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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.279 by root, Sat Jan 6 01:04:42 2018 UTC vs.
Revision 1.309 by root, Tue Dec 29 15:20:12 2020 UTC

171use common::sense; 171use common::sense;
172 172
173use base 'Exporter'; 173use base 'Exporter';
174 174
175BEGIN { 175BEGIN {
176 our $VERSION = 4.4; 176 our $VERSION = 4.74;
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
192 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 192 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
193 min_parallel max_parallel max_idle idle_timeout 193 min_parallel max_parallel max_idle idle_timeout
194 nreqs nready npending nthreads 194 nreqs nready npending nthreads
195 max_poll_time max_poll_reqs 195 max_poll_time max_poll_reqs
196 sendfile fadvise madvise 196 sendfile fadvise madvise
197 mmap munmap munlock munlockall); 197 mmap munmap mremap munlock munlockall);
198 198
199 push @AIO_REQ, qw(aio_busy); # not exported 199 push @AIO_REQ, qw(aio_busy); # not exported
200 200
201 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 201 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
202 202
278 IO::AIO::idle_timeout $seconds 278 IO::AIO::idle_timeout $seconds
279 IO::AIO::max_outstanding $maxreqs 279 IO::AIO::max_outstanding $maxreqs
280 IO::AIO::nreqs 280 IO::AIO::nreqs
281 IO::AIO::nready 281 IO::AIO::nready
282 IO::AIO::npending 282 IO::AIO::npending
283 IO::AIO::reinit
284
283 $nfd = IO::AIO::get_fdlimit [EXPERIMENTAL] 285 $nfd = IO::AIO::get_fdlimit
284 IO::AIO::min_fdlimit $nfd [EXPERIMENTAL] 286 IO::AIO::min_fdlimit $nfd
285 287
286 IO::AIO::sendfile $ofh, $ifh, $offset, $count 288 IO::AIO::sendfile $ofh, $ifh, $offset, $count
287 IO::AIO::fadvise $fh, $offset, $len, $advice 289 IO::AIO::fadvise $fh, $offset, $len, $advice
290
288 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]] 291 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
289 IO::AIO::munmap $scalar 292 IO::AIO::munmap $scalar
293 IO::AIO::mremap $scalar, $new_length, $flags[, $new_address]
290 IO::AIO::madvise $scalar, $offset, $length, $advice 294 IO::AIO::madvise $scalar, $offset, $length, $advice
291 IO::AIO::mprotect $scalar, $offset, $length, $protect 295 IO::AIO::mprotect $scalar, $offset, $length, $protect
292 IO::AIO::munlock $scalar, $offset = 0, $length = undef 296 IO::AIO::munlock $scalar, $offset = 0, $length = undef
293 IO::AIO::munlockall 297 IO::AIO::munlockall
298
299 # stat extensions
300 $counter = IO::AIO::st_gen
301 $seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime, IO::AIO::st_btime
302 ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtime
303 $nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec, IO::AIO::st_ctimensec, IO::AIO::st_btimensec
304 $seconds = IO::AIO::st_btimesec
305 ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtimensec
306
307 # very much unportable syscalls
308 IO::AIO::accept4 $r_fh, $sockaddr, $sockaddr_len, $flags
309 IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
310 IO::AIO::tee $r_fh, $w_fh, $length, $flags
311 $actual_size = IO::AIO::pipesize $r_fh[, $new_size]
312 ($rfh, $wfh) = IO::AIO::pipe2 [$flags]
313 $fh = IO::AIO::memfd_create $pathname[, $flags]
314 $fh = IO::AIO::eventfd [$initval, [$flags]]
315 $fh = IO::AIO::timerfd_create $clockid[, $flags]
316 ($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags, $new_interval, $nbw_value
317 ($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh
294 318
295=head2 API NOTES 319=head2 API NOTES
296 320
297All the C<aio_*> calls are more or less thin wrappers around the syscall 321All the C<aio_*> calls are more or less thin wrappers around the syscall
298with the same name (sans C<aio_>). The arguments are similar or identical, 322with the same name (sans C<aio_>). The arguments are similar or identical,
404following POSIX and non-POSIX constants are available (missing ones on 428following POSIX and non-POSIX constants are available (missing ones on
405your system are, as usual, C<0>): 429your system are, as usual, C<0>):
406 430
407C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>, 431C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,
408C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>, 432C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,
409C<O_RSYNC>, C<O_SYNC>, C<O_PATH>, C<O_TMPFILE>, and C<O_TTY_INIT>. 433C<O_RSYNC>, C<O_SYNC>, C<O_PATH>, C<O_TMPFILE>, C<O_TTY_INIT> and C<O_ACCMODE>.
410 434
411 435
412=item aio_close $fh, $callback->($status) 436=item aio_close $fh, $callback->($status)
413 437
414Asynchronously close a file and call the callback with the result 438Asynchronously close a file and call the callback with the result
540 564
541=item aio_stat $fh_or_path, $callback->($status) 565=item aio_stat $fh_or_path, $callback->($status)
542 566
543=item aio_lstat $fh, $callback->($status) 567=item aio_lstat $fh, $callback->($status)
544 568
545Works like perl's C<stat> or C<lstat> in void context. The callback will 569Works almost exactly like perl's C<stat> or C<lstat> in void context. The
546be called after the stat and the results will be available using C<stat _> 570callback will be called after the stat and the results will be available
547or C<-s _> etc... 571using C<stat _> or C<-s _> and other tests (with the exception of C<-B>
572and C<-T>).
548 573
549The pathname passed to C<aio_stat> must be absolute. See API NOTES, above, 574The pathname passed to C<aio_stat> must be absolute. See API NOTES, above,
550for an explanation. 575for an explanation.
551 576
552Currently, the stats are always 64-bit-stats, i.e. instead of returning an 577Currently, the stats are always 64-bit-stats, i.e. instead of returning an
559behaviour). 584behaviour).
560 585
561C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>, 586C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>,
562C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>, 587C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>,
563C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>. 588C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>.
589
590To access higher resolution stat timestamps, see L<SUBSECOND STAT TIME
591ACCESS>.
564 592
565Example: Print the length of F</etc/passwd>: 593Example: Print the length of F</etc/passwd>:
566 594
567 aio_stat "/etc/passwd", sub { 595 aio_stat "/etc/passwd", sub {
568 $_[0] and die "stat failed: $!"; 596 $_[0] and die "stat failed: $!";
612 namemax => 255, 640 namemax => 255,
613 frsize => 1024, 641 frsize => 1024,
614 fsid => 1810 642 fsid => 1810
615 } 643 }
616 644
617Here is a (likely partial - send me updates!) list of fsid values used by
618Linux - it is safe to hardcode these when C<$^O> is C<linux>:
619
620 0x0000adf5 adfs
621 0x0000adff affs
622 0x5346414f afs
623 0x09041934 anon-inode filesystem
624 0x00000187 autofs
625 0x42465331 befs
626 0x1badface bfs
627 0x42494e4d binfmt_misc
628 0x9123683e btrfs
629 0x0027e0eb cgroupfs
630 0xff534d42 cifs
631 0x73757245 coda
632 0x012ff7b7 coh
633 0x28cd3d45 cramfs
634 0x453dcd28 cramfs-wend (wrong endianness)
635 0x64626720 debugfs
636 0x00001373 devfs
637 0x00001cd1 devpts
638 0x0000f15f ecryptfs
639 0x00414a53 efs
640 0x0000137d ext
641 0x0000ef53 ext2/ext3/ext4
642 0x0000ef51 ext2
643 0xf2f52010 f2fs
644 0x00004006 fat
645 0x65735546 fuseblk
646 0x65735543 fusectl
647 0x0bad1dea futexfs
648 0x01161970 gfs2
649 0x47504653 gpfs
650 0x00004244 hfs
651 0xf995e849 hpfs
652 0x00c0ffee hostfs
653 0x958458f6 hugetlbfs
654 0x2bad1dea inotifyfs
655 0x00009660 isofs
656 0x000072b6 jffs2
657 0x3153464a jfs
658 0x6b414653 k-afs
659 0x0bd00bd0 lustre
660 0x0000137f minix
661 0x0000138f minix 30 char names
662 0x00002468 minix v2
663 0x00002478 minix v2 30 char names
664 0x00004d5a minix v3
665 0x19800202 mqueue
666 0x00004d44 msdos
667 0x0000564c novell
668 0x00006969 nfs
669 0x6e667364 nfsd
670 0x00003434 nilfs
671 0x5346544e ntfs
672 0x00009fa1 openprom
673 0x7461636F ocfs2
674 0x00009fa0 proc
675 0x6165676c pstorefs
676 0x0000002f qnx4
677 0x68191122 qnx6
678 0x858458f6 ramfs
679 0x52654973 reiserfs
680 0x00007275 romfs
681 0x67596969 rpc_pipefs
682 0x73636673 securityfs
683 0xf97cff8c selinux
684 0x0000517b smb
685 0x534f434b sockfs
686 0x73717368 squashfs
687 0x62656572 sysfs
688 0x012ff7b6 sysv2
689 0x012ff7b5 sysv4
690 0x01021994 tmpfs
691 0x15013346 udf
692 0x00011954 ufs
693 0x54190100 ufs byteswapped
694 0x00009fa2 usbdevfs
695 0x01021997 v9fs
696 0xa501fcf5 vxfs
697 0xabba1974 xenfs
698 0x012ff7b4 xenix
699 0x58465342 xfs
700 0x012fd16d xia
701
702=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 645=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
703 646
704Works like perl's C<utime> function (including the special case of $atime 647Works like perl's C<utime> function (including the special case of $atime
705and $mtime being undef). Fractional times are supported if the underlying 648and $mtime being undef). Fractional times are supported if the underlying
706syscalls support them. 649syscalls support them.
707 650
708When called with a pathname, uses utimes(2) if available, otherwise 651When called with a pathname, uses utimensat(2) or utimes(2) if available,
709utime(2). If called on a file descriptor, uses futimes(2) if available, 652otherwise utime(2). If called on a file descriptor, uses futimens(2)
710otherwise returns ENOSYS, so this is not portable. 653or futimes(2) if available, otherwise returns ENOSYS, so this is not
654portable.
711 655
712Examples: 656Examples:
713 657
714 # set atime and mtime to current time (basically touch(1)): 658 # set atime and mtime to current time (basically touch(1)):
715 aio_utime "path", undef, undef; 659 aio_utime "path", undef, undef;
874 818
875=over 4 819=over 4
876 820
877=item IO::AIO::READDIR_DENTS 821=item IO::AIO::READDIR_DENTS
878 822
879When this flag is off, then the callback gets an arrayref consisting of 823Normally the callback gets an arrayref consisting of names only (as
880names only (as with C<aio_readdir>), otherwise it gets an arrayref with 824with C<aio_readdir>). If this flag is set, then the callback gets an
881C<[$name, $type, $inode]> arrayrefs, each describing a single directory 825arrayref with C<[$name, $type, $inode]> arrayrefs, each describing a
882entry in more detail. 826single directory entry in more detail:
883 827
884C<$name> is the name of the entry. 828C<$name> is the name of the entry.
885 829
886C<$type> is one of the C<IO::AIO::DT_xxx> constants: 830C<$type> is one of the C<IO::AIO::DT_xxx> constants:
887 831
888C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>, 832C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
889C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>, 833C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
890C<IO::AIO::DT_WHT>. 834C<IO::AIO::DT_WHT>.
891 835
892C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to 836C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need
893know, you have to run stat yourself. Also, for speed reasons, the C<$type> 837to know, you have to run stat yourself. Also, for speed/memory reasons,
894scalars are read-only: you can not modify them. 838the C<$type> scalars are read-only: you must not modify them.
895 839
896C<$inode> is the inode number (which might not be exact on systems with 64 840C<$inode> is the inode number (which might not be exact on systems with 64
897bit inode numbers and 32 bit perls). This field has unspecified content on 841bit inode numbers and 32 bit perls). This field has unspecified content on
898systems that do not deliver the inode information. 842systems that do not deliver the inode information.
899 843
910short names are tried first. 854short names are tried first.
911 855
912=item IO::AIO::READDIR_STAT_ORDER 856=item IO::AIO::READDIR_STAT_ORDER
913 857
914When this flag is set, then the names will be returned in an order 858When this flag is set, then the names will be returned in an order
915suitable for stat()'ing each one. That is, when you plan to stat() 859suitable for stat()'ing each one. That is, when you plan to stat() most or
916all files in the given directory, then the returned order will likely 860all files in the given directory, then the returned order will likely be
917be fastest. 861faster.
918 862
919If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then 863If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified,
920the likely dirs come first, resulting in a less optimal stat order. 864then the likely dirs come first, resulting in a less optimal stat order
865for stat'ing all entries, but likely a more optimal order for finding
866subdirectories.
921 867
922=item IO::AIO::READDIR_FOUND_UNKNOWN 868=item IO::AIO::READDIR_FOUND_UNKNOWN
923 869
924This flag should not be set when calling C<aio_readdirx>. Instead, it 870This flag should not be set when calling C<aio_readdirx>. Instead, it
925is being set by C<aio_readdirx>, when any of the C<$type>'s found were 871is being set by C<aio_readdirx>, when any of the C<$type>'s found were
1186 aioreq_pri $pri; 1132 aioreq_pri $pri;
1187 add $grp aio_stat $wd, sub { 1133 add $grp aio_stat $wd, sub {
1188 return $grp->result () if $_[0]; 1134 return $grp->result () if $_[0];
1189 my $now = time; 1135 my $now = time;
1190 my $hash1 = join ":", (stat _)[0,1,3,7,9]; 1136 my $hash1 = join ":", (stat _)[0,1,3,7,9];
1137 my $rdxflags = READDIR_DIRS_FIRST;
1138
1139 if ((stat _)[3] < 2) {
1140 # at least one non-POSIX filesystem exists
1141 # that returns useful DT_type values: btrfs,
1142 # so optimise for this here by requesting dents
1143 $rdxflags |= READDIR_DENTS;
1144 }
1191 1145
1192 # read the directory entries 1146 # read the directory entries
1193 aioreq_pri $pri; 1147 aioreq_pri $pri;
1194 add $grp aio_readdirx $wd, READDIR_DIRS_FIRST, sub { 1148 add $grp aio_readdirx $wd, $rdxflags, sub {
1195 my $entries = shift 1149 my ($entries, $flags) = @_
1196 or return $grp->result (); 1150 or return $grp->result ();
1151
1152 if ($rdxflags & READDIR_DENTS) {
1153 # if we requested type values, see if we can use them directly.
1154
1155 # if there were any DT_UNKNOWN entries then we assume we
1156 # don't know. alternatively, we could assume that if we get
1157 # one DT_DIR, then all directories are indeed marked with
1158 # DT_DIR, but this seems not required for btrfs, and this
1159 # is basically the "btrfs can't get it's act together" code
1160 # branch.
1161 unless ($flags & READDIR_FOUND_UNKNOWN) {
1162 # now we have valid DT_ information for all entries,
1163 # so use it as an optimisation without further stat's.
1164 # they must also all be at the beginning of @$entries
1165 # by now.
1166
1167 my $dirs;
1168
1169 if (@$entries) {
1170 for (0 .. $#$entries) {
1171 if ($entries->[$_][1] != DT_DIR) {
1172 # splice out directories
1173 $dirs = [splice @$entries, 0, $_];
1174 last;
1175 }
1176 }
1177
1178 # if we didn't find any non-dir, then all entries are dirs
1179 unless ($dirs) {
1180 ($dirs, $entries) = ($entries, []);
1181 }
1182 } else {
1183 # directory is empty, so there are no sbdirs
1184 $dirs = [];
1185 }
1186
1187 # either splice'd the directories out or the dir was empty.
1188 # convert dents to filenames
1189 $_ = $_->[0] for @$dirs;
1190 $_ = $_->[0] for @$entries;
1191
1192 return $grp->result ($dirs, $entries);
1193 }
1194
1195 # cannot use, so return to our old ways
1196 # by pretending we only scanned for names.
1197 $_ = $_->[0] for @$entries;
1198 }
1197 1199
1198 # stat the dir another time 1200 # stat the dir another time
1199 aioreq_pri $pri; 1201 aioreq_pri $pri;
1200 add $grp aio_stat $wd, sub { 1202 add $grp aio_stat $wd, sub {
1201 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 1203 my $hash2 = join ":", (stat _)[0,1,3,7,9];
1307So in general, you should only use these calls for things that do 1309So in general, you should only use these calls for things that do
1308(filesystem) I/O, not for things that wait for other events (network, 1310(filesystem) I/O, not for things that wait for other events (network,
1309other processes), although if you are careful and know what you are doing, 1311other processes), although if you are careful and know what you are doing,
1310you still can. 1312you still can.
1311 1313
1312The following constants are available (missing ones are, as usual C<0>): 1314The following constants are available and can be used for normal C<ioctl>
1315and C<fcntl> as well (missing ones are, as usual C<0>):
1313 1316
1314C<F_DUPFD_CLOEXEC>, 1317C<F_DUPFD_CLOEXEC>,
1315 1318
1316C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>, 1319C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>,
1317 1320
1318C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>. 1321C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>.
1322
1323C<F_ADD_SEALS>, C<F_GET_SEALS>, C<F_SEAL_SEAL>, C<F_SEAL_SHRINK>, C<F_SEAL_GROW> and
1324C<F_SEAL_WRITE>.
1319 1325
1320C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>, 1326C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>,
1321C<FS_IOC_FIEMAP>. 1327C<FS_IOC_FIEMAP>.
1322 1328
1323C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>, 1329C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>,
1462 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh; 1468 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
1463 aio_mlock $data; # mlock in background 1469 aio_mlock $data; # mlock in background
1464 1470
1465=item aio_mlockall $flags, $callback->($status) 1471=item aio_mlockall $flags, $callback->($status)
1466 1472
1467Calls the C<mlockall> function with the given C<$flags> (a combination of 1473Calls the C<mlockall> function with the given C<$flags> (a
1468C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>). 1474combination of C<IO::AIO::MCL_CURRENT>, C<IO::AIO::MCL_FUTURE> and
1475C<IO::AIO::MCL_ONFAULT>).
1469 1476
1470On systems that do not implement C<mlockall>, this function returns C<-1> 1477On systems that do not implement C<mlockall>, this function returns C<-1>
1471and sets errno to C<ENOSYS>. 1478and sets errno to C<ENOSYS>. Similarly, flag combinations not supported
1479by the system result in a return value of C<-1> with errno being set to
1480C<EINVAL>.
1472 1481
1473Note that the corresponding C<munlockall> is synchronous and is 1482Note that the corresponding C<munlockall> is synchronous and is
1474documented under L<MISCELLANEOUS FUNCTIONS>. 1483documented under L<MISCELLANEOUS FUNCTIONS>.
1475 1484
1476Example: asynchronously lock all current and future pages into memory. 1485Example: asynchronously lock all current and future pages into memory.
1670C<aio_wd> callback, as future requests using the value will fail in the 1679C<aio_wd> callback, as future requests using the value will fail in the
1671expected way. 1680expected way.
1672 1681
1673=item IO::AIO::CWD 1682=item IO::AIO::CWD
1674 1683
1675This is a compiletime constant (object) that represents the process 1684This is a compile time constant (object) that represents the process
1676current working directory. 1685current working directory.
1677 1686
1678Specifying this object as working directory object for a pathname is as if 1687Specifying this object as working directory object for a pathname is as if
1679the pathname would be specified directly, without a directory object. For 1688the pathname would be specified directly, without a directory object. For
1680example, these calls are functionally identical: 1689example, these calls are functionally identical:
1861The default value for the limit is C<0>, but note that setting a feeder 1870The default value for the limit is C<0>, but note that setting a feeder
1862automatically bumps it up to C<2>. 1871automatically bumps it up to C<2>.
1863 1872
1864=back 1873=back
1865 1874
1875
1866=head2 SUPPORT FUNCTIONS 1876=head2 SUPPORT FUNCTIONS
1867 1877
1868=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1878=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
1869 1879
1870=over 4 1880=over 4
1935Strictly equivalent to: 1945Strictly equivalent to:
1936 1946
1937 IO::AIO::poll_wait, IO::AIO::poll_cb 1947 IO::AIO::poll_wait, IO::AIO::poll_cb
1938 while IO::AIO::nreqs; 1948 while IO::AIO::nreqs;
1939 1949
1950This function can be useful at program aborts, to make sure outstanding
1951I/O has been done (C<IO::AIO> uses an C<END> block which already calls
1952this function on normal exits), or when you are merely using C<IO::AIO>
1953for its more advanced functions, rather than for async I/O, e.g.:
1954
1955 my ($dirs, $nondirs);
1956 IO::AIO::aio_scandir "/tmp", 0, sub { ($dirs, $nondirs) = @_ };
1957 IO::AIO::flush;
1958 # $dirs, $nondirs are now set
1959
1940=item IO::AIO::max_poll_reqs $nreqs 1960=item IO::AIO::max_poll_reqs $nreqs
1941 1961
1942=item IO::AIO::max_poll_time $seconds 1962=item IO::AIO::max_poll_time $seconds
1943 1963
1944These set the maximum number of requests (default C<0>, meaning infinity) 1964These set the maximum number of requests (default C<0>, meaning infinity)
1970 poll => 'r', nice => 1, 1990 poll => 'r', nice => 1,
1971 cb => &IO::AIO::poll_cb); 1991 cb => &IO::AIO::poll_cb);
1972 1992
1973=back 1993=back
1974 1994
1995
1975=head3 CONTROLLING THE NUMBER OF THREADS 1996=head3 CONTROLLING THE NUMBER OF THREADS
1976 1997
1977=over 1998=over
1978 1999
1979=item IO::AIO::min_parallel $nthreads 2000=item IO::AIO::min_parallel $nthreads
2066The default value for C<max_outstanding> is very large, so there is no 2087The default value for C<max_outstanding> is very large, so there is no
2067practical limit on the number of outstanding requests. 2088practical limit on the number of outstanding requests.
2068 2089
2069=back 2090=back
2070 2091
2092
2071=head3 STATISTICAL INFORMATION 2093=head3 STATISTICAL INFORMATION
2072 2094
2073=over 2095=over
2074 2096
2075=item IO::AIO::nreqs 2097=item IO::AIO::nreqs
2091 2113
2092Returns the number of requests currently in the pending state (executed, 2114Returns the number of requests currently in the pending state (executed,
2093but not yet processed by poll_cb). 2115but not yet processed by poll_cb).
2094 2116
2095=back 2117=back
2118
2119
2120=head3 SUBSECOND STAT TIME ACCESS
2121
2122Both C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> functions can
2123generally find access/modification and change times with subsecond time
2124accuracy of the system supports it, but perl's built-in functions only
2125return the integer part.
2126
2127The following functions return the timestamps of the most recent
2128stat with subsecond precision on most systems and work both after
2129C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> calls. Their return
2130value is only meaningful after a successful C<stat>/C<lstat> call, or
2131during/after a successful C<aio_stat>/C<aio_lstat> callback.
2132
2133This is similar to the L<Time::HiRes> C<stat> functions, but can return
2134full resolution without rounding and work with standard perl C<stat>,
2135alleviating the need to call the special C<Time::HiRes> functions, which
2136do not act like their perl counterparts.
2137
2138On operating systems or file systems where subsecond time resolution is
2139not supported or could not be detected, a fractional part of C<0> is
2140returned, so it is always safe to call these functions.
2141
2142=over 4
2143
2144=item $seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime, IO::AIO::st_btime
2145
2146Return the access, modication, change or birth time, respectively,
2147including fractional part. Due to the limited precision of floating point,
2148the accuracy on most platforms is only a bit better than milliseconds
2149for times around now - see the I<nsec> function family, below, for full
2150accuracy.
2151
2152File birth time is only available when the OS and perl support it (on
2153FreeBSD and NetBSD at the time of this writing, although support is
2154adaptive, so if your OS/perl gains support, IO::AIO can take advantage of
2155it). On systems where it isn't available, C<0> is currently returned, but
2156this might change to C<undef> in a future version.
2157
2158=item ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtime
2159
2160Returns access, modification, change and birth time all in one go, and
2161maybe more times in the future version.
2162
2163=item $nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec, IO::AIO::st_ctimensec, IO::AIO::st_btimensec
2164
2165Return the fractional access, modifcation, change or birth time, in nanoseconds,
2166as an integer in the range C<0> to C<999999999>.
2167
2168Note that no accessors are provided for access, modification and
2169change times - you need to get those from C<stat _> if required (C<int
2170IO::AIO::st_atime> and so on will I<not> generally give you the correct
2171value).
2172
2173=item $seconds = IO::AIO::st_btimesec
2174
2175The (integral) seconds part of the file birth time, if available.
2176
2177=item ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtimensec
2178
2179Like the functions above, but returns all four times in one go (and maybe
2180more in future versions).
2181
2182=item $counter = IO::AIO::st_gen
2183
2184Returns the generation counter (in practice this is just a random number)
2185of the file. This is only available on platforms which have this member in
2186their C<struct stat> (most BSDs at the time of this writing) and generally
2187only to the root usert. If unsupported, C<0> is returned, but this might
2188change to C<undef> in a future version.
2189
2190=back
2191
2192Example: print the high resolution modification time of F</etc>, using
2193C<stat>, and C<IO::AIO::aio_stat>.
2194
2195 if (stat "/etc") {
2196 printf "stat(/etc) mtime: %f\n", IO::AIO::st_mtime;
2197 }
2198
2199 IO::AIO::aio_stat "/etc", sub {
2200 $_[0]
2201 and return;
2202
2203 printf "aio_stat(/etc) mtime: %d.%09d\n", (stat _)[9], IO::AIO::st_mtimensec;
2204 };
2205
2206 IO::AIO::flush;
2207
2208Output of the awbove on my system, showing reduced and full accuracy:
2209
2210 stat(/etc) mtime: 1534043702.020808
2211 aio_stat(/etc) mtime: 1534043702.020807792
2212
2096 2213
2097=head3 MISCELLANEOUS FUNCTIONS 2214=head3 MISCELLANEOUS FUNCTIONS
2098 2215
2099IO::AIO implements some functions that are useful when you want to use 2216IO::AIO implements some functions that are useful when you want to use
2100some "Advanced I/O" function not available to in Perl, without going the 2217some "Advanced I/O" function not available to in Perl, without going the
2103 2220
2104=over 4 2221=over 4
2105 2222
2106=item $numfd = IO::AIO::get_fdlimit 2223=item $numfd = IO::AIO::get_fdlimit
2107 2224
2108This function is I<EXPERIMENTAL> and subject to change.
2109
2110Tries to find the current file descriptor limit and returns it, or 2225Tries to find the current file descriptor limit and returns it, or
2111C<undef> and sets C<$!> in case of an error. The limit is one larger than 2226C<undef> and sets C<$!> in case of an error. The limit is one larger than
2112the highest valid file descriptor number. 2227the highest valid file descriptor number.
2113 2228
2114=item IO::AIO::min_fdlimit [$numfd] 2229=item IO::AIO::min_fdlimit [$numfd]
2115
2116This function is I<EXPERIMENTAL> and subject to change.
2117 2230
2118Try to increase the current file descriptor limit(s) to at least C<$numfd> 2231Try to increase the current file descriptor limit(s) to at least C<$numfd>
2119by changing the soft or hard file descriptor resource limit. If C<$numfd> 2232by changing the soft or hard file descriptor resource limit. If C<$numfd>
2120is missing, it will try to set a very high limit, although this is not 2233is missing, it will try to set a very high limit, although this is not
2121recommended when you know the actual minimum that you require. 2234recommended when you know the actual minimum that you require.
2241 2354
2242=item IO::AIO::munmap $scalar 2355=item IO::AIO::munmap $scalar
2243 2356
2244Removes a previous mmap and undefines the C<$scalar>. 2357Removes a previous mmap and undefines the C<$scalar>.
2245 2358
2359=item IO::AIO::mremap $scalar, $new_length, $flags = MREMAP_MAYMOVE[, $new_address = 0]
2360
2361Calls the Linux-specific mremap(2) system call. The C<$scalar> must have
2362been mapped by C<IO::AIO::mmap>, and C<$flags> must currently either be
2363C<0> or C<IO::AIO::MREMAP_MAYMOVE>.
2364
2365Returns true if successful, and false otherwise. If the underlying mmapped
2366region has changed address, then the true value has the numerical value
2367C<1>, otherwise it has the numerical value C<0>:
2368
2369 my $success = IO::AIO::mremap $mmapped, 8192, IO::AIO::MREMAP_MAYMOVE
2370 or die "mremap: $!";
2371
2372 if ($success*1) {
2373 warn "scalar has chanegd address in memory\n";
2374 }
2375
2376C<IO::AIO::MREMAP_FIXED> and the C<$new_address> argument are currently
2377implemented, but not supported and might go away in a future version.
2378
2379On systems where this call is not supported or is not emulated, this call
2380returns falls and sets C<$!> to C<ENOSYS>.
2381
2382=item IO::AIO::mlockall $flags
2383
2384Calls the C<eio_mlockall_sync> function, which is like C<aio_mlockall>,
2385but is blocking.
2386
2246=item IO::AIO::munlock $scalar, $offset = 0, $length = undef 2387=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
2247 2388
2248Calls the C<munlock> function, undoing the effects of a previous 2389Calls the C<munlock> function, undoing the effects of a previous
2249C<aio_mlock> call (see its description for details). 2390C<aio_mlock> call (see its description for details).
2250 2391
2252 2393
2253Calls the C<munlockall> function. 2394Calls the C<munlockall> function.
2254 2395
2255On systems that do not implement C<munlockall>, this function returns 2396On systems that do not implement C<munlockall>, this function returns
2256ENOSYS, otherwise the return value of C<munlockall>. 2397ENOSYS, otherwise the return value of C<munlockall>.
2398
2399=item $fh = IO::AIO::accept4 $r_fh, $sockaddr, $sockaddr_maxlen, $flags
2400
2401Uses the GNU/Linux C<accept4(2)> syscall, if available, to accept a socket
2402and return the new file handle on success, or sets C<$!> and returns
2403C<undef> on error.
2404
2405The remote name of the new socket will be stored in C<$sockaddr>, which
2406will be extended to allow for at least C<$sockaddr_maxlen> octets. If the
2407socket name does not fit into C<$sockaddr_maxlen> octets, this is signaled
2408by returning a longer string in C<$sockaddr>, which might or might not be
2409truncated.
2410
2411To accept name-less sockets, use C<undef> for C<$sockaddr> and C<0> for
2412C<$sockaddr_maxlen>.
2413
2414The main reasons to use this syscall rather than portable C<accept(2)>
2415are that you can specify C<SOCK_NONBLOCK> and/or C<SOCK_CLOEXEC>
2416flags and you can accept name-less sockets by specifying C<0> for
2417C<$sockaddr_maxlen>, which is sadly not possible with perl's interface to
2418C<accept>.
2257 2419
2258=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags 2420=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
2259 2421
2260Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or 2422Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or
2261C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they 2423C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
2299C<$flags> is non-zero, fails with C<ENOSYS>. 2461C<$flags> is non-zero, fails with C<ENOSYS>.
2300 2462
2301Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the 2463Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the
2302time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and 2464time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and
2303C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported. 2465C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported.
2466
2467Example: create a pipe race-free w.r.t. threads and fork:
2468
2469 my ($rfh, $wfh) = IO::AIO::pipe2 IO::AIO::O_CLOEXEC
2470 or die "pipe2: $!\n";
2471
2472=item $fh = IO::AIO::memfd_create $pathname[, $flags]
2473
2474This is a direct interface to the Linux L<memfd_create(2)> system
2475call. The (unhelpful) default for C<$flags> is C<0>, but your default
2476should be C<IO::AIO::MFD_CLOEXEC>.
2477
2478On success, the new memfd filehandle is returned, otherwise returns
2479C<undef>. If the memfd_create syscall is missing, fails with C<ENOSYS>.
2480
2481Please refer to L<memfd_create(2)> for more info on this call.
2482
2483The following C<$flags> values are available: C<IO::AIO::MFD_CLOEXEC>,
2484C<IO::AIO::MFD_ALLOW_SEALING> and C<IO::AIO::MFD_HUGETLB>.
2485
2486Example: create a new memfd.
2487
2488 my $fh = IO::AIO::memfd_create "somenameforprocfd", IO::AIO::MFD_CLOEXEC
2489 or die "memfd_create: $!\n";
2490
2491=item $fh = IO::AIO::pidfd_open $pid[, $flags]
2492
2493This is an interface to the Linux L<pidfd_open(2)> system call. The
2494default for C<$flags> is C<0>.
2495
2496On success, a new pidfd filehandle is returned (that is already set to
2497close-on-exec), otherwise returns C<undef>. If the syscall is missing,
2498fails with C<ENOSYS>.
2499
2500Example: open pid 6341 as pidfd.
2501
2502 my $fh = IO::AIO::pidfd_open 6341
2503 or die "pidfd_open: $!\n";
2504
2505=item $status = IO::AIO::pidfd_send_signal $pidfh, $signal[, $siginfo[, $flags]]
2506
2507This is an interface to the Linux L<pidfd_send_signal> system call. The
2508default for C<$siginfo> is C<undef> and the default for C<$flags> is C<0>.
2509
2510Returns the system call status. If the syscall is missing, fails with
2511C<ENOSYS>.
2512
2513When specified, C<$siginfo> must be a reference to a hash with one or more
2514of the following members:
2515
2516=over
2517
2518=item code - the C<si_code> member
2519
2520=item pid - the C<si_pid> member
2521
2522=item uid - the C<si_uid> member
2523
2524=item value_int - the C<si_value.sival_int> member
2525
2526=item value_ptr - the C<si_value.sival_ptr> member, specified as an integer
2527
2528=back
2529
2530Example: send a SIGKILL to the specified process.
2531
2532 my $status = IO::AIO::pidfd_send_signal $pidfh, 9, undef
2533 and die "pidfd_send_signal: $!\n";
2534
2535Example: send a SIGKILL to the specified process with extra data.
2536
2537 my $status = IO::AIO::pidfd_send_signal $pidfh, 9, { code => -1, value_int => 7 }
2538 and die "pidfd_send_signal: $!\n";
2539
2540=item $fh = IO::AIO::pidfd_getfd $pidfh, $targetfd[, $flags]
2541
2542This is an interface to the Linux L<pidfd_getfd> system call. The default
2543for C<$flags> is C<0>.
2544
2545On success, returns a dup'ed copy of the target file descriptor (specified
2546as an integer) returned (that is already set to close-on-exec), otherwise
2547returns C<undef>. If the syscall is missing, fails with C<ENOSYS>.
2548
2549Example: get a copy of standard error of another process and print soemthing to it.
2550
2551 my $errfh = IO::AIO::pidfd_getfd $pidfh, 2
2552 or die "pidfd_getfd: $!\n";
2553 print $errfh "stderr\n";
2554
2555=item $fh = IO::AIO::eventfd [$initval, [$flags]]
2556
2557This is a direct interface to the Linux L<eventfd(2)> system call. The
2558(unhelpful) defaults for C<$initval> and C<$flags> are C<0> for both.
2559
2560On success, the new eventfd filehandle is returned, otherwise returns
2561C<undef>. If the eventfd syscall is missing, fails with C<ENOSYS>.
2562
2563Please refer to L<eventfd(2)> for more info on this call.
2564
2565The following symbol flag values are available: C<IO::AIO::EFD_CLOEXEC>,
2566C<IO::AIO::EFD_NONBLOCK> and C<IO::AIO::EFD_SEMAPHORE> (Linux 2.6.30).
2567
2568Example: create a new eventfd filehandle:
2569
2570 $fh = IO::AIO::eventfd 0, IO::AIO::EFD_CLOEXEC
2571 or die "eventfd: $!\n";
2572
2573=item $fh = IO::AIO::timerfd_create $clockid[, $flags]
2574
2575This is a direct interface to the Linux L<timerfd_create(2)> system
2576call. The (unhelpful) default for C<$flags> is C<0>, but your default
2577should be C<IO::AIO::TFD_CLOEXEC>.
2578
2579On success, the new timerfd filehandle is returned, otherwise returns
2580C<undef>. If the timerfd_create syscall is missing, fails with C<ENOSYS>.
2581
2582Please refer to L<timerfd_create(2)> for more info on this call.
2583
2584The following C<$clockid> values are
2585available: C<IO::AIO::CLOCK_REALTIME>, C<IO::AIO::CLOCK_MONOTONIC>
2586C<IO::AIO::CLOCK_CLOCK_BOOTTIME> (Linux 3.15)
2587C<IO::AIO::CLOCK_CLOCK_REALTIME_ALARM> (Linux 3.11) and
2588C<IO::AIO::CLOCK_CLOCK_BOOTTIME_ALARM> (Linux 3.11).
2589
2590The following C<$flags> values are available (Linux
25912.6.27): C<IO::AIO::TFD_NONBLOCK> and C<IO::AIO::TFD_CLOEXEC>.
2592
2593Example: create a new timerfd and set it to one-second repeated alarms,
2594then wait for two alarms:
2595
2596 my $fh = IO::AIO::timerfd_create IO::AIO::CLOCK_BOOTTIME, IO::AIO::TFD_CLOEXEC
2597 or die "timerfd_create: $!\n";
2598
2599 defined IO::AIO::timerfd_settime $fh, 0, 1, 1
2600 or die "timerfd_settime: $!\n";
2601
2602 for (1..2) {
2603 8 == sysread $fh, my $buf, 8
2604 or die "timerfd read failure\n";
2605
2606 printf "number of expirations (likely 1): %d\n",
2607 unpack "Q", $buf;
2608 }
2609
2610=item ($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags, $new_interval, $nbw_value
2611
2612This is a direct interface to the Linux L<timerfd_settime(2)> system
2613call. Please refer to its manpage for more info on this call.
2614
2615The new itimerspec is specified using two (possibly fractional) second
2616values, C<$new_interval> and C<$new_value>).
2617
2618On success, the current interval and value are returned (as per
2619C<timerfd_gettime>). On failure, the empty list is returned.
2620
2621The following C<$flags> values are
2622available: C<IO::AIO::TFD_TIMER_ABSTIME> and
2623C<IO::AIO::TFD_TIMER_CANCEL_ON_SET>.
2624
2625See C<IO::AIO::timerfd_create> for a full example.
2626
2627=item ($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh
2628
2629This is a direct interface to the Linux L<timerfd_gettime(2)> system
2630call. Please refer to its manpage for more info on this call.
2631
2632On success, returns the current values of interval and value for the given
2633timerfd (as potentially fractional second values). On failure, the empty
2634list is returned.
2304 2635
2305=back 2636=back
2306 2637
2307=cut 2638=cut
2308 2639
2374the process will result in undefined behaviour. Calling it at any time 2705the process will result in undefined behaviour. Calling it at any time
2375will also result in any undefined (by POSIX) behaviour. 2706will also result in any undefined (by POSIX) behaviour.
2376 2707
2377=back 2708=back
2378 2709
2710=head2 LINUX-SPECIFIC CALLS
2711
2712When a call is documented as "linux-specific" then this means it
2713originated on GNU/Linux. C<IO::AIO> will usually try to autodetect the
2714availability and compatibility of such calls regardless of the platform
2715it is compiled on, so platforms such as FreeBSD which often implement
2716these calls will work. When in doubt, call them and see if they fail wth
2717C<ENOSYS>.
2718
2379=head2 MEMORY USAGE 2719=head2 MEMORY USAGE
2380 2720
2381Per-request usage: 2721Per-request usage:
2382 2722
2383Each aio request uses - depending on your architecture - around 100-200 2723Each aio request uses - depending on your architecture - around 100-200
2395temporary buffers, and each thread requires a stack and other data 2735temporary buffers, and each thread requires a stack and other data
2396structures (usually around 16k-128k, depending on the OS). 2736structures (usually around 16k-128k, depending on the OS).
2397 2737
2398=head1 KNOWN BUGS 2738=head1 KNOWN BUGS
2399 2739
2400Known bugs will be fixed in the next release. 2740Known bugs will be fixed in the next release :)
2741
2742=head1 KNOWN ISSUES
2743
2744Calls that try to "import" foreign memory areas (such as C<IO::AIO::mmap>
2745or C<IO::AIO::aio_slurp>) do not work with generic lvalues, such as
2746non-created hash slots or other scalars I didn't think of. It's best to
2747avoid such and either use scalar variables or making sure that the scalar
2748exists (e.g. by storing C<undef>) and isn't "funny" (e.g. tied).
2749
2750I am not sure anything can be done about this, so this is considered a
2751known issue, rather than a bug.
2401 2752
2402=head1 SEE ALSO 2753=head1 SEE ALSO
2403 2754
2404L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a 2755L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
2405more natural syntax. 2756more natural syntax and L<IO::FDPass> for file descriptor passing.
2406 2757
2407=head1 AUTHOR 2758=head1 AUTHOR
2408 2759
2409 Marc Lehmann <schmorp@schmorp.de> 2760 Marc Lehmann <schmorp@schmorp.de>
2410 http://home.schmorp.de/ 2761 http://home.schmorp.de/

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