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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.266 by root, Tue Aug 9 11:37:53 2016 UTC vs.
Revision 1.296 by root, Sun Aug 26 03:17:35 2018 UTC

… …
171use common::sense; 171use common::sense;
172 172
173use base 'Exporter'; 173use base 'Exporter';
174 174
175BEGIN { 175BEGIN {
176 our $VERSION = 4.34; 176 our $VERSION = 4.6;
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
182 aio_pathsync aio_readahead aio_fiemap aio_allocate 182 aio_pathsync aio_readahead aio_fiemap aio_allocate
183 aio_rename aio_link aio_move aio_copy aio_group 183 aio_rename aio_rename2 aio_link aio_move aio_copy aio_group
184 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown 184 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
185 aio_chmod aio_utime aio_truncate 185 aio_chmod aio_utime aio_truncate
186 aio_msync aio_mtouch aio_mlock aio_mlockall 186 aio_msync aio_mtouch aio_mlock aio_mlockall
187 aio_statvfs 187 aio_statvfs
188 aio_slurp
188 aio_wd); 189 aio_wd);
189 190
190 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); 191 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
191 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 192 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
192 min_parallel max_parallel max_idle idle_timeout 193 min_parallel max_parallel max_idle idle_timeout
193 nreqs nready npending nthreads 194 nreqs nready npending nthreads
194 max_poll_time max_poll_reqs 195 max_poll_time max_poll_reqs
195 sendfile fadvise madvise 196 sendfile fadvise madvise
196 mmap munmap munlock munlockall); 197 mmap munmap mremap munlock munlockall);
197 198
198 push @AIO_REQ, qw(aio_busy); # not exported 199 push @AIO_REQ, qw(aio_busy); # not exported
199 200
200 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 201 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
201 202
… …
233 aio_link $srcpath, $dstpath, $callback->($status) 234 aio_link $srcpath, $dstpath, $callback->($status)
234 aio_symlink $srcpath, $dstpath, $callback->($status) 235 aio_symlink $srcpath, $dstpath, $callback->($status)
235 aio_readlink $pathname, $callback->($link) 236 aio_readlink $pathname, $callback->($link)
236 aio_realpath $pathname, $callback->($path) 237 aio_realpath $pathname, $callback->($path)
237 aio_rename $srcpath, $dstpath, $callback->($status) 238 aio_rename $srcpath, $dstpath, $callback->($status)
239 aio_rename2 $srcpath, $dstpath, $flags, $callback->($status)
238 aio_mkdir $pathname, $mode, $callback->($status) 240 aio_mkdir $pathname, $mode, $callback->($status)
239 aio_rmdir $pathname, $callback->($status) 241 aio_rmdir $pathname, $callback->($status)
240 aio_readdir $pathname, $callback->($entries) 242 aio_readdir $pathname, $callback->($entries)
241 aio_readdirx $pathname, $flags, $callback->($entries, $flags) 243 aio_readdirx $pathname, $flags, $callback->($entries, $flags)
242 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST 244 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
… …
252 aio_syncfs $fh, $callback->($status) 254 aio_syncfs $fh, $callback->($status)
253 aio_fsync $fh, $callback->($status) 255 aio_fsync $fh, $callback->($status)
254 aio_fdatasync $fh, $callback->($status) 256 aio_fdatasync $fh, $callback->($status)
255 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) 257 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
256 aio_pathsync $pathname, $callback->($status) 258 aio_pathsync $pathname, $callback->($status)
257 aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 259 aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status)
258 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 260 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
259 aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) 261 aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
260 aio_mlockall $flags, $callback->($status) 262 aio_mlockall $flags, $callback->($status)
261 aio_group $callback->(...) 263 aio_group $callback->(...)
262 aio_nop $callback->() 264 aio_nop $callback->()
… …
276 IO::AIO::idle_timeout $seconds 278 IO::AIO::idle_timeout $seconds
277 IO::AIO::max_outstanding $maxreqs 279 IO::AIO::max_outstanding $maxreqs
278 IO::AIO::nreqs 280 IO::AIO::nreqs
279 IO::AIO::nready 281 IO::AIO::nready
280 IO::AIO::npending 282 IO::AIO::npending
283 $nfd = IO::AIO::get_fdlimit [EXPERIMENTAL]
284 IO::AIO::min_fdlimit $nfd [EXPERIMENTAL]
281 285
282 IO::AIO::sendfile $ofh, $ifh, $offset, $count 286 IO::AIO::sendfile $ofh, $ifh, $offset, $count
283 IO::AIO::fadvise $fh, $offset, $len, $advice 287 IO::AIO::fadvise $fh, $offset, $len, $advice
284 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]] 288 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
285 IO::AIO::munmap $scalar 289 IO::AIO::munmap $scalar
290 IO::AIO::mremap $scalar, $new_length, $flags[, $new_address]
286 IO::AIO::madvise $scalar, $offset, $length, $advice 291 IO::AIO::madvise $scalar, $offset, $length, $advice
287 IO::AIO::mprotect $scalar, $offset, $length, $protect 292 IO::AIO::mprotect $scalar, $offset, $length, $protect
288 IO::AIO::munlock $scalar, $offset = 0, $length = undef 293 IO::AIO::munlock $scalar, $offset = 0, $length = undef
289 IO::AIO::munlockall 294 IO::AIO::munlockall
290 295
… …
400following POSIX and non-POSIX constants are available (missing ones on 405following POSIX and non-POSIX constants are available (missing ones on
401your system are, as usual, C<0>): 406your system are, as usual, C<0>):
402 407
403C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>, 408C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,
404C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>, 409C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,
405C<O_RSYNC>, C<O_SYNC>, C<O_PATH>, C<O_TMPFILE>, and C<O_TTY_INIT>. 410C<O_RSYNC>, C<O_SYNC>, C<O_PATH>, C<O_TMPFILE>, C<O_TTY_INIT> and C<O_ACCMODE>.
406 411
407 412
408=item aio_close $fh, $callback->($status) 413=item aio_close $fh, $callback->($status)
409 414
410Asynchronously close a file and call the callback with the result 415Asynchronously close a file and call the callback with the result
… …
445=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 450=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
446 451
447=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 452=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
448 453
449Reads or writes C<$length> bytes from or to the specified C<$fh> and 454Reads or writes C<$length> bytes from or to the specified C<$fh> and
450C<$offset> into the scalar given by C<$data> and offset C<$dataoffset> 455C<$offset> into the scalar given by C<$data> and offset C<$dataoffset> and
451and calls the callback with the actual number of bytes read (or -1 on 456calls the callback with the actual number of bytes transferred (or -1 on
452error, just like the syscall). 457error, just like the syscall).
453 458
454C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to 459C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
455offset plus the actual number of bytes read. 460offset plus the actual number of bytes read.
456 461
… …
536 541
537=item aio_stat $fh_or_path, $callback->($status) 542=item aio_stat $fh_or_path, $callback->($status)
538 543
539=item aio_lstat $fh, $callback->($status) 544=item aio_lstat $fh, $callback->($status)
540 545
541Works like perl's C<stat> or C<lstat> in void context. The callback will 546Works almost exactly like perl's C<stat> or C<lstat> in void context. The
542be called after the stat and the results will be available using C<stat _> 547callback will be called after the stat and the results will be available
543or C<-s _> etc... 548using C<stat _> or C<-s _> and other tests (with the exception of C<-B>
549and C<-T>).
544 550
545The pathname passed to C<aio_stat> must be absolute. See API NOTES, above, 551The pathname passed to C<aio_stat> must be absolute. See API NOTES, above,
546for an explanation. 552for an explanation.
547 553
548Currently, the stats are always 64-bit-stats, i.e. instead of returning an 554Currently, the stats are always 64-bit-stats, i.e. instead of returning an
… …
555behaviour). 561behaviour).
556 562
557C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>, 563C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>,
558C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>, 564C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>,
559C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>. 565C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>.
566
567To access higher resolution stat timestamps, see L<SUBSECOND STAT TIME
568ACCESS>.
560 569
561Example: Print the length of F</etc/passwd>: 570Example: Print the length of F</etc/passwd>:
562 571
563 aio_stat "/etc/passwd", sub { 572 aio_stat "/etc/passwd", sub {
564 $_[0] and die "stat failed: $!"; 573 $_[0] and die "stat failed: $!";
… …
608 namemax => 255, 617 namemax => 255,
609 frsize => 1024, 618 frsize => 1024,
610 fsid => 1810 619 fsid => 1810
611 } 620 }
612 621
613Here is a (likely partial - send me updates!) list of fsid values used by
614Linux - it is safe to hardcode these when C<$^O> is C<linux>:
615
616 0x0000adf5 adfs
617 0x0000adff affs
618 0x5346414f afs
619 0x09041934 anon-inode filesystem
620 0x00000187 autofs
621 0x42465331 befs
622 0x1badface bfs
623 0x42494e4d binfmt_misc
624 0x9123683e btrfs
625 0x0027e0eb cgroupfs
626 0xff534d42 cifs
627 0x73757245 coda
628 0x012ff7b7 coh
629 0x28cd3d45 cramfs
630 0x453dcd28 cramfs-wend (wrong endianness)
631 0x64626720 debugfs
632 0x00001373 devfs
633 0x00001cd1 devpts
634 0x0000f15f ecryptfs
635 0x00414a53 efs
636 0x0000137d ext
637 0x0000ef53 ext2/ext3/ext4
638 0x0000ef51 ext2
639 0xf2f52010 f2fs
640 0x00004006 fat
641 0x65735546 fuseblk
642 0x65735543 fusectl
643 0x0bad1dea futexfs
644 0x01161970 gfs2
645 0x47504653 gpfs
646 0x00004244 hfs
647 0xf995e849 hpfs
648 0x00c0ffee hostfs
649 0x958458f6 hugetlbfs
650 0x2bad1dea inotifyfs
651 0x00009660 isofs
652 0x000072b6 jffs2
653 0x3153464a jfs
654 0x6b414653 k-afs
655 0x0bd00bd0 lustre
656 0x0000137f minix
657 0x0000138f minix 30 char names
658 0x00002468 minix v2
659 0x00002478 minix v2 30 char names
660 0x00004d5a minix v3
661 0x19800202 mqueue
662 0x00004d44 msdos
663 0x0000564c novell
664 0x00006969 nfs
665 0x6e667364 nfsd
666 0x00003434 nilfs
667 0x5346544e ntfs
668 0x00009fa1 openprom
669 0x7461636F ocfs2
670 0x00009fa0 proc
671 0x6165676c pstorefs
672 0x0000002f qnx4
673 0x68191122 qnx6
674 0x858458f6 ramfs
675 0x52654973 reiserfs
676 0x00007275 romfs
677 0x67596969 rpc_pipefs
678 0x73636673 securityfs
679 0xf97cff8c selinux
680 0x0000517b smb
681 0x534f434b sockfs
682 0x73717368 squashfs
683 0x62656572 sysfs
684 0x012ff7b6 sysv2
685 0x012ff7b5 sysv4
686 0x01021994 tmpfs
687 0x15013346 udf
688 0x00011954 ufs
689 0x54190100 ufs byteswapped
690 0x00009fa2 usbdevfs
691 0x01021997 v9fs
692 0xa501fcf5 vxfs
693 0xabba1974 xenfs
694 0x012ff7b4 xenix
695 0x58465342 xfs
696 0x012fd16d xia
697
698=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 622=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
699 623
700Works like perl's C<utime> function (including the special case of $atime 624Works like perl's C<utime> function (including the special case of $atime
701and $mtime being undef). Fractional times are supported if the underlying 625and $mtime being undef). Fractional times are supported if the underlying
702syscalls support them. 626syscalls support them.
703 627
704When called with a pathname, uses utimes(2) if available, otherwise 628When called with a pathname, uses utimensat(2) or utimes(2) if available,
705utime(2). If called on a file descriptor, uses futimes(2) if available, 629otherwise utime(2). If called on a file descriptor, uses futimens(2)
706otherwise returns ENOSYS, so this is not portable. 630or futimes(2) if available, otherwise returns ENOSYS, so this is not
631portable.
707 632
708Examples: 633Examples:
709 634
710 # set atime and mtime to current time (basically touch(1)): 635 # set atime and mtime to current time (basically touch(1)):
711 aio_utime "path", undef, undef; 636 aio_utime "path", undef, undef;
… …
739C<$mode> is usually C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> to allocate 664C<$mode> is usually C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> to allocate
740space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE | IO::AIO::FALLOC_FL_KEEP_SIZE>, 665space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE | IO::AIO::FALLOC_FL_KEEP_SIZE>,
741to deallocate a file range. 666to deallocate a file range.
742 667
743IO::AIO also supports C<FALLOC_FL_COLLAPSE_RANGE>, to remove a range 668IO::AIO also supports C<FALLOC_FL_COLLAPSE_RANGE>, to remove a range
744(without leaving a hole) and C<FALLOC_FL_ZERO_RANGE>, to zero a range (see 669(without leaving a hole), C<FALLOC_FL_ZERO_RANGE>, to zero a range,
745your L<fallocate(2)> manpage). 670C<FALLOC_FL_INSERT_RANGE> to insert a range and C<FALLOC_FL_UNSHARE_RANGE>
671to unshare shared blocks (see your L<fallocate(2)> manpage).
746 672
747The file system block size used by C<fallocate> is presumably the 673The file system block size used by C<fallocate> is presumably the
748C<f_bsize> returned by C<statvfs>. 674C<f_bsize> returned by C<statvfs>, but different filesystems and filetypes
675can dictate other limitations.
749 676
750If C<fallocate> isn't available or cannot be emulated (currently no 677If C<fallocate> isn't available or cannot be emulated (currently no
751emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>. 678emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>.
752 679
753 680
… …
812On systems that support the AIO::WD working directory abstraction 739On systems that support the AIO::WD working directory abstraction
813natively, the case C<[$wd, "."]> as C<$srcpath> is specialcased - instead 740natively, the case C<[$wd, "."]> as C<$srcpath> is specialcased - instead
814of failing, C<rename> is called on the absolute path of C<$wd>. 741of failing, C<rename> is called on the absolute path of C<$wd>.
815 742
816 743
744=item aio_rename2 $srcpath, $dstpath, $flags, $callback->($status)
745
746Basically a version of C<aio_rename> with an additional C<$flags>
747argument. Calling this with C<$flags=0> is the same as calling
748C<aio_rename>.
749
750Non-zero flags are currently only supported on GNU/Linux systems that
751support renameat2. Other systems fail with C<ENOSYS> in this case.
752
753The following constants are available (missing ones are, as usual C<0>),
754see renameat2(2) for details:
755
756C<IO::AIO::RENAME_NOREPLACE>, C<IO::AIO::RENAME_EXCHANGE>
757and C<IO::AIO::RENAME_WHITEOUT>.
758
759
817=item aio_mkdir $pathname, $mode, $callback->($status) 760=item aio_mkdir $pathname, $mode, $callback->($status)
818 761
819Asynchronously mkdir (create) a directory and call the callback with 762Asynchronously mkdir (create) a directory and call the callback with
820the result code. C<$mode> will be modified by the umask at the time the 763the result code. C<$mode> will be modified by the umask at the time the
821request is executed, so do not change your umask. 764request is executed, so do not change your umask.
… …
852 795
853=over 4 796=over 4
854 797
855=item IO::AIO::READDIR_DENTS 798=item IO::AIO::READDIR_DENTS
856 799
857When this flag is off, then the callback gets an arrayref consisting of 800Normally the callback gets an arrayref consisting of names only (as
858names only (as with C<aio_readdir>), otherwise it gets an arrayref with 801with C<aio_readdir>). If this flag is set, then the callback gets an
859C<[$name, $type, $inode]> arrayrefs, each describing a single directory 802arrayref with C<[$name, $type, $inode]> arrayrefs, each describing a
860entry in more detail. 803single directory entry in more detail:
861 804
862C<$name> is the name of the entry. 805C<$name> is the name of the entry.
863 806
864C<$type> is one of the C<IO::AIO::DT_xxx> constants: 807C<$type> is one of the C<IO::AIO::DT_xxx> constants:
865 808
866C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>, 809C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
867C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>, 810C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
868C<IO::AIO::DT_WHT>. 811C<IO::AIO::DT_WHT>.
869 812
870C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to 813C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need
871know, you have to run stat yourself. Also, for speed reasons, the C<$type> 814to know, you have to run stat yourself. Also, for speed/memory reasons,
872scalars are read-only: you can not modify them. 815the C<$type> scalars are read-only: you must not modify them.
873 816
874C<$inode> is the inode number (which might not be exact on systems with 64 817C<$inode> is the inode number (which might not be exact on systems with 64
875bit inode numbers and 32 bit perls). This field has unspecified content on 818bit inode numbers and 32 bit perls). This field has unspecified content on
876systems that do not deliver the inode information. 819systems that do not deliver the inode information.
877 820
… …
888short names are tried first. 831short names are tried first.
889 832
890=item IO::AIO::READDIR_STAT_ORDER 833=item IO::AIO::READDIR_STAT_ORDER
891 834
892When this flag is set, then the names will be returned in an order 835When this flag is set, then the names will be returned in an order
893suitable for stat()'ing each one. That is, when you plan to stat() 836suitable for stat()'ing each one. That is, when you plan to stat() most or
894all files in the given directory, then the returned order will likely 837all files in the given directory, then the returned order will likely be
895be fastest. 838faster.
896 839
897If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then 840If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified,
898the likely dirs come first, resulting in a less optimal stat order. 841then the likely dirs come first, resulting in a less optimal stat order
842for stat'ing all entries, but likely a more optimal order for finding
843subdirectories.
899 844
900=item IO::AIO::READDIR_FOUND_UNKNOWN 845=item IO::AIO::READDIR_FOUND_UNKNOWN
901 846
902This flag should not be set when calling C<aio_readdirx>. Instead, it 847This flag should not be set when calling C<aio_readdirx>. Instead, it
903is being set by C<aio_readdirx>, when any of the C<$type>'s found were 848is being set by C<aio_readdirx>, when any of the C<$type>'s found were
… …
905C<$type>'s are known, which can be used to speed up some algorithms. 850C<$type>'s are known, which can be used to speed up some algorithms.
906 851
907=back 852=back
908 853
909 854
855=item aio_slurp $pathname, $offset, $length, $data, $callback->($status)
856
857Opens, reads and closes the given file. The data is put into C<$data>,
858which is resized as required.
859
860If C<$offset> is negative, then it is counted from the end of the file.
861
862If C<$length> is zero, then the remaining length of the file is
863used. Also, in this case, the same limitations to modifying C<$data> apply
864as when IO::AIO::mmap is used, i.e. it must only be modified in-place
865with C<substr>. If the size of the file is known, specifying a non-zero
866C<$length> results in a performance advantage.
867
868This request is similar to the older C<aio_load> request, but since it is
869a single request, it might be more efficient to use.
870
871Example: load F</etc/passwd> into C<$passwd>.
872
873 my $passwd;
874 aio_slurp "/etc/passwd", 0, 0, $passwd, sub {
875 $_[0] >= 0
876 or die "/etc/passwd: $!\n";
877
878 printf "/etc/passwd is %d bytes long, and contains:\n", length $passwd;
879 print $passwd;
880 };
881 IO::AIO::flush;
882
883
910=item aio_load $pathname, $data, $callback->($status) 884=item aio_load $pathname, $data, $callback->($status)
911 885
912This is a composite request that tries to fully load the given file into 886This is a composite request that tries to fully load the given file into
913memory. Status is the same as with aio_read. 887memory. Status is the same as with aio_read.
888
889Using C<aio_slurp> might be more efficient, as it is a single request.
914 890
915=cut 891=cut
916 892
917sub aio_load($$;$) { 893sub aio_load($$;$) {
918 my ($path, undef, $cb) = @_; 894 my ($path, undef, $cb) = @_;
… …
938=item aio_copy $srcpath, $dstpath, $callback->($status) 914=item aio_copy $srcpath, $dstpath, $callback->($status)
939 915
940Try to copy the I<file> (directories not supported as either source or 916Try to copy the I<file> (directories not supported as either source or
941destination) from C<$srcpath> to C<$dstpath> and call the callback with 917destination) from C<$srcpath> to C<$dstpath> and call the callback with
942a status of C<0> (ok) or C<-1> (error, see C<$!>). 918a status of C<0> (ok) or C<-1> (error, see C<$!>).
919
920Existing destination files will be truncated.
943 921
944This is a composite request that creates the destination file with 922This is a composite request that creates the destination file with
945mode 0200 and copies the contents of the source file into it using 923mode 0200 and copies the contents of the source file into it using
946C<aio_sendfile>, followed by restoring atime, mtime, access mode and 924C<aio_sendfile>, followed by restoring atime, mtime, access mode and
947uid/gid, in that order. 925uid/gid, in that order.
… …
1057Scans a directory (similar to C<aio_readdir>) but additionally tries to 1035Scans a directory (similar to C<aio_readdir>) but additionally tries to
1058efficiently separate the entries of directory C<$path> into two sets of 1036efficiently separate the entries of directory C<$path> into two sets of
1059names, directories you can recurse into (directories), and ones you cannot 1037names, directories you can recurse into (directories), and ones you cannot
1060recurse into (everything else, including symlinks to directories). 1038recurse into (everything else, including symlinks to directories).
1061 1039
1062C<aio_scandir> is a composite request that creates of many sub requests_ 1040C<aio_scandir> is a composite request that generates many sub requests.
1063C<$maxreq> specifies the maximum number of outstanding aio requests that 1041C<$maxreq> specifies the maximum number of outstanding aio requests that
1064this function generates. If it is C<< <= 0 >>, then a suitable default 1042this function generates. If it is C<< <= 0 >>, then a suitable default
1065will be chosen (currently 4). 1043will be chosen (currently 4).
1066 1044
1067On error, the callback is called without arguments, otherwise it receives 1045On error, the callback is called without arguments, otherwise it receives
… …
1254other processes), although if you are careful and know what you are doing, 1232other processes), although if you are careful and know what you are doing,
1255you still can. 1233you still can.
1256 1234
1257The following constants are available (missing ones are, as usual C<0>): 1235The following constants are available (missing ones are, as usual C<0>):
1258 1236
1237C<F_DUPFD_CLOEXEC>,
1238
1239C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>,
1240
1259C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>. 1241C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>.
1260 1242
1261C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>, 1243C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>,
1262C<FS_IOC_FIEMAP>. 1244C<FS_IOC_FIEMAP>.
1263 1245
… …
1350 }; 1332 };
1351 1333
1352 $grp 1334 $grp
1353} 1335}
1354 1336
1355=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 1337=item aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status)
1356 1338
1357This is a rather advanced IO::AIO call, which only works on mmap(2)ed 1339This is a rather advanced IO::AIO call, which only works on mmap(2)ed
1358scalars (see the C<IO::AIO::mmap> function, although it also works on data 1340scalars (see the C<IO::AIO::mmap> function, although it also works on data
1359scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the 1341scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
1360scalar must only be modified in-place while an aio operation is pending on 1342scalar must only be modified in-place while an aio operation is pending on
… …
1362 1344
1363It calls the C<msync> function of your OS, if available, with the memory 1345It calls the C<msync> function of your OS, if available, with the memory
1364area starting at C<$offset> in the string and ending C<$length> bytes 1346area starting at C<$offset> in the string and ending C<$length> bytes
1365later. If C<$length> is negative, counts from the end, and if C<$length> 1347later. If C<$length> is negative, counts from the end, and if C<$length>
1366is C<undef>, then it goes till the end of the string. The flags can be 1348is C<undef>, then it goes till the end of the string. The flags can be
1367a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and 1349either C<IO::AIO::MS_ASYNC> or C<IO::AIO::MS_SYNC>, plus an optional
1368C<IO::AIO::MS_SYNC>. 1350C<IO::AIO::MS_INVALIDATE>.
1369 1351
1370=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 1352=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1371 1353
1372This is a rather advanced IO::AIO call, which works best on mmap(2)ed 1354This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1373scalars. 1355scalars.
… …
1456C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>, 1438C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
1457C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>, 1439C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
1458C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or 1440C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
1459C<IO::AIO::FIEMAP_EXTENT_SHARED>. 1441C<IO::AIO::FIEMAP_EXTENT_SHARED>.
1460 1442
1461At the time of this writing (Linux 3.2), this requets is unreliable unless 1443At the time of this writing (Linux 3.2), this request is unreliable unless
1462C<$count> is C<undef>, as the kernel has all sorts of bugs preventing 1444C<$count> is C<undef>, as the kernel has all sorts of bugs preventing
1463it to return all extents of a range for files with large number of 1445it to return all extents of a range for files with a large number of
1464extents. The code works around all these issues if C<$count> is undef. 1446extents. The code (only) works around all these issues if C<$count> is
1447C<undef>.
1465 1448
1466=item aio_group $callback->(...) 1449=item aio_group $callback->(...)
1467 1450
1468This is a very special aio request: Instead of doing something, it is a 1451This is a very special aio request: Instead of doing something, it is a
1469container for other aio requests, which is useful if you want to bundle 1452container for other aio requests, which is useful if you want to bundle
… …
1582There are some caveats: when directories get renamed (or deleted), the 1565There are some caveats: when directories get renamed (or deleted), the
1583pathname string doesn't change, so will point to the new directory (or 1566pathname string doesn't change, so will point to the new directory (or
1584nowhere at all), while the directory fd, if available on the system, 1567nowhere at all), while the directory fd, if available on the system,
1585will still point to the original directory. Most functions accepting a 1568will still point to the original directory. Most functions accepting a
1586pathname will use the directory fd on newer systems, and the string on 1569pathname will use the directory fd on newer systems, and the string on
1587older systems. Some functions (such as realpath) will always rely on the 1570older systems. Some functions (such as C<aio_realpath>) will always rely on
1588string form of the pathname. 1571the string form of the pathname.
1589 1572
1590So this functionality is mainly useful to get some protection against 1573So this functionality is mainly useful to get some protection against
1591C<chdir>, to easily get an absolute path out of a relative path for future 1574C<chdir>, to easily get an absolute path out of a relative path for future
1592reference, and to speed up doing many operations in the same directory 1575reference, and to speed up doing many operations in the same directory
1593(e.g. when stat'ing all files in a directory). 1576(e.g. when stat'ing all files in a directory).
… …
1801The default value for the limit is C<0>, but note that setting a feeder 1784The default value for the limit is C<0>, but note that setting a feeder
1802automatically bumps it up to C<2>. 1785automatically bumps it up to C<2>.
1803 1786
1804=back 1787=back
1805 1788
1789
1806=head2 SUPPORT FUNCTIONS 1790=head2 SUPPORT FUNCTIONS
1807 1791
1808=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1792=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
1809 1793
1810=over 4 1794=over 4
… …
1875Strictly equivalent to: 1859Strictly equivalent to:
1876 1860
1877 IO::AIO::poll_wait, IO::AIO::poll_cb 1861 IO::AIO::poll_wait, IO::AIO::poll_cb
1878 while IO::AIO::nreqs; 1862 while IO::AIO::nreqs;
1879 1863
1864This function can be useful at program aborts, to make sure outstanding
1865I/O has been done (C<IO::AIO> uses an C<END> block which already calls
1866this function on normal exits), or when you are merely using C<IO::AIO>
1867for its more advanced functions, rather than for async I/O, e.g.:
1868
1869 my ($dirs, $nondirs);
1870 IO::AIO::aio_scandir "/tmp", 0, sub { ($dirs, $nondirs) = @_ };
1871 IO::AIO::flush;
1872 # $dirs, $nondirs are now set
1873
1880=item IO::AIO::max_poll_reqs $nreqs 1874=item IO::AIO::max_poll_reqs $nreqs
1881 1875
1882=item IO::AIO::max_poll_time $seconds 1876=item IO::AIO::max_poll_time $seconds
1883 1877
1884These set the maximum number of requests (default C<0>, meaning infinity) 1878These set the maximum number of requests (default C<0>, meaning infinity)
… …
1910 poll => 'r', nice => 1, 1904 poll => 'r', nice => 1,
1911 cb => &IO::AIO::poll_cb); 1905 cb => &IO::AIO::poll_cb);
1912 1906
1913=back 1907=back
1914 1908
1909
1915=head3 CONTROLLING THE NUMBER OF THREADS 1910=head3 CONTROLLING THE NUMBER OF THREADS
1916 1911
1917=over 1912=over
1918 1913
1919=item IO::AIO::min_parallel $nthreads 1914=item IO::AIO::min_parallel $nthreads
… …
1985This is a very bad function to use in interactive programs because it 1980This is a very bad function to use in interactive programs because it
1986blocks, and a bad way to reduce concurrency because it is inexact: Better 1981blocks, and a bad way to reduce concurrency because it is inexact: Better
1987use an C<aio_group> together with a feed callback. 1982use an C<aio_group> together with a feed callback.
1988 1983
1989Its main use is in scripts without an event loop - when you want to stat 1984Its main use is in scripts without an event loop - when you want to stat
1990a lot of files, you can write somehting like this: 1985a lot of files, you can write something like this:
1991 1986
1992 IO::AIO::max_outstanding 32; 1987 IO::AIO::max_outstanding 32;
1993 1988
1994 for my $path (...) { 1989 for my $path (...) {
1995 aio_stat $path , ...; 1990 aio_stat $path , ...;
… …
2006The default value for C<max_outstanding> is very large, so there is no 2001The default value for C<max_outstanding> is very large, so there is no
2007practical limit on the number of outstanding requests. 2002practical limit on the number of outstanding requests.
2008 2003
2009=back 2004=back
2010 2005
2006
2011=head3 STATISTICAL INFORMATION 2007=head3 STATISTICAL INFORMATION
2012 2008
2013=over 2009=over
2014 2010
2015=item IO::AIO::nreqs 2011=item IO::AIO::nreqs
… …
2031 2027
2032Returns the number of requests currently in the pending state (executed, 2028Returns the number of requests currently in the pending state (executed,
2033but not yet processed by poll_cb). 2029but not yet processed by poll_cb).
2034 2030
2035=back 2031=back
2032
2033
2034=head3 SUBSECOND STAT TIME ACCESS
2035
2036Both C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> functions can
2037generally find access/modification and change times with subsecond time
2038accuracy of the system supports it, but perl's built-in functions only
2039return the integer part.
2040
2041The following functions return the timestamps of the most recent
2042stat with subsecond precision on most systems and work both after
2043C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> calls. Their return
2044value is only meaningful after a successful C<stat>/C<lstat> call, or
2045during/after a successful C<aio_stat>/C<aio_lstat> callback.
2046
2047This is similar to the L<Time::HiRes> C<stat> functions, but can return
2048full resolution without rounding and work with standard perl C<stat>,
2049alleviating the need to call the special C<Time::HiRes> functions, which
2050do not act like their perl counterparts.
2051
2052On operating systems or file systems where subsecond time resolution is
2053not supported or could not be detected, a fractional part of C<0> is
2054returned, so it is always safe to call these functions.
2055
2056=over 4
2057
2058=item $seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime, IO::AIO::st_btime
2059
2060Return the access, modication, change or birth time, respectively,
2061including fractional part. Due to the limited precision of floating point,
2062the accuracy on most platforms is only a bit better than milliseconds
2063for times around now - see the I<nsec> function family, below, for full
2064accuracy.
2065
2066File birth time is only available when the OS and perl support it (on
2067FreeBSD and NetBSD at the time of this writing, although support is
2068adaptive, so if your OS/perl gains support, IO::AIO can take avdantage of
2069it). On systems where it isn't available, C<0> is currently returned, but
2070this might change to C<undef> in a future version.
2071
2072=item ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtime
2073
2074Returns access, modification, change and birth time all in one go, and
2075maybe more times in the future version.
2076
2077=item $nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec, IO::AIO::st_ctimensec, IO::AIO::st_btimensec
2078
2079Return the fractional access, modifcation, change or birth time, in nanoseconds,
2080as an integer in the range C<0> to C<999999999>.
2081
2082Note that no accessors are provided for access, modification and
2083change times - you need to get those from C<stat _> if required (C<int
2084IO::AIO::st_atime> and so on will I<not> generally give you the correct
2085value).
2086
2087=item $seconds = IO::AIO::st_btimesec
2088
2089The (integral) seconds part of the file birth time, if available.
2090
2091=item ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtimensec
2092
2093Like the functions above, but returns all four times in one go (and maybe
2094more in future versions).
2095
2096=item $counter = IO::AIO::st_gen
2097
2098Returns the generation counter (in practice this is just a random number)
2099of the file. This is only available on platforms which have this member in
2100their C<struct stat> (most BSDs at the time of this writing) and generally
2101only to the root usert. If unsupported, C<0> is returned, but this might
2102change to C<undef> in a future version.
2103
2104=back
2105
2106Example: print the high resolution modification time of F</etc>, using
2107C<stat>, and C<IO::AIO::aio_stat>.
2108
2109 if (stat "/etc") {
2110 printf "stat(/etc) mtime: %f\n", IO::AIO::st_mtime;
2111 }
2112
2113 IO::AIO::aio_stat "/etc", sub {
2114 $_[0]
2115 and return;
2116
2117 printf "aio_stat(/etc) mtime: %d.%09d\n", (stat _)[9], IO::AIO::st_mtimensec;
2118 };
2119
2120 IO::AIO::flush;
2121
2122Output of the awbove on my system, showing reduced and full accuracy:
2123
2124 stat(/etc) mtime: 1534043702.020808
2125 aio_stat(/etc) mtime: 1534043702.020807792
2126
2036 2127
2037=head3 MISCELLANEOUS FUNCTIONS 2128=head3 MISCELLANEOUS FUNCTIONS
2038 2129
2039IO::AIO implements some functions that are useful when you want to use 2130IO::AIO implements some functions that are useful when you want to use
2040some "Advanced I/O" function not available to in Perl, without going the 2131some "Advanced I/O" function not available to in Perl, without going the
2041"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*> 2132"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*>
2042counterpart. 2133counterpart.
2043 2134
2044=over 4 2135=over 4
2136
2137=item $numfd = IO::AIO::get_fdlimit
2138
2139This function is I<EXPERIMENTAL> and subject to change.
2140
2141Tries to find the current file descriptor limit and returns it, or
2142C<undef> and sets C<$!> in case of an error. The limit is one larger than
2143the highest valid file descriptor number.
2144
2145=item IO::AIO::min_fdlimit [$numfd]
2146
2147This function is I<EXPERIMENTAL> and subject to change.
2148
2149Try to increase the current file descriptor limit(s) to at least C<$numfd>
2150by changing the soft or hard file descriptor resource limit. If C<$numfd>
2151is missing, it will try to set a very high limit, although this is not
2152recommended when you know the actual minimum that you require.
2153
2154If the limit cannot be raised enough, the function makes a best-effort
2155attempt to increase the limit as much as possible, using various
2156tricks, while still failing. You can query the resulting limit using
2157C<IO::AIO::get_fdlimit>.
2158
2159If an error occurs, returns C<undef> and sets C<$!>, otherwise returns
2160true.
2045 2161
2046=item IO::AIO::sendfile $ofh, $ifh, $offset, $count 2162=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
2047 2163
2048Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>, 2164Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
2049but is blocking (this makes most sense if you know the input data is 2165but is blocking (this makes most sense if you know the input data is
… …
2066=item IO::AIO::madvise $scalar, $offset, $len, $advice 2182=item IO::AIO::madvise $scalar, $offset, $len, $advice
2067 2183
2068Simply calls the C<posix_madvise> function (see its 2184Simply calls the C<posix_madvise> function (see its
2069manpage for details). The following advice constants are 2185manpage for details). The following advice constants are
2070available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>, 2186available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
2071C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>, 2187C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>,
2072C<IO::AIO::MADV_FREE>. 2188C<IO::AIO::MADV_DONTNEED>.
2189
2190If C<$offset> is negative, counts from the end. If C<$length> is negative,
2191the remaining length of the C<$scalar> is used. If possible, C<$length>
2192will be reduced to fit into the C<$scalar>.
2073 2193
2074On systems that do not implement C<posix_madvise>, this function returns 2194On systems that do not implement C<posix_madvise>, this function returns
2075ENOSYS, otherwise the return value of C<posix_madvise>. 2195ENOSYS, otherwise the return value of C<posix_madvise>.
2076 2196
2077=item IO::AIO::mprotect $scalar, $offset, $len, $protect 2197=item IO::AIO::mprotect $scalar, $offset, $len, $protect
… …
2079Simply calls the C<mprotect> function on the preferably AIO::mmap'ed 2199Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
2080$scalar (see its manpage for details). The following protect 2200$scalar (see its manpage for details). The following protect
2081constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>, 2201constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
2082C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>. 2202C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
2083 2203
2204If C<$offset> is negative, counts from the end. If C<$length> is negative,
2205the remaining length of the C<$scalar> is used. If possible, C<$length>
2206will be reduced to fit into the C<$scalar>.
2207
2084On systems that do not implement C<mprotect>, this function returns 2208On systems that do not implement C<mprotect>, this function returns
2085ENOSYS, otherwise the return value of C<mprotect>. 2209ENOSYS, otherwise the return value of C<mprotect>.
2086 2210
2087=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] 2211=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
2088 2212
2089Memory-maps a file (or anonymous memory range) and attaches it to the 2213Memory-maps a file (or anonymous memory range) and attaches it to the
2090given C<$scalar>, which will act like a string scalar. Returns true on 2214given C<$scalar>, which will act like a string scalar. Returns true on
2091success, and false otherwise. 2215success, and false otherwise.
2092 2216
2217The scalar must exist, but its contents do not matter - this means you
2218cannot use a nonexistant array or hash element. When in doubt, C<undef>
2219the scalar first.
2220
2093The only operations allowed on the scalar are C<substr>/C<vec> that don't 2221The only operations allowed on the mmapped scalar are C<substr>/C<vec>,
2094change the string length, and most read-only operations such as copying it 2222which don't change the string length, and most read-only operations such
2095or searching it with regexes and so on. 2223as copying it or searching it with regexes and so on.
2096 2224
2097Anything else is unsafe and will, at best, result in memory leaks. 2225Anything else is unsafe and will, at best, result in memory leaks.
2098 2226
2099The memory map associated with the C<$scalar> is automatically removed 2227The memory map associated with the C<$scalar> is automatically removed
2100when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or 2228when the C<$scalar> is undef'd or destroyed, or when the C<IO::AIO::mmap>
2101C<IO::AIO::munmap> functions are called. 2229or C<IO::AIO::munmap> functions are called on it.
2102 2230
2103This calls the C<mmap>(2) function internally. See your system's manual 2231This calls the C<mmap>(2) function internally. See your system's manual
2104page for details on the C<$length>, C<$prot> and C<$flags> parameters. 2232page for details on the C<$length>, C<$prot> and C<$flags> parameters.
2105 2233
2106The C<$length> must be larger than zero and smaller than the actual 2234The C<$length> must be larger than zero and smaller than the actual
… …
2144 2272
2145=item IO::AIO::munmap $scalar 2273=item IO::AIO::munmap $scalar
2146 2274
2147Removes a previous mmap and undefines the C<$scalar>. 2275Removes a previous mmap and undefines the C<$scalar>.
2148 2276
2277=item IO::AIO::mremap $scalar, $new_length, $flags = MREMAP_MAYMOVE[, $new_address = 0]
2278
2279Calls the Linux-specific mremap(2) system call. The C<$scalar> must have
2280been mapped by C<IO::AIO::mmap>, and C<$flags> must currently either be
2281C<0> or C<IO::AIO::MREMAP_MAYMOVE>.
2282
2283Returns true if successful, and false otherwise. If the underlying mmapped
2284region has changed address, then the true value has the numerical value
2285C<1>, otherwise it has the numerical value C<0>:
2286
2287 my $success = IO::AIO::mremap $mmapped, 8192, IO::AIO::MREMAP_MAYMOVE
2288 or die "mremap: $!";
2289
2290 if ($success*1) {
2291 warn "scalar has chanegd address in memory\n";
2292 }
2293
2294C<IO::AIO::MREMAP_FIXED> and the C<$new_address> argument are currently
2295implemented, but not supported and might go away in a future version.
2296
2297On systems where this call is not supported or is not emulated, this call
2298returns falls and sets C<$!> to C<ENOSYS>.
2299
2149=item IO::AIO::munlock $scalar, $offset = 0, $length = undef 2300=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
2150 2301
2151Calls the C<munlock> function, undoing the effects of a previous 2302Calls the C<munlock> function, undoing the effects of a previous
2152C<aio_mlock> call (see its description for details). 2303C<aio_mlock> call (see its description for details).
2153 2304
… …
2202C<$flags> is non-zero, fails with C<ENOSYS>. 2353C<$flags> is non-zero, fails with C<ENOSYS>.
2203 2354
2204Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the 2355Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the
2205time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and 2356time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and
2206C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported. 2357C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported.
2358
2359Example: create a pipe race-free w.r.t. threads and fork:
2360
2361 my ($rfh, $wfh) = IO::AIO::pipe2 IO::AIO::O_CLOEXEC
2362 or die "pipe2: $!\n";
2363
2364=item $fh = IO::AIO::eventfd [$initval, [$flags]]
2365
2366This is a direct interface to the Linux L<eventfd(2)> system call. The
2367(unhelpful) defaults for C<$initval> and C<$flags> are C<0> for both.
2368
2369On success, the new eventfd filehandle is returned, otherwise returns
2370C<undef>. If the eventfd syscall is missing, fails with C<ENOSYS>.
2371
2372Please refer to L<eventfd(2)> for more info on this call.
2373
2374The following symbol flag values are available: C<IO::AIO::EFD_CLOEXEC>,
2375C<IO::AIO::EFD_NONBLOCK> and C<IO::AIO::EFD_SEMAPHORE> (Linux 2.6.30).
2376
2377Example: create a new eventfd filehandle:
2378
2379 $fh = IO::AIO::eventfd 0, IO::AIO::O_CLOEXEC
2380 or die "eventfd: $!\n";
2381
2382=item $fh = IO::AIO::timerfd_create $clockid[, $flags]
2383
2384This is a direct interface to the Linux L<timerfd_create(2)> system call. The
2385(unhelpful) default for C<$flags> is C<0>.
2386
2387On success, the new timerfd filehandle is returned, otherwise returns
2388C<undef>. If the eventfd syscall is missing, fails with C<ENOSYS>.
2389
2390Please refer to L<timerfd_create(2)> for more info on this call.
2391
2392The following C<$clockid> values are
2393available: C<IO::AIO::CLOCK_REALTIME>, C<IO::AIO::CLOCK_MONOTONIC>
2394C<IO::AIO::CLOCK_CLOCK_BOOTTIME> (Linux 3.15)
2395C<IO::AIO::CLOCK_CLOCK_REALTIME_ALARM> (Linux 3.11) and
2396C<IO::AIO::CLOCK_CLOCK_BOOTTIME_ALARM> (Linux 3.11).
2397
2398The following C<$flags> values are available (Linux
23992.6.27): C<IO::AIO::TFD_NONBLOCK> and C<IO::AIO::TFD_CLOEXEC>.
2400
2401Example: create a new timerfd and set it to one-second repeated alarms,
2402then wait for two alarms:
2403
2404 my $fh = IO::AIO::timerfd_create IO::AIO::CLOCK_BOOTTIME, IO::AIO::TFD_CLOEXEC
2405 or die "timerfd_create: $!\n";
2406
2407 defined IO::AIO::timerfd_settime $fh, 0, 1, 1
2408 or die "timerfd_settime: $!\n";
2409
2410 for (1..2) {
2411 8 == sysread $fh, my $buf, 8
2412 or die "timerfd read failure\n";
2413
2414 printf "number of expirations (likely 1): %d\n",
2415 unpack "Q", $buf;
2416 }
2417
2418=item ($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags, $new_interval, $nbw_value
2419
2420This is a direct interface to the Linux L<timerfd_settime(2)> system
2421call. Please refer to its manpage for more info on this call.
2422
2423The new itimerspec is specified using two (possibly fractional) second
2424values, C<$new_interval> and C<$new_value>).
2425
2426On success, the current interval and value are returned (as per
2427C<timerfd_gettime>). On failure, the empty list is returned.
2428
2429The following C<$flags> values are
2430available: C<IO::AIO::TFD_TIMER_ABSTIME> and
2431C<IO::AIO::TFD_TIMER_CANCEL_ON_SET>.
2432
2433See C<IO::AIO::timerfd_create> for a full example.
2434
2435=item ($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh
2436
2437This is a direct interface to the Linux L<timerfd_gettime(2)> system
2438call. Please refer to its manpage for more info on this call.
2439
2440On success, returns the current values of interval and value for the given
2441timerfd (as potentially fractional second values). On failure, the empty
2442list is returned.
2207 2443
2208=back 2444=back
2209 2445
2210=cut 2446=cut
2211 2447
… …
2277the process will result in undefined behaviour. Calling it at any time 2513the process will result in undefined behaviour. Calling it at any time
2278will also result in any undefined (by POSIX) behaviour. 2514will also result in any undefined (by POSIX) behaviour.
2279 2515
2280=back 2516=back
2281 2517
2518=head2 LINUX-SPECIFIC CALLS
2519
2520When a call is documented as "linux-specific" then this means it
2521originated on GNU/Linux. C<IO::AIO> will usually try to autodetect the
2522availability and compatibility of such calls regardless of the platform
2523it is compiled on, so platforms such as FreeBSD which often implement
2524these calls will work. When in doubt, call them and see if they fail wth
2525C<ENOSYS>.
2526
2282=head2 MEMORY USAGE 2527=head2 MEMORY USAGE
2283 2528
2284Per-request usage: 2529Per-request usage:
2285 2530
2286Each aio request uses - depending on your architecture - around 100-200 2531Each aio request uses - depending on your architecture - around 100-200
… …
2298temporary buffers, and each thread requires a stack and other data 2543temporary buffers, and each thread requires a stack and other data
2299structures (usually around 16k-128k, depending on the OS). 2544structures (usually around 16k-128k, depending on the OS).
2300 2545
2301=head1 KNOWN BUGS 2546=head1 KNOWN BUGS
2302 2547
2303Known bugs will be fixed in the next release. 2548Known bugs will be fixed in the next release :)
2549
2550=head1 KNOWN ISSUES
2551
2552Calls that try to "import" foreign memory areas (such as C<IO::AIO::mmap>
2553or C<IO::AIO::aio_slurp>) do not work with generic lvalues, such as
2554non-created hash slots or other scalars I didn't think of. It's best to
2555avoid such and either use scalar variables or making sure that the scalar
2556exists (e.g. by storing C<undef>) and isn't "funny" (e.g. tied).
2557
2558I am not sure anything can be done about this, so this is considered a
2559known issue, rather than a bug.
2304 2560
2305=head1 SEE ALSO 2561=head1 SEE ALSO
2306 2562
2307L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a 2563L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
2308more natural syntax. 2564more natural syntax.

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