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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.280 by root, Mon Feb 19 13:37:13 2018 UTC vs.
Revision 1.310 by root, Wed Dec 30 07:45:32 2020 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 = 4.75;
177		177
178	our @AIO_REQ = qw(aio_sendfile aio_seek aio_read aio_write aio_open aio_close	178	our @AIO_REQ = qw(aio_sendfile aio_seek aio_read aio_write aio_open aio_close
179	aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx	179	aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
180	aio_scandir aio_symlink aio_readlink aio_realpath aio_fcntl aio_ioctl	180	aio_scandir aio_symlink aio_readlink aio_realpath aio_fcntl aio_ioctl
181	aio_sync aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range	181	aio_sync aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range
…		…
192	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush	192	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
193	min_parallel max_parallel max_idle idle_timeout	193	min_parallel max_parallel max_idle idle_timeout
194	nreqs nready npending nthreads	194	nreqs nready npending nthreads
195	max_poll_time max_poll_reqs	195	max_poll_time max_poll_reqs
196	sendfile fadvise madvise	196	sendfile fadvise madvise
197	mmap munmap munlock munlockall);	197	mmap munmap mremap munlock munlockall);
198		198
199	push @AIO_REQ, qw(aio_busy); # not exported	199	push @AIO_REQ, qw(aio_busy); # not exported
200		200
201	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';	201	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';
202		202
…		…
278	IO::AIO::idle_timeout $seconds	278	IO::AIO::idle_timeout $seconds
279	IO::AIO::max_outstanding $maxreqs	279	IO::AIO::max_outstanding $maxreqs
280	IO::AIO::nreqs	280	IO::AIO::nreqs
281	IO::AIO::nready	281	IO::AIO::nready
282	IO::AIO::npending	282	IO::AIO::npending
		283	IO::AIO::reinit
		284
283	$nfd = IO::AIO::get_fdlimit [EXPERIMENTAL]	285	$nfd = IO::AIO::get_fdlimit
284	IO::AIO::min_fdlimit $nfd [EXPERIMENTAL]	286	IO::AIO::min_fdlimit $nfd
285		287
286	IO::AIO::sendfile $ofh, $ifh, $offset, $count	288	IO::AIO::sendfile $ofh, $ifh, $offset, $count
287	IO::AIO::fadvise $fh, $offset, $len, $advice	289	IO::AIO::fadvise $fh, $offset, $len, $advice
		290
288	IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]	291	IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
289	IO::AIO::munmap $scalar	292	IO::AIO::munmap $scalar
		293	IO::AIO::mremap $scalar, $new_length, $flags[, $new_address]
290	IO::AIO::madvise $scalar, $offset, $length, $advice	294	IO::AIO::madvise $scalar, $offset, $length, $advice
291	IO::AIO::mprotect $scalar, $offset, $length, $protect	295	IO::AIO::mprotect $scalar, $offset, $length, $protect
292	IO::AIO::munlock $scalar, $offset = 0, $length = undef	296	IO::AIO::munlock $scalar, $offset = 0, $length = undef
293	IO::AIO::munlockall	297	IO::AIO::munlockall
		298
		299	# stat extensions
		300	$counter = IO::AIO::st_gen
		301	$seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime, IO::AIO::st_btime
		302	($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtime
		303	$nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec, IO::AIO::st_ctimensec, IO::AIO::st_btimensec
		304	$seconds = IO::AIO::st_btimesec
		305	($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtimensec
		306
		307	# very much unportable syscalls
		308	IO::AIO::accept4 $r_fh, $sockaddr, $sockaddr_len, $flags
		309	IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
		310	IO::AIO::tee $r_fh, $w_fh, $length, $flags
		311	$actual_size = IO::AIO::pipesize $r_fh[, $new_size]
		312	($rfh, $wfh) = IO::AIO::pipe2 [$flags]
		313	$fh = IO::AIO::memfd_create $pathname[, $flags]
		314	$fh = IO::AIO::eventfd [$initval, [$flags]]
		315	$fh = IO::AIO::timerfd_create $clockid[, $flags]
		316	($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags, $new_interval, $nbw_value
		317	($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh
294		318
295	=head2 API NOTES	319	=head2 API NOTES
296		320
297	All the C<aio_*> calls are more or less thin wrappers around the syscall	321	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,	322	with the same name (sans C<aio_>). The arguments are similar or identical,
…		…
404	following POSIX and non-POSIX constants are available (missing ones on	428	following POSIX and non-POSIX constants are available (missing ones on
405	your system are, as usual, C<0>):	429	your system are, as usual, C<0>):
406		430
407	C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,	431	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>,	432	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>.	433	C<O_RSYNC>, C<O_SYNC>, C<O_PATH>, C<O_TMPFILE>, C<O_TTY_INIT> and C<O_ACCMODE>.
410		434
411		435
412	=item aio_close $fh, $callback->($status)	436	=item aio_close $fh, $callback->($status)
413		437
414	Asynchronously close a file and call the callback with the result	438	Asynchronously close a file and call the callback with the result
…		…
540		564
541	=item aio_stat $fh_or_path, $callback->($status)	565	=item aio_stat $fh_or_path, $callback->($status)
542		566
543	=item aio_lstat $fh, $callback->($status)	567	=item aio_lstat $fh, $callback->($status)
544		568
545	Works like perl's C<stat> or C<lstat> in void context. The callback will	569	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 _>	570	callback will be called after the stat and the results will be available
547	or C<-s _> etc...	571	using C<stat _> or C<-s _> and other tests (with the exception of C<-B>
		572	and C<-T>).
548		573
549	The pathname passed to C<aio_stat> must be absolute. See API NOTES, above,	574	The pathname passed to C<aio_stat> must be absolute. See API NOTES, above,
550	for an explanation.	575	for an explanation.
551		576
552	Currently, the stats are always 64-bit-stats, i.e. instead of returning an	577	Currently, the stats are always 64-bit-stats, i.e. instead of returning an
…		…
559	behaviour).	584	behaviour).
560		585
561	C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>,	586	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>,	587	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>.	588	C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>.
		589
		590	To access higher resolution stat timestamps, see L<SUBSECOND STAT TIME
		591	ACCESS>.
564		592
565	Example: Print the length of F</etc/passwd>:	593	Example: Print the length of F</etc/passwd>:
566		594
567	aio_stat "/etc/passwd", sub {	595	aio_stat "/etc/passwd", sub {
568	$_[0] and die "stat failed: $!";	596	$_[0] and die "stat failed: $!";
…		…
618		646
619	Works like perl's C<utime> function (including the special case of $atime	647	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	648	and $mtime being undef). Fractional times are supported if the underlying
621	syscalls support them.	649	syscalls support them.
622		650
623	When called with a pathname, uses utimes(2) if available, otherwise	651	When called with a pathname, uses utimensat(2) or utimes(2) if available,
624	utime(2). If called on a file descriptor, uses futimes(2) if available,	652	otherwise utime(2). If called on a file descriptor, uses futimens(2)
625	otherwise returns ENOSYS, so this is not portable.	653	or futimes(2) if available, otherwise returns ENOSYS, so this is not
		654	portable.
626		655
627	Examples:	656	Examples:
628		657
629	# set atime and mtime to current time (basically touch(1)):	658	# set atime and mtime to current time (basically touch(1)):
630	aio_utime "path", undef, undef;	659	aio_utime "path", undef, undef;
…		…
789		818
790	=over 4	819	=over 4
791		820
792	=item IO::AIO::READDIR_DENTS	821	=item IO::AIO::READDIR_DENTS
793		822
794	When this flag is off, then the callback gets an arrayref consisting of	823	Normally the callback gets an arrayref consisting of names only (as
795	names only (as with C<aio_readdir>), otherwise it gets an arrayref with	824	with C<aio_readdir>). If this flag is set, then the callback gets an
796	C<[$name, $type, $inode]> arrayrefs, each describing a single directory	825	arrayref with C<[$name, $type, $inode]> arrayrefs, each describing a
797	entry in more detail.	826	single directory entry in more detail:
798		827
799	C<$name> is the name of the entry.	828	C<$name> is the name of the entry.
800		829
801	C<$type> is one of the C<IO::AIO::DT_xxx> constants:	830	C<$type> is one of the C<IO::AIO::DT_xxx> constants:
802		831
803	C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,	832	C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
804	C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,	833	C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
805	C<IO::AIO::DT_WHT>.	834	C<IO::AIO::DT_WHT>.
806		835
807	C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to	836	C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need
808	know, you have to run stat yourself. Also, for speed reasons, the C<$type>	837	to know, you have to run stat yourself. Also, for speed/memory reasons,
809	scalars are read-only: you can not modify them.	838	the C<$type> scalars are read-only: you must not modify them.
810		839
811	C<$inode> is the inode number (which might not be exact on systems with 64	840	C<$inode> is the inode number (which might not be exact on systems with 64
812	bit inode numbers and 32 bit perls). This field has unspecified content on	841	bit inode numbers and 32 bit perls). This field has unspecified content on
813	systems that do not deliver the inode information.	842	systems that do not deliver the inode information.
814		843
…		…
825	short names are tried first.	854	short names are tried first.
826		855
827	=item IO::AIO::READDIR_STAT_ORDER	856	=item IO::AIO::READDIR_STAT_ORDER
828		857
829	When this flag is set, then the names will be returned in an order	858	When this flag is set, then the names will be returned in an order
830	suitable for stat()'ing each one. That is, when you plan to stat()	859	suitable for stat()'ing each one. That is, when you plan to stat() most or
831	all files in the given directory, then the returned order will likely	860	all files in the given directory, then the returned order will likely be
832	be fastest.	861	faster.
833		862
834	If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then	863	If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified,
835	the likely dirs come first, resulting in a less optimal stat order.	864	then the likely dirs come first, resulting in a less optimal stat order
		865	for stat'ing all entries, but likely a more optimal order for finding
		866	subdirectories.
836		867
837	=item IO::AIO::READDIR_FOUND_UNKNOWN	868	=item IO::AIO::READDIR_FOUND_UNKNOWN
838		869
839	This flag should not be set when calling C<aio_readdirx>. Instead, it	870	This flag should not be set when calling C<aio_readdirx>. Instead, it
840	is being set by C<aio_readdirx>, when any of the C<$type>'s found were	871	is being set by C<aio_readdirx>, when any of the C<$type>'s found were
…		…
1101	aioreq_pri $pri;	1132	aioreq_pri $pri;
1102	add $grp aio_stat $wd, sub {	1133	add $grp aio_stat $wd, sub {
1103	return $grp->result () if $_[0];	1134	return $grp->result () if $_[0];
1104	my $now = time;	1135	my $now = time;
1105	my $hash1 = join ":", (stat _)[0,1,3,7,9];	1136	my $hash1 = join ":", (stat _)[0,1,3,7,9];
		1137	my $rdxflags = READDIR_DIRS_FIRST;
		1138
		1139	if ((stat _)[3] < 2) {
		1140	# at least one non-POSIX filesystem exists
		1141	# that returns useful DT_type values: btrfs,
		1142	# so optimise for this here by requesting dents
		1143	$rdxflags \|= READDIR_DENTS;
		1144	}
1106		1145
1107	# read the directory entries	1146	# read the directory entries
1108	aioreq_pri $pri;	1147	aioreq_pri $pri;
1109	add $grp aio_readdirx $wd, READDIR_DIRS_FIRST, sub {	1148	add $grp aio_readdirx $wd, $rdxflags, sub {
1110	my $entries = shift	1149	my ($entries, $flags) = @_
1111	or return $grp->result ();	1150	or return $grp->result ();
		1151
		1152	if ($rdxflags & READDIR_DENTS) {
		1153	# if we requested type values, see if we can use them directly.
		1154
		1155	# if there were any DT_UNKNOWN entries then we assume we
		1156	# don't know. alternatively, we could assume that if we get
		1157	# one DT_DIR, then all directories are indeed marked with
		1158	# DT_DIR, but this seems not required for btrfs, and this
		1159	# is basically the "btrfs can't get it's act together" code
		1160	# branch.
		1161	unless ($flags & READDIR_FOUND_UNKNOWN) {
		1162	# now we have valid DT_ information for all entries,
		1163	# so use it as an optimisation without further stat's.
		1164	# they must also all be at the beginning of @$entries
		1165	# by now.
		1166
		1167	my $dirs;
		1168
		1169	if (@$entries) {
		1170	for (0 .. $#$entries) {
		1171	if ($entries->[$_][1] != DT_DIR) {
		1172	# splice out directories
		1173	$dirs = [splice @$entries, 0, $_];
		1174	last;
		1175	}
		1176	}
		1177
		1178	# if we didn't find any non-dir, then all entries are dirs
		1179	unless ($dirs) {
		1180	($dirs, $entries) = ($entries, []);
		1181	}
		1182	} else {
		1183	# directory is empty, so there are no sbdirs
		1184	$dirs = [];
		1185	}
		1186
		1187	# either splice'd the directories out or the dir was empty.
		1188	# convert dents to filenames
		1189	$_ = $_->[0] for @$dirs;
		1190	$_ = $_->[0] for @$entries;
		1191
		1192	return $grp->result ($dirs, $entries);
		1193	}
		1194
		1195	# cannot use, so return to our old ways
		1196	# by pretending we only scanned for names.
		1197	$_ = $_->[0] for @$entries;
		1198	}
1112		1199
1113	# stat the dir another time	1200	# stat the dir another time
1114	aioreq_pri $pri;	1201	aioreq_pri $pri;
1115	add $grp aio_stat $wd, sub {	1202	add $grp aio_stat $wd, sub {
1116	my $hash2 = join ":", (stat _)[0,1,3,7,9];	1203	my $hash2 = join ":", (stat _)[0,1,3,7,9];
…		…
1222	So in general, you should only use these calls for things that do	1309	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,	1310	(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,	1311	other processes), although if you are careful and know what you are doing,
1225	you still can.	1312	you still can.
1226		1313
1227	The following constants are available (missing ones are, as usual C<0>):	1314	The following constants are available and can be used for normal C<ioctl>
		1315	and C<fcntl> as well (missing ones are, as usual C<0>):
1228		1316
1229	C<F_DUPFD_CLOEXEC>,	1317	C<F_DUPFD_CLOEXEC>,
1230		1318
1231	C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>,	1319	C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>,
1232		1320
1233	C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>.	1321	C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>.
		1322
		1323	C<F_ADD_SEALS>, C<F_GET_SEALS>, C<F_SEAL_SEAL>, C<F_SEAL_SHRINK>, C<F_SEAL_GROW> and
		1324	C<F_SEAL_WRITE>.
1234		1325
1235	C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>,	1326	C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>,
1236	C<FS_IOC_FIEMAP>.	1327	C<FS_IOC_FIEMAP>.
1237		1328
1238	C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>,	1329	C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>,
…		…
1377	IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;	1468	IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
1378	aio_mlock $data; # mlock in background	1469	aio_mlock $data; # mlock in background
1379		1470
1380	=item aio_mlockall $flags, $callback->($status)	1471	=item aio_mlockall $flags, $callback->($status)
1381		1472
1382	Calls the C<mlockall> function with the given C<$flags> (a combination of	1473	Calls the C<mlockall> function with the given C<$flags> (a
1383	C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).	1474	combination of C<IO::AIO::MCL_CURRENT>, C<IO::AIO::MCL_FUTURE> and
		1475	C<IO::AIO::MCL_ONFAULT>).
1384		1476
1385	On systems that do not implement C<mlockall>, this function returns C<-1>	1477	On systems that do not implement C<mlockall>, this function returns C<-1>
1386	and sets errno to C<ENOSYS>.	1478	and sets errno to C<ENOSYS>. Similarly, flag combinations not supported
		1479	by the system result in a return value of C<-1> with errno being set to
		1480	C<EINVAL>.
1387		1481
1388	Note that the corresponding C<munlockall> is synchronous and is	1482	Note that the corresponding C<munlockall> is synchronous and is
1389	documented under L<MISCELLANEOUS FUNCTIONS>.	1483	documented under L<MISCELLANEOUS FUNCTIONS>.
1390		1484
1391	Example: asynchronously lock all current and future pages into memory.	1485	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	1679	C<aio_wd> callback, as future requests using the value will fail in the
1586	expected way.	1680	expected way.
1587		1681
1588	=item IO::AIO::CWD	1682	=item IO::AIO::CWD
1589		1683
1590	This is a compiletime constant (object) that represents the process	1684	This is a compile time constant (object) that represents the process
1591	current working directory.	1685	current working directory.
1592		1686
1593	Specifying this object as working directory object for a pathname is as if	1687	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	1688	the pathname would be specified directly, without a directory object. For
1595	example, these calls are functionally identical:	1689	example, these calls are functionally identical:
…		…
1776	The default value for the limit is C<0>, but note that setting a feeder	1870	The default value for the limit is C<0>, but note that setting a feeder
1777	automatically bumps it up to C<2>.	1871	automatically bumps it up to C<2>.
1778		1872
1779	=back	1873	=back
1780		1874
		1875
1781	=head2 SUPPORT FUNCTIONS	1876	=head2 SUPPORT FUNCTIONS
1782		1877
1783	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION	1878	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
1784		1879
1785	=over 4	1880	=over 4
…		…
1850	Strictly equivalent to:	1945	Strictly equivalent to:
1851		1946
1852	IO::AIO::poll_wait, IO::AIO::poll_cb	1947	IO::AIO::poll_wait, IO::AIO::poll_cb
1853	while IO::AIO::nreqs;	1948	while IO::AIO::nreqs;
1854		1949
		1950	This function can be useful at program aborts, to make sure outstanding
		1951	I/O has been done (C<IO::AIO> uses an C<END> block which already calls
		1952	this function on normal exits), or when you are merely using C<IO::AIO>
		1953	for its more advanced functions, rather than for async I/O, e.g.:
		1954
		1955	my ($dirs, $nondirs);
		1956	IO::AIO::aio_scandir "/tmp", 0, sub { ($dirs, $nondirs) = @_ };
		1957	IO::AIO::flush;
		1958	# $dirs, $nondirs are now set
		1959
1855	=item IO::AIO::max_poll_reqs $nreqs	1960	=item IO::AIO::max_poll_reqs $nreqs
1856		1961
1857	=item IO::AIO::max_poll_time $seconds	1962	=item IO::AIO::max_poll_time $seconds
1858		1963
1859	These set the maximum number of requests (default C<0>, meaning infinity)	1964	These set the maximum number of requests (default C<0>, meaning infinity)
…		…
1885	poll => 'r', nice => 1,	1990	poll => 'r', nice => 1,
1886	cb => &IO::AIO::poll_cb);	1991	cb => &IO::AIO::poll_cb);
1887		1992
1888	=back	1993	=back
1889		1994
		1995
1890	=head3 CONTROLLING THE NUMBER OF THREADS	1996	=head3 CONTROLLING THE NUMBER OF THREADS
1891		1997
1892	=over	1998	=over
1893		1999
1894	=item IO::AIO::min_parallel $nthreads	2000	=item IO::AIO::min_parallel $nthreads
…		…
1981	The default value for C<max_outstanding> is very large, so there is no	2087	The default value for C<max_outstanding> is very large, so there is no
1982	practical limit on the number of outstanding requests.	2088	practical limit on the number of outstanding requests.
1983		2089
1984	=back	2090	=back
1985		2091
		2092
1986	=head3 STATISTICAL INFORMATION	2093	=head3 STATISTICAL INFORMATION
1987		2094
1988	=over	2095	=over
1989		2096
1990	=item IO::AIO::nreqs	2097	=item IO::AIO::nreqs
…		…
2006		2113
2007	Returns the number of requests currently in the pending state (executed,	2114	Returns the number of requests currently in the pending state (executed,
2008	but not yet processed by poll_cb).	2115	but not yet processed by poll_cb).
2009		2116
2010	=back	2117	=back
		2118
		2119
		2120	=head3 SUBSECOND STAT TIME ACCESS
		2121
		2122	Both C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> functions can
		2123	generally find access/modification and change times with subsecond time
		2124	accuracy of the system supports it, but perl's built-in functions only
		2125	return the integer part.
		2126
		2127	The following functions return the timestamps of the most recent
		2128	stat with subsecond precision on most systems and work both after
		2129	C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> calls. Their return
		2130	value is only meaningful after a successful C<stat>/C<lstat> call, or
		2131	during/after a successful C<aio_stat>/C<aio_lstat> callback.
		2132
		2133	This is similar to the L<Time::HiRes> C<stat> functions, but can return
		2134	full resolution without rounding and work with standard perl C<stat>,
		2135	alleviating the need to call the special C<Time::HiRes> functions, which
		2136	do not act like their perl counterparts.
		2137
		2138	On operating systems or file systems where subsecond time resolution is
		2139	not supported or could not be detected, a fractional part of C<0> is
		2140	returned, so it is always safe to call these functions.
		2141
		2142	=over 4
		2143
		2144	=item $seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime, IO::AIO::st_btime
		2145
		2146	Return the access, modication, change or birth time, respectively,
		2147	including fractional part. Due to the limited precision of floating point,
		2148	the accuracy on most platforms is only a bit better than milliseconds
		2149	for times around now - see the I<nsec> function family, below, for full
		2150	accuracy.
		2151
		2152	File birth time is only available when the OS and perl support it (on
		2153	FreeBSD and NetBSD at the time of this writing, although support is
		2154	adaptive, so if your OS/perl gains support, IO::AIO can take advantage of
		2155	it). On systems where it isn't available, C<0> is currently returned, but
		2156	this might change to C<undef> in a future version.
		2157
		2158	=item ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtime
		2159
		2160	Returns access, modification, change and birth time all in one go, and
		2161	maybe more times in the future version.
		2162
		2163	=item $nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec, IO::AIO::st_ctimensec, IO::AIO::st_btimensec
		2164
		2165	Return the fractional access, modifcation, change or birth time, in nanoseconds,
		2166	as an integer in the range C<0> to C<999999999>.
		2167
		2168	Note that no accessors are provided for access, modification and
		2169	change times - you need to get those from C<stat _> if required (C<int
		2170	IO::AIO::st_atime> and so on will I<not> generally give you the correct
		2171	value).
		2172
		2173	=item $seconds = IO::AIO::st_btimesec
		2174
		2175	The (integral) seconds part of the file birth time, if available.
		2176
		2177	=item ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtimensec
		2178
		2179	Like the functions above, but returns all four times in one go (and maybe
		2180	more in future versions).
		2181
		2182	=item $counter = IO::AIO::st_gen
		2183
		2184	Returns the generation counter (in practice this is just a random number)
		2185	of the file. This is only available on platforms which have this member in
		2186	their C<struct stat> (most BSDs at the time of this writing) and generally
		2187	only to the root usert. If unsupported, C<0> is returned, but this might
		2188	change to C<undef> in a future version.
		2189
		2190	=back
		2191
		2192	Example: print the high resolution modification time of F</etc>, using
		2193	C<stat>, and C<IO::AIO::aio_stat>.
		2194
		2195	if (stat "/etc") {
		2196	printf "stat(/etc) mtime: %f\n", IO::AIO::st_mtime;
		2197	}
		2198
		2199	IO::AIO::aio_stat "/etc", sub {
		2200	$_[0]
		2201	and return;
		2202
		2203	printf "aio_stat(/etc) mtime: %d.%09d\n", (stat _)[9], IO::AIO::st_mtimensec;
		2204	};
		2205
		2206	IO::AIO::flush;
		2207
		2208	Output of the awbove on my system, showing reduced and full accuracy:
		2209
		2210	stat(/etc) mtime: 1534043702.020808
		2211	aio_stat(/etc) mtime: 1534043702.020807792
		2212
2011		2213
2012	=head3 MISCELLANEOUS FUNCTIONS	2214	=head3 MISCELLANEOUS FUNCTIONS
2013		2215
2014	IO::AIO implements some functions that are useful when you want to use	2216	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	2217	some "Advanced I/O" function not available to in Perl, without going the
…		…
2018		2220
2019	=over 4	2221	=over 4
2020		2222
2021	=item $numfd = IO::AIO::get_fdlimit	2223	=item $numfd = IO::AIO::get_fdlimit
2022		2224
2023	This function is I<EXPERIMENTAL> and subject to change.
2024
2025	Tries to find the current file descriptor limit and returns it, or	2225	Tries to find the current file descriptor limit and returns it, or
2026	C<undef> and sets C<$!> in case of an error. The limit is one larger than	2226	C<undef> and sets C<$!> in case of an error. The limit is one larger than
2027	the highest valid file descriptor number.	2227	the highest valid file descriptor number.
2028		2228
2029	=item IO::AIO::min_fdlimit [$numfd]	2229	=item IO::AIO::min_fdlimit [$numfd]
2030
2031	This function is I<EXPERIMENTAL> and subject to change.
2032		2230
2033	Try to increase the current file descriptor limit(s) to at least C<$numfd>	2231	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>	2232	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	2233	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.	2234	recommended when you know the actual minimum that you require.
…		…
2156		2354
2157	=item IO::AIO::munmap $scalar	2355	=item IO::AIO::munmap $scalar
2158		2356
2159	Removes a previous mmap and undefines the C<$scalar>.	2357	Removes a previous mmap and undefines the C<$scalar>.
2160		2358
		2359	=item IO::AIO::mremap $scalar, $new_length, $flags = MREMAP_MAYMOVE[, $new_address = 0]
		2360
		2361	Calls the Linux-specific mremap(2) system call. The C<$scalar> must have
		2362	been mapped by C<IO::AIO::mmap>, and C<$flags> must currently either be
		2363	C<0> or C<IO::AIO::MREMAP_MAYMOVE>.
		2364
		2365	Returns true if successful, and false otherwise. If the underlying mmapped
		2366	region has changed address, then the true value has the numerical value
		2367	C<1>, otherwise it has the numerical value C<0>:
		2368
		2369	my $success = IO::AIO::mremap $mmapped, 8192, IO::AIO::MREMAP_MAYMOVE
		2370	or die "mremap: $!";
		2371
		2372	if ($success*1) {
		2373	warn "scalar has chanegd address in memory\n";
		2374	}
		2375
		2376	C<IO::AIO::MREMAP_FIXED> and the C<$new_address> argument are currently
		2377	implemented, but not supported and might go away in a future version.
		2378
		2379	On systems where this call is not supported or is not emulated, this call
		2380	returns falls and sets C<$!> to C<ENOSYS>.
		2381
		2382	=item IO::AIO::mlockall $flags
		2383
		2384	Calls the C<eio_mlockall_sync> function, which is like C<aio_mlockall>,
		2385	but is blocking.
		2386
2161	=item IO::AIO::munlock $scalar, $offset = 0, $length = undef	2387	=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
2162		2388
2163	Calls the C<munlock> function, undoing the effects of a previous	2389	Calls the C<munlock> function, undoing the effects of a previous
2164	C<aio_mlock> call (see its description for details).	2390	C<aio_mlock> call (see its description for details).
2165		2391
…		…
2167		2393
2168	Calls the C<munlockall> function.	2394	Calls the C<munlockall> function.
2169		2395
2170	On systems that do not implement C<munlockall>, this function returns	2396	On systems that do not implement C<munlockall>, this function returns
2171	ENOSYS, otherwise the return value of C<munlockall>.	2397	ENOSYS, otherwise the return value of C<munlockall>.
		2398
		2399	=item $fh = IO::AIO::accept4 $r_fh, $sockaddr, $sockaddr_maxlen, $flags
		2400
		2401	Uses the GNU/Linux C<accept4(2)> syscall, if available, to accept a socket
		2402	and return the new file handle on success, or sets C<$!> and returns
		2403	C<undef> on error.
		2404
		2405	The remote name of the new socket will be stored in C<$sockaddr>, which
		2406	will be extended to allow for at least C<$sockaddr_maxlen> octets. If the
		2407	socket name does not fit into C<$sockaddr_maxlen> octets, this is signaled
		2408	by returning a longer string in C<$sockaddr>, which might or might not be
		2409	truncated.
		2410
		2411	To accept name-less sockets, use C<undef> for C<$sockaddr> and C<0> for
		2412	C<$sockaddr_maxlen>.
		2413
		2414	The main reasons to use this syscall rather than portable C<accept(2)>
		2415	are that you can specify C<SOCK_NONBLOCK> and/or C<SOCK_CLOEXEC>
		2416	flags and you can accept name-less sockets by specifying C<0> for
		2417	C<$sockaddr_maxlen>, which is sadly not possible with perl's interface to
		2418	C<accept>.
2172		2419
2173	=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags	2420	=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
2174		2421
2175	Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or	2422	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	2423	C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
…		…
2214	C<$flags> is non-zero, fails with C<ENOSYS>.	2461	C<$flags> is non-zero, fails with C<ENOSYS>.
2215		2462
2216	Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the	2463	Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the
2217	time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and	2464	time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and
2218	C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported.	2465	C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported.
		2466
		2467	Example: create a pipe race-free w.r.t. threads and fork:
		2468
		2469	my ($rfh, $wfh) = IO::AIO::pipe2 IO::AIO::O_CLOEXEC
		2470	or die "pipe2: $!\n";
		2471
		2472	=item $fh = IO::AIO::memfd_create $pathname[, $flags]
		2473
		2474	This is a direct interface to the Linux L<memfd_create(2)> system
		2475	call. The (unhelpful) default for C<$flags> is C<0>, but your default
		2476	should be C<IO::AIO::MFD_CLOEXEC>.
		2477
		2478	On success, the new memfd filehandle is returned, otherwise returns
		2479	C<undef>. If the memfd_create syscall is missing, fails with C<ENOSYS>.
		2480
		2481	Please refer to L<memfd_create(2)> for more info on this call.
		2482
		2483	The following C<$flags> values are available: C<IO::AIO::MFD_CLOEXEC>,
		2484	C<IO::AIO::MFD_ALLOW_SEALING> and C<IO::AIO::MFD_HUGETLB>.
		2485
		2486	Example: create a new memfd.
		2487
		2488	my $fh = IO::AIO::memfd_create "somenameforprocfd", IO::AIO::MFD_CLOEXEC
		2489	or die "memfd_create: $!\n";
		2490
		2491	=item $fh = IO::AIO::pidfd_open $pid[, $flags]
		2492
		2493	This is an interface to the Linux L<pidfd_open(2)> system call. The
		2494	default for C<$flags> is C<0>.
		2495
		2496	On success, a new pidfd filehandle is returned (that is already set to
		2497	close-on-exec), otherwise returns C<undef>. If the syscall is missing,
		2498	fails with C<ENOSYS>.
		2499
		2500	Example: open pid 6341 as pidfd.
		2501
		2502	my $fh = IO::AIO::pidfd_open 6341
		2503	or die "pidfd_open: $!\n";
		2504
		2505	=item $status = IO::AIO::pidfd_send_signal $pidfh, $signal[, $siginfo[, $flags]]
		2506
		2507	This is an interface to the Linux L<pidfd_send_signal> system call. The
		2508	default for C<$siginfo> is C<undef> and the default for C<$flags> is C<0>.
		2509
		2510	Returns the system call status. If the syscall is missing, fails with
		2511	C<ENOSYS>.
		2512
		2513	When specified, C<$siginfo> must be a reference to a hash with one or more
		2514	of the following members:
		2515
		2516	=over
		2517
		2518	=item code - the C<si_code> member
		2519
		2520	=item pid - the C<si_pid> member
		2521
		2522	=item uid - the C<si_uid> member
		2523
		2524	=item value_int - the C<si_value.sival_int> member
		2525
		2526	=item value_ptr - the C<si_value.sival_ptr> member, specified as an integer
		2527
		2528	=back
		2529
		2530	Example: send a SIGKILL to the specified process.
		2531
		2532	my $status = IO::AIO::pidfd_send_signal $pidfh, 9, undef
		2533	and die "pidfd_send_signal: $!\n";
		2534
		2535	Example: send a SIGKILL to the specified process with extra data.
		2536
		2537	my $status = IO::AIO::pidfd_send_signal $pidfh, 9, { code => -1, value_int => 7 }
		2538	and die "pidfd_send_signal: $!\n";
		2539
		2540	=item $fh = IO::AIO::pidfd_getfd $pidfh, $targetfd[, $flags]
		2541
		2542	This is an interface to the Linux L<pidfd_getfd> system call. The default
		2543	for C<$flags> is C<0>.
		2544
		2545	On success, returns a dup'ed copy of the target file descriptor (specified
		2546	as an integer) returned (that is already set to close-on-exec), otherwise
		2547	returns C<undef>. If the syscall is missing, fails with C<ENOSYS>.
		2548
		2549	Example: get a copy of standard error of another process and print soemthing to it.
		2550
		2551	my $errfh = IO::AIO::pidfd_getfd $pidfh, 2
		2552	or die "pidfd_getfd: $!\n";
		2553	print $errfh "stderr\n";
		2554
		2555	=item $fh = IO::AIO::eventfd [$initval, [$flags]]
		2556
		2557	This is a direct interface to the Linux L<eventfd(2)> system call. The
		2558	(unhelpful) defaults for C<$initval> and C<$flags> are C<0> for both.
		2559
		2560	On success, the new eventfd filehandle is returned, otherwise returns
		2561	C<undef>. If the eventfd syscall is missing, fails with C<ENOSYS>.
		2562
		2563	Please refer to L<eventfd(2)> for more info on this call.
		2564
		2565	The following symbol flag values are available: C<IO::AIO::EFD_CLOEXEC>,
		2566	C<IO::AIO::EFD_NONBLOCK> and C<IO::AIO::EFD_SEMAPHORE> (Linux 2.6.30).
		2567
		2568	Example: create a new eventfd filehandle:
		2569
		2570	$fh = IO::AIO::eventfd 0, IO::AIO::EFD_CLOEXEC
		2571	or die "eventfd: $!\n";
		2572
		2573	=item $fh = IO::AIO::timerfd_create $clockid[, $flags]
		2574
		2575	This is a direct interface to the Linux L<timerfd_create(2)> system
		2576	call. The (unhelpful) default for C<$flags> is C<0>, but your default
		2577	should be C<IO::AIO::TFD_CLOEXEC>.
		2578
		2579	On success, the new timerfd filehandle is returned, otherwise returns
		2580	C<undef>. If the timerfd_create syscall is missing, fails with C<ENOSYS>.
		2581
		2582	Please refer to L<timerfd_create(2)> for more info on this call.
		2583
		2584	The following C<$clockid> values are
		2585	available: C<IO::AIO::CLOCK_REALTIME>, C<IO::AIO::CLOCK_MONOTONIC>
		2586	C<IO::AIO::CLOCK_CLOCK_BOOTTIME> (Linux 3.15)
		2587	C<IO::AIO::CLOCK_CLOCK_REALTIME_ALARM> (Linux 3.11) and
		2588	C<IO::AIO::CLOCK_CLOCK_BOOTTIME_ALARM> (Linux 3.11).
		2589
		2590	The following C<$flags> values are available (Linux
		2591	2.6.27): C<IO::AIO::TFD_NONBLOCK> and C<IO::AIO::TFD_CLOEXEC>.
		2592
		2593	Example: create a new timerfd and set it to one-second repeated alarms,
		2594	then wait for two alarms:
		2595
		2596	my $fh = IO::AIO::timerfd_create IO::AIO::CLOCK_BOOTTIME, IO::AIO::TFD_CLOEXEC
		2597	or die "timerfd_create: $!\n";
		2598
		2599	defined IO::AIO::timerfd_settime $fh, 0, 1, 1
		2600	or die "timerfd_settime: $!\n";
		2601
		2602	for (1..2) {
		2603	8 == sysread $fh, my $buf, 8
		2604	or die "timerfd read failure\n";
		2605
		2606	printf "number of expirations (likely 1): %d\n",
		2607	unpack "Q", $buf;
		2608	}
		2609
		2610	=item ($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags, $new_interval, $nbw_value
		2611
		2612	This is a direct interface to the Linux L<timerfd_settime(2)> system
		2613	call. Please refer to its manpage for more info on this call.
		2614
		2615	The new itimerspec is specified using two (possibly fractional) second
		2616	values, C<$new_interval> and C<$new_value>).
		2617
		2618	On success, the current interval and value are returned (as per
		2619	C<timerfd_gettime>). On failure, the empty list is returned.
		2620
		2621	The following C<$flags> values are
		2622	available: C<IO::AIO::TFD_TIMER_ABSTIME> and
		2623	C<IO::AIO::TFD_TIMER_CANCEL_ON_SET>.
		2624
		2625	See C<IO::AIO::timerfd_create> for a full example.
		2626
		2627	=item ($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh
		2628
		2629	This is a direct interface to the Linux L<timerfd_gettime(2)> system
		2630	call. Please refer to its manpage for more info on this call.
		2631
		2632	On success, returns the current values of interval and value for the given
		2633	timerfd (as potentially fractional second values). On failure, the empty
		2634	list is returned.
2219		2635
2220	=back	2636	=back
2221		2637
2222	=cut	2638	=cut
2223		2639
…		…
2289	the process will result in undefined behaviour. Calling it at any time	2705	the process will result in undefined behaviour. Calling it at any time
2290	will also result in any undefined (by POSIX) behaviour.	2706	will also result in any undefined (by POSIX) behaviour.
2291		2707
2292	=back	2708	=back
2293		2709
		2710	=head2 LINUX-SPECIFIC CALLS
		2711
		2712	When a call is documented as "linux-specific" then this means it
		2713	originated on GNU/Linux. C<IO::AIO> will usually try to autodetect the
		2714	availability and compatibility of such calls regardless of the platform
		2715	it is compiled on, so platforms such as FreeBSD which often implement
		2716	these calls will work. When in doubt, call them and see if they fail wth
		2717	C<ENOSYS>.
		2718
2294	=head2 MEMORY USAGE	2719	=head2 MEMORY USAGE
2295		2720
2296	Per-request usage:	2721	Per-request usage:
2297		2722
2298	Each aio request uses - depending on your architecture - around 100-200	2723	Each aio request uses - depending on your architecture - around 100-200
…		…
2310	temporary buffers, and each thread requires a stack and other data	2735	temporary buffers, and each thread requires a stack and other data
2311	structures (usually around 16k-128k, depending on the OS).	2736	structures (usually around 16k-128k, depending on the OS).
2312		2737
2313	=head1 KNOWN BUGS	2738	=head1 KNOWN BUGS
2314		2739
2315	Known bugs will be fixed in the next release.	2740	Known bugs will be fixed in the next release :)
		2741
		2742	=head1 KNOWN ISSUES
		2743
		2744	Calls that try to "import" foreign memory areas (such as C<IO::AIO::mmap>
		2745	or C<IO::AIO::aio_slurp>) do not work with generic lvalues, such as
		2746	non-created hash slots or other scalars I didn't think of. It's best to
		2747	avoid such and either use scalar variables or making sure that the scalar
		2748	exists (e.g. by storing C<undef>) and isn't "funny" (e.g. tied).
		2749
		2750	I am not sure anything can be done about this, so this is considered a
		2751	known issue, rather than a bug.
2316		2752
2317	=head1 SEE ALSO	2753	=head1 SEE ALSO
2318		2754
2319	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a	2755	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
2320	more natural syntax.	2756	more natural syntax and L<IO::FDPass> for file descriptor passing.
2321		2757
2322	=head1 AUTHOR	2758	=head1 AUTHOR
2323		2759
2324	Marc Lehmann <schmorp@schmorp.de>	2760	Marc Lehmann <schmorp@schmorp.de>
2325	http://home.schmorp.de/	2761	http://home.schmorp.de/

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.280 by root, Mon Feb 19 13:37:13 2018 UTC vs. Revision 1.310 by root, Wed Dec 30 07:45:32 2020 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.280 by root, Mon Feb 19 13:37:13 2018 UTC vs.
Revision 1.310 by root, Wed Dec 30 07:45:32 2020 UTC