… | |
… | |
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 | |
19 | |
20 | # AnyEvent |
20 | # version 2+ has request and group objects |
|
|
21 | use IO::AIO 2; |
|
|
22 | |
|
|
23 | aioreq_pri 4; # give next request a very high priority |
|
|
24 | my $req = aio_unlink "/tmp/file", sub { }; |
|
|
25 | $req->cancel; # cancel request if still in queue |
|
|
26 | |
|
|
27 | my $grp = aio_group sub { print "all stats done\n" }; |
|
|
28 | add $grp aio_stat "..." for ...; |
|
|
29 | |
|
|
30 | # AnyEvent integration |
21 | open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!"; |
31 | open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!"; |
22 | my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb }); |
32 | my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb }); |
23 | |
33 | |
24 | # Event |
34 | # Event integration |
25 | Event->io (fd => IO::AIO::poll_fileno, |
35 | Event->io (fd => IO::AIO::poll_fileno, |
26 | poll => 'r', |
36 | poll => 'r', |
27 | cb => \&IO::AIO::poll_cb); |
37 | cb => \&IO::AIO::poll_cb); |
28 | |
38 | |
29 | # Glib/Gtk2 |
39 | # Glib/Gtk2 integration |
30 | add_watch Glib::IO IO::AIO::poll_fileno, |
40 | add_watch Glib::IO IO::AIO::poll_fileno, |
31 | in => sub { IO::AIO::poll_cb; 1 }; |
41 | in => sub { IO::AIO::poll_cb; 1 }; |
32 | |
42 | |
33 | # Tk |
43 | # Tk integration |
34 | Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "", |
44 | Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "", |
35 | readable => \&IO::AIO::poll_cb); |
45 | readable => \&IO::AIO::poll_cb); |
36 | |
46 | |
37 | # Danga::Socket |
47 | # Danga::Socket integration |
38 | Danga::Socket->AddOtherFds (IO::AIO::poll_fileno => |
48 | Danga::Socket->AddOtherFds (IO::AIO::poll_fileno => |
39 | \&IO::AIO::poll_cb); |
49 | \&IO::AIO::poll_cb); |
40 | |
50 | |
41 | |
|
|
42 | =head1 DESCRIPTION |
51 | =head1 DESCRIPTION |
43 | |
52 | |
44 | This module implements asynchronous I/O using whatever means your |
53 | This module implements asynchronous I/O using whatever means your |
45 | operating system supports. |
54 | operating system supports. |
46 | |
55 | |
47 | Currently, a number of threads are started that execute your read/writes |
56 | In this version, a number of threads are started that execute your |
48 | and signal their completion. You don't need thread support in your libc or |
57 | requests and signal their completion. You don't need thread support |
49 | perl, and the threads created by this module will not be visible to the |
58 | in perl, and the threads created by this module will not be visible |
50 | pthreads library. In the future, this module might make use of the native |
59 | to perl. In the future, this module might make use of the native aio |
51 | aio functions available on many operating systems. However, they are often |
60 | functions available on many operating systems. However, they are often |
52 | not well-supported (Linux doesn't allow them on normal files currently, |
61 | not well-supported or restricted (Linux doesn't allow them on normal |
53 | for example), and they would only support aio_read and aio_write, so the |
62 | files currently, for example), and they would only support aio_read and |
54 | remaining functionality would have to be implemented using threads anyway. |
63 | aio_write, so the remaining functionality would have to be implemented |
|
|
64 | using threads anyway. |
55 | |
65 | |
56 | Although the module will work with in the presence of other threads, it is |
66 | Although the module will work with in the presence of other (Perl-) |
57 | currently not reentrant, so use appropriate locking yourself, always call |
67 | threads, it is currently not reentrant in any way, so use appropriate |
58 | C<poll_cb> from within the same thread, or never call C<poll_cb> (or other |
68 | locking yourself, always call C<poll_cb> from within the same thread, or |
59 | C<aio_> functions) recursively. |
69 | never call C<poll_cb> (or other C<aio_> functions) recursively. |
|
|
70 | |
|
|
71 | =head1 REQUEST ANATOMY AND LIFETIME |
|
|
72 | |
|
|
73 | Every C<aio_*> function creates a request. which is a C data structure not |
|
|
74 | directly visible to Perl. |
|
|
75 | |
|
|
76 | If called in non-void context, every request function returns a Perl |
|
|
77 | object representing the request. In void context, nothing is returned, |
|
|
78 | which saves a bit of memory. |
|
|
79 | |
|
|
80 | The perl object is a fairly standard ref-to-hash object. The hash contents |
|
|
81 | are not used by IO::AIO so you are free to store anything you like in it. |
|
|
82 | |
|
|
83 | During their existance, aio requests travel through the following states, |
|
|
84 | in order: |
|
|
85 | |
|
|
86 | =over 4 |
|
|
87 | |
|
|
88 | =item ready |
|
|
89 | |
|
|
90 | Immediately after a request is created it is put into the ready state, |
|
|
91 | waiting for a thread to execute it. |
|
|
92 | |
|
|
93 | =item execute |
|
|
94 | |
|
|
95 | A thread has accepted the request for processing and is currently |
|
|
96 | executing it (e.g. blocking in read). |
|
|
97 | |
|
|
98 | =item pending |
|
|
99 | |
|
|
100 | The request has been executed and is waiting for result processing. |
|
|
101 | |
|
|
102 | While request submission and execution is fully asynchronous, result |
|
|
103 | processing is not and relies on the perl interpreter calling C<poll_cb> |
|
|
104 | (or another function with the same effect). |
|
|
105 | |
|
|
106 | =item result |
|
|
107 | |
|
|
108 | The request results are processed synchronously by C<poll_cb>. |
|
|
109 | |
|
|
110 | The C<poll_cb> function will process all outstanding aio requests by |
|
|
111 | calling their callbacks, freeing memory associated with them and managing |
|
|
112 | any groups they are contained in. |
|
|
113 | |
|
|
114 | =item done |
|
|
115 | |
|
|
116 | Request has reached the end of its lifetime and holds no resources anymore |
|
|
117 | (except possibly for the Perl object, but its connection to the actual |
|
|
118 | aio request is severed and calling its methods will either do nothing or |
|
|
119 | result in a runtime error). |
60 | |
120 | |
61 | =cut |
121 | =cut |
62 | |
122 | |
63 | package IO::AIO; |
123 | package IO::AIO; |
64 | |
124 | |
65 | no warnings; |
125 | no warnings; |
|
|
126 | use strict 'vars'; |
66 | |
127 | |
67 | use base 'Exporter'; |
128 | use base 'Exporter'; |
68 | |
129 | |
69 | use Fcntl (); |
|
|
70 | |
|
|
71 | BEGIN { |
130 | BEGIN { |
72 | $VERSION = '1.71'; |
131 | our $VERSION = '2.0'; |
73 | |
132 | |
74 | @EXPORT = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat |
133 | our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat |
75 | aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink |
134 | aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink |
76 | aio_fsync aio_fdatasync aio_readahead); |
135 | aio_fsync aio_fdatasync aio_readahead aio_rename aio_link aio_move |
77 | @EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel |
136 | aio_group aio_nop); |
78 | max_outstanding nreqs); |
137 | our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); |
|
|
138 | our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush |
|
|
139 | min_parallel max_parallel nreqs nready npending); |
|
|
140 | |
|
|
141 | @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; |
79 | |
142 | |
80 | require XSLoader; |
143 | require XSLoader; |
81 | XSLoader::load IO::AIO, $VERSION; |
144 | XSLoader::load ("IO::AIO", $VERSION); |
82 | } |
145 | } |
83 | |
146 | |
84 | =head1 FUNCTIONS |
147 | =head1 FUNCTIONS |
85 | |
148 | |
86 | =head2 AIO FUNCTIONS |
149 | =head2 AIO FUNCTIONS |
… | |
… | |
94 | syscall has been executed asynchronously. |
157 | syscall has been executed asynchronously. |
95 | |
158 | |
96 | All functions expecting a filehandle keep a copy of the filehandle |
159 | All functions expecting a filehandle keep a copy of the filehandle |
97 | internally until the request has finished. |
160 | internally until the request has finished. |
98 | |
161 | |
|
|
162 | All requests return objects of type L<IO::AIO::REQ> that allow further |
|
|
163 | manipulation of those requests while they are in-flight. |
|
|
164 | |
99 | The pathnames you pass to these routines I<must> be absolute and |
165 | The pathnames you pass to these routines I<must> be absolute and |
100 | encoded in byte form. The reason for the former is that at the time the |
166 | encoded in byte form. The reason for the former is that at the time the |
101 | request is being executed, the current working directory could have |
167 | request is being executed, the current working directory could have |
102 | changed. Alternatively, you can make sure that you never change the |
168 | changed. Alternatively, you can make sure that you never change the |
103 | current working directory. |
169 | current working directory. |
… | |
… | |
108 | your pathnames to the locale (or other) encoding in effect in the user |
174 | your pathnames to the locale (or other) encoding in effect in the user |
109 | environment, d) use Glib::filename_from_unicode on unicode filenames or e) |
175 | environment, d) use Glib::filename_from_unicode on unicode filenames or e) |
110 | use something else. |
176 | use something else. |
111 | |
177 | |
112 | =over 4 |
178 | =over 4 |
|
|
179 | |
|
|
180 | =item $prev_pri = aioreq_pri [$pri] |
|
|
181 | |
|
|
182 | Returns the priority value that would be used for the next request and, if |
|
|
183 | C<$pri> is given, sets the priority for the next aio request. |
|
|
184 | |
|
|
185 | The default priority is C<0>, the minimum and maximum priorities are C<-4> |
|
|
186 | and C<4>, respectively. Requests with higher priority will be serviced |
|
|
187 | first. |
|
|
188 | |
|
|
189 | The priority will be reset to C<0> after each call to one of the C<aio_*> |
|
|
190 | functions. |
|
|
191 | |
|
|
192 | Example: open a file with low priority, then read something from it with |
|
|
193 | higher priority so the read request is serviced before other low priority |
|
|
194 | open requests (potentially spamming the cache): |
|
|
195 | |
|
|
196 | aioreq_pri -3; |
|
|
197 | aio_open ..., sub { |
|
|
198 | return unless $_[0]; |
|
|
199 | |
|
|
200 | aioreq_pri -2; |
|
|
201 | aio_read $_[0], ..., sub { |
|
|
202 | ... |
|
|
203 | }; |
|
|
204 | }; |
|
|
205 | |
|
|
206 | =item aioreq_nice $pri_adjust |
|
|
207 | |
|
|
208 | Similar to C<aioreq_pri>, but subtracts the given value from the current |
|
|
209 | priority, so effects are cumulative. |
113 | |
210 | |
114 | =item aio_open $pathname, $flags, $mode, $callback->($fh) |
211 | =item aio_open $pathname, $flags, $mode, $callback->($fh) |
115 | |
212 | |
116 | Asynchronously open or create a file and call the callback with a newly |
213 | Asynchronously open or create a file and call the callback with a newly |
117 | created filehandle for the file. |
214 | created filehandle for the file. |
… | |
… | |
168 | aio_read $fh, 7, 15, $buffer, 0, sub { |
265 | aio_read $fh, 7, 15, $buffer, 0, sub { |
169 | $_[0] > 0 or die "read error: $!"; |
266 | $_[0] > 0 or die "read error: $!"; |
170 | print "read $_[0] bytes: <$buffer>\n"; |
267 | print "read $_[0] bytes: <$buffer>\n"; |
171 | }; |
268 | }; |
172 | |
269 | |
|
|
270 | =item aio_move $srcpath, $dstpath, $callback->($status) |
|
|
271 | |
|
|
272 | Try to move the I<file> (directories not supported as either source or |
|
|
273 | destination) from C<$srcpath> to C<$dstpath> and call the callback with |
|
|
274 | the C<0> (error) or C<-1> ok. |
|
|
275 | |
|
|
276 | This is a composite request that tries to rename(2) the file first. If |
|
|
277 | rename files with C<EXDEV>, it creates the destination file with mode 0200 |
|
|
278 | and copies the contents of the source file into it using C<aio_sendfile>, |
|
|
279 | followed by restoring atime, mtime, access mode and uid/gid, in that |
|
|
280 | order, and unlinking the C<$srcpath>. |
|
|
281 | |
|
|
282 | If an error occurs, the partial destination file will be unlinked, if |
|
|
283 | possible, except when setting atime, mtime, access mode and uid/gid, where |
|
|
284 | errors are being ignored. |
|
|
285 | |
|
|
286 | =cut |
|
|
287 | |
|
|
288 | sub aio_move($$$) { |
|
|
289 | my ($src, $dst, $cb) = @_; |
|
|
290 | |
|
|
291 | my $pri = aioreq_pri; |
|
|
292 | my $grp = aio_group $cb; |
|
|
293 | |
|
|
294 | aioreq_pri $pri; |
|
|
295 | add $grp aio_rename $src, $dst, sub { |
|
|
296 | if ($_[0] && $! == EXDEV) { |
|
|
297 | aioreq_pri $pri; |
|
|
298 | add $grp aio_open $src, O_RDONLY, 0, sub { |
|
|
299 | if (my $src_fh = $_[0]) { |
|
|
300 | my @stat = stat $src_fh; |
|
|
301 | |
|
|
302 | aioreq_pri $pri; |
|
|
303 | add $grp aio_open $dst, O_WRONLY, 0200, sub { |
|
|
304 | if (my $dst_fh = $_[0]) { |
|
|
305 | aioreq_pri $pri; |
|
|
306 | add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { |
|
|
307 | close $src_fh; |
|
|
308 | |
|
|
309 | if ($_[0] == $stat[7]) { |
|
|
310 | utime $stat[8], $stat[9], $dst; |
|
|
311 | chmod $stat[2] & 07777, $dst_fh; |
|
|
312 | chown $stat[4], $stat[5], $dst_fh; |
|
|
313 | close $dst_fh; |
|
|
314 | |
|
|
315 | aioreq_pri $pri; |
|
|
316 | add $grp aio_unlink $src, sub { |
|
|
317 | $grp->result ($_[0]); |
|
|
318 | }; |
|
|
319 | } else { |
|
|
320 | my $errno = $!; |
|
|
321 | aioreq_pri $pri; |
|
|
322 | add $grp aio_unlink $dst, sub { |
|
|
323 | $! = $errno; |
|
|
324 | $grp->result (-1); |
|
|
325 | }; |
|
|
326 | } |
|
|
327 | }; |
|
|
328 | } else { |
|
|
329 | $grp->result (-1); |
|
|
330 | } |
|
|
331 | }, |
|
|
332 | |
|
|
333 | } else { |
|
|
334 | $grp->result (-1); |
|
|
335 | } |
|
|
336 | }; |
|
|
337 | } else { |
|
|
338 | $grp->result ($_[0]); |
|
|
339 | } |
|
|
340 | }; |
|
|
341 | |
|
|
342 | $grp |
|
|
343 | } |
|
|
344 | |
173 | =item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
345 | =item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
174 | |
346 | |
175 | Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts |
347 | Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts |
176 | reading at byte offset C<$in_offset>, and starts writing at the current |
348 | reading at byte offset C<$in_offset>, and starts writing at the current |
177 | file offset of C<$out_fh>. Because of that, it is not safe to issue more |
349 | file offset of C<$out_fh>. Because of that, it is not safe to issue more |
… | |
… | |
232 | =item aio_unlink $pathname, $callback->($status) |
404 | =item aio_unlink $pathname, $callback->($status) |
233 | |
405 | |
234 | Asynchronously unlink (delete) a file and call the callback with the |
406 | Asynchronously unlink (delete) a file and call the callback with the |
235 | result code. |
407 | result code. |
236 | |
408 | |
|
|
409 | =item aio_link $srcpath, $dstpath, $callback->($status) |
|
|
410 | |
|
|
411 | Asynchronously create a new link to the existing object at C<$srcpath> at |
|
|
412 | the path C<$dstpath> and call the callback with the result code. |
|
|
413 | |
|
|
414 | =item aio_symlink $srcpath, $dstpath, $callback->($status) |
|
|
415 | |
|
|
416 | Asynchronously create a new symbolic link to the existing object at C<$srcpath> at |
|
|
417 | the path C<$dstpath> and call the callback with the result code. |
|
|
418 | |
|
|
419 | =item aio_rename $srcpath, $dstpath, $callback->($status) |
|
|
420 | |
|
|
421 | Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as |
|
|
422 | rename(2) and call the callback with the result code. |
|
|
423 | |
237 | =item aio_rmdir $pathname, $callback->($status) |
424 | =item aio_rmdir $pathname, $callback->($status) |
238 | |
425 | |
239 | Asynchronously rmdir (delete) a directory and call the callback with the |
426 | Asynchronously rmdir (delete) a directory and call the callback with the |
240 | result code. |
427 | result code. |
241 | |
428 | |
242 | =item aio_readdir $pathname $callback->($entries) |
429 | =item aio_readdir $pathname, $callback->($entries) |
243 | |
430 | |
244 | Unlike the POSIX call of the same name, C<aio_readdir> reads an entire |
431 | Unlike the POSIX call of the same name, C<aio_readdir> reads an entire |
245 | directory (i.e. opendir + readdir + closedir). The entries will not be |
432 | directory (i.e. opendir + readdir + closedir). The entries will not be |
246 | sorted, and will B<NOT> include the C<.> and C<..> entries. |
433 | sorted, and will B<NOT> include the C<.> and C<..> entries. |
247 | |
434 | |
248 | The callback a single argument which is either C<undef> or an array-ref |
435 | The callback a single argument which is either C<undef> or an array-ref |
249 | with the filenames. |
436 | with the filenames. |
250 | |
437 | |
251 | =item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
438 | =item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
252 | |
439 | |
253 | Scans a directory (similar to C<aio_readdir>) and tries to separate the |
440 | Scans a directory (similar to C<aio_readdir>) but additionally tries to |
254 | entries of directory C<$path> into two sets of names, ones you can recurse |
441 | efficiently separate the entries of directory C<$path> into two sets of |
255 | into (directories), and ones you cannot recurse into (everything else). |
442 | names, directories you can recurse into (directories), and ones you cannot |
|
|
443 | recurse into (everything else, including symlinks to directories). |
256 | |
444 | |
257 | C<aio_scandir> is a composite request that consists of many |
445 | C<aio_scandir> is a composite request that creates of many sub requests_ |
258 | aio-primitives. C<$maxreq> specifies the maximum number of outstanding |
446 | C<$maxreq> specifies the maximum number of outstanding aio requests that |
259 | aio requests that this function generates. If it is C<< <= 0 >>, then a |
447 | this function generates. If it is C<< <= 0 >>, then a suitable default |
260 | suitable default will be chosen (currently 8). |
448 | will be chosen (currently 6). |
261 | |
449 | |
262 | On error, the callback is called without arguments, otherwise it receives |
450 | On error, the callback is called without arguments, otherwise it receives |
263 | two array-refs with path-relative entry names. |
451 | two array-refs with path-relative entry names. |
264 | |
452 | |
265 | Example: |
453 | Example: |
… | |
… | |
273 | Implementation notes. |
461 | Implementation notes. |
274 | |
462 | |
275 | The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can. |
463 | The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can. |
276 | |
464 | |
277 | After reading the directory, the modification time, size etc. of the |
465 | After reading the directory, the modification time, size etc. of the |
278 | directory before and after the readdir is checked, and if they match, the |
466 | directory before and after the readdir is checked, and if they match (and |
279 | link count will be used to decide how many entries are directories (if |
467 | isn't the current time), the link count will be used to decide how many |
280 | >= 2). Otherwise, no knowledge of the number of subdirectories will be |
468 | entries are directories (if >= 2). Otherwise, no knowledge of the number |
281 | assumed. |
469 | of subdirectories will be assumed. |
282 | |
470 | |
283 | Then entires will be sorted into likely directories (everything without a |
471 | Then entries will be sorted into likely directories (everything without |
284 | non-initial dot) and likely non-directories (everything else). Then every |
472 | a non-initial dot currently) and likely non-directories (everything |
285 | entry + C</.> will be C<stat>'ed, likely directories first. This is often |
473 | else). Then every entry plus an appended C</.> will be C<stat>'ed, |
|
|
474 | likely directories first. If that succeeds, it assumes that the entry |
|
|
475 | is a directory or a symlink to directory (which will be checked |
|
|
476 | seperately). This is often faster than stat'ing the entry itself because |
286 | faster because filesystems might detect the type of the entry without |
477 | filesystems might detect the type of the entry without reading the inode |
287 | reading the inode data (e.g. ext2s filetype feature). If that succeeds, |
478 | data (e.g. ext2fs filetype feature). |
288 | it assumes that the entry is a directory or a symlink to directory (which |
|
|
289 | will be checked seperately). |
|
|
290 | |
479 | |
291 | If the known number of directories has been reached, the rest of the |
480 | If the known number of directories (link count - 2) has been reached, the |
292 | entries is assumed to be non-directories. |
481 | rest of the entries is assumed to be non-directories. |
|
|
482 | |
|
|
483 | This only works with certainty on POSIX (= UNIX) filesystems, which |
|
|
484 | fortunately are the vast majority of filesystems around. |
|
|
485 | |
|
|
486 | It will also likely work on non-POSIX filesystems with reduced efficiency |
|
|
487 | as those tend to return 0 or 1 as link counts, which disables the |
|
|
488 | directory counting heuristic. |
293 | |
489 | |
294 | =cut |
490 | =cut |
295 | |
491 | |
296 | sub aio_scandir($$$) { |
492 | sub aio_scandir($$$) { |
297 | my ($path, $maxreq, $cb) = @_; |
493 | my ($path, $maxreq, $cb) = @_; |
298 | |
494 | |
|
|
495 | my $pri = aioreq_pri; |
|
|
496 | |
|
|
497 | my $grp = aio_group $cb; |
|
|
498 | |
299 | $maxreq = 8 if $maxreq <= 0; |
499 | $maxreq = 6 if $maxreq <= 0; |
300 | |
500 | |
301 | # stat once |
501 | # stat once |
|
|
502 | aioreq_pri $pri; |
302 | aio_stat $path, sub { |
503 | add $grp aio_stat $path, sub { |
303 | $cb->() if $_[0]; |
504 | return $grp->result () if $_[0]; |
|
|
505 | my $now = time; |
304 | my $hash1 = join ":", (stat _)[0,1,3,7,9]; |
506 | my $hash1 = join ":", (stat _)[0,1,3,7,9]; |
305 | |
507 | |
306 | # read the directory entries |
508 | # read the directory entries |
|
|
509 | aioreq_pri $pri; |
307 | aio_readdir $path, sub { |
510 | add $grp aio_readdir $path, sub { |
308 | my $entries = shift |
511 | my $entries = shift |
309 | or return $cb->(); |
512 | or return $grp->result (); |
310 | |
513 | |
311 | # stat the dir another time |
514 | # stat the dir another time |
|
|
515 | aioreq_pri $pri; |
312 | aio_stat $path, sub { |
516 | add $grp aio_stat $path, sub { |
313 | my $hash2 = join ":", (stat _)[0,1,3,7,9]; |
517 | my $hash2 = join ":", (stat _)[0,1,3,7,9]; |
314 | |
518 | |
315 | my $ndirs; |
519 | my $ndirs; |
316 | |
520 | |
317 | # take the slow route if anything looks fishy |
521 | # take the slow route if anything looks fishy |
318 | if ($hash1 ne $hash2) { |
522 | if ($hash1 ne $hash2 or (stat _)[9] == $now) { |
319 | $ndirs = -1; |
523 | $ndirs = -1; |
320 | } else { |
524 | } else { |
321 | # if nlink == 2, we are finished |
525 | # if nlink == 2, we are finished |
322 | # on non-posix-fs's, we rely on nlink < 2 |
526 | # on non-posix-fs's, we rely on nlink < 2 |
323 | $ndirs = (stat _)[3] - 2 |
527 | $ndirs = (stat _)[3] - 2 |
324 | or return $cb->([], $entries); |
528 | or return $grp->result ([], $entries); |
325 | } |
529 | } |
326 | |
530 | |
327 | # sort into likely dirs and likely nondirs |
531 | # sort into likely dirs and likely nondirs |
328 | # dirs == files without ".", short entries first |
532 | # dirs == files without ".", short entries first |
329 | $entries = [map $_->[0], |
533 | $entries = [map $_->[0], |
… | |
… | |
331 | map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length], |
535 | map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length], |
332 | @$entries]; |
536 | @$entries]; |
333 | |
537 | |
334 | my (@dirs, @nondirs); |
538 | my (@dirs, @nondirs); |
335 | |
539 | |
336 | my ($statcb, $schedcb); |
540 | my $statgrp = add $grp aio_group sub { |
337 | my $nreq = 0; |
541 | $grp->result (\@dirs, \@nondirs); |
|
|
542 | }; |
338 | |
543 | |
339 | $schedcb = sub { |
544 | limit $statgrp $maxreq; |
340 | if (@$entries) { |
545 | feed $statgrp sub { |
341 | if ($nreq < $maxreq) { |
546 | return unless @$entries; |
342 | my $ent = pop @$entries; |
547 | my $entry = pop @$entries; |
|
|
548 | |
|
|
549 | aioreq_pri $pri; |
|
|
550 | add $statgrp aio_stat "$path/$entry/.", sub { |
|
|
551 | if ($_[0] < 0) { |
|
|
552 | push @nondirs, $entry; |
|
|
553 | } else { |
|
|
554 | # need to check for real directory |
|
|
555 | aioreq_pri $pri; |
|
|
556 | add $statgrp aio_lstat "$path/$entry", sub { |
|
|
557 | if (-d _) { |
|
|
558 | push @dirs, $entry; |
|
|
559 | |
|
|
560 | unless (--$ndirs) { |
|
|
561 | push @nondirs, @$entries; |
|
|
562 | feed $statgrp; |
|
|
563 | } |
|
|
564 | } else { |
|
|
565 | push @nondirs, $entry; |
|
|
566 | } |
343 | $nreq++; |
567 | } |
344 | aio_stat "$path/$ent/.", sub { $statcb->($_[0], $ent) }; |
|
|
345 | } |
568 | } |
346 | } elsif (!$nreq) { |
|
|
347 | # finished |
|
|
348 | undef $statcb; |
|
|
349 | undef $schedcb; |
|
|
350 | $cb->(\@dirs, \@nondirs) if $cb; |
|
|
351 | undef $cb; |
|
|
352 | } |
569 | }; |
353 | }; |
570 | }; |
354 | $statcb = sub { |
|
|
355 | my ($status, $entry) = @_; |
|
|
356 | |
|
|
357 | if ($status < 0) { |
|
|
358 | $nreq--; |
|
|
359 | push @nondirs, $entry; |
|
|
360 | &$schedcb; |
|
|
361 | } else { |
|
|
362 | # need to check for real directory |
|
|
363 | aio_lstat "$path/$entry", sub { |
|
|
364 | $nreq--; |
|
|
365 | |
|
|
366 | if (-d _) { |
|
|
367 | push @dirs, $entry; |
|
|
368 | |
|
|
369 | if (!--$ndirs) { |
|
|
370 | push @nondirs, @$entries; |
|
|
371 | $entries = []; |
|
|
372 | } |
|
|
373 | } else { |
|
|
374 | push @nondirs, $entry; |
|
|
375 | } |
|
|
376 | |
|
|
377 | &$schedcb; |
|
|
378 | } |
|
|
379 | } |
|
|
380 | }; |
|
|
381 | |
|
|
382 | &$schedcb while @$entries && $nreq < $maxreq; |
|
|
383 | }; |
571 | }; |
384 | }; |
572 | }; |
385 | }; |
573 | }; |
|
|
574 | |
|
|
575 | $grp |
386 | } |
576 | } |
387 | |
577 | |
388 | =item aio_fsync $fh, $callback->($status) |
578 | =item aio_fsync $fh, $callback->($status) |
389 | |
579 | |
390 | Asynchronously call fsync on the given filehandle and call the callback |
580 | Asynchronously call fsync on the given filehandle and call the callback |
… | |
… | |
395 | Asynchronously call fdatasync on the given filehandle and call the |
585 | Asynchronously call fdatasync on the given filehandle and call the |
396 | callback with the fdatasync result code. |
586 | callback with the fdatasync result code. |
397 | |
587 | |
398 | If this call isn't available because your OS lacks it or it couldn't be |
588 | If this call isn't available because your OS lacks it or it couldn't be |
399 | detected, it will be emulated by calling C<fsync> instead. |
589 | detected, it will be emulated by calling C<fsync> instead. |
|
|
590 | |
|
|
591 | =item aio_group $callback->(...) |
|
|
592 | |
|
|
593 | This is a very special aio request: Instead of doing something, it is a |
|
|
594 | container for other aio requests, which is useful if you want to bundle |
|
|
595 | many requests into a single, composite, request with a definite callback |
|
|
596 | and the ability to cancel the whole request with its subrequests. |
|
|
597 | |
|
|
598 | Returns an object of class L<IO::AIO::GRP>. See its documentation below |
|
|
599 | for more info. |
|
|
600 | |
|
|
601 | Example: |
|
|
602 | |
|
|
603 | my $grp = aio_group sub { |
|
|
604 | print "all stats done\n"; |
|
|
605 | }; |
|
|
606 | |
|
|
607 | add $grp |
|
|
608 | (aio_stat ...), |
|
|
609 | (aio_stat ...), |
|
|
610 | ...; |
|
|
611 | |
|
|
612 | =item aio_nop $callback->() |
|
|
613 | |
|
|
614 | This is a special request - it does nothing in itself and is only used for |
|
|
615 | side effects, such as when you want to add a dummy request to a group so |
|
|
616 | that finishing the requests in the group depends on executing the given |
|
|
617 | code. |
|
|
618 | |
|
|
619 | While this request does nothing, it still goes through the execution |
|
|
620 | phase and still requires a worker thread. Thus, the callback will not |
|
|
621 | be executed immediately but only after other requests in the queue have |
|
|
622 | entered their execution phase. This can be used to measure request |
|
|
623 | latency. |
|
|
624 | |
|
|
625 | =item IO::AIO::aio_busy $fractional_seconds, $callback->() *NOT EXPORTED* |
|
|
626 | |
|
|
627 | Mainly used for debugging and benchmarking, this aio request puts one of |
|
|
628 | the request workers to sleep for the given time. |
|
|
629 | |
|
|
630 | While it is theoretically handy to have simple I/O scheduling requests |
|
|
631 | like sleep and file handle readable/writable, the overhead this creates is |
|
|
632 | immense (it blocks a thread for a long time) so do not use this function |
|
|
633 | except to put your application under artificial I/O pressure. |
|
|
634 | |
|
|
635 | =back |
|
|
636 | |
|
|
637 | =head2 IO::AIO::REQ CLASS |
|
|
638 | |
|
|
639 | All non-aggregate C<aio_*> functions return an object of this class when |
|
|
640 | called in non-void context. |
|
|
641 | |
|
|
642 | =over 4 |
|
|
643 | |
|
|
644 | =item cancel $req |
|
|
645 | |
|
|
646 | Cancels the request, if possible. Has the effect of skipping execution |
|
|
647 | when entering the B<execute> state and skipping calling the callback when |
|
|
648 | entering the the B<result> state, but will leave the request otherwise |
|
|
649 | untouched. That means that requests that currently execute will not be |
|
|
650 | stopped and resources held by the request will not be freed prematurely. |
|
|
651 | |
|
|
652 | =item cb $req $callback->(...) |
|
|
653 | |
|
|
654 | Replace (or simply set) the callback registered to the request. |
|
|
655 | |
|
|
656 | =back |
|
|
657 | |
|
|
658 | =head2 IO::AIO::GRP CLASS |
|
|
659 | |
|
|
660 | This class is a subclass of L<IO::AIO::REQ>, so all its methods apply to |
|
|
661 | objects of this class, too. |
|
|
662 | |
|
|
663 | A IO::AIO::GRP object is a special request that can contain multiple other |
|
|
664 | aio requests. |
|
|
665 | |
|
|
666 | You create one by calling the C<aio_group> constructing function with a |
|
|
667 | callback that will be called when all contained requests have entered the |
|
|
668 | C<done> state: |
|
|
669 | |
|
|
670 | my $grp = aio_group sub { |
|
|
671 | print "all requests are done\n"; |
|
|
672 | }; |
|
|
673 | |
|
|
674 | You add requests by calling the C<add> method with one or more |
|
|
675 | C<IO::AIO::REQ> objects: |
|
|
676 | |
|
|
677 | $grp->add (aio_unlink "..."); |
|
|
678 | |
|
|
679 | add $grp aio_stat "...", sub { |
|
|
680 | $_[0] or return $grp->result ("error"); |
|
|
681 | |
|
|
682 | # add another request dynamically, if first succeeded |
|
|
683 | add $grp aio_open "...", sub { |
|
|
684 | $grp->result ("ok"); |
|
|
685 | }; |
|
|
686 | }; |
|
|
687 | |
|
|
688 | This makes it very easy to create composite requests (see the source of |
|
|
689 | C<aio_move> for an application) that work and feel like simple requests. |
|
|
690 | |
|
|
691 | =over 4 |
|
|
692 | |
|
|
693 | =item * The IO::AIO::GRP objects will be cleaned up during calls to |
|
|
694 | C<IO::AIO::poll_cb>, just like any other request. |
|
|
695 | |
|
|
696 | =item * They can be canceled like any other request. Canceling will cancel not |
|
|
697 | only the request itself, but also all requests it contains. |
|
|
698 | |
|
|
699 | =item * They can also can also be added to other IO::AIO::GRP objects. |
|
|
700 | |
|
|
701 | =item * You must not add requests to a group from within the group callback (or |
|
|
702 | any later time). |
|
|
703 | |
|
|
704 | =back |
|
|
705 | |
|
|
706 | Their lifetime, simplified, looks like this: when they are empty, they |
|
|
707 | will finish very quickly. If they contain only requests that are in the |
|
|
708 | C<done> state, they will also finish. Otherwise they will continue to |
|
|
709 | exist. |
|
|
710 | |
|
|
711 | That means after creating a group you have some time to add requests. And |
|
|
712 | in the callbacks of those requests, you can add further requests to the |
|
|
713 | group. And only when all those requests have finished will the the group |
|
|
714 | itself finish. |
|
|
715 | |
|
|
716 | =over 4 |
|
|
717 | |
|
|
718 | =item add $grp ... |
|
|
719 | |
|
|
720 | =item $grp->add (...) |
|
|
721 | |
|
|
722 | Add one or more requests to the group. Any type of L<IO::AIO::REQ> can |
|
|
723 | be added, including other groups, as long as you do not create circular |
|
|
724 | dependencies. |
|
|
725 | |
|
|
726 | Returns all its arguments. |
|
|
727 | |
|
|
728 | =item $grp->cancel_subs |
|
|
729 | |
|
|
730 | Cancel all subrequests and clears any feeder, but not the group request |
|
|
731 | itself. Useful when you queued a lot of events but got a result early. |
|
|
732 | |
|
|
733 | =item $grp->result (...) |
|
|
734 | |
|
|
735 | Set the result value(s) that will be passed to the group callback when all |
|
|
736 | subrequests have finished and set thre groups errno to the current value |
|
|
737 | of errno (just like calling C<errno> without an error number). By default, |
|
|
738 | no argument will be passed and errno is zero. |
|
|
739 | |
|
|
740 | =item $grp->errno ([$errno]) |
|
|
741 | |
|
|
742 | Sets the group errno value to C<$errno>, or the current value of errno |
|
|
743 | when the argument is missing. |
|
|
744 | |
|
|
745 | Every aio request has an associated errno value that is restored when |
|
|
746 | the callback is invoked. This method lets you change this value from its |
|
|
747 | default (0). |
|
|
748 | |
|
|
749 | Calling C<result> will also set errno, so make sure you either set C<$!> |
|
|
750 | before the call to C<result>, or call c<errno> after it. |
|
|
751 | |
|
|
752 | =item feed $grp $callback->($grp) |
|
|
753 | |
|
|
754 | Sets a feeder/generator on this group: every group can have an attached |
|
|
755 | generator that generates requests if idle. The idea behind this is that, |
|
|
756 | although you could just queue as many requests as you want in a group, |
|
|
757 | this might starve other requests for a potentially long time. For |
|
|
758 | example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> |
|
|
759 | requests, delaying any later requests for a long time. |
|
|
760 | |
|
|
761 | To avoid this, and allow incremental generation of requests, you can |
|
|
762 | instead a group and set a feeder on it that generates those requests. The |
|
|
763 | feed callback will be called whenever there are few enough (see C<limit>, |
|
|
764 | below) requests active in the group itself and is expected to queue more |
|
|
765 | requests. |
|
|
766 | |
|
|
767 | The feed callback can queue as many requests as it likes (i.e. C<add> does |
|
|
768 | not impose any limits). |
|
|
769 | |
|
|
770 | If the feed does not queue more requests when called, it will be |
|
|
771 | automatically removed from the group. |
|
|
772 | |
|
|
773 | If the feed limit is C<0>, it will be set to C<2> automatically. |
|
|
774 | |
|
|
775 | Example: |
|
|
776 | |
|
|
777 | # stat all files in @files, but only ever use four aio requests concurrently: |
|
|
778 | |
|
|
779 | my $grp = aio_group sub { print "finished\n" }; |
|
|
780 | limit $grp 4; |
|
|
781 | feed $grp sub { |
|
|
782 | my $file = pop @files |
|
|
783 | or return; |
|
|
784 | |
|
|
785 | add $grp aio_stat $file, sub { ... }; |
|
|
786 | }; |
|
|
787 | |
|
|
788 | =item limit $grp $num |
|
|
789 | |
|
|
790 | Sets the feeder limit for the group: The feeder will be called whenever |
|
|
791 | the group contains less than this many requests. |
|
|
792 | |
|
|
793 | Setting the limit to C<0> will pause the feeding process. |
400 | |
794 | |
401 | =back |
795 | =back |
402 | |
796 | |
403 | =head2 SUPPORT FUNCTIONS |
797 | =head2 SUPPORT FUNCTIONS |
404 | |
798 | |
… | |
… | |
417 | |
811 | |
418 | Process all outstanding events on the result pipe. You have to call this |
812 | Process all outstanding events on the result pipe. You have to call this |
419 | regularly. Returns the number of events processed. Returns immediately |
813 | regularly. Returns the number of events processed. Returns immediately |
420 | when no events are outstanding. |
814 | when no events are outstanding. |
421 | |
815 | |
|
|
816 | If not all requests were processed for whatever reason, the filehandle |
|
|
817 | will still be ready when C<poll_cb> returns. |
|
|
818 | |
422 | Example: Install an Event watcher that automatically calls |
819 | Example: Install an Event watcher that automatically calls |
423 | IO::AIO::poll_cb with high priority: |
820 | IO::AIO::poll_cb with high priority: |
424 | |
821 | |
425 | Event->io (fd => IO::AIO::poll_fileno, |
822 | Event->io (fd => IO::AIO::poll_fileno, |
426 | poll => 'r', async => 1, |
823 | poll => 'r', async => 1, |
427 | cb => \&IO::AIO::poll_cb); |
824 | cb => \&IO::AIO::poll_cb); |
428 | |
825 | |
|
|
826 | =item IO::AIO::poll_some $max_requests |
|
|
827 | |
|
|
828 | Similar to C<poll_cb>, but only processes up to C<$max_requests> requests |
|
|
829 | at a time. |
|
|
830 | |
|
|
831 | Useful if you want to ensure some level of interactiveness when perl is |
|
|
832 | not fast enough to process all requests in time. |
|
|
833 | |
|
|
834 | Example: Install an Event watcher that automatically calls |
|
|
835 | IO::AIO::poll_some with low priority, to ensure that other parts of the |
|
|
836 | program get the CPU sometimes even under high AIO load. |
|
|
837 | |
|
|
838 | Event->io (fd => IO::AIO::poll_fileno, |
|
|
839 | poll => 'r', nice => 1, |
|
|
840 | cb => sub { IO::AIO::poll_some 256 }); |
|
|
841 | |
429 | =item IO::AIO::poll_wait |
842 | =item IO::AIO::poll_wait |
430 | |
843 | |
431 | Wait till the result filehandle becomes ready for reading (simply does a |
844 | Wait till the result filehandle becomes ready for reading (simply does a |
432 | C<select> on the filehandle. This is useful if you want to synchronously wait |
845 | C<select> on the filehandle. This is useful if you want to synchronously wait |
433 | for some requests to finish). |
846 | for some requests to finish). |
434 | |
847 | |
435 | See C<nreqs> for an example. |
848 | See C<nreqs> for an example. |
436 | |
849 | |
437 | =item IO::AIO::nreqs |
850 | =item IO::AIO::nreqs |
438 | |
851 | |
439 | Returns the number of requests currently outstanding (i.e. for which their |
852 | Returns the number of requests currently in the ready, execute or pending |
440 | callback has not been invoked yet). |
853 | states (i.e. for which their callback has not been invoked yet). |
441 | |
854 | |
442 | Example: wait till there are no outstanding requests anymore: |
855 | Example: wait till there are no outstanding requests anymore: |
443 | |
856 | |
444 | IO::AIO::poll_wait, IO::AIO::poll_cb |
857 | IO::AIO::poll_wait, IO::AIO::poll_cb |
445 | while IO::AIO::nreqs; |
858 | while IO::AIO::nreqs; |
446 | |
859 | |
|
|
860 | =item IO::AIO::nready |
|
|
861 | |
|
|
862 | Returns the number of requests currently in the ready state (not yet |
|
|
863 | executed). |
|
|
864 | |
|
|
865 | =item IO::AIO::npending |
|
|
866 | |
|
|
867 | Returns the number of requests currently in the pending state (executed, |
|
|
868 | but not yet processed by poll_cb). |
|
|
869 | |
447 | =item IO::AIO::flush |
870 | =item IO::AIO::flush |
448 | |
871 | |
449 | Wait till all outstanding AIO requests have been handled. |
872 | Wait till all outstanding AIO requests have been handled. |
450 | |
873 | |
451 | Strictly equivalent to: |
874 | Strictly equivalent to: |
… | |
… | |
462 | IO::AIO::poll_wait, IO::AIO::poll_cb |
885 | IO::AIO::poll_wait, IO::AIO::poll_cb |
463 | if IO::AIO::nreqs; |
886 | if IO::AIO::nreqs; |
464 | |
887 | |
465 | =item IO::AIO::min_parallel $nthreads |
888 | =item IO::AIO::min_parallel $nthreads |
466 | |
889 | |
467 | Set the minimum number of AIO threads to C<$nthreads>. The current default |
890 | Set the minimum number of AIO threads to C<$nthreads>. The current |
468 | is C<4>, which means four asynchronous operations can be done at one time |
891 | default is C<8>, which means eight asynchronous operations can execute |
469 | (the number of outstanding operations, however, is unlimited). |
892 | concurrently at any one time (the number of outstanding requests, |
|
|
893 | however, is unlimited). |
470 | |
894 | |
471 | IO::AIO starts threads only on demand, when an AIO request is queued and |
895 | IO::AIO starts threads only on demand, when an AIO request is queued and |
472 | no free thread exists. |
896 | no free thread exists. |
473 | |
897 | |
474 | It is recommended to keep the number of threads low, as some Linux |
898 | It is recommended to keep the number of threads relatively low, as some |
475 | kernel versions will scale negatively with the number of threads (higher |
899 | Linux kernel versions will scale negatively with the number of threads |
476 | parallelity => MUCH higher latency). With current Linux 2.6 versions, 4-32 |
900 | (higher parallelity => MUCH higher latency). With current Linux 2.6 |
477 | threads should be fine. |
901 | versions, 4-32 threads should be fine. |
478 | |
902 | |
479 | Under most circumstances you don't need to call this function, as the |
903 | Under most circumstances you don't need to call this function, as the |
480 | module selects a default that is suitable for low to moderate load. |
904 | module selects a default that is suitable for low to moderate load. |
481 | |
905 | |
482 | =item IO::AIO::max_parallel $nthreads |
906 | =item IO::AIO::max_parallel $nthreads |
… | |
… | |
491 | This module automatically runs C<max_parallel 0> at program end, to ensure |
915 | This module automatically runs C<max_parallel 0> at program end, to ensure |
492 | that all threads are killed and that there are no outstanding requests. |
916 | that all threads are killed and that there are no outstanding requests. |
493 | |
917 | |
494 | Under normal circumstances you don't need to call this function. |
918 | Under normal circumstances you don't need to call this function. |
495 | |
919 | |
496 | =item $oldnreqs = IO::AIO::max_outstanding $nreqs |
920 | =item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs |
|
|
921 | |
|
|
922 | This is a very bad function to use in interactive programs because it |
|
|
923 | blocks, and a bad way to reduce concurrency because it is inexact: Better |
|
|
924 | use an C<aio_group> together with a feed callback. |
497 | |
925 | |
498 | Sets the maximum number of outstanding requests to C<$nreqs>. If you |
926 | Sets the maximum number of outstanding requests to C<$nreqs>. If you |
499 | try to queue up more than this number of requests, the caller will block until |
927 | to queue up more than this number of requests, the next call to the |
500 | some requests have been handled. |
928 | C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>) |
|
|
929 | function will block until the limit is no longer exceeded. |
501 | |
930 | |
502 | The default is very large, so normally there is no practical limit. If you |
931 | The default value is very large, so there is no practical limit on the |
503 | queue up many requests in a loop it often improves speed if you set |
932 | number of outstanding requests. |
504 | this to a relatively low number, such as C<100>. |
|
|
505 | |
933 | |
506 | Under normal circumstances you don't need to call this function. |
934 | You can still queue as many requests as you want. Therefore, |
|
|
935 | C<max_oustsanding> is mainly useful in simple scripts (with low values) or |
|
|
936 | as a stop gap to shield against fatal memory overflow (with large values). |
507 | |
937 | |
508 | =back |
938 | =back |
509 | |
939 | |
510 | =cut |
940 | =cut |
511 | |
941 | |
… | |
… | |
523 | or return undef; |
953 | or return undef; |
524 | |
954 | |
525 | *$sym |
955 | *$sym |
526 | } |
956 | } |
527 | |
957 | |
528 | min_parallel 4; |
958 | min_parallel 8; |
529 | |
959 | |
530 | END { |
960 | END { |
531 | max_parallel 0; |
961 | max_parallel 0; |
532 | } |
962 | } |
533 | |
963 | |
534 | 1; |
964 | 1; |
535 | |
965 | |
536 | =head2 FORK BEHAVIOUR |
966 | =head2 FORK BEHAVIOUR |
537 | |
967 | |
|
|
968 | This module should do "the right thing" when the process using it forks: |
|
|
969 | |
538 | Before the fork, IO::AIO enters a quiescent state where no requests |
970 | Before the fork, IO::AIO enters a quiescent state where no requests |
539 | can be added in other threads and no results will be processed. After |
971 | can be added in other threads and no results will be processed. After |
540 | the fork the parent simply leaves the quiescent state and continues |
972 | the fork the parent simply leaves the quiescent state and continues |
541 | request/result processing, while the child clears the request/result |
973 | request/result processing, while the child frees the request/result queue |
542 | queue (so the requests started before the fork will only be handled in |
974 | (so that the requests started before the fork will only be handled in the |
543 | the parent). Threats will be started on demand until the limit ste in the |
975 | parent). Threads will be started on demand until the limit set in the |
544 | parent process has been reached again. |
976 | parent process has been reached again. |
545 | |
977 | |
|
|
978 | In short: the parent will, after a short pause, continue as if fork had |
|
|
979 | not been called, while the child will act as if IO::AIO has not been used |
|
|
980 | yet. |
|
|
981 | |
|
|
982 | =head2 MEMORY USAGE |
|
|
983 | |
|
|
984 | Per-request usage: |
|
|
985 | |
|
|
986 | Each aio request uses - depending on your architecture - around 100-200 |
|
|
987 | bytes of memory. In addition, stat requests need a stat buffer (possibly |
|
|
988 | a few hundred bytes), readdir requires a result buffer and so on. Perl |
|
|
989 | scalars and other data passed into aio requests will also be locked and |
|
|
990 | will consume memory till the request has entered the done state. |
|
|
991 | |
|
|
992 | This is now awfully much, so queuing lots of requests is not usually a |
|
|
993 | problem. |
|
|
994 | |
|
|
995 | Per-thread usage: |
|
|
996 | |
|
|
997 | In the execution phase, some aio requests require more memory for |
|
|
998 | temporary buffers, and each thread requires a stack and other data |
|
|
999 | structures (usually around 16k-128k, depending on the OS). |
|
|
1000 | |
|
|
1001 | =head1 KNOWN BUGS |
|
|
1002 | |
|
|
1003 | Known bugs will be fixed in the next release. |
|
|
1004 | |
546 | =head1 SEE ALSO |
1005 | =head1 SEE ALSO |
547 | |
1006 | |
548 | L<Coro>, L<Linux::AIO>. |
1007 | L<Coro::AIO>. |
549 | |
1008 | |
550 | =head1 AUTHOR |
1009 | =head1 AUTHOR |
551 | |
1010 | |
552 | Marc Lehmann <schmorp@schmorp.de> |
1011 | Marc Lehmann <schmorp@schmorp.de> |
553 | http://home.schmorp.de/ |
1012 | http://home.schmorp.de/ |