Removes a previous mmap and undefines the C<$scalar>. 2382Removes a previous mmap and undefines the C<$scalar>.
2207 2383
2384=item IO::AIO::mremap $scalar, $new_length, $flags = MREMAP_MAYMOVE[, $new_address = 0]
2385
2386Calls the Linux-specific mremap(2) system call. The C<$scalar> must have
2387been mapped by C<IO::AIO::mmap>, and C<$flags> must currently either be
2388C<0> or C<IO::AIO::MREMAP_MAYMOVE>.
2389
2390Returns true if successful, and false otherwise. If the underlying mmapped
2391region has changed address, then the true value has the numerical value
2392C<1>, otherwise it has the numerical value C<0>:
2393
2394 my $success = IO::AIO::mremap $mmapped, 8192, IO::AIO::MREMAP_MAYMOVE
2395 or die "mremap: $!";
2396
2397 if ($success*1) {
2398 warn "scalar has chanegd address in memory\n";
2399 }
2400
2401C<IO::AIO::MREMAP_FIXED> and the C<$new_address> argument are currently
2402implemented, but not supported and might go away in a future version.
2403
2404On systems where this call is not supported or is not emulated, this call
2405returns falls and sets C<$!> to C<ENOSYS>.
2406
2407=item IO::AIO::mlockall $flags
2408
2409Calls the C<eio_mlockall_sync> function, which is like C<aio_mlockall>,
2410but is blocking.
2411
2208=item IO::AIO::munlock $scalar, $offset = 0, $length = undef 2412=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
2209 2413
2210Calls the C<munlock> function, undoing the effects of a previous 2414Calls the C<munlock> function, undoing the effects of a previous
2211C<aio_mlock> call (see its description for details). 2415C<aio_mlock> call (see its description for details).
2212 2416
2214 2418
2215Calls the C<munlockall> function. 2419Calls the C<munlockall> function.
2216 2420
2217On systems that do not implement C<munlockall>, this function returns 2421On systems that do not implement C<munlockall>, this function returns
2218ENOSYS, otherwise the return value of C<munlockall>. 2422ENOSYS, otherwise the return value of C<munlockall>.
2423
2424=item $fh = IO::AIO::accept4 $r_fh, $sockaddr, $sockaddr_maxlen, $flags
2425
2426Uses the GNU/Linux C<accept4(2)> syscall, if available, to accept a socket
2427and return the new file handle on success, or sets C<$!> and returns
2428C<undef> on error.
2429
2430The remote name of the new socket will be stored in C<$sockaddr>, which
2431will be extended to allow for at least C<$sockaddr_maxlen> octets. If the
2432socket name does not fit into C<$sockaddr_maxlen> octets, this is signaled
2433by returning a longer string in C<$sockaddr>, which might or might not be
2434truncated.
2435
2436To accept name-less sockets, use C<undef> for C<$sockaddr> and C<0> for
2437C<$sockaddr_maxlen>.
2438
2439The main reasons to use this syscall rather than portable C<accept(2)>
2440are that you can specify C<SOCK_NONBLOCK> and/or C<SOCK_CLOEXEC>
2441flags and you can accept name-less sockets by specifying C<0> for
2442C<$sockaddr_maxlen>, which is sadly not possible with perl's interface to
2443C<accept>.
2219 2444
2220=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags 2445=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
2221 2446
2222Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or 2447Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or
2223C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they 2448C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
2261C<$flags> is non-zero, fails with C<ENOSYS>. 2486C<$flags> is non-zero, fails with C<ENOSYS>.
2262 2487
2263Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the 2488Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the
2264time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and 2489time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and
2265C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported. 2490C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported.
2491
2492Example: create a pipe race-free w.r.t. threads and fork:
2493
2494 my ($rfh, $wfh) = IO::AIO::pipe2 IO::AIO::O_CLOEXEC
2495 or die "pipe2: $!\n";
2496
2497=item $fh = IO::AIO::memfd_create $pathname[, $flags]
2498
2499This is a direct interface to the Linux L<memfd_create(2)> system
2500call. The (unhelpful) default for C<$flags> is C<0>, but your default
2501should be C<IO::AIO::MFD_CLOEXEC>.
2502
2503On success, the new memfd filehandle is returned, otherwise returns
2504C<undef>. If the memfd_create syscall is missing, fails with C<ENOSYS>.
2505
2506Please refer to L<memfd_create(2)> for more info on this call.
2507
2508The following C<$flags> values are available: C<IO::AIO::MFD_CLOEXEC>,
2509C<IO::AIO::MFD_ALLOW_SEALING>, C<IO::AIO::MFD_HUGETLB>,
2510C<IO::AIO::MFD_HUGETLB_2MB> and C<IO::AIO::MFD_HUGETLB_1GB>.
2511
2512Example: create a new memfd.
2513
2514 my $fh = IO::AIO::memfd_create "somenameforprocfd", IO::AIO::MFD_CLOEXEC
2515 or die "memfd_create: $!\n";
2516
2517=item $fh = IO::AIO::pidfd_open $pid[, $flags]
2518
2519This is an interface to the Linux L<pidfd_open(2)> system call. The
2520default for C<$flags> is C<0>.
2521
2522On success, a new pidfd filehandle is returned (that is already set to
2523close-on-exec), otherwise returns C<undef>. If the syscall is missing,
2524fails with C<ENOSYS>.
2525
2526Example: open pid 6341 as pidfd.
2527
2528 my $fh = IO::AIO::pidfd_open 6341
2529 or die "pidfd_open: $!\n";
2530
2531=item $status = IO::AIO::pidfd_send_signal $pidfh, $signal[, $siginfo[, $flags]]
2532
2533This is an interface to the Linux L<pidfd_send_signal> system call. The
2534default for C<$siginfo> is C<undef> and the default for C<$flags> is C<0>.
2535
2536Returns the system call status. If the syscall is missing, fails with
2537C<ENOSYS>.
2538
2539When specified, C<$siginfo> must be a reference to a hash with one or more
2540of the following members:
2541
2542=over
2543
2544=item code - the C<si_code> member
2545
2546=item pid - the C<si_pid> member
2547
2548=item uid - the C<si_uid> member
2549
2550=item value_int - the C<si_value.sival_int> member
2551
2552=item value_ptr - the C<si_value.sival_ptr> member, specified as an integer
2553
2554=back
2555
2556Example: send a SIGKILL to the specified process.
2557
2558 my $status = IO::AIO::pidfd_send_signal $pidfh, 9, undef
2559 and die "pidfd_send_signal: $!\n";
2560
2561Example: send a SIGKILL to the specified process with extra data.
2562
2563 my $status = IO::AIO::pidfd_send_signal $pidfh, 9, { code => -1, value_int => 7 }
2564 and die "pidfd_send_signal: $!\n";
2565
2566=item $fh = IO::AIO::pidfd_getfd $pidfh, $targetfd[, $flags]
2567
2568This is an interface to the Linux L<pidfd_getfd> system call. The default
2569for C<$flags> is C<0>.
2570
2571On success, returns a dup'ed copy of the target file descriptor (specified
2572as an integer) returned (that is already set to close-on-exec), otherwise
2573returns C<undef>. If the syscall is missing, fails with C<ENOSYS>.
2574
2575Example: get a copy of standard error of another process and print soemthing to it.
2576
2577 my $errfh = IO::AIO::pidfd_getfd $pidfh, 2
2578 or die "pidfd_getfd: $!\n";
2579 print $errfh "stderr\n";
2580
2581=item $fh = IO::AIO::eventfd [$initval, [$flags]]
2582
2583This is a direct interface to the Linux L<eventfd(2)> system call. The
2584(unhelpful) defaults for C<$initval> and C<$flags> are C<0> for both.
2585
2586On success, the new eventfd filehandle is returned, otherwise returns
2587C<undef>. If the eventfd syscall is missing, fails with C<ENOSYS>.
2588
2589Please refer to L<eventfd(2)> for more info on this call.
2590
2591The following symbol flag values are available: C<IO::AIO::EFD_CLOEXEC>,
2592C<IO::AIO::EFD_NONBLOCK> and C<IO::AIO::EFD_SEMAPHORE> (Linux 2.6.30).
2593
2594Example: create a new eventfd filehandle:
2595
2596 $fh = IO::AIO::eventfd 0, IO::AIO::EFD_CLOEXEC
2597 or die "eventfd: $!\n";
2598
2599=item $fh = IO::AIO::timerfd_create $clockid[, $flags]
2600
2601This is a direct interface to the Linux L<timerfd_create(2)> system
2602call. The (unhelpful) default for C<$flags> is C<0>, but your default
2603should be C<IO::AIO::TFD_CLOEXEC>.
2604
2605On success, the new timerfd filehandle is returned, otherwise returns
2606C<undef>. If the timerfd_create syscall is missing, fails with C<ENOSYS>.
2607
2608Please refer to L<timerfd_create(2)> for more info on this call.
2609
2610The following C<$clockid> values are
2611available: C<IO::AIO::CLOCK_REALTIME>, C<IO::AIO::CLOCK_MONOTONIC>
2612C<IO::AIO::CLOCK_CLOCK_BOOTTIME> (Linux 3.15)
2613C<IO::AIO::CLOCK_CLOCK_REALTIME_ALARM> (Linux 3.11) and
2614C<IO::AIO::CLOCK_CLOCK_BOOTTIME_ALARM> (Linux 3.11).
2615
2616The following C<$flags> values are available (Linux
26172.6.27): C<IO::AIO::TFD_NONBLOCK> and C<IO::AIO::TFD_CLOEXEC>.
2618
2619Example: create a new timerfd and set it to one-second repeated alarms,
2620then wait for two alarms:
2621
2622 my $fh = IO::AIO::timerfd_create IO::AIO::CLOCK_BOOTTIME, IO::AIO::TFD_CLOEXEC
2623 or die "timerfd_create: $!\n";
2624
2625 defined IO::AIO::timerfd_settime $fh, 0, 1, 1
2626 or die "timerfd_settime: $!\n";
2627
2628 for (1..2) {
2629 8 == sysread $fh, my $buf, 8
2630 or die "timerfd read failure\n";
2631
2632 printf "number of expirations (likely 1): %d\n",
2633 unpack "Q", $buf;
2634 }
2635
2636=item ($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags, $new_interval, $nbw_value
2637
2638This is a direct interface to the Linux L<timerfd_settime(2)> system
2639call. Please refer to its manpage for more info on this call.
2640
2641The new itimerspec is specified using two (possibly fractional) second
2642values, C<$new_interval> and C<$new_value>).
2643
2644On success, the current interval and value are returned (as per
2645C<timerfd_gettime>). On failure, the empty list is returned.
2646
2647The following C<$flags> values are
2648available: C<IO::AIO::TFD_TIMER_ABSTIME> and
2649C<IO::AIO::TFD_TIMER_CANCEL_ON_SET>.
2650
2651See C<IO::AIO::timerfd_create> for a full example.
2652
2653=item ($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh
2654
2655This is a direct interface to the Linux L<timerfd_gettime(2)> system
2656call. Please refer to its manpage for more info on this call.
2657
2658On success, returns the current values of interval and value for the given
2659timerfd (as potentially fractional second values). On failure, the empty
2660list is returned.
2266 2661
2267=back 2662=back
2268 2663
2269=cut 2664=cut
2270 2665
2336the process will result in undefined behaviour. Calling it at any time 2731the process will result in undefined behaviour. Calling it at any time
2337will also result in any undefined (by POSIX) behaviour. 2732will also result in any undefined (by POSIX) behaviour.
2338 2733
2339=back 2734=back
2340 2735
2736=head2 LINUX-SPECIFIC CALLS
2737
2738When a call is documented as "linux-specific" then this means it
2739originated on GNU/Linux. C<IO::AIO> will usually try to autodetect the
2740availability and compatibility of such calls regardless of the platform
2741it is compiled on, so platforms such as FreeBSD which often implement
2742these calls will work. When in doubt, call them and see if they fail wth
2743C<ENOSYS>.
2744
2341=head2 MEMORY USAGE 2745=head2 MEMORY USAGE
2342 2746
2343Per-request usage: 2747Per-request usage:
2344 2748
2345Each aio request uses - depending on your architecture - around 100-200 2749Each aio request uses - depending on your architecture - around 100-200
2357temporary buffers, and each thread requires a stack and other data 2761temporary buffers, and each thread requires a stack and other data
2358structures (usually around 16k-128k, depending on the OS). 2762structures (usually around 16k-128k, depending on the OS).
2359 2763
2360=head1 KNOWN BUGS 2764=head1 KNOWN BUGS
2361 2765
2362Known bugs will be fixed in the next release. 2766Known bugs will be fixed in the next release :)
2767
2768=head1 KNOWN ISSUES
2769
2770Calls that try to "import" foreign memory areas (such as C<IO::AIO::mmap>
2771or C<IO::AIO::aio_slurp>) do not work with generic lvalues, such as
2772non-created hash slots or other scalars I didn't think of. It's best to
2773avoid such and either use scalar variables or making sure that the scalar
2774exists (e.g. by storing C<undef>) and isn't "funny" (e.g. tied).
2775
2776I am not sure anything can be done about this, so this is considered a
2777known issue, rather than a bug.
2363 2778
2364=head1 SEE ALSO 2779=head1 SEE ALSO
2365 2780
2366L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a 2781L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
2367more natural syntax. 2782more natural syntax and L<IO::FDPass> for file descriptor passing.
2368 2783
2369=head1 AUTHOR 2784=head1 AUTHOR
2370 2785
2371 Marc Lehmann <schmorp@schmorp.de> 2786 Marc Lehmann <schmorp@schmorp.de>
2372 http://home.schmorp.de/ 2787 http://home.schmorp.de/

Diff Legend

Removed lines
+ Added lines
< Changed lines
> Changed lines