ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/IO-AIO/AIO.pm
(Generate patch)

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.230 by root, Fri Jul 27 17:24:06 2012 UTC vs.
Revision 1.315 by root, Mon Sep 5 00:03:32 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
68=head2 EXAMPLE 72=head2 EXAMPLE
69 73
70This is a simple example that uses the EV module and loads 74This is a simple example that uses the EV module and loads
71F</etc/passwd> asynchronously: 75F</etc/passwd> asynchronously:
72 76
73 use Fcntl;
74 use EV; 77 use EV;
75 use IO::AIO; 78 use IO::AIO;
76 79
77 # register the IO::AIO callback with EV 80 # register the IO::AIO callback with EV
78 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; 81 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
95 98
96 # file contents now in $contents 99 # file contents now in $contents
97 print $contents; 100 print $contents;
98 101
99 # exit event loop and program 102 # exit event loop and program
100 EV::unloop; 103 EV::break;
101 }; 104 };
102 }; 105 };
103 106
104 # possibly queue up other requests, or open GUI windows, 107 # possibly queue up other requests, or open GUI windows,
105 # check for sockets etc. etc. 108 # check for sockets etc. etc.
106 109
107 # process events as long as there are some: 110 # process events as long as there are some:
108 EV::loop; 111 EV::run;
109 112
110=head1 REQUEST ANATOMY AND LIFETIME 113=head1 REQUEST ANATOMY AND LIFETIME
111 114
112Every 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
113directly visible to Perl. 116directly visible to Perl.
168use common::sense; 171use common::sense;
169 172
170use base 'Exporter'; 173use base 'Exporter';
171 174
172BEGIN { 175BEGIN {
173 our $VERSION = '4.15'; 176 our $VERSION = 4.77;
174 177
175 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
176 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
177 aio_scandir aio_symlink aio_readlink aio_realpath aio_sync 180 aio_scandir aio_symlink aio_readlink aio_realpath aio_fcntl aio_ioctl
178 aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range aio_fallocate 181 aio_sync aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range
179 aio_pathsync aio_readahead aio_fiemap 182 aio_pathsync aio_readahead aio_fiemap aio_allocate
180 aio_rename aio_link aio_move aio_copy aio_group 183 aio_rename aio_rename2 aio_link aio_move aio_copy aio_group
181 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
182 aio_chmod aio_utime aio_truncate 185 aio_chmod aio_utime aio_truncate
183 aio_msync aio_mtouch aio_mlock aio_mlockall 186 aio_msync aio_mtouch aio_mlock aio_mlockall
184 aio_statvfs 187 aio_statvfs
188 aio_slurp
185 aio_wd); 189 aio_wd);
186 190
187 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); 191 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
188 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 192 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
189 min_parallel max_parallel max_idle idle_timeout 193 min_parallel max_parallel max_idle idle_timeout
190 nreqs nready npending nthreads 194 nreqs nready npending nthreads
191 max_poll_time max_poll_reqs 195 max_poll_time max_poll_reqs
192 sendfile fadvise madvise 196 sendfile fadvise madvise
193 mmap munmap munlock munlockall); 197 mmap munmap mremap munlock munlockall
198
199 accept4 tee splice pipe2 pipesize
200 fexecve memfd_create eventfd
201 timerfd_create timerfd_settime timerfd_gettime
202 pidfd_open pidfd_send_signal pidfd_getfd);
194 203
195 push @AIO_REQ, qw(aio_busy); # not exported 204 push @AIO_REQ, qw(aio_busy); # not exported
196 205
197 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 206 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
198 207
228 aio_unlink $pathname, $callback->($status) 237 aio_unlink $pathname, $callback->($status)
229 aio_mknod $pathname, $mode, $dev, $callback->($status) 238 aio_mknod $pathname, $mode, $dev, $callback->($status)
230 aio_link $srcpath, $dstpath, $callback->($status) 239 aio_link $srcpath, $dstpath, $callback->($status)
231 aio_symlink $srcpath, $dstpath, $callback->($status) 240 aio_symlink $srcpath, $dstpath, $callback->($status)
232 aio_readlink $pathname, $callback->($link) 241 aio_readlink $pathname, $callback->($link)
233 aio_realpath $pathname, $callback->($link) 242 aio_realpath $pathname, $callback->($path)
234 aio_rename $srcpath, $dstpath, $callback->($status) 243 aio_rename $srcpath, $dstpath, $callback->($status)
244 aio_rename2 $srcpath, $dstpath, $flags, $callback->($status)
235 aio_mkdir $pathname, $mode, $callback->($status) 245 aio_mkdir $pathname, $mode, $callback->($status)
236 aio_rmdir $pathname, $callback->($status) 246 aio_rmdir $pathname, $callback->($status)
237 aio_readdir $pathname, $callback->($entries) 247 aio_readdir $pathname, $callback->($entries)
238 aio_readdirx $pathname, $flags, $callback->($entries, $flags) 248 aio_readdirx $pathname, $flags, $callback->($entries, $flags)
239 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST 249 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
241 aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) 251 aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
242 aio_load $pathname, $data, $callback->($status) 252 aio_load $pathname, $data, $callback->($status)
243 aio_copy $srcpath, $dstpath, $callback->($status) 253 aio_copy $srcpath, $dstpath, $callback->($status)
244 aio_move $srcpath, $dstpath, $callback->($status) 254 aio_move $srcpath, $dstpath, $callback->($status)
245 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)
246 aio_sync $callback->($status) 258 aio_sync $callback->($status)
247 aio_syncfs $fh, $callback->($status) 259 aio_syncfs $fh, $callback->($status)
248 aio_fsync $fh, $callback->($status) 260 aio_fsync $fh, $callback->($status)
249 aio_fdatasync $fh, $callback->($status) 261 aio_fdatasync $fh, $callback->($status)
250 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) 262 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
251 aio_pathsync $pathname, $callback->($status) 263 aio_pathsync $pathname, $callback->($status)
252 aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 264 aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status)
253 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 265 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
254 aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) 266 aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
255 aio_mlockall $flags, $callback->($status) 267 aio_mlockall $flags, $callback->($status)
256 aio_group $callback->(...) 268 aio_group $callback->(...)
257 aio_nop $callback->() 269 aio_nop $callback->()
271 IO::AIO::idle_timeout $seconds 283 IO::AIO::idle_timeout $seconds
272 IO::AIO::max_outstanding $maxreqs 284 IO::AIO::max_outstanding $maxreqs
273 IO::AIO::nreqs 285 IO::AIO::nreqs
274 IO::AIO::nready 286 IO::AIO::nready
275 IO::AIO::npending 287 IO::AIO::npending
288 IO::AIO::reinit
289
290 $nfd = IO::AIO::get_fdlimit
291 IO::AIO::min_fdlimit $nfd
276 292
277 IO::AIO::sendfile $ofh, $ifh, $offset, $count 293 IO::AIO::sendfile $ofh, $ifh, $offset, $count
278 IO::AIO::fadvise $fh, $offset, $len, $advice 294 IO::AIO::fadvise $fh, $offset, $len, $advice
295 IO::AIO::fexecve $fh, $argv, $envp
296
279 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]] 297 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
280 IO::AIO::munmap $scalar 298 IO::AIO::munmap $scalar
299 IO::AIO::mremap $scalar, $new_length, $flags[, $new_address]
281 IO::AIO::madvise $scalar, $offset, $length, $advice 300 IO::AIO::madvise $scalar, $offset, $length, $advice
282 IO::AIO::mprotect $scalar, $offset, $length, $protect 301 IO::AIO::mprotect $scalar, $offset, $length, $protect
283 IO::AIO::munlock $scalar, $offset = 0, $length = undef 302 IO::AIO::munlock $scalar, $offset = 0, $length = undef
284 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]
285 331
286=head2 API NOTES 332=head2 API NOTES
287 333
288All the C<aio_*> calls are more or less thin wrappers around the syscall 334All the C<aio_*> calls are more or less thin wrappers around the syscall
289with the same name (sans C<aio_>). The arguments are similar or identical, 335with the same name (sans C<aio_>). The arguments are similar or identical,
362 408
363 409
364=item aio_open $pathname, $flags, $mode, $callback->($fh) 410=item aio_open $pathname, $flags, $mode, $callback->($fh)
365 411
366Asynchronously open or create a file and call the callback with a newly 412Asynchronously open or create a file and call the callback with a newly
367created filehandle for the file. 413created filehandle for the file (or C<undef> in case of an error).
368 414
369The pathname passed to C<aio_open> must be absolute. See API NOTES, above, 415The pathname passed to C<aio_open> must be absolute. See API NOTES, above,
370for an explanation. 416for an explanation.
371 417
372The C<$flags> argument is a bitmask. See the C<Fcntl> module for a 418The C<$flags> argument is a bitmask. See the C<Fcntl> module for a
395following POSIX and non-POSIX constants are available (missing ones on 441following POSIX and non-POSIX constants are available (missing ones on
396your system are, as usual, C<0>): 442your system are, as usual, C<0>):
397 443
398C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>, 444C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,
399C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>, 445C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,
400C<O_RSYNC>, C<O_SYNC> and C<O_TTY_INIT>. 446C<O_RSYNC>, C<O_SYNC>, C<O_PATH>, C<O_TMPFILE>, C<O_TTY_INIT> and C<O_ACCMODE>.
401 447
402 448
403=item aio_close $fh, $callback->($status) 449=item aio_close $fh, $callback->($status)
404 450
405Asynchronously close a file and call the callback with the result 451Asynchronously close a file and call the callback with the result
440=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 486=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
441 487
442=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 488=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
443 489
444Reads or writes C<$length> bytes from or to the specified C<$fh> and 490Reads or writes C<$length> bytes from or to the specified C<$fh> and
445C<$offset> into the scalar given by C<$data> and offset C<$dataoffset> 491C<$offset> into the scalar given by C<$data> and offset C<$dataoffset> and
446and calls the callback without the actual number of bytes read (or -1 on 492calls the callback with the actual number of bytes transferred (or -1 on
447error, just like the syscall). 493error, just like the syscall).
448 494
449C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to 495C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
450offset plus the actual number of bytes read. 496offset plus the actual number of bytes read.
451 497
509As native sendfile syscalls (as practically any non-POSIX interface hacked 555As native sendfile syscalls (as practically any non-POSIX interface hacked
510together in a hurry to improve benchmark numbers) tend to be rather buggy 556together in a hurry to improve benchmark numbers) tend to be rather buggy
511on many systems, this implementation tries to work around some known bugs 557on many systems, this implementation tries to work around some known bugs
512in Linux and FreeBSD kernels (probably others, too), but that might fail, 558in Linux and FreeBSD kernels (probably others, too), but that might fail,
513so you really really should check the return value of C<aio_sendfile> - 559so you really really should check the return value of C<aio_sendfile> -
514fewre bytes than expected might have been transferred. 560fewer bytes than expected might have been transferred.
515 561
516 562
517=item aio_readahead $fh,$offset,$length, $callback->($retval) 563=item aio_readahead $fh,$offset,$length, $callback->($retval)
518 564
519C<aio_readahead> populates the page cache with data from a file so that 565C<aio_readahead> populates the page cache with data from a file so that
523whole pages, so that offset is effectively rounded down to a page boundary 569whole pages, so that offset is effectively rounded down to a page boundary
524and bytes are read up to the next page boundary greater than or equal to 570and bytes are read up to the next page boundary greater than or equal to
525(off-set+length). C<aio_readahead> does not read beyond the end of the 571(off-set+length). C<aio_readahead> does not read beyond the end of the
526file. The current file offset of the file is left unchanged. 572file. The current file offset of the file is left unchanged.
527 573
528If that syscall doesn't exist (likely if your OS isn't Linux) it will be 574If that syscall doesn't exist (likely if your kernel isn't Linux) it will
529emulated by simply reading the data, which would have a similar effect. 575be emulated by simply reading the data, which would have a similar effect.
530 576
531 577
532=item aio_stat $fh_or_path, $callback->($status) 578=item aio_stat $fh_or_path, $callback->($status)
533 579
534=item aio_lstat $fh, $callback->($status) 580=item aio_lstat $fh, $callback->($status)
535 581
536Works like perl's C<stat> or C<lstat> in void context. The callback will 582Works almost exactly like perl's C<stat> or C<lstat> in void context. The
537be called after the stat and the results will be available using C<stat _> 583callback will be called after the stat and the results will be available
538or C<-s _> etc... 584using C<stat _> or C<-s _> and other tests (with the exception of C<-B>
585and C<-T>).
539 586
540The pathname passed to C<aio_stat> must be absolute. See API NOTES, above, 587The pathname passed to C<aio_stat> must be absolute. See API NOTES, above,
541for an explanation. 588for an explanation.
542 589
543Currently, the stats are always 64-bit-stats, i.e. instead of returning an 590Currently, the stats are always 64-bit-stats, i.e. instead of returning an
550behaviour). 597behaviour).
551 598
552C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>, 599C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>,
553C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>, 600C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>,
554C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>. 601C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>.
602
603To access higher resolution stat timestamps, see L<SUBSECOND STAT TIME
604ACCESS>.
555 605
556Example: Print the length of F</etc/passwd>: 606Example: Print the length of F</etc/passwd>:
557 607
558 aio_stat "/etc/passwd", sub { 608 aio_stat "/etc/passwd", sub {
559 $_[0] and die "stat failed: $!"; 609 $_[0] and die "stat failed: $!";
603 namemax => 255, 653 namemax => 255,
604 frsize => 1024, 654 frsize => 1024,
605 fsid => 1810 655 fsid => 1810
606 } 656 }
607 657
608
609=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 658=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
610 659
611Works like perl's C<utime> function (including the special case of $atime 660Works like perl's C<utime> function (including the special case of $atime
612and $mtime being undef). Fractional times are supported if the underlying 661and $mtime being undef). Fractional times are supported if the underlying
613syscalls support them. 662syscalls support them.
614 663
615When called with a pathname, uses utimes(2) if available, otherwise 664When called with a pathname, uses utimensat(2) or utimes(2) if available,
616utime(2). If called on a file descriptor, uses futimes(2) if available, 665otherwise utime(2). If called on a file descriptor, uses futimens(2)
617otherwise returns ENOSYS, so this is not portable. 666or futimes(2) if available, otherwise returns ENOSYS, so this is not
667portable.
618 668
619Examples: 669Examples:
620 670
621 # set atime and mtime to current time (basically touch(1)): 671 # set atime and mtime to current time (basically touch(1)):
622 aio_utime "path", undef, undef; 672 aio_utime "path", undef, undef;
642Works like truncate(2) or ftruncate(2). 692Works like truncate(2) or ftruncate(2).
643 693
644 694
645=item aio_allocate $fh, $mode, $offset, $len, $callback->($status) 695=item aio_allocate $fh, $mode, $offset, $len, $callback->($status)
646 696
647Allocates or freed disk space according to the C<$mode> argument. See the 697Allocates or frees disk space according to the C<$mode> argument. See the
648linux C<fallocate> docuemntation for details. 698linux C<fallocate> documentation for details.
649 699
650C<$mode> can currently be C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> 700C<$mode> is usually C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> to allocate
651to allocate space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE | 701space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE | IO::AIO::FALLOC_FL_KEEP_SIZE>,
652IO::AIO::FALLOC_FL_KEEP_SIZE>, to deallocate a file range. 702to deallocate a file range.
703
704IO::AIO also supports C<FALLOC_FL_COLLAPSE_RANGE>, to remove a range
705(without leaving a hole), C<FALLOC_FL_ZERO_RANGE>, to zero a range,
706C<FALLOC_FL_INSERT_RANGE> to insert a range and C<FALLOC_FL_UNSHARE_RANGE>
707to unshare shared blocks (see your L<fallocate(2)> manpage).
653 708
654The file system block size used by C<fallocate> is presumably the 709The file system block size used by C<fallocate> is presumably the
655C<f_bsize> returned by C<statvfs>. 710C<f_bsize> returned by C<statvfs>, but different filesystems and filetypes
711can dictate other limitations.
656 712
657If C<fallocate> isn't available or cannot be emulated (currently no 713If C<fallocate> isn't available or cannot be emulated (currently no
658emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>. 714emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>.
659 715
660 716
702 758
703 759
704=item aio_realpath $pathname, $callback->($path) 760=item aio_realpath $pathname, $callback->($path)
705 761
706Asynchronously make the path absolute and resolve any symlinks in 762Asynchronously make the path absolute and resolve any symlinks in
707C<$path>. The resulting path only consists of directories (Same as 763C<$path>. The resulting path only consists of directories (same as
708L<Cwd::realpath>). 764L<Cwd::realpath>).
709 765
710This request can be used to get the absolute path of the current working 766This request can be used to get the absolute path of the current working
711directory by passing it a path of F<.> (a single dot). 767directory by passing it a path of F<.> (a single dot).
712 768
713 769
714=item aio_rename $srcpath, $dstpath, $callback->($status) 770=item aio_rename $srcpath, $dstpath, $callback->($status)
715 771
716Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as 772Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
717rename(2) and call the callback with the result code. 773rename(2) and call the callback with the result code.
774
775On systems that support the AIO::WD working directory abstraction
776natively, the case C<[$wd, "."]> as C<$srcpath> is specialcased - instead
777of failing, C<rename> is called on the absolute path of C<$wd>.
778
779
780=item aio_rename2 $srcpath, $dstpath, $flags, $callback->($status)
781
782Basically a version of C<aio_rename> with an additional C<$flags>
783argument. Calling this with C<$flags=0> is the same as calling
784C<aio_rename>.
785
786Non-zero flags are currently only supported on GNU/Linux systems that
787support renameat2. Other systems fail with C<ENOSYS> in this case.
788
789The following constants are available (missing ones are, as usual C<0>),
790see renameat2(2) for details:
791
792C<IO::AIO::RENAME_NOREPLACE>, C<IO::AIO::RENAME_EXCHANGE>
793and C<IO::AIO::RENAME_WHITEOUT>.
718 794
719 795
720=item aio_mkdir $pathname, $mode, $callback->($status) 796=item aio_mkdir $pathname, $mode, $callback->($status)
721 797
722Asynchronously mkdir (create) a directory and call the callback with 798Asynchronously mkdir (create) a directory and call the callback with
727=item aio_rmdir $pathname, $callback->($status) 803=item aio_rmdir $pathname, $callback->($status)
728 804
729Asynchronously rmdir (delete) a directory and call the callback with the 805Asynchronously rmdir (delete) a directory and call the callback with the
730result code. 806result code.
731 807
808On systems that support the AIO::WD working directory abstraction
809natively, the case C<[$wd, "."]> is specialcased - instead of failing,
810C<rmdir> is called on the absolute path of C<$wd>.
811
732 812
733=item aio_readdir $pathname, $callback->($entries) 813=item aio_readdir $pathname, $callback->($entries)
734 814
735Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 815Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
736directory (i.e. opendir + readdir + closedir). The entries will not be 816directory (i.e. opendir + readdir + closedir). The entries will not be
751 831
752=over 4 832=over 4
753 833
754=item IO::AIO::READDIR_DENTS 834=item IO::AIO::READDIR_DENTS
755 835
756When this flag is off, then the callback gets an arrayref consisting of 836Normally the callback gets an arrayref consisting of names only (as
757names only (as with C<aio_readdir>), otherwise it gets an arrayref with 837with C<aio_readdir>). If this flag is set, then the callback gets an
758C<[$name, $type, $inode]> arrayrefs, each describing a single directory 838arrayref with C<[$name, $type, $inode]> arrayrefs, each describing a
759entry in more detail. 839single directory entry in more detail:
760 840
761C<$name> is the name of the entry. 841C<$name> is the name of the entry.
762 842
763C<$type> is one of the C<IO::AIO::DT_xxx> constants: 843C<$type> is one of the C<IO::AIO::DT_xxx> constants:
764 844
765C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>, 845C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
766C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>, 846C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
767C<IO::AIO::DT_WHT>. 847C<IO::AIO::DT_WHT>.
768 848
769C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to 849C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need
770know, you have to run stat yourself. Also, for speed reasons, the C<$type> 850to know, you have to run stat yourself. Also, for speed/memory reasons,
771scalars are read-only: you can not modify them. 851the C<$type> scalars are read-only: you must not modify them.
772 852
773C<$inode> is the inode number (which might not be exact on systems with 64 853C<$inode> is the inode number (which might not be exact on systems with 64
774bit inode numbers and 32 bit perls). This field has unspecified content on 854bit inode numbers and 32 bit perls). This field has unspecified content on
775systems that do not deliver the inode information. 855systems that do not deliver the inode information.
776 856
787short names are tried first. 867short names are tried first.
788 868
789=item IO::AIO::READDIR_STAT_ORDER 869=item IO::AIO::READDIR_STAT_ORDER
790 870
791When this flag is set, then the names will be returned in an order 871When this flag is set, then the names will be returned in an order
792suitable for stat()'ing each one. That is, when you plan to stat() 872suitable for stat()'ing each one. That is, when you plan to stat() most or
793all files in the given directory, then the returned order will likely 873all files in the given directory, then the returned order will likely be
794be fastest. 874faster.
795 875
796If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then 876If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified,
797the likely dirs come first, resulting in a less optimal stat order. 877then the likely dirs come first, resulting in a less optimal stat order
878for stat'ing all entries, but likely a more optimal order for finding
879subdirectories.
798 880
799=item IO::AIO::READDIR_FOUND_UNKNOWN 881=item IO::AIO::READDIR_FOUND_UNKNOWN
800 882
801This flag should not be set when calling C<aio_readdirx>. Instead, it 883This flag should not be set when calling C<aio_readdirx>. Instead, it
802is being set by C<aio_readdirx>, when any of the C<$type>'s found were 884is being set by C<aio_readdirx>, when any of the C<$type>'s found were
804C<$type>'s are known, which can be used to speed up some algorithms. 886C<$type>'s are known, which can be used to speed up some algorithms.
805 887
806=back 888=back
807 889
808 890
891=item aio_slurp $pathname, $offset, $length, $data, $callback->($status)
892
893Opens, reads and closes the given file. The data is put into C<$data>,
894which is resized as required.
895
896If C<$offset> is negative, then it is counted from the end of the file.
897
898If C<$length> is zero, then the remaining length of the file is
899used. Also, in this case, the same limitations to modifying C<$data> apply
900as when IO::AIO::mmap is used, i.e. it must only be modified in-place
901with C<substr>. If the size of the file is known, specifying a non-zero
902C<$length> results in a performance advantage.
903
904This request is similar to the older C<aio_load> request, but since it is
905a single request, it might be more efficient to use.
906
907Example: load F</etc/passwd> into C<$passwd>.
908
909 my $passwd;
910 aio_slurp "/etc/passwd", 0, 0, $passwd, sub {
911 $_[0] >= 0
912 or die "/etc/passwd: $!\n";
913
914 printf "/etc/passwd is %d bytes long, and contains:\n", length $passwd;
915 print $passwd;
916 };
917 IO::AIO::flush;
918
919
809=item aio_load $pathname, $data, $callback->($status) 920=item aio_load $pathname, $data, $callback->($status)
810 921
811This is a composite request that tries to fully load the given file into 922This is a composite request that tries to fully load the given file into
812memory. Status is the same as with aio_read. 923memory. Status is the same as with aio_read.
924
925Using C<aio_slurp> might be more efficient, as it is a single request.
813 926
814=cut 927=cut
815 928
816sub aio_load($$;$) { 929sub aio_load($$;$) {
817 my ($path, undef, $cb) = @_; 930 my ($path, undef, $cb) = @_;
837=item aio_copy $srcpath, $dstpath, $callback->($status) 950=item aio_copy $srcpath, $dstpath, $callback->($status)
838 951
839Try to copy the I<file> (directories not supported as either source or 952Try to copy the I<file> (directories not supported as either source or
840destination) from C<$srcpath> to C<$dstpath> and call the callback with 953destination) from C<$srcpath> to C<$dstpath> and call the callback with
841a status of C<0> (ok) or C<-1> (error, see C<$!>). 954a status of C<0> (ok) or C<-1> (error, see C<$!>).
955
956Existing destination files will be truncated.
842 957
843This is a composite request that creates the destination file with 958This is a composite request that creates the destination file with
844mode 0200 and copies the contents of the source file into it using 959mode 0200 and copies the contents of the source file into it using
845C<aio_sendfile>, followed by restoring atime, mtime, access mode and 960C<aio_sendfile>, followed by restoring atime, mtime, access mode and
846uid/gid, in that order. 961uid/gid, in that order.
956Scans a directory (similar to C<aio_readdir>) but additionally tries to 1071Scans a directory (similar to C<aio_readdir>) but additionally tries to
957efficiently separate the entries of directory C<$path> into two sets of 1072efficiently separate the entries of directory C<$path> into two sets of
958names, directories you can recurse into (directories), and ones you cannot 1073names, directories you can recurse into (directories), and ones you cannot
959recurse into (everything else, including symlinks to directories). 1074recurse into (everything else, including symlinks to directories).
960 1075
961C<aio_scandir> is a composite request that creates of many sub requests_ 1076C<aio_scandir> is a composite request that generates many sub requests.
962C<$maxreq> specifies the maximum number of outstanding aio requests that 1077C<$maxreq> specifies the maximum number of outstanding aio requests that
963this function generates. If it is C<< <= 0 >>, then a suitable default 1078this function generates. If it is C<< <= 0 >>, then a suitable default
964will be chosen (currently 4). 1079will be chosen (currently 4).
965 1080
966On error, the callback is called without arguments, otherwise it receives 1081On error, the callback is called without arguments, otherwise it receives
1030 aioreq_pri $pri; 1145 aioreq_pri $pri;
1031 add $grp aio_stat $wd, sub { 1146 add $grp aio_stat $wd, sub {
1032 return $grp->result () if $_[0]; 1147 return $grp->result () if $_[0];
1033 my $now = time; 1148 my $now = time;
1034 my $hash1 = join ":", (stat _)[0,1,3,7,9]; 1149 my $hash1 = join ":", (stat _)[0,1,3,7,9];
1150 my $rdxflags = READDIR_DIRS_FIRST;
1151
1152 if ((stat _)[3] < 2) {
1153 # at least one non-POSIX filesystem exists
1154 # that returns useful DT_type values: btrfs,
1155 # so optimise for this here by requesting dents
1156 $rdxflags |= READDIR_DENTS;
1157 }
1035 1158
1036 # read the directory entries 1159 # read the directory entries
1037 aioreq_pri $pri; 1160 aioreq_pri $pri;
1038 add $grp aio_readdirx $wd, READDIR_DIRS_FIRST, sub { 1161 add $grp aio_readdirx $wd, $rdxflags, sub {
1039 my $entries = shift 1162 my ($entries, $flags) = @_
1040 or return $grp->result (); 1163 or return $grp->result ();
1164
1165 if ($rdxflags & READDIR_DENTS) {
1166 # if we requested type values, see if we can use them directly.
1167
1168 # if there were any DT_UNKNOWN entries then we assume we
1169 # don't know. alternatively, we could assume that if we get
1170 # one DT_DIR, then all directories are indeed marked with
1171 # DT_DIR, but this seems not required for btrfs, and this
1172 # is basically the "btrfs can't get it's act together" code
1173 # branch.
1174 unless ($flags & READDIR_FOUND_UNKNOWN) {
1175 # now we have valid DT_ information for all entries,
1176 # so use it as an optimisation without further stat's.
1177 # they must also all be at the beginning of @$entries
1178 # by now.
1179
1180 my $dirs;
1181
1182 if (@$entries) {
1183 for (0 .. $#$entries) {
1184 if ($entries->[$_][1] != DT_DIR) {
1185 # splice out directories
1186 $dirs = [splice @$entries, 0, $_];
1187 last;
1188 }
1189 }
1190
1191 # if we didn't find any non-dir, then all entries are dirs
1192 unless ($dirs) {
1193 ($dirs, $entries) = ($entries, []);
1194 }
1195 } else {
1196 # directory is empty, so there are no sbdirs
1197 $dirs = [];
1198 }
1199
1200 # either splice'd the directories out or the dir was empty.
1201 # convert dents to filenames
1202 $_ = $_->[0] for @$dirs;
1203 $_ = $_->[0] for @$entries;
1204
1205 return $grp->result ($dirs, $entries);
1206 }
1207
1208 # cannot use, so return to our old ways
1209 # by pretending we only scanned for names.
1210 $_ = $_->[0] for @$entries;
1211 }
1041 1212
1042 # stat the dir another time 1213 # stat the dir another time
1043 aioreq_pri $pri; 1214 aioreq_pri $pri;
1044 add $grp aio_stat $wd, sub { 1215 add $grp aio_stat $wd, sub {
1045 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 1216 my $hash2 = join ":", (stat _)[0,1,3,7,9];
1100} 1271}
1101 1272
1102=item aio_rmtree $pathname, $callback->($status) 1273=item aio_rmtree $pathname, $callback->($status)
1103 1274
1104Delete a directory tree starting (and including) C<$path>, return the 1275Delete a directory tree starting (and including) C<$path>, return the
1105status of the final C<rmdir> only. This is a composite request that 1276status of the final C<rmdir> only. This is a composite request that
1106uses C<aio_scandir> to recurse into and rmdir directories, and unlink 1277uses C<aio_scandir> to recurse into and rmdir directories, and unlink
1107everything else. 1278everything else.
1108 1279
1109=cut 1280=cut
1110 1281
1131 add $grp $dirgrp; 1302 add $grp $dirgrp;
1132 }; 1303 };
1133 1304
1134 $grp 1305 $grp
1135} 1306}
1307
1308=item aio_fcntl $fh, $cmd, $arg, $callback->($status)
1309
1310=item aio_ioctl $fh, $request, $buf, $callback->($status)
1311
1312These work just like the C<fcntl> and C<ioctl> built-in functions, except
1313they execute asynchronously and pass the return value to the callback.
1314
1315Both calls can be used for a lot of things, some of which make more sense
1316to run asynchronously in their own thread, while some others make less
1317sense. For example, calls that block waiting for external events, such
1318as locking, will also lock down an I/O thread while it is waiting, which
1319can deadlock the whole I/O system. At the same time, there might be no
1320alternative to using a thread to wait.
1321
1322So in general, you should only use these calls for things that do
1323(filesystem) I/O, not for things that wait for other events (network,
1324other processes), although if you are careful and know what you are doing,
1325you still can.
1326
1327The following constants are available and can be used for normal C<ioctl>
1328and C<fcntl> as well (missing ones are, as usual C<0>):
1329
1330C<F_DUPFD_CLOEXEC>,
1331
1332C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>,
1333
1334C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>.
1335
1336C<F_ADD_SEALS>, C<F_GET_SEALS>, C<F_SEAL_SEAL>, C<F_SEAL_SHRINK>, C<F_SEAL_GROW> and
1337C<F_SEAL_WRITE>.
1338
1339C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>,
1340C<FS_IOC_FIEMAP>.
1341
1342C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>,
1343C<FS_IOC_GET_ENCRYPTION_PWSALT>, C<FS_IOC_GET_ENCRYPTION_POLICY>, C<FS_KEY_DESCRIPTOR_SIZE>.
1344
1345C<FS_SECRM_FL>, C<FS_UNRM_FL>, C<FS_COMPR_FL>, C<FS_SYNC_FL>, C<FS_IMMUTABLE_FL>,
1346C<FS_APPEND_FL>, C<FS_NODUMP_FL>, C<FS_NOATIME_FL>, C<FS_DIRTY_FL>,
1347C<FS_COMPRBLK_FL>, C<FS_NOCOMP_FL>, C<FS_ENCRYPT_FL>, C<FS_BTREE_FL>,
1348C<FS_INDEX_FL>, C<FS_JOURNAL_DATA_FL>, C<FS_NOTAIL_FL>, C<FS_DIRSYNC_FL>, C<FS_TOPDIR_FL>,
1349C<FS_FL_USER_MODIFIABLE>.
1350
1351C<FS_XFLAG_REALTIME>, C<FS_XFLAG_PREALLOC>, C<FS_XFLAG_IMMUTABLE>, C<FS_XFLAG_APPEND>,
1352C<FS_XFLAG_SYNC>, C<FS_XFLAG_NOATIME>, C<FS_XFLAG_NODUMP>, C<FS_XFLAG_RTINHERIT>,
1353C<FS_XFLAG_PROJINHERIT>, C<FS_XFLAG_NOSYMLINKS>, C<FS_XFLAG_EXTSIZE>, C<FS_XFLAG_EXTSZINHERIT>,
1354C<FS_XFLAG_NODEFRAG>, C<FS_XFLAG_FILESTREAM>, C<FS_XFLAG_DAX>, C<FS_XFLAG_HASATTR>,
1136 1355
1137=item aio_sync $callback->($status) 1356=item aio_sync $callback->($status)
1138 1357
1139Asynchronously call sync and call the callback when finished. 1358Asynchronously call sync and call the callback when finished.
1140 1359
1209 }; 1428 };
1210 1429
1211 $grp 1430 $grp
1212} 1431}
1213 1432
1214=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 1433=item aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status)
1215 1434
1216This is a rather advanced IO::AIO call, which only works on mmap(2)ed 1435This is a rather advanced IO::AIO call, which only works on mmap(2)ed
1217scalars (see the C<IO::AIO::mmap> function, although it also works on data 1436scalars (see the C<IO::AIO::mmap> function, although it also works on data
1218scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the 1437scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
1219scalar must only be modified in-place while an aio operation is pending on 1438scalar must only be modified in-place while an aio operation is pending on
1221 1440
1222It calls the C<msync> function of your OS, if available, with the memory 1441It calls the C<msync> function of your OS, if available, with the memory
1223area starting at C<$offset> in the string and ending C<$length> bytes 1442area starting at C<$offset> in the string and ending C<$length> bytes
1224later. If C<$length> is negative, counts from the end, and if C<$length> 1443later. If C<$length> is negative, counts from the end, and if C<$length>
1225is C<undef>, then it goes till the end of the string. The flags can be 1444is C<undef>, then it goes till the end of the string. The flags can be
1226a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and 1445either C<IO::AIO::MS_ASYNC> or C<IO::AIO::MS_SYNC>, plus an optional
1227C<IO::AIO::MS_SYNC>. 1446C<IO::AIO::MS_INVALIDATE>.
1228 1447
1229=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 1448=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1230 1449
1231This is a rather advanced IO::AIO call, which works best on mmap(2)ed 1450This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1232scalars. 1451scalars.
1233 1452
1234It touches (reads or writes) all memory pages in the specified 1453It touches (reads or writes) all memory pages in the specified
1235range inside the scalar. All caveats and parameters are the same 1454range inside the scalar. All caveats and parameters are the same
1236as for C<aio_msync>, above, except for flags, which must be either 1455as for C<aio_msync>, above, except for flags, which must be either
1237C<0> (which reads all pages and ensures they are instantiated) or 1456C<0> (which reads all pages and ensures they are instantiated) or
1238C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and 1457C<IO::AIO::MT_MODIFY>, which modifies the memory pages (by reading and
1239writing an octet from it, which dirties the page). 1458writing an octet from it, which dirties the page).
1240 1459
1241=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) 1460=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1242 1461
1243This is a rather advanced IO::AIO call, which works best on mmap(2)ed 1462This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1262 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh; 1481 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
1263 aio_mlock $data; # mlock in background 1482 aio_mlock $data; # mlock in background
1264 1483
1265=item aio_mlockall $flags, $callback->($status) 1484=item aio_mlockall $flags, $callback->($status)
1266 1485
1267Calls the C<mlockall> function with the given C<$flags> (a combination of 1486Calls the C<mlockall> function with the given C<$flags> (a
1268C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>). 1487combination of C<IO::AIO::MCL_CURRENT>, C<IO::AIO::MCL_FUTURE> and
1488C<IO::AIO::MCL_ONFAULT>).
1269 1489
1270On systems that do not implement C<mlockall>, this function returns C<-1> 1490On systems that do not implement C<mlockall>, this function returns C<-1>
1271and sets errno to C<ENOSYS>. 1491and sets errno to C<ENOSYS>. Similarly, flag combinations not supported
1492by the system result in a return value of C<-1> with errno being set to
1493C<EINVAL>.
1272 1494
1273Note that the corresponding C<munlockall> is synchronous and is 1495Note that the corresponding C<munlockall> is synchronous and is
1274documented under L<MISCELLANEOUS FUNCTIONS>. 1496documented under L<MISCELLANEOUS FUNCTIONS>.
1275 1497
1276Example: asynchronously lock all current and future pages into memory. 1498Example: asynchronously lock all current and future pages into memory.
1277 1499
1278 aio_mlockall IO::AIO::MCL_FUTURE; 1500 aio_mlockall IO::AIO::MCL_FUTURE;
1279 1501
1280=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents) 1502=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
1281 1503
1282Queries the extents of the given file (by calling the Linux FIEMAP ioctl, 1504Queries the extents of the given file (by calling the Linux C<FIEMAP>
1283see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If the 1505ioctl, see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If
1284C<ioctl> is not available on your OS, then this request will fail with 1506the ioctl is not available on your OS, then this request will fail with
1285C<ENOSYS>. 1507C<ENOSYS>.
1286 1508
1287C<$start> is the starting offset to query extents for, C<$length> is the 1509C<$start> is the starting offset to query extents for, C<$length> is the
1288size of the range to query - if it is C<undef>, then the whole file will 1510size of the range to query - if it is C<undef>, then the whole file will
1289be queried. 1511be queried.
1292C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also 1514C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also
1293exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query 1515exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query
1294the data portion. 1516the data portion.
1295 1517
1296C<$count> is the maximum number of extent records to return. If it is 1518C<$count> is the maximum number of extent records to return. If it is
1297C<undef>, then IO::AIO queries all extents of the file. As a very special 1519C<undef>, then IO::AIO queries all extents of the range. As a very special
1298case, if it is C<0>, then the callback receives the number of extents 1520case, if it is C<0>, then the callback receives the number of extents
1299instead of the extents themselves. 1521instead of the extents themselves (which is unreliable, see below).
1300 1522
1301If an error occurs, the callback receives no arguments. The special 1523If an error occurs, the callback receives no arguments. The special
1302C<errno> value C<IO::AIO::EBADR> is available to test for flag errors. 1524C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.
1303 1525
1304Otherwise, the callback receives an array reference with extent 1526Otherwise, the callback receives an array reference with extent
1306following members: 1528following members:
1307 1529
1308 [$logical, $physical, $length, $flags] 1530 [$logical, $physical, $length, $flags]
1309 1531
1310Flags is any combination of the following flag values (typically either C<0> 1532Flags is any combination of the following flag values (typically either C<0>
1311or C<IO::AIO::FIEMAP_EXTENT_LAST>): 1533or C<IO::AIO::FIEMAP_EXTENT_LAST> (1)):
1312 1534
1313C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>, 1535C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,
1314C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>, 1536C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,
1315C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>, 1537C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
1316C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>, 1538C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
1317C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or 1539C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
1318C<IO::AIO::FIEMAP_EXTENT_SHARED>. 1540C<IO::AIO::FIEMAP_EXTENT_SHARED>.
1319 1541
1542At the time of this writing (Linux 3.2), this request is unreliable unless
1543C<$count> is C<undef>, as the kernel has all sorts of bugs preventing
1544it to return all extents of a range for files with a large number of
1545extents. The code (only) works around all these issues if C<$count> is
1546C<undef>.
1547
1320=item aio_group $callback->(...) 1548=item aio_group $callback->(...)
1321 1549
1322This is a very special aio request: Instead of doing something, it is a 1550This is a very special aio request: Instead of doing something, it is a
1323container for other aio requests, which is useful if you want to bundle 1551container for other aio requests, which is useful if you want to bundle
1324many requests into a single, composite, request with a definite callback 1552many requests into a single, composite, request with a definite callback
1407 aio_stat [$etcdir, "passwd"], sub { 1635 aio_stat [$etcdir, "passwd"], sub {
1408 # yay 1636 # yay
1409 }; 1637 };
1410 }; 1638 };
1411 1639
1412That C<aio_wd> is a request and not a normal function shows that creating 1640The fact that C<aio_wd> is a request and not a normal function shows that
1413an IO::AIO::WD object is itself a potentially blocking operation, which is 1641creating an IO::AIO::WD object is itself a potentially blocking operation,
1414why it is done asynchronously. 1642which is why it is done asynchronously.
1415 1643
1416To stat the directory obtained with C<aio_wd> above, one could write 1644To stat the directory obtained with C<aio_wd> above, one could write
1417either of the following three request calls: 1645either of the following three request calls:
1418 1646
1419 aio_lstat "/etc" , sub { ... # pathname as normal string 1647 aio_lstat "/etc" , sub { ... # pathname as normal string
1436There are some caveats: when directories get renamed (or deleted), the 1664There are some caveats: when directories get renamed (or deleted), the
1437pathname string doesn't change, so will point to the new directory (or 1665pathname string doesn't change, so will point to the new directory (or
1438nowhere at all), while the directory fd, if available on the system, 1666nowhere at all), while the directory fd, if available on the system,
1439will still point to the original directory. Most functions accepting a 1667will still point to the original directory. Most functions accepting a
1440pathname will use the directory fd on newer systems, and the string on 1668pathname will use the directory fd on newer systems, and the string on
1441older systems. Some functions (such as realpath) will always rely on the 1669older systems. Some functions (such as C<aio_realpath>) will always rely on
1442string form of the pathname. 1670the string form of the pathname.
1443 1671
1444So this fucntionality is mainly useful to get some protection against 1672So this functionality is mainly useful to get some protection against
1445C<chdir>, to easily get an absolute path out of a relative path for future 1673C<chdir>, to easily get an absolute path out of a relative path for future
1446reference, and to speed up doing many operations in the same directory 1674reference, and to speed up doing many operations in the same directory
1447(e.g. when stat'ing all files in a directory). 1675(e.g. when stat'ing all files in a directory).
1448 1676
1449The following functions implement this working directory abstraction: 1677The following functions implement this working directory abstraction:
1462passing C<undef> as working directory component of a pathname fails the 1690passing C<undef> as working directory component of a pathname fails the
1463request with C<ENOENT>, there is often no need for error checking in the 1691request with C<ENOENT>, there is often no need for error checking in the
1464C<aio_wd> callback, as future requests using the value will fail in the 1692C<aio_wd> callback, as future requests using the value will fail in the
1465expected way. 1693expected way.
1466 1694
1467If this call isn't available because your OS lacks it or it couldn't be
1468detected, it will be emulated by calling C<fsync> instead.
1469
1470=item IO::AIO::CWD 1695=item IO::AIO::CWD
1471 1696
1472This is a compiletime constant (object) that represents the process 1697This is a compile time constant (object) that represents the process
1473current working directory. 1698current working directory.
1474 1699
1475Specifying this object as working directory object for a pathname is as 1700Specifying this object as working directory object for a pathname is as if
1476if the pathname would be specified directly, without a directory object, 1701the pathname would be specified directly, without a directory object. For
1477e.g., these calls are functionally identical: 1702example, these calls are functionally identical:
1478 1703
1479 aio_stat "somefile", sub { ... }; 1704 aio_stat "somefile", sub { ... };
1480 aio_stat [IO::AIO::CWD, "somefile"], sub { ... }; 1705 aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
1481 1706
1482=back 1707=back
1483 1708
1709To recover the path associated with an IO::AIO::WD object, you can use
1710C<aio_realpath>:
1711
1712 aio_realpath $wd, sub {
1713 warn "path is $_[0]\n";
1714 };
1715
1716Currently, C<aio_statvfs> always, and C<aio_rename> and C<aio_rmdir>
1717sometimes, fall back to using an absolue path.
1484 1718
1485=head2 IO::AIO::REQ CLASS 1719=head2 IO::AIO::REQ CLASS
1486 1720
1487All non-aggregate C<aio_*> functions return an object of this class when 1721All non-aggregate C<aio_*> functions return an object of this class when
1488called in non-void context. 1722called in non-void context.
1649The default value for the limit is C<0>, but note that setting a feeder 1883The default value for the limit is C<0>, but note that setting a feeder
1650automatically bumps it up to C<2>. 1884automatically bumps it up to C<2>.
1651 1885
1652=back 1886=back
1653 1887
1888
1654=head2 SUPPORT FUNCTIONS 1889=head2 SUPPORT FUNCTIONS
1655 1890
1656=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1891=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
1657 1892
1658=over 4 1893=over 4
1666 1901
1667See C<poll_cb> for an example. 1902See C<poll_cb> for an example.
1668 1903
1669=item IO::AIO::poll_cb 1904=item IO::AIO::poll_cb
1670 1905
1671Process some outstanding events on the result pipe. You have to call 1906Process some requests that have reached the result phase (i.e. they have
1907been executed but the results are not yet reported). You have to call
1908this "regularly" to finish outstanding requests.
1909
1672this regularly. Returns C<0> if all events could be processed (or there 1910Returns C<0> if all events could be processed (or there were no
1673were no events to process), or C<-1> if it returned earlier for whatever 1911events to process), or C<-1> if it returned earlier for whatever
1674reason. Returns immediately when no events are outstanding. The amount of 1912reason. Returns immediately when no events are outstanding. The amount
1675events processed depends on the settings of C<IO::AIO::max_poll_req> and 1913of events processed depends on the settings of C<IO::AIO::max_poll_req>,
1676C<IO::AIO::max_poll_time>. 1914C<IO::AIO::max_poll_time> and C<IO::AIO::max_outstanding>.
1677 1915
1678If not all requests were processed for whatever reason, the filehandle 1916If not all requests were processed for whatever reason, the poll file
1679will still be ready when C<poll_cb> returns, so normally you don't have to 1917descriptor will still be ready when C<poll_cb> returns, so normally you
1680do anything special to have it called later. 1918don't have to do anything special to have it called later.
1681 1919
1682Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes 1920Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes
1683ready, it can be beneficial to call this function from loops which submit 1921ready, it can be beneficial to call this function from loops which submit
1684a lot of requests, to make sure the results get processed when they become 1922a lot of requests, to make sure the results get processed when they become
1685available and not just when the loop is finished and the event loop takes 1923available and not just when the loop is finished and the event loop takes
1694 poll => 'r', async => 1, 1932 poll => 'r', async => 1,
1695 cb => \&IO::AIO::poll_cb); 1933 cb => \&IO::AIO::poll_cb);
1696 1934
1697=item IO::AIO::poll_wait 1935=item IO::AIO::poll_wait
1698 1936
1699If there are any outstanding requests and none of them in the result 1937Wait until either at least one request is in the result phase or no
1700phase, wait till the result filehandle becomes ready for reading (simply 1938requests are outstanding anymore.
1701does a C<select> on the filehandle. This is useful if you want to 1939
1702synchronously wait for some requests to finish). 1940This is useful if you want to synchronously wait for some requests to
1941become ready, without actually handling them.
1703 1942
1704See C<nreqs> for an example. 1943See C<nreqs> for an example.
1705 1944
1706=item IO::AIO::poll 1945=item IO::AIO::poll
1707 1946
1718 1957
1719Strictly equivalent to: 1958Strictly equivalent to:
1720 1959
1721 IO::AIO::poll_wait, IO::AIO::poll_cb 1960 IO::AIO::poll_wait, IO::AIO::poll_cb
1722 while IO::AIO::nreqs; 1961 while IO::AIO::nreqs;
1962
1963This function can be useful at program aborts, to make sure outstanding
1964I/O has been done (C<IO::AIO> uses an C<END> block which already calls
1965this function on normal exits), or when you are merely using C<IO::AIO>
1966for its more advanced functions, rather than for async I/O, e.g.:
1967
1968 my ($dirs, $nondirs);
1969 IO::AIO::aio_scandir "/tmp", 0, sub { ($dirs, $nondirs) = @_ };
1970 IO::AIO::flush;
1971 # $dirs, $nondirs are now set
1723 1972
1724=item IO::AIO::max_poll_reqs $nreqs 1973=item IO::AIO::max_poll_reqs $nreqs
1725 1974
1726=item IO::AIO::max_poll_time $seconds 1975=item IO::AIO::max_poll_time $seconds
1727 1976
1754 poll => 'r', nice => 1, 2003 poll => 'r', nice => 1,
1755 cb => &IO::AIO::poll_cb); 2004 cb => &IO::AIO::poll_cb);
1756 2005
1757=back 2006=back
1758 2007
2008
1759=head3 CONTROLLING THE NUMBER OF THREADS 2009=head3 CONTROLLING THE NUMBER OF THREADS
1760 2010
1761=over 2011=over
1762 2012
1763=item IO::AIO::min_parallel $nthreads 2013=item IO::AIO::min_parallel $nthreads
1824longer exceeded. 2074longer exceeded.
1825 2075
1826In other words, this setting does not enforce a queue limit, but can be 2076In other words, this setting does not enforce a queue limit, but can be
1827used to make poll functions block if the limit is exceeded. 2077used to make poll functions block if the limit is exceeded.
1828 2078
1829This is a very bad function to use in interactive programs because it 2079This is a bad function to use in interactive programs because it blocks,
1830blocks, and a bad way to reduce concurrency because it is inexact: Better 2080and a bad way to reduce concurrency because it is inexact. If you need to
2081issue many requests without being able to call a poll function on demand,
1831use an C<aio_group> together with a feed callback. 2082it is better to use an C<aio_group> together with a feed callback.
1832 2083
1833It's main use is in scripts without an event loop - when you want to stat 2084Its main use is in scripts without an event loop - when you want to stat a
1834a lot of files, you can write somehting like this: 2085lot of files, you can write something like this:
1835 2086
1836 IO::AIO::max_outstanding 32; 2087 IO::AIO::max_outstanding 32;
1837 2088
1838 for my $path (...) { 2089 for my $path (...) {
1839 aio_stat $path , ...; 2090 aio_stat $path , ...;
1840 IO::AIO::poll_cb; 2091 IO::AIO::poll_cb;
1841 } 2092 }
1842 2093
1843 IO::AIO::flush; 2094 IO::AIO::flush;
1844 2095
1845The call to C<poll_cb> inside the loop will normally return instantly, but 2096The call to C<poll_cb> inside the loop will normally return instantly,
1846as soon as more thna C<32> reqeusts are in-flight, it will block until 2097allowing the loop to progress, but as soon as more than C<32> requests
1847some requests have been handled. This keeps the loop from pushing a large 2098are in-flight, it will block until some requests have been handled. This
1848number of C<aio_stat> requests onto the queue. 2099keeps the loop from pushing a large number of C<aio_stat> requests onto
2100the queue (which, with many paths to stat, can use up a lot of memory).
1849 2101
1850The default value for C<max_outstanding> is very large, so there is no 2102The default value for C<max_outstanding> is very large, so there is no
1851practical limit on the number of outstanding requests. 2103practical limit on the number of outstanding requests.
1852 2104
1853=back 2105=back
1854 2106
2107
1855=head3 STATISTICAL INFORMATION 2108=head3 STATISTICAL INFORMATION
1856 2109
1857=over 2110=over
1858 2111
1859=item IO::AIO::nreqs 2112=item IO::AIO::nreqs
1876Returns the number of requests currently in the pending state (executed, 2129Returns the number of requests currently in the pending state (executed,
1877but not yet processed by poll_cb). 2130but not yet processed by poll_cb).
1878 2131
1879=back 2132=back
1880 2133
2134
2135=head3 SUBSECOND STAT TIME ACCESS
2136
2137Both C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> functions can
2138generally find access/modification and change times with subsecond time
2139accuracy of the system supports it, but perl's built-in functions only
2140return the integer part.
2141
2142The following functions return the timestamps of the most recent
2143stat with subsecond precision on most systems and work both after
2144C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> calls. Their return
2145value is only meaningful after a successful C<stat>/C<lstat> call, or
2146during/after a successful C<aio_stat>/C<aio_lstat> callback.
2147
2148This is similar to the L<Time::HiRes> C<stat> functions, but can return
2149full resolution without rounding and work with standard perl C<stat>,
2150alleviating the need to call the special C<Time::HiRes> functions, which
2151do not act like their perl counterparts.
2152
2153On operating systems or file systems where subsecond time resolution is
2154not supported or could not be detected, a fractional part of C<0> is
2155returned, so it is always safe to call these functions.
2156
2157=over 4
2158
2159=item $seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime, IO::AIO::st_btime
2160
2161Return the access, modication, change or birth time, respectively,
2162including fractional part. Due to the limited precision of floating point,
2163the accuracy on most platforms is only a bit better than milliseconds
2164for times around now - see the I<nsec> function family, below, for full
2165accuracy.
2166
2167File birth time is only available when the OS and perl support it (on
2168FreeBSD and NetBSD at the time of this writing, although support is
2169adaptive, so if your OS/perl gains support, IO::AIO can take advantage of
2170it). On systems where it isn't available, C<0> is currently returned, but
2171this might change to C<undef> in a future version.
2172
2173=item ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtime
2174
2175Returns access, modification, change and birth time all in one go, and
2176maybe more times in the future version.
2177
2178=item $nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec, IO::AIO::st_ctimensec, IO::AIO::st_btimensec
2179
2180Return the fractional access, modifcation, change or birth time, in nanoseconds,
2181as an integer in the range C<0> to C<999999999>.
2182
2183Note that no accessors are provided for access, modification and
2184change times - you need to get those from C<stat _> if required (C<int
2185IO::AIO::st_atime> and so on will I<not> generally give you the correct
2186value).
2187
2188=item $seconds = IO::AIO::st_btimesec
2189
2190The (integral) seconds part of the file birth time, if available.
2191
2192=item ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtimensec
2193
2194Like the functions above, but returns all four times in one go (and maybe
2195more in future versions).
2196
2197=item $counter = IO::AIO::st_gen
2198
2199Returns the generation counter (in practice this is just a random number)
2200of the file. This is only available on platforms which have this member in
2201their C<struct stat> (most BSDs at the time of this writing) and generally
2202only to the root usert. If unsupported, C<0> is returned, but this might
2203change to C<undef> in a future version.
2204
2205=back
2206
2207Example: print the high resolution modification time of F</etc>, using
2208C<stat>, and C<IO::AIO::aio_stat>.
2209
2210 if (stat "/etc") {
2211 printf "stat(/etc) mtime: %f\n", IO::AIO::st_mtime;
2212 }
2213
2214 IO::AIO::aio_stat "/etc", sub {
2215 $_[0]
2216 and return;
2217
2218 printf "aio_stat(/etc) mtime: %d.%09d\n", (stat _)[9], IO::AIO::st_mtimensec;
2219 };
2220
2221 IO::AIO::flush;
2222
2223Output of the awbove on my system, showing reduced and full accuracy:
2224
2225 stat(/etc) mtime: 1534043702.020808
2226 aio_stat(/etc) mtime: 1534043702.020807792
2227
2228
1881=head3 MISCELLANEOUS FUNCTIONS 2229=head3 MISCELLANEOUS FUNCTIONS
1882 2230
1883IO::AIO implements some functions that might be useful, but are not 2231IO::AIO implements some functions that are useful when you want to use
1884asynchronous. 2232some "Advanced I/O" function not available to in Perl, without going the
2233"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*>
2234counterpart.
1885 2235
1886=over 4 2236=over 4
2237
2238=item $retval = IO::AIO::fexecve $fh, $argv, $envp
2239
2240A more-or-less direct equivalent to the POSIX C<fexecve> functions, which
2241allows you to specify the program to be executed via a file descriptor (or
2242handle). Returns C<-1> and sets errno to C<ENOSYS> if not available.
2243
2244=item $numfd = IO::AIO::get_fdlimit
2245
2246Tries to find the current file descriptor limit and returns it, or
2247C<undef> and sets C<$!> in case of an error. The limit is one larger than
2248the highest valid file descriptor number.
2249
2250=item IO::AIO::min_fdlimit [$numfd]
2251
2252Try to increase the current file descriptor limit(s) to at least C<$numfd>
2253by changing the soft or hard file descriptor resource limit. If C<$numfd>
2254is missing, it will try to set a very high limit, although this is not
2255recommended when you know the actual minimum that you require.
2256
2257If the limit cannot be raised enough, the function makes a best-effort
2258attempt to increase the limit as much as possible, using various
2259tricks, while still failing. You can query the resulting limit using
2260C<IO::AIO::get_fdlimit>.
2261
2262If an error occurs, returns C<undef> and sets C<$!>, otherwise returns
2263true.
1887 2264
1888=item IO::AIO::sendfile $ofh, $ifh, $offset, $count 2265=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1889 2266
1890Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>, 2267Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
1891but is blocking (this makes most sense if you know the input data is 2268but is blocking (this makes most sense if you know the input data is
1908=item IO::AIO::madvise $scalar, $offset, $len, $advice 2285=item IO::AIO::madvise $scalar, $offset, $len, $advice
1909 2286
1910Simply calls the C<posix_madvise> function (see its 2287Simply calls the C<posix_madvise> function (see its
1911manpage for details). The following advice constants are 2288manpage for details). The following advice constants are
1912available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>, 2289available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
1913C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>. 2290C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>,
2291C<IO::AIO::MADV_DONTNEED>.
2292
2293If C<$offset> is negative, counts from the end. If C<$length> is negative,
2294the remaining length of the C<$scalar> is used. If possible, C<$length>
2295will be reduced to fit into the C<$scalar>.
1914 2296
1915On systems that do not implement C<posix_madvise>, this function returns 2297On systems that do not implement C<posix_madvise>, this function returns
1916ENOSYS, otherwise the return value of C<posix_madvise>. 2298ENOSYS, otherwise the return value of C<posix_madvise>.
1917 2299
1918=item IO::AIO::mprotect $scalar, $offset, $len, $protect 2300=item IO::AIO::mprotect $scalar, $offset, $len, $protect
1920Simply calls the C<mprotect> function on the preferably AIO::mmap'ed 2302Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
1921$scalar (see its manpage for details). The following protect 2303$scalar (see its manpage for details). The following protect
1922constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>, 2304constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
1923C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>. 2305C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
1924 2306
2307If C<$offset> is negative, counts from the end. If C<$length> is negative,
2308the remaining length of the C<$scalar> is used. If possible, C<$length>
2309will be reduced to fit into the C<$scalar>.
2310
1925On systems that do not implement C<mprotect>, this function returns 2311On systems that do not implement C<mprotect>, this function returns
1926ENOSYS, otherwise the return value of C<mprotect>. 2312ENOSYS, otherwise the return value of C<mprotect>.
1927 2313
1928=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] 2314=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1929 2315
1930Memory-maps a file (or anonymous memory range) and attaches it to the 2316Memory-maps a file (or anonymous memory range) and attaches it to the
1931given C<$scalar>, which will act like a string scalar. Returns true on 2317given C<$scalar>, which will act like a string scalar. Returns true on
1932success, and false otherwise. 2318success, and false otherwise.
1933 2319
2320The scalar must exist, but its contents do not matter - this means you
2321cannot use a nonexistant array or hash element. When in doubt, C<undef>
2322the scalar first.
2323
1934The only operations allowed on the scalar are C<substr>/C<vec> that don't 2324The only operations allowed on the mmapped scalar are C<substr>/C<vec>,
1935change the string length, and most read-only operations such as copying it 2325which don't change the string length, and most read-only operations such
1936or searching it with regexes and so on. 2326as copying it or searching it with regexes and so on.
1937 2327
1938Anything else is unsafe and will, at best, result in memory leaks. 2328Anything else is unsafe and will, at best, result in memory leaks.
1939 2329
1940The memory map associated with the C<$scalar> is automatically removed 2330The memory map associated with the C<$scalar> is automatically removed
1941when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or 2331when the C<$scalar> is undef'd or destroyed, or when the C<IO::AIO::mmap>
1942C<IO::AIO::munmap> functions are called. 2332or C<IO::AIO::munmap> functions are called on it.
1943 2333
1944This calls the C<mmap>(2) function internally. See your system's manual 2334This calls the C<mmap>(2) function internally. See your system's manual
1945page for details on the C<$length>, C<$prot> and C<$flags> parameters. 2335page for details on the C<$length>, C<$prot> and C<$flags> parameters.
1946 2336
1947The C<$length> must be larger than zero and smaller than the actual 2337The C<$length> must be larger than zero and smaller than the actual
1948filesize. 2338filesize.
1949 2339
1950C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>, 2340C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1951C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>, 2341C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1952 2342
1953C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or 2343C<$flags> can be a combination of
1954C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when 2344C<IO::AIO::MAP_SHARED> or
1955not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS> 2345C<IO::AIO::MAP_PRIVATE>,
2346or a number of system-specific flags (when not available, the are C<0>):
1956(which is set to C<MAP_ANON> if your system only provides this 2347C<IO::AIO::MAP_ANONYMOUS> (which is set to C<MAP_ANON> if your system only provides this constant),
1957constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>, 2348C<IO::AIO::MAP_LOCKED>,
1958C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or 2349C<IO::AIO::MAP_NORESERVE>,
2350C<IO::AIO::MAP_POPULATE>,
1959C<IO::AIO::MAP_NONBLOCK> 2351C<IO::AIO::MAP_NONBLOCK>,
2352C<IO::AIO::MAP_FIXED>,
2353C<IO::AIO::MAP_GROWSDOWN>,
2354C<IO::AIO::MAP_32BIT>,
2355C<IO::AIO::MAP_HUGETLB>,
2356C<IO::AIO::MAP_STACK>,
2357C<IO::AIO::MAP_FIXED_NOREPLACE>,
2358C<IO::AIO::MAP_SHARED_VALIDATE>,
2359C<IO::AIO::MAP_SYNC> or
2360C<IO::AIO::MAP_UNINITIALIZED>.
1960 2361
1961If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed. 2362If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1962 2363
1963C<$offset> is the offset from the start of the file - it generally must be 2364C<$offset> is the offset from the start of the file - it generally must be
1964a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>. 2365a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
1978 2379
1979=item IO::AIO::munmap $scalar 2380=item IO::AIO::munmap $scalar
1980 2381
1981Removes a previous mmap and undefines the C<$scalar>. 2382Removes a previous mmap and undefines the C<$scalar>.
1982 2383
2384=item IO::AIO::mremap $scalar, $new_length, $flags = MREMAP_MAYMOVE[, $new_address = 0]
2385
2386Calls the Linux-specific mremap(2) system call. The C<$scalar> must have
2387been mapped by C<IO::AIO::mmap>, and C<$flags> must currently either be
2388C<0> or C<IO::AIO::MREMAP_MAYMOVE>.
2389
2390Returns true if successful, and false otherwise. If the underlying mmapped
2391region has changed address, then the true value has the numerical value
2392C<1>, otherwise it has the numerical value C<0>:
2393
2394 my $success = IO::AIO::mremap $mmapped, 8192, IO::AIO::MREMAP_MAYMOVE
2395 or die "mremap: $!";
2396
2397 if ($success*1) {
2398 warn "scalar has chanegd address in memory\n";
2399 }
2400
2401C<IO::AIO::MREMAP_FIXED> and the C<$new_address> argument are currently
2402implemented, but not supported and might go away in a future version.
2403
2404On systems where this call is not supported or is not emulated, this call
2405returns falls and sets C<$!> to C<ENOSYS>.
2406
2407=item IO::AIO::mlockall $flags
2408
2409Calls the C<eio_mlockall_sync> function, which is like C<aio_mlockall>,
2410but is blocking.
2411
1983=item IO::AIO::munlock $scalar, $offset = 0, $length = undef 2412=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
1984 2413
1985Calls the C<munlock> function, undoing the effects of a previous 2414Calls the C<munlock> function, undoing the effects of a previous
1986C<aio_mlock> call (see its description for details). 2415C<aio_mlock> call (see its description for details).
1987 2416
1989 2418
1990Calls the C<munlockall> function. 2419Calls the C<munlockall> function.
1991 2420
1992On systems that do not implement C<munlockall>, this function returns 2421On systems that do not implement C<munlockall>, this function returns
1993ENOSYS, otherwise the return value of C<munlockall>. 2422ENOSYS, otherwise the return value of C<munlockall>.
2423
2424=item $fh = IO::AIO::accept4 $r_fh, $sockaddr, $sockaddr_maxlen, $flags
2425
2426Uses the GNU/Linux C<accept4(2)> syscall, if available, to accept a socket
2427and return the new file handle on success, or sets C<$!> and returns
2428C<undef> on error.
2429
2430The remote name of the new socket will be stored in C<$sockaddr>, which
2431will be extended to allow for at least C<$sockaddr_maxlen> octets. If the
2432socket name does not fit into C<$sockaddr_maxlen> octets, this is signaled
2433by returning a longer string in C<$sockaddr>, which might or might not be
2434truncated.
2435
2436To accept name-less sockets, use C<undef> for C<$sockaddr> and C<0> for
2437C<$sockaddr_maxlen>.
2438
2439The main reasons to use this syscall rather than portable C<accept(2)>
2440are that you can specify C<SOCK_NONBLOCK> and/or C<SOCK_CLOEXEC>
2441flags and you can accept name-less sockets by specifying C<0> for
2442C<$sockaddr_maxlen>, which is sadly not possible with perl's interface to
2443C<accept>.
1994 2444
1995=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags 2445=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
1996 2446
1997Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or 2447Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or
1998C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they 2448C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
2007 2457
2008See the C<splice(2)> manpage for details. 2458See the C<splice(2)> manpage for details.
2009 2459
2010=item IO::AIO::tee $r_fh, $w_fh, $length, $flags 2460=item IO::AIO::tee $r_fh, $w_fh, $length, $flags
2011 2461
2012Calls the GNU/Linux C<tee(2)> syscall, see it's manpage and the 2462Calls the GNU/Linux C<tee(2)> syscall, see its manpage and the
2013description for C<IO::AIO::splice> above for details. 2463description for C<IO::AIO::splice> above for details.
2464
2465=item $actual_size = IO::AIO::pipesize $r_fh[, $new_size]
2466
2467Attempts to query or change the pipe buffer size. Obviously works only
2468on pipes, and currently works only on GNU/Linux systems, and fails with
2469C<-1>/C<ENOSYS> everywhere else. If anybody knows how to influence pipe buffer
2470size on other systems, drop me a note.
2471
2472=item ($rfh, $wfh) = IO::AIO::pipe2 [$flags]
2473
2474This is a direct interface to the Linux L<pipe2(2)> system call. If
2475C<$flags> is missing or C<0>, then this should be the same as a call to
2476perl's built-in C<pipe> function and create a new pipe, and works on
2477systems that lack the pipe2 syscall. On win32, this case invokes C<_pipe
2478(..., 4096, O_BINARY)>.
2479
2480If C<$flags> is non-zero, it tries to invoke the pipe2 system call with
2481the given flags (Linux 2.6.27, glibc 2.9).
2482
2483On success, the read and write file handles are returned.
2484
2485On error, nothing will be returned. If the pipe2 syscall is missing and
2486C<$flags> is non-zero, fails with C<ENOSYS>.
2487
2488Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the
2489time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and
2490C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported.
2491
2492Example: create a pipe race-free w.r.t. threads and fork:
2493
2494 my ($rfh, $wfh) = IO::AIO::pipe2 IO::AIO::O_CLOEXEC
2495 or die "pipe2: $!\n";
2496
2497=item $fh = IO::AIO::memfd_create $pathname[, $flags]
2498
2499This is a direct interface to the Linux L<memfd_create(2)> system
2500call. The (unhelpful) default for C<$flags> is C<0>, but your default
2501should be C<IO::AIO::MFD_CLOEXEC>.
2502
2503On success, the new memfd filehandle is returned, otherwise returns
2504C<undef>. If the memfd_create syscall is missing, fails with C<ENOSYS>.
2505
2506Please refer to L<memfd_create(2)> for more info on this call.
2507
2508The following C<$flags> values are available: C<IO::AIO::MFD_CLOEXEC>,
2509C<IO::AIO::MFD_ALLOW_SEALING>, C<IO::AIO::MFD_HUGETLB>,
2510C<IO::AIO::MFD_HUGETLB_2MB> and C<IO::AIO::MFD_HUGETLB_1GB>.
2511
2512Example: create a new memfd.
2513
2514 my $fh = IO::AIO::memfd_create "somenameforprocfd", IO::AIO::MFD_CLOEXEC
2515 or die "memfd_create: $!\n";
2516
2517=item $fh = IO::AIO::pidfd_open $pid[, $flags]
2518
2519This is an interface to the Linux L<pidfd_open(2)> system call. The
2520default for C<$flags> is C<0>.
2521
2522On success, a new pidfd filehandle is returned (that is already set to
2523close-on-exec), otherwise returns C<undef>. If the syscall is missing,
2524fails with C<ENOSYS>.
2525
2526Example: open pid 6341 as pidfd.
2527
2528 my $fh = IO::AIO::pidfd_open 6341
2529 or die "pidfd_open: $!\n";
2530
2531=item $status = IO::AIO::pidfd_send_signal $pidfh, $signal[, $siginfo[, $flags]]
2532
2533This is an interface to the Linux L<pidfd_send_signal> system call. The
2534default for C<$siginfo> is C<undef> and the default for C<$flags> is C<0>.
2535
2536Returns the system call status. If the syscall is missing, fails with
2537C<ENOSYS>.
2538
2539When specified, C<$siginfo> must be a reference to a hash with one or more
2540of the following members:
2541
2542=over
2543
2544=item code - the C<si_code> member
2545
2546=item pid - the C<si_pid> member
2547
2548=item uid - the C<si_uid> member
2549
2550=item value_int - the C<si_value.sival_int> member
2551
2552=item value_ptr - the C<si_value.sival_ptr> member, specified as an integer
2553
2554=back
2555
2556Example: send a SIGKILL to the specified process.
2557
2558 my $status = IO::AIO::pidfd_send_signal $pidfh, 9, undef
2559 and die "pidfd_send_signal: $!\n";
2560
2561Example: send a SIGKILL to the specified process with extra data.
2562
2563 my $status = IO::AIO::pidfd_send_signal $pidfh, 9, { code => -1, value_int => 7 }
2564 and die "pidfd_send_signal: $!\n";
2565
2566=item $fh = IO::AIO::pidfd_getfd $pidfh, $targetfd[, $flags]
2567
2568This is an interface to the Linux L<pidfd_getfd> system call. The default
2569for C<$flags> is C<0>.
2570
2571On success, returns a dup'ed copy of the target file descriptor (specified
2572as an integer) returned (that is already set to close-on-exec), otherwise
2573returns C<undef>. If the syscall is missing, fails with C<ENOSYS>.
2574
2575Example: get a copy of standard error of another process and print soemthing to it.
2576
2577 my $errfh = IO::AIO::pidfd_getfd $pidfh, 2
2578 or die "pidfd_getfd: $!\n";
2579 print $errfh "stderr\n";
2580
2581=item $fh = IO::AIO::eventfd [$initval, [$flags]]
2582
2583This is a direct interface to the Linux L<eventfd(2)> system call. The
2584(unhelpful) defaults for C<$initval> and C<$flags> are C<0> for both.
2585
2586On success, the new eventfd filehandle is returned, otherwise returns
2587C<undef>. If the eventfd syscall is missing, fails with C<ENOSYS>.
2588
2589Please refer to L<eventfd(2)> for more info on this call.
2590
2591The following symbol flag values are available: C<IO::AIO::EFD_CLOEXEC>,
2592C<IO::AIO::EFD_NONBLOCK> and C<IO::AIO::EFD_SEMAPHORE> (Linux 2.6.30).
2593
2594Example: create a new eventfd filehandle:
2595
2596 $fh = IO::AIO::eventfd 0, IO::AIO::EFD_CLOEXEC
2597 or die "eventfd: $!\n";
2598
2599=item $fh = IO::AIO::timerfd_create $clockid[, $flags]
2600
2601This is a direct interface to the Linux L<timerfd_create(2)> system
2602call. The (unhelpful) default for C<$flags> is C<0>, but your default
2603should be C<IO::AIO::TFD_CLOEXEC>.
2604
2605On success, the new timerfd filehandle is returned, otherwise returns
2606C<undef>. If the timerfd_create syscall is missing, fails with C<ENOSYS>.
2607
2608Please refer to L<timerfd_create(2)> for more info on this call.
2609
2610The following C<$clockid> values are
2611available: C<IO::AIO::CLOCK_REALTIME>, C<IO::AIO::CLOCK_MONOTONIC>
2612C<IO::AIO::CLOCK_CLOCK_BOOTTIME> (Linux 3.15)
2613C<IO::AIO::CLOCK_CLOCK_REALTIME_ALARM> (Linux 3.11) and
2614C<IO::AIO::CLOCK_CLOCK_BOOTTIME_ALARM> (Linux 3.11).
2615
2616The following C<$flags> values are available (Linux
26172.6.27): C<IO::AIO::TFD_NONBLOCK> and C<IO::AIO::TFD_CLOEXEC>.
2618
2619Example: create a new timerfd and set it to one-second repeated alarms,
2620then wait for two alarms:
2621
2622 my $fh = IO::AIO::timerfd_create IO::AIO::CLOCK_BOOTTIME, IO::AIO::TFD_CLOEXEC
2623 or die "timerfd_create: $!\n";
2624
2625 defined IO::AIO::timerfd_settime $fh, 0, 1, 1
2626 or die "timerfd_settime: $!\n";
2627
2628 for (1..2) {
2629 8 == sysread $fh, my $buf, 8
2630 or die "timerfd read failure\n";
2631
2632 printf "number of expirations (likely 1): %d\n",
2633 unpack "Q", $buf;
2634 }
2635
2636=item ($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags, $new_interval, $nbw_value
2637
2638This is a direct interface to the Linux L<timerfd_settime(2)> system
2639call. Please refer to its manpage for more info on this call.
2640
2641The new itimerspec is specified using two (possibly fractional) second
2642values, C<$new_interval> and C<$new_value>).
2643
2644On success, the current interval and value are returned (as per
2645C<timerfd_gettime>). On failure, the empty list is returned.
2646
2647The following C<$flags> values are
2648available: C<IO::AIO::TFD_TIMER_ABSTIME> and
2649C<IO::AIO::TFD_TIMER_CANCEL_ON_SET>.
2650
2651See C<IO::AIO::timerfd_create> for a full example.
2652
2653=item ($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh
2654
2655This is a direct interface to the Linux L<timerfd_gettime(2)> system
2656call. Please refer to its manpage for more info on this call.
2657
2658On success, returns the current values of interval and value for the given
2659timerfd (as potentially fractional second values). On failure, the empty
2660list is returned.
2014 2661
2015=back 2662=back
2016 2663
2017=cut 2664=cut
2018 2665
2084the process will result in undefined behaviour. Calling it at any time 2731the process will result in undefined behaviour. Calling it at any time
2085will also result in any undefined (by POSIX) behaviour. 2732will also result in any undefined (by POSIX) behaviour.
2086 2733
2087=back 2734=back
2088 2735
2736=head2 LINUX-SPECIFIC CALLS
2737
2738When a call is documented as "linux-specific" then this means it
2739originated on GNU/Linux. C<IO::AIO> will usually try to autodetect the
2740availability and compatibility of such calls regardless of the platform
2741it is compiled on, so platforms such as FreeBSD which often implement
2742these calls will work. When in doubt, call them and see if they fail wth
2743C<ENOSYS>.
2744
2089=head2 MEMORY USAGE 2745=head2 MEMORY USAGE
2090 2746
2091Per-request usage: 2747Per-request usage:
2092 2748
2093Each aio request uses - depending on your architecture - around 100-200 2749Each aio request uses - depending on your architecture - around 100-200
2105temporary buffers, and each thread requires a stack and other data 2761temporary buffers, and each thread requires a stack and other data
2106structures (usually around 16k-128k, depending on the OS). 2762structures (usually around 16k-128k, depending on the OS).
2107 2763
2108=head1 KNOWN BUGS 2764=head1 KNOWN BUGS
2109 2765
2110Known bugs will be fixed in the next release. 2766Known bugs will be fixed in the next release :)
2767
2768=head1 KNOWN ISSUES
2769
2770Calls that try to "import" foreign memory areas (such as C<IO::AIO::mmap>
2771or C<IO::AIO::aio_slurp>) do not work with generic lvalues, such as
2772non-created hash slots or other scalars I didn't think of. It's best to
2773avoid such and either use scalar variables or making sure that the scalar
2774exists (e.g. by storing C<undef>) and isn't "funny" (e.g. tied).
2775
2776I am not sure anything can be done about this, so this is considered a
2777known issue, rather than a bug.
2111 2778
2112=head1 SEE ALSO 2779=head1 SEE ALSO
2113 2780
2114L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a 2781L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
2115more natural syntax. 2782more natural syntax and L<IO::FDPass> for file descriptor passing.
2116 2783
2117=head1 AUTHOR 2784=head1 AUTHOR
2118 2785
2119 Marc Lehmann <schmorp@schmorp.de> 2786 Marc Lehmann <schmorp@schmorp.de>
2120 http://home.schmorp.de/ 2787 http://home.schmorp.de/

Diff Legend

Removed lines
+ Added lines
< Changed lines
> Changed lines