… | |
… | |
14 | aio_unlink "/tmp/file", sub { }; |
14 | aio_unlink "/tmp/file", sub { }; |
15 | |
15 | |
16 | aio_read $fh, 30000, 1024, $buffer, 0, sub { |
16 | aio_read $fh, 30000, 1024, $buffer, 0, sub { |
17 | $_[0] > 0 or die "read error: $!"; |
17 | $_[0] > 0 or die "read error: $!"; |
18 | }; |
18 | }; |
|
|
19 | |
|
|
20 | use IO::AIO 2; # version has aio objects |
|
|
21 | |
|
|
22 | my $req = aio_unlink "/tmp/file", sub { }; |
|
|
23 | $req->cancel; # cancel request if still in queue |
|
|
24 | |
|
|
25 | # AnyEvent |
|
|
26 | open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!"; |
|
|
27 | my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb }); |
19 | |
28 | |
20 | # Event |
29 | # Event |
21 | Event->io (fd => IO::AIO::poll_fileno, |
30 | Event->io (fd => IO::AIO::poll_fileno, |
22 | poll => 'r', |
31 | poll => 'r', |
23 | cb => \&IO::AIO::poll_cb); |
32 | cb => \&IO::AIO::poll_cb); |
… | |
… | |
57 | =cut |
66 | =cut |
58 | |
67 | |
59 | package IO::AIO; |
68 | package IO::AIO; |
60 | |
69 | |
61 | no warnings; |
70 | no warnings; |
|
|
71 | use strict 'vars'; |
62 | |
72 | |
63 | use base 'Exporter'; |
73 | use base 'Exporter'; |
64 | |
74 | |
65 | use Fcntl (); |
|
|
66 | |
|
|
67 | BEGIN { |
75 | BEGIN { |
68 | $VERSION = 1.6; |
76 | our $VERSION = '1.8'; |
69 | |
77 | |
70 | @EXPORT = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat |
78 | our @EXPORT = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat |
71 | aio_lstat aio_unlink aio_rmdir aio_readdir aio_symlink |
79 | aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink |
72 | aio_fsync aio_fdatasync aio_readahead); |
80 | aio_fsync aio_fdatasync aio_readahead aio_rename aio_link aio_move); |
73 | @EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel |
81 | our @EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel max_outstanding nreqs); |
74 | max_outstanding nreqs); |
|
|
75 | |
82 | |
76 | require XSLoader; |
83 | require XSLoader; |
77 | XSLoader::load IO::AIO, $VERSION; |
84 | XSLoader::load ("IO::AIO", $VERSION); |
78 | } |
85 | } |
79 | |
86 | |
80 | =head1 FUNCTIONS |
87 | =head1 FUNCTIONS |
81 | |
88 | |
82 | =head2 AIO FUNCTIONS |
89 | =head2 AIO FUNCTIONS |
… | |
… | |
90 | syscall has been executed asynchronously. |
97 | syscall has been executed asynchronously. |
91 | |
98 | |
92 | All functions expecting a filehandle keep a copy of the filehandle |
99 | All functions expecting a filehandle keep a copy of the filehandle |
93 | internally until the request has finished. |
100 | internally until the request has finished. |
94 | |
101 | |
|
|
102 | All non-composite requests (requests that are not broken down into |
|
|
103 | multiple requests) return objects of type L<IO::AIO::REQ> that allow |
|
|
104 | further manipulation of running requests. |
|
|
105 | |
95 | The pathnames you pass to these routines I<must> be absolute and |
106 | The pathnames you pass to these routines I<must> be absolute and |
96 | encoded in byte form. The reason for the former is that at the time the |
107 | encoded in byte form. The reason for the former is that at the time the |
97 | request is being executed, the current working directory could have |
108 | request is being executed, the current working directory could have |
98 | changed. Alternatively, you can make sure that you never change the |
109 | changed. Alternatively, you can make sure that you never change the |
99 | current working directory. |
110 | current working directory. |
… | |
… | |
105 | environment, d) use Glib::filename_from_unicode on unicode filenames or e) |
116 | environment, d) use Glib::filename_from_unicode on unicode filenames or e) |
106 | use something else. |
117 | use something else. |
107 | |
118 | |
108 | =over 4 |
119 | =over 4 |
109 | |
120 | |
110 | =item aio_open $pathname, $flags, $mode, $callback |
121 | =item aio_open $pathname, $flags, $mode, $callback->($fh) |
111 | |
122 | |
112 | Asynchronously open or create a file and call the callback with a newly |
123 | Asynchronously open or create a file and call the callback with a newly |
113 | created filehandle for the file. |
124 | created filehandle for the file. |
114 | |
125 | |
115 | The pathname passed to C<aio_open> must be absolute. See API NOTES, above, |
126 | The pathname passed to C<aio_open> must be absolute. See API NOTES, above, |
… | |
… | |
132 | } else { |
143 | } else { |
133 | die "open failed: $!\n"; |
144 | die "open failed: $!\n"; |
134 | } |
145 | } |
135 | }; |
146 | }; |
136 | |
147 | |
137 | =item aio_close $fh, $callback |
148 | =item aio_close $fh, $callback->($status) |
138 | |
149 | |
139 | Asynchronously close a file and call the callback with the result |
150 | Asynchronously close a file and call the callback with the result |
140 | code. I<WARNING:> although accepted, you should not pass in a perl |
151 | code. I<WARNING:> although accepted, you should not pass in a perl |
141 | filehandle here, as perl will likely close the file descriptor another |
152 | filehandle here, as perl will likely close the file descriptor another |
142 | time when the filehandle is destroyed. Normally, you can safely call perls |
153 | time when the filehandle is destroyed. Normally, you can safely call perls |
143 | C<close> or just let filehandles go out of scope. |
154 | C<close> or just let filehandles go out of scope. |
144 | |
155 | |
145 | This is supposed to be a bug in the API, so that might change. It's |
156 | This is supposed to be a bug in the API, so that might change. It's |
146 | therefore best to avoid this function. |
157 | therefore best to avoid this function. |
147 | |
158 | |
148 | =item aio_read $fh,$offset,$length, $data,$dataoffset,$callback |
159 | =item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
149 | |
160 | |
150 | =item aio_write $fh,$offset,$length, $data,$dataoffset,$callback |
161 | =item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
151 | |
162 | |
152 | Reads or writes C<length> bytes from the specified C<fh> and C<offset> |
163 | Reads or writes C<length> bytes from the specified C<fh> and C<offset> |
153 | into the scalar given by C<data> and offset C<dataoffset> and calls the |
164 | into the scalar given by C<data> and offset C<dataoffset> and calls the |
154 | callback without the actual number of bytes read (or -1 on error, just |
165 | callback without the actual number of bytes read (or -1 on error, just |
155 | like the syscall). |
166 | like the syscall). |
… | |
… | |
164 | aio_read $fh, 7, 15, $buffer, 0, sub { |
175 | aio_read $fh, 7, 15, $buffer, 0, sub { |
165 | $_[0] > 0 or die "read error: $!"; |
176 | $_[0] > 0 or die "read error: $!"; |
166 | print "read $_[0] bytes: <$buffer>\n"; |
177 | print "read $_[0] bytes: <$buffer>\n"; |
167 | }; |
178 | }; |
168 | |
179 | |
|
|
180 | =item aio_move $srcpath, $dstpath, $callback->($status) |
|
|
181 | |
|
|
182 | Try to move the I<file> (directories not supported as either source or |
|
|
183 | destination) from C<$srcpath> to C<$dstpath> and call the callback with |
|
|
184 | the C<0> (error) or C<-1> ok. |
|
|
185 | |
|
|
186 | This is a composite request that tries to rename(2) the file first. If |
|
|
187 | rename files with C<EXDEV>, it creates the destination file with mode 0200 |
|
|
188 | and copies the contents of the source file into it using C<aio_sendfile>, |
|
|
189 | followed by restoring atime, mtime, access mode and uid/gid, in that |
|
|
190 | order, and unlinking the C<$srcpath>. |
|
|
191 | |
|
|
192 | If an error occurs, the partial destination file will be unlinked, if |
|
|
193 | possible, except when setting atime, mtime, access mode and uid/gid, where |
|
|
194 | errors are being ignored. |
|
|
195 | |
|
|
196 | =cut |
|
|
197 | |
|
|
198 | sub aio_move($$$) { |
|
|
199 | my ($src, $dst, $cb) = @_; |
|
|
200 | |
|
|
201 | aio_rename $src, $dst, sub { |
|
|
202 | if ($_[0] && $! == EXDEV) { |
|
|
203 | aio_open $src, O_RDONLY, 0, sub { |
|
|
204 | if (my $src_fh = $_[0]) { |
|
|
205 | my @stat = stat $src_fh; |
|
|
206 | |
|
|
207 | aio_open $dst, O_WRONLY, 0200, sub { |
|
|
208 | if (my $dst_fh = $_[0]) { |
|
|
209 | aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { |
|
|
210 | close $src_fh; |
|
|
211 | |
|
|
212 | if ($_[0] == $stat[7]) { |
|
|
213 | utime $stat[8], $stat[9], $dst; |
|
|
214 | chmod $stat[2] & 07777, $dst_fh; |
|
|
215 | chown $stat[4], $stat[5], $dst_fh; |
|
|
216 | close $dst_fh; |
|
|
217 | |
|
|
218 | aio_unlink $src, sub { |
|
|
219 | $cb->($_[0]); |
|
|
220 | }; |
|
|
221 | } else { |
|
|
222 | my $errno = $!; |
|
|
223 | aio_unlink $dst, sub { |
|
|
224 | $! = $errno; |
|
|
225 | $cb->(-1); |
|
|
226 | }; |
|
|
227 | } |
|
|
228 | }; |
|
|
229 | } else { |
|
|
230 | $cb->(-1); |
|
|
231 | } |
|
|
232 | }, |
|
|
233 | |
|
|
234 | } else { |
|
|
235 | $cb->(-1); |
|
|
236 | } |
|
|
237 | }; |
|
|
238 | } else { |
|
|
239 | $cb->($_[0]); |
|
|
240 | } |
|
|
241 | }; |
|
|
242 | } |
|
|
243 | |
169 | =item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback |
244 | =item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
170 | |
245 | |
171 | Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts |
246 | Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts |
172 | reading at byte offset C<$in_offset>, and starts writing at the current |
247 | reading at byte offset C<$in_offset>, and starts writing at the current |
173 | file offset of C<$out_fh>. Because of that, it is not safe to issue more |
248 | file offset of C<$out_fh>. Because of that, it is not safe to issue more |
174 | than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each |
249 | than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each |
… | |
… | |
187 | bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only |
262 | bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only |
188 | provides the number of bytes written to C<$out_fh>. Only if the result |
263 | provides the number of bytes written to C<$out_fh>. Only if the result |
189 | value equals C<$length> one can assume that C<$length> bytes have been |
264 | value equals C<$length> one can assume that C<$length> bytes have been |
190 | read. |
265 | read. |
191 | |
266 | |
192 | =item aio_readahead $fh,$offset,$length, $callback |
267 | =item aio_readahead $fh,$offset,$length, $callback->($retval) |
193 | |
268 | |
194 | C<aio_readahead> populates the page cache with data from a file so that |
269 | C<aio_readahead> populates the page cache with data from a file so that |
195 | subsequent reads from that file will not block on disk I/O. The C<$offset> |
270 | subsequent reads from that file will not block on disk I/O. The C<$offset> |
196 | argument specifies the starting point from which data is to be read and |
271 | argument specifies the starting point from which data is to be read and |
197 | C<$length> specifies the number of bytes to be read. I/O is performed in |
272 | C<$length> specifies the number of bytes to be read. I/O is performed in |
… | |
… | |
201 | file. The current file offset of the file is left unchanged. |
276 | file. The current file offset of the file is left unchanged. |
202 | |
277 | |
203 | If that syscall doesn't exist (likely if your OS isn't Linux) it will be |
278 | If that syscall doesn't exist (likely if your OS isn't Linux) it will be |
204 | emulated by simply reading the data, which would have a similar effect. |
279 | emulated by simply reading the data, which would have a similar effect. |
205 | |
280 | |
206 | =item aio_stat $fh_or_path, $callback |
281 | =item aio_stat $fh_or_path, $callback->($status) |
207 | |
282 | |
208 | =item aio_lstat $fh, $callback |
283 | =item aio_lstat $fh, $callback->($status) |
209 | |
284 | |
210 | Works like perl's C<stat> or C<lstat> in void context. The callback will |
285 | Works like perl's C<stat> or C<lstat> in void context. The callback will |
211 | be called after the stat and the results will be available using C<stat _> |
286 | be called after the stat and the results will be available using C<stat _> |
212 | or C<-s _> etc... |
287 | or C<-s _> etc... |
213 | |
288 | |
… | |
… | |
223 | aio_stat "/etc/passwd", sub { |
298 | aio_stat "/etc/passwd", sub { |
224 | $_[0] and die "stat failed: $!"; |
299 | $_[0] and die "stat failed: $!"; |
225 | print "size is ", -s _, "\n"; |
300 | print "size is ", -s _, "\n"; |
226 | }; |
301 | }; |
227 | |
302 | |
228 | =item aio_unlink $pathname, $callback |
303 | =item aio_unlink $pathname, $callback->($status) |
229 | |
304 | |
230 | Asynchronously unlink (delete) a file and call the callback with the |
305 | Asynchronously unlink (delete) a file and call the callback with the |
231 | result code. |
306 | result code. |
232 | |
307 | |
|
|
308 | =item aio_link $srcpath, $dstpath, $callback->($status) |
|
|
309 | |
|
|
310 | Asynchronously create a new link to the existing object at C<$srcpath> at |
|
|
311 | the path C<$dstpath> and call the callback with the result code. |
|
|
312 | |
|
|
313 | =item aio_symlink $srcpath, $dstpath, $callback->($status) |
|
|
314 | |
|
|
315 | Asynchronously create a new symbolic link to the existing object at C<$srcpath> at |
|
|
316 | the path C<$dstpath> and call the callback with the result code. |
|
|
317 | |
|
|
318 | =item aio_rename $srcpath, $dstpath, $callback->($status) |
|
|
319 | |
|
|
320 | Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as |
|
|
321 | rename(2) and call the callback with the result code. |
|
|
322 | |
233 | =item aio_rmdir $pathname, $callback |
323 | =item aio_rmdir $pathname, $callback->($status) |
234 | |
324 | |
235 | Asynchronously rmdir (delete) a directory and call the callback with the |
325 | Asynchronously rmdir (delete) a directory and call the callback with the |
236 | result code. |
326 | result code. |
237 | |
327 | |
238 | =item aio_readdir $pathname $callback |
328 | =item aio_readdir $pathname, $callback->($entries) |
239 | |
329 | |
240 | Unlike the POSIX call of the same name, C<aio_readdir> reads an entire |
330 | Unlike the POSIX call of the same name, C<aio_readdir> reads an entire |
241 | directory (i.e. opendir + readdir + closedir). The entries will not be |
331 | directory (i.e. opendir + readdir + closedir). The entries will not be |
242 | sorted, and will B<NOT> include the C<.> and C<..> entries. |
332 | sorted, and will B<NOT> include the C<.> and C<..> entries. |
243 | |
333 | |
244 | The callback a single argument which is either C<undef> or an array-ref |
334 | The callback a single argument which is either C<undef> or an array-ref |
245 | with the filenames. |
335 | with the filenames. |
246 | |
336 | |
|
|
337 | =item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
|
|
338 | |
|
|
339 | Scans a directory (similar to C<aio_readdir>) but additionally tries to |
|
|
340 | separate the entries of directory C<$path> into two sets of names, ones |
|
|
341 | you can recurse into (directories or links to them), and ones you cannot |
|
|
342 | recurse into (everything else). |
|
|
343 | |
|
|
344 | C<aio_scandir> is a composite request that consists of many sub |
|
|
345 | requests. C<$maxreq> specifies the maximum number of outstanding aio |
|
|
346 | requests that this function generates. If it is C<< <= 0 >>, then a |
|
|
347 | suitable default will be chosen (currently 8). |
|
|
348 | |
|
|
349 | On error, the callback is called without arguments, otherwise it receives |
|
|
350 | two array-refs with path-relative entry names. |
|
|
351 | |
|
|
352 | Example: |
|
|
353 | |
|
|
354 | aio_scandir $dir, 0, sub { |
|
|
355 | my ($dirs, $nondirs) = @_; |
|
|
356 | print "real directories: @$dirs\n"; |
|
|
357 | print "everything else: @$nondirs\n"; |
|
|
358 | }; |
|
|
359 | |
|
|
360 | Implementation notes. |
|
|
361 | |
|
|
362 | The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can. |
|
|
363 | |
|
|
364 | After reading the directory, the modification time, size etc. of the |
|
|
365 | directory before and after the readdir is checked, and if they match (and |
|
|
366 | isn't the current time), the link count will be used to decide how many |
|
|
367 | entries are directories (if >= 2). Otherwise, no knowledge of the number |
|
|
368 | of subdirectories will be assumed. |
|
|
369 | |
|
|
370 | Then entries will be sorted into likely directories (everything without |
|
|
371 | a non-initial dot currently) and likely non-directories (everything |
|
|
372 | else). Then every entry plus an appended C</.> will be C<stat>'ed, |
|
|
373 | likely directories first. If that succeeds, it assumes that the entry |
|
|
374 | is a directory or a symlink to directory (which will be checked |
|
|
375 | seperately). This is often faster than stat'ing the entry itself because |
|
|
376 | filesystems might detect the type of the entry without reading the inode |
|
|
377 | data (e.g. ext2fs filetype feature). |
|
|
378 | |
|
|
379 | If the known number of directories (link count - 2) has been reached, the |
|
|
380 | rest of the entries is assumed to be non-directories. |
|
|
381 | |
|
|
382 | This only works with certainty on POSIX (= UNIX) filesystems, which |
|
|
383 | fortunately are the vast majority of filesystems around. |
|
|
384 | |
|
|
385 | It will also likely work on non-POSIX filesystems with reduced efficiency |
|
|
386 | as those tend to return 0 or 1 as link counts, which disables the |
|
|
387 | directory counting heuristic. |
|
|
388 | |
|
|
389 | =cut |
|
|
390 | |
|
|
391 | sub aio_scandir($$$) { |
|
|
392 | my ($path, $maxreq, $cb) = @_; |
|
|
393 | |
|
|
394 | $maxreq = 8 if $maxreq <= 0; |
|
|
395 | |
|
|
396 | # stat once |
|
|
397 | aio_stat $path, sub { |
|
|
398 | return $cb->() if $_[0]; |
|
|
399 | my $now = time; |
|
|
400 | my $hash1 = join ":", (stat _)[0,1,3,7,9]; |
|
|
401 | |
|
|
402 | # read the directory entries |
|
|
403 | aio_readdir $path, sub { |
|
|
404 | my $entries = shift |
|
|
405 | or return $cb->(); |
|
|
406 | |
|
|
407 | # stat the dir another time |
|
|
408 | aio_stat $path, sub { |
|
|
409 | my $hash2 = join ":", (stat _)[0,1,3,7,9]; |
|
|
410 | |
|
|
411 | my $ndirs; |
|
|
412 | |
|
|
413 | # take the slow route if anything looks fishy |
|
|
414 | if ($hash1 ne $hash2 or (stat _)[9] == $now) { |
|
|
415 | $ndirs = -1; |
|
|
416 | } else { |
|
|
417 | # if nlink == 2, we are finished |
|
|
418 | # on non-posix-fs's, we rely on nlink < 2 |
|
|
419 | $ndirs = (stat _)[3] - 2 |
|
|
420 | or return $cb->([], $entries); |
|
|
421 | } |
|
|
422 | |
|
|
423 | # sort into likely dirs and likely nondirs |
|
|
424 | # dirs == files without ".", short entries first |
|
|
425 | $entries = [map $_->[0], |
|
|
426 | sort { $b->[1] cmp $a->[1] } |
|
|
427 | map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length], |
|
|
428 | @$entries]; |
|
|
429 | |
|
|
430 | my (@dirs, @nondirs); |
|
|
431 | |
|
|
432 | my ($statcb, $schedcb); |
|
|
433 | my $nreq = 0; |
|
|
434 | |
|
|
435 | $schedcb = sub { |
|
|
436 | if (@$entries) { |
|
|
437 | if ($nreq < $maxreq) { |
|
|
438 | my $ent = pop @$entries; |
|
|
439 | $nreq++; |
|
|
440 | aio_stat "$path/$ent/.", sub { $statcb->($_[0], $ent) }; |
|
|
441 | } |
|
|
442 | } elsif (!$nreq) { |
|
|
443 | # finished |
|
|
444 | undef $statcb; |
|
|
445 | undef $schedcb; |
|
|
446 | $cb->(\@dirs, \@nondirs) if $cb; |
|
|
447 | undef $cb; |
|
|
448 | } |
|
|
449 | }; |
|
|
450 | $statcb = sub { |
|
|
451 | my ($status, $entry) = @_; |
|
|
452 | |
|
|
453 | if ($status < 0) { |
|
|
454 | $nreq--; |
|
|
455 | push @nondirs, $entry; |
|
|
456 | &$schedcb; |
|
|
457 | } else { |
|
|
458 | # need to check for real directory |
|
|
459 | aio_lstat "$path/$entry", sub { |
|
|
460 | $nreq--; |
|
|
461 | |
|
|
462 | if (-d _) { |
|
|
463 | push @dirs, $entry; |
|
|
464 | |
|
|
465 | if (!--$ndirs) { |
|
|
466 | push @nondirs, @$entries; |
|
|
467 | $entries = []; |
|
|
468 | } |
|
|
469 | } else { |
|
|
470 | push @nondirs, $entry; |
|
|
471 | } |
|
|
472 | |
|
|
473 | &$schedcb; |
|
|
474 | } |
|
|
475 | } |
|
|
476 | }; |
|
|
477 | |
|
|
478 | &$schedcb while @$entries && $nreq < $maxreq; |
|
|
479 | }; |
|
|
480 | }; |
|
|
481 | }; |
|
|
482 | } |
|
|
483 | |
247 | =item aio_fsync $fh, $callback |
484 | =item aio_fsync $fh, $callback->($status) |
248 | |
485 | |
249 | Asynchronously call fsync on the given filehandle and call the callback |
486 | Asynchronously call fsync on the given filehandle and call the callback |
250 | with the fsync result code. |
487 | with the fsync result code. |
251 | |
488 | |
252 | =item aio_fdatasync $fh, $callback |
489 | =item aio_fdatasync $fh, $callback->($status) |
253 | |
490 | |
254 | Asynchronously call fdatasync on the given filehandle and call the |
491 | Asynchronously call fdatasync on the given filehandle and call the |
255 | callback with the fdatasync result code. |
492 | callback with the fdatasync result code. |
256 | |
493 | |
257 | If this call isn't available because your OS lacks it or it couldn't be |
494 | If this call isn't available because your OS lacks it or it couldn't be |
258 | detected, it will be emulated by calling C<fsync> instead. |
495 | detected, it will be emulated by calling C<fsync> instead. |
|
|
496 | |
|
|
497 | =back |
|
|
498 | |
|
|
499 | =head2 IO::AIO::CB CLASS |
|
|
500 | |
|
|
501 | All non-aggregate C<aio_*> functions return an object of this class when |
|
|
502 | called in non-void context. |
|
|
503 | |
|
|
504 | A request always moves through the following five states in its lifetime, |
|
|
505 | in order: B<ready> (request has been created, but has not been executed |
|
|
506 | yet), B<execute> (request is currently being executed), B<pending> |
|
|
507 | (request has been executed but callback has not been called yet), |
|
|
508 | B<result> (results are being processed synchronously, includes calling the |
|
|
509 | callback) and B<done> (request has reached the end of its lifetime and |
|
|
510 | holds no resources anymore). |
|
|
511 | |
|
|
512 | =over 4 |
|
|
513 | |
|
|
514 | =item $req->cancel |
|
|
515 | |
|
|
516 | Cancels the request, if possible. Has the effect of skipping execution |
|
|
517 | when entering the B<execute> state and skipping calling the callback when |
|
|
518 | entering the the B<result> state, but will leave the request otherwise |
|
|
519 | untouched. That means that requests that currently execute will not be |
|
|
520 | stopped and resources held by the request will not be freed prematurely. |
259 | |
521 | |
260 | =back |
522 | =back |
261 | |
523 | |
262 | =head2 SUPPORT FUNCTIONS |
524 | =head2 SUPPORT FUNCTIONS |
263 | |
525 | |
… | |
… | |
391 | } |
653 | } |
392 | |
654 | |
393 | 1; |
655 | 1; |
394 | |
656 | |
395 | =head2 FORK BEHAVIOUR |
657 | =head2 FORK BEHAVIOUR |
|
|
658 | |
|
|
659 | This module should do "the right thing" when the process using it forks: |
396 | |
660 | |
397 | Before the fork, IO::AIO enters a quiescent state where no requests |
661 | Before the fork, IO::AIO enters a quiescent state where no requests |
398 | can be added in other threads and no results will be processed. After |
662 | can be added in other threads and no results will be processed. After |
399 | the fork the parent simply leaves the quiescent state and continues |
663 | the fork the parent simply leaves the quiescent state and continues |
400 | request/result processing, while the child clears the request/result |
664 | request/result processing, while the child clears the request/result |
401 | queue (so the requests started before the fork will only be handled in |
665 | queue (so the requests started before the fork will only be handled in |
402 | the parent). Threats will be started on demand until the limit ste in the |
666 | the parent). Threads will be started on demand until the limit ste in the |
403 | parent process has been reached again. |
667 | parent process has been reached again. |
404 | |
668 | |
|
|
669 | In short: the parent will, after a short pause, continue as if fork had |
|
|
670 | not been called, while the child will act as if IO::AIO has not been used |
|
|
671 | yet. |
|
|
672 | |
405 | =head1 SEE ALSO |
673 | =head1 SEE ALSO |
406 | |
674 | |
407 | L<Coro>, L<Linux::AIO>. |
675 | L<Coro>, L<Linux::AIO> (obsolete). |
408 | |
676 | |
409 | =head1 AUTHOR |
677 | =head1 AUTHOR |
410 | |
678 | |
411 | Marc Lehmann <schmorp@schmorp.de> |
679 | Marc Lehmann <schmorp@schmorp.de> |
412 | http://home.schmorp.de/ |
680 | http://home.schmorp.de/ |