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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.267 by root, Tue Aug 9 11:39:17 2016 UTC vs.
Revision 1.309 by root, Tue Dec 29 15:20:12 2020 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 = 4.74;
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->()
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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 IO::AIO::reinit
284
285 $nfd = IO::AIO::get_fdlimit
286 IO::AIO::min_fdlimit $nfd
281 287
282 IO::AIO::sendfile $ofh, $ifh, $offset, $count 288 IO::AIO::sendfile $ofh, $ifh, $offset, $count
283 IO::AIO::fadvise $fh, $offset, $len, $advice 289 IO::AIO::fadvise $fh, $offset, $len, $advice
290
284 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]] 291 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
285 IO::AIO::munmap $scalar 292 IO::AIO::munmap $scalar
293 IO::AIO::mremap $scalar, $new_length, $flags[, $new_address]
286 IO::AIO::madvise $scalar, $offset, $length, $advice 294 IO::AIO::madvise $scalar, $offset, $length, $advice
287 IO::AIO::mprotect $scalar, $offset, $length, $protect 295 IO::AIO::mprotect $scalar, $offset, $length, $protect
288 IO::AIO::munlock $scalar, $offset = 0, $length = undef 296 IO::AIO::munlock $scalar, $offset = 0, $length = undef
289 IO::AIO::munlockall 297 IO::AIO::munlockall
298
299 # stat extensions
300 $counter = IO::AIO::st_gen
301 $seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime, IO::AIO::st_btime
302 ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtime
303 $nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec, IO::AIO::st_ctimensec, IO::AIO::st_btimensec
304 $seconds = IO::AIO::st_btimesec
305 ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtimensec
306
307 # very much unportable syscalls
308 IO::AIO::accept4 $r_fh, $sockaddr, $sockaddr_len, $flags
309 IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
310 IO::AIO::tee $r_fh, $w_fh, $length, $flags
311 $actual_size = IO::AIO::pipesize $r_fh[, $new_size]
312 ($rfh, $wfh) = IO::AIO::pipe2 [$flags]
313 $fh = IO::AIO::memfd_create $pathname[, $flags]
314 $fh = IO::AIO::eventfd [$initval, [$flags]]
315 $fh = IO::AIO::timerfd_create $clockid[, $flags]
316 ($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags, $new_interval, $nbw_value
317 ($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh
290 318
291=head2 API NOTES 319=head2 API NOTES
292 320
293All the C<aio_*> calls are more or less thin wrappers around the syscall 321All the C<aio_*> calls are more or less thin wrappers around the syscall
294with the same name (sans C<aio_>). The arguments are similar or identical, 322with the same name (sans C<aio_>). The arguments are similar or identical,
… …
400following POSIX and non-POSIX constants are available (missing ones on 428following POSIX and non-POSIX constants are available (missing ones on
401your system are, as usual, C<0>): 429your system are, as usual, C<0>):
402 430
403C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>, 431C<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>, 432C<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>. 433C<O_RSYNC>, C<O_SYNC>, C<O_PATH>, C<O_TMPFILE>, C<O_TTY_INIT> and C<O_ACCMODE>.
406 434
407 435
408=item aio_close $fh, $callback->($status) 436=item aio_close $fh, $callback->($status)
409 437
410Asynchronously close a file and call the callback with the result 438Asynchronously close a file and call the callback with the result
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536 564
537=item aio_stat $fh_or_path, $callback->($status) 565=item aio_stat $fh_or_path, $callback->($status)
538 566
539=item aio_lstat $fh, $callback->($status) 567=item aio_lstat $fh, $callback->($status)
540 568
541Works like perl's C<stat> or C<lstat> in void context. The callback will 569Works 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 _> 570callback will be called after the stat and the results will be available
543or C<-s _> etc... 571using C<stat _> or C<-s _> and other tests (with the exception of C<-B>
572and C<-T>).
544 573
545The pathname passed to C<aio_stat> must be absolute. See API NOTES, above, 574The pathname passed to C<aio_stat> must be absolute. See API NOTES, above,
546for an explanation. 575for an explanation.
547 576
548Currently, the stats are always 64-bit-stats, i.e. instead of returning an 577Currently, the stats are always 64-bit-stats, i.e. instead of returning an
… …
555behaviour). 584behaviour).
556 585
557C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>, 586C<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>, 587C<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>. 588C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>.
589
590To access higher resolution stat timestamps, see L<SUBSECOND STAT TIME
591ACCESS>.
560 592
561Example: Print the length of F</etc/passwd>: 593Example: Print the length of F</etc/passwd>:
562 594
563 aio_stat "/etc/passwd", sub { 595 aio_stat "/etc/passwd", sub {
564 $_[0] and die "stat failed: $!"; 596 $_[0] and die "stat failed: $!";
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608 namemax => 255, 640 namemax => 255,
609 frsize => 1024, 641 frsize => 1024,
610 fsid => 1810 642 fsid => 1810
611 } 643 }
612 644
613Here is a (likely partial - send me updates!) list of fsid values used by
614Linux - it is safe to hardcode these when C<$^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) 645=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
699 646
700Works like perl's C<utime> function (including the special case of $atime 647Works like perl's C<utime> function (including the special case of $atime
701and $mtime being undef). Fractional times are supported if the underlying 648and $mtime being undef). Fractional times are supported if the underlying
702syscalls support them. 649syscalls support them.
703 650
704When called with a pathname, uses utimes(2) if available, otherwise 651When called with a pathname, uses utimensat(2) or utimes(2) if available,
705utime(2). If called on a file descriptor, uses futimes(2) if available, 652otherwise utime(2). If called on a file descriptor, uses futimens(2)
706otherwise returns ENOSYS, so this is not portable. 653or futimes(2) if available, otherwise returns ENOSYS, so this is not
654portable.
707 655
708Examples: 656Examples:
709 657
710 # set atime and mtime to current time (basically touch(1)): 658 # set atime and mtime to current time (basically touch(1)):
711 aio_utime "path", undef, undef; 659 aio_utime "path", undef, undef;
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739C<$mode> is usually C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> to allocate 687C<$mode> is usually C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> to allocate
740space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE | IO::AIO::FALLOC_FL_KEEP_SIZE>, 688space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE | IO::AIO::FALLOC_FL_KEEP_SIZE>,
741to deallocate a file range. 689to deallocate a file range.
742 690
743IO::AIO also supports C<FALLOC_FL_COLLAPSE_RANGE>, to remove a range 691IO::AIO also supports C<FALLOC_FL_COLLAPSE_RANGE>, to remove a range
744(without leaving a hole) and C<FALLOC_FL_ZERO_RANGE>, to zero a range (see 692(without leaving a hole), C<FALLOC_FL_ZERO_RANGE>, to zero a range,
745your L<fallocate(2)> manpage). 693C<FALLOC_FL_INSERT_RANGE> to insert a range and C<FALLOC_FL_UNSHARE_RANGE>
694to unshare shared blocks (see your L<fallocate(2)> manpage).
746 695
747The file system block size used by C<fallocate> is presumably the 696The file system block size used by C<fallocate> is presumably the
748C<f_bsize> returned by C<statvfs>. 697C<f_bsize> returned by C<statvfs>, but different filesystems and filetypes
698can dictate other limitations.
749 699
750If C<fallocate> isn't available or cannot be emulated (currently no 700If C<fallocate> isn't available or cannot be emulated (currently no
751emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>. 701emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>.
752 702
753 703
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812On systems that support the AIO::WD working directory abstraction 762On systems that support the AIO::WD working directory abstraction
813natively, the case C<[$wd, "."]> as C<$srcpath> is specialcased - instead 763natively, the case C<[$wd, "."]> as C<$srcpath> is specialcased - instead
814of failing, C<rename> is called on the absolute path of C<$wd>. 764of failing, C<rename> is called on the absolute path of C<$wd>.
815 765
816 766
767=item aio_rename2 $srcpath, $dstpath, $flags, $callback->($status)
768
769Basically a version of C<aio_rename> with an additional C<$flags>
770argument. Calling this with C<$flags=0> is the same as calling
771C<aio_rename>.
772
773Non-zero flags are currently only supported on GNU/Linux systems that
774support renameat2. Other systems fail with C<ENOSYS> in this case.
775
776The following constants are available (missing ones are, as usual C<0>),
777see renameat2(2) for details:
778
779C<IO::AIO::RENAME_NOREPLACE>, C<IO::AIO::RENAME_EXCHANGE>
780and C<IO::AIO::RENAME_WHITEOUT>.
781
782
817=item aio_mkdir $pathname, $mode, $callback->($status) 783=item aio_mkdir $pathname, $mode, $callback->($status)
818 784
819Asynchronously mkdir (create) a directory and call the callback with 785Asynchronously mkdir (create) a directory and call the callback with
820the result code. C<$mode> will be modified by the umask at the time the 786the result code. C<$mode> will be modified by the umask at the time the
821request is executed, so do not change your umask. 787request is executed, so do not change your umask.
… …
852 818
853=over 4 819=over 4
854 820
855=item IO::AIO::READDIR_DENTS 821=item IO::AIO::READDIR_DENTS
856 822
857When this flag is off, then the callback gets an arrayref consisting of 823Normally the callback gets an arrayref consisting of names only (as
858names only (as with C<aio_readdir>), otherwise it gets an arrayref with 824with C<aio_readdir>). If this flag is set, then the callback gets an
859C<[$name, $type, $inode]> arrayrefs, each describing a single directory 825arrayref with C<[$name, $type, $inode]> arrayrefs, each describing a
860entry in more detail. 826single directory entry in more detail:
861 827
862C<$name> is the name of the entry. 828C<$name> is the name of the entry.
863 829
864C<$type> is one of the C<IO::AIO::DT_xxx> constants: 830C<$type> is one of the C<IO::AIO::DT_xxx> constants:
865 831
866C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>, 832C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
867C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>, 833C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
868C<IO::AIO::DT_WHT>. 834C<IO::AIO::DT_WHT>.
869 835
870C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to 836C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need
871know, you have to run stat yourself. Also, for speed reasons, the C<$type> 837to know, you have to run stat yourself. Also, for speed/memory reasons,
872scalars are read-only: you can not modify them. 838the C<$type> scalars are read-only: you must not modify them.
873 839
874C<$inode> is the inode number (which might not be exact on systems with 64 840C<$inode> is the inode number (which might not be exact on systems with 64
875bit inode numbers and 32 bit perls). This field has unspecified content on 841bit inode numbers and 32 bit perls). This field has unspecified content on
876systems that do not deliver the inode information. 842systems that do not deliver the inode information.
877 843
… …
888short names are tried first. 854short names are tried first.
889 855
890=item IO::AIO::READDIR_STAT_ORDER 856=item IO::AIO::READDIR_STAT_ORDER
891 857
892When this flag is set, then the names will be returned in an order 858When this flag is set, then the names will be returned in an order
893suitable for stat()'ing each one. That is, when you plan to stat() 859suitable for stat()'ing each one. That is, when you plan to stat() most or
894all files in the given directory, then the returned order will likely 860all files in the given directory, then the returned order will likely be
895be fastest. 861faster.
896 862
897If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then 863If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified,
898the likely dirs come first, resulting in a less optimal stat order. 864then the likely dirs come first, resulting in a less optimal stat order
865for stat'ing all entries, but likely a more optimal order for finding
866subdirectories.
899 867
900=item IO::AIO::READDIR_FOUND_UNKNOWN 868=item IO::AIO::READDIR_FOUND_UNKNOWN
901 869
902This flag should not be set when calling C<aio_readdirx>. Instead, it 870This flag should not be set when calling C<aio_readdirx>. Instead, it
903is being set by C<aio_readdirx>, when any of the C<$type>'s found were 871is 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. 873C<$type>'s are known, which can be used to speed up some algorithms.
906 874
907=back 875=back
908 876
909 877
878=item aio_slurp $pathname, $offset, $length, $data, $callback->($status)
879
880Opens, reads and closes the given file. The data is put into C<$data>,
881which is resized as required.
882
883If C<$offset> is negative, then it is counted from the end of the file.
884
885If C<$length> is zero, then the remaining length of the file is
886used. Also, in this case, the same limitations to modifying C<$data> apply
887as when IO::AIO::mmap is used, i.e. it must only be modified in-place
888with C<substr>. If the size of the file is known, specifying a non-zero
889C<$length> results in a performance advantage.
890
891This request is similar to the older C<aio_load> request, but since it is
892a single request, it might be more efficient to use.
893
894Example: load F</etc/passwd> into C<$passwd>.
895
896 my $passwd;
897 aio_slurp "/etc/passwd", 0, 0, $passwd, sub {
898 $_[0] >= 0
899 or die "/etc/passwd: $!\n";
900
901 printf "/etc/passwd is %d bytes long, and contains:\n", length $passwd;
902 print $passwd;
903 };
904 IO::AIO::flush;
905
906
910=item aio_load $pathname, $data, $callback->($status) 907=item aio_load $pathname, $data, $callback->($status)
911 908
912This is a composite request that tries to fully load the given file into 909This is a composite request that tries to fully load the given file into
913memory. Status is the same as with aio_read. 910memory. Status is the same as with aio_read.
911
912Using C<aio_slurp> might be more efficient, as it is a single request.
914 913
915=cut 914=cut
916 915
917sub aio_load($$;$) { 916sub aio_load($$;$) {
918 my ($path, undef, $cb) = @_; 917 my ($path, undef, $cb) = @_;
… …
938=item aio_copy $srcpath, $dstpath, $callback->($status) 937=item aio_copy $srcpath, $dstpath, $callback->($status)
939 938
940Try to copy the I<file> (directories not supported as either source or 939Try to copy the I<file> (directories not supported as either source or
941destination) from C<$srcpath> to C<$dstpath> and call the callback with 940destination) from C<$srcpath> to C<$dstpath> and call the callback with
942a status of C<0> (ok) or C<-1> (error, see C<$!>). 941a status of C<0> (ok) or C<-1> (error, see C<$!>).
942
943Existing destination files will be truncated.
943 944
944This is a composite request that creates the destination file with 945This is a composite request that creates the destination file with
945mode 0200 and copies the contents of the source file into it using 946mode 0200 and copies the contents of the source file into it using
946C<aio_sendfile>, followed by restoring atime, mtime, access mode and 947C<aio_sendfile>, followed by restoring atime, mtime, access mode and
947uid/gid, in that order. 948uid/gid, in that order.
… …
1057Scans a directory (similar to C<aio_readdir>) but additionally tries to 1058Scans a directory (similar to C<aio_readdir>) but additionally tries to
1058efficiently separate the entries of directory C<$path> into two sets of 1059efficiently separate the entries of directory C<$path> into two sets of
1059names, directories you can recurse into (directories), and ones you cannot 1060names, directories you can recurse into (directories), and ones you cannot
1060recurse into (everything else, including symlinks to directories). 1061recurse into (everything else, including symlinks to directories).
1061 1062
1062C<aio_scandir> is a composite request that creates of many sub requests_ 1063C<aio_scandir> is a composite request that generates many sub requests.
1063C<$maxreq> specifies the maximum number of outstanding aio requests that 1064C<$maxreq> specifies the maximum number of outstanding aio requests that
1064this function generates. If it is C<< <= 0 >>, then a suitable default 1065this function generates. If it is C<< <= 0 >>, then a suitable default
1065will be chosen (currently 4). 1066will be chosen (currently 4).
1066 1067
1067On error, the callback is called without arguments, otherwise it receives 1068On error, the callback is called without arguments, otherwise it receives
… …
1131 aioreq_pri $pri; 1132 aioreq_pri $pri;
1132 add $grp aio_stat $wd, sub { 1133 add $grp aio_stat $wd, sub {
1133 return $grp->result () if $_[0]; 1134 return $grp->result () if $_[0];
1134 my $now = time; 1135 my $now = time;
1135 my $hash1 = join ":", (stat _)[0,1,3,7,9]; 1136 my $hash1 = join ":", (stat _)[0,1,3,7,9];
1137 my $rdxflags = READDIR_DIRS_FIRST;
1138
1139 if ((stat _)[3] < 2) {
1140 # at least one non-POSIX filesystem exists
1141 # that returns useful DT_type values: btrfs,
1142 # so optimise for this here by requesting dents
1143 $rdxflags |= READDIR_DENTS;
1144 }
1136 1145
1137 # read the directory entries 1146 # read the directory entries
1138 aioreq_pri $pri; 1147 aioreq_pri $pri;
1139 add $grp aio_readdirx $wd, READDIR_DIRS_FIRST, sub { 1148 add $grp aio_readdirx $wd, $rdxflags, sub {
1140 my $entries = shift 1149 my ($entries, $flags) = @_
1141 or return $grp->result (); 1150 or return $grp->result ();
1151
1152 if ($rdxflags & READDIR_DENTS) {
1153 # if we requested type values, see if we can use them directly.
1154
1155 # if there were any DT_UNKNOWN entries then we assume we
1156 # don't know. alternatively, we could assume that if we get
1157 # one DT_DIR, then all directories are indeed marked with
1158 # DT_DIR, but this seems not required for btrfs, and this
1159 # is basically the "btrfs can't get it's act together" code
1160 # branch.
1161 unless ($flags & READDIR_FOUND_UNKNOWN) {
1162 # now we have valid DT_ information for all entries,
1163 # so use it as an optimisation without further stat's.
1164 # they must also all be at the beginning of @$entries
1165 # by now.
1166
1167 my $dirs;
1168
1169 if (@$entries) {
1170 for (0 .. $#$entries) {
1171 if ($entries->[$_][1] != DT_DIR) {
1172 # splice out directories
1173 $dirs = [splice @$entries, 0, $_];
1174 last;
1175 }
1176 }
1177
1178 # if we didn't find any non-dir, then all entries are dirs
1179 unless ($dirs) {
1180 ($dirs, $entries) = ($entries, []);
1181 }
1182 } else {
1183 # directory is empty, so there are no sbdirs
1184 $dirs = [];
1185 }
1186
1187 # either splice'd the directories out or the dir was empty.
1188 # convert dents to filenames
1189 $_ = $_->[0] for @$dirs;
1190 $_ = $_->[0] for @$entries;
1191
1192 return $grp->result ($dirs, $entries);
1193 }
1194
1195 # cannot use, so return to our old ways
1196 # by pretending we only scanned for names.
1197 $_ = $_->[0] for @$entries;
1198 }
1142 1199
1143 # stat the dir another time 1200 # stat the dir another time
1144 aioreq_pri $pri; 1201 aioreq_pri $pri;
1145 add $grp aio_stat $wd, sub { 1202 add $grp aio_stat $wd, sub {
1146 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 1203 my $hash2 = join ":", (stat _)[0,1,3,7,9];
… …
1252So in general, you should only use these calls for things that do 1309So in general, you should only use these calls for things that do
1253(filesystem) I/O, not for things that wait for other events (network, 1310(filesystem) I/O, not for things that wait for other events (network,
1254other processes), although if you are careful and know what you are doing, 1311other processes), although if you are careful and know what you are doing,
1255you still can. 1312you still can.
1256 1313
1257The following constants are available (missing ones are, as usual C<0>): 1314The following constants are available and can be used for normal C<ioctl>
1315and C<fcntl> as well (missing ones are, as usual C<0>):
1316
1317C<F_DUPFD_CLOEXEC>,
1318
1319C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>,
1258 1320
1259C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>. 1321C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>.
1322
1323C<F_ADD_SEALS>, C<F_GET_SEALS>, C<F_SEAL_SEAL>, C<F_SEAL_SHRINK>, C<F_SEAL_GROW> and
1324C<F_SEAL_WRITE>.
1260 1325
1261C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>, 1326C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>,
1262C<FS_IOC_FIEMAP>. 1327C<FS_IOC_FIEMAP>.
1263 1328
1264C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>, 1329C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>,
… …
1350 }; 1415 };
1351 1416
1352 $grp 1417 $grp
1353} 1418}
1354 1419
1355=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 1420=item aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status)
1356 1421
1357This is a rather advanced IO::AIO call, which only works on mmap(2)ed 1422This 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 1423scalars (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 1424scalars 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 1425scalar must only be modified in-place while an aio operation is pending on
… …
1362 1427
1363It calls the C<msync> function of your OS, if available, with the memory 1428It 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 1429area 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> 1430later. 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 1431is 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 1432either C<IO::AIO::MS_ASYNC> or C<IO::AIO::MS_SYNC>, plus an optional
1368C<IO::AIO::MS_SYNC>. 1433C<IO::AIO::MS_INVALIDATE>.
1369 1434
1370=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 1435=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1371 1436
1372This is a rather advanced IO::AIO call, which works best on mmap(2)ed 1437This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1373scalars. 1438scalars.
… …
1403 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh; 1468 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
1404 aio_mlock $data; # mlock in background 1469 aio_mlock $data; # mlock in background
1405 1470
1406=item aio_mlockall $flags, $callback->($status) 1471=item aio_mlockall $flags, $callback->($status)
1407 1472
1408Calls the C<mlockall> function with the given C<$flags> (a combination of 1473Calls the C<mlockall> function with the given C<$flags> (a
1409C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>). 1474combination of C<IO::AIO::MCL_CURRENT>, C<IO::AIO::MCL_FUTURE> and
1475C<IO::AIO::MCL_ONFAULT>).
1410 1476
1411On systems that do not implement C<mlockall>, this function returns C<-1> 1477On systems that do not implement C<mlockall>, this function returns C<-1>
1412and sets errno to C<ENOSYS>. 1478and sets errno to C<ENOSYS>. Similarly, flag combinations not supported
1479by the system result in a return value of C<-1> with errno being set to
1480C<EINVAL>.
1413 1481
1414Note that the corresponding C<munlockall> is synchronous and is 1482Note that the corresponding C<munlockall> is synchronous and is
1415documented under L<MISCELLANEOUS FUNCTIONS>. 1483documented under L<MISCELLANEOUS FUNCTIONS>.
1416 1484
1417Example: asynchronously lock all current and future pages into memory. 1485Example: asynchronously lock all current and future pages into memory.
… …
1456C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>, 1524C<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>, 1525C<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 1526C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
1459C<IO::AIO::FIEMAP_EXTENT_SHARED>. 1527C<IO::AIO::FIEMAP_EXTENT_SHARED>.
1460 1528
1461At the time of this writing (Linux 3.2), this requets is unreliable unless 1529At the time of this writing (Linux 3.2), this request is unreliable unless
1462C<$count> is C<undef>, as the kernel has all sorts of bugs preventing 1530C<$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 1531it to return all extents of a range for files with a large number of
1464extents. The code works around all these issues if C<$count> is undef. 1532extents. The code (only) works around all these issues if C<$count> is
1533C<undef>.
1465 1534
1466=item aio_group $callback->(...) 1535=item aio_group $callback->(...)
1467 1536
1468This is a very special aio request: Instead of doing something, it is a 1537This 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 1538container for other aio requests, which is useful if you want to bundle
… …
1582There are some caveats: when directories get renamed (or deleted), the 1651There are some caveats: when directories get renamed (or deleted), the
1583pathname string doesn't change, so will point to the new directory (or 1652pathname string doesn't change, so will point to the new directory (or
1584nowhere at all), while the directory fd, if available on the system, 1653nowhere at all), while the directory fd, if available on the system,
1585will still point to the original directory. Most functions accepting a 1654will still point to the original directory. Most functions accepting a
1586pathname will use the directory fd on newer systems, and the string on 1655pathname will use the directory fd on newer systems, and the string on
1587older systems. Some functions (such as realpath) will always rely on the 1656older systems. Some functions (such as C<aio_realpath>) will always rely on
1588string form of the pathname. 1657the string form of the pathname.
1589 1658
1590So this functionality is mainly useful to get some protection against 1659So 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 1660C<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 1661reference, and to speed up doing many operations in the same directory
1593(e.g. when stat'ing all files in a directory). 1662(e.g. when stat'ing all files in a directory).
… …
1610C<aio_wd> callback, as future requests using the value will fail in the 1679C<aio_wd> callback, as future requests using the value will fail in the
1611expected way. 1680expected way.
1612 1681
1613=item IO::AIO::CWD 1682=item IO::AIO::CWD
1614 1683
1615This is a compiletime constant (object) that represents the process 1684This is a compile time constant (object) that represents the process
1616current working directory. 1685current working directory.
1617 1686
1618Specifying this object as working directory object for a pathname is as if 1687Specifying this object as working directory object for a pathname is as if
1619the pathname would be specified directly, without a directory object. For 1688the pathname would be specified directly, without a directory object. For
1620example, these calls are functionally identical: 1689example, these calls are functionally identical:
… …
1801The default value for the limit is C<0>, but note that setting a feeder 1870The default value for the limit is C<0>, but note that setting a feeder
1802automatically bumps it up to C<2>. 1871automatically bumps it up to C<2>.
1803 1872
1804=back 1873=back
1805 1874
1875
1806=head2 SUPPORT FUNCTIONS 1876=head2 SUPPORT FUNCTIONS
1807 1877
1808=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1878=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
1809 1879
1810=over 4 1880=over 4
… …
1875Strictly equivalent to: 1945Strictly equivalent to:
1876 1946
1877 IO::AIO::poll_wait, IO::AIO::poll_cb 1947 IO::AIO::poll_wait, IO::AIO::poll_cb
1878 while IO::AIO::nreqs; 1948 while IO::AIO::nreqs;
1879 1949
1950This function can be useful at program aborts, to make sure outstanding
1951I/O has been done (C<IO::AIO> uses an C<END> block which already calls
1952this function on normal exits), or when you are merely using C<IO::AIO>
1953for its more advanced functions, rather than for async I/O, e.g.:
1954
1955 my ($dirs, $nondirs);
1956 IO::AIO::aio_scandir "/tmp", 0, sub { ($dirs, $nondirs) = @_ };
1957 IO::AIO::flush;
1958 # $dirs, $nondirs are now set
1959
1880=item IO::AIO::max_poll_reqs $nreqs 1960=item IO::AIO::max_poll_reqs $nreqs
1881 1961
1882=item IO::AIO::max_poll_time $seconds 1962=item IO::AIO::max_poll_time $seconds
1883 1963
1884These set the maximum number of requests (default C<0>, meaning infinity) 1964These set the maximum number of requests (default C<0>, meaning infinity)
… …
1910 poll => 'r', nice => 1, 1990 poll => 'r', nice => 1,
1911 cb => &IO::AIO::poll_cb); 1991 cb => &IO::AIO::poll_cb);
1912 1992
1913=back 1993=back
1914 1994
1995
1915=head3 CONTROLLING THE NUMBER OF THREADS 1996=head3 CONTROLLING THE NUMBER OF THREADS
1916 1997
1917=over 1998=over
1918 1999
1919=item IO::AIO::min_parallel $nthreads 2000=item IO::AIO::min_parallel $nthreads
… …
1985This is a very bad function to use in interactive programs because it 2066This 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 2067blocks, and a bad way to reduce concurrency because it is inexact: Better
1987use an C<aio_group> together with a feed callback. 2068use an C<aio_group> together with a feed callback.
1988 2069
1989Its main use is in scripts without an event loop - when you want to stat 2070Its main use is in scripts without an event loop - when you want to stat
1990a lot of files, you can write somehting like this: 2071a lot of files, you can write something like this:
1991 2072
1992 IO::AIO::max_outstanding 32; 2073 IO::AIO::max_outstanding 32;
1993 2074
1994 for my $path (...) { 2075 for my $path (...) {
1995 aio_stat $path , ...; 2076 aio_stat $path , ...;
… …
2006The default value for C<max_outstanding> is very large, so there is no 2087The default value for C<max_outstanding> is very large, so there is no
2007practical limit on the number of outstanding requests. 2088practical limit on the number of outstanding requests.
2008 2089
2009=back 2090=back
2010 2091
2092
2011=head3 STATISTICAL INFORMATION 2093=head3 STATISTICAL INFORMATION
2012 2094
2013=over 2095=over
2014 2096
2015=item IO::AIO::nreqs 2097=item IO::AIO::nreqs
… …
2031 2113
2032Returns the number of requests currently in the pending state (executed, 2114Returns the number of requests currently in the pending state (executed,
2033but not yet processed by poll_cb). 2115but not yet processed by poll_cb).
2034 2116
2035=back 2117=back
2118
2119
2120=head3 SUBSECOND STAT TIME ACCESS
2121
2122Both C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> functions can
2123generally find access/modification and change times with subsecond time
2124accuracy of the system supports it, but perl's built-in functions only
2125return the integer part.
2126
2127The following functions return the timestamps of the most recent
2128stat with subsecond precision on most systems and work both after
2129C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> calls. Their return
2130value is only meaningful after a successful C<stat>/C<lstat> call, or
2131during/after a successful C<aio_stat>/C<aio_lstat> callback.
2132
2133This is similar to the L<Time::HiRes> C<stat> functions, but can return
2134full resolution without rounding and work with standard perl C<stat>,
2135alleviating the need to call the special C<Time::HiRes> functions, which
2136do not act like their perl counterparts.
2137
2138On operating systems or file systems where subsecond time resolution is
2139not supported or could not be detected, a fractional part of C<0> is
2140returned, so it is always safe to call these functions.
2141
2142=over 4
2143
2144=item $seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime, IO::AIO::st_btime
2145
2146Return the access, modication, change or birth time, respectively,
2147including fractional part. Due to the limited precision of floating point,
2148the accuracy on most platforms is only a bit better than milliseconds
2149for times around now - see the I<nsec> function family, below, for full
2150accuracy.
2151
2152File birth time is only available when the OS and perl support it (on
2153FreeBSD and NetBSD at the time of this writing, although support is
2154adaptive, so if your OS/perl gains support, IO::AIO can take advantage of
2155it). On systems where it isn't available, C<0> is currently returned, but
2156this might change to C<undef> in a future version.
2157
2158=item ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtime
2159
2160Returns access, modification, change and birth time all in one go, and
2161maybe more times in the future version.
2162
2163=item $nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec, IO::AIO::st_ctimensec, IO::AIO::st_btimensec
2164
2165Return the fractional access, modifcation, change or birth time, in nanoseconds,
2166as an integer in the range C<0> to C<999999999>.
2167
2168Note that no accessors are provided for access, modification and
2169change times - you need to get those from C<stat _> if required (C<int
2170IO::AIO::st_atime> and so on will I<not> generally give you the correct
2171value).
2172
2173=item $seconds = IO::AIO::st_btimesec
2174
2175The (integral) seconds part of the file birth time, if available.
2176
2177=item ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtimensec
2178
2179Like the functions above, but returns all four times in one go (and maybe
2180more in future versions).
2181
2182=item $counter = IO::AIO::st_gen
2183
2184Returns the generation counter (in practice this is just a random number)
2185of the file. This is only available on platforms which have this member in
2186their C<struct stat> (most BSDs at the time of this writing) and generally
2187only to the root usert. If unsupported, C<0> is returned, but this might
2188change to C<undef> in a future version.
2189
2190=back
2191
2192Example: print the high resolution modification time of F</etc>, using
2193C<stat>, and C<IO::AIO::aio_stat>.
2194
2195 if (stat "/etc") {
2196 printf "stat(/etc) mtime: %f\n", IO::AIO::st_mtime;
2197 }
2198
2199 IO::AIO::aio_stat "/etc", sub {
2200 $_[0]
2201 and return;
2202
2203 printf "aio_stat(/etc) mtime: %d.%09d\n", (stat _)[9], IO::AIO::st_mtimensec;
2204 };
2205
2206 IO::AIO::flush;
2207
2208Output of the awbove on my system, showing reduced and full accuracy:
2209
2210 stat(/etc) mtime: 1534043702.020808
2211 aio_stat(/etc) mtime: 1534043702.020807792
2212
2036 2213
2037=head3 MISCELLANEOUS FUNCTIONS 2214=head3 MISCELLANEOUS FUNCTIONS
2038 2215
2039IO::AIO implements some functions that are useful when you want to use 2216IO::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 2217some "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_*> 2218"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*>
2042counterpart. 2219counterpart.
2043 2220
2044=over 4 2221=over 4
2222
2223=item $numfd = IO::AIO::get_fdlimit
2224
2225Tries to find the current file descriptor limit and returns it, or
2226C<undef> and sets C<$!> in case of an error. The limit is one larger than
2227the highest valid file descriptor number.
2228
2229=item IO::AIO::min_fdlimit [$numfd]
2230
2231Try to increase the current file descriptor limit(s) to at least C<$numfd>
2232by changing the soft or hard file descriptor resource limit. If C<$numfd>
2233is missing, it will try to set a very high limit, although this is not
2234recommended when you know the actual minimum that you require.
2235
2236If the limit cannot be raised enough, the function makes a best-effort
2237attempt to increase the limit as much as possible, using various
2238tricks, while still failing. You can query the resulting limit using
2239C<IO::AIO::get_fdlimit>.
2240
2241If an error occurs, returns C<undef> and sets C<$!>, otherwise returns
2242true.
2045 2243
2046=item IO::AIO::sendfile $ofh, $ifh, $offset, $count 2244=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
2047 2245
2048Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>, 2246Calls 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 2247but is blocking (this makes most sense if you know the input data is
… …
2066=item IO::AIO::madvise $scalar, $offset, $len, $advice 2264=item IO::AIO::madvise $scalar, $offset, $len, $advice
2067 2265
2068Simply calls the C<posix_madvise> function (see its 2266Simply calls the C<posix_madvise> function (see its
2069manpage for details). The following advice constants are 2267manpage for details). The following advice constants are
2070available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>, 2268available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
2071C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>, 2269C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>,
2072C<IO::AIO::MADV_FREE>. 2270C<IO::AIO::MADV_DONTNEED>.
2271
2272If C<$offset> is negative, counts from the end. If C<$length> is negative,
2273the remaining length of the C<$scalar> is used. If possible, C<$length>
2274will be reduced to fit into the C<$scalar>.
2073 2275
2074On systems that do not implement C<posix_madvise>, this function returns 2276On systems that do not implement C<posix_madvise>, this function returns
2075ENOSYS, otherwise the return value of C<posix_madvise>. 2277ENOSYS, otherwise the return value of C<posix_madvise>.
2076 2278
2077=item IO::AIO::mprotect $scalar, $offset, $len, $protect 2279=item IO::AIO::mprotect $scalar, $offset, $len, $protect
… …
2079Simply calls the C<mprotect> function on the preferably AIO::mmap'ed 2281Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
2080$scalar (see its manpage for details). The following protect 2282$scalar (see its manpage for details). The following protect
2081constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>, 2283constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
2082C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>. 2284C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
2083 2285
2286If C<$offset> is negative, counts from the end. If C<$length> is negative,
2287the remaining length of the C<$scalar> is used. If possible, C<$length>
2288will be reduced to fit into the C<$scalar>.
2289
2084On systems that do not implement C<mprotect>, this function returns 2290On systems that do not implement C<mprotect>, this function returns
2085ENOSYS, otherwise the return value of C<mprotect>. 2291ENOSYS, otherwise the return value of C<mprotect>.
2086 2292
2087=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] 2293=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
2088 2294
2089Memory-maps a file (or anonymous memory range) and attaches it to the 2295Memory-maps a file (or anonymous memory range) and attaches it to the
2090given C<$scalar>, which will act like a string scalar. Returns true on 2296given C<$scalar>, which will act like a string scalar. Returns true on
2091success, and false otherwise. 2297success, and false otherwise.
2092 2298
2299The scalar must exist, but its contents do not matter - this means you
2300cannot use a nonexistant array or hash element. When in doubt, C<undef>
2301the scalar first.
2302
2093The only operations allowed on the scalar are C<substr>/C<vec> that don't 2303The only operations allowed on the mmapped scalar are C<substr>/C<vec>,
2094change the string length, and most read-only operations such as copying it 2304which don't change the string length, and most read-only operations such
2095or searching it with regexes and so on. 2305as copying it or searching it with regexes and so on.
2096 2306
2097Anything else is unsafe and will, at best, result in memory leaks. 2307Anything else is unsafe and will, at best, result in memory leaks.
2098 2308
2099The memory map associated with the C<$scalar> is automatically removed 2309The memory map associated with the C<$scalar> is automatically removed
2100when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or 2310when the C<$scalar> is undef'd or destroyed, or when the C<IO::AIO::mmap>
2101C<IO::AIO::munmap> functions are called. 2311or C<IO::AIO::munmap> functions are called on it.
2102 2312
2103This calls the C<mmap>(2) function internally. See your system's manual 2313This calls the C<mmap>(2) function internally. See your system's manual
2104page for details on the C<$length>, C<$prot> and C<$flags> parameters. 2314page for details on the C<$length>, C<$prot> and C<$flags> parameters.
2105 2315
2106The C<$length> must be larger than zero and smaller than the actual 2316The C<$length> must be larger than zero and smaller than the actual
… …
2144 2354
2145=item IO::AIO::munmap $scalar 2355=item IO::AIO::munmap $scalar
2146 2356
2147Removes a previous mmap and undefines the C<$scalar>. 2357Removes a previous mmap and undefines the C<$scalar>.
2148 2358
2359=item IO::AIO::mremap $scalar, $new_length, $flags = MREMAP_MAYMOVE[, $new_address = 0]
2360
2361Calls the Linux-specific mremap(2) system call. The C<$scalar> must have
2362been mapped by C<IO::AIO::mmap>, and C<$flags> must currently either be
2363C<0> or C<IO::AIO::MREMAP_MAYMOVE>.
2364
2365Returns true if successful, and false otherwise. If the underlying mmapped
2366region has changed address, then the true value has the numerical value
2367C<1>, otherwise it has the numerical value C<0>:
2368
2369 my $success = IO::AIO::mremap $mmapped, 8192, IO::AIO::MREMAP_MAYMOVE
2370 or die "mremap: $!";
2371
2372 if ($success*1) {
2373 warn "scalar has chanegd address in memory\n";
2374 }
2375
2376C<IO::AIO::MREMAP_FIXED> and the C<$new_address> argument are currently
2377implemented, but not supported and might go away in a future version.
2378
2379On systems where this call is not supported or is not emulated, this call
2380returns falls and sets C<$!> to C<ENOSYS>.
2381
2382=item IO::AIO::mlockall $flags
2383
2384Calls the C<eio_mlockall_sync> function, which is like C<aio_mlockall>,
2385but is blocking.
2386
2149=item IO::AIO::munlock $scalar, $offset = 0, $length = undef 2387=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
2150 2388
2151Calls the C<munlock> function, undoing the effects of a previous 2389Calls the C<munlock> function, undoing the effects of a previous
2152C<aio_mlock> call (see its description for details). 2390C<aio_mlock> call (see its description for details).
2153 2391
… …
2155 2393
2156Calls the C<munlockall> function. 2394Calls the C<munlockall> function.
2157 2395
2158On systems that do not implement C<munlockall>, this function returns 2396On systems that do not implement C<munlockall>, this function returns
2159ENOSYS, otherwise the return value of C<munlockall>. 2397ENOSYS, otherwise the return value of C<munlockall>.
2398
2399=item $fh = IO::AIO::accept4 $r_fh, $sockaddr, $sockaddr_maxlen, $flags
2400
2401Uses the GNU/Linux C<accept4(2)> syscall, if available, to accept a socket
2402and return the new file handle on success, or sets C<$!> and returns
2403C<undef> on error.
2404
2405The remote name of the new socket will be stored in C<$sockaddr>, which
2406will be extended to allow for at least C<$sockaddr_maxlen> octets. If the
2407socket name does not fit into C<$sockaddr_maxlen> octets, this is signaled
2408by returning a longer string in C<$sockaddr>, which might or might not be
2409truncated.
2410
2411To accept name-less sockets, use C<undef> for C<$sockaddr> and C<0> for
2412C<$sockaddr_maxlen>.
2413
2414The main reasons to use this syscall rather than portable C<accept(2)>
2415are that you can specify C<SOCK_NONBLOCK> and/or C<SOCK_CLOEXEC>
2416flags and you can accept name-less sockets by specifying C<0> for
2417C<$sockaddr_maxlen>, which is sadly not possible with perl's interface to
2418C<accept>.
2160 2419
2161=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags 2420=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
2162 2421
2163Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or 2422Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or
2164C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they 2423C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
… …
2202C<$flags> is non-zero, fails with C<ENOSYS>. 2461C<$flags> is non-zero, fails with C<ENOSYS>.
2203 2462
2204Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the 2463Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the
2205time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and 2464time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and
2206C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported. 2465C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported.
2466
2467Example: create a pipe race-free w.r.t. threads and fork:
2468
2469 my ($rfh, $wfh) = IO::AIO::pipe2 IO::AIO::O_CLOEXEC
2470 or die "pipe2: $!\n";
2471
2472=item $fh = IO::AIO::memfd_create $pathname[, $flags]
2473
2474This is a direct interface to the Linux L<memfd_create(2)> system
2475call. The (unhelpful) default for C<$flags> is C<0>, but your default
2476should be C<IO::AIO::MFD_CLOEXEC>.
2477
2478On success, the new memfd filehandle is returned, otherwise returns
2479C<undef>. If the memfd_create syscall is missing, fails with C<ENOSYS>.
2480
2481Please refer to L<memfd_create(2)> for more info on this call.
2482
2483The following C<$flags> values are available: C<IO::AIO::MFD_CLOEXEC>,
2484C<IO::AIO::MFD_ALLOW_SEALING> and C<IO::AIO::MFD_HUGETLB>.
2485
2486Example: create a new memfd.
2487
2488 my $fh = IO::AIO::memfd_create "somenameforprocfd", IO::AIO::MFD_CLOEXEC
2489 or die "memfd_create: $!\n";
2490
2491=item $fh = IO::AIO::pidfd_open $pid[, $flags]
2492
2493This is an interface to the Linux L<pidfd_open(2)> system call. The
2494default for C<$flags> is C<0>.
2495
2496On success, a new pidfd filehandle is returned (that is already set to
2497close-on-exec), otherwise returns C<undef>. If the syscall is missing,
2498fails with C<ENOSYS>.
2499
2500Example: open pid 6341 as pidfd.
2501
2502 my $fh = IO::AIO::pidfd_open 6341
2503 or die "pidfd_open: $!\n";
2504
2505=item $status = IO::AIO::pidfd_send_signal $pidfh, $signal[, $siginfo[, $flags]]
2506
2507This is an interface to the Linux L<pidfd_send_signal> system call. The
2508default for C<$siginfo> is C<undef> and the default for C<$flags> is C<0>.
2509
2510Returns the system call status. If the syscall is missing, fails with
2511C<ENOSYS>.
2512
2513When specified, C<$siginfo> must be a reference to a hash with one or more
2514of the following members:
2515
2516=over
2517
2518=item code - the C<si_code> member
2519
2520=item pid - the C<si_pid> member
2521
2522=item uid - the C<si_uid> member
2523
2524=item value_int - the C<si_value.sival_int> member
2525
2526=item value_ptr - the C<si_value.sival_ptr> member, specified as an integer
2527
2528=back
2529
2530Example: send a SIGKILL to the specified process.
2531
2532 my $status = IO::AIO::pidfd_send_signal $pidfh, 9, undef
2533 and die "pidfd_send_signal: $!\n";
2534
2535Example: send a SIGKILL to the specified process with extra data.
2536
2537 my $status = IO::AIO::pidfd_send_signal $pidfh, 9, { code => -1, value_int => 7 }
2538 and die "pidfd_send_signal: $!\n";
2539
2540=item $fh = IO::AIO::pidfd_getfd $pidfh, $targetfd[, $flags]
2541
2542This is an interface to the Linux L<pidfd_getfd> system call. The default
2543for C<$flags> is C<0>.
2544
2545On success, returns a dup'ed copy of the target file descriptor (specified
2546as an integer) returned (that is already set to close-on-exec), otherwise
2547returns C<undef>. If the syscall is missing, fails with C<ENOSYS>.
2548
2549Example: get a copy of standard error of another process and print soemthing to it.
2550
2551 my $errfh = IO::AIO::pidfd_getfd $pidfh, 2
2552 or die "pidfd_getfd: $!\n";
2553 print $errfh "stderr\n";
2554
2555=item $fh = IO::AIO::eventfd [$initval, [$flags]]
2556
2557This is a direct interface to the Linux L<eventfd(2)> system call. The
2558(unhelpful) defaults for C<$initval> and C<$flags> are C<0> for both.
2559
2560On success, the new eventfd filehandle is returned, otherwise returns
2561C<undef>. If the eventfd syscall is missing, fails with C<ENOSYS>.
2562
2563Please refer to L<eventfd(2)> for more info on this call.
2564
2565The following symbol flag values are available: C<IO::AIO::EFD_CLOEXEC>,
2566C<IO::AIO::EFD_NONBLOCK> and C<IO::AIO::EFD_SEMAPHORE> (Linux 2.6.30).
2567
2568Example: create a new eventfd filehandle:
2569
2570 $fh = IO::AIO::eventfd 0, IO::AIO::EFD_CLOEXEC
2571 or die "eventfd: $!\n";
2572
2573=item $fh = IO::AIO::timerfd_create $clockid[, $flags]
2574
2575This is a direct interface to the Linux L<timerfd_create(2)> system
2576call. The (unhelpful) default for C<$flags> is C<0>, but your default
2577should be C<IO::AIO::TFD_CLOEXEC>.
2578
2579On success, the new timerfd filehandle is returned, otherwise returns
2580C<undef>. If the timerfd_create syscall is missing, fails with C<ENOSYS>.
2581
2582Please refer to L<timerfd_create(2)> for more info on this call.
2583
2584The following C<$clockid> values are
2585available: C<IO::AIO::CLOCK_REALTIME>, C<IO::AIO::CLOCK_MONOTONIC>
2586C<IO::AIO::CLOCK_CLOCK_BOOTTIME> (Linux 3.15)
2587C<IO::AIO::CLOCK_CLOCK_REALTIME_ALARM> (Linux 3.11) and
2588C<IO::AIO::CLOCK_CLOCK_BOOTTIME_ALARM> (Linux 3.11).
2589
2590The following C<$flags> values are available (Linux
25912.6.27): C<IO::AIO::TFD_NONBLOCK> and C<IO::AIO::TFD_CLOEXEC>.
2592
2593Example: create a new timerfd and set it to one-second repeated alarms,
2594then wait for two alarms:
2595
2596 my $fh = IO::AIO::timerfd_create IO::AIO::CLOCK_BOOTTIME, IO::AIO::TFD_CLOEXEC
2597 or die "timerfd_create: $!\n";
2598
2599 defined IO::AIO::timerfd_settime $fh, 0, 1, 1
2600 or die "timerfd_settime: $!\n";
2601
2602 for (1..2) {
2603 8 == sysread $fh, my $buf, 8
2604 or die "timerfd read failure\n";
2605
2606 printf "number of expirations (likely 1): %d\n",
2607 unpack "Q", $buf;
2608 }
2609
2610=item ($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags, $new_interval, $nbw_value
2611
2612This is a direct interface to the Linux L<timerfd_settime(2)> system
2613call. Please refer to its manpage for more info on this call.
2614
2615The new itimerspec is specified using two (possibly fractional) second
2616values, C<$new_interval> and C<$new_value>).
2617
2618On success, the current interval and value are returned (as per
2619C<timerfd_gettime>). On failure, the empty list is returned.
2620
2621The following C<$flags> values are
2622available: C<IO::AIO::TFD_TIMER_ABSTIME> and
2623C<IO::AIO::TFD_TIMER_CANCEL_ON_SET>.
2624
2625See C<IO::AIO::timerfd_create> for a full example.
2626
2627=item ($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh
2628
2629This is a direct interface to the Linux L<timerfd_gettime(2)> system
2630call. Please refer to its manpage for more info on this call.
2631
2632On success, returns the current values of interval and value for the given
2633timerfd (as potentially fractional second values). On failure, the empty
2634list is returned.
2207 2635
2208=back 2636=back
2209 2637
2210=cut 2638=cut
2211 2639
… …
2277the process will result in undefined behaviour. Calling it at any time 2705the process will result in undefined behaviour. Calling it at any time
2278will also result in any undefined (by POSIX) behaviour. 2706will also result in any undefined (by POSIX) behaviour.
2279 2707
2280=back 2708=back
2281 2709
2710=head2 LINUX-SPECIFIC CALLS
2711
2712When a call is documented as "linux-specific" then this means it
2713originated on GNU/Linux. C<IO::AIO> will usually try to autodetect the
2714availability and compatibility of such calls regardless of the platform
2715it is compiled on, so platforms such as FreeBSD which often implement
2716these calls will work. When in doubt, call them and see if they fail wth
2717C<ENOSYS>.
2718
2282=head2 MEMORY USAGE 2719=head2 MEMORY USAGE
2283 2720
2284Per-request usage: 2721Per-request usage:
2285 2722
2286Each aio request uses - depending on your architecture - around 100-200 2723Each aio request uses - depending on your architecture - around 100-200
… …
2298temporary buffers, and each thread requires a stack and other data 2735temporary buffers, and each thread requires a stack and other data
2299structures (usually around 16k-128k, depending on the OS). 2736structures (usually around 16k-128k, depending on the OS).
2300 2737
2301=head1 KNOWN BUGS 2738=head1 KNOWN BUGS
2302 2739
2303Known bugs will be fixed in the next release. 2740Known bugs will be fixed in the next release :)
2741
2742=head1 KNOWN ISSUES
2743
2744Calls that try to "import" foreign memory areas (such as C<IO::AIO::mmap>
2745or C<IO::AIO::aio_slurp>) do not work with generic lvalues, such as
2746non-created hash slots or other scalars I didn't think of. It's best to
2747avoid such and either use scalar variables or making sure that the scalar
2748exists (e.g. by storing C<undef>) and isn't "funny" (e.g. tied).
2749
2750I am not sure anything can be done about this, so this is considered a
2751known issue, rather than a bug.
2304 2752
2305=head1 SEE ALSO 2753=head1 SEE ALSO
2306 2754
2307L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a 2755L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
2308more natural syntax. 2756more natural syntax and L<IO::FDPass> for file descriptor passing.
2309 2757
2310=head1 AUTHOR 2758=head1 AUTHOR
2311 2759
2312 Marc Lehmann <schmorp@schmorp.de> 2760 Marc Lehmann <schmorp@schmorp.de>
2313 http://home.schmorp.de/ 2761 http://home.schmorp.de/

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