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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.256 by root, Thu Jun 25 15:47:01 2015 UTC vs.
Revision 1.317 by root, Sun Sep 25 16:30:50 2022 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
… …
94 98
95 # file contents now in $contents 99 # file contents now in $contents
96 print $contents; 100 print $contents;
97 101
98 # exit event loop and program 102 # exit event loop and program
99 EV::unloop; 103 EV::break;
100 }; 104 };
101 }; 105 };
102 106
103 # possibly queue up other requests, or open GUI windows, 107 # possibly queue up other requests, or open GUI windows,
104 # check for sockets etc. etc. 108 # check for sockets etc. etc.
105 109
106 # process events as long as there are some: 110 # process events as long as there are some:
107 EV::loop; 111 EV::run;
108 112
109=head1 REQUEST ANATOMY AND LIFETIME 113=head1 REQUEST ANATOMY AND LIFETIME
110 114
111Every C<aio_*> function creates a request. which is a C data structure not 115Every C<aio_*> function creates a request. which is a C data structure not
112directly visible to Perl. 116directly visible to Perl.
… …
167use common::sense; 171use common::sense;
168 172
169use base 'Exporter'; 173use base 'Exporter';
170 174
171BEGIN { 175BEGIN {
172 our $VERSION = 4.32; 176 our $VERSION = 4.79;
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_sync 180 aio_scandir aio_symlink aio_readlink aio_realpath aio_fcntl aio_ioctl
177 aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range aio_allocate 181 aio_sync aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range
178 aio_pathsync aio_readahead aio_fiemap 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
198
199 accept4 tee splice pipe2 pipesize
200 fexecve mount umount memfd_create eventfd
201 timerfd_create timerfd_settime timerfd_gettime
202 pidfd_open pidfd_send_signal pidfd_getfd);
193 203
194 push @AIO_REQ, qw(aio_busy); # not exported 204 push @AIO_REQ, qw(aio_busy); # not exported
195 205
196 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 206 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
197 207
… …
229 aio_link $srcpath, $dstpath, $callback->($status) 239 aio_link $srcpath, $dstpath, $callback->($status)
230 aio_symlink $srcpath, $dstpath, $callback->($status) 240 aio_symlink $srcpath, $dstpath, $callback->($status)
231 aio_readlink $pathname, $callback->($link) 241 aio_readlink $pathname, $callback->($link)
232 aio_realpath $pathname, $callback->($path) 242 aio_realpath $pathname, $callback->($path)
233 aio_rename $srcpath, $dstpath, $callback->($status) 243 aio_rename $srcpath, $dstpath, $callback->($status)
244 aio_rename2 $srcpath, $dstpath, $flags, $callback->($status)
234 aio_mkdir $pathname, $mode, $callback->($status) 245 aio_mkdir $pathname, $mode, $callback->($status)
235 aio_rmdir $pathname, $callback->($status) 246 aio_rmdir $pathname, $callback->($status)
236 aio_readdir $pathname, $callback->($entries) 247 aio_readdir $pathname, $callback->($entries)
237 aio_readdirx $pathname, $flags, $callback->($entries, $flags) 248 aio_readdirx $pathname, $flags, $callback->($entries, $flags)
238 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST 249 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
… …
240 aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) 251 aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
241 aio_load $pathname, $data, $callback->($status) 252 aio_load $pathname, $data, $callback->($status)
242 aio_copy $srcpath, $dstpath, $callback->($status) 253 aio_copy $srcpath, $dstpath, $callback->($status)
243 aio_move $srcpath, $dstpath, $callback->($status) 254 aio_move $srcpath, $dstpath, $callback->($status)
244 aio_rmtree $pathname, $callback->($status) 255 aio_rmtree $pathname, $callback->($status)
256 aio_fcntl $fh, $cmd, $arg, $callback->($status)
257 aio_ioctl $fh, $request, $buf, $callback->($status)
245 aio_sync $callback->($status) 258 aio_sync $callback->($status)
246 aio_syncfs $fh, $callback->($status) 259 aio_syncfs $fh, $callback->($status)
247 aio_fsync $fh, $callback->($status) 260 aio_fsync $fh, $callback->($status)
248 aio_fdatasync $fh, $callback->($status) 261 aio_fdatasync $fh, $callback->($status)
249 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) 262 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
250 aio_pathsync $pathname, $callback->($status) 263 aio_pathsync $pathname, $callback->($status)
251 aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 264 aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status)
252 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 265 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
253 aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) 266 aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
254 aio_mlockall $flags, $callback->($status) 267 aio_mlockall $flags, $callback->($status)
255 aio_group $callback->(...) 268 aio_group $callback->(...)
256 aio_nop $callback->() 269 aio_nop $callback->()
… …
270 IO::AIO::idle_timeout $seconds 283 IO::AIO::idle_timeout $seconds
271 IO::AIO::max_outstanding $maxreqs 284 IO::AIO::max_outstanding $maxreqs
272 IO::AIO::nreqs 285 IO::AIO::nreqs
273 IO::AIO::nready 286 IO::AIO::nready
274 IO::AIO::npending 287 IO::AIO::npending
288 IO::AIO::reinit
289
290 $nfd = IO::AIO::get_fdlimit
291 IO::AIO::min_fdlimit $nfd
275 292
276 IO::AIO::sendfile $ofh, $ifh, $offset, $count 293 IO::AIO::sendfile $ofh, $ifh, $offset, $count
277 IO::AIO::fadvise $fh, $offset, $len, $advice 294 IO::AIO::fadvise $fh, $offset, $len, $advice
295 IO::AIO::fexecve $fh, $argv, $envp
296
278 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]] 297 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
279 IO::AIO::munmap $scalar 298 IO::AIO::munmap $scalar
299 IO::AIO::mremap $scalar, $new_length, $flags[, $new_address]
280 IO::AIO::madvise $scalar, $offset, $length, $advice 300 IO::AIO::madvise $scalar, $offset, $length, $advice
281 IO::AIO::mprotect $scalar, $offset, $length, $protect 301 IO::AIO::mprotect $scalar, $offset, $length, $protect
282 IO::AIO::munlock $scalar, $offset = 0, $length = undef 302 IO::AIO::munlock $scalar, $offset = 0, $length = undef
283 IO::AIO::munlockall 303 IO::AIO::munlockall
304
305 # stat extensions
306 $counter = IO::AIO::st_gen
307 $seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime, IO::AIO::st_btime
308 ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtime
309 $nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec, IO::AIO::st_ctimensec, IO::AIO::st_btimensec
310 $seconds = IO::AIO::st_btimesec
311 ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtimensec
312
313 # very much unportable syscalls
314 IO::AIO::accept4 $r_fh, $sockaddr, $sockaddr_len, $flags
315 IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
316 IO::AIO::tee $r_fh, $w_fh, $length, $flags
317
318 $actual_size = IO::AIO::pipesize $r_fh[, $new_size]
319 ($rfh, $wfh) = IO::AIO::pipe2 [$flags]
320
321 $fh = IO::AIO::eventfd [$initval, [$flags]]
322 $fh = IO::AIO::memfd_create $pathname[, $flags]
323
324 $fh = IO::AIO::timerfd_create $clockid[, $flags]
325 ($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags, $new_interval, $nbw_value
326 ($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh
327
328 $fh = IO::AIO::pidfd_open $pid[, $flags]
329 $status = IO::AIO::pidfd_send_signal $pidfh, $signal[, $siginfo[, $flags]]
330 $fh = IO::AIO::pidfd_getfd $pidfh, $targetfd[, $flags]
331
332 $retval = IO::AIO::mount $special, $path, $fstype, $flags = 0, $data = undef
333 $retval = IO::AIO::umount $path, $flags = 0
284 334
285=head2 API NOTES 335=head2 API NOTES
286 336
287All the C<aio_*> calls are more or less thin wrappers around the syscall 337All the C<aio_*> calls are more or less thin wrappers around the syscall
288with the same name (sans C<aio_>). The arguments are similar or identical, 338with the same name (sans C<aio_>). The arguments are similar or identical,
… …
394following POSIX and non-POSIX constants are available (missing ones on 444following POSIX and non-POSIX constants are available (missing ones on
395your system are, as usual, C<0>): 445your system are, as usual, C<0>):
396 446
397C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>, 447C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,
398C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>, 448C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,
399C<O_RSYNC>, C<O_SYNC>, C<O_PATH>, C<O_TMPFILE>, and C<O_TTY_INIT>. 449C<O_RSYNC>, C<O_SYNC>, C<O_PATH>, C<O_TMPFILE>, C<O_TTY_INIT> and C<O_ACCMODE>.
400 450
401 451
402=item aio_close $fh, $callback->($status) 452=item aio_close $fh, $callback->($status)
403 453
404Asynchronously close a file and call the callback with the result 454Asynchronously close a file and call the callback with the result
… …
439=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 489=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
440 490
441=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 491=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
442 492
443Reads or writes C<$length> bytes from or to the specified C<$fh> and 493Reads or writes C<$length> bytes from or to the specified C<$fh> and
444C<$offset> into the scalar given by C<$data> and offset C<$dataoffset> 494C<$offset> into the scalar given by C<$data> and offset C<$dataoffset> and
445and calls the callback without the actual number of bytes read (or -1 on 495calls the callback with the actual number of bytes transferred (or -1 on
446error, just like the syscall). 496error, just like the syscall).
447 497
448C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to 498C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
449offset plus the actual number of bytes read. 499offset plus the actual number of bytes read.
450 500
… …
508As native sendfile syscalls (as practically any non-POSIX interface hacked 558As native sendfile syscalls (as practically any non-POSIX interface hacked
509together in a hurry to improve benchmark numbers) tend to be rather buggy 559together in a hurry to improve benchmark numbers) tend to be rather buggy
510on many systems, this implementation tries to work around some known bugs 560on many systems, this implementation tries to work around some known bugs
511in Linux and FreeBSD kernels (probably others, too), but that might fail, 561in Linux and FreeBSD kernels (probably others, too), but that might fail,
512so you really really should check the return value of C<aio_sendfile> - 562so you really really should check the return value of C<aio_sendfile> -
513fewre bytes than expected might have been transferred. 563fewer bytes than expected might have been transferred.
514 564
515 565
516=item aio_readahead $fh,$offset,$length, $callback->($retval) 566=item aio_readahead $fh,$offset,$length, $callback->($retval)
517 567
518C<aio_readahead> populates the page cache with data from a file so that 568C<aio_readahead> populates the page cache with data from a file so that
… …
522whole pages, so that offset is effectively rounded down to a page boundary 572whole pages, so that offset is effectively rounded down to a page boundary
523and bytes are read up to the next page boundary greater than or equal to 573and bytes are read up to the next page boundary greater than or equal to
524(off-set+length). C<aio_readahead> does not read beyond the end of the 574(off-set+length). C<aio_readahead> does not read beyond the end of the
525file. The current file offset of the file is left unchanged. 575file. The current file offset of the file is left unchanged.
526 576
527If that syscall doesn't exist (likely if your OS isn't Linux) it will be 577If that syscall doesn't exist (likely if your kernel isn't Linux) it will
528emulated by simply reading the data, which would have a similar effect. 578be emulated by simply reading the data, which would have a similar effect.
529 579
530 580
531=item aio_stat $fh_or_path, $callback->($status) 581=item aio_stat $fh_or_path, $callback->($status)
532 582
533=item aio_lstat $fh, $callback->($status) 583=item aio_lstat $fh, $callback->($status)
534 584
535Works like perl's C<stat> or C<lstat> in void context. The callback will 585Works almost exactly like perl's C<stat> or C<lstat> in void context. The
536be called after the stat and the results will be available using C<stat _> 586callback will be called after the stat and the results will be available
537or C<-s _> etc... 587using C<stat _> or C<-s _> and other tests (with the exception of C<-B>
588and C<-T>).
538 589
539The pathname passed to C<aio_stat> must be absolute. See API NOTES, above, 590The pathname passed to C<aio_stat> must be absolute. See API NOTES, above,
540for an explanation. 591for an explanation.
541 592
542Currently, the stats are always 64-bit-stats, i.e. instead of returning an 593Currently, the stats are always 64-bit-stats, i.e. instead of returning an
… …
549behaviour). 600behaviour).
550 601
551C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>, 602C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>,
552C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>, 603C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>,
553C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>. 604C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>.
605
606To access higher resolution stat timestamps, see L<SUBSECOND STAT TIME
607ACCESS>.
554 608
555Example: Print the length of F</etc/passwd>: 609Example: Print the length of F</etc/passwd>:
556 610
557 aio_stat "/etc/passwd", sub { 611 aio_stat "/etc/passwd", sub {
558 $_[0] and die "stat failed: $!"; 612 $_[0] and die "stat failed: $!";
… …
602 namemax => 255, 656 namemax => 255,
603 frsize => 1024, 657 frsize => 1024,
604 fsid => 1810 658 fsid => 1810
605 } 659 }
606 660
607Here is a (likely partial - send me updates!) list of fsid values used by
608Linux - it is safe to hardcode these when C<$^O> is C<linux>:
609
610 0x0000adf5 adfs
611 0x0000adff affs
612 0x5346414f afs
613 0x09041934 anon-inode filesystem
614 0x00000187 autofs
615 0x42465331 befs
616 0x1badface bfs
617 0x42494e4d binfmt_misc
618 0x9123683e btrfs
619 0x0027e0eb cgroupfs
620 0xff534d42 cifs
621 0x73757245 coda
622 0x012ff7b7 coh
623 0x28cd3d45 cramfs
624 0x453dcd28 cramfs-wend (wrong endianness)
625 0x64626720 debugfs
626 0x00001373 devfs
627 0x00001cd1 devpts
628 0x0000f15f ecryptfs
629 0x00414a53 efs
630 0x0000137d ext
631 0x0000ef53 ext2/ext3
632 0x0000ef51 ext2
633 0x00004006 fat
634 0x65735546 fuseblk
635 0x65735543 fusectl
636 0x0bad1dea futexfs
637 0x01161970 gfs2
638 0x47504653 gpfs
639 0x00004244 hfs
640 0xf995e849 hpfs
641 0x958458f6 hugetlbfs
642 0x2bad1dea inotifyfs
643 0x00009660 isofs
644 0x000072b6 jffs2
645 0x3153464a jfs
646 0x6b414653 k-afs
647 0x0bd00bd0 lustre
648 0x0000137f minix
649 0x0000138f minix 30 char names
650 0x00002468 minix v2
651 0x00002478 minix v2 30 char names
652 0x00004d5a minix v3
653 0x19800202 mqueue
654 0x00004d44 msdos
655 0x0000564c novell
656 0x00006969 nfs
657 0x6e667364 nfsd
658 0x00003434 nilfs
659 0x5346544e ntfs
660 0x00009fa1 openprom
661 0x7461636F ocfs2
662 0x00009fa0 proc
663 0x6165676c pstorefs
664 0x0000002f qnx4
665 0x858458f6 ramfs
666 0x52654973 reiserfs
667 0x00007275 romfs
668 0x67596969 rpc_pipefs
669 0x73636673 securityfs
670 0xf97cff8c selinux
671 0x0000517b smb
672 0x534f434b sockfs
673 0x73717368 squashfs
674 0x62656572 sysfs
675 0x012ff7b6 sysv2
676 0x012ff7b5 sysv4
677 0x01021994 tmpfs
678 0x15013346 udf
679 0x00011954 ufs
680 0x54190100 ufs byteswapped
681 0x00009fa2 usbdevfs
682 0x01021997 v9fs
683 0xa501fcf5 vxfs
684 0xabba1974 xenfs
685 0x012ff7b4 xenix
686 0x58465342 xfs
687 0x012fd16d xia
688
689=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 661=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
690 662
691Works like perl's C<utime> function (including the special case of $atime 663Works like perl's C<utime> function (including the special case of $atime
692and $mtime being undef). Fractional times are supported if the underlying 664and $mtime being undef). Fractional times are supported if the underlying
693syscalls support them. 665syscalls support them.
694 666
695When called with a pathname, uses utimes(2) if available, otherwise 667When called with a pathname, uses utimensat(2) or utimes(2) if available,
696utime(2). If called on a file descriptor, uses futimes(2) if available, 668otherwise utime(2). If called on a file descriptor, uses futimens(2)
697otherwise returns ENOSYS, so this is not portable. 669or futimes(2) if available, otherwise returns ENOSYS, so this is not
670portable.
698 671
699Examples: 672Examples:
700 673
701 # set atime and mtime to current time (basically touch(1)): 674 # set atime and mtime to current time (basically touch(1)):
702 aio_utime "path", undef, undef; 675 aio_utime "path", undef, undef;
… …
730C<$mode> is usually C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> to allocate 703C<$mode> is usually C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> to allocate
731space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE | IO::AIO::FALLOC_FL_KEEP_SIZE>, 704space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE | IO::AIO::FALLOC_FL_KEEP_SIZE>,
732to deallocate a file range. 705to deallocate a file range.
733 706
734IO::AIO also supports C<FALLOC_FL_COLLAPSE_RANGE>, to remove a range 707IO::AIO also supports C<FALLOC_FL_COLLAPSE_RANGE>, to remove a range
735(without leaving a hole) and C<FALLOC_FL_ZERO_RANGE>, to zero a range (see 708(without leaving a hole), C<FALLOC_FL_ZERO_RANGE>, to zero a range,
736your L<fallocate(2)> manpage). 709C<FALLOC_FL_INSERT_RANGE> to insert a range and C<FALLOC_FL_UNSHARE_RANGE>
710to unshare shared blocks (see your L<fallocate(2)> manpage).
737 711
738The file system block size used by C<fallocate> is presumably the 712The file system block size used by C<fallocate> is presumably the
739C<f_bsize> returned by C<statvfs>. 713C<f_bsize> returned by C<statvfs>, but different filesystems and filetypes
714can dictate other limitations.
740 715
741If C<fallocate> isn't available or cannot be emulated (currently no 716If C<fallocate> isn't available or cannot be emulated (currently no
742emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>. 717emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>.
743 718
744 719
… …
803On systems that support the AIO::WD working directory abstraction 778On systems that support the AIO::WD working directory abstraction
804natively, the case C<[$wd, "."]> as C<$srcpath> is specialcased - instead 779natively, the case C<[$wd, "."]> as C<$srcpath> is specialcased - instead
805of failing, C<rename> is called on the absolute path of C<$wd>. 780of failing, C<rename> is called on the absolute path of C<$wd>.
806 781
807 782
783=item aio_rename2 $srcpath, $dstpath, $flags, $callback->($status)
784
785Basically a version of C<aio_rename> with an additional C<$flags>
786argument. Calling this with C<$flags=0> is the same as calling
787C<aio_rename>.
788
789Non-zero flags are currently only supported on GNU/Linux systems that
790support renameat2. Other systems fail with C<ENOSYS> in this case.
791
792The following constants are available (missing ones are, as usual C<0>),
793see renameat2(2) for details:
794
795C<IO::AIO::RENAME_NOREPLACE>, C<IO::AIO::RENAME_EXCHANGE>
796and C<IO::AIO::RENAME_WHITEOUT>.
797
798
808=item aio_mkdir $pathname, $mode, $callback->($status) 799=item aio_mkdir $pathname, $mode, $callback->($status)
809 800
810Asynchronously mkdir (create) a directory and call the callback with 801Asynchronously mkdir (create) a directory and call the callback with
811the result code. C<$mode> will be modified by the umask at the time the 802the result code. C<$mode> will be modified by the umask at the time the
812request is executed, so do not change your umask. 803request is executed, so do not change your umask.
… …
843 834
844=over 4 835=over 4
845 836
846=item IO::AIO::READDIR_DENTS 837=item IO::AIO::READDIR_DENTS
847 838
848When this flag is off, then the callback gets an arrayref consisting of 839Normally the callback gets an arrayref consisting of names only (as
849names only (as with C<aio_readdir>), otherwise it gets an arrayref with 840with C<aio_readdir>). If this flag is set, then the callback gets an
850C<[$name, $type, $inode]> arrayrefs, each describing a single directory 841arrayref with C<[$name, $type, $inode]> arrayrefs, each describing a
851entry in more detail. 842single directory entry in more detail:
852 843
853C<$name> is the name of the entry. 844C<$name> is the name of the entry.
854 845
855C<$type> is one of the C<IO::AIO::DT_xxx> constants: 846C<$type> is one of the C<IO::AIO::DT_xxx> constants:
856 847
857C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>, 848C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
858C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>, 849C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
859C<IO::AIO::DT_WHT>. 850C<IO::AIO::DT_WHT>.
860 851
861C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to 852C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need
862know, you have to run stat yourself. Also, for speed reasons, the C<$type> 853to know, you have to run stat yourself. Also, for speed/memory reasons,
863scalars are read-only: you can not modify them. 854the C<$type> scalars are read-only: you must not modify them.
864 855
865C<$inode> is the inode number (which might not be exact on systems with 64 856C<$inode> is the inode number (which might not be exact on systems with 64
866bit inode numbers and 32 bit perls). This field has unspecified content on 857bit inode numbers and 32 bit perls). This field has unspecified content on
867systems that do not deliver the inode information. 858systems that do not deliver the inode information.
868 859
… …
879short names are tried first. 870short names are tried first.
880 871
881=item IO::AIO::READDIR_STAT_ORDER 872=item IO::AIO::READDIR_STAT_ORDER
882 873
883When this flag is set, then the names will be returned in an order 874When this flag is set, then the names will be returned in an order
884suitable for stat()'ing each one. That is, when you plan to stat() 875suitable for stat()'ing each one. That is, when you plan to stat() most or
885all files in the given directory, then the returned order will likely 876all files in the given directory, then the returned order will likely be
886be fastest. 877faster.
887 878
888If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then 879If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified,
889the likely dirs come first, resulting in a less optimal stat order. 880then the likely dirs come first, resulting in a less optimal stat order
881for stat'ing all entries, but likely a more optimal order for finding
882subdirectories.
890 883
891=item IO::AIO::READDIR_FOUND_UNKNOWN 884=item IO::AIO::READDIR_FOUND_UNKNOWN
892 885
893This flag should not be set when calling C<aio_readdirx>. Instead, it 886This flag should not be set when calling C<aio_readdirx>. Instead, it
894is being set by C<aio_readdirx>, when any of the C<$type>'s found were 887is being set by C<aio_readdirx>, when any of the C<$type>'s found were
… …
896C<$type>'s are known, which can be used to speed up some algorithms. 889C<$type>'s are known, which can be used to speed up some algorithms.
897 890
898=back 891=back
899 892
900 893
894=item aio_slurp $pathname, $offset, $length, $data, $callback->($status)
895
896Opens, reads and closes the given file. The data is put into C<$data>,
897which is resized as required.
898
899If C<$offset> is negative, then it is counted from the end of the file.
900
901If C<$length> is zero, then the remaining length of the file is
902used. Also, in this case, the same limitations to modifying C<$data> apply
903as when IO::AIO::mmap is used, i.e. it must only be modified in-place
904with C<substr>. If the size of the file is known, specifying a non-zero
905C<$length> results in a performance advantage.
906
907This request is similar to the older C<aio_load> request, but since it is
908a single request, it might be more efficient to use.
909
910Example: load F</etc/passwd> into C<$passwd>.
911
912 my $passwd;
913 aio_slurp "/etc/passwd", 0, 0, $passwd, sub {
914 $_[0] >= 0
915 or die "/etc/passwd: $!\n";
916
917 printf "/etc/passwd is %d bytes long, and contains:\n", length $passwd;
918 print $passwd;
919 };
920 IO::AIO::flush;
921
922
901=item aio_load $pathname, $data, $callback->($status) 923=item aio_load $pathname, $data, $callback->($status)
902 924
903This is a composite request that tries to fully load the given file into 925This is a composite request that tries to fully load the given file into
904memory. Status is the same as with aio_read. 926memory. Status is the same as with aio_read.
927
928Using C<aio_slurp> might be more efficient, as it is a single request.
905 929
906=cut 930=cut
907 931
908sub aio_load($$;$) { 932sub aio_load($$;$) {
909 my ($path, undef, $cb) = @_; 933 my ($path, undef, $cb) = @_;
… …
929=item aio_copy $srcpath, $dstpath, $callback->($status) 953=item aio_copy $srcpath, $dstpath, $callback->($status)
930 954
931Try to copy the I<file> (directories not supported as either source or 955Try to copy the I<file> (directories not supported as either source or
932destination) from C<$srcpath> to C<$dstpath> and call the callback with 956destination) from C<$srcpath> to C<$dstpath> and call the callback with
933a status of C<0> (ok) or C<-1> (error, see C<$!>). 957a status of C<0> (ok) or C<-1> (error, see C<$!>).
958
959Existing destination files will be truncated.
934 960
935This is a composite request that creates the destination file with 961This is a composite request that creates the destination file with
936mode 0200 and copies the contents of the source file into it using 962mode 0200 and copies the contents of the source file into it using
937C<aio_sendfile>, followed by restoring atime, mtime, access mode and 963C<aio_sendfile>, followed by restoring atime, mtime, access mode and
938uid/gid, in that order. 964uid/gid, in that order.
… …
1048Scans a directory (similar to C<aio_readdir>) but additionally tries to 1074Scans a directory (similar to C<aio_readdir>) but additionally tries to
1049efficiently separate the entries of directory C<$path> into two sets of 1075efficiently separate the entries of directory C<$path> into two sets of
1050names, directories you can recurse into (directories), and ones you cannot 1076names, directories you can recurse into (directories), and ones you cannot
1051recurse into (everything else, including symlinks to directories). 1077recurse into (everything else, including symlinks to directories).
1052 1078
1053C<aio_scandir> is a composite request that creates of many sub requests_ 1079C<aio_scandir> is a composite request that generates many sub requests.
1054C<$maxreq> specifies the maximum number of outstanding aio requests that 1080C<$maxreq> specifies the maximum number of outstanding aio requests that
1055this function generates. If it is C<< <= 0 >>, then a suitable default 1081this function generates. If it is C<< <= 0 >>, then a suitable default
1056will be chosen (currently 4). 1082will be chosen (currently 4).
1057 1083
1058On error, the callback is called without arguments, otherwise it receives 1084On error, the callback is called without arguments, otherwise it receives
… …
1122 aioreq_pri $pri; 1148 aioreq_pri $pri;
1123 add $grp aio_stat $wd, sub { 1149 add $grp aio_stat $wd, sub {
1124 return $grp->result () if $_[0]; 1150 return $grp->result () if $_[0];
1125 my $now = time; 1151 my $now = time;
1126 my $hash1 = join ":", (stat _)[0,1,3,7,9]; 1152 my $hash1 = join ":", (stat _)[0,1,3,7,9];
1153 my $rdxflags = READDIR_DIRS_FIRST;
1154
1155 if ((stat _)[3] < 2) {
1156 # at least one non-POSIX filesystem exists
1157 # that returns useful DT_type values: btrfs,
1158 # so optimise for this here by requesting dents
1159 $rdxflags |= READDIR_DENTS;
1160 }
1127 1161
1128 # read the directory entries 1162 # read the directory entries
1129 aioreq_pri $pri; 1163 aioreq_pri $pri;
1130 add $grp aio_readdirx $wd, READDIR_DIRS_FIRST, sub { 1164 add $grp aio_readdirx $wd, $rdxflags, sub {
1131 my $entries = shift 1165 my ($entries, $flags) = @_
1132 or return $grp->result (); 1166 or return $grp->result ();
1167
1168 if ($rdxflags & READDIR_DENTS) {
1169 # if we requested type values, see if we can use them directly.
1170
1171 # if there were any DT_UNKNOWN entries then we assume we
1172 # don't know. alternatively, we could assume that if we get
1173 # one DT_DIR, then all directories are indeed marked with
1174 # DT_DIR, but this seems not required for btrfs, and this
1175 # is basically the "btrfs can't get it's act together" code
1176 # branch.
1177 unless ($flags & READDIR_FOUND_UNKNOWN) {
1178 # now we have valid DT_ information for all entries,
1179 # so use it as an optimisation without further stat's.
1180 # they must also all be at the beginning of @$entries
1181 # by now.
1182
1183 my $dirs;
1184
1185 if (@$entries) {
1186 for (0 .. $#$entries) {
1187 if ($entries->[$_][1] != DT_DIR) {
1188 # splice out directories
1189 $dirs = [splice @$entries, 0, $_];
1190 last;
1191 }
1192 }
1193
1194 # if we didn't find any non-dir, then all entries are dirs
1195 unless ($dirs) {
1196 ($dirs, $entries) = ($entries, []);
1197 }
1198 } else {
1199 # directory is empty, so there are no sbdirs
1200 $dirs = [];
1201 }
1202
1203 # either splice'd the directories out or the dir was empty.
1204 # convert dents to filenames
1205 $_ = $_->[0] for @$dirs;
1206 $_ = $_->[0] for @$entries;
1207
1208 return $grp->result ($dirs, $entries);
1209 }
1210
1211 # cannot use, so return to our old ways
1212 # by pretending we only scanned for names.
1213 $_ = $_->[0] for @$entries;
1214 }
1133 1215
1134 # stat the dir another time 1216 # stat the dir another time
1135 aioreq_pri $pri; 1217 aioreq_pri $pri;
1136 add $grp aio_stat $wd, sub { 1218 add $grp aio_stat $wd, sub {
1137 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 1219 my $hash2 = join ":", (stat _)[0,1,3,7,9];
… …
1224 }; 1306 };
1225 1307
1226 $grp 1308 $grp
1227} 1309}
1228 1310
1311=item aio_fcntl $fh, $cmd, $arg, $callback->($status)
1312
1313=item aio_ioctl $fh, $request, $buf, $callback->($status)
1314
1315These work just like the C<fcntl> and C<ioctl> built-in functions, except
1316they execute asynchronously and pass the return value to the callback.
1317
1318Both calls can be used for a lot of things, some of which make more sense
1319to run asynchronously in their own thread, while some others make less
1320sense. For example, calls that block waiting for external events, such
1321as locking, will also lock down an I/O thread while it is waiting, which
1322can deadlock the whole I/O system. At the same time, there might be no
1323alternative to using a thread to wait.
1324
1325So in general, you should only use these calls for things that do
1326(filesystem) I/O, not for things that wait for other events (network,
1327other processes), although if you are careful and know what you are doing,
1328you still can.
1329
1330The following constants are available and can be used for normal C<ioctl>
1331and C<fcntl> as well (missing ones are, as usual C<0>):
1332
1333C<F_DUPFD_CLOEXEC>,
1334
1335C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>,
1336
1337C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>.
1338
1339C<F_ADD_SEALS>, C<F_GET_SEALS>, C<F_SEAL_SEAL>, C<F_SEAL_SHRINK>, C<F_SEAL_GROW> and
1340C<F_SEAL_WRITE>.
1341
1342C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>,
1343C<FS_IOC_FIEMAP>.
1344
1345C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>,
1346C<FS_IOC_GET_ENCRYPTION_PWSALT>, C<FS_IOC_GET_ENCRYPTION_POLICY>, C<FS_KEY_DESCRIPTOR_SIZE>.
1347
1348C<FS_SECRM_FL>, C<FS_UNRM_FL>, C<FS_COMPR_FL>, C<FS_SYNC_FL>, C<FS_IMMUTABLE_FL>,
1349C<FS_APPEND_FL>, C<FS_NODUMP_FL>, C<FS_NOATIME_FL>, C<FS_DIRTY_FL>,
1350C<FS_COMPRBLK_FL>, C<FS_NOCOMP_FL>, C<FS_ENCRYPT_FL>, C<FS_BTREE_FL>,
1351C<FS_INDEX_FL>, C<FS_JOURNAL_DATA_FL>, C<FS_NOTAIL_FL>, C<FS_DIRSYNC_FL>, C<FS_TOPDIR_FL>,
1352C<FS_FL_USER_MODIFIABLE>.
1353
1354C<FS_XFLAG_REALTIME>, C<FS_XFLAG_PREALLOC>, C<FS_XFLAG_IMMUTABLE>, C<FS_XFLAG_APPEND>,
1355C<FS_XFLAG_SYNC>, C<FS_XFLAG_NOATIME>, C<FS_XFLAG_NODUMP>, C<FS_XFLAG_RTINHERIT>,
1356C<FS_XFLAG_PROJINHERIT>, C<FS_XFLAG_NOSYMLINKS>, C<FS_XFLAG_EXTSIZE>, C<FS_XFLAG_EXTSZINHERIT>,
1357C<FS_XFLAG_NODEFRAG>, C<FS_XFLAG_FILESTREAM>, C<FS_XFLAG_DAX>, C<FS_XFLAG_HASATTR>,
1358
1359C<BLKROSET>, C<BLKROGET>, C<BLKRRPART>, C<BLKGETSIZE>, C<BLKFLSBUF>, C<BLKRASET>,
1360C<BLKRAGET>, C<BLKFRASET>, C<BLKFRAGET>, C<BLKSECTSET>, C<BLKSECTGET>, C<BLKSSZGET>,
1361C<BLKBSZGET>, C<BLKBSZSET>, C<BLKGETSIZE64>,
1362
1363
1229=item aio_sync $callback->($status) 1364=item aio_sync $callback->($status)
1230 1365
1231Asynchronously call sync and call the callback when finished. 1366Asynchronously call sync and call the callback when finished.
1232 1367
1233=item aio_fsync $fh, $callback->($status) 1368=item aio_fsync $fh, $callback->($status)
… …
1301 }; 1436 };
1302 1437
1303 $grp 1438 $grp
1304} 1439}
1305 1440
1306=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 1441=item aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status)
1307 1442
1308This is a rather advanced IO::AIO call, which only works on mmap(2)ed 1443This is a rather advanced IO::AIO call, which only works on mmap(2)ed
1309scalars (see the C<IO::AIO::mmap> function, although it also works on data 1444scalars (see the C<IO::AIO::mmap> function, although it also works on data
1310scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the 1445scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
1311scalar must only be modified in-place while an aio operation is pending on 1446scalar must only be modified in-place while an aio operation is pending on
… …
1313 1448
1314It calls the C<msync> function of your OS, if available, with the memory 1449It calls the C<msync> function of your OS, if available, with the memory
1315area starting at C<$offset> in the string and ending C<$length> bytes 1450area starting at C<$offset> in the string and ending C<$length> bytes
1316later. If C<$length> is negative, counts from the end, and if C<$length> 1451later. If C<$length> is negative, counts from the end, and if C<$length>
1317is C<undef>, then it goes till the end of the string. The flags can be 1452is C<undef>, then it goes till the end of the string. The flags can be
1318a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and 1453either C<IO::AIO::MS_ASYNC> or C<IO::AIO::MS_SYNC>, plus an optional
1319C<IO::AIO::MS_SYNC>. 1454C<IO::AIO::MS_INVALIDATE>.
1320 1455
1321=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 1456=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1322 1457
1323This is a rather advanced IO::AIO call, which works best on mmap(2)ed 1458This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1324scalars. 1459scalars.
… …
1354 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh; 1489 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
1355 aio_mlock $data; # mlock in background 1490 aio_mlock $data; # mlock in background
1356 1491
1357=item aio_mlockall $flags, $callback->($status) 1492=item aio_mlockall $flags, $callback->($status)
1358 1493
1359Calls the C<mlockall> function with the given C<$flags> (a combination of 1494Calls the C<mlockall> function with the given C<$flags> (a
1360C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>). 1495combination of C<IO::AIO::MCL_CURRENT>, C<IO::AIO::MCL_FUTURE> and
1496C<IO::AIO::MCL_ONFAULT>).
1361 1497
1362On systems that do not implement C<mlockall>, this function returns C<-1> 1498On systems that do not implement C<mlockall>, this function returns C<-1>
1363and sets errno to C<ENOSYS>. 1499and sets errno to C<ENOSYS>. Similarly, flag combinations not supported
1500by the system result in a return value of C<-1> with errno being set to
1501C<EINVAL>.
1364 1502
1365Note that the corresponding C<munlockall> is synchronous and is 1503Note that the corresponding C<munlockall> is synchronous and is
1366documented under L<MISCELLANEOUS FUNCTIONS>. 1504documented under L<MISCELLANEOUS FUNCTIONS>.
1367 1505
1368Example: asynchronously lock all current and future pages into memory. 1506Example: asynchronously lock all current and future pages into memory.
… …
1407C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>, 1545C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
1408C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>, 1546C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
1409C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or 1547C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
1410C<IO::AIO::FIEMAP_EXTENT_SHARED>. 1548C<IO::AIO::FIEMAP_EXTENT_SHARED>.
1411 1549
1412At the time of this writing (Linux 3.2), this requets is unreliable unless 1550At the time of this writing (Linux 3.2), this request is unreliable unless
1413C<$count> is C<undef>, as the kernel has all sorts of bugs preventing 1551C<$count> is C<undef>, as the kernel has all sorts of bugs preventing
1414it to return all extents of a range for files with large number of 1552it to return all extents of a range for files with a large number of
1415extents. The code works around all these issues if C<$count> is undef. 1553extents. The code (only) works around all these issues if C<$count> is
1554C<undef>.
1416 1555
1417=item aio_group $callback->(...) 1556=item aio_group $callback->(...)
1418 1557
1419This is a very special aio request: Instead of doing something, it is a 1558This is a very special aio request: Instead of doing something, it is a
1420container for other aio requests, which is useful if you want to bundle 1559container for other aio requests, which is useful if you want to bundle
… …
1533There are some caveats: when directories get renamed (or deleted), the 1672There are some caveats: when directories get renamed (or deleted), the
1534pathname string doesn't change, so will point to the new directory (or 1673pathname string doesn't change, so will point to the new directory (or
1535nowhere at all), while the directory fd, if available on the system, 1674nowhere at all), while the directory fd, if available on the system,
1536will still point to the original directory. Most functions accepting a 1675will still point to the original directory. Most functions accepting a
1537pathname will use the directory fd on newer systems, and the string on 1676pathname will use the directory fd on newer systems, and the string on
1538older systems. Some functions (such as realpath) will always rely on the 1677older systems. Some functions (such as C<aio_realpath>) will always rely on
1539string form of the pathname. 1678the string form of the pathname.
1540 1679
1541So this functionality is mainly useful to get some protection against 1680So this functionality is mainly useful to get some protection against
1542C<chdir>, to easily get an absolute path out of a relative path for future 1681C<chdir>, to easily get an absolute path out of a relative path for future
1543reference, and to speed up doing many operations in the same directory 1682reference, and to speed up doing many operations in the same directory
1544(e.g. when stat'ing all files in a directory). 1683(e.g. when stat'ing all files in a directory).
… …
1561C<aio_wd> callback, as future requests using the value will fail in the 1700C<aio_wd> callback, as future requests using the value will fail in the
1562expected way. 1701expected way.
1563 1702
1564=item IO::AIO::CWD 1703=item IO::AIO::CWD
1565 1704
1566This is a compiletime constant (object) that represents the process 1705This is a compile time constant (object) that represents the process
1567current working directory. 1706current working directory.
1568 1707
1569Specifying this object as working directory object for a pathname is as if 1708Specifying this object as working directory object for a pathname is as if
1570the pathname would be specified directly, without a directory object. For 1709the pathname would be specified directly, without a directory object. For
1571example, these calls are functionally identical: 1710example, these calls are functionally identical:
… …
1752The default value for the limit is C<0>, but note that setting a feeder 1891The default value for the limit is C<0>, but note that setting a feeder
1753automatically bumps it up to C<2>. 1892automatically bumps it up to C<2>.
1754 1893
1755=back 1894=back
1756 1895
1896
1757=head2 SUPPORT FUNCTIONS 1897=head2 SUPPORT FUNCTIONS
1758 1898
1759=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1899=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
1760 1900
1761=over 4 1901=over 4
… …
1826Strictly equivalent to: 1966Strictly equivalent to:
1827 1967
1828 IO::AIO::poll_wait, IO::AIO::poll_cb 1968 IO::AIO::poll_wait, IO::AIO::poll_cb
1829 while IO::AIO::nreqs; 1969 while IO::AIO::nreqs;
1830 1970
1971This function can be useful at program aborts, to make sure outstanding
1972I/O has been done (C<IO::AIO> uses an C<END> block which already calls
1973this function on normal exits), or when you are merely using C<IO::AIO>
1974for its more advanced functions, rather than for async I/O, e.g.:
1975
1976 my ($dirs, $nondirs);
1977 IO::AIO::aio_scandir "/tmp", 0, sub { ($dirs, $nondirs) = @_ };
1978 IO::AIO::flush;
1979 # $dirs, $nondirs are now set
1980
1831=item IO::AIO::max_poll_reqs $nreqs 1981=item IO::AIO::max_poll_reqs $nreqs
1832 1982
1833=item IO::AIO::max_poll_time $seconds 1983=item IO::AIO::max_poll_time $seconds
1834 1984
1835These set the maximum number of requests (default C<0>, meaning infinity) 1985These set the maximum number of requests (default C<0>, meaning infinity)
… …
1861 poll => 'r', nice => 1, 2011 poll => 'r', nice => 1,
1862 cb => &IO::AIO::poll_cb); 2012 cb => &IO::AIO::poll_cb);
1863 2013
1864=back 2014=back
1865 2015
2016
1866=head3 CONTROLLING THE NUMBER OF THREADS 2017=head3 CONTROLLING THE NUMBER OF THREADS
1867 2018
1868=over 2019=over
1869 2020
1870=item IO::AIO::min_parallel $nthreads 2021=item IO::AIO::min_parallel $nthreads
… …
1931longer exceeded. 2082longer exceeded.
1932 2083
1933In other words, this setting does not enforce a queue limit, but can be 2084In other words, this setting does not enforce a queue limit, but can be
1934used to make poll functions block if the limit is exceeded. 2085used to make poll functions block if the limit is exceeded.
1935 2086
1936This is a very bad function to use in interactive programs because it 2087This is a bad function to use in interactive programs because it blocks,
1937blocks, and a bad way to reduce concurrency because it is inexact: Better 2088and a bad way to reduce concurrency because it is inexact. If you need to
2089issue many requests without being able to call a poll function on demand,
1938use an C<aio_group> together with a feed callback. 2090it is better to use an C<aio_group> together with a feed callback.
1939 2091
1940Its main use is in scripts without an event loop - when you want to stat 2092Its main use is in scripts without an event loop - when you want to stat a
1941a lot of files, you can write somehting like this: 2093lot of files, you can write something like this:
1942 2094
1943 IO::AIO::max_outstanding 32; 2095 IO::AIO::max_outstanding 32;
1944 2096
1945 for my $path (...) { 2097 for my $path (...) {
1946 aio_stat $path , ...; 2098 aio_stat $path , ...;
1947 IO::AIO::poll_cb; 2099 IO::AIO::poll_cb;
1948 } 2100 }
1949 2101
1950 IO::AIO::flush; 2102 IO::AIO::flush;
1951 2103
1952The call to C<poll_cb> inside the loop will normally return instantly, but 2104The call to C<poll_cb> inside the loop will normally return instantly,
1953as soon as more thna C<32> reqeusts are in-flight, it will block until 2105allowing the loop to progress, but as soon as more than C<32> requests
1954some requests have been handled. This keeps the loop from pushing a large 2106are in-flight, it will block until some requests have been handled. This
1955number of C<aio_stat> requests onto the queue. 2107keeps the loop from pushing a large number of C<aio_stat> requests onto
2108the queue (which, with many paths to stat, can use up a lot of memory).
1956 2109
1957The default value for C<max_outstanding> is very large, so there is no 2110The default value for C<max_outstanding> is very large, so there is no
1958practical limit on the number of outstanding requests. 2111practical limit on the number of outstanding requests.
1959 2112
1960=back 2113=back
1961 2114
2115
1962=head3 STATISTICAL INFORMATION 2116=head3 STATISTICAL INFORMATION
1963 2117
1964=over 2118=over
1965 2119
1966=item IO::AIO::nreqs 2120=item IO::AIO::nreqs
… …
1982 2136
1983Returns the number of requests currently in the pending state (executed, 2137Returns the number of requests currently in the pending state (executed,
1984but not yet processed by poll_cb). 2138but not yet processed by poll_cb).
1985 2139
1986=back 2140=back
2141
2142
2143=head3 SUBSECOND STAT TIME ACCESS
2144
2145Both C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> functions can
2146generally find access/modification and change times with subsecond time
2147accuracy of the system supports it, but perl's built-in functions only
2148return the integer part.
2149
2150The following functions return the timestamps of the most recent
2151stat with subsecond precision on most systems and work both after
2152C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> calls. Their return
2153value is only meaningful after a successful C<stat>/C<lstat> call, or
2154during/after a successful C<aio_stat>/C<aio_lstat> callback.
2155
2156This is similar to the L<Time::HiRes> C<stat> functions, but can return
2157full resolution without rounding and work with standard perl C<stat>,
2158alleviating the need to call the special C<Time::HiRes> functions, which
2159do not act like their perl counterparts.
2160
2161On operating systems or file systems where subsecond time resolution is
2162not supported or could not be detected, a fractional part of C<0> is
2163returned, so it is always safe to call these functions.
2164
2165=over 4
2166
2167=item $seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime, IO::AIO::st_btime
2168
2169Return the access, modication, change or birth time, respectively,
2170including fractional part. Due to the limited precision of floating point,
2171the accuracy on most platforms is only a bit better than milliseconds
2172for times around now - see the I<nsec> function family, below, for full
2173accuracy.
2174
2175File birth time is only available when the OS and perl support it (on
2176FreeBSD and NetBSD at the time of this writing, although support is
2177adaptive, so if your OS/perl gains support, IO::AIO can take advantage of
2178it). On systems where it isn't available, C<0> is currently returned, but
2179this might change to C<undef> in a future version.
2180
2181=item ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtime
2182
2183Returns access, modification, change and birth time all in one go, and
2184maybe more times in the future version.
2185
2186=item $nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec, IO::AIO::st_ctimensec, IO::AIO::st_btimensec
2187
2188Return the fractional access, modifcation, change or birth time, in nanoseconds,
2189as an integer in the range C<0> to C<999999999>.
2190
2191Note that no accessors are provided for access, modification and
2192change times - you need to get those from C<stat _> if required (C<int
2193IO::AIO::st_atime> and so on will I<not> generally give you the correct
2194value).
2195
2196=item $seconds = IO::AIO::st_btimesec
2197
2198The (integral) seconds part of the file birth time, if available.
2199
2200=item ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtimensec
2201
2202Like the functions above, but returns all four times in one go (and maybe
2203more in future versions).
2204
2205=item $counter = IO::AIO::st_gen
2206
2207Returns the generation counter (in practice this is just a random number)
2208of the file. This is only available on platforms which have this member in
2209their C<struct stat> (most BSDs at the time of this writing) and generally
2210only to the root usert. If unsupported, C<0> is returned, but this might
2211change to C<undef> in a future version.
2212
2213=back
2214
2215Example: print the high resolution modification time of F</etc>, using
2216C<stat>, and C<IO::AIO::aio_stat>.
2217
2218 if (stat "/etc") {
2219 printf "stat(/etc) mtime: %f\n", IO::AIO::st_mtime;
2220 }
2221
2222 IO::AIO::aio_stat "/etc", sub {
2223 $_[0]
2224 and return;
2225
2226 printf "aio_stat(/etc) mtime: %d.%09d\n", (stat _)[9], IO::AIO::st_mtimensec;
2227 };
2228
2229 IO::AIO::flush;
2230
2231Output of the awbove on my system, showing reduced and full accuracy:
2232
2233 stat(/etc) mtime: 1534043702.020808
2234 aio_stat(/etc) mtime: 1534043702.020807792
2235
1987 2236
1988=head3 MISCELLANEOUS FUNCTIONS 2237=head3 MISCELLANEOUS FUNCTIONS
1989 2238
1990IO::AIO implements some functions that are useful when you want to use 2239IO::AIO implements some functions that are useful when you want to use
1991some "Advanced I/O" function not available to in Perl, without going the 2240some "Advanced I/O" function not available to in Perl, without going the
1992"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*> 2241"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*>
1993counterpart. 2242counterpart.
1994 2243
1995=over 4 2244=over 4
2245
2246=item $retval = IO::AIO::fexecve $fh, $argv, $envp
2247
2248A more-or-less direct equivalent to the POSIX C<fexecve> functions, which
2249allows you to specify the program to be executed via a file descriptor (or
2250handle). Returns C<-1> and sets errno to C<ENOSYS> if not available.
2251
2252=item $retval = IO::AIO::mount $special, $path, $fstype, $flags = 0, $data = undef
2253
2254Calls the GNU/Linux mount syscall with the given arguments. All except
2255C<$flags> are strings, and if C<$data> is C<undef>, a C<NULL> will be
2256passed.
2257
2258The following values for C<$flags> are available:
2259
2260C<IO::AIO::MS_RDONLY>, C<IO::AIO::MS_NOSUID>, C<IO::AIO::MS_NODEV>, C<IO::AIO::MS_NOEXEC>, C<IO::AIO::MS_SYNCHRONOUS>,
2261C<IO::AIO::MS_REMOUNT>, C<IO::AIO::MS_MANDLOCK>, C<IO::AIO::MS_DIRSYNC>, C<IO::AIO::MS_NOATIME>,
2262C<IO::AIO::MS_NODIRATIME>, C<IO::AIO::MS_BIND>, C<IO::AIO::MS_MOVE>, C<IO::AIO::MS_REC>, C<IO::AIO::MS_SILENT>,
2263C<IO::AIO::MS_POSIXACL>, C<IO::AIO::MS_UNBINDABLE>, C<IO::AIO::MS_PRIVATE>, C<IO::AIO::MS_SLAVE>, C<IO::AIO::MS_SHARED>,
2264C<IO::AIO::MS_RELATIME>, C<IO::AIO::MS_KERNMOUNT>, C<IO::AIO::MS_I_VERSION>, C<IO::AIO::MS_STRICTATIME>,
2265C<IO::AIO::MS_LAZYTIME>, C<IO::AIO::MS_ACTIVE>, C<IO::AIO::MS_NOUSER>, C<IO::AIO::MS_RMT_MASK>, C<IO::AIO::MS_MGC_VAL> and
2266C<IO::AIO::MS_MGC_MSK>.
2267
2268=item $retval = IO::AIO::umount $path, $flags = 0
2269
2270Invokes the GNU/Linux C<umount> or C<umount2> syscalls. Always calls
2271C<umount> if C<$flags> is C<0>, otherwqise always tries to call
2272C<umount2>.
2273
2274The following C<$flags> are available:
2275
2276C<IO::AIO::MNT_FORCE>, C<IO::AIO::MNT_DETACH>, C<IO::AIO::MNT_EXPIRE> and C<IO::AIO::UMOUNT_NOFOLLOW>.
2277
2278=item $numfd = IO::AIO::get_fdlimit
2279
2280Tries to find the current file descriptor limit and returns it, or
2281C<undef> and sets C<$!> in case of an error. The limit is one larger than
2282the highest valid file descriptor number.
2283
2284=item IO::AIO::min_fdlimit [$numfd]
2285
2286Try to increase the current file descriptor limit(s) to at least C<$numfd>
2287by changing the soft or hard file descriptor resource limit. If C<$numfd>
2288is missing, it will try to set a very high limit, although this is not
2289recommended when you know the actual minimum that you require.
2290
2291If the limit cannot be raised enough, the function makes a best-effort
2292attempt to increase the limit as much as possible, using various
2293tricks, while still failing. You can query the resulting limit using
2294C<IO::AIO::get_fdlimit>.
2295
2296If an error occurs, returns C<undef> and sets C<$!>, otherwise returns
2297true.
1996 2298
1997=item IO::AIO::sendfile $ofh, $ifh, $offset, $count 2299=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1998 2300
1999Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>, 2301Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
2000but is blocking (this makes most sense if you know the input data is 2302but is blocking (this makes most sense if you know the input data is
… …
2017=item IO::AIO::madvise $scalar, $offset, $len, $advice 2319=item IO::AIO::madvise $scalar, $offset, $len, $advice
2018 2320
2019Simply calls the C<posix_madvise> function (see its 2321Simply calls the C<posix_madvise> function (see its
2020manpage for details). The following advice constants are 2322manpage for details). The following advice constants are
2021available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>, 2323available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
2022C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>. 2324C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>,
2325C<IO::AIO::MADV_DONTNEED>.
2326
2327If C<$offset> is negative, counts from the end. If C<$length> is negative,
2328the remaining length of the C<$scalar> is used. If possible, C<$length>
2329will be reduced to fit into the C<$scalar>.
2023 2330
2024On systems that do not implement C<posix_madvise>, this function returns 2331On systems that do not implement C<posix_madvise>, this function returns
2025ENOSYS, otherwise the return value of C<posix_madvise>. 2332ENOSYS, otherwise the return value of C<posix_madvise>.
2026 2333
2027=item IO::AIO::mprotect $scalar, $offset, $len, $protect 2334=item IO::AIO::mprotect $scalar, $offset, $len, $protect
… …
2029Simply calls the C<mprotect> function on the preferably AIO::mmap'ed 2336Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
2030$scalar (see its manpage for details). The following protect 2337$scalar (see its manpage for details). The following protect
2031constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>, 2338constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
2032C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>. 2339C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
2033 2340
2341If C<$offset> is negative, counts from the end. If C<$length> is negative,
2342the remaining length of the C<$scalar> is used. If possible, C<$length>
2343will be reduced to fit into the C<$scalar>.
2344
2034On systems that do not implement C<mprotect>, this function returns 2345On systems that do not implement C<mprotect>, this function returns
2035ENOSYS, otherwise the return value of C<mprotect>. 2346ENOSYS, otherwise the return value of C<mprotect>.
2036 2347
2037=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] 2348=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
2038 2349
2039Memory-maps a file (or anonymous memory range) and attaches it to the 2350Memory-maps a file (or anonymous memory range) and attaches it to the
2040given C<$scalar>, which will act like a string scalar. Returns true on 2351given C<$scalar>, which will act like a string scalar. Returns true on
2041success, and false otherwise. 2352success, and false otherwise.
2042 2353
2354The scalar must exist, but its contents do not matter - this means you
2355cannot use a nonexistant array or hash element. When in doubt, C<undef>
2356the scalar first.
2357
2043The only operations allowed on the scalar are C<substr>/C<vec> that don't 2358The only operations allowed on the mmapped scalar are C<substr>/C<vec>,
2044change the string length, and most read-only operations such as copying it 2359which don't change the string length, and most read-only operations such
2045or searching it with regexes and so on. 2360as copying it or searching it with regexes and so on.
2046 2361
2047Anything else is unsafe and will, at best, result in memory leaks. 2362Anything else is unsafe and will, at best, result in memory leaks.
2048 2363
2049The memory map associated with the C<$scalar> is automatically removed 2364The memory map associated with the C<$scalar> is automatically removed
2050when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or 2365when the C<$scalar> is undef'd or destroyed, or when the C<IO::AIO::mmap>
2051C<IO::AIO::munmap> functions are called. 2366or C<IO::AIO::munmap> functions are called on it.
2052 2367
2053This calls the C<mmap>(2) function internally. See your system's manual 2368This calls the C<mmap>(2) function internally. See your system's manual
2054page for details on the C<$length>, C<$prot> and C<$flags> parameters. 2369page for details on the C<$length>, C<$prot> and C<$flags> parameters.
2055 2370
2056The C<$length> must be larger than zero and smaller than the actual 2371The C<$length> must be larger than zero and smaller than the actual
… …
2062C<$flags> can be a combination of 2377C<$flags> can be a combination of
2063C<IO::AIO::MAP_SHARED> or 2378C<IO::AIO::MAP_SHARED> or
2064C<IO::AIO::MAP_PRIVATE>, 2379C<IO::AIO::MAP_PRIVATE>,
2065or a number of system-specific flags (when not available, the are C<0>): 2380or a number of system-specific flags (when not available, the are C<0>):
2066C<IO::AIO::MAP_ANONYMOUS> (which is set to C<MAP_ANON> if your system only provides this constant), 2381C<IO::AIO::MAP_ANONYMOUS> (which is set to C<MAP_ANON> if your system only provides this constant),
2067C<IO::AIO::MAP_HUGETLB>,
2068C<IO::AIO::MAP_LOCKED>, 2382C<IO::AIO::MAP_LOCKED>,
2069C<IO::AIO::MAP_NORESERVE>, 2383C<IO::AIO::MAP_NORESERVE>,
2070C<IO::AIO::MAP_POPULATE>, 2384C<IO::AIO::MAP_POPULATE>,
2071C<IO::AIO::MAP_NONBLOCK>, 2385C<IO::AIO::MAP_NONBLOCK>,
2072C<IO::AIO::MAP_FIXED>, 2386C<IO::AIO::MAP_FIXED>,
2073C<IO::AIO::MAP_GROWSDOWN>, 2387C<IO::AIO::MAP_GROWSDOWN>,
2074C<IO::AIO::MAP_32BIT>, 2388C<IO::AIO::MAP_32BIT>,
2075C<IO::AIO::MAP_HUGETLB> or 2389C<IO::AIO::MAP_HUGETLB>,
2076C<IO::AIO::MAP_STACK>. 2390C<IO::AIO::MAP_STACK>,
2391C<IO::AIO::MAP_FIXED_NOREPLACE>,
2392C<IO::AIO::MAP_SHARED_VALIDATE>,
2393C<IO::AIO::MAP_SYNC> or
2394C<IO::AIO::MAP_UNINITIALIZED>.
2077 2395
2078If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed. 2396If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
2079 2397
2080C<$offset> is the offset from the start of the file - it generally must be 2398C<$offset> is the offset from the start of the file - it generally must be
2081a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>. 2399a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
… …
2095 2413
2096=item IO::AIO::munmap $scalar 2414=item IO::AIO::munmap $scalar
2097 2415
2098Removes a previous mmap and undefines the C<$scalar>. 2416Removes a previous mmap and undefines the C<$scalar>.
2099 2417
2418=item IO::AIO::mremap $scalar, $new_length, $flags = MREMAP_MAYMOVE[, $new_address = 0]
2419
2420Calls the Linux-specific mremap(2) system call. The C<$scalar> must have
2421been mapped by C<IO::AIO::mmap>, and C<$flags> must currently either be
2422C<0> or C<IO::AIO::MREMAP_MAYMOVE>.
2423
2424Returns true if successful, and false otherwise. If the underlying mmapped
2425region has changed address, then the true value has the numerical value
2426C<1>, otherwise it has the numerical value C<0>:
2427
2428 my $success = IO::AIO::mremap $mmapped, 8192, IO::AIO::MREMAP_MAYMOVE
2429 or die "mremap: $!";
2430
2431 if ($success*1) {
2432 warn "scalar has chanegd address in memory\n";
2433 }
2434
2435C<IO::AIO::MREMAP_FIXED> and the C<$new_address> argument are currently
2436implemented, but not supported and might go away in a future version.
2437
2438On systems where this call is not supported or is not emulated, this call
2439returns falls and sets C<$!> to C<ENOSYS>.
2440
2441=item IO::AIO::mlockall $flags
2442
2443Calls the C<eio_mlockall_sync> function, which is like C<aio_mlockall>,
2444but is blocking.
2445
2100=item IO::AIO::munlock $scalar, $offset = 0, $length = undef 2446=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
2101 2447
2102Calls the C<munlock> function, undoing the effects of a previous 2448Calls the C<munlock> function, undoing the effects of a previous
2103C<aio_mlock> call (see its description for details). 2449C<aio_mlock> call (see its description for details).
2104 2450
… …
2106 2452
2107Calls the C<munlockall> function. 2453Calls the C<munlockall> function.
2108 2454
2109On systems that do not implement C<munlockall>, this function returns 2455On systems that do not implement C<munlockall>, this function returns
2110ENOSYS, otherwise the return value of C<munlockall>. 2456ENOSYS, otherwise the return value of C<munlockall>.
2457
2458=item $fh = IO::AIO::accept4 $r_fh, $sockaddr, $sockaddr_maxlen, $flags
2459
2460Uses the GNU/Linux C<accept4(2)> syscall, if available, to accept a socket
2461and return the new file handle on success, or sets C<$!> and returns
2462C<undef> on error.
2463
2464The remote name of the new socket will be stored in C<$sockaddr>, which
2465will be extended to allow for at least C<$sockaddr_maxlen> octets. If the
2466socket name does not fit into C<$sockaddr_maxlen> octets, this is signaled
2467by returning a longer string in C<$sockaddr>, which might or might not be
2468truncated.
2469
2470To accept name-less sockets, use C<undef> for C<$sockaddr> and C<0> for
2471C<$sockaddr_maxlen>.
2472
2473The main reasons to use this syscall rather than portable C<accept(2)>
2474are that you can specify C<SOCK_NONBLOCK> and/or C<SOCK_CLOEXEC>
2475flags and you can accept name-less sockets by specifying C<0> for
2476C<$sockaddr_maxlen>, which is sadly not possible with perl's interface to
2477C<accept>.
2111 2478
2112=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags 2479=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
2113 2480
2114Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or 2481Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or
2115C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they 2482C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
… …
2153C<$flags> is non-zero, fails with C<ENOSYS>. 2520C<$flags> is non-zero, fails with C<ENOSYS>.
2154 2521
2155Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the 2522Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the
2156time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and 2523time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and
2157C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported. 2524C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported.
2525
2526Example: create a pipe race-free w.r.t. threads and fork:
2527
2528 my ($rfh, $wfh) = IO::AIO::pipe2 IO::AIO::O_CLOEXEC
2529 or die "pipe2: $!\n";
2530
2531=item $fh = IO::AIO::memfd_create $pathname[, $flags]
2532
2533This is a direct interface to the Linux L<memfd_create(2)> system
2534call. The (unhelpful) default for C<$flags> is C<0>, but your default
2535should be C<IO::AIO::MFD_CLOEXEC>.
2536
2537On success, the new memfd filehandle is returned, otherwise returns
2538C<undef>. If the memfd_create syscall is missing, fails with C<ENOSYS>.
2539
2540Please refer to L<memfd_create(2)> for more info on this call.
2541
2542The following C<$flags> values are available: C<IO::AIO::MFD_CLOEXEC>,
2543C<IO::AIO::MFD_ALLOW_SEALING>, C<IO::AIO::MFD_HUGETLB>,
2544C<IO::AIO::MFD_HUGETLB_2MB> and C<IO::AIO::MFD_HUGETLB_1GB>.
2545
2546Example: create a new memfd.
2547
2548 my $fh = IO::AIO::memfd_create "somenameforprocfd", IO::AIO::MFD_CLOEXEC
2549 or die "memfd_create: $!\n";
2550
2551=item $fh = IO::AIO::pidfd_open $pid[, $flags]
2552
2553This is an interface to the Linux L<pidfd_open(2)> system call. The
2554default for C<$flags> is C<0>.
2555
2556On success, a new pidfd filehandle is returned (that is already set to
2557close-on-exec), otherwise returns C<undef>. If the syscall is missing,
2558fails with C<ENOSYS>.
2559
2560Example: open pid 6341 as pidfd.
2561
2562 my $fh = IO::AIO::pidfd_open 6341
2563 or die "pidfd_open: $!\n";
2564
2565=item $status = IO::AIO::pidfd_send_signal $pidfh, $signal[, $siginfo[, $flags]]
2566
2567This is an interface to the Linux L<pidfd_send_signal> system call. The
2568default for C<$siginfo> is C<undef> and the default for C<$flags> is C<0>.
2569
2570Returns the system call status. If the syscall is missing, fails with
2571C<ENOSYS>.
2572
2573When specified, C<$siginfo> must be a reference to a hash with one or more
2574of the following members:
2575
2576=over
2577
2578=item code - the C<si_code> member
2579
2580=item pid - the C<si_pid> member
2581
2582=item uid - the C<si_uid> member
2583
2584=item value_int - the C<si_value.sival_int> member
2585
2586=item value_ptr - the C<si_value.sival_ptr> member, specified as an integer
2587
2588=back
2589
2590Example: send a SIGKILL to the specified process.
2591
2592 my $status = IO::AIO::pidfd_send_signal $pidfh, 9, undef
2593 and die "pidfd_send_signal: $!\n";
2594
2595Example: send a SIGKILL to the specified process with extra data.
2596
2597 my $status = IO::AIO::pidfd_send_signal $pidfh, 9, { code => -1, value_int => 7 }
2598 and die "pidfd_send_signal: $!\n";
2599
2600=item $fh = IO::AIO::pidfd_getfd $pidfh, $targetfd[, $flags]
2601
2602This is an interface to the Linux L<pidfd_getfd> system call. The default
2603for C<$flags> is C<0>.
2604
2605On success, returns a dup'ed copy of the target file descriptor (specified
2606as an integer) returned (that is already set to close-on-exec), otherwise
2607returns C<undef>. If the syscall is missing, fails with C<ENOSYS>.
2608
2609Example: get a copy of standard error of another process and print soemthing to it.
2610
2611 my $errfh = IO::AIO::pidfd_getfd $pidfh, 2
2612 or die "pidfd_getfd: $!\n";
2613 print $errfh "stderr\n";
2614
2615=item $fh = IO::AIO::eventfd [$initval, [$flags]]
2616
2617This is a direct interface to the Linux L<eventfd(2)> system call. The
2618(unhelpful) defaults for C<$initval> and C<$flags> are C<0> for both.
2619
2620On success, the new eventfd filehandle is returned, otherwise returns
2621C<undef>. If the eventfd syscall is missing, fails with C<ENOSYS>.
2622
2623Please refer to L<eventfd(2)> for more info on this call.
2624
2625The following symbol flag values are available: C<IO::AIO::EFD_CLOEXEC>,
2626C<IO::AIO::EFD_NONBLOCK> and C<IO::AIO::EFD_SEMAPHORE> (Linux 2.6.30).
2627
2628Example: create a new eventfd filehandle:
2629
2630 $fh = IO::AIO::eventfd 0, IO::AIO::EFD_CLOEXEC
2631 or die "eventfd: $!\n";
2632
2633=item $fh = IO::AIO::timerfd_create $clockid[, $flags]
2634
2635This is a direct interface to the Linux L<timerfd_create(2)> system
2636call. The (unhelpful) default for C<$flags> is C<0>, but your default
2637should be C<IO::AIO::TFD_CLOEXEC>.
2638
2639On success, the new timerfd filehandle is returned, otherwise returns
2640C<undef>. If the timerfd_create syscall is missing, fails with C<ENOSYS>.
2641
2642Please refer to L<timerfd_create(2)> for more info on this call.
2643
2644The following C<$clockid> values are
2645available: C<IO::AIO::CLOCK_REALTIME>, C<IO::AIO::CLOCK_MONOTONIC>
2646C<IO::AIO::CLOCK_CLOCK_BOOTTIME> (Linux 3.15)
2647C<IO::AIO::CLOCK_CLOCK_REALTIME_ALARM> (Linux 3.11) and
2648C<IO::AIO::CLOCK_CLOCK_BOOTTIME_ALARM> (Linux 3.11).
2649
2650The following C<$flags> values are available (Linux
26512.6.27): C<IO::AIO::TFD_NONBLOCK> and C<IO::AIO::TFD_CLOEXEC>.
2652
2653Example: create a new timerfd and set it to one-second repeated alarms,
2654then wait for two alarms:
2655
2656 my $fh = IO::AIO::timerfd_create IO::AIO::CLOCK_BOOTTIME, IO::AIO::TFD_CLOEXEC
2657 or die "timerfd_create: $!\n";
2658
2659 defined IO::AIO::timerfd_settime $fh, 0, 1, 1
2660 or die "timerfd_settime: $!\n";
2661
2662 for (1..2) {
2663 8 == sysread $fh, my $buf, 8
2664 or die "timerfd read failure\n";
2665
2666 printf "number of expirations (likely 1): %d\n",
2667 unpack "Q", $buf;
2668 }
2669
2670=item ($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags, $new_interval, $nbw_value
2671
2672This is a direct interface to the Linux L<timerfd_settime(2)> system
2673call. Please refer to its manpage for more info on this call.
2674
2675The new itimerspec is specified using two (possibly fractional) second
2676values, C<$new_interval> and C<$new_value>).
2677
2678On success, the current interval and value are returned (as per
2679C<timerfd_gettime>). On failure, the empty list is returned.
2680
2681The following C<$flags> values are
2682available: C<IO::AIO::TFD_TIMER_ABSTIME> and
2683C<IO::AIO::TFD_TIMER_CANCEL_ON_SET>.
2684
2685See C<IO::AIO::timerfd_create> for a full example.
2686
2687=item ($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh
2688
2689This is a direct interface to the Linux L<timerfd_gettime(2)> system
2690call. Please refer to its manpage for more info on this call.
2691
2692On success, returns the current values of interval and value for the given
2693timerfd (as potentially fractional second values). On failure, the empty
2694list is returned.
2158 2695
2159=back 2696=back
2160 2697
2161=cut 2698=cut
2162 2699
… …
2228the process will result in undefined behaviour. Calling it at any time 2765the process will result in undefined behaviour. Calling it at any time
2229will also result in any undefined (by POSIX) behaviour. 2766will also result in any undefined (by POSIX) behaviour.
2230 2767
2231=back 2768=back
2232 2769
2770=head2 LINUX-SPECIFIC CALLS
2771
2772When a call is documented as "linux-specific" then this means it
2773originated on GNU/Linux. C<IO::AIO> will usually try to autodetect the
2774availability and compatibility of such calls regardless of the platform
2775it is compiled on, so platforms such as FreeBSD which often implement
2776these calls will work. When in doubt, call them and see if they fail wth
2777C<ENOSYS>.
2778
2233=head2 MEMORY USAGE 2779=head2 MEMORY USAGE
2234 2780
2235Per-request usage: 2781Per-request usage:
2236 2782
2237Each aio request uses - depending on your architecture - around 100-200 2783Each aio request uses - depending on your architecture - around 100-200
… …
2249temporary buffers, and each thread requires a stack and other data 2795temporary buffers, and each thread requires a stack and other data
2250structures (usually around 16k-128k, depending on the OS). 2796structures (usually around 16k-128k, depending on the OS).
2251 2797
2252=head1 KNOWN BUGS 2798=head1 KNOWN BUGS
2253 2799
2254Known bugs will be fixed in the next release. 2800Known bugs will be fixed in the next release :)
2801
2802=head1 KNOWN ISSUES
2803
2804Calls that try to "import" foreign memory areas (such as C<IO::AIO::mmap>
2805or C<IO::AIO::aio_slurp>) do not work with generic lvalues, such as
2806non-created hash slots or other scalars I didn't think of. It's best to
2807avoid such and either use scalar variables or making sure that the scalar
2808exists (e.g. by storing C<undef>) and isn't "funny" (e.g. tied).
2809
2810I am not sure anything can be done about this, so this is considered a
2811known issue, rather than a bug.
2255 2812
2256=head1 SEE ALSO 2813=head1 SEE ALSO
2257 2814
2258L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a 2815L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
2259more natural syntax. 2816more natural syntax and L<IO::FDPass> for file descriptor passing.
2260 2817
2261=head1 AUTHOR 2818=head1 AUTHOR
2262 2819
2263 Marc Lehmann <schmorp@schmorp.de> 2820 Marc Lehmann <schmorp@schmorp.de>
2264 http://home.schmorp.de/ 2821 http://home.schmorp.de/

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