… | |
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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 = '3.7'; |
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 |
178 | aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead |
178 | aio_fsync aio_syncfs 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_mlock aio_mlockall |
183 | aio_msync aio_mtouch aio_mlock aio_mlockall |
183 | aio_statvfs); |
184 | aio_statvfs); |
184 | |
185 | |
185 | our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); |
186 | our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); |
186 | our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush |
187 | our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush |
187 | min_parallel max_parallel max_idle |
188 | min_parallel max_parallel max_idle idle_timeout |
188 | nreqs nready npending nthreads |
189 | nreqs nready npending nthreads |
189 | max_poll_time max_poll_reqs |
190 | max_poll_time max_poll_reqs |
190 | sendfile fadvise madvise |
191 | sendfile fadvise madvise |
191 | mmap munmap munlock munlockall); |
192 | mmap munmap munlock munlockall); |
192 | |
193 | |
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222 | aio_unlink $pathname, $callback->($status) |
223 | aio_unlink $pathname, $callback->($status) |
223 | aio_mknod $path, $mode, $dev, $callback->($status) |
224 | aio_mknod $path, $mode, $dev, $callback->($status) |
224 | aio_link $srcpath, $dstpath, $callback->($status) |
225 | aio_link $srcpath, $dstpath, $callback->($status) |
225 | aio_symlink $srcpath, $dstpath, $callback->($status) |
226 | aio_symlink $srcpath, $dstpath, $callback->($status) |
226 | aio_readlink $path, $callback->($link) |
227 | aio_readlink $path, $callback->($link) |
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228 | aio_realpath $path, $callback->($link) |
227 | aio_rename $srcpath, $dstpath, $callback->($status) |
229 | aio_rename $srcpath, $dstpath, $callback->($status) |
228 | aio_mkdir $pathname, $mode, $callback->($status) |
230 | aio_mkdir $pathname, $mode, $callback->($status) |
229 | aio_rmdir $pathname, $callback->($status) |
231 | aio_rmdir $pathname, $callback->($status) |
230 | aio_readdir $pathname, $callback->($entries) |
232 | aio_readdir $pathname, $callback->($entries) |
231 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
233 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
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235 | aio_copy $srcpath, $dstpath, $callback->($status) |
237 | aio_copy $srcpath, $dstpath, $callback->($status) |
236 | aio_move $srcpath, $dstpath, $callback->($status) |
238 | aio_move $srcpath, $dstpath, $callback->($status) |
237 | aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
239 | aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
238 | aio_rmtree $path, $callback->($status) |
240 | aio_rmtree $path, $callback->($status) |
239 | aio_sync $callback->($status) |
241 | aio_sync $callback->($status) |
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242 | aio_syncfs $fh, $callback->($status) |
240 | aio_fsync $fh, $callback->($status) |
243 | aio_fsync $fh, $callback->($status) |
241 | aio_fdatasync $fh, $callback->($status) |
244 | aio_fdatasync $fh, $callback->($status) |
242 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
245 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
243 | aio_pathsync $path, $callback->($status) |
246 | aio_pathsync $path, $callback->($status) |
244 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
247 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
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… | |
258 | IO::AIO::max_poll_reqs $nreqs |
261 | IO::AIO::max_poll_reqs $nreqs |
259 | IO::AIO::max_poll_time $seconds |
262 | IO::AIO::max_poll_time $seconds |
260 | IO::AIO::min_parallel $nthreads |
263 | IO::AIO::min_parallel $nthreads |
261 | IO::AIO::max_parallel $nthreads |
264 | IO::AIO::max_parallel $nthreads |
262 | IO::AIO::max_idle $nthreads |
265 | IO::AIO::max_idle $nthreads |
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266 | IO::AIO::idle_timeout $seconds |
263 | IO::AIO::max_outstanding $maxreqs |
267 | IO::AIO::max_outstanding $maxreqs |
264 | IO::AIO::nreqs |
268 | IO::AIO::nreqs |
265 | IO::AIO::nready |
269 | IO::AIO::nready |
266 | IO::AIO::npending |
270 | IO::AIO::npending |
267 | |
271 | |
… | |
… | |
367 | } else { |
371 | } else { |
368 | die "open failed: $!\n"; |
372 | die "open failed: $!\n"; |
369 | } |
373 | } |
370 | }; |
374 | }; |
371 | |
375 | |
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376 | In addition to all the common open modes/flags (C<O_RDONLY>, C<O_WRONLY>, |
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377 | C<O_RDWR>, C<O_CREAT>, C<O_TRUNC>, C<O_EXCL> and C<O_APPEND>), the |
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378 | following POSIX and non-POSIX constants are available (missing ones on |
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379 | your system are, as usual, C<0>): |
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380 | |
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381 | C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>, |
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382 | C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>, |
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383 | C<O_RSYNC>, C<O_SYNC> and C<O_TTY_INIT>. |
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384 | |
372 | |
385 | |
373 | =item aio_close $fh, $callback->($status) |
386 | =item aio_close $fh, $callback->($status) |
374 | |
387 | |
375 | Asynchronously close a file and call the callback with the result |
388 | Asynchronously close a file and call the callback with the result |
376 | code. |
389 | code. |
… | |
… | |
426 | |
439 | |
427 | Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts |
440 | Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts |
428 | reading at byte offset C<$in_offset>, and starts writing at the current |
441 | reading at byte offset C<$in_offset>, and starts writing at the current |
429 | file offset of C<$out_fh>. Because of that, it is not safe to issue more |
442 | file offset of C<$out_fh>. Because of that, it is not safe to issue more |
430 | than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each |
443 | than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each |
431 | other. |
444 | other. The same C<$in_fh> works fine though, as this function does not |
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445 | move or use the file offset of C<$in_fh>. |
432 | |
446 | |
433 | Please note that C<aio_sendfile> can read more bytes from C<$in_fh> than |
447 | Please note that C<aio_sendfile> can read more bytes from C<$in_fh> than |
434 | are written, and there is no way to find out how many bytes have been read |
448 | are written, and there is no way to find out how many more bytes have been |
435 | from C<aio_sendfile> alone, as C<aio_sendfile> only provides the number of |
449 | read from C<aio_sendfile> alone, as C<aio_sendfile> only provides the |
436 | bytes written to C<$out_fh>. Only if the result value equals C<$length> |
450 | number of bytes written to C<$out_fh>. Only if the result value equals |
437 | one can assume that C<$length> bytes have been read. |
451 | C<$length> one can assume that C<$length> bytes have been read. |
438 | |
452 | |
439 | Unlike with other C<aio_> functions, it makes a lot of sense to use |
453 | Unlike with other C<aio_> functions, it makes a lot of sense to use |
440 | C<aio_sendfile> on non-blocking sockets, as long as one end (typically |
454 | C<aio_sendfile> on non-blocking sockets, as long as one end (typically |
441 | the C<$in_fh>) is a file - the file I/O will then be asynchronous, while |
455 | the C<$in_fh>) is a file - the file I/O will then be asynchronous, while |
442 | the socket I/O will be non-blocking. Note, however, that you can run into |
456 | the socket I/O will be non-blocking. Note, however, that you can run |
443 | a trap where C<aio_sendfile> reads some data with readahead, then fails |
457 | into a trap where C<aio_sendfile> reads some data with readahead, then |
444 | to write all data, and when the socket is ready the next time, the data |
458 | fails to write all data, and when the socket is ready the next time, the |
445 | in the cache is already lost, forcing C<aio_sendfile> to again hit the |
459 | data in the cache is already lost, forcing C<aio_sendfile> to again hit |
446 | disk. Explicit C<aio_read> + C<aio_write> let's you control resource usage |
460 | the disk. Explicit C<aio_read> + C<aio_write> let's you better control |
447 | much better. |
461 | resource usage. |
448 | |
462 | |
449 | This call tries to make use of a native C<sendfile> syscall to provide |
463 | This call tries to make use of a native C<sendfile>-like syscall to |
450 | zero-copy operation. For this to work, C<$out_fh> should refer to a |
464 | provide zero-copy operation. For this to work, C<$out_fh> should refer to |
451 | socket, and C<$in_fh> should refer to an mmap'able file. |
465 | a socket, and C<$in_fh> should refer to an mmap'able file. |
452 | |
466 | |
453 | If a native sendfile cannot be found or it fails with C<ENOSYS>, |
467 | If a native sendfile cannot be found or it fails with C<ENOSYS>, |
454 | C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>, |
468 | C<EINVAL>, C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or |
455 | it will be emulated, so you can call C<aio_sendfile> on any type of |
469 | C<ENOTSOCK>, it will be emulated, so you can call C<aio_sendfile> on any |
456 | filehandle regardless of the limitations of the operating system. |
470 | type of filehandle regardless of the limitations of the operating system. |
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471 | |
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472 | As native sendfile syscalls (as practically any non-POSIX interface hacked |
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473 | together in a hurry to improve benchmark numbers) tend to be rather buggy |
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474 | on many systems, this implementation tries to work around some known bugs |
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475 | in Linux and FreeBSD kernels (probably others, too), but that might fail, |
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476 | so you really really should check the return value of C<aio_sendfile> - |
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477 | fewre bytes than expected might have been transferred. |
457 | |
478 | |
458 | |
479 | |
459 | =item aio_readahead $fh,$offset,$length, $callback->($retval) |
480 | =item aio_readahead $fh,$offset,$length, $callback->($retval) |
460 | |
481 | |
461 | C<aio_readahead> populates the page cache with data from a file so that |
482 | C<aio_readahead> populates the page cache with data from a file so that |
… | |
… | |
483 | for an explanation. |
504 | for an explanation. |
484 | |
505 | |
485 | Currently, the stats are always 64-bit-stats, i.e. instead of returning an |
506 | Currently, the stats are always 64-bit-stats, i.e. instead of returning an |
486 | error when stat'ing a large file, the results will be silently truncated |
507 | error when stat'ing a large file, the results will be silently truncated |
487 | unless perl itself is compiled with large file support. |
508 | unless perl itself is compiled with large file support. |
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509 | |
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510 | To help interpret the mode and dev/rdev stat values, IO::AIO offers the |
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511 | following constants and functions (if not implemented, the constants will |
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512 | be C<0> and the functions will either C<croak> or fall back on traditional |
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513 | behaviour). |
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514 | |
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515 | C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>, |
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516 | C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>, |
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517 | C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>. |
488 | |
518 | |
489 | Example: Print the length of F</etc/passwd>: |
519 | Example: Print the length of F</etc/passwd>: |
490 | |
520 | |
491 | aio_stat "/etc/passwd", sub { |
521 | aio_stat "/etc/passwd", sub { |
492 | $_[0] and die "stat failed: $!"; |
522 | $_[0] and die "stat failed: $!"; |
… | |
… | |
594 | |
624 | |
595 | The only (POSIX-) portable way of calling this function is: |
625 | The only (POSIX-) portable way of calling this function is: |
596 | |
626 | |
597 | aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
627 | aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
598 | |
628 | |
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629 | See C<aio_stat> for info about some potentially helpful extra constants |
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630 | and functions. |
599 | |
631 | |
600 | =item aio_link $srcpath, $dstpath, $callback->($status) |
632 | =item aio_link $srcpath, $dstpath, $callback->($status) |
601 | |
633 | |
602 | Asynchronously create a new link to the existing object at C<$srcpath> at |
634 | Asynchronously create a new link to the existing object at C<$srcpath> at |
603 | the path C<$dstpath> and call the callback with the result code. |
635 | the path C<$dstpath> and call the callback with the result code. |
… | |
… | |
614 | Asynchronously read the symlink specified by C<$path> and pass it to |
646 | Asynchronously read the symlink specified by C<$path> and pass it to |
615 | the callback. If an error occurs, nothing or undef gets passed to the |
647 | the callback. If an error occurs, nothing or undef gets passed to the |
616 | callback. |
648 | callback. |
617 | |
649 | |
618 | |
650 | |
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651 | =item aio_realpath $path, $callback->($path) |
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652 | |
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653 | Asynchronously make the path absolute and resolve any symlinks in |
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654 | C<$path>. The resulting path only consists of directories (Same as |
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655 | L<Cwd::realpath>). |
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656 | |
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657 | This request can be used to get the absolute path of the current working |
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658 | directory by passing it a path of F<.> (a single dot). |
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659 | |
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660 | |
619 | =item aio_rename $srcpath, $dstpath, $callback->($status) |
661 | =item aio_rename $srcpath, $dstpath, $callback->($status) |
620 | |
662 | |
621 | Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as |
663 | Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as |
622 | rename(2) and call the callback with the result code. |
664 | rename(2) and call the callback with the result code. |
623 | |
665 | |
… | |
… | |
645 | array-ref with the filenames. |
687 | array-ref with the filenames. |
646 | |
688 | |
647 | |
689 | |
648 | =item aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
690 | =item aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
649 | |
691 | |
650 | Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune |
692 | Quite similar to C<aio_readdir>, but the C<$flags> argument allows one to |
651 | behaviour and output format. In case of an error, C<$entries> will be |
693 | tune behaviour and output format. In case of an error, C<$entries> will be |
652 | C<undef>. |
694 | C<undef>. |
653 | |
695 | |
654 | The flags are a combination of the following constants, ORed together (the |
696 | The flags are a combination of the following constants, ORed together (the |
655 | flags will also be passed to the callback, possibly modified): |
697 | flags will also be passed to the callback, possibly modified): |
656 | |
698 | |
657 | =over 4 |
699 | =over 4 |
658 | |
700 | |
659 | =item IO::AIO::READDIR_DENTS |
701 | =item IO::AIO::READDIR_DENTS |
660 | |
702 | |
661 | When this flag is off, then the callback gets an arrayref with of names |
703 | When this flag is off, then the callback gets an arrayref consisting of |
662 | only (as with C<aio_readdir>), otherwise it gets an arrayref with |
704 | names only (as with C<aio_readdir>), otherwise it gets an arrayref with |
663 | C<[$name, $type, $inode]> arrayrefs, each describing a single directory |
705 | C<[$name, $type, $inode]> arrayrefs, each describing a single directory |
664 | entry in more detail. |
706 | entry in more detail. |
665 | |
707 | |
666 | C<$name> is the name of the entry. |
708 | C<$name> is the name of the entry. |
667 | |
709 | |
… | |
… | |
680 | systems that do not deliver the inode information. |
722 | systems that do not deliver the inode information. |
681 | |
723 | |
682 | =item IO::AIO::READDIR_DIRS_FIRST |
724 | =item IO::AIO::READDIR_DIRS_FIRST |
683 | |
725 | |
684 | When this flag is set, then the names will be returned in an order where |
726 | When this flag is set, then the names will be returned in an order where |
685 | likely directories come first. This is useful when you need to quickly |
727 | likely directories come first, in optimal stat order. This is useful when |
686 | find directories, or you want to find all directories while avoiding to |
728 | you need to quickly find directories, or you want to find all directories |
687 | stat() each entry. |
729 | while avoiding to stat() each entry. |
688 | |
730 | |
689 | If the system returns type information in readdir, then this is used |
731 | If the system returns type information in readdir, then this is used |
690 | to find directories directly. Otherwise, likely directories are files |
732 | to find directories directly. Otherwise, likely directories are names |
691 | beginning with ".", or otherwise files with no dots, of which files with |
733 | beginning with ".", or otherwise names with no dots, of which names with |
692 | short names are tried first. |
734 | short names are tried first. |
693 | |
735 | |
694 | =item IO::AIO::READDIR_STAT_ORDER |
736 | =item IO::AIO::READDIR_STAT_ORDER |
695 | |
737 | |
696 | When this flag is set, then the names will be returned in an order |
738 | When this flag is set, then the names will be returned in an order |
… | |
… | |
703 | |
745 | |
704 | =item IO::AIO::READDIR_FOUND_UNKNOWN |
746 | =item IO::AIO::READDIR_FOUND_UNKNOWN |
705 | |
747 | |
706 | This flag should not be set when calling C<aio_readdirx>. Instead, it |
748 | This flag should not be set when calling C<aio_readdirx>. Instead, it |
707 | is being set by C<aio_readdirx>, when any of the C<$type>'s found were |
749 | is being set by C<aio_readdirx>, when any of the C<$type>'s found were |
708 | C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all |
750 | C<IO::AIO::DT_UNKNOWN>. The absence of this flag therefore indicates that all |
709 | C<$type>'s are known, which can be used to speed up some algorithms. |
751 | C<$type>'s are known, which can be used to speed up some algorithms. |
710 | |
752 | |
711 | =back |
753 | =back |
712 | |
754 | |
713 | |
755 | |
… | |
… | |
841 | if ($_[0] && $! == EXDEV) { |
883 | if ($_[0] && $! == EXDEV) { |
842 | aioreq_pri $pri; |
884 | aioreq_pri $pri; |
843 | add $grp aio_copy $src, $dst, sub { |
885 | add $grp aio_copy $src, $dst, sub { |
844 | $grp->result ($_[0]); |
886 | $grp->result ($_[0]); |
845 | |
887 | |
846 | if (!$_[0]) { |
888 | unless ($_[0]) { |
847 | aioreq_pri $pri; |
889 | aioreq_pri $pri; |
848 | add $grp aio_unlink $src; |
890 | add $grp aio_unlink $src; |
849 | } |
891 | } |
850 | }; |
892 | }; |
851 | } else { |
893 | } else { |
… | |
… | |
895 | Then entries will be sorted into likely directories a non-initial dot |
937 | Then entries will be sorted into likely directories a non-initial dot |
896 | currently) and likely non-directories (see C<aio_readdirx>). Then every |
938 | currently) and likely non-directories (see C<aio_readdirx>). Then every |
897 | entry plus an appended C</.> will be C<stat>'ed, likely directories first, |
939 | entry plus an appended C</.> will be C<stat>'ed, likely directories first, |
898 | in order of their inode numbers. If that succeeds, it assumes that the |
940 | in order of their inode numbers. If that succeeds, it assumes that the |
899 | entry is a directory or a symlink to directory (which will be checked |
941 | entry is a directory or a symlink to directory (which will be checked |
900 | seperately). This is often faster than stat'ing the entry itself because |
942 | separately). This is often faster than stat'ing the entry itself because |
901 | filesystems might detect the type of the entry without reading the inode |
943 | filesystems might detect the type of the entry without reading the inode |
902 | data (e.g. ext2fs filetype feature), even on systems that cannot return |
944 | data (e.g. ext2fs filetype feature), even on systems that cannot return |
903 | the filetype information on readdir. |
945 | the filetype information on readdir. |
904 | |
946 | |
905 | If the known number of directories (link count - 2) has been reached, the |
947 | If the known number of directories (link count - 2) has been reached, the |
… | |
… | |
1043 | callback with the fdatasync result code. |
1085 | callback with the fdatasync result code. |
1044 | |
1086 | |
1045 | If this call isn't available because your OS lacks it or it couldn't be |
1087 | If this call isn't available because your OS lacks it or it couldn't be |
1046 | detected, it will be emulated by calling C<fsync> instead. |
1088 | detected, it will be emulated by calling C<fsync> instead. |
1047 | |
1089 | |
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1090 | =item aio_syncfs $fh, $callback->($status) |
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1091 | |
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1092 | Asynchronously call the syncfs syscall to sync the filesystem associated |
|
|
1093 | to the given filehandle and call the callback with the syncfs result |
|
|
1094 | code. If syncfs is not available, calls sync(), but returns C<-1> and sets |
|
|
1095 | errno to C<ENOSYS> nevertheless. |
|
|
1096 | |
1048 | =item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
1097 | =item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
1049 | |
1098 | |
1050 | Sync the data portion of the file specified by C<$offset> and C<$length> |
1099 | Sync the data portion of the file specified by C<$offset> and C<$length> |
1051 | to disk (but NOT the metadata), by calling the Linux-specific |
1100 | to disk (but NOT the metadata), by calling the Linux-specific |
1052 | sync_file_range call. If sync_file_range is not available or it returns |
1101 | sync_file_range call. If sync_file_range is not available or it returns |
… | |
… | |
1394 | |
1443 | |
1395 | See C<poll_cb> for an example. |
1444 | See C<poll_cb> for an example. |
1396 | |
1445 | |
1397 | =item IO::AIO::poll_cb |
1446 | =item IO::AIO::poll_cb |
1398 | |
1447 | |
1399 | Process some outstanding events on the result pipe. You have to call this |
1448 | Process some outstanding events on the result pipe. You have to call |
1400 | regularly. Returns C<0> if all events could be processed, or C<-1> if it |
1449 | this regularly. Returns C<0> if all events could be processed (or there |
1401 | returned earlier for whatever reason. Returns immediately when no events |
1450 | were no events to process), or C<-1> if it returned earlier for whatever |
1402 | are outstanding. The amount of events processed depends on the settings of |
1451 | reason. Returns immediately when no events are outstanding. The amount of |
1403 | C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>. |
1452 | events processed depends on the settings of C<IO::AIO::max_poll_req> and |
|
|
1453 | C<IO::AIO::max_poll_time>. |
1404 | |
1454 | |
1405 | If not all requests were processed for whatever reason, the filehandle |
1455 | If not all requests were processed for whatever reason, the filehandle |
1406 | will still be ready when C<poll_cb> returns, so normally you don't have to |
1456 | will still be ready when C<poll_cb> returns, so normally you don't have to |
1407 | do anything special to have it called later. |
1457 | do anything special to have it called later. |
|
|
1458 | |
|
|
1459 | Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes |
|
|
1460 | ready, it can be beneficial to call this function from loops which submit |
|
|
1461 | a lot of requests, to make sure the results get processed when they become |
|
|
1462 | available and not just when the loop is finished and the event loop takes |
|
|
1463 | over again. This function returns very fast when there are no outstanding |
|
|
1464 | requests. |
1408 | |
1465 | |
1409 | Example: Install an Event watcher that automatically calls |
1466 | Example: Install an Event watcher that automatically calls |
1410 | IO::AIO::poll_cb with high priority (more examples can be found in the |
1467 | IO::AIO::poll_cb with high priority (more examples can be found in the |
1411 | SYNOPSIS section, at the top of this document): |
1468 | SYNOPSIS section, at the top of this document): |
1412 | |
1469 | |
… | |
… | |
1514 | |
1571 | |
1515 | Under normal circumstances you don't need to call this function. |
1572 | Under normal circumstances you don't need to call this function. |
1516 | |
1573 | |
1517 | =item IO::AIO::max_idle $nthreads |
1574 | =item IO::AIO::max_idle $nthreads |
1518 | |
1575 | |
1519 | Limit the number of threads (default: 4) that are allowed to idle (i.e., |
1576 | Limit the number of threads (default: 4) that are allowed to idle |
1520 | threads that did not get a request to process within 10 seconds). That |
1577 | (i.e., threads that did not get a request to process within the idle |
1521 | means if a thread becomes idle while C<$nthreads> other threads are also |
1578 | timeout (default: 10 seconds). That means if a thread becomes idle while |
1522 | idle, it will free its resources and exit. |
1579 | C<$nthreads> other threads are also idle, it will free its resources and |
|
|
1580 | exit. |
1523 | |
1581 | |
1524 | This is useful when you allow a large number of threads (e.g. 100 or 1000) |
1582 | This is useful when you allow a large number of threads (e.g. 100 or 1000) |
1525 | to allow for extremely high load situations, but want to free resources |
1583 | to allow for extremely high load situations, but want to free resources |
1526 | under normal circumstances (1000 threads can easily consume 30MB of RAM). |
1584 | under normal circumstances (1000 threads can easily consume 30MB of RAM). |
1527 | |
1585 | |
1528 | The default is probably ok in most situations, especially if thread |
1586 | The default is probably ok in most situations, especially if thread |
1529 | creation is fast. If thread creation is very slow on your system you might |
1587 | creation is fast. If thread creation is very slow on your system you might |
1530 | want to use larger values. |
1588 | want to use larger values. |
1531 | |
1589 | |
|
|
1590 | =item IO::AIO::idle_timeout $seconds |
|
|
1591 | |
|
|
1592 | Sets the minimum idle timeout (default 10) after which worker threads are |
|
|
1593 | allowed to exit. SEe C<IO::AIO::max_idle>. |
|
|
1594 | |
1532 | =item IO::AIO::max_outstanding $maxreqs |
1595 | =item IO::AIO::max_outstanding $maxreqs |
|
|
1596 | |
|
|
1597 | Sets the maximum number of outstanding requests to C<$nreqs>. If |
|
|
1598 | you do queue up more than this number of requests, the next call to |
|
|
1599 | C<IO::AIO::poll_cb> (and other functions calling C<poll_cb>, such as |
|
|
1600 | C<IO::AIO::flush> or C<IO::AIO::poll>) will block until the limit is no |
|
|
1601 | longer exceeded. |
|
|
1602 | |
|
|
1603 | In other words, this setting does not enforce a queue limit, but can be |
|
|
1604 | used to make poll functions block if the limit is exceeded. |
1533 | |
1605 | |
1534 | This is a very bad function to use in interactive programs because it |
1606 | This is a very bad function to use in interactive programs because it |
1535 | blocks, and a bad way to reduce concurrency because it is inexact: Better |
1607 | blocks, and a bad way to reduce concurrency because it is inexact: Better |
1536 | use an C<aio_group> together with a feed callback. |
1608 | use an C<aio_group> together with a feed callback. |
1537 | |
1609 | |
1538 | Sets the maximum number of outstanding requests to C<$nreqs>. If you |
1610 | It's main use is in scripts without an event loop - when you want to stat |
1539 | do queue up more than this number of requests, the next call to the |
1611 | a lot of files, you can write somehting like this: |
1540 | C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>) |
|
|
1541 | function will block until the limit is no longer exceeded. |
|
|
1542 | |
1612 | |
1543 | The default value is very large, so there is no practical limit on the |
1613 | IO::AIO::max_outstanding 32; |
1544 | number of outstanding requests. |
|
|
1545 | |
1614 | |
1546 | You can still queue as many requests as you want. Therefore, |
1615 | for my $path (...) { |
1547 | C<max_outstanding> is mainly useful in simple scripts (with low values) or |
1616 | aio_stat $path , ...; |
1548 | as a stop gap to shield against fatal memory overflow (with large values). |
1617 | IO::AIO::poll_cb; |
|
|
1618 | } |
|
|
1619 | |
|
|
1620 | IO::AIO::flush; |
|
|
1621 | |
|
|
1622 | The call to C<poll_cb> inside the loop will normally return instantly, but |
|
|
1623 | as soon as more thna C<32> reqeusts are in-flight, it will block until |
|
|
1624 | some requests have been handled. This keeps the loop from pushing a large |
|
|
1625 | number of C<aio_stat> requests onto the queue. |
|
|
1626 | |
|
|
1627 | The default value for C<max_outstanding> is very large, so there is no |
|
|
1628 | practical limit on the number of outstanding requests. |
1549 | |
1629 | |
1550 | =back |
1630 | =back |
1551 | |
1631 | |
1552 | =head3 STATISTICAL INFORMATION |
1632 | =head3 STATISTICAL INFORMATION |
1553 | |
1633 | |
… | |
… | |
1593 | |
1673 | |
1594 | =item IO::AIO::fadvise $fh, $offset, $len, $advice |
1674 | =item IO::AIO::fadvise $fh, $offset, $len, $advice |
1595 | |
1675 | |
1596 | Simply calls the C<posix_fadvise> function (see its |
1676 | Simply calls the C<posix_fadvise> function (see its |
1597 | manpage for details). The following advice constants are |
1677 | manpage for details). The following advice constants are |
1598 | avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>, |
1678 | available: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>, |
1599 | C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>, |
1679 | C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>, |
1600 | C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>. |
1680 | C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>. |
1601 | |
1681 | |
1602 | On systems that do not implement C<posix_fadvise>, this function returns |
1682 | On systems that do not implement C<posix_fadvise>, this function returns |
1603 | ENOSYS, otherwise the return value of C<posix_fadvise>. |
1683 | ENOSYS, otherwise the return value of C<posix_fadvise>. |
1604 | |
1684 | |
1605 | =item IO::AIO::madvise $scalar, $offset, $len, $advice |
1685 | =item IO::AIO::madvise $scalar, $offset, $len, $advice |
1606 | |
1686 | |
1607 | Simply calls the C<posix_madvise> function (see its |
1687 | Simply calls the C<posix_madvise> function (see its |
1608 | manpage for details). The following advice constants are |
1688 | manpage for details). The following advice constants are |
1609 | avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>, |
1689 | available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>, |
1610 | C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>. |
1690 | C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>. |
1611 | |
1691 | |
1612 | On systems that do not implement C<posix_madvise>, this function returns |
1692 | On systems that do not implement C<posix_madvise>, this function returns |
1613 | ENOSYS, otherwise the return value of C<posix_madvise>. |
1693 | ENOSYS, otherwise the return value of C<posix_madvise>. |
1614 | |
1694 | |
1615 | =item IO::AIO::mprotect $scalar, $offset, $len, $protect |
1695 | =item IO::AIO::mprotect $scalar, $offset, $len, $protect |
1616 | |
1696 | |
1617 | Simply calls the C<mprotect> function on the preferably AIO::mmap'ed |
1697 | Simply calls the C<mprotect> function on the preferably AIO::mmap'ed |
1618 | $scalar (see its manpage for details). The following protect |
1698 | $scalar (see its manpage for details). The following protect |
1619 | constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>, |
1699 | constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>, |
1620 | C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>. |
1700 | C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>. |
1621 | |
1701 | |
1622 | On systems that do not implement C<mprotect>, this function returns |
1702 | On systems that do not implement C<mprotect>, this function returns |
1623 | ENOSYS, otherwise the return value of C<mprotect>. |
1703 | ENOSYS, otherwise the return value of C<mprotect>. |
1624 | |
1704 | |
… | |
… | |
1729 | Danga::Socket->AddOtherFds (IO::AIO::poll_fileno => |
1809 | Danga::Socket->AddOtherFds (IO::AIO::poll_fileno => |
1730 | \&IO::AIO::poll_cb); |
1810 | \&IO::AIO::poll_cb); |
1731 | |
1811 | |
1732 | =head2 FORK BEHAVIOUR |
1812 | =head2 FORK BEHAVIOUR |
1733 | |
1813 | |
1734 | This module should do "the right thing" when the process using it forks: |
1814 | Usage of pthreads in a program changes the semantics of fork |
|
|
1815 | considerably. Specifically, only async-safe functions can be called after |
|
|
1816 | fork. Perl doesn't know about this, so in general, you cannot call fork |
|
|
1817 | with defined behaviour in perl if pthreads are involved. IO::AIO uses |
|
|
1818 | pthreads, so this applies, but many other extensions and (for inexplicable |
|
|
1819 | reasons) perl itself often is linked against pthreads, so this limitation |
|
|
1820 | applies to quite a lot of perls. |
1735 | |
1821 | |
1736 | Before the fork, IO::AIO enters a quiescent state where no requests |
1822 | This module no longer tries to fight your OS, or POSIX. That means IO::AIO |
1737 | can be added in other threads and no results will be processed. After |
1823 | only works in the process that loaded it. Forking is fully supported, but |
1738 | the fork the parent simply leaves the quiescent state and continues |
1824 | using IO::AIO in the child is not. |
1739 | request/result processing, while the child frees the request/result queue |
|
|
1740 | (so that the requests started before the fork will only be handled in the |
|
|
1741 | parent). Threads will be started on demand until the limit set in the |
|
|
1742 | parent process has been reached again. |
|
|
1743 | |
1825 | |
1744 | In short: the parent will, after a short pause, continue as if fork had |
1826 | You might get around by not I<using> IO::AIO before (or after) |
1745 | not been called, while the child will act as if IO::AIO has not been used |
1827 | forking. You could also try to call the L<IO::AIO::reinit> function in the |
1746 | yet. |
1828 | child: |
|
|
1829 | |
|
|
1830 | =over 4 |
|
|
1831 | |
|
|
1832 | =item IO::AIO::reinit |
|
|
1833 | |
|
|
1834 | Abandons all current requests and I/O threads and simply reinitialises all |
|
|
1835 | data structures. This is not an operation supported by any standards, but |
|
|
1836 | happens to work on GNU/Linux and some newer BSD systems. |
|
|
1837 | |
|
|
1838 | The only reasonable use for this function is to call it after forking, if |
|
|
1839 | C<IO::AIO> was used in the parent. Calling it while IO::AIO is active in |
|
|
1840 | the process will result in undefined behaviour. Calling it at any time |
|
|
1841 | will also result in any undefined (by POSIX) behaviour. |
|
|
1842 | |
|
|
1843 | =back |
1747 | |
1844 | |
1748 | =head2 MEMORY USAGE |
1845 | =head2 MEMORY USAGE |
1749 | |
1846 | |
1750 | Per-request usage: |
1847 | Per-request usage: |
1751 | |
1848 | |