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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.264 by root, Mon Jul 18 07:48:01 2016 UTC vs.
Revision 1.294 by root, Sat Aug 25 19:25:32 2018 UTC

1=head1 NAME 1=head1 NAME
2 2
3IO::AIO - Asynchronous Input/Output 3IO::AIO - Asynchronous/Advanced Input/Output
4 4
5=head1 SYNOPSIS 5=head1 SYNOPSIS
6 6
7 use IO::AIO; 7 use IO::AIO;
8 8
… …
58not well-supported or restricted (GNU/Linux doesn't allow them on normal 58not well-supported or restricted (GNU/Linux doesn't allow them on normal
59files currently, for example), and they would only support aio_read and 59files currently, for example), and they would only support aio_read and
60aio_write, so the remaining functionality would have to be implemented 60aio_write, so the remaining functionality would have to be implemented
61using threads anyway. 61using threads anyway.
62 62
63In addition to asynchronous I/O, this module also exports some rather
64arcane interfaces, such as C<madvise> or linux's C<splice> system call,
65which is why the C<A> in C<AIO> can also mean I<advanced>.
66
63Although the module will work in the presence of other (Perl-) threads, 67Although the module will work in the presence of other (Perl-) threads,
64it is currently not reentrant in any way, so use appropriate locking 68it is currently not reentrant in any way, so use appropriate locking
65yourself, always call C<poll_cb> from within the same thread, or never 69yourself, always call C<poll_cb> from within the same thread, or never
66call C<poll_cb> (or other C<aio_> functions) recursively. 70call C<poll_cb> (or other C<aio_> functions) recursively.
67 71
… …
167use common::sense; 171use common::sense;
168 172
169use base 'Exporter'; 173use base 'Exporter';
170 174
171BEGIN { 175BEGIN {
172 our $VERSION = 4.34; 176 our $VERSION = 4.54;
173 177
174 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
175 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
176 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
177 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
178 aio_pathsync aio_readahead aio_fiemap aio_allocate 182 aio_pathsync aio_readahead aio_fiemap aio_allocate
179 aio_rename aio_link aio_move aio_copy aio_group 183 aio_rename aio_rename2 aio_link aio_move aio_copy aio_group
180 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
181 aio_chmod aio_utime aio_truncate 185 aio_chmod aio_utime aio_truncate
182 aio_msync aio_mtouch aio_mlock aio_mlockall 186 aio_msync aio_mtouch aio_mlock aio_mlockall
183 aio_statvfs 187 aio_statvfs
188 aio_slurp
184 aio_wd); 189 aio_wd);
185 190
186 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); 191 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
187 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 192 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
188 min_parallel max_parallel max_idle idle_timeout 193 min_parallel max_parallel max_idle idle_timeout
189 nreqs nready npending nthreads 194 nreqs nready npending nthreads
190 max_poll_time max_poll_reqs 195 max_poll_time max_poll_reqs
191 sendfile fadvise madvise 196 sendfile fadvise madvise
192 mmap munmap munlock munlockall); 197 mmap munmap mremap munlock munlockall);
193 198
194 push @AIO_REQ, qw(aio_busy); # not exported 199 push @AIO_REQ, qw(aio_busy); # not exported
195 200
196 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 201 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
197 202
… …
229 aio_link $srcpath, $dstpath, $callback->($status) 234 aio_link $srcpath, $dstpath, $callback->($status)
230 aio_symlink $srcpath, $dstpath, $callback->($status) 235 aio_symlink $srcpath, $dstpath, $callback->($status)
231 aio_readlink $pathname, $callback->($link) 236 aio_readlink $pathname, $callback->($link)
232 aio_realpath $pathname, $callback->($path) 237 aio_realpath $pathname, $callback->($path)
233 aio_rename $srcpath, $dstpath, $callback->($status) 238 aio_rename $srcpath, $dstpath, $callback->($status)
239 aio_rename2 $srcpath, $dstpath, $flags, $callback->($status)
234 aio_mkdir $pathname, $mode, $callback->($status) 240 aio_mkdir $pathname, $mode, $callback->($status)
235 aio_rmdir $pathname, $callback->($status) 241 aio_rmdir $pathname, $callback->($status)
236 aio_readdir $pathname, $callback->($entries) 242 aio_readdir $pathname, $callback->($entries)
237 aio_readdirx $pathname, $flags, $callback->($entries, $flags) 243 aio_readdirx $pathname, $flags, $callback->($entries, $flags)
238 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST 244 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
… …
248 aio_syncfs $fh, $callback->($status) 254 aio_syncfs $fh, $callback->($status)
249 aio_fsync $fh, $callback->($status) 255 aio_fsync $fh, $callback->($status)
250 aio_fdatasync $fh, $callback->($status) 256 aio_fdatasync $fh, $callback->($status)
251 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) 257 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
252 aio_pathsync $pathname, $callback->($status) 258 aio_pathsync $pathname, $callback->($status)
253 aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 259 aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status)
254 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 260 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
255 aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) 261 aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
256 aio_mlockall $flags, $callback->($status) 262 aio_mlockall $flags, $callback->($status)
257 aio_group $callback->(...) 263 aio_group $callback->(...)
258 aio_nop $callback->() 264 aio_nop $callback->()
… …
272 IO::AIO::idle_timeout $seconds 278 IO::AIO::idle_timeout $seconds
273 IO::AIO::max_outstanding $maxreqs 279 IO::AIO::max_outstanding $maxreqs
274 IO::AIO::nreqs 280 IO::AIO::nreqs
275 IO::AIO::nready 281 IO::AIO::nready
276 IO::AIO::npending 282 IO::AIO::npending
283 $nfd = IO::AIO::get_fdlimit [EXPERIMENTAL]
284 IO::AIO::min_fdlimit $nfd [EXPERIMENTAL]
277 285
278 IO::AIO::sendfile $ofh, $ifh, $offset, $count 286 IO::AIO::sendfile $ofh, $ifh, $offset, $count
279 IO::AIO::fadvise $fh, $offset, $len, $advice 287 IO::AIO::fadvise $fh, $offset, $len, $advice
280 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]] 288 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
281 IO::AIO::munmap $scalar 289 IO::AIO::munmap $scalar
290 IO::AIO::mremap $scalar, $new_length, $flags[, $new_address]
282 IO::AIO::madvise $scalar, $offset, $length, $advice 291 IO::AIO::madvise $scalar, $offset, $length, $advice
283 IO::AIO::mprotect $scalar, $offset, $length, $protect 292 IO::AIO::mprotect $scalar, $offset, $length, $protect
284 IO::AIO::munlock $scalar, $offset = 0, $length = undef 293 IO::AIO::munlock $scalar, $offset = 0, $length = undef
285 IO::AIO::munlockall 294 IO::AIO::munlockall
286 295
… …
396following POSIX and non-POSIX constants are available (missing ones on 405following POSIX and non-POSIX constants are available (missing ones on
397your system are, as usual, C<0>): 406your system are, as usual, C<0>):
398 407
399C<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>,
400C<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>,
401C<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>.
402 411
403 412
404=item aio_close $fh, $callback->($status) 413=item aio_close $fh, $callback->($status)
405 414
406Asynchronously close a file and call the callback with the result 415Asynchronously close a file and call the callback with the result
… …
441=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 450=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
442 451
443=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 452=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
444 453
445Reads 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
446C<$offset> into the scalar given by C<$data> and offset C<$dataoffset> 455C<$offset> into the scalar given by C<$data> and offset C<$dataoffset> and
447and calls the callback without the actual number of bytes read (or -1 on 456calls the callback with the actual number of bytes transferred (or -1 on
448error, just like the syscall). 457error, just like the syscall).
449 458
450C<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
451offset plus the actual number of bytes read. 460offset plus the actual number of bytes read.
452 461
… …
532 541
533=item aio_stat $fh_or_path, $callback->($status) 542=item aio_stat $fh_or_path, $callback->($status)
534 543
535=item aio_lstat $fh, $callback->($status) 544=item aio_lstat $fh, $callback->($status)
536 545
537Works 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
538be 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
539or C<-s _> etc... 548using C<stat _> or C<-s _> and other tests (with the exception of C<-B>
549and C<-T>).
540 550
541The 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,
542for an explanation. 552for an explanation.
543 553
544Currently, 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
… …
551behaviour). 561behaviour).
552 562
553C<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>,
554C<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>,
555C<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>.
556 569
557Example: Print the length of F</etc/passwd>: 570Example: Print the length of F</etc/passwd>:
558 571
559 aio_stat "/etc/passwd", sub { 572 aio_stat "/etc/passwd", sub {
560 $_[0] and die "stat failed: $!"; 573 $_[0] and die "stat failed: $!";
… …
604 namemax => 255, 617 namemax => 255,
605 frsize => 1024, 618 frsize => 1024,
606 fsid => 1810 619 fsid => 1810
607 } 620 }
608 621
609Here is a (likely partial - send me updates!) list of fsid values used by
610Linux - it is safe to hardcode these when C<$^O> is C<linux>:
611
612 0x0000adf5 adfs
613 0x0000adff affs
614 0x5346414f afs
615 0x09041934 anon-inode filesystem
616 0x00000187 autofs
617 0x42465331 befs
618 0x1badface bfs
619 0x42494e4d binfmt_misc
620 0x9123683e btrfs
621 0x0027e0eb cgroupfs
622 0xff534d42 cifs
623 0x73757245 coda
624 0x012ff7b7 coh
625 0x28cd3d45 cramfs
626 0x453dcd28 cramfs-wend (wrong endianness)
627 0x64626720 debugfs
628 0x00001373 devfs
629 0x00001cd1 devpts
630 0x0000f15f ecryptfs
631 0x00414a53 efs
632 0x0000137d ext
633 0x0000ef53 ext2/ext3/ext4
634 0x0000ef51 ext2
635 0xf2f52010 f2fs
636 0x00004006 fat
637 0x65735546 fuseblk
638 0x65735543 fusectl
639 0x0bad1dea futexfs
640 0x01161970 gfs2
641 0x47504653 gpfs
642 0x00004244 hfs
643 0xf995e849 hpfs
644 0x00c0ffee hostfs
645 0x958458f6 hugetlbfs
646 0x2bad1dea inotifyfs
647 0x00009660 isofs
648 0x000072b6 jffs2
649 0x3153464a jfs
650 0x6b414653 k-afs
651 0x0bd00bd0 lustre
652 0x0000137f minix
653 0x0000138f minix 30 char names
654 0x00002468 minix v2
655 0x00002478 minix v2 30 char names
656 0x00004d5a minix v3
657 0x19800202 mqueue
658 0x00004d44 msdos
659 0x0000564c novell
660 0x00006969 nfs
661 0x6e667364 nfsd
662 0x00003434 nilfs
663 0x5346544e ntfs
664 0x00009fa1 openprom
665 0x7461636F ocfs2
666 0x00009fa0 proc
667 0x6165676c pstorefs
668 0x0000002f qnx4
669 0x68191122 qnx6
670 0x858458f6 ramfs
671 0x52654973 reiserfs
672 0x00007275 romfs
673 0x67596969 rpc_pipefs
674 0x73636673 securityfs
675 0xf97cff8c selinux
676 0x0000517b smb
677 0x534f434b sockfs
678 0x73717368 squashfs
679 0x62656572 sysfs
680 0x012ff7b6 sysv2
681 0x012ff7b5 sysv4
682 0x01021994 tmpfs
683 0x15013346 udf
684 0x00011954 ufs
685 0x54190100 ufs byteswapped
686 0x00009fa2 usbdevfs
687 0x01021997 v9fs
688 0xa501fcf5 vxfs
689 0xabba1974 xenfs
690 0x012ff7b4 xenix
691 0x58465342 xfs
692 0x012fd16d xia
693
694=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 622=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
695 623
696Works 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
697and $mtime being undef). Fractional times are supported if the underlying 625and $mtime being undef). Fractional times are supported if the underlying
698syscalls support them. 626syscalls support them.
699 627
700When called with a pathname, uses utimes(2) if available, otherwise 628When called with a pathname, uses utimensat(2) or utimes(2) if available,
701utime(2). If called on a file descriptor, uses futimes(2) if available, 629otherwise utime(2). If called on a file descriptor, uses futimens(2)
702otherwise returns ENOSYS, so this is not portable. 630or futimes(2) if available, otherwise returns ENOSYS, so this is not
631portable.
703 632
704Examples: 633Examples:
705 634
706 # set atime and mtime to current time (basically touch(1)): 635 # set atime and mtime to current time (basically touch(1)):
707 aio_utime "path", undef, undef; 636 aio_utime "path", undef, undef;
… …
735C<$mode> is usually C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> to allocate 664C<$mode> is usually C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> to allocate
736space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE | IO::AIO::FALLOC_FL_KEEP_SIZE>, 665space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE | IO::AIO::FALLOC_FL_KEEP_SIZE>,
737to deallocate a file range. 666to deallocate a file range.
738 667
739IO::AIO also supports C<FALLOC_FL_COLLAPSE_RANGE>, to remove a range 668IO::AIO also supports C<FALLOC_FL_COLLAPSE_RANGE>, to remove a range
740(without leaving a hole) and C<FALLOC_FL_ZERO_RANGE>, to zero a range (see 669(without leaving a hole), C<FALLOC_FL_ZERO_RANGE>, to zero a range,
741your L<fallocate(2)> manpage). 670C<FALLOC_FL_INSERT_RANGE> to insert a range and C<FALLOC_FL_UNSHARE_RANGE>
671to unshare shared blocks (see your L<fallocate(2)> manpage).
742 672
743The file system block size used by C<fallocate> is presumably the 673The file system block size used by C<fallocate> is presumably the
744C<f_bsize> returned by C<statvfs>. 674C<f_bsize> returned by C<statvfs>, but different filesystems and filetypes
675can dictate other limitations.
745 676
746If C<fallocate> isn't available or cannot be emulated (currently no 677If C<fallocate> isn't available or cannot be emulated (currently no
747emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>. 678emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>.
748 679
749 680
… …
808On systems that support the AIO::WD working directory abstraction 739On systems that support the AIO::WD working directory abstraction
809natively, the case C<[$wd, "."]> as C<$srcpath> is specialcased - instead 740natively, the case C<[$wd, "."]> as C<$srcpath> is specialcased - instead
810of failing, C<rename> is called on the absolute path of C<$wd>. 741of failing, C<rename> is called on the absolute path of C<$wd>.
811 742
812 743
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
813=item aio_mkdir $pathname, $mode, $callback->($status) 760=item aio_mkdir $pathname, $mode, $callback->($status)
814 761
815Asynchronously mkdir (create) a directory and call the callback with 762Asynchronously mkdir (create) a directory and call the callback with
816the 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
817request is executed, so do not change your umask. 764request is executed, so do not change your umask.
… …
848 795
849=over 4 796=over 4
850 797
851=item IO::AIO::READDIR_DENTS 798=item IO::AIO::READDIR_DENTS
852 799
853When this flag is off, then the callback gets an arrayref consisting of 800Normally the callback gets an arrayref consisting of names only (as
854names 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
855C<[$name, $type, $inode]> arrayrefs, each describing a single directory 802arrayref with C<[$name, $type, $inode]> arrayrefs, each describing a
856entry in more detail. 803single directory entry in more detail:
857 804
858C<$name> is the name of the entry. 805C<$name> is the name of the entry.
859 806
860C<$type> is one of the C<IO::AIO::DT_xxx> constants: 807C<$type> is one of the C<IO::AIO::DT_xxx> constants:
861 808
862C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>, 809C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
863C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>, 810C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
864C<IO::AIO::DT_WHT>. 811C<IO::AIO::DT_WHT>.
865 812
866C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to 813C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need
867know, you have to run stat yourself. Also, for speed reasons, the C<$type> 814to know, you have to run stat yourself. Also, for speed/memory reasons,
868scalars are read-only: you can not modify them. 815the C<$type> scalars are read-only: you must not modify them.
869 816
870C<$inode> is the inode number (which might not be exact on systems with 64 817C<$inode> is the inode number (which might not be exact on systems with 64
871bit inode numbers and 32 bit perls). This field has unspecified content on 818bit inode numbers and 32 bit perls). This field has unspecified content on
872systems that do not deliver the inode information. 819systems that do not deliver the inode information.
873 820
… …
884short names are tried first. 831short names are tried first.
885 832
886=item IO::AIO::READDIR_STAT_ORDER 833=item IO::AIO::READDIR_STAT_ORDER
887 834
888When this flag is set, then the names will be returned in an order 835When this flag is set, then the names will be returned in an order
889suitable for stat()'ing each one. That is, when you plan to stat() 836suitable for stat()'ing each one. That is, when you plan to stat() most or
890all files in the given directory, then the returned order will likely 837all files in the given directory, then the returned order will likely be
891be fastest. 838faster.
892 839
893If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then 840If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified,
894the likely dirs come first, resulting in a less optimal stat order. 841then the likely dirs come first, resulting in a less optimal stat order
842for stat'ing all entries, but likely a more optimal order for finding
843subdirectories.
895 844
896=item IO::AIO::READDIR_FOUND_UNKNOWN 845=item IO::AIO::READDIR_FOUND_UNKNOWN
897 846
898This flag should not be set when calling C<aio_readdirx>. Instead, it 847This flag should not be set when calling C<aio_readdirx>. Instead, it
899is being set by C<aio_readdirx>, when any of the C<$type>'s found were 848is being set by C<aio_readdirx>, when any of the C<$type>'s found were
… …
901C<$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.
902 851
903=back 852=back
904 853
905 854
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
906=item aio_load $pathname, $data, $callback->($status) 884=item aio_load $pathname, $data, $callback->($status)
907 885
908This 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
909memory. 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.
910 890
911=cut 891=cut
912 892
913sub aio_load($$;$) { 893sub aio_load($$;$) {
914 my ($path, undef, $cb) = @_; 894 my ($path, undef, $cb) = @_;
… …
934=item aio_copy $srcpath, $dstpath, $callback->($status) 914=item aio_copy $srcpath, $dstpath, $callback->($status)
935 915
936Try 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
937destination) from C<$srcpath> to C<$dstpath> and call the callback with 917destination) from C<$srcpath> to C<$dstpath> and call the callback with
938a 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.
939 921
940This is a composite request that creates the destination file with 922This is a composite request that creates the destination file with
941mode 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
942C<aio_sendfile>, followed by restoring atime, mtime, access mode and 924C<aio_sendfile>, followed by restoring atime, mtime, access mode and
943uid/gid, in that order. 925uid/gid, in that order.
… …
1053Scans a directory (similar to C<aio_readdir>) but additionally tries to 1035Scans a directory (similar to C<aio_readdir>) but additionally tries to
1054efficiently separate the entries of directory C<$path> into two sets of 1036efficiently separate the entries of directory C<$path> into two sets of
1055names, directories you can recurse into (directories), and ones you cannot 1037names, directories you can recurse into (directories), and ones you cannot
1056recurse into (everything else, including symlinks to directories). 1038recurse into (everything else, including symlinks to directories).
1057 1039
1058C<aio_scandir> is a composite request that creates of many sub requests_ 1040C<aio_scandir> is a composite request that generates many sub requests.
1059C<$maxreq> specifies the maximum number of outstanding aio requests that 1041C<$maxreq> specifies the maximum number of outstanding aio requests that
1060this function generates. If it is C<< <= 0 >>, then a suitable default 1042this function generates. If it is C<< <= 0 >>, then a suitable default
1061will be chosen (currently 4). 1043will be chosen (currently 4).
1062 1044
1063On error, the callback is called without arguments, otherwise it receives 1045On error, the callback is called without arguments, otherwise it receives
… …
1250other 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,
1251you still can. 1233you still can.
1252 1234
1253The following constants are available (missing ones are, as usual C<0>): 1235The following constants are available (missing ones are, as usual C<0>):
1254 1236
1237C<F_DUPFD_CLOEXEC>,
1238
1239C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>,
1240
1255C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>. 1241C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>.
1256 1242
1257C<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>,
1258C<FS_IOC_FIEMAP>. 1244C<FS_IOC_FIEMAP>.
1259 1245
… …
1346 }; 1332 };
1347 1333
1348 $grp 1334 $grp
1349} 1335}
1350 1336
1351=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)
1352 1338
1353This 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
1354scalars (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
1355scalars 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
1356scalar 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
… …
1358 1344
1359It 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
1360area 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
1361later. 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>
1362is 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
1363a 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
1364C<IO::AIO::MS_SYNC>. 1350C<IO::AIO::MS_INVALIDATE>.
1365 1351
1366=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)
1367 1353
1368This 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
1369scalars. 1355scalars.
… …
1452C<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>,
1453C<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>,
1454C<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
1455C<IO::AIO::FIEMAP_EXTENT_SHARED>. 1441C<IO::AIO::FIEMAP_EXTENT_SHARED>.
1456 1442
1457At 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
1458C<$count> is C<undef>, as the kernel has all sorts of bugs preventing 1444C<$count> is C<undef>, as the kernel has all sorts of bugs preventing
1459it 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
1460extents. 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>.
1461 1448
1462=item aio_group $callback->(...) 1449=item aio_group $callback->(...)
1463 1450
1464This 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
1465container 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
… …
1578There are some caveats: when directories get renamed (or deleted), the 1565There are some caveats: when directories get renamed (or deleted), the
1579pathname 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
1580nowhere at all), while the directory fd, if available on the system, 1567nowhere at all), while the directory fd, if available on the system,
1581will still point to the original directory. Most functions accepting a 1568will still point to the original directory. Most functions accepting a
1582pathname 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
1583older systems. Some functions (such as realpath) will always rely on the 1570older systems. Some functions (such as C<aio_realpath>) will always rely on
1584string form of the pathname. 1571the string form of the pathname.
1585 1572
1586So this functionality is mainly useful to get some protection against 1573So this functionality is mainly useful to get some protection against
1587C<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
1588reference, and to speed up doing many operations in the same directory 1575reference, and to speed up doing many operations in the same directory
1589(e.g. when stat'ing all files in a directory). 1576(e.g. when stat'ing all files in a directory).
… …
1797The 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
1798automatically bumps it up to C<2>. 1785automatically bumps it up to C<2>.
1799 1786
1800=back 1787=back
1801 1788
1789
1802=head2 SUPPORT FUNCTIONS 1790=head2 SUPPORT FUNCTIONS
1803 1791
1804=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1792=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
1805 1793
1806=over 4 1794=over 4
… …
1871Strictly equivalent to: 1859Strictly equivalent to:
1872 1860
1873 IO::AIO::poll_wait, IO::AIO::poll_cb 1861 IO::AIO::poll_wait, IO::AIO::poll_cb
1874 while IO::AIO::nreqs; 1862 while IO::AIO::nreqs;
1875 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
1876=item IO::AIO::max_poll_reqs $nreqs 1874=item IO::AIO::max_poll_reqs $nreqs
1877 1875
1878=item IO::AIO::max_poll_time $seconds 1876=item IO::AIO::max_poll_time $seconds
1879 1877
1880These set the maximum number of requests (default C<0>, meaning infinity) 1878These set the maximum number of requests (default C<0>, meaning infinity)
… …
1906 poll => 'r', nice => 1, 1904 poll => 'r', nice => 1,
1907 cb => &IO::AIO::poll_cb); 1905 cb => &IO::AIO::poll_cb);
1908 1906
1909=back 1907=back
1910 1908
1909
1911=head3 CONTROLLING THE NUMBER OF THREADS 1910=head3 CONTROLLING THE NUMBER OF THREADS
1912 1911
1913=over 1912=over
1914 1913
1915=item IO::AIO::min_parallel $nthreads 1914=item IO::AIO::min_parallel $nthreads
… …
1981This 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
1982blocks, 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
1983use an C<aio_group> together with a feed callback. 1982use an C<aio_group> together with a feed callback.
1984 1983
1985Its 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
1986a lot of files, you can write somehting like this: 1985a lot of files, you can write something like this:
1987 1986
1988 IO::AIO::max_outstanding 32; 1987 IO::AIO::max_outstanding 32;
1989 1988
1990 for my $path (...) { 1989 for my $path (...) {
1991 aio_stat $path , ...; 1990 aio_stat $path , ...;
… …
2002The 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
2003practical limit on the number of outstanding requests. 2002practical limit on the number of outstanding requests.
2004 2003
2005=back 2004=back
2006 2005
2006
2007=head3 STATISTICAL INFORMATION 2007=head3 STATISTICAL INFORMATION
2008 2008
2009=over 2009=over
2010 2010
2011=item IO::AIO::nreqs 2011=item IO::AIO::nreqs
… …
2027 2027
2028Returns the number of requests currently in the pending state (executed, 2028Returns the number of requests currently in the pending state (executed,
2029but not yet processed by poll_cb). 2029but not yet processed by poll_cb).
2030 2030
2031=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 of the file. This is only available on
2099platforms which have this member in their C<struct stat> (most BSDs
2100at the time of this writing) and generally only to the root usert. If
2101unsupported, C<0> is returned, but this might change to C<undef> in a
2102future 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
2032 2127
2033=head3 MISCELLANEOUS FUNCTIONS 2128=head3 MISCELLANEOUS FUNCTIONS
2034 2129
2035IO::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
2036some "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
2037"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_*>
2038counterpart. 2133counterpart.
2039 2134
2040=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.
2041 2161
2042=item IO::AIO::sendfile $ofh, $ifh, $offset, $count 2162=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
2043 2163
2044Calls 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>,
2045but 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
… …
2062=item IO::AIO::madvise $scalar, $offset, $len, $advice 2182=item IO::AIO::madvise $scalar, $offset, $len, $advice
2063 2183
2064Simply calls the C<posix_madvise> function (see its 2184Simply calls the C<posix_madvise> function (see its
2065manpage for details). The following advice constants are 2185manpage for details). The following advice constants are
2066available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>, 2186available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
2067C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>, 2187C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>,
2068C<IO::AIO::MADV_FREE>. 2188C<IO::AIO::MADV_DONTNEED>.
2189
2190If C<$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>.
2069 2193
2070On systems that do not implement C<posix_madvise>, this function returns 2194On systems that do not implement C<posix_madvise>, this function returns
2071ENOSYS, otherwise the return value of C<posix_madvise>. 2195ENOSYS, otherwise the return value of C<posix_madvise>.
2072 2196
2073=item IO::AIO::mprotect $scalar, $offset, $len, $protect 2197=item IO::AIO::mprotect $scalar, $offset, $len, $protect
… …
2075Simply calls the C<mprotect> function on the preferably AIO::mmap'ed 2199Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
2076$scalar (see its manpage for details). The following protect 2200$scalar (see its manpage for details). The following protect
2077constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>, 2201constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
2078C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>. 2202C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
2079 2203
2204If C<$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
2080On systems that do not implement C<mprotect>, this function returns 2208On systems that do not implement C<mprotect>, this function returns
2081ENOSYS, otherwise the return value of C<mprotect>. 2209ENOSYS, otherwise the return value of C<mprotect>.
2082 2210
2083=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] 2211=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
2084 2212
2085Memory-maps a file (or anonymous memory range) and attaches it to the 2213Memory-maps a file (or anonymous memory range) and attaches it to the
2086given C<$scalar>, which will act like a string scalar. Returns true on 2214given C<$scalar>, which will act like a string scalar. Returns true on
2087success, and false otherwise. 2215success, and false otherwise.
2088 2216
2217The scalar must exist, but its contents do not matter - this means you
2218cannot use a nonexistant array or hash element. When in doubt, C<undef>
2219the scalar first.
2220
2089The only operations allowed on the scalar are C<substr>/C<vec> that don't 2221The only operations allowed on the mmapped scalar are C<substr>/C<vec>,
2090change the string length, and most read-only operations such as copying it 2222which don't change the string length, and most read-only operations such
2091or searching it with regexes and so on. 2223as copying it or searching it with regexes and so on.
2092 2224
2093Anything else is unsafe and will, at best, result in memory leaks. 2225Anything else is unsafe and will, at best, result in memory leaks.
2094 2226
2095The memory map associated with the C<$scalar> is automatically removed 2227The memory map associated with the C<$scalar> is automatically removed
2096when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or 2228when the C<$scalar> is undef'd or destroyed, or when the C<IO::AIO::mmap>
2097C<IO::AIO::munmap> functions are called. 2229or C<IO::AIO::munmap> functions are called on it.
2098 2230
2099This calls the C<mmap>(2) function internally. See your system's manual 2231This calls the C<mmap>(2) function internally. See your system's manual
2100page for details on the C<$length>, C<$prot> and C<$flags> parameters. 2232page for details on the C<$length>, C<$prot> and C<$flags> parameters.
2101 2233
2102The C<$length> must be larger than zero and smaller than the actual 2234The C<$length> must be larger than zero and smaller than the actual
… …
2140 2272
2141=item IO::AIO::munmap $scalar 2273=item IO::AIO::munmap $scalar
2142 2274
2143Removes a previous mmap and undefines the C<$scalar>. 2275Removes a previous mmap and undefines the C<$scalar>.
2144 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
2145=item IO::AIO::munlock $scalar, $offset = 0, $length = undef 2300=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
2146 2301
2147Calls the C<munlock> function, undoing the effects of a previous 2302Calls the C<munlock> function, undoing the effects of a previous
2148C<aio_mlock> call (see its description for details). 2303C<aio_mlock> call (see its description for details).
2149 2304
… …
2198C<$flags> is non-zero, fails with C<ENOSYS>. 2353C<$flags> is non-zero, fails with C<ENOSYS>.
2199 2354
2200Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the 2355Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the
2201time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and 2356time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and
2202C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported. 2357C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported.
2358
2359Example: create a pipe race-free w.r.t. threads and fork:
2360
2361 my ($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.
2203 2443
2204=back 2444=back
2205 2445
2206=cut 2446=cut
2207 2447
… …
2273the process will result in undefined behaviour. Calling it at any time 2513the process will result in undefined behaviour. Calling it at any time
2274will also result in any undefined (by POSIX) behaviour. 2514will also result in any undefined (by POSIX) behaviour.
2275 2515
2276=back 2516=back
2277 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
2278=head2 MEMORY USAGE 2527=head2 MEMORY USAGE
2279 2528
2280Per-request usage: 2529Per-request usage:
2281 2530
2282Each aio request uses - depending on your architecture - around 100-200 2531Each aio request uses - depending on your architecture - around 100-200
… …
2294temporary buffers, and each thread requires a stack and other data 2543temporary buffers, and each thread requires a stack and other data
2295structures (usually around 16k-128k, depending on the OS). 2544structures (usually around 16k-128k, depending on the OS).
2296 2545
2297=head1 KNOWN BUGS 2546=head1 KNOWN BUGS
2298 2547
2299Known 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.
2300 2560
2301=head1 SEE ALSO 2561=head1 SEE ALSO
2302 2562
2303L<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
2304more natural syntax. 2564more natural syntax.

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