… | |
… | |
12 | }; |
12 | }; |
13 | |
13 | |
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 | |
19 | |
20 | # Event |
20 | # Event |
21 | Event->io (fd => IO::AIO::poll_fileno, |
21 | Event->io (fd => IO::AIO::poll_fileno, |
22 | poll => 'r', |
22 | poll => 'r', |
23 | cb => \&IO::AIO::poll_cb); |
23 | cb => \&IO::AIO::poll_cb); |
24 | |
24 | |
25 | # Glib/Gtk2 |
25 | # Glib/Gtk2 |
26 | add_watch Glib::IO IO::AIO::poll_fileno, |
26 | add_watch Glib::IO IO::AIO::poll_fileno, |
27 | \&IO::AIO::poll_cb; |
27 | in => sub { IO::AIO::poll_cb; 1 }; |
28 | |
28 | |
29 | # Tk |
29 | # Tk |
30 | Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "", |
30 | Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "", |
31 | readable => \&IO::AIO::poll_cb); |
31 | readable => \&IO::AIO::poll_cb); |
|
|
32 | |
|
|
33 | # Danga::Socket |
|
|
34 | Danga::Socket->AddOtherFds (IO::AIO::poll_fileno => |
|
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35 | \&IO::AIO::poll_cb); |
|
|
36 | |
32 | |
37 | |
33 | =head1 DESCRIPTION |
38 | =head1 DESCRIPTION |
34 | |
39 | |
35 | This module implements asynchronous I/O using whatever means your |
40 | This module implements asynchronous I/O using whatever means your |
36 | operating system supports. |
41 | operating system supports. |
… | |
… | |
43 | not well-supported (Linux doesn't allow them on normal files currently, |
48 | not well-supported (Linux doesn't allow them on normal files currently, |
44 | for example), and they would only support aio_read and aio_write, so the |
49 | for example), and they would only support aio_read and aio_write, so the |
45 | remaining functionality would have to be implemented using threads anyway. |
50 | remaining functionality would have to be implemented using threads anyway. |
46 | |
51 | |
47 | Although the module will work with in the presence of other threads, it is |
52 | Although the module will work with in the presence of other threads, it is |
48 | currently not reentrant, so use appropriate locking yourself. |
53 | currently not reentrant, so use appropriate locking yourself, always call |
|
|
54 | C<poll_cb> from within the same thread, or never call C<poll_cb> (or other |
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55 | C<aio_> functions) recursively. |
49 | |
56 | |
50 | =cut |
57 | =cut |
51 | |
58 | |
52 | package IO::AIO; |
59 | package IO::AIO; |
53 | |
60 | |
|
|
61 | no warnings; |
|
|
62 | |
54 | use base 'Exporter'; |
63 | use base 'Exporter'; |
55 | |
64 | |
56 | use Fcntl (); |
65 | use Fcntl (); |
57 | |
66 | |
58 | BEGIN { |
67 | BEGIN { |
59 | $VERSION = 0.2; |
68 | $VERSION = 1.3; |
|
|
69 | |
60 | |
70 | |
61 | @EXPORT = qw(aio_read aio_write aio_open aio_close aio_stat aio_lstat aio_unlink |
71 | @EXPORT = qw(aio_read aio_write aio_open aio_close aio_stat aio_lstat aio_unlink |
62 | aio_fsync aio_fdatasync aio_readahead); |
72 | aio_rmdir aio_symlink aio_fsync aio_fdatasync aio_readahead); |
63 | @EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel max_outstanding nreqs); |
73 | @EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel max_outstanding nreqs); |
64 | |
74 | |
65 | require XSLoader; |
75 | require XSLoader; |
66 | XSLoader::load IO::AIO, $VERSION; |
76 | XSLoader::load IO::AIO, $VERSION; |
67 | } |
77 | } |
… | |
… | |
70 | |
80 | |
71 | =head2 AIO FUNCTIONS |
81 | =head2 AIO FUNCTIONS |
72 | |
82 | |
73 | All the C<aio_*> calls are more or less thin wrappers around the syscall |
83 | All the C<aio_*> calls are more or less thin wrappers around the syscall |
74 | with the same name (sans C<aio_>). The arguments are similar or identical, |
84 | with the same name (sans C<aio_>). The arguments are similar or identical, |
75 | and they all accept an additional C<$callback> argument which must be |
85 | and they all accept an additional (and optional) C<$callback> argument |
76 | a code reference. This code reference will get called with the syscall |
86 | which must be a code reference. This code reference will get called with |
77 | return code (e.g. most syscalls return C<-1> on error, unlike perl, which |
87 | the syscall return code (e.g. most syscalls return C<-1> on error, unlike |
78 | usually delivers "false") as it's sole argument when the given syscall has |
88 | perl, which usually delivers "false") as it's sole argument when the given |
79 | been executed asynchronously. |
89 | syscall has been executed asynchronously. |
80 | |
90 | |
81 | All functions that expect a filehandle will also accept a file descriptor. |
91 | All functions expecting a filehandle keep a copy of the filehandle |
|
|
92 | internally until the request has finished. |
82 | |
93 | |
83 | The filenames you pass to these routines I<must> be absolute. The reason |
94 | The pathnames you pass to these routines I<must> be absolute and |
84 | is that at the time the request is being executed, the current working |
95 | encoded in byte form. The reason for the former is that at the time the |
85 | directory could have changed. Alternatively, you can make sure that you |
96 | request is being executed, the current working directory could have |
|
|
97 | changed. Alternatively, you can make sure that you never change the |
86 | never change the current working directory. |
98 | current working directory. |
|
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99 | |
|
|
100 | To encode pathnames to byte form, either make sure you either: a) |
|
|
101 | always pass in filenames you got from outside (command line, readdir |
|
|
102 | etc.), b) are ASCII or ISO 8859-1, c) use the Encode module and encode |
|
|
103 | your pathnames to the locale (or other) encoding in effect in the user |
|
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104 | environment, d) use Glib::filename_from_unicode on unicode filenames or e) |
|
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105 | use something else. |
87 | |
106 | |
88 | =over 4 |
107 | =over 4 |
89 | |
108 | |
90 | =item aio_open $pathname, $flags, $mode, $callback |
109 | =item aio_open $pathname, $flags, $mode, $callback |
91 | |
110 | |
… | |
… | |
93 | created filehandle for the file. |
112 | created filehandle for the file. |
94 | |
113 | |
95 | The pathname passed to C<aio_open> must be absolute. See API NOTES, above, |
114 | The pathname passed to C<aio_open> must be absolute. See API NOTES, above, |
96 | for an explanation. |
115 | for an explanation. |
97 | |
116 | |
98 | The C<$mode> argument is a bitmask. See the C<Fcntl> module for a |
117 | The C<$flags> argument is a bitmask. See the C<Fcntl> module for a |
99 | list. They are the same as used in C<sysopen>. |
118 | list. They are the same as used by C<sysopen>. |
|
|
119 | |
|
|
120 | Likewise, C<$mode> specifies the mode of the newly created file, if it |
|
|
121 | didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>, |
|
|
122 | except that it is mandatory (i.e. use C<0> if you don't create new files, |
|
|
123 | and C<0666> or C<0777> if you do). |
100 | |
124 | |
101 | Example: |
125 | Example: |
102 | |
126 | |
103 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
127 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
104 | if ($_[0]) { |
128 | if ($_[0]) { |
… | |
… | |
111 | |
135 | |
112 | =item aio_close $fh, $callback |
136 | =item aio_close $fh, $callback |
113 | |
137 | |
114 | Asynchronously close a file and call the callback with the result |
138 | Asynchronously close a file and call the callback with the result |
115 | code. I<WARNING:> although accepted, you should not pass in a perl |
139 | code. I<WARNING:> although accepted, you should not pass in a perl |
116 | filehandle here, as perl will likely close the file descriptor itself when |
140 | filehandle here, as perl will likely close the file descriptor another |
117 | the filehandle is destroyed. Normally, you can safely call perls C<close> |
141 | time when the filehandle is destroyed. Normally, you can safely call perls |
118 | or just let filehandles go out of scope. |
142 | C<close> or just let filehandles go out of scope. |
|
|
143 | |
|
|
144 | This is supposed to be a bug in the API, so that might change. It's |
|
|
145 | therefore best to avoid this function. |
119 | |
146 | |
120 | =item aio_read $fh,$offset,$length, $data,$dataoffset,$callback |
147 | =item aio_read $fh,$offset,$length, $data,$dataoffset,$callback |
121 | |
148 | |
122 | =item aio_write $fh,$offset,$length, $data,$dataoffset,$callback |
149 | =item aio_write $fh,$offset,$length, $data,$dataoffset,$callback |
123 | |
150 | |
124 | Reads or writes C<length> bytes from the specified C<fh> and C<offset> |
151 | Reads or writes C<length> bytes from the specified C<fh> and C<offset> |
125 | into the scalar given by C<data> and offset C<dataoffset> and calls the |
152 | into the scalar given by C<data> and offset C<dataoffset> and calls the |
126 | callback without the actual number of bytes read (or -1 on error, just |
153 | callback without the actual number of bytes read (or -1 on error, just |
127 | like the syscall). |
154 | like the syscall). |
128 | |
155 | |
|
|
156 | The C<$data> scalar I<MUST NOT> be modified in any way while the request |
|
|
157 | is outstanding. Modifying it can result in segfaults or WW3 (if the |
|
|
158 | necessary/optional hardware is installed). |
|
|
159 | |
129 | Example: Read 15 bytes at offset 7 into scalar C<$buffer>, strating at |
160 | Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at |
130 | offset C<0> within the scalar: |
161 | offset C<0> within the scalar: |
131 | |
162 | |
132 | aio_read $fh, 7, 15, $buffer, 0, sub { |
163 | aio_read $fh, 7, 15, $buffer, 0, sub { |
133 | $_[0] >= 0 or die "read error: $!"; |
164 | $_[0] > 0 or die "read error: $!"; |
134 | print "read <$buffer>\n"; |
165 | print "read $_[0] bytes: <$buffer>\n"; |
135 | }; |
166 | }; |
136 | |
167 | |
137 | =item aio_readahead $fh,$offset,$length, $callback |
168 | =item aio_readahead $fh,$offset,$length, $callback |
138 | |
169 | |
139 | Asynchronously reads the specified byte range into the page cache, using |
|
|
140 | the C<readahead> syscall. If that syscall doesn't exist the status will be |
|
|
141 | C<-1> and C<$!> is set to ENOSYS. |
|
|
142 | |
|
|
143 | readahead() populates the page cache with data from a file so that |
170 | C<aio_readahead> populates the page cache with data from a file so that |
144 | subsequent reads from that file will not block on disk I/O. The C<$offset> |
171 | subsequent reads from that file will not block on disk I/O. The C<$offset> |
145 | argument specifies the starting point from which data is to be read and |
172 | argument specifies the starting point from which data is to be read and |
146 | C<$length> specifies the number of bytes to be read. I/O is performed in |
173 | C<$length> specifies the number of bytes to be read. I/O is performed in |
147 | whole pages, so that offset is effectively rounded down to a page boundary |
174 | whole pages, so that offset is effectively rounded down to a page boundary |
148 | and bytes are read up to the next page boundary greater than or equal to |
175 | and bytes are read up to the next page boundary greater than or equal to |
149 | (off-set+length). aio_readahead() does not read beyond the end of the |
176 | (off-set+length). C<aio_readahead> does not read beyond the end of the |
150 | file. The current file offset of the file is left unchanged. |
177 | file. The current file offset of the file is left unchanged. |
|
|
178 | |
|
|
179 | If that syscall doesn't exist (likely if your OS isn't Linux) it will be |
|
|
180 | emulated by simply reading the data, which would have a similar effect. |
151 | |
181 | |
152 | =item aio_stat $fh_or_path, $callback |
182 | =item aio_stat $fh_or_path, $callback |
153 | |
183 | |
154 | =item aio_lstat $fh, $callback |
184 | =item aio_lstat $fh, $callback |
155 | |
185 | |
… | |
… | |
174 | =item aio_unlink $pathname, $callback |
204 | =item aio_unlink $pathname, $callback |
175 | |
205 | |
176 | Asynchronously unlink (delete) a file and call the callback with the |
206 | Asynchronously unlink (delete) a file and call the callback with the |
177 | result code. |
207 | result code. |
178 | |
208 | |
|
|
209 | =item aio_rmdir $pathname, $callback |
|
|
210 | |
|
|
211 | Asynchronously rmdir (delete) a directory and call the callback with the |
|
|
212 | result code. |
|
|
213 | |
179 | =item aio_fsync $fh, $callback |
214 | =item aio_fsync $fh, $callback |
180 | |
215 | |
181 | Asynchronously call fsync on the given filehandle and call the callback |
216 | Asynchronously call fsync on the given filehandle and call the callback |
182 | with the fsync result code. |
217 | with the fsync result code. |
183 | |
218 | |
184 | =item aio_fdatasync $fh, $callback |
219 | =item aio_fdatasync $fh, $callback |
185 | |
220 | |
186 | Asynchronously call fdatasync on the given filehandle and call the |
221 | Asynchronously call fdatasync on the given filehandle and call the |
187 | callback with the fdatasync result code. |
222 | callback with the fdatasync result code. |
188 | |
223 | |
|
|
224 | If this call isn't available because your OS lacks it or it couldn't be |
|
|
225 | detected, it will be emulated by calling C<fsync> instead. |
|
|
226 | |
189 | =back |
227 | =back |
190 | |
228 | |
191 | =head2 SUPPORT FUNCTIONS |
229 | =head2 SUPPORT FUNCTIONS |
192 | |
230 | |
193 | =over 4 |
231 | =over 4 |
194 | |
232 | |
195 | =item $fileno = IO::AIO::poll_fileno |
233 | =item $fileno = IO::AIO::poll_fileno |
196 | |
234 | |
197 | Return the I<request result pipe filehandle>. This filehandle must be |
235 | Return the I<request result pipe file descriptor>. This filehandle must be |
198 | polled for reading by some mechanism outside this module (e.g. Event |
236 | polled for reading by some mechanism outside this module (e.g. Event or |
199 | or select, see below). If the pipe becomes readable you have to call |
237 | select, see below or the SYNOPSIS). If the pipe becomes readable you have |
200 | C<poll_cb> to check the results. |
238 | to call C<poll_cb> to check the results. |
201 | |
239 | |
202 | See C<poll_cb> for an example. |
240 | See C<poll_cb> for an example. |
203 | |
241 | |
204 | =item IO::AIO::poll_cb |
242 | =item IO::AIO::poll_cb |
205 | |
243 | |
206 | Process all outstanding events on the result pipe. You have to call this |
244 | Process all outstanding events on the result pipe. You have to call this |
207 | regularly. Returns the number of events processed. Returns immediately |
245 | regularly. Returns the number of events processed. Returns immediately |
208 | when no events are outstanding. |
246 | when no events are outstanding. |
209 | |
247 | |
210 | You can use Event to multiplex, e.g.: |
248 | Example: Install an Event watcher that automatically calls |
|
|
249 | IO::AIO::poll_cb with high priority: |
211 | |
250 | |
212 | Event->io (fd => IO::AIO::poll_fileno, |
251 | Event->io (fd => IO::AIO::poll_fileno, |
213 | poll => 'r', async => 1, |
252 | poll => 'r', async => 1, |
214 | cb => \&IO::AIO::poll_cb); |
253 | cb => \&IO::AIO::poll_cb); |
215 | |
254 | |
216 | =item IO::AIO::poll_wait |
255 | =item IO::AIO::poll_wait |
217 | |
256 | |
218 | Wait till the result filehandle becomes ready for reading (simply does a |
257 | Wait till the result filehandle becomes ready for reading (simply does a |
219 | select on the filehandle. This is useful if you want to synchronously wait |
258 | C<select> on the filehandle. This is useful if you want to synchronously wait |
220 | for some requests to finish). |
259 | for some requests to finish). |
221 | |
260 | |
222 | See C<nreqs> for an example. |
261 | See C<nreqs> for an example. |
223 | |
262 | |
224 | =item IO::AIO::nreqs |
263 | =item IO::AIO::nreqs |
225 | |
264 | |
226 | Returns the number of requests currently outstanding. |
265 | Returns the number of requests currently outstanding (i.e. for which their |
|
|
266 | callback has not been invoked yet). |
227 | |
267 | |
228 | Example: wait till there are no outstanding requests anymore: |
268 | Example: wait till there are no outstanding requests anymore: |
229 | |
269 | |
230 | IO::AIO::poll_wait, IO::AIO::poll_cb |
270 | IO::AIO::poll_wait, IO::AIO::poll_cb |
231 | while IO::AIO::nreqs; |
271 | while IO::AIO::nreqs; |
|
|
272 | |
|
|
273 | =item IO::AIO::flush |
|
|
274 | |
|
|
275 | Wait till all outstanding AIO requests have been handled. |
|
|
276 | |
|
|
277 | Strictly equivalent to: |
|
|
278 | |
|
|
279 | IO::AIO::poll_wait, IO::AIO::poll_cb |
|
|
280 | while IO::AIO::nreqs; |
|
|
281 | |
|
|
282 | =item IO::AIO::poll |
|
|
283 | |
|
|
284 | Waits until some requests have been handled. |
|
|
285 | |
|
|
286 | Strictly equivalent to: |
|
|
287 | |
|
|
288 | IO::AIO::poll_wait, IO::AIO::poll_cb |
|
|
289 | if IO::AIO::nreqs; |
232 | |
290 | |
233 | =item IO::AIO::min_parallel $nthreads |
291 | =item IO::AIO::min_parallel $nthreads |
234 | |
292 | |
235 | Set the minimum number of AIO threads to C<$nthreads>. The default is |
293 | Set the minimum number of AIO threads to C<$nthreads>. The default is |
236 | C<1>, which means a single asynchronous operation can be done at one time |
294 | C<1>, which means a single asynchronous operation can be done at one time |
… | |
… | |
274 | |
332 | |
275 | # support function to convert a fd into a perl filehandle |
333 | # support function to convert a fd into a perl filehandle |
276 | sub _fd2fh { |
334 | sub _fd2fh { |
277 | return undef if $_[0] < 0; |
335 | return undef if $_[0] < 0; |
278 | |
336 | |
279 | # try to be perl5.6-compatible |
337 | # try to generate nice filehandles |
280 | local *AIO_FH; |
338 | my $sym = "IO::AIO::fd#$_[0]"; |
281 | open AIO_FH, "+<&=$_[0]" |
339 | local *$sym; |
|
|
340 | |
|
|
341 | open *$sym, "+<&=$_[0]" # usually works under any unix |
|
|
342 | or open *$sym, "<&=$_[0]" # cygwin needs this |
|
|
343 | or open *$sym, ">&=$_[0]" # or this |
282 | or return undef; |
344 | or return undef; |
283 | |
345 | |
284 | *AIO_FH |
346 | *$sym |
285 | } |
347 | } |
286 | |
348 | |
287 | min_parallel 4; |
349 | min_parallel 4; |
288 | |
350 | |
289 | END { |
351 | END { |
290 | max_parallel 0; |
352 | max_parallel 0; |
291 | } |
353 | } |
292 | |
354 | |
293 | 1; |
355 | 1; |
294 | |
356 | |
|
|
357 | =head2 FORK BEHAVIOUR |
|
|
358 | |
|
|
359 | Before the fork IO::AIO enters a quiescent state where no requests can be |
|
|
360 | added in other threads and no results will be processed. After the fork |
|
|
361 | the parent simply leaves the quiescent state and continues request/result |
|
|
362 | processing, while the child clears the request/result queue and starts the |
|
|
363 | same number of threads as were in use by the parent. |
|
|
364 | |
295 | =head1 SEE ALSO |
365 | =head1 SEE ALSO |
296 | |
366 | |
297 | L<Coro>, L<Linux::AIO>. |
367 | L<Coro>, L<Linux::AIO>. |
298 | |
368 | |
299 | =head1 AUTHOR |
369 | =head1 AUTHOR |