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 | |
… | |
… | |
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 | |
|
|
63 | In addition to asynchronous I/O, this module also exports some rather |
|
|
64 | arcane interfaces, such as C<madvise> or linux's C<splice> system call, |
|
|
65 | which is why the C<A> in C<AIO> can also mean I<advanced>. |
|
|
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; |
|
|
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; |
… | |
… | |
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. |
… | |
… | |
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 = '3.93'; |
176 | our $VERSION = 4.52; |
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_realpath 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_fallocate |
181 | aio_sync aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range |
179 | aio_pathsync aio_readahead |
182 | aio_pathsync aio_readahead aio_fiemap aio_allocate |
180 | aio_rename aio_link aio_move aio_copy aio_group |
183 | aio_rename aio_rename2 aio_link aio_move aio_copy aio_group |
181 | 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 |
182 | aio_chmod aio_utime aio_truncate |
185 | aio_chmod aio_utime aio_truncate |
183 | aio_msync aio_mtouch aio_mlock aio_mlockall |
186 | aio_msync aio_mtouch aio_mlock aio_mlockall |
184 | aio_statvfs); |
187 | aio_statvfs |
|
|
188 | aio_slurp |
|
|
189 | aio_wd); |
185 | |
190 | |
186 | our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); |
191 | our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); |
187 | our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush |
192 | our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush |
188 | min_parallel max_parallel max_idle idle_timeout |
193 | min_parallel max_parallel max_idle idle_timeout |
189 | nreqs nready npending nthreads |
194 | nreqs nready npending nthreads |
190 | max_poll_time max_poll_reqs |
195 | max_poll_time max_poll_reqs |
191 | sendfile fadvise madvise |
196 | sendfile fadvise madvise |
192 | mmap munmap munlock munlockall); |
197 | mmap munmap mremap munlock munlockall); |
193 | |
198 | |
194 | push @AIO_REQ, qw(aio_busy); # not exported |
199 | push @AIO_REQ, qw(aio_busy); # not exported |
195 | |
200 | |
196 | @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; |
201 | @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; |
197 | |
202 | |
… | |
… | |
201 | |
206 | |
202 | =head1 FUNCTIONS |
207 | =head1 FUNCTIONS |
203 | |
208 | |
204 | =head2 QUICK OVERVIEW |
209 | =head2 QUICK OVERVIEW |
205 | |
210 | |
206 | This section simply lists the prototypes of the most important functions |
211 | This section simply lists the prototypes most of the functions for |
207 | for quick reference. See the following sections for function-by-function |
212 | quick reference. See the following sections for function-by-function |
208 | documentation. |
213 | documentation. |
209 | |
214 | |
|
|
215 | aio_wd $pathname, $callback->($wd) |
210 | aio_open $pathname, $flags, $mode, $callback->($fh) |
216 | aio_open $pathname, $flags, $mode, $callback->($fh) |
211 | aio_close $fh, $callback->($status) |
217 | aio_close $fh, $callback->($status) |
|
|
218 | aio_seek $fh,$offset,$whence, $callback->($offs) |
212 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
219 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
213 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
220 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
214 | aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
221 | aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
215 | aio_readahead $fh,$offset,$length, $callback->($retval) |
222 | aio_readahead $fh,$offset,$length, $callback->($retval) |
216 | aio_stat $fh_or_path, $callback->($status) |
223 | aio_stat $fh_or_path, $callback->($status) |
217 | aio_lstat $fh, $callback->($status) |
224 | aio_lstat $fh, $callback->($status) |
218 | aio_statvfs $fh_or_path, $callback->($statvfs) |
225 | aio_statvfs $fh_or_path, $callback->($statvfs) |
219 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
226 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
220 | aio_chown $fh_or_path, $uid, $gid, $callback->($status) |
227 | aio_chown $fh_or_path, $uid, $gid, $callback->($status) |
|
|
228 | aio_chmod $fh_or_path, $mode, $callback->($status) |
221 | aio_truncate $fh_or_path, $offset, $callback->($status) |
229 | aio_truncate $fh_or_path, $offset, $callback->($status) |
222 | aio_chmod $fh_or_path, $mode, $callback->($status) |
230 | aio_allocate $fh, $mode, $offset, $len, $callback->($status) |
|
|
231 | aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents) |
223 | aio_unlink $pathname, $callback->($status) |
232 | aio_unlink $pathname, $callback->($status) |
224 | aio_mknod $path, $mode, $dev, $callback->($status) |
233 | aio_mknod $pathname, $mode, $dev, $callback->($status) |
225 | aio_link $srcpath, $dstpath, $callback->($status) |
234 | aio_link $srcpath, $dstpath, $callback->($status) |
226 | aio_symlink $srcpath, $dstpath, $callback->($status) |
235 | aio_symlink $srcpath, $dstpath, $callback->($status) |
227 | aio_readlink $path, $callback->($link) |
236 | aio_readlink $pathname, $callback->($link) |
228 | aio_realpath $path, $callback->($link) |
237 | aio_realpath $pathname, $callback->($path) |
229 | aio_rename $srcpath, $dstpath, $callback->($status) |
238 | aio_rename $srcpath, $dstpath, $callback->($status) |
|
|
239 | aio_rename2 $srcpath, $dstpath, $flags, $callback->($status) |
230 | aio_mkdir $pathname, $mode, $callback->($status) |
240 | aio_mkdir $pathname, $mode, $callback->($status) |
231 | aio_rmdir $pathname, $callback->($status) |
241 | aio_rmdir $pathname, $callback->($status) |
232 | aio_readdir $pathname, $callback->($entries) |
242 | aio_readdir $pathname, $callback->($entries) |
233 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
243 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
234 | IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST |
244 | IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST |
235 | IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN |
245 | IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN |
|
|
246 | aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) |
236 | aio_load $path, $data, $callback->($status) |
247 | aio_load $pathname, $data, $callback->($status) |
237 | aio_copy $srcpath, $dstpath, $callback->($status) |
248 | aio_copy $srcpath, $dstpath, $callback->($status) |
238 | aio_move $srcpath, $dstpath, $callback->($status) |
249 | aio_move $srcpath, $dstpath, $callback->($status) |
239 | aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
|
|
240 | aio_rmtree $path, $callback->($status) |
250 | aio_rmtree $pathname, $callback->($status) |
|
|
251 | aio_fcntl $fh, $cmd, $arg, $callback->($status) |
|
|
252 | aio_ioctl $fh, $request, $buf, $callback->($status) |
241 | aio_sync $callback->($status) |
253 | aio_sync $callback->($status) |
|
|
254 | aio_syncfs $fh, $callback->($status) |
242 | aio_fsync $fh, $callback->($status) |
255 | aio_fsync $fh, $callback->($status) |
243 | aio_fdatasync $fh, $callback->($status) |
256 | aio_fdatasync $fh, $callback->($status) |
244 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
257 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
245 | aio_pathsync $path, $callback->($status) |
258 | aio_pathsync $pathname, $callback->($status) |
246 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
259 | aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status) |
247 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
260 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
248 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
261 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
249 | aio_mlockall $flags, $callback->($status) |
262 | aio_mlockall $flags, $callback->($status) |
250 | aio_group $callback->(...) |
263 | aio_group $callback->(...) |
251 | aio_nop $callback->() |
264 | aio_nop $callback->() |
… | |
… | |
265 | IO::AIO::idle_timeout $seconds |
278 | IO::AIO::idle_timeout $seconds |
266 | IO::AIO::max_outstanding $maxreqs |
279 | IO::AIO::max_outstanding $maxreqs |
267 | IO::AIO::nreqs |
280 | IO::AIO::nreqs |
268 | IO::AIO::nready |
281 | IO::AIO::nready |
269 | IO::AIO::npending |
282 | IO::AIO::npending |
|
|
283 | $nfd = IO::AIO::get_fdlimit [EXPERIMENTAL] |
|
|
284 | IO::AIO::min_fdlimit $nfd [EXPERIMENTAL] |
270 | |
285 | |
271 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
286 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
272 | IO::AIO::fadvise $fh, $offset, $len, $advice |
287 | IO::AIO::fadvise $fh, $offset, $len, $advice |
|
|
288 | IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]] |
|
|
289 | IO::AIO::munmap $scalar |
|
|
290 | IO::AIO::mremap $scalar, $new_length, $flags[, $new_address] |
273 | IO::AIO::madvise $scalar, $offset, $length, $advice |
291 | IO::AIO::madvise $scalar, $offset, $length, $advice |
274 | IO::AIO::mprotect $scalar, $offset, $length, $protect |
292 | IO::AIO::mprotect $scalar, $offset, $length, $protect |
275 | IO::AIO::munlock $scalar, $offset = 0, $length = undef |
293 | IO::AIO::munlock $scalar, $offset = 0, $length = undef |
276 | IO::AIO::munlockall |
294 | IO::AIO::munlockall |
277 | |
295 | |
278 | =head2 AIO REQUEST FUNCTIONS |
296 | =head2 API NOTES |
279 | |
297 | |
280 | All the C<aio_*> calls are more or less thin wrappers around the syscall |
298 | All the C<aio_*> calls are more or less thin wrappers around the syscall |
281 | with the same name (sans C<aio_>). The arguments are similar or identical, |
299 | with the same name (sans C<aio_>). The arguments are similar or identical, |
282 | and they all accept an additional (and optional) C<$callback> argument |
300 | and they all accept an additional (and optional) C<$callback> argument |
283 | which must be a code reference. This code reference will get called with |
301 | which must be a code reference. This code reference will be called after |
284 | the syscall return code (e.g. most syscalls return C<-1> on error, unlike |
302 | the syscall has been executed in an asynchronous fashion. The results |
285 | perl, which usually delivers "false") as its sole argument after the given |
303 | of the request will be passed as arguments to the callback (and, if an |
286 | syscall has been executed asynchronously. |
304 | error occured, in C<$!>) - for most requests the syscall return code (e.g. |
|
|
305 | most syscalls return C<-1> on error, unlike perl, which usually delivers |
|
|
306 | "false"). |
|
|
307 | |
|
|
308 | Some requests (such as C<aio_readdir>) pass the actual results and |
|
|
309 | communicate failures by passing C<undef>. |
287 | |
310 | |
288 | All functions expecting a filehandle keep a copy of the filehandle |
311 | All functions expecting a filehandle keep a copy of the filehandle |
289 | internally until the request has finished. |
312 | internally until the request has finished. |
290 | |
313 | |
291 | All functions return request objects of type L<IO::AIO::REQ> that allow |
314 | All functions return request objects of type L<IO::AIO::REQ> that allow |
292 | further manipulation of those requests while they are in-flight. |
315 | further manipulation of those requests while they are in-flight. |
293 | |
316 | |
294 | The pathnames you pass to these routines I<must> be absolute and |
317 | The pathnames you pass to these routines I<should> be absolute. The |
295 | encoded as octets. The reason for the former is that at the time the |
318 | reason for this is that at the time the request is being executed, the |
296 | request is being executed, the current working directory could have |
319 | current working directory could have changed. Alternatively, you can |
297 | changed. Alternatively, you can make sure that you never change the |
320 | make sure that you never change the current working directory anywhere |
298 | current working directory anywhere in the program and then use relative |
321 | in the program and then use relative paths. You can also take advantage |
299 | paths. |
322 | of IO::AIOs working directory abstraction, that lets you specify paths |
|
|
323 | relative to some previously-opened "working directory object" - see the |
|
|
324 | description of the C<IO::AIO::WD> class later in this document. |
300 | |
325 | |
301 | To encode pathnames as octets, either make sure you either: a) always pass |
326 | To encode pathnames as octets, either make sure you either: a) always pass |
302 | in filenames you got from outside (command line, readdir etc.) without |
327 | in filenames you got from outside (command line, readdir etc.) without |
303 | tinkering, b) are ASCII or ISO 8859-1, c) use the Encode module and encode |
328 | tinkering, b) are in your native filesystem encoding, c) use the Encode |
304 | your pathnames to the locale (or other) encoding in effect in the user |
329 | module and encode your pathnames to the locale (or other) encoding in |
305 | environment, d) use Glib::filename_from_unicode on unicode filenames or e) |
330 | effect in the user environment, d) use Glib::filename_from_unicode on |
306 | use something else to ensure your scalar has the correct contents. |
331 | unicode filenames or e) use something else to ensure your scalar has the |
|
|
332 | correct contents. |
307 | |
333 | |
308 | This works, btw. independent of the internal UTF-8 bit, which IO::AIO |
334 | This works, btw. independent of the internal UTF-8 bit, which IO::AIO |
309 | handles correctly whether it is set or not. |
335 | handles correctly whether it is set or not. |
|
|
336 | |
|
|
337 | =head2 AIO REQUEST FUNCTIONS |
310 | |
338 | |
311 | =over 4 |
339 | =over 4 |
312 | |
340 | |
313 | =item $prev_pri = aioreq_pri [$pri] |
341 | =item $prev_pri = aioreq_pri [$pri] |
314 | |
342 | |
… | |
… | |
344 | |
372 | |
345 | |
373 | |
346 | =item aio_open $pathname, $flags, $mode, $callback->($fh) |
374 | =item aio_open $pathname, $flags, $mode, $callback->($fh) |
347 | |
375 | |
348 | Asynchronously open or create a file and call the callback with a newly |
376 | Asynchronously open or create a file and call the callback with a newly |
349 | created filehandle for the file. |
377 | created filehandle for the file (or C<undef> in case of an error). |
350 | |
378 | |
351 | The pathname passed to C<aio_open> must be absolute. See API NOTES, above, |
379 | The pathname passed to C<aio_open> must be absolute. See API NOTES, above, |
352 | for an explanation. |
380 | for an explanation. |
353 | |
381 | |
354 | The C<$flags> argument is a bitmask. See the C<Fcntl> module for a |
382 | The C<$flags> argument is a bitmask. See the C<Fcntl> module for a |
… | |
… | |
377 | following POSIX and non-POSIX constants are available (missing ones on |
405 | following POSIX and non-POSIX constants are available (missing ones on |
378 | your system are, as usual, C<0>): |
406 | your system are, as usual, C<0>): |
379 | |
407 | |
380 | C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>, |
408 | C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>, |
381 | C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>, |
409 | C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>, |
382 | C<O_RSYNC>, C<O_SYNC> and C<O_TTY_INIT>. |
410 | C<O_RSYNC>, C<O_SYNC>, C<O_PATH>, C<O_TMPFILE>, C<O_TTY_INIT> and C<O_ACCMODE>. |
383 | |
411 | |
384 | |
412 | |
385 | =item aio_close $fh, $callback->($status) |
413 | =item aio_close $fh, $callback->($status) |
386 | |
414 | |
387 | Asynchronously close a file and call the callback with the result |
415 | Asynchronously close a file and call the callback with the result |
… | |
… | |
397 | Or in other words: the file descriptor will be closed, but it will not be |
425 | Or in other words: the file descriptor will be closed, but it will not be |
398 | free for reuse until the perl filehandle is closed. |
426 | free for reuse until the perl filehandle is closed. |
399 | |
427 | |
400 | =cut |
428 | =cut |
401 | |
429 | |
|
|
430 | =item aio_seek $fh, $offset, $whence, $callback->($offs) |
|
|
431 | |
|
|
432 | Seeks the filehandle to the new C<$offset>, similarly to perl's |
|
|
433 | C<sysseek>. The C<$whence> can use the traditional values (C<0> for |
|
|
434 | C<IO::AIO::SEEK_SET>, C<1> for C<IO::AIO::SEEK_CUR> or C<2> for |
|
|
435 | C<IO::AIO::SEEK_END>). |
|
|
436 | |
|
|
437 | The resulting absolute offset will be passed to the callback, or C<-1> in |
|
|
438 | case of an error. |
|
|
439 | |
|
|
440 | In theory, the C<$whence> constants could be different than the |
|
|
441 | corresponding values from L<Fcntl>, but perl guarantees they are the same, |
|
|
442 | so don't panic. |
|
|
443 | |
|
|
444 | As a GNU/Linux (and maybe Solaris) extension, also the constants |
|
|
445 | C<IO::AIO::SEEK_DATA> and C<IO::AIO::SEEK_HOLE> are available, if they |
|
|
446 | could be found. No guarantees about suitability for use in C<aio_seek> or |
|
|
447 | Perl's C<sysseek> can be made though, although I would naively assume they |
|
|
448 | "just work". |
|
|
449 | |
402 | =item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
450 | =item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
403 | |
451 | |
404 | =item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
452 | =item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
405 | |
453 | |
406 | Reads or writes C<$length> bytes from or to the specified C<$fh> and |
454 | Reads or writes C<$length> bytes from or to the specified C<$fh> and |
407 | C<$offset> into the scalar given by C<$data> and offset C<$dataoffset> |
455 | C<$offset> into the scalar given by C<$data> and offset C<$dataoffset> and |
408 | and calls the callback without the actual number of bytes read (or -1 on |
456 | calls the callback with the actual number of bytes transferred (or -1 on |
409 | error, just like the syscall). |
457 | error, just like the syscall). |
410 | |
458 | |
411 | C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to |
459 | C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to |
412 | offset plus the actual number of bytes read. |
460 | offset plus the actual number of bytes read. |
413 | |
461 | |
… | |
… | |
471 | As native sendfile syscalls (as practically any non-POSIX interface hacked |
519 | As native sendfile syscalls (as practically any non-POSIX interface hacked |
472 | together in a hurry to improve benchmark numbers) tend to be rather buggy |
520 | together in a hurry to improve benchmark numbers) tend to be rather buggy |
473 | on many systems, this implementation tries to work around some known bugs |
521 | on many systems, this implementation tries to work around some known bugs |
474 | in Linux and FreeBSD kernels (probably others, too), but that might fail, |
522 | in Linux and FreeBSD kernels (probably others, too), but that might fail, |
475 | so you really really should check the return value of C<aio_sendfile> - |
523 | so you really really should check the return value of C<aio_sendfile> - |
476 | fewre bytes than expected might have been transferred. |
524 | fewer bytes than expected might have been transferred. |
477 | |
525 | |
478 | |
526 | |
479 | =item aio_readahead $fh,$offset,$length, $callback->($retval) |
527 | =item aio_readahead $fh,$offset,$length, $callback->($retval) |
480 | |
528 | |
481 | C<aio_readahead> populates the page cache with data from a file so that |
529 | C<aio_readahead> populates the page cache with data from a file so that |
… | |
… | |
485 | whole pages, so that offset is effectively rounded down to a page boundary |
533 | whole pages, so that offset is effectively rounded down to a page boundary |
486 | and bytes are read up to the next page boundary greater than or equal to |
534 | and bytes are read up to the next page boundary greater than or equal to |
487 | (off-set+length). C<aio_readahead> does not read beyond the end of the |
535 | (off-set+length). C<aio_readahead> does not read beyond the end of the |
488 | file. The current file offset of the file is left unchanged. |
536 | file. The current file offset of the file is left unchanged. |
489 | |
537 | |
490 | If that syscall doesn't exist (likely if your OS isn't Linux) it will be |
538 | If that syscall doesn't exist (likely if your kernel isn't Linux) it will |
491 | emulated by simply reading the data, which would have a similar effect. |
539 | be emulated by simply reading the data, which would have a similar effect. |
492 | |
540 | |
493 | |
541 | |
494 | =item aio_stat $fh_or_path, $callback->($status) |
542 | =item aio_stat $fh_or_path, $callback->($status) |
495 | |
543 | |
496 | =item aio_lstat $fh, $callback->($status) |
544 | =item aio_lstat $fh, $callback->($status) |
… | |
… | |
512 | behaviour). |
560 | behaviour). |
513 | |
561 | |
514 | C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>, |
562 | C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>, |
515 | C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>, |
563 | C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>, |
516 | C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>. |
564 | C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>. |
|
|
565 | |
|
|
566 | To access higher resolution stat timestamps, see L<SUBSECOND STAT TIME |
|
|
567 | ACCESS>. |
517 | |
568 | |
518 | Example: Print the length of F</etc/passwd>: |
569 | Example: Print the length of F</etc/passwd>: |
519 | |
570 | |
520 | aio_stat "/etc/passwd", sub { |
571 | aio_stat "/etc/passwd", sub { |
521 | $_[0] and die "stat failed: $!"; |
572 | $_[0] and die "stat failed: $!"; |
… | |
… | |
565 | namemax => 255, |
616 | namemax => 255, |
566 | frsize => 1024, |
617 | frsize => 1024, |
567 | fsid => 1810 |
618 | fsid => 1810 |
568 | } |
619 | } |
569 | |
620 | |
570 | |
|
|
571 | =item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
621 | =item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
572 | |
622 | |
573 | Works like perl's C<utime> function (including the special case of $atime |
623 | Works like perl's C<utime> function (including the special case of $atime |
574 | and $mtime being undef). Fractional times are supported if the underlying |
624 | and $mtime being undef). Fractional times are supported if the underlying |
575 | syscalls support them. |
625 | syscalls support them. |
… | |
… | |
602 | =item aio_truncate $fh_or_path, $offset, $callback->($status) |
652 | =item aio_truncate $fh_or_path, $offset, $callback->($status) |
603 | |
653 | |
604 | Works like truncate(2) or ftruncate(2). |
654 | Works like truncate(2) or ftruncate(2). |
605 | |
655 | |
606 | |
656 | |
|
|
657 | =item aio_allocate $fh, $mode, $offset, $len, $callback->($status) |
|
|
658 | |
|
|
659 | Allocates or frees disk space according to the C<$mode> argument. See the |
|
|
660 | linux C<fallocate> documentation for details. |
|
|
661 | |
|
|
662 | C<$mode> is usually C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> to allocate |
|
|
663 | space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE | IO::AIO::FALLOC_FL_KEEP_SIZE>, |
|
|
664 | to deallocate a file range. |
|
|
665 | |
|
|
666 | IO::AIO also supports C<FALLOC_FL_COLLAPSE_RANGE>, to remove a range |
|
|
667 | (without leaving a hole), C<FALLOC_FL_ZERO_RANGE>, to zero a range, |
|
|
668 | C<FALLOC_FL_INSERT_RANGE> to insert a range and C<FALLOC_FL_UNSHARE_RANGE> |
|
|
669 | to unshare shared blocks (see your L<fallocate(2)> manpage). |
|
|
670 | |
|
|
671 | The file system block size used by C<fallocate> is presumably the |
|
|
672 | C<f_bsize> returned by C<statvfs>, but different filesystems and filetypes |
|
|
673 | can dictate other limitations. |
|
|
674 | |
|
|
675 | If C<fallocate> isn't available or cannot be emulated (currently no |
|
|
676 | emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>. |
|
|
677 | |
|
|
678 | |
607 | =item aio_chmod $fh_or_path, $mode, $callback->($status) |
679 | =item aio_chmod $fh_or_path, $mode, $callback->($status) |
608 | |
680 | |
609 | Works like perl's C<chmod> function. |
681 | Works like perl's C<chmod> function. |
610 | |
682 | |
611 | |
683 | |
… | |
… | |
613 | |
685 | |
614 | Asynchronously unlink (delete) a file and call the callback with the |
686 | Asynchronously unlink (delete) a file and call the callback with the |
615 | result code. |
687 | result code. |
616 | |
688 | |
617 | |
689 | |
618 | =item aio_mknod $path, $mode, $dev, $callback->($status) |
690 | =item aio_mknod $pathname, $mode, $dev, $callback->($status) |
619 | |
691 | |
620 | [EXPERIMENTAL] |
692 | [EXPERIMENTAL] |
621 | |
693 | |
622 | Asynchronously create a device node (or fifo). See mknod(2). |
694 | Asynchronously create a device node (or fifo). See mknod(2). |
623 | |
695 | |
624 | The only (POSIX-) portable way of calling this function is: |
696 | The only (POSIX-) portable way of calling this function is: |
625 | |
697 | |
626 | aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
698 | aio_mknod $pathname, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
627 | |
699 | |
628 | See C<aio_stat> for info about some potentially helpful extra constants |
700 | See C<aio_stat> for info about some potentially helpful extra constants |
629 | and functions. |
701 | and functions. |
630 | |
702 | |
631 | =item aio_link $srcpath, $dstpath, $callback->($status) |
703 | =item aio_link $srcpath, $dstpath, $callback->($status) |
… | |
… | |
638 | |
710 | |
639 | Asynchronously create a new symbolic link to the existing object at C<$srcpath> at |
711 | Asynchronously create a new symbolic link to the existing object at C<$srcpath> at |
640 | the path C<$dstpath> and call the callback with the result code. |
712 | the path C<$dstpath> and call the callback with the result code. |
641 | |
713 | |
642 | |
714 | |
643 | =item aio_readlink $path, $callback->($link) |
715 | =item aio_readlink $pathname, $callback->($link) |
644 | |
716 | |
645 | Asynchronously read the symlink specified by C<$path> and pass it to |
717 | Asynchronously read the symlink specified by C<$path> and pass it to |
646 | the callback. If an error occurs, nothing or undef gets passed to the |
718 | the callback. If an error occurs, nothing or undef gets passed to the |
647 | callback. |
719 | callback. |
648 | |
720 | |
649 | |
721 | |
650 | =item aio_realpath $path, $callback->($path) |
722 | =item aio_realpath $pathname, $callback->($path) |
651 | |
723 | |
652 | Asynchronously make the path absolute and resolve any symlinks in |
724 | Asynchronously make the path absolute and resolve any symlinks in |
653 | C<$path>. The resulting path only consists of directories (Same as |
725 | C<$path>. The resulting path only consists of directories (same as |
654 | L<Cwd::realpath>). |
726 | L<Cwd::realpath>). |
655 | |
727 | |
656 | This request can be used to get the absolute path of the current working |
728 | This request can be used to get the absolute path of the current working |
657 | directory by passing it a path of F<.> (a single dot). |
729 | directory by passing it a path of F<.> (a single dot). |
658 | |
730 | |
659 | |
731 | |
660 | =item aio_rename $srcpath, $dstpath, $callback->($status) |
732 | =item aio_rename $srcpath, $dstpath, $callback->($status) |
661 | |
733 | |
662 | Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as |
734 | Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as |
663 | rename(2) and call the callback with the result code. |
735 | rename(2) and call the callback with the result code. |
|
|
736 | |
|
|
737 | On systems that support the AIO::WD working directory abstraction |
|
|
738 | natively, the case C<[$wd, "."]> as C<$srcpath> is specialcased - instead |
|
|
739 | of failing, C<rename> is called on the absolute path of C<$wd>. |
|
|
740 | |
|
|
741 | |
|
|
742 | =item aio_rename2 $srcpath, $dstpath, $flags, $callback->($status) |
|
|
743 | |
|
|
744 | Basically a version of C<aio_rename> with an additional C<$flags> |
|
|
745 | argument. Calling this with C<$flags=0> is the same as calling |
|
|
746 | C<aio_rename>. |
|
|
747 | |
|
|
748 | Non-zero flags are currently only supported on GNU/Linux systems that |
|
|
749 | support renameat2. Other systems fail with C<ENOSYS> in this case. |
|
|
750 | |
|
|
751 | The following constants are available (missing ones are, as usual C<0>), |
|
|
752 | see renameat2(2) for details: |
|
|
753 | |
|
|
754 | C<IO::AIO::RENAME_NOREPLACE>, C<IO::AIO::RENAME_EXCHANGE> |
|
|
755 | and C<IO::AIO::RENAME_WHITEOUT>. |
664 | |
756 | |
665 | |
757 | |
666 | =item aio_mkdir $pathname, $mode, $callback->($status) |
758 | =item aio_mkdir $pathname, $mode, $callback->($status) |
667 | |
759 | |
668 | Asynchronously mkdir (create) a directory and call the callback with |
760 | Asynchronously mkdir (create) a directory and call the callback with |
… | |
… | |
673 | =item aio_rmdir $pathname, $callback->($status) |
765 | =item aio_rmdir $pathname, $callback->($status) |
674 | |
766 | |
675 | Asynchronously rmdir (delete) a directory and call the callback with the |
767 | Asynchronously rmdir (delete) a directory and call the callback with the |
676 | result code. |
768 | result code. |
677 | |
769 | |
|
|
770 | On systems that support the AIO::WD working directory abstraction |
|
|
771 | natively, the case C<[$wd, "."]> is specialcased - instead of failing, |
|
|
772 | C<rmdir> is called on the absolute path of C<$wd>. |
|
|
773 | |
678 | |
774 | |
679 | =item aio_readdir $pathname, $callback->($entries) |
775 | =item aio_readdir $pathname, $callback->($entries) |
680 | |
776 | |
681 | Unlike the POSIX call of the same name, C<aio_readdir> reads an entire |
777 | Unlike the POSIX call of the same name, C<aio_readdir> reads an entire |
682 | directory (i.e. opendir + readdir + closedir). The entries will not be |
778 | directory (i.e. opendir + readdir + closedir). The entries will not be |
… | |
… | |
686 | array-ref with the filenames. |
782 | array-ref with the filenames. |
687 | |
783 | |
688 | |
784 | |
689 | =item aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
785 | =item aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
690 | |
786 | |
691 | Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune |
787 | Quite similar to C<aio_readdir>, but the C<$flags> argument allows one to |
692 | behaviour and output format. In case of an error, C<$entries> will be |
788 | tune behaviour and output format. In case of an error, C<$entries> will be |
693 | C<undef>. |
789 | C<undef>. |
694 | |
790 | |
695 | The flags are a combination of the following constants, ORed together (the |
791 | The flags are a combination of the following constants, ORed together (the |
696 | flags will also be passed to the callback, possibly modified): |
792 | flags will also be passed to the callback, possibly modified): |
697 | |
793 | |
698 | =over 4 |
794 | =over 4 |
699 | |
795 | |
700 | =item IO::AIO::READDIR_DENTS |
796 | =item IO::AIO::READDIR_DENTS |
701 | |
797 | |
702 | When this flag is off, then the callback gets an arrayref consisting of |
798 | Normally the callback gets an arrayref consisting of names only (as |
703 | names only (as with C<aio_readdir>), otherwise it gets an arrayref with |
799 | with C<aio_readdir>). If this flag is set, then the callback gets an |
704 | C<[$name, $type, $inode]> arrayrefs, each describing a single directory |
800 | arrayref with C<[$name, $type, $inode]> arrayrefs, each describing a |
705 | entry in more detail. |
801 | single directory entry in more detail: |
706 | |
802 | |
707 | C<$name> is the name of the entry. |
803 | C<$name> is the name of the entry. |
708 | |
804 | |
709 | C<$type> is one of the C<IO::AIO::DT_xxx> constants: |
805 | C<$type> is one of the C<IO::AIO::DT_xxx> constants: |
710 | |
806 | |
711 | C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>, |
807 | C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>, |
712 | C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>, |
808 | C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>, |
713 | C<IO::AIO::DT_WHT>. |
809 | C<IO::AIO::DT_WHT>. |
714 | |
810 | |
715 | C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to |
811 | C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need |
716 | know, you have to run stat yourself. Also, for speed reasons, the C<$type> |
812 | to know, you have to run stat yourself. Also, for speed/memory reasons, |
717 | scalars are read-only: you can not modify them. |
813 | the C<$type> scalars are read-only: you must not modify them. |
718 | |
814 | |
719 | C<$inode> is the inode number (which might not be exact on systems with 64 |
815 | C<$inode> is the inode number (which might not be exact on systems with 64 |
720 | bit inode numbers and 32 bit perls). This field has unspecified content on |
816 | bit inode numbers and 32 bit perls). This field has unspecified content on |
721 | systems that do not deliver the inode information. |
817 | systems that do not deliver the inode information. |
722 | |
818 | |
… | |
… | |
733 | short names are tried first. |
829 | short names are tried first. |
734 | |
830 | |
735 | =item IO::AIO::READDIR_STAT_ORDER |
831 | =item IO::AIO::READDIR_STAT_ORDER |
736 | |
832 | |
737 | When this flag is set, then the names will be returned in an order |
833 | When this flag is set, then the names will be returned in an order |
738 | suitable for stat()'ing each one. That is, when you plan to stat() |
834 | suitable for stat()'ing each one. That is, when you plan to stat() most or |
739 | all files in the given directory, then the returned order will likely |
835 | all files in the given directory, then the returned order will likely be |
740 | be fastest. |
836 | faster. |
741 | |
837 | |
742 | If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then |
838 | If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, |
743 | the likely dirs come first, resulting in a less optimal stat order. |
839 | then the likely dirs come first, resulting in a less optimal stat order |
|
|
840 | for stat'ing all entries, but likely a more optimal order for finding |
|
|
841 | subdirectories. |
744 | |
842 | |
745 | =item IO::AIO::READDIR_FOUND_UNKNOWN |
843 | =item IO::AIO::READDIR_FOUND_UNKNOWN |
746 | |
844 | |
747 | This flag should not be set when calling C<aio_readdirx>. Instead, it |
845 | This flag should not be set when calling C<aio_readdirx>. Instead, it |
748 | is being set by C<aio_readdirx>, when any of the C<$type>'s found were |
846 | is being set by C<aio_readdirx>, when any of the C<$type>'s found were |
749 | C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all |
847 | C<IO::AIO::DT_UNKNOWN>. The absence of this flag therefore indicates that all |
750 | C<$type>'s are known, which can be used to speed up some algorithms. |
848 | C<$type>'s are known, which can be used to speed up some algorithms. |
751 | |
849 | |
752 | =back |
850 | =back |
753 | |
851 | |
754 | |
852 | |
|
|
853 | =item aio_slurp $pathname, $offset, $length, $data, $callback->($status) |
|
|
854 | |
|
|
855 | Opens, reads and closes the given file. The data is put into C<$data>, |
|
|
856 | which is resized as required. |
|
|
857 | |
|
|
858 | If C<$offset> is negative, then it is counted from the end of the file. |
|
|
859 | |
|
|
860 | If C<$length> is zero, then the remaining length of the file is |
|
|
861 | used. Also, in this case, the same limitations to modifying C<$data> apply |
|
|
862 | as when IO::AIO::mmap is used, i.e. it must only be modified in-place |
|
|
863 | with C<substr>. If the size of the file is known, specifying a non-zero |
|
|
864 | C<$length> results in a performance advantage. |
|
|
865 | |
|
|
866 | This request is similar to the older C<aio_load> request, but since it is |
|
|
867 | a single request, it might be more efficient to use. |
|
|
868 | |
|
|
869 | Example: load F</etc/passwd> into C<$passwd>. |
|
|
870 | |
|
|
871 | my $passwd; |
|
|
872 | aio_slurp "/etc/passwd", 0, 0, $passwd, sub { |
|
|
873 | $_[0] >= 0 |
|
|
874 | or die "/etc/passwd: $!\n"; |
|
|
875 | |
|
|
876 | printf "/etc/passwd is %d bytes long, and contains:\n", length $passwd; |
|
|
877 | print $passwd; |
|
|
878 | }; |
|
|
879 | IO::AIO::flush; |
|
|
880 | |
|
|
881 | |
755 | =item aio_load $path, $data, $callback->($status) |
882 | =item aio_load $pathname, $data, $callback->($status) |
756 | |
883 | |
757 | This is a composite request that tries to fully load the given file into |
884 | This is a composite request that tries to fully load the given file into |
758 | memory. Status is the same as with aio_read. |
885 | memory. Status is the same as with aio_read. |
|
|
886 | |
|
|
887 | Using C<aio_slurp> might be more efficient, as it is a single request. |
759 | |
888 | |
760 | =cut |
889 | =cut |
761 | |
890 | |
762 | sub aio_load($$;$) { |
891 | sub aio_load($$;$) { |
763 | my ($path, undef, $cb) = @_; |
892 | my ($path, undef, $cb) = @_; |
… | |
… | |
783 | =item aio_copy $srcpath, $dstpath, $callback->($status) |
912 | =item aio_copy $srcpath, $dstpath, $callback->($status) |
784 | |
913 | |
785 | Try to copy the I<file> (directories not supported as either source or |
914 | Try to copy the I<file> (directories not supported as either source or |
786 | destination) from C<$srcpath> to C<$dstpath> and call the callback with |
915 | destination) from C<$srcpath> to C<$dstpath> and call the callback with |
787 | a status of C<0> (ok) or C<-1> (error, see C<$!>). |
916 | a status of C<0> (ok) or C<-1> (error, see C<$!>). |
|
|
917 | |
|
|
918 | Existing destination files will be truncated. |
788 | |
919 | |
789 | This is a composite request that creates the destination file with |
920 | This is a composite request that creates the destination file with |
790 | mode 0200 and copies the contents of the source file into it using |
921 | mode 0200 and copies the contents of the source file into it using |
791 | C<aio_sendfile>, followed by restoring atime, mtime, access mode and |
922 | C<aio_sendfile>, followed by restoring atime, mtime, access mode and |
792 | uid/gid, in that order. |
923 | uid/gid, in that order. |
… | |
… | |
895 | }; |
1026 | }; |
896 | |
1027 | |
897 | $grp |
1028 | $grp |
898 | } |
1029 | } |
899 | |
1030 | |
900 | =item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
1031 | =item aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) |
901 | |
1032 | |
902 | Scans a directory (similar to C<aio_readdir>) but additionally tries to |
1033 | Scans a directory (similar to C<aio_readdir>) but additionally tries to |
903 | efficiently separate the entries of directory C<$path> into two sets of |
1034 | efficiently separate the entries of directory C<$path> into two sets of |
904 | names, directories you can recurse into (directories), and ones you cannot |
1035 | names, directories you can recurse into (directories), and ones you cannot |
905 | recurse into (everything else, including symlinks to directories). |
1036 | recurse into (everything else, including symlinks to directories). |
906 | |
1037 | |
907 | C<aio_scandir> is a composite request that creates of many sub requests_ |
1038 | C<aio_scandir> is a composite request that generates many sub requests. |
908 | C<$maxreq> specifies the maximum number of outstanding aio requests that |
1039 | C<$maxreq> specifies the maximum number of outstanding aio requests that |
909 | this function generates. If it is C<< <= 0 >>, then a suitable default |
1040 | this function generates. If it is C<< <= 0 >>, then a suitable default |
910 | will be chosen (currently 4). |
1041 | will be chosen (currently 4). |
911 | |
1042 | |
912 | On error, the callback is called without arguments, otherwise it receives |
1043 | On error, the callback is called without arguments, otherwise it receives |
… | |
… | |
936 | Then entries will be sorted into likely directories a non-initial dot |
1067 | Then entries will be sorted into likely directories a non-initial dot |
937 | currently) and likely non-directories (see C<aio_readdirx>). Then every |
1068 | currently) and likely non-directories (see C<aio_readdirx>). Then every |
938 | entry plus an appended C</.> will be C<stat>'ed, likely directories first, |
1069 | entry plus an appended C</.> will be C<stat>'ed, likely directories first, |
939 | in order of their inode numbers. If that succeeds, it assumes that the |
1070 | in order of their inode numbers. If that succeeds, it assumes that the |
940 | entry is a directory or a symlink to directory (which will be checked |
1071 | entry is a directory or a symlink to directory (which will be checked |
941 | seperately). This is often faster than stat'ing the entry itself because |
1072 | separately). This is often faster than stat'ing the entry itself because |
942 | filesystems might detect the type of the entry without reading the inode |
1073 | filesystems might detect the type of the entry without reading the inode |
943 | data (e.g. ext2fs filetype feature), even on systems that cannot return |
1074 | data (e.g. ext2fs filetype feature), even on systems that cannot return |
944 | the filetype information on readdir. |
1075 | the filetype information on readdir. |
945 | |
1076 | |
946 | If the known number of directories (link count - 2) has been reached, the |
1077 | If the known number of directories (link count - 2) has been reached, the |
… | |
… | |
962 | |
1093 | |
963 | my $grp = aio_group $cb; |
1094 | my $grp = aio_group $cb; |
964 | |
1095 | |
965 | $maxreq = 4 if $maxreq <= 0; |
1096 | $maxreq = 4 if $maxreq <= 0; |
966 | |
1097 | |
967 | # stat once |
1098 | # get a wd object |
968 | aioreq_pri $pri; |
1099 | aioreq_pri $pri; |
969 | add $grp aio_stat $path, sub { |
1100 | add $grp aio_wd $path, sub { |
|
|
1101 | $_[0] |
970 | return $grp->result () if $_[0]; |
1102 | or return $grp->result (); |
971 | my $now = time; |
|
|
972 | my $hash1 = join ":", (stat _)[0,1,3,7,9]; |
|
|
973 | |
1103 | |
974 | # read the directory entries |
1104 | my $wd = [shift, "."]; |
|
|
1105 | |
|
|
1106 | # stat once |
975 | aioreq_pri $pri; |
1107 | aioreq_pri $pri; |
976 | add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub { |
1108 | add $grp aio_stat $wd, sub { |
977 | my $entries = shift |
|
|
978 | or return $grp->result (); |
1109 | return $grp->result () if $_[0]; |
|
|
1110 | my $now = time; |
|
|
1111 | my $hash1 = join ":", (stat _)[0,1,3,7,9]; |
979 | |
1112 | |
980 | # stat the dir another time |
1113 | # read the directory entries |
981 | aioreq_pri $pri; |
1114 | aioreq_pri $pri; |
|
|
1115 | add $grp aio_readdirx $wd, READDIR_DIRS_FIRST, sub { |
|
|
1116 | my $entries = shift |
|
|
1117 | or return $grp->result (); |
|
|
1118 | |
|
|
1119 | # stat the dir another time |
|
|
1120 | aioreq_pri $pri; |
982 | add $grp aio_stat $path, sub { |
1121 | add $grp aio_stat $wd, sub { |
983 | my $hash2 = join ":", (stat _)[0,1,3,7,9]; |
1122 | my $hash2 = join ":", (stat _)[0,1,3,7,9]; |
984 | |
1123 | |
985 | my $ndirs; |
1124 | my $ndirs; |
986 | |
1125 | |
987 | # take the slow route if anything looks fishy |
1126 | # take the slow route if anything looks fishy |
988 | if ($hash1 ne $hash2 or (stat _)[9] == $now) { |
1127 | if ($hash1 ne $hash2 or (stat _)[9] == $now) { |
989 | $ndirs = -1; |
1128 | $ndirs = -1; |
990 | } else { |
1129 | } else { |
991 | # if nlink == 2, we are finished |
1130 | # if nlink == 2, we are finished |
992 | # for non-posix-fs's, we rely on nlink < 2 |
1131 | # for non-posix-fs's, we rely on nlink < 2 |
993 | $ndirs = (stat _)[3] - 2 |
1132 | $ndirs = (stat _)[3] - 2 |
994 | or return $grp->result ([], $entries); |
1133 | or return $grp->result ([], $entries); |
995 | } |
1134 | } |
996 | |
1135 | |
997 | my (@dirs, @nondirs); |
1136 | my (@dirs, @nondirs); |
998 | |
1137 | |
999 | my $statgrp = add $grp aio_group sub { |
1138 | my $statgrp = add $grp aio_group sub { |
1000 | $grp->result (\@dirs, \@nondirs); |
1139 | $grp->result (\@dirs, \@nondirs); |
1001 | }; |
1140 | }; |
1002 | |
1141 | |
1003 | limit $statgrp $maxreq; |
1142 | limit $statgrp $maxreq; |
1004 | feed $statgrp sub { |
1143 | feed $statgrp sub { |
1005 | return unless @$entries; |
1144 | return unless @$entries; |
1006 | my $entry = shift @$entries; |
1145 | my $entry = shift @$entries; |
1007 | |
1146 | |
1008 | aioreq_pri $pri; |
1147 | aioreq_pri $pri; |
|
|
1148 | $wd->[1] = "$entry/."; |
1009 | add $statgrp aio_stat "$path/$entry/.", sub { |
1149 | add $statgrp aio_stat $wd, sub { |
1010 | if ($_[0] < 0) { |
1150 | if ($_[0] < 0) { |
1011 | push @nondirs, $entry; |
1151 | push @nondirs, $entry; |
1012 | } else { |
1152 | } else { |
1013 | # need to check for real directory |
1153 | # need to check for real directory |
1014 | aioreq_pri $pri; |
1154 | aioreq_pri $pri; |
|
|
1155 | $wd->[1] = $entry; |
1015 | add $statgrp aio_lstat "$path/$entry", sub { |
1156 | add $statgrp aio_lstat $wd, sub { |
1016 | if (-d _) { |
1157 | if (-d _) { |
1017 | push @dirs, $entry; |
1158 | push @dirs, $entry; |
1018 | |
1159 | |
1019 | unless (--$ndirs) { |
1160 | unless (--$ndirs) { |
1020 | push @nondirs, @$entries; |
1161 | push @nondirs, @$entries; |
1021 | feed $statgrp; |
1162 | feed $statgrp; |
|
|
1163 | } |
|
|
1164 | } else { |
|
|
1165 | push @nondirs, $entry; |
1022 | } |
1166 | } |
1023 | } else { |
|
|
1024 | push @nondirs, $entry; |
|
|
1025 | } |
1167 | } |
1026 | } |
1168 | } |
1027 | } |
1169 | }; |
1028 | }; |
1170 | }; |
1029 | }; |
1171 | }; |
1030 | }; |
1172 | }; |
1031 | }; |
1173 | }; |
1032 | }; |
1174 | }; |
1033 | |
1175 | |
1034 | $grp |
1176 | $grp |
1035 | } |
1177 | } |
1036 | |
1178 | |
1037 | =item aio_rmtree $path, $callback->($status) |
1179 | =item aio_rmtree $pathname, $callback->($status) |
1038 | |
1180 | |
1039 | Delete a directory tree starting (and including) C<$path>, return the |
1181 | Delete a directory tree starting (and including) C<$path>, return the |
1040 | status of the final C<rmdir> only. This is a composite request that |
1182 | status of the final C<rmdir> only. This is a composite request that |
1041 | uses C<aio_scandir> to recurse into and rmdir directories, and unlink |
1183 | uses C<aio_scandir> to recurse into and rmdir directories, and unlink |
1042 | everything else. |
1184 | everything else. |
1043 | |
1185 | |
1044 | =cut |
1186 | =cut |
1045 | |
1187 | |
… | |
… | |
1067 | }; |
1209 | }; |
1068 | |
1210 | |
1069 | $grp |
1211 | $grp |
1070 | } |
1212 | } |
1071 | |
1213 | |
|
|
1214 | =item aio_fcntl $fh, $cmd, $arg, $callback->($status) |
|
|
1215 | |
|
|
1216 | =item aio_ioctl $fh, $request, $buf, $callback->($status) |
|
|
1217 | |
|
|
1218 | These work just like the C<fcntl> and C<ioctl> built-in functions, except |
|
|
1219 | they execute asynchronously and pass the return value to the callback. |
|
|
1220 | |
|
|
1221 | Both calls can be used for a lot of things, some of which make more sense |
|
|
1222 | to run asynchronously in their own thread, while some others make less |
|
|
1223 | sense. For example, calls that block waiting for external events, such |
|
|
1224 | as locking, will also lock down an I/O thread while it is waiting, which |
|
|
1225 | can deadlock the whole I/O system. At the same time, there might be no |
|
|
1226 | alternative to using a thread to wait. |
|
|
1227 | |
|
|
1228 | So in general, you should only use these calls for things that do |
|
|
1229 | (filesystem) I/O, not for things that wait for other events (network, |
|
|
1230 | other processes), although if you are careful and know what you are doing, |
|
|
1231 | you still can. |
|
|
1232 | |
|
|
1233 | The following constants are available (missing ones are, as usual C<0>): |
|
|
1234 | |
|
|
1235 | C<F_DUPFD_CLOEXEC>, |
|
|
1236 | |
|
|
1237 | C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>, |
|
|
1238 | |
|
|
1239 | C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>. |
|
|
1240 | |
|
|
1241 | C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>, |
|
|
1242 | C<FS_IOC_FIEMAP>. |
|
|
1243 | |
|
|
1244 | C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>, |
|
|
1245 | C<FS_IOC_GET_ENCRYPTION_PWSALT>, C<FS_IOC_GET_ENCRYPTION_POLICY>, C<FS_KEY_DESCRIPTOR_SIZE>. |
|
|
1246 | |
|
|
1247 | C<FS_SECRM_FL>, C<FS_UNRM_FL>, C<FS_COMPR_FL>, C<FS_SYNC_FL>, C<FS_IMMUTABLE_FL>, |
|
|
1248 | C<FS_APPEND_FL>, C<FS_NODUMP_FL>, C<FS_NOATIME_FL>, C<FS_DIRTY_FL>, |
|
|
1249 | C<FS_COMPRBLK_FL>, C<FS_NOCOMP_FL>, C<FS_ENCRYPT_FL>, C<FS_BTREE_FL>, |
|
|
1250 | C<FS_INDEX_FL>, C<FS_JOURNAL_DATA_FL>, C<FS_NOTAIL_FL>, C<FS_DIRSYNC_FL>, C<FS_TOPDIR_FL>, |
|
|
1251 | C<FS_FL_USER_MODIFIABLE>. |
|
|
1252 | |
|
|
1253 | C<FS_XFLAG_REALTIME>, C<FS_XFLAG_PREALLOC>, C<FS_XFLAG_IMMUTABLE>, C<FS_XFLAG_APPEND>, |
|
|
1254 | C<FS_XFLAG_SYNC>, C<FS_XFLAG_NOATIME>, C<FS_XFLAG_NODUMP>, C<FS_XFLAG_RTINHERIT>, |
|
|
1255 | C<FS_XFLAG_PROJINHERIT>, C<FS_XFLAG_NOSYMLINKS>, C<FS_XFLAG_EXTSIZE>, C<FS_XFLAG_EXTSZINHERIT>, |
|
|
1256 | C<FS_XFLAG_NODEFRAG>, C<FS_XFLAG_FILESTREAM>, C<FS_XFLAG_DAX>, C<FS_XFLAG_HASATTR>, |
|
|
1257 | |
1072 | =item aio_sync $callback->($status) |
1258 | =item aio_sync $callback->($status) |
1073 | |
1259 | |
1074 | Asynchronously call sync and call the callback when finished. |
1260 | Asynchronously call sync and call the callback when finished. |
1075 | |
1261 | |
1076 | =item aio_fsync $fh, $callback->($status) |
1262 | =item aio_fsync $fh, $callback->($status) |
… | |
… | |
1083 | Asynchronously call fdatasync on the given filehandle and call the |
1269 | Asynchronously call fdatasync on the given filehandle and call the |
1084 | callback with the fdatasync result code. |
1270 | callback with the fdatasync result code. |
1085 | |
1271 | |
1086 | If this call isn't available because your OS lacks it or it couldn't be |
1272 | If this call isn't available because your OS lacks it or it couldn't be |
1087 | detected, it will be emulated by calling C<fsync> instead. |
1273 | detected, it will be emulated by calling C<fsync> instead. |
|
|
1274 | |
|
|
1275 | =item aio_syncfs $fh, $callback->($status) |
|
|
1276 | |
|
|
1277 | Asynchronously call the syncfs syscall to sync the filesystem associated |
|
|
1278 | to the given filehandle and call the callback with the syncfs result |
|
|
1279 | code. If syncfs is not available, calls sync(), but returns C<-1> and sets |
|
|
1280 | errno to C<ENOSYS> nevertheless. |
1088 | |
1281 | |
1089 | =item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
1282 | =item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
1090 | |
1283 | |
1091 | Sync the data portion of the file specified by C<$offset> and C<$length> |
1284 | Sync the data portion of the file specified by C<$offset> and C<$length> |
1092 | to disk (but NOT the metadata), by calling the Linux-specific |
1285 | to disk (but NOT the metadata), by calling the Linux-specific |
… | |
… | |
1096 | C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>, |
1289 | C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>, |
1097 | C<IO::AIO::SYNC_FILE_RANGE_WRITE> and |
1290 | C<IO::AIO::SYNC_FILE_RANGE_WRITE> and |
1098 | C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range |
1291 | C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range |
1099 | manpage for details. |
1292 | manpage for details. |
1100 | |
1293 | |
1101 | =item aio_pathsync $path, $callback->($status) |
1294 | =item aio_pathsync $pathname, $callback->($status) |
1102 | |
1295 | |
1103 | This request tries to open, fsync and close the given path. This is a |
1296 | This request tries to open, fsync and close the given path. This is a |
1104 | composite request intended to sync directories after directory operations |
1297 | composite request intended to sync directories after directory operations |
1105 | (E.g. rename). This might not work on all operating systems or have any |
1298 | (E.g. rename). This might not work on all operating systems or have any |
1106 | specific effect, but usually it makes sure that directory changes get |
1299 | specific effect, but usually it makes sure that directory changes get |
… | |
… | |
1137 | }; |
1330 | }; |
1138 | |
1331 | |
1139 | $grp |
1332 | $grp |
1140 | } |
1333 | } |
1141 | |
1334 | |
1142 | =item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
1335 | =item aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status) |
1143 | |
1336 | |
1144 | This is a rather advanced IO::AIO call, which only works on mmap(2)ed |
1337 | This is a rather advanced IO::AIO call, which only works on mmap(2)ed |
1145 | scalars (see the C<IO::AIO::mmap> function, although it also works on data |
1338 | scalars (see the C<IO::AIO::mmap> function, although it also works on data |
1146 | scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the |
1339 | scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the |
1147 | scalar must only be modified in-place while an aio operation is pending on |
1340 | scalar must only be modified in-place while an aio operation is pending on |
… | |
… | |
1149 | |
1342 | |
1150 | It calls the C<msync> function of your OS, if available, with the memory |
1343 | It calls the C<msync> function of your OS, if available, with the memory |
1151 | area starting at C<$offset> in the string and ending C<$length> bytes |
1344 | area starting at C<$offset> in the string and ending C<$length> bytes |
1152 | later. If C<$length> is negative, counts from the end, and if C<$length> |
1345 | later. If C<$length> is negative, counts from the end, and if C<$length> |
1153 | is C<undef>, then it goes till the end of the string. The flags can be |
1346 | is C<undef>, then it goes till the end of the string. The flags can be |
1154 | a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and |
1347 | either C<IO::AIO::MS_ASYNC> or C<IO::AIO::MS_SYNC>, plus an optional |
1155 | C<IO::AIO::MS_SYNC>. |
1348 | C<IO::AIO::MS_INVALIDATE>. |
1156 | |
1349 | |
1157 | =item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
1350 | =item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
1158 | |
1351 | |
1159 | This is a rather advanced IO::AIO call, which works best on mmap(2)ed |
1352 | This is a rather advanced IO::AIO call, which works best on mmap(2)ed |
1160 | scalars. |
1353 | scalars. |
1161 | |
1354 | |
1162 | It touches (reads or writes) all memory pages in the specified |
1355 | It touches (reads or writes) all memory pages in the specified |
1163 | range inside the scalar. All caveats and parameters are the same |
1356 | range inside the scalar. All caveats and parameters are the same |
1164 | as for C<aio_msync>, above, except for flags, which must be either |
1357 | as for C<aio_msync>, above, except for flags, which must be either |
1165 | C<0> (which reads all pages and ensures they are instantiated) or |
1358 | C<0> (which reads all pages and ensures they are instantiated) or |
1166 | C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and |
1359 | C<IO::AIO::MT_MODIFY>, which modifies the memory pages (by reading and |
1167 | writing an octet from it, which dirties the page). |
1360 | writing an octet from it, which dirties the page). |
1168 | |
1361 | |
1169 | =item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
1362 | =item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
1170 | |
1363 | |
1171 | This is a rather advanced IO::AIO call, which works best on mmap(2)ed |
1364 | This is a rather advanced IO::AIO call, which works best on mmap(2)ed |
… | |
… | |
1202 | documented under L<MISCELLANEOUS FUNCTIONS>. |
1395 | documented under L<MISCELLANEOUS FUNCTIONS>. |
1203 | |
1396 | |
1204 | Example: asynchronously lock all current and future pages into memory. |
1397 | Example: asynchronously lock all current and future pages into memory. |
1205 | |
1398 | |
1206 | aio_mlockall IO::AIO::MCL_FUTURE; |
1399 | aio_mlockall IO::AIO::MCL_FUTURE; |
|
|
1400 | |
|
|
1401 | =item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents) |
|
|
1402 | |
|
|
1403 | Queries the extents of the given file (by calling the Linux C<FIEMAP> |
|
|
1404 | ioctl, see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If |
|
|
1405 | the ioctl is not available on your OS, then this request will fail with |
|
|
1406 | C<ENOSYS>. |
|
|
1407 | |
|
|
1408 | C<$start> is the starting offset to query extents for, C<$length> is the |
|
|
1409 | size of the range to query - if it is C<undef>, then the whole file will |
|
|
1410 | be queried. |
|
|
1411 | |
|
|
1412 | C<$flags> is a combination of flags (C<IO::AIO::FIEMAP_FLAG_SYNC> or |
|
|
1413 | C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also |
|
|
1414 | exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query |
|
|
1415 | the data portion. |
|
|
1416 | |
|
|
1417 | C<$count> is the maximum number of extent records to return. If it is |
|
|
1418 | C<undef>, then IO::AIO queries all extents of the range. As a very special |
|
|
1419 | case, if it is C<0>, then the callback receives the number of extents |
|
|
1420 | instead of the extents themselves (which is unreliable, see below). |
|
|
1421 | |
|
|
1422 | If an error occurs, the callback receives no arguments. The special |
|
|
1423 | C<errno> value C<IO::AIO::EBADR> is available to test for flag errors. |
|
|
1424 | |
|
|
1425 | Otherwise, the callback receives an array reference with extent |
|
|
1426 | structures. Each extent structure is an array reference itself, with the |
|
|
1427 | following members: |
|
|
1428 | |
|
|
1429 | [$logical, $physical, $length, $flags] |
|
|
1430 | |
|
|
1431 | Flags is any combination of the following flag values (typically either C<0> |
|
|
1432 | or C<IO::AIO::FIEMAP_EXTENT_LAST> (1)): |
|
|
1433 | |
|
|
1434 | C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>, |
|
|
1435 | C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>, |
|
|
1436 | C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>, |
|
|
1437 | C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>, |
|
|
1438 | C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or |
|
|
1439 | C<IO::AIO::FIEMAP_EXTENT_SHARED>. |
|
|
1440 | |
|
|
1441 | At the time of this writing (Linux 3.2), this request is unreliable unless |
|
|
1442 | C<$count> is C<undef>, as the kernel has all sorts of bugs preventing |
|
|
1443 | it to return all extents of a range for files with a large number of |
|
|
1444 | extents. The code (only) works around all these issues if C<$count> is |
|
|
1445 | C<undef>. |
1207 | |
1446 | |
1208 | =item aio_group $callback->(...) |
1447 | =item aio_group $callback->(...) |
1209 | |
1448 | |
1210 | This is a very special aio request: Instead of doing something, it is a |
1449 | This is a very special aio request: Instead of doing something, it is a |
1211 | container for other aio requests, which is useful if you want to bundle |
1450 | container for other aio requests, which is useful if you want to bundle |
… | |
… | |
1248 | like sleep and file handle readable/writable, the overhead this creates is |
1487 | like sleep and file handle readable/writable, the overhead this creates is |
1249 | immense (it blocks a thread for a long time) so do not use this function |
1488 | immense (it blocks a thread for a long time) so do not use this function |
1250 | except to put your application under artificial I/O pressure. |
1489 | except to put your application under artificial I/O pressure. |
1251 | |
1490 | |
1252 | =back |
1491 | =back |
|
|
1492 | |
|
|
1493 | |
|
|
1494 | =head2 IO::AIO::WD - multiple working directories |
|
|
1495 | |
|
|
1496 | Your process only has one current working directory, which is used by all |
|
|
1497 | threads. This makes it hard to use relative paths (some other component |
|
|
1498 | could call C<chdir> at any time, and it is hard to control when the path |
|
|
1499 | will be used by IO::AIO). |
|
|
1500 | |
|
|
1501 | One solution for this is to always use absolute paths. This usually works, |
|
|
1502 | but can be quite slow (the kernel has to walk the whole path on every |
|
|
1503 | access), and can also be a hassle to implement. |
|
|
1504 | |
|
|
1505 | Newer POSIX systems have a number of functions (openat, fdopendir, |
|
|
1506 | futimensat and so on) that make it possible to specify working directories |
|
|
1507 | per operation. |
|
|
1508 | |
|
|
1509 | For portability, and because the clowns who "designed", or shall I write, |
|
|
1510 | perpetrated this new interface were obviously half-drunk, this abstraction |
|
|
1511 | cannot be perfect, though. |
|
|
1512 | |
|
|
1513 | IO::AIO allows you to convert directory paths into a so-called IO::AIO::WD |
|
|
1514 | object. This object stores the canonicalised, absolute version of the |
|
|
1515 | path, and on systems that allow it, also a directory file descriptor. |
|
|
1516 | |
|
|
1517 | Everywhere where a pathname is accepted by IO::AIO (e.g. in C<aio_stat> |
|
|
1518 | or C<aio_unlink>), one can specify an array reference with an IO::AIO::WD |
|
|
1519 | object and a pathname instead (or the IO::AIO::WD object alone, which |
|
|
1520 | gets interpreted as C<[$wd, "."]>). If the pathname is absolute, the |
|
|
1521 | IO::AIO::WD object is ignored, otherwise the pathname is resolved relative |
|
|
1522 | to that IO::AIO::WD object. |
|
|
1523 | |
|
|
1524 | For example, to get a wd object for F</etc> and then stat F<passwd> |
|
|
1525 | inside, you would write: |
|
|
1526 | |
|
|
1527 | aio_wd "/etc", sub { |
|
|
1528 | my $etcdir = shift; |
|
|
1529 | |
|
|
1530 | # although $etcdir can be undef on error, there is generally no reason |
|
|
1531 | # to check for errors here, as aio_stat will fail with ENOENT |
|
|
1532 | # when $etcdir is undef. |
|
|
1533 | |
|
|
1534 | aio_stat [$etcdir, "passwd"], sub { |
|
|
1535 | # yay |
|
|
1536 | }; |
|
|
1537 | }; |
|
|
1538 | |
|
|
1539 | The fact that C<aio_wd> is a request and not a normal function shows that |
|
|
1540 | creating an IO::AIO::WD object is itself a potentially blocking operation, |
|
|
1541 | which is why it is done asynchronously. |
|
|
1542 | |
|
|
1543 | To stat the directory obtained with C<aio_wd> above, one could write |
|
|
1544 | either of the following three request calls: |
|
|
1545 | |
|
|
1546 | aio_lstat "/etc" , sub { ... # pathname as normal string |
|
|
1547 | aio_lstat [$wd, "."], sub { ... # "." relative to $wd (i.e. $wd itself) |
|
|
1548 | aio_lstat $wd , sub { ... # shorthand for the previous |
|
|
1549 | |
|
|
1550 | As with normal pathnames, IO::AIO keeps a copy of the working directory |
|
|
1551 | object and the pathname string, so you could write the following without |
|
|
1552 | causing any issues due to C<$path> getting reused: |
|
|
1553 | |
|
|
1554 | my $path = [$wd, undef]; |
|
|
1555 | |
|
|
1556 | for my $name (qw(abc def ghi)) { |
|
|
1557 | $path->[1] = $name; |
|
|
1558 | aio_stat $path, sub { |
|
|
1559 | # ... |
|
|
1560 | }; |
|
|
1561 | } |
|
|
1562 | |
|
|
1563 | There are some caveats: when directories get renamed (or deleted), the |
|
|
1564 | pathname string doesn't change, so will point to the new directory (or |
|
|
1565 | nowhere at all), while the directory fd, if available on the system, |
|
|
1566 | will still point to the original directory. Most functions accepting a |
|
|
1567 | pathname will use the directory fd on newer systems, and the string on |
|
|
1568 | older systems. Some functions (such as C<aio_realpath>) will always rely on |
|
|
1569 | the string form of the pathname. |
|
|
1570 | |
|
|
1571 | So this functionality is mainly useful to get some protection against |
|
|
1572 | C<chdir>, to easily get an absolute path out of a relative path for future |
|
|
1573 | reference, and to speed up doing many operations in the same directory |
|
|
1574 | (e.g. when stat'ing all files in a directory). |
|
|
1575 | |
|
|
1576 | The following functions implement this working directory abstraction: |
|
|
1577 | |
|
|
1578 | =over 4 |
|
|
1579 | |
|
|
1580 | =item aio_wd $pathname, $callback->($wd) |
|
|
1581 | |
|
|
1582 | Asynchonously canonicalise the given pathname and convert it to an |
|
|
1583 | IO::AIO::WD object representing it. If possible and supported on the |
|
|
1584 | system, also open a directory fd to speed up pathname resolution relative |
|
|
1585 | to this working directory. |
|
|
1586 | |
|
|
1587 | If something goes wrong, then C<undef> is passwd to the callback instead |
|
|
1588 | of a working directory object and C<$!> is set appropriately. Since |
|
|
1589 | passing C<undef> as working directory component of a pathname fails the |
|
|
1590 | request with C<ENOENT>, there is often no need for error checking in the |
|
|
1591 | C<aio_wd> callback, as future requests using the value will fail in the |
|
|
1592 | expected way. |
|
|
1593 | |
|
|
1594 | =item IO::AIO::CWD |
|
|
1595 | |
|
|
1596 | This is a compiletime constant (object) that represents the process |
|
|
1597 | current working directory. |
|
|
1598 | |
|
|
1599 | Specifying this object as working directory object for a pathname is as if |
|
|
1600 | the pathname would be specified directly, without a directory object. For |
|
|
1601 | example, these calls are functionally identical: |
|
|
1602 | |
|
|
1603 | aio_stat "somefile", sub { ... }; |
|
|
1604 | aio_stat [IO::AIO::CWD, "somefile"], sub { ... }; |
|
|
1605 | |
|
|
1606 | =back |
|
|
1607 | |
|
|
1608 | To recover the path associated with an IO::AIO::WD object, you can use |
|
|
1609 | C<aio_realpath>: |
|
|
1610 | |
|
|
1611 | aio_realpath $wd, sub { |
|
|
1612 | warn "path is $_[0]\n"; |
|
|
1613 | }; |
|
|
1614 | |
|
|
1615 | Currently, C<aio_statvfs> always, and C<aio_rename> and C<aio_rmdir> |
|
|
1616 | sometimes, fall back to using an absolue path. |
1253 | |
1617 | |
1254 | =head2 IO::AIO::REQ CLASS |
1618 | =head2 IO::AIO::REQ CLASS |
1255 | |
1619 | |
1256 | All non-aggregate C<aio_*> functions return an object of this class when |
1620 | All non-aggregate C<aio_*> functions return an object of this class when |
1257 | called in non-void context. |
1621 | called in non-void context. |
… | |
… | |
1375 | |
1739 | |
1376 | Sets a feeder/generator on this group: every group can have an attached |
1740 | Sets a feeder/generator on this group: every group can have an attached |
1377 | generator that generates requests if idle. The idea behind this is that, |
1741 | generator that generates requests if idle. The idea behind this is that, |
1378 | although you could just queue as many requests as you want in a group, |
1742 | although you could just queue as many requests as you want in a group, |
1379 | this might starve other requests for a potentially long time. For example, |
1743 | this might starve other requests for a potentially long time. For example, |
1380 | C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests, |
1744 | C<aio_scandir> might generate hundreds of thousands of C<aio_stat> |
1381 | delaying any later requests for a long time. |
1745 | requests, delaying any later requests for a long time. |
1382 | |
1746 | |
1383 | To avoid this, and allow incremental generation of requests, you can |
1747 | To avoid this, and allow incremental generation of requests, you can |
1384 | instead a group and set a feeder on it that generates those requests. The |
1748 | instead a group and set a feeder on it that generates those requests. The |
1385 | feed callback will be called whenever there are few enough (see C<limit>, |
1749 | feed callback will be called whenever there are few enough (see C<limit>, |
1386 | below) requests active in the group itself and is expected to queue more |
1750 | below) requests active in the group itself and is expected to queue more |
… | |
… | |
1435 | |
1799 | |
1436 | See C<poll_cb> for an example. |
1800 | See C<poll_cb> for an example. |
1437 | |
1801 | |
1438 | =item IO::AIO::poll_cb |
1802 | =item IO::AIO::poll_cb |
1439 | |
1803 | |
1440 | Process some outstanding events on the result pipe. You have to call |
1804 | Process some requests that have reached the result phase (i.e. they have |
|
|
1805 | been executed but the results are not yet reported). You have to call |
|
|
1806 | this "regularly" to finish outstanding requests. |
|
|
1807 | |
1441 | this regularly. Returns C<0> if all events could be processed (or there |
1808 | Returns C<0> if all events could be processed (or there were no |
1442 | were no events to process), or C<-1> if it returned earlier for whatever |
1809 | events to process), or C<-1> if it returned earlier for whatever |
1443 | reason. Returns immediately when no events are outstanding. The amount of |
1810 | reason. Returns immediately when no events are outstanding. The amount |
1444 | events processed depends on the settings of C<IO::AIO::max_poll_req> and |
1811 | of events processed depends on the settings of C<IO::AIO::max_poll_req>, |
1445 | C<IO::AIO::max_poll_time>. |
1812 | C<IO::AIO::max_poll_time> and C<IO::AIO::max_outstanding>. |
1446 | |
1813 | |
1447 | If not all requests were processed for whatever reason, the filehandle |
1814 | If not all requests were processed for whatever reason, the poll file |
1448 | will still be ready when C<poll_cb> returns, so normally you don't have to |
1815 | descriptor will still be ready when C<poll_cb> returns, so normally you |
1449 | do anything special to have it called later. |
1816 | don't have to do anything special to have it called later. |
1450 | |
1817 | |
1451 | Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes |
1818 | Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes |
1452 | ready, it can be beneficial to call this function from loops which submit |
1819 | ready, it can be beneficial to call this function from loops which submit |
1453 | a lot of requests, to make sure the results get processed when they become |
1820 | a lot of requests, to make sure the results get processed when they become |
1454 | available and not just when the loop is finished and the event loop takes |
1821 | available and not just when the loop is finished and the event loop takes |
… | |
… | |
1463 | poll => 'r', async => 1, |
1830 | poll => 'r', async => 1, |
1464 | cb => \&IO::AIO::poll_cb); |
1831 | cb => \&IO::AIO::poll_cb); |
1465 | |
1832 | |
1466 | =item IO::AIO::poll_wait |
1833 | =item IO::AIO::poll_wait |
1467 | |
1834 | |
1468 | If there are any outstanding requests and none of them in the result |
1835 | Wait until either at least one request is in the result phase or no |
1469 | phase, wait till the result filehandle becomes ready for reading (simply |
1836 | requests are outstanding anymore. |
1470 | does a C<select> on the filehandle. This is useful if you want to |
1837 | |
1471 | synchronously wait for some requests to finish). |
1838 | This is useful if you want to synchronously wait for some requests to |
|
|
1839 | become ready, without actually handling them. |
1472 | |
1840 | |
1473 | See C<nreqs> for an example. |
1841 | See C<nreqs> for an example. |
1474 | |
1842 | |
1475 | =item IO::AIO::poll |
1843 | =item IO::AIO::poll |
1476 | |
1844 | |
… | |
… | |
1597 | |
1965 | |
1598 | This is a very bad function to use in interactive programs because it |
1966 | This is a very bad function to use in interactive programs because it |
1599 | blocks, and a bad way to reduce concurrency because it is inexact: Better |
1967 | blocks, and a bad way to reduce concurrency because it is inexact: Better |
1600 | use an C<aio_group> together with a feed callback. |
1968 | use an C<aio_group> together with a feed callback. |
1601 | |
1969 | |
1602 | It's main use is in scripts without an event loop - when you want to stat |
1970 | Its main use is in scripts without an event loop - when you want to stat |
1603 | a lot of files, you can write somehting like this: |
1971 | a lot of files, you can write something like this: |
1604 | |
1972 | |
1605 | IO::AIO::max_outstanding 32; |
1973 | IO::AIO::max_outstanding 32; |
1606 | |
1974 | |
1607 | for my $path (...) { |
1975 | for my $path (...) { |
1608 | aio_stat $path , ...; |
1976 | aio_stat $path , ...; |
… | |
… | |
1645 | Returns the number of requests currently in the pending state (executed, |
2013 | Returns the number of requests currently in the pending state (executed, |
1646 | but not yet processed by poll_cb). |
2014 | but not yet processed by poll_cb). |
1647 | |
2015 | |
1648 | =back |
2016 | =back |
1649 | |
2017 | |
|
|
2018 | =head3 SUBSECOND STAT TIME ACCESS |
|
|
2019 | |
|
|
2020 | Both C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> functions can |
|
|
2021 | generally find access/modification and change times with subsecond time |
|
|
2022 | accuracy of the system supports it, but perl's built-in functions only |
|
|
2023 | return the integer part. |
|
|
2024 | |
|
|
2025 | The following functions return the timestamps of the most recent |
|
|
2026 | stat with subsecond precision on most systems and work both after |
|
|
2027 | C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> calls. Their return |
|
|
2028 | value is only meaningful after a successful C<stat>/C<lstat> call, or |
|
|
2029 | during/after a successful C<aio_stat>/C<aio_lstat> callback. |
|
|
2030 | |
|
|
2031 | This is similar to the L<Time::HiRes> C<stat> functions, but can return |
|
|
2032 | full resolution without rounding and work with standard perl C<stat>, |
|
|
2033 | alleviating the need to call the special C<Time::HiRes> functions, which |
|
|
2034 | do not act like their perl counterparts. |
|
|
2035 | |
|
|
2036 | On operating systems or file systems where subsecond time resolution is |
|
|
2037 | not supported or could not be detected, a fractional part of C<0> is |
|
|
2038 | returned, so it is always safe to call these functions. |
|
|
2039 | |
|
|
2040 | =over 4 |
|
|
2041 | |
|
|
2042 | =item $seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime |
|
|
2043 | |
|
|
2044 | Return the access, modication or change time, respectively, including |
|
|
2045 | fractional part. Due to the limited precision of floating point, the |
|
|
2046 | accuracy on most platforms is only a bit better than milliseconds for |
|
|
2047 | times around now - see the I<nsec> function family, below, for full |
|
|
2048 | accuracy. |
|
|
2049 | |
|
|
2050 | =item ($atime, $mtime, $ctime, ...) = IO::AIO::st_xtime |
|
|
2051 | |
|
|
2052 | Returns access, modification and change time all in one go, and maybe more |
|
|
2053 | times in the future version. |
|
|
2054 | |
|
|
2055 | =item $nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec, IO::AIO::st_ctimensec |
|
|
2056 | |
|
|
2057 | Return the fractional access, modifcation or change time, in nanoseconds, |
|
|
2058 | as an integer in the range C<0> to C<999999999>. |
|
|
2059 | |
|
|
2060 | =item ($atime, $mtime, $ctime, ...) = IO::AIO::st_xtimensec |
|
|
2061 | |
|
|
2062 | Like the functions above, but returns all three times in one go (and maybe |
|
|
2063 | more in future versions). |
|
|
2064 | |
|
|
2065 | =back |
|
|
2066 | |
|
|
2067 | Example: print the high resolution modification time of F</etc>, using |
|
|
2068 | C<stat>, and C<IO::AIO::aio_stat>. |
|
|
2069 | |
|
|
2070 | if (stat "/etc") { |
|
|
2071 | printf "stat(/etc) mtime: %f\n", IO::AIO::st_mtime; |
|
|
2072 | } |
|
|
2073 | |
|
|
2074 | IO::AIO::aio_stat "/etc", sub { |
|
|
2075 | $_[0] |
|
|
2076 | and return; |
|
|
2077 | |
|
|
2078 | printf "aio_stat(/etc) mtime: %d.%09d\n", (stat _)[9], IO::AIO::st_mtimensec; |
|
|
2079 | }; |
|
|
2080 | |
|
|
2081 | IO::AIO::flush; |
|
|
2082 | |
|
|
2083 | Output of the awbove on my system, showing reduced and full accuracy: |
|
|
2084 | |
|
|
2085 | stat(/etc) mtime: 1534043702.020808 |
|
|
2086 | aio_stat(/etc) mtime: 1534043702.020807792 |
|
|
2087 | |
1650 | =head3 MISCELLANEOUS FUNCTIONS |
2088 | =head3 MISCELLANEOUS FUNCTIONS |
1651 | |
2089 | |
1652 | IO::AIO implements some functions that might be useful, but are not |
2090 | IO::AIO implements some functions that are useful when you want to use |
1653 | asynchronous. |
2091 | some "Advanced I/O" function not available to in Perl, without going the |
|
|
2092 | "Asynchronous I/O" route. Many of these have an asynchronous C<aio_*> |
|
|
2093 | counterpart. |
1654 | |
2094 | |
1655 | =over 4 |
2095 | =over 4 |
|
|
2096 | |
|
|
2097 | =item $numfd = IO::AIO::get_fdlimit |
|
|
2098 | |
|
|
2099 | This function is I<EXPERIMENTAL> and subject to change. |
|
|
2100 | |
|
|
2101 | Tries to find the current file descriptor limit and returns it, or |
|
|
2102 | C<undef> and sets C<$!> in case of an error. The limit is one larger than |
|
|
2103 | the highest valid file descriptor number. |
|
|
2104 | |
|
|
2105 | =item IO::AIO::min_fdlimit [$numfd] |
|
|
2106 | |
|
|
2107 | This function is I<EXPERIMENTAL> and subject to change. |
|
|
2108 | |
|
|
2109 | Try to increase the current file descriptor limit(s) to at least C<$numfd> |
|
|
2110 | by changing the soft or hard file descriptor resource limit. If C<$numfd> |
|
|
2111 | is missing, it will try to set a very high limit, although this is not |
|
|
2112 | recommended when you know the actual minimum that you require. |
|
|
2113 | |
|
|
2114 | If the limit cannot be raised enough, the function makes a best-effort |
|
|
2115 | attempt to increase the limit as much as possible, using various |
|
|
2116 | tricks, while still failing. You can query the resulting limit using |
|
|
2117 | C<IO::AIO::get_fdlimit>. |
|
|
2118 | |
|
|
2119 | If an error occurs, returns C<undef> and sets C<$!>, otherwise returns |
|
|
2120 | true. |
1656 | |
2121 | |
1657 | =item IO::AIO::sendfile $ofh, $ifh, $offset, $count |
2122 | =item IO::AIO::sendfile $ofh, $ifh, $offset, $count |
1658 | |
2123 | |
1659 | Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>, |
2124 | Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>, |
1660 | but is blocking (this makes most sense if you know the input data is |
2125 | but is blocking (this makes most sense if you know the input data is |
… | |
… | |
1665 | |
2130 | |
1666 | =item IO::AIO::fadvise $fh, $offset, $len, $advice |
2131 | =item IO::AIO::fadvise $fh, $offset, $len, $advice |
1667 | |
2132 | |
1668 | Simply calls the C<posix_fadvise> function (see its |
2133 | Simply calls the C<posix_fadvise> function (see its |
1669 | manpage for details). The following advice constants are |
2134 | manpage for details). The following advice constants are |
1670 | avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>, |
2135 | available: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>, |
1671 | C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>, |
2136 | C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>, |
1672 | C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>. |
2137 | C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>. |
1673 | |
2138 | |
1674 | On systems that do not implement C<posix_fadvise>, this function returns |
2139 | On systems that do not implement C<posix_fadvise>, this function returns |
1675 | ENOSYS, otherwise the return value of C<posix_fadvise>. |
2140 | ENOSYS, otherwise the return value of C<posix_fadvise>. |
1676 | |
2141 | |
1677 | =item IO::AIO::madvise $scalar, $offset, $len, $advice |
2142 | =item IO::AIO::madvise $scalar, $offset, $len, $advice |
1678 | |
2143 | |
1679 | Simply calls the C<posix_madvise> function (see its |
2144 | Simply calls the C<posix_madvise> function (see its |
1680 | manpage for details). The following advice constants are |
2145 | manpage for details). The following advice constants are |
1681 | avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>, |
2146 | available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>, |
1682 | C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>. |
2147 | C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, |
|
|
2148 | C<IO::AIO::MADV_DONTNEED>. |
|
|
2149 | |
|
|
2150 | If C<$offset> is negative, counts from the end. If C<$length> is negative, |
|
|
2151 | the remaining length of the C<$scalar> is used. If possible, C<$length> |
|
|
2152 | will be reduced to fit into the C<$scalar>. |
1683 | |
2153 | |
1684 | On systems that do not implement C<posix_madvise>, this function returns |
2154 | On systems that do not implement C<posix_madvise>, this function returns |
1685 | ENOSYS, otherwise the return value of C<posix_madvise>. |
2155 | ENOSYS, otherwise the return value of C<posix_madvise>. |
1686 | |
2156 | |
1687 | =item IO::AIO::mprotect $scalar, $offset, $len, $protect |
2157 | =item IO::AIO::mprotect $scalar, $offset, $len, $protect |
1688 | |
2158 | |
1689 | Simply calls the C<mprotect> function on the preferably AIO::mmap'ed |
2159 | Simply calls the C<mprotect> function on the preferably AIO::mmap'ed |
1690 | $scalar (see its manpage for details). The following protect |
2160 | $scalar (see its manpage for details). The following protect |
1691 | constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>, |
2161 | constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>, |
1692 | C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>. |
2162 | C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>. |
|
|
2163 | |
|
|
2164 | If C<$offset> is negative, counts from the end. If C<$length> is negative, |
|
|
2165 | the remaining length of the C<$scalar> is used. If possible, C<$length> |
|
|
2166 | will be reduced to fit into the C<$scalar>. |
1693 | |
2167 | |
1694 | On systems that do not implement C<mprotect>, this function returns |
2168 | On systems that do not implement C<mprotect>, this function returns |
1695 | ENOSYS, otherwise the return value of C<mprotect>. |
2169 | ENOSYS, otherwise the return value of C<mprotect>. |
1696 | |
2170 | |
1697 | =item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] |
2171 | =item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] |
1698 | |
2172 | |
1699 | Memory-maps a file (or anonymous memory range) and attaches it to the |
2173 | Memory-maps a file (or anonymous memory range) and attaches it to the |
1700 | given C<$scalar>, which will act like a string scalar. |
2174 | given C<$scalar>, which will act like a string scalar. Returns true on |
|
|
2175 | success, and false otherwise. |
1701 | |
2176 | |
|
|
2177 | The scalar must exist, but its contents do not matter - this means you |
|
|
2178 | cannot use a nonexistant array or hash element. When in doubt, C<undef> |
|
|
2179 | the scalar first. |
|
|
2180 | |
1702 | The only operations allowed on the scalar are C<substr>/C<vec> that don't |
2181 | The only operations allowed on the mmapped scalar are C<substr>/C<vec>, |
1703 | change the string length, and most read-only operations such as copying it |
2182 | which don't change the string length, and most read-only operations such |
1704 | or searching it with regexes and so on. |
2183 | as copying it or searching it with regexes and so on. |
1705 | |
2184 | |
1706 | Anything else is unsafe and will, at best, result in memory leaks. |
2185 | Anything else is unsafe and will, at best, result in memory leaks. |
1707 | |
2186 | |
1708 | The memory map associated with the C<$scalar> is automatically removed |
2187 | The memory map associated with the C<$scalar> is automatically removed |
1709 | when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or |
2188 | when the C<$scalar> is undef'd or destroyed, or when the C<IO::AIO::mmap> |
1710 | C<IO::AIO::munmap> functions are called. |
2189 | or C<IO::AIO::munmap> functions are called on it. |
1711 | |
2190 | |
1712 | This calls the C<mmap>(2) function internally. See your system's manual |
2191 | This calls the C<mmap>(2) function internally. See your system's manual |
1713 | page for details on the C<$length>, C<$prot> and C<$flags> parameters. |
2192 | page for details on the C<$length>, C<$prot> and C<$flags> parameters. |
1714 | |
2193 | |
1715 | The C<$length> must be larger than zero and smaller than the actual |
2194 | The C<$length> must be larger than zero and smaller than the actual |
1716 | filesize. |
2195 | filesize. |
1717 | |
2196 | |
1718 | C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>, |
2197 | C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>, |
1719 | C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>, |
2198 | C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>, |
1720 | |
2199 | |
1721 | C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or |
2200 | C<$flags> can be a combination of |
1722 | C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when |
2201 | C<IO::AIO::MAP_SHARED> or |
1723 | not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS> |
2202 | C<IO::AIO::MAP_PRIVATE>, |
|
|
2203 | or a number of system-specific flags (when not available, the are C<0>): |
1724 | (which is set to C<MAP_ANON> if your system only provides this |
2204 | C<IO::AIO::MAP_ANONYMOUS> (which is set to C<MAP_ANON> if your system only provides this constant), |
1725 | constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>, |
2205 | C<IO::AIO::MAP_LOCKED>, |
1726 | C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or |
2206 | C<IO::AIO::MAP_NORESERVE>, |
|
|
2207 | C<IO::AIO::MAP_POPULATE>, |
1727 | C<IO::AIO::MAP_NONBLOCK> |
2208 | C<IO::AIO::MAP_NONBLOCK>, |
|
|
2209 | C<IO::AIO::MAP_FIXED>, |
|
|
2210 | C<IO::AIO::MAP_GROWSDOWN>, |
|
|
2211 | C<IO::AIO::MAP_32BIT>, |
|
|
2212 | C<IO::AIO::MAP_HUGETLB> or |
|
|
2213 | C<IO::AIO::MAP_STACK>. |
1728 | |
2214 | |
1729 | If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed. |
2215 | If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed. |
1730 | |
2216 | |
1731 | C<$offset> is the offset from the start of the file - it generally must be |
2217 | C<$offset> is the offset from the start of the file - it generally must be |
1732 | a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>. |
2218 | a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>. |
… | |
… | |
1746 | |
2232 | |
1747 | =item IO::AIO::munmap $scalar |
2233 | =item IO::AIO::munmap $scalar |
1748 | |
2234 | |
1749 | Removes a previous mmap and undefines the C<$scalar>. |
2235 | Removes a previous mmap and undefines the C<$scalar>. |
1750 | |
2236 | |
|
|
2237 | =item IO::AIO::mremap $scalar, $new_length, $flags = MREMAP_MAYMOVE[, $new_address = 0] |
|
|
2238 | |
|
|
2239 | Calls the Linux-specific mremap(2) system call. The C<$scalar> must have |
|
|
2240 | been mapped by C<IO::AIO::mmap>, and C<$flags> must currently either be |
|
|
2241 | C<0> or C<IO::AIO::MREMAP_MAYMOVE>. |
|
|
2242 | |
|
|
2243 | Returns true if successful, and false otherwise. If the underlying mmapped |
|
|
2244 | region has changed address, then the true value has the numerical value |
|
|
2245 | C<1>, otherwise it has the numerical value C<0>: |
|
|
2246 | |
|
|
2247 | my $success = IO::AIO::mremap $mmapped, 8192, IO::AIO::MREMAP_MAYMOVE |
|
|
2248 | or die "mremap: $!"; |
|
|
2249 | |
|
|
2250 | if ($success*1) { |
|
|
2251 | warn "scalar has chanegd address in memory\n"; |
|
|
2252 | } |
|
|
2253 | |
|
|
2254 | C<IO::AIO::MREMAP_FIXED> and the C<$new_address> argument are currently |
|
|
2255 | implemented, but not supported and might go away in a future version. |
|
|
2256 | |
|
|
2257 | On systems where this call is not supported or is not emulated, this call |
|
|
2258 | returns falls and sets C<$!> to C<ENOSYS>. |
|
|
2259 | |
1751 | =item IO::AIO::munlock $scalar, $offset = 0, $length = undef |
2260 | =item IO::AIO::munlock $scalar, $offset = 0, $length = undef |
1752 | |
2261 | |
1753 | Calls the C<munlock> function, undoing the effects of a previous |
2262 | Calls the C<munlock> function, undoing the effects of a previous |
1754 | C<aio_mlock> call (see its description for details). |
2263 | C<aio_mlock> call (see its description for details). |
1755 | |
2264 | |
… | |
… | |
1757 | |
2266 | |
1758 | Calls the C<munlockall> function. |
2267 | Calls the C<munlockall> function. |
1759 | |
2268 | |
1760 | On systems that do not implement C<munlockall>, this function returns |
2269 | On systems that do not implement C<munlockall>, this function returns |
1761 | ENOSYS, otherwise the return value of C<munlockall>. |
2270 | ENOSYS, otherwise the return value of C<munlockall>. |
|
|
2271 | |
|
|
2272 | =item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags |
|
|
2273 | |
|
|
2274 | Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or |
|
|
2275 | C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they |
|
|
2276 | should be the file offset. |
|
|
2277 | |
|
|
2278 | C<$r_fh> and C<$w_fh> should not refer to the same file, as splice might |
|
|
2279 | silently corrupt the data in this case. |
|
|
2280 | |
|
|
2281 | The following symbol flag values are available: C<IO::AIO::SPLICE_F_MOVE>, |
|
|
2282 | C<IO::AIO::SPLICE_F_NONBLOCK>, C<IO::AIO::SPLICE_F_MORE> and |
|
|
2283 | C<IO::AIO::SPLICE_F_GIFT>. |
|
|
2284 | |
|
|
2285 | See the C<splice(2)> manpage for details. |
|
|
2286 | |
|
|
2287 | =item IO::AIO::tee $r_fh, $w_fh, $length, $flags |
|
|
2288 | |
|
|
2289 | Calls the GNU/Linux C<tee(2)> syscall, see its manpage and the |
|
|
2290 | description for C<IO::AIO::splice> above for details. |
|
|
2291 | |
|
|
2292 | =item $actual_size = IO::AIO::pipesize $r_fh[, $new_size] |
|
|
2293 | |
|
|
2294 | Attempts to query or change the pipe buffer size. Obviously works only |
|
|
2295 | on pipes, and currently works only on GNU/Linux systems, and fails with |
|
|
2296 | C<-1>/C<ENOSYS> everywhere else. If anybody knows how to influence pipe buffer |
|
|
2297 | size on other systems, drop me a note. |
|
|
2298 | |
|
|
2299 | =item ($rfh, $wfh) = IO::AIO::pipe2 [$flags] |
|
|
2300 | |
|
|
2301 | This is a direct interface to the Linux L<pipe2(2)> system call. If |
|
|
2302 | C<$flags> is missing or C<0>, then this should be the same as a call to |
|
|
2303 | perl's built-in C<pipe> function and create a new pipe, and works on |
|
|
2304 | systems that lack the pipe2 syscall. On win32, this case invokes C<_pipe |
|
|
2305 | (..., 4096, O_BINARY)>. |
|
|
2306 | |
|
|
2307 | If C<$flags> is non-zero, it tries to invoke the pipe2 system call with |
|
|
2308 | the given flags (Linux 2.6.27, glibc 2.9). |
|
|
2309 | |
|
|
2310 | On success, the read and write file handles are returned. |
|
|
2311 | |
|
|
2312 | On error, nothing will be returned. If the pipe2 syscall is missing and |
|
|
2313 | C<$flags> is non-zero, fails with C<ENOSYS>. |
|
|
2314 | |
|
|
2315 | Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the |
|
|
2316 | time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and |
|
|
2317 | C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported. |
|
|
2318 | |
|
|
2319 | Example: create a pipe race-free w.r.t. threads and fork: |
|
|
2320 | |
|
|
2321 | my ($rfh, $wfh) = IO::AIO::pipe2 IO::AIO::O_CLOEXEC |
|
|
2322 | or die "pipe2: $!\n"; |
|
|
2323 | |
|
|
2324 | =item $fh = IO::AIO::eventfd [$initval, [$flags]] |
|
|
2325 | |
|
|
2326 | This is a direct interface to the Linux L<eventfd(2)> system call. The |
|
|
2327 | (unhelpful) defaults for C<$initval> and C<$flags> are C<0> for both. |
|
|
2328 | |
|
|
2329 | On success, the new eventfd filehandle is returned, otherwise returns |
|
|
2330 | C<undef>. If the eventfd syscall is missing, fails with C<ENOSYS>. |
|
|
2331 | |
|
|
2332 | Please refer to L<eventfd(2)> for more info on this call. |
|
|
2333 | |
|
|
2334 | The following symbol flag values are available: C<IO::AIO::EFD_CLOEXEC>, |
|
|
2335 | C<IO::AIO::EFD_NONBLOCK> and C<IO::AIO::EFD_SEMAPHORE> (Linux 2.6.30). |
|
|
2336 | |
|
|
2337 | Example: create a new eventfd filehandle: |
|
|
2338 | |
|
|
2339 | $fh = IO::AIO::eventfd 0, IO::AIO::O_CLOEXEC |
|
|
2340 | or die "eventfd: $!\n"; |
|
|
2341 | |
|
|
2342 | =item $fh = IO::AIO::timerfd_create $clockid[, $flags] |
|
|
2343 | |
|
|
2344 | This is a direct interface to the Linux L<timerfd_create(2)> system call. The |
|
|
2345 | (unhelpful) default for C<$flags> is C<0>. |
|
|
2346 | |
|
|
2347 | On success, the new timerfd filehandle is returned, otherwise returns |
|
|
2348 | C<undef>. If the eventfd syscall is missing, fails with C<ENOSYS>. |
|
|
2349 | |
|
|
2350 | Please refer to L<timerfd_create(2)> for more info on this call. |
|
|
2351 | |
|
|
2352 | The following C<$clockid> values are |
|
|
2353 | available: C<IO::AIO::CLOCK_REALTIME>, C<IO::AIO::CLOCK_MONOTONIC> |
|
|
2354 | C<IO::AIO::CLOCK_CLOCK_BOOTTIME> (Linux 3.15) |
|
|
2355 | C<IO::AIO::CLOCK_CLOCK_REALTIME_ALARM> (Linux 3.11) and |
|
|
2356 | C<IO::AIO::CLOCK_CLOCK_BOOTTIME_ALARM> (Linux 3.11). |
|
|
2357 | |
|
|
2358 | The following C<$flags> values are available (Linux |
|
|
2359 | 2.6.27): C<IO::AIO::TFD_NONBLOCK> and C<IO::AIO::TFD_CLOEXEC>. |
|
|
2360 | |
|
|
2361 | Example: create a new timerfd and set it to one-second repeated alarms, |
|
|
2362 | then wait for two alarms: |
|
|
2363 | |
|
|
2364 | my $fh = IO::AIO::timerfd_create IO::AIO::CLOCK_BOOTTIME, IO::AIO::TFD_CLOEXEC |
|
|
2365 | or die "timerfd_create: $!\n"; |
|
|
2366 | |
|
|
2367 | defined IO::AIO::timerfd_settime $fh, 0, 1, 1 |
|
|
2368 | or die "timerfd_settime: $!\n"; |
|
|
2369 | |
|
|
2370 | for (1..2) { |
|
|
2371 | 8 == sysread $fh, my $buf, 8 |
|
|
2372 | or die "timerfd read failure\n"; |
|
|
2373 | |
|
|
2374 | printf "number of expirations (likely 1): %d\n", |
|
|
2375 | unpack "Q", $buf; |
|
|
2376 | } |
|
|
2377 | |
|
|
2378 | =item ($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags, $new_interval, $nbw_value |
|
|
2379 | |
|
|
2380 | This is a direct interface to the Linux L<timerfd_settime(2)> system |
|
|
2381 | call. Please refer to its manpage for more info on this call. |
|
|
2382 | |
|
|
2383 | The new itimerspec is specified using two (possibly fractional) second |
|
|
2384 | values, C<$new_interval> and C<$new_value>). |
|
|
2385 | |
|
|
2386 | On success, the current interval and value are returned (as per |
|
|
2387 | C<timerfd_gettime>). On failure, the empty list is returned. |
|
|
2388 | |
|
|
2389 | The following C<$flags> values are |
|
|
2390 | available: C<IO::AIO::TFD_TIMER_ABSTIME> and |
|
|
2391 | C<IO::AIO::TFD_TIMER_CANCEL_ON_SET>. |
|
|
2392 | |
|
|
2393 | See C<IO::AIO::timerfd_create> for a full example. |
|
|
2394 | |
|
|
2395 | =item ($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh |
|
|
2396 | |
|
|
2397 | This is a direct interface to the Linux L<timerfd_gettime(2)> system |
|
|
2398 | call. Please refer to its manpage for more info on this call. |
|
|
2399 | |
|
|
2400 | On success, returns the current values of interval and value for the given |
|
|
2401 | timerfd (as potentially fractional second values). On failure, the empty |
|
|
2402 | list is returned. |
1762 | |
2403 | |
1763 | =back |
2404 | =back |
1764 | |
2405 | |
1765 | =cut |
2406 | =cut |
1766 | |
2407 | |
… | |
… | |
1804 | =head2 FORK BEHAVIOUR |
2445 | =head2 FORK BEHAVIOUR |
1805 | |
2446 | |
1806 | Usage of pthreads in a program changes the semantics of fork |
2447 | Usage of pthreads in a program changes the semantics of fork |
1807 | considerably. Specifically, only async-safe functions can be called after |
2448 | considerably. Specifically, only async-safe functions can be called after |
1808 | fork. Perl doesn't know about this, so in general, you cannot call fork |
2449 | fork. Perl doesn't know about this, so in general, you cannot call fork |
1809 | with defined behaviour in perl. IO::AIO uses pthreads, so this applies, |
2450 | with defined behaviour in perl if pthreads are involved. IO::AIO uses |
1810 | but many other extensions and (for inexplicable reasons) perl itself often |
2451 | pthreads, so this applies, but many other extensions and (for inexplicable |
1811 | is linked against pthreads, so this limitation applies. |
2452 | reasons) perl itself often is linked against pthreads, so this limitation |
|
|
2453 | applies to quite a lot of perls. |
1812 | |
2454 | |
1813 | Some operating systems have extensions that allow safe use of fork, and |
2455 | This module no longer tries to fight your OS, or POSIX. That means IO::AIO |
1814 | this module should do "the right thing" on those, and tries on others. At |
2456 | only works in the process that loaded it. Forking is fully supported, but |
1815 | the time of this writing (2011) only GNU/Linux supports these extensions |
2457 | using IO::AIO in the child is not. |
1816 | to POSIX. |
2458 | |
|
|
2459 | You might get around by not I<using> IO::AIO before (or after) |
|
|
2460 | forking. You could also try to call the L<IO::AIO::reinit> function in the |
|
|
2461 | child: |
|
|
2462 | |
|
|
2463 | =over 4 |
|
|
2464 | |
|
|
2465 | =item IO::AIO::reinit |
|
|
2466 | |
|
|
2467 | Abandons all current requests and I/O threads and simply reinitialises all |
|
|
2468 | data structures. This is not an operation supported by any standards, but |
|
|
2469 | happens to work on GNU/Linux and some newer BSD systems. |
|
|
2470 | |
|
|
2471 | The only reasonable use for this function is to call it after forking, if |
|
|
2472 | C<IO::AIO> was used in the parent. Calling it while IO::AIO is active in |
|
|
2473 | the process will result in undefined behaviour. Calling it at any time |
|
|
2474 | will also result in any undefined (by POSIX) behaviour. |
|
|
2475 | |
|
|
2476 | =back |
|
|
2477 | |
|
|
2478 | =head2 LINUX-SPECIFIC CALLS |
|
|
2479 | |
|
|
2480 | When a call is documented as "linux-specific" then this means it |
|
|
2481 | originated on GNU/Linux. C<IO::AIO> will usually try to autodetect the |
|
|
2482 | availability and compatibility of such calls regardless of the platform |
|
|
2483 | it is compiled on, so platforms such as FreeBSD which often implement |
|
|
2484 | these calls will work. When in doubt, call them and see if they fail wth |
|
|
2485 | C<ENOSYS>. |
1817 | |
2486 | |
1818 | =head2 MEMORY USAGE |
2487 | =head2 MEMORY USAGE |
1819 | |
2488 | |
1820 | Per-request usage: |
2489 | Per-request usage: |
1821 | |
2490 | |
… | |
… | |
1834 | temporary buffers, and each thread requires a stack and other data |
2503 | temporary buffers, and each thread requires a stack and other data |
1835 | structures (usually around 16k-128k, depending on the OS). |
2504 | structures (usually around 16k-128k, depending on the OS). |
1836 | |
2505 | |
1837 | =head1 KNOWN BUGS |
2506 | =head1 KNOWN BUGS |
1838 | |
2507 | |
1839 | Known bugs will be fixed in the next release. |
2508 | Known bugs will be fixed in the next release :) |
|
|
2509 | |
|
|
2510 | =head1 KNOWN ISSUES |
|
|
2511 | |
|
|
2512 | Calls that try to "import" foreign memory areas (such as C<IO::AIO::mmap> |
|
|
2513 | or C<IO::AIO::aio_slurp>) do not work with generic lvalues, such as |
|
|
2514 | non-created hash slots or other scalars I didn't think of. It's best to |
|
|
2515 | avoid such and either use scalar variables or making sure that the scalar |
|
|
2516 | exists (e.g. by storing C<undef>) and isn't "funny" (e.g. tied). |
|
|
2517 | |
|
|
2518 | I am not sure anything can be done about this, so this is considered a |
|
|
2519 | known issue, rather than a bug. |
1840 | |
2520 | |
1841 | =head1 SEE ALSO |
2521 | =head1 SEE ALSO |
1842 | |
2522 | |
1843 | L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a |
2523 | L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a |
1844 | more natural syntax. |
2524 | more natural syntax. |