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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.14 by root, Mon Jul 11 02:53:59 2005 UTC vs.
Revision 1.29 by root, Wed Aug 17 04:47:02 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 = 1.2;
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}
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81which must be a code reference. This code reference will get called with 85which must be a code reference. This code reference will get called with
82the syscall return code (e.g. most syscalls return C<-1> on error, unlike 86the syscall return code (e.g. most syscalls return C<-1> on error, unlike
83perl, which usually delivers "false") as it's sole argument when the given 87perl, which usually delivers "false") as it's sole argument when the given
84syscall has been 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 pathnames you pass to these routines I<must> be absolute and
89is that at the time the request is being executed, the current working 94encoded in byte form. The reason for the former is that at the time the
90directory could have changed. Alternatively, you can make sure that you 95request is being executed, the current working directory could have
96changed. Alternatively, you can make sure that you never change the
91never change the current working directory. 97current working directory.
98
99To encode pathnames to byte form, either make sure you either: a)
100always pass in filenames you got from outside (command line, readdir
101etc.), b) are ASCII or ISO 8859-1, c) use the Encode module and encode
102your pathnames to the locale (or other) encoding in effect in the user
103environment, d) use Glib::filename_from_unicode on unicode filenames or e)
104use something else.
92 105
93=over 4 106=over 4
94 107
95=item aio_open $pathname, $flags, $mode, $callback 108=item aio_open $pathname, $flags, $mode, $callback
96 109
… …
98created filehandle for the file. 111created filehandle for the file.
99 112
100The pathname passed to C<aio_open> must be absolute. See API NOTES, above, 113The pathname passed to C<aio_open> must be absolute. See API NOTES, above,
101for an explanation. 114for an explanation.
102 115
103The C<$mode> argument is a bitmask. See the C<Fcntl> module for a 116The C<$flags> argument is a bitmask. See the C<Fcntl> module for a
104list. They are the same as used in C<sysopen>. 117list. They are the same as used by C<sysopen>.
118
119Likewise, C<$mode> specifies the mode of the newly created file, if it
120didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>,
121except that it is mandatory (i.e. use C<0> if you don't create new files,
122and C<0666> or C<0777> if you do).
105 123
106Example: 124Example:
107 125
108 aio_open "/etc/passwd", O_RDONLY, 0, sub { 126 aio_open "/etc/passwd", O_RDONLY, 0, sub {
109 if ($_[0]) { 127 if ($_[0]) {
… …
116 134
117=item aio_close $fh, $callback 135=item aio_close $fh, $callback
118 136
119Asynchronously close a file and call the callback with the result 137Asynchronously close a file and call the callback with the result
120code. I<WARNING:> although accepted, you should not pass in a perl 138code. I<WARNING:> although accepted, you should not pass in a perl
121filehandle here, as perl will likely close the file descriptor itself when 139filehandle here, as perl will likely close the file descriptor another
122the filehandle is destroyed. Normally, you can safely call perls C<close> 140time when the filehandle is destroyed. Normally, you can safely call perls
123or just let filehandles go out of scope. 141C<close> or just let filehandles go out of scope.
142
143This is supposed to be a bug in the API, so that might change. It's
144therefore best to avoid this function.
124 145
125=item aio_read $fh,$offset,$length, $data,$dataoffset,$callback 146=item aio_read $fh,$offset,$length, $data,$dataoffset,$callback
126 147
127=item aio_write $fh,$offset,$length, $data,$dataoffset,$callback 148=item aio_write $fh,$offset,$length, $data,$dataoffset,$callback
128 149
129Reads or writes C<length> bytes from the specified C<fh> and C<offset> 150Reads or writes C<length> bytes from the specified C<fh> and C<offset>
130into the scalar given by C<data> and offset C<dataoffset> and calls the 151into the scalar given by C<data> and offset C<dataoffset> and calls the
131callback without the actual number of bytes read (or -1 on error, just 152callback without the actual number of bytes read (or -1 on error, just
132like the syscall). 153like the syscall).
133 154
134Example: Read 15 bytes at offset 7 into scalar C<$buffer>, strating at 155Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
135offset C<0> within the scalar: 156offset C<0> within the scalar:
136 157
137 aio_read $fh, 7, 15, $buffer, 0, sub { 158 aio_read $fh, 7, 15, $buffer, 0, sub {
138 $_[0] > 0 or die "read error: $!"; 159 $_[0] > 0 or die "read error: $!";
139 print "read $_[0] bytes: <$buffer>\n"; 160 print "read $_[0] bytes: <$buffer>\n";
140 }; 161 };
141 162
142=item aio_readahead $fh,$offset,$length, $callback 163=item aio_readahead $fh,$offset,$length, $callback
143 164
144Asynchronously reads the specified byte range into the page cache, using
145the C<readahead> syscall. If that syscall doesn't exist the status will be
146C<-1> and C<$!> is set to ENOSYS.
147
148readahead() populates the page cache with data from a file so that 165C<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<$offset> 166subsequent reads from that file will not block on disk I/O. The C<$offset>
150argument specifies the starting point from which data is to be read and 167argument specifies the starting point from which data is to be read and
151C<$length> specifies the number of bytes to be read. I/O is performed in 168C<$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 169whole 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 170and 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 171(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. 172file. The current file offset of the file is left unchanged.
173
174If that syscall doesn't exist (likely if your OS isn't Linux) it will be
175emulated by simply reading the data, which would have a similar effect.
156 176
157=item aio_stat $fh_or_path, $callback 177=item aio_stat $fh_or_path, $callback
158 178
159=item aio_lstat $fh, $callback 179=item aio_lstat $fh, $callback
160 180
… …
179=item aio_unlink $pathname, $callback 199=item aio_unlink $pathname, $callback
180 200
181Asynchronously unlink (delete) a file and call the callback with the 201Asynchronously unlink (delete) a file and call the callback with the
182result code. 202result code.
183 203
204=item aio_rmdir $pathname, $callback
205
206Asynchronously rmdir (delete) a directory and call the callback with the
207result code.
208
184=item aio_fsync $fh, $callback 209=item aio_fsync $fh, $callback
185 210
186Asynchronously call fsync on the given filehandle and call the callback 211Asynchronously call fsync on the given filehandle and call the callback
187with the fsync result code. 212with the fsync result code.
188 213
189=item aio_fdatasync $fh, $callback 214=item aio_fdatasync $fh, $callback
190 215
191Asynchronously call fdatasync on the given filehandle and call the 216Asynchronously call fdatasync on the given filehandle and call the
192callback with the fdatasync result code. 217callback with the fdatasync result code.
193 218
219If this call isn't available because your OS lacks it or it couldn't be
220detected, it will be emulated by calling C<fsync> instead.
221
194=back 222=back
195 223
196=head2 SUPPORT FUNCTIONS 224=head2 SUPPORT FUNCTIONS
197 225
198=over 4 226=over 4
199 227
200=item $fileno = IO::AIO::poll_fileno 228=item $fileno = IO::AIO::poll_fileno
201 229
202Return the I<request result pipe filehandle>. This filehandle must be 230Return the I<request result pipe file descriptor>. This filehandle must be
203polled for reading by some mechanism outside this module (e.g. Event 231polled 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 232select, see below or the SYNOPSIS). If the pipe becomes readable you have
205C<poll_cb> to check the results. 233to call C<poll_cb> to check the results.
206 234
207See C<poll_cb> for an example. 235See C<poll_cb> for an example.
208 236
209=item IO::AIO::poll_cb 237=item IO::AIO::poll_cb
210 238
211Process all outstanding events on the result pipe. You have to call this 239Process all outstanding events on the result pipe. You have to call this
212regularly. Returns the number of events processed. Returns immediately 240regularly. Returns the number of events processed. Returns immediately
213when no events are outstanding. 241when no events are outstanding.
214 242
215You can use Event to multiplex, e.g.: 243Example: Install an Event watcher that automatically calls
244IO::AIO::poll_cb with high priority:
216 245
217 Event->io (fd => IO::AIO::poll_fileno, 246 Event->io (fd => IO::AIO::poll_fileno,
218 poll => 'r', async => 1, 247 poll => 'r', async => 1,
219 cb => \&IO::AIO::poll_cb); 248 cb => \&IO::AIO::poll_cb);
220 249
221=item IO::AIO::poll_wait 250=item IO::AIO::poll_wait
222 251
223Wait till the result filehandle becomes ready for reading (simply does a 252Wait till the result filehandle becomes ready for reading (simply does a
224select on the filehandle. This is useful if you want to synchronously wait 253C<select> on the filehandle. This is useful if you want to synchronously wait
225for some requests to finish). 254for some requests to finish).
226 255
227See C<nreqs> for an example. 256See C<nreqs> for an example.
228 257
229=item IO::AIO::nreqs 258=item IO::AIO::nreqs
230 259
231Returns the number of requests currently outstanding. 260Returns the number of requests currently outstanding (i.e. for which their
261callback has not been invoked yet).
232 262
233Example: wait till there are no outstanding requests anymore: 263Example: wait till there are no outstanding requests anymore:
234 264
235 IO::AIO::poll_wait, IO::AIO::poll_cb 265 IO::AIO::poll_wait, IO::AIO::poll_cb
236 while IO::AIO::nreqs; 266 while IO::AIO::nreqs;
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297 327
298# support function to convert a fd into a perl filehandle 328# support function to convert a fd into a perl filehandle
299sub _fd2fh { 329sub _fd2fh {
300 return undef if $_[0] < 0; 330 return undef if $_[0] < 0;
301 331
302 # try to be perl5.6-compatible 332 # try to generate nice filehandles
303 local *AIO_FH; 333 my $sym = "IO::AIO::fd#$_[0]";
304 open AIO_FH, "+<&=$_[0]" 334 local *$sym;
335
336 open *$sym, "+<&=$_[0]" # usually works under any unix
337 or open *$sym, "<&=$_[0]" # cygwin needs this
338 or open *$sym, ">&=$_[0]" # or this
305 or return undef; 339 or return undef;
306 340
307 *AIO_FH 341 *$sym
308} 342}
309 343
310min_parallel 4; 344min_parallel 4;
311 345
312END { 346END {
313 max_parallel 0; 347 max_parallel 0;
314} 348}
315 349
3161; 3501;
317 351
352=head2 FORK BEHAVIOUR
353
354Before the fork IO::AIO first handles all outstanding requests - if other
355threads add requests during this period, this time is prolonged. It then
356enters a quiescent state where no requests can be added in other threads
357and no results will be processed. After the fork the parent simply leaves
358the quiescent state and continues request processing, while the child will
359free the request and result queue and start the same number of threads as
360were in use by the parent.
361
318=head1 SEE ALSO 362=head1 SEE ALSO
319 363
320L<Coro>, L<Linux::AIO>. 364L<Coro>, L<Linux::AIO>.
321 365
322=head1 AUTHOR 366=head1 AUTHOR

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