[ViewVC] Diff of: cvs/IO-AIO/AIO.pm

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.278 by root, Sun Oct 1 07:24:34 2017 UTC vs.
Revision 1.315 by root, Mon Sep 5 00:03:32 2022 UTC

…		…
171	use common::sense;	171	use common::sense;
172		172
173	use base 'Exporter';	173	use base 'Exporter';
174		174
175	BEGIN {	175	BEGIN {
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
282	$nfd = IO::AIO::get_fdlimit [EXPERIMENTAL]	290	$nfd = IO::AIO::get_fdlimit
283	IO::AIO::min_fdlimit $nfd [EXPERIMENTAL]	291	IO::AIO::min_fdlimit $nfd
284		292
285	IO::AIO::sendfile $ofh, $ifh, $offset, $count	293	IO::AIO::sendfile $ofh, $ifh, $offset, $count
286	IO::AIO::fadvise $fh, $offset, $len, $advice	294	IO::AIO::fadvise $fh, $offset, $len, $advice
		295	IO::AIO::fexecve $fh, $argv, $envp
		296
287	IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]	297	IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
288	IO::AIO::munmap $scalar	298	IO::AIO::munmap $scalar
		299	IO::AIO::mremap $scalar, $new_length, $flags[, $new_address]
289	IO::AIO::madvise $scalar, $offset, $length, $advice	300	IO::AIO::madvise $scalar, $offset, $length, $advice
290	IO::AIO::mprotect $scalar, $offset, $length, $protect	301	IO::AIO::mprotect $scalar, $offset, $length, $protect
291	IO::AIO::munlock $scalar, $offset = 0, $length = undef	302	IO::AIO::munlock $scalar, $offset = 0, $length = undef
292	IO::AIO::munlockall	303	IO::AIO::munlockall
		304
		305	# stat extensions
		306	$counter = IO::AIO::st_gen
		307	$seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime, IO::AIO::st_btime
		308	($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtime
		309	$nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec, IO::AIO::st_ctimensec, IO::AIO::st_btimensec
		310	$seconds = IO::AIO::st_btimesec
		311	($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtimensec
		312
		313	# very much unportable syscalls
		314	IO::AIO::accept4 $r_fh, $sockaddr, $sockaddr_len, $flags
		315	IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
		316	IO::AIO::tee $r_fh, $w_fh, $length, $flags
		317
		318	$actual_size = IO::AIO::pipesize $r_fh[, $new_size]
		319	($rfh, $wfh) = IO::AIO::pipe2 [$flags]
		320
		321	$fh = IO::AIO::eventfd [$initval, [$flags]]
		322	$fh = IO::AIO::memfd_create $pathname[, $flags]
		323
		324	$fh = IO::AIO::timerfd_create $clockid[, $flags]
		325	($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags, $new_interval, $nbw_value
		326	($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh
		327
		328	$fh = IO::AIO::pidfd_open $pid[, $flags]
		329	$status = IO::AIO::pidfd_send_signal $pidfh, $signal[, $siginfo[, $flags]]
		330	$fh = IO::AIO::pidfd_getfd $pidfh, $targetfd[, $flags]
293		331
294	=head2 API NOTES	332	=head2 API NOTES
295		333
296	All the C<aio_*> calls are more or less thin wrappers around the syscall	334	All the C<aio_*> calls are more or less thin wrappers around the syscall
297	with the same name (sans C<aio_>). The arguments are similar or identical,	335	with the same name (sans C<aio_>). The arguments are similar or identical,
…		…
403	following POSIX and non-POSIX constants are available (missing ones on	441	following POSIX and non-POSIX constants are available (missing ones on
404	your system are, as usual, C<0>):	442	your system are, as usual, C<0>):
405		443
406	C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,	444	C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,
407	C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,	445	C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,
408	C<O_RSYNC>, C<O_SYNC>, C<O_PATH>, C<O_TMPFILE>, and C<O_TTY_INIT>.	446	C<O_RSYNC>, C<O_SYNC>, C<O_PATH>, C<O_TMPFILE>, C<O_TTY_INIT> and C<O_ACCMODE>.
409		447
410		448
411	=item aio_close $fh, $callback->($status)	449	=item aio_close $fh, $callback->($status)
412		450
413	Asynchronously close a file and call the callback with the result	451	Asynchronously close a file and call the callback with the result
…		…
539		577
540	=item aio_stat $fh_or_path, $callback->($status)	578	=item aio_stat $fh_or_path, $callback->($status)
541		579
542	=item aio_lstat $fh, $callback->($status)	580	=item aio_lstat $fh, $callback->($status)
543		581
544	Works like perl's C<stat> or C<lstat> in void context. The callback will	582	Works almost exactly like perl's C<stat> or C<lstat> in void context. The
545	be called after the stat and the results will be available using C<stat _>	583	callback will be called after the stat and the results will be available
546	or C<-s _> etc...	584	using C<stat _> or C<-s _> and other tests (with the exception of C<-B>
		585	and C<-T>).
547		586
548	The pathname passed to C<aio_stat> must be absolute. See API NOTES, above,	587	The pathname passed to C<aio_stat> must be absolute. See API NOTES, above,
549	for an explanation.	588	for an explanation.
550		589
551	Currently, the stats are always 64-bit-stats, i.e. instead of returning an	590	Currently, the stats are always 64-bit-stats, i.e. instead of returning an
…		…
558	behaviour).	597	behaviour).
559		598
560	C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>,	599	C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>,
561	C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>,	600	C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>,
562	C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>.	601	C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>.
		602
		603	To access higher resolution stat timestamps, see L<SUBSECOND STAT TIME
		604	ACCESS>.
563		605
564	Example: Print the length of F</etc/passwd>:	606	Example: Print the length of F</etc/passwd>:
565		607
566	aio_stat "/etc/passwd", sub {	608	aio_stat "/etc/passwd", sub {
567	$_[0] and die "stat failed: $!";	609	$_[0] and die "stat failed: $!";
…		…
611	namemax => 255,	653	namemax => 255,
612	frsize => 1024,	654	frsize => 1024,
613	fsid => 1810	655	fsid => 1810
614	}	656	}
615		657
616	Here is a (likely partial - send me updates!) list of fsid values used by
617	Linux - it is safe to hardcode these when C<$^O> is C<linux>:
618
619	0x0000adf5 adfs
620	0x0000adff affs
621	0x5346414f afs
622	0x09041934 anon-inode filesystem
623	0x00000187 autofs
624	0x42465331 befs
625	0x1badface bfs
626	0x42494e4d binfmt_misc
627	0x9123683e btrfs
628	0x0027e0eb cgroupfs
629	0xff534d42 cifs
630	0x73757245 coda
631	0x012ff7b7 coh
632	0x28cd3d45 cramfs
633	0x453dcd28 cramfs-wend (wrong endianness)
634	0x64626720 debugfs
635	0x00001373 devfs
636	0x00001cd1 devpts
637	0x0000f15f ecryptfs
638	0x00414a53 efs
639	0x0000137d ext
640	0x0000ef53 ext2/ext3/ext4
641	0x0000ef51 ext2
642	0xf2f52010 f2fs
643	0x00004006 fat
644	0x65735546 fuseblk
645	0x65735543 fusectl
646	0x0bad1dea futexfs
647	0x01161970 gfs2
648	0x47504653 gpfs
649	0x00004244 hfs
650	0xf995e849 hpfs
651	0x00c0ffee hostfs
652	0x958458f6 hugetlbfs
653	0x2bad1dea inotifyfs
654	0x00009660 isofs
655	0x000072b6 jffs2
656	0x3153464a jfs
657	0x6b414653 k-afs
658	0x0bd00bd0 lustre
659	0x0000137f minix
660	0x0000138f minix 30 char names
661	0x00002468 minix v2
662	0x00002478 minix v2 30 char names
663	0x00004d5a minix v3
664	0x19800202 mqueue
665	0x00004d44 msdos
666	0x0000564c novell
667	0x00006969 nfs
668	0x6e667364 nfsd
669	0x00003434 nilfs
670	0x5346544e ntfs
671	0x00009fa1 openprom
672	0x7461636F ocfs2
673	0x00009fa0 proc
674	0x6165676c pstorefs
675	0x0000002f qnx4
676	0x68191122 qnx6
677	0x858458f6 ramfs
678	0x52654973 reiserfs
679	0x00007275 romfs
680	0x67596969 rpc_pipefs
681	0x73636673 securityfs
682	0xf97cff8c selinux
683	0x0000517b smb
684	0x534f434b sockfs
685	0x73717368 squashfs
686	0x62656572 sysfs
687	0x012ff7b6 sysv2
688	0x012ff7b5 sysv4
689	0x01021994 tmpfs
690	0x15013346 udf
691	0x00011954 ufs
692	0x54190100 ufs byteswapped
693	0x00009fa2 usbdevfs
694	0x01021997 v9fs
695	0xa501fcf5 vxfs
696	0xabba1974 xenfs
697	0x012ff7b4 xenix
698	0x58465342 xfs
699	0x012fd16d xia
700
701	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	658	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
702		659
703	Works like perl's C<utime> function (including the special case of $atime	660	Works like perl's C<utime> function (including the special case of $atime
704	and $mtime being undef). Fractional times are supported if the underlying	661	and $mtime being undef). Fractional times are supported if the underlying
705	syscalls support them.	662	syscalls support them.
706		663
707	When called with a pathname, uses utimes(2) if available, otherwise	664	When called with a pathname, uses utimensat(2) or utimes(2) if available,
708	utime(2). If called on a file descriptor, uses futimes(2) if available,	665	otherwise utime(2). If called on a file descriptor, uses futimens(2)
709	otherwise returns ENOSYS, so this is not portable.	666	or futimes(2) if available, otherwise returns ENOSYS, so this is not
		667	portable.
710		668
711	Examples:	669	Examples:
712		670
713	# set atime and mtime to current time (basically touch(1)):	671	# set atime and mtime to current time (basically touch(1)):
714	aio_utime "path", undef, undef;	672	aio_utime "path", undef, undef;
…		…
873		831
874	=over 4	832	=over 4
875		833
876	=item IO::AIO::READDIR_DENTS	834	=item IO::AIO::READDIR_DENTS
877		835
878	When this flag is off, then the callback gets an arrayref consisting of	836	Normally the callback gets an arrayref consisting of names only (as
879	names only (as with C<aio_readdir>), otherwise it gets an arrayref with	837	with C<aio_readdir>). If this flag is set, then the callback gets an
880	C<[$name, $type, $inode]> arrayrefs, each describing a single directory	838	arrayref with C<[$name, $type, $inode]> arrayrefs, each describing a
881	entry in more detail.	839	single directory entry in more detail:
882		840
883	C<$name> is the name of the entry.	841	C<$name> is the name of the entry.
884		842
885	C<$type> is one of the C<IO::AIO::DT_xxx> constants:	843	C<$type> is one of the C<IO::AIO::DT_xxx> constants:
886		844
887	C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,	845	C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
888	C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,	846	C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
889	C<IO::AIO::DT_WHT>.	847	C<IO::AIO::DT_WHT>.
890		848
891	C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to	849	C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need
892	know, you have to run stat yourself. Also, for speed reasons, the C<$type>	850	to know, you have to run stat yourself. Also, for speed/memory reasons,
893	scalars are read-only: you can not modify them.	851	the C<$type> scalars are read-only: you must not modify them.
894		852
895	C<$inode> is the inode number (which might not be exact on systems with 64	853	C<$inode> is the inode number (which might not be exact on systems with 64
896	bit inode numbers and 32 bit perls). This field has unspecified content on	854	bit inode numbers and 32 bit perls). This field has unspecified content on
897	systems that do not deliver the inode information.	855	systems that do not deliver the inode information.
898		856
…		…
909	short names are tried first.	867	short names are tried first.
910		868
911	=item IO::AIO::READDIR_STAT_ORDER	869	=item IO::AIO::READDIR_STAT_ORDER
912		870
913	When this flag is set, then the names will be returned in an order	871	When this flag is set, then the names will be returned in an order
914	suitable for stat()'ing each one. That is, when you plan to stat()	872	suitable for stat()'ing each one. That is, when you plan to stat() most or
915	all files in the given directory, then the returned order will likely	873	all files in the given directory, then the returned order will likely be
916	be fastest.	874	faster.
917		875
918	If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then	876	If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified,
919	the likely dirs come first, resulting in a less optimal stat order.	877	then the likely dirs come first, resulting in a less optimal stat order
		878	for stat'ing all entries, but likely a more optimal order for finding
		879	subdirectories.
920		880
921	=item IO::AIO::READDIR_FOUND_UNKNOWN	881	=item IO::AIO::READDIR_FOUND_UNKNOWN
922		882
923	This flag should not be set when calling C<aio_readdirx>. Instead, it	883	This flag should not be set when calling C<aio_readdirx>. Instead, it
924	is being set by C<aio_readdirx>, when any of the C<$type>'s found were	884	is being set by C<aio_readdirx>, when any of the C<$type>'s found were
…		…
926	C<$type>'s are known, which can be used to speed up some algorithms.	886	C<$type>'s are known, which can be used to speed up some algorithms.
927		887
928	=back	888	=back
929		889
930		890
		891	=item aio_slurp $pathname, $offset, $length, $data, $callback->($status)
		892
		893	Opens, reads and closes the given file. The data is put into C<$data>,
		894	which is resized as required.
		895
		896	If C<$offset> is negative, then it is counted from the end of the file.
		897
		898	If C<$length> is zero, then the remaining length of the file is
		899	used. Also, in this case, the same limitations to modifying C<$data> apply
		900	as when IO::AIO::mmap is used, i.e. it must only be modified in-place
		901	with C<substr>. If the size of the file is known, specifying a non-zero
		902	C<$length> results in a performance advantage.
		903
		904	This request is similar to the older C<aio_load> request, but since it is
		905	a single request, it might be more efficient to use.
		906
		907	Example: load F</etc/passwd> into C<$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
931	=item aio_load $pathname, $data, $callback->($status)	920	=item aio_load $pathname, $data, $callback->($status)
932		921
933	This is a composite request that tries to fully load the given file into	922	This is a composite request that tries to fully load the given file into
934	memory. Status is the same as with aio_read.	923	memory. Status is the same as with aio_read.
		924
		925	Using C<aio_slurp> might be more efficient, as it is a single request.
935		926
936	=cut	927	=cut
937		928
938	sub aio_load($$;$) {	929	sub aio_load($$;$) {
939	my ($path, undef, $cb) = @_;	930	my ($path, undef, $cb) = @_;
…		…
1154	aioreq_pri $pri;	1145	aioreq_pri $pri;
1155	add $grp aio_stat $wd, sub {	1146	add $grp aio_stat $wd, sub {
1156	return $grp->result () if $_[0];	1147	return $grp->result () if $_[0];
1157	my $now = time;	1148	my $now = time;
1158	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	}
1159		1158
1160	# read the directory entries	1159	# read the directory entries
1161	aioreq_pri $pri;	1160	aioreq_pri $pri;
1162	add $grp aio_readdirx $wd, READDIR_DIRS_FIRST, sub {	1161	add $grp aio_readdirx $wd, $rdxflags, sub {
1163	my $entries = shift	1162	my ($entries, $flags) = @_
1164	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	}
1165		1212
1166	# stat the dir another time	1213	# stat the dir another time
1167	aioreq_pri $pri;	1214	aioreq_pri $pri;
1168	add $grp aio_stat $wd, sub {	1215	add $grp aio_stat $wd, sub {
1169	my $hash2 = join ":", (stat _)[0,1,3,7,9];	1216	my $hash2 = join ":", (stat _)[0,1,3,7,9];
…		…
1275	So in general, you should only use these calls for things that do	1322	So in general, you should only use these calls for things that do
1276	(filesystem) I/O, not for things that wait for other events (network,	1323	(filesystem) I/O, not for things that wait for other events (network,
1277	other processes), although if you are careful and know what you are doing,	1324	other processes), although if you are careful and know what you are doing,
1278	you still can.	1325	you still can.
1279		1326
1280	The following constants are available (missing ones are, as usual C<0>):	1327	The following constants are available and can be used for normal C<ioctl>
		1328	and C<fcntl> as well (missing ones are, as usual C<0>):
1281		1329
1282	C<F_DUPFD_CLOEXEC>,	1330	C<F_DUPFD_CLOEXEC>,
1283		1331
1284	C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>,	1332	C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>,
1285		1333
1286	C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>.	1334	C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>.
		1335
		1336	C<F_ADD_SEALS>, C<F_GET_SEALS>, C<F_SEAL_SEAL>, C<F_SEAL_SHRINK>, C<F_SEAL_GROW> and
		1337	C<F_SEAL_WRITE>.
1287		1338
1288	C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>,	1339	C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>,
1289	C<FS_IOC_FIEMAP>.	1340	C<FS_IOC_FIEMAP>.
1290		1341
1291	C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>,	1342	C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>,
…		…
1430	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;
1431	aio_mlock $data; # mlock in background	1482	aio_mlock $data; # mlock in background
1432		1483
1433	=item aio_mlockall $flags, $callback->($status)	1484	=item aio_mlockall $flags, $callback->($status)
1434		1485
1435	Calls the C<mlockall> function with the given C<$flags> (a combination of	1486	Calls the C<mlockall> function with the given C<$flags> (a
1436	C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).	1487	combination of C<IO::AIO::MCL_CURRENT>, C<IO::AIO::MCL_FUTURE> and
		1488	C<IO::AIO::MCL_ONFAULT>).
1437		1489
1438	On systems that do not implement C<mlockall>, this function returns C<-1>	1490	On systems that do not implement C<mlockall>, this function returns C<-1>
1439	and sets errno to C<ENOSYS>.	1491	and sets errno to C<ENOSYS>. Similarly, flag combinations not supported
		1492	by the system result in a return value of C<-1> with errno being set to
		1493	C<EINVAL>.
1440		1494
1441	Note that the corresponding C<munlockall> is synchronous and is	1495	Note that the corresponding C<munlockall> is synchronous and is
1442	documented under L<MISCELLANEOUS FUNCTIONS>.	1496	documented under L<MISCELLANEOUS FUNCTIONS>.
1443		1497
1444	Example: asynchronously lock all current and future pages into memory.	1498	Example: asynchronously lock all current and future pages into memory.
…		…
1638	C<aio_wd> callback, as future requests using the value will fail in the	1692	C<aio_wd> callback, as future requests using the value will fail in the
1639	expected way.	1693	expected way.
1640		1694
1641	=item IO::AIO::CWD	1695	=item IO::AIO::CWD
1642		1696
1643	This is a compiletime constant (object) that represents the process	1697	This is a compile time constant (object) that represents the process
1644	current working directory.	1698	current working directory.
1645		1699
1646	Specifying this object as working directory object for a pathname is as if	1700	Specifying this object as working directory object for a pathname is as if
1647	the pathname would be specified directly, without a directory object. For	1701	the pathname would be specified directly, without a directory object. For
1648	example, these calls are functionally identical:	1702	example, these calls are functionally identical:
…		…
1829	The default value for the limit is C<0>, but note that setting a feeder	1883	The default value for the limit is C<0>, but note that setting a feeder
1830	automatically bumps it up to C<2>.	1884	automatically bumps it up to C<2>.
1831		1885
1832	=back	1886	=back
1833		1887
		1888
1834	=head2 SUPPORT FUNCTIONS	1889	=head2 SUPPORT FUNCTIONS
1835		1890
1836	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION	1891	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
1837		1892
1838	=over 4	1893	=over 4
…		…
1903	Strictly equivalent to:	1958	Strictly equivalent to:
1904		1959
1905	IO::AIO::poll_wait, IO::AIO::poll_cb	1960	IO::AIO::poll_wait, IO::AIO::poll_cb
1906	while IO::AIO::nreqs;	1961	while IO::AIO::nreqs;
1907		1962
		1963	This function can be useful at program aborts, to make sure outstanding
		1964	I/O has been done (C<IO::AIO> uses an C<END> block which already calls
		1965	this function on normal exits), or when you are merely using C<IO::AIO>
		1966	for 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
1908	=item IO::AIO::max_poll_reqs $nreqs	1973	=item IO::AIO::max_poll_reqs $nreqs
1909		1974
1910	=item IO::AIO::max_poll_time $seconds	1975	=item IO::AIO::max_poll_time $seconds
1911		1976
1912	These set the maximum number of requests (default C<0>, meaning infinity)	1977	These set the maximum number of requests (default C<0>, meaning infinity)
…		…
1938	poll => 'r', nice => 1,	2003	poll => 'r', nice => 1,
1939	cb => &IO::AIO::poll_cb);	2004	cb => &IO::AIO::poll_cb);
1940		2005
1941	=back	2006	=back
1942		2007
		2008
1943	=head3 CONTROLLING THE NUMBER OF THREADS	2009	=head3 CONTROLLING THE NUMBER OF THREADS
1944		2010
1945	=over	2011	=over
1946		2012
1947	=item IO::AIO::min_parallel $nthreads	2013	=item IO::AIO::min_parallel $nthreads
…		…
2008	longer exceeded.	2074	longer exceeded.
2009		2075
2010	In other words, this setting does not enforce a queue limit, but can be	2076	In other words, this setting does not enforce a queue limit, but can be
2011	used to make poll functions block if the limit is exceeded.	2077	used to make poll functions block if the limit is exceeded.
2012		2078
2013	This is a very bad function to use in interactive programs because it	2079	This is a bad function to use in interactive programs because it blocks,
2014	blocks, and a bad way to reduce concurrency because it is inexact: Better	2080	and a bad way to reduce concurrency because it is inexact. If you need to
		2081	issue many requests without being able to call a poll function on demand,
2015	use an C<aio_group> together with a feed callback.	2082	it is better to use an C<aio_group> together with a feed callback.
2016		2083
2017	Its main use is in scripts without an event loop - when you want to stat	2084	Its main use is in scripts without an event loop - when you want to stat a
2018	a lot of files, you can write something like this:	2085	lot of files, you can write something like this:
2019		2086
2020	IO::AIO::max_outstanding 32;	2087	IO::AIO::max_outstanding 32;
2021		2088
2022	for my $path (...) {	2089	for my $path (...) {
2023	aio_stat $path , ...;	2090	aio_stat $path , ...;
2024	IO::AIO::poll_cb;	2091	IO::AIO::poll_cb;
2025	}	2092	}
2026		2093
2027	IO::AIO::flush;	2094	IO::AIO::flush;
2028		2095
2029	The call to C<poll_cb> inside the loop will normally return instantly, but	2096	The call to C<poll_cb> inside the loop will normally return instantly,
2030	as soon as more thna C<32> reqeusts are in-flight, it will block until	2097	allowing the loop to progress, but as soon as more than C<32> requests
2031	some requests have been handled. This keeps the loop from pushing a large	2098	are in-flight, it will block until some requests have been handled. This
2032	number of C<aio_stat> requests onto the queue.	2099	keeps the loop from pushing a large number of C<aio_stat> requests onto
		2100	the queue (which, with many paths to stat, can use up a lot of memory).
2033		2101
2034	The default value for C<max_outstanding> is very large, so there is no	2102	The default value for C<max_outstanding> is very large, so there is no
2035	practical limit on the number of outstanding requests.	2103	practical limit on the number of outstanding requests.
2036		2104
2037	=back	2105	=back
2038		2106
		2107
2039	=head3 STATISTICAL INFORMATION	2108	=head3 STATISTICAL INFORMATION
2040		2109
2041	=over	2110	=over
2042		2111
2043	=item IO::AIO::nreqs	2112	=item IO::AIO::nreqs
…		…
2059		2128
2060	Returns the number of requests currently in the pending state (executed,	2129	Returns the number of requests currently in the pending state (executed,
2061	but not yet processed by poll_cb).	2130	but not yet processed by poll_cb).
2062		2131
2063	=back	2132	=back
		2133
		2134
		2135	=head3 SUBSECOND STAT TIME ACCESS
		2136
		2137	Both C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> functions can
		2138	generally find access/modification and change times with subsecond time
		2139	accuracy of the system supports it, but perl's built-in functions only
		2140	return the integer part.
		2141
		2142	The following functions return the timestamps of the most recent
		2143	stat with subsecond precision on most systems and work both after
		2144	C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> calls. Their return
		2145	value is only meaningful after a successful C<stat>/C<lstat> call, or
		2146	during/after a successful C<aio_stat>/C<aio_lstat> callback.
		2147
		2148	This is similar to the L<Time::HiRes> C<stat> functions, but can return
		2149	full resolution without rounding and work with standard perl C<stat>,
		2150	alleviating the need to call the special C<Time::HiRes> functions, which
		2151	do not act like their perl counterparts.
		2152
		2153	On operating systems or file systems where subsecond time resolution is
		2154	not supported or could not be detected, a fractional part of C<0> is
		2155	returned, so it is always safe to call these functions.
		2156
		2157	=over 4
		2158
		2159	=item $seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime, IO::AIO::st_btime
		2160
		2161	Return the access, modication, change or birth time, respectively,
		2162	including fractional part. Due to the limited precision of floating point,
		2163	the accuracy on most platforms is only a bit better than milliseconds
		2164	for times around now - see the I<nsec> function family, below, for full
		2165	accuracy.
		2166
		2167	File birth time is only available when the OS and perl support it (on
		2168	FreeBSD and NetBSD at the time of this writing, although support is
		2169	adaptive, so if your OS/perl gains support, IO::AIO can take advantage of
		2170	it). On systems where it isn't available, C<0> is currently returned, but
		2171	this might change to C<undef> in a future version.
		2172
		2173	=item ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtime
		2174
		2175	Returns access, modification, change and birth time all in one go, and
		2176	maybe 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
		2180	Return the fractional access, modifcation, change or birth time, in nanoseconds,
		2181	as an integer in the range C<0> to C<999999999>.
		2182
		2183	Note that no accessors are provided for access, modification and
		2184	change times - you need to get those from C<stat _> if required (C<int
		2185	IO::AIO::st_atime> and so on will I<not> generally give you the correct
		2186	value).
		2187
		2188	=item $seconds = IO::AIO::st_btimesec
		2189
		2190	The (integral) seconds part of the file birth time, if available.
		2191
		2192	=item ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtimensec
		2193
		2194	Like the functions above, but returns all four times in one go (and maybe
		2195	more in future versions).
		2196
		2197	=item $counter = IO::AIO::st_gen
		2198
		2199	Returns the generation counter (in practice this is just a random number)
		2200	of the file. This is only available on platforms which have this member in
		2201	their C<struct stat> (most BSDs at the time of this writing) and generally
		2202	only to the root usert. If unsupported, C<0> is returned, but this might
		2203	change to C<undef> in a future version.
		2204
		2205	=back
		2206
		2207	Example: print the high resolution modification time of F</etc>, using
		2208	C<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
		2223	Output 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
2064		2228
2065	=head3 MISCELLANEOUS FUNCTIONS	2229	=head3 MISCELLANEOUS FUNCTIONS
2066		2230
2067	IO::AIO implements some functions that are useful when you want to use	2231	IO::AIO implements some functions that are useful when you want to use
2068	some "Advanced I/O" function not available to in Perl, without going the	2232	some "Advanced I/O" function not available to in Perl, without going the
2069	"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*>	2233	"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*>
2070	counterpart.	2234	counterpart.
2071		2235
2072	=over 4	2236	=over 4
2073		2237
		2238	=item $retval = IO::AIO::fexecve $fh, $argv, $envp
		2239
		2240	A more-or-less direct equivalent to the POSIX C<fexecve> functions, which
		2241	allows you to specify the program to be executed via a file descriptor (or
		2242	handle). Returns C<-1> and sets errno to C<ENOSYS> if not available.
		2243
2074	=item $numfd = IO::AIO::get_fdlimit	2244	=item $numfd = IO::AIO::get_fdlimit
2075
2076	This function is I<EXPERIMENTAL> and subject to change.
2077		2245
2078	Tries to find the current file descriptor limit and returns it, or	2246	Tries to find the current file descriptor limit and returns it, or
2079	C<undef> and sets C<$!> in case of an error. The limit is one larger than	2247	C<undef> and sets C<$!> in case of an error. The limit is one larger than
2080	the highest valid file descriptor number.	2248	the highest valid file descriptor number.
2081		2249
2082	=item IO::AIO::min_fdlimit [$numfd]	2250	=item IO::AIO::min_fdlimit [$numfd]
2083
2084	This function is I<EXPERIMENTAL> and subject to change.
2085		2251
2086	Try to increase the current file descriptor limit(s) to at least C<$numfd>	2252	Try to increase the current file descriptor limit(s) to at least C<$numfd>
2087	by changing the soft or hard file descriptor resource limit. If C<$numfd>	2253	by changing the soft or hard file descriptor resource limit. If C<$numfd>
2088	is missing, it will try to set a very high limit, although this is not	2254	is missing, it will try to set a very high limit, although this is not
2089	recommended when you know the actual minimum that you require.	2255	recommended when you know the actual minimum that you require.
…		…
2184	C<IO::AIO::MAP_POPULATE>,	2350	C<IO::AIO::MAP_POPULATE>,
2185	C<IO::AIO::MAP_NONBLOCK>,	2351	C<IO::AIO::MAP_NONBLOCK>,
2186	C<IO::AIO::MAP_FIXED>,	2352	C<IO::AIO::MAP_FIXED>,
2187	C<IO::AIO::MAP_GROWSDOWN>,	2353	C<IO::AIO::MAP_GROWSDOWN>,
2188	C<IO::AIO::MAP_32BIT>,	2354	C<IO::AIO::MAP_32BIT>,
2189	C<IO::AIO::MAP_HUGETLB> or	2355	C<IO::AIO::MAP_HUGETLB>,
2190	C<IO::AIO::MAP_STACK>.	2356	C<IO::AIO::MAP_STACK>,
		2357	C<IO::AIO::MAP_FIXED_NOREPLACE>,
		2358	C<IO::AIO::MAP_SHARED_VALIDATE>,
		2359	C<IO::AIO::MAP_SYNC> or
		2360	C<IO::AIO::MAP_UNINITIALIZED>.
2191		2361
2192	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.	2362	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
2193		2363
2194	C<$offset> is the offset from the start of the file - it generally must be	2364	C<$offset> is the offset from the start of the file - it generally must be
2195	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.	2365	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
…		…
2209		2379
2210	=item IO::AIO::munmap $scalar	2380	=item IO::AIO::munmap $scalar
2211		2381
2212	Removes a previous mmap and undefines the C<$scalar>.	2382	Removes a previous mmap and undefines the C<$scalar>.
2213		2383
		2384	=item IO::AIO::mremap $scalar, $new_length, $flags = MREMAP_MAYMOVE[, $new_address = 0]
		2385
		2386	Calls the Linux-specific mremap(2) system call. The C<$scalar> must have
		2387	been mapped by C<IO::AIO::mmap>, and C<$flags> must currently either be
		2388	C<0> or C<IO::AIO::MREMAP_MAYMOVE>.
		2389
		2390	Returns true if successful, and false otherwise. If the underlying mmapped
		2391	region has changed address, then the true value has the numerical value
		2392	C<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
		2401	C<IO::AIO::MREMAP_FIXED> and the C<$new_address> argument are currently
		2402	implemented, but not supported and might go away in a future version.
		2403
		2404	On systems where this call is not supported or is not emulated, this call
		2405	returns falls and sets C<$!> to C<ENOSYS>.
		2406
		2407	=item IO::AIO::mlockall $flags
		2408
		2409	Calls the C<eio_mlockall_sync> function, which is like C<aio_mlockall>,
		2410	but is blocking.
		2411
2214	=item IO::AIO::munlock $scalar, $offset = 0, $length = undef	2412	=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
2215		2413
2216	Calls the C<munlock> function, undoing the effects of a previous	2414	Calls the C<munlock> function, undoing the effects of a previous
2217	C<aio_mlock> call (see its description for details).	2415	C<aio_mlock> call (see its description for details).
2218		2416
…		…
2220		2418
2221	Calls the C<munlockall> function.	2419	Calls the C<munlockall> function.
2222		2420
2223	On systems that do not implement C<munlockall>, this function returns	2421	On systems that do not implement C<munlockall>, this function returns
2224	ENOSYS, otherwise the return value of C<munlockall>.	2422	ENOSYS, otherwise the return value of C<munlockall>.
		2423
		2424	=item $fh = IO::AIO::accept4 $r_fh, $sockaddr, $sockaddr_maxlen, $flags
		2425
		2426	Uses the GNU/Linux C<accept4(2)> syscall, if available, to accept a socket
		2427	and return the new file handle on success, or sets C<$!> and returns
		2428	C<undef> on error.
		2429
		2430	The remote name of the new socket will be stored in C<$sockaddr>, which
		2431	will be extended to allow for at least C<$sockaddr_maxlen> octets. If the
		2432	socket name does not fit into C<$sockaddr_maxlen> octets, this is signaled
		2433	by returning a longer string in C<$sockaddr>, which might or might not be
		2434	truncated.
		2435
		2436	To accept name-less sockets, use C<undef> for C<$sockaddr> and C<0> for
		2437	C<$sockaddr_maxlen>.
		2438
		2439	The main reasons to use this syscall rather than portable C<accept(2)>
		2440	are that you can specify C<SOCK_NONBLOCK> and/or C<SOCK_CLOEXEC>
		2441	flags and you can accept name-less sockets by specifying C<0> for
		2442	C<$sockaddr_maxlen>, which is sadly not possible with perl's interface to
		2443	C<accept>.
2225		2444
2226	=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, $flags
2227		2446
2228	Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or	2447	Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or
2229	C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they	2448	C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
…		…
2267	C<$flags> is non-zero, fails with C<ENOSYS>.	2486	C<$flags> is non-zero, fails with C<ENOSYS>.
2268		2487
2269	Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the	2488	Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the
2270	time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and	2489	time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and
2271	C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported.	2490	C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported.
		2491
		2492	Example: create a pipe race-free w.r.t. threads and fork:
		2493
		2494	my ($rfh, $wfh) = IO::AIO::pipe2 IO::AIO::O_CLOEXEC
		2495	or die "pipe2: $!\n";
		2496
		2497	=item $fh = IO::AIO::memfd_create $pathname[, $flags]
		2498
		2499	This is a direct interface to the Linux L<memfd_create(2)> system
		2500	call. The (unhelpful) default for C<$flags> is C<0>, but your default
		2501	should be C<IO::AIO::MFD_CLOEXEC>.
		2502
		2503	On success, the new memfd filehandle is returned, otherwise returns
		2504	C<undef>. If the memfd_create syscall is missing, fails with C<ENOSYS>.
		2505
		2506	Please refer to L<memfd_create(2)> for more info on this call.
		2507
		2508	The following C<$flags> values are available: C<IO::AIO::MFD_CLOEXEC>,
		2509	C<IO::AIO::MFD_ALLOW_SEALING>, C<IO::AIO::MFD_HUGETLB>,
		2510	C<IO::AIO::MFD_HUGETLB_2MB> and C<IO::AIO::MFD_HUGETLB_1GB>.
		2511
		2512	Example: 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[, $flags]
		2518
		2519	This is an interface to the Linux L<pidfd_open(2)> system call. The
		2520	default for C<$flags> is C<0>.
		2521
		2522	On success, a new pidfd filehandle is returned (that is already set to
		2523	close-on-exec), otherwise returns C<undef>. If the syscall is missing,
		2524	fails with C<ENOSYS>.
		2525
		2526	Example: 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[, $flags]]
		2532
		2533	This is an interface to the Linux L<pidfd_send_signal> system call. The
		2534	default for C<$siginfo> is C<undef> and the default for C<$flags> is C<0>.
		2535
		2536	Returns the system call status. If the syscall is missing, fails with
		2537	C<ENOSYS>.
		2538
		2539	When specified, C<$siginfo> must be a reference to a hash with one or more
		2540	of 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
		2556	Example: 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
		2561	Example: 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[, $flags]
		2567
		2568	This is an interface to the Linux L<pidfd_getfd> system call. The default
		2569	for C<$flags> is C<0>.
		2570
		2571	On success, returns a dup'ed copy of the target file descriptor (specified
		2572	as an integer) returned (that is already set to close-on-exec), otherwise
		2573	returns C<undef>. If the syscall is missing, fails with C<ENOSYS>.
		2574
		2575	Example: 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, [$flags]]
		2582
		2583	This is a direct interface to the Linux L<eventfd(2)> system call. The
		2584	(unhelpful) defaults for C<$initval> and C<$flags> are C<0> for both.
		2585
		2586	On success, the new eventfd filehandle is returned, otherwise returns
		2587	C<undef>. If the eventfd syscall is missing, fails with C<ENOSYS>.
		2588
		2589	Please refer to L<eventfd(2)> for more info on this call.
		2590
		2591	The following symbol flag values are available: C<IO::AIO::EFD_CLOEXEC>,
		2592	C<IO::AIO::EFD_NONBLOCK> and C<IO::AIO::EFD_SEMAPHORE> (Linux 2.6.30).
		2593
		2594	Example: 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[, $flags]
		2600
		2601	This is a direct interface to the Linux L<timerfd_create(2)> system
		2602	call. The (unhelpful) default for C<$flags> is C<0>, but your default
		2603	should be C<IO::AIO::TFD_CLOEXEC>.
		2604
		2605	On success, the new timerfd filehandle is returned, otherwise returns
		2606	C<undef>. If the timerfd_create syscall is missing, fails with C<ENOSYS>.
		2607
		2608	Please refer to L<timerfd_create(2)> for more info on this call.
		2609
		2610	The following C<$clockid> values are
		2611	available: C<IO::AIO::CLOCK_REALTIME>, C<IO::AIO::CLOCK_MONOTONIC>
		2612	C<IO::AIO::CLOCK_CLOCK_BOOTTIME> (Linux 3.15)
		2613	C<IO::AIO::CLOCK_CLOCK_REALTIME_ALARM> (Linux 3.11) and
		2614	C<IO::AIO::CLOCK_CLOCK_BOOTTIME_ALARM> (Linux 3.11).
		2615
		2616	The following C<$flags> values are available (Linux
		2617	2.6.27): C<IO::AIO::TFD_NONBLOCK> and C<IO::AIO::TFD_CLOEXEC>.
		2618
		2619	Example: create a new timerfd and set it to one-second repeated alarms,
		2620	then 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, $nbw_value
		2637
		2638	This is a direct interface to the Linux L<timerfd_settime(2)> system
		2639	call. Please refer to its manpage for more info on this call.
		2640
		2641	The new itimerspec is specified using two (possibly fractional) second
		2642	values, C<$new_interval> and C<$new_value>).
		2643
		2644	On success, the current interval and value are returned (as per
		2645	C<timerfd_gettime>). On failure, the empty list is returned.
		2646
		2647	The following C<$flags> values are
		2648	available: C<IO::AIO::TFD_TIMER_ABSTIME> and
		2649	C<IO::AIO::TFD_TIMER_CANCEL_ON_SET>.
		2650
		2651	See C<IO::AIO::timerfd_create> for a full example.
		2652
		2653	=item ($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh
		2654
		2655	This is a direct interface to the Linux L<timerfd_gettime(2)> system
		2656	call. Please refer to its manpage for more info on this call.
		2657
		2658	On success, returns the current values of interval and value for the given
		2659	timerfd (as potentially fractional second values). On failure, the empty
		2660	list is returned.
2272		2661
2273	=back	2662	=back
2274		2663
2275	=cut	2664	=cut
2276		2665
…		…
2342	the process will result in undefined behaviour. Calling it at any time	2731	the process will result in undefined behaviour. Calling it at any time
2343	will also result in any undefined (by POSIX) behaviour.	2732	will also result in any undefined (by POSIX) behaviour.
2344		2733
2345	=back	2734	=back
2346		2735
		2736	=head2 LINUX-SPECIFIC CALLS
		2737
		2738	When a call is documented as "linux-specific" then this means it
		2739	originated on GNU/Linux. C<IO::AIO> will usually try to autodetect the
		2740	availability and compatibility of such calls regardless of the platform
		2741	it is compiled on, so platforms such as FreeBSD which often implement
		2742	these calls will work. When in doubt, call them and see if they fail wth
		2743	C<ENOSYS>.
		2744
2347	=head2 MEMORY USAGE	2745	=head2 MEMORY USAGE
2348		2746
2349	Per-request usage:	2747	Per-request usage:
2350		2748
2351	Each aio request uses - depending on your architecture - around 100-200	2749	Each aio request uses - depending on your architecture - around 100-200
…		…
2363	temporary buffers, and each thread requires a stack and other data	2761	temporary buffers, and each thread requires a stack and other data
2364	structures (usually around 16k-128k, depending on the OS).	2762	structures (usually around 16k-128k, depending on the OS).
2365		2763
2366	=head1 KNOWN BUGS	2764	=head1 KNOWN BUGS
2367		2765
2368	Known bugs will be fixed in the next release.	2766	Known bugs will be fixed in the next release :)
		2767
		2768	=head1 KNOWN ISSUES
		2769
		2770	Calls that try to "import" foreign memory areas (such as C<IO::AIO::mmap>
		2771	or C<IO::AIO::aio_slurp>) do not work with generic lvalues, such as
		2772	non-created hash slots or other scalars I didn't think of. It's best to
		2773	avoid such and either use scalar variables or making sure that the scalar
		2774	exists (e.g. by storing C<undef>) and isn't "funny" (e.g. tied).
		2775
		2776	I am not sure anything can be done about this, so this is considered a
		2777	known issue, rather than a bug.
2369		2778
2370	=head1 SEE ALSO	2779	=head1 SEE ALSO
2371		2780
2372	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a	2781	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
2373	more natural syntax.	2782	more natural syntax and L<IO::FDPass> for file descriptor passing.
2374		2783
2375	=head1 AUTHOR	2784	=head1 AUTHOR
2376		2785
2377	Marc Lehmann <schmorp@schmorp.de>	2786	Marc Lehmann <schmorp@schmorp.de>
2378	http://home.schmorp.de/	2787	http://home.schmorp.de/

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.278 by root, Sun Oct 1 07:24:34 2017 UTC vs. Revision 1.315 by root, Mon Sep 5 00:03:32 2022 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.278 by root, Sun Oct 1 07:24:34 2017 UTC vs.
Revision 1.315 by root, Mon Sep 5 00:03:32 2022 UTC