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2 | IO::AIO - Asynchronous Input/Output |
2 | IO::AIO - Asynchronous Input/Output |
3 | |
3 | |
4 | SYNOPSIS |
4 | SYNOPSIS |
5 | use IO::AIO; |
5 | use IO::AIO; |
6 | |
6 | |
7 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
7 | aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub { |
8 | my $fh = shift |
8 | my $fh = shift |
9 | or die "/etc/passwd: $!"; |
9 | or die "/etc/passwd: $!"; |
10 | ... |
10 | ... |
11 | }; |
11 | }; |
12 | |
12 | |
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64 | |
64 | |
65 | EXAMPLE |
65 | EXAMPLE |
66 | This is a simple example that uses the EV module and loads /etc/passwd |
66 | This is a simple example that uses the EV module and loads /etc/passwd |
67 | asynchronously: |
67 | asynchronously: |
68 | |
68 | |
69 | use Fcntl; |
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70 | use EV; |
69 | use EV; |
71 | use IO::AIO; |
70 | use IO::AIO; |
72 | |
71 | |
73 | # register the IO::AIO callback with EV |
72 | # register the IO::AIO callback with EV |
74 | my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
73 | my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
75 | |
74 | |
76 | # queue the request to open /etc/passwd |
75 | # queue the request to open /etc/passwd |
77 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
76 | aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub { |
78 | my $fh = shift |
77 | my $fh = shift |
79 | or die "error while opening: $!"; |
78 | or die "error while opening: $!"; |
80 | |
79 | |
81 | # stat'ing filehandles is generally non-blocking |
80 | # stat'ing filehandles is generally non-blocking |
82 | my $size = -s $fh; |
81 | my $size = -s $fh; |
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146 | the actual aio request is severed and calling its methods will |
145 | the actual aio request is severed and calling its methods will |
147 | either do nothing or result in a runtime error). |
146 | either do nothing or result in a runtime error). |
148 | |
147 | |
149 | FUNCTIONS |
148 | FUNCTIONS |
150 | QUICK OVERVIEW |
149 | QUICK OVERVIEW |
151 | This section simply lists the prototypes of the most important functions |
150 | This section simply lists the prototypes most of the functions for quick |
152 | for quick reference. See the following sections for function-by-function |
151 | reference. See the following sections for function-by-function |
153 | documentation. |
152 | documentation. |
154 | |
153 | |
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154 | aio_wd $pathname, $callback->($wd) |
155 | aio_open $pathname, $flags, $mode, $callback->($fh) |
155 | aio_open $pathname, $flags, $mode, $callback->($fh) |
156 | aio_close $fh, $callback->($status) |
156 | aio_close $fh, $callback->($status) |
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157 | aio_seek $fh,$offset,$whence, $callback->($offs) |
157 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
158 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
158 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
159 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
159 | aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
160 | aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
160 | aio_readahead $fh,$offset,$length, $callback->($retval) |
161 | aio_readahead $fh,$offset,$length, $callback->($retval) |
161 | aio_stat $fh_or_path, $callback->($status) |
162 | aio_stat $fh_or_path, $callback->($status) |
162 | aio_lstat $fh, $callback->($status) |
163 | aio_lstat $fh, $callback->($status) |
163 | aio_statvfs $fh_or_path, $callback->($statvfs) |
164 | aio_statvfs $fh_or_path, $callback->($statvfs) |
164 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
165 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
165 | aio_chown $fh_or_path, $uid, $gid, $callback->($status) |
166 | aio_chown $fh_or_path, $uid, $gid, $callback->($status) |
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167 | aio_chmod $fh_or_path, $mode, $callback->($status) |
166 | aio_truncate $fh_or_path, $offset, $callback->($status) |
168 | aio_truncate $fh_or_path, $offset, $callback->($status) |
167 | aio_chmod $fh_or_path, $mode, $callback->($status) |
169 | aio_allocate $fh, $mode, $offset, $len, $callback->($status) |
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170 | aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents) |
168 | aio_unlink $pathname, $callback->($status) |
171 | aio_unlink $pathname, $callback->($status) |
169 | aio_mknod $path, $mode, $dev, $callback->($status) |
172 | aio_mknod $pathname, $mode, $dev, $callback->($status) |
170 | aio_link $srcpath, $dstpath, $callback->($status) |
173 | aio_link $srcpath, $dstpath, $callback->($status) |
171 | aio_symlink $srcpath, $dstpath, $callback->($status) |
174 | aio_symlink $srcpath, $dstpath, $callback->($status) |
172 | aio_readlink $path, $callback->($link) |
175 | aio_readlink $pathname, $callback->($link) |
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176 | aio_realpath $pathname, $callback->($link) |
173 | aio_rename $srcpath, $dstpath, $callback->($status) |
177 | aio_rename $srcpath, $dstpath, $callback->($status) |
174 | aio_mkdir $pathname, $mode, $callback->($status) |
178 | aio_mkdir $pathname, $mode, $callback->($status) |
175 | aio_rmdir $pathname, $callback->($status) |
179 | aio_rmdir $pathname, $callback->($status) |
176 | aio_readdir $pathname, $callback->($entries) |
180 | aio_readdir $pathname, $callback->($entries) |
177 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
181 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
178 | IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST |
182 | IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST |
179 | IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN |
183 | IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN |
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184 | aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) |
180 | aio_load $path, $data, $callback->($status) |
185 | aio_load $pathname, $data, $callback->($status) |
181 | aio_copy $srcpath, $dstpath, $callback->($status) |
186 | aio_copy $srcpath, $dstpath, $callback->($status) |
182 | aio_move $srcpath, $dstpath, $callback->($status) |
187 | aio_move $srcpath, $dstpath, $callback->($status) |
183 | aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
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184 | aio_rmtree $path, $callback->($status) |
188 | aio_rmtree $pathname, $callback->($status) |
185 | aio_sync $callback->($status) |
189 | aio_sync $callback->($status) |
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190 | aio_syncfs $fh, $callback->($status) |
186 | aio_fsync $fh, $callback->($status) |
191 | aio_fsync $fh, $callback->($status) |
187 | aio_fdatasync $fh, $callback->($status) |
192 | aio_fdatasync $fh, $callback->($status) |
188 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
193 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
189 | aio_pathsync $path, $callback->($status) |
194 | aio_pathsync $pathname, $callback->($status) |
190 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
195 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
191 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
196 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
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197 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
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198 | aio_mlockall $flags, $callback->($status) |
192 | aio_group $callback->(...) |
199 | aio_group $callback->(...) |
193 | aio_nop $callback->() |
200 | aio_nop $callback->() |
194 | |
201 | |
195 | $prev_pri = aioreq_pri [$pri] |
202 | $prev_pri = aioreq_pri [$pri] |
196 | aioreq_nice $pri_adjust |
203 | aioreq_nice $pri_adjust |
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202 | IO::AIO::max_poll_reqs $nreqs |
209 | IO::AIO::max_poll_reqs $nreqs |
203 | IO::AIO::max_poll_time $seconds |
210 | IO::AIO::max_poll_time $seconds |
204 | IO::AIO::min_parallel $nthreads |
211 | IO::AIO::min_parallel $nthreads |
205 | IO::AIO::max_parallel $nthreads |
212 | IO::AIO::max_parallel $nthreads |
206 | IO::AIO::max_idle $nthreads |
213 | IO::AIO::max_idle $nthreads |
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214 | IO::AIO::idle_timeout $seconds |
207 | IO::AIO::max_outstanding $maxreqs |
215 | IO::AIO::max_outstanding $maxreqs |
208 | IO::AIO::nreqs |
216 | IO::AIO::nreqs |
209 | IO::AIO::nready |
217 | IO::AIO::nready |
210 | IO::AIO::npending |
218 | IO::AIO::npending |
211 | |
219 | |
212 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
220 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
213 | IO::AIO::fadvise $fh, $offset, $len, $advice |
221 | IO::AIO::fadvise $fh, $offset, $len, $advice |
214 | IO::AIO::mlockall $flags |
222 | IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]] |
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223 | IO::AIO::munmap $scalar |
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224 | IO::AIO::madvise $scalar, $offset, $length, $advice |
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225 | IO::AIO::mprotect $scalar, $offset, $length, $protect |
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226 | IO::AIO::munlock $scalar, $offset = 0, $length = undef |
215 | IO::AIO::munlockall |
227 | IO::AIO::munlockall |
216 | |
228 | |
217 | AIO REQUEST FUNCTIONS |
229 | API NOTES |
218 | All the "aio_*" calls are more or less thin wrappers around the syscall |
230 | All the "aio_*" calls are more or less thin wrappers around the syscall |
219 | with the same name (sans "aio_"). The arguments are similar or |
231 | with the same name (sans "aio_"). The arguments are similar or |
220 | identical, and they all accept an additional (and optional) $callback |
232 | identical, and they all accept an additional (and optional) $callback |
221 | argument which must be a code reference. This code reference will get |
233 | argument which must be a code reference. This code reference will be |
222 | called with the syscall return code (e.g. most syscalls return -1 on |
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223 | error, unlike perl, which usually delivers "false") as its sole argument |
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224 | after the given syscall has been executed asynchronously. |
234 | called after the syscall has been executed in an asynchronous fashion. |
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235 | The results of the request will be passed as arguments to the callback |
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236 | (and, if an error occured, in $!) - for most requests the syscall return |
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237 | code (e.g. most syscalls return -1 on error, unlike perl, which usually |
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238 | delivers "false"). |
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239 | |
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240 | Some requests (such as "aio_readdir") pass the actual results and |
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241 | communicate failures by passing "undef". |
225 | |
242 | |
226 | All functions expecting a filehandle keep a copy of the filehandle |
243 | All functions expecting a filehandle keep a copy of the filehandle |
227 | internally until the request has finished. |
244 | internally until the request has finished. |
228 | |
245 | |
229 | All functions return request objects of type IO::AIO::REQ that allow |
246 | All functions return request objects of type IO::AIO::REQ that allow |
230 | further manipulation of those requests while they are in-flight. |
247 | further manipulation of those requests while they are in-flight. |
231 | |
248 | |
232 | The pathnames you pass to these routines *must* be absolute and encoded |
249 | The pathnames you pass to these routines *should* be absolute. The |
233 | as octets. The reason for the former is that at the time the request is |
250 | reason for this is that at the time the request is being executed, the |
234 | being executed, the current working directory could have changed. |
251 | current working directory could have changed. Alternatively, you can |
235 | Alternatively, you can make sure that you never change the current |
252 | make sure that you never change the current working directory anywhere |
236 | working directory anywhere in the program and then use relative paths. |
253 | in the program and then use relative paths. You can also take advantage |
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254 | of IO::AIOs working directory abstraction, that lets you specify paths |
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255 | relative to some previously-opened "working directory object" - see the |
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256 | description of the "IO::AIO::WD" class later in this document. |
237 | |
257 | |
238 | To encode pathnames as octets, either make sure you either: a) always |
258 | To encode pathnames as octets, either make sure you either: a) always |
239 | pass in filenames you got from outside (command line, readdir etc.) |
259 | pass in filenames you got from outside (command line, readdir etc.) |
240 | without tinkering, b) are ASCII or ISO 8859-1, c) use the Encode module |
260 | without tinkering, b) are in your native filesystem encoding, c) use the |
241 | and encode your pathnames to the locale (or other) encoding in effect in |
261 | Encode module and encode your pathnames to the locale (or other) |
242 | the user environment, d) use Glib::filename_from_unicode on unicode |
262 | encoding in effect in the user environment, d) use |
243 | filenames or e) use something else to ensure your scalar has the correct |
263 | Glib::filename_from_unicode on unicode filenames or e) use something |
244 | contents. |
264 | else to ensure your scalar has the correct contents. |
245 | |
265 | |
246 | This works, btw. independent of the internal UTF-8 bit, which IO::AIO |
266 | This works, btw. independent of the internal UTF-8 bit, which IO::AIO |
247 | handles correctly whether it is set or not. |
267 | handles correctly whether it is set or not. |
248 | |
268 | |
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269 | AIO REQUEST FUNCTIONS |
249 | $prev_pri = aioreq_pri [$pri] |
270 | $prev_pri = aioreq_pri [$pri] |
250 | Returns the priority value that would be used for the next request |
271 | Returns the priority value that would be used for the next request |
251 | and, if $pri is given, sets the priority for the next aio request. |
272 | and, if $pri is given, sets the priority for the next aio request. |
252 | |
273 | |
253 | The default priority is 0, the minimum and maximum priorities are -4 |
274 | The default priority is 0, the minimum and maximum priorities are -4 |
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275 | Similar to "aioreq_pri", but subtracts the given value from the |
296 | Similar to "aioreq_pri", but subtracts the given value from the |
276 | current priority, so the effect is cumulative. |
297 | current priority, so the effect is cumulative. |
277 | |
298 | |
278 | aio_open $pathname, $flags, $mode, $callback->($fh) |
299 | aio_open $pathname, $flags, $mode, $callback->($fh) |
279 | Asynchronously open or create a file and call the callback with a |
300 | Asynchronously open or create a file and call the callback with a |
280 | newly created filehandle for the file. |
301 | newly created filehandle for the file (or "undef" in case of an |
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302 | error). |
281 | |
303 | |
282 | The pathname passed to "aio_open" must be absolute. See API NOTES, |
304 | The pathname passed to "aio_open" must be absolute. See API NOTES, |
283 | above, for an explanation. |
305 | above, for an explanation. |
284 | |
306 | |
285 | The $flags argument is a bitmask. See the "Fcntl" module for a list. |
307 | The $flags argument is a bitmask. See the "Fcntl" module for a list. |
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292 | will be modified by the umask in effect then the request is being |
314 | will be modified by the umask in effect then the request is being |
293 | executed, so better never change the umask. |
315 | executed, so better never change the umask. |
294 | |
316 | |
295 | Example: |
317 | Example: |
296 | |
318 | |
297 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
319 | aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub { |
298 | if ($_[0]) { |
320 | if ($_[0]) { |
299 | print "open successful, fh is $_[0]\n"; |
321 | print "open successful, fh is $_[0]\n"; |
300 | ... |
322 | ... |
301 | } else { |
323 | } else { |
302 | die "open failed: $!\n"; |
324 | die "open failed: $!\n"; |
303 | } |
325 | } |
304 | }; |
326 | }; |
305 | |
327 | |
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328 | In addition to all the common open modes/flags ("O_RDONLY", |
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329 | "O_WRONLY", "O_RDWR", "O_CREAT", "O_TRUNC", "O_EXCL" and |
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330 | "O_APPEND"), the following POSIX and non-POSIX constants are |
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331 | available (missing ones on your system are, as usual, 0): |
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332 | |
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333 | "O_ASYNC", "O_DIRECT", "O_NOATIME", "O_CLOEXEC", "O_NOCTTY", |
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334 | "O_NOFOLLOW", "O_NONBLOCK", "O_EXEC", "O_SEARCH", "O_DIRECTORY", |
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335 | "O_DSYNC", "O_RSYNC", "O_SYNC" and "O_TTY_INIT". |
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336 | |
306 | aio_close $fh, $callback->($status) |
337 | aio_close $fh, $callback->($status) |
307 | Asynchronously close a file and call the callback with the result |
338 | Asynchronously close a file and call the callback with the result |
308 | code. |
339 | code. |
309 | |
340 | |
310 | Unfortunately, you can't do this to perl. Perl *insists* very |
341 | Unfortunately, you can't do this to perl. Perl *insists* very |
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315 | will use dup2 to overwrite the file descriptor with the write-end of |
346 | will use dup2 to overwrite the file descriptor with the write-end of |
316 | a pipe (the pipe fd will be created on demand and will be cached). |
347 | a pipe (the pipe fd will be created on demand and will be cached). |
317 | |
348 | |
318 | Or in other words: the file descriptor will be closed, but it will |
349 | Or in other words: the file descriptor will be closed, but it will |
319 | not be free for reuse until the perl filehandle is closed. |
350 | not be free for reuse until the perl filehandle is closed. |
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351 | |
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352 | aio_seek $fh, $offset, $whence, $callback->($offs) |
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353 | Seeks the filehandle to the new $offset, similarly to perl's |
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354 | "sysseek". The $whence can use the traditional values (0 for |
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355 | "IO::AIO::SEEK_SET", 1 for "IO::AIO::SEEK_CUR" or 2 for |
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356 | "IO::AIO::SEEK_END"). |
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357 | |
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358 | The resulting absolute offset will be passed to the callback, or -1 |
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359 | in case of an error. |
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360 | |
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361 | In theory, the $whence constants could be different than the |
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362 | corresponding values from Fcntl, but perl guarantees they are the |
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363 | same, so don't panic. |
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364 | |
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365 | As a GNU/Linux (and maybe Solaris) extension, also the constants |
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366 | "IO::AIO::SEEK_DATA" and "IO::AIO::SEEK_HOLE" are available, if they |
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367 | could be found. No guarantees about suitability for use in |
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368 | "aio_seek" or Perl's "sysseek" can be made though, although I would |
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369 | naively assume they "just work". |
320 | |
370 | |
321 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
371 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
322 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
372 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
323 | Reads or writes $length bytes from or to the specified $fh and |
373 | Reads or writes $length bytes from or to the specified $fh and |
324 | $offset into the scalar given by $data and offset $dataoffset and |
374 | $offset into the scalar given by $data and offset $dataoffset and |
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353 | aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
403 | aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
354 | Tries to copy $length bytes from $in_fh to $out_fh. It starts |
404 | Tries to copy $length bytes from $in_fh to $out_fh. It starts |
355 | reading at byte offset $in_offset, and starts writing at the current |
405 | reading at byte offset $in_offset, and starts writing at the current |
356 | file offset of $out_fh. Because of that, it is not safe to issue |
406 | file offset of $out_fh. Because of that, it is not safe to issue |
357 | more than one "aio_sendfile" per $out_fh, as they will interfere |
407 | more than one "aio_sendfile" per $out_fh, as they will interfere |
358 | with each other. |
408 | with each other. The same $in_fh works fine though, as this function |
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409 | does not move or use the file offset of $in_fh. |
359 | |
410 | |
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411 | Please note that "aio_sendfile" can read more bytes from $in_fh than |
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412 | are written, and there is no way to find out how many more bytes |
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413 | have been read from "aio_sendfile" alone, as "aio_sendfile" only |
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414 | provides the number of bytes written to $out_fh. Only if the result |
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415 | value equals $length one can assume that $length bytes have been |
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416 | read. |
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417 | |
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418 | Unlike with other "aio_" functions, it makes a lot of sense to use |
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419 | "aio_sendfile" on non-blocking sockets, as long as one end |
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420 | (typically the $in_fh) is a file - the file I/O will then be |
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421 | asynchronous, while the socket I/O will be non-blocking. Note, |
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422 | however, that you can run into a trap where "aio_sendfile" reads |
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423 | some data with readahead, then fails to write all data, and when the |
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424 | socket is ready the next time, the data in the cache is already |
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425 | lost, forcing "aio_sendfile" to again hit the disk. Explicit |
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426 | "aio_read" + "aio_write" let's you better control resource usage. |
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427 | |
360 | This call tries to make use of a native "sendfile" syscall to |
428 | This call tries to make use of a native "sendfile"-like syscall to |
361 | provide zero-copy operation. For this to work, $out_fh should refer |
429 | provide zero-copy operation. For this to work, $out_fh should refer |
362 | to a socket, and $in_fh should refer to an mmap'able file. |
430 | to a socket, and $in_fh should refer to an mmap'able file. |
363 | |
431 | |
364 | If a native sendfile cannot be found or it fails with "ENOSYS", |
432 | If a native sendfile cannot be found or it fails with "ENOSYS", |
365 | "ENOTSUP", "EOPNOTSUPP", "EAFNOSUPPORT", "EPROTOTYPE" or "ENOTSOCK", |
433 | "EINVAL", "ENOTSUP", "EOPNOTSUPP", "EAFNOSUPPORT", "EPROTOTYPE" or |
366 | it will be emulated, so you can call "aio_sendfile" on any type of |
434 | "ENOTSOCK", it will be emulated, so you can call "aio_sendfile" on |
367 | filehandle regardless of the limitations of the operating system. |
435 | any type of filehandle regardless of the limitations of the |
|
|
436 | operating system. |
368 | |
437 | |
369 | Please note, however, that "aio_sendfile" can read more bytes from |
438 | As native sendfile syscalls (as practically any non-POSIX interface |
370 | $in_fh than are written, and there is no way to find out how many |
439 | hacked together in a hurry to improve benchmark numbers) tend to be |
371 | bytes have been read from "aio_sendfile" alone, as "aio_sendfile" |
440 | rather buggy on many systems, this implementation tries to work |
372 | only provides the number of bytes written to $out_fh. Only if the |
441 | around some known bugs in Linux and FreeBSD kernels (probably |
373 | result value equals $length one can assume that $length bytes have |
442 | others, too), but that might fail, so you really really should check |
374 | been read. |
443 | the return value of "aio_sendfile" - fewre bytes than expected might |
|
|
444 | have been transferred. |
375 | |
445 | |
376 | aio_readahead $fh,$offset,$length, $callback->($retval) |
446 | aio_readahead $fh,$offset,$length, $callback->($retval) |
377 | "aio_readahead" populates the page cache with data from a file so |
447 | "aio_readahead" populates the page cache with data from a file so |
378 | that subsequent reads from that file will not block on disk I/O. The |
448 | that subsequent reads from that file will not block on disk I/O. The |
379 | $offset argument specifies the starting point from which data is to |
449 | $offset argument specifies the starting point from which data is to |
… | |
… | |
399 | |
469 | |
400 | Currently, the stats are always 64-bit-stats, i.e. instead of |
470 | Currently, the stats are always 64-bit-stats, i.e. instead of |
401 | returning an error when stat'ing a large file, the results will be |
471 | returning an error when stat'ing a large file, the results will be |
402 | silently truncated unless perl itself is compiled with large file |
472 | silently truncated unless perl itself is compiled with large file |
403 | support. |
473 | support. |
|
|
474 | |
|
|
475 | To help interpret the mode and dev/rdev stat values, IO::AIO offers |
|
|
476 | the following constants and functions (if not implemented, the |
|
|
477 | constants will be 0 and the functions will either "croak" or fall |
|
|
478 | back on traditional behaviour). |
|
|
479 | |
|
|
480 | "S_IFMT", "S_IFIFO", "S_IFCHR", "S_IFBLK", "S_IFLNK", "S_IFREG", |
|
|
481 | "S_IFDIR", "S_IFWHT", "S_IFSOCK", "IO::AIO::major $dev_t", |
|
|
482 | "IO::AIO::minor $dev_t", "IO::AIO::makedev $major, $minor". |
404 | |
483 | |
405 | Example: Print the length of /etc/passwd: |
484 | Example: Print the length of /etc/passwd: |
406 | |
485 | |
407 | aio_stat "/etc/passwd", sub { |
486 | aio_stat "/etc/passwd", sub { |
408 | $_[0] and die "stat failed: $!"; |
487 | $_[0] and die "stat failed: $!"; |
… | |
… | |
450 | namemax => 255, |
529 | namemax => 255, |
451 | frsize => 1024, |
530 | frsize => 1024, |
452 | fsid => 1810 |
531 | fsid => 1810 |
453 | } |
532 | } |
454 | |
533 | |
|
|
534 | Here is a (likely partial - send me updates!) list of fsid values |
|
|
535 | used by Linux - it is safe to hardcode these when $^O is "linux": |
|
|
536 | |
|
|
537 | 0x0000adf5 adfs |
|
|
538 | 0x0000adff affs |
|
|
539 | 0x5346414f afs |
|
|
540 | 0x09041934 anon-inode filesystem |
|
|
541 | 0x00000187 autofs |
|
|
542 | 0x42465331 befs |
|
|
543 | 0x1badface bfs |
|
|
544 | 0x42494e4d binfmt_misc |
|
|
545 | 0x9123683e btrfs |
|
|
546 | 0x0027e0eb cgroupfs |
|
|
547 | 0xff534d42 cifs |
|
|
548 | 0x73757245 coda |
|
|
549 | 0x012ff7b7 coh |
|
|
550 | 0x28cd3d45 cramfs |
|
|
551 | 0x453dcd28 cramfs-wend (wrong endianness) |
|
|
552 | 0x64626720 debugfs |
|
|
553 | 0x00001373 devfs |
|
|
554 | 0x00001cd1 devpts |
|
|
555 | 0x0000f15f ecryptfs |
|
|
556 | 0x00414a53 efs |
|
|
557 | 0x0000137d ext |
|
|
558 | 0x0000ef53 ext2/ext3 |
|
|
559 | 0x0000ef51 ext2 |
|
|
560 | 0x00004006 fat |
|
|
561 | 0x65735546 fuseblk |
|
|
562 | 0x65735543 fusectl |
|
|
563 | 0x0bad1dea futexfs |
|
|
564 | 0x01161970 gfs2 |
|
|
565 | 0x47504653 gpfs |
|
|
566 | 0x00004244 hfs |
|
|
567 | 0xf995e849 hpfs |
|
|
568 | 0x958458f6 hugetlbfs |
|
|
569 | 0x2bad1dea inotifyfs |
|
|
570 | 0x00009660 isofs |
|
|
571 | 0x000072b6 jffs2 |
|
|
572 | 0x3153464a jfs |
|
|
573 | 0x6b414653 k-afs |
|
|
574 | 0x0bd00bd0 lustre |
|
|
575 | 0x0000137f minix |
|
|
576 | 0x0000138f minix 30 char names |
|
|
577 | 0x00002468 minix v2 |
|
|
578 | 0x00002478 minix v2 30 char names |
|
|
579 | 0x00004d5a minix v3 |
|
|
580 | 0x19800202 mqueue |
|
|
581 | 0x00004d44 msdos |
|
|
582 | 0x0000564c novell |
|
|
583 | 0x00006969 nfs |
|
|
584 | 0x6e667364 nfsd |
|
|
585 | 0x00003434 nilfs |
|
|
586 | 0x5346544e ntfs |
|
|
587 | 0x00009fa1 openprom |
|
|
588 | 0x7461636F ocfs2 |
|
|
589 | 0x00009fa0 proc |
|
|
590 | 0x6165676c pstorefs |
|
|
591 | 0x0000002f qnx4 |
|
|
592 | 0x858458f6 ramfs |
|
|
593 | 0x52654973 reiserfs |
|
|
594 | 0x00007275 romfs |
|
|
595 | 0x67596969 rpc_pipefs |
|
|
596 | 0x73636673 securityfs |
|
|
597 | 0xf97cff8c selinux |
|
|
598 | 0x0000517b smb |
|
|
599 | 0x534f434b sockfs |
|
|
600 | 0x73717368 squashfs |
|
|
601 | 0x62656572 sysfs |
|
|
602 | 0x012ff7b6 sysv2 |
|
|
603 | 0x012ff7b5 sysv4 |
|
|
604 | 0x01021994 tmpfs |
|
|
605 | 0x15013346 udf |
|
|
606 | 0x00011954 ufs |
|
|
607 | 0x54190100 ufs byteswapped |
|
|
608 | 0x00009fa2 usbdevfs |
|
|
609 | 0x01021997 v9fs |
|
|
610 | 0xa501fcf5 vxfs |
|
|
611 | 0xabba1974 xenfs |
|
|
612 | 0x012ff7b4 xenix |
|
|
613 | 0x58465342 xfs |
|
|
614 | 0x012fd16d xia |
|
|
615 | |
455 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
616 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
456 | Works like perl's "utime" function (including the special case of |
617 | Works like perl's "utime" function (including the special case of |
457 | $atime and $mtime being undef). Fractional times are supported if |
618 | $atime and $mtime being undef). Fractional times are supported if |
458 | the underlying syscalls support them. |
619 | the underlying syscalls support them. |
459 | |
620 | |
… | |
… | |
481 | aio_chown "path", 0, undef; |
642 | aio_chown "path", 0, undef; |
482 | |
643 | |
483 | aio_truncate $fh_or_path, $offset, $callback->($status) |
644 | aio_truncate $fh_or_path, $offset, $callback->($status) |
484 | Works like truncate(2) or ftruncate(2). |
645 | Works like truncate(2) or ftruncate(2). |
485 | |
646 | |
|
|
647 | aio_allocate $fh, $mode, $offset, $len, $callback->($status) |
|
|
648 | Allocates or freed disk space according to the $mode argument. See |
|
|
649 | the linux "fallocate" docuemntation for details. |
|
|
650 | |
|
|
651 | $mode can currently be 0 or "IO::AIO::FALLOC_FL_KEEP_SIZE" to |
|
|
652 | allocate space, or "IO::AIO::FALLOC_FL_PUNCH_HOLE | |
|
|
653 | IO::AIO::FALLOC_FL_KEEP_SIZE", to deallocate a file range. |
|
|
654 | |
|
|
655 | The file system block size used by "fallocate" is presumably the |
|
|
656 | "f_bsize" returned by "statvfs". |
|
|
657 | |
|
|
658 | If "fallocate" isn't available or cannot be emulated (currently no |
|
|
659 | emulation will be attempted), passes -1 and sets $! to "ENOSYS". |
|
|
660 | |
486 | aio_chmod $fh_or_path, $mode, $callback->($status) |
661 | aio_chmod $fh_or_path, $mode, $callback->($status) |
487 | Works like perl's "chmod" function. |
662 | Works like perl's "chmod" function. |
488 | |
663 | |
489 | aio_unlink $pathname, $callback->($status) |
664 | aio_unlink $pathname, $callback->($status) |
490 | Asynchronously unlink (delete) a file and call the callback with the |
665 | Asynchronously unlink (delete) a file and call the callback with the |
491 | result code. |
666 | result code. |
492 | |
667 | |
493 | aio_mknod $path, $mode, $dev, $callback->($status) |
668 | aio_mknod $pathname, $mode, $dev, $callback->($status) |
494 | [EXPERIMENTAL] |
669 | [EXPERIMENTAL] |
495 | |
670 | |
496 | Asynchronously create a device node (or fifo). See mknod(2). |
671 | Asynchronously create a device node (or fifo). See mknod(2). |
497 | |
672 | |
498 | The only (POSIX-) portable way of calling this function is: |
673 | The only (POSIX-) portable way of calling this function is: |
499 | |
674 | |
500 | aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
675 | aio_mknod $pathname, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
|
|
676 | |
|
|
677 | See "aio_stat" for info about some potentially helpful extra |
|
|
678 | constants and functions. |
501 | |
679 | |
502 | aio_link $srcpath, $dstpath, $callback->($status) |
680 | aio_link $srcpath, $dstpath, $callback->($status) |
503 | Asynchronously create a new link to the existing object at $srcpath |
681 | Asynchronously create a new link to the existing object at $srcpath |
504 | at the path $dstpath and call the callback with the result code. |
682 | at the path $dstpath and call the callback with the result code. |
505 | |
683 | |
506 | aio_symlink $srcpath, $dstpath, $callback->($status) |
684 | aio_symlink $srcpath, $dstpath, $callback->($status) |
507 | Asynchronously create a new symbolic link to the existing object at |
685 | Asynchronously create a new symbolic link to the existing object at |
508 | $srcpath at the path $dstpath and call the callback with the result |
686 | $srcpath at the path $dstpath and call the callback with the result |
509 | code. |
687 | code. |
510 | |
688 | |
511 | aio_readlink $path, $callback->($link) |
689 | aio_readlink $pathname, $callback->($link) |
512 | Asynchronously read the symlink specified by $path and pass it to |
690 | Asynchronously read the symlink specified by $path and pass it to |
513 | the callback. If an error occurs, nothing or undef gets passed to |
691 | the callback. If an error occurs, nothing or undef gets passed to |
514 | the callback. |
692 | the callback. |
515 | |
693 | |
|
|
694 | aio_realpath $pathname, $callback->($path) |
|
|
695 | Asynchronously make the path absolute and resolve any symlinks in |
|
|
696 | $path. The resulting path only consists of directories (same as |
|
|
697 | Cwd::realpath). |
|
|
698 | |
|
|
699 | This request can be used to get the absolute path of the current |
|
|
700 | working directory by passing it a path of . (a single dot). |
|
|
701 | |
516 | aio_rename $srcpath, $dstpath, $callback->($status) |
702 | aio_rename $srcpath, $dstpath, $callback->($status) |
517 | Asynchronously rename the object at $srcpath to $dstpath, just as |
703 | Asynchronously rename the object at $srcpath to $dstpath, just as |
518 | rename(2) and call the callback with the result code. |
704 | rename(2) and call the callback with the result code. |
|
|
705 | |
|
|
706 | On systems that support the AIO::WD working directory abstraction |
|
|
707 | natively, the case "[$wd, "."]" as $srcpath is specialcased - |
|
|
708 | instead of failing, "rename" is called on the absolute path of $wd. |
519 | |
709 | |
520 | aio_mkdir $pathname, $mode, $callback->($status) |
710 | aio_mkdir $pathname, $mode, $callback->($status) |
521 | Asynchronously mkdir (create) a directory and call the callback with |
711 | Asynchronously mkdir (create) a directory and call the callback with |
522 | the result code. $mode will be modified by the umask at the time the |
712 | the result code. $mode will be modified by the umask at the time the |
523 | request is executed, so do not change your umask. |
713 | request is executed, so do not change your umask. |
524 | |
714 | |
525 | aio_rmdir $pathname, $callback->($status) |
715 | aio_rmdir $pathname, $callback->($status) |
526 | Asynchronously rmdir (delete) a directory and call the callback with |
716 | Asynchronously rmdir (delete) a directory and call the callback with |
527 | the result code. |
717 | the result code. |
528 | |
718 | |
|
|
719 | On systems that support the AIO::WD working directory abstraction |
|
|
720 | natively, the case "[$wd, "."]" is specialcased - instead of |
|
|
721 | failing, "rmdir" is called on the absolute path of $wd. |
|
|
722 | |
529 | aio_readdir $pathname, $callback->($entries) |
723 | aio_readdir $pathname, $callback->($entries) |
530 | Unlike the POSIX call of the same name, "aio_readdir" reads an |
724 | Unlike the POSIX call of the same name, "aio_readdir" reads an |
531 | entire directory (i.e. opendir + readdir + closedir). The entries |
725 | entire directory (i.e. opendir + readdir + closedir). The entries |
532 | will not be sorted, and will NOT include the "." and ".." entries. |
726 | will not be sorted, and will NOT include the "." and ".." entries. |
533 | |
727 | |
534 | The callback is passed a single argument which is either "undef" or |
728 | The callback is passed a single argument which is either "undef" or |
535 | an array-ref with the filenames. |
729 | an array-ref with the filenames. |
536 | |
730 | |
537 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
731 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
538 | Quite similar to "aio_readdir", but the $flags argument allows to |
732 | Quite similar to "aio_readdir", but the $flags argument allows one |
539 | tune behaviour and output format. In case of an error, $entries will |
733 | to tune behaviour and output format. In case of an error, $entries |
540 | be "undef". |
734 | will be "undef". |
541 | |
735 | |
542 | The flags are a combination of the following constants, ORed |
736 | The flags are a combination of the following constants, ORed |
543 | together (the flags will also be passed to the callback, possibly |
737 | together (the flags will also be passed to the callback, possibly |
544 | modified): |
738 | modified): |
545 | |
739 | |
546 | IO::AIO::READDIR_DENTS |
740 | IO::AIO::READDIR_DENTS |
547 | When this flag is off, then the callback gets an arrayref with |
741 | When this flag is off, then the callback gets an arrayref |
548 | of names only (as with "aio_readdir"), otherwise it gets an |
742 | consisting of names only (as with "aio_readdir"), otherwise it |
549 | arrayref with "[$name, $type, $inode]" arrayrefs, each |
743 | gets an arrayref with "[$name, $type, $inode]" arrayrefs, each |
550 | describing a single directory entry in more detail. |
744 | describing a single directory entry in more detail. |
551 | |
745 | |
552 | $name is the name of the entry. |
746 | $name is the name of the entry. |
553 | |
747 | |
554 | $type is one of the "IO::AIO::DT_xxx" constants: |
748 | $type is one of the "IO::AIO::DT_xxx" constants: |
… | |
… | |
567 | unspecified content on systems that do not deliver the inode |
761 | unspecified content on systems that do not deliver the inode |
568 | information. |
762 | information. |
569 | |
763 | |
570 | IO::AIO::READDIR_DIRS_FIRST |
764 | IO::AIO::READDIR_DIRS_FIRST |
571 | When this flag is set, then the names will be returned in an |
765 | When this flag is set, then the names will be returned in an |
572 | order where likely directories come first. This is useful when |
766 | order where likely directories come first, in optimal stat |
573 | you need to quickly find directories, or you want to find all |
767 | order. This is useful when you need to quickly find directories, |
574 | directories while avoiding to stat() each entry. |
768 | or you want to find all directories while avoiding to stat() |
|
|
769 | each entry. |
575 | |
770 | |
576 | If the system returns type information in readdir, then this is |
771 | If the system returns type information in readdir, then this is |
577 | used to find directories directly. Otherwise, likely directories |
772 | used to find directories directly. Otherwise, likely directories |
578 | are files beginning with ".", or otherwise files with no dots, |
773 | are names beginning with ".", or otherwise names with no dots, |
579 | of which files with short names are tried first. |
774 | of which names with short names are tried first. |
580 | |
775 | |
581 | IO::AIO::READDIR_STAT_ORDER |
776 | IO::AIO::READDIR_STAT_ORDER |
582 | When this flag is set, then the names will be returned in an |
777 | When this flag is set, then the names will be returned in an |
583 | order suitable for stat()'ing each one. That is, when you plan |
778 | order suitable for stat()'ing each one. That is, when you plan |
584 | to stat() all files in the given directory, then the returned |
779 | to stat() all files in the given directory, then the returned |
… | |
… | |
589 | optimal stat order. |
784 | optimal stat order. |
590 | |
785 | |
591 | IO::AIO::READDIR_FOUND_UNKNOWN |
786 | IO::AIO::READDIR_FOUND_UNKNOWN |
592 | This flag should not be set when calling "aio_readdirx". |
787 | This flag should not be set when calling "aio_readdirx". |
593 | Instead, it is being set by "aio_readdirx", when any of the |
788 | Instead, it is being set by "aio_readdirx", when any of the |
594 | $type's found were "IO::AIO::DT_UNKNOWN". The absense of this |
789 | $type's found were "IO::AIO::DT_UNKNOWN". The absence of this |
595 | flag therefore indicates that all $type's are known, which can |
790 | flag therefore indicates that all $type's are known, which can |
596 | be used to speed up some algorithms. |
791 | be used to speed up some algorithms. |
597 | |
792 | |
598 | aio_load $path, $data, $callback->($status) |
793 | aio_load $pathname, $data, $callback->($status) |
599 | This is a composite request that tries to fully load the given file |
794 | This is a composite request that tries to fully load the given file |
600 | into memory. Status is the same as with aio_read. |
795 | into memory. Status is the same as with aio_read. |
601 | |
796 | |
602 | aio_copy $srcpath, $dstpath, $callback->($status) |
797 | aio_copy $srcpath, $dstpath, $callback->($status) |
603 | Try to copy the *file* (directories not supported as either source |
798 | Try to copy the *file* (directories not supported as either source |
… | |
… | |
620 | |
815 | |
621 | This is a composite request that tries to rename(2) the file first; |
816 | This is a composite request that tries to rename(2) the file first; |
622 | if rename fails with "EXDEV", it copies the file with "aio_copy" |
817 | if rename fails with "EXDEV", it copies the file with "aio_copy" |
623 | and, if that is successful, unlinks the $srcpath. |
818 | and, if that is successful, unlinks the $srcpath. |
624 | |
819 | |
625 | aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
820 | aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) |
626 | Scans a directory (similar to "aio_readdir") but additionally tries |
821 | Scans a directory (similar to "aio_readdir") but additionally tries |
627 | to efficiently separate the entries of directory $path into two sets |
822 | to efficiently separate the entries of directory $path into two sets |
628 | of names, directories you can recurse into (directories), and ones |
823 | of names, directories you can recurse into (directories), and ones |
629 | you cannot recurse into (everything else, including symlinks to |
824 | you cannot recurse into (everything else, including symlinks to |
630 | directories). |
825 | directories). |
… | |
… | |
663 | Then entries will be sorted into likely directories a non-initial |
858 | Then entries will be sorted into likely directories a non-initial |
664 | dot currently) and likely non-directories (see "aio_readdirx"). Then |
859 | dot currently) and likely non-directories (see "aio_readdirx"). Then |
665 | every entry plus an appended "/." will be "stat"'ed, likely |
860 | every entry plus an appended "/." will be "stat"'ed, likely |
666 | directories first, in order of their inode numbers. If that |
861 | directories first, in order of their inode numbers. If that |
667 | succeeds, it assumes that the entry is a directory or a symlink to |
862 | succeeds, it assumes that the entry is a directory or a symlink to |
668 | directory (which will be checked seperately). This is often faster |
863 | directory (which will be checked separately). This is often faster |
669 | than stat'ing the entry itself because filesystems might detect the |
864 | than stat'ing the entry itself because filesystems might detect the |
670 | type of the entry without reading the inode data (e.g. ext2fs |
865 | type of the entry without reading the inode data (e.g. ext2fs |
671 | filetype feature), even on systems that cannot return the filetype |
866 | filetype feature), even on systems that cannot return the filetype |
672 | information on readdir. |
867 | information on readdir. |
673 | |
868 | |
… | |
… | |
679 | |
874 | |
680 | It will also likely work on non-POSIX filesystems with reduced |
875 | It will also likely work on non-POSIX filesystems with reduced |
681 | efficiency as those tend to return 0 or 1 as link counts, which |
876 | efficiency as those tend to return 0 or 1 as link counts, which |
682 | disables the directory counting heuristic. |
877 | disables the directory counting heuristic. |
683 | |
878 | |
684 | aio_rmtree $path, $callback->($status) |
879 | aio_rmtree $pathname, $callback->($status) |
685 | Delete a directory tree starting (and including) $path, return the |
880 | Delete a directory tree starting (and including) $path, return the |
686 | status of the final "rmdir" only. This is a composite request that |
881 | status of the final "rmdir" only. This is a composite request that |
687 | uses "aio_scandir" to recurse into and rmdir directories, and unlink |
882 | uses "aio_scandir" to recurse into and rmdir directories, and unlink |
688 | everything else. |
883 | everything else. |
689 | |
884 | |
… | |
… | |
698 | Asynchronously call fdatasync on the given filehandle and call the |
893 | Asynchronously call fdatasync on the given filehandle and call the |
699 | callback with the fdatasync result code. |
894 | callback with the fdatasync result code. |
700 | |
895 | |
701 | If this call isn't available because your OS lacks it or it couldn't |
896 | If this call isn't available because your OS lacks it or it couldn't |
702 | be detected, it will be emulated by calling "fsync" instead. |
897 | be detected, it will be emulated by calling "fsync" instead. |
|
|
898 | |
|
|
899 | aio_syncfs $fh, $callback->($status) |
|
|
900 | Asynchronously call the syncfs syscall to sync the filesystem |
|
|
901 | associated to the given filehandle and call the callback with the |
|
|
902 | syncfs result code. If syncfs is not available, calls sync(), but |
|
|
903 | returns -1 and sets errno to "ENOSYS" nevertheless. |
703 | |
904 | |
704 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
905 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
705 | Sync the data portion of the file specified by $offset and $length |
906 | Sync the data portion of the file specified by $offset and $length |
706 | to disk (but NOT the metadata), by calling the Linux-specific |
907 | to disk (but NOT the metadata), by calling the Linux-specific |
707 | sync_file_range call. If sync_file_range is not available or it |
908 | sync_file_range call. If sync_file_range is not available or it |
… | |
… | |
711 | "IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE", |
912 | "IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE", |
712 | "IO::AIO::SYNC_FILE_RANGE_WRITE" and |
913 | "IO::AIO::SYNC_FILE_RANGE_WRITE" and |
713 | "IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER": refer to the sync_file_range |
914 | "IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER": refer to the sync_file_range |
714 | manpage for details. |
915 | manpage for details. |
715 | |
916 | |
716 | aio_pathsync $path, $callback->($status) |
917 | aio_pathsync $pathname, $callback->($status) |
717 | This request tries to open, fsync and close the given path. This is |
918 | This request tries to open, fsync and close the given path. This is |
718 | a composite request intended to sync directories after directory |
919 | a composite request intended to sync directories after directory |
719 | operations (E.g. rename). This might not work on all operating |
920 | operations (E.g. rename). This might not work on all operating |
720 | systems or have any specific effect, but usually it makes sure that |
921 | systems or have any specific effect, but usually it makes sure that |
721 | directory changes get written to disc. It works for anything that |
922 | directory changes get written to disc. It works for anything that |
… | |
… | |
748 | |
949 | |
749 | It touches (reads or writes) all memory pages in the specified range |
950 | It touches (reads or writes) all memory pages in the specified range |
750 | inside the scalar. All caveats and parameters are the same as for |
951 | inside the scalar. All caveats and parameters are the same as for |
751 | "aio_msync", above, except for flags, which must be either 0 (which |
952 | "aio_msync", above, except for flags, which must be either 0 (which |
752 | reads all pages and ensures they are instantiated) or |
953 | reads all pages and ensures they are instantiated) or |
753 | "IO::AIO::MT_MODIFY", which modifies the memory page s(by reading |
954 | "IO::AIO::MT_MODIFY", which modifies the memory pages (by reading |
754 | and writing an octet from it, which dirties the page). |
955 | and writing an octet from it, which dirties the page). |
|
|
956 | |
|
|
957 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
|
|
958 | This is a rather advanced IO::AIO call, which works best on |
|
|
959 | mmap(2)ed scalars. |
|
|
960 | |
|
|
961 | It reads in all the pages of the underlying storage into memory (if |
|
|
962 | any) and locks them, so they are not getting swapped/paged out or |
|
|
963 | removed. |
|
|
964 | |
|
|
965 | If $length is undefined, then the scalar will be locked till the |
|
|
966 | end. |
|
|
967 | |
|
|
968 | On systems that do not implement "mlock", this function returns -1 |
|
|
969 | and sets errno to "ENOSYS". |
|
|
970 | |
|
|
971 | Note that the corresponding "munlock" is synchronous and is |
|
|
972 | documented under "MISCELLANEOUS FUNCTIONS". |
|
|
973 | |
|
|
974 | Example: open a file, mmap and mlock it - both will be undone when |
|
|
975 | $data gets destroyed. |
|
|
976 | |
|
|
977 | open my $fh, "<", $path or die "$path: $!"; |
|
|
978 | my $data; |
|
|
979 | IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh; |
|
|
980 | aio_mlock $data; # mlock in background |
|
|
981 | |
|
|
982 | aio_mlockall $flags, $callback->($status) |
|
|
983 | Calls the "mlockall" function with the given $flags (a combination |
|
|
984 | of "IO::AIO::MCL_CURRENT" and "IO::AIO::MCL_FUTURE"). |
|
|
985 | |
|
|
986 | On systems that do not implement "mlockall", this function returns |
|
|
987 | -1 and sets errno to "ENOSYS". |
|
|
988 | |
|
|
989 | Note that the corresponding "munlockall" is synchronous and is |
|
|
990 | documented under "MISCELLANEOUS FUNCTIONS". |
|
|
991 | |
|
|
992 | Example: asynchronously lock all current and future pages into |
|
|
993 | memory. |
|
|
994 | |
|
|
995 | aio_mlockall IO::AIO::MCL_FUTURE; |
|
|
996 | |
|
|
997 | aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents) |
|
|
998 | Queries the extents of the given file (by calling the Linux "FIEMAP" |
|
|
999 | ioctl, see <http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for |
|
|
1000 | details). If the ioctl is not available on your OS, then this |
|
|
1001 | request will fail with "ENOSYS". |
|
|
1002 | |
|
|
1003 | $start is the starting offset to query extents for, $length is the |
|
|
1004 | size of the range to query - if it is "undef", then the whole file |
|
|
1005 | will be queried. |
|
|
1006 | |
|
|
1007 | $flags is a combination of flags ("IO::AIO::FIEMAP_FLAG_SYNC" or |
|
|
1008 | "IO::AIO::FIEMAP_FLAG_XATTR" - "IO::AIO::FIEMAP_FLAGS_COMPAT" is |
|
|
1009 | also exported), and is normally 0 or "IO::AIO::FIEMAP_FLAG_SYNC" to |
|
|
1010 | query the data portion. |
|
|
1011 | |
|
|
1012 | $count is the maximum number of extent records to return. If it is |
|
|
1013 | "undef", then IO::AIO queries all extents of the range. As a very |
|
|
1014 | special case, if it is 0, then the callback receives the number of |
|
|
1015 | extents instead of the extents themselves (which is unreliable, see |
|
|
1016 | below). |
|
|
1017 | |
|
|
1018 | If an error occurs, the callback receives no arguments. The special |
|
|
1019 | "errno" value "IO::AIO::EBADR" is available to test for flag errors. |
|
|
1020 | |
|
|
1021 | Otherwise, the callback receives an array reference with extent |
|
|
1022 | structures. Each extent structure is an array reference itself, with |
|
|
1023 | the following members: |
|
|
1024 | |
|
|
1025 | [$logical, $physical, $length, $flags] |
|
|
1026 | |
|
|
1027 | Flags is any combination of the following flag values (typically |
|
|
1028 | either 0 or "IO::AIO::FIEMAP_EXTENT_LAST" (1)): |
|
|
1029 | |
|
|
1030 | "IO::AIO::FIEMAP_EXTENT_LAST", "IO::AIO::FIEMAP_EXTENT_UNKNOWN", |
|
|
1031 | "IO::AIO::FIEMAP_EXTENT_DELALLOC", "IO::AIO::FIEMAP_EXTENT_ENCODED", |
|
|
1032 | "IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED", |
|
|
1033 | "IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED", |
|
|
1034 | "IO::AIO::FIEMAP_EXTENT_DATA_INLINE", |
|
|
1035 | "IO::AIO::FIEMAP_EXTENT_DATA_TAIL", |
|
|
1036 | "IO::AIO::FIEMAP_EXTENT_UNWRITTEN", "IO::AIO::FIEMAP_EXTENT_MERGED" |
|
|
1037 | or "IO::AIO::FIEMAP_EXTENT_SHARED". |
|
|
1038 | |
|
|
1039 | At the time of this writing (Linux 3.2), this requets is unreliable |
|
|
1040 | unless $count is "undef", as the kernel has all sorts of bugs |
|
|
1041 | preventing it to return all extents of a range for files with large |
|
|
1042 | number of extents. The code works around all these issues if $count |
|
|
1043 | is undef. |
755 | |
1044 | |
756 | aio_group $callback->(...) |
1045 | aio_group $callback->(...) |
757 | This is a very special aio request: Instead of doing something, it |
1046 | This is a very special aio request: Instead of doing something, it |
758 | is a container for other aio requests, which is useful if you want |
1047 | is a container for other aio requests, which is useful if you want |
759 | to bundle many requests into a single, composite, request with a |
1048 | to bundle many requests into a single, composite, request with a |
… | |
… | |
793 | While it is theoretically handy to have simple I/O scheduling |
1082 | While it is theoretically handy to have simple I/O scheduling |
794 | requests like sleep and file handle readable/writable, the overhead |
1083 | requests like sleep and file handle readable/writable, the overhead |
795 | this creates is immense (it blocks a thread for a long time) so do |
1084 | this creates is immense (it blocks a thread for a long time) so do |
796 | not use this function except to put your application under |
1085 | not use this function except to put your application under |
797 | artificial I/O pressure. |
1086 | artificial I/O pressure. |
|
|
1087 | |
|
|
1088 | IO::AIO::WD - multiple working directories |
|
|
1089 | Your process only has one current working directory, which is used by |
|
|
1090 | all threads. This makes it hard to use relative paths (some other |
|
|
1091 | component could call "chdir" at any time, and it is hard to control when |
|
|
1092 | the path will be used by IO::AIO). |
|
|
1093 | |
|
|
1094 | One solution for this is to always use absolute paths. This usually |
|
|
1095 | works, but can be quite slow (the kernel has to walk the whole path on |
|
|
1096 | every access), and can also be a hassle to implement. |
|
|
1097 | |
|
|
1098 | Newer POSIX systems have a number of functions (openat, fdopendir, |
|
|
1099 | futimensat and so on) that make it possible to specify working |
|
|
1100 | directories per operation. |
|
|
1101 | |
|
|
1102 | For portability, and because the clowns who "designed", or shall I |
|
|
1103 | write, perpetrated this new interface were obviously half-drunk, this |
|
|
1104 | abstraction cannot be perfect, though. |
|
|
1105 | |
|
|
1106 | IO::AIO allows you to convert directory paths into a so-called |
|
|
1107 | IO::AIO::WD object. This object stores the canonicalised, absolute |
|
|
1108 | version of the path, and on systems that allow it, also a directory file |
|
|
1109 | descriptor. |
|
|
1110 | |
|
|
1111 | Everywhere where a pathname is accepted by IO::AIO (e.g. in "aio_stat" |
|
|
1112 | or "aio_unlink"), one can specify an array reference with an IO::AIO::WD |
|
|
1113 | object and a pathname instead (or the IO::AIO::WD object alone, which |
|
|
1114 | gets interpreted as "[$wd, "."]"). If the pathname is absolute, the |
|
|
1115 | IO::AIO::WD object is ignored, otherwise the pathname is resolved |
|
|
1116 | relative to that IO::AIO::WD object. |
|
|
1117 | |
|
|
1118 | For example, to get a wd object for /etc and then stat passwd inside, |
|
|
1119 | you would write: |
|
|
1120 | |
|
|
1121 | aio_wd "/etc", sub { |
|
|
1122 | my $etcdir = shift; |
|
|
1123 | |
|
|
1124 | # although $etcdir can be undef on error, there is generally no reason |
|
|
1125 | # to check for errors here, as aio_stat will fail with ENOENT |
|
|
1126 | # when $etcdir is undef. |
|
|
1127 | |
|
|
1128 | aio_stat [$etcdir, "passwd"], sub { |
|
|
1129 | # yay |
|
|
1130 | }; |
|
|
1131 | }; |
|
|
1132 | |
|
|
1133 | That "aio_wd" is a request and not a normal function shows that creating |
|
|
1134 | an IO::AIO::WD object is itself a potentially blocking operation, which |
|
|
1135 | is why it is done asynchronously. |
|
|
1136 | |
|
|
1137 | To stat the directory obtained with "aio_wd" above, one could write |
|
|
1138 | either of the following three request calls: |
|
|
1139 | |
|
|
1140 | aio_lstat "/etc" , sub { ... # pathname as normal string |
|
|
1141 | aio_lstat [$wd, "."], sub { ... # "." relative to $wd (i.e. $wd itself) |
|
|
1142 | aio_lstat $wd , sub { ... # shorthand for the previous |
|
|
1143 | |
|
|
1144 | As with normal pathnames, IO::AIO keeps a copy of the working directory |
|
|
1145 | object and the pathname string, so you could write the following without |
|
|
1146 | causing any issues due to $path getting reused: |
|
|
1147 | |
|
|
1148 | my $path = [$wd, undef]; |
|
|
1149 | |
|
|
1150 | for my $name (qw(abc def ghi)) { |
|
|
1151 | $path->[1] = $name; |
|
|
1152 | aio_stat $path, sub { |
|
|
1153 | # ... |
|
|
1154 | }; |
|
|
1155 | } |
|
|
1156 | |
|
|
1157 | There are some caveats: when directories get renamed (or deleted), the |
|
|
1158 | pathname string doesn't change, so will point to the new directory (or |
|
|
1159 | nowhere at all), while the directory fd, if available on the system, |
|
|
1160 | will still point to the original directory. Most functions accepting a |
|
|
1161 | pathname will use the directory fd on newer systems, and the string on |
|
|
1162 | older systems. Some functions (such as realpath) will always rely on the |
|
|
1163 | string form of the pathname. |
|
|
1164 | |
|
|
1165 | So this functionality is mainly useful to get some protection against |
|
|
1166 | "chdir", to easily get an absolute path out of a relative path for |
|
|
1167 | future reference, and to speed up doing many operations in the same |
|
|
1168 | directory (e.g. when stat'ing all files in a directory). |
|
|
1169 | |
|
|
1170 | The following functions implement this working directory abstraction: |
|
|
1171 | |
|
|
1172 | aio_wd $pathname, $callback->($wd) |
|
|
1173 | Asynchonously canonicalise the given pathname and convert it to an |
|
|
1174 | IO::AIO::WD object representing it. If possible and supported on the |
|
|
1175 | system, also open a directory fd to speed up pathname resolution |
|
|
1176 | relative to this working directory. |
|
|
1177 | |
|
|
1178 | If something goes wrong, then "undef" is passwd to the callback |
|
|
1179 | instead of a working directory object and $! is set appropriately. |
|
|
1180 | Since passing "undef" as working directory component of a pathname |
|
|
1181 | fails the request with "ENOENT", there is often no need for error |
|
|
1182 | checking in the "aio_wd" callback, as future requests using the |
|
|
1183 | value will fail in the expected way. |
|
|
1184 | |
|
|
1185 | IO::AIO::CWD |
|
|
1186 | This is a compiletime constant (object) that represents the process |
|
|
1187 | current working directory. |
|
|
1188 | |
|
|
1189 | Specifying this object as working directory object for a pathname is |
|
|
1190 | as if the pathname would be specified directly, without a directory |
|
|
1191 | object. For example, these calls are functionally identical: |
|
|
1192 | |
|
|
1193 | aio_stat "somefile", sub { ... }; |
|
|
1194 | aio_stat [IO::AIO::CWD, "somefile"], sub { ... }; |
|
|
1195 | |
|
|
1196 | To recover the path associated with an IO::AIO::WD object, you can use |
|
|
1197 | "aio_realpath": |
|
|
1198 | |
|
|
1199 | aio_realpath $wd, sub { |
|
|
1200 | warn "path is $_[0]\n"; |
|
|
1201 | }; |
|
|
1202 | |
|
|
1203 | Currently, "aio_statvfs" always, and "aio_rename" and "aio_rmdir" |
|
|
1204 | sometimes, fall back to using an absolue path. |
798 | |
1205 | |
799 | IO::AIO::REQ CLASS |
1206 | IO::AIO::REQ CLASS |
800 | All non-aggregate "aio_*" functions return an object of this class when |
1207 | All non-aggregate "aio_*" functions return an object of this class when |
801 | called in non-void context. |
1208 | called in non-void context. |
802 | |
1209 | |
… | |
… | |
902 | Sets a feeder/generator on this group: every group can have an |
1309 | Sets a feeder/generator on this group: every group can have an |
903 | attached generator that generates requests if idle. The idea behind |
1310 | attached generator that generates requests if idle. The idea behind |
904 | this is that, although you could just queue as many requests as you |
1311 | this is that, although you could just queue as many requests as you |
905 | want in a group, this might starve other requests for a potentially |
1312 | want in a group, this might starve other requests for a potentially |
906 | long time. For example, "aio_scandir" might generate hundreds of |
1313 | long time. For example, "aio_scandir" might generate hundreds of |
907 | thousands "aio_stat" requests, delaying any later requests for a |
1314 | thousands of "aio_stat" requests, delaying any later requests for a |
908 | long time. |
1315 | long time. |
909 | |
1316 | |
910 | To avoid this, and allow incremental generation of requests, you can |
1317 | To avoid this, and allow incremental generation of requests, you can |
911 | instead a group and set a feeder on it that generates those |
1318 | instead a group and set a feeder on it that generates those |
912 | requests. The feed callback will be called whenever there are few |
1319 | requests. The feed callback will be called whenever there are few |
… | |
… | |
954 | results. |
1361 | results. |
955 | |
1362 | |
956 | See "poll_cb" for an example. |
1363 | See "poll_cb" for an example. |
957 | |
1364 | |
958 | IO::AIO::poll_cb |
1365 | IO::AIO::poll_cb |
959 | Process some outstanding events on the result pipe. You have to call |
1366 | Process some requests that have reached the result phase (i.e. they |
960 | this regularly. Returns 0 if all events could be processed, or -1 if |
1367 | have been executed but the results are not yet reported). You have |
961 | it returned earlier for whatever reason. Returns immediately when no |
1368 | to call this "regularly" to finish outstanding requests. |
962 | events are outstanding. The amount of events processed depends on |
|
|
963 | the settings of "IO::AIO::max_poll_req" and |
|
|
964 | "IO::AIO::max_poll_time". |
|
|
965 | |
1369 | |
|
|
1370 | Returns 0 if all events could be processed (or there were no events |
|
|
1371 | to process), or -1 if it returned earlier for whatever reason. |
|
|
1372 | Returns immediately when no events are outstanding. The amount of |
|
|
1373 | events processed depends on the settings of "IO::AIO::max_poll_req", |
|
|
1374 | "IO::AIO::max_poll_time" and "IO::AIO::max_outstanding". |
|
|
1375 | |
966 | If not all requests were processed for whatever reason, the |
1376 | If not all requests were processed for whatever reason, the poll |
967 | filehandle will still be ready when "poll_cb" returns, so normally |
1377 | file descriptor will still be ready when "poll_cb" returns, so |
968 | you don't have to do anything special to have it called later. |
1378 | normally you don't have to do anything special to have it called |
|
|
1379 | later. |
|
|
1380 | |
|
|
1381 | Apart from calling "IO::AIO::poll_cb" when the event filehandle |
|
|
1382 | becomes ready, it can be beneficial to call this function from loops |
|
|
1383 | which submit a lot of requests, to make sure the results get |
|
|
1384 | processed when they become available and not just when the loop is |
|
|
1385 | finished and the event loop takes over again. This function returns |
|
|
1386 | very fast when there are no outstanding requests. |
969 | |
1387 | |
970 | Example: Install an Event watcher that automatically calls |
1388 | Example: Install an Event watcher that automatically calls |
971 | IO::AIO::poll_cb with high priority (more examples can be found in |
1389 | IO::AIO::poll_cb with high priority (more examples can be found in |
972 | the SYNOPSIS section, at the top of this document): |
1390 | the SYNOPSIS section, at the top of this document): |
973 | |
1391 | |
974 | Event->io (fd => IO::AIO::poll_fileno, |
1392 | Event->io (fd => IO::AIO::poll_fileno, |
975 | poll => 'r', async => 1, |
1393 | poll => 'r', async => 1, |
976 | cb => \&IO::AIO::poll_cb); |
1394 | cb => \&IO::AIO::poll_cb); |
977 | |
1395 | |
978 | IO::AIO::poll_wait |
1396 | IO::AIO::poll_wait |
979 | If there are any outstanding requests and none of them in the result |
1397 | Wait until either at least one request is in the result phase or no |
980 | phase, wait till the result filehandle becomes ready for reading |
1398 | requests are outstanding anymore. |
981 | (simply does a "select" on the filehandle. This is useful if you |
1399 | |
982 | want to synchronously wait for some requests to finish). |
1400 | This is useful if you want to synchronously wait for some requests |
|
|
1401 | to become ready, without actually handling them. |
983 | |
1402 | |
984 | See "nreqs" for an example. |
1403 | See "nreqs" for an example. |
985 | |
1404 | |
986 | IO::AIO::poll |
1405 | IO::AIO::poll |
987 | Waits until some requests have been handled. |
1406 | Waits until some requests have been handled. |
… | |
… | |
1067 | |
1486 | |
1068 | Under normal circumstances you don't need to call this function. |
1487 | Under normal circumstances you don't need to call this function. |
1069 | |
1488 | |
1070 | IO::AIO::max_idle $nthreads |
1489 | IO::AIO::max_idle $nthreads |
1071 | Limit the number of threads (default: 4) that are allowed to idle |
1490 | Limit the number of threads (default: 4) that are allowed to idle |
1072 | (i.e., threads that did not get a request to process within 10 |
1491 | (i.e., threads that did not get a request to process within the idle |
1073 | seconds). That means if a thread becomes idle while $nthreads other |
1492 | timeout (default: 10 seconds). That means if a thread becomes idle |
1074 | threads are also idle, it will free its resources and exit. |
1493 | while $nthreads other threads are also idle, it will free its |
|
|
1494 | resources and exit. |
1075 | |
1495 | |
1076 | This is useful when you allow a large number of threads (e.g. 100 or |
1496 | This is useful when you allow a large number of threads (e.g. 100 or |
1077 | 1000) to allow for extremely high load situations, but want to free |
1497 | 1000) to allow for extremely high load situations, but want to free |
1078 | resources under normal circumstances (1000 threads can easily |
1498 | resources under normal circumstances (1000 threads can easily |
1079 | consume 30MB of RAM). |
1499 | consume 30MB of RAM). |
1080 | |
1500 | |
1081 | The default is probably ok in most situations, especially if thread |
1501 | The default is probably ok in most situations, especially if thread |
1082 | creation is fast. If thread creation is very slow on your system you |
1502 | creation is fast. If thread creation is very slow on your system you |
1083 | might want to use larger values. |
1503 | might want to use larger values. |
1084 | |
1504 | |
|
|
1505 | IO::AIO::idle_timeout $seconds |
|
|
1506 | Sets the minimum idle timeout (default 10) after which worker |
|
|
1507 | threads are allowed to exit. SEe "IO::AIO::max_idle". |
|
|
1508 | |
1085 | IO::AIO::max_outstanding $maxreqs |
1509 | IO::AIO::max_outstanding $maxreqs |
|
|
1510 | Sets the maximum number of outstanding requests to $nreqs. If you do |
|
|
1511 | queue up more than this number of requests, the next call to |
|
|
1512 | "IO::AIO::poll_cb" (and other functions calling "poll_cb", such as |
|
|
1513 | "IO::AIO::flush" or "IO::AIO::poll") will block until the limit is |
|
|
1514 | no longer exceeded. |
|
|
1515 | |
|
|
1516 | In other words, this setting does not enforce a queue limit, but can |
|
|
1517 | be used to make poll functions block if the limit is exceeded. |
|
|
1518 | |
1086 | This is a very bad function to use in interactive programs because |
1519 | This is a very bad function to use in interactive programs because |
1087 | it blocks, and a bad way to reduce concurrency because it is |
1520 | it blocks, and a bad way to reduce concurrency because it is |
1088 | inexact: Better use an "aio_group" together with a feed callback. |
1521 | inexact: Better use an "aio_group" together with a feed callback. |
1089 | |
1522 | |
1090 | Sets the maximum number of outstanding requests to $nreqs. If you do |
1523 | It's main use is in scripts without an event loop - when you want to |
1091 | queue up more than this number of requests, the next call to the |
1524 | stat a lot of files, you can write somehting like this: |
1092 | "poll_cb" (and "poll_some" and other functions calling "poll_cb") |
|
|
1093 | function will block until the limit is no longer exceeded. |
|
|
1094 | |
1525 | |
1095 | The default value is very large, so there is no practical limit on |
1526 | IO::AIO::max_outstanding 32; |
|
|
1527 | |
|
|
1528 | for my $path (...) { |
|
|
1529 | aio_stat $path , ...; |
|
|
1530 | IO::AIO::poll_cb; |
|
|
1531 | } |
|
|
1532 | |
|
|
1533 | IO::AIO::flush; |
|
|
1534 | |
|
|
1535 | The call to "poll_cb" inside the loop will normally return |
|
|
1536 | instantly, but as soon as more thna 32 reqeusts are in-flight, it |
|
|
1537 | will block until some requests have been handled. This keeps the |
|
|
1538 | loop from pushing a large number of "aio_stat" requests onto the |
|
|
1539 | queue. |
|
|
1540 | |
|
|
1541 | The default value for "max_outstanding" is very large, so there is |
1096 | the number of outstanding requests. |
1542 | no practical limit on the number of outstanding requests. |
1097 | |
|
|
1098 | You can still queue as many requests as you want. Therefore, |
|
|
1099 | "max_outstanding" is mainly useful in simple scripts (with low |
|
|
1100 | values) or as a stop gap to shield against fatal memory overflow |
|
|
1101 | (with large values). |
|
|
1102 | |
1543 | |
1103 | STATISTICAL INFORMATION |
1544 | STATISTICAL INFORMATION |
1104 | IO::AIO::nreqs |
1545 | IO::AIO::nreqs |
1105 | Returns the number of requests currently in the ready, execute or |
1546 | Returns the number of requests currently in the ready, execute or |
1106 | pending states (i.e. for which their callback has not been invoked |
1547 | pending states (i.e. for which their callback has not been invoked |
… | |
… | |
1130 | set to non-blocking operations). |
1571 | set to non-blocking operations). |
1131 | |
1572 | |
1132 | Returns the number of bytes copied, or -1 on error. |
1573 | Returns the number of bytes copied, or -1 on error. |
1133 | |
1574 | |
1134 | IO::AIO::fadvise $fh, $offset, $len, $advice |
1575 | IO::AIO::fadvise $fh, $offset, $len, $advice |
1135 | Simply calls the "posix_fadvise" function (see it's manpage for |
1576 | Simply calls the "posix_fadvise" function (see its manpage for |
1136 | details). The following advice constants are avaiable: |
1577 | details). The following advice constants are available: |
1137 | "IO::AIO::FADV_NORMAL", "IO::AIO::FADV_SEQUENTIAL", |
1578 | "IO::AIO::FADV_NORMAL", "IO::AIO::FADV_SEQUENTIAL", |
1138 | "IO::AIO::FADV_RANDOM", "IO::AIO::FADV_NOREUSE", |
1579 | "IO::AIO::FADV_RANDOM", "IO::AIO::FADV_NOREUSE", |
1139 | "IO::AIO::FADV_WILLNEED", "IO::AIO::FADV_DONTNEED". |
1580 | "IO::AIO::FADV_WILLNEED", "IO::AIO::FADV_DONTNEED". |
1140 | |
1581 | |
1141 | On systems that do not implement "posix_fadvise", this function |
1582 | On systems that do not implement "posix_fadvise", this function |
1142 | returns ENOSYS, otherwise the return value of "posix_fadvise". |
1583 | returns ENOSYS, otherwise the return value of "posix_fadvise". |
1143 | |
1584 | |
|
|
1585 | IO::AIO::madvise $scalar, $offset, $len, $advice |
|
|
1586 | Simply calls the "posix_madvise" function (see its manpage for |
|
|
1587 | details). The following advice constants are available: |
|
|
1588 | "IO::AIO::MADV_NORMAL", "IO::AIO::MADV_SEQUENTIAL", |
|
|
1589 | "IO::AIO::MADV_RANDOM", "IO::AIO::MADV_WILLNEED", |
|
|
1590 | "IO::AIO::MADV_DONTNEED". |
|
|
1591 | |
|
|
1592 | On systems that do not implement "posix_madvise", this function |
|
|
1593 | returns ENOSYS, otherwise the return value of "posix_madvise". |
|
|
1594 | |
|
|
1595 | IO::AIO::mprotect $scalar, $offset, $len, $protect |
|
|
1596 | Simply calls the "mprotect" function on the preferably AIO::mmap'ed |
|
|
1597 | $scalar (see its manpage for details). The following protect |
|
|
1598 | constants are available: "IO::AIO::PROT_NONE", "IO::AIO::PROT_READ", |
|
|
1599 | "IO::AIO::PROT_WRITE", "IO::AIO::PROT_EXEC". |
|
|
1600 | |
|
|
1601 | On systems that do not implement "mprotect", this function returns |
|
|
1602 | ENOSYS, otherwise the return value of "mprotect". |
|
|
1603 | |
1144 | IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] |
1604 | IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] |
1145 | Memory-maps a file (or anonymous memory range) and attaches it to |
1605 | Memory-maps a file (or anonymous memory range) and attaches it to |
1146 | the given $scalar, which will act like a string scalar. |
1606 | the given $scalar, which will act like a string scalar. Returns true |
|
|
1607 | on success, and false otherwise. |
1147 | |
1608 | |
1148 | The only operations allowed on the scalar are "substr"/"vec" that |
1609 | The only operations allowed on the scalar are "substr"/"vec" that |
1149 | don't change the string length, and most read-only operations such |
1610 | don't change the string length, and most read-only operations such |
1150 | as copying it or searching it with regexes and so on. |
1611 | as copying it or searching it with regexes and so on. |
1151 | |
1612 | |
… | |
… | |
1192 | my $fast_md5 = md5 $data; |
1653 | my $fast_md5 = md5 $data; |
1193 | |
1654 | |
1194 | IO::AIO::munmap $scalar |
1655 | IO::AIO::munmap $scalar |
1195 | Removes a previous mmap and undefines the $scalar. |
1656 | Removes a previous mmap and undefines the $scalar. |
1196 | |
1657 | |
1197 | IO::AIO::mlockall $flags |
1658 | IO::AIO::munlock $scalar, $offset = 0, $length = undef |
1198 | Calls the "mlockall" function with the given $flags (a combination |
1659 | Calls the "munlock" function, undoing the effects of a previous |
1199 | of "IO::AIO::MCL_CURRENT" and "IO::AIO::MCL__FUTURE"). |
1660 | "aio_mlock" call (see its description for details). |
1200 | |
|
|
1201 | On systems that do not implement "mlockall", this function returns |
|
|
1202 | ENOSYS, otherwise the return value of "mlockall". |
|
|
1203 | |
1661 | |
1204 | IO::AIO::munlockall |
1662 | IO::AIO::munlockall |
1205 | Calls the "munlockall" function. |
1663 | Calls the "munlockall" function. |
1206 | |
1664 | |
1207 | On systems that do not implement "munlockall", this function returns |
1665 | On systems that do not implement "munlockall", this function returns |
1208 | ENOSYS, otherwise the return value of "munlockall". |
1666 | ENOSYS, otherwise the return value of "munlockall". |
|
|
1667 | |
|
|
1668 | IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags |
|
|
1669 | Calls the GNU/Linux splice(2) syscall, if available. If $r_off or |
|
|
1670 | $w_off are "undef", then "NULL" is passed for these, otherwise they |
|
|
1671 | should be the file offset. |
|
|
1672 | |
|
|
1673 | $r_fh and $w_fh should not refer to the same file, as splice might |
|
|
1674 | silently corrupt the data in this case. |
|
|
1675 | |
|
|
1676 | The following symbol flag values are available: |
|
|
1677 | "IO::AIO::SPLICE_F_MOVE", "IO::AIO::SPLICE_F_NONBLOCK", |
|
|
1678 | "IO::AIO::SPLICE_F_MORE" and "IO::AIO::SPLICE_F_GIFT". |
|
|
1679 | |
|
|
1680 | See the splice(2) manpage for details. |
|
|
1681 | |
|
|
1682 | IO::AIO::tee $r_fh, $w_fh, $length, $flags |
|
|
1683 | Calls the GNU/Linux tee(2) syscall, see it's manpage and the |
|
|
1684 | description for "IO::AIO::splice" above for details. |
|
|
1685 | |
|
|
1686 | $actual_size = IO::AIO::pipesize $r_fh[, $new_size] |
|
|
1687 | Attempts to query or change the pipe buffer size. Obviously works |
|
|
1688 | only on pipes, and currently works only on GNU/Linux systems, and |
|
|
1689 | fails with -1/"ENOSYS" everywhere else. If anybody knows how to |
|
|
1690 | influence pipe buffer size on other systems, drop me a note. |
1209 | |
1691 | |
1210 | EVENT LOOP INTEGRATION |
1692 | EVENT LOOP INTEGRATION |
1211 | It is recommended to use AnyEvent::AIO to integrate IO::AIO |
1693 | It is recommended to use AnyEvent::AIO to integrate IO::AIO |
1212 | automatically into many event loops: |
1694 | automatically into many event loops: |
1213 | |
1695 | |
… | |
… | |
1236 | # Danga::Socket integration |
1718 | # Danga::Socket integration |
1237 | Danga::Socket->AddOtherFds (IO::AIO::poll_fileno => |
1719 | Danga::Socket->AddOtherFds (IO::AIO::poll_fileno => |
1238 | \&IO::AIO::poll_cb); |
1720 | \&IO::AIO::poll_cb); |
1239 | |
1721 | |
1240 | FORK BEHAVIOUR |
1722 | FORK BEHAVIOUR |
1241 | This module should do "the right thing" when the process using it forks: |
1723 | Usage of pthreads in a program changes the semantics of fork |
|
|
1724 | considerably. Specifically, only async-safe functions can be called |
|
|
1725 | after fork. Perl doesn't know about this, so in general, you cannot call |
|
|
1726 | fork with defined behaviour in perl if pthreads are involved. IO::AIO |
|
|
1727 | uses pthreads, so this applies, but many other extensions and (for |
|
|
1728 | inexplicable reasons) perl itself often is linked against pthreads, so |
|
|
1729 | this limitation applies to quite a lot of perls. |
1242 | |
1730 | |
1243 | Before the fork, IO::AIO enters a quiescent state where no requests can |
1731 | This module no longer tries to fight your OS, or POSIX. That means |
1244 | be added in other threads and no results will be processed. After the |
1732 | IO::AIO only works in the process that loaded it. Forking is fully |
1245 | fork the parent simply leaves the quiescent state and continues |
1733 | supported, but using IO::AIO in the child is not. |
1246 | request/result processing, while the child frees the request/result |
|
|
1247 | queue (so that the requests started before the fork will only be handled |
|
|
1248 | in the parent). Threads will be started on demand until the limit set in |
|
|
1249 | the parent process has been reached again. |
|
|
1250 | |
1734 | |
1251 | In short: the parent will, after a short pause, continue as if fork had |
1735 | You might get around by not *using* IO::AIO before (or after) forking. |
1252 | not been called, while the child will act as if IO::AIO has not been |
1736 | You could also try to call the IO::AIO::reinit function in the child: |
1253 | used yet. |
1737 | |
|
|
1738 | IO::AIO::reinit |
|
|
1739 | Abandons all current requests and I/O threads and simply |
|
|
1740 | reinitialises all data structures. This is not an operation |
|
|
1741 | supported by any standards, but happens to work on GNU/Linux and |
|
|
1742 | some newer BSD systems. |
|
|
1743 | |
|
|
1744 | The only reasonable use for this function is to call it after |
|
|
1745 | forking, if "IO::AIO" was used in the parent. Calling it while |
|
|
1746 | IO::AIO is active in the process will result in undefined behaviour. |
|
|
1747 | Calling it at any time will also result in any undefined (by POSIX) |
|
|
1748 | behaviour. |
1254 | |
1749 | |
1255 | MEMORY USAGE |
1750 | MEMORY USAGE |
1256 | Per-request usage: |
1751 | Per-request usage: |
1257 | |
1752 | |
1258 | Each aio request uses - depending on your architecture - around 100-200 |
1753 | Each aio request uses - depending on your architecture - around 100-200 |