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 | |
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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 | |
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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 = 4.33; |
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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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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439 | =item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
445 | =item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
440 | |
446 | |
441 | =item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
447 | =item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
442 | |
448 | |
443 | Reads or writes C<$length> bytes from or to the specified C<$fh> and |
449 | Reads or writes C<$length> bytes from or to the specified C<$fh> and |
444 | C<$offset> into the scalar given by C<$data> and offset C<$dataoffset> |
450 | C<$offset> into the scalar given by C<$data> and offset C<$dataoffset> and |
445 | and calls the callback without the actual number of bytes read (or -1 on |
451 | calls the callback with the actual number of bytes transferred (or -1 on |
446 | error, just like the syscall). |
452 | error, just like the syscall). |
447 | |
453 | |
448 | C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to |
454 | C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to |
449 | offset plus the actual number of bytes read. |
455 | offset plus the actual number of bytes read. |
450 | |
456 | |
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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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1227 | }; |
1233 | }; |
1228 | |
1234 | |
1229 | $grp |
1235 | $grp |
1230 | } |
1236 | } |
1231 | |
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 | |
1232 | =item aio_sync $callback->($status) |
1278 | =item aio_sync $callback->($status) |
1233 | |
1279 | |
1234 | Asynchronously call sync and call the callback when finished. |
1280 | Asynchronously call sync and call the callback when finished. |
1235 | |
1281 | |
1236 | =item aio_fsync $fh, $callback->($status) |
1282 | =item aio_fsync $fh, $callback->($status) |
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2020 | =item IO::AIO::madvise $scalar, $offset, $len, $advice |
2066 | =item IO::AIO::madvise $scalar, $offset, $len, $advice |
2021 | |
2067 | |
2022 | Simply calls the C<posix_madvise> function (see its |
2068 | Simply calls the C<posix_madvise> function (see its |
2023 | manpage for details). The following advice constants are |
2069 | manpage for details). The following advice constants are |
2024 | available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>, |
2070 | available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>, |
2025 | 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>, |
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2072 | C<IO::AIO::MADV_FREE>. |
2026 | |
2073 | |
2027 | 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 |
2028 | ENOSYS, otherwise the return value of C<posix_madvise>. |
2075 | ENOSYS, otherwise the return value of C<posix_madvise>. |
2029 | |
2076 | |
2030 | =item IO::AIO::mprotect $scalar, $offset, $len, $protect |
2077 | =item IO::AIO::mprotect $scalar, $offset, $len, $protect |