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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.281 by root, Tue Feb 20 04:32:59 2018 UTC vs.
Revision 1.320 by root, Tue Feb 20 06:40:23 2024 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 = 4.4;	176	our $VERSION = 4.81;
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
		199	accept4 tee splice pipe2 pipesize
		200	fexecve mount umount memfd_create eventfd
		201	timerfd_create timerfd_settime timerfd_gettime
		202	pidfd_open pidfd_send_signal pidfd_getfd);
198		203
199	push @AIO_REQ, qw(aio_busy); # not exported	204	push @AIO_REQ, qw(aio_busy); # not exported
200		205
201	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';	206	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';
202		207
…		…
278	IO::AIO::idle_timeout $seconds	283	IO::AIO::idle_timeout $seconds
279	IO::AIO::max_outstanding $maxreqs	284	IO::AIO::max_outstanding $maxreqs
280	IO::AIO::nreqs	285	IO::AIO::nreqs
281	IO::AIO::nready	286	IO::AIO::nready
282	IO::AIO::npending	287	IO::AIO::npending
		288	IO::AIO::reinit
		289
283	$nfd = IO::AIO::get_fdlimit [EXPERIMENTAL]	290	$nfd = IO::AIO::get_fdlimit
284	IO::AIO::min_fdlimit $nfd [EXPERIMENTAL]	291	IO::AIO::min_fdlimit $nfd
285		292
286	IO::AIO::sendfile $ofh, $ifh, $offset, $count	293	IO::AIO::sendfile $ofh, $ifh, $offset, $count
287	IO::AIO::fadvise $fh, $offset, $len, $advice	294	IO::AIO::fadvise $fh, $offset, $len, $advice
		295	IO::AIO::fexecve $fh, $argv, $envp
		296
288	IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]	297	IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
289	IO::AIO::munmap $scalar	298	IO::AIO::munmap $scalar
		299	IO::AIO::mremap $scalar, $new_length, $flags[, $new_address]
290	IO::AIO::madvise $scalar, $offset, $length, $advice	300	IO::AIO::madvise $scalar, $offset, $length, $advice
291	IO::AIO::mprotect $scalar, $offset, $length, $protect	301	IO::AIO::mprotect $scalar, $offset, $length, $protect
292	IO::AIO::munlock $scalar, $offset = 0, $length = undef	302	IO::AIO::munlock $scalar, $offset = 0, $length = undef
293	IO::AIO::munlockall	303	IO::AIO::munlockall
		304
		305	# stat extensions
		306	$counter = IO::AIO::st_gen
		307	$seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime, IO::AIO::st_btime
		308	($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtime
		309	$nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec, IO::AIO::st_ctimensec, IO::AIO::st_btimensec
		310	$seconds = IO::AIO::st_btimesec
		311	($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtimensec
		312
		313	# very much unportable syscalls
		314	IO::AIO::accept4 $r_fh, $sockaddr, $sockaddr_len, $flags
		315	IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
		316	IO::AIO::tee $r_fh, $w_fh, $length, $flags
		317
		318	$actual_size = IO::AIO::pipesize $r_fh[, $new_size]
		319	($rfh, $wfh) = IO::AIO::pipe2 [$flags]
		320
		321	$fh = IO::AIO::eventfd [$initval, [$flags]]
		322	$fh = IO::AIO::memfd_create $pathname[, $flags]
		323
		324	$fh = IO::AIO::timerfd_create $clockid[, $flags]
		325	($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags, $new_interval, $nbw_value
		326	($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh
		327
		328	$fh = IO::AIO::pidfd_open $pid[, $flags]
		329	$status = IO::AIO::pidfd_send_signal $pidfh, $signal[, $siginfo[, $flags]]
		330	$fh = IO::AIO::pidfd_getfd $pidfh, $targetfd[, $flags]
		331
		332	$retval = IO::AIO::mount $special, $path, $fstype, $flags = 0, $data = undef
		333	$retval = IO::AIO::umount $path, $flags = 0
294		334
295	=head2 API NOTES	335	=head2 API NOTES
296		336
297	All the C<aio_*> calls are more or less thin wrappers around the syscall	337	All the C<aio_*> calls are more or less thin wrappers around the syscall
298	with the same name (sans C<aio_>). The arguments are similar or identical,	338	with the same name (sans C<aio_>). The arguments are similar or identical,
…		…
373	=item aio_open $pathname, $flags, $mode, $callback->($fh)	413	=item aio_open $pathname, $flags, $mode, $callback->($fh)
374		414
375	Asynchronously open or create a file and call the callback with a newly	415	Asynchronously open or create a file and call the callback with a newly
376	created filehandle for the file (or C<undef> in case of an error).	416	created filehandle for the file (or C<undef> in case of an error).
377		417
378	The pathname passed to C<aio_open> must be absolute. See API NOTES, above,
379	for an explanation.
380
381	The C<$flags> argument is a bitmask. See the C<Fcntl> module for a	418	The C<$flags> argument is a bitmask. See the C<Fcntl> module for a
382	list. They are the same as used by C<sysopen>.	419	list. They are the same as used by C<sysopen>.
383		420
384	Likewise, C<$mode> specifies the mode of the newly created file, if it	421	Likewise, C<$mode> specifies the mode of the newly created file, if it
385	didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>,	422	didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>,
…		…
404	following POSIX and non-POSIX constants are available (missing ones on	441	following POSIX and non-POSIX constants are available (missing ones on
405	your system are, as usual, C<0>):	442	your system are, as usual, C<0>):
406		443
407	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>,
408	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>,
409	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>.
410		447
411		448
412	=item aio_close $fh, $callback->($status)	449	=item aio_close $fh, $callback->($status)
413		450
414	Asynchronously close a file and call the callback with the result	451	Asynchronously close a file and call the callback with the result
…		…
540		577
541	=item aio_stat $fh_or_path, $callback->($status)	578	=item aio_stat $fh_or_path, $callback->($status)
542		579
543	=item aio_lstat $fh, $callback->($status)	580	=item aio_lstat $fh, $callback->($status)
544		581
545	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
546	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
547	or C<-s _> etc...	584	using C<stat _> or C<-s _> and other tests (with the exception of C<-B>
548		585	and C<-T>).
549	The pathname passed to C<aio_stat> must be absolute. See API NOTES, above,
550	for an explanation.
551		586
552	Currently, the stats are always 64-bit-stats, i.e. instead of returning an	587	Currently, the stats are always 64-bit-stats, i.e. instead of returning an
553	error when stat'ing a large file, the results will be silently truncated	588	error when stat'ing a large file, the results will be silently truncated
554	unless perl itself is compiled with large file support.	589	unless perl itself is compiled with large file support.
555		590
…		…
559	behaviour).	594	behaviour).
560		595
561	C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>,	596	C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>,
562	C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>,	597	C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>,
563	C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>.	598	C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>.
		599
		600	To access higher resolution stat timestamps, see L<SUBSECOND STAT TIME
		601	ACCESS>.
564		602
565	Example: Print the length of F</etc/passwd>:	603	Example: Print the length of F</etc/passwd>:
566		604
567	aio_stat "/etc/passwd", sub {	605	aio_stat "/etc/passwd", sub {
568	$_[0] and die "stat failed: $!";	606	$_[0] and die "stat failed: $!";
…		…
618		656
619	Works like perl's C<utime> function (including the special case of $atime	657	Works like perl's C<utime> function (including the special case of $atime
620	and $mtime being undef). Fractional times are supported if the underlying	658	and $mtime being undef). Fractional times are supported if the underlying
621	syscalls support them.	659	syscalls support them.
622		660
623	When called with a pathname, uses utimes(2) if available, otherwise	661	When called with a pathname, uses utimensat(2) or utimes(2) if available,
624	utime(2). If called on a file descriptor, uses futimes(2) if available,	662	otherwise utime(2). If called on a file descriptor, uses futimens(2)
625	otherwise returns ENOSYS, so this is not portable.	663	or futimes(2) if available, otherwise returns ENOSYS, so this is not
		664	portable.
626		665
627	Examples:	666	Examples:
628		667
629	# set atime and mtime to current time (basically touch(1)):	668	# set atime and mtime to current time (basically touch(1)):
630	aio_utime "path", undef, undef;	669	aio_utime "path", undef, undef;
…		…
789		828
790	=over 4	829	=over 4
791		830
792	=item IO::AIO::READDIR_DENTS	831	=item IO::AIO::READDIR_DENTS
793		832
794	When this flag is off, then the callback gets an arrayref consisting of	833	Normally the callback gets an arrayref consisting of names only (as
795	names only (as with C<aio_readdir>), otherwise it gets an arrayref with	834	with C<aio_readdir>). If this flag is set, then the callback gets an
796	C<[$name, $type, $inode]> arrayrefs, each describing a single directory	835	arrayref with C<[$name, $type, $inode]> arrayrefs, each describing a
797	entry in more detail.	836	single directory entry in more detail:
798		837
799	C<$name> is the name of the entry.	838	C<$name> is the name of the entry.
800		839
801	C<$type> is one of the C<IO::AIO::DT_xxx> constants:	840	C<$type> is one of the C<IO::AIO::DT_xxx> constants:
802		841
803	C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,	842	C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
804	C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,	843	C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
805	C<IO::AIO::DT_WHT>.	844	C<IO::AIO::DT_WHT>.
806		845
807	C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to	846	C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need
808	know, you have to run stat yourself. Also, for speed reasons, the C<$type>	847	to know, you have to run stat yourself. Also, for speed/memory reasons,
809	scalars are read-only: you can not modify them.	848	the C<$type> scalars are read-only: you must not modify them.
810		849
811	C<$inode> is the inode number (which might not be exact on systems with 64	850	C<$inode> is the inode number (which might not be exact on systems with 64
812	bit inode numbers and 32 bit perls). This field has unspecified content on	851	bit inode numbers and 32 bit perls). This field has unspecified content on
813	systems that do not deliver the inode information.	852	systems that do not deliver the inode information.
814		853
…		…
825	short names are tried first.	864	short names are tried first.
826		865
827	=item IO::AIO::READDIR_STAT_ORDER	866	=item IO::AIO::READDIR_STAT_ORDER
828		867
829	When this flag is set, then the names will be returned in an order	868	When this flag is set, then the names will be returned in an order
830	suitable for stat()'ing each one. That is, when you plan to stat()	869	suitable for stat()'ing each one. That is, when you plan to stat() most or
831	all files in the given directory, then the returned order will likely	870	all files in the given directory, then the returned order will likely be
832	be fastest.	871	faster.
833		872
834	If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then	873	If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified,
835	the likely dirs come first, resulting in a less optimal stat order.	874	then the likely dirs come first, resulting in a less optimal stat order
		875	for stat'ing all entries, but likely a more optimal order for finding
		876	subdirectories.
836		877
837	=item IO::AIO::READDIR_FOUND_UNKNOWN	878	=item IO::AIO::READDIR_FOUND_UNKNOWN
838		879
839	This flag should not be set when calling C<aio_readdirx>. Instead, it	880	This flag should not be set when calling C<aio_readdirx>. Instead, it
840	is being set by C<aio_readdirx>, when any of the C<$type>'s found were	881	is being set by C<aio_readdirx>, when any of the C<$type>'s found were
…		…
934	my @stat = stat $src_fh; # hmm, might block over nfs?	975	my @stat = stat $src_fh; # hmm, might block over nfs?
935		976
936	aioreq_pri $pri;	977	aioreq_pri $pri;
937	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {	978	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {
938	if (my $dst_fh = $_[0]) {	979	if (my $dst_fh = $_[0]) {
		980
		981	# best-effort preallocate
		982	aioreq_pri $pri;
		983	add $grp aio_allocate $dst_fh, IO::AIO::FALLOC_FL_KEEP_SIZE, 0, $stat[7], sub { };
		984
939	aioreq_pri $pri;	985	aioreq_pri $pri;
940	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {	986	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
941	if ($_[0] == $stat[7]) {	987	if ($_[0] == $stat[7]) {
942	$grp->result (0);	988	$grp->result (0);
943	close $src_fh;	989	close $src_fh;
…		…
1101	aioreq_pri $pri;	1147	aioreq_pri $pri;
1102	add $grp aio_stat $wd, sub {	1148	add $grp aio_stat $wd, sub {
1103	return $grp->result () if $_[0];	1149	return $grp->result () if $_[0];
1104	my $now = time;	1150	my $now = time;
1105	my $hash1 = join ":", (stat _)[0,1,3,7,9];	1151	my $hash1 = join ":", (stat _)[0,1,3,7,9];
		1152	my $rdxflags = READDIR_DIRS_FIRST;
		1153
		1154	if ((stat _)[3] < 2) {
		1155	# at least one non-POSIX filesystem exists
		1156	# that returns useful DT_type values: btrfs,
		1157	# so optimise for this here by requesting dents
		1158	$rdxflags \|= READDIR_DENTS;
		1159	}
1106		1160
1107	# read the directory entries	1161	# read the directory entries
1108	aioreq_pri $pri;	1162	aioreq_pri $pri;
1109	add $grp aio_readdirx $wd, READDIR_DIRS_FIRST, sub {	1163	add $grp aio_readdirx $wd, $rdxflags, sub {
1110	my $entries = shift	1164	my ($entries, $flags) = @_
1111	or return $grp->result ();	1165	or return $grp->result ();
		1166
		1167	if ($rdxflags & READDIR_DENTS) {
		1168	# if we requested type values, see if we can use them directly.
		1169
		1170	# if there were any DT_UNKNOWN entries then we assume we
		1171	# don't know. alternatively, we could assume that if we get
		1172	# one DT_DIR, then all directories are indeed marked with
		1173	# DT_DIR, but this seems not required for btrfs, and this
		1174	# is basically the "btrfs can't get it's act together" code
		1175	# branch.
		1176	unless ($flags & READDIR_FOUND_UNKNOWN) {
		1177	# now we have valid DT_ information for all entries,
		1178	# so use it as an optimisation without further stat's.
		1179	# they must also all be at the beginning of @$entries
		1180	# by now.
		1181
		1182	my $dirs;
		1183
		1184	if (@$entries) {
		1185	for (0 .. $#$entries) {
		1186	if ($entries->[$_][1] != DT_DIR) {
		1187	# splice out directories
		1188	$dirs = [splice @$entries, 0, $_];
		1189	last;
		1190	}
		1191	}
		1192
		1193	# if we didn't find any non-dir, then all entries are dirs
		1194	unless ($dirs) {
		1195	($dirs, $entries) = ($entries, []);
		1196	}
		1197	} else {
		1198	# directory is empty, so there are no sbdirs
		1199	$dirs = [];
		1200	}
		1201
		1202	# either splice'd the directories out or the dir was empty.
		1203	# convert dents to filenames
		1204	$_ = $_->[0] for @$dirs;
		1205	$_ = $_->[0] for @$entries;
		1206
		1207	return $grp->result ($dirs, $entries);
		1208	}
		1209
		1210	# cannot use, so return to our old ways
		1211	# by pretending we only scanned for names.
		1212	$_ = $_->[0] for @$entries;
		1213	}
1112		1214
1113	# stat the dir another time	1215	# stat the dir another time
1114	aioreq_pri $pri;	1216	aioreq_pri $pri;
1115	add $grp aio_stat $wd, sub {	1217	add $grp aio_stat $wd, sub {
1116	my $hash2 = join ":", (stat _)[0,1,3,7,9];	1218	my $hash2 = join ":", (stat _)[0,1,3,7,9];
…		…
1222	So in general, you should only use these calls for things that do	1324	So in general, you should only use these calls for things that do
1223	(filesystem) I/O, not for things that wait for other events (network,	1325	(filesystem) I/O, not for things that wait for other events (network,
1224	other processes), although if you are careful and know what you are doing,	1326	other processes), although if you are careful and know what you are doing,
1225	you still can.	1327	you still can.
1226		1328
1227	The following constants are available (missing ones are, as usual C<0>):	1329	The following constants are available and can be used for normal C<ioctl>
		1330	and C<fcntl> as well (missing ones are, as usual C<0>):
1228		1331
1229	C<F_DUPFD_CLOEXEC>,	1332	C<F_DUPFD_CLOEXEC>,
1230		1333
1231	C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>,	1334	C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>,
1232		1335
1233	C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>.	1336	C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>.
		1337
		1338	C<F_ADD_SEALS>, C<F_GET_SEALS>, C<F_SEAL_SEAL>, C<F_SEAL_SHRINK>, C<F_SEAL_GROW> and
		1339	C<F_SEAL_WRITE>.
1234		1340
1235	C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>,	1341	C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>,
1236	C<FS_IOC_FIEMAP>.	1342	C<FS_IOC_FIEMAP>.
1237		1343
1238	C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>,	1344	C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>,
…		…
1246		1352
1247	C<FS_XFLAG_REALTIME>, C<FS_XFLAG_PREALLOC>, C<FS_XFLAG_IMMUTABLE>, C<FS_XFLAG_APPEND>,	1353	C<FS_XFLAG_REALTIME>, C<FS_XFLAG_PREALLOC>, C<FS_XFLAG_IMMUTABLE>, C<FS_XFLAG_APPEND>,
1248	C<FS_XFLAG_SYNC>, C<FS_XFLAG_NOATIME>, C<FS_XFLAG_NODUMP>, C<FS_XFLAG_RTINHERIT>,	1354	C<FS_XFLAG_SYNC>, C<FS_XFLAG_NOATIME>, C<FS_XFLAG_NODUMP>, C<FS_XFLAG_RTINHERIT>,
1249	C<FS_XFLAG_PROJINHERIT>, C<FS_XFLAG_NOSYMLINKS>, C<FS_XFLAG_EXTSIZE>, C<FS_XFLAG_EXTSZINHERIT>,	1355	C<FS_XFLAG_PROJINHERIT>, C<FS_XFLAG_NOSYMLINKS>, C<FS_XFLAG_EXTSIZE>, C<FS_XFLAG_EXTSZINHERIT>,
1250	C<FS_XFLAG_NODEFRAG>, C<FS_XFLAG_FILESTREAM>, C<FS_XFLAG_DAX>, C<FS_XFLAG_HASATTR>,	1356	C<FS_XFLAG_NODEFRAG>, C<FS_XFLAG_FILESTREAM>, C<FS_XFLAG_DAX>, C<FS_XFLAG_HASATTR>,
		1357
		1358	C<BLKROSET>, C<BLKROGET>, C<BLKRRPART>, C<BLKGETSIZE>, C<BLKFLSBUF>, C<BLKRASET>,
		1359	C<BLKRAGET>, C<BLKFRASET>, C<BLKFRAGET>, C<BLKSECTSET>, C<BLKSECTGET>, C<BLKSSZGET>,
		1360	C<BLKBSZGET>, C<BLKBSZSET>, C<BLKGETSIZE64>,
		1361
1251		1362
1252	=item aio_sync $callback->($status)	1363	=item aio_sync $callback->($status)
1253		1364
1254	Asynchronously call sync and call the callback when finished.	1365	Asynchronously call sync and call the callback when finished.
1255		1366
…		…
1377	IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;	1488	IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
1378	aio_mlock $data; # mlock in background	1489	aio_mlock $data; # mlock in background
1379		1490
1380	=item aio_mlockall $flags, $callback->($status)	1491	=item aio_mlockall $flags, $callback->($status)
1381		1492
1382	Calls the C<mlockall> function with the given C<$flags> (a combination of	1493	Calls the C<mlockall> function with the given C<$flags> (a
1383	C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).	1494	combination of C<IO::AIO::MCL_CURRENT>, C<IO::AIO::MCL_FUTURE> and
		1495	C<IO::AIO::MCL_ONFAULT>).
1384		1496
1385	On systems that do not implement C<mlockall>, this function returns C<-1>	1497	On systems that do not implement C<mlockall>, this function returns C<-1>
1386	and sets errno to C<ENOSYS>.	1498	and sets errno to C<ENOSYS>. Similarly, flag combinations not supported
		1499	by the system result in a return value of C<-1> with errno being set to
		1500	C<EINVAL>.
1387		1501
1388	Note that the corresponding C<munlockall> is synchronous and is	1502	Note that the corresponding C<munlockall> is synchronous and is
1389	documented under L<MISCELLANEOUS FUNCTIONS>.	1503	documented under L<MISCELLANEOUS FUNCTIONS>.
1390		1504
1391	Example: asynchronously lock all current and future pages into memory.	1505	Example: asynchronously lock all current and future pages into memory.
…		…
1585	C<aio_wd> callback, as future requests using the value will fail in the	1699	C<aio_wd> callback, as future requests using the value will fail in the
1586	expected way.	1700	expected way.
1587		1701
1588	=item IO::AIO::CWD	1702	=item IO::AIO::CWD
1589		1703
1590	This is a compiletime constant (object) that represents the process	1704	This is a compile time constant (object) that represents the process
1591	current working directory.	1705	current working directory.
1592		1706
1593	Specifying this object as working directory object for a pathname is as if	1707	Specifying this object as working directory object for a pathname is as if
1594	the pathname would be specified directly, without a directory object. For	1708	the pathname would be specified directly, without a directory object. For
1595	example, these calls are functionally identical:	1709	example, these calls are functionally identical:
…		…
1776	The default value for the limit is C<0>, but note that setting a feeder	1890	The default value for the limit is C<0>, but note that setting a feeder
1777	automatically bumps it up to C<2>.	1891	automatically bumps it up to C<2>.
1778		1892
1779	=back	1893	=back
1780		1894
		1895
1781	=head2 SUPPORT FUNCTIONS	1896	=head2 SUPPORT FUNCTIONS
1782		1897
1783	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION	1898	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
1784		1899
1785	=over 4	1900	=over 4
…		…
1850	Strictly equivalent to:	1965	Strictly equivalent to:
1851		1966
1852	IO::AIO::poll_wait, IO::AIO::poll_cb	1967	IO::AIO::poll_wait, IO::AIO::poll_cb
1853	while IO::AIO::nreqs;	1968	while IO::AIO::nreqs;
1854		1969
		1970	This function can be useful at program aborts, to make sure outstanding
		1971	I/O has been done (C<IO::AIO> uses an C<END> block which already calls
		1972	this function on normal exits), or when you are merely using C<IO::AIO>
		1973	for its more advanced functions, rather than for async I/O, e.g.:
		1974
		1975	my ($dirs, $nondirs);
		1976	IO::AIO::aio_scandir "/tmp", 0, sub { ($dirs, $nondirs) = @_ };
		1977	IO::AIO::flush;
		1978	# $dirs, $nondirs are now set
		1979
1855	=item IO::AIO::max_poll_reqs $nreqs	1980	=item IO::AIO::max_poll_reqs $nreqs
1856		1981
1857	=item IO::AIO::max_poll_time $seconds	1982	=item IO::AIO::max_poll_time $seconds
1858		1983
1859	These set the maximum number of requests (default C<0>, meaning infinity)	1984	These set the maximum number of requests (default C<0>, meaning infinity)
…		…
1885	poll => 'r', nice => 1,	2010	poll => 'r', nice => 1,
1886	cb => &IO::AIO::poll_cb);	2011	cb => &IO::AIO::poll_cb);
1887		2012
1888	=back	2013	=back
1889		2014
		2015
1890	=head3 CONTROLLING THE NUMBER OF THREADS	2016	=head3 CONTROLLING THE NUMBER OF THREADS
1891		2017
1892	=over	2018	=over
1893		2019
1894	=item IO::AIO::min_parallel $nthreads	2020	=item IO::AIO::min_parallel $nthreads
…		…
1955	longer exceeded.	2081	longer exceeded.
1956		2082
1957	In other words, this setting does not enforce a queue limit, but can be	2083	In other words, this setting does not enforce a queue limit, but can be
1958	used to make poll functions block if the limit is exceeded.	2084	used to make poll functions block if the limit is exceeded.
1959		2085
1960	This is a very bad function to use in interactive programs because it	2086	This is a bad function to use in interactive programs because it blocks,
1961	blocks, and a bad way to reduce concurrency because it is inexact: Better	2087	and a bad way to reduce concurrency because it is inexact. If you need to
		2088	issue many requests without being able to call a poll function on demand,
1962	use an C<aio_group> together with a feed callback.	2089	it is better to use an C<aio_group> together with a feed callback.
1963		2090
1964	Its main use is in scripts without an event loop - when you want to stat	2091	Its main use is in scripts without an event loop - when you want to stat a
1965	a lot of files, you can write something like this:	2092	lot of files, you can write something like this:
1966		2093
1967	IO::AIO::max_outstanding 32;	2094	IO::AIO::max_outstanding 32;
1968		2095
1969	for my $path (...) {	2096	for my $path (...) {
1970	aio_stat $path , ...;	2097	aio_stat $path , ...;
1971	IO::AIO::poll_cb;	2098	IO::AIO::poll_cb;
1972	}	2099	}
1973		2100
1974	IO::AIO::flush;	2101	IO::AIO::flush;
1975		2102
1976	The call to C<poll_cb> inside the loop will normally return instantly, but	2103	The call to C<poll_cb> inside the loop will normally return instantly,
1977	as soon as more thna C<32> reqeusts are in-flight, it will block until	2104	allowing the loop to progress, but as soon as more than C<32> requests
1978	some requests have been handled. This keeps the loop from pushing a large	2105	are in-flight, it will block until some requests have been handled. This
1979	number of C<aio_stat> requests onto the queue.	2106	keeps the loop from pushing a large number of C<aio_stat> requests onto
		2107	the queue (which, with many paths to stat, can use up a lot of memory).
1980		2108
1981	The default value for C<max_outstanding> is very large, so there is no	2109	The default value for C<max_outstanding> is very large, so there is no
1982	practical limit on the number of outstanding requests.	2110	practical limit on the number of outstanding requests.
1983		2111
1984	=back	2112	=back
1985		2113
		2114
1986	=head3 STATISTICAL INFORMATION	2115	=head3 STATISTICAL INFORMATION
1987		2116
1988	=over	2117	=over
1989		2118
1990	=item IO::AIO::nreqs	2119	=item IO::AIO::nreqs
…		…
2006		2135
2007	Returns the number of requests currently in the pending state (executed,	2136	Returns the number of requests currently in the pending state (executed,
2008	but not yet processed by poll_cb).	2137	but not yet processed by poll_cb).
2009		2138
2010	=back	2139	=back
		2140
		2141
		2142	=head3 SUBSECOND STAT TIME ACCESS
		2143
		2144	Both C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> functions can
		2145	generally find access/modification and change times with subsecond time
		2146	accuracy of the system supports it, but perl's built-in functions only
		2147	return the integer part.
		2148
		2149	The following functions return the timestamps of the most recent
		2150	stat with subsecond precision on most systems and work both after
		2151	C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> calls. Their return
		2152	value is only meaningful after a successful C<stat>/C<lstat> call, or
		2153	during/after a successful C<aio_stat>/C<aio_lstat> callback.
		2154
		2155	This is similar to the L<Time::HiRes> C<stat> functions, but can return
		2156	full resolution without rounding and work with standard perl C<stat>,
		2157	alleviating the need to call the special C<Time::HiRes> functions, which
		2158	do not act like their perl counterparts.
		2159
		2160	On operating systems or file systems where subsecond time resolution is
		2161	not supported or could not be detected, a fractional part of C<0> is
		2162	returned, so it is always safe to call these functions.
		2163
		2164	=over 4
		2165
		2166	=item $seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime, IO::AIO::st_btime
		2167
		2168	Return the access, modication, change or birth time, respectively,
		2169	including fractional part. Due to the limited precision of floating point,
		2170	the accuracy on most platforms is only a bit better than milliseconds
		2171	for times around now - see the I<nsec> function family, below, for full
		2172	accuracy.
		2173
		2174	File birth time is only available when the OS and perl support it (on
		2175	FreeBSD and NetBSD at the time of this writing, although support is
		2176	adaptive, so if your OS/perl gains support, IO::AIO can take advantage of
		2177	it). On systems where it isn't available, C<0> is currently returned, but
		2178	this might change to C<undef> in a future version.
		2179
		2180	=item ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtime
		2181
		2182	Returns access, modification, change and birth time all in one go, and
		2183	maybe more times in the future version.
		2184
		2185	=item $nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec, IO::AIO::st_ctimensec, IO::AIO::st_btimensec
		2186
		2187	Return the fractional access, modifcation, change or birth time, in nanoseconds,
		2188	as an integer in the range C<0> to C<999999999>.
		2189
		2190	Note that no accessors are provided for access, modification and
		2191	change times - you need to get those from C<stat _> if required (C<int
		2192	IO::AIO::st_atime> and so on will I<not> generally give you the correct
		2193	value).
		2194
		2195	=item $seconds = IO::AIO::st_btimesec
		2196
		2197	The (integral) seconds part of the file birth time, if available.
		2198
		2199	=item ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtimensec
		2200
		2201	Like the functions above, but returns all four times in one go (and maybe
		2202	more in future versions).
		2203
		2204	=item $counter = IO::AIO::st_gen
		2205
		2206	Returns the generation counter (in practice this is just a random number)
		2207	of the file. This is only available on platforms which have this member in
		2208	their C<struct stat> (most BSDs at the time of this writing) and generally
		2209	only to the root usert. If unsupported, C<0> is returned, but this might
		2210	change to C<undef> in a future version.
		2211
		2212	=back
		2213
		2214	Example: print the high resolution modification time of F</etc>, using
		2215	C<stat>, and C<IO::AIO::aio_stat>.
		2216
		2217	if (stat "/etc") {
		2218	printf "stat(/etc) mtime: %f\n", IO::AIO::st_mtime;
		2219	}
		2220
		2221	IO::AIO::aio_stat "/etc", sub {
		2222	$_[0]
		2223	and return;
		2224
		2225	printf "aio_stat(/etc) mtime: %d.%09d\n", (stat _)[9], IO::AIO::st_mtimensec;
		2226	};
		2227
		2228	IO::AIO::flush;
		2229
		2230	Output of the awbove on my system, showing reduced and full accuracy:
		2231
		2232	stat(/etc) mtime: 1534043702.020808
		2233	aio_stat(/etc) mtime: 1534043702.020807792
		2234
2011		2235
2012	=head3 MISCELLANEOUS FUNCTIONS	2236	=head3 MISCELLANEOUS FUNCTIONS
2013		2237
2014	IO::AIO implements some functions that are useful when you want to use	2238	IO::AIO implements some functions that are useful when you want to use
2015	some "Advanced I/O" function not available to in Perl, without going the	2239	some "Advanced I/O" function not available to in Perl, without going the
2016	"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*>	2240	"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*>
2017	counterpart.	2241	counterpart.
2018		2242
2019	=over 4	2243	=over 4
2020		2244
		2245	=item $retval = IO::AIO::fexecve $fh, $argv, $envp
		2246
		2247	A more-or-less direct equivalent to the POSIX C<fexecve> functions, which
		2248	allows you to specify the program to be executed via a file descriptor (or
		2249	handle). Returns C<-1> and sets errno to C<ENOSYS> if not available.
		2250
		2251	=item $retval = IO::AIO::mount $special, $path, $fstype, $flags = 0, $data = undef
		2252
		2253	Calls the GNU/Linux mount syscall with the given arguments. All except
		2254	C<$flags> are strings, and if C<$data> is C<undef>, a C<NULL> will be
		2255	passed.
		2256
		2257	The following values for C<$flags> are available:
		2258
		2259	C<IO::AIO::MS_RDONLY>, C<IO::AIO::MS_NOSUID>, C<IO::AIO::MS_NODEV>, C<IO::AIO::MS_NOEXEC>, C<IO::AIO::MS_SYNCHRONOUS>,
		2260	C<IO::AIO::MS_REMOUNT>, C<IO::AIO::MS_MANDLOCK>, C<IO::AIO::MS_DIRSYNC>, C<IO::AIO::MS_NOATIME>,
		2261	C<IO::AIO::MS_NODIRATIME>, C<IO::AIO::MS_BIND>, C<IO::AIO::MS_MOVE>, C<IO::AIO::MS_REC>, C<IO::AIO::MS_SILENT>,
		2262	C<IO::AIO::MS_POSIXACL>, C<IO::AIO::MS_UNBINDABLE>, C<IO::AIO::MS_PRIVATE>, C<IO::AIO::MS_SLAVE>, C<IO::AIO::MS_SHARED>,
		2263	C<IO::AIO::MS_RELATIME>, C<IO::AIO::MS_KERNMOUNT>, C<IO::AIO::MS_I_VERSION>, C<IO::AIO::MS_STRICTATIME>,
		2264	C<IO::AIO::MS_LAZYTIME>, C<IO::AIO::MS_ACTIVE>, C<IO::AIO::MS_NOUSER>, C<IO::AIO::MS_RMT_MASK>, C<IO::AIO::MS_MGC_VAL> and
		2265	C<IO::AIO::MS_MGC_MSK>.
		2266
		2267	=item $retval = IO::AIO::umount $path, $flags = 0
		2268
		2269	Invokes the GNU/Linux C<umount> or C<umount2> syscalls. Always calls
		2270	C<umount> if C<$flags> is C<0>, otherwqise always tries to call
		2271	C<umount2>.
		2272
		2273	The following C<$flags> are available:
		2274
		2275	C<IO::AIO::MNT_FORCE>, C<IO::AIO::MNT_DETACH>, C<IO::AIO::MNT_EXPIRE> and C<IO::AIO::UMOUNT_NOFOLLOW>.
		2276
2021	=item $numfd = IO::AIO::get_fdlimit	2277	=item $numfd = IO::AIO::get_fdlimit
2022
2023	This function is I<EXPERIMENTAL> and subject to change.
2024		2278
2025	Tries to find the current file descriptor limit and returns it, or	2279	Tries to find the current file descriptor limit and returns it, or
2026	C<undef> and sets C<$!> in case of an error. The limit is one larger than	2280	C<undef> and sets C<$!> in case of an error. The limit is one larger than
2027	the highest valid file descriptor number.	2281	the highest valid file descriptor number.
2028		2282
2029	=item IO::AIO::min_fdlimit [$numfd]	2283	=item IO::AIO::min_fdlimit [$numfd]
2030
2031	This function is I<EXPERIMENTAL> and subject to change.
2032		2284
2033	Try to increase the current file descriptor limit(s) to at least C<$numfd>	2285	Try to increase the current file descriptor limit(s) to at least C<$numfd>
2034	by changing the soft or hard file descriptor resource limit. If C<$numfd>	2286	by changing the soft or hard file descriptor resource limit. If C<$numfd>
2035	is missing, it will try to set a very high limit, although this is not	2287	is missing, it will try to set a very high limit, although this is not
2036	recommended when you know the actual minimum that you require.	2288	recommended when you know the actual minimum that you require.
…		…
2131	C<IO::AIO::MAP_POPULATE>,	2383	C<IO::AIO::MAP_POPULATE>,
2132	C<IO::AIO::MAP_NONBLOCK>,	2384	C<IO::AIO::MAP_NONBLOCK>,
2133	C<IO::AIO::MAP_FIXED>,	2385	C<IO::AIO::MAP_FIXED>,
2134	C<IO::AIO::MAP_GROWSDOWN>,	2386	C<IO::AIO::MAP_GROWSDOWN>,
2135	C<IO::AIO::MAP_32BIT>,	2387	C<IO::AIO::MAP_32BIT>,
2136	C<IO::AIO::MAP_HUGETLB> or	2388	C<IO::AIO::MAP_HUGETLB>,
2137	C<IO::AIO::MAP_STACK>.	2389	C<IO::AIO::MAP_STACK>,
		2390	C<IO::AIO::MAP_FIXED_NOREPLACE>,
		2391	C<IO::AIO::MAP_SHARED_VALIDATE>,
		2392	C<IO::AIO::MAP_SYNC> or
		2393	C<IO::AIO::MAP_UNINITIALIZED>.
2138		2394
2139	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.	2395	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
2140		2396
2141	C<$offset> is the offset from the start of the file - it generally must be	2397	C<$offset> is the offset from the start of the file - it generally must be
2142	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.	2398	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
…		…
2156		2412
2157	=item IO::AIO::munmap $scalar	2413	=item IO::AIO::munmap $scalar
2158		2414
2159	Removes a previous mmap and undefines the C<$scalar>.	2415	Removes a previous mmap and undefines the C<$scalar>.
2160		2416
		2417	=item IO::AIO::mremap $scalar, $new_length, $flags = MREMAP_MAYMOVE[, $new_address = 0]
		2418
		2419	Calls the Linux-specific mremap(2) system call. The C<$scalar> must have
		2420	been mapped by C<IO::AIO::mmap>, and C<$flags> must currently either be
		2421	C<0> or C<IO::AIO::MREMAP_MAYMOVE>.
		2422
		2423	Returns true if successful, and false otherwise. If the underlying mmapped
		2424	region has changed address, then the true value has the numerical value
		2425	C<1>, otherwise it has the numerical value C<0>:
		2426
		2427	my $success = IO::AIO::mremap $mmapped, 8192, IO::AIO::MREMAP_MAYMOVE
		2428	or die "mremap: $!";
		2429
		2430	if ($success*1) {
		2431	warn "scalar has chanegd address in memory\n";
		2432	}
		2433
		2434	C<IO::AIO::MREMAP_FIXED> and the C<$new_address> argument are currently
		2435	implemented, but not supported and might go away in a future version.
		2436
		2437	On systems where this call is not supported or is not emulated, this call
		2438	returns falls and sets C<$!> to C<ENOSYS>.
		2439
		2440	=item IO::AIO::mlockall $flags
		2441
		2442	Calls the C<eio_mlockall_sync> function, which is like C<aio_mlockall>,
		2443	but is blocking.
		2444
2161	=item IO::AIO::munlock $scalar, $offset = 0, $length = undef	2445	=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
2162		2446
2163	Calls the C<munlock> function, undoing the effects of a previous	2447	Calls the C<munlock> function, undoing the effects of a previous
2164	C<aio_mlock> call (see its description for details).	2448	C<aio_mlock> call (see its description for details).
2165		2449
…		…
2167		2451
2168	Calls the C<munlockall> function.	2452	Calls the C<munlockall> function.
2169		2453
2170	On systems that do not implement C<munlockall>, this function returns	2454	On systems that do not implement C<munlockall>, this function returns
2171	ENOSYS, otherwise the return value of C<munlockall>.	2455	ENOSYS, otherwise the return value of C<munlockall>.
		2456
		2457	=item $fh = IO::AIO::accept4 $r_fh, $sockaddr, $sockaddr_maxlen, $flags
		2458
		2459	Uses the GNU/Linux C<accept4(2)> syscall, if available, to accept a socket
		2460	and return the new file handle on success, or sets C<$!> and returns
		2461	C<undef> on error.
		2462
		2463	The remote name of the new socket will be stored in C<$sockaddr>, which
		2464	will be extended to allow for at least C<$sockaddr_maxlen> octets. If the
		2465	socket name does not fit into C<$sockaddr_maxlen> octets, this is signaled
		2466	by returning a longer string in C<$sockaddr>, which might or might not be
		2467	truncated.
		2468
		2469	To accept name-less sockets, use C<undef> for C<$sockaddr> and C<0> for
		2470	C<$sockaddr_maxlen>.
		2471
		2472	The main reasons to use this syscall rather than portable C<accept(2)>
		2473	are that you can specify C<SOCK_NONBLOCK> and/or C<SOCK_CLOEXEC>
		2474	flags and you can accept name-less sockets by specifying C<0> for
		2475	C<$sockaddr_maxlen>, which is sadly not possible with perl's interface to
		2476	C<accept>.
2172		2477
2173	=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags	2478	=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
2174		2479
2175	Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or	2480	Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or
2176	C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they	2481	C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
…		…
2220	Example: create a pipe race-free w.r.t. threads and fork:	2525	Example: create a pipe race-free w.r.t. threads and fork:
2221		2526
2222	my ($rfh, $wfh) = IO::AIO::pipe2 IO::AIO::O_CLOEXEC	2527	my ($rfh, $wfh) = IO::AIO::pipe2 IO::AIO::O_CLOEXEC
2223	or die "pipe2: $!\n";	2528	or die "pipe2: $!\n";
2224		2529
		2530	=item $fh = IO::AIO::memfd_create $pathname[, $flags]
		2531
		2532	This is a direct interface to the Linux L<memfd_create(2)> system
		2533	call. The (unhelpful) default for C<$flags> is C<0>, but your default
		2534	should be C<IO::AIO::MFD_CLOEXEC>.
		2535
		2536	On success, the new memfd filehandle is returned, otherwise returns
		2537	C<undef>. If the memfd_create syscall is missing, fails with C<ENOSYS>.
		2538
		2539	Please refer to L<memfd_create(2)> for more info on this call.
		2540
		2541	The following C<$flags> values are available: C<IO::AIO::MFD_CLOEXEC>,
		2542	C<IO::AIO::MFD_ALLOW_SEALING>, C<IO::AIO::MFD_HUGETLB>,
		2543	C<IO::AIO::MFD_HUGETLB_2MB> and C<IO::AIO::MFD_HUGETLB_1GB>.
		2544
		2545	Example: create a new memfd.
		2546
		2547	my $fh = IO::AIO::memfd_create "somenameforprocfd", IO::AIO::MFD_CLOEXEC
		2548	or die "memfd_create: $!\n";
		2549
		2550	=item $fh = IO::AIO::pidfd_open $pid[, $flags]
		2551
		2552	This is an interface to the Linux L<pidfd_open(2)> system call. The
		2553	default for C<$flags> is C<0>.
		2554
		2555	On success, a new pidfd filehandle is returned (that is already set to
		2556	close-on-exec), otherwise returns C<undef>. If the syscall is missing,
		2557	fails with C<ENOSYS>.
		2558
		2559	Example: open pid 6341 as pidfd.
		2560
		2561	my $fh = IO::AIO::pidfd_open 6341
		2562	or die "pidfd_open: $!\n";
		2563
		2564	=item $status = IO::AIO::pidfd_send_signal $pidfh, $signal[, $siginfo[, $flags]]
		2565
		2566	This is an interface to the Linux L<pidfd_send_signal> system call. The
		2567	default for C<$siginfo> is C<undef> and the default for C<$flags> is C<0>.
		2568
		2569	Returns the system call status. If the syscall is missing, fails with
		2570	C<ENOSYS>.
		2571
		2572	When specified, C<$siginfo> must be a reference to a hash with one or more
		2573	of the following members:
		2574
		2575	=over
		2576
		2577	=item code - the C<si_code> member
		2578
		2579	=item pid - the C<si_pid> member
		2580
		2581	=item uid - the C<si_uid> member
		2582
		2583	=item value_int - the C<si_value.sival_int> member
		2584
		2585	=item value_ptr - the C<si_value.sival_ptr> member, specified as an integer
		2586
		2587	=back
		2588
		2589	Example: send a SIGKILL to the specified process.
		2590
		2591	my $status = IO::AIO::pidfd_send_signal $pidfh, 9, undef
		2592	and die "pidfd_send_signal: $!\n";
		2593
		2594	Example: send a SIGKILL to the specified process with extra data.
		2595
		2596	my $status = IO::AIO::pidfd_send_signal $pidfh, 9, { code => -1, value_int => 7 }
		2597	and die "pidfd_send_signal: $!\n";
		2598
		2599	=item $fh = IO::AIO::pidfd_getfd $pidfh, $targetfd[, $flags]
		2600
		2601	This is an interface to the Linux L<pidfd_getfd> system call. The default
		2602	for C<$flags> is C<0>.
		2603
		2604	On success, returns a dup'ed copy of the target file descriptor (specified
		2605	as an integer) returned (that is already set to close-on-exec), otherwise
		2606	returns C<undef>. If the syscall is missing, fails with C<ENOSYS>.
		2607
		2608	Example: get a copy of standard error of another process and print soemthing to it.
		2609
		2610	my $errfh = IO::AIO::pidfd_getfd $pidfh, 2
		2611	or die "pidfd_getfd: $!\n";
		2612	print $errfh "stderr\n";
		2613
2225	=item $fh = IO::AIO::eventfd ([$initval, [$flags]])	2614	=item $fh = IO::AIO::eventfd [$initval, [$flags]]
2226		2615
2227	This is a direct interface to the Linux L<eventfd(2)> system call. The	2616	This is a direct interface to the Linux L<eventfd(2)> system call. The
2228	(unhelpful) defaults for C<$initval> and C<$flags> are C<0> for both.	2617	(unhelpful) defaults for C<$initval> and C<$flags> are C<0> for both.
2229		2618
2230	On success, the new eventfd filehandle is returned, otherwise returns	2619	On success, the new eventfd filehandle is returned, otherwise returns
…		…
2232		2621
2233	Please refer to L<eventfd(2)> for more info on this call.	2622	Please refer to L<eventfd(2)> for more info on this call.
2234		2623
2235	The following symbol flag values are available: C<IO::AIO::EFD_CLOEXEC>,	2624	The following symbol flag values are available: C<IO::AIO::EFD_CLOEXEC>,
2236	C<IO::AIO::EFD_NONBLOCK> and C<IO::AIO::EFD_SEMAPHORE> (Linux 2.6.30).	2625	C<IO::AIO::EFD_NONBLOCK> and C<IO::AIO::EFD_SEMAPHORE> (Linux 2.6.30).
		2626
		2627	Example: create a new eventfd filehandle:
		2628
		2629	$fh = IO::AIO::eventfd 0, IO::AIO::EFD_CLOEXEC
		2630	or die "eventfd: $!\n";
		2631
		2632	=item $fh = IO::AIO::timerfd_create $clockid[, $flags]
		2633
		2634	This is a direct interface to the Linux L<timerfd_create(2)> system
		2635	call. The (unhelpful) default for C<$flags> is C<0>, but your default
		2636	should be C<IO::AIO::TFD_CLOEXEC>.
		2637
		2638	On success, the new timerfd filehandle is returned, otherwise returns
		2639	C<undef>. If the timerfd_create syscall is missing, fails with C<ENOSYS>.
		2640
		2641	Please refer to L<timerfd_create(2)> for more info on this call.
		2642
		2643	The following C<$clockid> values are
		2644	available: C<IO::AIO::CLOCK_REALTIME>, C<IO::AIO::CLOCK_MONOTONIC>
		2645	C<IO::AIO::CLOCK_CLOCK_BOOTTIME> (Linux 3.15)
		2646	C<IO::AIO::CLOCK_CLOCK_REALTIME_ALARM> (Linux 3.11) and
		2647	C<IO::AIO::CLOCK_CLOCK_BOOTTIME_ALARM> (Linux 3.11).
		2648
		2649	The following C<$flags> values are available (Linux
		2650	2.6.27): C<IO::AIO::TFD_NONBLOCK> and C<IO::AIO::TFD_CLOEXEC>.
		2651
		2652	Example: create a new timerfd and set it to one-second repeated alarms,
		2653	then wait for two alarms:
		2654
		2655	my $fh = IO::AIO::timerfd_create IO::AIO::CLOCK_BOOTTIME, IO::AIO::TFD_CLOEXEC
		2656	or die "timerfd_create: $!\n";
		2657
		2658	defined IO::AIO::timerfd_settime $fh, 0, 1, 1
		2659	or die "timerfd_settime: $!\n";
		2660
		2661	for (1..2) {
		2662	8 == sysread $fh, my $buf, 8
		2663	or die "timerfd read failure\n";
		2664
		2665	printf "number of expirations (likely 1): %d\n",
		2666	unpack "Q", $buf;
		2667	}
		2668
		2669	=item ($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags, $new_interval, $nbw_value
		2670
		2671	This is a direct interface to the Linux L<timerfd_settime(2)> system
		2672	call. Please refer to its manpage for more info on this call.
		2673
		2674	The new itimerspec is specified using two (possibly fractional) second
		2675	values, C<$new_interval> and C<$new_value>).
		2676
		2677	On success, the current interval and value are returned (as per
		2678	C<timerfd_gettime>). On failure, the empty list is returned.
		2679
		2680	The following C<$flags> values are
		2681	available: C<IO::AIO::TFD_TIMER_ABSTIME> and
		2682	C<IO::AIO::TFD_TIMER_CANCEL_ON_SET>.
		2683
		2684	See C<IO::AIO::timerfd_create> for a full example.
		2685
		2686	=item ($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh
		2687
		2688	This is a direct interface to the Linux L<timerfd_gettime(2)> system
		2689	call. Please refer to its manpage for more info on this call.
		2690
		2691	On success, returns the current values of interval and value for the given
		2692	timerfd (as potentially fractional second values). On failure, the empty
		2693	list is returned.
2237		2694
2238	=back	2695	=back
2239		2696
2240	=cut	2697	=cut
2241		2698
…		…
2307	the process will result in undefined behaviour. Calling it at any time	2764	the process will result in undefined behaviour. Calling it at any time
2308	will also result in any undefined (by POSIX) behaviour.	2765	will also result in any undefined (by POSIX) behaviour.
2309		2766
2310	=back	2767	=back
2311		2768
		2769	=head2 LINUX-SPECIFIC CALLS
		2770
		2771	When a call is documented as "linux-specific" then this means it
		2772	originated on GNU/Linux. C<IO::AIO> will usually try to autodetect the
		2773	availability and compatibility of such calls regardless of the platform
		2774	it is compiled on, so platforms such as FreeBSD which often implement
		2775	these calls will work. When in doubt, call them and see if they fail wth
		2776	C<ENOSYS>.
		2777
2312	=head2 MEMORY USAGE	2778	=head2 MEMORY USAGE
2313		2779
2314	Per-request usage:	2780	Per-request usage:
2315		2781
2316	Each aio request uses - depending on your architecture - around 100-200	2782	Each aio request uses - depending on your architecture - around 100-200
…		…
2328	temporary buffers, and each thread requires a stack and other data	2794	temporary buffers, and each thread requires a stack and other data
2329	structures (usually around 16k-128k, depending on the OS).	2795	structures (usually around 16k-128k, depending on the OS).
2330		2796
2331	=head1 KNOWN BUGS	2797	=head1 KNOWN BUGS
2332		2798
2333	Known bugs will be fixed in the next release.	2799	Known bugs will be fixed in the next release :)
		2800
		2801	=head1 KNOWN ISSUES
		2802
		2803	Calls that try to "import" foreign memory areas (such as C<IO::AIO::mmap>
		2804	or C<IO::AIO::aio_slurp>) do not work with generic lvalues, such as
		2805	non-created hash slots or other scalars I didn't think of. It's best to
		2806	avoid such and either use scalar variables or making sure that the scalar
		2807	exists (e.g. by storing C<undef>) and isn't "funny" (e.g. tied).
		2808
		2809	I am not sure anything can be done about this, so this is considered a
		2810	known issue, rather than a bug.
2334		2811
2335	=head1 SEE ALSO	2812	=head1 SEE ALSO
2336		2813
2337	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a	2814	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
2338	more natural syntax.	2815	more natural syntax and L<IO::FDPass> for file descriptor passing.
2339		2816
2340	=head1 AUTHOR	2817	=head1 AUTHOR
2341		2818
2342	Marc Lehmann <schmorp@schmorp.de>	2819	Marc Lehmann <schmorp@schmorp.de>
2343	http://home.schmorp.de/	2820	http://home.schmorp.de/

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.281 by root, Tue Feb 20 04:32:59 2018 UTC vs. Revision 1.320 by root, Tue Feb 20 06:40:23 2024 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.281 by root, Tue Feb 20 04:32:59 2018 UTC vs.
Revision 1.320 by root, Tue Feb 20 06:40:23 2024 UTC