| … | |
… | |
| 183 | |
183 | |
| 184 | =cut |
184 | =cut |
| 185 | |
185 | |
| 186 | package IO::AIO; |
186 | package IO::AIO; |
| 187 | |
187 | |
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188 | use Carp (); |
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189 | |
| 188 | no warnings; |
190 | no warnings; |
| 189 | use strict 'vars'; |
191 | use strict 'vars'; |
| 190 | |
192 | |
| 191 | use base 'Exporter'; |
193 | use base 'Exporter'; |
| 192 | |
194 | |
| 193 | BEGIN { |
195 | BEGIN { |
| 194 | our $VERSION = '2.5'; |
196 | our $VERSION = '2.51'; |
| 195 | |
197 | |
| 196 | our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat |
198 | our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat |
| 197 | aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink |
199 | aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink |
| 198 | aio_readlink aio_fsync aio_fdatasync aio_readahead aio_rename aio_link |
200 | aio_readlink aio_fsync aio_fdatasync aio_readahead aio_rename aio_link |
| 199 | aio_move aio_copy aio_group aio_nop aio_mknod aio_load aio_rmtree aio_mkdir |
201 | aio_move aio_copy aio_group aio_nop aio_mknod aio_load aio_rmtree aio_mkdir |
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| 313 | =item aio_close $fh, $callback->($status) |
315 | =item aio_close $fh, $callback->($status) |
| 314 | |
316 | |
| 315 | Asynchronously close a file and call the callback with the result |
317 | Asynchronously close a file and call the callback with the result |
| 316 | code. |
318 | code. |
| 317 | |
319 | |
| 318 | Unlike the other functions operating on files, this function uses the |
320 | Unfortunately, you can't do this to perl. Perl I<insists> very strongly on |
| 319 | PerlIO layer to close the filehandle. The reason is that the PerlIO API |
321 | closing the file descriptor associated with the filehandle itself. Here is |
| 320 | insists on closing the underlying fd itself, no matter what, and doesn't |
322 | what aio_close will try: |
| 321 | allow modifications to the fd. Unfortunately, it is not clear that you can |
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| 322 | call PerlIO from different threads (actually, its quite clear that this |
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| 323 | won't work in some cases), so while it likely works perfectly with simple |
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| 324 | file handles (such as the ones created by C<aio_open>) it might fail in |
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| 325 | interesting ways for others. |
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| 326 | |
323 | |
| 327 | Having said that, aio_close tries to clean up the filehandle as much as |
324 | 1. dup()licate the fd |
| 328 | possible before handing it to an io thread, and generally does work. |
325 | 2. asynchronously close() the duplicated fd |
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326 | 3. dup()licate the fd once more |
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327 | 4. let perl close() the filehandle |
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328 | 5. asynchronously close the duplicated fd |
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329 | |
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330 | The idea is that the first close() flushes stuff to disk that closing an |
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331 | fd will flush, so when perl closes the fd, nothing much will need to be |
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332 | flushed. The second async. close() will then flush stuff to disk that |
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333 | closing the last fd to the file will flush. |
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334 | |
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335 | Just FYI, SuSv3 has this to say on close: |
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336 | |
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337 | All outstanding record locks owned by the process on the file |
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338 | associated with the file descriptor shall be removed. |
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339 | |
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340 | If fildes refers to a socket, close() shall cause the socket to be |
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341 | destroyed. ... close() shall block for up to the current linger |
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342 | interval until all data is transmitted. |
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343 | [this actually sounds like a specification bug, but who knows] |
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344 | |
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345 | And at least Linux additionally actually flushes stuff on every close, |
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346 | even when the file itself is still open. |
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347 | |
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348 | Sounds enourmously inefficient and complicated? Yes... please show me how |
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349 | to nuke perl's fd out of existence... |
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350 | |
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351 | =cut |
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352 | |
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353 | sub aio_close($;$) { |
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354 | aio_block { |
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355 | my ($fh, $cb) = @_; |
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356 | |
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357 | my $pri = aioreq_pri; |
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358 | my $grp = aio_group $cb; |
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359 | |
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360 | my $fd = fileno $fh; |
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361 | |
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362 | defined $fd or Carp::croak "aio_close called with fd-less filehandle"; |
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363 | |
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364 | # if the dups fail we will simply get EBADF |
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365 | my $fd2 = _dup $fd; |
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366 | aioreq_pri $pri; |
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367 | add $grp _aio_close $fd2, sub { |
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368 | my $fd2 = _dup $fd; |
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369 | close $fh; |
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370 | aioreq_pri $pri; |
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371 | add $grp _aio_close $fd2, sub { |
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372 | $grp->result ($_[0]); |
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373 | }; |
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374 | }; |
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375 | |
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376 | $grp |
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377 | } |
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378 | } |
| 329 | |
379 | |
| 330 | |
380 | |
| 331 | =item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
381 | =item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
| 332 | |
382 | |
| 333 | =item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
383 | =item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
