1 | =head1 NAME |
1 | =head1 NAME |
2 | |
2 | |
3 | IO::AIO - Asynchronous Input/Output |
3 | IO::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 | |
… | |
… | |
58 | not well-supported or restricted (GNU/Linux doesn't allow them on normal |
58 | not well-supported or restricted (GNU/Linux doesn't allow them on normal |
59 | files currently, for example), and they would only support aio_read and |
59 | files currently, for example), and they would only support aio_read and |
60 | aio_write, so the remaining functionality would have to be implemented |
60 | aio_write, so the remaining functionality would have to be implemented |
61 | using threads anyway. |
61 | using threads anyway. |
62 | |
62 | |
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63 | In addition to asynchronous I/O, this module also exports some rather |
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64 | arcane interfaces, such as C<madvise> or linux's C<splice> system call, |
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65 | which is why the C<A> in C<AIO> can also mean I<advanced>. |
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66 | |
63 | Although the module will work in the presence of other (Perl-) threads, |
67 | Although the module will work in the presence of other (Perl-) threads, |
64 | it is currently not reentrant in any way, so use appropriate locking |
68 | it is currently not reentrant in any way, so use appropriate locking |
65 | yourself, always call C<poll_cb> from within the same thread, or never |
69 | yourself, always call C<poll_cb> from within the same thread, or never |
66 | call C<poll_cb> (or other C<aio_> functions) recursively. |
70 | call C<poll_cb> (or other C<aio_> functions) recursively. |
67 | |
71 | |
… | |
… | |
94 | |
98 | |
95 | # file contents now in $contents |
99 | # file contents now in $contents |
96 | print $contents; |
100 | print $contents; |
97 | |
101 | |
98 | # exit event loop and program |
102 | # exit event loop and program |
99 | EV::unloop; |
103 | EV::break; |
100 | }; |
104 | }; |
101 | }; |
105 | }; |
102 | |
106 | |
103 | # possibly queue up other requests, or open GUI windows, |
107 | # possibly queue up other requests, or open GUI windows, |
104 | # check for sockets etc. etc. |
108 | # check for sockets etc. etc. |
105 | |
109 | |
106 | # process events as long as there are some: |
110 | # process events as long as there are some: |
107 | EV::loop; |
111 | EV::run; |
108 | |
112 | |
109 | =head1 REQUEST ANATOMY AND LIFETIME |
113 | =head1 REQUEST ANATOMY AND LIFETIME |
110 | |
114 | |
111 | Every C<aio_*> function creates a request. which is a C data structure not |
115 | Every C<aio_*> function creates a request. which is a C data structure not |
112 | directly visible to Perl. |
116 | directly visible to Perl. |
… | |
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167 | use common::sense; |
171 | use common::sense; |
168 | |
172 | |
169 | use base 'Exporter'; |
173 | use base 'Exporter'; |
170 | |
174 | |
171 | BEGIN { |
175 | BEGIN { |
172 | our $VERSION = '4.19'; |
176 | our $VERSION = 4.34; |
173 | |
177 | |
174 | our @AIO_REQ = qw(aio_sendfile aio_seek aio_read aio_write aio_open aio_close |
178 | our @AIO_REQ = qw(aio_sendfile aio_seek aio_read aio_write aio_open aio_close |
175 | aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx |
179 | aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx |
176 | aio_scandir aio_symlink aio_readlink aio_realpath aio_sync |
180 | aio_scandir aio_symlink aio_readlink aio_realpath aio_fcntl aio_ioctl |
177 | aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range aio_allocate |
181 | aio_sync aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range |
178 | aio_pathsync aio_readahead aio_fiemap |
182 | aio_pathsync aio_readahead aio_fiemap aio_allocate |
179 | aio_rename aio_link aio_move aio_copy aio_group |
183 | aio_rename aio_link aio_move aio_copy aio_group |
180 | aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown |
184 | aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown |
181 | aio_chmod aio_utime aio_truncate |
185 | aio_chmod aio_utime aio_truncate |
182 | aio_msync aio_mtouch aio_mlock aio_mlockall |
186 | aio_msync aio_mtouch aio_mlock aio_mlockall |
183 | aio_statvfs |
187 | aio_statvfs |
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227 | aio_unlink $pathname, $callback->($status) |
231 | aio_unlink $pathname, $callback->($status) |
228 | aio_mknod $pathname, $mode, $dev, $callback->($status) |
232 | aio_mknod $pathname, $mode, $dev, $callback->($status) |
229 | aio_link $srcpath, $dstpath, $callback->($status) |
233 | aio_link $srcpath, $dstpath, $callback->($status) |
230 | aio_symlink $srcpath, $dstpath, $callback->($status) |
234 | aio_symlink $srcpath, $dstpath, $callback->($status) |
231 | aio_readlink $pathname, $callback->($link) |
235 | aio_readlink $pathname, $callback->($link) |
232 | aio_realpath $pathname, $callback->($link) |
236 | aio_realpath $pathname, $callback->($path) |
233 | aio_rename $srcpath, $dstpath, $callback->($status) |
237 | aio_rename $srcpath, $dstpath, $callback->($status) |
234 | aio_mkdir $pathname, $mode, $callback->($status) |
238 | aio_mkdir $pathname, $mode, $callback->($status) |
235 | aio_rmdir $pathname, $callback->($status) |
239 | aio_rmdir $pathname, $callback->($status) |
236 | aio_readdir $pathname, $callback->($entries) |
240 | aio_readdir $pathname, $callback->($entries) |
237 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
241 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
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240 | aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) |
244 | aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) |
241 | aio_load $pathname, $data, $callback->($status) |
245 | aio_load $pathname, $data, $callback->($status) |
242 | aio_copy $srcpath, $dstpath, $callback->($status) |
246 | aio_copy $srcpath, $dstpath, $callback->($status) |
243 | aio_move $srcpath, $dstpath, $callback->($status) |
247 | aio_move $srcpath, $dstpath, $callback->($status) |
244 | aio_rmtree $pathname, $callback->($status) |
248 | aio_rmtree $pathname, $callback->($status) |
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249 | aio_fcntl $fh, $cmd, $arg, $callback->($status) |
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250 | aio_ioctl $fh, $request, $buf, $callback->($status) |
245 | aio_sync $callback->($status) |
251 | aio_sync $callback->($status) |
246 | aio_syncfs $fh, $callback->($status) |
252 | aio_syncfs $fh, $callback->($status) |
247 | aio_fsync $fh, $callback->($status) |
253 | aio_fsync $fh, $callback->($status) |
248 | aio_fdatasync $fh, $callback->($status) |
254 | aio_fdatasync $fh, $callback->($status) |
249 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
255 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
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394 | following POSIX and non-POSIX constants are available (missing ones on |
400 | following POSIX and non-POSIX constants are available (missing ones on |
395 | your system are, as usual, C<0>): |
401 | your system are, as usual, C<0>): |
396 | |
402 | |
397 | C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>, |
403 | C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>, |
398 | C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>, |
404 | C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>, |
399 | C<O_RSYNC>, C<O_SYNC> and C<O_TTY_INIT>. |
405 | C<O_RSYNC>, C<O_SYNC>, C<O_PATH>, C<O_TMPFILE>, and C<O_TTY_INIT>. |
400 | |
406 | |
401 | |
407 | |
402 | =item aio_close $fh, $callback->($status) |
408 | =item aio_close $fh, $callback->($status) |
403 | |
409 | |
404 | Asynchronously close a file and call the callback with the result |
410 | Asynchronously close a file and call the callback with the result |
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508 | As native sendfile syscalls (as practically any non-POSIX interface hacked |
514 | As native sendfile syscalls (as practically any non-POSIX interface hacked |
509 | together in a hurry to improve benchmark numbers) tend to be rather buggy |
515 | together in a hurry to improve benchmark numbers) tend to be rather buggy |
510 | on many systems, this implementation tries to work around some known bugs |
516 | on many systems, this implementation tries to work around some known bugs |
511 | in Linux and FreeBSD kernels (probably others, too), but that might fail, |
517 | in Linux and FreeBSD kernels (probably others, too), but that might fail, |
512 | so you really really should check the return value of C<aio_sendfile> - |
518 | so you really really should check the return value of C<aio_sendfile> - |
513 | fewre bytes than expected might have been transferred. |
519 | fewer bytes than expected might have been transferred. |
514 | |
520 | |
515 | |
521 | |
516 | =item aio_readahead $fh,$offset,$length, $callback->($retval) |
522 | =item aio_readahead $fh,$offset,$length, $callback->($retval) |
517 | |
523 | |
518 | C<aio_readahead> populates the page cache with data from a file so that |
524 | C<aio_readahead> populates the page cache with data from a file so that |
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522 | whole pages, so that offset is effectively rounded down to a page boundary |
528 | whole pages, so that offset is effectively rounded down to a page boundary |
523 | and bytes are read up to the next page boundary greater than or equal to |
529 | and bytes are read up to the next page boundary greater than or equal to |
524 | (off-set+length). C<aio_readahead> does not read beyond the end of the |
530 | (off-set+length). C<aio_readahead> does not read beyond the end of the |
525 | file. The current file offset of the file is left unchanged. |
531 | file. The current file offset of the file is left unchanged. |
526 | |
532 | |
527 | If that syscall doesn't exist (likely if your OS isn't Linux) it will be |
533 | If that syscall doesn't exist (likely if your kernel isn't Linux) it will |
528 | emulated by simply reading the data, which would have a similar effect. |
534 | be emulated by simply reading the data, which would have a similar effect. |
529 | |
535 | |
530 | |
536 | |
531 | =item aio_stat $fh_or_path, $callback->($status) |
537 | =item aio_stat $fh_or_path, $callback->($status) |
532 | |
538 | |
533 | =item aio_lstat $fh, $callback->($status) |
539 | =item aio_lstat $fh, $callback->($status) |
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626 | 0x00001373 devfs |
632 | 0x00001373 devfs |
627 | 0x00001cd1 devpts |
633 | 0x00001cd1 devpts |
628 | 0x0000f15f ecryptfs |
634 | 0x0000f15f ecryptfs |
629 | 0x00414a53 efs |
635 | 0x00414a53 efs |
630 | 0x0000137d ext |
636 | 0x0000137d ext |
631 | 0x0000ef53 ext2/ext3 |
637 | 0x0000ef53 ext2/ext3/ext4 |
632 | 0x0000ef51 ext2 |
638 | 0x0000ef51 ext2 |
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639 | 0xf2f52010 f2fs |
633 | 0x00004006 fat |
640 | 0x00004006 fat |
634 | 0x65735546 fuseblk |
641 | 0x65735546 fuseblk |
635 | 0x65735543 fusectl |
642 | 0x65735543 fusectl |
636 | 0x0bad1dea futexfs |
643 | 0x0bad1dea futexfs |
637 | 0x01161970 gfs2 |
644 | 0x01161970 gfs2 |
638 | 0x47504653 gpfs |
645 | 0x47504653 gpfs |
639 | 0x00004244 hfs |
646 | 0x00004244 hfs |
640 | 0xf995e849 hpfs |
647 | 0xf995e849 hpfs |
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648 | 0x00c0ffee hostfs |
641 | 0x958458f6 hugetlbfs |
649 | 0x958458f6 hugetlbfs |
642 | 0x2bad1dea inotifyfs |
650 | 0x2bad1dea inotifyfs |
643 | 0x00009660 isofs |
651 | 0x00009660 isofs |
644 | 0x000072b6 jffs2 |
652 | 0x000072b6 jffs2 |
645 | 0x3153464a jfs |
653 | 0x3153464a jfs |
… | |
… | |
660 | 0x00009fa1 openprom |
668 | 0x00009fa1 openprom |
661 | 0x7461636F ocfs2 |
669 | 0x7461636F ocfs2 |
662 | 0x00009fa0 proc |
670 | 0x00009fa0 proc |
663 | 0x6165676c pstorefs |
671 | 0x6165676c pstorefs |
664 | 0x0000002f qnx4 |
672 | 0x0000002f qnx4 |
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673 | 0x68191122 qnx6 |
665 | 0x858458f6 ramfs |
674 | 0x858458f6 ramfs |
666 | 0x52654973 reiserfs |
675 | 0x52654973 reiserfs |
667 | 0x00007275 romfs |
676 | 0x00007275 romfs |
668 | 0x67596969 rpc_pipefs |
677 | 0x67596969 rpc_pipefs |
669 | 0x73636673 securityfs |
678 | 0x73636673 securityfs |
… | |
… | |
722 | Works like truncate(2) or ftruncate(2). |
731 | Works like truncate(2) or ftruncate(2). |
723 | |
732 | |
724 | |
733 | |
725 | =item aio_allocate $fh, $mode, $offset, $len, $callback->($status) |
734 | =item aio_allocate $fh, $mode, $offset, $len, $callback->($status) |
726 | |
735 | |
727 | Allocates or freed disk space according to the C<$mode> argument. See the |
736 | Allocates or frees disk space according to the C<$mode> argument. See the |
728 | linux C<fallocate> docuemntation for details. |
737 | linux C<fallocate> documentation for details. |
729 | |
738 | |
730 | C<$mode> can currently be C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> |
739 | C<$mode> is usually C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> to allocate |
731 | to allocate space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE | |
740 | space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE | IO::AIO::FALLOC_FL_KEEP_SIZE>, |
732 | IO::AIO::FALLOC_FL_KEEP_SIZE>, to deallocate a file range. |
741 | to deallocate a file range. |
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742 | |
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743 | IO::AIO also supports C<FALLOC_FL_COLLAPSE_RANGE>, to remove a range |
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744 | (without leaving a hole) and C<FALLOC_FL_ZERO_RANGE>, to zero a range (see |
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745 | your L<fallocate(2)> manpage). |
733 | |
746 | |
734 | The file system block size used by C<fallocate> is presumably the |
747 | The file system block size used by C<fallocate> is presumably the |
735 | C<f_bsize> returned by C<statvfs>. |
748 | C<f_bsize> returned by C<statvfs>. |
736 | |
749 | |
737 | If C<fallocate> isn't available or cannot be emulated (currently no |
750 | If C<fallocate> isn't available or cannot be emulated (currently no |
… | |
… | |
1220 | }; |
1233 | }; |
1221 | |
1234 | |
1222 | $grp |
1235 | $grp |
1223 | } |
1236 | } |
1224 | |
1237 | |
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1238 | =item aio_fcntl $fh, $cmd, $arg, $callback->($status) |
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1239 | |
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1240 | =item aio_ioctl $fh, $request, $buf, $callback->($status) |
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1241 | |
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1242 | These work just like the C<fcntl> and C<ioctl> built-in functions, except |
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1243 | they execute asynchronously and pass the return value to the callback. |
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1244 | |
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1245 | Both calls can be used for a lot of things, some of which make more sense |
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1246 | to run asynchronously in their own thread, while some others make less |
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1247 | sense. For example, calls that block waiting for external events, such |
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1248 | as locking, will also lock down an I/O thread while it is waiting, which |
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1249 | can deadlock the whole I/O system. At the same time, there might be no |
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1250 | alternative to using a thread to wait. |
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1251 | |
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1252 | So in general, you should only use these calls for things that do |
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1253 | (filesystem) I/O, not for things that wait for other events (network, |
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1254 | other processes), although if you are careful and know what you are doing, |
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1255 | you still can. |
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1256 | |
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1257 | The following constants are available (missing ones are, as usual C<0>): |
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1258 | |
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1259 | C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>. |
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1260 | |
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1261 | C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>, |
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1262 | C<FS_IOC_FIEMAP>. |
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1263 | |
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1264 | C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>, |
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1265 | C<FS_IOC_GET_ENCRYPTION_PWSALT>, C<FS_IOC_GET_ENCRYPTION_POLICY>, C<FS_KEY_DESCRIPTOR_SIZE>. |
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1266 | |
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1267 | C<FS_SECRM_FL>, C<FS_UNRM_FL>, C<FS_COMPR_FL>, C<FS_SYNC_FL>, C<FS_IMMUTABLE_FL>, |
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1268 | C<FS_APPEND_FL>, C<FS_NODUMP_FL>, C<FS_NOATIME_FL>, C<FS_DIRTY_FL>, |
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1269 | C<FS_COMPRBLK_FL>, C<FS_NOCOMP_FL>, C<FS_ENCRYPT_FL>, C<FS_BTREE_FL>, |
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1270 | C<FS_INDEX_FL>, C<FS_JOURNAL_DATA_FL>, C<FS_NOTAIL_FL>, C<FS_DIRSYNC_FL>, C<FS_TOPDIR_FL>, |
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1271 | C<FS_FL_USER_MODIFIABLE>. |
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1272 | |
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1273 | C<FS_XFLAG_REALTIME>, C<FS_XFLAG_PREALLOC>, C<FS_XFLAG_IMMUTABLE>, C<FS_XFLAG_APPEND>, |
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1274 | C<FS_XFLAG_SYNC>, C<FS_XFLAG_NOATIME>, C<FS_XFLAG_NODUMP>, C<FS_XFLAG_RTINHERIT>, |
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1275 | C<FS_XFLAG_PROJINHERIT>, C<FS_XFLAG_NOSYMLINKS>, C<FS_XFLAG_EXTSIZE>, C<FS_XFLAG_EXTSZINHERIT>, |
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1276 | C<FS_XFLAG_NODEFRAG>, C<FS_XFLAG_FILESTREAM>, C<FS_XFLAG_DAX>, C<FS_XFLAG_HASATTR>, |
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1277 | |
1225 | =item aio_sync $callback->($status) |
1278 | =item aio_sync $callback->($status) |
1226 | |
1279 | |
1227 | Asynchronously call sync and call the callback when finished. |
1280 | Asynchronously call sync and call the callback when finished. |
1228 | |
1281 | |
1229 | =item aio_fsync $fh, $callback->($status) |
1282 | =item aio_fsync $fh, $callback->($status) |
… | |
… | |
1500 | aio_stat [$etcdir, "passwd"], sub { |
1553 | aio_stat [$etcdir, "passwd"], sub { |
1501 | # yay |
1554 | # yay |
1502 | }; |
1555 | }; |
1503 | }; |
1556 | }; |
1504 | |
1557 | |
1505 | That C<aio_wd> is a request and not a normal function shows that creating |
1558 | The fact that C<aio_wd> is a request and not a normal function shows that |
1506 | an IO::AIO::WD object is itself a potentially blocking operation, which is |
1559 | creating an IO::AIO::WD object is itself a potentially blocking operation, |
1507 | why it is done asynchronously. |
1560 | which is why it is done asynchronously. |
1508 | |
1561 | |
1509 | To stat the directory obtained with C<aio_wd> above, one could write |
1562 | To stat the directory obtained with C<aio_wd> above, one could write |
1510 | either of the following three request calls: |
1563 | either of the following three request calls: |
1511 | |
1564 | |
1512 | aio_lstat "/etc" , sub { ... # pathname as normal string |
1565 | aio_lstat "/etc" , sub { ... # pathname as normal string |
… | |
… | |
1555 | passing C<undef> as working directory component of a pathname fails the |
1608 | passing C<undef> as working directory component of a pathname fails the |
1556 | request with C<ENOENT>, there is often no need for error checking in the |
1609 | request with C<ENOENT>, there is often no need for error checking in the |
1557 | C<aio_wd> callback, as future requests using the value will fail in the |
1610 | C<aio_wd> callback, as future requests using the value will fail in the |
1558 | expected way. |
1611 | expected way. |
1559 | |
1612 | |
1560 | If this call isn't available because your OS lacks it or it couldn't be |
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1561 | detected, it will be emulated by calling C<fsync> instead. |
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1562 | |
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1563 | =item IO::AIO::CWD |
1613 | =item IO::AIO::CWD |
1564 | |
1614 | |
1565 | This is a compiletime constant (object) that represents the process |
1615 | This is a compiletime constant (object) that represents the process |
1566 | current working directory. |
1616 | current working directory. |
1567 | |
1617 | |
… | |
… | |
1934 | |
1984 | |
1935 | This is a very bad function to use in interactive programs because it |
1985 | This is a very bad function to use in interactive programs because it |
1936 | blocks, and a bad way to reduce concurrency because it is inexact: Better |
1986 | blocks, and a bad way to reduce concurrency because it is inexact: Better |
1937 | use an C<aio_group> together with a feed callback. |
1987 | use an C<aio_group> together with a feed callback. |
1938 | |
1988 | |
1939 | It's main use is in scripts without an event loop - when you want to stat |
1989 | Its main use is in scripts without an event loop - when you want to stat |
1940 | a lot of files, you can write somehting like this: |
1990 | a lot of files, you can write somehting like this: |
1941 | |
1991 | |
1942 | IO::AIO::max_outstanding 32; |
1992 | IO::AIO::max_outstanding 32; |
1943 | |
1993 | |
1944 | for my $path (...) { |
1994 | for my $path (...) { |
… | |
… | |
1984 | |
2034 | |
1985 | =back |
2035 | =back |
1986 | |
2036 | |
1987 | =head3 MISCELLANEOUS FUNCTIONS |
2037 | =head3 MISCELLANEOUS FUNCTIONS |
1988 | |
2038 | |
1989 | IO::AIO implements some functions that might be useful, but are not |
2039 | IO::AIO implements some functions that are useful when you want to use |
1990 | asynchronous. |
2040 | some "Advanced I/O" function not available to in Perl, without going the |
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|
2041 | "Asynchronous I/O" route. Many of these have an asynchronous C<aio_*> |
|
|
2042 | counterpart. |
1991 | |
2043 | |
1992 | =over 4 |
2044 | =over 4 |
1993 | |
2045 | |
1994 | =item IO::AIO::sendfile $ofh, $ifh, $offset, $count |
2046 | =item IO::AIO::sendfile $ofh, $ifh, $offset, $count |
1995 | |
2047 | |
… | |
… | |
2014 | =item IO::AIO::madvise $scalar, $offset, $len, $advice |
2066 | =item IO::AIO::madvise $scalar, $offset, $len, $advice |
2015 | |
2067 | |
2016 | Simply calls the C<posix_madvise> function (see its |
2068 | Simply calls the C<posix_madvise> function (see its |
2017 | manpage for details). The following advice constants are |
2069 | manpage for details). The following advice constants are |
2018 | available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>, |
2070 | available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>, |
2019 | C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>. |
2071 | C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>, |
|
|
2072 | C<IO::AIO::MADV_FREE>. |
2020 | |
2073 | |
2021 | On systems that do not implement C<posix_madvise>, this function returns |
2074 | On systems that do not implement C<posix_madvise>, this function returns |
2022 | ENOSYS, otherwise the return value of C<posix_madvise>. |
2075 | ENOSYS, otherwise the return value of C<posix_madvise>. |
2023 | |
2076 | |
2024 | =item IO::AIO::mprotect $scalar, $offset, $len, $protect |
2077 | =item IO::AIO::mprotect $scalar, $offset, $len, $protect |
… | |
… | |
2054 | filesize. |
2107 | filesize. |
2055 | |
2108 | |
2056 | C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>, |
2109 | C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>, |
2057 | C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>, |
2110 | C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>, |
2058 | |
2111 | |
2059 | C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or |
2112 | C<$flags> can be a combination of |
2060 | C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when |
2113 | C<IO::AIO::MAP_SHARED> or |
2061 | not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS> |
2114 | C<IO::AIO::MAP_PRIVATE>, |
|
|
2115 | or a number of system-specific flags (when not available, the are C<0>): |
2062 | (which is set to C<MAP_ANON> if your system only provides this |
2116 | C<IO::AIO::MAP_ANONYMOUS> (which is set to C<MAP_ANON> if your system only provides this constant), |
2063 | constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>, |
2117 | C<IO::AIO::MAP_LOCKED>, |
2064 | C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or |
2118 | C<IO::AIO::MAP_NORESERVE>, |
|
|
2119 | C<IO::AIO::MAP_POPULATE>, |
2065 | C<IO::AIO::MAP_NONBLOCK> |
2120 | C<IO::AIO::MAP_NONBLOCK>, |
|
|
2121 | C<IO::AIO::MAP_FIXED>, |
|
|
2122 | C<IO::AIO::MAP_GROWSDOWN>, |
|
|
2123 | C<IO::AIO::MAP_32BIT>, |
|
|
2124 | C<IO::AIO::MAP_HUGETLB> or |
|
|
2125 | C<IO::AIO::MAP_STACK>. |
2066 | |
2126 | |
2067 | If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed. |
2127 | If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed. |
2068 | |
2128 | |
2069 | C<$offset> is the offset from the start of the file - it generally must be |
2129 | C<$offset> is the offset from the start of the file - it generally must be |
2070 | a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>. |
2130 | a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>. |
… | |
… | |
2113 | |
2173 | |
2114 | See the C<splice(2)> manpage for details. |
2174 | See the C<splice(2)> manpage for details. |
2115 | |
2175 | |
2116 | =item IO::AIO::tee $r_fh, $w_fh, $length, $flags |
2176 | =item IO::AIO::tee $r_fh, $w_fh, $length, $flags |
2117 | |
2177 | |
2118 | Calls the GNU/Linux C<tee(2)> syscall, see it's manpage and the |
2178 | Calls the GNU/Linux C<tee(2)> syscall, see its manpage and the |
2119 | description for C<IO::AIO::splice> above for details. |
2179 | description for C<IO::AIO::splice> above for details. |
2120 | |
2180 | |
2121 | =item $actual_size = IO::AIO::pipesize $r_fh[, $new_size] |
2181 | =item $actual_size = IO::AIO::pipesize $r_fh[, $new_size] |
2122 | |
2182 | |
2123 | Attempts to query or change the pipe buffer size. Obviously works only |
2183 | Attempts to query or change the pipe buffer size. Obviously works only |
2124 | on pipes, and currently works only on GNU/Linux systems, and fails with |
2184 | on pipes, and currently works only on GNU/Linux systems, and fails with |
2125 | C<-1>/C<ENOSYS> everywhere else. If anybody knows how to influence pipe buffer |
2185 | C<-1>/C<ENOSYS> everywhere else. If anybody knows how to influence pipe buffer |
2126 | size on other systems, drop me a note. |
2186 | size on other systems, drop me a note. |
|
|
2187 | |
|
|
2188 | =item ($rfh, $wfh) = IO::AIO::pipe2 [$flags] |
|
|
2189 | |
|
|
2190 | This is a direct interface to the Linux L<pipe2(2)> system call. If |
|
|
2191 | C<$flags> is missing or C<0>, then this should be the same as a call to |
|
|
2192 | perl's built-in C<pipe> function and create a new pipe, and works on |
|
|
2193 | systems that lack the pipe2 syscall. On win32, this case invokes C<_pipe |
|
|
2194 | (..., 4096, O_BINARY)>. |
|
|
2195 | |
|
|
2196 | If C<$flags> is non-zero, it tries to invoke the pipe2 system call with |
|
|
2197 | the given flags (Linux 2.6.27, glibc 2.9). |
|
|
2198 | |
|
|
2199 | On success, the read and write file handles are returned. |
|
|
2200 | |
|
|
2201 | On error, nothing will be returned. If the pipe2 syscall is missing and |
|
|
2202 | C<$flags> is non-zero, fails with C<ENOSYS>. |
|
|
2203 | |
|
|
2204 | Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the |
|
|
2205 | time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and |
|
|
2206 | C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported. |
2127 | |
2207 | |
2128 | =back |
2208 | =back |
2129 | |
2209 | |
2130 | =cut |
2210 | =cut |
2131 | |
2211 | |