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Revision 1.12 by root, Mon Jul 11 01:03:17 2005 UTC vs.
Revision 1.27 by root, Tue Aug 16 22:22:18 2005 UTC

… …
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 32
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48not well-supported (Linux doesn't allow them on normal files currently, 48not well-supported (Linux doesn't allow them on normal files currently,
49for example), and they would only support aio_read and aio_write, so the 49for example), and they would only support aio_read and aio_write, so the
50remaining functionality would have to be implemented using threads anyway. 50remaining functionality would have to be implemented using threads anyway.
51 51
52Although the module will work with in the presence of other threads, it is 52Although the module will work with in the presence of other threads, it is
53currently not reentrant, so use appropriate locking yourself. 53currently not reentrant, so use appropriate locking yourself, always call
54C<poll_cb> from within the same thread, or never call C<poll_cb> (or other
55C<aio_> functions) recursively.
54 56
55=cut 57=cut
56 58
57package IO::AIO; 59package IO::AIO;
58 60
61no warnings;
62
59use base 'Exporter'; 63use base 'Exporter';
60 64
61use Fcntl (); 65use Fcntl ();
62 66
63BEGIN { 67BEGIN {
64 $VERSION = 0.3; 68 $VERSION = 1.1;
65 69
66 @EXPORT = qw(aio_read aio_write aio_open aio_close aio_stat aio_lstat aio_unlink 70 @EXPORT = qw(aio_read aio_write aio_open aio_close aio_stat aio_lstat aio_unlink
67 aio_fsync aio_fdatasync aio_readahead); 71 aio_rmdir aio_symlink aio_fsync aio_fdatasync aio_readahead);
68 @EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel max_outstanding nreqs); 72 @EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel max_outstanding nreqs);
69 73
70 require XSLoader; 74 require XSLoader;
71 XSLoader::load IO::AIO, $VERSION; 75 XSLoader::load IO::AIO, $VERSION;
72} 76}
… …
75 79
76=head2 AIO FUNCTIONS 80=head2 AIO FUNCTIONS
77 81
78All the C<aio_*> calls are more or less thin wrappers around the syscall 82All the C<aio_*> calls are more or less thin wrappers around the syscall
79with the same name (sans C<aio_>). The arguments are similar or identical, 83with the same name (sans C<aio_>). The arguments are similar or identical,
80and they all accept an additional C<$callback> argument which must be 84and they all accept an additional (and optional) C<$callback> argument
81a code reference. This code reference will get called with the syscall 85which must be a code reference. This code reference will get called with
82return code (e.g. most syscalls return C<-1> on error, unlike perl, which 86the syscall return code (e.g. most syscalls return C<-1> on error, unlike
83usually delivers "false") as it's sole argument when the given syscall has 87perl, which usually delivers "false") as it's sole argument when the given
84been executed asynchronously. 88syscall has been executed asynchronously.
85 89
86All functions that expect a filehandle will also accept a file descriptor. 90All functions expecting a filehandle keep a copy of the filehandle
91internally until the request has finished.
87 92
88The filenames you pass to these routines I<must> be absolute. The reason 93The filenames you pass to these routines I<must> be absolute. The reason
89is that at the time the request is being executed, the current working 94for this is that at the time the request is being executed, the current
90directory could have changed. Alternatively, you can make sure that you 95working directory could have changed. Alternatively, you can make sure
91never change the current working directory. 96that you never change the current working directory.
92 97
93=over 4 98=over 4
94 99
95=item aio_open $pathname, $flags, $mode, $callback 100=item aio_open $pathname, $flags, $mode, $callback
96 101
… …
98created filehandle for the file. 103created filehandle for the file.
99 104
100The pathname passed to C<aio_open> must be absolute. See API NOTES, above, 105The pathname passed to C<aio_open> must be absolute. See API NOTES, above,
101for an explanation. 106for an explanation.
102 107
103The C<$mode> argument is a bitmask. See the C<Fcntl> module for a 108The C<$flags> argument is a bitmask. See the C<Fcntl> module for a
104list. They are the same as used in C<sysopen>. 109list. They are the same as used by C<sysopen>.
110
111Likewise, C<$mode> specifies the mode of the newly created file, if it
112didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>,
113except that it is mandatory (i.e. use C<0> if you don't create new files,
114and C<0666> or C<0777> if you do).
105 115
106Example: 116Example:
107 117
108 aio_open "/etc/passwd", O_RDONLY, 0, sub { 118 aio_open "/etc/passwd", O_RDONLY, 0, sub {
109 if ($_[0]) { 119 if ($_[0]) {
… …
116 126
117=item aio_close $fh, $callback 127=item aio_close $fh, $callback
118 128
119Asynchronously close a file and call the callback with the result 129Asynchronously close a file and call the callback with the result
120code. I<WARNING:> although accepted, you should not pass in a perl 130code. I<WARNING:> although accepted, you should not pass in a perl
121filehandle here, as perl will likely close the file descriptor itself when 131filehandle here, as perl will likely close the file descriptor another
122the filehandle is destroyed. Normally, you can safely call perls C<close> 132time when the filehandle is destroyed. Normally, you can safely call perls
123or just let filehandles go out of scope. 133C<close> or just let filehandles go out of scope.
134
135This is supposed to be a bug in the API, so that might change. It's
136therefore best to avoid this function.
124 137
125=item aio_read $fh,$offset,$length, $data,$dataoffset,$callback 138=item aio_read $fh,$offset,$length, $data,$dataoffset,$callback
126 139
127=item aio_write $fh,$offset,$length, $data,$dataoffset,$callback 140=item aio_write $fh,$offset,$length, $data,$dataoffset,$callback
128 141
129Reads or writes C<length> bytes from the specified C<fh> and C<offset> 142Reads or writes C<length> bytes from the specified C<fh> and C<offset>
130into the scalar given by C<data> and offset C<dataoffset> and calls the 143into the scalar given by C<data> and offset C<dataoffset> and calls the
131callback without the actual number of bytes read (or -1 on error, just 144callback without the actual number of bytes read (or -1 on error, just
132like the syscall). 145like the syscall).
133 146
134Example: Read 15 bytes at offset 7 into scalar C<$buffer>, strating at 147Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
135offset C<0> within the scalar: 148offset C<0> within the scalar:
136 149
137 aio_read $fh, 7, 15, $buffer, 0, sub { 150 aio_read $fh, 7, 15, $buffer, 0, sub {
138 $_[0] > 0 or die "read error: $!"; 151 $_[0] > 0 or die "read error: $!";
139 print "read $_[0] bytes: <$buffer>\n"; 152 print "read $_[0] bytes: <$buffer>\n";
140 }; 153 };
141 154
142=item aio_readahead $fh,$offset,$length, $callback 155=item aio_readahead $fh,$offset,$length, $callback
143 156
144Asynchronously reads the specified byte range into the page cache, using
145the C<readahead> syscall. If that syscall doesn't exist the status will be
146C<-1> and C<$!> is set to ENOSYS.
147
148readahead() populates the page cache with data from a file so that 157C<aio_readahead> populates the page cache with data from a file so that
149subsequent reads from that file will not block on disk I/O. The C<$offset> 158subsequent reads from that file will not block on disk I/O. The C<$offset>
150argument specifies the starting point from which data is to be read and 159argument specifies the starting point from which data is to be read and
151C<$length> specifies the number of bytes to be read. I/O is performed in 160C<$length> specifies the number of bytes to be read. I/O is performed in
152whole pages, so that offset is effectively rounded down to a page boundary 161whole pages, so that offset is effectively rounded down to a page boundary
153and bytes are read up to the next page boundary greater than or equal to 162and bytes are read up to the next page boundary greater than or equal to
154(off-set+length). aio_readahead() does not read beyond the end of the 163(off-set+length). C<aio_readahead> does not read beyond the end of the
155file. The current file offset of the file is left unchanged. 164file. The current file offset of the file is left unchanged.
165
166If that syscall doesn't exist (likely if your OS isn't Linux) it will be
167emulated by simply reading the data, which would have a similar effect.
156 168
157=item aio_stat $fh_or_path, $callback 169=item aio_stat $fh_or_path, $callback
158 170
159=item aio_lstat $fh, $callback 171=item aio_lstat $fh, $callback
160 172
… …
179=item aio_unlink $pathname, $callback 191=item aio_unlink $pathname, $callback
180 192
181Asynchronously unlink (delete) a file and call the callback with the 193Asynchronously unlink (delete) a file and call the callback with the
182result code. 194result code.
183 195
196=item aio_rmdir $pathname, $callback
197
198Asynchronously rmdir (delete) a directory and call the callback with the
199result code.
200
184=item aio_fsync $fh, $callback 201=item aio_fsync $fh, $callback
185 202
186Asynchronously call fsync on the given filehandle and call the callback 203Asynchronously call fsync on the given filehandle and call the callback
187with the fsync result code. 204with the fsync result code.
188 205
189=item aio_fdatasync $fh, $callback 206=item aio_fdatasync $fh, $callback
190 207
191Asynchronously call fdatasync on the given filehandle and call the 208Asynchronously call fdatasync on the given filehandle and call the
192callback with the fdatasync result code. 209callback with the fdatasync result code.
193 210
211If this call isn't available because your OS lacks it or it couldn't be
212detected, it will be emulated by calling C<fsync> instead.
213
194=back 214=back
195 215
196=head2 SUPPORT FUNCTIONS 216=head2 SUPPORT FUNCTIONS
197 217
198=over 4 218=over 4
199 219
200=item $fileno = IO::AIO::poll_fileno 220=item $fileno = IO::AIO::poll_fileno
201 221
202Return the I<request result pipe filehandle>. This filehandle must be 222Return the I<request result pipe file descriptor>. This filehandle must be
203polled for reading by some mechanism outside this module (e.g. Event 223polled for reading by some mechanism outside this module (e.g. Event or
204or select, see below). If the pipe becomes readable you have to call 224select, see below or the SYNOPSIS). If the pipe becomes readable you have
205C<poll_cb> to check the results. 225to call C<poll_cb> to check the results.
206 226
207See C<poll_cb> for an example. 227See C<poll_cb> for an example.
208 228
209=item IO::AIO::poll_cb 229=item IO::AIO::poll_cb
210 230
211Process all outstanding events on the result pipe. You have to call this 231Process all outstanding events on the result pipe. You have to call this
212regularly. Returns the number of events processed. Returns immediately 232regularly. Returns the number of events processed. Returns immediately
213when no events are outstanding. 233when no events are outstanding.
214 234
215You can use Event to multiplex, e.g.: 235Example: Install an Event watcher that automatically calls
236IO::AIO::poll_cb with high priority:
216 237
217 Event->io (fd => IO::AIO::poll_fileno, 238 Event->io (fd => IO::AIO::poll_fileno,
218 poll => 'r', async => 1, 239 poll => 'r', async => 1,
219 cb => \&IO::AIO::poll_cb); 240 cb => \&IO::AIO::poll_cb);
220 241
221=item IO::AIO::poll_wait 242=item IO::AIO::poll_wait
222 243
223Wait till the result filehandle becomes ready for reading (simply does a 244Wait till the result filehandle becomes ready for reading (simply does a
224select on the filehandle. This is useful if you want to synchronously wait 245C<select> on the filehandle. This is useful if you want to synchronously wait
225for some requests to finish). 246for some requests to finish).
226 247
227See C<nreqs> for an example. 248See C<nreqs> for an example.
228 249
229=item IO::AIO::nreqs 250=item IO::AIO::nreqs
230 251
231Returns the number of requests currently outstanding. 252Returns the number of requests currently outstanding (i.e. for which their
253callback has not been invoked yet).
232 254
233Example: wait till there are no outstanding requests anymore: 255Example: wait till there are no outstanding requests anymore:
234 256
235 IO::AIO::poll_wait, IO::AIO::poll_cb 257 IO::AIO::poll_wait, IO::AIO::poll_cb
236 while IO::AIO::nreqs; 258 while IO::AIO::nreqs;
237 259
238=item IO::AIO::flush 260=item IO::AIO::flush
239 261
240Wait till all outstanding AIO requests have been handled. 262Wait till all outstanding AIO requests have been handled.
263
264Strictly equivalent to:
265
266 IO::AIO::poll_wait, IO::AIO::poll_cb
267 while IO::AIO::nreqs;
268
269=item IO::AIO::poll
270
271Waits until some requests have been handled.
272
273Strictly equivalent to:
274
275 IO::AIO::poll_wait, IO::AIO::poll_cb
276 if IO::AIO::nreqs;
241 277
242=item IO::AIO::min_parallel $nthreads 278=item IO::AIO::min_parallel $nthreads
243 279
244Set the minimum number of AIO threads to C<$nthreads>. The default is 280Set the minimum number of AIO threads to C<$nthreads>. The default is
245C<1>, which means a single asynchronous operation can be done at one time 281C<1>, which means a single asynchronous operation can be done at one time
… …
283 319
284# support function to convert a fd into a perl filehandle 320# support function to convert a fd into a perl filehandle
285sub _fd2fh { 321sub _fd2fh {
286 return undef if $_[0] < 0; 322 return undef if $_[0] < 0;
287 323
288 # try to be perl5.6-compatible 324 # try to generate nice filehandles
289 local *AIO_FH; 325 my $sym = "IO::AIO::fd#$_[0]";
290 open AIO_FH, "+<&=$_[0]" 326 local *$sym;
327
328 open *$sym, "+<&=$_[0]" # usually works under any unix
329 or open *$sym, "<&=$_[0]" # cygwin needs this
330 or open *$sym, ">&=$_[0]" # or this
291 or return undef; 331 or return undef;
292 332
293 *AIO_FH 333 *$sym
294} 334}
295 335
296min_parallel 4; 336min_parallel 4;
297 337
298END { 338END {
299 max_parallel 0; 339 max_parallel 0;
300} 340}
301 341
3021; 3421;
303 343
344=head2 FORK BEHAVIOUR
345
346IO::AIO handles all outstanding AIO requests before the fork, destroys all
347AIO threads, and recreates them in both the parent and the child after the
348fork.
349
350
304=head1 SEE ALSO 351=head1 SEE ALSO
305 352
306L<Coro>, L<Linux::AIO>. 353L<Coro>, L<Linux::AIO>.
307 354
308=head1 AUTHOR 355=head1 AUTHOR

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