1 | =head1 NAME |
1 | =head1 NAME |
2 | |
2 | |
3 | IO::AIO - Asynchronous Input/Output |
3 | IO::AIO - Asynchronous/Advanced Input/Output |
4 | |
4 | |
5 | =head1 SYNOPSIS |
5 | =head1 SYNOPSIS |
6 | |
6 | |
7 | use IO::AIO; |
7 | use IO::AIO; |
8 | |
8 | |
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58 | not well-supported or restricted (GNU/Linux doesn't allow them on normal |
58 | not well-supported or restricted (GNU/Linux doesn't allow them on normal |
59 | files currently, for example), and they would only support aio_read and |
59 | files currently, for example), and they would only support aio_read and |
60 | aio_write, so the remaining functionality would have to be implemented |
60 | aio_write, so the remaining functionality would have to be implemented |
61 | using threads anyway. |
61 | using threads anyway. |
62 | |
62 | |
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63 | In addition to asynchronous I/O, this module also exports some rather |
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64 | arcane interfaces, such as C<madvise> or linux's C<splice> system call, |
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65 | which is why the C<A> in C<AIO> can also mean I<advanced>. |
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66 | |
63 | Although the module will work in the presence of other (Perl-) threads, |
67 | Although the module will work in the presence of other (Perl-) threads, |
64 | it is currently not reentrant in any way, so use appropriate locking |
68 | it is currently not reentrant in any way, so use appropriate locking |
65 | yourself, always call C<poll_cb> from within the same thread, or never |
69 | yourself, always call C<poll_cb> from within the same thread, or never |
66 | call C<poll_cb> (or other C<aio_> functions) recursively. |
70 | call C<poll_cb> (or other C<aio_> functions) recursively. |
67 | |
71 | |
68 | =head2 EXAMPLE |
72 | =head2 EXAMPLE |
69 | |
73 | |
70 | This is a simple example that uses the EV module and loads |
74 | This is a simple example that uses the EV module and loads |
71 | F</etc/passwd> asynchronously: |
75 | F</etc/passwd> asynchronously: |
72 | |
76 | |
73 | use Fcntl; |
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74 | use EV; |
77 | use EV; |
75 | use IO::AIO; |
78 | use IO::AIO; |
76 | |
79 | |
77 | # register the IO::AIO callback with EV |
80 | # register the IO::AIO callback with EV |
78 | my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
81 | my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
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95 | |
98 | |
96 | # file contents now in $contents |
99 | # file contents now in $contents |
97 | print $contents; |
100 | print $contents; |
98 | |
101 | |
99 | # exit event loop and program |
102 | # exit event loop and program |
100 | EV::unloop; |
103 | EV::break; |
101 | }; |
104 | }; |
102 | }; |
105 | }; |
103 | |
106 | |
104 | # possibly queue up other requests, or open GUI windows, |
107 | # possibly queue up other requests, or open GUI windows, |
105 | # check for sockets etc. etc. |
108 | # check for sockets etc. etc. |
106 | |
109 | |
107 | # process events as long as there are some: |
110 | # process events as long as there are some: |
108 | EV::loop; |
111 | EV::run; |
109 | |
112 | |
110 | =head1 REQUEST ANATOMY AND LIFETIME |
113 | =head1 REQUEST ANATOMY AND LIFETIME |
111 | |
114 | |
112 | Every C<aio_*> function creates a request. which is a C data structure not |
115 | Every C<aio_*> function creates a request. which is a C data structure not |
113 | directly visible to Perl. |
116 | directly visible to Perl. |
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168 | use common::sense; |
171 | use common::sense; |
169 | |
172 | |
170 | use base 'Exporter'; |
173 | use base 'Exporter'; |
171 | |
174 | |
172 | BEGIN { |
175 | BEGIN { |
173 | our $VERSION = '3.91'; |
176 | our $VERSION = 4.35; |
174 | |
177 | |
175 | our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close |
178 | our @AIO_REQ = qw(aio_sendfile aio_seek aio_read aio_write aio_open aio_close |
176 | aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx |
179 | aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx |
177 | aio_scandir aio_symlink aio_readlink aio_sync aio_fsync |
180 | aio_scandir aio_symlink aio_readlink aio_realpath aio_fcntl aio_ioctl |
178 | aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead |
181 | aio_sync aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range |
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182 | aio_pathsync aio_readahead aio_fiemap aio_allocate |
179 | aio_rename aio_link aio_move aio_copy aio_group |
183 | aio_rename aio_link aio_move aio_copy aio_group |
180 | aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown |
184 | aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown |
181 | aio_chmod aio_utime aio_truncate |
185 | aio_chmod aio_utime aio_truncate |
182 | aio_msync aio_mtouch aio_mlock aio_mlockall |
186 | aio_msync aio_mtouch aio_mlock aio_mlockall |
183 | aio_statvfs); |
187 | aio_statvfs |
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188 | aio_wd); |
184 | |
189 | |
185 | our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); |
190 | our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); |
186 | our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush |
191 | our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush |
187 | min_parallel max_parallel max_idle idle_timeout |
192 | min_parallel max_parallel max_idle idle_timeout |
188 | nreqs nready npending nthreads |
193 | nreqs nready npending nthreads |
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200 | |
205 | |
201 | =head1 FUNCTIONS |
206 | =head1 FUNCTIONS |
202 | |
207 | |
203 | =head2 QUICK OVERVIEW |
208 | =head2 QUICK OVERVIEW |
204 | |
209 | |
205 | This section simply lists the prototypes of the most important functions |
210 | This section simply lists the prototypes most of the functions for |
206 | for quick reference. See the following sections for function-by-function |
211 | quick reference. See the following sections for function-by-function |
207 | documentation. |
212 | documentation. |
208 | |
213 | |
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214 | aio_wd $pathname, $callback->($wd) |
209 | aio_open $pathname, $flags, $mode, $callback->($fh) |
215 | aio_open $pathname, $flags, $mode, $callback->($fh) |
210 | aio_close $fh, $callback->($status) |
216 | aio_close $fh, $callback->($status) |
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217 | aio_seek $fh,$offset,$whence, $callback->($offs) |
211 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
218 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
212 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
219 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
213 | aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
220 | aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
214 | aio_readahead $fh,$offset,$length, $callback->($retval) |
221 | aio_readahead $fh,$offset,$length, $callback->($retval) |
215 | aio_stat $fh_or_path, $callback->($status) |
222 | aio_stat $fh_or_path, $callback->($status) |
216 | aio_lstat $fh, $callback->($status) |
223 | aio_lstat $fh, $callback->($status) |
217 | aio_statvfs $fh_or_path, $callback->($statvfs) |
224 | aio_statvfs $fh_or_path, $callback->($statvfs) |
218 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
225 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
219 | aio_chown $fh_or_path, $uid, $gid, $callback->($status) |
226 | aio_chown $fh_or_path, $uid, $gid, $callback->($status) |
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227 | aio_chmod $fh_or_path, $mode, $callback->($status) |
220 | aio_truncate $fh_or_path, $offset, $callback->($status) |
228 | aio_truncate $fh_or_path, $offset, $callback->($status) |
221 | aio_chmod $fh_or_path, $mode, $callback->($status) |
229 | aio_allocate $fh, $mode, $offset, $len, $callback->($status) |
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230 | aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents) |
222 | aio_unlink $pathname, $callback->($status) |
231 | aio_unlink $pathname, $callback->($status) |
223 | aio_mknod $path, $mode, $dev, $callback->($status) |
232 | aio_mknod $pathname, $mode, $dev, $callback->($status) |
224 | aio_link $srcpath, $dstpath, $callback->($status) |
233 | aio_link $srcpath, $dstpath, $callback->($status) |
225 | aio_symlink $srcpath, $dstpath, $callback->($status) |
234 | aio_symlink $srcpath, $dstpath, $callback->($status) |
226 | aio_readlink $path, $callback->($link) |
235 | aio_readlink $pathname, $callback->($link) |
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236 | aio_realpath $pathname, $callback->($path) |
227 | aio_rename $srcpath, $dstpath, $callback->($status) |
237 | aio_rename $srcpath, $dstpath, $callback->($status) |
228 | aio_mkdir $pathname, $mode, $callback->($status) |
238 | aio_mkdir $pathname, $mode, $callback->($status) |
229 | aio_rmdir $pathname, $callback->($status) |
239 | aio_rmdir $pathname, $callback->($status) |
230 | aio_readdir $pathname, $callback->($entries) |
240 | aio_readdir $pathname, $callback->($entries) |
231 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
241 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
232 | IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST |
242 | IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST |
233 | IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN |
243 | IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN |
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244 | aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) |
234 | aio_load $path, $data, $callback->($status) |
245 | aio_load $pathname, $data, $callback->($status) |
235 | aio_copy $srcpath, $dstpath, $callback->($status) |
246 | aio_copy $srcpath, $dstpath, $callback->($status) |
236 | aio_move $srcpath, $dstpath, $callback->($status) |
247 | aio_move $srcpath, $dstpath, $callback->($status) |
237 | aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
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238 | aio_rmtree $path, $callback->($status) |
248 | aio_rmtree $pathname, $callback->($status) |
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249 | aio_fcntl $fh, $cmd, $arg, $callback->($status) |
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250 | aio_ioctl $fh, $request, $buf, $callback->($status) |
239 | aio_sync $callback->($status) |
251 | aio_sync $callback->($status) |
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252 | aio_syncfs $fh, $callback->($status) |
240 | aio_fsync $fh, $callback->($status) |
253 | aio_fsync $fh, $callback->($status) |
241 | aio_fdatasync $fh, $callback->($status) |
254 | aio_fdatasync $fh, $callback->($status) |
242 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
255 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
243 | aio_pathsync $path, $callback->($status) |
256 | aio_pathsync $pathname, $callback->($status) |
244 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
257 | aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status) |
245 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
258 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
246 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
259 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
247 | aio_mlockall $flags, $callback->($status) |
260 | aio_mlockall $flags, $callback->($status) |
248 | aio_group $callback->(...) |
261 | aio_group $callback->(...) |
249 | aio_nop $callback->() |
262 | aio_nop $callback->() |
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266 | IO::AIO::nready |
279 | IO::AIO::nready |
267 | IO::AIO::npending |
280 | IO::AIO::npending |
268 | |
281 | |
269 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
282 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
270 | IO::AIO::fadvise $fh, $offset, $len, $advice |
283 | IO::AIO::fadvise $fh, $offset, $len, $advice |
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284 | IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]] |
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285 | IO::AIO::munmap $scalar |
271 | IO::AIO::madvise $scalar, $offset, $length, $advice |
286 | IO::AIO::madvise $scalar, $offset, $length, $advice |
272 | IO::AIO::mprotect $scalar, $offset, $length, $protect |
287 | IO::AIO::mprotect $scalar, $offset, $length, $protect |
273 | IO::AIO::munlock $scalar, $offset = 0, $length = undef |
288 | IO::AIO::munlock $scalar, $offset = 0, $length = undef |
274 | IO::AIO::munlockall |
289 | IO::AIO::munlockall |
275 | |
290 | |
276 | =head2 AIO REQUEST FUNCTIONS |
291 | =head2 API NOTES |
277 | |
292 | |
278 | All the C<aio_*> calls are more or less thin wrappers around the syscall |
293 | All the C<aio_*> calls are more or less thin wrappers around the syscall |
279 | with the same name (sans C<aio_>). The arguments are similar or identical, |
294 | with the same name (sans C<aio_>). The arguments are similar or identical, |
280 | and they all accept an additional (and optional) C<$callback> argument |
295 | and they all accept an additional (and optional) C<$callback> argument |
281 | which must be a code reference. This code reference will get called with |
296 | which must be a code reference. This code reference will be called after |
282 | the syscall return code (e.g. most syscalls return C<-1> on error, unlike |
297 | the syscall has been executed in an asynchronous fashion. The results |
283 | perl, which usually delivers "false") as its sole argument after the given |
298 | of the request will be passed as arguments to the callback (and, if an |
284 | syscall has been executed asynchronously. |
299 | error occured, in C<$!>) - for most requests the syscall return code (e.g. |
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300 | most syscalls return C<-1> on error, unlike perl, which usually delivers |
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301 | "false"). |
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302 | |
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303 | Some requests (such as C<aio_readdir>) pass the actual results and |
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304 | communicate failures by passing C<undef>. |
285 | |
305 | |
286 | All functions expecting a filehandle keep a copy of the filehandle |
306 | All functions expecting a filehandle keep a copy of the filehandle |
287 | internally until the request has finished. |
307 | internally until the request has finished. |
288 | |
308 | |
289 | All functions return request objects of type L<IO::AIO::REQ> that allow |
309 | All functions return request objects of type L<IO::AIO::REQ> that allow |
290 | further manipulation of those requests while they are in-flight. |
310 | further manipulation of those requests while they are in-flight. |
291 | |
311 | |
292 | The pathnames you pass to these routines I<must> be absolute and |
312 | The pathnames you pass to these routines I<should> be absolute. The |
293 | encoded as octets. The reason for the former is that at the time the |
313 | reason for this is that at the time the request is being executed, the |
294 | request is being executed, the current working directory could have |
314 | current working directory could have changed. Alternatively, you can |
295 | changed. Alternatively, you can make sure that you never change the |
315 | make sure that you never change the current working directory anywhere |
296 | current working directory anywhere in the program and then use relative |
316 | in the program and then use relative paths. You can also take advantage |
297 | paths. |
317 | of IO::AIOs working directory abstraction, that lets you specify paths |
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318 | relative to some previously-opened "working directory object" - see the |
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319 | description of the C<IO::AIO::WD> class later in this document. |
298 | |
320 | |
299 | To encode pathnames as octets, either make sure you either: a) always pass |
321 | To encode pathnames as octets, either make sure you either: a) always pass |
300 | in filenames you got from outside (command line, readdir etc.) without |
322 | in filenames you got from outside (command line, readdir etc.) without |
301 | tinkering, b) are ASCII or ISO 8859-1, c) use the Encode module and encode |
323 | tinkering, b) are in your native filesystem encoding, c) use the Encode |
302 | your pathnames to the locale (or other) encoding in effect in the user |
324 | module and encode your pathnames to the locale (or other) encoding in |
303 | environment, d) use Glib::filename_from_unicode on unicode filenames or e) |
325 | effect in the user environment, d) use Glib::filename_from_unicode on |
304 | use something else to ensure your scalar has the correct contents. |
326 | unicode filenames or e) use something else to ensure your scalar has the |
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327 | correct contents. |
305 | |
328 | |
306 | This works, btw. independent of the internal UTF-8 bit, which IO::AIO |
329 | This works, btw. independent of the internal UTF-8 bit, which IO::AIO |
307 | handles correctly whether it is set or not. |
330 | handles correctly whether it is set or not. |
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331 | |
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332 | =head2 AIO REQUEST FUNCTIONS |
308 | |
333 | |
309 | =over 4 |
334 | =over 4 |
310 | |
335 | |
311 | =item $prev_pri = aioreq_pri [$pri] |
336 | =item $prev_pri = aioreq_pri [$pri] |
312 | |
337 | |
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342 | |
367 | |
343 | |
368 | |
344 | =item aio_open $pathname, $flags, $mode, $callback->($fh) |
369 | =item aio_open $pathname, $flags, $mode, $callback->($fh) |
345 | |
370 | |
346 | Asynchronously open or create a file and call the callback with a newly |
371 | Asynchronously open or create a file and call the callback with a newly |
347 | created filehandle for the file. |
372 | created filehandle for the file (or C<undef> in case of an error). |
348 | |
373 | |
349 | The pathname passed to C<aio_open> must be absolute. See API NOTES, above, |
374 | The pathname passed to C<aio_open> must be absolute. See API NOTES, above, |
350 | for an explanation. |
375 | for an explanation. |
351 | |
376 | |
352 | The C<$flags> argument is a bitmask. See the C<Fcntl> module for a |
377 | The C<$flags> argument is a bitmask. See the C<Fcntl> module for a |
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375 | following POSIX and non-POSIX constants are available (missing ones on |
400 | following POSIX and non-POSIX constants are available (missing ones on |
376 | your system are, as usual, C<0>): |
401 | your system are, as usual, C<0>): |
377 | |
402 | |
378 | C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>, |
403 | C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>, |
379 | C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>, |
404 | C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>, |
380 | C<O_RSYNC>, C<O_SYNC> and C<O_TTY_INIT>. |
405 | C<O_RSYNC>, C<O_SYNC>, C<O_PATH>, C<O_TMPFILE>, and C<O_TTY_INIT>. |
381 | |
406 | |
382 | |
407 | |
383 | =item aio_close $fh, $callback->($status) |
408 | =item aio_close $fh, $callback->($status) |
384 | |
409 | |
385 | Asynchronously close a file and call the callback with the result |
410 | Asynchronously close a file and call the callback with the result |
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395 | Or in other words: the file descriptor will be closed, but it will not be |
420 | Or in other words: the file descriptor will be closed, but it will not be |
396 | free for reuse until the perl filehandle is closed. |
421 | free for reuse until the perl filehandle is closed. |
397 | |
422 | |
398 | =cut |
423 | =cut |
399 | |
424 | |
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425 | =item aio_seek $fh, $offset, $whence, $callback->($offs) |
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426 | |
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427 | Seeks the filehandle to the new C<$offset>, similarly to perl's |
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428 | C<sysseek>. The C<$whence> can use the traditional values (C<0> for |
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429 | C<IO::AIO::SEEK_SET>, C<1> for C<IO::AIO::SEEK_CUR> or C<2> for |
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430 | C<IO::AIO::SEEK_END>). |
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431 | |
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432 | The resulting absolute offset will be passed to the callback, or C<-1> in |
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433 | case of an error. |
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434 | |
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435 | In theory, the C<$whence> constants could be different than the |
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436 | corresponding values from L<Fcntl>, but perl guarantees they are the same, |
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437 | so don't panic. |
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438 | |
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439 | As a GNU/Linux (and maybe Solaris) extension, also the constants |
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440 | C<IO::AIO::SEEK_DATA> and C<IO::AIO::SEEK_HOLE> are available, if they |
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441 | could be found. No guarantees about suitability for use in C<aio_seek> or |
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442 | Perl's C<sysseek> can be made though, although I would naively assume they |
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443 | "just work". |
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444 | |
400 | =item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
445 | =item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
401 | |
446 | |
402 | =item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
447 | =item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
403 | |
448 | |
404 | Reads or writes C<$length> bytes from or to the specified C<$fh> and |
449 | Reads or writes C<$length> bytes from or to the specified C<$fh> and |
405 | C<$offset> into the scalar given by C<$data> and offset C<$dataoffset> |
450 | C<$offset> into the scalar given by C<$data> and offset C<$dataoffset> and |
406 | and calls the callback without the actual number of bytes read (or -1 on |
451 | calls the callback with the actual number of bytes transferred (or -1 on |
407 | error, just like the syscall). |
452 | error, just like the syscall). |
408 | |
453 | |
409 | C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to |
454 | C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to |
410 | offset plus the actual number of bytes read. |
455 | offset plus the actual number of bytes read. |
411 | |
456 | |
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469 | As native sendfile syscalls (as practically any non-POSIX interface hacked |
514 | As native sendfile syscalls (as practically any non-POSIX interface hacked |
470 | together in a hurry to improve benchmark numbers) tend to be rather buggy |
515 | together in a hurry to improve benchmark numbers) tend to be rather buggy |
471 | on many systems, this implementation tries to work around some known bugs |
516 | on many systems, this implementation tries to work around some known bugs |
472 | in Linux and FreeBSD kernels (probably others, too), but that might fail, |
517 | in Linux and FreeBSD kernels (probably others, too), but that might fail, |
473 | so you really really should check the return value of C<aio_sendfile> - |
518 | so you really really should check the return value of C<aio_sendfile> - |
474 | fewre bytes than expected might have been transferred. |
519 | fewer bytes than expected might have been transferred. |
475 | |
520 | |
476 | |
521 | |
477 | =item aio_readahead $fh,$offset,$length, $callback->($retval) |
522 | =item aio_readahead $fh,$offset,$length, $callback->($retval) |
478 | |
523 | |
479 | C<aio_readahead> populates the page cache with data from a file so that |
524 | C<aio_readahead> populates the page cache with data from a file so that |
… | |
… | |
483 | whole pages, so that offset is effectively rounded down to a page boundary |
528 | whole pages, so that offset is effectively rounded down to a page boundary |
484 | and bytes are read up to the next page boundary greater than or equal to |
529 | and bytes are read up to the next page boundary greater than or equal to |
485 | (off-set+length). C<aio_readahead> does not read beyond the end of the |
530 | (off-set+length). C<aio_readahead> does not read beyond the end of the |
486 | file. The current file offset of the file is left unchanged. |
531 | file. The current file offset of the file is left unchanged. |
487 | |
532 | |
488 | If that syscall doesn't exist (likely if your OS isn't Linux) it will be |
533 | If that syscall doesn't exist (likely if your kernel isn't Linux) it will |
489 | emulated by simply reading the data, which would have a similar effect. |
534 | be emulated by simply reading the data, which would have a similar effect. |
490 | |
535 | |
491 | |
536 | |
492 | =item aio_stat $fh_or_path, $callback->($status) |
537 | =item aio_stat $fh_or_path, $callback->($status) |
493 | |
538 | |
494 | =item aio_lstat $fh, $callback->($status) |
539 | =item aio_lstat $fh, $callback->($status) |
… | |
… | |
563 | namemax => 255, |
608 | namemax => 255, |
564 | frsize => 1024, |
609 | frsize => 1024, |
565 | fsid => 1810 |
610 | fsid => 1810 |
566 | } |
611 | } |
567 | |
612 | |
|
|
613 | Here is a (likely partial - send me updates!) list of fsid values used by |
|
|
614 | Linux - it is safe to hardcode these when C<$^O> is C<linux>: |
|
|
615 | |
|
|
616 | 0x0000adf5 adfs |
|
|
617 | 0x0000adff affs |
|
|
618 | 0x5346414f afs |
|
|
619 | 0x09041934 anon-inode filesystem |
|
|
620 | 0x00000187 autofs |
|
|
621 | 0x42465331 befs |
|
|
622 | 0x1badface bfs |
|
|
623 | 0x42494e4d binfmt_misc |
|
|
624 | 0x9123683e btrfs |
|
|
625 | 0x0027e0eb cgroupfs |
|
|
626 | 0xff534d42 cifs |
|
|
627 | 0x73757245 coda |
|
|
628 | 0x012ff7b7 coh |
|
|
629 | 0x28cd3d45 cramfs |
|
|
630 | 0x453dcd28 cramfs-wend (wrong endianness) |
|
|
631 | 0x64626720 debugfs |
|
|
632 | 0x00001373 devfs |
|
|
633 | 0x00001cd1 devpts |
|
|
634 | 0x0000f15f ecryptfs |
|
|
635 | 0x00414a53 efs |
|
|
636 | 0x0000137d ext |
|
|
637 | 0x0000ef53 ext2/ext3/ext4 |
|
|
638 | 0x0000ef51 ext2 |
|
|
639 | 0xf2f52010 f2fs |
|
|
640 | 0x00004006 fat |
|
|
641 | 0x65735546 fuseblk |
|
|
642 | 0x65735543 fusectl |
|
|
643 | 0x0bad1dea futexfs |
|
|
644 | 0x01161970 gfs2 |
|
|
645 | 0x47504653 gpfs |
|
|
646 | 0x00004244 hfs |
|
|
647 | 0xf995e849 hpfs |
|
|
648 | 0x00c0ffee hostfs |
|
|
649 | 0x958458f6 hugetlbfs |
|
|
650 | 0x2bad1dea inotifyfs |
|
|
651 | 0x00009660 isofs |
|
|
652 | 0x000072b6 jffs2 |
|
|
653 | 0x3153464a jfs |
|
|
654 | 0x6b414653 k-afs |
|
|
655 | 0x0bd00bd0 lustre |
|
|
656 | 0x0000137f minix |
|
|
657 | 0x0000138f minix 30 char names |
|
|
658 | 0x00002468 minix v2 |
|
|
659 | 0x00002478 minix v2 30 char names |
|
|
660 | 0x00004d5a minix v3 |
|
|
661 | 0x19800202 mqueue |
|
|
662 | 0x00004d44 msdos |
|
|
663 | 0x0000564c novell |
|
|
664 | 0x00006969 nfs |
|
|
665 | 0x6e667364 nfsd |
|
|
666 | 0x00003434 nilfs |
|
|
667 | 0x5346544e ntfs |
|
|
668 | 0x00009fa1 openprom |
|
|
669 | 0x7461636F ocfs2 |
|
|
670 | 0x00009fa0 proc |
|
|
671 | 0x6165676c pstorefs |
|
|
672 | 0x0000002f qnx4 |
|
|
673 | 0x68191122 qnx6 |
|
|
674 | 0x858458f6 ramfs |
|
|
675 | 0x52654973 reiserfs |
|
|
676 | 0x00007275 romfs |
|
|
677 | 0x67596969 rpc_pipefs |
|
|
678 | 0x73636673 securityfs |
|
|
679 | 0xf97cff8c selinux |
|
|
680 | 0x0000517b smb |
|
|
681 | 0x534f434b sockfs |
|
|
682 | 0x73717368 squashfs |
|
|
683 | 0x62656572 sysfs |
|
|
684 | 0x012ff7b6 sysv2 |
|
|
685 | 0x012ff7b5 sysv4 |
|
|
686 | 0x01021994 tmpfs |
|
|
687 | 0x15013346 udf |
|
|
688 | 0x00011954 ufs |
|
|
689 | 0x54190100 ufs byteswapped |
|
|
690 | 0x00009fa2 usbdevfs |
|
|
691 | 0x01021997 v9fs |
|
|
692 | 0xa501fcf5 vxfs |
|
|
693 | 0xabba1974 xenfs |
|
|
694 | 0x012ff7b4 xenix |
|
|
695 | 0x58465342 xfs |
|
|
696 | 0x012fd16d xia |
568 | |
697 | |
569 | =item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
698 | =item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
570 | |
699 | |
571 | Works like perl's C<utime> function (including the special case of $atime |
700 | Works like perl's C<utime> function (including the special case of $atime |
572 | and $mtime being undef). Fractional times are supported if the underlying |
701 | and $mtime being undef). Fractional times are supported if the underlying |
… | |
… | |
600 | =item aio_truncate $fh_or_path, $offset, $callback->($status) |
729 | =item aio_truncate $fh_or_path, $offset, $callback->($status) |
601 | |
730 | |
602 | Works like truncate(2) or ftruncate(2). |
731 | Works like truncate(2) or ftruncate(2). |
603 | |
732 | |
604 | |
733 | |
|
|
734 | =item aio_allocate $fh, $mode, $offset, $len, $callback->($status) |
|
|
735 | |
|
|
736 | Allocates or frees disk space according to the C<$mode> argument. See the |
|
|
737 | linux C<fallocate> documentation for details. |
|
|
738 | |
|
|
739 | C<$mode> is usually C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> to allocate |
|
|
740 | space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE | IO::AIO::FALLOC_FL_KEEP_SIZE>, |
|
|
741 | to deallocate a file range. |
|
|
742 | |
|
|
743 | IO::AIO also supports C<FALLOC_FL_COLLAPSE_RANGE>, to remove a range |
|
|
744 | (without leaving a hole) and C<FALLOC_FL_ZERO_RANGE>, to zero a range (see |
|
|
745 | your L<fallocate(2)> manpage). |
|
|
746 | |
|
|
747 | The file system block size used by C<fallocate> is presumably the |
|
|
748 | C<f_bsize> returned by C<statvfs>. |
|
|
749 | |
|
|
750 | If C<fallocate> isn't available or cannot be emulated (currently no |
|
|
751 | emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>. |
|
|
752 | |
|
|
753 | |
605 | =item aio_chmod $fh_or_path, $mode, $callback->($status) |
754 | =item aio_chmod $fh_or_path, $mode, $callback->($status) |
606 | |
755 | |
607 | Works like perl's C<chmod> function. |
756 | Works like perl's C<chmod> function. |
608 | |
757 | |
609 | |
758 | |
… | |
… | |
611 | |
760 | |
612 | Asynchronously unlink (delete) a file and call the callback with the |
761 | Asynchronously unlink (delete) a file and call the callback with the |
613 | result code. |
762 | result code. |
614 | |
763 | |
615 | |
764 | |
616 | =item aio_mknod $path, $mode, $dev, $callback->($status) |
765 | =item aio_mknod $pathname, $mode, $dev, $callback->($status) |
617 | |
766 | |
618 | [EXPERIMENTAL] |
767 | [EXPERIMENTAL] |
619 | |
768 | |
620 | Asynchronously create a device node (or fifo). See mknod(2). |
769 | Asynchronously create a device node (or fifo). See mknod(2). |
621 | |
770 | |
622 | The only (POSIX-) portable way of calling this function is: |
771 | The only (POSIX-) portable way of calling this function is: |
623 | |
772 | |
624 | aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
773 | aio_mknod $pathname, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
625 | |
774 | |
626 | See C<aio_stat> for info about some potentially helpful extra constants |
775 | See C<aio_stat> for info about some potentially helpful extra constants |
627 | and functions. |
776 | and functions. |
628 | |
777 | |
629 | =item aio_link $srcpath, $dstpath, $callback->($status) |
778 | =item aio_link $srcpath, $dstpath, $callback->($status) |
… | |
… | |
636 | |
785 | |
637 | Asynchronously create a new symbolic link to the existing object at C<$srcpath> at |
786 | Asynchronously create a new symbolic link to the existing object at C<$srcpath> at |
638 | the path C<$dstpath> and call the callback with the result code. |
787 | the path C<$dstpath> and call the callback with the result code. |
639 | |
788 | |
640 | |
789 | |
641 | =item aio_readlink $path, $callback->($link) |
790 | =item aio_readlink $pathname, $callback->($link) |
642 | |
791 | |
643 | Asynchronously read the symlink specified by C<$path> and pass it to |
792 | Asynchronously read the symlink specified by C<$path> and pass it to |
644 | the callback. If an error occurs, nothing or undef gets passed to the |
793 | the callback. If an error occurs, nothing or undef gets passed to the |
645 | callback. |
794 | callback. |
646 | |
795 | |
647 | |
796 | |
|
|
797 | =item aio_realpath $pathname, $callback->($path) |
|
|
798 | |
|
|
799 | Asynchronously make the path absolute and resolve any symlinks in |
|
|
800 | C<$path>. The resulting path only consists of directories (same as |
|
|
801 | L<Cwd::realpath>). |
|
|
802 | |
|
|
803 | This request can be used to get the absolute path of the current working |
|
|
804 | directory by passing it a path of F<.> (a single dot). |
|
|
805 | |
|
|
806 | |
648 | =item aio_rename $srcpath, $dstpath, $callback->($status) |
807 | =item aio_rename $srcpath, $dstpath, $callback->($status) |
649 | |
808 | |
650 | Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as |
809 | Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as |
651 | rename(2) and call the callback with the result code. |
810 | rename(2) and call the callback with the result code. |
|
|
811 | |
|
|
812 | On systems that support the AIO::WD working directory abstraction |
|
|
813 | natively, the case C<[$wd, "."]> as C<$srcpath> is specialcased - instead |
|
|
814 | of failing, C<rename> is called on the absolute path of C<$wd>. |
652 | |
815 | |
653 | |
816 | |
654 | =item aio_mkdir $pathname, $mode, $callback->($status) |
817 | =item aio_mkdir $pathname, $mode, $callback->($status) |
655 | |
818 | |
656 | Asynchronously mkdir (create) a directory and call the callback with |
819 | Asynchronously mkdir (create) a directory and call the callback with |
… | |
… | |
661 | =item aio_rmdir $pathname, $callback->($status) |
824 | =item aio_rmdir $pathname, $callback->($status) |
662 | |
825 | |
663 | Asynchronously rmdir (delete) a directory and call the callback with the |
826 | Asynchronously rmdir (delete) a directory and call the callback with the |
664 | result code. |
827 | result code. |
665 | |
828 | |
|
|
829 | On systems that support the AIO::WD working directory abstraction |
|
|
830 | natively, the case C<[$wd, "."]> is specialcased - instead of failing, |
|
|
831 | C<rmdir> is called on the absolute path of C<$wd>. |
|
|
832 | |
666 | |
833 | |
667 | =item aio_readdir $pathname, $callback->($entries) |
834 | =item aio_readdir $pathname, $callback->($entries) |
668 | |
835 | |
669 | Unlike the POSIX call of the same name, C<aio_readdir> reads an entire |
836 | Unlike the POSIX call of the same name, C<aio_readdir> reads an entire |
670 | directory (i.e. opendir + readdir + closedir). The entries will not be |
837 | directory (i.e. opendir + readdir + closedir). The entries will not be |
… | |
… | |
674 | array-ref with the filenames. |
841 | array-ref with the filenames. |
675 | |
842 | |
676 | |
843 | |
677 | =item aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
844 | =item aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
678 | |
845 | |
679 | Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune |
846 | Quite similar to C<aio_readdir>, but the C<$flags> argument allows one to |
680 | behaviour and output format. In case of an error, C<$entries> will be |
847 | tune behaviour and output format. In case of an error, C<$entries> will be |
681 | C<undef>. |
848 | C<undef>. |
682 | |
849 | |
683 | The flags are a combination of the following constants, ORed together (the |
850 | The flags are a combination of the following constants, ORed together (the |
684 | flags will also be passed to the callback, possibly modified): |
851 | flags will also be passed to the callback, possibly modified): |
685 | |
852 | |
… | |
… | |
732 | |
899 | |
733 | =item IO::AIO::READDIR_FOUND_UNKNOWN |
900 | =item IO::AIO::READDIR_FOUND_UNKNOWN |
734 | |
901 | |
735 | This flag should not be set when calling C<aio_readdirx>. Instead, it |
902 | This flag should not be set when calling C<aio_readdirx>. Instead, it |
736 | is being set by C<aio_readdirx>, when any of the C<$type>'s found were |
903 | is being set by C<aio_readdirx>, when any of the C<$type>'s found were |
737 | C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all |
904 | C<IO::AIO::DT_UNKNOWN>. The absence of this flag therefore indicates that all |
738 | C<$type>'s are known, which can be used to speed up some algorithms. |
905 | C<$type>'s are known, which can be used to speed up some algorithms. |
739 | |
906 | |
740 | =back |
907 | =back |
741 | |
908 | |
742 | |
909 | |
743 | =item aio_load $path, $data, $callback->($status) |
910 | =item aio_load $pathname, $data, $callback->($status) |
744 | |
911 | |
745 | This is a composite request that tries to fully load the given file into |
912 | This is a composite request that tries to fully load the given file into |
746 | memory. Status is the same as with aio_read. |
913 | memory. Status is the same as with aio_read. |
747 | |
914 | |
748 | =cut |
915 | =cut |
… | |
… | |
883 | }; |
1050 | }; |
884 | |
1051 | |
885 | $grp |
1052 | $grp |
886 | } |
1053 | } |
887 | |
1054 | |
888 | =item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
1055 | =item aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) |
889 | |
1056 | |
890 | Scans a directory (similar to C<aio_readdir>) but additionally tries to |
1057 | Scans a directory (similar to C<aio_readdir>) but additionally tries to |
891 | efficiently separate the entries of directory C<$path> into two sets of |
1058 | efficiently separate the entries of directory C<$path> into two sets of |
892 | names, directories you can recurse into (directories), and ones you cannot |
1059 | names, directories you can recurse into (directories), and ones you cannot |
893 | recurse into (everything else, including symlinks to directories). |
1060 | recurse into (everything else, including symlinks to directories). |
… | |
… | |
924 | Then entries will be sorted into likely directories a non-initial dot |
1091 | Then entries will be sorted into likely directories a non-initial dot |
925 | currently) and likely non-directories (see C<aio_readdirx>). Then every |
1092 | currently) and likely non-directories (see C<aio_readdirx>). Then every |
926 | entry plus an appended C</.> will be C<stat>'ed, likely directories first, |
1093 | entry plus an appended C</.> will be C<stat>'ed, likely directories first, |
927 | in order of their inode numbers. If that succeeds, it assumes that the |
1094 | in order of their inode numbers. If that succeeds, it assumes that the |
928 | entry is a directory or a symlink to directory (which will be checked |
1095 | entry is a directory or a symlink to directory (which will be checked |
929 | seperately). This is often faster than stat'ing the entry itself because |
1096 | separately). This is often faster than stat'ing the entry itself because |
930 | filesystems might detect the type of the entry without reading the inode |
1097 | filesystems might detect the type of the entry without reading the inode |
931 | data (e.g. ext2fs filetype feature), even on systems that cannot return |
1098 | data (e.g. ext2fs filetype feature), even on systems that cannot return |
932 | the filetype information on readdir. |
1099 | the filetype information on readdir. |
933 | |
1100 | |
934 | If the known number of directories (link count - 2) has been reached, the |
1101 | If the known number of directories (link count - 2) has been reached, the |
… | |
… | |
950 | |
1117 | |
951 | my $grp = aio_group $cb; |
1118 | my $grp = aio_group $cb; |
952 | |
1119 | |
953 | $maxreq = 4 if $maxreq <= 0; |
1120 | $maxreq = 4 if $maxreq <= 0; |
954 | |
1121 | |
955 | # stat once |
1122 | # get a wd object |
956 | aioreq_pri $pri; |
1123 | aioreq_pri $pri; |
957 | add $grp aio_stat $path, sub { |
1124 | add $grp aio_wd $path, sub { |
|
|
1125 | $_[0] |
958 | return $grp->result () if $_[0]; |
1126 | or return $grp->result (); |
959 | my $now = time; |
|
|
960 | my $hash1 = join ":", (stat _)[0,1,3,7,9]; |
|
|
961 | |
1127 | |
962 | # read the directory entries |
1128 | my $wd = [shift, "."]; |
|
|
1129 | |
|
|
1130 | # stat once |
963 | aioreq_pri $pri; |
1131 | aioreq_pri $pri; |
964 | add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub { |
1132 | add $grp aio_stat $wd, sub { |
965 | my $entries = shift |
|
|
966 | or return $grp->result (); |
1133 | return $grp->result () if $_[0]; |
|
|
1134 | my $now = time; |
|
|
1135 | my $hash1 = join ":", (stat _)[0,1,3,7,9]; |
967 | |
1136 | |
968 | # stat the dir another time |
1137 | # read the directory entries |
969 | aioreq_pri $pri; |
1138 | aioreq_pri $pri; |
|
|
1139 | add $grp aio_readdirx $wd, READDIR_DIRS_FIRST, sub { |
|
|
1140 | my $entries = shift |
|
|
1141 | or return $grp->result (); |
|
|
1142 | |
|
|
1143 | # stat the dir another time |
|
|
1144 | aioreq_pri $pri; |
970 | add $grp aio_stat $path, sub { |
1145 | add $grp aio_stat $wd, sub { |
971 | my $hash2 = join ":", (stat _)[0,1,3,7,9]; |
1146 | my $hash2 = join ":", (stat _)[0,1,3,7,9]; |
972 | |
1147 | |
973 | my $ndirs; |
1148 | my $ndirs; |
974 | |
1149 | |
975 | # take the slow route if anything looks fishy |
1150 | # take the slow route if anything looks fishy |
976 | if ($hash1 ne $hash2 or (stat _)[9] == $now) { |
1151 | if ($hash1 ne $hash2 or (stat _)[9] == $now) { |
977 | $ndirs = -1; |
1152 | $ndirs = -1; |
978 | } else { |
1153 | } else { |
979 | # if nlink == 2, we are finished |
1154 | # if nlink == 2, we are finished |
980 | # for non-posix-fs's, we rely on nlink < 2 |
1155 | # for non-posix-fs's, we rely on nlink < 2 |
981 | $ndirs = (stat _)[3] - 2 |
1156 | $ndirs = (stat _)[3] - 2 |
982 | or return $grp->result ([], $entries); |
1157 | or return $grp->result ([], $entries); |
983 | } |
1158 | } |
984 | |
1159 | |
985 | my (@dirs, @nondirs); |
1160 | my (@dirs, @nondirs); |
986 | |
1161 | |
987 | my $statgrp = add $grp aio_group sub { |
1162 | my $statgrp = add $grp aio_group sub { |
988 | $grp->result (\@dirs, \@nondirs); |
1163 | $grp->result (\@dirs, \@nondirs); |
989 | }; |
1164 | }; |
990 | |
1165 | |
991 | limit $statgrp $maxreq; |
1166 | limit $statgrp $maxreq; |
992 | feed $statgrp sub { |
1167 | feed $statgrp sub { |
993 | return unless @$entries; |
1168 | return unless @$entries; |
994 | my $entry = shift @$entries; |
1169 | my $entry = shift @$entries; |
995 | |
1170 | |
996 | aioreq_pri $pri; |
1171 | aioreq_pri $pri; |
|
|
1172 | $wd->[1] = "$entry/."; |
997 | add $statgrp aio_stat "$path/$entry/.", sub { |
1173 | add $statgrp aio_stat $wd, sub { |
998 | if ($_[0] < 0) { |
1174 | if ($_[0] < 0) { |
999 | push @nondirs, $entry; |
1175 | push @nondirs, $entry; |
1000 | } else { |
1176 | } else { |
1001 | # need to check for real directory |
1177 | # need to check for real directory |
1002 | aioreq_pri $pri; |
1178 | aioreq_pri $pri; |
|
|
1179 | $wd->[1] = $entry; |
1003 | add $statgrp aio_lstat "$path/$entry", sub { |
1180 | add $statgrp aio_lstat $wd, sub { |
1004 | if (-d _) { |
1181 | if (-d _) { |
1005 | push @dirs, $entry; |
1182 | push @dirs, $entry; |
1006 | |
1183 | |
1007 | unless (--$ndirs) { |
1184 | unless (--$ndirs) { |
1008 | push @nondirs, @$entries; |
1185 | push @nondirs, @$entries; |
1009 | feed $statgrp; |
1186 | feed $statgrp; |
|
|
1187 | } |
|
|
1188 | } else { |
|
|
1189 | push @nondirs, $entry; |
1010 | } |
1190 | } |
1011 | } else { |
|
|
1012 | push @nondirs, $entry; |
|
|
1013 | } |
1191 | } |
1014 | } |
1192 | } |
1015 | } |
1193 | }; |
1016 | }; |
1194 | }; |
1017 | }; |
1195 | }; |
1018 | }; |
1196 | }; |
1019 | }; |
1197 | }; |
1020 | }; |
1198 | }; |
1021 | |
1199 | |
1022 | $grp |
1200 | $grp |
1023 | } |
1201 | } |
1024 | |
1202 | |
1025 | =item aio_rmtree $path, $callback->($status) |
1203 | =item aio_rmtree $pathname, $callback->($status) |
1026 | |
1204 | |
1027 | Delete a directory tree starting (and including) C<$path>, return the |
1205 | Delete a directory tree starting (and including) C<$path>, return the |
1028 | status of the final C<rmdir> only. This is a composite request that |
1206 | status of the final C<rmdir> only. This is a composite request that |
1029 | uses C<aio_scandir> to recurse into and rmdir directories, and unlink |
1207 | uses C<aio_scandir> to recurse into and rmdir directories, and unlink |
1030 | everything else. |
1208 | everything else. |
1031 | |
1209 | |
1032 | =cut |
1210 | =cut |
1033 | |
1211 | |
… | |
… | |
1055 | }; |
1233 | }; |
1056 | |
1234 | |
1057 | $grp |
1235 | $grp |
1058 | } |
1236 | } |
1059 | |
1237 | |
|
|
1238 | =item aio_fcntl $fh, $cmd, $arg, $callback->($status) |
|
|
1239 | |
|
|
1240 | =item aio_ioctl $fh, $request, $buf, $callback->($status) |
|
|
1241 | |
|
|
1242 | These work just like the C<fcntl> and C<ioctl> built-in functions, except |
|
|
1243 | they execute asynchronously and pass the return value to the callback. |
|
|
1244 | |
|
|
1245 | Both calls can be used for a lot of things, some of which make more sense |
|
|
1246 | to run asynchronously in their own thread, while some others make less |
|
|
1247 | sense. For example, calls that block waiting for external events, such |
|
|
1248 | as locking, will also lock down an I/O thread while it is waiting, which |
|
|
1249 | can deadlock the whole I/O system. At the same time, there might be no |
|
|
1250 | alternative to using a thread to wait. |
|
|
1251 | |
|
|
1252 | So in general, you should only use these calls for things that do |
|
|
1253 | (filesystem) I/O, not for things that wait for other events (network, |
|
|
1254 | other processes), although if you are careful and know what you are doing, |
|
|
1255 | you still can. |
|
|
1256 | |
|
|
1257 | The following constants are available (missing ones are, as usual C<0>): |
|
|
1258 | |
|
|
1259 | C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>. |
|
|
1260 | |
|
|
1261 | C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>, |
|
|
1262 | C<FS_IOC_FIEMAP>. |
|
|
1263 | |
|
|
1264 | C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>, |
|
|
1265 | C<FS_IOC_GET_ENCRYPTION_PWSALT>, C<FS_IOC_GET_ENCRYPTION_POLICY>, C<FS_KEY_DESCRIPTOR_SIZE>. |
|
|
1266 | |
|
|
1267 | C<FS_SECRM_FL>, C<FS_UNRM_FL>, C<FS_COMPR_FL>, C<FS_SYNC_FL>, C<FS_IMMUTABLE_FL>, |
|
|
1268 | C<FS_APPEND_FL>, C<FS_NODUMP_FL>, C<FS_NOATIME_FL>, C<FS_DIRTY_FL>, |
|
|
1269 | C<FS_COMPRBLK_FL>, C<FS_NOCOMP_FL>, C<FS_ENCRYPT_FL>, C<FS_BTREE_FL>, |
|
|
1270 | C<FS_INDEX_FL>, C<FS_JOURNAL_DATA_FL>, C<FS_NOTAIL_FL>, C<FS_DIRSYNC_FL>, C<FS_TOPDIR_FL>, |
|
|
1271 | C<FS_FL_USER_MODIFIABLE>. |
|
|
1272 | |
|
|
1273 | C<FS_XFLAG_REALTIME>, C<FS_XFLAG_PREALLOC>, C<FS_XFLAG_IMMUTABLE>, C<FS_XFLAG_APPEND>, |
|
|
1274 | C<FS_XFLAG_SYNC>, C<FS_XFLAG_NOATIME>, C<FS_XFLAG_NODUMP>, C<FS_XFLAG_RTINHERIT>, |
|
|
1275 | C<FS_XFLAG_PROJINHERIT>, C<FS_XFLAG_NOSYMLINKS>, C<FS_XFLAG_EXTSIZE>, C<FS_XFLAG_EXTSZINHERIT>, |
|
|
1276 | C<FS_XFLAG_NODEFRAG>, C<FS_XFLAG_FILESTREAM>, C<FS_XFLAG_DAX>, C<FS_XFLAG_HASATTR>, |
|
|
1277 | |
1060 | =item aio_sync $callback->($status) |
1278 | =item aio_sync $callback->($status) |
1061 | |
1279 | |
1062 | Asynchronously call sync and call the callback when finished. |
1280 | Asynchronously call sync and call the callback when finished. |
1063 | |
1281 | |
1064 | =item aio_fsync $fh, $callback->($status) |
1282 | =item aio_fsync $fh, $callback->($status) |
… | |
… | |
1071 | Asynchronously call fdatasync on the given filehandle and call the |
1289 | Asynchronously call fdatasync on the given filehandle and call the |
1072 | callback with the fdatasync result code. |
1290 | callback with the fdatasync result code. |
1073 | |
1291 | |
1074 | If this call isn't available because your OS lacks it or it couldn't be |
1292 | If this call isn't available because your OS lacks it or it couldn't be |
1075 | detected, it will be emulated by calling C<fsync> instead. |
1293 | detected, it will be emulated by calling C<fsync> instead. |
|
|
1294 | |
|
|
1295 | =item aio_syncfs $fh, $callback->($status) |
|
|
1296 | |
|
|
1297 | Asynchronously call the syncfs syscall to sync the filesystem associated |
|
|
1298 | to the given filehandle and call the callback with the syncfs result |
|
|
1299 | code. If syncfs is not available, calls sync(), but returns C<-1> and sets |
|
|
1300 | errno to C<ENOSYS> nevertheless. |
1076 | |
1301 | |
1077 | =item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
1302 | =item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
1078 | |
1303 | |
1079 | Sync the data portion of the file specified by C<$offset> and C<$length> |
1304 | Sync the data portion of the file specified by C<$offset> and C<$length> |
1080 | to disk (but NOT the metadata), by calling the Linux-specific |
1305 | to disk (but NOT the metadata), by calling the Linux-specific |
… | |
… | |
1084 | C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>, |
1309 | C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>, |
1085 | C<IO::AIO::SYNC_FILE_RANGE_WRITE> and |
1310 | C<IO::AIO::SYNC_FILE_RANGE_WRITE> and |
1086 | C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range |
1311 | C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range |
1087 | manpage for details. |
1312 | manpage for details. |
1088 | |
1313 | |
1089 | =item aio_pathsync $path, $callback->($status) |
1314 | =item aio_pathsync $pathname, $callback->($status) |
1090 | |
1315 | |
1091 | This request tries to open, fsync and close the given path. This is a |
1316 | This request tries to open, fsync and close the given path. This is a |
1092 | composite request intended to sync directories after directory operations |
1317 | composite request intended to sync directories after directory operations |
1093 | (E.g. rename). This might not work on all operating systems or have any |
1318 | (E.g. rename). This might not work on all operating systems or have any |
1094 | specific effect, but usually it makes sure that directory changes get |
1319 | specific effect, but usually it makes sure that directory changes get |
… | |
… | |
1125 | }; |
1350 | }; |
1126 | |
1351 | |
1127 | $grp |
1352 | $grp |
1128 | } |
1353 | } |
1129 | |
1354 | |
1130 | =item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
1355 | =item aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status) |
1131 | |
1356 | |
1132 | This is a rather advanced IO::AIO call, which only works on mmap(2)ed |
1357 | This is a rather advanced IO::AIO call, which only works on mmap(2)ed |
1133 | scalars (see the C<IO::AIO::mmap> function, although it also works on data |
1358 | scalars (see the C<IO::AIO::mmap> function, although it also works on data |
1134 | scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the |
1359 | scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the |
1135 | scalar must only be modified in-place while an aio operation is pending on |
1360 | scalar must only be modified in-place while an aio operation is pending on |
… | |
… | |
1137 | |
1362 | |
1138 | It calls the C<msync> function of your OS, if available, with the memory |
1363 | It calls the C<msync> function of your OS, if available, with the memory |
1139 | area starting at C<$offset> in the string and ending C<$length> bytes |
1364 | area starting at C<$offset> in the string and ending C<$length> bytes |
1140 | later. If C<$length> is negative, counts from the end, and if C<$length> |
1365 | later. If C<$length> is negative, counts from the end, and if C<$length> |
1141 | is C<undef>, then it goes till the end of the string. The flags can be |
1366 | is C<undef>, then it goes till the end of the string. The flags can be |
1142 | a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and |
1367 | either C<IO::AIO::MS_ASYNC> or C<IO::AIO::MS_SYNC>, plus an optional |
1143 | C<IO::AIO::MS_SYNC>. |
1368 | C<IO::AIO::MS_INVALIDATE>. |
1144 | |
1369 | |
1145 | =item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
1370 | =item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
1146 | |
1371 | |
1147 | This is a rather advanced IO::AIO call, which works best on mmap(2)ed |
1372 | This is a rather advanced IO::AIO call, which works best on mmap(2)ed |
1148 | scalars. |
1373 | scalars. |
1149 | |
1374 | |
1150 | It touches (reads or writes) all memory pages in the specified |
1375 | It touches (reads or writes) all memory pages in the specified |
1151 | range inside the scalar. All caveats and parameters are the same |
1376 | range inside the scalar. All caveats and parameters are the same |
1152 | as for C<aio_msync>, above, except for flags, which must be either |
1377 | as for C<aio_msync>, above, except for flags, which must be either |
1153 | C<0> (which reads all pages and ensures they are instantiated) or |
1378 | C<0> (which reads all pages and ensures they are instantiated) or |
1154 | C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and |
1379 | C<IO::AIO::MT_MODIFY>, which modifies the memory pages (by reading and |
1155 | writing an octet from it, which dirties the page). |
1380 | writing an octet from it, which dirties the page). |
1156 | |
1381 | |
1157 | =item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
1382 | =item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
1158 | |
1383 | |
1159 | This is a rather advanced IO::AIO call, which works best on mmap(2)ed |
1384 | This is a rather advanced IO::AIO call, which works best on mmap(2)ed |
… | |
… | |
1190 | documented under L<MISCELLANEOUS FUNCTIONS>. |
1415 | documented under L<MISCELLANEOUS FUNCTIONS>. |
1191 | |
1416 | |
1192 | Example: asynchronously lock all current and future pages into memory. |
1417 | Example: asynchronously lock all current and future pages into memory. |
1193 | |
1418 | |
1194 | aio_mlockall IO::AIO::MCL_FUTURE; |
1419 | aio_mlockall IO::AIO::MCL_FUTURE; |
|
|
1420 | |
|
|
1421 | =item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents) |
|
|
1422 | |
|
|
1423 | Queries the extents of the given file (by calling the Linux C<FIEMAP> |
|
|
1424 | ioctl, see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If |
|
|
1425 | the ioctl is not available on your OS, then this request will fail with |
|
|
1426 | C<ENOSYS>. |
|
|
1427 | |
|
|
1428 | C<$start> is the starting offset to query extents for, C<$length> is the |
|
|
1429 | size of the range to query - if it is C<undef>, then the whole file will |
|
|
1430 | be queried. |
|
|
1431 | |
|
|
1432 | C<$flags> is a combination of flags (C<IO::AIO::FIEMAP_FLAG_SYNC> or |
|
|
1433 | C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also |
|
|
1434 | exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query |
|
|
1435 | the data portion. |
|
|
1436 | |
|
|
1437 | C<$count> is the maximum number of extent records to return. If it is |
|
|
1438 | C<undef>, then IO::AIO queries all extents of the range. As a very special |
|
|
1439 | case, if it is C<0>, then the callback receives the number of extents |
|
|
1440 | instead of the extents themselves (which is unreliable, see below). |
|
|
1441 | |
|
|
1442 | If an error occurs, the callback receives no arguments. The special |
|
|
1443 | C<errno> value C<IO::AIO::EBADR> is available to test for flag errors. |
|
|
1444 | |
|
|
1445 | Otherwise, the callback receives an array reference with extent |
|
|
1446 | structures. Each extent structure is an array reference itself, with the |
|
|
1447 | following members: |
|
|
1448 | |
|
|
1449 | [$logical, $physical, $length, $flags] |
|
|
1450 | |
|
|
1451 | Flags is any combination of the following flag values (typically either C<0> |
|
|
1452 | or C<IO::AIO::FIEMAP_EXTENT_LAST> (1)): |
|
|
1453 | |
|
|
1454 | C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>, |
|
|
1455 | C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>, |
|
|
1456 | C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>, |
|
|
1457 | C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>, |
|
|
1458 | C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or |
|
|
1459 | C<IO::AIO::FIEMAP_EXTENT_SHARED>. |
|
|
1460 | |
|
|
1461 | At the time of this writing (Linux 3.2), this requets is unreliable unless |
|
|
1462 | C<$count> is C<undef>, as the kernel has all sorts of bugs preventing |
|
|
1463 | it to return all extents of a range for files with large number of |
|
|
1464 | extents. The code works around all these issues if C<$count> is undef. |
1195 | |
1465 | |
1196 | =item aio_group $callback->(...) |
1466 | =item aio_group $callback->(...) |
1197 | |
1467 | |
1198 | This is a very special aio request: Instead of doing something, it is a |
1468 | This is a very special aio request: Instead of doing something, it is a |
1199 | container for other aio requests, which is useful if you want to bundle |
1469 | container for other aio requests, which is useful if you want to bundle |
… | |
… | |
1236 | like sleep and file handle readable/writable, the overhead this creates is |
1506 | like sleep and file handle readable/writable, the overhead this creates is |
1237 | immense (it blocks a thread for a long time) so do not use this function |
1507 | immense (it blocks a thread for a long time) so do not use this function |
1238 | except to put your application under artificial I/O pressure. |
1508 | except to put your application under artificial I/O pressure. |
1239 | |
1509 | |
1240 | =back |
1510 | =back |
|
|
1511 | |
|
|
1512 | |
|
|
1513 | =head2 IO::AIO::WD - multiple working directories |
|
|
1514 | |
|
|
1515 | Your process only has one current working directory, which is used by all |
|
|
1516 | threads. This makes it hard to use relative paths (some other component |
|
|
1517 | could call C<chdir> at any time, and it is hard to control when the path |
|
|
1518 | will be used by IO::AIO). |
|
|
1519 | |
|
|
1520 | One solution for this is to always use absolute paths. This usually works, |
|
|
1521 | but can be quite slow (the kernel has to walk the whole path on every |
|
|
1522 | access), and can also be a hassle to implement. |
|
|
1523 | |
|
|
1524 | Newer POSIX systems have a number of functions (openat, fdopendir, |
|
|
1525 | futimensat and so on) that make it possible to specify working directories |
|
|
1526 | per operation. |
|
|
1527 | |
|
|
1528 | For portability, and because the clowns who "designed", or shall I write, |
|
|
1529 | perpetrated this new interface were obviously half-drunk, this abstraction |
|
|
1530 | cannot be perfect, though. |
|
|
1531 | |
|
|
1532 | IO::AIO allows you to convert directory paths into a so-called IO::AIO::WD |
|
|
1533 | object. This object stores the canonicalised, absolute version of the |
|
|
1534 | path, and on systems that allow it, also a directory file descriptor. |
|
|
1535 | |
|
|
1536 | Everywhere where a pathname is accepted by IO::AIO (e.g. in C<aio_stat> |
|
|
1537 | or C<aio_unlink>), one can specify an array reference with an IO::AIO::WD |
|
|
1538 | object and a pathname instead (or the IO::AIO::WD object alone, which |
|
|
1539 | gets interpreted as C<[$wd, "."]>). If the pathname is absolute, the |
|
|
1540 | IO::AIO::WD object is ignored, otherwise the pathname is resolved relative |
|
|
1541 | to that IO::AIO::WD object. |
|
|
1542 | |
|
|
1543 | For example, to get a wd object for F</etc> and then stat F<passwd> |
|
|
1544 | inside, you would write: |
|
|
1545 | |
|
|
1546 | aio_wd "/etc", sub { |
|
|
1547 | my $etcdir = shift; |
|
|
1548 | |
|
|
1549 | # although $etcdir can be undef on error, there is generally no reason |
|
|
1550 | # to check for errors here, as aio_stat will fail with ENOENT |
|
|
1551 | # when $etcdir is undef. |
|
|
1552 | |
|
|
1553 | aio_stat [$etcdir, "passwd"], sub { |
|
|
1554 | # yay |
|
|
1555 | }; |
|
|
1556 | }; |
|
|
1557 | |
|
|
1558 | The fact that C<aio_wd> is a request and not a normal function shows that |
|
|
1559 | creating an IO::AIO::WD object is itself a potentially blocking operation, |
|
|
1560 | which is why it is done asynchronously. |
|
|
1561 | |
|
|
1562 | To stat the directory obtained with C<aio_wd> above, one could write |
|
|
1563 | either of the following three request calls: |
|
|
1564 | |
|
|
1565 | aio_lstat "/etc" , sub { ... # pathname as normal string |
|
|
1566 | aio_lstat [$wd, "."], sub { ... # "." relative to $wd (i.e. $wd itself) |
|
|
1567 | aio_lstat $wd , sub { ... # shorthand for the previous |
|
|
1568 | |
|
|
1569 | As with normal pathnames, IO::AIO keeps a copy of the working directory |
|
|
1570 | object and the pathname string, so you could write the following without |
|
|
1571 | causing any issues due to C<$path> getting reused: |
|
|
1572 | |
|
|
1573 | my $path = [$wd, undef]; |
|
|
1574 | |
|
|
1575 | for my $name (qw(abc def ghi)) { |
|
|
1576 | $path->[1] = $name; |
|
|
1577 | aio_stat $path, sub { |
|
|
1578 | # ... |
|
|
1579 | }; |
|
|
1580 | } |
|
|
1581 | |
|
|
1582 | There are some caveats: when directories get renamed (or deleted), the |
|
|
1583 | pathname string doesn't change, so will point to the new directory (or |
|
|
1584 | nowhere at all), while the directory fd, if available on the system, |
|
|
1585 | will still point to the original directory. Most functions accepting a |
|
|
1586 | pathname will use the directory fd on newer systems, and the string on |
|
|
1587 | older systems. Some functions (such as realpath) will always rely on the |
|
|
1588 | string form of the pathname. |
|
|
1589 | |
|
|
1590 | So this functionality is mainly useful to get some protection against |
|
|
1591 | C<chdir>, to easily get an absolute path out of a relative path for future |
|
|
1592 | reference, and to speed up doing many operations in the same directory |
|
|
1593 | (e.g. when stat'ing all files in a directory). |
|
|
1594 | |
|
|
1595 | The following functions implement this working directory abstraction: |
|
|
1596 | |
|
|
1597 | =over 4 |
|
|
1598 | |
|
|
1599 | =item aio_wd $pathname, $callback->($wd) |
|
|
1600 | |
|
|
1601 | Asynchonously canonicalise the given pathname and convert it to an |
|
|
1602 | IO::AIO::WD object representing it. If possible and supported on the |
|
|
1603 | system, also open a directory fd to speed up pathname resolution relative |
|
|
1604 | to this working directory. |
|
|
1605 | |
|
|
1606 | If something goes wrong, then C<undef> is passwd to the callback instead |
|
|
1607 | of a working directory object and C<$!> is set appropriately. Since |
|
|
1608 | passing C<undef> as working directory component of a pathname fails the |
|
|
1609 | request with C<ENOENT>, there is often no need for error checking in the |
|
|
1610 | C<aio_wd> callback, as future requests using the value will fail in the |
|
|
1611 | expected way. |
|
|
1612 | |
|
|
1613 | =item IO::AIO::CWD |
|
|
1614 | |
|
|
1615 | This is a compiletime constant (object) that represents the process |
|
|
1616 | current working directory. |
|
|
1617 | |
|
|
1618 | Specifying this object as working directory object for a pathname is as if |
|
|
1619 | the pathname would be specified directly, without a directory object. For |
|
|
1620 | example, these calls are functionally identical: |
|
|
1621 | |
|
|
1622 | aio_stat "somefile", sub { ... }; |
|
|
1623 | aio_stat [IO::AIO::CWD, "somefile"], sub { ... }; |
|
|
1624 | |
|
|
1625 | =back |
|
|
1626 | |
|
|
1627 | To recover the path associated with an IO::AIO::WD object, you can use |
|
|
1628 | C<aio_realpath>: |
|
|
1629 | |
|
|
1630 | aio_realpath $wd, sub { |
|
|
1631 | warn "path is $_[0]\n"; |
|
|
1632 | }; |
|
|
1633 | |
|
|
1634 | Currently, C<aio_statvfs> always, and C<aio_rename> and C<aio_rmdir> |
|
|
1635 | sometimes, fall back to using an absolue path. |
1241 | |
1636 | |
1242 | =head2 IO::AIO::REQ CLASS |
1637 | =head2 IO::AIO::REQ CLASS |
1243 | |
1638 | |
1244 | All non-aggregate C<aio_*> functions return an object of this class when |
1639 | All non-aggregate C<aio_*> functions return an object of this class when |
1245 | called in non-void context. |
1640 | called in non-void context. |
… | |
… | |
1363 | |
1758 | |
1364 | Sets a feeder/generator on this group: every group can have an attached |
1759 | Sets a feeder/generator on this group: every group can have an attached |
1365 | generator that generates requests if idle. The idea behind this is that, |
1760 | generator that generates requests if idle. The idea behind this is that, |
1366 | although you could just queue as many requests as you want in a group, |
1761 | although you could just queue as many requests as you want in a group, |
1367 | this might starve other requests for a potentially long time. For example, |
1762 | this might starve other requests for a potentially long time. For example, |
1368 | C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests, |
1763 | C<aio_scandir> might generate hundreds of thousands of C<aio_stat> |
1369 | delaying any later requests for a long time. |
1764 | requests, delaying any later requests for a long time. |
1370 | |
1765 | |
1371 | To avoid this, and allow incremental generation of requests, you can |
1766 | To avoid this, and allow incremental generation of requests, you can |
1372 | instead a group and set a feeder on it that generates those requests. The |
1767 | instead a group and set a feeder on it that generates those requests. The |
1373 | feed callback will be called whenever there are few enough (see C<limit>, |
1768 | feed callback will be called whenever there are few enough (see C<limit>, |
1374 | below) requests active in the group itself and is expected to queue more |
1769 | below) requests active in the group itself and is expected to queue more |
… | |
… | |
1423 | |
1818 | |
1424 | See C<poll_cb> for an example. |
1819 | See C<poll_cb> for an example. |
1425 | |
1820 | |
1426 | =item IO::AIO::poll_cb |
1821 | =item IO::AIO::poll_cb |
1427 | |
1822 | |
1428 | Process some outstanding events on the result pipe. You have to call |
1823 | Process some requests that have reached the result phase (i.e. they have |
|
|
1824 | been executed but the results are not yet reported). You have to call |
|
|
1825 | this "regularly" to finish outstanding requests. |
|
|
1826 | |
1429 | this regularly. Returns C<0> if all events could be processed (or there |
1827 | Returns C<0> if all events could be processed (or there were no |
1430 | were no events to process), or C<-1> if it returned earlier for whatever |
1828 | events to process), or C<-1> if it returned earlier for whatever |
1431 | reason. Returns immediately when no events are outstanding. The amount of |
1829 | reason. Returns immediately when no events are outstanding. The amount |
1432 | events processed depends on the settings of C<IO::AIO::max_poll_req> and |
1830 | of events processed depends on the settings of C<IO::AIO::max_poll_req>, |
1433 | C<IO::AIO::max_poll_time>. |
1831 | C<IO::AIO::max_poll_time> and C<IO::AIO::max_outstanding>. |
1434 | |
1832 | |
1435 | If not all requests were processed for whatever reason, the filehandle |
1833 | If not all requests were processed for whatever reason, the poll file |
1436 | will still be ready when C<poll_cb> returns, so normally you don't have to |
1834 | descriptor will still be ready when C<poll_cb> returns, so normally you |
1437 | do anything special to have it called later. |
1835 | don't have to do anything special to have it called later. |
1438 | |
1836 | |
1439 | Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes |
1837 | Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes |
1440 | ready, it can be beneficial to call this function from loops which submit |
1838 | ready, it can be beneficial to call this function from loops which submit |
1441 | a lot of requests, to make sure the results get processed when they become |
1839 | a lot of requests, to make sure the results get processed when they become |
1442 | available and not just when the loop is finished and the event loop takes |
1840 | available and not just when the loop is finished and the event loop takes |
… | |
… | |
1451 | poll => 'r', async => 1, |
1849 | poll => 'r', async => 1, |
1452 | cb => \&IO::AIO::poll_cb); |
1850 | cb => \&IO::AIO::poll_cb); |
1453 | |
1851 | |
1454 | =item IO::AIO::poll_wait |
1852 | =item IO::AIO::poll_wait |
1455 | |
1853 | |
1456 | If there are any outstanding requests and none of them in the result |
1854 | Wait until either at least one request is in the result phase or no |
1457 | phase, wait till the result filehandle becomes ready for reading (simply |
1855 | requests are outstanding anymore. |
1458 | does a C<select> on the filehandle. This is useful if you want to |
1856 | |
1459 | synchronously wait for some requests to finish). |
1857 | This is useful if you want to synchronously wait for some requests to |
|
|
1858 | become ready, without actually handling them. |
1460 | |
1859 | |
1461 | See C<nreqs> for an example. |
1860 | See C<nreqs> for an example. |
1462 | |
1861 | |
1463 | =item IO::AIO::poll |
1862 | =item IO::AIO::poll |
1464 | |
1863 | |
… | |
… | |
1585 | |
1984 | |
1586 | This is a very bad function to use in interactive programs because it |
1985 | This is a very bad function to use in interactive programs because it |
1587 | blocks, and a bad way to reduce concurrency because it is inexact: Better |
1986 | blocks, and a bad way to reduce concurrency because it is inexact: Better |
1588 | use an C<aio_group> together with a feed callback. |
1987 | use an C<aio_group> together with a feed callback. |
1589 | |
1988 | |
1590 | It's main use is in scripts without an event loop - when you want to stat |
1989 | Its main use is in scripts without an event loop - when you want to stat |
1591 | a lot of files, you can write somehting like this: |
1990 | a lot of files, you can write somehting like this: |
1592 | |
1991 | |
1593 | IO::AIO::max_outstanding 32; |
1992 | IO::AIO::max_outstanding 32; |
1594 | |
1993 | |
1595 | for my $path (...) { |
1994 | for my $path (...) { |
… | |
… | |
1635 | |
2034 | |
1636 | =back |
2035 | =back |
1637 | |
2036 | |
1638 | =head3 MISCELLANEOUS FUNCTIONS |
2037 | =head3 MISCELLANEOUS FUNCTIONS |
1639 | |
2038 | |
1640 | IO::AIO implements some functions that might be useful, but are not |
2039 | IO::AIO implements some functions that are useful when you want to use |
1641 | asynchronous. |
2040 | some "Advanced I/O" function not available to in Perl, without going the |
|
|
2041 | "Asynchronous I/O" route. Many of these have an asynchronous C<aio_*> |
|
|
2042 | counterpart. |
1642 | |
2043 | |
1643 | =over 4 |
2044 | =over 4 |
1644 | |
2045 | |
1645 | =item IO::AIO::sendfile $ofh, $ifh, $offset, $count |
2046 | =item IO::AIO::sendfile $ofh, $ifh, $offset, $count |
1646 | |
2047 | |
… | |
… | |
1653 | |
2054 | |
1654 | =item IO::AIO::fadvise $fh, $offset, $len, $advice |
2055 | =item IO::AIO::fadvise $fh, $offset, $len, $advice |
1655 | |
2056 | |
1656 | Simply calls the C<posix_fadvise> function (see its |
2057 | Simply calls the C<posix_fadvise> function (see its |
1657 | manpage for details). The following advice constants are |
2058 | manpage for details). The following advice constants are |
1658 | avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>, |
2059 | available: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>, |
1659 | C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>, |
2060 | C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>, |
1660 | C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>. |
2061 | C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>. |
1661 | |
2062 | |
1662 | On systems that do not implement C<posix_fadvise>, this function returns |
2063 | On systems that do not implement C<posix_fadvise>, this function returns |
1663 | ENOSYS, otherwise the return value of C<posix_fadvise>. |
2064 | ENOSYS, otherwise the return value of C<posix_fadvise>. |
1664 | |
2065 | |
1665 | =item IO::AIO::madvise $scalar, $offset, $len, $advice |
2066 | =item IO::AIO::madvise $scalar, $offset, $len, $advice |
1666 | |
2067 | |
1667 | Simply calls the C<posix_madvise> function (see its |
2068 | Simply calls the C<posix_madvise> function (see its |
1668 | manpage for details). The following advice constants are |
2069 | manpage for details). The following advice constants are |
1669 | avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>, |
2070 | available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>, |
1670 | C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>. |
2071 | C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>, |
|
|
2072 | C<IO::AIO::MADV_FREE>. |
|
|
2073 | |
|
|
2074 | If C<$offset> is negative, counts from the end. If C<$length> is negative, |
|
|
2075 | the remaining length of the C<$scalar> is used. If possible, C<$length> |
|
|
2076 | will be reduced to fit into the C<$scalar>. |
1671 | |
2077 | |
1672 | On systems that do not implement C<posix_madvise>, this function returns |
2078 | On systems that do not implement C<posix_madvise>, this function returns |
1673 | ENOSYS, otherwise the return value of C<posix_madvise>. |
2079 | ENOSYS, otherwise the return value of C<posix_madvise>. |
1674 | |
2080 | |
1675 | =item IO::AIO::mprotect $scalar, $offset, $len, $protect |
2081 | =item IO::AIO::mprotect $scalar, $offset, $len, $protect |
1676 | |
2082 | |
1677 | Simply calls the C<mprotect> function on the preferably AIO::mmap'ed |
2083 | Simply calls the C<mprotect> function on the preferably AIO::mmap'ed |
1678 | $scalar (see its manpage for details). The following protect |
2084 | $scalar (see its manpage for details). The following protect |
1679 | constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>, |
2085 | constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>, |
1680 | C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>. |
2086 | C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>. |
|
|
2087 | |
|
|
2088 | If C<$offset> is negative, counts from the end. If C<$length> is negative, |
|
|
2089 | the remaining length of the C<$scalar> is used. If possible, C<$length> |
|
|
2090 | will be reduced to fit into the C<$scalar>. |
1681 | |
2091 | |
1682 | On systems that do not implement C<mprotect>, this function returns |
2092 | On systems that do not implement C<mprotect>, this function returns |
1683 | ENOSYS, otherwise the return value of C<mprotect>. |
2093 | ENOSYS, otherwise the return value of C<mprotect>. |
1684 | |
2094 | |
1685 | =item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] |
2095 | =item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] |
1686 | |
2096 | |
1687 | Memory-maps a file (or anonymous memory range) and attaches it to the |
2097 | Memory-maps a file (or anonymous memory range) and attaches it to the |
1688 | given C<$scalar>, which will act like a string scalar. |
2098 | given C<$scalar>, which will act like a string scalar. Returns true on |
|
|
2099 | success, and false otherwise. |
1689 | |
2100 | |
|
|
2101 | The scalar must exist, but its contents do not matter - this means you |
|
|
2102 | cannot use a nonexistant array or hash element. When in doubt, C<undef> |
|
|
2103 | the scalar first. |
|
|
2104 | |
1690 | The only operations allowed on the scalar are C<substr>/C<vec> that don't |
2105 | The only operations allowed on the mmapped scalar are C<substr>/C<vec>, |
1691 | change the string length, and most read-only operations such as copying it |
2106 | which don't change the string length, and most read-only operations such |
1692 | or searching it with regexes and so on. |
2107 | as copying it or searching it with regexes and so on. |
1693 | |
2108 | |
1694 | Anything else is unsafe and will, at best, result in memory leaks. |
2109 | Anything else is unsafe and will, at best, result in memory leaks. |
1695 | |
2110 | |
1696 | The memory map associated with the C<$scalar> is automatically removed |
2111 | The memory map associated with the C<$scalar> is automatically removed |
1697 | when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or |
2112 | when the C<$scalar> is undef'd or destroyed, or when the C<IO::AIO::mmap> |
1698 | C<IO::AIO::munmap> functions are called. |
2113 | or C<IO::AIO::munmap> functions are called on it. |
1699 | |
2114 | |
1700 | This calls the C<mmap>(2) function internally. See your system's manual |
2115 | This calls the C<mmap>(2) function internally. See your system's manual |
1701 | page for details on the C<$length>, C<$prot> and C<$flags> parameters. |
2116 | page for details on the C<$length>, C<$prot> and C<$flags> parameters. |
1702 | |
2117 | |
1703 | The C<$length> must be larger than zero and smaller than the actual |
2118 | The C<$length> must be larger than zero and smaller than the actual |
1704 | filesize. |
2119 | filesize. |
1705 | |
2120 | |
1706 | C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>, |
2121 | C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>, |
1707 | C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>, |
2122 | C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>, |
1708 | |
2123 | |
1709 | C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or |
2124 | C<$flags> can be a combination of |
1710 | C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when |
2125 | C<IO::AIO::MAP_SHARED> or |
1711 | not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS> |
2126 | C<IO::AIO::MAP_PRIVATE>, |
|
|
2127 | or a number of system-specific flags (when not available, the are C<0>): |
1712 | (which is set to C<MAP_ANON> if your system only provides this |
2128 | C<IO::AIO::MAP_ANONYMOUS> (which is set to C<MAP_ANON> if your system only provides this constant), |
1713 | constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>, |
2129 | C<IO::AIO::MAP_LOCKED>, |
1714 | C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or |
2130 | C<IO::AIO::MAP_NORESERVE>, |
|
|
2131 | C<IO::AIO::MAP_POPULATE>, |
1715 | C<IO::AIO::MAP_NONBLOCK> |
2132 | C<IO::AIO::MAP_NONBLOCK>, |
|
|
2133 | C<IO::AIO::MAP_FIXED>, |
|
|
2134 | C<IO::AIO::MAP_GROWSDOWN>, |
|
|
2135 | C<IO::AIO::MAP_32BIT>, |
|
|
2136 | C<IO::AIO::MAP_HUGETLB> or |
|
|
2137 | C<IO::AIO::MAP_STACK>. |
1716 | |
2138 | |
1717 | If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed. |
2139 | If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed. |
1718 | |
2140 | |
1719 | C<$offset> is the offset from the start of the file - it generally must be |
2141 | C<$offset> is the offset from the start of the file - it generally must be |
1720 | a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>. |
2142 | a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>. |
… | |
… | |
1745 | |
2167 | |
1746 | Calls the C<munlockall> function. |
2168 | Calls the C<munlockall> function. |
1747 | |
2169 | |
1748 | On systems that do not implement C<munlockall>, this function returns |
2170 | On systems that do not implement C<munlockall>, this function returns |
1749 | ENOSYS, otherwise the return value of C<munlockall>. |
2171 | ENOSYS, otherwise the return value of C<munlockall>. |
|
|
2172 | |
|
|
2173 | =item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags |
|
|
2174 | |
|
|
2175 | Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or |
|
|
2176 | C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they |
|
|
2177 | should be the file offset. |
|
|
2178 | |
|
|
2179 | C<$r_fh> and C<$w_fh> should not refer to the same file, as splice might |
|
|
2180 | silently corrupt the data in this case. |
|
|
2181 | |
|
|
2182 | The following symbol flag values are available: C<IO::AIO::SPLICE_F_MOVE>, |
|
|
2183 | C<IO::AIO::SPLICE_F_NONBLOCK>, C<IO::AIO::SPLICE_F_MORE> and |
|
|
2184 | C<IO::AIO::SPLICE_F_GIFT>. |
|
|
2185 | |
|
|
2186 | See the C<splice(2)> manpage for details. |
|
|
2187 | |
|
|
2188 | =item IO::AIO::tee $r_fh, $w_fh, $length, $flags |
|
|
2189 | |
|
|
2190 | Calls the GNU/Linux C<tee(2)> syscall, see its manpage and the |
|
|
2191 | description for C<IO::AIO::splice> above for details. |
|
|
2192 | |
|
|
2193 | =item $actual_size = IO::AIO::pipesize $r_fh[, $new_size] |
|
|
2194 | |
|
|
2195 | Attempts to query or change the pipe buffer size. Obviously works only |
|
|
2196 | on pipes, and currently works only on GNU/Linux systems, and fails with |
|
|
2197 | C<-1>/C<ENOSYS> everywhere else. If anybody knows how to influence pipe buffer |
|
|
2198 | size on other systems, drop me a note. |
|
|
2199 | |
|
|
2200 | =item ($rfh, $wfh) = IO::AIO::pipe2 [$flags] |
|
|
2201 | |
|
|
2202 | This is a direct interface to the Linux L<pipe2(2)> system call. If |
|
|
2203 | C<$flags> is missing or C<0>, then this should be the same as a call to |
|
|
2204 | perl's built-in C<pipe> function and create a new pipe, and works on |
|
|
2205 | systems that lack the pipe2 syscall. On win32, this case invokes C<_pipe |
|
|
2206 | (..., 4096, O_BINARY)>. |
|
|
2207 | |
|
|
2208 | If C<$flags> is non-zero, it tries to invoke the pipe2 system call with |
|
|
2209 | the given flags (Linux 2.6.27, glibc 2.9). |
|
|
2210 | |
|
|
2211 | On success, the read and write file handles are returned. |
|
|
2212 | |
|
|
2213 | On error, nothing will be returned. If the pipe2 syscall is missing and |
|
|
2214 | C<$flags> is non-zero, fails with C<ENOSYS>. |
|
|
2215 | |
|
|
2216 | Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the |
|
|
2217 | time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and |
|
|
2218 | C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported. |
1750 | |
2219 | |
1751 | =back |
2220 | =back |
1752 | |
2221 | |
1753 | =cut |
2222 | =cut |
1754 | |
2223 | |
… | |
… | |
1792 | =head2 FORK BEHAVIOUR |
2261 | =head2 FORK BEHAVIOUR |
1793 | |
2262 | |
1794 | Usage of pthreads in a program changes the semantics of fork |
2263 | Usage of pthreads in a program changes the semantics of fork |
1795 | considerably. Specifically, only async-safe functions can be called after |
2264 | considerably. Specifically, only async-safe functions can be called after |
1796 | fork. Perl doesn't know about this, so in general, you cannot call fork |
2265 | fork. Perl doesn't know about this, so in general, you cannot call fork |
1797 | with defined behaviour in perl. IO::AIO uses pthreads, so this applies, |
2266 | with defined behaviour in perl if pthreads are involved. IO::AIO uses |
1798 | but many other extensions and (for inexplicable reasons) perl itself often |
2267 | pthreads, so this applies, but many other extensions and (for inexplicable |
1799 | is linked against pthreads, so this limitation applies. |
2268 | reasons) perl itself often is linked against pthreads, so this limitation |
|
|
2269 | applies to quite a lot of perls. |
1800 | |
2270 | |
1801 | Some operating systems have extensions that allow safe use of fork, and |
2271 | This module no longer tries to fight your OS, or POSIX. That means IO::AIO |
1802 | this module should do "the right thing" on those, and tries on others. At |
2272 | only works in the process that loaded it. Forking is fully supported, but |
1803 | the time of this writing (2011) only GNU/Linux supports these extensions |
2273 | using IO::AIO in the child is not. |
1804 | to POSIX. |
2274 | |
|
|
2275 | You might get around by not I<using> IO::AIO before (or after) |
|
|
2276 | forking. You could also try to call the L<IO::AIO::reinit> function in the |
|
|
2277 | child: |
|
|
2278 | |
|
|
2279 | =over 4 |
|
|
2280 | |
|
|
2281 | =item IO::AIO::reinit |
|
|
2282 | |
|
|
2283 | Abandons all current requests and I/O threads and simply reinitialises all |
|
|
2284 | data structures. This is not an operation supported by any standards, but |
|
|
2285 | happens to work on GNU/Linux and some newer BSD systems. |
|
|
2286 | |
|
|
2287 | The only reasonable use for this function is to call it after forking, if |
|
|
2288 | C<IO::AIO> was used in the parent. Calling it while IO::AIO is active in |
|
|
2289 | the process will result in undefined behaviour. Calling it at any time |
|
|
2290 | will also result in any undefined (by POSIX) behaviour. |
|
|
2291 | |
|
|
2292 | =back |
1805 | |
2293 | |
1806 | =head2 MEMORY USAGE |
2294 | =head2 MEMORY USAGE |
1807 | |
2295 | |
1808 | Per-request usage: |
2296 | Per-request usage: |
1809 | |
2297 | |