… | |
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168 | use common::sense; |
168 | use common::sense; |
169 | |
169 | |
170 | use base 'Exporter'; |
170 | use base 'Exporter'; |
171 | |
171 | |
172 | BEGIN { |
172 | BEGIN { |
173 | our $VERSION = '3.65'; |
173 | our $VERSION = '4.0'; |
174 | |
174 | |
175 | our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close |
175 | our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close |
176 | aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx |
176 | aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx |
177 | aio_scandir aio_symlink aio_readlink aio_sync aio_fsync |
177 | aio_scandir aio_symlink aio_readlink aio_realpath aio_sync aio_fsync |
178 | aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead |
178 | aio_fdatasync aio_sync_file_range aio_fallocate |
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179 | aio_pathsync aio_readahead |
179 | aio_rename aio_link aio_move aio_copy aio_group |
180 | aio_rename aio_link aio_move aio_copy aio_group |
180 | aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown |
181 | aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown |
181 | aio_chmod aio_utime aio_truncate |
182 | aio_chmod aio_utime aio_truncate |
182 | aio_msync aio_mtouch aio_statvfs); |
183 | aio_msync aio_mtouch aio_mlock aio_mlockall |
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184 | aio_statvfs); |
183 | |
185 | |
184 | our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); |
186 | our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); |
185 | our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush |
187 | our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush |
186 | min_parallel max_parallel max_idle |
188 | min_parallel max_parallel max_idle idle_timeout |
187 | nreqs nready npending nthreads |
189 | nreqs nready npending nthreads |
188 | max_poll_time max_poll_reqs |
190 | max_poll_time max_poll_reqs |
189 | sendfile fadvise); |
191 | sendfile fadvise madvise |
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192 | mmap munmap munlock munlockall); |
190 | |
193 | |
191 | push @AIO_REQ, qw(aio_busy); # not exported |
194 | push @AIO_REQ, qw(aio_busy); # not exported |
192 | |
195 | |
193 | @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; |
196 | @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; |
194 | |
197 | |
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220 | aio_unlink $pathname, $callback->($status) |
223 | aio_unlink $pathname, $callback->($status) |
221 | aio_mknod $path, $mode, $dev, $callback->($status) |
224 | aio_mknod $path, $mode, $dev, $callback->($status) |
222 | aio_link $srcpath, $dstpath, $callback->($status) |
225 | aio_link $srcpath, $dstpath, $callback->($status) |
223 | aio_symlink $srcpath, $dstpath, $callback->($status) |
226 | aio_symlink $srcpath, $dstpath, $callback->($status) |
224 | aio_readlink $path, $callback->($link) |
227 | aio_readlink $path, $callback->($link) |
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228 | aio_realpath $path, $callback->($link) |
225 | aio_rename $srcpath, $dstpath, $callback->($status) |
229 | aio_rename $srcpath, $dstpath, $callback->($status) |
226 | aio_mkdir $pathname, $mode, $callback->($status) |
230 | aio_mkdir $pathname, $mode, $callback->($status) |
227 | aio_rmdir $pathname, $callback->($status) |
231 | aio_rmdir $pathname, $callback->($status) |
228 | aio_readdir $pathname, $callback->($entries) |
232 | aio_readdir $pathname, $callback->($entries) |
229 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
233 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
… | |
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239 | aio_fdatasync $fh, $callback->($status) |
243 | aio_fdatasync $fh, $callback->($status) |
240 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
244 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
241 | aio_pathsync $path, $callback->($status) |
245 | aio_pathsync $path, $callback->($status) |
242 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
246 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
243 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
247 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
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248 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
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249 | aio_mlockall $flags, $callback->($status) |
244 | aio_group $callback->(...) |
250 | aio_group $callback->(...) |
245 | aio_nop $callback->() |
251 | aio_nop $callback->() |
246 | |
252 | |
247 | $prev_pri = aioreq_pri [$pri] |
253 | $prev_pri = aioreq_pri [$pri] |
248 | aioreq_nice $pri_adjust |
254 | aioreq_nice $pri_adjust |
… | |
… | |
254 | IO::AIO::max_poll_reqs $nreqs |
260 | IO::AIO::max_poll_reqs $nreqs |
255 | IO::AIO::max_poll_time $seconds |
261 | IO::AIO::max_poll_time $seconds |
256 | IO::AIO::min_parallel $nthreads |
262 | IO::AIO::min_parallel $nthreads |
257 | IO::AIO::max_parallel $nthreads |
263 | IO::AIO::max_parallel $nthreads |
258 | IO::AIO::max_idle $nthreads |
264 | IO::AIO::max_idle $nthreads |
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265 | IO::AIO::idle_timeout $seconds |
259 | IO::AIO::max_outstanding $maxreqs |
266 | IO::AIO::max_outstanding $maxreqs |
260 | IO::AIO::nreqs |
267 | IO::AIO::nreqs |
261 | IO::AIO::nready |
268 | IO::AIO::nready |
262 | IO::AIO::npending |
269 | IO::AIO::npending |
263 | |
270 | |
264 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
271 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
265 | IO::AIO::fadvise $fh, $offset, $len, $advice |
272 | IO::AIO::fadvise $fh, $offset, $len, $advice |
266 | IO::AIO::mlockall $flags |
273 | IO::AIO::madvise $scalar, $offset, $length, $advice |
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274 | IO::AIO::mprotect $scalar, $offset, $length, $protect |
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275 | IO::AIO::munlock $scalar, $offset = 0, $length = undef |
267 | IO::AIO::munlockall |
276 | IO::AIO::munlockall |
268 | |
277 | |
269 | =head2 AIO REQUEST FUNCTIONS |
278 | =head2 AIO REQUEST FUNCTIONS |
270 | |
279 | |
271 | All the C<aio_*> calls are more or less thin wrappers around the syscall |
280 | All the C<aio_*> calls are more or less thin wrappers around the syscall |
… | |
… | |
361 | } else { |
370 | } else { |
362 | die "open failed: $!\n"; |
371 | die "open failed: $!\n"; |
363 | } |
372 | } |
364 | }; |
373 | }; |
365 | |
374 | |
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375 | In addition to all the common open modes/flags (C<O_RDONLY>, C<O_WRONLY>, |
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376 | C<O_RDWR>, C<O_CREAT>, C<O_TRUNC>, C<O_EXCL> and C<O_APPEND>), the |
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377 | following POSIX and non-POSIX constants are available (missing ones on |
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378 | your system are, as usual, C<0>): |
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379 | |
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380 | C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>, |
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381 | C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>, |
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382 | C<O_RSYNC>, C<O_SYNC> and C<O_TTY_INIT>. |
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383 | |
366 | |
384 | |
367 | =item aio_close $fh, $callback->($status) |
385 | =item aio_close $fh, $callback->($status) |
368 | |
386 | |
369 | Asynchronously close a file and call the callback with the result |
387 | Asynchronously close a file and call the callback with the result |
370 | code. |
388 | code. |
… | |
… | |
420 | |
438 | |
421 | Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts |
439 | Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts |
422 | reading at byte offset C<$in_offset>, and starts writing at the current |
440 | reading at byte offset C<$in_offset>, and starts writing at the current |
423 | file offset of C<$out_fh>. Because of that, it is not safe to issue more |
441 | file offset of C<$out_fh>. Because of that, it is not safe to issue more |
424 | than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each |
442 | than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each |
425 | other. |
443 | other. The same C<$in_fh> works fine though, as this function does not |
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444 | move or use the file offset of C<$in_fh>. |
426 | |
445 | |
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446 | Please note that C<aio_sendfile> can read more bytes from C<$in_fh> than |
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447 | are written, and there is no way to find out how many more bytes have been |
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448 | read from C<aio_sendfile> alone, as C<aio_sendfile> only provides the |
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449 | number of bytes written to C<$out_fh>. Only if the result value equals |
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450 | C<$length> one can assume that C<$length> bytes have been read. |
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451 | |
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452 | Unlike with other C<aio_> functions, it makes a lot of sense to use |
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453 | C<aio_sendfile> on non-blocking sockets, as long as one end (typically |
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454 | the C<$in_fh>) is a file - the file I/O will then be asynchronous, while |
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455 | the socket I/O will be non-blocking. Note, however, that you can run |
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456 | into a trap where C<aio_sendfile> reads some data with readahead, then |
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457 | fails to write all data, and when the socket is ready the next time, the |
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458 | data in the cache is already lost, forcing C<aio_sendfile> to again hit |
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459 | the disk. Explicit C<aio_read> + C<aio_write> let's you better control |
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460 | resource usage. |
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461 | |
427 | This call tries to make use of a native C<sendfile> syscall to provide |
462 | This call tries to make use of a native C<sendfile>-like syscall to |
428 | zero-copy operation. For this to work, C<$out_fh> should refer to a |
463 | provide zero-copy operation. For this to work, C<$out_fh> should refer to |
429 | socket, and C<$in_fh> should refer to an mmap'able file. |
464 | a socket, and C<$in_fh> should refer to an mmap'able file. |
430 | |
465 | |
431 | If a native sendfile cannot be found or it fails with C<ENOSYS>, |
466 | If a native sendfile cannot be found or it fails with C<ENOSYS>, |
432 | C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>, |
467 | C<EINVAL>, C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or |
433 | it will be emulated, so you can call C<aio_sendfile> on any type of |
468 | C<ENOTSOCK>, it will be emulated, so you can call C<aio_sendfile> on any |
434 | filehandle regardless of the limitations of the operating system. |
469 | type of filehandle regardless of the limitations of the operating system. |
435 | |
470 | |
436 | Please note, however, that C<aio_sendfile> can read more bytes from |
471 | As native sendfile syscalls (as practically any non-POSIX interface hacked |
437 | C<$in_fh> than are written, and there is no way to find out how many |
472 | together in a hurry to improve benchmark numbers) tend to be rather buggy |
438 | bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only |
473 | on many systems, this implementation tries to work around some known bugs |
439 | provides the number of bytes written to C<$out_fh>. Only if the result |
474 | in Linux and FreeBSD kernels (probably others, too), but that might fail, |
440 | value equals C<$length> one can assume that C<$length> bytes have been |
475 | so you really really should check the return value of C<aio_sendfile> - |
441 | read. |
476 | fewre bytes than expected might have been transferred. |
442 | |
477 | |
443 | |
478 | |
444 | =item aio_readahead $fh,$offset,$length, $callback->($retval) |
479 | =item aio_readahead $fh,$offset,$length, $callback->($retval) |
445 | |
480 | |
446 | C<aio_readahead> populates the page cache with data from a file so that |
481 | C<aio_readahead> populates the page cache with data from a file so that |
… | |
… | |
468 | for an explanation. |
503 | for an explanation. |
469 | |
504 | |
470 | Currently, the stats are always 64-bit-stats, i.e. instead of returning an |
505 | Currently, the stats are always 64-bit-stats, i.e. instead of returning an |
471 | error when stat'ing a large file, the results will be silently truncated |
506 | error when stat'ing a large file, the results will be silently truncated |
472 | unless perl itself is compiled with large file support. |
507 | unless perl itself is compiled with large file support. |
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508 | |
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509 | To help interpret the mode and dev/rdev stat values, IO::AIO offers the |
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510 | following constants and functions (if not implemented, the constants will |
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511 | be C<0> and the functions will either C<croak> or fall back on traditional |
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512 | behaviour). |
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513 | |
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514 | C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>, |
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515 | C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>, |
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516 | C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>. |
473 | |
517 | |
474 | Example: Print the length of F</etc/passwd>: |
518 | Example: Print the length of F</etc/passwd>: |
475 | |
519 | |
476 | aio_stat "/etc/passwd", sub { |
520 | aio_stat "/etc/passwd", sub { |
477 | $_[0] and die "stat failed: $!"; |
521 | $_[0] and die "stat failed: $!"; |
… | |
… | |
579 | |
623 | |
580 | The only (POSIX-) portable way of calling this function is: |
624 | The only (POSIX-) portable way of calling this function is: |
581 | |
625 | |
582 | aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
626 | aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
583 | |
627 | |
|
|
628 | See C<aio_stat> for info about some potentially helpful extra constants |
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|
629 | and functions. |
584 | |
630 | |
585 | =item aio_link $srcpath, $dstpath, $callback->($status) |
631 | =item aio_link $srcpath, $dstpath, $callback->($status) |
586 | |
632 | |
587 | Asynchronously create a new link to the existing object at C<$srcpath> at |
633 | Asynchronously create a new link to the existing object at C<$srcpath> at |
588 | the path C<$dstpath> and call the callback with the result code. |
634 | the path C<$dstpath> and call the callback with the result code. |
… | |
… | |
599 | Asynchronously read the symlink specified by C<$path> and pass it to |
645 | Asynchronously read the symlink specified by C<$path> and pass it to |
600 | the callback. If an error occurs, nothing or undef gets passed to the |
646 | the callback. If an error occurs, nothing or undef gets passed to the |
601 | callback. |
647 | callback. |
602 | |
648 | |
603 | |
649 | |
|
|
650 | =item aio_realpath $path, $callback->($path) |
|
|
651 | |
|
|
652 | Asynchronously make the path absolute and resolve any symlinks in |
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|
653 | C<$path>. The resulting path only consists of directories (Same as |
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|
654 | L<Cwd::realpath>). |
|
|
655 | |
|
|
656 | This request can be used to get the absolute path of the current working |
|
|
657 | directory by passing it a path of F<.> (a single dot). |
|
|
658 | |
|
|
659 | |
604 | =item aio_rename $srcpath, $dstpath, $callback->($status) |
660 | =item aio_rename $srcpath, $dstpath, $callback->($status) |
605 | |
661 | |
606 | Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as |
662 | Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as |
607 | rename(2) and call the callback with the result code. |
663 | rename(2) and call the callback with the result code. |
608 | |
664 | |
… | |
… | |
641 | |
697 | |
642 | =over 4 |
698 | =over 4 |
643 | |
699 | |
644 | =item IO::AIO::READDIR_DENTS |
700 | =item IO::AIO::READDIR_DENTS |
645 | |
701 | |
646 | When this flag is off, then the callback gets an arrayref with of names |
702 | When this flag is off, then the callback gets an arrayref consisting of |
647 | only (as with C<aio_readdir>), otherwise it gets an arrayref with |
703 | names only (as with C<aio_readdir>), otherwise it gets an arrayref with |
648 | C<[$name, $type, $inode]> arrayrefs, each describing a single directory |
704 | C<[$name, $type, $inode]> arrayrefs, each describing a single directory |
649 | entry in more detail. |
705 | entry in more detail. |
650 | |
706 | |
651 | C<$name> is the name of the entry. |
707 | C<$name> is the name of the entry. |
652 | |
708 | |
… | |
… | |
665 | systems that do not deliver the inode information. |
721 | systems that do not deliver the inode information. |
666 | |
722 | |
667 | =item IO::AIO::READDIR_DIRS_FIRST |
723 | =item IO::AIO::READDIR_DIRS_FIRST |
668 | |
724 | |
669 | When this flag is set, then the names will be returned in an order where |
725 | When this flag is set, then the names will be returned in an order where |
670 | likely directories come first. This is useful when you need to quickly |
726 | likely directories come first, in optimal stat order. This is useful when |
671 | find directories, or you want to find all directories while avoiding to |
727 | you need to quickly find directories, or you want to find all directories |
672 | stat() each entry. |
728 | while avoiding to stat() each entry. |
673 | |
729 | |
674 | If the system returns type information in readdir, then this is used |
730 | If the system returns type information in readdir, then this is used |
675 | to find directories directly. Otherwise, likely directories are files |
731 | to find directories directly. Otherwise, likely directories are names |
676 | beginning with ".", or otherwise files with no dots, of which files with |
732 | beginning with ".", or otherwise names with no dots, of which names with |
677 | short names are tried first. |
733 | short names are tried first. |
678 | |
734 | |
679 | =item IO::AIO::READDIR_STAT_ORDER |
735 | =item IO::AIO::READDIR_STAT_ORDER |
680 | |
736 | |
681 | When this flag is set, then the names will be returned in an order |
737 | When this flag is set, then the names will be returned in an order |
… | |
… | |
826 | if ($_[0] && $! == EXDEV) { |
882 | if ($_[0] && $! == EXDEV) { |
827 | aioreq_pri $pri; |
883 | aioreq_pri $pri; |
828 | add $grp aio_copy $src, $dst, sub { |
884 | add $grp aio_copy $src, $dst, sub { |
829 | $grp->result ($_[0]); |
885 | $grp->result ($_[0]); |
830 | |
886 | |
831 | if (!$_[0]) { |
887 | unless ($_[0]) { |
832 | aioreq_pri $pri; |
888 | aioreq_pri $pri; |
833 | add $grp aio_unlink $src; |
889 | add $grp aio_unlink $src; |
834 | } |
890 | } |
835 | }; |
891 | }; |
836 | } else { |
892 | } else { |
… | |
… | |
1108 | as for C<aio_msync>, above, except for flags, which must be either |
1164 | as for C<aio_msync>, above, except for flags, which must be either |
1109 | C<0> (which reads all pages and ensures they are instantiated) or |
1165 | C<0> (which reads all pages and ensures they are instantiated) or |
1110 | C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and |
1166 | C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and |
1111 | writing an octet from it, which dirties the page). |
1167 | writing an octet from it, which dirties the page). |
1112 | |
1168 | |
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|
1169 | =item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
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|
1170 | |
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1171 | This is a rather advanced IO::AIO call, which works best on mmap(2)ed |
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1172 | scalars. |
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|
1173 | |
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|
1174 | It reads in all the pages of the underlying storage into memory (if any) |
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1175 | and locks them, so they are not getting swapped/paged out or removed. |
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|
1176 | |
|
|
1177 | If C<$length> is undefined, then the scalar will be locked till the end. |
|
|
1178 | |
|
|
1179 | On systems that do not implement C<mlock>, this function returns C<-1> |
|
|
1180 | and sets errno to C<ENOSYS>. |
|
|
1181 | |
|
|
1182 | Note that the corresponding C<munlock> is synchronous and is |
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|
1183 | documented under L<MISCELLANEOUS FUNCTIONS>. |
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|
1184 | |
|
|
1185 | Example: open a file, mmap and mlock it - both will be undone when |
|
|
1186 | C<$data> gets destroyed. |
|
|
1187 | |
|
|
1188 | open my $fh, "<", $path or die "$path: $!"; |
|
|
1189 | my $data; |
|
|
1190 | IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh; |
|
|
1191 | aio_mlock $data; # mlock in background |
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|
1192 | |
|
|
1193 | =item aio_mlockall $flags, $callback->($status) |
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|
1194 | |
|
|
1195 | Calls the C<mlockall> function with the given C<$flags> (a combination of |
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|
1196 | C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>). |
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|
1197 | |
|
|
1198 | On systems that do not implement C<mlockall>, this function returns C<-1> |
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|
1199 | and sets errno to C<ENOSYS>. |
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|
1200 | |
|
|
1201 | Note that the corresponding C<munlockall> is synchronous and is |
|
|
1202 | documented under L<MISCELLANEOUS FUNCTIONS>. |
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|
1203 | |
|
|
1204 | Example: asynchronously lock all current and future pages into memory. |
|
|
1205 | |
|
|
1206 | aio_mlockall IO::AIO::MCL_FUTURE; |
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|
1207 | |
1113 | =item aio_group $callback->(...) |
1208 | =item aio_group $callback->(...) |
1114 | |
1209 | |
1115 | This is a very special aio request: Instead of doing something, it is a |
1210 | This is a very special aio request: Instead of doing something, it is a |
1116 | container for other aio requests, which is useful if you want to bundle |
1211 | container for other aio requests, which is useful if you want to bundle |
1117 | many requests into a single, composite, request with a definite callback |
1212 | many requests into a single, composite, request with a definite callback |
… | |
… | |
1340 | |
1435 | |
1341 | See C<poll_cb> for an example. |
1436 | See C<poll_cb> for an example. |
1342 | |
1437 | |
1343 | =item IO::AIO::poll_cb |
1438 | =item IO::AIO::poll_cb |
1344 | |
1439 | |
1345 | Process some outstanding events on the result pipe. You have to call this |
1440 | Process some outstanding events on the result pipe. You have to call |
1346 | regularly. Returns C<0> if all events could be processed, or C<-1> if it |
1441 | this regularly. Returns C<0> if all events could be processed (or there |
1347 | returned earlier for whatever reason. Returns immediately when no events |
1442 | were no events to process), or C<-1> if it returned earlier for whatever |
1348 | are outstanding. The amount of events processed depends on the settings of |
1443 | reason. Returns immediately when no events are outstanding. The amount of |
1349 | C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>. |
1444 | events processed depends on the settings of C<IO::AIO::max_poll_req> and |
|
|
1445 | C<IO::AIO::max_poll_time>. |
1350 | |
1446 | |
1351 | If not all requests were processed for whatever reason, the filehandle |
1447 | If not all requests were processed for whatever reason, the filehandle |
1352 | will still be ready when C<poll_cb> returns, so normally you don't have to |
1448 | will still be ready when C<poll_cb> returns, so normally you don't have to |
1353 | do anything special to have it called later. |
1449 | do anything special to have it called later. |
|
|
1450 | |
|
|
1451 | Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes |
|
|
1452 | ready, it can be beneficial to call this function from loops which submit |
|
|
1453 | a lot of requests, to make sure the results get processed when they become |
|
|
1454 | available and not just when the loop is finished and the event loop takes |
|
|
1455 | over again. This function returns very fast when there are no outstanding |
|
|
1456 | requests. |
1354 | |
1457 | |
1355 | Example: Install an Event watcher that automatically calls |
1458 | Example: Install an Event watcher that automatically calls |
1356 | IO::AIO::poll_cb with high priority (more examples can be found in the |
1459 | IO::AIO::poll_cb with high priority (more examples can be found in the |
1357 | SYNOPSIS section, at the top of this document): |
1460 | SYNOPSIS section, at the top of this document): |
1358 | |
1461 | |
… | |
… | |
1460 | |
1563 | |
1461 | Under normal circumstances you don't need to call this function. |
1564 | Under normal circumstances you don't need to call this function. |
1462 | |
1565 | |
1463 | =item IO::AIO::max_idle $nthreads |
1566 | =item IO::AIO::max_idle $nthreads |
1464 | |
1567 | |
1465 | Limit the number of threads (default: 4) that are allowed to idle (i.e., |
1568 | Limit the number of threads (default: 4) that are allowed to idle |
1466 | threads that did not get a request to process within 10 seconds). That |
1569 | (i.e., threads that did not get a request to process within the idle |
1467 | means if a thread becomes idle while C<$nthreads> other threads are also |
1570 | timeout (default: 10 seconds). That means if a thread becomes idle while |
1468 | idle, it will free its resources and exit. |
1571 | C<$nthreads> other threads are also idle, it will free its resources and |
|
|
1572 | exit. |
1469 | |
1573 | |
1470 | This is useful when you allow a large number of threads (e.g. 100 or 1000) |
1574 | This is useful when you allow a large number of threads (e.g. 100 or 1000) |
1471 | to allow for extremely high load situations, but want to free resources |
1575 | to allow for extremely high load situations, but want to free resources |
1472 | under normal circumstances (1000 threads can easily consume 30MB of RAM). |
1576 | under normal circumstances (1000 threads can easily consume 30MB of RAM). |
1473 | |
1577 | |
1474 | The default is probably ok in most situations, especially if thread |
1578 | The default is probably ok in most situations, especially if thread |
1475 | creation is fast. If thread creation is very slow on your system you might |
1579 | creation is fast. If thread creation is very slow on your system you might |
1476 | want to use larger values. |
1580 | want to use larger values. |
1477 | |
1581 | |
|
|
1582 | =item IO::AIO::idle_timeout $seconds |
|
|
1583 | |
|
|
1584 | Sets the minimum idle timeout (default 10) after which worker threads are |
|
|
1585 | allowed to exit. SEe C<IO::AIO::max_idle>. |
|
|
1586 | |
1478 | =item IO::AIO::max_outstanding $maxreqs |
1587 | =item IO::AIO::max_outstanding $maxreqs |
|
|
1588 | |
|
|
1589 | Sets the maximum number of outstanding requests to C<$nreqs>. If |
|
|
1590 | you do queue up more than this number of requests, the next call to |
|
|
1591 | C<IO::AIO::poll_cb> (and other functions calling C<poll_cb>, such as |
|
|
1592 | C<IO::AIO::flush> or C<IO::AIO::poll>) will block until the limit is no |
|
|
1593 | longer exceeded. |
|
|
1594 | |
|
|
1595 | In other words, this setting does not enforce a queue limit, but can be |
|
|
1596 | used to make poll functions block if the limit is exceeded. |
1479 | |
1597 | |
1480 | This is a very bad function to use in interactive programs because it |
1598 | This is a very bad function to use in interactive programs because it |
1481 | blocks, and a bad way to reduce concurrency because it is inexact: Better |
1599 | blocks, and a bad way to reduce concurrency because it is inexact: Better |
1482 | use an C<aio_group> together with a feed callback. |
1600 | use an C<aio_group> together with a feed callback. |
1483 | |
1601 | |
1484 | Sets the maximum number of outstanding requests to C<$nreqs>. If you |
1602 | It's main use is in scripts without an event loop - when you want to stat |
1485 | do queue up more than this number of requests, the next call to the |
1603 | a lot of files, you can write somehting like this: |
1486 | C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>) |
|
|
1487 | function will block until the limit is no longer exceeded. |
|
|
1488 | |
1604 | |
1489 | The default value is very large, so there is no practical limit on the |
1605 | IO::AIO::max_outstanding 32; |
1490 | number of outstanding requests. |
|
|
1491 | |
1606 | |
1492 | You can still queue as many requests as you want. Therefore, |
1607 | for my $path (...) { |
1493 | C<max_outstanding> is mainly useful in simple scripts (with low values) or |
1608 | aio_stat $path , ...; |
1494 | as a stop gap to shield against fatal memory overflow (with large values). |
1609 | IO::AIO::poll_cb; |
|
|
1610 | } |
|
|
1611 | |
|
|
1612 | IO::AIO::flush; |
|
|
1613 | |
|
|
1614 | The call to C<poll_cb> inside the loop will normally return instantly, but |
|
|
1615 | as soon as more thna C<32> reqeusts are in-flight, it will block until |
|
|
1616 | some requests have been handled. This keeps the loop from pushing a large |
|
|
1617 | number of C<aio_stat> requests onto the queue. |
|
|
1618 | |
|
|
1619 | The default value for C<max_outstanding> is very large, so there is no |
|
|
1620 | practical limit on the number of outstanding requests. |
1495 | |
1621 | |
1496 | =back |
1622 | =back |
1497 | |
1623 | |
1498 | =head3 STATISTICAL INFORMATION |
1624 | =head3 STATISTICAL INFORMATION |
1499 | |
1625 | |
… | |
… | |
1537 | |
1663 | |
1538 | Returns the number of bytes copied, or C<-1> on error. |
1664 | Returns the number of bytes copied, or C<-1> on error. |
1539 | |
1665 | |
1540 | =item IO::AIO::fadvise $fh, $offset, $len, $advice |
1666 | =item IO::AIO::fadvise $fh, $offset, $len, $advice |
1541 | |
1667 | |
1542 | Simply calls the C<posix_fadvise> function (see it's |
1668 | Simply calls the C<posix_fadvise> function (see its |
1543 | manpage for details). The following advice constants are |
1669 | manpage for details). The following advice constants are |
1544 | avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>, |
1670 | avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>, |
1545 | C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>, |
1671 | C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>, |
1546 | C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>. |
1672 | C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>. |
1547 | |
1673 | |
1548 | On systems that do not implement C<posix_fadvise>, this function returns |
1674 | On systems that do not implement C<posix_fadvise>, this function returns |
1549 | ENOSYS, otherwise the return value of C<posix_fadvise>. |
1675 | ENOSYS, otherwise the return value of C<posix_fadvise>. |
|
|
1676 | |
|
|
1677 | =item IO::AIO::madvise $scalar, $offset, $len, $advice |
|
|
1678 | |
|
|
1679 | Simply calls the C<posix_madvise> function (see its |
|
|
1680 | manpage for details). The following advice constants are |
|
|
1681 | avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>, |
|
|
1682 | C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>. |
|
|
1683 | |
|
|
1684 | On systems that do not implement C<posix_madvise>, this function returns |
|
|
1685 | ENOSYS, otherwise the return value of C<posix_madvise>. |
|
|
1686 | |
|
|
1687 | =item IO::AIO::mprotect $scalar, $offset, $len, $protect |
|
|
1688 | |
|
|
1689 | Simply calls the C<mprotect> function on the preferably AIO::mmap'ed |
|
|
1690 | $scalar (see its manpage for details). The following protect |
|
|
1691 | constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>, |
|
|
1692 | C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>. |
|
|
1693 | |
|
|
1694 | On systems that do not implement C<mprotect>, this function returns |
|
|
1695 | ENOSYS, otherwise the return value of C<mprotect>. |
1550 | |
1696 | |
1551 | =item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] |
1697 | =item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] |
1552 | |
1698 | |
1553 | Memory-maps a file (or anonymous memory range) and attaches it to the |
1699 | Memory-maps a file (or anonymous memory range) and attaches it to the |
1554 | given C<$scalar>, which will act like a string scalar. |
1700 | given C<$scalar>, which will act like a string scalar. |
… | |
… | |
1600 | |
1746 | |
1601 | =item IO::AIO::munmap $scalar |
1747 | =item IO::AIO::munmap $scalar |
1602 | |
1748 | |
1603 | Removes a previous mmap and undefines the C<$scalar>. |
1749 | Removes a previous mmap and undefines the C<$scalar>. |
1604 | |
1750 | |
1605 | =item IO::AIO::mlockall $flags |
1751 | =item IO::AIO::munlock $scalar, $offset = 0, $length = undef |
1606 | |
1752 | |
1607 | Calls the C<mlockall> function with the given C<$flags> (a combination of |
1753 | Calls the C<munlock> function, undoing the effects of a previous |
1608 | C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL__FUTURE>). |
1754 | C<aio_mlock> call (see its description for details). |
1609 | |
|
|
1610 | On systems that do not implement C<mlockall>, this function returns |
|
|
1611 | ENOSYS, otherwise the return value of C<mlockall>. |
|
|
1612 | |
1755 | |
1613 | =item IO::AIO::munlockall |
1756 | =item IO::AIO::munlockall |
1614 | |
1757 | |
1615 | Calls the C<munlockall> function. |
1758 | Calls the C<munlockall> function. |
1616 | |
1759 | |
… | |
… | |
1658 | Danga::Socket->AddOtherFds (IO::AIO::poll_fileno => |
1801 | Danga::Socket->AddOtherFds (IO::AIO::poll_fileno => |
1659 | \&IO::AIO::poll_cb); |
1802 | \&IO::AIO::poll_cb); |
1660 | |
1803 | |
1661 | =head2 FORK BEHAVIOUR |
1804 | =head2 FORK BEHAVIOUR |
1662 | |
1805 | |
1663 | This module should do "the right thing" when the process using it forks: |
1806 | Usage of pthreads in a program changes the semantics of fork |
|
|
1807 | considerably. Specifically, only async-safe functions can be called after |
|
|
1808 | fork. Perl doesn't know about this, so in general, you cannot call fork |
|
|
1809 | with defined behaviour in perl if pthreads are involved. IO::AIO uses |
|
|
1810 | pthreads, so this applies, but many other extensions and (for inexplicable |
|
|
1811 | reasons) perl itself often is linked against pthreads, so this limitation |
|
|
1812 | applies to quite a lot of perls. |
1664 | |
1813 | |
1665 | Before the fork, IO::AIO enters a quiescent state where no requests |
1814 | This module no longer tries to fight your OS, or POSIX. That means IO::AIO |
1666 | can be added in other threads and no results will be processed. After |
1815 | only works in the process that loaded it. Forking is fully supported, but |
1667 | the fork the parent simply leaves the quiescent state and continues |
1816 | using IO::AIO in the child is not. |
1668 | request/result processing, while the child frees the request/result queue |
|
|
1669 | (so that the requests started before the fork will only be handled in the |
|
|
1670 | parent). Threads will be started on demand until the limit set in the |
|
|
1671 | parent process has been reached again. |
|
|
1672 | |
1817 | |
1673 | In short: the parent will, after a short pause, continue as if fork had |
1818 | You might get around by not I<using> IO::AIO before (or after) |
1674 | not been called, while the child will act as if IO::AIO has not been used |
1819 | forking. You could also try to call the L<IO::AIO::reinit> function in the |
1675 | yet. |
1820 | child: |
|
|
1821 | |
|
|
1822 | =over 4 |
|
|
1823 | |
|
|
1824 | =item IO::AIO::reinit |
|
|
1825 | |
|
|
1826 | Abondons all current requests and I/O threads and simply reinitialises all |
|
|
1827 | data structures. This is not an operation suppported by any standards, but |
|
|
1828 | happens to work on GNU/Linux and some newer BSD systems. |
|
|
1829 | |
|
|
1830 | The only reasonable use for this function is to call it after forking, if |
|
|
1831 | C<IO::AIO> was used in the parent. Calling it while IO::AIO is active in |
|
|
1832 | the process will result in undefined behaviour. Calling it at any time |
|
|
1833 | will also result in any undefined (by POSIX) behaviour. |
|
|
1834 | |
|
|
1835 | =back |
1676 | |
1836 | |
1677 | =head2 MEMORY USAGE |
1837 | =head2 MEMORY USAGE |
1678 | |
1838 | |
1679 | Per-request usage: |
1839 | Per-request usage: |
1680 | |
1840 | |