… | |
… | |
4 | |
4 | |
5 | =head1 SYNOPSIS |
5 | =head1 SYNOPSIS |
6 | |
6 | |
7 | use IO::AIO; |
7 | use IO::AIO; |
8 | |
8 | |
9 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
9 | aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub { |
10 | my $fh = shift |
10 | my $fh = shift |
11 | or die "/etc/passwd: $!"; |
11 | or die "/etc/passwd: $!"; |
12 | ... |
12 | ... |
13 | }; |
13 | }; |
14 | |
14 | |
… | |
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76 | |
76 | |
77 | # register the IO::AIO callback with EV |
77 | # register the IO::AIO callback with EV |
78 | my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
78 | my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
79 | |
79 | |
80 | # queue the request to open /etc/passwd |
80 | # queue the request to open /etc/passwd |
81 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
81 | aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub { |
82 | my $fh = shift |
82 | my $fh = shift |
83 | or die "error while opening: $!"; |
83 | or die "error while opening: $!"; |
84 | |
84 | |
85 | # stat'ing filehandles is generally non-blocking |
85 | # stat'ing filehandles is generally non-blocking |
86 | my $size = -s $fh; |
86 | my $size = -s $fh; |
… | |
… | |
168 | use common::sense; |
168 | use common::sense; |
169 | |
169 | |
170 | use base 'Exporter'; |
170 | use base 'Exporter'; |
171 | |
171 | |
172 | BEGIN { |
172 | BEGIN { |
173 | our $VERSION = '3.5'; |
173 | our $VERSION = '4.11'; |
174 | |
174 | |
175 | our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close |
175 | our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close |
176 | aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx |
176 | aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx |
177 | aio_scandir aio_symlink aio_readlink aio_sync aio_fsync |
177 | aio_scandir aio_symlink aio_readlink aio_realpath aio_sync |
178 | aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead |
178 | aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range aio_fallocate |
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179 | aio_pathsync aio_readahead |
179 | aio_rename aio_link aio_move aio_copy aio_group |
180 | aio_rename aio_link aio_move aio_copy aio_group |
180 | aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown |
181 | aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown |
181 | aio_chmod aio_utime aio_truncate |
182 | aio_chmod aio_utime aio_truncate |
182 | aio_msync aio_mtouch aio_statvfs); |
183 | aio_msync aio_mtouch aio_mlock aio_mlockall |
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184 | aio_statvfs |
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185 | aio_wd); |
183 | |
186 | |
184 | our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); |
187 | our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); |
185 | our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush |
188 | our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush |
186 | min_parallel max_parallel max_idle |
189 | min_parallel max_parallel max_idle idle_timeout |
187 | nreqs nready npending nthreads |
190 | nreqs nready npending nthreads |
188 | max_poll_time max_poll_reqs |
191 | max_poll_time max_poll_reqs |
189 | sendfile fadvise); |
192 | sendfile fadvise madvise |
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193 | mmap munmap munlock munlockall); |
190 | |
194 | |
191 | push @AIO_REQ, qw(aio_busy); # not exported |
195 | push @AIO_REQ, qw(aio_busy); # not exported |
192 | |
196 | |
193 | @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; |
197 | @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; |
194 | |
198 | |
… | |
… | |
202 | |
206 | |
203 | This section simply lists the prototypes of the most important functions |
207 | This section simply lists the prototypes of the most important functions |
204 | for quick reference. See the following sections for function-by-function |
208 | for quick reference. See the following sections for function-by-function |
205 | documentation. |
209 | documentation. |
206 | |
210 | |
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211 | aio_wd $pathname, $callback->($wd) |
207 | aio_open $pathname, $flags, $mode, $callback->($fh) |
212 | aio_open $pathname, $flags, $mode, $callback->($fh) |
208 | aio_close $fh, $callback->($status) |
213 | aio_close $fh, $callback->($status) |
209 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
214 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
210 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
215 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
211 | aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
216 | aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
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216 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
221 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
217 | aio_chown $fh_or_path, $uid, $gid, $callback->($status) |
222 | aio_chown $fh_or_path, $uid, $gid, $callback->($status) |
218 | aio_truncate $fh_or_path, $offset, $callback->($status) |
223 | aio_truncate $fh_or_path, $offset, $callback->($status) |
219 | aio_chmod $fh_or_path, $mode, $callback->($status) |
224 | aio_chmod $fh_or_path, $mode, $callback->($status) |
220 | aio_unlink $pathname, $callback->($status) |
225 | aio_unlink $pathname, $callback->($status) |
221 | aio_mknod $path, $mode, $dev, $callback->($status) |
226 | aio_mknod $pathname, $mode, $dev, $callback->($status) |
222 | aio_link $srcpath, $dstpath, $callback->($status) |
227 | aio_link $srcpath, $dstpath, $callback->($status) |
223 | aio_symlink $srcpath, $dstpath, $callback->($status) |
228 | aio_symlink $srcpath, $dstpath, $callback->($status) |
224 | aio_readlink $path, $callback->($link) |
229 | aio_readlink $pathname, $callback->($link) |
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230 | aio_realpath $pathname, $callback->($link) |
225 | aio_rename $srcpath, $dstpath, $callback->($status) |
231 | aio_rename $srcpath, $dstpath, $callback->($status) |
226 | aio_mkdir $pathname, $mode, $callback->($status) |
232 | aio_mkdir $pathname, $mode, $callback->($status) |
227 | aio_rmdir $pathname, $callback->($status) |
233 | aio_rmdir $pathname, $callback->($status) |
228 | aio_readdir $pathname, $callback->($entries) |
234 | aio_readdir $pathname, $callback->($entries) |
229 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
235 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
230 | IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST |
236 | IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST |
231 | IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN |
237 | IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN |
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238 | aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) |
232 | aio_load $path, $data, $callback->($status) |
239 | aio_load $pathname, $data, $callback->($status) |
233 | aio_copy $srcpath, $dstpath, $callback->($status) |
240 | aio_copy $srcpath, $dstpath, $callback->($status) |
234 | aio_move $srcpath, $dstpath, $callback->($status) |
241 | aio_move $srcpath, $dstpath, $callback->($status) |
235 | aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
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236 | aio_rmtree $path, $callback->($status) |
242 | aio_rmtree $pathname, $callback->($status) |
237 | aio_sync $callback->($status) |
243 | aio_sync $callback->($status) |
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244 | aio_syncfs $fh, $callback->($status) |
238 | aio_fsync $fh, $callback->($status) |
245 | aio_fsync $fh, $callback->($status) |
239 | aio_fdatasync $fh, $callback->($status) |
246 | aio_fdatasync $fh, $callback->($status) |
240 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
247 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
241 | aio_pathsync $path, $callback->($status) |
248 | aio_pathsync $pathname, $callback->($status) |
242 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
249 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
243 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
250 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
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251 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
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252 | aio_mlockall $flags, $callback->($status) |
244 | aio_group $callback->(...) |
253 | aio_group $callback->(...) |
245 | aio_nop $callback->() |
254 | aio_nop $callback->() |
246 | |
255 | |
247 | $prev_pri = aioreq_pri [$pri] |
256 | $prev_pri = aioreq_pri [$pri] |
248 | aioreq_nice $pri_adjust |
257 | aioreq_nice $pri_adjust |
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254 | IO::AIO::max_poll_reqs $nreqs |
263 | IO::AIO::max_poll_reqs $nreqs |
255 | IO::AIO::max_poll_time $seconds |
264 | IO::AIO::max_poll_time $seconds |
256 | IO::AIO::min_parallel $nthreads |
265 | IO::AIO::min_parallel $nthreads |
257 | IO::AIO::max_parallel $nthreads |
266 | IO::AIO::max_parallel $nthreads |
258 | IO::AIO::max_idle $nthreads |
267 | IO::AIO::max_idle $nthreads |
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268 | IO::AIO::idle_timeout $seconds |
259 | IO::AIO::max_outstanding $maxreqs |
269 | IO::AIO::max_outstanding $maxreqs |
260 | IO::AIO::nreqs |
270 | IO::AIO::nreqs |
261 | IO::AIO::nready |
271 | IO::AIO::nready |
262 | IO::AIO::npending |
272 | IO::AIO::npending |
263 | |
273 | |
264 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
274 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
265 | IO::AIO::fadvise $fh, $offset, $len, $advice |
275 | IO::AIO::fadvise $fh, $offset, $len, $advice |
266 | IO::AIO::mlockall $flags |
276 | IO::AIO::madvise $scalar, $offset, $length, $advice |
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277 | IO::AIO::mprotect $scalar, $offset, $length, $protect |
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278 | IO::AIO::munlock $scalar, $offset = 0, $length = undef |
267 | IO::AIO::munlockall |
279 | IO::AIO::munlockall |
268 | |
280 | |
269 | =head2 AIO REQUEST FUNCTIONS |
281 | =head2 AIO REQUEST FUNCTIONS |
270 | |
282 | |
271 | All the C<aio_*> calls are more or less thin wrappers around the syscall |
283 | All the C<aio_*> calls are more or less thin wrappers around the syscall |
272 | with the same name (sans C<aio_>). The arguments are similar or identical, |
284 | with the same name (sans C<aio_>). The arguments are similar or identical, |
273 | and they all accept an additional (and optional) C<$callback> argument |
285 | and they all accept an additional (and optional) C<$callback> argument |
274 | which must be a code reference. This code reference will get called with |
286 | which must be a code reference. This code reference will be called after |
275 | the syscall return code (e.g. most syscalls return C<-1> on error, unlike |
287 | the syscall has been executed in an asynchronous fashion. The results |
276 | perl, which usually delivers "false") as its sole argument after the given |
288 | of the request will be passed as arguments to the callback (and, if an |
277 | syscall has been executed asynchronously. |
289 | error occured, in C<$!>) - for most requests the syscall return code (e.g. |
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290 | most syscalls return C<-1> on error, unlike perl, which usually delivers |
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291 | "false"). |
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292 | |
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293 | Some requests (such as C<aio_readdir>) pass the actual results and |
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294 | communicate failures by passing C<undef>. |
278 | |
295 | |
279 | All functions expecting a filehandle keep a copy of the filehandle |
296 | All functions expecting a filehandle keep a copy of the filehandle |
280 | internally until the request has finished. |
297 | internally until the request has finished. |
281 | |
298 | |
282 | All functions return request objects of type L<IO::AIO::REQ> that allow |
299 | All functions return request objects of type L<IO::AIO::REQ> that allow |
283 | further manipulation of those requests while they are in-flight. |
300 | further manipulation of those requests while they are in-flight. |
284 | |
301 | |
285 | The pathnames you pass to these routines I<must> be absolute and |
302 | The pathnames you pass to these routines I<should> be absolute. The |
286 | encoded as octets. The reason for the former is that at the time the |
303 | reason for this is that at the time the request is being executed, the |
287 | request is being executed, the current working directory could have |
304 | current working directory could have changed. Alternatively, you can |
288 | changed. Alternatively, you can make sure that you never change the |
305 | make sure that you never change the current working directory anywhere |
289 | current working directory anywhere in the program and then use relative |
306 | in the program and then use relative paths. You can also take advantage |
290 | paths. |
307 | of IO::AIOs working directory abstraction, that lets you specify paths |
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308 | relative to some previously-opened "working directory object" - see the |
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309 | description of the C<IO::AIO::WD> class later in this document. |
291 | |
310 | |
292 | To encode pathnames as octets, either make sure you either: a) always pass |
311 | To encode pathnames as octets, either make sure you either: a) always pass |
293 | in filenames you got from outside (command line, readdir etc.) without |
312 | in filenames you got from outside (command line, readdir etc.) without |
294 | tinkering, b) are ASCII or ISO 8859-1, c) use the Encode module and encode |
313 | tinkering, b) are in your native filesystem encoding, c) use the Encode |
295 | your pathnames to the locale (or other) encoding in effect in the user |
314 | module and encode your pathnames to the locale (or other) encoding in |
296 | environment, d) use Glib::filename_from_unicode on unicode filenames or e) |
315 | effect in the user environment, d) use Glib::filename_from_unicode on |
297 | use something else to ensure your scalar has the correct contents. |
316 | unicode filenames or e) use something else to ensure your scalar has the |
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317 | correct contents. |
298 | |
318 | |
299 | This works, btw. independent of the internal UTF-8 bit, which IO::AIO |
319 | This works, btw. independent of the internal UTF-8 bit, which IO::AIO |
300 | handles correctly whether it is set or not. |
320 | handles correctly whether it is set or not. |
301 | |
321 | |
302 | =over 4 |
322 | =over 4 |
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352 | by the umask in effect then the request is being executed, so better never |
372 | by the umask in effect then the request is being executed, so better never |
353 | change the umask. |
373 | change the umask. |
354 | |
374 | |
355 | Example: |
375 | Example: |
356 | |
376 | |
357 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
377 | aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub { |
358 | if ($_[0]) { |
378 | if ($_[0]) { |
359 | print "open successful, fh is $_[0]\n"; |
379 | print "open successful, fh is $_[0]\n"; |
360 | ... |
380 | ... |
361 | } else { |
381 | } else { |
362 | die "open failed: $!\n"; |
382 | die "open failed: $!\n"; |
363 | } |
383 | } |
364 | }; |
384 | }; |
365 | |
385 | |
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386 | In addition to all the common open modes/flags (C<O_RDONLY>, C<O_WRONLY>, |
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387 | C<O_RDWR>, C<O_CREAT>, C<O_TRUNC>, C<O_EXCL> and C<O_APPEND>), the |
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388 | following POSIX and non-POSIX constants are available (missing ones on |
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389 | your system are, as usual, C<0>): |
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390 | |
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391 | C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>, |
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392 | C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>, |
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393 | C<O_RSYNC>, C<O_SYNC> and C<O_TTY_INIT>. |
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394 | |
366 | |
395 | |
367 | =item aio_close $fh, $callback->($status) |
396 | =item aio_close $fh, $callback->($status) |
368 | |
397 | |
369 | Asynchronously close a file and call the callback with the result |
398 | Asynchronously close a file and call the callback with the result |
370 | code. |
399 | code. |
… | |
… | |
420 | |
449 | |
421 | Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts |
450 | Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts |
422 | reading at byte offset C<$in_offset>, and starts writing at the current |
451 | reading at byte offset C<$in_offset>, and starts writing at the current |
423 | file offset of C<$out_fh>. Because of that, it is not safe to issue more |
452 | file offset of C<$out_fh>. Because of that, it is not safe to issue more |
424 | than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each |
453 | than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each |
425 | other. |
454 | other. The same C<$in_fh> works fine though, as this function does not |
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455 | move or use the file offset of C<$in_fh>. |
426 | |
456 | |
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457 | Please note that C<aio_sendfile> can read more bytes from C<$in_fh> than |
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458 | are written, and there is no way to find out how many more bytes have been |
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459 | read from C<aio_sendfile> alone, as C<aio_sendfile> only provides the |
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460 | number of bytes written to C<$out_fh>. Only if the result value equals |
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461 | C<$length> one can assume that C<$length> bytes have been read. |
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462 | |
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463 | Unlike with other C<aio_> functions, it makes a lot of sense to use |
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464 | C<aio_sendfile> on non-blocking sockets, as long as one end (typically |
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465 | the C<$in_fh>) is a file - the file I/O will then be asynchronous, while |
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466 | the socket I/O will be non-blocking. Note, however, that you can run |
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467 | into a trap where C<aio_sendfile> reads some data with readahead, then |
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468 | fails to write all data, and when the socket is ready the next time, the |
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469 | data in the cache is already lost, forcing C<aio_sendfile> to again hit |
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470 | the disk. Explicit C<aio_read> + C<aio_write> let's you better control |
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471 | resource usage. |
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472 | |
427 | This call tries to make use of a native C<sendfile> syscall to provide |
473 | This call tries to make use of a native C<sendfile>-like syscall to |
428 | zero-copy operation. For this to work, C<$out_fh> should refer to a |
474 | provide zero-copy operation. For this to work, C<$out_fh> should refer to |
429 | socket, and C<$in_fh> should refer to mmap'able file. |
475 | a socket, and C<$in_fh> should refer to an mmap'able file. |
430 | |
476 | |
431 | If a native sendfile cannot be found or it fails with C<ENOSYS>, |
477 | If a native sendfile cannot be found or it fails with C<ENOSYS>, |
432 | C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>, |
478 | C<EINVAL>, C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or |
433 | it will be emulated, so you can call C<aio_sendfile> on any type of |
479 | C<ENOTSOCK>, it will be emulated, so you can call C<aio_sendfile> on any |
434 | filehandle regardless of the limitations of the operating system. |
480 | type of filehandle regardless of the limitations of the operating system. |
435 | |
481 | |
436 | Please note, however, that C<aio_sendfile> can read more bytes from |
482 | As native sendfile syscalls (as practically any non-POSIX interface hacked |
437 | C<$in_fh> than are written, and there is no way to find out how many |
483 | together in a hurry to improve benchmark numbers) tend to be rather buggy |
438 | bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only |
484 | on many systems, this implementation tries to work around some known bugs |
439 | provides the number of bytes written to C<$out_fh>. Only if the result |
485 | in Linux and FreeBSD kernels (probably others, too), but that might fail, |
440 | value equals C<$length> one can assume that C<$length> bytes have been |
486 | so you really really should check the return value of C<aio_sendfile> - |
441 | read. |
487 | fewre bytes than expected might have been transferred. |
442 | |
488 | |
443 | |
489 | |
444 | =item aio_readahead $fh,$offset,$length, $callback->($retval) |
490 | =item aio_readahead $fh,$offset,$length, $callback->($retval) |
445 | |
491 | |
446 | C<aio_readahead> populates the page cache with data from a file so that |
492 | C<aio_readahead> populates the page cache with data from a file so that |
… | |
… | |
468 | for an explanation. |
514 | for an explanation. |
469 | |
515 | |
470 | Currently, the stats are always 64-bit-stats, i.e. instead of returning an |
516 | Currently, the stats are always 64-bit-stats, i.e. instead of returning an |
471 | error when stat'ing a large file, the results will be silently truncated |
517 | error when stat'ing a large file, the results will be silently truncated |
472 | unless perl itself is compiled with large file support. |
518 | unless perl itself is compiled with large file support. |
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519 | |
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520 | To help interpret the mode and dev/rdev stat values, IO::AIO offers the |
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521 | following constants and functions (if not implemented, the constants will |
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522 | be C<0> and the functions will either C<croak> or fall back on traditional |
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523 | behaviour). |
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524 | |
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525 | C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>, |
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526 | C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>, |
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527 | C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>. |
473 | |
528 | |
474 | Example: Print the length of F</etc/passwd>: |
529 | Example: Print the length of F</etc/passwd>: |
475 | |
530 | |
476 | aio_stat "/etc/passwd", sub { |
531 | aio_stat "/etc/passwd", sub { |
477 | $_[0] and die "stat failed: $!"; |
532 | $_[0] and die "stat failed: $!"; |
… | |
… | |
569 | |
624 | |
570 | Asynchronously unlink (delete) a file and call the callback with the |
625 | Asynchronously unlink (delete) a file and call the callback with the |
571 | result code. |
626 | result code. |
572 | |
627 | |
573 | |
628 | |
574 | =item aio_mknod $path, $mode, $dev, $callback->($status) |
629 | =item aio_mknod $pathname, $mode, $dev, $callback->($status) |
575 | |
630 | |
576 | [EXPERIMENTAL] |
631 | [EXPERIMENTAL] |
577 | |
632 | |
578 | Asynchronously create a device node (or fifo). See mknod(2). |
633 | Asynchronously create a device node (or fifo). See mknod(2). |
579 | |
634 | |
580 | The only (POSIX-) portable way of calling this function is: |
635 | The only (POSIX-) portable way of calling this function is: |
581 | |
636 | |
582 | aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
637 | aio_mknod $pathname, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
583 | |
638 | |
|
|
639 | See C<aio_stat> for info about some potentially helpful extra constants |
|
|
640 | and functions. |
584 | |
641 | |
585 | =item aio_link $srcpath, $dstpath, $callback->($status) |
642 | =item aio_link $srcpath, $dstpath, $callback->($status) |
586 | |
643 | |
587 | Asynchronously create a new link to the existing object at C<$srcpath> at |
644 | Asynchronously create a new link to the existing object at C<$srcpath> at |
588 | the path C<$dstpath> and call the callback with the result code. |
645 | the path C<$dstpath> and call the callback with the result code. |
… | |
… | |
592 | |
649 | |
593 | Asynchronously create a new symbolic link to the existing object at C<$srcpath> at |
650 | Asynchronously create a new symbolic link to the existing object at C<$srcpath> at |
594 | the path C<$dstpath> and call the callback with the result code. |
651 | the path C<$dstpath> and call the callback with the result code. |
595 | |
652 | |
596 | |
653 | |
597 | =item aio_readlink $path, $callback->($link) |
654 | =item aio_readlink $pathname, $callback->($link) |
598 | |
655 | |
599 | Asynchronously read the symlink specified by C<$path> and pass it to |
656 | Asynchronously read the symlink specified by C<$path> and pass it to |
600 | the callback. If an error occurs, nothing or undef gets passed to the |
657 | the callback. If an error occurs, nothing or undef gets passed to the |
601 | callback. |
658 | callback. |
602 | |
659 | |
603 | |
660 | |
|
|
661 | =item aio_realpath $pathname, $callback->($path) |
|
|
662 | |
|
|
663 | Asynchronously make the path absolute and resolve any symlinks in |
|
|
664 | C<$path>. The resulting path only consists of directories (Same as |
|
|
665 | L<Cwd::realpath>). |
|
|
666 | |
|
|
667 | This request can be used to get the absolute path of the current working |
|
|
668 | directory by passing it a path of F<.> (a single dot). |
|
|
669 | |
|
|
670 | |
604 | =item aio_rename $srcpath, $dstpath, $callback->($status) |
671 | =item aio_rename $srcpath, $dstpath, $callback->($status) |
605 | |
672 | |
606 | Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as |
673 | Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as |
607 | rename(2) and call the callback with the result code. |
674 | rename(2) and call the callback with the result code. |
608 | |
675 | |
… | |
… | |
630 | array-ref with the filenames. |
697 | array-ref with the filenames. |
631 | |
698 | |
632 | |
699 | |
633 | =item aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
700 | =item aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
634 | |
701 | |
635 | Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune |
702 | Quite similar to C<aio_readdir>, but the C<$flags> argument allows one to |
636 | behaviour and output format. In case of an error, C<$entries> will be |
703 | tune behaviour and output format. In case of an error, C<$entries> will be |
637 | C<undef>. |
704 | C<undef>. |
638 | |
705 | |
639 | The flags are a combination of the following constants, ORed together (the |
706 | The flags are a combination of the following constants, ORed together (the |
640 | flags will also be passed to the callback, possibly modified): |
707 | flags will also be passed to the callback, possibly modified): |
641 | |
708 | |
642 | =over 4 |
709 | =over 4 |
643 | |
710 | |
644 | =item IO::AIO::READDIR_DENTS |
711 | =item IO::AIO::READDIR_DENTS |
645 | |
712 | |
646 | When this flag is off, then the callback gets an arrayref with of names |
713 | When this flag is off, then the callback gets an arrayref consisting of |
647 | only (as with C<aio_readdir>), otherwise it gets an arrayref with |
714 | names only (as with C<aio_readdir>), otherwise it gets an arrayref with |
648 | C<[$name, $type, $inode]> arrayrefs, each describing a single directory |
715 | C<[$name, $type, $inode]> arrayrefs, each describing a single directory |
649 | entry in more detail. |
716 | entry in more detail. |
650 | |
717 | |
651 | C<$name> is the name of the entry. |
718 | C<$name> is the name of the entry. |
652 | |
719 | |
… | |
… | |
665 | systems that do not deliver the inode information. |
732 | systems that do not deliver the inode information. |
666 | |
733 | |
667 | =item IO::AIO::READDIR_DIRS_FIRST |
734 | =item IO::AIO::READDIR_DIRS_FIRST |
668 | |
735 | |
669 | When this flag is set, then the names will be returned in an order where |
736 | When this flag is set, then the names will be returned in an order where |
670 | likely directories come first. This is useful when you need to quickly |
737 | likely directories come first, in optimal stat order. This is useful when |
671 | find directories, or you want to find all directories while avoiding to |
738 | you need to quickly find directories, or you want to find all directories |
672 | stat() each entry. |
739 | while avoiding to stat() each entry. |
673 | |
740 | |
674 | If the system returns type information in readdir, then this is used |
741 | If the system returns type information in readdir, then this is used |
675 | to find directories directly. Otherwise, likely directories are files |
742 | to find directories directly. Otherwise, likely directories are names |
676 | beginning with ".", or otherwise files with no dots, of which files with |
743 | beginning with ".", or otherwise names with no dots, of which names with |
677 | short names are tried first. |
744 | short names are tried first. |
678 | |
745 | |
679 | =item IO::AIO::READDIR_STAT_ORDER |
746 | =item IO::AIO::READDIR_STAT_ORDER |
680 | |
747 | |
681 | When this flag is set, then the names will be returned in an order |
748 | When this flag is set, then the names will be returned in an order |
… | |
… | |
688 | |
755 | |
689 | =item IO::AIO::READDIR_FOUND_UNKNOWN |
756 | =item IO::AIO::READDIR_FOUND_UNKNOWN |
690 | |
757 | |
691 | This flag should not be set when calling C<aio_readdirx>. Instead, it |
758 | This flag should not be set when calling C<aio_readdirx>. Instead, it |
692 | is being set by C<aio_readdirx>, when any of the C<$type>'s found were |
759 | is being set by C<aio_readdirx>, when any of the C<$type>'s found were |
693 | C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all |
760 | C<IO::AIO::DT_UNKNOWN>. The absence of this flag therefore indicates that all |
694 | C<$type>'s are known, which can be used to speed up some algorithms. |
761 | C<$type>'s are known, which can be used to speed up some algorithms. |
695 | |
762 | |
696 | =back |
763 | =back |
697 | |
764 | |
698 | |
765 | |
699 | =item aio_load $path, $data, $callback->($status) |
766 | =item aio_load $pathname, $data, $callback->($status) |
700 | |
767 | |
701 | This is a composite request that tries to fully load the given file into |
768 | This is a composite request that tries to fully load the given file into |
702 | memory. Status is the same as with aio_read. |
769 | memory. Status is the same as with aio_read. |
703 | |
770 | |
704 | =cut |
771 | =cut |
… | |
… | |
826 | if ($_[0] && $! == EXDEV) { |
893 | if ($_[0] && $! == EXDEV) { |
827 | aioreq_pri $pri; |
894 | aioreq_pri $pri; |
828 | add $grp aio_copy $src, $dst, sub { |
895 | add $grp aio_copy $src, $dst, sub { |
829 | $grp->result ($_[0]); |
896 | $grp->result ($_[0]); |
830 | |
897 | |
831 | if (!$_[0]) { |
898 | unless ($_[0]) { |
832 | aioreq_pri $pri; |
899 | aioreq_pri $pri; |
833 | add $grp aio_unlink $src; |
900 | add $grp aio_unlink $src; |
834 | } |
901 | } |
835 | }; |
902 | }; |
836 | } else { |
903 | } else { |
… | |
… | |
839 | }; |
906 | }; |
840 | |
907 | |
841 | $grp |
908 | $grp |
842 | } |
909 | } |
843 | |
910 | |
844 | =item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
911 | =item aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) |
845 | |
912 | |
846 | Scans a directory (similar to C<aio_readdir>) but additionally tries to |
913 | Scans a directory (similar to C<aio_readdir>) but additionally tries to |
847 | efficiently separate the entries of directory C<$path> into two sets of |
914 | efficiently separate the entries of directory C<$path> into two sets of |
848 | names, directories you can recurse into (directories), and ones you cannot |
915 | names, directories you can recurse into (directories), and ones you cannot |
849 | recurse into (everything else, including symlinks to directories). |
916 | recurse into (everything else, including symlinks to directories). |
… | |
… | |
880 | Then entries will be sorted into likely directories a non-initial dot |
947 | Then entries will be sorted into likely directories a non-initial dot |
881 | currently) and likely non-directories (see C<aio_readdirx>). Then every |
948 | currently) and likely non-directories (see C<aio_readdirx>). Then every |
882 | entry plus an appended C</.> will be C<stat>'ed, likely directories first, |
949 | entry plus an appended C</.> will be C<stat>'ed, likely directories first, |
883 | in order of their inode numbers. If that succeeds, it assumes that the |
950 | in order of their inode numbers. If that succeeds, it assumes that the |
884 | entry is a directory or a symlink to directory (which will be checked |
951 | entry is a directory or a symlink to directory (which will be checked |
885 | seperately). This is often faster than stat'ing the entry itself because |
952 | separately). This is often faster than stat'ing the entry itself because |
886 | filesystems might detect the type of the entry without reading the inode |
953 | filesystems might detect the type of the entry without reading the inode |
887 | data (e.g. ext2fs filetype feature), even on systems that cannot return |
954 | data (e.g. ext2fs filetype feature), even on systems that cannot return |
888 | the filetype information on readdir. |
955 | the filetype information on readdir. |
889 | |
956 | |
890 | If the known number of directories (link count - 2) has been reached, the |
957 | If the known number of directories (link count - 2) has been reached, the |
… | |
… | |
906 | |
973 | |
907 | my $grp = aio_group $cb; |
974 | my $grp = aio_group $cb; |
908 | |
975 | |
909 | $maxreq = 4 if $maxreq <= 0; |
976 | $maxreq = 4 if $maxreq <= 0; |
910 | |
977 | |
911 | # stat once |
978 | # get a wd object |
912 | aioreq_pri $pri; |
979 | aioreq_pri $pri; |
913 | add $grp aio_stat $path, sub { |
980 | add $grp aio_wd $path, sub { |
|
|
981 | $_[0] |
914 | return $grp->result () if $_[0]; |
982 | or return $grp->result (); |
915 | my $now = time; |
|
|
916 | my $hash1 = join ":", (stat _)[0,1,3,7,9]; |
|
|
917 | |
983 | |
918 | # read the directory entries |
984 | my $wd = [shift, "."]; |
|
|
985 | |
|
|
986 | # stat once |
919 | aioreq_pri $pri; |
987 | aioreq_pri $pri; |
920 | add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub { |
988 | add $grp aio_stat $wd, sub { |
921 | my $entries = shift |
|
|
922 | or return $grp->result (); |
989 | return $grp->result () if $_[0]; |
|
|
990 | my $now = time; |
|
|
991 | my $hash1 = join ":", (stat _)[0,1,3,7,9]; |
923 | |
992 | |
924 | # stat the dir another time |
993 | # read the directory entries |
925 | aioreq_pri $pri; |
994 | aioreq_pri $pri; |
|
|
995 | add $grp aio_readdirx $wd, READDIR_DIRS_FIRST, sub { |
|
|
996 | my $entries = shift |
|
|
997 | or return $grp->result (); |
|
|
998 | |
|
|
999 | # stat the dir another time |
|
|
1000 | aioreq_pri $pri; |
926 | add $grp aio_stat $path, sub { |
1001 | add $grp aio_stat $wd, sub { |
927 | my $hash2 = join ":", (stat _)[0,1,3,7,9]; |
1002 | my $hash2 = join ":", (stat _)[0,1,3,7,9]; |
928 | |
1003 | |
929 | my $ndirs; |
1004 | my $ndirs; |
930 | |
1005 | |
931 | # take the slow route if anything looks fishy |
1006 | # take the slow route if anything looks fishy |
932 | if ($hash1 ne $hash2 or (stat _)[9] == $now) { |
1007 | if ($hash1 ne $hash2 or (stat _)[9] == $now) { |
933 | $ndirs = -1; |
1008 | $ndirs = -1; |
934 | } else { |
1009 | } else { |
935 | # if nlink == 2, we are finished |
1010 | # if nlink == 2, we are finished |
936 | # for non-posix-fs's, we rely on nlink < 2 |
1011 | # for non-posix-fs's, we rely on nlink < 2 |
937 | $ndirs = (stat _)[3] - 2 |
1012 | $ndirs = (stat _)[3] - 2 |
938 | or return $grp->result ([], $entries); |
1013 | or return $grp->result ([], $entries); |
939 | } |
1014 | } |
940 | |
1015 | |
941 | my (@dirs, @nondirs); |
1016 | my (@dirs, @nondirs); |
942 | |
1017 | |
943 | my $statgrp = add $grp aio_group sub { |
1018 | my $statgrp = add $grp aio_group sub { |
944 | $grp->result (\@dirs, \@nondirs); |
1019 | $grp->result (\@dirs, \@nondirs); |
945 | }; |
1020 | }; |
946 | |
1021 | |
947 | limit $statgrp $maxreq; |
1022 | limit $statgrp $maxreq; |
948 | feed $statgrp sub { |
1023 | feed $statgrp sub { |
949 | return unless @$entries; |
1024 | return unless @$entries; |
950 | my $entry = shift @$entries; |
1025 | my $entry = shift @$entries; |
951 | |
1026 | |
952 | aioreq_pri $pri; |
1027 | aioreq_pri $pri; |
|
|
1028 | $wd->[1] = "$entry/."; |
953 | add $statgrp aio_stat "$path/$entry/.", sub { |
1029 | add $statgrp aio_stat $wd, sub { |
954 | if ($_[0] < 0) { |
1030 | if ($_[0] < 0) { |
955 | push @nondirs, $entry; |
1031 | push @nondirs, $entry; |
956 | } else { |
1032 | } else { |
957 | # need to check for real directory |
1033 | # need to check for real directory |
958 | aioreq_pri $pri; |
1034 | aioreq_pri $pri; |
|
|
1035 | $wd->[1] = $entry; |
959 | add $statgrp aio_lstat "$path/$entry", sub { |
1036 | add $statgrp aio_lstat $wd, sub { |
960 | if (-d _) { |
1037 | if (-d _) { |
961 | push @dirs, $entry; |
1038 | push @dirs, $entry; |
962 | |
1039 | |
963 | unless (--$ndirs) { |
1040 | unless (--$ndirs) { |
964 | push @nondirs, @$entries; |
1041 | push @nondirs, @$entries; |
965 | feed $statgrp; |
1042 | feed $statgrp; |
|
|
1043 | } |
|
|
1044 | } else { |
|
|
1045 | push @nondirs, $entry; |
966 | } |
1046 | } |
967 | } else { |
|
|
968 | push @nondirs, $entry; |
|
|
969 | } |
1047 | } |
970 | } |
1048 | } |
971 | } |
1049 | }; |
972 | }; |
1050 | }; |
973 | }; |
1051 | }; |
974 | }; |
1052 | }; |
975 | }; |
1053 | }; |
976 | }; |
1054 | }; |
977 | |
1055 | |
978 | $grp |
1056 | $grp |
979 | } |
1057 | } |
980 | |
1058 | |
981 | =item aio_rmtree $path, $callback->($status) |
1059 | =item aio_rmtree $pathname, $callback->($status) |
982 | |
1060 | |
983 | Delete a directory tree starting (and including) C<$path>, return the |
1061 | Delete a directory tree starting (and including) C<$path>, return the |
984 | status of the final C<rmdir> only. This is a composite request that |
1062 | status of the final C<rmdir> only. This is a composite request that |
985 | uses C<aio_scandir> to recurse into and rmdir directories, and unlink |
1063 | uses C<aio_scandir> to recurse into and rmdir directories, and unlink |
986 | everything else. |
1064 | everything else. |
… | |
… | |
1028 | callback with the fdatasync result code. |
1106 | callback with the fdatasync result code. |
1029 | |
1107 | |
1030 | If this call isn't available because your OS lacks it or it couldn't be |
1108 | If this call isn't available because your OS lacks it or it couldn't be |
1031 | detected, it will be emulated by calling C<fsync> instead. |
1109 | detected, it will be emulated by calling C<fsync> instead. |
1032 | |
1110 | |
|
|
1111 | =item aio_syncfs $fh, $callback->($status) |
|
|
1112 | |
|
|
1113 | Asynchronously call the syncfs syscall to sync the filesystem associated |
|
|
1114 | to the given filehandle and call the callback with the syncfs result |
|
|
1115 | code. If syncfs is not available, calls sync(), but returns C<-1> and sets |
|
|
1116 | errno to C<ENOSYS> nevertheless. |
|
|
1117 | |
1033 | =item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
1118 | =item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
1034 | |
1119 | |
1035 | Sync the data portion of the file specified by C<$offset> and C<$length> |
1120 | Sync the data portion of the file specified by C<$offset> and C<$length> |
1036 | to disk (but NOT the metadata), by calling the Linux-specific |
1121 | to disk (but NOT the metadata), by calling the Linux-specific |
1037 | sync_file_range call. If sync_file_range is not available or it returns |
1122 | sync_file_range call. If sync_file_range is not available or it returns |
… | |
… | |
1040 | C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>, |
1125 | C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>, |
1041 | C<IO::AIO::SYNC_FILE_RANGE_WRITE> and |
1126 | C<IO::AIO::SYNC_FILE_RANGE_WRITE> and |
1042 | C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range |
1127 | C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range |
1043 | manpage for details. |
1128 | manpage for details. |
1044 | |
1129 | |
1045 | =item aio_pathsync $path, $callback->($status) |
1130 | =item aio_pathsync $pathname, $callback->($status) |
1046 | |
1131 | |
1047 | This request tries to open, fsync and close the given path. This is a |
1132 | This request tries to open, fsync and close the given path. This is a |
1048 | composite request intended to sync directories after directory operations |
1133 | composite request intended to sync directories after directory operations |
1049 | (E.g. rename). This might not work on all operating systems or have any |
1134 | (E.g. rename). This might not work on all operating systems or have any |
1050 | specific effect, but usually it makes sure that directory changes get |
1135 | specific effect, but usually it makes sure that directory changes get |
… | |
… | |
1084 | } |
1169 | } |
1085 | |
1170 | |
1086 | =item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
1171 | =item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
1087 | |
1172 | |
1088 | This is a rather advanced IO::AIO call, which only works on mmap(2)ed |
1173 | This is a rather advanced IO::AIO call, which only works on mmap(2)ed |
1089 | scalars (see the L<Sys::Mmap> or L<Mmap> modules for details on this, note |
1174 | scalars (see the C<IO::AIO::mmap> function, although it also works on data |
|
|
1175 | scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the |
1090 | that the scalar must only be modified in-place while an aio operation is |
1176 | scalar must only be modified in-place while an aio operation is pending on |
1091 | pending on it). |
1177 | it). |
1092 | |
1178 | |
1093 | It calls the C<msync> function of your OS, if available, with the memory |
1179 | It calls the C<msync> function of your OS, if available, with the memory |
1094 | area starting at C<$offset> in the string and ending C<$length> bytes |
1180 | area starting at C<$offset> in the string and ending C<$length> bytes |
1095 | later. If C<$length> is negative, counts from the end, and if C<$length> |
1181 | later. If C<$length> is negative, counts from the end, and if C<$length> |
1096 | is C<undef>, then it goes till the end of the string. The flags can be |
1182 | is C<undef>, then it goes till the end of the string. The flags can be |
… | |
… | |
1107 | as for C<aio_msync>, above, except for flags, which must be either |
1193 | as for C<aio_msync>, above, except for flags, which must be either |
1108 | C<0> (which reads all pages and ensures they are instantiated) or |
1194 | C<0> (which reads all pages and ensures they are instantiated) or |
1109 | C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and |
1195 | C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and |
1110 | writing an octet from it, which dirties the page). |
1196 | writing an octet from it, which dirties the page). |
1111 | |
1197 | |
|
|
1198 | =item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
|
|
1199 | |
|
|
1200 | This is a rather advanced IO::AIO call, which works best on mmap(2)ed |
|
|
1201 | scalars. |
|
|
1202 | |
|
|
1203 | It reads in all the pages of the underlying storage into memory (if any) |
|
|
1204 | and locks them, so they are not getting swapped/paged out or removed. |
|
|
1205 | |
|
|
1206 | If C<$length> is undefined, then the scalar will be locked till the end. |
|
|
1207 | |
|
|
1208 | On systems that do not implement C<mlock>, this function returns C<-1> |
|
|
1209 | and sets errno to C<ENOSYS>. |
|
|
1210 | |
|
|
1211 | Note that the corresponding C<munlock> is synchronous and is |
|
|
1212 | documented under L<MISCELLANEOUS FUNCTIONS>. |
|
|
1213 | |
|
|
1214 | Example: open a file, mmap and mlock it - both will be undone when |
|
|
1215 | C<$data> gets destroyed. |
|
|
1216 | |
|
|
1217 | open my $fh, "<", $path or die "$path: $!"; |
|
|
1218 | my $data; |
|
|
1219 | IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh; |
|
|
1220 | aio_mlock $data; # mlock in background |
|
|
1221 | |
|
|
1222 | =item aio_mlockall $flags, $callback->($status) |
|
|
1223 | |
|
|
1224 | Calls the C<mlockall> function with the given C<$flags> (a combination of |
|
|
1225 | C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>). |
|
|
1226 | |
|
|
1227 | On systems that do not implement C<mlockall>, this function returns C<-1> |
|
|
1228 | and sets errno to C<ENOSYS>. |
|
|
1229 | |
|
|
1230 | Note that the corresponding C<munlockall> is synchronous and is |
|
|
1231 | documented under L<MISCELLANEOUS FUNCTIONS>. |
|
|
1232 | |
|
|
1233 | Example: asynchronously lock all current and future pages into memory. |
|
|
1234 | |
|
|
1235 | aio_mlockall IO::AIO::MCL_FUTURE; |
|
|
1236 | |
1112 | =item aio_group $callback->(...) |
1237 | =item aio_group $callback->(...) |
1113 | |
1238 | |
1114 | This is a very special aio request: Instead of doing something, it is a |
1239 | This is a very special aio request: Instead of doing something, it is a |
1115 | container for other aio requests, which is useful if you want to bundle |
1240 | container for other aio requests, which is useful if you want to bundle |
1116 | many requests into a single, composite, request with a definite callback |
1241 | many requests into a single, composite, request with a definite callback |
… | |
… | |
1152 | like sleep and file handle readable/writable, the overhead this creates is |
1277 | like sleep and file handle readable/writable, the overhead this creates is |
1153 | immense (it blocks a thread for a long time) so do not use this function |
1278 | immense (it blocks a thread for a long time) so do not use this function |
1154 | except to put your application under artificial I/O pressure. |
1279 | except to put your application under artificial I/O pressure. |
1155 | |
1280 | |
1156 | =back |
1281 | =back |
|
|
1282 | |
|
|
1283 | |
|
|
1284 | =head2 IO::AIO::WD - multiple working directories |
|
|
1285 | |
|
|
1286 | Your process only has one current working directory, which is used by all |
|
|
1287 | threads. This makes it hard to use relative paths (some other component |
|
|
1288 | could call C<chdir> at any time, and it is hard to control when the path |
|
|
1289 | will be used by IO::AIO). |
|
|
1290 | |
|
|
1291 | One solution for this is to always use absolute paths. This usually works, |
|
|
1292 | but can be quite slow (the kernel has to walk the whole path on every |
|
|
1293 | access), and can also be a hassle to implement. |
|
|
1294 | |
|
|
1295 | Newer POSIX systems have a number of functions (openat, fdopendir, |
|
|
1296 | futimensat and so on) that make it possible to specify working directories |
|
|
1297 | per operation. |
|
|
1298 | |
|
|
1299 | For portability, and because the clowns who "designed", or shall I write, |
|
|
1300 | perpetrated this new interface were obviously half-drunk, this abstraction |
|
|
1301 | cannot be perfect, though. |
|
|
1302 | |
|
|
1303 | IO::AIO allows you to convert directory paths into a so-called IO::AIO::WD |
|
|
1304 | object. This object stores the canonicalised, absolute version of the |
|
|
1305 | path, and on systems that allow it, also a directory file descriptor. |
|
|
1306 | |
|
|
1307 | Everywhere where a pathname is accepted by IO::AIO (e.g. in C<aio_stat> |
|
|
1308 | or C<aio_unlink>), one can specify an array reference with an IO::AIO::WD |
|
|
1309 | object and a pathname instead (or the IO::AIO::WD object alone, which |
|
|
1310 | gets interpreted as C<[$wd, "."]>). If the pathname is absolute, the |
|
|
1311 | IO::AIO::WD object is ignored, otherwise the pathname is resolved relative |
|
|
1312 | to that IO::AIO::WD object. |
|
|
1313 | |
|
|
1314 | For example, to get a wd object for F</etc> and then stat F<passwd> |
|
|
1315 | inside, you would write: |
|
|
1316 | |
|
|
1317 | aio_wd "/etc", sub { |
|
|
1318 | my $etcdir = shift; |
|
|
1319 | |
|
|
1320 | # although $etcdir can be undef on error, there is generally no reason |
|
|
1321 | # to check for errors here, as aio_stat will fail with ENOENT |
|
|
1322 | # when $etcdir is undef. |
|
|
1323 | |
|
|
1324 | aio_stat [$etcdir, "passwd"], sub { |
|
|
1325 | # yay |
|
|
1326 | }; |
|
|
1327 | }; |
|
|
1328 | |
|
|
1329 | That C<aio_wd> is a request and not a normal function shows that creating |
|
|
1330 | an IO::AIO::WD object is itself a potentially blocking operation, which is |
|
|
1331 | why it is done asynchronously. |
|
|
1332 | |
|
|
1333 | To stat the directory obtained with C<aio_wd> above, one could write |
|
|
1334 | either of the following three request calls: |
|
|
1335 | |
|
|
1336 | aio_lstat "/etc" , sub { ... # pathname as normal string |
|
|
1337 | aio_lstat [$wd, "."], sub { ... # "." relative to $wd (i.e. $wd itself) |
|
|
1338 | aio_lstat $wd , sub { ... # shorthand for the previous |
|
|
1339 | |
|
|
1340 | As with normal pathnames, IO::AIO keeps a copy of the working directory |
|
|
1341 | object and the pathname string, so you could write the following without |
|
|
1342 | causing any issues due to C<$path> getting reused: |
|
|
1343 | |
|
|
1344 | my $path = [$wd, undef]; |
|
|
1345 | |
|
|
1346 | for my $name (qw(abc def ghi)) { |
|
|
1347 | $path->[1] = $name; |
|
|
1348 | aio_stat $path, sub { |
|
|
1349 | # ... |
|
|
1350 | }; |
|
|
1351 | } |
|
|
1352 | |
|
|
1353 | There are some caveats: when directories get renamed (or deleted), the |
|
|
1354 | pathname string doesn't change, so will point to the new directory (or |
|
|
1355 | nowhere at all), while the directory fd, if available on the system, |
|
|
1356 | will still point to the original directory. Most functions accepting a |
|
|
1357 | pathname will use the directory fd on newer systems, and the string on |
|
|
1358 | older systems. Some functions (such as realpath) will always rely on the |
|
|
1359 | string form of the pathname. |
|
|
1360 | |
|
|
1361 | So this fucntionality is mainly useful to get some protection against |
|
|
1362 | C<chdir>, to easily get an absolute path out of a relative path for future |
|
|
1363 | reference, and to speed up doing many operations in the same directory |
|
|
1364 | (e.g. when stat'ing all files in a directory). |
|
|
1365 | |
|
|
1366 | The following functions implement this working directory abstraction: |
|
|
1367 | |
|
|
1368 | =over 4 |
|
|
1369 | |
|
|
1370 | =item aio_wd $pathname, $callback->($wd) |
|
|
1371 | |
|
|
1372 | Asynchonously canonicalise the given pathname and convert it to an |
|
|
1373 | IO::AIO::WD object representing it. If possible and supported on the |
|
|
1374 | system, also open a directory fd to speed up pathname resolution relative |
|
|
1375 | to this working directory. |
|
|
1376 | |
|
|
1377 | If something goes wrong, then C<undef> is passwd to the callback instead |
|
|
1378 | of a working directory object and C<$!> is set appropriately. Since |
|
|
1379 | passing C<undef> as working directory component of a pathname fails the |
|
|
1380 | request with C<ENOENT>, there is often no need for error checking in the |
|
|
1381 | C<aio_wd> callback, as future requests using the value will fail in the |
|
|
1382 | expected way. |
|
|
1383 | |
|
|
1384 | If this call isn't available because your OS lacks it or it couldn't be |
|
|
1385 | detected, it will be emulated by calling C<fsync> instead. |
|
|
1386 | |
|
|
1387 | =item IO::AIO::CWD |
|
|
1388 | |
|
|
1389 | This is a compiletime constant (object) that represents the process |
|
|
1390 | current working directory. |
|
|
1391 | |
|
|
1392 | Specifying this object as working directory object for a pathname is as |
|
|
1393 | if the pathname would be specified directly, without a directory object, |
|
|
1394 | e.g., these calls are functionally identical: |
|
|
1395 | |
|
|
1396 | aio_stat "somefile", sub { ... }; |
|
|
1397 | aio_stat [IO::AIO::CWD, "somefile"], sub { ... }; |
|
|
1398 | |
|
|
1399 | =back |
|
|
1400 | |
1157 | |
1401 | |
1158 | =head2 IO::AIO::REQ CLASS |
1402 | =head2 IO::AIO::REQ CLASS |
1159 | |
1403 | |
1160 | All non-aggregate C<aio_*> functions return an object of this class when |
1404 | All non-aggregate C<aio_*> functions return an object of this class when |
1161 | called in non-void context. |
1405 | called in non-void context. |
… | |
… | |
1279 | |
1523 | |
1280 | Sets a feeder/generator on this group: every group can have an attached |
1524 | Sets a feeder/generator on this group: every group can have an attached |
1281 | generator that generates requests if idle. The idea behind this is that, |
1525 | generator that generates requests if idle. The idea behind this is that, |
1282 | although you could just queue as many requests as you want in a group, |
1526 | although you could just queue as many requests as you want in a group, |
1283 | this might starve other requests for a potentially long time. For example, |
1527 | this might starve other requests for a potentially long time. For example, |
1284 | C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests, |
1528 | C<aio_scandir> might generate hundreds of thousands of C<aio_stat> |
1285 | delaying any later requests for a long time. |
1529 | requests, delaying any later requests for a long time. |
1286 | |
1530 | |
1287 | To avoid this, and allow incremental generation of requests, you can |
1531 | To avoid this, and allow incremental generation of requests, you can |
1288 | instead a group and set a feeder on it that generates those requests. The |
1532 | instead a group and set a feeder on it that generates those requests. The |
1289 | feed callback will be called whenever there are few enough (see C<limit>, |
1533 | feed callback will be called whenever there are few enough (see C<limit>, |
1290 | below) requests active in the group itself and is expected to queue more |
1534 | below) requests active in the group itself and is expected to queue more |
… | |
… | |
1339 | |
1583 | |
1340 | See C<poll_cb> for an example. |
1584 | See C<poll_cb> for an example. |
1341 | |
1585 | |
1342 | =item IO::AIO::poll_cb |
1586 | =item IO::AIO::poll_cb |
1343 | |
1587 | |
1344 | Process some outstanding events on the result pipe. You have to call this |
1588 | Process some outstanding events on the result pipe. You have to call |
1345 | regularly. Returns C<0> if all events could be processed, or C<-1> if it |
1589 | this regularly. Returns C<0> if all events could be processed (or there |
1346 | returned earlier for whatever reason. Returns immediately when no events |
1590 | were no events to process), or C<-1> if it returned earlier for whatever |
1347 | are outstanding. The amount of events processed depends on the settings of |
1591 | reason. Returns immediately when no events are outstanding. The amount of |
1348 | C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>. |
1592 | events processed depends on the settings of C<IO::AIO::max_poll_req> and |
|
|
1593 | C<IO::AIO::max_poll_time>. |
1349 | |
1594 | |
1350 | If not all requests were processed for whatever reason, the filehandle |
1595 | If not all requests were processed for whatever reason, the filehandle |
1351 | will still be ready when C<poll_cb> returns, so normally you don't have to |
1596 | will still be ready when C<poll_cb> returns, so normally you don't have to |
1352 | do anything special to have it called later. |
1597 | do anything special to have it called later. |
|
|
1598 | |
|
|
1599 | Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes |
|
|
1600 | ready, it can be beneficial to call this function from loops which submit |
|
|
1601 | a lot of requests, to make sure the results get processed when they become |
|
|
1602 | available and not just when the loop is finished and the event loop takes |
|
|
1603 | over again. This function returns very fast when there are no outstanding |
|
|
1604 | requests. |
1353 | |
1605 | |
1354 | Example: Install an Event watcher that automatically calls |
1606 | Example: Install an Event watcher that automatically calls |
1355 | IO::AIO::poll_cb with high priority (more examples can be found in the |
1607 | IO::AIO::poll_cb with high priority (more examples can be found in the |
1356 | SYNOPSIS section, at the top of this document): |
1608 | SYNOPSIS section, at the top of this document): |
1357 | |
1609 | |
… | |
… | |
1459 | |
1711 | |
1460 | Under normal circumstances you don't need to call this function. |
1712 | Under normal circumstances you don't need to call this function. |
1461 | |
1713 | |
1462 | =item IO::AIO::max_idle $nthreads |
1714 | =item IO::AIO::max_idle $nthreads |
1463 | |
1715 | |
1464 | Limit the number of threads (default: 4) that are allowed to idle (i.e., |
1716 | Limit the number of threads (default: 4) that are allowed to idle |
1465 | threads that did not get a request to process within 10 seconds). That |
1717 | (i.e., threads that did not get a request to process within the idle |
1466 | means if a thread becomes idle while C<$nthreads> other threads are also |
1718 | timeout (default: 10 seconds). That means if a thread becomes idle while |
1467 | idle, it will free its resources and exit. |
1719 | C<$nthreads> other threads are also idle, it will free its resources and |
|
|
1720 | exit. |
1468 | |
1721 | |
1469 | This is useful when you allow a large number of threads (e.g. 100 or 1000) |
1722 | This is useful when you allow a large number of threads (e.g. 100 or 1000) |
1470 | to allow for extremely high load situations, but want to free resources |
1723 | to allow for extremely high load situations, but want to free resources |
1471 | under normal circumstances (1000 threads can easily consume 30MB of RAM). |
1724 | under normal circumstances (1000 threads can easily consume 30MB of RAM). |
1472 | |
1725 | |
1473 | The default is probably ok in most situations, especially if thread |
1726 | The default is probably ok in most situations, especially if thread |
1474 | creation is fast. If thread creation is very slow on your system you might |
1727 | creation is fast. If thread creation is very slow on your system you might |
1475 | want to use larger values. |
1728 | want to use larger values. |
1476 | |
1729 | |
|
|
1730 | =item IO::AIO::idle_timeout $seconds |
|
|
1731 | |
|
|
1732 | Sets the minimum idle timeout (default 10) after which worker threads are |
|
|
1733 | allowed to exit. SEe C<IO::AIO::max_idle>. |
|
|
1734 | |
1477 | =item IO::AIO::max_outstanding $maxreqs |
1735 | =item IO::AIO::max_outstanding $maxreqs |
|
|
1736 | |
|
|
1737 | Sets the maximum number of outstanding requests to C<$nreqs>. If |
|
|
1738 | you do queue up more than this number of requests, the next call to |
|
|
1739 | C<IO::AIO::poll_cb> (and other functions calling C<poll_cb>, such as |
|
|
1740 | C<IO::AIO::flush> or C<IO::AIO::poll>) will block until the limit is no |
|
|
1741 | longer exceeded. |
|
|
1742 | |
|
|
1743 | In other words, this setting does not enforce a queue limit, but can be |
|
|
1744 | used to make poll functions block if the limit is exceeded. |
1478 | |
1745 | |
1479 | This is a very bad function to use in interactive programs because it |
1746 | This is a very bad function to use in interactive programs because it |
1480 | blocks, and a bad way to reduce concurrency because it is inexact: Better |
1747 | blocks, and a bad way to reduce concurrency because it is inexact: Better |
1481 | use an C<aio_group> together with a feed callback. |
1748 | use an C<aio_group> together with a feed callback. |
1482 | |
1749 | |
1483 | Sets the maximum number of outstanding requests to C<$nreqs>. If you |
1750 | It's main use is in scripts without an event loop - when you want to stat |
1484 | do queue up more than this number of requests, the next call to the |
1751 | a lot of files, you can write somehting like this: |
1485 | C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>) |
|
|
1486 | function will block until the limit is no longer exceeded. |
|
|
1487 | |
1752 | |
1488 | The default value is very large, so there is no practical limit on the |
1753 | IO::AIO::max_outstanding 32; |
1489 | number of outstanding requests. |
|
|
1490 | |
1754 | |
1491 | You can still queue as many requests as you want. Therefore, |
1755 | for my $path (...) { |
1492 | C<max_outstanding> is mainly useful in simple scripts (with low values) or |
1756 | aio_stat $path , ...; |
1493 | as a stop gap to shield against fatal memory overflow (with large values). |
1757 | IO::AIO::poll_cb; |
|
|
1758 | } |
|
|
1759 | |
|
|
1760 | IO::AIO::flush; |
|
|
1761 | |
|
|
1762 | The call to C<poll_cb> inside the loop will normally return instantly, but |
|
|
1763 | as soon as more thna C<32> reqeusts are in-flight, it will block until |
|
|
1764 | some requests have been handled. This keeps the loop from pushing a large |
|
|
1765 | number of C<aio_stat> requests onto the queue. |
|
|
1766 | |
|
|
1767 | The default value for C<max_outstanding> is very large, so there is no |
|
|
1768 | practical limit on the number of outstanding requests. |
1494 | |
1769 | |
1495 | =back |
1770 | =back |
1496 | |
1771 | |
1497 | =head3 STATISTICAL INFORMATION |
1772 | =head3 STATISTICAL INFORMATION |
1498 | |
1773 | |
… | |
… | |
1536 | |
1811 | |
1537 | Returns the number of bytes copied, or C<-1> on error. |
1812 | Returns the number of bytes copied, or C<-1> on error. |
1538 | |
1813 | |
1539 | =item IO::AIO::fadvise $fh, $offset, $len, $advice |
1814 | =item IO::AIO::fadvise $fh, $offset, $len, $advice |
1540 | |
1815 | |
1541 | Simply calls the C<posix_fadvise> function (see it's |
1816 | Simply calls the C<posix_fadvise> function (see its |
1542 | manpage for details). The following advice constants are |
1817 | manpage for details). The following advice constants are |
1543 | avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>, |
1818 | available: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>, |
1544 | C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>, |
1819 | C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>, |
1545 | C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>. |
1820 | C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>. |
1546 | |
1821 | |
1547 | On systems that do not implement C<posix_fadvise>, this function returns |
1822 | On systems that do not implement C<posix_fadvise>, this function returns |
1548 | ENOSYS, otherwise the return value of C<posix_fadvise>. |
1823 | ENOSYS, otherwise the return value of C<posix_fadvise>. |
1549 | |
1824 | |
1550 | =item IO::AIO::mlockall $flags |
1825 | =item IO::AIO::madvise $scalar, $offset, $len, $advice |
1551 | |
1826 | |
1552 | Calls the C<mlockall> function with the given C<$flags> (a combination of |
1827 | Simply calls the C<posix_madvise> function (see its |
1553 | C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL__FUTURE>). |
1828 | manpage for details). The following advice constants are |
|
|
1829 | available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>, |
|
|
1830 | C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>. |
1554 | |
1831 | |
|
|
1832 | On systems that do not implement C<posix_madvise>, this function returns |
|
|
1833 | ENOSYS, otherwise the return value of C<posix_madvise>. |
|
|
1834 | |
|
|
1835 | =item IO::AIO::mprotect $scalar, $offset, $len, $protect |
|
|
1836 | |
|
|
1837 | Simply calls the C<mprotect> function on the preferably AIO::mmap'ed |
|
|
1838 | $scalar (see its manpage for details). The following protect |
|
|
1839 | constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>, |
|
|
1840 | C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>. |
|
|
1841 | |
1555 | On systems that do not implement C<mlockall>, this function returns |
1842 | On systems that do not implement C<mprotect>, this function returns |
1556 | ENOSYS, otherwise the return value of C<mlockall>. |
1843 | ENOSYS, otherwise the return value of C<mprotect>. |
|
|
1844 | |
|
|
1845 | =item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] |
|
|
1846 | |
|
|
1847 | Memory-maps a file (or anonymous memory range) and attaches it to the |
|
|
1848 | given C<$scalar>, which will act like a string scalar. |
|
|
1849 | |
|
|
1850 | The only operations allowed on the scalar are C<substr>/C<vec> that don't |
|
|
1851 | change the string length, and most read-only operations such as copying it |
|
|
1852 | or searching it with regexes and so on. |
|
|
1853 | |
|
|
1854 | Anything else is unsafe and will, at best, result in memory leaks. |
|
|
1855 | |
|
|
1856 | The memory map associated with the C<$scalar> is automatically removed |
|
|
1857 | when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or |
|
|
1858 | C<IO::AIO::munmap> functions are called. |
|
|
1859 | |
|
|
1860 | This calls the C<mmap>(2) function internally. See your system's manual |
|
|
1861 | page for details on the C<$length>, C<$prot> and C<$flags> parameters. |
|
|
1862 | |
|
|
1863 | The C<$length> must be larger than zero and smaller than the actual |
|
|
1864 | filesize. |
|
|
1865 | |
|
|
1866 | C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>, |
|
|
1867 | C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>, |
|
|
1868 | |
|
|
1869 | C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or |
|
|
1870 | C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when |
|
|
1871 | not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS> |
|
|
1872 | (which is set to C<MAP_ANON> if your system only provides this |
|
|
1873 | constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>, |
|
|
1874 | C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or |
|
|
1875 | C<IO::AIO::MAP_NONBLOCK> |
|
|
1876 | |
|
|
1877 | If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed. |
|
|
1878 | |
|
|
1879 | C<$offset> is the offset from the start of the file - it generally must be |
|
|
1880 | a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>. |
|
|
1881 | |
|
|
1882 | Example: |
|
|
1883 | |
|
|
1884 | use Digest::MD5; |
|
|
1885 | use IO::AIO; |
|
|
1886 | |
|
|
1887 | open my $fh, "<verybigfile" |
|
|
1888 | or die "$!"; |
|
|
1889 | |
|
|
1890 | IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh |
|
|
1891 | or die "verybigfile: $!"; |
|
|
1892 | |
|
|
1893 | my $fast_md5 = md5 $data; |
|
|
1894 | |
|
|
1895 | =item IO::AIO::munmap $scalar |
|
|
1896 | |
|
|
1897 | Removes a previous mmap and undefines the C<$scalar>. |
|
|
1898 | |
|
|
1899 | =item IO::AIO::munlock $scalar, $offset = 0, $length = undef |
|
|
1900 | |
|
|
1901 | Calls the C<munlock> function, undoing the effects of a previous |
|
|
1902 | C<aio_mlock> call (see its description for details). |
1557 | |
1903 | |
1558 | =item IO::AIO::munlockall |
1904 | =item IO::AIO::munlockall |
1559 | |
1905 | |
1560 | Calls the C<munlockall> function. |
1906 | Calls the C<munlockall> function. |
1561 | |
1907 | |
… | |
… | |
1603 | Danga::Socket->AddOtherFds (IO::AIO::poll_fileno => |
1949 | Danga::Socket->AddOtherFds (IO::AIO::poll_fileno => |
1604 | \&IO::AIO::poll_cb); |
1950 | \&IO::AIO::poll_cb); |
1605 | |
1951 | |
1606 | =head2 FORK BEHAVIOUR |
1952 | =head2 FORK BEHAVIOUR |
1607 | |
1953 | |
1608 | This module should do "the right thing" when the process using it forks: |
1954 | Usage of pthreads in a program changes the semantics of fork |
|
|
1955 | considerably. Specifically, only async-safe functions can be called after |
|
|
1956 | fork. Perl doesn't know about this, so in general, you cannot call fork |
|
|
1957 | with defined behaviour in perl if pthreads are involved. IO::AIO uses |
|
|
1958 | pthreads, so this applies, but many other extensions and (for inexplicable |
|
|
1959 | reasons) perl itself often is linked against pthreads, so this limitation |
|
|
1960 | applies to quite a lot of perls. |
1609 | |
1961 | |
1610 | Before the fork, IO::AIO enters a quiescent state where no requests |
1962 | This module no longer tries to fight your OS, or POSIX. That means IO::AIO |
1611 | can be added in other threads and no results will be processed. After |
1963 | only works in the process that loaded it. Forking is fully supported, but |
1612 | the fork the parent simply leaves the quiescent state and continues |
1964 | using IO::AIO in the child is not. |
1613 | request/result processing, while the child frees the request/result queue |
|
|
1614 | (so that the requests started before the fork will only be handled in the |
|
|
1615 | parent). Threads will be started on demand until the limit set in the |
|
|
1616 | parent process has been reached again. |
|
|
1617 | |
1965 | |
1618 | In short: the parent will, after a short pause, continue as if fork had |
1966 | You might get around by not I<using> IO::AIO before (or after) |
1619 | not been called, while the child will act as if IO::AIO has not been used |
1967 | forking. You could also try to call the L<IO::AIO::reinit> function in the |
1620 | yet. |
1968 | child: |
|
|
1969 | |
|
|
1970 | =over 4 |
|
|
1971 | |
|
|
1972 | =item IO::AIO::reinit |
|
|
1973 | |
|
|
1974 | Abandons all current requests and I/O threads and simply reinitialises all |
|
|
1975 | data structures. This is not an operation supported by any standards, but |
|
|
1976 | happens to work on GNU/Linux and some newer BSD systems. |
|
|
1977 | |
|
|
1978 | The only reasonable use for this function is to call it after forking, if |
|
|
1979 | C<IO::AIO> was used in the parent. Calling it while IO::AIO is active in |
|
|
1980 | the process will result in undefined behaviour. Calling it at any time |
|
|
1981 | will also result in any undefined (by POSIX) behaviour. |
|
|
1982 | |
|
|
1983 | =back |
1621 | |
1984 | |
1622 | =head2 MEMORY USAGE |
1985 | =head2 MEMORY USAGE |
1623 | |
1986 | |
1624 | Per-request usage: |
1987 | Per-request usage: |
1625 | |
1988 | |