[ViewVC] Diff of: cvs/IO-AIO/README

Comparing IO-AIO/README (file contents):
Revision 1.53 by root, Thu Oct 11 03:20:52 2012 UTC vs.
Revision 1.64 by root, Wed Apr 3 03:03:53 2019 UTC

…		…
1	NAME	1	NAME
2	IO::AIO - Asynchronous Input/Output	2	IO::AIO - Asynchronous/Advanced Input/Output
3		3
4	SYNOPSIS	4	SYNOPSIS
5	use IO::AIO;	5	use IO::AIO;
6		6
7	aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {	7	aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
55	not well-supported or restricted (GNU/Linux doesn't allow them on normal	55	not well-supported or restricted (GNU/Linux doesn't allow them on normal
56	files currently, for example), and they would only support aio_read and	56	files currently, for example), and they would only support aio_read and
57	aio_write, so the remaining functionality would have to be implemented	57	aio_write, so the remaining functionality would have to be implemented
58	using threads anyway.	58	using threads anyway.
59		59
		60	In addition to asynchronous I/O, this module also exports some rather
		61	arcane interfaces, such as "madvise" or linux's "splice" system call,
		62	which is why the "A" in "AIO" can also mean advanced.
		63
60	Although the module will work in the presence of other (Perl-) threads,	64	Although the module will work in the presence of other (Perl-) threads,
61	it is currently not reentrant in any way, so use appropriate locking	65	it is currently not reentrant in any way, so use appropriate locking
62	yourself, always call "poll_cb" from within the same thread, or never	66	yourself, always call "poll_cb" from within the same thread, or never
63	call "poll_cb" (or other "aio_" functions) recursively.	67	call "poll_cb" (or other "aio_" functions) recursively.
64		68
65	EXAMPLE	69	EXAMPLE
66	This is a simple example that uses the EV module and loads /etc/passwd	70	This is a simple example that uses the EV module and loads /etc/passwd
67	asynchronously:	71	asynchronously:
68		72
69	use Fcntl;
70	use EV;	73	use EV;
71	use IO::AIO;	74	use IO::AIO;
72		75
73	# register the IO::AIO callback with EV	76	# register the IO::AIO callback with EV
74	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;	77	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
…		…
91		94
92	# file contents now in $contents	95	# file contents now in $contents
93	print $contents;	96	print $contents;
94		97
95	# exit event loop and program	98	# exit event loop and program
96	EV::unloop;	99	EV::break;
97	};	100	};
98	};	101	};
99		102
100	# possibly queue up other requests, or open GUI windows,	103	# possibly queue up other requests, or open GUI windows,
101	# check for sockets etc. etc.	104	# check for sockets etc. etc.
102		105
103	# process events as long as there are some:	106	# process events as long as there are some:
104	EV::loop;	107	EV::run;
105		108
106	REQUEST ANATOMY AND LIFETIME	109	REQUEST ANATOMY AND LIFETIME
107	Every "aio_*" function creates a request. which is a C data structure	110	Every "aio_*" function creates a request. which is a C data structure
108	not directly visible to Perl.	111	not directly visible to Perl.
109		112
…		…
172	aio_unlink $pathname, $callback->($status)	175	aio_unlink $pathname, $callback->($status)
173	aio_mknod $pathname, $mode, $dev, $callback->($status)	176	aio_mknod $pathname, $mode, $dev, $callback->($status)
174	aio_link $srcpath, $dstpath, $callback->($status)	177	aio_link $srcpath, $dstpath, $callback->($status)
175	aio_symlink $srcpath, $dstpath, $callback->($status)	178	aio_symlink $srcpath, $dstpath, $callback->($status)
176	aio_readlink $pathname, $callback->($link)	179	aio_readlink $pathname, $callback->($link)
177	aio_realpath $pathname, $callback->($link)	180	aio_realpath $pathname, $callback->($path)
178	aio_rename $srcpath, $dstpath, $callback->($status)	181	aio_rename $srcpath, $dstpath, $callback->($status)
		182	aio_rename2 $srcpath, $dstpath, $flags, $callback->($status)
179	aio_mkdir $pathname, $mode, $callback->($status)	183	aio_mkdir $pathname, $mode, $callback->($status)
180	aio_rmdir $pathname, $callback->($status)	184	aio_rmdir $pathname, $callback->($status)
181	aio_readdir $pathname, $callback->($entries)	185	aio_readdir $pathname, $callback->($entries)
182	aio_readdirx $pathname, $flags, $callback->($entries, $flags)	186	aio_readdirx $pathname, $flags, $callback->($entries, $flags)
183	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST	187	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
…		…
185	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)	189	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
186	aio_load $pathname, $data, $callback->($status)	190	aio_load $pathname, $data, $callback->($status)
187	aio_copy $srcpath, $dstpath, $callback->($status)	191	aio_copy $srcpath, $dstpath, $callback->($status)
188	aio_move $srcpath, $dstpath, $callback->($status)	192	aio_move $srcpath, $dstpath, $callback->($status)
189	aio_rmtree $pathname, $callback->($status)	193	aio_rmtree $pathname, $callback->($status)
		194	aio_fcntl $fh, $cmd, $arg, $callback->($status)
		195	aio_ioctl $fh, $request, $buf, $callback->($status)
190	aio_sync $callback->($status)	196	aio_sync $callback->($status)
191	aio_syncfs $fh, $callback->($status)	197	aio_syncfs $fh, $callback->($status)
192	aio_fsync $fh, $callback->($status)	198	aio_fsync $fh, $callback->($status)
193	aio_fdatasync $fh, $callback->($status)	199	aio_fdatasync $fh, $callback->($status)
194	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)	200	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
195	aio_pathsync $pathname, $callback->($status)	201	aio_pathsync $pathname, $callback->($status)
196	aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	202	aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status)
197	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	203	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
198	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	204	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
199	aio_mlockall $flags, $callback->($status)	205	aio_mlockall $flags, $callback->($status)
200	aio_group $callback->(...)	206	aio_group $callback->(...)
201	aio_nop $callback->()	207	aio_nop $callback->()
…		…
215	IO::AIO::idle_timeout $seconds	221	IO::AIO::idle_timeout $seconds
216	IO::AIO::max_outstanding $maxreqs	222	IO::AIO::max_outstanding $maxreqs
217	IO::AIO::nreqs	223	IO::AIO::nreqs
218	IO::AIO::nready	224	IO::AIO::nready
219	IO::AIO::npending	225	IO::AIO::npending
		226	IO::AIO::reinit
		227
		228	$nfd = IO::AIO::get_fdlimit [EXPERIMENTAL]
		229	IO::AIO::min_fdlimit $nfd [EXPERIMENTAL]
220		230
221	IO::AIO::sendfile $ofh, $ifh, $offset, $count	231	IO::AIO::sendfile $ofh, $ifh, $offset, $count
222	IO::AIO::fadvise $fh, $offset, $len, $advice	232	IO::AIO::fadvise $fh, $offset, $len, $advice
		233
223	IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]	234	IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
224	IO::AIO::munmap $scalar	235	IO::AIO::munmap $scalar
		236	IO::AIO::mremap $scalar, $new_length, $flags[, $new_address]
225	IO::AIO::madvise $scalar, $offset, $length, $advice	237	IO::AIO::madvise $scalar, $offset, $length, $advice
226	IO::AIO::mprotect $scalar, $offset, $length, $protect	238	IO::AIO::mprotect $scalar, $offset, $length, $protect
227	IO::AIO::munlock $scalar, $offset = 0, $length = undef	239	IO::AIO::munlock $scalar, $offset = 0, $length = undef
228	IO::AIO::munlockall	240	IO::AIO::munlockall
		241
		242	# stat extensions
		243	$counter = IO::AIO::st_gen
		244	$seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime, IO::AIO::st_btime
		245	($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtime
		246	$nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec, IO::AIO::st_ctimensec, IO::AIO::st_btimensec
		247	$seconds = IO::AIO::st_btimesec
		248	($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtimensec
		249
		250	# very much unportable syscalls
		251	IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
		252	IO::AIO::tee $r_fh, $w_fh, $length, $flags
		253	$actual_size = IO::AIO::pipesize $r_fh[, $new_size]
		254	($rfh, $wfh) = IO::AIO::pipe2 [$flags]
		255	$fh = IO::AIO::memfd_create $pathname[, $flags]
		256	$fh = IO::AIO::eventfd [$initval, [$flags]]
		257	$fh = IO::AIO::timerfd_create $clockid[, $flags]
		258	($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags, $new_interval, $nbw_value
		259	($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh
229		260
230	API NOTES	261	API NOTES
231	All the "aio_*" calls are more or less thin wrappers around the syscall	262	All the "aio_*" calls are more or less thin wrappers around the syscall
232	with the same name (sans "aio_"). The arguments are similar or	263	with the same name (sans "aio_"). The arguments are similar or
233	identical, and they all accept an additional (and optional) $callback	264	identical, and they all accept an additional (and optional) $callback
…		…
331	"O_APPEND"), the following POSIX and non-POSIX constants are	362	"O_APPEND"), the following POSIX and non-POSIX constants are
332	available (missing ones on your system are, as usual, 0):	363	available (missing ones on your system are, as usual, 0):
333		364
334	"O_ASYNC", "O_DIRECT", "O_NOATIME", "O_CLOEXEC", "O_NOCTTY",	365	"O_ASYNC", "O_DIRECT", "O_NOATIME", "O_CLOEXEC", "O_NOCTTY",
335	"O_NOFOLLOW", "O_NONBLOCK", "O_EXEC", "O_SEARCH", "O_DIRECTORY",	366	"O_NOFOLLOW", "O_NONBLOCK", "O_EXEC", "O_SEARCH", "O_DIRECTORY",
336	"O_DSYNC", "O_RSYNC", "O_SYNC" and "O_TTY_INIT".	367	"O_DSYNC", "O_RSYNC", "O_SYNC", "O_PATH", "O_TMPFILE", "O_TTY_INIT"
		368	and "O_ACCMODE".
337		369
338	aio_close $fh, $callback->($status)	370	aio_close $fh, $callback->($status)
339	Asynchronously close a file and call the callback with the result	371	Asynchronously close a file and call the callback with the result
340	code.	372	code.
341		373
…		…
371		403
372	aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	404	aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
373	aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	405	aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
374	Reads or writes $length bytes from or to the specified $fh and	406	Reads or writes $length bytes from or to the specified $fh and
375	$offset into the scalar given by $data and offset $dataoffset and	407	$offset into the scalar given by $data and offset $dataoffset and
376	calls the callback without the actual number of bytes read (or -1 on	408	calls the callback with the actual number of bytes transferred (or
377	error, just like the syscall).	409	-1 on error, just like the syscall).
378		410
379	"aio_read" will, like "sysread", shrink or grow the $data scalar to	411	"aio_read" will, like "sysread", shrink or grow the $data scalar to
380	offset plus the actual number of bytes read.	412	offset plus the actual number of bytes read.
381		413
382	If $offset is undefined, then the current file descriptor offset	414	If $offset is undefined, then the current file descriptor offset
…		…
439	As native sendfile syscalls (as practically any non-POSIX interface	471	As native sendfile syscalls (as practically any non-POSIX interface
440	hacked together in a hurry to improve benchmark numbers) tend to be	472	hacked together in a hurry to improve benchmark numbers) tend to be
441	rather buggy on many systems, this implementation tries to work	473	rather buggy on many systems, this implementation tries to work
442	around some known bugs in Linux and FreeBSD kernels (probably	474	around some known bugs in Linux and FreeBSD kernels (probably
443	others, too), but that might fail, so you really really should check	475	others, too), but that might fail, so you really really should check
444	the return value of "aio_sendfile" - fewre bytes than expected might	476	the return value of "aio_sendfile" - fewer bytes than expected might
445	have been transferred.	477	have been transferred.
446		478
447	aio_readahead $fh,$offset,$length, $callback->($retval)	479	aio_readahead $fh,$offset,$length, $callback->($retval)
448	"aio_readahead" populates the page cache with data from a file so	480	"aio_readahead" populates the page cache with data from a file so
449	that subsequent reads from that file will not block on disk I/O. The	481	that subsequent reads from that file will not block on disk I/O. The
…		…
453	to a page boundary and bytes are read up to the next page boundary	485	to a page boundary and bytes are read up to the next page boundary
454	greater than or equal to (off-set+length). "aio_readahead" does not	486	greater than or equal to (off-set+length). "aio_readahead" does not
455	read beyond the end of the file. The current file offset of the file	487	read beyond the end of the file. The current file offset of the file
456	is left unchanged.	488	is left unchanged.
457		489
458	If that syscall doesn't exist (likely if your OS isn't Linux) it	490	If that syscall doesn't exist (likely if your kernel isn't Linux) it
459	will be emulated by simply reading the data, which would have a	491	will be emulated by simply reading the data, which would have a
460	similar effect.	492	similar effect.
461		493
462	aio_stat $fh_or_path, $callback->($status)	494	aio_stat $fh_or_path, $callback->($status)
463	aio_lstat $fh, $callback->($status)	495	aio_lstat $fh, $callback->($status)
464	Works like perl's "stat" or "lstat" in void context. The callback	496	Works almost exactly like perl's "stat" or "lstat" in void context.
465	will be called after the stat and the results will be available	497	The callback will be called after the stat and the results will be
466	using "stat _" or "-s _" etc...	498	available using "stat _" or "-s _" and other tests (with the
		499	exception of "-B" and "-T").
467		500
468	The pathname passed to "aio_stat" must be absolute. See API NOTES,	501	The pathname passed to "aio_stat" must be absolute. See API NOTES,
469	above, for an explanation.	502	above, for an explanation.
470		503
471	Currently, the stats are always 64-bit-stats, i.e. instead of	504	Currently, the stats are always 64-bit-stats, i.e. instead of
…		…
479	back on traditional behaviour).	512	back on traditional behaviour).
480		513
481	"S_IFMT", "S_IFIFO", "S_IFCHR", "S_IFBLK", "S_IFLNK", "S_IFREG",	514	"S_IFMT", "S_IFIFO", "S_IFCHR", "S_IFBLK", "S_IFLNK", "S_IFREG",
482	"S_IFDIR", "S_IFWHT", "S_IFSOCK", "IO::AIO::major $dev_t",	515	"S_IFDIR", "S_IFWHT", "S_IFSOCK", "IO::AIO::major $dev_t",
483	"IO::AIO::minor $dev_t", "IO::AIO::makedev $major, $minor".	516	"IO::AIO::minor $dev_t", "IO::AIO::makedev $major, $minor".
		517
		518	To access higher resolution stat timestamps, see "SUBSECOND STAT
		519	TIME ACCESS".
484		520
485	Example: Print the length of /etc/passwd:	521	Example: Print the length of /etc/passwd:
486		522
487	aio_stat "/etc/passwd", sub {	523	aio_stat "/etc/passwd", sub {
488	$_[0] and die "stat failed: $!";	524	$_[0] and die "stat failed: $!";
…		…
530	namemax => 255,	566	namemax => 255,
531	frsize => 1024,	567	frsize => 1024,
532	fsid => 1810	568	fsid => 1810
533	}	569	}
534		570
535	Here is a (likely partial) list of fsid values used by Linux - it is
536	safe to hardcode these when the $^O is "linux":
537
538	0x0000adf5 adfs
539	0x0000adff affs
540	0x5346414f afs
541	0x09041934 anon-inode filesystem
542	0x00000187 autofs
543	0x42465331 befs
544	0x1badface bfs
545	0x42494e4d binfmt_misc
546	0x9123683e btrfs
547	0x0027e0eb cgroupfs
548	0xff534d42 cifs
549	0x73757245 coda
550	0x012ff7b7 coh
551	0x28cd3d45 cramfs
552	0x453dcd28 cramfs-wend (wrong endianness)
553	0x64626720 debugfs
554	0x00001373 devfs
555	0x00001cd1 devpts
556	0x0000f15f ecryptfs
557	0x00414a53 efs
558	0x0000137d ext
559	0x0000ef53 ext2/ext3
560	0x0000ef51 ext2
561	0x00004006 fat
562	0x65735546 fuseblk
563	0x65735543 fusectl
564	0x0bad1dea futexfs
565	0x01161970 gfs2
566	0x47504653 gpfs
567	0x00004244 hfs
568	0xf995e849 hpfs
569	0x958458f6 hugetlbfs
570	0x2bad1dea inotifyfs
571	0x00009660 isofs
572	0x000072b6 jffs2
573	0x3153464a jfs
574	0x6b414653 k-afs
575	0x0bd00bd0 lustre
576	0x0000137f minix
577	0x0000138f minix 30 char names
578	0x00002468 minix v2
579	0x00002478 minix v2 30 char names
580	0x00004d5a minix v3
581	0x19800202 mqueue
582	0x00004d44 msdos
583	0x0000564c novell
584	0x00006969 nfs
585	0x6e667364 nfsd
586	0x00003434 nilfs
587	0x5346544e ntfs
588	0x00009fa1 openprom
589	0x7461636F ocfs2
590	0x00009fa0 proc
591	0x6165676c pstorefs
592	0x0000002f qnx4
593	0x858458f6 ramfs
594	0x52654973 reiserfs
595	0x00007275 romfs
596	0x67596969 rpc_pipefs
597	0x73636673 securityfs
598	0xf97cff8c selinux
599	0x0000517b smb
600	0x534f434b sockfs
601	0x73717368 squashfs
602	0x62656572 sysfs
603	0x012ff7b6 sysv2
604	0x012ff7b5 sysv4
605	0x01021994 tmpfs
606	0x15013346 udf
607	0x00011954 ufs
608	0x54190100 ufs byteswapped
609	0x00009fa2 usbdevfs
610	0x01021997 v9fs
611	0xa501fcf5 vxfs
612	0xabba1974 xenfs
613	0x012ff7b4 xenix
614	0x58465342 xfs
615	0x012fd16d xia
616
617	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	571	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
618	Works like perl's "utime" function (including the special case of	572	Works like perl's "utime" function (including the special case of
619	$atime and $mtime being undef). Fractional times are supported if	573	$atime and $mtime being undef). Fractional times are supported if
620	the underlying syscalls support them.	574	the underlying syscalls support them.
621		575
622	When called with a pathname, uses utimes(2) if available, otherwise	576	When called with a pathname, uses utimensat(2) or utimes(2) if
623	utime(2). If called on a file descriptor, uses futimes(2) if	577	available, otherwise utime(2). If called on a file descriptor, uses
624	available, otherwise returns ENOSYS, so this is not portable.	578	futimens(2) or futimes(2) if available, otherwise returns ENOSYS, so
		579	this is not portable.
625		580
626	Examples:	581	Examples:
627		582
628	# set atime and mtime to current time (basically touch(1)):	583	# set atime and mtime to current time (basically touch(1)):
629	aio_utime "path", undef, undef;	584	aio_utime "path", undef, undef;
…		…
644		599
645	aio_truncate $fh_or_path, $offset, $callback->($status)	600	aio_truncate $fh_or_path, $offset, $callback->($status)
646	Works like truncate(2) or ftruncate(2).	601	Works like truncate(2) or ftruncate(2).
647		602
648	aio_allocate $fh, $mode, $offset, $len, $callback->($status)	603	aio_allocate $fh, $mode, $offset, $len, $callback->($status)
649	Allocates or freed disk space according to the $mode argument. See	604	Allocates or frees disk space according to the $mode argument. See
650	the linux "fallocate" docuemntation for details.	605	the linux "fallocate" documentation for details.
651		606
652	$mode can currently be 0 or "IO::AIO::FALLOC_FL_KEEP_SIZE" to	607	$mode is usually 0 or "IO::AIO::FALLOC_FL_KEEP_SIZE" to allocate
653	allocate space, or "IO::AIO::FALLOC_FL_PUNCH_HOLE \|	608	space, or "IO::AIO::FALLOC_FL_PUNCH_HOLE \|
654	IO::AIO::FALLOC_FL_KEEP_SIZE", to deallocate a file range.	609	IO::AIO::FALLOC_FL_KEEP_SIZE", to deallocate a file range.
655		610
		611	IO::AIO also supports "FALLOC_FL_COLLAPSE_RANGE", to remove a range
		612	(without leaving a hole), "FALLOC_FL_ZERO_RANGE", to zero a range,
		613	"FALLOC_FL_INSERT_RANGE" to insert a range and
		614	"FALLOC_FL_UNSHARE_RANGE" to unshare shared blocks (see your
		615	fallocate(2) manpage).
		616
656	The file system block size used by "fallocate" is presumably the	617	The file system block size used by "fallocate" is presumably the
657	"f_bsize" returned by "statvfs".	618	"f_bsize" returned by "statvfs", but different filesystems and
		619	filetypes can dictate other limitations.
658		620
659	If "fallocate" isn't available or cannot be emulated (currently no	621	If "fallocate" isn't available or cannot be emulated (currently no
660	emulation will be attempted), passes -1 and sets $! to "ENOSYS".	622	emulation will be attempted), passes -1 and sets $! to "ENOSYS".
661		623
662	aio_chmod $fh_or_path, $mode, $callback->($status)	624	aio_chmod $fh_or_path, $mode, $callback->($status)
…		…
692	the callback. If an error occurs, nothing or undef gets passed to	654	the callback. If an error occurs, nothing or undef gets passed to
693	the callback.	655	the callback.
694		656
695	aio_realpath $pathname, $callback->($path)	657	aio_realpath $pathname, $callback->($path)
696	Asynchronously make the path absolute and resolve any symlinks in	658	Asynchronously make the path absolute and resolve any symlinks in
697	$path. The resulting path only consists of directories (Same as	659	$path. The resulting path only consists of directories (same as
698	Cwd::realpath).	660	Cwd::realpath).
699		661
700	This request can be used to get the absolute path of the current	662	This request can be used to get the absolute path of the current
701	working directory by passing it a path of . (a single dot).	663	working directory by passing it a path of . (a single dot).
702		664
703	aio_rename $srcpath, $dstpath, $callback->($status)	665	aio_rename $srcpath, $dstpath, $callback->($status)
704	Asynchronously rename the object at $srcpath to $dstpath, just as	666	Asynchronously rename the object at $srcpath to $dstpath, just as
705	rename(2) and call the callback with the result code.	667	rename(2) and call the callback with the result code.
		668
		669	On systems that support the AIO::WD working directory abstraction
		670	natively, the case "[$wd, "."]" as $srcpath is specialcased -
		671	instead of failing, "rename" is called on the absolute path of $wd.
		672
		673	aio_rename2 $srcpath, $dstpath, $flags, $callback->($status)
		674	Basically a version of "aio_rename" with an additional $flags
		675	argument. Calling this with "$flags=0" is the same as calling
		676	"aio_rename".
		677
		678	Non-zero flags are currently only supported on GNU/Linux systems
		679	that support renameat2. Other systems fail with "ENOSYS" in this
		680	case.
		681
		682	The following constants are available (missing ones are, as usual
		683	0), see renameat2(2) for details:
		684
		685	"IO::AIO::RENAME_NOREPLACE", "IO::AIO::RENAME_EXCHANGE" and
		686	"IO::AIO::RENAME_WHITEOUT".
706		687
707	aio_mkdir $pathname, $mode, $callback->($status)	688	aio_mkdir $pathname, $mode, $callback->($status)
708	Asynchronously mkdir (create) a directory and call the callback with	689	Asynchronously mkdir (create) a directory and call the callback with
709	the result code. $mode will be modified by the umask at the time the	690	the result code. $mode will be modified by the umask at the time the
710	request is executed, so do not change your umask.	691	request is executed, so do not change your umask.
711		692
712	aio_rmdir $pathname, $callback->($status)	693	aio_rmdir $pathname, $callback->($status)
713	Asynchronously rmdir (delete) a directory and call the callback with	694	Asynchronously rmdir (delete) a directory and call the callback with
714	the result code.	695	the result code.
715		696
		697	On systems that support the AIO::WD working directory abstraction
		698	natively, the case "[$wd, "."]" is specialcased - instead of
		699	failing, "rmdir" is called on the absolute path of $wd.
		700
716	aio_readdir $pathname, $callback->($entries)	701	aio_readdir $pathname, $callback->($entries)
717	Unlike the POSIX call of the same name, "aio_readdir" reads an	702	Unlike the POSIX call of the same name, "aio_readdir" reads an
718	entire directory (i.e. opendir + readdir + closedir). The entries	703	entire directory (i.e. opendir + readdir + closedir). The entries
719	will not be sorted, and will NOT include the "." and ".." entries.	704	will not be sorted, and will NOT include the "." and ".." entries.
720		705
…		…
729	The flags are a combination of the following constants, ORed	714	The flags are a combination of the following constants, ORed
730	together (the flags will also be passed to the callback, possibly	715	together (the flags will also be passed to the callback, possibly
731	modified):	716	modified):
732		717
733	IO::AIO::READDIR_DENTS	718	IO::AIO::READDIR_DENTS
734	When this flag is off, then the callback gets an arrayref	719	Normally the callback gets an arrayref consisting of names only
735	consisting of names only (as with "aio_readdir"), otherwise it	720	(as with "aio_readdir"). If this flag is set, then the callback
736	gets an arrayref with "[$name, $type, $inode]" arrayrefs, each	721	gets an arrayref with "[$name, $type, $inode]" arrayrefs, each
737	describing a single directory entry in more detail.	722	describing a single directory entry in more detail:
738		723
739	$name is the name of the entry.	724	$name is the name of the entry.
740		725
741	$type is one of the "IO::AIO::DT_xxx" constants:	726	$type is one of the "IO::AIO::DT_xxx" constants:
742		727
743	"IO::AIO::DT_UNKNOWN", "IO::AIO::DT_FIFO", "IO::AIO::DT_CHR",	728	"IO::AIO::DT_UNKNOWN", "IO::AIO::DT_FIFO", "IO::AIO::DT_CHR",
744	"IO::AIO::DT_DIR", "IO::AIO::DT_BLK", "IO::AIO::DT_REG",	729	"IO::AIO::DT_DIR", "IO::AIO::DT_BLK", "IO::AIO::DT_REG",
745	"IO::AIO::DT_LNK", "IO::AIO::DT_SOCK", "IO::AIO::DT_WHT".	730	"IO::AIO::DT_LNK", "IO::AIO::DT_SOCK", "IO::AIO::DT_WHT".
746		731
747	"IO::AIO::DT_UNKNOWN" means just that: readdir does not know. If	732	"IO::AIO::DT_UNKNOWN" means just that: readdir does not know. If
748	you need to know, you have to run stat yourself. Also, for speed	733	you need to know, you have to run stat yourself. Also, for
749	reasons, the $type scalars are read-only: you can not modify	734	speed/memory reasons, the $type scalars are read-only: you must
750	them.	735	not modify them.
751		736
752	$inode is the inode number (which might not be exact on systems	737	$inode is the inode number (which might not be exact on systems
753	with 64 bit inode numbers and 32 bit perls). This field has	738	with 64 bit inode numbers and 32 bit perls). This field has
754	unspecified content on systems that do not deliver the inode	739	unspecified content on systems that do not deliver the inode
755	information.	740	information.
…		…
767	of which names with short names are tried first.	752	of which names with short names are tried first.
768		753
769	IO::AIO::READDIR_STAT_ORDER	754	IO::AIO::READDIR_STAT_ORDER
770	When this flag is set, then the names will be returned in an	755	When this flag is set, then the names will be returned in an
771	order suitable for stat()'ing each one. That is, when you plan	756	order suitable for stat()'ing each one. That is, when you plan
772	to stat() all files in the given directory, then the returned	757	to stat() most or all files in the given directory, then the
773	order will likely be fastest.	758	returned order will likely be faster.
774		759
775	If both this flag and "IO::AIO::READDIR_DIRS_FIRST" are	760	If both this flag and "IO::AIO::READDIR_DIRS_FIRST" are
776	specified, then the likely dirs come first, resulting in a less	761	specified, then the likely dirs come first, resulting in a less
777	optimal stat order.	762	optimal stat order for stat'ing all entries, but likely a more
		763	optimal order for finding subdirectories.
778		764
779	IO::AIO::READDIR_FOUND_UNKNOWN	765	IO::AIO::READDIR_FOUND_UNKNOWN
780	This flag should not be set when calling "aio_readdirx".	766	This flag should not be set when calling "aio_readdirx".
781	Instead, it is being set by "aio_readdirx", when any of the	767	Instead, it is being set by "aio_readdirx", when any of the
782	$type's found were "IO::AIO::DT_UNKNOWN". The absence of this	768	$type's found were "IO::AIO::DT_UNKNOWN". The absence of this
783	flag therefore indicates that all $type's are known, which can	769	flag therefore indicates that all $type's are known, which can
784	be used to speed up some algorithms.	770	be used to speed up some algorithms.
785		771
		772	aio_slurp $pathname, $offset, $length, $data, $callback->($status)
		773	Opens, reads and closes the given file. The data is put into $data,
		774	which is resized as required.
		775
		776	If $offset is negative, then it is counted from the end of the file.
		777
		778	If $length is zero, then the remaining length of the file is used.
		779	Also, in this case, the same limitations to modifying $data apply as
		780	when IO::AIO::mmap is used, i.e. it must only be modified in-place
		781	with "substr". If the size of the file is known, specifying a
		782	non-zero $length results in a performance advantage.
		783
		784	This request is similar to the older "aio_load" request, but since
		785	it is a single request, it might be more efficient to use.
		786
		787	Example: load /etc/passwd into $passwd.
		788
		789	my $passwd;
		790	aio_slurp "/etc/passwd", 0, 0, $passwd, sub {
		791	$_[0] >= 0
		792	or die "/etc/passwd: $!\n";
		793
		794	printf "/etc/passwd is %d bytes long, and contains:\n", length $passwd;
		795	print $passwd;
		796	};
		797	IO::AIO::flush;
		798
786	aio_load $pathname, $data, $callback->($status)	799	aio_load $pathname, $data, $callback->($status)
787	This is a composite request that tries to fully load the given file	800	This is a composite request that tries to fully load the given file
788	into memory. Status is the same as with aio_read.	801	into memory. Status is the same as with aio_read.
		802
		803	Using "aio_slurp" might be more efficient, as it is a single
		804	request.
789		805
790	aio_copy $srcpath, $dstpath, $callback->($status)	806	aio_copy $srcpath, $dstpath, $callback->($status)
791	Try to copy the file (directories not supported as either source	807	Try to copy the file (directories not supported as either source
792	or destination) from $srcpath to $dstpath and call the callback with	808	or destination) from $srcpath to $dstpath and call the callback with
793	a status of 0 (ok) or -1 (error, see $!).	809	a status of 0 (ok) or -1 (error, see $!).
		810
		811	Existing destination files will be truncated.
794		812
795	This is a composite request that creates the destination file with	813	This is a composite request that creates the destination file with
796	mode 0200 and copies the contents of the source file into it using	814	mode 0200 and copies the contents of the source file into it using
797	"aio_sendfile", followed by restoring atime, mtime, access mode and	815	"aio_sendfile", followed by restoring atime, mtime, access mode and
798	uid/gid, in that order.	816	uid/gid, in that order.
…		…
815	to efficiently separate the entries of directory $path into two sets	833	to efficiently separate the entries of directory $path into two sets
816	of names, directories you can recurse into (directories), and ones	834	of names, directories you can recurse into (directories), and ones
817	you cannot recurse into (everything else, including symlinks to	835	you cannot recurse into (everything else, including symlinks to
818	directories).	836	directories).
819		837
820	"aio_scandir" is a composite request that creates of many sub	838	"aio_scandir" is a composite request that generates many sub
821	requests_ $maxreq specifies the maximum number of outstanding aio	839	requests. $maxreq specifies the maximum number of outstanding aio
822	requests that this function generates. If it is "<= 0", then a	840	requests that this function generates. If it is "<= 0", then a
823	suitable default will be chosen (currently 4).	841	suitable default will be chosen (currently 4).
824		842
825	On error, the callback is called without arguments, otherwise it	843	On error, the callback is called without arguments, otherwise it
826	receives two array-refs with path-relative entry names.	844	receives two array-refs with path-relative entry names.
…		…
873	Delete a directory tree starting (and including) $path, return the	891	Delete a directory tree starting (and including) $path, return the
874	status of the final "rmdir" only. This is a composite request that	892	status of the final "rmdir" only. This is a composite request that
875	uses "aio_scandir" to recurse into and rmdir directories, and unlink	893	uses "aio_scandir" to recurse into and rmdir directories, and unlink
876	everything else.	894	everything else.
877		895
		896	aio_fcntl $fh, $cmd, $arg, $callback->($status)
		897	aio_ioctl $fh, $request, $buf, $callback->($status)
		898	These work just like the "fcntl" and "ioctl" built-in functions,
		899	except they execute asynchronously and pass the return value to the
		900	callback.
		901
		902	Both calls can be used for a lot of things, some of which make more
		903	sense to run asynchronously in their own thread, while some others
		904	make less sense. For example, calls that block waiting for external
		905	events, such as locking, will also lock down an I/O thread while it
		906	is waiting, which can deadlock the whole I/O system. At the same
		907	time, there might be no alternative to using a thread to wait.
		908
		909	So in general, you should only use these calls for things that do
		910	(filesystem) I/O, not for things that wait for other events
		911	(network, other processes), although if you are careful and know
		912	what you are doing, you still can.
		913
		914	The following constants are available (missing ones are, as usual
		915	0):
		916
		917	"F_DUPFD_CLOEXEC",
		918
		919	"F_OFD_GETLK", "F_OFD_SETLK", "F_OFD_GETLKW",
		920
		921	"FIFREEZE", "FITHAW", "FITRIM", "FICLONE", "FICLONERANGE",
		922	"FIDEDUPERANGE".
		923
		924	"FS_IOC_GETFLAGS", "FS_IOC_SETFLAGS", "FS_IOC_GETVERSION",
		925	"FS_IOC_SETVERSION", "FS_IOC_FIEMAP".
		926
		927	"FS_IOC_FSGETXATTR", "FS_IOC_FSSETXATTR",
		928	"FS_IOC_SET_ENCRYPTION_POLICY", "FS_IOC_GET_ENCRYPTION_PWSALT",
		929	"FS_IOC_GET_ENCRYPTION_POLICY", "FS_KEY_DESCRIPTOR_SIZE".
		930
		931	"FS_SECRM_FL", "FS_UNRM_FL", "FS_COMPR_FL", "FS_SYNC_FL",
		932	"FS_IMMUTABLE_FL", "FS_APPEND_FL", "FS_NODUMP_FL", "FS_NOATIME_FL",
		933	"FS_DIRTY_FL", "FS_COMPRBLK_FL", "FS_NOCOMP_FL", "FS_ENCRYPT_FL",
		934	"FS_BTREE_FL", "FS_INDEX_FL", "FS_JOURNAL_DATA_FL", "FS_NOTAIL_FL",
		935	"FS_DIRSYNC_FL", "FS_TOPDIR_FL", "FS_FL_USER_MODIFIABLE".
		936
		937	"FS_XFLAG_REALTIME", "FS_XFLAG_PREALLOC", "FS_XFLAG_IMMUTABLE",
		938	"FS_XFLAG_APPEND", "FS_XFLAG_SYNC", "FS_XFLAG_NOATIME",
		939	"FS_XFLAG_NODUMP", "FS_XFLAG_RTINHERIT", "FS_XFLAG_PROJINHERIT",
		940	"FS_XFLAG_NOSYMLINKS", "FS_XFLAG_EXTSIZE", "FS_XFLAG_EXTSZINHERIT",
		941	"FS_XFLAG_NODEFRAG", "FS_XFLAG_FILESTREAM", "FS_XFLAG_DAX",
		942	"FS_XFLAG_HASATTR",
		943
878	aio_sync $callback->($status)	944	aio_sync $callback->($status)
879	Asynchronously call sync and call the callback when finished.	945	Asynchronously call sync and call the callback when finished.
880		946
881	aio_fsync $fh, $callback->($status)	947	aio_fsync $fh, $callback->($status)
882	Asynchronously call fsync on the given filehandle and call the	948	Asynchronously call fsync on the given filehandle and call the
…		…
918	Future versions of this function might fall back to other methods	984	Future versions of this function might fall back to other methods
919	when "fsync" on the directory fails (such as calling "sync").	985	when "fsync" on the directory fails (such as calling "sync").
920		986
921	Passes 0 when everything went ok, and -1 on error.	987	Passes 0 when everything went ok, and -1 on error.
922		988
923	aio_msync $scalar, $offset = 0, $length = undef, flags = 0,	989	aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC,
924	$callback->($status)	990	$callback->($status)
925	This is a rather advanced IO::AIO call, which only works on	991	This is a rather advanced IO::AIO call, which only works on
926	mmap(2)ed scalars (see the "IO::AIO::mmap" function, although it	992	mmap(2)ed scalars (see the "IO::AIO::mmap" function, although it
927	also works on data scalars managed by the Sys::Mmap or Mmap modules,	993	also works on data scalars managed by the Sys::Mmap or Mmap modules,
928	note that the scalar must only be modified in-place while an aio	994	note that the scalar must only be modified in-place while an aio
…		…
930		996
931	It calls the "msync" function of your OS, if available, with the	997	It calls the "msync" function of your OS, if available, with the
932	memory area starting at $offset in the string and ending $length	998	memory area starting at $offset in the string and ending $length
933	bytes later. If $length is negative, counts from the end, and if	999	bytes later. If $length is negative, counts from the end, and if
934	$length is "undef", then it goes till the end of the string. The	1000	$length is "undef", then it goes till the end of the string. The
935	flags can be a combination of "IO::AIO::MS_ASYNC",	1001	flags can be either "IO::AIO::MS_ASYNC" or "IO::AIO::MS_SYNC", plus
936	"IO::AIO::MS_INVALIDATE" and "IO::AIO::MS_SYNC".	1002	an optional "IO::AIO::MS_INVALIDATE".
937		1003
938	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0,	1004	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0,
939	$callback->($status)	1005	$callback->($status)
940	This is a rather advanced IO::AIO call, which works best on	1006	This is a rather advanced IO::AIO call, which works best on
941	mmap(2)ed scalars.	1007	mmap(2)ed scalars.
942		1008
943	It touches (reads or writes) all memory pages in the specified range	1009	It touches (reads or writes) all memory pages in the specified range
944	inside the scalar. All caveats and parameters are the same as for	1010	inside the scalar. All caveats and parameters are the same as for
945	"aio_msync", above, except for flags, which must be either 0 (which	1011	"aio_msync", above, except for flags, which must be either 0 (which
946	reads all pages and ensures they are instantiated) or	1012	reads all pages and ensures they are instantiated) or
947	"IO::AIO::MT_MODIFY", which modifies the memory page s(by reading	1013	"IO::AIO::MT_MODIFY", which modifies the memory pages (by reading
948	and writing an octet from it, which dirties the page).	1014	and writing an octet from it, which dirties the page).
949		1015
950	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	1016	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
951	This is a rather advanced IO::AIO call, which works best on	1017	This is a rather advanced IO::AIO call, which works best on
952	mmap(2)ed scalars.	1018	mmap(2)ed scalars.
…		…
972	IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;	1038	IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
973	aio_mlock $data; # mlock in background	1039	aio_mlock $data; # mlock in background
974		1040
975	aio_mlockall $flags, $callback->($status)	1041	aio_mlockall $flags, $callback->($status)
976	Calls the "mlockall" function with the given $flags (a combination	1042	Calls the "mlockall" function with the given $flags (a combination
977	of "IO::AIO::MCL_CURRENT" and "IO::AIO::MCL_FUTURE").	1043	of "IO::AIO::MCL_CURRENT", "IO::AIO::MCL_FUTURE" and
		1044	"IO::AIO::MCL_ONFAULT").
978		1045
979	On systems that do not implement "mlockall", this function returns	1046	On systems that do not implement "mlockall", this function returns
980	-1 and sets errno to "ENOSYS".	1047	-1 and sets errno to "ENOSYS". Similarly, flag combinations not
		1048	supported by the system result in a return value of -1 with errno
		1049	being set to "EINVAL".
981		1050
982	Note that the corresponding "munlockall" is synchronous and is	1051	Note that the corresponding "munlockall" is synchronous and is
983	documented under "MISCELLANEOUS FUNCTIONS".	1052	documented under "MISCELLANEOUS FUNCTIONS".
984		1053
985	Example: asynchronously lock all current and future pages into	1054	Example: asynchronously lock all current and future pages into
…		…
1027	"IO::AIO::FIEMAP_EXTENT_DATA_INLINE",	1096	"IO::AIO::FIEMAP_EXTENT_DATA_INLINE",
1028	"IO::AIO::FIEMAP_EXTENT_DATA_TAIL",	1097	"IO::AIO::FIEMAP_EXTENT_DATA_TAIL",
1029	"IO::AIO::FIEMAP_EXTENT_UNWRITTEN", "IO::AIO::FIEMAP_EXTENT_MERGED"	1098	"IO::AIO::FIEMAP_EXTENT_UNWRITTEN", "IO::AIO::FIEMAP_EXTENT_MERGED"
1030	or "IO::AIO::FIEMAP_EXTENT_SHARED".	1099	or "IO::AIO::FIEMAP_EXTENT_SHARED".
1031		1100
1032	At the time of this writing (Linux 3.2), this requets is unreliable	1101	At the time of this writing (Linux 3.2), this request is unreliable
1033	unless $count is "undef", as the kernel has all sorts of bugs	1102	unless $count is "undef", as the kernel has all sorts of bugs
1034	preventing it to return all extents of a range for files with large	1103	preventing it to return all extents of a range for files with a
1035	number of extents. The code works around all these issues if $count	1104	large number of extents. The code (only) works around all these
1036	is undef.	1105	issues if $count is "undef".
1037		1106
1038	aio_group $callback->(...)	1107	aio_group $callback->(...)
1039	This is a very special aio request: Instead of doing something, it	1108	This is a very special aio request: Instead of doing something, it
1040	is a container for other aio requests, which is useful if you want	1109	is a container for other aio requests, which is useful if you want
1041	to bundle many requests into a single, composite, request with a	1110	to bundle many requests into a single, composite, request with a
…		…
1121	aio_stat [$etcdir, "passwd"], sub {	1190	aio_stat [$etcdir, "passwd"], sub {
1122	# yay	1191	# yay
1123	};	1192	};
1124	};	1193	};
1125		1194
1126	That "aio_wd" is a request and not a normal function shows that creating	1195	The fact that "aio_wd" is a request and not a normal function shows that
1127	an IO::AIO::WD object is itself a potentially blocking operation, which	1196	creating an IO::AIO::WD object is itself a potentially blocking
1128	is why it is done asynchronously.	1197	operation, which is why it is done asynchronously.
1129		1198
1130	To stat the directory obtained with "aio_wd" above, one could write	1199	To stat the directory obtained with "aio_wd" above, one could write
1131	either of the following three request calls:	1200	either of the following three request calls:
1132		1201
1133	aio_lstat "/etc" , sub { ... # pathname as normal string	1202	aio_lstat "/etc" , sub { ... # pathname as normal string
…		…
1150	There are some caveats: when directories get renamed (or deleted), the	1219	There are some caveats: when directories get renamed (or deleted), the
1151	pathname string doesn't change, so will point to the new directory (or	1220	pathname string doesn't change, so will point to the new directory (or
1152	nowhere at all), while the directory fd, if available on the system,	1221	nowhere at all), while the directory fd, if available on the system,
1153	will still point to the original directory. Most functions accepting a	1222	will still point to the original directory. Most functions accepting a
1154	pathname will use the directory fd on newer systems, and the string on	1223	pathname will use the directory fd on newer systems, and the string on
1155	older systems. Some functions (such as realpath) will always rely on the	1224	older systems. Some functions (such as "aio_realpath") will always rely
1156	string form of the pathname.	1225	on the string form of the pathname.
1157		1226
1158	So this fucntionality is mainly useful to get some protection against	1227	So this functionality is mainly useful to get some protection against
1159	"chdir", to easily get an absolute path out of a relative path for	1228	"chdir", to easily get an absolute path out of a relative path for
1160	future reference, and to speed up doing many operations in the same	1229	future reference, and to speed up doing many operations in the same
1161	directory (e.g. when stat'ing all files in a directory).	1230	directory (e.g. when stat'ing all files in a directory).
1162		1231
1163	The following functions implement this working directory abstraction:	1232	The following functions implement this working directory abstraction:
…		…
1173	Since passing "undef" as working directory component of a pathname	1242	Since passing "undef" as working directory component of a pathname
1174	fails the request with "ENOENT", there is often no need for error	1243	fails the request with "ENOENT", there is often no need for error
1175	checking in the "aio_wd" callback, as future requests using the	1244	checking in the "aio_wd" callback, as future requests using the
1176	value will fail in the expected way.	1245	value will fail in the expected way.
1177		1246
1178	If this call isn't available because your OS lacks it or it couldn't
1179	be detected, it will be emulated by calling "fsync" instead.
1180
1181	IO::AIO::CWD	1247	IO::AIO::CWD
1182	This is a compiletime constant (object) that represents the process	1248	This is a compiletime constant (object) that represents the process
1183	current working directory.	1249	current working directory.
1184		1250
1185	Specifying this object as working directory object for a pathname is	1251	Specifying this object as working directory object for a pathname is
1186	as if the pathname would be specified directly, without a directory	1252	as if the pathname would be specified directly, without a directory
1187	object, e.g., these calls are functionally identical:	1253	object. For example, these calls are functionally identical:
1188		1254
1189	aio_stat "somefile", sub { ... };	1255	aio_stat "somefile", sub { ... };
1190	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };	1256	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
		1257
		1258	To recover the path associated with an IO::AIO::WD object, you can use
		1259	"aio_realpath":
		1260
		1261	aio_realpath $wd, sub {
		1262	warn "path is $_[0]\n";
		1263	};
		1264
		1265	Currently, "aio_statvfs" always, and "aio_rename" and "aio_rmdir"
		1266	sometimes, fall back to using an absolue path.
1191		1267
1192	IO::AIO::REQ CLASS	1268	IO::AIO::REQ CLASS
1193	All non-aggregate "aio_*" functions return an object of this class when	1269	All non-aggregate "aio_*" functions return an object of this class when
1194	called in non-void context.	1270	called in non-void context.
1195		1271
…		…
1347	results.	1423	results.
1348		1424
1349	See "poll_cb" for an example.	1425	See "poll_cb" for an example.
1350		1426
1351	IO::AIO::poll_cb	1427	IO::AIO::poll_cb
1352	Process some outstanding events on the result pipe. You have to call	1428	Process some requests that have reached the result phase (i.e. they
		1429	have been executed but the results are not yet reported). You have
		1430	to call this "regularly" to finish outstanding requests.
		1431
1353	this regularly. Returns 0 if all events could be processed (or there	1432	Returns 0 if all events could be processed (or there were no events
1354	were no events to process), or -1 if it returned earlier for	1433	to process), or -1 if it returned earlier for whatever reason.
1355	whatever reason. Returns immediately when no events are outstanding.	1434	Returns immediately when no events are outstanding. The amount of
1356	The amount of events processed depends on the settings of	1435	events processed depends on the settings of "IO::AIO::max_poll_req",
1357	"IO::AIO::max_poll_req" and "IO::AIO::max_poll_time".	1436	"IO::AIO::max_poll_time" and "IO::AIO::max_outstanding".
1358		1437
1359	If not all requests were processed for whatever reason, the	1438	If not all requests were processed for whatever reason, the poll
1360	filehandle will still be ready when "poll_cb" returns, so normally	1439	file descriptor will still be ready when "poll_cb" returns, so
1361	you don't have to do anything special to have it called later.	1440	normally you don't have to do anything special to have it called
		1441	later.
1362		1442
1363	Apart from calling "IO::AIO::poll_cb" when the event filehandle	1443	Apart from calling "IO::AIO::poll_cb" when the event filehandle
1364	becomes ready, it can be beneficial to call this function from loops	1444	becomes ready, it can be beneficial to call this function from loops
1365	which submit a lot of requests, to make sure the results get	1445	which submit a lot of requests, to make sure the results get
1366	processed when they become available and not just when the loop is	1446	processed when they become available and not just when the loop is
…		…
1374	Event->io (fd => IO::AIO::poll_fileno,	1454	Event->io (fd => IO::AIO::poll_fileno,
1375	poll => 'r', async => 1,	1455	poll => 'r', async => 1,
1376	cb => \&IO::AIO::poll_cb);	1456	cb => \&IO::AIO::poll_cb);
1377		1457
1378	IO::AIO::poll_wait	1458	IO::AIO::poll_wait
1379	If there are any outstanding requests and none of them in the result	1459	Wait until either at least one request is in the result phase or no
1380	phase, wait till the result filehandle becomes ready for reading	1460	requests are outstanding anymore.
1381	(simply does a "select" on the filehandle. This is useful if you	1461
1382	want to synchronously wait for some requests to finish).	1462	This is useful if you want to synchronously wait for some requests
		1463	to become ready, without actually handling them.
1383		1464
1384	See "nreqs" for an example.	1465	See "nreqs" for an example.
1385		1466
1386	IO::AIO::poll	1467	IO::AIO::poll
1387	Waits until some requests have been handled.	1468	Waits until some requests have been handled.
…		…
1396		1477
1397	Strictly equivalent to:	1478	Strictly equivalent to:
1398		1479
1399	IO::AIO::poll_wait, IO::AIO::poll_cb	1480	IO::AIO::poll_wait, IO::AIO::poll_cb
1400	while IO::AIO::nreqs;	1481	while IO::AIO::nreqs;
		1482
		1483	This function can be useful at program aborts, to make sure
		1484	outstanding I/O has been done ("IO::AIO" uses an "END" block which
		1485	already calls this function on normal exits), or when you are merely
		1486	using "IO::AIO" for its more advanced functions, rather than for
		1487	async I/O, e.g.:
		1488
		1489	my ($dirs, $nondirs);
		1490	IO::AIO::aio_scandir "/tmp", 0, sub { ($dirs, $nondirs) = @_ };
		1491	IO::AIO::flush;
		1492	# $dirs, $nondirs are now set
1401		1493
1402	IO::AIO::max_poll_reqs $nreqs	1494	IO::AIO::max_poll_reqs $nreqs
1403	IO::AIO::max_poll_time $seconds	1495	IO::AIO::max_poll_time $seconds
1404	These set the maximum number of requests (default 0, meaning	1496	These set the maximum number of requests (default 0, meaning
1405	infinity) that are being processed by "IO::AIO::poll_cb" in one	1497	infinity) that are being processed by "IO::AIO::poll_cb" in one
…		…
1499		1591
1500	This is a very bad function to use in interactive programs because	1592	This is a very bad function to use in interactive programs because
1501	it blocks, and a bad way to reduce concurrency because it is	1593	it blocks, and a bad way to reduce concurrency because it is
1502	inexact: Better use an "aio_group" together with a feed callback.	1594	inexact: Better use an "aio_group" together with a feed callback.
1503		1595
1504	It's main use is in scripts without an event loop - when you want to	1596	Its main use is in scripts without an event loop - when you want to
1505	stat a lot of files, you can write somehting like this:	1597	stat a lot of files, you can write something like this:
1506		1598
1507	IO::AIO::max_outstanding 32;	1599	IO::AIO::max_outstanding 32;
1508		1600
1509	for my $path (...) {	1601	for my $path (...) {
1510	aio_stat $path , ...;	1602	aio_stat $path , ...;
…		…
1539		1631
1540	IO::AIO::npending	1632	IO::AIO::npending
1541	Returns the number of requests currently in the pending state	1633	Returns the number of requests currently in the pending state
1542	(executed, but not yet processed by poll_cb).	1634	(executed, but not yet processed by poll_cb).
1543		1635
		1636	SUBSECOND STAT TIME ACCESS
		1637	Both "aio_stat"/"aio_lstat" and perl's "stat"/"lstat" functions can
		1638	generally find access/modification and change times with subsecond time
		1639	accuracy of the system supports it, but perl's built-in functions only
		1640	return the integer part.
		1641
		1642	The following functions return the timestamps of the most recent stat
		1643	with subsecond precision on most systems and work both after
		1644	"aio_stat"/"aio_lstat" and perl's "stat"/"lstat" calls. Their return
		1645	value is only meaningful after a successful "stat"/"lstat" call, or
		1646	during/after a successful "aio_stat"/"aio_lstat" callback.
		1647
		1648	This is similar to the Time::HiRes "stat" functions, but can return full
		1649	resolution without rounding and work with standard perl "stat",
		1650	alleviating the need to call the special "Time::HiRes" functions, which
		1651	do not act like their perl counterparts.
		1652
		1653	On operating systems or file systems where subsecond time resolution is
		1654	not supported or could not be detected, a fractional part of 0 is
		1655	returned, so it is always safe to call these functions.
		1656
		1657	$seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime,
		1658	IO::AIO::st_btime
		1659	Return the access, modication, change or birth time, respectively,
		1660	including fractional part. Due to the limited precision of floating
		1661	point, the accuracy on most platforms is only a bit better than
		1662	milliseconds for times around now - see the nsec function family,
		1663	below, for full accuracy.
		1664
		1665	File birth time is only available when the OS and perl support it
		1666	(on FreeBSD and NetBSD at the time of this writing, although support
		1667	is adaptive, so if your OS/perl gains support, IO::AIO can take
		1668	advantage of it). On systems where it isn't available, 0 is
		1669	currently returned, but this might change to "undef" in a future
		1670	version.
		1671
		1672	($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtime
		1673	Returns access, modification, change and birth time all in one go,
		1674	and maybe more times in the future version.
		1675
		1676	$nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec,
		1677	IO::AIO::st_ctimensec, IO::AIO::st_btimensec
		1678	Return the fractional access, modifcation, change or birth time, in
		1679	nanoseconds, as an integer in the range 0 to 999999999.
		1680
		1681	Note that no accessors are provided for access, modification and
		1682	change times - you need to get those from "stat _" if required ("int
		1683	IO::AIO::st_atime" and so on will not generally give you the
		1684	correct value).
		1685
		1686	$seconds = IO::AIO::st_btimesec
		1687	The (integral) seconds part of the file birth time, if available.
		1688
		1689	($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtimensec
		1690	Like the functions above, but returns all four times in one go (and
		1691	maybe more in future versions).
		1692
		1693	$counter = IO::AIO::st_gen
		1694	Returns the generation counter (in practice this is just a random
		1695	number) of the file. This is only available on platforms which have
		1696	this member in their "struct stat" (most BSDs at the time of this
		1697	writing) and generally only to the root usert. If unsupported, 0 is
		1698	returned, but this might change to "undef" in a future version.
		1699
		1700	Example: print the high resolution modification time of /etc, using
		1701	"stat", and "IO::AIO::aio_stat".
		1702
		1703	if (stat "/etc") {
		1704	printf "stat(/etc) mtime: %f\n", IO::AIO::st_mtime;
		1705	}
		1706
		1707	IO::AIO::aio_stat "/etc", sub {
		1708	$_[0]
		1709	and return;
		1710
		1711	printf "aio_stat(/etc) mtime: %d.%09d\n", (stat _)[9], IO::AIO::st_mtimensec;
		1712	};
		1713
		1714	IO::AIO::flush;
		1715
		1716	Output of the awbove on my system, showing reduced and full accuracy:
		1717
		1718	stat(/etc) mtime: 1534043702.020808
		1719	aio_stat(/etc) mtime: 1534043702.020807792
		1720
1544	MISCELLANEOUS FUNCTIONS	1721	MISCELLANEOUS FUNCTIONS
1545	IO::AIO implements some functions that might be useful, but are not	1722	IO::AIO implements some functions that are useful when you want to use
1546	asynchronous.	1723	some "Advanced I/O" function not available to in Perl, without going the
		1724	"Asynchronous I/O" route. Many of these have an asynchronous "aio_*"
		1725	counterpart.
		1726
		1727	$numfd = IO::AIO::get_fdlimit
		1728	This function is EXPERIMENTAL and subject to change.
		1729
		1730	Tries to find the current file descriptor limit and returns it, or
		1731	"undef" and sets $! in case of an error. The limit is one larger
		1732	than the highest valid file descriptor number.
		1733
		1734	IO::AIO::min_fdlimit [$numfd]
		1735	This function is EXPERIMENTAL and subject to change.
		1736
		1737	Try to increase the current file descriptor limit(s) to at least
		1738	$numfd by changing the soft or hard file descriptor resource limit.
		1739	If $numfd is missing, it will try to set a very high limit, although
		1740	this is not recommended when you know the actual minimum that you
		1741	require.
		1742
		1743	If the limit cannot be raised enough, the function makes a
		1744	best-effort attempt to increase the limit as much as possible, using
		1745	various tricks, while still failing. You can query the resulting
		1746	limit using "IO::AIO::get_fdlimit".
		1747
		1748	If an error occurs, returns "undef" and sets $!, otherwise returns
		1749	true.
1547		1750
1548	IO::AIO::sendfile $ofh, $ifh, $offset, $count	1751	IO::AIO::sendfile $ofh, $ifh, $offset, $count
1549	Calls the "eio_sendfile_sync" function, which is like	1752	Calls the "eio_sendfile_sync" function, which is like
1550	"aio_sendfile", but is blocking (this makes most sense if you know	1753	"aio_sendfile", but is blocking (this makes most sense if you know
1551	the input data is likely cached already and the output filehandle is	1754	the input data is likely cached already and the output filehandle is
…		…
1568	details). The following advice constants are available:	1771	details). The following advice constants are available:
1569	"IO::AIO::MADV_NORMAL", "IO::AIO::MADV_SEQUENTIAL",	1772	"IO::AIO::MADV_NORMAL", "IO::AIO::MADV_SEQUENTIAL",
1570	"IO::AIO::MADV_RANDOM", "IO::AIO::MADV_WILLNEED",	1773	"IO::AIO::MADV_RANDOM", "IO::AIO::MADV_WILLNEED",
1571	"IO::AIO::MADV_DONTNEED".	1774	"IO::AIO::MADV_DONTNEED".
1572		1775
		1776	If $offset is negative, counts from the end. If $length is negative,
		1777	the remaining length of the $scalar is used. If possible, $length
		1778	will be reduced to fit into the $scalar.
		1779
1573	On systems that do not implement "posix_madvise", this function	1780	On systems that do not implement "posix_madvise", this function
1574	returns ENOSYS, otherwise the return value of "posix_madvise".	1781	returns ENOSYS, otherwise the return value of "posix_madvise".
1575		1782
1576	IO::AIO::mprotect $scalar, $offset, $len, $protect	1783	IO::AIO::mprotect $scalar, $offset, $len, $protect
1577	Simply calls the "mprotect" function on the preferably AIO::mmap'ed	1784	Simply calls the "mprotect" function on the preferably AIO::mmap'ed
1578	$scalar (see its manpage for details). The following protect	1785	$scalar (see its manpage for details). The following protect
1579	constants are available: "IO::AIO::PROT_NONE", "IO::AIO::PROT_READ",	1786	constants are available: "IO::AIO::PROT_NONE", "IO::AIO::PROT_READ",
1580	"IO::AIO::PROT_WRITE", "IO::AIO::PROT_EXEC".	1787	"IO::AIO::PROT_WRITE", "IO::AIO::PROT_EXEC".
1581		1788
		1789	If $offset is negative, counts from the end. If $length is negative,
		1790	the remaining length of the $scalar is used. If possible, $length
		1791	will be reduced to fit into the $scalar.
		1792
1582	On systems that do not implement "mprotect", this function returns	1793	On systems that do not implement "mprotect", this function returns
1583	ENOSYS, otherwise the return value of "mprotect".	1794	ENOSYS, otherwise the return value of "mprotect".
1584		1795
1585	IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]	1796	IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1586	Memory-maps a file (or anonymous memory range) and attaches it to	1797	Memory-maps a file (or anonymous memory range) and attaches it to
1587	the given $scalar, which will act like a string scalar. Returns true	1798	the given $scalar, which will act like a string scalar. Returns true
1588	on success, and false otherwise.	1799	on success, and false otherwise.
1589		1800
		1801	The scalar must exist, but its contents do not matter - this means
		1802	you cannot use a nonexistant array or hash element. When in doubt,
		1803	"undef" the scalar first.
		1804
1590	The only operations allowed on the scalar are "substr"/"vec" that	1805	The only operations allowed on the mmapped scalar are
1591	don't change the string length, and most read-only operations such	1806	"substr"/"vec", which don't change the string length, and most
1592	as copying it or searching it with regexes and so on.	1807	read-only operations such as copying it or searching it with regexes
		1808	and so on.
1593		1809
1594	Anything else is unsafe and will, at best, result in memory leaks.	1810	Anything else is unsafe and will, at best, result in memory leaks.
1595		1811
1596	The memory map associated with the $scalar is automatically removed	1812	The memory map associated with the $scalar is automatically removed
1597	when the $scalar is destroyed, or when the "IO::AIO::mmap" or	1813	when the $scalar is undef'd or destroyed, or when the
1598	"IO::AIO::munmap" functions are called.	1814	"IO::AIO::mmap" or "IO::AIO::munmap" functions are called on it.
1599		1815
1600	This calls the "mmap"(2) function internally. See your system's	1816	This calls the "mmap"(2) function internally. See your system's
1601	manual page for details on the $length, $prot and $flags parameters.	1817	manual page for details on the $length, $prot and $flags parameters.
1602		1818
1603	The $length must be larger than zero and smaller than the actual	1819	The $length must be larger than zero and smaller than the actual
…		…
1607	"IO::AIO::PROT_EXEC", "IO::AIO::PROT_READ" and/or	1823	"IO::AIO::PROT_EXEC", "IO::AIO::PROT_READ" and/or
1608	"IO::AIO::PROT_WRITE",	1824	"IO::AIO::PROT_WRITE",
1609		1825
1610	$flags can be a combination of "IO::AIO::MAP_SHARED" or	1826	$flags can be a combination of "IO::AIO::MAP_SHARED" or
1611	"IO::AIO::MAP_PRIVATE", or a number of system-specific flags (when	1827	"IO::AIO::MAP_PRIVATE", or a number of system-specific flags (when
1612	not available, the are defined as 0): "IO::AIO::MAP_ANONYMOUS"	1828	not available, the are 0): "IO::AIO::MAP_ANONYMOUS" (which is set to
1613	(which is set to "MAP_ANON" if your system only provides this	1829	"MAP_ANON" if your system only provides this constant),
		1830	"IO::AIO::MAP_LOCKED", "IO::AIO::MAP_NORESERVE",
1614	constant), "IO::AIO::MAP_HUGETLB", "IO::AIO::MAP_LOCKED",	1831	"IO::AIO::MAP_POPULATE", "IO::AIO::MAP_NONBLOCK",
		1832	"IO::AIO::MAP_FIXED", "IO::AIO::MAP_GROWSDOWN",
1615	"IO::AIO::MAP_NORESERVE", "IO::AIO::MAP_POPULATE" or	1833	"IO::AIO::MAP_32BIT", "IO::AIO::MAP_HUGETLB" or
1616	"IO::AIO::MAP_NONBLOCK"	1834	"IO::AIO::MAP_STACK".
1617		1835
1618	If $fh is "undef", then a file descriptor of -1 is passed.	1836	If $fh is "undef", then a file descriptor of -1 is passed.
1619		1837
1620	$offset is the offset from the start of the file - it generally must	1838	$offset is the offset from the start of the file - it generally must
1621	be a multiple of "IO::AIO::PAGESIZE" and defaults to 0.	1839	be a multiple of "IO::AIO::PAGESIZE" and defaults to 0.
…		…
1633		1851
1634	my $fast_md5 = md5 $data;	1852	my $fast_md5 = md5 $data;
1635		1853
1636	IO::AIO::munmap $scalar	1854	IO::AIO::munmap $scalar
1637	Removes a previous mmap and undefines the $scalar.	1855	Removes a previous mmap and undefines the $scalar.
		1856
		1857	IO::AIO::mremap $scalar, $new_length, $flags = MREMAP_MAYMOVE[,
		1858	$new_address = 0]
		1859	Calls the Linux-specific mremap(2) system call. The $scalar must
		1860	have been mapped by "IO::AIO::mmap", and $flags must currently
		1861	either be 0 or "IO::AIO::MREMAP_MAYMOVE".
		1862
		1863	Returns true if successful, and false otherwise. If the underlying
		1864	mmapped region has changed address, then the true value has the
		1865	numerical value 1, otherwise it has the numerical value 0:
		1866
		1867	my $success = IO::AIO::mremap $mmapped, 8192, IO::AIO::MREMAP_MAYMOVE
		1868	or die "mremap: $!";
		1869
		1870	if ($success*1) {
		1871	warn "scalar has chanegd address in memory\n";
		1872	}
		1873
		1874	"IO::AIO::MREMAP_FIXED" and the $new_address argument are currently
		1875	implemented, but not supported and might go away in a future
		1876	version.
		1877
		1878	On systems where this call is not supported or is not emulated, this
		1879	call returns falls and sets $! to "ENOSYS".
		1880
		1881	IO::AIO::mlockall $flags
		1882	Calls the "eio_mlockall_sync" function, which is like
		1883	"aio_mlockall", but is blocking.
1638		1884
1639	IO::AIO::munlock $scalar, $offset = 0, $length = undef	1885	IO::AIO::munlock $scalar, $offset = 0, $length = undef
1640	Calls the "munlock" function, undoing the effects of a previous	1886	Calls the "munlock" function, undoing the effects of a previous
1641	"aio_mlock" call (see its description for details).	1887	"aio_mlock" call (see its description for details).
1642		1888
…		…
1659	"IO::AIO::SPLICE_F_MORE" and "IO::AIO::SPLICE_F_GIFT".	1905	"IO::AIO::SPLICE_F_MORE" and "IO::AIO::SPLICE_F_GIFT".
1660		1906
1661	See the splice(2) manpage for details.	1907	See the splice(2) manpage for details.
1662		1908
1663	IO::AIO::tee $r_fh, $w_fh, $length, $flags	1909	IO::AIO::tee $r_fh, $w_fh, $length, $flags
1664	Calls the GNU/Linux tee(2) syscall, see it's manpage and the	1910	Calls the GNU/Linux tee(2) syscall, see its manpage and the
1665	description for "IO::AIO::splice" above for details.	1911	description for "IO::AIO::splice" above for details.
		1912
		1913	$actual_size = IO::AIO::pipesize $r_fh[, $new_size]
		1914	Attempts to query or change the pipe buffer size. Obviously works
		1915	only on pipes, and currently works only on GNU/Linux systems, and
		1916	fails with -1/"ENOSYS" everywhere else. If anybody knows how to
		1917	influence pipe buffer size on other systems, drop me a note.
		1918
		1919	($rfh, $wfh) = IO::AIO::pipe2 [$flags]
		1920	This is a direct interface to the Linux pipe2(2) system call. If
		1921	$flags is missing or 0, then this should be the same as a call to
		1922	perl's built-in "pipe" function and create a new pipe, and works on
		1923	systems that lack the pipe2 syscall. On win32, this case invokes
		1924	"_pipe (..., 4096, O_BINARY)".
		1925
		1926	If $flags is non-zero, it tries to invoke the pipe2 system call with
		1927	the given flags (Linux 2.6.27, glibc 2.9).
		1928
		1929	On success, the read and write file handles are returned.
		1930
		1931	On error, nothing will be returned. If the pipe2 syscall is missing
		1932	and $flags is non-zero, fails with "ENOSYS".
		1933
		1934	Please refer to pipe2(2) for more info on the $flags, but at the
		1935	time of this writing, "IO::AIO::O_CLOEXEC", "IO::AIO::O_NONBLOCK"
		1936	and "IO::AIO::O_DIRECT" (Linux 3.4, for packet-based pipes) were
		1937	supported.
		1938
		1939	Example: create a pipe race-free w.r.t. threads and fork:
		1940
		1941	my ($rfh, $wfh) = IO::AIO::pipe2 IO::AIO::O_CLOEXEC
		1942	or die "pipe2: $!\n";
		1943
		1944	$fh = IO::AIO::memfd_create $pathname[, $flags]
		1945	This is a direct interface to the Linux memfd_create(2) system call.
		1946	The (unhelpful) default for $flags is 0, but your default should be
		1947	"IO::AIO::MFD_CLOEXEC".
		1948
		1949	On success, the new memfd filehandle is returned, otherwise returns
		1950	"undef". If the memfd_create syscall is missing, fails with
		1951	"ENOSYS".
		1952
		1953	Please refer to memfd_create(2) for more info on this call.
		1954
		1955	The following $flags values are available: "IO::AIO::MFD_CLOEXEC",
		1956	"IO::AIO::MFD_ALLOW_SEALING" and "IO::AIO::MFD_HUGETLB".
		1957
		1958	Example: create a new memfd.
		1959
		1960	my $fh = IO::AIO::memfd_create "somenameforprocfd", IO::AIO::MFD_CLOEXEC
		1961	or die "m,emfd_create: $!\n";
		1962	=item $fh = IO::AIO::eventfd [$initval, [$flags]]
		1963
		1964	This is a direct interface to the Linux eventfd(2) system call. The
		1965	(unhelpful) defaults for $initval and $flags are 0 for both.
		1966
		1967	On success, the new eventfd filehandle is returned, otherwise
		1968	returns "undef". If the eventfd syscall is missing, fails with
		1969	"ENOSYS".
		1970
		1971	Please refer to eventfd(2) for more info on this call.
		1972
		1973	The following symbol flag values are available:
		1974	"IO::AIO::EFD_CLOEXEC", "IO::AIO::EFD_NONBLOCK" and
		1975	"IO::AIO::EFD_SEMAPHORE" (Linux 2.6.30).
		1976
		1977	Example: create a new eventfd filehandle:
		1978
		1979	$fh = IO::AIO::eventfd 0, IO::AIO::EFD_CLOEXEC
		1980	or die "eventfd: $!\n";
		1981
		1982	$fh = IO::AIO::timerfd_create $clockid[, $flags]
		1983	This is a direct interface to the Linux timerfd_create(2) system
		1984	call. The (unhelpful) default for $flags is 0, but your default
		1985	should be "IO::AIO::TFD_CLOEXEC".
		1986
		1987	On success, the new timerfd filehandle is returned, otherwise
		1988	returns "undef". If the timerfd_create syscall is missing, fails
		1989	with "ENOSYS".
		1990
		1991	Please refer to timerfd_create(2) for more info on this call.
		1992
		1993	The following $clockid values are available:
		1994	"IO::AIO::CLOCK_REALTIME", "IO::AIO::CLOCK_MONOTONIC"
		1995	"IO::AIO::CLOCK_CLOCK_BOOTTIME" (Linux 3.15)
		1996	"IO::AIO::CLOCK_CLOCK_REALTIME_ALARM" (Linux 3.11) and
		1997	"IO::AIO::CLOCK_CLOCK_BOOTTIME_ALARM" (Linux 3.11).
		1998
		1999	The following $flags values are available (Linux 2.6.27):
		2000	"IO::AIO::TFD_NONBLOCK" and "IO::AIO::TFD_CLOEXEC".
		2001
		2002	Example: create a new timerfd and set it to one-second repeated
		2003	alarms, then wait for two alarms:
		2004
		2005	my $fh = IO::AIO::timerfd_create IO::AIO::CLOCK_BOOTTIME, IO::AIO::TFD_CLOEXEC
		2006	or die "timerfd_create: $!\n";
		2007
		2008	defined IO::AIO::timerfd_settime $fh, 0, 1, 1
		2009	or die "timerfd_settime: $!\n";
		2010
		2011	for (1..2) {
		2012	8 == sysread $fh, my $buf, 8
		2013	or die "timerfd read failure\n";
		2014
		2015	printf "number of expirations (likely 1): %d\n",
		2016	unpack "Q", $buf;
		2017	}
		2018
		2019	($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags,
		2020	$new_interval, $nbw_value
		2021	This is a direct interface to the Linux timerfd_settime(2) system
		2022	call. Please refer to its manpage for more info on this call.
		2023
		2024	The new itimerspec is specified using two (possibly fractional)
		2025	second values, $new_interval and $new_value).
		2026
		2027	On success, the current interval and value are returned (as per
		2028	"timerfd_gettime"). On failure, the empty list is returned.
		2029
		2030	The following $flags values are available:
		2031	"IO::AIO::TFD_TIMER_ABSTIME" and "IO::AIO::TFD_TIMER_CANCEL_ON_SET".
		2032
		2033	See "IO::AIO::timerfd_create" for a full example.
		2034
		2035	($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh
		2036	This is a direct interface to the Linux timerfd_gettime(2) system
		2037	call. Please refer to its manpage for more info on this call.
		2038
		2039	On success, returns the current values of interval and value for the
		2040	given timerfd (as potentially fractional second values). On failure,
		2041	the empty list is returned.
1666		2042
1667	EVENT LOOP INTEGRATION	2043	EVENT LOOP INTEGRATION
1668	It is recommended to use AnyEvent::AIO to integrate IO::AIO	2044	It is recommended to use AnyEvent::AIO to integrate IO::AIO
1669	automatically into many event loops:	2045	automatically into many event loops:
1670		2046
…		…
1720	forking, if "IO::AIO" was used in the parent. Calling it while	2096	forking, if "IO::AIO" was used in the parent. Calling it while
1721	IO::AIO is active in the process will result in undefined behaviour.	2097	IO::AIO is active in the process will result in undefined behaviour.
1722	Calling it at any time will also result in any undefined (by POSIX)	2098	Calling it at any time will also result in any undefined (by POSIX)
1723	behaviour.	2099	behaviour.
1724		2100
		2101	LINUX-SPECIFIC CALLS
		2102	When a call is documented as "linux-specific" then this means it
		2103	originated on GNU/Linux. "IO::AIO" will usually try to autodetect the
		2104	availability and compatibility of such calls regardless of the platform
		2105	it is compiled on, so platforms such as FreeBSD which often implement
		2106	these calls will work. When in doubt, call them and see if they fail wth
		2107	"ENOSYS".
		2108
1725	MEMORY USAGE	2109	MEMORY USAGE
1726	Per-request usage:	2110	Per-request usage:
1727		2111
1728	Each aio request uses - depending on your architecture - around 100-200	2112	Each aio request uses - depending on your architecture - around 100-200
1729	bytes of memory. In addition, stat requests need a stat buffer (possibly	2113	bytes of memory. In addition, stat requests need a stat buffer (possibly
…		…
1739	In the execution phase, some aio requests require more memory for	2123	In the execution phase, some aio requests require more memory for
1740	temporary buffers, and each thread requires a stack and other data	2124	temporary buffers, and each thread requires a stack and other data
1741	structures (usually around 16k-128k, depending on the OS).	2125	structures (usually around 16k-128k, depending on the OS).
1742		2126
1743	KNOWN BUGS	2127	KNOWN BUGS
1744	Known bugs will be fixed in the next release.	2128	Known bugs will be fixed in the next release :)
		2129
		2130	KNOWN ISSUES
		2131	Calls that try to "import" foreign memory areas (such as "IO::AIO::mmap"
		2132	or "IO::AIO::aio_slurp") do not work with generic lvalues, such as
		2133	non-created hash slots or other scalars I didn't think of. It's best to
		2134	avoid such and either use scalar variables or making sure that the
		2135	scalar exists (e.g. by storing "undef") and isn't "funny" (e.g. tied).
		2136
		2137	I am not sure anything can be done about this, so this is considered a
		2138	known issue, rather than a bug.
1745		2139
1746	SEE ALSO	2140	SEE ALSO
1747	AnyEvent::AIO for easy integration into event loops, Coro::AIO for a	2141	AnyEvent::AIO for easy integration into event loops, Coro::AIO for a
1748	more natural syntax.	2142	more natural syntax.
1749		2143

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Comparing IO-AIO/README (file contents): Revision 1.53 by root, Thu Oct 11 03:20:52 2012 UTC vs. Revision 1.64 by root, Wed Apr 3 03:03:53 2019 UTC

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Revision 1.53 by root, Thu Oct 11 03:20:52 2012 UTC vs.
Revision 1.64 by root, Wed Apr 3 03:03:53 2019 UTC