… | |
… | |
18 | }; |
18 | }; |
19 | |
19 | |
20 | # version 2+ has request and group objects |
20 | # version 2+ has request and group objects |
21 | use IO::AIO 2; |
21 | use IO::AIO 2; |
22 | |
22 | |
|
|
23 | aioreq_pri 4; # give next request a very high priority |
23 | my $req = aio_unlink "/tmp/file", sub { }; |
24 | my $req = aio_unlink "/tmp/file", sub { }; |
24 | $req->cancel; # cancel request if still in queue |
25 | $req->cancel; # cancel request if still in queue |
25 | |
26 | |
26 | my $grp = aio_group sub { print "all stats done\n" }; |
27 | my $grp = aio_group sub { print "all stats done\n" }; |
27 | add $grp aio_stat "..." for ...; |
28 | add $grp aio_stat "..." for ...; |
… | |
… | |
50 | =head1 DESCRIPTION |
51 | =head1 DESCRIPTION |
51 | |
52 | |
52 | This module implements asynchronous I/O using whatever means your |
53 | This module implements asynchronous I/O using whatever means your |
53 | operating system supports. |
54 | operating system supports. |
54 | |
55 | |
|
|
56 | Asynchronous means that operations that can normally block your program |
|
|
57 | (e.g. reading from disk) will be done asynchronously: the operation |
|
|
58 | will still block, but you can do something else in the meantime. This |
|
|
59 | is extremely useful for programs that need to stay interactive even |
|
|
60 | when doing heavy I/O (GUI programs, high performance network servers |
|
|
61 | etc.), but can also be used to easily do operations in parallel that are |
|
|
62 | normally done sequentially, e.g. stat'ing many files, which is much faster |
|
|
63 | on a RAID volume or over NFS when you do a number of stat operations |
|
|
64 | concurrently. |
|
|
65 | |
|
|
66 | While this works on all types of file descriptors (for example sockets), |
|
|
67 | using these functions on file descriptors that support nonblocking |
|
|
68 | operation (again, sockets, pipes etc.) is very inefficient. Use an event |
|
|
69 | loop for that (such as the L<Event|Event> module): IO::AIO will naturally |
|
|
70 | fit into such an event loop itself. |
|
|
71 | |
55 | Currently, a number of threads are started that execute your read/writes |
72 | In this version, a number of threads are started that execute your |
56 | and signal their completion. You don't need thread support in your libc or |
73 | requests and signal their completion. You don't need thread support |
57 | perl, and the threads created by this module will not be visible to the |
74 | in perl, and the threads created by this module will not be visible |
58 | pthreads library. In the future, this module might make use of the native |
75 | to perl. In the future, this module might make use of the native aio |
59 | aio functions available on many operating systems. However, they are often |
76 | functions available on many operating systems. However, they are often |
60 | not well-supported (Linux doesn't allow them on normal files currently, |
77 | not well-supported or restricted (GNU/Linux doesn't allow them on normal |
61 | for example), and they would only support aio_read and aio_write, so the |
78 | files currently, for example), and they would only support aio_read and |
62 | remaining functionality would have to be implemented using threads anyway. |
79 | aio_write, so the remaining functionality would have to be implemented |
|
|
80 | using threads anyway. |
63 | |
81 | |
64 | Although the module will work with in the presence of other threads, it is |
82 | Although the module will work with in the presence of other (Perl-) |
65 | currently not reentrant, so use appropriate locking yourself, always call |
83 | threads, it is currently not reentrant in any way, so use appropriate |
66 | C<poll_cb> from within the same thread, or never call C<poll_cb> (or other |
84 | locking yourself, always call C<poll_cb> from within the same thread, or |
67 | C<aio_> functions) recursively. |
85 | never call C<poll_cb> (or other C<aio_> functions) recursively. |
|
|
86 | |
|
|
87 | =head1 REQUEST ANATOMY AND LIFETIME |
|
|
88 | |
|
|
89 | Every C<aio_*> function creates a request. which is a C data structure not |
|
|
90 | directly visible to Perl. |
|
|
91 | |
|
|
92 | If called in non-void context, every request function returns a Perl |
|
|
93 | object representing the request. In void context, nothing is returned, |
|
|
94 | which saves a bit of memory. |
|
|
95 | |
|
|
96 | The perl object is a fairly standard ref-to-hash object. The hash contents |
|
|
97 | are not used by IO::AIO so you are free to store anything you like in it. |
|
|
98 | |
|
|
99 | During their existance, aio requests travel through the following states, |
|
|
100 | in order: |
|
|
101 | |
|
|
102 | =over 4 |
|
|
103 | |
|
|
104 | =item ready |
|
|
105 | |
|
|
106 | Immediately after a request is created it is put into the ready state, |
|
|
107 | waiting for a thread to execute it. |
|
|
108 | |
|
|
109 | =item execute |
|
|
110 | |
|
|
111 | A thread has accepted the request for processing and is currently |
|
|
112 | executing it (e.g. blocking in read). |
|
|
113 | |
|
|
114 | =item pending |
|
|
115 | |
|
|
116 | The request has been executed and is waiting for result processing. |
|
|
117 | |
|
|
118 | While request submission and execution is fully asynchronous, result |
|
|
119 | processing is not and relies on the perl interpreter calling C<poll_cb> |
|
|
120 | (or another function with the same effect). |
|
|
121 | |
|
|
122 | =item result |
|
|
123 | |
|
|
124 | The request results are processed synchronously by C<poll_cb>. |
|
|
125 | |
|
|
126 | The C<poll_cb> function will process all outstanding aio requests by |
|
|
127 | calling their callbacks, freeing memory associated with them and managing |
|
|
128 | any groups they are contained in. |
|
|
129 | |
|
|
130 | =item done |
|
|
131 | |
|
|
132 | Request has reached the end of its lifetime and holds no resources anymore |
|
|
133 | (except possibly for the Perl object, but its connection to the actual |
|
|
134 | aio request is severed and calling its methods will either do nothing or |
|
|
135 | result in a runtime error). |
68 | |
136 | |
69 | =cut |
137 | =cut |
70 | |
138 | |
71 | package IO::AIO; |
139 | package IO::AIO; |
72 | |
140 | |
… | |
… | |
76 | use base 'Exporter'; |
144 | use base 'Exporter'; |
77 | |
145 | |
78 | BEGIN { |
146 | BEGIN { |
79 | our $VERSION = '2.0'; |
147 | our $VERSION = '2.0'; |
80 | |
148 | |
81 | our @EXPORT = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat |
149 | our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat |
82 | aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink |
150 | aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink |
83 | aio_fsync aio_fdatasync aio_readahead aio_rename aio_link aio_move |
151 | aio_fsync aio_fdatasync aio_readahead aio_rename aio_link aio_move |
84 | aio_group); |
152 | aio_copy aio_group aio_nop aio_mknod); |
85 | our @EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel max_outstanding nreqs); |
153 | our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); |
|
|
154 | our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush |
|
|
155 | min_parallel max_parallel nreqs nready npending); |
86 | |
156 | |
87 | @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; |
157 | @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; |
88 | |
158 | |
89 | require XSLoader; |
159 | require XSLoader; |
90 | XSLoader::load ("IO::AIO", $VERSION); |
160 | XSLoader::load ("IO::AIO", $VERSION); |
… | |
… | |
121 | environment, d) use Glib::filename_from_unicode on unicode filenames or e) |
191 | environment, d) use Glib::filename_from_unicode on unicode filenames or e) |
122 | use something else. |
192 | use something else. |
123 | |
193 | |
124 | =over 4 |
194 | =over 4 |
125 | |
195 | |
|
|
196 | =item $prev_pri = aioreq_pri [$pri] |
|
|
197 | |
|
|
198 | Returns the priority value that would be used for the next request and, if |
|
|
199 | C<$pri> is given, sets the priority for the next aio request. |
|
|
200 | |
|
|
201 | The default priority is C<0>, the minimum and maximum priorities are C<-4> |
|
|
202 | and C<4>, respectively. Requests with higher priority will be serviced |
|
|
203 | first. |
|
|
204 | |
|
|
205 | The priority will be reset to C<0> after each call to one of the C<aio_*> |
|
|
206 | functions. |
|
|
207 | |
|
|
208 | Example: open a file with low priority, then read something from it with |
|
|
209 | higher priority so the read request is serviced before other low priority |
|
|
210 | open requests (potentially spamming the cache): |
|
|
211 | |
|
|
212 | aioreq_pri -3; |
|
|
213 | aio_open ..., sub { |
|
|
214 | return unless $_[0]; |
|
|
215 | |
|
|
216 | aioreq_pri -2; |
|
|
217 | aio_read $_[0], ..., sub { |
|
|
218 | ... |
|
|
219 | }; |
|
|
220 | }; |
|
|
221 | |
|
|
222 | =item aioreq_nice $pri_adjust |
|
|
223 | |
|
|
224 | Similar to C<aioreq_pri>, but subtracts the given value from the current |
|
|
225 | priority, so effects are cumulative. |
|
|
226 | |
126 | =item aio_open $pathname, $flags, $mode, $callback->($fh) |
227 | =item aio_open $pathname, $flags, $mode, $callback->($fh) |
127 | |
228 | |
128 | Asynchronously open or create a file and call the callback with a newly |
229 | Asynchronously open or create a file and call the callback with a newly |
129 | created filehandle for the file. |
230 | created filehandle for the file. |
130 | |
231 | |
… | |
… | |
179 | |
280 | |
180 | aio_read $fh, 7, 15, $buffer, 0, sub { |
281 | aio_read $fh, 7, 15, $buffer, 0, sub { |
181 | $_[0] > 0 or die "read error: $!"; |
282 | $_[0] > 0 or die "read error: $!"; |
182 | print "read $_[0] bytes: <$buffer>\n"; |
283 | print "read $_[0] bytes: <$buffer>\n"; |
183 | }; |
284 | }; |
184 | |
|
|
185 | =item aio_move $srcpath, $dstpath, $callback->($status) |
|
|
186 | |
|
|
187 | [EXPERIMENTAL due to internal aio_group use] |
|
|
188 | |
|
|
189 | Try to move the I<file> (directories not supported as either source or |
|
|
190 | destination) from C<$srcpath> to C<$dstpath> and call the callback with |
|
|
191 | the C<0> (error) or C<-1> ok. |
|
|
192 | |
|
|
193 | This is a composite request that tries to rename(2) the file first. If |
|
|
194 | rename files with C<EXDEV>, it creates the destination file with mode 0200 |
|
|
195 | and copies the contents of the source file into it using C<aio_sendfile>, |
|
|
196 | followed by restoring atime, mtime, access mode and uid/gid, in that |
|
|
197 | order, and unlinking the C<$srcpath>. |
|
|
198 | |
|
|
199 | If an error occurs, the partial destination file will be unlinked, if |
|
|
200 | possible, except when setting atime, mtime, access mode and uid/gid, where |
|
|
201 | errors are being ignored. |
|
|
202 | |
|
|
203 | =cut |
|
|
204 | |
|
|
205 | sub aio_move($$$) { |
|
|
206 | my ($src, $dst, $cb) = @_; |
|
|
207 | |
|
|
208 | my $grp = aio_group $cb; |
|
|
209 | |
|
|
210 | add $grp aio_rename $src, $dst, sub { |
|
|
211 | if ($_[0] && $! == EXDEV) { |
|
|
212 | add $grp aio_open $src, O_RDONLY, 0, sub { |
|
|
213 | if (my $src_fh = $_[0]) { |
|
|
214 | my @stat = stat $src_fh; |
|
|
215 | |
|
|
216 | add $grp aio_open $dst, O_WRONLY, 0200, sub { |
|
|
217 | if (my $dst_fh = $_[0]) { |
|
|
218 | add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { |
|
|
219 | close $src_fh; |
|
|
220 | |
|
|
221 | if ($_[0] == $stat[7]) { |
|
|
222 | utime $stat[8], $stat[9], $dst; |
|
|
223 | chmod $stat[2] & 07777, $dst_fh; |
|
|
224 | chown $stat[4], $stat[5], $dst_fh; |
|
|
225 | close $dst_fh; |
|
|
226 | |
|
|
227 | add $grp aio_unlink $src, sub { |
|
|
228 | $grp->result ($_[0]); |
|
|
229 | }; |
|
|
230 | } else { |
|
|
231 | my $errno = $!; |
|
|
232 | add $grp aio_unlink $dst, sub { |
|
|
233 | $! = $errno; |
|
|
234 | $grp->result (-1); |
|
|
235 | }; |
|
|
236 | } |
|
|
237 | }; |
|
|
238 | } else { |
|
|
239 | $grp->result (-1); |
|
|
240 | } |
|
|
241 | }, |
|
|
242 | |
|
|
243 | } else { |
|
|
244 | $grp->result (-1); |
|
|
245 | } |
|
|
246 | }; |
|
|
247 | } else { |
|
|
248 | $grp->result ($_[0]); |
|
|
249 | } |
|
|
250 | }; |
|
|
251 | |
|
|
252 | $grp |
|
|
253 | } |
|
|
254 | |
285 | |
255 | =item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
286 | =item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
256 | |
287 | |
257 | Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts |
288 | Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts |
258 | reading at byte offset C<$in_offset>, and starts writing at the current |
289 | reading at byte offset C<$in_offset>, and starts writing at the current |
… | |
… | |
314 | =item aio_unlink $pathname, $callback->($status) |
345 | =item aio_unlink $pathname, $callback->($status) |
315 | |
346 | |
316 | Asynchronously unlink (delete) a file and call the callback with the |
347 | Asynchronously unlink (delete) a file and call the callback with the |
317 | result code. |
348 | result code. |
318 | |
349 | |
|
|
350 | =item aio_mknod $path, $mode, $dev, $callback->($status) |
|
|
351 | |
|
|
352 | Asynchronously create a device node (or fifo). See mknod(2). |
|
|
353 | |
|
|
354 | The only portable (POSIX) way of calling this function is: |
|
|
355 | |
|
|
356 | aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
|
|
357 | |
319 | =item aio_link $srcpath, $dstpath, $callback->($status) |
358 | =item aio_link $srcpath, $dstpath, $callback->($status) |
320 | |
359 | |
321 | Asynchronously create a new link to the existing object at C<$srcpath> at |
360 | Asynchronously create a new link to the existing object at C<$srcpath> at |
322 | the path C<$dstpath> and call the callback with the result code. |
361 | the path C<$dstpath> and call the callback with the result code. |
323 | |
362 | |
… | |
… | |
343 | sorted, and will B<NOT> include the C<.> and C<..> entries. |
382 | sorted, and will B<NOT> include the C<.> and C<..> entries. |
344 | |
383 | |
345 | The callback a single argument which is either C<undef> or an array-ref |
384 | The callback a single argument which is either C<undef> or an array-ref |
346 | with the filenames. |
385 | with the filenames. |
347 | |
386 | |
|
|
387 | =item aio_copy $srcpath, $dstpath, $callback->($status) |
|
|
388 | |
|
|
389 | Try to copy the I<file> (directories not supported as either source or |
|
|
390 | destination) from C<$srcpath> to C<$dstpath> and call the callback with |
|
|
391 | the C<0> (error) or C<-1> ok. |
|
|
392 | |
|
|
393 | This is a composite request that it creates the destination file with |
|
|
394 | mode 0200 and copies the contents of the source file into it using |
|
|
395 | C<aio_sendfile>, followed by restoring atime, mtime, access mode and |
|
|
396 | uid/gid, in that order. |
|
|
397 | |
|
|
398 | If an error occurs, the partial destination file will be unlinked, if |
|
|
399 | possible, except when setting atime, mtime, access mode and uid/gid, where |
|
|
400 | errors are being ignored. |
|
|
401 | |
|
|
402 | =cut |
|
|
403 | |
|
|
404 | sub aio_copy($$;$) { |
|
|
405 | my ($src, $dst, $cb) = @_; |
|
|
406 | |
|
|
407 | my $pri = aioreq_pri; |
|
|
408 | my $grp = aio_group $cb; |
|
|
409 | |
|
|
410 | aioreq_pri $pri; |
|
|
411 | add $grp aio_open $src, O_RDONLY, 0, sub { |
|
|
412 | if (my $src_fh = $_[0]) { |
|
|
413 | my @stat = stat $src_fh; |
|
|
414 | |
|
|
415 | aioreq_pri $pri; |
|
|
416 | add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub { |
|
|
417 | if (my $dst_fh = $_[0]) { |
|
|
418 | aioreq_pri $pri; |
|
|
419 | add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { |
|
|
420 | if ($_[0] == $stat[7]) { |
|
|
421 | $grp->result (0); |
|
|
422 | close $src_fh; |
|
|
423 | |
|
|
424 | # those should not normally block. should. should. |
|
|
425 | utime $stat[8], $stat[9], $dst; |
|
|
426 | chmod $stat[2] & 07777, $dst_fh; |
|
|
427 | chown $stat[4], $stat[5], $dst_fh; |
|
|
428 | close $dst_fh; |
|
|
429 | } else { |
|
|
430 | $grp->result (-1); |
|
|
431 | close $src_fh; |
|
|
432 | close $dst_fh; |
|
|
433 | |
|
|
434 | aioreq $pri; |
|
|
435 | add $grp aio_unlink $dst; |
|
|
436 | } |
|
|
437 | }; |
|
|
438 | } else { |
|
|
439 | $grp->result (-1); |
|
|
440 | } |
|
|
441 | }, |
|
|
442 | |
|
|
443 | } else { |
|
|
444 | $grp->result (-1); |
|
|
445 | } |
|
|
446 | }; |
|
|
447 | |
|
|
448 | $grp |
|
|
449 | } |
|
|
450 | |
|
|
451 | =item aio_move $srcpath, $dstpath, $callback->($status) |
|
|
452 | |
|
|
453 | Try to move the I<file> (directories not supported as either source or |
|
|
454 | destination) from C<$srcpath> to C<$dstpath> and call the callback with |
|
|
455 | the C<0> (error) or C<-1> ok. |
|
|
456 | |
|
|
457 | This is a composite request that tries to rename(2) the file first. If |
|
|
458 | rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if |
|
|
459 | that is successful, unlinking the C<$srcpath>. |
|
|
460 | |
|
|
461 | =cut |
|
|
462 | |
|
|
463 | sub aio_move($$;$) { |
|
|
464 | my ($src, $dst, $cb) = @_; |
|
|
465 | |
|
|
466 | my $pri = aioreq_pri; |
|
|
467 | my $grp = aio_group $cb; |
|
|
468 | |
|
|
469 | aioreq_pri $pri; |
|
|
470 | add $grp aio_rename $src, $dst, sub { |
|
|
471 | if ($_[0] && $! == EXDEV) { |
|
|
472 | aioreq_pri $pri; |
|
|
473 | add $grp aio_copy $src, $dst, sub { |
|
|
474 | $grp->result ($_[0]); |
|
|
475 | |
|
|
476 | if (!$_[0]) { |
|
|
477 | aioreq_pri $pri; |
|
|
478 | add $grp aio_unlink $src; |
|
|
479 | } |
|
|
480 | }; |
|
|
481 | } else { |
|
|
482 | $grp->result ($_[0]); |
|
|
483 | } |
|
|
484 | }; |
|
|
485 | |
|
|
486 | $grp |
|
|
487 | } |
|
|
488 | |
348 | =item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
489 | =item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
349 | |
490 | |
350 | [EXPERIMENTAL due to internal aio_group use] |
|
|
351 | |
|
|
352 | Scans a directory (similar to C<aio_readdir>) but additionally tries to |
491 | Scans a directory (similar to C<aio_readdir>) but additionally tries to |
353 | separate the entries of directory C<$path> into two sets of names, ones |
492 | efficiently separate the entries of directory C<$path> into two sets of |
354 | you can recurse into (directories or links to them), and ones you cannot |
493 | names, directories you can recurse into (directories), and ones you cannot |
355 | recurse into (everything else). |
494 | recurse into (everything else, including symlinks to directories). |
356 | |
495 | |
357 | C<aio_scandir> is a composite request that consists of many sub |
496 | C<aio_scandir> is a composite request that creates of many sub requests_ |
358 | requests. C<$maxreq> specifies the maximum number of outstanding aio |
497 | C<$maxreq> specifies the maximum number of outstanding aio requests that |
359 | requests that this function generates. If it is C<< <= 0 >>, then a |
498 | this function generates. If it is C<< <= 0 >>, then a suitable default |
360 | suitable default will be chosen (currently 8). |
499 | will be chosen (currently 4). |
361 | |
500 | |
362 | On error, the callback is called without arguments, otherwise it receives |
501 | On error, the callback is called without arguments, otherwise it receives |
363 | two array-refs with path-relative entry names. |
502 | two array-refs with path-relative entry names. |
364 | |
503 | |
365 | Example: |
504 | Example: |
… | |
… | |
402 | =cut |
541 | =cut |
403 | |
542 | |
404 | sub aio_scandir($$$) { |
543 | sub aio_scandir($$$) { |
405 | my ($path, $maxreq, $cb) = @_; |
544 | my ($path, $maxreq, $cb) = @_; |
406 | |
545 | |
|
|
546 | my $pri = aioreq_pri; |
|
|
547 | |
407 | my $grp = aio_group $cb; |
548 | my $grp = aio_group $cb; |
408 | |
549 | |
409 | $maxreq = 8 if $maxreq <= 0; |
550 | $maxreq = 4 if $maxreq <= 0; |
410 | |
551 | |
411 | # stat once |
552 | # stat once |
|
|
553 | aioreq_pri $pri; |
412 | add $grp aio_stat $path, sub { |
554 | add $grp aio_stat $path, sub { |
413 | return $grp->result () if $_[0]; |
555 | return $grp->result () if $_[0]; |
414 | my $now = time; |
556 | my $now = time; |
415 | my $hash1 = join ":", (stat _)[0,1,3,7,9]; |
557 | my $hash1 = join ":", (stat _)[0,1,3,7,9]; |
416 | |
558 | |
417 | # read the directory entries |
559 | # read the directory entries |
|
|
560 | aioreq_pri $pri; |
418 | add $grp aio_readdir $path, sub { |
561 | add $grp aio_readdir $path, sub { |
419 | my $entries = shift |
562 | my $entries = shift |
420 | or return $grp->result (); |
563 | or return $grp->result (); |
421 | |
564 | |
422 | # stat the dir another time |
565 | # stat the dir another time |
|
|
566 | aioreq_pri $pri; |
423 | add $grp aio_stat $path, sub { |
567 | add $grp aio_stat $path, sub { |
424 | my $hash2 = join ":", (stat _)[0,1,3,7,9]; |
568 | my $hash2 = join ":", (stat _)[0,1,3,7,9]; |
425 | |
569 | |
426 | my $ndirs; |
570 | my $ndirs; |
427 | |
571 | |
… | |
… | |
442 | map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length], |
586 | map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length], |
443 | @$entries]; |
587 | @$entries]; |
444 | |
588 | |
445 | my (@dirs, @nondirs); |
589 | my (@dirs, @nondirs); |
446 | |
590 | |
447 | my ($statcb, $schedcb); |
|
|
448 | my $nreq = 0; |
|
|
449 | |
|
|
450 | my $statgrp = add $grp aio_group; |
591 | my $statgrp = add $grp aio_group sub { |
|
|
592 | $grp->result (\@dirs, \@nondirs); |
|
|
593 | }; |
451 | |
594 | |
452 | $schedcb = sub { |
595 | limit $statgrp $maxreq; |
453 | if (@$entries) { |
596 | feed $statgrp sub { |
454 | if ($nreq < $maxreq) { |
597 | return unless @$entries; |
455 | my $ent = pop @$entries; |
598 | my $entry = pop @$entries; |
|
|
599 | |
|
|
600 | aioreq_pri $pri; |
|
|
601 | add $statgrp aio_stat "$path/$entry/.", sub { |
|
|
602 | if ($_[0] < 0) { |
|
|
603 | push @nondirs, $entry; |
|
|
604 | } else { |
|
|
605 | # need to check for real directory |
|
|
606 | aioreq_pri $pri; |
|
|
607 | add $statgrp aio_lstat "$path/$entry", sub { |
|
|
608 | if (-d _) { |
|
|
609 | push @dirs, $entry; |
|
|
610 | |
|
|
611 | unless (--$ndirs) { |
|
|
612 | push @nondirs, @$entries; |
|
|
613 | feed $statgrp; |
|
|
614 | } |
|
|
615 | } else { |
|
|
616 | push @nondirs, $entry; |
|
|
617 | } |
456 | $nreq++; |
618 | } |
457 | add $statgrp aio_stat "$path/$ent/.", sub { $statcb->($_[0], $ent) }; |
|
|
458 | } |
619 | } |
459 | } elsif (!$nreq) { |
|
|
460 | # finished |
|
|
461 | $statgrp->cancel; |
|
|
462 | undef $statcb; |
|
|
463 | undef $schedcb; |
|
|
464 | $grp->result (\@dirs, \@nondirs); |
|
|
465 | } |
620 | }; |
466 | }; |
621 | }; |
467 | $statcb = sub { |
|
|
468 | my ($status, $entry) = @_; |
|
|
469 | |
|
|
470 | if ($status < 0) { |
|
|
471 | $nreq--; |
|
|
472 | push @nondirs, $entry; |
|
|
473 | &$schedcb; |
|
|
474 | } else { |
|
|
475 | # need to check for real directory |
|
|
476 | add $grp aio_lstat "$path/$entry", sub { |
|
|
477 | $nreq--; |
|
|
478 | |
|
|
479 | if (-d _) { |
|
|
480 | push @dirs, $entry; |
|
|
481 | |
|
|
482 | if (!--$ndirs) { |
|
|
483 | push @nondirs, @$entries; |
|
|
484 | $entries = []; |
|
|
485 | } |
|
|
486 | } else { |
|
|
487 | push @nondirs, $entry; |
|
|
488 | } |
|
|
489 | |
|
|
490 | &$schedcb; |
|
|
491 | } |
|
|
492 | } |
|
|
493 | }; |
|
|
494 | |
|
|
495 | &$schedcb while @$entries && $nreq < $maxreq; |
|
|
496 | }; |
622 | }; |
497 | }; |
623 | }; |
498 | }; |
624 | }; |
499 | |
625 | |
500 | $grp |
626 | $grp |
… | |
… | |
513 | If this call isn't available because your OS lacks it or it couldn't be |
639 | If this call isn't available because your OS lacks it or it couldn't be |
514 | detected, it will be emulated by calling C<fsync> instead. |
640 | detected, it will be emulated by calling C<fsync> instead. |
515 | |
641 | |
516 | =item aio_group $callback->(...) |
642 | =item aio_group $callback->(...) |
517 | |
643 | |
518 | [EXPERIMENTAL] |
|
|
519 | |
|
|
520 | This is a very special aio request: Instead of doing something, it is a |
644 | This is a very special aio request: Instead of doing something, it is a |
521 | container for other aio requests, which is useful if you want to bundle |
645 | container for other aio requests, which is useful if you want to bundle |
522 | many requests into a single, composite, request. |
646 | many requests into a single, composite, request with a definite callback |
|
|
647 | and the ability to cancel the whole request with its subrequests. |
523 | |
648 | |
524 | Returns an object of class L<IO::AIO::GRP>. See its documentation below |
649 | Returns an object of class L<IO::AIO::GRP>. See its documentation below |
525 | for more info. |
650 | for more info. |
526 | |
651 | |
527 | Example: |
652 | Example: |
… | |
… | |
533 | add $grp |
658 | add $grp |
534 | (aio_stat ...), |
659 | (aio_stat ...), |
535 | (aio_stat ...), |
660 | (aio_stat ...), |
536 | ...; |
661 | ...; |
537 | |
662 | |
|
|
663 | =item aio_nop $callback->() |
|
|
664 | |
|
|
665 | This is a special request - it does nothing in itself and is only used for |
|
|
666 | side effects, such as when you want to add a dummy request to a group so |
|
|
667 | that finishing the requests in the group depends on executing the given |
|
|
668 | code. |
|
|
669 | |
|
|
670 | While this request does nothing, it still goes through the execution |
|
|
671 | phase and still requires a worker thread. Thus, the callback will not |
|
|
672 | be executed immediately but only after other requests in the queue have |
|
|
673 | entered their execution phase. This can be used to measure request |
|
|
674 | latency. |
|
|
675 | |
538 | =item IO::AIO::aio_sleep $fractional_seconds, $callback->() *NOT EXPORTED* |
676 | =item IO::AIO::aio_busy $fractional_seconds, $callback->() *NOT EXPORTED* |
539 | |
677 | |
540 | Mainly used for debugging and benchmarking, this aio request puts one of |
678 | Mainly used for debugging and benchmarking, this aio request puts one of |
541 | the request workers to sleep for the given time. |
679 | the request workers to sleep for the given time. |
542 | |
680 | |
543 | While it is theoretically handy to have simple I/O scheduling requests |
681 | While it is theoretically handy to have simple I/O scheduling requests |
544 | like sleep and file handle readable/writable, the overhead this creates |
682 | like sleep and file handle readable/writable, the overhead this creates is |
545 | is immense, so do not use this function except to put your application |
683 | immense (it blocks a thread for a long time) so do not use this function |
546 | under artificial I/O pressure. |
684 | except to put your application under artificial I/O pressure. |
547 | |
685 | |
548 | =back |
686 | =back |
549 | |
687 | |
550 | =head2 IO::AIO::REQ CLASS |
688 | =head2 IO::AIO::REQ CLASS |
551 | |
689 | |
552 | All non-aggregate C<aio_*> functions return an object of this class when |
690 | All non-aggregate C<aio_*> functions return an object of this class when |
553 | called in non-void context. |
691 | called in non-void context. |
554 | |
692 | |
555 | A request always moves through the following five states in its lifetime, |
|
|
556 | in order: B<ready> (request has been created, but has not been executed |
|
|
557 | yet), B<execute> (request is currently being executed), B<pending> |
|
|
558 | (request has been executed but callback has not been called yet), |
|
|
559 | B<result> (results are being processed synchronously, includes calling the |
|
|
560 | callback) and B<done> (request has reached the end of its lifetime and |
|
|
561 | holds no resources anymore). |
|
|
562 | |
|
|
563 | =over 4 |
693 | =over 4 |
564 | |
694 | |
565 | =item $req->cancel |
695 | =item cancel $req |
566 | |
696 | |
567 | Cancels the request, if possible. Has the effect of skipping execution |
697 | Cancels the request, if possible. Has the effect of skipping execution |
568 | when entering the B<execute> state and skipping calling the callback when |
698 | when entering the B<execute> state and skipping calling the callback when |
569 | entering the the B<result> state, but will leave the request otherwise |
699 | entering the the B<result> state, but will leave the request otherwise |
570 | untouched. That means that requests that currently execute will not be |
700 | untouched. That means that requests that currently execute will not be |
571 | stopped and resources held by the request will not be freed prematurely. |
701 | stopped and resources held by the request will not be freed prematurely. |
572 | |
702 | |
|
|
703 | =item cb $req $callback->(...) |
|
|
704 | |
|
|
705 | Replace (or simply set) the callback registered to the request. |
|
|
706 | |
573 | =back |
707 | =back |
574 | |
708 | |
575 | =head2 IO::AIO::GRP CLASS |
709 | =head2 IO::AIO::GRP CLASS |
576 | |
710 | |
577 | This class is a subclass of L<IO::AIO::REQ>, so all its methods apply to |
711 | This class is a subclass of L<IO::AIO::REQ>, so all its methods apply to |
… | |
… | |
603 | }; |
737 | }; |
604 | |
738 | |
605 | This makes it very easy to create composite requests (see the source of |
739 | This makes it very easy to create composite requests (see the source of |
606 | C<aio_move> for an application) that work and feel like simple requests. |
740 | C<aio_move> for an application) that work and feel like simple requests. |
607 | |
741 | |
|
|
742 | =over 4 |
|
|
743 | |
608 | The IO::AIO::GRP objects will be cleaned up during calls to |
744 | =item * The IO::AIO::GRP objects will be cleaned up during calls to |
609 | C<IO::AIO::poll_cb>, just like any other request. |
745 | C<IO::AIO::poll_cb>, just like any other request. |
610 | |
746 | |
611 | They can be canceled like any other request. Canceling will cancel not |
747 | =item * They can be canceled like any other request. Canceling will cancel not |
612 | only the request itself, but also all requests it contains. |
748 | only the request itself, but also all requests it contains. |
613 | |
749 | |
614 | They can also can also be added to other IO::AIO::GRP objects. |
750 | =item * They can also can also be added to other IO::AIO::GRP objects. |
615 | |
751 | |
616 | You must not add requests to a group from within the group callback (or |
752 | =item * You must not add requests to a group from within the group callback (or |
617 | any later time). |
753 | any later time). |
|
|
754 | |
|
|
755 | =back |
618 | |
756 | |
619 | Their lifetime, simplified, looks like this: when they are empty, they |
757 | Their lifetime, simplified, looks like this: when they are empty, they |
620 | will finish very quickly. If they contain only requests that are in the |
758 | will finish very quickly. If they contain only requests that are in the |
621 | C<done> state, they will also finish. Otherwise they will continue to |
759 | C<done> state, they will also finish. Otherwise they will continue to |
622 | exist. |
760 | exist. |
… | |
… | |
626 | group. And only when all those requests have finished will the the group |
764 | group. And only when all those requests have finished will the the group |
627 | itself finish. |
765 | itself finish. |
628 | |
766 | |
629 | =over 4 |
767 | =over 4 |
630 | |
768 | |
|
|
769 | =item add $grp ... |
|
|
770 | |
631 | =item $grp->add (...) |
771 | =item $grp->add (...) |
632 | |
|
|
633 | =item add $grp ... |
|
|
634 | |
772 | |
635 | Add one or more requests to the group. Any type of L<IO::AIO::REQ> can |
773 | Add one or more requests to the group. Any type of L<IO::AIO::REQ> can |
636 | be added, including other groups, as long as you do not create circular |
774 | be added, including other groups, as long as you do not create circular |
637 | dependencies. |
775 | dependencies. |
638 | |
776 | |
639 | Returns all its arguments. |
777 | Returns all its arguments. |
640 | |
778 | |
|
|
779 | =item $grp->cancel_subs |
|
|
780 | |
|
|
781 | Cancel all subrequests and clears any feeder, but not the group request |
|
|
782 | itself. Useful when you queued a lot of events but got a result early. |
|
|
783 | |
641 | =item $grp->result (...) |
784 | =item $grp->result (...) |
642 | |
785 | |
643 | Set the result value(s) that will be passed to the group callback when all |
786 | Set the result value(s) that will be passed to the group callback when all |
644 | subrequests have finished. By default, no argument will be passed. |
787 | subrequests have finished and set thre groups errno to the current value |
|
|
788 | of errno (just like calling C<errno> without an error number). By default, |
|
|
789 | no argument will be passed and errno is zero. |
645 | |
790 | |
646 | =item $grp->set_feeder ($callback->($grp)) |
791 | =item $grp->errno ([$errno]) |
647 | |
792 | |
648 | [VERY EXPERIMENTAL] |
793 | Sets the group errno value to C<$errno>, or the current value of errno |
|
|
794 | when the argument is missing. |
|
|
795 | |
|
|
796 | Every aio request has an associated errno value that is restored when |
|
|
797 | the callback is invoked. This method lets you change this value from its |
|
|
798 | default (0). |
|
|
799 | |
|
|
800 | Calling C<result> will also set errno, so make sure you either set C<$!> |
|
|
801 | before the call to C<result>, or call c<errno> after it. |
|
|
802 | |
|
|
803 | =item feed $grp $callback->($grp) |
649 | |
804 | |
650 | Sets a feeder/generator on this group: every group can have an attached |
805 | Sets a feeder/generator on this group: every group can have an attached |
651 | generator that generates requests if idle. The idea behind this is that, |
806 | generator that generates requests if idle. The idea behind this is that, |
652 | although you could just queue as many requests as you want in a group, |
807 | although you could just queue as many requests as you want in a group, |
653 | this might starve other requests for a potentially long time. For |
808 | this might starve other requests for a potentially long time. For |
654 | example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> |
809 | example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> |
655 | requests, delaying any later requests for a long time. |
810 | requests, delaying any later requests for a long time. |
656 | |
811 | |
657 | To avoid this, and allow incremental generation of requests, you can |
812 | To avoid this, and allow incremental generation of requests, you can |
658 | instead a group and set a feeder on it that generates those requests. The |
813 | instead a group and set a feeder on it that generates those requests. The |
659 | feeder will be called whenever there are few enough (see C<feeder_limit>, |
814 | feed callback will be called whenever there are few enough (see C<limit>, |
660 | below) requests active in the group itself and is expected to queue more |
815 | below) requests active in the group itself and is expected to queue more |
661 | requests. |
816 | requests. |
662 | |
817 | |
663 | The feeder can queue as many requests as it likes (i.e. C<add> does not |
818 | The feed callback can queue as many requests as it likes (i.e. C<add> does |
664 | impose any limits). |
819 | not impose any limits). |
665 | |
820 | |
666 | If the feeder does not queue more requests when called, it will be |
821 | If the feed does not queue more requests when called, it will be |
667 | automatically removed from the group. |
822 | automatically removed from the group. |
668 | |
823 | |
669 | If the feeder limit is C<0>, it will be set to C<2> automatically. |
824 | If the feed limit is C<0>, it will be set to C<2> automatically. |
670 | |
825 | |
671 | Example: |
826 | Example: |
672 | |
827 | |
673 | # stat all files in @files, but only ever use four aio requests concurrently: |
828 | # stat all files in @files, but only ever use four aio requests concurrently: |
674 | |
829 | |
675 | my $grp = aio_group sub { print "finished\n" }; |
830 | my $grp = aio_group sub { print "finished\n" }; |
676 | $grp->feeder_limit (4); |
831 | limit $grp 4; |
677 | $grp->set_feeder (sub { |
832 | feed $grp sub { |
678 | my $file = pop @files |
833 | my $file = pop @files |
679 | or return; |
834 | or return; |
680 | |
835 | |
681 | add $grp aio_stat $file, sub { ... }; |
836 | add $grp aio_stat $file, sub { ... }; |
682 | }); |
837 | }; |
683 | |
838 | |
684 | =item $grp->feeder_limit ($num) |
839 | =item limit $grp $num |
685 | |
840 | |
686 | Sets the feeder limit for the group: The feeder will be called whenever |
841 | Sets the feeder limit for the group: The feeder will be called whenever |
687 | the group contains less than this many requests. |
842 | the group contains less than this many requests. |
688 | |
843 | |
689 | Setting the limit to C<0> will pause the feeding process. |
844 | Setting the limit to C<0> will pause the feeding process. |
… | |
… | |
707 | |
862 | |
708 | Process all outstanding events on the result pipe. You have to call this |
863 | Process all outstanding events on the result pipe. You have to call this |
709 | regularly. Returns the number of events processed. Returns immediately |
864 | regularly. Returns the number of events processed. Returns immediately |
710 | when no events are outstanding. |
865 | when no events are outstanding. |
711 | |
866 | |
|
|
867 | If not all requests were processed for whatever reason, the filehandle |
|
|
868 | will still be ready when C<poll_cb> returns. |
|
|
869 | |
712 | Example: Install an Event watcher that automatically calls |
870 | Example: Install an Event watcher that automatically calls |
713 | IO::AIO::poll_cb with high priority: |
871 | IO::AIO::poll_cb with high priority: |
714 | |
872 | |
715 | Event->io (fd => IO::AIO::poll_fileno, |
873 | Event->io (fd => IO::AIO::poll_fileno, |
716 | poll => 'r', async => 1, |
874 | poll => 'r', async => 1, |
717 | cb => \&IO::AIO::poll_cb); |
875 | cb => \&IO::AIO::poll_cb); |
718 | |
876 | |
|
|
877 | =item IO::AIO::poll_some $max_requests |
|
|
878 | |
|
|
879 | Similar to C<poll_cb>, but only processes up to C<$max_requests> requests |
|
|
880 | at a time. |
|
|
881 | |
|
|
882 | Useful if you want to ensure some level of interactiveness when perl is |
|
|
883 | not fast enough to process all requests in time. |
|
|
884 | |
|
|
885 | Example: Install an Event watcher that automatically calls |
|
|
886 | IO::AIO::poll_some with low priority, to ensure that other parts of the |
|
|
887 | program get the CPU sometimes even under high AIO load. |
|
|
888 | |
|
|
889 | Event->io (fd => IO::AIO::poll_fileno, |
|
|
890 | poll => 'r', nice => 1, |
|
|
891 | cb => sub { IO::AIO::poll_some 256 }); |
|
|
892 | |
719 | =item IO::AIO::poll_wait |
893 | =item IO::AIO::poll_wait |
720 | |
894 | |
721 | Wait till the result filehandle becomes ready for reading (simply does a |
895 | Wait till the result filehandle becomes ready for reading (simply does a |
722 | C<select> on the filehandle. This is useful if you want to synchronously wait |
896 | C<select> on the filehandle. This is useful if you want to synchronously wait |
723 | for some requests to finish). |
897 | for some requests to finish). |
724 | |
898 | |
725 | See C<nreqs> for an example. |
899 | See C<nreqs> for an example. |
726 | |
900 | |
727 | =item IO::AIO::nreqs |
901 | =item IO::AIO::nreqs |
728 | |
902 | |
729 | Returns the number of requests currently outstanding (i.e. for which their |
903 | Returns the number of requests currently in the ready, execute or pending |
730 | callback has not been invoked yet). |
904 | states (i.e. for which their callback has not been invoked yet). |
731 | |
905 | |
732 | Example: wait till there are no outstanding requests anymore: |
906 | Example: wait till there are no outstanding requests anymore: |
733 | |
907 | |
734 | IO::AIO::poll_wait, IO::AIO::poll_cb |
908 | IO::AIO::poll_wait, IO::AIO::poll_cb |
735 | while IO::AIO::nreqs; |
909 | while IO::AIO::nreqs; |
736 | |
910 | |
|
|
911 | =item IO::AIO::nready |
|
|
912 | |
|
|
913 | Returns the number of requests currently in the ready state (not yet |
|
|
914 | executed). |
|
|
915 | |
|
|
916 | =item IO::AIO::npending |
|
|
917 | |
|
|
918 | Returns the number of requests currently in the pending state (executed, |
|
|
919 | but not yet processed by poll_cb). |
|
|
920 | |
737 | =item IO::AIO::flush |
921 | =item IO::AIO::flush |
738 | |
922 | |
739 | Wait till all outstanding AIO requests have been handled. |
923 | Wait till all outstanding AIO requests have been handled. |
740 | |
924 | |
741 | Strictly equivalent to: |
925 | Strictly equivalent to: |
… | |
… | |
752 | IO::AIO::poll_wait, IO::AIO::poll_cb |
936 | IO::AIO::poll_wait, IO::AIO::poll_cb |
753 | if IO::AIO::nreqs; |
937 | if IO::AIO::nreqs; |
754 | |
938 | |
755 | =item IO::AIO::min_parallel $nthreads |
939 | =item IO::AIO::min_parallel $nthreads |
756 | |
940 | |
757 | Set the minimum number of AIO threads to C<$nthreads>. The current default |
941 | Set the minimum number of AIO threads to C<$nthreads>. The current |
758 | is C<4>, which means four asynchronous operations can be done at one time |
942 | default is C<8>, which means eight asynchronous operations can execute |
759 | (the number of outstanding operations, however, is unlimited). |
943 | concurrently at any one time (the number of outstanding requests, |
|
|
944 | however, is unlimited). |
760 | |
945 | |
761 | IO::AIO starts threads only on demand, when an AIO request is queued and |
946 | IO::AIO starts threads only on demand, when an AIO request is queued and |
762 | no free thread exists. |
947 | no free thread exists. |
763 | |
948 | |
764 | It is recommended to keep the number of threads low, as some Linux |
949 | It is recommended to keep the number of threads relatively low, as some |
765 | kernel versions will scale negatively with the number of threads (higher |
950 | Linux kernel versions will scale negatively with the number of threads |
766 | parallelity => MUCH higher latency). With current Linux 2.6 versions, 4-32 |
951 | (higher parallelity => MUCH higher latency). With current Linux 2.6 |
767 | threads should be fine. |
952 | versions, 4-32 threads should be fine. |
768 | |
953 | |
769 | Under most circumstances you don't need to call this function, as the |
954 | Under most circumstances you don't need to call this function, as the |
770 | module selects a default that is suitable for low to moderate load. |
955 | module selects a default that is suitable for low to moderate load. |
771 | |
956 | |
772 | =item IO::AIO::max_parallel $nthreads |
957 | =item IO::AIO::max_parallel $nthreads |
… | |
… | |
781 | This module automatically runs C<max_parallel 0> at program end, to ensure |
966 | This module automatically runs C<max_parallel 0> at program end, to ensure |
782 | that all threads are killed and that there are no outstanding requests. |
967 | that all threads are killed and that there are no outstanding requests. |
783 | |
968 | |
784 | Under normal circumstances you don't need to call this function. |
969 | Under normal circumstances you don't need to call this function. |
785 | |
970 | |
786 | =item $oldnreqs = IO::AIO::max_outstanding $nreqs |
971 | =item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs |
|
|
972 | |
|
|
973 | This is a very bad function to use in interactive programs because it |
|
|
974 | blocks, and a bad way to reduce concurrency because it is inexact: Better |
|
|
975 | use an C<aio_group> together with a feed callback. |
787 | |
976 | |
788 | Sets the maximum number of outstanding requests to C<$nreqs>. If you |
977 | Sets the maximum number of outstanding requests to C<$nreqs>. If you |
789 | try to queue up more than this number of requests, the caller will block until |
978 | to queue up more than this number of requests, the next call to the |
790 | some requests have been handled. |
979 | C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>) |
|
|
980 | function will block until the limit is no longer exceeded. |
791 | |
981 | |
792 | The default is very large, so normally there is no practical limit. If you |
982 | The default value is very large, so there is no practical limit on the |
793 | queue up many requests in a loop it often improves speed if you set |
983 | number of outstanding requests. |
794 | this to a relatively low number, such as C<100>. |
|
|
795 | |
984 | |
796 | Under normal circumstances you don't need to call this function. |
985 | You can still queue as many requests as you want. Therefore, |
|
|
986 | C<max_oustsanding> is mainly useful in simple scripts (with low values) or |
|
|
987 | as a stop gap to shield against fatal memory overflow (with large values). |
797 | |
988 | |
798 | =back |
989 | =back |
799 | |
990 | |
800 | =cut |
991 | =cut |
801 | |
992 | |
… | |
… | |
813 | or return undef; |
1004 | or return undef; |
814 | |
1005 | |
815 | *$sym |
1006 | *$sym |
816 | } |
1007 | } |
817 | |
1008 | |
818 | min_parallel 4; |
1009 | min_parallel 8; |
819 | |
1010 | |
820 | END { |
1011 | END { |
821 | max_parallel 0; |
1012 | min_parallel 1; |
822 | } |
1013 | flush; |
|
|
1014 | }; |
823 | |
1015 | |
824 | 1; |
1016 | 1; |
825 | |
1017 | |
826 | =head2 FORK BEHAVIOUR |
1018 | =head2 FORK BEHAVIOUR |
827 | |
1019 | |
828 | This module should do "the right thing" when the process using it forks: |
1020 | This module should do "the right thing" when the process using it forks: |
829 | |
1021 | |
830 | Before the fork, IO::AIO enters a quiescent state where no requests |
1022 | Before the fork, IO::AIO enters a quiescent state where no requests |
831 | can be added in other threads and no results will be processed. After |
1023 | can be added in other threads and no results will be processed. After |
832 | the fork the parent simply leaves the quiescent state and continues |
1024 | the fork the parent simply leaves the quiescent state and continues |
833 | request/result processing, while the child clears the request/result |
1025 | request/result processing, while the child frees the request/result queue |
834 | queue (so the requests started before the fork will only be handled in |
1026 | (so that the requests started before the fork will only be handled in the |
835 | the parent). Threads will be started on demand until the limit ste in the |
1027 | parent). Threads will be started on demand until the limit set in the |
836 | parent process has been reached again. |
1028 | parent process has been reached again. |
837 | |
1029 | |
838 | In short: the parent will, after a short pause, continue as if fork had |
1030 | In short: the parent will, after a short pause, continue as if fork had |
839 | not been called, while the child will act as if IO::AIO has not been used |
1031 | not been called, while the child will act as if IO::AIO has not been used |
840 | yet. |
1032 | yet. |
841 | |
1033 | |
842 | =head2 MEMORY USAGE |
1034 | =head2 MEMORY USAGE |
843 | |
1035 | |
|
|
1036 | Per-request usage: |
|
|
1037 | |
844 | Each aio request uses - depending on your architecture - around 128 bytes |
1038 | Each aio request uses - depending on your architecture - around 100-200 |
845 | of memory. In addition, stat requests need a stat buffer (possibly a few |
1039 | bytes of memory. In addition, stat requests need a stat buffer (possibly |
846 | hundred bytes). Perl scalars and other data passed into aio requests will |
1040 | a few hundred bytes), readdir requires a result buffer and so on. Perl |
847 | also be locked. |
1041 | scalars and other data passed into aio requests will also be locked and |
|
|
1042 | will consume memory till the request has entered the done state. |
848 | |
1043 | |
849 | This is now awfully much, so queuing lots of requests is not usually a |
1044 | This is now awfully much, so queuing lots of requests is not usually a |
850 | problem. |
1045 | problem. |
851 | |
1046 | |
852 | Each thread needs a stack area which is usually around 16k, sometimes much |
1047 | Per-thread usage: |
853 | larger, depending on the OS. |
1048 | |
|
|
1049 | In the execution phase, some aio requests require more memory for |
|
|
1050 | temporary buffers, and each thread requires a stack and other data |
|
|
1051 | structures (usually around 16k-128k, depending on the OS). |
|
|
1052 | |
|
|
1053 | =head1 KNOWN BUGS |
|
|
1054 | |
|
|
1055 | Known bugs will be fixed in the next release. |
854 | |
1056 | |
855 | =head1 SEE ALSO |
1057 | =head1 SEE ALSO |
856 | |
1058 | |
857 | L<Coro>, L<Linux::AIO> (obsolete). |
1059 | L<Coro::AIO>. |
858 | |
1060 | |
859 | =head1 AUTHOR |
1061 | =head1 AUTHOR |
860 | |
1062 | |
861 | Marc Lehmann <schmorp@schmorp.de> |
1063 | Marc Lehmann <schmorp@schmorp.de> |
862 | http://home.schmorp.de/ |
1064 | http://home.schmorp.de/ |