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 { |
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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; |
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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 | |
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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 | |
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158 | aio_wd $pathname, $callback->($wd) |
155 | aio_open $pathname, $flags, $mode, $callback->($fh) |
159 | aio_open $pathname, $flags, $mode, $callback->($fh) |
156 | aio_close $fh, $callback->($status) |
160 | aio_close $fh, $callback->($status) |
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161 | aio_seek $fh,$offset,$whence, $callback->($offs) |
157 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
162 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
158 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
163 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
159 | aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
164 | aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
160 | aio_readahead $fh,$offset,$length, $callback->($retval) |
165 | aio_readahead $fh,$offset,$length, $callback->($retval) |
161 | aio_stat $fh_or_path, $callback->($status) |
166 | aio_stat $fh_or_path, $callback->($status) |
162 | aio_lstat $fh, $callback->($status) |
167 | aio_lstat $fh, $callback->($status) |
163 | aio_statvfs $fh_or_path, $callback->($statvfs) |
168 | aio_statvfs $fh_or_path, $callback->($statvfs) |
164 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
169 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
165 | 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) |
166 | aio_truncate $fh_or_path, $offset, $callback->($status) |
172 | aio_truncate $fh_or_path, $offset, $callback->($status) |
167 | 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) |
168 | aio_unlink $pathname, $callback->($status) |
175 | aio_unlink $pathname, $callback->($status) |
169 | aio_mknod $path, $mode, $dev, $callback->($status) |
176 | aio_mknod $pathname, $mode, $dev, $callback->($status) |
170 | aio_link $srcpath, $dstpath, $callback->($status) |
177 | aio_link $srcpath, $dstpath, $callback->($status) |
171 | aio_symlink $srcpath, $dstpath, $callback->($status) |
178 | aio_symlink $srcpath, $dstpath, $callback->($status) |
172 | aio_readlink $path, $callback->($link) |
179 | aio_readlink $pathname, $callback->($link) |
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180 | aio_realpath $pathname, $callback->($path) |
173 | 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) |
174 | aio_mkdir $pathname, $mode, $callback->($status) |
183 | aio_mkdir $pathname, $mode, $callback->($status) |
175 | aio_rmdir $pathname, $callback->($status) |
184 | aio_rmdir $pathname, $callback->($status) |
176 | aio_readdir $pathname, $callback->($entries) |
185 | aio_readdir $pathname, $callback->($entries) |
177 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
186 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
178 | IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST |
187 | IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST |
179 | IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN |
188 | IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN |
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189 | aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) |
180 | aio_load $path, $data, $callback->($status) |
190 | aio_load $pathname, $data, $callback->($status) |
181 | aio_copy $srcpath, $dstpath, $callback->($status) |
191 | aio_copy $srcpath, $dstpath, $callback->($status) |
182 | aio_move $srcpath, $dstpath, $callback->($status) |
192 | aio_move $srcpath, $dstpath, $callback->($status) |
183 | aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
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184 | aio_rmtree $path, $callback->($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) |
185 | aio_sync $callback->($status) |
196 | aio_sync $callback->($status) |
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197 | aio_syncfs $fh, $callback->($status) |
186 | aio_fsync $fh, $callback->($status) |
198 | aio_fsync $fh, $callback->($status) |
187 | aio_fdatasync $fh, $callback->($status) |
199 | aio_fdatasync $fh, $callback->($status) |
188 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
200 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
189 | aio_pathsync $path, $callback->($status) |
201 | aio_pathsync $pathname, $callback->($status) |
190 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
202 | aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status) |
191 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
203 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
192 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
204 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
193 | aio_mlockall $flags, $callback->($status) |
205 | aio_mlockall $flags, $callback->($status) |
194 | aio_group $callback->(...) |
206 | aio_group $callback->(...) |
195 | aio_nop $callback->() |
207 | aio_nop $callback->() |
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209 | IO::AIO::idle_timeout $seconds |
221 | IO::AIO::idle_timeout $seconds |
210 | IO::AIO::max_outstanding $maxreqs |
222 | IO::AIO::max_outstanding $maxreqs |
211 | IO::AIO::nreqs |
223 | IO::AIO::nreqs |
212 | IO::AIO::nready |
224 | IO::AIO::nready |
213 | 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] |
214 | |
228 | |
215 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
229 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
216 | 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] |
217 | IO::AIO::madvise $scalar, $offset, $length, $advice |
234 | IO::AIO::madvise $scalar, $offset, $length, $advice |
218 | IO::AIO::mprotect $scalar, $offset, $length, $protect |
235 | IO::AIO::mprotect $scalar, $offset, $length, $protect |
219 | IO::AIO::munlock $scalar, $offset = 0, $length = undef |
236 | IO::AIO::munlock $scalar, $offset = 0, $length = undef |
220 | IO::AIO::munlockall |
237 | IO::AIO::munlockall |
221 | |
238 | |
222 | AIO REQUEST FUNCTIONS |
239 | API NOTES |
223 | 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 |
224 | with the same name (sans "aio_"). The arguments are similar or |
241 | with the same name (sans "aio_"). The arguments are similar or |
225 | identical, and they all accept an additional (and optional) $callback |
242 | identical, and they all accept an additional (and optional) $callback |
226 | argument which must be a code reference. This code reference will get |
243 | argument which must be a code reference. This code reference will be |
227 | called with the syscall return code (e.g. most syscalls return -1 on |
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228 | error, unlike perl, which usually delivers "false") as its sole argument |
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229 | after the given syscall has been executed asynchronously. |
244 | called after the syscall has been executed in an asynchronous fashion. |
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245 | The results of the request will be passed as arguments to the callback |
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246 | (and, if an error occured, in $!) - for most requests the syscall return |
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247 | code (e.g. most syscalls return -1 on error, unlike perl, which usually |
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248 | delivers "false"). |
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249 | |
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250 | Some requests (such as "aio_readdir") pass the actual results and |
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251 | communicate failures by passing "undef". |
230 | |
252 | |
231 | All functions expecting a filehandle keep a copy of the filehandle |
253 | All functions expecting a filehandle keep a copy of the filehandle |
232 | internally until the request has finished. |
254 | internally until the request has finished. |
233 | |
255 | |
234 | All functions return request objects of type IO::AIO::REQ that allow |
256 | All functions return request objects of type IO::AIO::REQ that allow |
235 | further manipulation of those requests while they are in-flight. |
257 | further manipulation of those requests while they are in-flight. |
236 | |
258 | |
237 | The pathnames you pass to these routines *must* be absolute and encoded |
259 | The pathnames you pass to these routines *should* be absolute. The |
238 | as octets. The reason for the former is that at the time the request is |
260 | reason for this is that at the time the request is being executed, the |
239 | being executed, the current working directory could have changed. |
261 | current working directory could have changed. Alternatively, you can |
240 | Alternatively, you can make sure that you never change the current |
262 | make sure that you never change the current working directory anywhere |
241 | working directory anywhere in the program and then use relative paths. |
263 | in the program and then use relative paths. You can also take advantage |
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264 | of IO::AIOs working directory abstraction, that lets you specify paths |
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265 | relative to some previously-opened "working directory object" - see the |
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266 | description of the "IO::AIO::WD" class later in this document. |
242 | |
267 | |
243 | To encode pathnames as octets, either make sure you either: a) always |
268 | To encode pathnames as octets, either make sure you either: a) always |
244 | pass in filenames you got from outside (command line, readdir etc.) |
269 | pass in filenames you got from outside (command line, readdir etc.) |
245 | without tinkering, b) are ASCII or ISO 8859-1, c) use the Encode module |
270 | without tinkering, b) are in your native filesystem encoding, c) use the |
246 | and encode your pathnames to the locale (or other) encoding in effect in |
271 | Encode module and encode your pathnames to the locale (or other) |
247 | the user environment, d) use Glib::filename_from_unicode on unicode |
272 | encoding in effect in the user environment, d) use |
248 | filenames or e) use something else to ensure your scalar has the correct |
273 | Glib::filename_from_unicode on unicode filenames or e) use something |
249 | contents. |
274 | else to ensure your scalar has the correct contents. |
250 | |
275 | |
251 | 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 |
252 | handles correctly whether it is set or not. |
277 | handles correctly whether it is set or not. |
253 | |
278 | |
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279 | AIO REQUEST FUNCTIONS |
254 | $prev_pri = aioreq_pri [$pri] |
280 | $prev_pri = aioreq_pri [$pri] |
255 | 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 |
256 | 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. |
257 | |
283 | |
258 | 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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280 | Similar to "aioreq_pri", but subtracts the given value from the |
306 | Similar to "aioreq_pri", but subtracts the given value from the |
281 | current priority, so the effect is cumulative. |
307 | current priority, so the effect is cumulative. |
282 | |
308 | |
283 | aio_open $pathname, $flags, $mode, $callback->($fh) |
309 | aio_open $pathname, $flags, $mode, $callback->($fh) |
284 | 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 |
285 | 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). |
286 | |
313 | |
287 | 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, |
288 | above, for an explanation. |
315 | above, for an explanation. |
289 | |
316 | |
290 | 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. |
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313 | "O_APPEND"), the following POSIX and non-POSIX constants are |
340 | "O_APPEND"), the following POSIX and non-POSIX constants are |
314 | available (missing ones on your system are, as usual, 0): |
341 | available (missing ones on your system are, as usual, 0): |
315 | |
342 | |
316 | "O_ASYNC", "O_DIRECT", "O_NOATIME", "O_CLOEXEC", "O_NOCTTY", |
343 | "O_ASYNC", "O_DIRECT", "O_NOATIME", "O_CLOEXEC", "O_NOCTTY", |
317 | "O_NOFOLLOW", "O_NONBLOCK", "O_EXEC", "O_SEARCH", "O_DIRECTORY", |
344 | "O_NOFOLLOW", "O_NONBLOCK", "O_EXEC", "O_SEARCH", "O_DIRECTORY", |
318 | "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". |
319 | |
347 | |
320 | aio_close $fh, $callback->($status) |
348 | aio_close $fh, $callback->($status) |
321 | Asynchronously close a file and call the callback with the result |
349 | Asynchronously close a file and call the callback with the result |
322 | code. |
350 | code. |
323 | |
351 | |
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329 | 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 |
330 | 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). |
331 | |
359 | |
332 | 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 |
333 | 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". |
334 | |
381 | |
335 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
382 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
336 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
383 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
337 | 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 |
338 | $offset into the scalar given by $data and offset $dataoffset and |
385 | $offset into the scalar given by $data and offset $dataoffset and |
339 | 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 |
340 | error, just like the syscall). |
387 | -1 on error, just like the syscall). |
341 | |
388 | |
342 | "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 |
343 | offset plus the actual number of bytes read. |
390 | offset plus the actual number of bytes read. |
344 | |
391 | |
345 | If $offset is undefined, then the current file descriptor offset |
392 | If $offset is undefined, then the current file descriptor offset |
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402 | As native sendfile syscalls (as practically any non-POSIX interface |
449 | As native sendfile syscalls (as practically any non-POSIX interface |
403 | 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 |
404 | rather buggy on many systems, this implementation tries to work |
451 | rather buggy on many systems, this implementation tries to work |
405 | around some known bugs in Linux and FreeBSD kernels (probably |
452 | around some known bugs in Linux and FreeBSD kernels (probably |
406 | 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 |
407 | the return value of "aio_sendfile" - fewre bytes than expected might |
454 | the return value of "aio_sendfile" - fewer bytes than expected might |
408 | have been transferred. |
455 | have been transferred. |
409 | |
456 | |
410 | aio_readahead $fh,$offset,$length, $callback->($retval) |
457 | aio_readahead $fh,$offset,$length, $callback->($retval) |
411 | "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 |
412 | 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 |
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416 | 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 |
417 | 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 |
418 | 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 |
419 | is left unchanged. |
466 | is left unchanged. |
420 | |
467 | |
421 | 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 |
422 | 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 |
423 | similar effect. |
470 | similar effect. |
424 | |
471 | |
425 | aio_stat $fh_or_path, $callback->($status) |
472 | aio_stat $fh_or_path, $callback->($status) |
426 | aio_lstat $fh, $callback->($status) |
473 | aio_lstat $fh, $callback->($status) |
427 | Works like perl's "stat" or "lstat" in void context. The callback |
474 | Works almost exactly like perl's "stat" or "lstat" in void context. |
428 | will be called after the stat and the results will be available |
475 | The callback will be called after the stat and the results will be |
429 | using "stat _" or "-s _" etc... |
476 | available using "stat _" or "-s _" and other tests (with the |
|
|
477 | exception of "-B" and "-T"). |
430 | |
478 | |
431 | The pathname passed to "aio_stat" must be absolute. See API NOTES, |
479 | The pathname passed to "aio_stat" must be absolute. See API NOTES, |
432 | above, for an explanation. |
480 | above, for an explanation. |
433 | |
481 | |
434 | Currently, the stats are always 64-bit-stats, i.e. instead of |
482 | Currently, the stats are always 64-bit-stats, i.e. instead of |
… | |
… | |
442 | back on traditional behaviour). |
490 | back on traditional behaviour). |
443 | |
491 | |
444 | "S_IFMT", "S_IFIFO", "S_IFCHR", "S_IFBLK", "S_IFLNK", "S_IFREG", |
492 | "S_IFMT", "S_IFIFO", "S_IFCHR", "S_IFBLK", "S_IFLNK", "S_IFREG", |
445 | "S_IFDIR", "S_IFWHT", "S_IFSOCK", "IO::AIO::major $dev_t", |
493 | "S_IFDIR", "S_IFWHT", "S_IFSOCK", "IO::AIO::major $dev_t", |
446 | "IO::AIO::minor $dev_t", "IO::AIO::makedev $major, $minor". |
494 | "IO::AIO::minor $dev_t", "IO::AIO::makedev $major, $minor". |
|
|
495 | |
|
|
496 | To access higher resolution stat timestamps, see "SUBSECOND STAT |
|
|
497 | TIME ACCESS". |
447 | |
498 | |
448 | Example: Print the length of /etc/passwd: |
499 | Example: Print the length of /etc/passwd: |
449 | |
500 | |
450 | aio_stat "/etc/passwd", sub { |
501 | aio_stat "/etc/passwd", sub { |
451 | $_[0] and die "stat failed: $!"; |
502 | $_[0] and die "stat failed: $!"; |
… | |
… | |
498 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
549 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
499 | Works like perl's "utime" function (including the special case of |
550 | Works like perl's "utime" function (including the special case of |
500 | $atime and $mtime being undef). Fractional times are supported if |
551 | $atime and $mtime being undef). Fractional times are supported if |
501 | the underlying syscalls support them. |
552 | the underlying syscalls support them. |
502 | |
553 | |
503 | When called with a pathname, uses utimes(2) if available, otherwise |
554 | When called with a pathname, uses utimensat(2) or utimes(2) if |
504 | utime(2). If called on a file descriptor, uses futimes(2) if |
555 | available, otherwise utime(2). If called on a file descriptor, uses |
505 | available, otherwise returns ENOSYS, so this is not portable. |
556 | futimens(2) or futimes(2) if available, otherwise returns ENOSYS, so |
|
|
557 | this is not portable. |
506 | |
558 | |
507 | Examples: |
559 | Examples: |
508 | |
560 | |
509 | # set atime and mtime to current time (basically touch(1)): |
561 | # set atime and mtime to current time (basically touch(1)): |
510 | aio_utime "path", undef, undef; |
562 | aio_utime "path", undef, undef; |
… | |
… | |
524 | aio_chown "path", 0, undef; |
576 | aio_chown "path", 0, undef; |
525 | |
577 | |
526 | aio_truncate $fh_or_path, $offset, $callback->($status) |
578 | aio_truncate $fh_or_path, $offset, $callback->($status) |
527 | Works like truncate(2) or ftruncate(2). |
579 | Works like truncate(2) or ftruncate(2). |
528 | |
580 | |
|
|
581 | aio_allocate $fh, $mode, $offset, $len, $callback->($status) |
|
|
582 | Allocates or frees disk space according to the $mode argument. See |
|
|
583 | the linux "fallocate" documentation for details. |
|
|
584 | |
|
|
585 | $mode is usually 0 or "IO::AIO::FALLOC_FL_KEEP_SIZE" to allocate |
|
|
586 | space, or "IO::AIO::FALLOC_FL_PUNCH_HOLE | |
|
|
587 | IO::AIO::FALLOC_FL_KEEP_SIZE", to deallocate a file range. |
|
|
588 | |
|
|
589 | IO::AIO also supports "FALLOC_FL_COLLAPSE_RANGE", to remove a range |
|
|
590 | (without leaving a hole), "FALLOC_FL_ZERO_RANGE", to zero a range, |
|
|
591 | "FALLOC_FL_INSERT_RANGE" to insert a range and |
|
|
592 | "FALLOC_FL_UNSHARE_RANGE" to unshare shared blocks (see your |
|
|
593 | fallocate(2) manpage). |
|
|
594 | |
|
|
595 | The file system block size used by "fallocate" is presumably the |
|
|
596 | "f_bsize" returned by "statvfs", but different filesystems and |
|
|
597 | filetypes can dictate other limitations. |
|
|
598 | |
|
|
599 | If "fallocate" isn't available or cannot be emulated (currently no |
|
|
600 | emulation will be attempted), passes -1 and sets $! to "ENOSYS". |
|
|
601 | |
529 | aio_chmod $fh_or_path, $mode, $callback->($status) |
602 | aio_chmod $fh_or_path, $mode, $callback->($status) |
530 | Works like perl's "chmod" function. |
603 | Works like perl's "chmod" function. |
531 | |
604 | |
532 | aio_unlink $pathname, $callback->($status) |
605 | aio_unlink $pathname, $callback->($status) |
533 | Asynchronously unlink (delete) a file and call the callback with the |
606 | Asynchronously unlink (delete) a file and call the callback with the |
534 | result code. |
607 | result code. |
535 | |
608 | |
536 | aio_mknod $path, $mode, $dev, $callback->($status) |
609 | aio_mknod $pathname, $mode, $dev, $callback->($status) |
537 | [EXPERIMENTAL] |
610 | [EXPERIMENTAL] |
538 | |
611 | |
539 | Asynchronously create a device node (or fifo). See mknod(2). |
612 | Asynchronously create a device node (or fifo). See mknod(2). |
540 | |
613 | |
541 | The only (POSIX-) portable way of calling this function is: |
614 | The only (POSIX-) portable way of calling this function is: |
542 | |
615 | |
543 | aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
616 | aio_mknod $pathname, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
544 | |
617 | |
545 | See "aio_stat" for info about some potentially helpful extra |
618 | See "aio_stat" for info about some potentially helpful extra |
546 | constants and functions. |
619 | constants and functions. |
547 | |
620 | |
548 | aio_link $srcpath, $dstpath, $callback->($status) |
621 | aio_link $srcpath, $dstpath, $callback->($status) |
… | |
… | |
552 | aio_symlink $srcpath, $dstpath, $callback->($status) |
625 | aio_symlink $srcpath, $dstpath, $callback->($status) |
553 | Asynchronously create a new symbolic link to the existing object at |
626 | Asynchronously create a new symbolic link to the existing object at |
554 | $srcpath at the path $dstpath and call the callback with the result |
627 | $srcpath at the path $dstpath and call the callback with the result |
555 | code. |
628 | code. |
556 | |
629 | |
557 | aio_readlink $path, $callback->($link) |
630 | aio_readlink $pathname, $callback->($link) |
558 | Asynchronously read the symlink specified by $path and pass it to |
631 | Asynchronously read the symlink specified by $path and pass it to |
559 | the callback. If an error occurs, nothing or undef gets passed to |
632 | the callback. If an error occurs, nothing or undef gets passed to |
560 | the callback. |
633 | the callback. |
561 | |
634 | |
|
|
635 | aio_realpath $pathname, $callback->($path) |
|
|
636 | Asynchronously make the path absolute and resolve any symlinks in |
|
|
637 | $path. The resulting path only consists of directories (same as |
|
|
638 | Cwd::realpath). |
|
|
639 | |
|
|
640 | This request can be used to get the absolute path of the current |
|
|
641 | working directory by passing it a path of . (a single dot). |
|
|
642 | |
562 | aio_rename $srcpath, $dstpath, $callback->($status) |
643 | aio_rename $srcpath, $dstpath, $callback->($status) |
563 | Asynchronously rename the object at $srcpath to $dstpath, just as |
644 | Asynchronously rename the object at $srcpath to $dstpath, just as |
564 | rename(2) and call the callback with the result code. |
645 | rename(2) and call the callback with the result code. |
|
|
646 | |
|
|
647 | On systems that support the AIO::WD working directory abstraction |
|
|
648 | natively, the case "[$wd, "."]" as $srcpath is specialcased - |
|
|
649 | instead of failing, "rename" is called on the absolute path of $wd. |
|
|
650 | |
|
|
651 | aio_rename2 $srcpath, $dstpath, $flags, $callback->($status) |
|
|
652 | Basically a version of "aio_rename" with an additional $flags |
|
|
653 | argument. Calling this with "$flags=0" is the same as calling |
|
|
654 | "aio_rename". |
|
|
655 | |
|
|
656 | Non-zero flags are currently only supported on GNU/Linux systems |
|
|
657 | that support renameat2. Other systems fail with "ENOSYS" in this |
|
|
658 | case. |
|
|
659 | |
|
|
660 | The following constants are available (missing ones are, as usual |
|
|
661 | 0), see renameat2(2) for details: |
|
|
662 | |
|
|
663 | "IO::AIO::RENAME_NOREPLACE", "IO::AIO::RENAME_EXCHANGE" and |
|
|
664 | "IO::AIO::RENAME_WHITEOUT". |
565 | |
665 | |
566 | aio_mkdir $pathname, $mode, $callback->($status) |
666 | aio_mkdir $pathname, $mode, $callback->($status) |
567 | Asynchronously mkdir (create) a directory and call the callback with |
667 | Asynchronously mkdir (create) a directory and call the callback with |
568 | the result code. $mode will be modified by the umask at the time the |
668 | the result code. $mode will be modified by the umask at the time the |
569 | request is executed, so do not change your umask. |
669 | request is executed, so do not change your umask. |
570 | |
670 | |
571 | aio_rmdir $pathname, $callback->($status) |
671 | aio_rmdir $pathname, $callback->($status) |
572 | Asynchronously rmdir (delete) a directory and call the callback with |
672 | Asynchronously rmdir (delete) a directory and call the callback with |
573 | the result code. |
673 | the result code. |
574 | |
674 | |
|
|
675 | On systems that support the AIO::WD working directory abstraction |
|
|
676 | natively, the case "[$wd, "."]" is specialcased - instead of |
|
|
677 | failing, "rmdir" is called on the absolute path of $wd. |
|
|
678 | |
575 | aio_readdir $pathname, $callback->($entries) |
679 | aio_readdir $pathname, $callback->($entries) |
576 | Unlike the POSIX call of the same name, "aio_readdir" reads an |
680 | Unlike the POSIX call of the same name, "aio_readdir" reads an |
577 | entire directory (i.e. opendir + readdir + closedir). The entries |
681 | entire directory (i.e. opendir + readdir + closedir). The entries |
578 | will not be sorted, and will NOT include the "." and ".." entries. |
682 | will not be sorted, and will NOT include the "." and ".." entries. |
579 | |
683 | |
580 | The callback is passed a single argument which is either "undef" or |
684 | The callback is passed a single argument which is either "undef" or |
581 | an array-ref with the filenames. |
685 | an array-ref with the filenames. |
582 | |
686 | |
583 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
687 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
584 | Quite similar to "aio_readdir", but the $flags argument allows to |
688 | Quite similar to "aio_readdir", but the $flags argument allows one |
585 | tune behaviour and output format. In case of an error, $entries will |
689 | to tune behaviour and output format. In case of an error, $entries |
586 | be "undef". |
690 | will be "undef". |
587 | |
691 | |
588 | The flags are a combination of the following constants, ORed |
692 | The flags are a combination of the following constants, ORed |
589 | together (the flags will also be passed to the callback, possibly |
693 | together (the flags will also be passed to the callback, possibly |
590 | modified): |
694 | modified): |
591 | |
695 | |
592 | IO::AIO::READDIR_DENTS |
696 | IO::AIO::READDIR_DENTS |
593 | When this flag is off, then the callback gets an arrayref |
697 | Normally the callback gets an arrayref consisting of names only |
594 | consisting of names only (as with "aio_readdir"), otherwise it |
698 | (as with "aio_readdir"). If this flag is set, then the callback |
595 | gets an arrayref with "[$name, $type, $inode]" arrayrefs, each |
699 | gets an arrayref with "[$name, $type, $inode]" arrayrefs, each |
596 | describing a single directory entry in more detail. |
700 | describing a single directory entry in more detail: |
597 | |
701 | |
598 | $name is the name of the entry. |
702 | $name is the name of the entry. |
599 | |
703 | |
600 | $type is one of the "IO::AIO::DT_xxx" constants: |
704 | $type is one of the "IO::AIO::DT_xxx" constants: |
601 | |
705 | |
602 | "IO::AIO::DT_UNKNOWN", "IO::AIO::DT_FIFO", "IO::AIO::DT_CHR", |
706 | "IO::AIO::DT_UNKNOWN", "IO::AIO::DT_FIFO", "IO::AIO::DT_CHR", |
603 | "IO::AIO::DT_DIR", "IO::AIO::DT_BLK", "IO::AIO::DT_REG", |
707 | "IO::AIO::DT_DIR", "IO::AIO::DT_BLK", "IO::AIO::DT_REG", |
604 | "IO::AIO::DT_LNK", "IO::AIO::DT_SOCK", "IO::AIO::DT_WHT". |
708 | "IO::AIO::DT_LNK", "IO::AIO::DT_SOCK", "IO::AIO::DT_WHT". |
605 | |
709 | |
606 | "IO::AIO::DT_UNKNOWN" means just that: readdir does not know. If |
710 | "IO::AIO::DT_UNKNOWN" means just that: readdir does not know. If |
607 | you need to know, you have to run stat yourself. Also, for speed |
711 | you need to know, you have to run stat yourself. Also, for |
608 | reasons, the $type scalars are read-only: you can not modify |
712 | speed/memory reasons, the $type scalars are read-only: you must |
609 | them. |
713 | not modify them. |
610 | |
714 | |
611 | $inode is the inode number (which might not be exact on systems |
715 | $inode is the inode number (which might not be exact on systems |
612 | with 64 bit inode numbers and 32 bit perls). This field has |
716 | with 64 bit inode numbers and 32 bit perls). This field has |
613 | unspecified content on systems that do not deliver the inode |
717 | unspecified content on systems that do not deliver the inode |
614 | information. |
718 | information. |
… | |
… | |
626 | of which names with short names are tried first. |
730 | of which names with short names are tried first. |
627 | |
731 | |
628 | IO::AIO::READDIR_STAT_ORDER |
732 | IO::AIO::READDIR_STAT_ORDER |
629 | When this flag is set, then the names will be returned in an |
733 | When this flag is set, then the names will be returned in an |
630 | order suitable for stat()'ing each one. That is, when you plan |
734 | order suitable for stat()'ing each one. That is, when you plan |
631 | to stat() all files in the given directory, then the returned |
735 | to stat() most or all files in the given directory, then the |
632 | order will likely be fastest. |
736 | returned order will likely be faster. |
633 | |
737 | |
634 | If both this flag and "IO::AIO::READDIR_DIRS_FIRST" are |
738 | If both this flag and "IO::AIO::READDIR_DIRS_FIRST" are |
635 | specified, then the likely dirs come first, resulting in a less |
739 | specified, then the likely dirs come first, resulting in a less |
636 | optimal stat order. |
740 | optimal stat order for stat'ing all entries, but likely a more |
|
|
741 | optimal order for finding subdirectories. |
637 | |
742 | |
638 | IO::AIO::READDIR_FOUND_UNKNOWN |
743 | IO::AIO::READDIR_FOUND_UNKNOWN |
639 | This flag should not be set when calling "aio_readdirx". |
744 | This flag should not be set when calling "aio_readdirx". |
640 | Instead, it is being set by "aio_readdirx", when any of the |
745 | Instead, it is being set by "aio_readdirx", when any of the |
641 | $type's found were "IO::AIO::DT_UNKNOWN". The absense of this |
746 | $type's found were "IO::AIO::DT_UNKNOWN". The absence of this |
642 | flag therefore indicates that all $type's are known, which can |
747 | flag therefore indicates that all $type's are known, which can |
643 | be used to speed up some algorithms. |
748 | be used to speed up some algorithms. |
644 | |
749 | |
|
|
750 | aio_slurp $pathname, $offset, $length, $data, $callback->($status) |
|
|
751 | Opens, reads and closes the given file. The data is put into $data, |
|
|
752 | which is resized as required. |
|
|
753 | |
|
|
754 | If $offset is negative, then it is counted from the end of the file. |
|
|
755 | |
|
|
756 | If $length is zero, then the remaining length of the file is used. |
|
|
757 | Also, in this case, the same limitations to modifying $data apply as |
|
|
758 | when IO::AIO::mmap is used, i.e. it must only be modified in-place |
|
|
759 | with "substr". If the size of the file is known, specifying a |
|
|
760 | non-zero $length results in a performance advantage. |
|
|
761 | |
|
|
762 | This request is similar to the older "aio_load" request, but since |
|
|
763 | it is a single request, it might be more efficient to use. |
|
|
764 | |
|
|
765 | Example: load /etc/passwd into $passwd. |
|
|
766 | |
|
|
767 | my $passwd; |
|
|
768 | aio_slurp "/etc/passwd", 0, 0, $passwd, sub { |
|
|
769 | $_[0] >= 0 |
|
|
770 | or die "/etc/passwd: $!\n"; |
|
|
771 | |
|
|
772 | printf "/etc/passwd is %d bytes long, and contains:\n", length $passwd; |
|
|
773 | print $passwd; |
|
|
774 | }; |
|
|
775 | IO::AIO::flush; |
|
|
776 | |
645 | aio_load $path, $data, $callback->($status) |
777 | aio_load $pathname, $data, $callback->($status) |
646 | This is a composite request that tries to fully load the given file |
778 | This is a composite request that tries to fully load the given file |
647 | into memory. Status is the same as with aio_read. |
779 | into memory. Status is the same as with aio_read. |
|
|
780 | |
|
|
781 | Using "aio_slurp" might be more efficient, as it is a single |
|
|
782 | request. |
648 | |
783 | |
649 | aio_copy $srcpath, $dstpath, $callback->($status) |
784 | aio_copy $srcpath, $dstpath, $callback->($status) |
650 | Try to copy the *file* (directories not supported as either source |
785 | Try to copy the *file* (directories not supported as either source |
651 | or destination) from $srcpath to $dstpath and call the callback with |
786 | or destination) from $srcpath to $dstpath and call the callback with |
652 | a status of 0 (ok) or -1 (error, see $!). |
787 | a status of 0 (ok) or -1 (error, see $!). |
653 | |
788 | |
|
|
789 | Existing destination files will be truncated. |
|
|
790 | |
654 | This is a composite request that creates the destination file with |
791 | This is a composite request that creates the destination file with |
655 | mode 0200 and copies the contents of the source file into it using |
792 | mode 0200 and copies the contents of the source file into it using |
656 | "aio_sendfile", followed by restoring atime, mtime, access mode and |
793 | "aio_sendfile", followed by restoring atime, mtime, access mode and |
657 | uid/gid, in that order. |
794 | uid/gid, in that order. |
658 | |
795 | |
… | |
… | |
667 | |
804 | |
668 | This is a composite request that tries to rename(2) the file first; |
805 | This is a composite request that tries to rename(2) the file first; |
669 | if rename fails with "EXDEV", it copies the file with "aio_copy" |
806 | if rename fails with "EXDEV", it copies the file with "aio_copy" |
670 | and, if that is successful, unlinks the $srcpath. |
807 | and, if that is successful, unlinks the $srcpath. |
671 | |
808 | |
672 | aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
809 | aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) |
673 | Scans a directory (similar to "aio_readdir") but additionally tries |
810 | Scans a directory (similar to "aio_readdir") but additionally tries |
674 | to efficiently separate the entries of directory $path into two sets |
811 | to efficiently separate the entries of directory $path into two sets |
675 | of names, directories you can recurse into (directories), and ones |
812 | of names, directories you can recurse into (directories), and ones |
676 | you cannot recurse into (everything else, including symlinks to |
813 | you cannot recurse into (everything else, including symlinks to |
677 | directories). |
814 | directories). |
678 | |
815 | |
679 | "aio_scandir" is a composite request that creates of many sub |
816 | "aio_scandir" is a composite request that generates many sub |
680 | requests_ $maxreq specifies the maximum number of outstanding aio |
817 | requests. $maxreq specifies the maximum number of outstanding aio |
681 | requests that this function generates. If it is "<= 0", then a |
818 | requests that this function generates. If it is "<= 0", then a |
682 | suitable default will be chosen (currently 4). |
819 | suitable default will be chosen (currently 4). |
683 | |
820 | |
684 | On error, the callback is called without arguments, otherwise it |
821 | On error, the callback is called without arguments, otherwise it |
685 | receives two array-refs with path-relative entry names. |
822 | receives two array-refs with path-relative entry names. |
… | |
… | |
710 | Then entries will be sorted into likely directories a non-initial |
847 | Then entries will be sorted into likely directories a non-initial |
711 | dot currently) and likely non-directories (see "aio_readdirx"). Then |
848 | dot currently) and likely non-directories (see "aio_readdirx"). Then |
712 | every entry plus an appended "/." will be "stat"'ed, likely |
849 | every entry plus an appended "/." will be "stat"'ed, likely |
713 | directories first, in order of their inode numbers. If that |
850 | directories first, in order of their inode numbers. If that |
714 | succeeds, it assumes that the entry is a directory or a symlink to |
851 | succeeds, it assumes that the entry is a directory or a symlink to |
715 | directory (which will be checked seperately). This is often faster |
852 | directory (which will be checked separately). This is often faster |
716 | than stat'ing the entry itself because filesystems might detect the |
853 | than stat'ing the entry itself because filesystems might detect the |
717 | type of the entry without reading the inode data (e.g. ext2fs |
854 | type of the entry without reading the inode data (e.g. ext2fs |
718 | filetype feature), even on systems that cannot return the filetype |
855 | filetype feature), even on systems that cannot return the filetype |
719 | information on readdir. |
856 | information on readdir. |
720 | |
857 | |
… | |
… | |
726 | |
863 | |
727 | It will also likely work on non-POSIX filesystems with reduced |
864 | It will also likely work on non-POSIX filesystems with reduced |
728 | efficiency as those tend to return 0 or 1 as link counts, which |
865 | efficiency as those tend to return 0 or 1 as link counts, which |
729 | disables the directory counting heuristic. |
866 | disables the directory counting heuristic. |
730 | |
867 | |
731 | aio_rmtree $path, $callback->($status) |
868 | aio_rmtree $pathname, $callback->($status) |
732 | Delete a directory tree starting (and including) $path, return the |
869 | Delete a directory tree starting (and including) $path, return the |
733 | status of the final "rmdir" only. This is a composite request that |
870 | status of the final "rmdir" only. This is a composite request that |
734 | uses "aio_scandir" to recurse into and rmdir directories, and unlink |
871 | uses "aio_scandir" to recurse into and rmdir directories, and unlink |
735 | everything else. |
872 | everything else. |
736 | |
873 | |
|
|
874 | aio_fcntl $fh, $cmd, $arg, $callback->($status) |
|
|
875 | aio_ioctl $fh, $request, $buf, $callback->($status) |
|
|
876 | These work just like the "fcntl" and "ioctl" built-in functions, |
|
|
877 | except they execute asynchronously and pass the return value to the |
|
|
878 | callback. |
|
|
879 | |
|
|
880 | Both calls can be used for a lot of things, some of which make more |
|
|
881 | sense to run asynchronously in their own thread, while some others |
|
|
882 | make less sense. For example, calls that block waiting for external |
|
|
883 | events, such as locking, will also lock down an I/O thread while it |
|
|
884 | is waiting, which can deadlock the whole I/O system. At the same |
|
|
885 | time, there might be no alternative to using a thread to wait. |
|
|
886 | |
|
|
887 | So in general, you should only use these calls for things that do |
|
|
888 | (filesystem) I/O, not for things that wait for other events |
|
|
889 | (network, other processes), although if you are careful and know |
|
|
890 | what you are doing, you still can. |
|
|
891 | |
|
|
892 | The following constants are available (missing ones are, as usual |
|
|
893 | 0): |
|
|
894 | |
|
|
895 | "F_DUPFD_CLOEXEC", |
|
|
896 | |
|
|
897 | "F_OFD_GETLK", "F_OFD_SETLK", "F_OFD_GETLKW", |
|
|
898 | |
|
|
899 | "FIFREEZE", "FITHAW", "FITRIM", "FICLONE", "FICLONERANGE", |
|
|
900 | "FIDEDUPERANGE". |
|
|
901 | |
|
|
902 | "FS_IOC_GETFLAGS", "FS_IOC_SETFLAGS", "FS_IOC_GETVERSION", |
|
|
903 | "FS_IOC_SETVERSION", "FS_IOC_FIEMAP". |
|
|
904 | |
|
|
905 | "FS_IOC_FSGETXATTR", "FS_IOC_FSSETXATTR", |
|
|
906 | "FS_IOC_SET_ENCRYPTION_POLICY", "FS_IOC_GET_ENCRYPTION_PWSALT", |
|
|
907 | "FS_IOC_GET_ENCRYPTION_POLICY", "FS_KEY_DESCRIPTOR_SIZE". |
|
|
908 | |
|
|
909 | "FS_SECRM_FL", "FS_UNRM_FL", "FS_COMPR_FL", "FS_SYNC_FL", |
|
|
910 | "FS_IMMUTABLE_FL", "FS_APPEND_FL", "FS_NODUMP_FL", "FS_NOATIME_FL", |
|
|
911 | "FS_DIRTY_FL", "FS_COMPRBLK_FL", "FS_NOCOMP_FL", "FS_ENCRYPT_FL", |
|
|
912 | "FS_BTREE_FL", "FS_INDEX_FL", "FS_JOURNAL_DATA_FL", "FS_NOTAIL_FL", |
|
|
913 | "FS_DIRSYNC_FL", "FS_TOPDIR_FL", "FS_FL_USER_MODIFIABLE". |
|
|
914 | |
|
|
915 | "FS_XFLAG_REALTIME", "FS_XFLAG_PREALLOC", "FS_XFLAG_IMMUTABLE", |
|
|
916 | "FS_XFLAG_APPEND", "FS_XFLAG_SYNC", "FS_XFLAG_NOATIME", |
|
|
917 | "FS_XFLAG_NODUMP", "FS_XFLAG_RTINHERIT", "FS_XFLAG_PROJINHERIT", |
|
|
918 | "FS_XFLAG_NOSYMLINKS", "FS_XFLAG_EXTSIZE", "FS_XFLAG_EXTSZINHERIT", |
|
|
919 | "FS_XFLAG_NODEFRAG", "FS_XFLAG_FILESTREAM", "FS_XFLAG_DAX", |
|
|
920 | "FS_XFLAG_HASATTR", |
|
|
921 | |
737 | aio_sync $callback->($status) |
922 | aio_sync $callback->($status) |
738 | Asynchronously call sync and call the callback when finished. |
923 | Asynchronously call sync and call the callback when finished. |
739 | |
924 | |
740 | aio_fsync $fh, $callback->($status) |
925 | aio_fsync $fh, $callback->($status) |
741 | Asynchronously call fsync on the given filehandle and call the |
926 | Asynchronously call fsync on the given filehandle and call the |
… | |
… | |
745 | Asynchronously call fdatasync on the given filehandle and call the |
930 | Asynchronously call fdatasync on the given filehandle and call the |
746 | callback with the fdatasync result code. |
931 | callback with the fdatasync result code. |
747 | |
932 | |
748 | If this call isn't available because your OS lacks it or it couldn't |
933 | If this call isn't available because your OS lacks it or it couldn't |
749 | be detected, it will be emulated by calling "fsync" instead. |
934 | be detected, it will be emulated by calling "fsync" instead. |
|
|
935 | |
|
|
936 | aio_syncfs $fh, $callback->($status) |
|
|
937 | Asynchronously call the syncfs syscall to sync the filesystem |
|
|
938 | associated to the given filehandle and call the callback with the |
|
|
939 | syncfs result code. If syncfs is not available, calls sync(), but |
|
|
940 | returns -1 and sets errno to "ENOSYS" nevertheless. |
750 | |
941 | |
751 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
942 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
752 | Sync the data portion of the file specified by $offset and $length |
943 | Sync the data portion of the file specified by $offset and $length |
753 | to disk (but NOT the metadata), by calling the Linux-specific |
944 | to disk (but NOT the metadata), by calling the Linux-specific |
754 | sync_file_range call. If sync_file_range is not available or it |
945 | sync_file_range call. If sync_file_range is not available or it |
… | |
… | |
758 | "IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE", |
949 | "IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE", |
759 | "IO::AIO::SYNC_FILE_RANGE_WRITE" and |
950 | "IO::AIO::SYNC_FILE_RANGE_WRITE" and |
760 | "IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER": refer to the sync_file_range |
951 | "IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER": refer to the sync_file_range |
761 | manpage for details. |
952 | manpage for details. |
762 | |
953 | |
763 | aio_pathsync $path, $callback->($status) |
954 | aio_pathsync $pathname, $callback->($status) |
764 | This request tries to open, fsync and close the given path. This is |
955 | This request tries to open, fsync and close the given path. This is |
765 | a composite request intended to sync directories after directory |
956 | a composite request intended to sync directories after directory |
766 | operations (E.g. rename). This might not work on all operating |
957 | operations (E.g. rename). This might not work on all operating |
767 | systems or have any specific effect, but usually it makes sure that |
958 | systems or have any specific effect, but usually it makes sure that |
768 | directory changes get written to disc. It works for anything that |
959 | directory changes get written to disc. It works for anything that |
… | |
… | |
771 | Future versions of this function might fall back to other methods |
962 | Future versions of this function might fall back to other methods |
772 | when "fsync" on the directory fails (such as calling "sync"). |
963 | when "fsync" on the directory fails (such as calling "sync"). |
773 | |
964 | |
774 | Passes 0 when everything went ok, and -1 on error. |
965 | Passes 0 when everything went ok, and -1 on error. |
775 | |
966 | |
776 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, |
967 | aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, |
777 | $callback->($status) |
968 | $callback->($status) |
778 | This is a rather advanced IO::AIO call, which only works on |
969 | This is a rather advanced IO::AIO call, which only works on |
779 | mmap(2)ed scalars (see the "IO::AIO::mmap" function, although it |
970 | mmap(2)ed scalars (see the "IO::AIO::mmap" function, although it |
780 | also works on data scalars managed by the Sys::Mmap or Mmap modules, |
971 | also works on data scalars managed by the Sys::Mmap or Mmap modules, |
781 | note that the scalar must only be modified in-place while an aio |
972 | note that the scalar must only be modified in-place while an aio |
… | |
… | |
783 | |
974 | |
784 | It calls the "msync" function of your OS, if available, with the |
975 | It calls the "msync" function of your OS, if available, with the |
785 | memory area starting at $offset in the string and ending $length |
976 | memory area starting at $offset in the string and ending $length |
786 | bytes later. If $length is negative, counts from the end, and if |
977 | bytes later. If $length is negative, counts from the end, and if |
787 | $length is "undef", then it goes till the end of the string. The |
978 | $length is "undef", then it goes till the end of the string. The |
788 | flags can be a combination of "IO::AIO::MS_ASYNC", |
979 | flags can be either "IO::AIO::MS_ASYNC" or "IO::AIO::MS_SYNC", plus |
789 | "IO::AIO::MS_INVALIDATE" and "IO::AIO::MS_SYNC". |
980 | an optional "IO::AIO::MS_INVALIDATE". |
790 | |
981 | |
791 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, |
982 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, |
792 | $callback->($status) |
983 | $callback->($status) |
793 | This is a rather advanced IO::AIO call, which works best on |
984 | This is a rather advanced IO::AIO call, which works best on |
794 | mmap(2)ed scalars. |
985 | mmap(2)ed scalars. |
795 | |
986 | |
796 | It touches (reads or writes) all memory pages in the specified range |
987 | It touches (reads or writes) all memory pages in the specified range |
797 | inside the scalar. All caveats and parameters are the same as for |
988 | inside the scalar. All caveats and parameters are the same as for |
798 | "aio_msync", above, except for flags, which must be either 0 (which |
989 | "aio_msync", above, except for flags, which must be either 0 (which |
799 | reads all pages and ensures they are instantiated) or |
990 | reads all pages and ensures they are instantiated) or |
800 | "IO::AIO::MT_MODIFY", which modifies the memory page s(by reading |
991 | "IO::AIO::MT_MODIFY", which modifies the memory pages (by reading |
801 | and writing an octet from it, which dirties the page). |
992 | and writing an octet from it, which dirties the page). |
802 | |
993 | |
803 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
994 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
804 | This is a rather advanced IO::AIO call, which works best on |
995 | This is a rather advanced IO::AIO call, which works best on |
805 | mmap(2)ed scalars. |
996 | mmap(2)ed scalars. |
… | |
… | |
837 | |
1028 | |
838 | Example: asynchronously lock all current and future pages into |
1029 | Example: asynchronously lock all current and future pages into |
839 | memory. |
1030 | memory. |
840 | |
1031 | |
841 | aio_mlockall IO::AIO::MCL_FUTURE; |
1032 | aio_mlockall IO::AIO::MCL_FUTURE; |
|
|
1033 | |
|
|
1034 | aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents) |
|
|
1035 | Queries the extents of the given file (by calling the Linux "FIEMAP" |
|
|
1036 | ioctl, see <http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for |
|
|
1037 | details). If the ioctl is not available on your OS, then this |
|
|
1038 | request will fail with "ENOSYS". |
|
|
1039 | |
|
|
1040 | $start is the starting offset to query extents for, $length is the |
|
|
1041 | size of the range to query - if it is "undef", then the whole file |
|
|
1042 | will be queried. |
|
|
1043 | |
|
|
1044 | $flags is a combination of flags ("IO::AIO::FIEMAP_FLAG_SYNC" or |
|
|
1045 | "IO::AIO::FIEMAP_FLAG_XATTR" - "IO::AIO::FIEMAP_FLAGS_COMPAT" is |
|
|
1046 | also exported), and is normally 0 or "IO::AIO::FIEMAP_FLAG_SYNC" to |
|
|
1047 | query the data portion. |
|
|
1048 | |
|
|
1049 | $count is the maximum number of extent records to return. If it is |
|
|
1050 | "undef", then IO::AIO queries all extents of the range. As a very |
|
|
1051 | special case, if it is 0, then the callback receives the number of |
|
|
1052 | extents instead of the extents themselves (which is unreliable, see |
|
|
1053 | below). |
|
|
1054 | |
|
|
1055 | If an error occurs, the callback receives no arguments. The special |
|
|
1056 | "errno" value "IO::AIO::EBADR" is available to test for flag errors. |
|
|
1057 | |
|
|
1058 | Otherwise, the callback receives an array reference with extent |
|
|
1059 | structures. Each extent structure is an array reference itself, with |
|
|
1060 | the following members: |
|
|
1061 | |
|
|
1062 | [$logical, $physical, $length, $flags] |
|
|
1063 | |
|
|
1064 | Flags is any combination of the following flag values (typically |
|
|
1065 | either 0 or "IO::AIO::FIEMAP_EXTENT_LAST" (1)): |
|
|
1066 | |
|
|
1067 | "IO::AIO::FIEMAP_EXTENT_LAST", "IO::AIO::FIEMAP_EXTENT_UNKNOWN", |
|
|
1068 | "IO::AIO::FIEMAP_EXTENT_DELALLOC", "IO::AIO::FIEMAP_EXTENT_ENCODED", |
|
|
1069 | "IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED", |
|
|
1070 | "IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED", |
|
|
1071 | "IO::AIO::FIEMAP_EXTENT_DATA_INLINE", |
|
|
1072 | "IO::AIO::FIEMAP_EXTENT_DATA_TAIL", |
|
|
1073 | "IO::AIO::FIEMAP_EXTENT_UNWRITTEN", "IO::AIO::FIEMAP_EXTENT_MERGED" |
|
|
1074 | or "IO::AIO::FIEMAP_EXTENT_SHARED". |
|
|
1075 | |
|
|
1076 | At the time of this writing (Linux 3.2), this request is unreliable |
|
|
1077 | unless $count is "undef", as the kernel has all sorts of bugs |
|
|
1078 | preventing it to return all extents of a range for files with a |
|
|
1079 | large number of extents. The code (only) works around all these |
|
|
1080 | issues if $count is "undef". |
842 | |
1081 | |
843 | aio_group $callback->(...) |
1082 | aio_group $callback->(...) |
844 | This is a very special aio request: Instead of doing something, it |
1083 | This is a very special aio request: Instead of doing something, it |
845 | is a container for other aio requests, which is useful if you want |
1084 | is a container for other aio requests, which is useful if you want |
846 | to bundle many requests into a single, composite, request with a |
1085 | to bundle many requests into a single, composite, request with a |
… | |
… | |
880 | While it is theoretically handy to have simple I/O scheduling |
1119 | While it is theoretically handy to have simple I/O scheduling |
881 | requests like sleep and file handle readable/writable, the overhead |
1120 | requests like sleep and file handle readable/writable, the overhead |
882 | this creates is immense (it blocks a thread for a long time) so do |
1121 | this creates is immense (it blocks a thread for a long time) so do |
883 | not use this function except to put your application under |
1122 | not use this function except to put your application under |
884 | artificial I/O pressure. |
1123 | artificial I/O pressure. |
|
|
1124 | |
|
|
1125 | IO::AIO::WD - multiple working directories |
|
|
1126 | Your process only has one current working directory, which is used by |
|
|
1127 | all threads. This makes it hard to use relative paths (some other |
|
|
1128 | component could call "chdir" at any time, and it is hard to control when |
|
|
1129 | the path will be used by IO::AIO). |
|
|
1130 | |
|
|
1131 | One solution for this is to always use absolute paths. This usually |
|
|
1132 | works, but can be quite slow (the kernel has to walk the whole path on |
|
|
1133 | every access), and can also be a hassle to implement. |
|
|
1134 | |
|
|
1135 | Newer POSIX systems have a number of functions (openat, fdopendir, |
|
|
1136 | futimensat and so on) that make it possible to specify working |
|
|
1137 | directories per operation. |
|
|
1138 | |
|
|
1139 | For portability, and because the clowns who "designed", or shall I |
|
|
1140 | write, perpetrated this new interface were obviously half-drunk, this |
|
|
1141 | abstraction cannot be perfect, though. |
|
|
1142 | |
|
|
1143 | IO::AIO allows you to convert directory paths into a so-called |
|
|
1144 | IO::AIO::WD object. This object stores the canonicalised, absolute |
|
|
1145 | version of the path, and on systems that allow it, also a directory file |
|
|
1146 | descriptor. |
|
|
1147 | |
|
|
1148 | Everywhere where a pathname is accepted by IO::AIO (e.g. in "aio_stat" |
|
|
1149 | or "aio_unlink"), one can specify an array reference with an IO::AIO::WD |
|
|
1150 | object and a pathname instead (or the IO::AIO::WD object alone, which |
|
|
1151 | gets interpreted as "[$wd, "."]"). If the pathname is absolute, the |
|
|
1152 | IO::AIO::WD object is ignored, otherwise the pathname is resolved |
|
|
1153 | relative to that IO::AIO::WD object. |
|
|
1154 | |
|
|
1155 | For example, to get a wd object for /etc and then stat passwd inside, |
|
|
1156 | you would write: |
|
|
1157 | |
|
|
1158 | aio_wd "/etc", sub { |
|
|
1159 | my $etcdir = shift; |
|
|
1160 | |
|
|
1161 | # although $etcdir can be undef on error, there is generally no reason |
|
|
1162 | # to check for errors here, as aio_stat will fail with ENOENT |
|
|
1163 | # when $etcdir is undef. |
|
|
1164 | |
|
|
1165 | aio_stat [$etcdir, "passwd"], sub { |
|
|
1166 | # yay |
|
|
1167 | }; |
|
|
1168 | }; |
|
|
1169 | |
|
|
1170 | The fact that "aio_wd" is a request and not a normal function shows that |
|
|
1171 | creating an IO::AIO::WD object is itself a potentially blocking |
|
|
1172 | operation, which is why it is done asynchronously. |
|
|
1173 | |
|
|
1174 | To stat the directory obtained with "aio_wd" above, one could write |
|
|
1175 | either of the following three request calls: |
|
|
1176 | |
|
|
1177 | aio_lstat "/etc" , sub { ... # pathname as normal string |
|
|
1178 | aio_lstat [$wd, "."], sub { ... # "." relative to $wd (i.e. $wd itself) |
|
|
1179 | aio_lstat $wd , sub { ... # shorthand for the previous |
|
|
1180 | |
|
|
1181 | As with normal pathnames, IO::AIO keeps a copy of the working directory |
|
|
1182 | object and the pathname string, so you could write the following without |
|
|
1183 | causing any issues due to $path getting reused: |
|
|
1184 | |
|
|
1185 | my $path = [$wd, undef]; |
|
|
1186 | |
|
|
1187 | for my $name (qw(abc def ghi)) { |
|
|
1188 | $path->[1] = $name; |
|
|
1189 | aio_stat $path, sub { |
|
|
1190 | # ... |
|
|
1191 | }; |
|
|
1192 | } |
|
|
1193 | |
|
|
1194 | There are some caveats: when directories get renamed (or deleted), the |
|
|
1195 | pathname string doesn't change, so will point to the new directory (or |
|
|
1196 | nowhere at all), while the directory fd, if available on the system, |
|
|
1197 | will still point to the original directory. Most functions accepting a |
|
|
1198 | pathname will use the directory fd on newer systems, and the string on |
|
|
1199 | older systems. Some functions (such as "aio_realpath") will always rely |
|
|
1200 | on the string form of the pathname. |
|
|
1201 | |
|
|
1202 | So this functionality is mainly useful to get some protection against |
|
|
1203 | "chdir", to easily get an absolute path out of a relative path for |
|
|
1204 | future reference, and to speed up doing many operations in the same |
|
|
1205 | directory (e.g. when stat'ing all files in a directory). |
|
|
1206 | |
|
|
1207 | The following functions implement this working directory abstraction: |
|
|
1208 | |
|
|
1209 | aio_wd $pathname, $callback->($wd) |
|
|
1210 | Asynchonously canonicalise the given pathname and convert it to an |
|
|
1211 | IO::AIO::WD object representing it. If possible and supported on the |
|
|
1212 | system, also open a directory fd to speed up pathname resolution |
|
|
1213 | relative to this working directory. |
|
|
1214 | |
|
|
1215 | If something goes wrong, then "undef" is passwd to the callback |
|
|
1216 | instead of a working directory object and $! is set appropriately. |
|
|
1217 | Since passing "undef" as working directory component of a pathname |
|
|
1218 | fails the request with "ENOENT", there is often no need for error |
|
|
1219 | checking in the "aio_wd" callback, as future requests using the |
|
|
1220 | value will fail in the expected way. |
|
|
1221 | |
|
|
1222 | IO::AIO::CWD |
|
|
1223 | This is a compiletime constant (object) that represents the process |
|
|
1224 | current working directory. |
|
|
1225 | |
|
|
1226 | Specifying this object as working directory object for a pathname is |
|
|
1227 | as if the pathname would be specified directly, without a directory |
|
|
1228 | object. For example, these calls are functionally identical: |
|
|
1229 | |
|
|
1230 | aio_stat "somefile", sub { ... }; |
|
|
1231 | aio_stat [IO::AIO::CWD, "somefile"], sub { ... }; |
|
|
1232 | |
|
|
1233 | To recover the path associated with an IO::AIO::WD object, you can use |
|
|
1234 | "aio_realpath": |
|
|
1235 | |
|
|
1236 | aio_realpath $wd, sub { |
|
|
1237 | warn "path is $_[0]\n"; |
|
|
1238 | }; |
|
|
1239 | |
|
|
1240 | Currently, "aio_statvfs" always, and "aio_rename" and "aio_rmdir" |
|
|
1241 | sometimes, fall back to using an absolue path. |
885 | |
1242 | |
886 | IO::AIO::REQ CLASS |
1243 | IO::AIO::REQ CLASS |
887 | All non-aggregate "aio_*" functions return an object of this class when |
1244 | All non-aggregate "aio_*" functions return an object of this class when |
888 | called in non-void context. |
1245 | called in non-void context. |
889 | |
1246 | |
… | |
… | |
989 | Sets a feeder/generator on this group: every group can have an |
1346 | Sets a feeder/generator on this group: every group can have an |
990 | attached generator that generates requests if idle. The idea behind |
1347 | attached generator that generates requests if idle. The idea behind |
991 | this is that, although you could just queue as many requests as you |
1348 | this is that, although you could just queue as many requests as you |
992 | want in a group, this might starve other requests for a potentially |
1349 | want in a group, this might starve other requests for a potentially |
993 | long time. For example, "aio_scandir" might generate hundreds of |
1350 | long time. For example, "aio_scandir" might generate hundreds of |
994 | thousands "aio_stat" requests, delaying any later requests for a |
1351 | thousands of "aio_stat" requests, delaying any later requests for a |
995 | long time. |
1352 | long time. |
996 | |
1353 | |
997 | To avoid this, and allow incremental generation of requests, you can |
1354 | To avoid this, and allow incremental generation of requests, you can |
998 | instead a group and set a feeder on it that generates those |
1355 | instead a group and set a feeder on it that generates those |
999 | requests. The feed callback will be called whenever there are few |
1356 | requests. The feed callback will be called whenever there are few |
… | |
… | |
1041 | results. |
1398 | results. |
1042 | |
1399 | |
1043 | See "poll_cb" for an example. |
1400 | See "poll_cb" for an example. |
1044 | |
1401 | |
1045 | IO::AIO::poll_cb |
1402 | IO::AIO::poll_cb |
1046 | Process some outstanding events on the result pipe. You have to call |
1403 | Process some requests that have reached the result phase (i.e. they |
|
|
1404 | have been executed but the results are not yet reported). You have |
|
|
1405 | to call this "regularly" to finish outstanding requests. |
|
|
1406 | |
1047 | this regularly. Returns 0 if all events could be processed (or there |
1407 | Returns 0 if all events could be processed (or there were no events |
1048 | were no events to process), or -1 if it returned earlier for |
1408 | to process), or -1 if it returned earlier for whatever reason. |
1049 | whatever reason. Returns immediately when no events are outstanding. |
1409 | Returns immediately when no events are outstanding. The amount of |
1050 | The amount of events processed depends on the settings of |
1410 | events processed depends on the settings of "IO::AIO::max_poll_req", |
1051 | "IO::AIO::max_poll_req" and "IO::AIO::max_poll_time". |
1411 | "IO::AIO::max_poll_time" and "IO::AIO::max_outstanding". |
1052 | |
1412 | |
1053 | If not all requests were processed for whatever reason, the |
1413 | If not all requests were processed for whatever reason, the poll |
1054 | filehandle will still be ready when "poll_cb" returns, so normally |
1414 | file descriptor will still be ready when "poll_cb" returns, so |
1055 | you don't have to do anything special to have it called later. |
1415 | normally you don't have to do anything special to have it called |
|
|
1416 | later. |
1056 | |
1417 | |
1057 | Apart from calling "IO::AIO::poll_cb" when the event filehandle |
1418 | Apart from calling "IO::AIO::poll_cb" when the event filehandle |
1058 | becomes ready, it can be beneficial to call this function from loops |
1419 | becomes ready, it can be beneficial to call this function from loops |
1059 | which submit a lot of requests, to make sure the results get |
1420 | which submit a lot of requests, to make sure the results get |
1060 | processed when they become available and not just when the loop is |
1421 | processed when they become available and not just when the loop is |
… | |
… | |
1068 | Event->io (fd => IO::AIO::poll_fileno, |
1429 | Event->io (fd => IO::AIO::poll_fileno, |
1069 | poll => 'r', async => 1, |
1430 | poll => 'r', async => 1, |
1070 | cb => \&IO::AIO::poll_cb); |
1431 | cb => \&IO::AIO::poll_cb); |
1071 | |
1432 | |
1072 | IO::AIO::poll_wait |
1433 | IO::AIO::poll_wait |
1073 | If there are any outstanding requests and none of them in the result |
1434 | Wait until either at least one request is in the result phase or no |
1074 | phase, wait till the result filehandle becomes ready for reading |
1435 | requests are outstanding anymore. |
1075 | (simply does a "select" on the filehandle. This is useful if you |
1436 | |
1076 | want to synchronously wait for some requests to finish). |
1437 | This is useful if you want to synchronously wait for some requests |
|
|
1438 | to become ready, without actually handling them. |
1077 | |
1439 | |
1078 | See "nreqs" for an example. |
1440 | See "nreqs" for an example. |
1079 | |
1441 | |
1080 | IO::AIO::poll |
1442 | IO::AIO::poll |
1081 | Waits until some requests have been handled. |
1443 | Waits until some requests have been handled. |
… | |
… | |
1090 | |
1452 | |
1091 | Strictly equivalent to: |
1453 | Strictly equivalent to: |
1092 | |
1454 | |
1093 | IO::AIO::poll_wait, IO::AIO::poll_cb |
1455 | IO::AIO::poll_wait, IO::AIO::poll_cb |
1094 | while IO::AIO::nreqs; |
1456 | while IO::AIO::nreqs; |
|
|
1457 | |
|
|
1458 | This function can be useful at program aborts, to make sure |
|
|
1459 | outstanding I/O has been done ("IO::AIO" uses an "END" block which |
|
|
1460 | already calls this function on normal exits), or when you are merely |
|
|
1461 | using "IO::AIO" for its more advanced functions, rather than for |
|
|
1462 | async I/O, e.g.: |
|
|
1463 | |
|
|
1464 | my ($dirs, $nondirs); |
|
|
1465 | IO::AIO::aio_scandir "/tmp", 0, sub { ($dirs, $nondirs) = @_ }; |
|
|
1466 | IO::AIO::flush; |
|
|
1467 | # $dirs, $nondirs are now set |
1095 | |
1468 | |
1096 | IO::AIO::max_poll_reqs $nreqs |
1469 | IO::AIO::max_poll_reqs $nreqs |
1097 | IO::AIO::max_poll_time $seconds |
1470 | IO::AIO::max_poll_time $seconds |
1098 | These set the maximum number of requests (default 0, meaning |
1471 | These set the maximum number of requests (default 0, meaning |
1099 | infinity) that are being processed by "IO::AIO::poll_cb" in one |
1472 | infinity) that are being processed by "IO::AIO::poll_cb" in one |
… | |
… | |
1193 | |
1566 | |
1194 | This is a very bad function to use in interactive programs because |
1567 | This is a very bad function to use in interactive programs because |
1195 | it blocks, and a bad way to reduce concurrency because it is |
1568 | it blocks, and a bad way to reduce concurrency because it is |
1196 | inexact: Better use an "aio_group" together with a feed callback. |
1569 | inexact: Better use an "aio_group" together with a feed callback. |
1197 | |
1570 | |
1198 | It's main use is in scripts without an event loop - when you want to |
1571 | Its main use is in scripts without an event loop - when you want to |
1199 | stat a lot of files, you can write somehting like this: |
1572 | stat a lot of files, you can write something like this: |
1200 | |
1573 | |
1201 | IO::AIO::max_outstanding 32; |
1574 | IO::AIO::max_outstanding 32; |
1202 | |
1575 | |
1203 | for my $path (...) { |
1576 | for my $path (...) { |
1204 | aio_stat $path , ...; |
1577 | aio_stat $path , ...; |
… | |
… | |
1233 | |
1606 | |
1234 | IO::AIO::npending |
1607 | IO::AIO::npending |
1235 | Returns the number of requests currently in the pending state |
1608 | Returns the number of requests currently in the pending state |
1236 | (executed, but not yet processed by poll_cb). |
1609 | (executed, but not yet processed by poll_cb). |
1237 | |
1610 | |
|
|
1611 | SUBSECOND STAT TIME ACCESS |
|
|
1612 | Both "aio_stat"/"aio_lstat" and perl's "stat"/"lstat" functions can |
|
|
1613 | generally find access/modification and change times with subsecond time |
|
|
1614 | accuracy of the system supports it, but perl's built-in functions only |
|
|
1615 | return the integer part. |
|
|
1616 | |
|
|
1617 | The following functions return the timestamps of the most recent stat |
|
|
1618 | with subsecond precision on most systems and work both after |
|
|
1619 | "aio_stat"/"aio_lstat" and perl's "stat"/"lstat" calls. Their return |
|
|
1620 | value is only meaningful after a successful "stat"/"lstat" call, or |
|
|
1621 | during/after a successful "aio_stat"/"aio_lstat" callback. |
|
|
1622 | |
|
|
1623 | This is similar to the Time::HiRes "stat" functions, but can return full |
|
|
1624 | resolution without rounding and work with standard perl "stat", |
|
|
1625 | alleviating the need to call the special "Time::HiRes" functions, which |
|
|
1626 | do not act like their perl counterparts. |
|
|
1627 | |
|
|
1628 | On operating systems or file systems where subsecond time resolution is |
|
|
1629 | not supported or could not be detected, a fractional part of 0 is |
|
|
1630 | returned, so it is always safe to call these functions. |
|
|
1631 | |
|
|
1632 | $seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime, |
|
|
1633 | IO::AIO::st_btime |
|
|
1634 | Return the access, modication, change or birth time, respectively, |
|
|
1635 | including fractional part. Due to the limited precision of floating |
|
|
1636 | point, the accuracy on most platforms is only a bit better than |
|
|
1637 | milliseconds for times around now - see the *nsec* function family, |
|
|
1638 | below, for full accuracy. |
|
|
1639 | |
|
|
1640 | File birth time is only available when the OS and perl support it |
|
|
1641 | (on FreeBSD and NetBSD at the time of this writing, although support |
|
|
1642 | is adaptive, so if your OS/perl gains support, IO::AIO can take |
|
|
1643 | avdantage of it). On systems where it isn't available, 0 is |
|
|
1644 | currently returned, but this might change to "undef" in a future |
|
|
1645 | version. |
|
|
1646 | |
|
|
1647 | ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtime |
|
|
1648 | Returns access, modification, change and birth time all in one go, |
|
|
1649 | and maybe more times in the future version. |
|
|
1650 | |
|
|
1651 | $nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec, |
|
|
1652 | IO::AIO::st_ctimensec, IO::AIO::st_btimensec |
|
|
1653 | Return the fractional access, modifcation, change or birth time, in |
|
|
1654 | nanoseconds, as an integer in the range 0 to 999999999. |
|
|
1655 | |
|
|
1656 | Note that no accessors are provided for access, modification and |
|
|
1657 | change times - you need to get those from "stat _" if required ("int |
|
|
1658 | IO::AIO::st_atime" and so on will *not* generally give you the |
|
|
1659 | correct value). |
|
|
1660 | |
|
|
1661 | $seconds = IO::AIO::st_btimesec |
|
|
1662 | The (integral) seconds part of the file birth time, if available. |
|
|
1663 | |
|
|
1664 | ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtimensec |
|
|
1665 | Like the functions above, but returns all four times in one go (and |
|
|
1666 | maybe more in future versions). |
|
|
1667 | |
|
|
1668 | $counter = IO::AIO::st_gen |
|
|
1669 | Returns the generation counter of the file. This is only available |
|
|
1670 | on platforms which have this member in their "struct stat" (most |
|
|
1671 | BSDs at the time of this writing) and generally only to the root |
|
|
1672 | usert. If unsupported, 0 is returned, but this might change to |
|
|
1673 | "undef" in a future version. |
|
|
1674 | |
|
|
1675 | Example: print the high resolution modification time of /etc, using |
|
|
1676 | "stat", and "IO::AIO::aio_stat". |
|
|
1677 | |
|
|
1678 | if (stat "/etc") { |
|
|
1679 | printf "stat(/etc) mtime: %f\n", IO::AIO::st_mtime; |
|
|
1680 | } |
|
|
1681 | |
|
|
1682 | IO::AIO::aio_stat "/etc", sub { |
|
|
1683 | $_[0] |
|
|
1684 | and return; |
|
|
1685 | |
|
|
1686 | printf "aio_stat(/etc) mtime: %d.%09d\n", (stat _)[9], IO::AIO::st_mtimensec; |
|
|
1687 | }; |
|
|
1688 | |
|
|
1689 | IO::AIO::flush; |
|
|
1690 | |
|
|
1691 | Output of the awbove on my system, showing reduced and full accuracy: |
|
|
1692 | |
|
|
1693 | stat(/etc) mtime: 1534043702.020808 |
|
|
1694 | aio_stat(/etc) mtime: 1534043702.020807792 |
|
|
1695 | |
1238 | MISCELLANEOUS FUNCTIONS |
1696 | MISCELLANEOUS FUNCTIONS |
1239 | IO::AIO implements some functions that might be useful, but are not |
1697 | IO::AIO implements some functions that are useful when you want to use |
1240 | asynchronous. |
1698 | some "Advanced I/O" function not available to in Perl, without going the |
|
|
1699 | "Asynchronous I/O" route. Many of these have an asynchronous "aio_*" |
|
|
1700 | counterpart. |
|
|
1701 | |
|
|
1702 | $numfd = IO::AIO::get_fdlimit |
|
|
1703 | This function is *EXPERIMENTAL* and subject to change. |
|
|
1704 | |
|
|
1705 | Tries to find the current file descriptor limit and returns it, or |
|
|
1706 | "undef" and sets $! in case of an error. The limit is one larger |
|
|
1707 | than the highest valid file descriptor number. |
|
|
1708 | |
|
|
1709 | IO::AIO::min_fdlimit [$numfd] |
|
|
1710 | This function is *EXPERIMENTAL* and subject to change. |
|
|
1711 | |
|
|
1712 | Try to increase the current file descriptor limit(s) to at least |
|
|
1713 | $numfd by changing the soft or hard file descriptor resource limit. |
|
|
1714 | If $numfd is missing, it will try to set a very high limit, although |
|
|
1715 | this is not recommended when you know the actual minimum that you |
|
|
1716 | require. |
|
|
1717 | |
|
|
1718 | If the limit cannot be raised enough, the function makes a |
|
|
1719 | best-effort attempt to increase the limit as much as possible, using |
|
|
1720 | various tricks, while still failing. You can query the resulting |
|
|
1721 | limit using "IO::AIO::get_fdlimit". |
|
|
1722 | |
|
|
1723 | If an error occurs, returns "undef" and sets $!, otherwise returns |
|
|
1724 | true. |
1241 | |
1725 | |
1242 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
1726 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
1243 | Calls the "eio_sendfile_sync" function, which is like |
1727 | Calls the "eio_sendfile_sync" function, which is like |
1244 | "aio_sendfile", but is blocking (this makes most sense if you know |
1728 | "aio_sendfile", but is blocking (this makes most sense if you know |
1245 | the input data is likely cached already and the output filehandle is |
1729 | the input data is likely cached already and the output filehandle is |
… | |
… | |
1247 | |
1731 | |
1248 | Returns the number of bytes copied, or -1 on error. |
1732 | Returns the number of bytes copied, or -1 on error. |
1249 | |
1733 | |
1250 | IO::AIO::fadvise $fh, $offset, $len, $advice |
1734 | IO::AIO::fadvise $fh, $offset, $len, $advice |
1251 | Simply calls the "posix_fadvise" function (see its manpage for |
1735 | Simply calls the "posix_fadvise" function (see its manpage for |
1252 | details). The following advice constants are avaiable: |
1736 | details). The following advice constants are available: |
1253 | "IO::AIO::FADV_NORMAL", "IO::AIO::FADV_SEQUENTIAL", |
1737 | "IO::AIO::FADV_NORMAL", "IO::AIO::FADV_SEQUENTIAL", |
1254 | "IO::AIO::FADV_RANDOM", "IO::AIO::FADV_NOREUSE", |
1738 | "IO::AIO::FADV_RANDOM", "IO::AIO::FADV_NOREUSE", |
1255 | "IO::AIO::FADV_WILLNEED", "IO::AIO::FADV_DONTNEED". |
1739 | "IO::AIO::FADV_WILLNEED", "IO::AIO::FADV_DONTNEED". |
1256 | |
1740 | |
1257 | On systems that do not implement "posix_fadvise", this function |
1741 | On systems that do not implement "posix_fadvise", this function |
1258 | returns ENOSYS, otherwise the return value of "posix_fadvise". |
1742 | returns ENOSYS, otherwise the return value of "posix_fadvise". |
1259 | |
1743 | |
1260 | IO::AIO::madvise $scalar, $offset, $len, $advice |
1744 | IO::AIO::madvise $scalar, $offset, $len, $advice |
1261 | Simply calls the "posix_madvise" function (see its manpage for |
1745 | Simply calls the "posix_madvise" function (see its manpage for |
1262 | details). The following advice constants are avaiable: |
1746 | details). The following advice constants are available: |
1263 | "IO::AIO::MADV_NORMAL", "IO::AIO::MADV_SEQUENTIAL", |
1747 | "IO::AIO::MADV_NORMAL", "IO::AIO::MADV_SEQUENTIAL", |
1264 | "IO::AIO::MADV_RANDOM", "IO::AIO::MADV_WILLNEED", |
1748 | "IO::AIO::MADV_RANDOM", "IO::AIO::MADV_WILLNEED", |
1265 | "IO::AIO::MADV_DONTNEED". |
1749 | "IO::AIO::MADV_DONTNEED". |
1266 | |
1750 | |
|
|
1751 | If $offset is negative, counts from the end. If $length is negative, |
|
|
1752 | the remaining length of the $scalar is used. If possible, $length |
|
|
1753 | will be reduced to fit into the $scalar. |
|
|
1754 | |
1267 | On systems that do not implement "posix_madvise", this function |
1755 | On systems that do not implement "posix_madvise", this function |
1268 | returns ENOSYS, otherwise the return value of "posix_madvise". |
1756 | returns ENOSYS, otherwise the return value of "posix_madvise". |
1269 | |
1757 | |
1270 | IO::AIO::mprotect $scalar, $offset, $len, $protect |
1758 | IO::AIO::mprotect $scalar, $offset, $len, $protect |
1271 | Simply calls the "mprotect" function on the preferably AIO::mmap'ed |
1759 | Simply calls the "mprotect" function on the preferably AIO::mmap'ed |
1272 | $scalar (see its manpage for details). The following protect |
1760 | $scalar (see its manpage for details). The following protect |
1273 | constants are avaiable: "IO::AIO::PROT_NONE", "IO::AIO::PROT_READ", |
1761 | constants are available: "IO::AIO::PROT_NONE", "IO::AIO::PROT_READ", |
1274 | "IO::AIO::PROT_WRITE", "IO::AIO::PROT_EXEC". |
1762 | "IO::AIO::PROT_WRITE", "IO::AIO::PROT_EXEC". |
|
|
1763 | |
|
|
1764 | If $offset is negative, counts from the end. If $length is negative, |
|
|
1765 | the remaining length of the $scalar is used. If possible, $length |
|
|
1766 | will be reduced to fit into the $scalar. |
1275 | |
1767 | |
1276 | On systems that do not implement "mprotect", this function returns |
1768 | On systems that do not implement "mprotect", this function returns |
1277 | ENOSYS, otherwise the return value of "mprotect". |
1769 | ENOSYS, otherwise the return value of "mprotect". |
1278 | |
1770 | |
1279 | IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] |
1771 | IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] |
1280 | Memory-maps a file (or anonymous memory range) and attaches it to |
1772 | Memory-maps a file (or anonymous memory range) and attaches it to |
1281 | the given $scalar, which will act like a string scalar. |
1773 | the given $scalar, which will act like a string scalar. Returns true |
|
|
1774 | on success, and false otherwise. |
1282 | |
1775 | |
|
|
1776 | The scalar must exist, but its contents do not matter - this means |
|
|
1777 | you cannot use a nonexistant array or hash element. When in doubt, |
|
|
1778 | "undef" the scalar first. |
|
|
1779 | |
1283 | The only operations allowed on the scalar are "substr"/"vec" that |
1780 | The only operations allowed on the mmapped scalar are |
1284 | don't change the string length, and most read-only operations such |
1781 | "substr"/"vec", which don't change the string length, and most |
1285 | as copying it or searching it with regexes and so on. |
1782 | read-only operations such as copying it or searching it with regexes |
|
|
1783 | and so on. |
1286 | |
1784 | |
1287 | Anything else is unsafe and will, at best, result in memory leaks. |
1785 | Anything else is unsafe and will, at best, result in memory leaks. |
1288 | |
1786 | |
1289 | The memory map associated with the $scalar is automatically removed |
1787 | The memory map associated with the $scalar is automatically removed |
1290 | when the $scalar is destroyed, or when the "IO::AIO::mmap" or |
1788 | when the $scalar is undef'd or destroyed, or when the |
1291 | "IO::AIO::munmap" functions are called. |
1789 | "IO::AIO::mmap" or "IO::AIO::munmap" functions are called on it. |
1292 | |
1790 | |
1293 | This calls the "mmap"(2) function internally. See your system's |
1791 | This calls the "mmap"(2) function internally. See your system's |
1294 | manual page for details on the $length, $prot and $flags parameters. |
1792 | manual page for details on the $length, $prot and $flags parameters. |
1295 | |
1793 | |
1296 | The $length must be larger than zero and smaller than the actual |
1794 | The $length must be larger than zero and smaller than the actual |
… | |
… | |
1300 | "IO::AIO::PROT_EXEC", "IO::AIO::PROT_READ" and/or |
1798 | "IO::AIO::PROT_EXEC", "IO::AIO::PROT_READ" and/or |
1301 | "IO::AIO::PROT_WRITE", |
1799 | "IO::AIO::PROT_WRITE", |
1302 | |
1800 | |
1303 | $flags can be a combination of "IO::AIO::MAP_SHARED" or |
1801 | $flags can be a combination of "IO::AIO::MAP_SHARED" or |
1304 | "IO::AIO::MAP_PRIVATE", or a number of system-specific flags (when |
1802 | "IO::AIO::MAP_PRIVATE", or a number of system-specific flags (when |
1305 | not available, the are defined as 0): "IO::AIO::MAP_ANONYMOUS" |
1803 | not available, the are 0): "IO::AIO::MAP_ANONYMOUS" (which is set to |
1306 | (which is set to "MAP_ANON" if your system only provides this |
1804 | "MAP_ANON" if your system only provides this constant), |
|
|
1805 | "IO::AIO::MAP_LOCKED", "IO::AIO::MAP_NORESERVE", |
1307 | constant), "IO::AIO::MAP_HUGETLB", "IO::AIO::MAP_LOCKED", |
1806 | "IO::AIO::MAP_POPULATE", "IO::AIO::MAP_NONBLOCK", |
|
|
1807 | "IO::AIO::MAP_FIXED", "IO::AIO::MAP_GROWSDOWN", |
1308 | "IO::AIO::MAP_NORESERVE", "IO::AIO::MAP_POPULATE" or |
1808 | "IO::AIO::MAP_32BIT", "IO::AIO::MAP_HUGETLB" or |
1309 | "IO::AIO::MAP_NONBLOCK" |
1809 | "IO::AIO::MAP_STACK". |
1310 | |
1810 | |
1311 | If $fh is "undef", then a file descriptor of -1 is passed. |
1811 | If $fh is "undef", then a file descriptor of -1 is passed. |
1312 | |
1812 | |
1313 | $offset is the offset from the start of the file - it generally must |
1813 | $offset is the offset from the start of the file - it generally must |
1314 | be a multiple of "IO::AIO::PAGESIZE" and defaults to 0. |
1814 | be a multiple of "IO::AIO::PAGESIZE" and defaults to 0. |
… | |
… | |
1326 | |
1826 | |
1327 | my $fast_md5 = md5 $data; |
1827 | my $fast_md5 = md5 $data; |
1328 | |
1828 | |
1329 | IO::AIO::munmap $scalar |
1829 | IO::AIO::munmap $scalar |
1330 | Removes a previous mmap and undefines the $scalar. |
1830 | Removes a previous mmap and undefines the $scalar. |
|
|
1831 | |
|
|
1832 | IO::AIO::mremap $scalar, $new_length, $flags = MREMAP_MAYMOVE[, |
|
|
1833 | $new_address = 0] |
|
|
1834 | Calls the Linux-specific mremap(2) system call. The $scalar must |
|
|
1835 | have been mapped by "IO::AIO::mmap", and $flags must currently |
|
|
1836 | either be 0 or "IO::AIO::MREMAP_MAYMOVE". |
|
|
1837 | |
|
|
1838 | Returns true if successful, and false otherwise. If the underlying |
|
|
1839 | mmapped region has changed address, then the true value has the |
|
|
1840 | numerical value 1, otherwise it has the numerical value 0: |
|
|
1841 | |
|
|
1842 | my $success = IO::AIO::mremap $mmapped, 8192, IO::AIO::MREMAP_MAYMOVE |
|
|
1843 | or die "mremap: $!"; |
|
|
1844 | |
|
|
1845 | if ($success*1) { |
|
|
1846 | warn "scalar has chanegd address in memory\n"; |
|
|
1847 | } |
|
|
1848 | |
|
|
1849 | "IO::AIO::MREMAP_FIXED" and the $new_address argument are currently |
|
|
1850 | implemented, but not supported and might go away in a future |
|
|
1851 | version. |
|
|
1852 | |
|
|
1853 | On systems where this call is not supported or is not emulated, this |
|
|
1854 | call returns falls and sets $! to "ENOSYS". |
1331 | |
1855 | |
1332 | IO::AIO::munlock $scalar, $offset = 0, $length = undef |
1856 | IO::AIO::munlock $scalar, $offset = 0, $length = undef |
1333 | Calls the "munlock" function, undoing the effects of a previous |
1857 | Calls the "munlock" function, undoing the effects of a previous |
1334 | "aio_mlock" call (see its description for details). |
1858 | "aio_mlock" call (see its description for details). |
1335 | |
1859 | |
1336 | IO::AIO::munlockall |
1860 | IO::AIO::munlockall |
1337 | Calls the "munlockall" function. |
1861 | Calls the "munlockall" function. |
1338 | |
1862 | |
1339 | On systems that do not implement "munlockall", this function returns |
1863 | On systems that do not implement "munlockall", this function returns |
1340 | ENOSYS, otherwise the return value of "munlockall". |
1864 | ENOSYS, otherwise the return value of "munlockall". |
|
|
1865 | |
|
|
1866 | IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags |
|
|
1867 | Calls the GNU/Linux splice(2) syscall, if available. If $r_off or |
|
|
1868 | $w_off are "undef", then "NULL" is passed for these, otherwise they |
|
|
1869 | should be the file offset. |
|
|
1870 | |
|
|
1871 | $r_fh and $w_fh should not refer to the same file, as splice might |
|
|
1872 | silently corrupt the data in this case. |
|
|
1873 | |
|
|
1874 | The following symbol flag values are available: |
|
|
1875 | "IO::AIO::SPLICE_F_MOVE", "IO::AIO::SPLICE_F_NONBLOCK", |
|
|
1876 | "IO::AIO::SPLICE_F_MORE" and "IO::AIO::SPLICE_F_GIFT". |
|
|
1877 | |
|
|
1878 | See the splice(2) manpage for details. |
|
|
1879 | |
|
|
1880 | IO::AIO::tee $r_fh, $w_fh, $length, $flags |
|
|
1881 | Calls the GNU/Linux tee(2) syscall, see its manpage and the |
|
|
1882 | description for "IO::AIO::splice" above for details. |
|
|
1883 | |
|
|
1884 | $actual_size = IO::AIO::pipesize $r_fh[, $new_size] |
|
|
1885 | Attempts to query or change the pipe buffer size. Obviously works |
|
|
1886 | only on pipes, and currently works only on GNU/Linux systems, and |
|
|
1887 | fails with -1/"ENOSYS" everywhere else. If anybody knows how to |
|
|
1888 | influence pipe buffer size on other systems, drop me a note. |
|
|
1889 | |
|
|
1890 | ($rfh, $wfh) = IO::AIO::pipe2 [$flags] |
|
|
1891 | This is a direct interface to the Linux pipe2(2) system call. If |
|
|
1892 | $flags is missing or 0, then this should be the same as a call to |
|
|
1893 | perl's built-in "pipe" function and create a new pipe, and works on |
|
|
1894 | systems that lack the pipe2 syscall. On win32, this case invokes |
|
|
1895 | "_pipe (..., 4096, O_BINARY)". |
|
|
1896 | |
|
|
1897 | If $flags is non-zero, it tries to invoke the pipe2 system call with |
|
|
1898 | the given flags (Linux 2.6.27, glibc 2.9). |
|
|
1899 | |
|
|
1900 | On success, the read and write file handles are returned. |
|
|
1901 | |
|
|
1902 | On error, nothing will be returned. If the pipe2 syscall is missing |
|
|
1903 | and $flags is non-zero, fails with "ENOSYS". |
|
|
1904 | |
|
|
1905 | Please refer to pipe2(2) for more info on the $flags, but at the |
|
|
1906 | time of this writing, "IO::AIO::O_CLOEXEC", "IO::AIO::O_NONBLOCK" |
|
|
1907 | and "IO::AIO::O_DIRECT" (Linux 3.4, for packet-based pipes) were |
|
|
1908 | supported. |
|
|
1909 | |
|
|
1910 | Example: create a pipe race-free w.r.t. threads and fork: |
|
|
1911 | |
|
|
1912 | my ($rfh, $wfh) = IO::AIO::pipe2 IO::AIO::O_CLOEXEC |
|
|
1913 | or die "pipe2: $!\n"; |
|
|
1914 | |
|
|
1915 | $fh = IO::AIO::eventfd [$initval, [$flags]] |
|
|
1916 | This is a direct interface to the Linux eventfd(2) system call. The |
|
|
1917 | (unhelpful) defaults for $initval and $flags are 0 for both. |
|
|
1918 | |
|
|
1919 | On success, the new eventfd filehandle is returned, otherwise |
|
|
1920 | returns "undef". If the eventfd syscall is missing, fails with |
|
|
1921 | "ENOSYS". |
|
|
1922 | |
|
|
1923 | Please refer to eventfd(2) for more info on this call. |
|
|
1924 | |
|
|
1925 | The following symbol flag values are available: |
|
|
1926 | "IO::AIO::EFD_CLOEXEC", "IO::AIO::EFD_NONBLOCK" and |
|
|
1927 | "IO::AIO::EFD_SEMAPHORE" (Linux 2.6.30). |
|
|
1928 | |
|
|
1929 | Example: create a new eventfd filehandle: |
|
|
1930 | |
|
|
1931 | $fh = IO::AIO::eventfd 0, IO::AIO::O_CLOEXEC |
|
|
1932 | or die "eventfd: $!\n"; |
|
|
1933 | |
|
|
1934 | $fh = IO::AIO::timerfd_create $clockid[, $flags] |
|
|
1935 | This is a direct interface to the Linux timerfd_create(2) system |
|
|
1936 | call. The (unhelpful) default for $flags is 0. |
|
|
1937 | |
|
|
1938 | On success, the new timerfd filehandle is returned, otherwise |
|
|
1939 | returns "undef". If the eventfd syscall is missing, fails with |
|
|
1940 | "ENOSYS". |
|
|
1941 | |
|
|
1942 | Please refer to timerfd_create(2) for more info on this call. |
|
|
1943 | |
|
|
1944 | The following $clockid values are available: |
|
|
1945 | "IO::AIO::CLOCK_REALTIME", "IO::AIO::CLOCK_MONOTONIC" |
|
|
1946 | "IO::AIO::CLOCK_CLOCK_BOOTTIME" (Linux 3.15) |
|
|
1947 | "IO::AIO::CLOCK_CLOCK_REALTIME_ALARM" (Linux 3.11) and |
|
|
1948 | "IO::AIO::CLOCK_CLOCK_BOOTTIME_ALARM" (Linux 3.11). |
|
|
1949 | |
|
|
1950 | The following $flags values are available (Linux 2.6.27): |
|
|
1951 | "IO::AIO::TFD_NONBLOCK" and "IO::AIO::TFD_CLOEXEC". |
|
|
1952 | |
|
|
1953 | Example: create a new timerfd and set it to one-second repeated |
|
|
1954 | alarms, then wait for two alarms: |
|
|
1955 | |
|
|
1956 | my $fh = IO::AIO::timerfd_create IO::AIO::CLOCK_BOOTTIME, IO::AIO::TFD_CLOEXEC |
|
|
1957 | or die "timerfd_create: $!\n"; |
|
|
1958 | |
|
|
1959 | defined IO::AIO::timerfd_settime $fh, 0, 1, 1 |
|
|
1960 | or die "timerfd_settime: $!\n"; |
|
|
1961 | |
|
|
1962 | for (1..2) { |
|
|
1963 | 8 == sysread $fh, my $buf, 8 |
|
|
1964 | or die "timerfd read failure\n"; |
|
|
1965 | |
|
|
1966 | printf "number of expirations (likely 1): %d\n", |
|
|
1967 | unpack "Q", $buf; |
|
|
1968 | } |
|
|
1969 | |
|
|
1970 | ($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags, |
|
|
1971 | $new_interval, $nbw_value |
|
|
1972 | This is a direct interface to the Linux timerfd_settime(2) system |
|
|
1973 | call. Please refer to its manpage for more info on this call. |
|
|
1974 | |
|
|
1975 | The new itimerspec is specified using two (possibly fractional) |
|
|
1976 | second values, $new_interval and $new_value). |
|
|
1977 | |
|
|
1978 | On success, the current interval and value are returned (as per |
|
|
1979 | "timerfd_gettime"). On failure, the empty list is returned. |
|
|
1980 | |
|
|
1981 | The following $flags values are available: |
|
|
1982 | "IO::AIO::TFD_TIMER_ABSTIME" and "IO::AIO::TFD_TIMER_CANCEL_ON_SET". |
|
|
1983 | |
|
|
1984 | See "IO::AIO::timerfd_create" for a full example. |
|
|
1985 | |
|
|
1986 | ($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh |
|
|
1987 | This is a direct interface to the Linux timerfd_gettime(2) system |
|
|
1988 | call. Please refer to its manpage for more info on this call. |
|
|
1989 | |
|
|
1990 | On success, returns the current values of interval and value for the |
|
|
1991 | given timerfd (as potentially fractional second values). On failure, |
|
|
1992 | the empty list is returned. |
1341 | |
1993 | |
1342 | EVENT LOOP INTEGRATION |
1994 | EVENT LOOP INTEGRATION |
1343 | It is recommended to use AnyEvent::AIO to integrate IO::AIO |
1995 | It is recommended to use AnyEvent::AIO to integrate IO::AIO |
1344 | automatically into many event loops: |
1996 | automatically into many event loops: |
1345 | |
1997 | |
… | |
… | |
1371 | |
2023 | |
1372 | FORK BEHAVIOUR |
2024 | FORK BEHAVIOUR |
1373 | Usage of pthreads in a program changes the semantics of fork |
2025 | Usage of pthreads in a program changes the semantics of fork |
1374 | considerably. Specifically, only async-safe functions can be called |
2026 | considerably. Specifically, only async-safe functions can be called |
1375 | after fork. Perl doesn't know about this, so in general, you cannot call |
2027 | after fork. Perl doesn't know about this, so in general, you cannot call |
1376 | fork with defined behaviour in perl. IO::AIO uses pthreads, so this |
2028 | fork with defined behaviour in perl if pthreads are involved. IO::AIO |
1377 | applies, but many other extensions and (for inexplicable reasons) perl |
2029 | uses pthreads, so this applies, but many other extensions and (for |
1378 | itself often is linked against pthreads, so this limitation applies. |
2030 | inexplicable reasons) perl itself often is linked against pthreads, so |
|
|
2031 | this limitation applies to quite a lot of perls. |
1379 | |
2032 | |
1380 | Some operating systems have extensions that allow safe use of fork, and |
2033 | This module no longer tries to fight your OS, or POSIX. That means |
1381 | this module should do "the right thing" on those, and tries on others. |
2034 | IO::AIO only works in the process that loaded it. Forking is fully |
1382 | At the time of this writing (2011) only GNU/Linux supports these |
2035 | supported, but using IO::AIO in the child is not. |
1383 | extensions to POSIX. |
2036 | |
|
|
2037 | You might get around by not *using* IO::AIO before (or after) forking. |
|
|
2038 | You could also try to call the IO::AIO::reinit function in the child: |
|
|
2039 | |
|
|
2040 | IO::AIO::reinit |
|
|
2041 | Abandons all current requests and I/O threads and simply |
|
|
2042 | reinitialises all data structures. This is not an operation |
|
|
2043 | supported by any standards, but happens to work on GNU/Linux and |
|
|
2044 | some newer BSD systems. |
|
|
2045 | |
|
|
2046 | The only reasonable use for this function is to call it after |
|
|
2047 | forking, if "IO::AIO" was used in the parent. Calling it while |
|
|
2048 | IO::AIO is active in the process will result in undefined behaviour. |
|
|
2049 | Calling it at any time will also result in any undefined (by POSIX) |
|
|
2050 | behaviour. |
|
|
2051 | |
|
|
2052 | LINUX-SPECIFIC CALLS |
|
|
2053 | When a call is documented as "linux-specific" then this means it |
|
|
2054 | originated on GNU/Linux. "IO::AIO" will usually try to autodetect the |
|
|
2055 | availability and compatibility of such calls regardless of the platform |
|
|
2056 | it is compiled on, so platforms such as FreeBSD which often implement |
|
|
2057 | these calls will work. When in doubt, call them and see if they fail wth |
|
|
2058 | "ENOSYS". |
1384 | |
2059 | |
1385 | MEMORY USAGE |
2060 | MEMORY USAGE |
1386 | Per-request usage: |
2061 | Per-request usage: |
1387 | |
2062 | |
1388 | Each aio request uses - depending on your architecture - around 100-200 |
2063 | Each aio request uses - depending on your architecture - around 100-200 |
… | |
… | |
1399 | In the execution phase, some aio requests require more memory for |
2074 | In the execution phase, some aio requests require more memory for |
1400 | temporary buffers, and each thread requires a stack and other data |
2075 | temporary buffers, and each thread requires a stack and other data |
1401 | structures (usually around 16k-128k, depending on the OS). |
2076 | structures (usually around 16k-128k, depending on the OS). |
1402 | |
2077 | |
1403 | KNOWN BUGS |
2078 | KNOWN BUGS |
1404 | Known bugs will be fixed in the next release. |
2079 | Known bugs will be fixed in the next release :) |
|
|
2080 | |
|
|
2081 | KNOWN ISSUES |
|
|
2082 | Calls that try to "import" foreign memory areas (such as "IO::AIO::mmap" |
|
|
2083 | or "IO::AIO::aio_slurp") do not work with generic lvalues, such as |
|
|
2084 | non-created hash slots or other scalars I didn't think of. It's best to |
|
|
2085 | avoid such and either use scalar variables or making sure that the |
|
|
2086 | scalar exists (e.g. by storing "undef") and isn't "funny" (e.g. tied). |
|
|
2087 | |
|
|
2088 | I am not sure anything can be done about this, so this is considered a |
|
|
2089 | known issue, rather than a bug. |
1405 | |
2090 | |
1406 | SEE ALSO |
2091 | SEE ALSO |
1407 | AnyEvent::AIO for easy integration into event loops, Coro::AIO for a |
2092 | AnyEvent::AIO for easy integration into event loops, Coro::AIO for a |
1408 | more natural syntax. |
2093 | more natural syntax. |
1409 | |
2094 | |