| 1 | NAME |
1 | NAME |
| 2 | IO::AIO - Asynchronous Input/Output |
2 | IO::AIO - Asynchronous/Advanced Input/Output |
| 3 | |
3 | |
| 4 | SYNOPSIS |
4 | SYNOPSIS |
| 5 | use IO::AIO; |
5 | use IO::AIO; |
| 6 | |
6 | |
| 7 | aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub { |
7 | aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub { |
| … | |
… | |
| 55 | not well-supported or restricted (GNU/Linux doesn't allow them on normal |
55 | not well-supported or restricted (GNU/Linux doesn't allow them on normal |
| 56 | files currently, for example), and they would only support aio_read and |
56 | files currently, for example), and they would only support aio_read and |
| 57 | aio_write, so the remaining functionality would have to be implemented |
57 | aio_write, so the remaining functionality would have to be implemented |
| 58 | using threads anyway. |
58 | using threads anyway. |
| 59 | |
59 | |
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60 | In addition to asynchronous I/O, this module also exports some rather |
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61 | arcane interfaces, such as "madvise" or linux's "splice" system call, |
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62 | which is why the "A" in "AIO" can also mean *advanced*. |
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63 | |
| 60 | Although the module will work in the presence of other (Perl-) threads, |
64 | Although the module will work in the presence of other (Perl-) threads, |
| 61 | it is currently not reentrant in any way, so use appropriate locking |
65 | it is currently not reentrant in any way, so use appropriate locking |
| 62 | yourself, always call "poll_cb" from within the same thread, or never |
66 | yourself, always call "poll_cb" from within the same thread, or never |
| 63 | call "poll_cb" (or other "aio_" functions) recursively. |
67 | call "poll_cb" (or other "aio_" functions) recursively. |
| 64 | |
68 | |
| 65 | EXAMPLE |
69 | EXAMPLE |
| 66 | This is a simple example that uses the EV module and loads /etc/passwd |
70 | This is a simple example that uses the EV module and loads /etc/passwd |
| 67 | asynchronously: |
71 | asynchronously: |
| 68 | |
72 | |
| 69 | use Fcntl; |
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| 70 | use EV; |
73 | use EV; |
| 71 | use IO::AIO; |
74 | use IO::AIO; |
| 72 | |
75 | |
| 73 | # register the IO::AIO callback with EV |
76 | # register the IO::AIO callback with EV |
| 74 | my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
77 | my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
| … | |
… | |
| 91 | |
94 | |
| 92 | # file contents now in $contents |
95 | # file contents now in $contents |
| 93 | print $contents; |
96 | print $contents; |
| 94 | |
97 | |
| 95 | # exit event loop and program |
98 | # exit event loop and program |
| 96 | EV::unloop; |
99 | EV::break; |
| 97 | }; |
100 | }; |
| 98 | }; |
101 | }; |
| 99 | |
102 | |
| 100 | # possibly queue up other requests, or open GUI windows, |
103 | # possibly queue up other requests, or open GUI windows, |
| 101 | # check for sockets etc. etc. |
104 | # check for sockets etc. etc. |
| 102 | |
105 | |
| 103 | # process events as long as there are some: |
106 | # process events as long as there are some: |
| 104 | EV::loop; |
107 | EV::run; |
| 105 | |
108 | |
| 106 | REQUEST ANATOMY AND LIFETIME |
109 | REQUEST ANATOMY AND LIFETIME |
| 107 | Every "aio_*" function creates a request. which is a C data structure |
110 | Every "aio_*" function creates a request. which is a C data structure |
| 108 | not directly visible to Perl. |
111 | not directly visible to Perl. |
| 109 | |
112 | |
| … | |
… | |
| 146 | the actual aio request is severed and calling its methods will |
149 | the actual aio request is severed and calling its methods will |
| 147 | either do nothing or result in a runtime error). |
150 | either do nothing or result in a runtime error). |
| 148 | |
151 | |
| 149 | FUNCTIONS |
152 | FUNCTIONS |
| 150 | QUICK OVERVIEW |
153 | QUICK OVERVIEW |
| 151 | This section simply lists the prototypes of the most important functions |
154 | This section simply lists the prototypes most of the functions for quick |
| 152 | for quick reference. See the following sections for function-by-function |
155 | reference. See the following sections for function-by-function |
| 153 | documentation. |
156 | documentation. |
| 154 | |
157 | |
| 155 | aio_wd $pathname, $callback->($wd) |
158 | aio_wd $pathname, $callback->($wd) |
| 156 | aio_open $pathname, $flags, $mode, $callback->($fh) |
159 | aio_open $pathname, $flags, $mode, $callback->($fh) |
| 157 | aio_close $fh, $callback->($status) |
160 | aio_close $fh, $callback->($status) |
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161 | aio_seek $fh,$offset,$whence, $callback->($offs) |
| 158 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
162 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
| 159 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
163 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
| 160 | aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
164 | aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
| 161 | aio_readahead $fh,$offset,$length, $callback->($retval) |
165 | aio_readahead $fh,$offset,$length, $callback->($retval) |
| 162 | aio_stat $fh_or_path, $callback->($status) |
166 | aio_stat $fh_or_path, $callback->($status) |
| 163 | aio_lstat $fh, $callback->($status) |
167 | aio_lstat $fh, $callback->($status) |
| 164 | aio_statvfs $fh_or_path, $callback->($statvfs) |
168 | aio_statvfs $fh_or_path, $callback->($statvfs) |
| 165 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
169 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
| 166 | aio_chown $fh_or_path, $uid, $gid, $callback->($status) |
170 | aio_chown $fh_or_path, $uid, $gid, $callback->($status) |
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171 | aio_chmod $fh_or_path, $mode, $callback->($status) |
| 167 | aio_truncate $fh_or_path, $offset, $callback->($status) |
172 | aio_truncate $fh_or_path, $offset, $callback->($status) |
| 168 | aio_chmod $fh_or_path, $mode, $callback->($status) |
173 | aio_allocate $fh, $mode, $offset, $len, $callback->($status) |
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174 | aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents) |
| 169 | aio_unlink $pathname, $callback->($status) |
175 | aio_unlink $pathname, $callback->($status) |
| 170 | aio_mknod $pathname, $mode, $dev, $callback->($status) |
176 | aio_mknod $pathname, $mode, $dev, $callback->($status) |
| 171 | aio_link $srcpath, $dstpath, $callback->($status) |
177 | aio_link $srcpath, $dstpath, $callback->($status) |
| 172 | aio_symlink $srcpath, $dstpath, $callback->($status) |
178 | aio_symlink $srcpath, $dstpath, $callback->($status) |
| 173 | aio_readlink $pathname, $callback->($link) |
179 | aio_readlink $pathname, $callback->($link) |
| 174 | aio_realpath $pathname, $callback->($link) |
180 | aio_realpath $pathname, $callback->($path) |
| 175 | aio_rename $srcpath, $dstpath, $callback->($status) |
181 | aio_rename $srcpath, $dstpath, $callback->($status) |
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182 | aio_rename2 $srcpath, $dstpath, $flags, $callback->($status) |
| 176 | aio_mkdir $pathname, $mode, $callback->($status) |
183 | aio_mkdir $pathname, $mode, $callback->($status) |
| 177 | aio_rmdir $pathname, $callback->($status) |
184 | aio_rmdir $pathname, $callback->($status) |
| 178 | aio_readdir $pathname, $callback->($entries) |
185 | aio_readdir $pathname, $callback->($entries) |
| 179 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
186 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
| 180 | IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST |
187 | IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST |
| … | |
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| 182 | aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) |
189 | aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) |
| 183 | aio_load $pathname, $data, $callback->($status) |
190 | aio_load $pathname, $data, $callback->($status) |
| 184 | aio_copy $srcpath, $dstpath, $callback->($status) |
191 | aio_copy $srcpath, $dstpath, $callback->($status) |
| 185 | aio_move $srcpath, $dstpath, $callback->($status) |
192 | aio_move $srcpath, $dstpath, $callback->($status) |
| 186 | aio_rmtree $pathname, $callback->($status) |
193 | aio_rmtree $pathname, $callback->($status) |
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194 | aio_fcntl $fh, $cmd, $arg, $callback->($status) |
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195 | aio_ioctl $fh, $request, $buf, $callback->($status) |
| 187 | aio_sync $callback->($status) |
196 | aio_sync $callback->($status) |
| 188 | aio_syncfs $fh, $callback->($status) |
197 | aio_syncfs $fh, $callback->($status) |
| 189 | aio_fsync $fh, $callback->($status) |
198 | aio_fsync $fh, $callback->($status) |
| 190 | aio_fdatasync $fh, $callback->($status) |
199 | aio_fdatasync $fh, $callback->($status) |
| 191 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
200 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
| 192 | aio_pathsync $pathname, $callback->($status) |
201 | aio_pathsync $pathname, $callback->($status) |
| 193 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
202 | aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status) |
| 194 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
203 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
| 195 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
204 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
| 196 | aio_mlockall $flags, $callback->($status) |
205 | aio_mlockall $flags, $callback->($status) |
| 197 | aio_group $callback->(...) |
206 | aio_group $callback->(...) |
| 198 | aio_nop $callback->() |
207 | aio_nop $callback->() |
| … | |
… | |
| 212 | IO::AIO::idle_timeout $seconds |
221 | IO::AIO::idle_timeout $seconds |
| 213 | IO::AIO::max_outstanding $maxreqs |
222 | IO::AIO::max_outstanding $maxreqs |
| 214 | IO::AIO::nreqs |
223 | IO::AIO::nreqs |
| 215 | IO::AIO::nready |
224 | IO::AIO::nready |
| 216 | IO::AIO::npending |
225 | IO::AIO::npending |
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226 | $nfd = IO::AIO::get_fdlimit [EXPERIMENTAL] |
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227 | IO::AIO::min_fdlimit $nfd [EXPERIMENTAL] |
| 217 | |
228 | |
| 218 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
229 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
| 219 | IO::AIO::fadvise $fh, $offset, $len, $advice |
230 | IO::AIO::fadvise $fh, $offset, $len, $advice |
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231 | IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]] |
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232 | IO::AIO::munmap $scalar |
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233 | IO::AIO::mremap $scalar, $new_length, $flags[, $new_address] |
| 220 | IO::AIO::madvise $scalar, $offset, $length, $advice |
234 | IO::AIO::madvise $scalar, $offset, $length, $advice |
| 221 | IO::AIO::mprotect $scalar, $offset, $length, $protect |
235 | IO::AIO::mprotect $scalar, $offset, $length, $protect |
| 222 | IO::AIO::munlock $scalar, $offset = 0, $length = undef |
236 | IO::AIO::munlock $scalar, $offset = 0, $length = undef |
| 223 | IO::AIO::munlockall |
237 | IO::AIO::munlockall |
| 224 | |
238 | |
| 225 | AIO REQUEST FUNCTIONS |
239 | API NOTES |
| 226 | All the "aio_*" calls are more or less thin wrappers around the syscall |
240 | All the "aio_*" calls are more or less thin wrappers around the syscall |
| 227 | with the same name (sans "aio_"). The arguments are similar or |
241 | with the same name (sans "aio_"). The arguments are similar or |
| 228 | identical, and they all accept an additional (and optional) $callback |
242 | identical, and they all accept an additional (and optional) $callback |
| 229 | argument which must be a code reference. This code reference will be |
243 | argument which must be a code reference. This code reference will be |
| 230 | called after the syscall has been executed in an asynchronous fashion. |
244 | called after the syscall has been executed in an asynchronous fashion. |
| … | |
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| 260 | else to ensure your scalar has the correct contents. |
274 | else to ensure your scalar has the correct contents. |
| 261 | |
275 | |
| 262 | This works, btw. independent of the internal UTF-8 bit, which IO::AIO |
276 | This works, btw. independent of the internal UTF-8 bit, which IO::AIO |
| 263 | handles correctly whether it is set or not. |
277 | handles correctly whether it is set or not. |
| 264 | |
278 | |
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279 | AIO REQUEST FUNCTIONS |
| 265 | $prev_pri = aioreq_pri [$pri] |
280 | $prev_pri = aioreq_pri [$pri] |
| 266 | Returns the priority value that would be used for the next request |
281 | Returns the priority value that would be used for the next request |
| 267 | and, if $pri is given, sets the priority for the next aio request. |
282 | and, if $pri is given, sets the priority for the next aio request. |
| 268 | |
283 | |
| 269 | The default priority is 0, the minimum and maximum priorities are -4 |
284 | The default priority is 0, the minimum and maximum priorities are -4 |
| … | |
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| 291 | Similar to "aioreq_pri", but subtracts the given value from the |
306 | Similar to "aioreq_pri", but subtracts the given value from the |
| 292 | current priority, so the effect is cumulative. |
307 | current priority, so the effect is cumulative. |
| 293 | |
308 | |
| 294 | aio_open $pathname, $flags, $mode, $callback->($fh) |
309 | aio_open $pathname, $flags, $mode, $callback->($fh) |
| 295 | Asynchronously open or create a file and call the callback with a |
310 | Asynchronously open or create a file and call the callback with a |
| 296 | newly created filehandle for the file. |
311 | newly created filehandle for the file (or "undef" in case of an |
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312 | error). |
| 297 | |
313 | |
| 298 | The pathname passed to "aio_open" must be absolute. See API NOTES, |
314 | The pathname passed to "aio_open" must be absolute. See API NOTES, |
| 299 | above, for an explanation. |
315 | above, for an explanation. |
| 300 | |
316 | |
| 301 | The $flags argument is a bitmask. See the "Fcntl" module for a list. |
317 | The $flags argument is a bitmask. See the "Fcntl" module for a list. |
| … | |
… | |
| 324 | "O_APPEND"), the following POSIX and non-POSIX constants are |
340 | "O_APPEND"), the following POSIX and non-POSIX constants are |
| 325 | available (missing ones on your system are, as usual, 0): |
341 | available (missing ones on your system are, as usual, 0): |
| 326 | |
342 | |
| 327 | "O_ASYNC", "O_DIRECT", "O_NOATIME", "O_CLOEXEC", "O_NOCTTY", |
343 | "O_ASYNC", "O_DIRECT", "O_NOATIME", "O_CLOEXEC", "O_NOCTTY", |
| 328 | "O_NOFOLLOW", "O_NONBLOCK", "O_EXEC", "O_SEARCH", "O_DIRECTORY", |
344 | "O_NOFOLLOW", "O_NONBLOCK", "O_EXEC", "O_SEARCH", "O_DIRECTORY", |
| 329 | "O_DSYNC", "O_RSYNC", "O_SYNC" and "O_TTY_INIT". |
345 | "O_DSYNC", "O_RSYNC", "O_SYNC", "O_PATH", "O_TMPFILE", "O_TTY_INIT" |
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346 | and "O_ACCMODE". |
| 330 | |
347 | |
| 331 | aio_close $fh, $callback->($status) |
348 | aio_close $fh, $callback->($status) |
| 332 | Asynchronously close a file and call the callback with the result |
349 | Asynchronously close a file and call the callback with the result |
| 333 | code. |
350 | code. |
| 334 | |
351 | |
| … | |
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| 340 | will use dup2 to overwrite the file descriptor with the write-end of |
357 | will use dup2 to overwrite the file descriptor with the write-end of |
| 341 | a pipe (the pipe fd will be created on demand and will be cached). |
358 | a pipe (the pipe fd will be created on demand and will be cached). |
| 342 | |
359 | |
| 343 | Or in other words: the file descriptor will be closed, but it will |
360 | Or in other words: the file descriptor will be closed, but it will |
| 344 | not be free for reuse until the perl filehandle is closed. |
361 | not be free for reuse until the perl filehandle is closed. |
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362 | |
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363 | aio_seek $fh, $offset, $whence, $callback->($offs) |
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364 | Seeks the filehandle to the new $offset, similarly to perl's |
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365 | "sysseek". The $whence can use the traditional values (0 for |
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366 | "IO::AIO::SEEK_SET", 1 for "IO::AIO::SEEK_CUR" or 2 for |
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367 | "IO::AIO::SEEK_END"). |
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368 | |
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369 | The resulting absolute offset will be passed to the callback, or -1 |
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370 | in case of an error. |
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371 | |
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372 | In theory, the $whence constants could be different than the |
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373 | corresponding values from Fcntl, but perl guarantees they are the |
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374 | same, so don't panic. |
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375 | |
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376 | As a GNU/Linux (and maybe Solaris) extension, also the constants |
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377 | "IO::AIO::SEEK_DATA" and "IO::AIO::SEEK_HOLE" are available, if they |
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378 | could be found. No guarantees about suitability for use in |
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379 | "aio_seek" or Perl's "sysseek" can be made though, although I would |
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380 | naively assume they "just work". |
| 345 | |
381 | |
| 346 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
382 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
| 347 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
383 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
| 348 | Reads or writes $length bytes from or to the specified $fh and |
384 | Reads or writes $length bytes from or to the specified $fh and |
| 349 | $offset into the scalar given by $data and offset $dataoffset and |
385 | $offset into the scalar given by $data and offset $dataoffset and |
| 350 | calls the callback without the actual number of bytes read (or -1 on |
386 | calls the callback with the actual number of bytes transferred (or |
| 351 | error, just like the syscall). |
387 | -1 on error, just like the syscall). |
| 352 | |
388 | |
| 353 | "aio_read" will, like "sysread", shrink or grow the $data scalar to |
389 | "aio_read" will, like "sysread", shrink or grow the $data scalar to |
| 354 | offset plus the actual number of bytes read. |
390 | offset plus the actual number of bytes read. |
| 355 | |
391 | |
| 356 | If $offset is undefined, then the current file descriptor offset |
392 | If $offset is undefined, then the current file descriptor offset |
| … | |
… | |
| 413 | As native sendfile syscalls (as practically any non-POSIX interface |
449 | As native sendfile syscalls (as practically any non-POSIX interface |
| 414 | hacked together in a hurry to improve benchmark numbers) tend to be |
450 | hacked together in a hurry to improve benchmark numbers) tend to be |
| 415 | rather buggy on many systems, this implementation tries to work |
451 | rather buggy on many systems, this implementation tries to work |
| 416 | around some known bugs in Linux and FreeBSD kernels (probably |
452 | around some known bugs in Linux and FreeBSD kernels (probably |
| 417 | others, too), but that might fail, so you really really should check |
453 | others, too), but that might fail, so you really really should check |
| 418 | the return value of "aio_sendfile" - fewre bytes than expected might |
454 | the return value of "aio_sendfile" - fewer bytes than expected might |
| 419 | have been transferred. |
455 | have been transferred. |
| 420 | |
456 | |
| 421 | aio_readahead $fh,$offset,$length, $callback->($retval) |
457 | aio_readahead $fh,$offset,$length, $callback->($retval) |
| 422 | "aio_readahead" populates the page cache with data from a file so |
458 | "aio_readahead" populates the page cache with data from a file so |
| 423 | that subsequent reads from that file will not block on disk I/O. The |
459 | that subsequent reads from that file will not block on disk I/O. The |
| … | |
… | |
| 427 | to a page boundary and bytes are read up to the next page boundary |
463 | to a page boundary and bytes are read up to the next page boundary |
| 428 | greater than or equal to (off-set+length). "aio_readahead" does not |
464 | greater than or equal to (off-set+length). "aio_readahead" does not |
| 429 | read beyond the end of the file. The current file offset of the file |
465 | read beyond the end of the file. The current file offset of the file |
| 430 | is left unchanged. |
466 | is left unchanged. |
| 431 | |
467 | |
| 432 | If that syscall doesn't exist (likely if your OS isn't Linux) it |
468 | If that syscall doesn't exist (likely if your kernel isn't Linux) it |
| 433 | will be emulated by simply reading the data, which would have a |
469 | will be emulated by simply reading the data, which would have a |
| 434 | similar effect. |
470 | similar effect. |
| 435 | |
471 | |
| 436 | aio_stat $fh_or_path, $callback->($status) |
472 | aio_stat $fh_or_path, $callback->($status) |
| 437 | aio_lstat $fh, $callback->($status) |
473 | aio_lstat $fh, $callback->($status) |
| … | |
… | |
| 453 | back on traditional behaviour). |
489 | back on traditional behaviour). |
| 454 | |
490 | |
| 455 | "S_IFMT", "S_IFIFO", "S_IFCHR", "S_IFBLK", "S_IFLNK", "S_IFREG", |
491 | "S_IFMT", "S_IFIFO", "S_IFCHR", "S_IFBLK", "S_IFLNK", "S_IFREG", |
| 456 | "S_IFDIR", "S_IFWHT", "S_IFSOCK", "IO::AIO::major $dev_t", |
492 | "S_IFDIR", "S_IFWHT", "S_IFSOCK", "IO::AIO::major $dev_t", |
| 457 | "IO::AIO::minor $dev_t", "IO::AIO::makedev $major, $minor". |
493 | "IO::AIO::minor $dev_t", "IO::AIO::makedev $major, $minor". |
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494 | |
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495 | To access higher resolution stat timestamps, see "SUBSECOND STAT |
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496 | TIME ACCESS". |
| 458 | |
497 | |
| 459 | Example: Print the length of /etc/passwd: |
498 | Example: Print the length of /etc/passwd: |
| 460 | |
499 | |
| 461 | aio_stat "/etc/passwd", sub { |
500 | aio_stat "/etc/passwd", sub { |
| 462 | $_[0] and die "stat failed: $!"; |
501 | $_[0] and die "stat failed: $!"; |
| … | |
… | |
| 535 | aio_chown "path", 0, undef; |
574 | aio_chown "path", 0, undef; |
| 536 | |
575 | |
| 537 | aio_truncate $fh_or_path, $offset, $callback->($status) |
576 | aio_truncate $fh_or_path, $offset, $callback->($status) |
| 538 | Works like truncate(2) or ftruncate(2). |
577 | Works like truncate(2) or ftruncate(2). |
| 539 | |
578 | |
|
|
579 | aio_allocate $fh, $mode, $offset, $len, $callback->($status) |
|
|
580 | Allocates or frees disk space according to the $mode argument. See |
|
|
581 | the linux "fallocate" documentation for details. |
|
|
582 | |
|
|
583 | $mode is usually 0 or "IO::AIO::FALLOC_FL_KEEP_SIZE" to allocate |
|
|
584 | space, or "IO::AIO::FALLOC_FL_PUNCH_HOLE | |
|
|
585 | IO::AIO::FALLOC_FL_KEEP_SIZE", to deallocate a file range. |
|
|
586 | |
|
|
587 | IO::AIO also supports "FALLOC_FL_COLLAPSE_RANGE", to remove a range |
|
|
588 | (without leaving a hole), "FALLOC_FL_ZERO_RANGE", to zero a range, |
|
|
589 | "FALLOC_FL_INSERT_RANGE" to insert a range and |
|
|
590 | "FALLOC_FL_UNSHARE_RANGE" to unshare shared blocks (see your |
|
|
591 | fallocate(2) manpage). |
|
|
592 | |
|
|
593 | The file system block size used by "fallocate" is presumably the |
|
|
594 | "f_bsize" returned by "statvfs", but different filesystems and |
|
|
595 | filetypes can dictate other limitations. |
|
|
596 | |
|
|
597 | If "fallocate" isn't available or cannot be emulated (currently no |
|
|
598 | emulation will be attempted), passes -1 and sets $! to "ENOSYS". |
|
|
599 | |
| 540 | aio_chmod $fh_or_path, $mode, $callback->($status) |
600 | aio_chmod $fh_or_path, $mode, $callback->($status) |
| 541 | Works like perl's "chmod" function. |
601 | Works like perl's "chmod" function. |
| 542 | |
602 | |
| 543 | aio_unlink $pathname, $callback->($status) |
603 | aio_unlink $pathname, $callback->($status) |
| 544 | Asynchronously unlink (delete) a file and call the callback with the |
604 | Asynchronously unlink (delete) a file and call the callback with the |
| … | |
… | |
| 570 | the callback. If an error occurs, nothing or undef gets passed to |
630 | the callback. If an error occurs, nothing or undef gets passed to |
| 571 | the callback. |
631 | the callback. |
| 572 | |
632 | |
| 573 | aio_realpath $pathname, $callback->($path) |
633 | aio_realpath $pathname, $callback->($path) |
| 574 | Asynchronously make the path absolute and resolve any symlinks in |
634 | Asynchronously make the path absolute and resolve any symlinks in |
| 575 | $path. The resulting path only consists of directories (Same as |
635 | $path. The resulting path only consists of directories (same as |
| 576 | Cwd::realpath). |
636 | Cwd::realpath). |
| 577 | |
637 | |
| 578 | This request can be used to get the absolute path of the current |
638 | This request can be used to get the absolute path of the current |
| 579 | working directory by passing it a path of . (a single dot). |
639 | working directory by passing it a path of . (a single dot). |
| 580 | |
640 | |
| 581 | aio_rename $srcpath, $dstpath, $callback->($status) |
641 | aio_rename $srcpath, $dstpath, $callback->($status) |
| 582 | Asynchronously rename the object at $srcpath to $dstpath, just as |
642 | Asynchronously rename the object at $srcpath to $dstpath, just as |
| 583 | rename(2) and call the callback with the result code. |
643 | rename(2) and call the callback with the result code. |
|
|
644 | |
|
|
645 | On systems that support the AIO::WD working directory abstraction |
|
|
646 | natively, the case "[$wd, "."]" as $srcpath is specialcased - |
|
|
647 | instead of failing, "rename" is called on the absolute path of $wd. |
|
|
648 | |
|
|
649 | aio_rename2 $srcpath, $dstpath, $flags, $callback->($status) |
|
|
650 | Basically a version of "aio_rename" with an additional $flags |
|
|
651 | argument. Calling this with "$flags=0" is the same as calling |
|
|
652 | "aio_rename". |
|
|
653 | |
|
|
654 | Non-zero flags are currently only supported on GNU/Linux systems |
|
|
655 | that support renameat2. Other systems fail with "ENOSYS" in this |
|
|
656 | case. |
|
|
657 | |
|
|
658 | The following constants are available (missing ones are, as usual |
|
|
659 | 0), see renameat2(2) for details: |
|
|
660 | |
|
|
661 | "IO::AIO::RENAME_NOREPLACE", "IO::AIO::RENAME_EXCHANGE" and |
|
|
662 | "IO::AIO::RENAME_WHITEOUT". |
| 584 | |
663 | |
| 585 | aio_mkdir $pathname, $mode, $callback->($status) |
664 | aio_mkdir $pathname, $mode, $callback->($status) |
| 586 | Asynchronously mkdir (create) a directory and call the callback with |
665 | Asynchronously mkdir (create) a directory and call the callback with |
| 587 | the result code. $mode will be modified by the umask at the time the |
666 | the result code. $mode will be modified by the umask at the time the |
| 588 | request is executed, so do not change your umask. |
667 | request is executed, so do not change your umask. |
| 589 | |
668 | |
| 590 | aio_rmdir $pathname, $callback->($status) |
669 | aio_rmdir $pathname, $callback->($status) |
| 591 | Asynchronously rmdir (delete) a directory and call the callback with |
670 | Asynchronously rmdir (delete) a directory and call the callback with |
| 592 | the result code. |
671 | the result code. |
| 593 | |
672 | |
|
|
673 | On systems that support the AIO::WD working directory abstraction |
|
|
674 | natively, the case "[$wd, "."]" is specialcased - instead of |
|
|
675 | failing, "rmdir" is called on the absolute path of $wd. |
|
|
676 | |
| 594 | aio_readdir $pathname, $callback->($entries) |
677 | aio_readdir $pathname, $callback->($entries) |
| 595 | Unlike the POSIX call of the same name, "aio_readdir" reads an |
678 | Unlike the POSIX call of the same name, "aio_readdir" reads an |
| 596 | entire directory (i.e. opendir + readdir + closedir). The entries |
679 | entire directory (i.e. opendir + readdir + closedir). The entries |
| 597 | will not be sorted, and will NOT include the "." and ".." entries. |
680 | will not be sorted, and will NOT include the "." and ".." entries. |
| 598 | |
681 | |
| … | |
… | |
| 607 | The flags are a combination of the following constants, ORed |
690 | The flags are a combination of the following constants, ORed |
| 608 | together (the flags will also be passed to the callback, possibly |
691 | together (the flags will also be passed to the callback, possibly |
| 609 | modified): |
692 | modified): |
| 610 | |
693 | |
| 611 | IO::AIO::READDIR_DENTS |
694 | IO::AIO::READDIR_DENTS |
| 612 | When this flag is off, then the callback gets an arrayref |
695 | Normally the callback gets an arrayref consisting of names only |
| 613 | consisting of names only (as with "aio_readdir"), otherwise it |
696 | (as with "aio_readdir"). If this flag is set, then the callback |
| 614 | gets an arrayref with "[$name, $type, $inode]" arrayrefs, each |
697 | gets an arrayref with "[$name, $type, $inode]" arrayrefs, each |
| 615 | describing a single directory entry in more detail. |
698 | describing a single directory entry in more detail: |
| 616 | |
699 | |
| 617 | $name is the name of the entry. |
700 | $name is the name of the entry. |
| 618 | |
701 | |
| 619 | $type is one of the "IO::AIO::DT_xxx" constants: |
702 | $type is one of the "IO::AIO::DT_xxx" constants: |
| 620 | |
703 | |
| 621 | "IO::AIO::DT_UNKNOWN", "IO::AIO::DT_FIFO", "IO::AIO::DT_CHR", |
704 | "IO::AIO::DT_UNKNOWN", "IO::AIO::DT_FIFO", "IO::AIO::DT_CHR", |
| 622 | "IO::AIO::DT_DIR", "IO::AIO::DT_BLK", "IO::AIO::DT_REG", |
705 | "IO::AIO::DT_DIR", "IO::AIO::DT_BLK", "IO::AIO::DT_REG", |
| 623 | "IO::AIO::DT_LNK", "IO::AIO::DT_SOCK", "IO::AIO::DT_WHT". |
706 | "IO::AIO::DT_LNK", "IO::AIO::DT_SOCK", "IO::AIO::DT_WHT". |
| 624 | |
707 | |
| 625 | "IO::AIO::DT_UNKNOWN" means just that: readdir does not know. If |
708 | "IO::AIO::DT_UNKNOWN" means just that: readdir does not know. If |
| 626 | you need to know, you have to run stat yourself. Also, for speed |
709 | you need to know, you have to run stat yourself. Also, for |
| 627 | reasons, the $type scalars are read-only: you can not modify |
710 | speed/memory reasons, the $type scalars are read-only: you must |
| 628 | them. |
711 | not modify them. |
| 629 | |
712 | |
| 630 | $inode is the inode number (which might not be exact on systems |
713 | $inode is the inode number (which might not be exact on systems |
| 631 | with 64 bit inode numbers and 32 bit perls). This field has |
714 | with 64 bit inode numbers and 32 bit perls). This field has |
| 632 | unspecified content on systems that do not deliver the inode |
715 | unspecified content on systems that do not deliver the inode |
| 633 | information. |
716 | information. |
| … | |
… | |
| 645 | of which names with short names are tried first. |
728 | of which names with short names are tried first. |
| 646 | |
729 | |
| 647 | IO::AIO::READDIR_STAT_ORDER |
730 | IO::AIO::READDIR_STAT_ORDER |
| 648 | When this flag is set, then the names will be returned in an |
731 | When this flag is set, then the names will be returned in an |
| 649 | order suitable for stat()'ing each one. That is, when you plan |
732 | order suitable for stat()'ing each one. That is, when you plan |
| 650 | to stat() all files in the given directory, then the returned |
733 | to stat() most or all files in the given directory, then the |
| 651 | order will likely be fastest. |
734 | returned order will likely be faster. |
| 652 | |
735 | |
| 653 | If both this flag and "IO::AIO::READDIR_DIRS_FIRST" are |
736 | If both this flag and "IO::AIO::READDIR_DIRS_FIRST" are |
| 654 | specified, then the likely dirs come first, resulting in a less |
737 | specified, then the likely dirs come first, resulting in a less |
| 655 | optimal stat order. |
738 | optimal stat order for stat'ing all entries, but likely a more |
|
|
739 | optimal order for finding subdirectories. |
| 656 | |
740 | |
| 657 | IO::AIO::READDIR_FOUND_UNKNOWN |
741 | IO::AIO::READDIR_FOUND_UNKNOWN |
| 658 | This flag should not be set when calling "aio_readdirx". |
742 | This flag should not be set when calling "aio_readdirx". |
| 659 | Instead, it is being set by "aio_readdirx", when any of the |
743 | Instead, it is being set by "aio_readdirx", when any of the |
| 660 | $type's found were "IO::AIO::DT_UNKNOWN". The absence of this |
744 | $type's found were "IO::AIO::DT_UNKNOWN". The absence of this |
| 661 | flag therefore indicates that all $type's are known, which can |
745 | flag therefore indicates that all $type's are known, which can |
| 662 | be used to speed up some algorithms. |
746 | be used to speed up some algorithms. |
| 663 | |
747 | |
|
|
748 | aio_slurp $pathname, $offset, $length, $data, $callback->($status) |
|
|
749 | Opens, reads and closes the given file. The data is put into $data, |
|
|
750 | which is resized as required. |
|
|
751 | |
|
|
752 | If $offset is negative, then it is counted from the end of the file. |
|
|
753 | |
|
|
754 | If $length is zero, then the remaining length of the file is used. |
|
|
755 | Also, in this case, the same limitations to modifying $data apply as |
|
|
756 | when IO::AIO::mmap is used, i.e. it must only be modified in-place |
|
|
757 | with "substr". If the size of the file is known, specifying a |
|
|
758 | non-zero $length results in a performance advantage. |
|
|
759 | |
|
|
760 | This request is similar to the older "aio_load" request, but since |
|
|
761 | it is a single request, it might be more efficient to use. |
|
|
762 | |
|
|
763 | Example: load /etc/passwd into $passwd. |
|
|
764 | |
|
|
765 | my $passwd; |
|
|
766 | aio_slurp "/etc/passwd", 0, 0, $passwd, sub { |
|
|
767 | $_[0] >= 0 |
|
|
768 | or die "/etc/passwd: $!\n"; |
|
|
769 | |
|
|
770 | printf "/etc/passwd is %d bytes long, and contains:\n", length $passwd; |
|
|
771 | print $passwd; |
|
|
772 | }; |
|
|
773 | IO::AIO::flush; |
|
|
774 | |
| 664 | aio_load $pathname, $data, $callback->($status) |
775 | aio_load $pathname, $data, $callback->($status) |
| 665 | This is a composite request that tries to fully load the given file |
776 | This is a composite request that tries to fully load the given file |
| 666 | into memory. Status is the same as with aio_read. |
777 | into memory. Status is the same as with aio_read. |
|
|
778 | |
|
|
779 | Using "aio_slurp" might be more efficient, as it is a single |
|
|
780 | request. |
| 667 | |
781 | |
| 668 | aio_copy $srcpath, $dstpath, $callback->($status) |
782 | aio_copy $srcpath, $dstpath, $callback->($status) |
| 669 | Try to copy the *file* (directories not supported as either source |
783 | Try to copy the *file* (directories not supported as either source |
| 670 | or destination) from $srcpath to $dstpath and call the callback with |
784 | or destination) from $srcpath to $dstpath and call the callback with |
| 671 | a status of 0 (ok) or -1 (error, see $!). |
785 | a status of 0 (ok) or -1 (error, see $!). |
|
|
786 | |
|
|
787 | Existing destination files will be truncated. |
| 672 | |
788 | |
| 673 | This is a composite request that creates the destination file with |
789 | This is a composite request that creates the destination file with |
| 674 | mode 0200 and copies the contents of the source file into it using |
790 | mode 0200 and copies the contents of the source file into it using |
| 675 | "aio_sendfile", followed by restoring atime, mtime, access mode and |
791 | "aio_sendfile", followed by restoring atime, mtime, access mode and |
| 676 | uid/gid, in that order. |
792 | uid/gid, in that order. |
| … | |
… | |
| 693 | to efficiently separate the entries of directory $path into two sets |
809 | to efficiently separate the entries of directory $path into two sets |
| 694 | of names, directories you can recurse into (directories), and ones |
810 | of names, directories you can recurse into (directories), and ones |
| 695 | you cannot recurse into (everything else, including symlinks to |
811 | you cannot recurse into (everything else, including symlinks to |
| 696 | directories). |
812 | directories). |
| 697 | |
813 | |
| 698 | "aio_scandir" is a composite request that creates of many sub |
814 | "aio_scandir" is a composite request that generates many sub |
| 699 | requests_ $maxreq specifies the maximum number of outstanding aio |
815 | requests. $maxreq specifies the maximum number of outstanding aio |
| 700 | requests that this function generates. If it is "<= 0", then a |
816 | requests that this function generates. If it is "<= 0", then a |
| 701 | suitable default will be chosen (currently 4). |
817 | suitable default will be chosen (currently 4). |
| 702 | |
818 | |
| 703 | On error, the callback is called without arguments, otherwise it |
819 | On error, the callback is called without arguments, otherwise it |
| 704 | receives two array-refs with path-relative entry names. |
820 | receives two array-refs with path-relative entry names. |
| … | |
… | |
| 751 | Delete a directory tree starting (and including) $path, return the |
867 | Delete a directory tree starting (and including) $path, return the |
| 752 | status of the final "rmdir" only. This is a composite request that |
868 | status of the final "rmdir" only. This is a composite request that |
| 753 | uses "aio_scandir" to recurse into and rmdir directories, and unlink |
869 | uses "aio_scandir" to recurse into and rmdir directories, and unlink |
| 754 | everything else. |
870 | everything else. |
| 755 | |
871 | |
|
|
872 | aio_fcntl $fh, $cmd, $arg, $callback->($status) |
|
|
873 | aio_ioctl $fh, $request, $buf, $callback->($status) |
|
|
874 | These work just like the "fcntl" and "ioctl" built-in functions, |
|
|
875 | except they execute asynchronously and pass the return value to the |
|
|
876 | callback. |
|
|
877 | |
|
|
878 | Both calls can be used for a lot of things, some of which make more |
|
|
879 | sense to run asynchronously in their own thread, while some others |
|
|
880 | make less sense. For example, calls that block waiting for external |
|
|
881 | events, such as locking, will also lock down an I/O thread while it |
|
|
882 | is waiting, which can deadlock the whole I/O system. At the same |
|
|
883 | time, there might be no alternative to using a thread to wait. |
|
|
884 | |
|
|
885 | So in general, you should only use these calls for things that do |
|
|
886 | (filesystem) I/O, not for things that wait for other events |
|
|
887 | (network, other processes), although if you are careful and know |
|
|
888 | what you are doing, you still can. |
|
|
889 | |
|
|
890 | The following constants are available (missing ones are, as usual |
|
|
891 | 0): |
|
|
892 | |
|
|
893 | "F_DUPFD_CLOEXEC", |
|
|
894 | |
|
|
895 | "F_OFD_GETLK", "F_OFD_SETLK", "F_OFD_GETLKW", |
|
|
896 | |
|
|
897 | "FIFREEZE", "FITHAW", "FITRIM", "FICLONE", "FICLONERANGE", |
|
|
898 | "FIDEDUPERANGE". |
|
|
899 | |
|
|
900 | "FS_IOC_GETFLAGS", "FS_IOC_SETFLAGS", "FS_IOC_GETVERSION", |
|
|
901 | "FS_IOC_SETVERSION", "FS_IOC_FIEMAP". |
|
|
902 | |
|
|
903 | "FS_IOC_FSGETXATTR", "FS_IOC_FSSETXATTR", |
|
|
904 | "FS_IOC_SET_ENCRYPTION_POLICY", "FS_IOC_GET_ENCRYPTION_PWSALT", |
|
|
905 | "FS_IOC_GET_ENCRYPTION_POLICY", "FS_KEY_DESCRIPTOR_SIZE". |
|
|
906 | |
|
|
907 | "FS_SECRM_FL", "FS_UNRM_FL", "FS_COMPR_FL", "FS_SYNC_FL", |
|
|
908 | "FS_IMMUTABLE_FL", "FS_APPEND_FL", "FS_NODUMP_FL", "FS_NOATIME_FL", |
|
|
909 | "FS_DIRTY_FL", "FS_COMPRBLK_FL", "FS_NOCOMP_FL", "FS_ENCRYPT_FL", |
|
|
910 | "FS_BTREE_FL", "FS_INDEX_FL", "FS_JOURNAL_DATA_FL", "FS_NOTAIL_FL", |
|
|
911 | "FS_DIRSYNC_FL", "FS_TOPDIR_FL", "FS_FL_USER_MODIFIABLE". |
|
|
912 | |
|
|
913 | "FS_XFLAG_REALTIME", "FS_XFLAG_PREALLOC", "FS_XFLAG_IMMUTABLE", |
|
|
914 | "FS_XFLAG_APPEND", "FS_XFLAG_SYNC", "FS_XFLAG_NOATIME", |
|
|
915 | "FS_XFLAG_NODUMP", "FS_XFLAG_RTINHERIT", "FS_XFLAG_PROJINHERIT", |
|
|
916 | "FS_XFLAG_NOSYMLINKS", "FS_XFLAG_EXTSIZE", "FS_XFLAG_EXTSZINHERIT", |
|
|
917 | "FS_XFLAG_NODEFRAG", "FS_XFLAG_FILESTREAM", "FS_XFLAG_DAX", |
|
|
918 | "FS_XFLAG_HASATTR", |
|
|
919 | |
| 756 | aio_sync $callback->($status) |
920 | aio_sync $callback->($status) |
| 757 | Asynchronously call sync and call the callback when finished. |
921 | Asynchronously call sync and call the callback when finished. |
| 758 | |
922 | |
| 759 | aio_fsync $fh, $callback->($status) |
923 | aio_fsync $fh, $callback->($status) |
| 760 | Asynchronously call fsync on the given filehandle and call the |
924 | Asynchronously call fsync on the given filehandle and call the |
| … | |
… | |
| 796 | Future versions of this function might fall back to other methods |
960 | Future versions of this function might fall back to other methods |
| 797 | when "fsync" on the directory fails (such as calling "sync"). |
961 | when "fsync" on the directory fails (such as calling "sync"). |
| 798 | |
962 | |
| 799 | Passes 0 when everything went ok, and -1 on error. |
963 | Passes 0 when everything went ok, and -1 on error. |
| 800 | |
964 | |
| 801 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, |
965 | aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, |
| 802 | $callback->($status) |
966 | $callback->($status) |
| 803 | This is a rather advanced IO::AIO call, which only works on |
967 | This is a rather advanced IO::AIO call, which only works on |
| 804 | mmap(2)ed scalars (see the "IO::AIO::mmap" function, although it |
968 | mmap(2)ed scalars (see the "IO::AIO::mmap" function, although it |
| 805 | also works on data scalars managed by the Sys::Mmap or Mmap modules, |
969 | also works on data scalars managed by the Sys::Mmap or Mmap modules, |
| 806 | note that the scalar must only be modified in-place while an aio |
970 | note that the scalar must only be modified in-place while an aio |
| … | |
… | |
| 808 | |
972 | |
| 809 | It calls the "msync" function of your OS, if available, with the |
973 | It calls the "msync" function of your OS, if available, with the |
| 810 | memory area starting at $offset in the string and ending $length |
974 | memory area starting at $offset in the string and ending $length |
| 811 | bytes later. If $length is negative, counts from the end, and if |
975 | bytes later. If $length is negative, counts from the end, and if |
| 812 | $length is "undef", then it goes till the end of the string. The |
976 | $length is "undef", then it goes till the end of the string. The |
| 813 | flags can be a combination of "IO::AIO::MS_ASYNC", |
977 | flags can be either "IO::AIO::MS_ASYNC" or "IO::AIO::MS_SYNC", plus |
| 814 | "IO::AIO::MS_INVALIDATE" and "IO::AIO::MS_SYNC". |
978 | an optional "IO::AIO::MS_INVALIDATE". |
| 815 | |
979 | |
| 816 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, |
980 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, |
| 817 | $callback->($status) |
981 | $callback->($status) |
| 818 | This is a rather advanced IO::AIO call, which works best on |
982 | This is a rather advanced IO::AIO call, which works best on |
| 819 | mmap(2)ed scalars. |
983 | mmap(2)ed scalars. |
| 820 | |
984 | |
| 821 | It touches (reads or writes) all memory pages in the specified range |
985 | It touches (reads or writes) all memory pages in the specified range |
| 822 | inside the scalar. All caveats and parameters are the same as for |
986 | inside the scalar. All caveats and parameters are the same as for |
| 823 | "aio_msync", above, except for flags, which must be either 0 (which |
987 | "aio_msync", above, except for flags, which must be either 0 (which |
| 824 | reads all pages and ensures they are instantiated) or |
988 | reads all pages and ensures they are instantiated) or |
| 825 | "IO::AIO::MT_MODIFY", which modifies the memory page s(by reading |
989 | "IO::AIO::MT_MODIFY", which modifies the memory pages (by reading |
| 826 | and writing an octet from it, which dirties the page). |
990 | and writing an octet from it, which dirties the page). |
| 827 | |
991 | |
| 828 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
992 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
| 829 | This is a rather advanced IO::AIO call, which works best on |
993 | This is a rather advanced IO::AIO call, which works best on |
| 830 | mmap(2)ed scalars. |
994 | mmap(2)ed scalars. |
| … | |
… | |
| 862 | |
1026 | |
| 863 | Example: asynchronously lock all current and future pages into |
1027 | Example: asynchronously lock all current and future pages into |
| 864 | memory. |
1028 | memory. |
| 865 | |
1029 | |
| 866 | aio_mlockall IO::AIO::MCL_FUTURE; |
1030 | aio_mlockall IO::AIO::MCL_FUTURE; |
|
|
1031 | |
|
|
1032 | aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents) |
|
|
1033 | Queries the extents of the given file (by calling the Linux "FIEMAP" |
|
|
1034 | ioctl, see <http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for |
|
|
1035 | details). If the ioctl is not available on your OS, then this |
|
|
1036 | request will fail with "ENOSYS". |
|
|
1037 | |
|
|
1038 | $start is the starting offset to query extents for, $length is the |
|
|
1039 | size of the range to query - if it is "undef", then the whole file |
|
|
1040 | will be queried. |
|
|
1041 | |
|
|
1042 | $flags is a combination of flags ("IO::AIO::FIEMAP_FLAG_SYNC" or |
|
|
1043 | "IO::AIO::FIEMAP_FLAG_XATTR" - "IO::AIO::FIEMAP_FLAGS_COMPAT" is |
|
|
1044 | also exported), and is normally 0 or "IO::AIO::FIEMAP_FLAG_SYNC" to |
|
|
1045 | query the data portion. |
|
|
1046 | |
|
|
1047 | $count is the maximum number of extent records to return. If it is |
|
|
1048 | "undef", then IO::AIO queries all extents of the range. As a very |
|
|
1049 | special case, if it is 0, then the callback receives the number of |
|
|
1050 | extents instead of the extents themselves (which is unreliable, see |
|
|
1051 | below). |
|
|
1052 | |
|
|
1053 | If an error occurs, the callback receives no arguments. The special |
|
|
1054 | "errno" value "IO::AIO::EBADR" is available to test for flag errors. |
|
|
1055 | |
|
|
1056 | Otherwise, the callback receives an array reference with extent |
|
|
1057 | structures. Each extent structure is an array reference itself, with |
|
|
1058 | the following members: |
|
|
1059 | |
|
|
1060 | [$logical, $physical, $length, $flags] |
|
|
1061 | |
|
|
1062 | Flags is any combination of the following flag values (typically |
|
|
1063 | either 0 or "IO::AIO::FIEMAP_EXTENT_LAST" (1)): |
|
|
1064 | |
|
|
1065 | "IO::AIO::FIEMAP_EXTENT_LAST", "IO::AIO::FIEMAP_EXTENT_UNKNOWN", |
|
|
1066 | "IO::AIO::FIEMAP_EXTENT_DELALLOC", "IO::AIO::FIEMAP_EXTENT_ENCODED", |
|
|
1067 | "IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED", |
|
|
1068 | "IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED", |
|
|
1069 | "IO::AIO::FIEMAP_EXTENT_DATA_INLINE", |
|
|
1070 | "IO::AIO::FIEMAP_EXTENT_DATA_TAIL", |
|
|
1071 | "IO::AIO::FIEMAP_EXTENT_UNWRITTEN", "IO::AIO::FIEMAP_EXTENT_MERGED" |
|
|
1072 | or "IO::AIO::FIEMAP_EXTENT_SHARED". |
|
|
1073 | |
|
|
1074 | At the time of this writing (Linux 3.2), this request is unreliable |
|
|
1075 | unless $count is "undef", as the kernel has all sorts of bugs |
|
|
1076 | preventing it to return all extents of a range for files with a |
|
|
1077 | large number of extents. The code (only) works around all these |
|
|
1078 | issues if $count is "undef". |
| 867 | |
1079 | |
| 868 | aio_group $callback->(...) |
1080 | aio_group $callback->(...) |
| 869 | This is a very special aio request: Instead of doing something, it |
1081 | This is a very special aio request: Instead of doing something, it |
| 870 | is a container for other aio requests, which is useful if you want |
1082 | is a container for other aio requests, which is useful if you want |
| 871 | to bundle many requests into a single, composite, request with a |
1083 | to bundle many requests into a single, composite, request with a |
| … | |
… | |
| 951 | aio_stat [$etcdir, "passwd"], sub { |
1163 | aio_stat [$etcdir, "passwd"], sub { |
| 952 | # yay |
1164 | # yay |
| 953 | }; |
1165 | }; |
| 954 | }; |
1166 | }; |
| 955 | |
1167 | |
| 956 | That "aio_wd" is a request and not a normal function shows that creating |
1168 | The fact that "aio_wd" is a request and not a normal function shows that |
| 957 | an IO::AIO::WD object is itself a potentially blocking operation, which |
1169 | creating an IO::AIO::WD object is itself a potentially blocking |
| 958 | is why it is done asynchronously. |
1170 | operation, which is why it is done asynchronously. |
| 959 | |
1171 | |
| 960 | To stat the directory obtained with "aio_wd" above, one could write |
1172 | To stat the directory obtained with "aio_wd" above, one could write |
| 961 | either of the following three request calls: |
1173 | either of the following three request calls: |
| 962 | |
1174 | |
| 963 | aio_lstat "/etc" , sub { ... # pathname as normal string |
1175 | aio_lstat "/etc" , sub { ... # pathname as normal string |
| … | |
… | |
| 980 | There are some caveats: when directories get renamed (or deleted), the |
1192 | There are some caveats: when directories get renamed (or deleted), the |
| 981 | pathname string doesn't change, so will point to the new directory (or |
1193 | pathname string doesn't change, so will point to the new directory (or |
| 982 | nowhere at all), while the directory fd, if available on the system, |
1194 | nowhere at all), while the directory fd, if available on the system, |
| 983 | will still point to the original directory. Most functions accepting a |
1195 | will still point to the original directory. Most functions accepting a |
| 984 | pathname will use the directory fd on newer systems, and the string on |
1196 | pathname will use the directory fd on newer systems, and the string on |
| 985 | older systems. Some functions (such as realpath) will always rely on the |
1197 | older systems. Some functions (such as "aio_realpath") will always rely |
| 986 | string form of the pathname. |
1198 | on the string form of the pathname. |
| 987 | |
1199 | |
| 988 | So this fucntionality is mainly useful to get some protection against |
1200 | So this functionality is mainly useful to get some protection against |
| 989 | "chdir", to easily get an absolute path out of a relative path for |
1201 | "chdir", to easily get an absolute path out of a relative path for |
| 990 | future reference, and to speed up doing many operations in the same |
1202 | future reference, and to speed up doing many operations in the same |
| 991 | directory (e.g. when stat'ing all files in a directory). |
1203 | directory (e.g. when stat'ing all files in a directory). |
| 992 | |
1204 | |
| 993 | The following functions implement this working directory abstraction: |
1205 | The following functions implement this working directory abstraction: |
| … | |
… | |
| 1003 | Since passing "undef" as working directory component of a pathname |
1215 | Since passing "undef" as working directory component of a pathname |
| 1004 | fails the request with "ENOENT", there is often no need for error |
1216 | fails the request with "ENOENT", there is often no need for error |
| 1005 | checking in the "aio_wd" callback, as future requests using the |
1217 | checking in the "aio_wd" callback, as future requests using the |
| 1006 | value will fail in the expected way. |
1218 | value will fail in the expected way. |
| 1007 | |
1219 | |
| 1008 | If this call isn't available because your OS lacks it or it couldn't |
|
|
| 1009 | be detected, it will be emulated by calling "fsync" instead. |
|
|
| 1010 | |
|
|
| 1011 | IO::AIO::CWD |
1220 | IO::AIO::CWD |
| 1012 | This is a compiletime constant (object) that represents the process |
1221 | This is a compiletime constant (object) that represents the process |
| 1013 | current working directory. |
1222 | current working directory. |
| 1014 | |
1223 | |
| 1015 | Specifying this object as working directory object for a pathname is |
1224 | Specifying this object as working directory object for a pathname is |
| 1016 | as if the pathname would be specified directly, without a directory |
1225 | as if the pathname would be specified directly, without a directory |
| 1017 | object, e.g., these calls are functionally identical: |
1226 | object. For example, these calls are functionally identical: |
| 1018 | |
1227 | |
| 1019 | aio_stat "somefile", sub { ... }; |
1228 | aio_stat "somefile", sub { ... }; |
| 1020 | aio_stat [IO::AIO::CWD, "somefile"], sub { ... }; |
1229 | aio_stat [IO::AIO::CWD, "somefile"], sub { ... }; |
|
|
1230 | |
|
|
1231 | To recover the path associated with an IO::AIO::WD object, you can use |
|
|
1232 | "aio_realpath": |
|
|
1233 | |
|
|
1234 | aio_realpath $wd, sub { |
|
|
1235 | warn "path is $_[0]\n"; |
|
|
1236 | }; |
|
|
1237 | |
|
|
1238 | Currently, "aio_statvfs" always, and "aio_rename" and "aio_rmdir" |
|
|
1239 | sometimes, fall back to using an absolue path. |
| 1021 | |
1240 | |
| 1022 | IO::AIO::REQ CLASS |
1241 | IO::AIO::REQ CLASS |
| 1023 | All non-aggregate "aio_*" functions return an object of this class when |
1242 | All non-aggregate "aio_*" functions return an object of this class when |
| 1024 | called in non-void context. |
1243 | called in non-void context. |
| 1025 | |
1244 | |
| … | |
… | |
| 1177 | results. |
1396 | results. |
| 1178 | |
1397 | |
| 1179 | See "poll_cb" for an example. |
1398 | See "poll_cb" for an example. |
| 1180 | |
1399 | |
| 1181 | IO::AIO::poll_cb |
1400 | IO::AIO::poll_cb |
| 1182 | Process some outstanding events on the result pipe. You have to call |
1401 | Process some requests that have reached the result phase (i.e. they |
|
|
1402 | have been executed but the results are not yet reported). You have |
|
|
1403 | to call this "regularly" to finish outstanding requests. |
|
|
1404 | |
| 1183 | this regularly. Returns 0 if all events could be processed (or there |
1405 | Returns 0 if all events could be processed (or there were no events |
| 1184 | were no events to process), or -1 if it returned earlier for |
1406 | to process), or -1 if it returned earlier for whatever reason. |
| 1185 | whatever reason. Returns immediately when no events are outstanding. |
1407 | Returns immediately when no events are outstanding. The amount of |
| 1186 | The amount of events processed depends on the settings of |
1408 | events processed depends on the settings of "IO::AIO::max_poll_req", |
| 1187 | "IO::AIO::max_poll_req" and "IO::AIO::max_poll_time". |
1409 | "IO::AIO::max_poll_time" and "IO::AIO::max_outstanding". |
| 1188 | |
1410 | |
| 1189 | If not all requests were processed for whatever reason, the |
1411 | If not all requests were processed for whatever reason, the poll |
| 1190 | filehandle will still be ready when "poll_cb" returns, so normally |
1412 | file descriptor will still be ready when "poll_cb" returns, so |
| 1191 | you don't have to do anything special to have it called later. |
1413 | normally you don't have to do anything special to have it called |
|
|
1414 | later. |
| 1192 | |
1415 | |
| 1193 | Apart from calling "IO::AIO::poll_cb" when the event filehandle |
1416 | Apart from calling "IO::AIO::poll_cb" when the event filehandle |
| 1194 | becomes ready, it can be beneficial to call this function from loops |
1417 | becomes ready, it can be beneficial to call this function from loops |
| 1195 | which submit a lot of requests, to make sure the results get |
1418 | which submit a lot of requests, to make sure the results get |
| 1196 | processed when they become available and not just when the loop is |
1419 | processed when they become available and not just when the loop is |
| … | |
… | |
| 1204 | Event->io (fd => IO::AIO::poll_fileno, |
1427 | Event->io (fd => IO::AIO::poll_fileno, |
| 1205 | poll => 'r', async => 1, |
1428 | poll => 'r', async => 1, |
| 1206 | cb => \&IO::AIO::poll_cb); |
1429 | cb => \&IO::AIO::poll_cb); |
| 1207 | |
1430 | |
| 1208 | IO::AIO::poll_wait |
1431 | IO::AIO::poll_wait |
| 1209 | If there are any outstanding requests and none of them in the result |
1432 | Wait until either at least one request is in the result phase or no |
| 1210 | phase, wait till the result filehandle becomes ready for reading |
1433 | requests are outstanding anymore. |
| 1211 | (simply does a "select" on the filehandle. This is useful if you |
1434 | |
| 1212 | want to synchronously wait for some requests to finish). |
1435 | This is useful if you want to synchronously wait for some requests |
|
|
1436 | to become ready, without actually handling them. |
| 1213 | |
1437 | |
| 1214 | See "nreqs" for an example. |
1438 | See "nreqs" for an example. |
| 1215 | |
1439 | |
| 1216 | IO::AIO::poll |
1440 | IO::AIO::poll |
| 1217 | Waits until some requests have been handled. |
1441 | Waits until some requests have been handled. |
| … | |
… | |
| 1329 | |
1553 | |
| 1330 | This is a very bad function to use in interactive programs because |
1554 | This is a very bad function to use in interactive programs because |
| 1331 | it blocks, and a bad way to reduce concurrency because it is |
1555 | it blocks, and a bad way to reduce concurrency because it is |
| 1332 | inexact: Better use an "aio_group" together with a feed callback. |
1556 | inexact: Better use an "aio_group" together with a feed callback. |
| 1333 | |
1557 | |
| 1334 | It's main use is in scripts without an event loop - when you want to |
1558 | Its main use is in scripts without an event loop - when you want to |
| 1335 | stat a lot of files, you can write somehting like this: |
1559 | stat a lot of files, you can write something like this: |
| 1336 | |
1560 | |
| 1337 | IO::AIO::max_outstanding 32; |
1561 | IO::AIO::max_outstanding 32; |
| 1338 | |
1562 | |
| 1339 | for my $path (...) { |
1563 | for my $path (...) { |
| 1340 | aio_stat $path , ...; |
1564 | aio_stat $path , ...; |
| … | |
… | |
| 1369 | |
1593 | |
| 1370 | IO::AIO::npending |
1594 | IO::AIO::npending |
| 1371 | Returns the number of requests currently in the pending state |
1595 | Returns the number of requests currently in the pending state |
| 1372 | (executed, but not yet processed by poll_cb). |
1596 | (executed, but not yet processed by poll_cb). |
| 1373 | |
1597 | |
|
|
1598 | SUBSECOND STAT TIME ACCESS |
|
|
1599 | Both "aio_stat"/"aio_lstat" and perl's "stat"/"lstat" functions can |
|
|
1600 | generally find access/modification and change times with subsecond time |
|
|
1601 | accuracy of the system supports it, but perl's built-in functions only |
|
|
1602 | return the integer part. |
|
|
1603 | |
|
|
1604 | The following functions return the timestamps of the most recent stat |
|
|
1605 | with subsecond precision on most systems and work both after |
|
|
1606 | "aio_stat"/"aio_lstat" and perl's "stat"/"lstat" calls. Their return |
|
|
1607 | value is only meaningful after a successful "stat"/"lstat" call, or |
|
|
1608 | during/after a successful "aio_stat"/"aio_lstat" callback. |
|
|
1609 | |
|
|
1610 | This is similar to the Time::HiRes "stat" functions, but can return full |
|
|
1611 | resolution without rounding and work with standard perl "stat", |
|
|
1612 | alleviating the need to call the special "Time::HiRes" functions, which |
|
|
1613 | do not act like their perl counterparts. |
|
|
1614 | |
|
|
1615 | On operating systems or file systems where subsecond time resolution is |
|
|
1616 | not supported or could not be detected, a fractional part of 0 is |
|
|
1617 | returned, so it is always safe to call these functions. |
|
|
1618 | |
|
|
1619 | $seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime |
|
|
1620 | Return the access, modication or change time, respectively, |
|
|
1621 | including fractional part. Due to the limited precision of floating |
|
|
1622 | point, the accuracy on most platforms is only a bit better than |
|
|
1623 | milliseconds for times around now - see the *nsec* function family, |
|
|
1624 | below, for full accuracy. |
|
|
1625 | |
|
|
1626 | ($atime, $mtime, $ctime, ...) = IO::AIO::st_xtime |
|
|
1627 | Returns access, modification and change time all in one go, and |
|
|
1628 | maybe more times in the future version. |
|
|
1629 | |
|
|
1630 | $nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec, |
|
|
1631 | IO::AIO::st_ctimensec |
|
|
1632 | Return the fractional access, modifcation or change time, in |
|
|
1633 | nanoseconds, as an integer in the range 0 to 999999999. |
|
|
1634 | |
|
|
1635 | ($atime, $mtime, $ctime, ...) = IO::AIO::st_xtimensec |
|
|
1636 | Like the functions above, but returns all three times in one go (and |
|
|
1637 | maybe more in future versions). |
|
|
1638 | |
|
|
1639 | Example: print the high resolution modification time of /etc, using |
|
|
1640 | "stat", and "IO::AIO::aio_stat". |
|
|
1641 | |
|
|
1642 | if (stat "/etc") { |
|
|
1643 | printf "stat(/etc) mtime: %f\n", IO::AIO::st_mtime; |
|
|
1644 | } |
|
|
1645 | |
|
|
1646 | IO::AIO::aio_stat "/etc", sub { |
|
|
1647 | $_[0] |
|
|
1648 | and return; |
|
|
1649 | |
|
|
1650 | printf "aio_stat(/etc) mtime: %d.%09d\n", (stat _)[9], IO::AIO::st_mtimensec; |
|
|
1651 | }; |
|
|
1652 | |
|
|
1653 | IO::AIO::flush; |
|
|
1654 | |
|
|
1655 | Output of the awbove on my system, showing reduced and full accuracy: |
|
|
1656 | |
|
|
1657 | stat(/etc) mtime: 1534043702.020808 |
|
|
1658 | aio_stat(/etc) mtime: 1534043702.020807792 |
|
|
1659 | |
| 1374 | MISCELLANEOUS FUNCTIONS |
1660 | MISCELLANEOUS FUNCTIONS |
| 1375 | IO::AIO implements some functions that might be useful, but are not |
1661 | IO::AIO implements some functions that are useful when you want to use |
| 1376 | asynchronous. |
1662 | some "Advanced I/O" function not available to in Perl, without going the |
|
|
1663 | "Asynchronous I/O" route. Many of these have an asynchronous "aio_*" |
|
|
1664 | counterpart. |
|
|
1665 | |
|
|
1666 | $numfd = IO::AIO::get_fdlimit |
|
|
1667 | This function is *EXPERIMENTAL* and subject to change. |
|
|
1668 | |
|
|
1669 | Tries to find the current file descriptor limit and returns it, or |
|
|
1670 | "undef" and sets $! in case of an error. The limit is one larger |
|
|
1671 | than the highest valid file descriptor number. |
|
|
1672 | |
|
|
1673 | IO::AIO::min_fdlimit [$numfd] |
|
|
1674 | This function is *EXPERIMENTAL* and subject to change. |
|
|
1675 | |
|
|
1676 | Try to increase the current file descriptor limit(s) to at least |
|
|
1677 | $numfd by changing the soft or hard file descriptor resource limit. |
|
|
1678 | If $numfd is missing, it will try to set a very high limit, although |
|
|
1679 | this is not recommended when you know the actual minimum that you |
|
|
1680 | require. |
|
|
1681 | |
|
|
1682 | If the limit cannot be raised enough, the function makes a |
|
|
1683 | best-effort attempt to increase the limit as much as possible, using |
|
|
1684 | various tricks, while still failing. You can query the resulting |
|
|
1685 | limit using "IO::AIO::get_fdlimit". |
|
|
1686 | |
|
|
1687 | If an error occurs, returns "undef" and sets $!, otherwise returns |
|
|
1688 | true. |
| 1377 | |
1689 | |
| 1378 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
1690 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
| 1379 | Calls the "eio_sendfile_sync" function, which is like |
1691 | Calls the "eio_sendfile_sync" function, which is like |
| 1380 | "aio_sendfile", but is blocking (this makes most sense if you know |
1692 | "aio_sendfile", but is blocking (this makes most sense if you know |
| 1381 | the input data is likely cached already and the output filehandle is |
1693 | the input data is likely cached already and the output filehandle is |
| … | |
… | |
| 1398 | details). The following advice constants are available: |
1710 | details). The following advice constants are available: |
| 1399 | "IO::AIO::MADV_NORMAL", "IO::AIO::MADV_SEQUENTIAL", |
1711 | "IO::AIO::MADV_NORMAL", "IO::AIO::MADV_SEQUENTIAL", |
| 1400 | "IO::AIO::MADV_RANDOM", "IO::AIO::MADV_WILLNEED", |
1712 | "IO::AIO::MADV_RANDOM", "IO::AIO::MADV_WILLNEED", |
| 1401 | "IO::AIO::MADV_DONTNEED". |
1713 | "IO::AIO::MADV_DONTNEED". |
| 1402 | |
1714 | |
|
|
1715 | If $offset is negative, counts from the end. If $length is negative, |
|
|
1716 | the remaining length of the $scalar is used. If possible, $length |
|
|
1717 | will be reduced to fit into the $scalar. |
|
|
1718 | |
| 1403 | On systems that do not implement "posix_madvise", this function |
1719 | On systems that do not implement "posix_madvise", this function |
| 1404 | returns ENOSYS, otherwise the return value of "posix_madvise". |
1720 | returns ENOSYS, otherwise the return value of "posix_madvise". |
| 1405 | |
1721 | |
| 1406 | IO::AIO::mprotect $scalar, $offset, $len, $protect |
1722 | IO::AIO::mprotect $scalar, $offset, $len, $protect |
| 1407 | Simply calls the "mprotect" function on the preferably AIO::mmap'ed |
1723 | Simply calls the "mprotect" function on the preferably AIO::mmap'ed |
| 1408 | $scalar (see its manpage for details). The following protect |
1724 | $scalar (see its manpage for details). The following protect |
| 1409 | constants are available: "IO::AIO::PROT_NONE", "IO::AIO::PROT_READ", |
1725 | constants are available: "IO::AIO::PROT_NONE", "IO::AIO::PROT_READ", |
| 1410 | "IO::AIO::PROT_WRITE", "IO::AIO::PROT_EXEC". |
1726 | "IO::AIO::PROT_WRITE", "IO::AIO::PROT_EXEC". |
| 1411 | |
1727 | |
|
|
1728 | If $offset is negative, counts from the end. If $length is negative, |
|
|
1729 | the remaining length of the $scalar is used. If possible, $length |
|
|
1730 | will be reduced to fit into the $scalar. |
|
|
1731 | |
| 1412 | On systems that do not implement "mprotect", this function returns |
1732 | On systems that do not implement "mprotect", this function returns |
| 1413 | ENOSYS, otherwise the return value of "mprotect". |
1733 | ENOSYS, otherwise the return value of "mprotect". |
| 1414 | |
1734 | |
| 1415 | IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] |
1735 | IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] |
| 1416 | Memory-maps a file (or anonymous memory range) and attaches it to |
1736 | Memory-maps a file (or anonymous memory range) and attaches it to |
| 1417 | the given $scalar, which will act like a string scalar. |
1737 | the given $scalar, which will act like a string scalar. Returns true |
|
|
1738 | on success, and false otherwise. |
| 1418 | |
1739 | |
|
|
1740 | The scalar must exist, but its contents do not matter - this means |
|
|
1741 | you cannot use a nonexistant array or hash element. When in doubt, |
|
|
1742 | "undef" the scalar first. |
|
|
1743 | |
| 1419 | The only operations allowed on the scalar are "substr"/"vec" that |
1744 | The only operations allowed on the mmapped scalar are |
| 1420 | don't change the string length, and most read-only operations such |
1745 | "substr"/"vec", which don't change the string length, and most |
| 1421 | as copying it or searching it with regexes and so on. |
1746 | read-only operations such as copying it or searching it with regexes |
|
|
1747 | and so on. |
| 1422 | |
1748 | |
| 1423 | Anything else is unsafe and will, at best, result in memory leaks. |
1749 | Anything else is unsafe and will, at best, result in memory leaks. |
| 1424 | |
1750 | |
| 1425 | The memory map associated with the $scalar is automatically removed |
1751 | The memory map associated with the $scalar is automatically removed |
| 1426 | when the $scalar is destroyed, or when the "IO::AIO::mmap" or |
1752 | when the $scalar is undef'd or destroyed, or when the |
| 1427 | "IO::AIO::munmap" functions are called. |
1753 | "IO::AIO::mmap" or "IO::AIO::munmap" functions are called on it. |
| 1428 | |
1754 | |
| 1429 | This calls the "mmap"(2) function internally. See your system's |
1755 | This calls the "mmap"(2) function internally. See your system's |
| 1430 | manual page for details on the $length, $prot and $flags parameters. |
1756 | manual page for details on the $length, $prot and $flags parameters. |
| 1431 | |
1757 | |
| 1432 | The $length must be larger than zero and smaller than the actual |
1758 | The $length must be larger than zero and smaller than the actual |
| … | |
… | |
| 1436 | "IO::AIO::PROT_EXEC", "IO::AIO::PROT_READ" and/or |
1762 | "IO::AIO::PROT_EXEC", "IO::AIO::PROT_READ" and/or |
| 1437 | "IO::AIO::PROT_WRITE", |
1763 | "IO::AIO::PROT_WRITE", |
| 1438 | |
1764 | |
| 1439 | $flags can be a combination of "IO::AIO::MAP_SHARED" or |
1765 | $flags can be a combination of "IO::AIO::MAP_SHARED" or |
| 1440 | "IO::AIO::MAP_PRIVATE", or a number of system-specific flags (when |
1766 | "IO::AIO::MAP_PRIVATE", or a number of system-specific flags (when |
| 1441 | not available, the are defined as 0): "IO::AIO::MAP_ANONYMOUS" |
1767 | not available, the are 0): "IO::AIO::MAP_ANONYMOUS" (which is set to |
| 1442 | (which is set to "MAP_ANON" if your system only provides this |
1768 | "MAP_ANON" if your system only provides this constant), |
|
|
1769 | "IO::AIO::MAP_LOCKED", "IO::AIO::MAP_NORESERVE", |
| 1443 | constant), "IO::AIO::MAP_HUGETLB", "IO::AIO::MAP_LOCKED", |
1770 | "IO::AIO::MAP_POPULATE", "IO::AIO::MAP_NONBLOCK", |
|
|
1771 | "IO::AIO::MAP_FIXED", "IO::AIO::MAP_GROWSDOWN", |
| 1444 | "IO::AIO::MAP_NORESERVE", "IO::AIO::MAP_POPULATE" or |
1772 | "IO::AIO::MAP_32BIT", "IO::AIO::MAP_HUGETLB" or |
| 1445 | "IO::AIO::MAP_NONBLOCK" |
1773 | "IO::AIO::MAP_STACK". |
| 1446 | |
1774 | |
| 1447 | If $fh is "undef", then a file descriptor of -1 is passed. |
1775 | If $fh is "undef", then a file descriptor of -1 is passed. |
| 1448 | |
1776 | |
| 1449 | $offset is the offset from the start of the file - it generally must |
1777 | $offset is the offset from the start of the file - it generally must |
| 1450 | be a multiple of "IO::AIO::PAGESIZE" and defaults to 0. |
1778 | be a multiple of "IO::AIO::PAGESIZE" and defaults to 0. |
| … | |
… | |
| 1462 | |
1790 | |
| 1463 | my $fast_md5 = md5 $data; |
1791 | my $fast_md5 = md5 $data; |
| 1464 | |
1792 | |
| 1465 | IO::AIO::munmap $scalar |
1793 | IO::AIO::munmap $scalar |
| 1466 | Removes a previous mmap and undefines the $scalar. |
1794 | Removes a previous mmap and undefines the $scalar. |
|
|
1795 | |
|
|
1796 | IO::AIO::mremap $scalar, $new_length, $flags = MREMAP_MAYMOVE[, |
|
|
1797 | $new_address = 0] |
|
|
1798 | Calls the Linux-specific mremap(2) system call. The $scalar must |
|
|
1799 | have been mapped by "IO::AIO::mmap", and $flags must currently |
|
|
1800 | either be 0 or "IO::AIO::MREMAP_MAYMOVE". |
|
|
1801 | |
|
|
1802 | Returns true if successful, and false otherwise. If the underlying |
|
|
1803 | mmapped region has changed address, then the true value has the |
|
|
1804 | numerical value 1, otherwise it has the numerical value 0: |
|
|
1805 | |
|
|
1806 | my $success = IO::AIO::mremap $mmapped, 8192, IO::AIO::MREMAP_MAYMOVE |
|
|
1807 | or die "mremap: $!"; |
|
|
1808 | |
|
|
1809 | if ($success*1) { |
|
|
1810 | warn "scalar has chanegd address in memory\n"; |
|
|
1811 | } |
|
|
1812 | |
|
|
1813 | "IO::AIO::MREMAP_FIXED" and the $new_address argument are currently |
|
|
1814 | implemented, but not supported and might go away in a future |
|
|
1815 | version. |
|
|
1816 | |
|
|
1817 | On systems where this call is not supported or is not emulated, this |
|
|
1818 | call returns falls and sets $! to "ENOSYS". |
| 1467 | |
1819 | |
| 1468 | IO::AIO::munlock $scalar, $offset = 0, $length = undef |
1820 | IO::AIO::munlock $scalar, $offset = 0, $length = undef |
| 1469 | Calls the "munlock" function, undoing the effects of a previous |
1821 | Calls the "munlock" function, undoing the effects of a previous |
| 1470 | "aio_mlock" call (see its description for details). |
1822 | "aio_mlock" call (see its description for details). |
| 1471 | |
1823 | |
| 1472 | IO::AIO::munlockall |
1824 | IO::AIO::munlockall |
| 1473 | Calls the "munlockall" function. |
1825 | Calls the "munlockall" function. |
| 1474 | |
1826 | |
| 1475 | On systems that do not implement "munlockall", this function returns |
1827 | On systems that do not implement "munlockall", this function returns |
| 1476 | ENOSYS, otherwise the return value of "munlockall". |
1828 | ENOSYS, otherwise the return value of "munlockall". |
|
|
1829 | |
|
|
1830 | IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags |
|
|
1831 | Calls the GNU/Linux splice(2) syscall, if available. If $r_off or |
|
|
1832 | $w_off are "undef", then "NULL" is passed for these, otherwise they |
|
|
1833 | should be the file offset. |
|
|
1834 | |
|
|
1835 | $r_fh and $w_fh should not refer to the same file, as splice might |
|
|
1836 | silently corrupt the data in this case. |
|
|
1837 | |
|
|
1838 | The following symbol flag values are available: |
|
|
1839 | "IO::AIO::SPLICE_F_MOVE", "IO::AIO::SPLICE_F_NONBLOCK", |
|
|
1840 | "IO::AIO::SPLICE_F_MORE" and "IO::AIO::SPLICE_F_GIFT". |
|
|
1841 | |
|
|
1842 | See the splice(2) manpage for details. |
|
|
1843 | |
|
|
1844 | IO::AIO::tee $r_fh, $w_fh, $length, $flags |
|
|
1845 | Calls the GNU/Linux tee(2) syscall, see its manpage and the |
|
|
1846 | description for "IO::AIO::splice" above for details. |
|
|
1847 | |
|
|
1848 | $actual_size = IO::AIO::pipesize $r_fh[, $new_size] |
|
|
1849 | Attempts to query or change the pipe buffer size. Obviously works |
|
|
1850 | only on pipes, and currently works only on GNU/Linux systems, and |
|
|
1851 | fails with -1/"ENOSYS" everywhere else. If anybody knows how to |
|
|
1852 | influence pipe buffer size on other systems, drop me a note. |
|
|
1853 | |
|
|
1854 | ($rfh, $wfh) = IO::AIO::pipe2 [$flags] |
|
|
1855 | This is a direct interface to the Linux pipe2(2) system call. If |
|
|
1856 | $flags is missing or 0, then this should be the same as a call to |
|
|
1857 | perl's built-in "pipe" function and create a new pipe, and works on |
|
|
1858 | systems that lack the pipe2 syscall. On win32, this case invokes |
|
|
1859 | "_pipe (..., 4096, O_BINARY)". |
|
|
1860 | |
|
|
1861 | If $flags is non-zero, it tries to invoke the pipe2 system call with |
|
|
1862 | the given flags (Linux 2.6.27, glibc 2.9). |
|
|
1863 | |
|
|
1864 | On success, the read and write file handles are returned. |
|
|
1865 | |
|
|
1866 | On error, nothing will be returned. If the pipe2 syscall is missing |
|
|
1867 | and $flags is non-zero, fails with "ENOSYS". |
|
|
1868 | |
|
|
1869 | Please refer to pipe2(2) for more info on the $flags, but at the |
|
|
1870 | time of this writing, "IO::AIO::O_CLOEXEC", "IO::AIO::O_NONBLOCK" |
|
|
1871 | and "IO::AIO::O_DIRECT" (Linux 3.4, for packet-based pipes) were |
|
|
1872 | supported. |
|
|
1873 | |
|
|
1874 | Example: create a pipe race-free w.r.t. threads and fork: |
|
|
1875 | |
|
|
1876 | my ($rfh, $wfh) = IO::AIO::pipe2 IO::AIO::O_CLOEXEC |
|
|
1877 | or die "pipe2: $!\n"; |
|
|
1878 | |
|
|
1879 | $fh = IO::AIO::eventfd [$initval, [$flags]] |
|
|
1880 | This is a direct interface to the Linux eventfd(2) system call. The |
|
|
1881 | (unhelpful) defaults for $initval and $flags are 0 for both. |
|
|
1882 | |
|
|
1883 | On success, the new eventfd filehandle is returned, otherwise |
|
|
1884 | returns "undef". If the eventfd syscall is missing, fails with |
|
|
1885 | "ENOSYS". |
|
|
1886 | |
|
|
1887 | Please refer to eventfd(2) for more info on this call. |
|
|
1888 | |
|
|
1889 | The following symbol flag values are available: |
|
|
1890 | "IO::AIO::EFD_CLOEXEC", "IO::AIO::EFD_NONBLOCK" and |
|
|
1891 | "IO::AIO::EFD_SEMAPHORE" (Linux 2.6.30). |
|
|
1892 | |
|
|
1893 | Example: create a new eventfd filehandle: |
|
|
1894 | |
|
|
1895 | $fh = IO::AIO::eventfd 0, IO::AIO::O_CLOEXEC |
|
|
1896 | or die "eventfd: $!\n"; |
|
|
1897 | |
|
|
1898 | $fh = IO::AIO::timerfd_create $clockid[, $flags] |
|
|
1899 | This is a direct interface to the Linux timerfd_create(2) system |
|
|
1900 | call. The (unhelpful) default for $flags is 0. |
|
|
1901 | |
|
|
1902 | On success, the new timerfd filehandle is returned, otherwise |
|
|
1903 | returns "undef". If the eventfd syscall is missing, fails with |
|
|
1904 | "ENOSYS". |
|
|
1905 | |
|
|
1906 | Please refer to timerfd_create(2) for more info on this call. |
|
|
1907 | |
|
|
1908 | The following $clockid values are available: |
|
|
1909 | "IO::AIO::CLOCK_REALTIME", "IO::AIO::CLOCK_MONOTONIC" |
|
|
1910 | "IO::AIO::CLOCK_CLOCK_BOOTTIME" (Linux 3.15) |
|
|
1911 | "IO::AIO::CLOCK_CLOCK_REALTIME_ALARM" (Linux 3.11) and |
|
|
1912 | "IO::AIO::CLOCK_CLOCK_BOOTTIME_ALARM" (Linux 3.11). |
|
|
1913 | |
|
|
1914 | The following $flags values are available (Linux 2.6.27): |
|
|
1915 | "IO::AIO::TFD_NONBLOCK" and "IO::AIO::TFD_CLOEXEC". |
|
|
1916 | |
|
|
1917 | Example: create a new timerfd and set it to one-second repeated |
|
|
1918 | alarms, then wait for two alarms: |
|
|
1919 | |
|
|
1920 | my $fh = IO::AIO::timerfd_create IO::AIO::CLOCK_BOOTTIME, IO::AIO::TFD_CLOEXEC |
|
|
1921 | or die "timerfd_create: $!\n"; |
|
|
1922 | |
|
|
1923 | defined IO::AIO::timerfd_settime $fh, 0, 1, 1 |
|
|
1924 | or die "timerfd_settime: $!\n"; |
|
|
1925 | |
|
|
1926 | for (1..2) { |
|
|
1927 | 8 == sysread $fh, my $buf, 8 |
|
|
1928 | or die "timerfd read failure\n"; |
|
|
1929 | |
|
|
1930 | printf "number of expirations (likely 1): %d\n", |
|
|
1931 | unpack "Q", $buf; |
|
|
1932 | } |
|
|
1933 | |
|
|
1934 | ($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags, |
|
|
1935 | $new_interval, $nbw_value |
|
|
1936 | This is a direct interface to the Linux timerfd_settime(2) system |
|
|
1937 | call. Please refer to its manpage for more info on this call. |
|
|
1938 | |
|
|
1939 | The new itimerspec is specified using two (possibly fractional) |
|
|
1940 | second values, $new_interval and $new_value). |
|
|
1941 | |
|
|
1942 | On success, the current interval and value are returned (as per |
|
|
1943 | "timerfd_gettime"). On failure, the empty list is returned. |
|
|
1944 | |
|
|
1945 | The following $flags values are available: |
|
|
1946 | "IO::AIO::TFD_TIMER_ABSTIME" and "IO::AIO::TFD_TIMER_CANCEL_ON_SET". |
|
|
1947 | |
|
|
1948 | See "IO::AIO::timerfd_create" for a full example. |
|
|
1949 | |
|
|
1950 | ($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh |
|
|
1951 | This is a direct interface to the Linux timerfd_gettime(2) system |
|
|
1952 | call. Please refer to its manpage for more info on this call. |
|
|
1953 | |
|
|
1954 | On success, returns the current values of interval and value for the |
|
|
1955 | given timerfd (as potentially fractional second values). On failure, |
|
|
1956 | the empty list is returned. |
| 1477 | |
1957 | |
| 1478 | EVENT LOOP INTEGRATION |
1958 | EVENT LOOP INTEGRATION |
| 1479 | It is recommended to use AnyEvent::AIO to integrate IO::AIO |
1959 | It is recommended to use AnyEvent::AIO to integrate IO::AIO |
| 1480 | automatically into many event loops: |
1960 | automatically into many event loops: |
| 1481 | |
1961 | |
| … | |
… | |
| 1531 | forking, if "IO::AIO" was used in the parent. Calling it while |
2011 | forking, if "IO::AIO" was used in the parent. Calling it while |
| 1532 | IO::AIO is active in the process will result in undefined behaviour. |
2012 | IO::AIO is active in the process will result in undefined behaviour. |
| 1533 | Calling it at any time will also result in any undefined (by POSIX) |
2013 | Calling it at any time will also result in any undefined (by POSIX) |
| 1534 | behaviour. |
2014 | behaviour. |
| 1535 | |
2015 | |
|
|
2016 | LINUX-SPECIFIC CALLS |
|
|
2017 | When a call is documented as "linux-specific" then this means it |
|
|
2018 | originated on GNU/Linux. "IO::AIO" will usually try to autodetect the |
|
|
2019 | availability and compatibility of such calls regardless of the platform |
|
|
2020 | it is compiled on, so platforms such as FreeBSD which often implement |
|
|
2021 | these calls will work. When in doubt, call them and see if they fail wth |
|
|
2022 | "ENOSYS". |
|
|
2023 | |
| 1536 | MEMORY USAGE |
2024 | MEMORY USAGE |
| 1537 | Per-request usage: |
2025 | Per-request usage: |
| 1538 | |
2026 | |
| 1539 | Each aio request uses - depending on your architecture - around 100-200 |
2027 | Each aio request uses - depending on your architecture - around 100-200 |
| 1540 | bytes of memory. In addition, stat requests need a stat buffer (possibly |
2028 | bytes of memory. In addition, stat requests need a stat buffer (possibly |
| … | |
… | |
| 1550 | In the execution phase, some aio requests require more memory for |
2038 | In the execution phase, some aio requests require more memory for |
| 1551 | temporary buffers, and each thread requires a stack and other data |
2039 | temporary buffers, and each thread requires a stack and other data |
| 1552 | structures (usually around 16k-128k, depending on the OS). |
2040 | structures (usually around 16k-128k, depending on the OS). |
| 1553 | |
2041 | |
| 1554 | KNOWN BUGS |
2042 | KNOWN BUGS |
| 1555 | Known bugs will be fixed in the next release. |
2043 | Known bugs will be fixed in the next release :) |
|
|
2044 | |
|
|
2045 | KNOWN ISSUES |
|
|
2046 | Calls that try to "import" foreign memory areas (such as "IO::AIO::mmap" |
|
|
2047 | or "IO::AIO::aio_slurp") do not work with generic lvalues, such as |
|
|
2048 | non-created hash slots or other scalars I didn't think of. It's best to |
|
|
2049 | avoid such and either use scalar variables or making sure that the |
|
|
2050 | scalar exists (e.g. by storing "undef") and isn't "funny" (e.g. tied). |
|
|
2051 | |
|
|
2052 | I am not sure anything can be done about this, so this is considered a |
|
|
2053 | known issue, rather than a bug. |
| 1556 | |
2054 | |
| 1557 | SEE ALSO |
2055 | SEE ALSO |
| 1558 | AnyEvent::AIO for easy integration into event loops, Coro::AIO for a |
2056 | AnyEvent::AIO for easy integration into event loops, Coro::AIO for a |
| 1559 | more natural syntax. |
2057 | more natural syntax. |
| 1560 | |
2058 | |
