… | |
… | |
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 | Currently, a number of threads are started that execute your read/writes |
48 | and signal their completion. You don't need thread support in your libc or |
57 | and signal their completion. You don't need thread support in perl, and |
49 | perl, and the threads created by this module will not be visible to the |
58 | the threads created by this module will not be visible to perl. In the |
50 | pthreads library. In the future, this module might make use of the native |
59 | future, this module might make use of the native aio functions available |
51 | aio functions available on many operating systems. However, they are often |
60 | on many operating systems. However, they are often not well-supported |
52 | not well-supported (Linux doesn't allow them on normal files currently, |
61 | (Linux doesn't allow them on normal files currently, for example), |
53 | for example), and they would only support aio_read and aio_write, so the |
62 | and they would only support aio_read and aio_write, so the remaining |
54 | remaining functionality would have to be implemented using threads anyway. |
63 | functionality would have to be implemented using threads anyway. |
55 | |
64 | |
56 | Although the module will work with in the presence of other threads, it is |
65 | Although the module will work with in the presence of other threads, |
57 | currently not reentrant, so use appropriate locking yourself, always call |
66 | it is currently not reentrant in any way, so use appropriate locking |
58 | C<poll_cb> from within the same thread, or never call C<poll_cb> (or other |
67 | yourself, always call C<poll_cb> from within the same thread, or never |
59 | C<aio_> functions) recursively. |
68 | call C<poll_cb> (or other C<aio_> functions) recursively. |
60 | |
69 | |
61 | =cut |
70 | =cut |
62 | |
71 | |
63 | package IO::AIO; |
72 | package IO::AIO; |
64 | |
73 | |
65 | no warnings; |
74 | no warnings; |
|
|
75 | use strict 'vars'; |
66 | |
76 | |
67 | use base 'Exporter'; |
77 | use base 'Exporter'; |
68 | |
78 | |
69 | use Fcntl (); |
|
|
70 | |
|
|
71 | BEGIN { |
79 | BEGIN { |
72 | $VERSION = '1.71'; |
80 | our $VERSION = '2.0'; |
73 | |
81 | |
74 | @EXPORT = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat |
82 | 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 |
83 | aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink |
76 | aio_fsync aio_fdatasync aio_readahead); |
84 | aio_fsync aio_fdatasync aio_readahead aio_rename aio_link aio_move |
77 | @EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel |
85 | aio_group aio_nop); |
78 | max_outstanding nreqs); |
86 | our @EXPORT = (@AIO_REQ, qw(aioreq_pri)); |
|
|
87 | our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush |
|
|
88 | min_parallel max_parallel max_outstanding nreqs); |
|
|
89 | |
|
|
90 | @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; |
79 | |
91 | |
80 | require XSLoader; |
92 | require XSLoader; |
81 | XSLoader::load IO::AIO, $VERSION; |
93 | XSLoader::load ("IO::AIO", $VERSION); |
82 | } |
94 | } |
83 | |
95 | |
84 | =head1 FUNCTIONS |
96 | =head1 FUNCTIONS |
85 | |
97 | |
86 | =head2 AIO FUNCTIONS |
98 | =head2 AIO FUNCTIONS |
… | |
… | |
94 | syscall has been executed asynchronously. |
106 | syscall has been executed asynchronously. |
95 | |
107 | |
96 | All functions expecting a filehandle keep a copy of the filehandle |
108 | All functions expecting a filehandle keep a copy of the filehandle |
97 | internally until the request has finished. |
109 | internally until the request has finished. |
98 | |
110 | |
|
|
111 | All requests return objects of type L<IO::AIO::REQ> that allow further |
|
|
112 | manipulation of those requests while they are in-flight. |
|
|
113 | |
99 | The pathnames you pass to these routines I<must> be absolute and |
114 | 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 |
115 | 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 |
116 | request is being executed, the current working directory could have |
102 | changed. Alternatively, you can make sure that you never change the |
117 | changed. Alternatively, you can make sure that you never change the |
103 | current working directory. |
118 | current working directory. |
… | |
… | |
108 | your pathnames to the locale (or other) encoding in effect in the user |
123 | 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) |
124 | environment, d) use Glib::filename_from_unicode on unicode filenames or e) |
110 | use something else. |
125 | use something else. |
111 | |
126 | |
112 | =over 4 |
127 | =over 4 |
|
|
128 | |
|
|
129 | =item aioreq_pri $pri |
|
|
130 | |
|
|
131 | Sets the priority for the next aio request. The default priority |
|
|
132 | is C<0>, the minimum and maximum priorities are C<-4> and C<4>, |
|
|
133 | respectively. Requests with higher priority will be serviced first. |
|
|
134 | |
|
|
135 | The priority will be reset to C<0> after each call to one of the C<aio_> |
|
|
136 | functions. |
113 | |
137 | |
114 | =item aio_open $pathname, $flags, $mode, $callback->($fh) |
138 | =item aio_open $pathname, $flags, $mode, $callback->($fh) |
115 | |
139 | |
116 | Asynchronously open or create a file and call the callback with a newly |
140 | Asynchronously open or create a file and call the callback with a newly |
117 | created filehandle for the file. |
141 | created filehandle for the file. |
… | |
… | |
168 | aio_read $fh, 7, 15, $buffer, 0, sub { |
192 | aio_read $fh, 7, 15, $buffer, 0, sub { |
169 | $_[0] > 0 or die "read error: $!"; |
193 | $_[0] > 0 or die "read error: $!"; |
170 | print "read $_[0] bytes: <$buffer>\n"; |
194 | print "read $_[0] bytes: <$buffer>\n"; |
171 | }; |
195 | }; |
172 | |
196 | |
|
|
197 | =item aio_move $srcpath, $dstpath, $callback->($status) |
|
|
198 | |
|
|
199 | [EXPERIMENTAL due to internal aio_group use] |
|
|
200 | |
|
|
201 | Try to move the I<file> (directories not supported as either source or |
|
|
202 | destination) from C<$srcpath> to C<$dstpath> and call the callback with |
|
|
203 | the C<0> (error) or C<-1> ok. |
|
|
204 | |
|
|
205 | This is a composite request that tries to rename(2) the file first. If |
|
|
206 | rename files with C<EXDEV>, it creates the destination file with mode 0200 |
|
|
207 | and copies the contents of the source file into it using C<aio_sendfile>, |
|
|
208 | followed by restoring atime, mtime, access mode and uid/gid, in that |
|
|
209 | order, and unlinking the C<$srcpath>. |
|
|
210 | |
|
|
211 | If an error occurs, the partial destination file will be unlinked, if |
|
|
212 | possible, except when setting atime, mtime, access mode and uid/gid, where |
|
|
213 | errors are being ignored. |
|
|
214 | |
|
|
215 | =cut |
|
|
216 | |
|
|
217 | sub aio_move($$$) { |
|
|
218 | my ($src, $dst, $cb) = @_; |
|
|
219 | |
|
|
220 | my $grp = aio_group $cb; |
|
|
221 | |
|
|
222 | add $grp aio_rename $src, $dst, sub { |
|
|
223 | if ($_[0] && $! == EXDEV) { |
|
|
224 | add $grp aio_open $src, O_RDONLY, 0, sub { |
|
|
225 | if (my $src_fh = $_[0]) { |
|
|
226 | my @stat = stat $src_fh; |
|
|
227 | |
|
|
228 | add $grp aio_open $dst, O_WRONLY, 0200, sub { |
|
|
229 | if (my $dst_fh = $_[0]) { |
|
|
230 | add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { |
|
|
231 | close $src_fh; |
|
|
232 | |
|
|
233 | if ($_[0] == $stat[7]) { |
|
|
234 | utime $stat[8], $stat[9], $dst; |
|
|
235 | chmod $stat[2] & 07777, $dst_fh; |
|
|
236 | chown $stat[4], $stat[5], $dst_fh; |
|
|
237 | close $dst_fh; |
|
|
238 | |
|
|
239 | add $grp aio_unlink $src, sub { |
|
|
240 | $grp->result ($_[0]); |
|
|
241 | }; |
|
|
242 | } else { |
|
|
243 | my $errno = $!; |
|
|
244 | add $grp aio_unlink $dst, sub { |
|
|
245 | $! = $errno; |
|
|
246 | $grp->result (-1); |
|
|
247 | }; |
|
|
248 | } |
|
|
249 | }; |
|
|
250 | } else { |
|
|
251 | $grp->result (-1); |
|
|
252 | } |
|
|
253 | }, |
|
|
254 | |
|
|
255 | } else { |
|
|
256 | $grp->result (-1); |
|
|
257 | } |
|
|
258 | }; |
|
|
259 | } else { |
|
|
260 | $grp->result ($_[0]); |
|
|
261 | } |
|
|
262 | }; |
|
|
263 | |
|
|
264 | $grp |
|
|
265 | } |
|
|
266 | |
173 | =item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
267 | =item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
174 | |
268 | |
175 | Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts |
269 | 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 |
270 | 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 |
271 | file offset of C<$out_fh>. Because of that, it is not safe to issue more |
… | |
… | |
232 | =item aio_unlink $pathname, $callback->($status) |
326 | =item aio_unlink $pathname, $callback->($status) |
233 | |
327 | |
234 | Asynchronously unlink (delete) a file and call the callback with the |
328 | Asynchronously unlink (delete) a file and call the callback with the |
235 | result code. |
329 | result code. |
236 | |
330 | |
|
|
331 | =item aio_link $srcpath, $dstpath, $callback->($status) |
|
|
332 | |
|
|
333 | Asynchronously create a new link to the existing object at C<$srcpath> at |
|
|
334 | the path C<$dstpath> and call the callback with the result code. |
|
|
335 | |
|
|
336 | =item aio_symlink $srcpath, $dstpath, $callback->($status) |
|
|
337 | |
|
|
338 | Asynchronously create a new symbolic link to the existing object at C<$srcpath> at |
|
|
339 | the path C<$dstpath> and call the callback with the result code. |
|
|
340 | |
|
|
341 | =item aio_rename $srcpath, $dstpath, $callback->($status) |
|
|
342 | |
|
|
343 | Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as |
|
|
344 | rename(2) and call the callback with the result code. |
|
|
345 | |
237 | =item aio_rmdir $pathname, $callback->($status) |
346 | =item aio_rmdir $pathname, $callback->($status) |
238 | |
347 | |
239 | Asynchronously rmdir (delete) a directory and call the callback with the |
348 | Asynchronously rmdir (delete) a directory and call the callback with the |
240 | result code. |
349 | result code. |
241 | |
350 | |
242 | =item aio_readdir $pathname $callback->($entries) |
351 | =item aio_readdir $pathname, $callback->($entries) |
243 | |
352 | |
244 | Unlike the POSIX call of the same name, C<aio_readdir> reads an entire |
353 | 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 |
354 | directory (i.e. opendir + readdir + closedir). The entries will not be |
246 | sorted, and will B<NOT> include the C<.> and C<..> entries. |
355 | sorted, and will B<NOT> include the C<.> and C<..> entries. |
247 | |
356 | |
248 | The callback a single argument which is either C<undef> or an array-ref |
357 | The callback a single argument which is either C<undef> or an array-ref |
249 | with the filenames. |
358 | with the filenames. |
250 | |
359 | |
251 | =item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
360 | =item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
252 | |
361 | |
|
|
362 | [EXPERIMENTAL due to internal aio_group use] |
|
|
363 | |
253 | Scans a directory (similar to C<aio_readdir>) and tries to separate the |
364 | 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 |
365 | separate the entries of directory C<$path> into two sets of names, ones |
255 | into (directories), and ones you cannot recurse into (everything else). |
366 | you can recurse into (directories or links to them), and ones you cannot |
|
|
367 | recurse into (everything else). |
256 | |
368 | |
257 | C<aio_scandir> is a composite request that consists of many |
369 | C<aio_scandir> is a composite request that creates of many sub requests_ |
258 | aio-primitives. C<$maxreq> specifies the maximum number of outstanding |
370 | 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 |
371 | this function generates. If it is C<< <= 0 >>, then a suitable default |
260 | suitable default will be chosen (currently 8). |
372 | will be chosen (currently 6). |
261 | |
373 | |
262 | On error, the callback is called without arguments, otherwise it receives |
374 | On error, the callback is called without arguments, otherwise it receives |
263 | two array-refs with path-relative entry names. |
375 | two array-refs with path-relative entry names. |
264 | |
376 | |
265 | Example: |
377 | Example: |
… | |
… | |
273 | Implementation notes. |
385 | Implementation notes. |
274 | |
386 | |
275 | The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can. |
387 | The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can. |
276 | |
388 | |
277 | After reading the directory, the modification time, size etc. of the |
389 | 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 |
390 | 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 |
391 | 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 |
392 | entries are directories (if >= 2). Otherwise, no knowledge of the number |
281 | assumed. |
393 | of subdirectories will be assumed. |
282 | |
394 | |
283 | Then entires will be sorted into likely directories (everything without a |
395 | Then entries will be sorted into likely directories (everything without |
284 | non-initial dot) and likely non-directories (everything else). Then every |
396 | a non-initial dot currently) and likely non-directories (everything |
285 | entry + C</.> will be C<stat>'ed, likely directories first. This is often |
397 | else). Then every entry plus an appended C</.> will be C<stat>'ed, |
|
|
398 | likely directories first. If that succeeds, it assumes that the entry |
|
|
399 | is a directory or a symlink to directory (which will be checked |
|
|
400 | seperately). This is often faster than stat'ing the entry itself because |
286 | faster because filesystems might detect the type of the entry without |
401 | 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, |
402 | 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 | |
403 | |
291 | If the known number of directories has been reached, the rest of the |
404 | If the known number of directories (link count - 2) has been reached, the |
292 | entries is assumed to be non-directories. |
405 | rest of the entries is assumed to be non-directories. |
|
|
406 | |
|
|
407 | This only works with certainty on POSIX (= UNIX) filesystems, which |
|
|
408 | fortunately are the vast majority of filesystems around. |
|
|
409 | |
|
|
410 | It will also likely work on non-POSIX filesystems with reduced efficiency |
|
|
411 | as those tend to return 0 or 1 as link counts, which disables the |
|
|
412 | directory counting heuristic. |
293 | |
413 | |
294 | =cut |
414 | =cut |
295 | |
415 | |
296 | sub aio_scandir($$$) { |
416 | sub aio_scandir($$$) { |
297 | my ($path, $maxreq, $cb) = @_; |
417 | my ($path, $maxreq, $cb) = @_; |
298 | |
418 | |
|
|
419 | my $grp = aio_group $cb; |
|
|
420 | |
299 | $maxreq = 8 if $maxreq <= 0; |
421 | $maxreq = 6 if $maxreq <= 0; |
300 | |
422 | |
301 | # stat once |
423 | # stat once |
302 | aio_stat $path, sub { |
424 | add $grp aio_stat $path, sub { |
303 | $cb->() if $_[0]; |
425 | return $grp->result () if $_[0]; |
|
|
426 | my $now = time; |
304 | my $hash1 = join ":", (stat _)[0,1,3,7,9]; |
427 | my $hash1 = join ":", (stat _)[0,1,3,7,9]; |
305 | |
428 | |
306 | # read the directory entries |
429 | # read the directory entries |
307 | aio_readdir $path, sub { |
430 | add $grp aio_readdir $path, sub { |
308 | my $entries = shift |
431 | my $entries = shift |
309 | or return $cb->(); |
432 | or return $grp->result (); |
310 | |
433 | |
311 | # stat the dir another time |
434 | # stat the dir another time |
312 | aio_stat $path, sub { |
435 | add $grp aio_stat $path, sub { |
313 | my $hash2 = join ":", (stat _)[0,1,3,7,9]; |
436 | my $hash2 = join ":", (stat _)[0,1,3,7,9]; |
314 | |
437 | |
315 | my $ndirs; |
438 | my $ndirs; |
316 | |
439 | |
317 | # take the slow route if anything looks fishy |
440 | # take the slow route if anything looks fishy |
318 | if ($hash1 ne $hash2) { |
441 | if ($hash1 ne $hash2 or (stat _)[9] == $now) { |
319 | $ndirs = -1; |
442 | $ndirs = -1; |
320 | } else { |
443 | } else { |
321 | # if nlink == 2, we are finished |
444 | # if nlink == 2, we are finished |
322 | # on non-posix-fs's, we rely on nlink < 2 |
445 | # on non-posix-fs's, we rely on nlink < 2 |
323 | $ndirs = (stat _)[3] - 2 |
446 | $ndirs = (stat _)[3] - 2 |
324 | or return $cb->([], $entries); |
447 | or return $grp->result ([], $entries); |
325 | } |
448 | } |
326 | |
449 | |
327 | # sort into likely dirs and likely nondirs |
450 | # sort into likely dirs and likely nondirs |
328 | # dirs == files without ".", short entries first |
451 | # dirs == files without ".", short entries first |
329 | $entries = [map $_->[0], |
452 | $entries = [map $_->[0], |
… | |
… | |
334 | my (@dirs, @nondirs); |
457 | my (@dirs, @nondirs); |
335 | |
458 | |
336 | my ($statcb, $schedcb); |
459 | my ($statcb, $schedcb); |
337 | my $nreq = 0; |
460 | my $nreq = 0; |
338 | |
461 | |
|
|
462 | my $statgrp = add $grp aio_group; |
|
|
463 | |
339 | $schedcb = sub { |
464 | $schedcb = sub { |
340 | if (@$entries) { |
465 | if (@$entries) { |
341 | if ($nreq < $maxreq) { |
466 | if ($nreq < $maxreq) { |
342 | my $ent = pop @$entries; |
467 | my $ent = pop @$entries; |
343 | $nreq++; |
468 | $nreq++; |
344 | aio_stat "$path/$ent/.", sub { $statcb->($_[0], $ent) }; |
469 | add $statgrp aio_stat "$path/$ent/.", sub { $statcb->($_[0], $ent) }; |
345 | } |
470 | } |
346 | } elsif (!$nreq) { |
471 | } elsif (!$nreq) { |
347 | # finished |
472 | # finished |
|
|
473 | $statgrp->cancel; |
348 | undef $statcb; |
474 | undef $statcb; |
349 | undef $schedcb; |
475 | undef $schedcb; |
350 | $cb->(\@dirs, \@nondirs) if $cb; |
476 | $grp->result (\@dirs, \@nondirs); |
351 | undef $cb; |
|
|
352 | } |
477 | } |
353 | }; |
478 | }; |
354 | $statcb = sub { |
479 | $statcb = sub { |
355 | my ($status, $entry) = @_; |
480 | my ($status, $entry) = @_; |
356 | |
481 | |
… | |
… | |
358 | $nreq--; |
483 | $nreq--; |
359 | push @nondirs, $entry; |
484 | push @nondirs, $entry; |
360 | &$schedcb; |
485 | &$schedcb; |
361 | } else { |
486 | } else { |
362 | # need to check for real directory |
487 | # need to check for real directory |
363 | aio_lstat "$path/$entry", sub { |
488 | add $grp aio_lstat "$path/$entry", sub { |
364 | $nreq--; |
489 | $nreq--; |
365 | |
490 | |
366 | if (-d _) { |
491 | if (-d _) { |
367 | push @dirs, $entry; |
492 | push @dirs, $entry; |
368 | |
493 | |
… | |
… | |
381 | |
506 | |
382 | &$schedcb while @$entries && $nreq < $maxreq; |
507 | &$schedcb while @$entries && $nreq < $maxreq; |
383 | }; |
508 | }; |
384 | }; |
509 | }; |
385 | }; |
510 | }; |
|
|
511 | |
|
|
512 | $grp |
386 | } |
513 | } |
387 | |
514 | |
388 | =item aio_fsync $fh, $callback->($status) |
515 | =item aio_fsync $fh, $callback->($status) |
389 | |
516 | |
390 | Asynchronously call fsync on the given filehandle and call the callback |
517 | Asynchronously call fsync on the given filehandle and call the callback |
… | |
… | |
395 | Asynchronously call fdatasync on the given filehandle and call the |
522 | Asynchronously call fdatasync on the given filehandle and call the |
396 | callback with the fdatasync result code. |
523 | callback with the fdatasync result code. |
397 | |
524 | |
398 | If this call isn't available because your OS lacks it or it couldn't be |
525 | 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. |
526 | detected, it will be emulated by calling C<fsync> instead. |
|
|
527 | |
|
|
528 | =item aio_group $callback->(...) |
|
|
529 | |
|
|
530 | [EXPERIMENTAL] |
|
|
531 | |
|
|
532 | This is a very special aio request: Instead of doing something, it is a |
|
|
533 | container for other aio requests, which is useful if you want to bundle |
|
|
534 | many requests into a single, composite, request. |
|
|
535 | |
|
|
536 | Returns an object of class L<IO::AIO::GRP>. See its documentation below |
|
|
537 | for more info. |
|
|
538 | |
|
|
539 | Example: |
|
|
540 | |
|
|
541 | my $grp = aio_group sub { |
|
|
542 | print "all stats done\n"; |
|
|
543 | }; |
|
|
544 | |
|
|
545 | add $grp |
|
|
546 | (aio_stat ...), |
|
|
547 | (aio_stat ...), |
|
|
548 | ...; |
|
|
549 | |
|
|
550 | =item aio_nop $callback->() |
|
|
551 | |
|
|
552 | This is a special request - it does nothing in itself and is only used for |
|
|
553 | side effects, such as when you want to add a dummy request to a group so |
|
|
554 | that finishing the requests in the group depends on executing the given |
|
|
555 | code. |
|
|
556 | |
|
|
557 | While this request does nothing, it still goes through the execution |
|
|
558 | phase and still requires a worker thread. Thus, the callback will not |
|
|
559 | be executed immediately but only after other requests in the queue have |
|
|
560 | entered their execution phase. This can be used to measure request |
|
|
561 | latency. |
|
|
562 | |
|
|
563 | =item IO::AIO::aio_sleep $fractional_seconds, $callback->() *NOT EXPORTED* |
|
|
564 | |
|
|
565 | Mainly used for debugging and benchmarking, this aio request puts one of |
|
|
566 | the request workers to sleep for the given time. |
|
|
567 | |
|
|
568 | While it is theoretically handy to have simple I/O scheduling requests |
|
|
569 | like sleep and file handle readable/writable, the overhead this creates |
|
|
570 | is immense, so do not use this function except to put your application |
|
|
571 | under artificial I/O pressure. |
|
|
572 | |
|
|
573 | =back |
|
|
574 | |
|
|
575 | =head2 IO::AIO::REQ CLASS |
|
|
576 | |
|
|
577 | All non-aggregate C<aio_*> functions return an object of this class when |
|
|
578 | called in non-void context. |
|
|
579 | |
|
|
580 | A request always moves through the following five states in its lifetime, |
|
|
581 | in order: B<ready> (request has been created, but has not been executed |
|
|
582 | yet), B<execute> (request is currently being executed), B<pending> |
|
|
583 | (request has been executed but callback has not been called yet), |
|
|
584 | B<result> (results are being processed synchronously, includes calling the |
|
|
585 | callback) and B<done> (request has reached the end of its lifetime and |
|
|
586 | holds no resources anymore). |
|
|
587 | |
|
|
588 | =over 4 |
|
|
589 | |
|
|
590 | =item cancel $req |
|
|
591 | |
|
|
592 | Cancels the request, if possible. Has the effect of skipping execution |
|
|
593 | when entering the B<execute> state and skipping calling the callback when |
|
|
594 | entering the the B<result> state, but will leave the request otherwise |
|
|
595 | untouched. That means that requests that currently execute will not be |
|
|
596 | stopped and resources held by the request will not be freed prematurely. |
|
|
597 | |
|
|
598 | =item cb $req $callback->(...) |
|
|
599 | |
|
|
600 | Replace (or simply set) the callback registered to the request. |
|
|
601 | |
|
|
602 | =back |
|
|
603 | |
|
|
604 | =head2 IO::AIO::GRP CLASS |
|
|
605 | |
|
|
606 | This class is a subclass of L<IO::AIO::REQ>, so all its methods apply to |
|
|
607 | objects of this class, too. |
|
|
608 | |
|
|
609 | A IO::AIO::GRP object is a special request that can contain multiple other |
|
|
610 | aio requests. |
|
|
611 | |
|
|
612 | You create one by calling the C<aio_group> constructing function with a |
|
|
613 | callback that will be called when all contained requests have entered the |
|
|
614 | C<done> state: |
|
|
615 | |
|
|
616 | my $grp = aio_group sub { |
|
|
617 | print "all requests are done\n"; |
|
|
618 | }; |
|
|
619 | |
|
|
620 | You add requests by calling the C<add> method with one or more |
|
|
621 | C<IO::AIO::REQ> objects: |
|
|
622 | |
|
|
623 | $grp->add (aio_unlink "..."); |
|
|
624 | |
|
|
625 | add $grp aio_stat "...", sub { |
|
|
626 | $_[0] or return $grp->result ("error"); |
|
|
627 | |
|
|
628 | # add another request dynamically, if first succeeded |
|
|
629 | add $grp aio_open "...", sub { |
|
|
630 | $grp->result ("ok"); |
|
|
631 | }; |
|
|
632 | }; |
|
|
633 | |
|
|
634 | This makes it very easy to create composite requests (see the source of |
|
|
635 | C<aio_move> for an application) that work and feel like simple requests. |
|
|
636 | |
|
|
637 | =over 4 |
|
|
638 | |
|
|
639 | =item * The IO::AIO::GRP objects will be cleaned up during calls to |
|
|
640 | C<IO::AIO::poll_cb>, just like any other request. |
|
|
641 | |
|
|
642 | =item * They can be canceled like any other request. Canceling will cancel not |
|
|
643 | only the request itself, but also all requests it contains. |
|
|
644 | |
|
|
645 | =item * They can also can also be added to other IO::AIO::GRP objects. |
|
|
646 | |
|
|
647 | =item * You must not add requests to a group from within the group callback (or |
|
|
648 | any later time). |
|
|
649 | |
|
|
650 | =item * This does not harmonise well with C<max_outstanding>, so best do |
|
|
651 | not combine C<aio_group> with it. Groups and feeders are recommended for |
|
|
652 | this kind of concurrency-limiting. |
|
|
653 | |
|
|
654 | =back |
|
|
655 | |
|
|
656 | Their lifetime, simplified, looks like this: when they are empty, they |
|
|
657 | will finish very quickly. If they contain only requests that are in the |
|
|
658 | C<done> state, they will also finish. Otherwise they will continue to |
|
|
659 | exist. |
|
|
660 | |
|
|
661 | That means after creating a group you have some time to add requests. And |
|
|
662 | in the callbacks of those requests, you can add further requests to the |
|
|
663 | group. And only when all those requests have finished will the the group |
|
|
664 | itself finish. |
|
|
665 | |
|
|
666 | =over 4 |
|
|
667 | |
|
|
668 | =item add $grp ... |
|
|
669 | |
|
|
670 | =item $grp->add (...) |
|
|
671 | |
|
|
672 | Add one or more requests to the group. Any type of L<IO::AIO::REQ> can |
|
|
673 | be added, including other groups, as long as you do not create circular |
|
|
674 | dependencies. |
|
|
675 | |
|
|
676 | Returns all its arguments. |
|
|
677 | |
|
|
678 | =item $grp->result (...) |
|
|
679 | |
|
|
680 | Set the result value(s) that will be passed to the group callback when all |
|
|
681 | subrequests have finished. By default, no argument will be passed. |
|
|
682 | |
|
|
683 | =item feed $grp $callback->($grp) |
|
|
684 | |
|
|
685 | [VERY EXPERIMENTAL] |
|
|
686 | |
|
|
687 | Sets a feeder/generator on this group: every group can have an attached |
|
|
688 | generator that generates requests if idle. The idea behind this is that, |
|
|
689 | although you could just queue as many requests as you want in a group, |
|
|
690 | this might starve other requests for a potentially long time. For |
|
|
691 | example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> |
|
|
692 | requests, delaying any later requests for a long time. |
|
|
693 | |
|
|
694 | To avoid this, and allow incremental generation of requests, you can |
|
|
695 | instead a group and set a feeder on it that generates those requests. The |
|
|
696 | feed callback will be called whenever there are few enough (see C<limit>, |
|
|
697 | below) requests active in the group itself and is expected to queue more |
|
|
698 | requests. |
|
|
699 | |
|
|
700 | The feed callback can queue as many requests as it likes (i.e. C<add> does |
|
|
701 | not impose any limits). |
|
|
702 | |
|
|
703 | If the feed does not queue more requests when called, it will be |
|
|
704 | automatically removed from the group. |
|
|
705 | |
|
|
706 | If the feed limit is C<0>, it will be set to C<2> automatically. |
|
|
707 | |
|
|
708 | Example: |
|
|
709 | |
|
|
710 | # stat all files in @files, but only ever use four aio requests concurrently: |
|
|
711 | |
|
|
712 | my $grp = aio_group sub { print "finished\n" }; |
|
|
713 | limit $grp 4; |
|
|
714 | feed $grp sub { |
|
|
715 | my $file = pop @files |
|
|
716 | or return; |
|
|
717 | |
|
|
718 | add $grp aio_stat $file, sub { ... }; |
|
|
719 | }; |
|
|
720 | |
|
|
721 | =item limit $grp $num |
|
|
722 | |
|
|
723 | Sets the feeder limit for the group: The feeder will be called whenever |
|
|
724 | the group contains less than this many requests. |
|
|
725 | |
|
|
726 | Setting the limit to C<0> will pause the feeding process. |
400 | |
727 | |
401 | =back |
728 | =back |
402 | |
729 | |
403 | =head2 SUPPORT FUNCTIONS |
730 | =head2 SUPPORT FUNCTIONS |
404 | |
731 | |
… | |
… | |
462 | IO::AIO::poll_wait, IO::AIO::poll_cb |
789 | IO::AIO::poll_wait, IO::AIO::poll_cb |
463 | if IO::AIO::nreqs; |
790 | if IO::AIO::nreqs; |
464 | |
791 | |
465 | =item IO::AIO::min_parallel $nthreads |
792 | =item IO::AIO::min_parallel $nthreads |
466 | |
793 | |
467 | Set the minimum number of AIO threads to C<$nthreads>. The current default |
794 | 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 |
795 | default is C<8>, which means eight asynchronous operations can execute |
469 | (the number of outstanding operations, however, is unlimited). |
796 | concurrently at any one time (the number of outstanding requests, |
|
|
797 | however, is unlimited). |
470 | |
798 | |
471 | IO::AIO starts threads only on demand, when an AIO request is queued and |
799 | IO::AIO starts threads only on demand, when an AIO request is queued and |
472 | no free thread exists. |
800 | no free thread exists. |
473 | |
801 | |
474 | It is recommended to keep the number of threads low, as some Linux |
802 | 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 |
803 | Linux kernel versions will scale negatively with the number of threads |
476 | parallelity => MUCH higher latency). With current Linux 2.6 versions, 4-32 |
804 | (higher parallelity => MUCH higher latency). With current Linux 2.6 |
477 | threads should be fine. |
805 | versions, 4-32 threads should be fine. |
478 | |
806 | |
479 | Under most circumstances you don't need to call this function, as the |
807 | 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. |
808 | module selects a default that is suitable for low to moderate load. |
481 | |
809 | |
482 | =item IO::AIO::max_parallel $nthreads |
810 | =item IO::AIO::max_parallel $nthreads |
… | |
… | |
493 | |
821 | |
494 | Under normal circumstances you don't need to call this function. |
822 | Under normal circumstances you don't need to call this function. |
495 | |
823 | |
496 | =item $oldnreqs = IO::AIO::max_outstanding $nreqs |
824 | =item $oldnreqs = IO::AIO::max_outstanding $nreqs |
497 | |
825 | |
|
|
826 | [DEPRECATED] |
|
|
827 | |
498 | Sets the maximum number of outstanding requests to C<$nreqs>. If you |
828 | Sets the maximum number of outstanding requests to C<$nreqs>. If you |
499 | try to queue up more than this number of requests, the caller will block until |
829 | try to queue up more than this number of requests, the caller will block until |
500 | some requests have been handled. |
830 | some requests have been handled. |
501 | |
831 | |
502 | The default is very large, so normally there is no practical limit. If you |
832 | The default is very large, so normally there is no practical limit. If you |
503 | queue up many requests in a loop it often improves speed if you set |
833 | queue up many requests in a loop it often improves speed if you set |
504 | this to a relatively low number, such as C<100>. |
834 | this to a relatively low number, such as C<100>. |
|
|
835 | |
|
|
836 | This function does not work well together with C<aio_group>'s, and their |
|
|
837 | feeder interface is better suited to limiting concurrency, so do not use |
|
|
838 | this function. |
505 | |
839 | |
506 | Under normal circumstances you don't need to call this function. |
840 | Under normal circumstances you don't need to call this function. |
507 | |
841 | |
508 | =back |
842 | =back |
509 | |
843 | |
… | |
… | |
523 | or return undef; |
857 | or return undef; |
524 | |
858 | |
525 | *$sym |
859 | *$sym |
526 | } |
860 | } |
527 | |
861 | |
528 | min_parallel 4; |
862 | min_parallel 8; |
529 | |
863 | |
530 | END { |
864 | END { |
531 | max_parallel 0; |
865 | max_parallel 0; |
532 | } |
866 | } |
533 | |
867 | |
534 | 1; |
868 | 1; |
535 | |
869 | |
536 | =head2 FORK BEHAVIOUR |
870 | =head2 FORK BEHAVIOUR |
|
|
871 | |
|
|
872 | This module should do "the right thing" when the process using it forks: |
537 | |
873 | |
538 | Before the fork, IO::AIO enters a quiescent state where no requests |
874 | 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 |
875 | 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 |
876 | the fork the parent simply leaves the quiescent state and continues |
541 | request/result processing, while the child clears the request/result |
877 | request/result processing, while the child clears the request/result |
542 | queue (so the requests started before the fork will only be handled in |
878 | queue (so the requests started before the fork will only be handled in |
543 | the parent). Threats will be started on demand until the limit ste in the |
879 | the parent). Threads will be started on demand until the limit ste in the |
544 | parent process has been reached again. |
880 | parent process has been reached again. |
545 | |
881 | |
|
|
882 | In short: the parent will, after a short pause, continue as if fork had |
|
|
883 | not been called, while the child will act as if IO::AIO has not been used |
|
|
884 | yet. |
|
|
885 | |
|
|
886 | =head2 MEMORY USAGE |
|
|
887 | |
|
|
888 | Each aio request uses - depending on your architecture - around 128 bytes |
|
|
889 | of memory. In addition, stat requests need a stat buffer (possibly a few |
|
|
890 | hundred bytes). Perl scalars and other data passed into aio requests will |
|
|
891 | also be locked. |
|
|
892 | |
|
|
893 | This is now awfully much, so queuing lots of requests is not usually a |
|
|
894 | problem. |
|
|
895 | |
|
|
896 | Each thread needs a stack area which is usually around 16k, sometimes much |
|
|
897 | larger, depending on the OS. |
|
|
898 | |
546 | =head1 SEE ALSO |
899 | =head1 SEE ALSO |
547 | |
900 | |
548 | L<Coro>, L<Linux::AIO>. |
901 | L<Coro::AIO>. |
549 | |
902 | |
550 | =head1 AUTHOR |
903 | =head1 AUTHOR |
551 | |
904 | |
552 | Marc Lehmann <schmorp@schmorp.de> |
905 | Marc Lehmann <schmorp@schmorp.de> |
553 | http://home.schmorp.de/ |
906 | http://home.schmorp.de/ |