… | |
… | |
14 | aio_unlink "/tmp/file", sub { }; |
14 | aio_unlink "/tmp/file", sub { }; |
15 | |
15 | |
16 | aio_read $fh, 30000, 1024, $buffer, 0, sub { |
16 | aio_read $fh, 30000, 1024, $buffer, 0, sub { |
17 | $_[0] > 0 or die "read error: $!"; |
17 | $_[0] > 0 or die "read error: $!"; |
18 | }; |
18 | }; |
|
|
19 | |
|
|
20 | # AnyEvent |
|
|
21 | open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!"; |
|
|
22 | my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb }); |
19 | |
23 | |
20 | # Event |
24 | # Event |
21 | Event->io (fd => IO::AIO::poll_fileno, |
25 | Event->io (fd => IO::AIO::poll_fileno, |
22 | poll => 'r', |
26 | poll => 'r', |
23 | cb => \&IO::AIO::poll_cb); |
27 | cb => \&IO::AIO::poll_cb); |
… | |
… | |
57 | =cut |
61 | =cut |
58 | |
62 | |
59 | package IO::AIO; |
63 | package IO::AIO; |
60 | |
64 | |
61 | no warnings; |
65 | no warnings; |
|
|
66 | use strict 'vars'; |
62 | |
67 | |
63 | use base 'Exporter'; |
68 | use base 'Exporter'; |
64 | |
69 | |
65 | use Fcntl (); |
|
|
66 | |
|
|
67 | BEGIN { |
70 | BEGIN { |
68 | $VERSION = 1.1; |
71 | our $VERSION = '1.8'; |
69 | |
72 | |
70 | @EXPORT = qw(aio_read aio_write aio_open aio_close aio_stat aio_lstat aio_unlink |
73 | our @EXPORT = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat |
|
|
74 | aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink |
71 | aio_fsync aio_fdatasync aio_readahead); |
75 | aio_fsync aio_fdatasync aio_readahead aio_rename aio_link aio_move); |
72 | @EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel max_outstanding nreqs); |
76 | our @EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel max_outstanding nreqs); |
73 | |
77 | |
74 | require XSLoader; |
78 | require XSLoader; |
75 | XSLoader::load IO::AIO, $VERSION; |
79 | XSLoader::load ("IO::AIO", $VERSION); |
76 | } |
80 | } |
77 | |
81 | |
78 | =head1 FUNCTIONS |
82 | =head1 FUNCTIONS |
79 | |
83 | |
80 | =head2 AIO FUNCTIONS |
84 | =head2 AIO FUNCTIONS |
… | |
… | |
88 | syscall has been executed asynchronously. |
92 | syscall has been executed asynchronously. |
89 | |
93 | |
90 | All functions expecting a filehandle keep a copy of the filehandle |
94 | All functions expecting a filehandle keep a copy of the filehandle |
91 | internally until the request has finished. |
95 | internally until the request has finished. |
92 | |
96 | |
93 | The filenames you pass to these routines I<must> be absolute. The reason |
97 | The pathnames you pass to these routines I<must> be absolute and |
94 | for this is that at the time the request is being executed, the current |
98 | encoded in byte form. The reason for the former is that at the time the |
95 | working directory could have changed. Alternatively, you can make sure |
99 | request is being executed, the current working directory could have |
96 | that you never change the current working directory. |
100 | changed. Alternatively, you can make sure that you never change the |
|
|
101 | current working directory. |
|
|
102 | |
|
|
103 | To encode pathnames to byte form, either make sure you either: a) |
|
|
104 | always pass in filenames you got from outside (command line, readdir |
|
|
105 | etc.), b) are ASCII or ISO 8859-1, c) use the Encode module and encode |
|
|
106 | your pathnames to the locale (or other) encoding in effect in the user |
|
|
107 | environment, d) use Glib::filename_from_unicode on unicode filenames or e) |
|
|
108 | use something else. |
97 | |
109 | |
98 | =over 4 |
110 | =over 4 |
99 | |
111 | |
100 | =item aio_open $pathname, $flags, $mode, $callback |
112 | =item aio_open $pathname, $flags, $mode, $callback->($fh) |
101 | |
113 | |
102 | Asynchronously open or create a file and call the callback with a newly |
114 | Asynchronously open or create a file and call the callback with a newly |
103 | created filehandle for the file. |
115 | created filehandle for the file. |
104 | |
116 | |
105 | The pathname passed to C<aio_open> must be absolute. See API NOTES, above, |
117 | The pathname passed to C<aio_open> must be absolute. See API NOTES, above, |
… | |
… | |
122 | } else { |
134 | } else { |
123 | die "open failed: $!\n"; |
135 | die "open failed: $!\n"; |
124 | } |
136 | } |
125 | }; |
137 | }; |
126 | |
138 | |
127 | =item aio_close $fh, $callback |
139 | =item aio_close $fh, $callback->($status) |
128 | |
140 | |
129 | Asynchronously close a file and call the callback with the result |
141 | Asynchronously close a file and call the callback with the result |
130 | code. I<WARNING:> although accepted, you should not pass in a perl |
142 | code. I<WARNING:> although accepted, you should not pass in a perl |
131 | filehandle here, as perl will likely close the file descriptor another |
143 | filehandle here, as perl will likely close the file descriptor another |
132 | time when the filehandle is destroyed. Normally, you can safely call perls |
144 | time when the filehandle is destroyed. Normally, you can safely call perls |
133 | C<close> or just let filehandles go out of scope. |
145 | C<close> or just let filehandles go out of scope. |
134 | |
146 | |
135 | This is supposed to be a bug in the API, so that might change. It's |
147 | This is supposed to be a bug in the API, so that might change. It's |
136 | therefore best to avoid this function. |
148 | therefore best to avoid this function. |
137 | |
149 | |
138 | =item aio_read $fh,$offset,$length, $data,$dataoffset,$callback |
150 | =item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
139 | |
151 | |
140 | =item aio_write $fh,$offset,$length, $data,$dataoffset,$callback |
152 | =item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
141 | |
153 | |
142 | Reads or writes C<length> bytes from the specified C<fh> and C<offset> |
154 | Reads or writes C<length> bytes from the specified C<fh> and C<offset> |
143 | into the scalar given by C<data> and offset C<dataoffset> and calls the |
155 | into the scalar given by C<data> and offset C<dataoffset> and calls the |
144 | callback without the actual number of bytes read (or -1 on error, just |
156 | callback without the actual number of bytes read (or -1 on error, just |
145 | like the syscall). |
157 | like the syscall). |
146 | |
158 | |
|
|
159 | The C<$data> scalar I<MUST NOT> be modified in any way while the request |
|
|
160 | is outstanding. Modifying it can result in segfaults or WW3 (if the |
|
|
161 | necessary/optional hardware is installed). |
|
|
162 | |
147 | Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at |
163 | Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at |
148 | offset C<0> within the scalar: |
164 | offset C<0> within the scalar: |
149 | |
165 | |
150 | aio_read $fh, 7, 15, $buffer, 0, sub { |
166 | aio_read $fh, 7, 15, $buffer, 0, sub { |
151 | $_[0] > 0 or die "read error: $!"; |
167 | $_[0] > 0 or die "read error: $!"; |
152 | print "read $_[0] bytes: <$buffer>\n"; |
168 | print "read $_[0] bytes: <$buffer>\n"; |
153 | }; |
169 | }; |
154 | |
170 | |
|
|
171 | =item aio_move $srcpath, $dstpath, $callback->($status) |
|
|
172 | |
|
|
173 | [EXPERIMENTAL] |
|
|
174 | |
|
|
175 | Try to move the I<file> (directories not supported as either source or destination) |
|
|
176 | from C<$srcpath> to C<$dstpath> and call the callback with the C<0> (error) or C<-1> ok. |
|
|
177 | |
|
|
178 | This is a composite request that tries to rename(2) the file first. If |
|
|
179 | rename files with C<EXDEV>, it creates the destination file with mode 0200 |
|
|
180 | and copies the contents of the source file into it using C<aio_sendfile>, |
|
|
181 | followed by restoring atime, mtime, access mode and uid/gid, in that |
|
|
182 | order, and unlinking the C<$srcpath>. |
|
|
183 | |
|
|
184 | If an error occurs, the partial destination file will be unlinked, if |
|
|
185 | possible, except when setting atime, mtime, access mode and uid/gid, where |
|
|
186 | errors are being ignored. |
|
|
187 | |
|
|
188 | =cut |
|
|
189 | |
|
|
190 | sub aio_move($$$) { |
|
|
191 | my ($src, $dst, $cb) = @_; |
|
|
192 | |
|
|
193 | aio_rename $src, $dst, sub { |
|
|
194 | if ($_[0] && $! == EXDEV) { |
|
|
195 | aio_open $src, O_RDONLY, 0, sub { |
|
|
196 | if (my $src_fh = $_[0]) { |
|
|
197 | my @stat = stat $src_fh; |
|
|
198 | |
|
|
199 | aio_open $dst, O_WRONLY, 0200, sub { |
|
|
200 | if (my $dst_fh = $_[0]) { |
|
|
201 | aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { |
|
|
202 | close $src_fh; |
|
|
203 | |
|
|
204 | if ($_[0] == $stat[7]) { |
|
|
205 | utime $stat[8], $stat[9], $dst; |
|
|
206 | chmod $stat[2] & 07777, $dst_fh; |
|
|
207 | chown $stat[4], $stat[5], $dst_fh; |
|
|
208 | close $dst_fh; |
|
|
209 | |
|
|
210 | aio_unlink $src, sub { |
|
|
211 | $cb->($_[0]); |
|
|
212 | }; |
|
|
213 | } else { |
|
|
214 | my $errno = $!; |
|
|
215 | aio_unlink $dst, sub { |
|
|
216 | $! = $errno; |
|
|
217 | $cb->(-1); |
|
|
218 | }; |
|
|
219 | } |
|
|
220 | }; |
|
|
221 | } else { |
|
|
222 | $cb->(-1); |
|
|
223 | } |
|
|
224 | }, |
|
|
225 | |
|
|
226 | } else { |
|
|
227 | $cb->(-1); |
|
|
228 | } |
|
|
229 | }; |
|
|
230 | } else { |
|
|
231 | $cb->($_[0]); |
|
|
232 | } |
|
|
233 | }; |
|
|
234 | } |
|
|
235 | |
|
|
236 | =item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
|
|
237 | |
|
|
238 | Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts |
|
|
239 | reading at byte offset C<$in_offset>, and starts writing at the current |
|
|
240 | file offset of C<$out_fh>. Because of that, it is not safe to issue more |
|
|
241 | than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each |
|
|
242 | other. |
|
|
243 | |
|
|
244 | This call tries to make use of a native C<sendfile> syscall to provide |
|
|
245 | zero-copy operation. For this to work, C<$out_fh> should refer to a |
|
|
246 | socket, and C<$in_fh> should refer to mmap'able file. |
|
|
247 | |
|
|
248 | If the native sendfile call fails or is not implemented, it will be |
|
|
249 | emulated, so you can call C<aio_sendfile> on any type of filehandle |
|
|
250 | regardless of the limitations of the operating system. |
|
|
251 | |
|
|
252 | Please note, however, that C<aio_sendfile> can read more bytes from |
|
|
253 | C<$in_fh> than are written, and there is no way to find out how many |
|
|
254 | bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only |
|
|
255 | provides the number of bytes written to C<$out_fh>. Only if the result |
|
|
256 | value equals C<$length> one can assume that C<$length> bytes have been |
|
|
257 | read. |
|
|
258 | |
155 | =item aio_readahead $fh,$offset,$length, $callback |
259 | =item aio_readahead $fh,$offset,$length, $callback->($retval) |
156 | |
|
|
157 | Asynchronously reads the specified byte range into the page cache, using |
|
|
158 | the C<readahead> syscall. If that syscall doesn't exist (likely if your OS |
|
|
159 | isn't Linux) the status will be C<-1> and C<$!> is set to C<ENOSYS>. |
|
|
160 | |
260 | |
161 | C<aio_readahead> populates the page cache with data from a file so that |
261 | C<aio_readahead> populates the page cache with data from a file so that |
162 | subsequent reads from that file will not block on disk I/O. The C<$offset> |
262 | subsequent reads from that file will not block on disk I/O. The C<$offset> |
163 | argument specifies the starting point from which data is to be read and |
263 | argument specifies the starting point from which data is to be read and |
164 | C<$length> specifies the number of bytes to be read. I/O is performed in |
264 | C<$length> specifies the number of bytes to be read. I/O is performed in |
165 | whole pages, so that offset is effectively rounded down to a page boundary |
265 | whole pages, so that offset is effectively rounded down to a page boundary |
166 | and bytes are read up to the next page boundary greater than or equal to |
266 | and bytes are read up to the next page boundary greater than or equal to |
167 | (off-set+length). C<aio_readahead> does not read beyond the end of the |
267 | (off-set+length). C<aio_readahead> does not read beyond the end of the |
168 | file. The current file offset of the file is left unchanged. |
268 | file. The current file offset of the file is left unchanged. |
169 | |
269 | |
|
|
270 | If that syscall doesn't exist (likely if your OS isn't Linux) it will be |
|
|
271 | emulated by simply reading the data, which would have a similar effect. |
|
|
272 | |
170 | =item aio_stat $fh_or_path, $callback |
273 | =item aio_stat $fh_or_path, $callback->($status) |
171 | |
274 | |
172 | =item aio_lstat $fh, $callback |
275 | =item aio_lstat $fh, $callback->($status) |
173 | |
276 | |
174 | Works like perl's C<stat> or C<lstat> in void context. The callback will |
277 | Works like perl's C<stat> or C<lstat> in void context. The callback will |
175 | be called after the stat and the results will be available using C<stat _> |
278 | be called after the stat and the results will be available using C<stat _> |
176 | or C<-s _> etc... |
279 | or C<-s _> etc... |
177 | |
280 | |
… | |
… | |
187 | aio_stat "/etc/passwd", sub { |
290 | aio_stat "/etc/passwd", sub { |
188 | $_[0] and die "stat failed: $!"; |
291 | $_[0] and die "stat failed: $!"; |
189 | print "size is ", -s _, "\n"; |
292 | print "size is ", -s _, "\n"; |
190 | }; |
293 | }; |
191 | |
294 | |
192 | =item aio_unlink $pathname, $callback |
295 | =item aio_unlink $pathname, $callback->($status) |
193 | |
296 | |
194 | Asynchronously unlink (delete) a file and call the callback with the |
297 | Asynchronously unlink (delete) a file and call the callback with the |
195 | result code. |
298 | result code. |
196 | |
299 | |
|
|
300 | =item aio_link $srcpath, $dstpath, $callback->($status) |
|
|
301 | |
|
|
302 | Asynchronously create a new link to the existing object at C<$srcpath> at |
|
|
303 | the path C<$dstpath> and call the callback with the result code. |
|
|
304 | |
|
|
305 | =item aio_symlink $srcpath, $dstpath, $callback->($status) |
|
|
306 | |
|
|
307 | Asynchronously create a new symbolic link to the existing object at C<$srcpath> at |
|
|
308 | the path C<$dstpath> and call the callback with the result code. |
|
|
309 | |
|
|
310 | =item aio_rename $srcpath, $dstpath, $callback->($status) |
|
|
311 | |
|
|
312 | Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as |
|
|
313 | rename(2) and call the callback with the result code. |
|
|
314 | |
|
|
315 | =item aio_rmdir $pathname, $callback->($status) |
|
|
316 | |
|
|
317 | Asynchronously rmdir (delete) a directory and call the callback with the |
|
|
318 | result code. |
|
|
319 | |
|
|
320 | =item aio_readdir $pathname, $callback->($entries) |
|
|
321 | |
|
|
322 | Unlike the POSIX call of the same name, C<aio_readdir> reads an entire |
|
|
323 | directory (i.e. opendir + readdir + closedir). The entries will not be |
|
|
324 | sorted, and will B<NOT> include the C<.> and C<..> entries. |
|
|
325 | |
|
|
326 | The callback a single argument which is either C<undef> or an array-ref |
|
|
327 | with the filenames. |
|
|
328 | |
|
|
329 | =item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
|
|
330 | |
|
|
331 | Scans a directory (similar to C<aio_readdir>) and tries to separate the |
|
|
332 | entries of directory C<$path> into two sets of names, ones you can recurse |
|
|
333 | into (directories), and ones you cannot recurse into (everything else). |
|
|
334 | |
|
|
335 | C<aio_scandir> is a composite request that consists of many |
|
|
336 | aio-primitives. C<$maxreq> specifies the maximum number of outstanding |
|
|
337 | aio requests that this function generates. If it is C<< <= 0 >>, then a |
|
|
338 | suitable default will be chosen (currently 8). |
|
|
339 | |
|
|
340 | On error, the callback is called without arguments, otherwise it receives |
|
|
341 | two array-refs with path-relative entry names. |
|
|
342 | |
|
|
343 | Example: |
|
|
344 | |
|
|
345 | aio_scandir $dir, 0, sub { |
|
|
346 | my ($dirs, $nondirs) = @_; |
|
|
347 | print "real directories: @$dirs\n"; |
|
|
348 | print "everything else: @$nondirs\n"; |
|
|
349 | }; |
|
|
350 | |
|
|
351 | Implementation notes. |
|
|
352 | |
|
|
353 | The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can. |
|
|
354 | |
|
|
355 | After reading the directory, the modification time, size etc. of the |
|
|
356 | directory before and after the readdir is checked, and if they match, the |
|
|
357 | link count will be used to decide how many entries are directories (if |
|
|
358 | >= 2). Otherwise, no knowledge of the number of subdirectories will be |
|
|
359 | assumed. |
|
|
360 | |
|
|
361 | Then entires will be sorted into likely directories (everything without a |
|
|
362 | non-initial dot) and likely non-directories (everything else). Then every |
|
|
363 | entry + C</.> will be C<stat>'ed, likely directories first. This is often |
|
|
364 | faster because filesystems might detect the type of the entry without |
|
|
365 | reading the inode data (e.g. ext2fs filetype feature). If that succeeds, |
|
|
366 | it assumes that the entry is a directory or a symlink to directory (which |
|
|
367 | will be checked seperately). |
|
|
368 | |
|
|
369 | If the known number of directories has been reached, the rest of the |
|
|
370 | entries is assumed to be non-directories. |
|
|
371 | |
|
|
372 | =cut |
|
|
373 | |
|
|
374 | sub aio_scandir($$$) { |
|
|
375 | my ($path, $maxreq, $cb) = @_; |
|
|
376 | |
|
|
377 | $maxreq = 8 if $maxreq <= 0; |
|
|
378 | |
|
|
379 | # stat once |
|
|
380 | aio_stat $path, sub { |
|
|
381 | return $cb->() if $_[0]; |
|
|
382 | my $hash1 = join ":", (stat _)[0,1,3,7,9]; |
|
|
383 | |
|
|
384 | # read the directory entries |
|
|
385 | aio_readdir $path, sub { |
|
|
386 | my $entries = shift |
|
|
387 | or return $cb->(); |
|
|
388 | |
|
|
389 | # stat the dir another time |
|
|
390 | aio_stat $path, sub { |
|
|
391 | my $hash2 = join ":", (stat _)[0,1,3,7,9]; |
|
|
392 | |
|
|
393 | my $ndirs; |
|
|
394 | |
|
|
395 | # take the slow route if anything looks fishy |
|
|
396 | if ($hash1 ne $hash2) { |
|
|
397 | $ndirs = -1; |
|
|
398 | } else { |
|
|
399 | # if nlink == 2, we are finished |
|
|
400 | # on non-posix-fs's, we rely on nlink < 2 |
|
|
401 | $ndirs = (stat _)[3] - 2 |
|
|
402 | or return $cb->([], $entries); |
|
|
403 | } |
|
|
404 | |
|
|
405 | # sort into likely dirs and likely nondirs |
|
|
406 | # dirs == files without ".", short entries first |
|
|
407 | $entries = [map $_->[0], |
|
|
408 | sort { $b->[1] cmp $a->[1] } |
|
|
409 | map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length], |
|
|
410 | @$entries]; |
|
|
411 | |
|
|
412 | my (@dirs, @nondirs); |
|
|
413 | |
|
|
414 | my ($statcb, $schedcb); |
|
|
415 | my $nreq = 0; |
|
|
416 | |
|
|
417 | $schedcb = sub { |
|
|
418 | if (@$entries) { |
|
|
419 | if ($nreq < $maxreq) { |
|
|
420 | my $ent = pop @$entries; |
|
|
421 | $nreq++; |
|
|
422 | aio_stat "$path/$ent/.", sub { $statcb->($_[0], $ent) }; |
|
|
423 | } |
|
|
424 | } elsif (!$nreq) { |
|
|
425 | # finished |
|
|
426 | undef $statcb; |
|
|
427 | undef $schedcb; |
|
|
428 | $cb->(\@dirs, \@nondirs) if $cb; |
|
|
429 | undef $cb; |
|
|
430 | } |
|
|
431 | }; |
|
|
432 | $statcb = sub { |
|
|
433 | my ($status, $entry) = @_; |
|
|
434 | |
|
|
435 | if ($status < 0) { |
|
|
436 | $nreq--; |
|
|
437 | push @nondirs, $entry; |
|
|
438 | &$schedcb; |
|
|
439 | } else { |
|
|
440 | # need to check for real directory |
|
|
441 | aio_lstat "$path/$entry", sub { |
|
|
442 | $nreq--; |
|
|
443 | |
|
|
444 | if (-d _) { |
|
|
445 | push @dirs, $entry; |
|
|
446 | |
|
|
447 | if (!--$ndirs) { |
|
|
448 | push @nondirs, @$entries; |
|
|
449 | $entries = []; |
|
|
450 | } |
|
|
451 | } else { |
|
|
452 | push @nondirs, $entry; |
|
|
453 | } |
|
|
454 | |
|
|
455 | &$schedcb; |
|
|
456 | } |
|
|
457 | } |
|
|
458 | }; |
|
|
459 | |
|
|
460 | &$schedcb while @$entries && $nreq < $maxreq; |
|
|
461 | }; |
|
|
462 | }; |
|
|
463 | }; |
|
|
464 | } |
|
|
465 | |
197 | =item aio_fsync $fh, $callback |
466 | =item aio_fsync $fh, $callback->($status) |
198 | |
467 | |
199 | Asynchronously call fsync on the given filehandle and call the callback |
468 | Asynchronously call fsync on the given filehandle and call the callback |
200 | with the fsync result code. |
469 | with the fsync result code. |
201 | |
470 | |
202 | =item aio_fdatasync $fh, $callback |
471 | =item aio_fdatasync $fh, $callback->($status) |
203 | |
472 | |
204 | Asynchronously call fdatasync on the given filehandle and call the |
473 | Asynchronously call fdatasync on the given filehandle and call the |
205 | callback with the fdatasync result code. Might set C<$!> to C<ENOSYS> if |
474 | callback with the fdatasync result code. |
206 | C<fdatasync> is not available. |
475 | |
|
|
476 | If this call isn't available because your OS lacks it or it couldn't be |
|
|
477 | detected, it will be emulated by calling C<fsync> instead. |
207 | |
478 | |
208 | =back |
479 | =back |
209 | |
480 | |
210 | =head2 SUPPORT FUNCTIONS |
481 | =head2 SUPPORT FUNCTIONS |
211 | |
482 | |
… | |
… | |
269 | IO::AIO::poll_wait, IO::AIO::poll_cb |
540 | IO::AIO::poll_wait, IO::AIO::poll_cb |
270 | if IO::AIO::nreqs; |
541 | if IO::AIO::nreqs; |
271 | |
542 | |
272 | =item IO::AIO::min_parallel $nthreads |
543 | =item IO::AIO::min_parallel $nthreads |
273 | |
544 | |
274 | Set the minimum number of AIO threads to C<$nthreads>. The default is |
545 | Set the minimum number of AIO threads to C<$nthreads>. The current default |
275 | C<1>, which means a single asynchronous operation can be done at one time |
546 | is C<4>, which means four asynchronous operations can be done at one time |
276 | (the number of outstanding operations, however, is unlimited). |
547 | (the number of outstanding operations, however, is unlimited). |
|
|
548 | |
|
|
549 | IO::AIO starts threads only on demand, when an AIO request is queued and |
|
|
550 | no free thread exists. |
277 | |
551 | |
278 | It is recommended to keep the number of threads low, as some Linux |
552 | It is recommended to keep the number of threads low, as some Linux |
279 | kernel versions will scale negatively with the number of threads (higher |
553 | kernel versions will scale negatively with the number of threads (higher |
280 | parallelity => MUCH higher latency). With current Linux 2.6 versions, 4-32 |
554 | parallelity => MUCH higher latency). With current Linux 2.6 versions, 4-32 |
281 | threads should be fine. |
555 | threads should be fine. |
282 | |
556 | |
283 | Under normal circumstances you don't need to call this function, as this |
557 | Under most circumstances you don't need to call this function, as the |
284 | module automatically starts some threads (the exact number might change, |
558 | module selects a default that is suitable for low to moderate load. |
285 | and is currently 4). |
|
|
286 | |
559 | |
287 | =item IO::AIO::max_parallel $nthreads |
560 | =item IO::AIO::max_parallel $nthreads |
288 | |
561 | |
289 | Sets the maximum number of AIO threads to C<$nthreads>. If more than |
562 | Sets the maximum number of AIO threads to C<$nthreads>. If more than the |
290 | the specified number of threads are currently running, kill them. This |
563 | specified number of threads are currently running, this function kills |
291 | function blocks until the limit is reached. |
564 | them. This function blocks until the limit is reached. |
|
|
565 | |
|
|
566 | While C<$nthreads> are zero, aio requests get queued but not executed |
|
|
567 | until the number of threads has been increased again. |
292 | |
568 | |
293 | This module automatically runs C<max_parallel 0> at program end, to ensure |
569 | This module automatically runs C<max_parallel 0> at program end, to ensure |
294 | that all threads are killed and that there are no outstanding requests. |
570 | that all threads are killed and that there are no outstanding requests. |
295 | |
571 | |
296 | Under normal circumstances you don't need to call this function. |
572 | Under normal circumstances you don't need to call this function. |
… | |
… | |
300 | Sets the maximum number of outstanding requests to C<$nreqs>. If you |
576 | Sets the maximum number of outstanding requests to C<$nreqs>. If you |
301 | try to queue up more than this number of requests, the caller will block until |
577 | try to queue up more than this number of requests, the caller will block until |
302 | some requests have been handled. |
578 | some requests have been handled. |
303 | |
579 | |
304 | The default is very large, so normally there is no practical limit. If you |
580 | The default is very large, so normally there is no practical limit. If you |
305 | queue up many requests in a loop it it often improves speed if you set |
581 | queue up many requests in a loop it often improves speed if you set |
306 | this to a relatively low number, such as C<100>. |
582 | this to a relatively low number, such as C<100>. |
307 | |
583 | |
308 | Under normal circumstances you don't need to call this function. |
584 | Under normal circumstances you don't need to call this function. |
309 | |
585 | |
310 | =back |
586 | =back |
… | |
… | |
317 | |
593 | |
318 | # try to generate nice filehandles |
594 | # try to generate nice filehandles |
319 | my $sym = "IO::AIO::fd#$_[0]"; |
595 | my $sym = "IO::AIO::fd#$_[0]"; |
320 | local *$sym; |
596 | local *$sym; |
321 | |
597 | |
322 | open *$sym, "+<&$_[0]" # usually under any unix |
598 | open *$sym, "+<&=$_[0]" # usually works under any unix |
323 | or open *$sym, "<&$_[0]" # cygwin needs this |
599 | or open *$sym, "<&=$_[0]" # cygwin needs this |
324 | or open *$sym, ">&$_[0]" # cygwin needs this |
600 | or open *$sym, ">&=$_[0]" # or this |
325 | or return undef; |
601 | or return undef; |
326 | |
602 | |
327 | *$sym |
603 | *$sym |
328 | } |
604 | } |
329 | |
605 | |
… | |
… | |
333 | max_parallel 0; |
609 | max_parallel 0; |
334 | } |
610 | } |
335 | |
611 | |
336 | 1; |
612 | 1; |
337 | |
613 | |
|
|
614 | =head2 FORK BEHAVIOUR |
|
|
615 | |
|
|
616 | Before the fork, IO::AIO enters a quiescent state where no requests |
|
|
617 | can be added in other threads and no results will be processed. After |
|
|
618 | the fork the parent simply leaves the quiescent state and continues |
|
|
619 | request/result processing, while the child clears the request/result |
|
|
620 | queue (so the requests started before the fork will only be handled in |
|
|
621 | the parent). Threats will be started on demand until the limit ste in the |
|
|
622 | parent process has been reached again. |
|
|
623 | |
338 | =head1 SEE ALSO |
624 | =head1 SEE ALSO |
339 | |
625 | |
340 | L<Coro>, L<Linux::AIO>. |
626 | L<Coro>, L<Linux::AIO>. |
341 | |
627 | |
342 | =head1 AUTHOR |
628 | =head1 AUTHOR |