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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.12 by root, Mon Jul 11 01:03:17 2005 UTC vs.
Revision 1.22 by root, Wed Jul 20 21:55:27 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
59use base 'Exporter'; 61use base 'Exporter';
60 62
61use Fcntl (); 63use Fcntl ();
62 64
63BEGIN { 65BEGIN {
64 $VERSION = 0.3; 66 $VERSION = 0.9;
65 67
66 @EXPORT = qw(aio_read aio_write aio_open aio_close aio_stat aio_lstat aio_unlink 68 @EXPORT = qw(aio_read aio_write aio_open aio_close aio_stat aio_lstat aio_unlink
67 aio_fsync aio_fdatasync aio_readahead); 69 aio_fsync aio_fdatasync aio_readahead);
68 @EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel max_outstanding nreqs); 70 @EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel max_outstanding nreqs);
69 71
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75 77
76=head2 AIO FUNCTIONS 78=head2 AIO FUNCTIONS
77 79
78All the C<aio_*> calls are more or less thin wrappers around the syscall 80All the C<aio_*> calls are more or less thin wrappers around the syscall
79with the same name (sans C<aio_>). The arguments are similar or identical, 81with the same name (sans C<aio_>). The arguments are similar or identical,
80and they all accept an additional C<$callback> argument which must be 82and they all accept an additional (and optional) C<$callback> argument
81a code reference. This code reference will get called with the syscall 83which 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 84the 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 85perl, which usually delivers "false") as it's sole argument when the given
84been executed asynchronously. 86syscall has been executed asynchronously.
85 87
86All functions that expect a filehandle will also accept a file descriptor. 88All functions that expect a filehandle will also accept a file descriptor.
87 89
88The filenames you pass to these routines I<must> be absolute. The reason 90The 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 91for this is that at the time the request is being executed, the current
90directory could have changed. Alternatively, you can make sure that you 92working directory could have changed. Alternatively, you can make sure
91never change the current working directory. 93that you never change the current working directory.
92 94
93=over 4 95=over 4
94 96
95=item aio_open $pathname, $flags, $mode, $callback 97=item aio_open $pathname, $flags, $mode, $callback
96 98
… …
98created filehandle for the file. 100created filehandle for the file.
99 101
100The pathname passed to C<aio_open> must be absolute. See API NOTES, above, 102The pathname passed to C<aio_open> must be absolute. See API NOTES, above,
101for an explanation. 103for an explanation.
102 104
103The C<$mode> argument is a bitmask. See the C<Fcntl> module for a 105The C<$flags> argument is a bitmask. See the C<Fcntl> module for a
104list. They are the same as used in C<sysopen>. 106list. They are the same as used by C<sysopen>.
107
108Likewise, C<$mode> specifies the mode of the newly created file, if it
109didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>,
110except that it is mandatory (i.e. use C<0> if you don't create new files,
111and C<0666> or C<0777> if you do).
105 112
106Example: 113Example:
107 114
108 aio_open "/etc/passwd", O_RDONLY, 0, sub { 115 aio_open "/etc/passwd", O_RDONLY, 0, sub {
109 if ($_[0]) { 116 if ($_[0]) {
… …
116 123
117=item aio_close $fh, $callback 124=item aio_close $fh, $callback
118 125
119Asynchronously close a file and call the callback with the result 126Asynchronously close a file and call the callback with the result
120code. I<WARNING:> although accepted, you should not pass in a perl 127code. I<WARNING:> although accepted, you should not pass in a perl
121filehandle here, as perl will likely close the file descriptor itself when 128filehandle here, as perl will likely close the file descriptor another
122the filehandle is destroyed. Normally, you can safely call perls C<close> 129time when the filehandle is destroyed. Normally, you can safely call perls
123or just let filehandles go out of scope. 130C<close> or just let filehandles go out of scope.
131
132This is supposed to be a bug in the API, so that might change. It's
133therefore best to avoid this function.
124 134
125=item aio_read $fh,$offset,$length, $data,$dataoffset,$callback 135=item aio_read $fh,$offset,$length, $data,$dataoffset,$callback
126 136
127=item aio_write $fh,$offset,$length, $data,$dataoffset,$callback 137=item aio_write $fh,$offset,$length, $data,$dataoffset,$callback
128 138
129Reads or writes C<length> bytes from the specified C<fh> and C<offset> 139Reads or writes C<length> bytes from the specified C<fh> and C<offset>
130into the scalar given by C<data> and offset C<dataoffset> and calls the 140into the scalar given by C<data> and offset C<dataoffset> and calls the
131callback without the actual number of bytes read (or -1 on error, just 141callback without the actual number of bytes read (or -1 on error, just
132like the syscall). 142like the syscall).
133 143
134Example: Read 15 bytes at offset 7 into scalar C<$buffer>, strating at 144Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
135offset C<0> within the scalar: 145offset C<0> within the scalar:
136 146
137 aio_read $fh, 7, 15, $buffer, 0, sub { 147 aio_read $fh, 7, 15, $buffer, 0, sub {
138 $_[0] > 0 or die "read error: $!"; 148 $_[0] > 0 or die "read error: $!";
139 print "read $_[0] bytes: <$buffer>\n"; 149 print "read $_[0] bytes: <$buffer>\n";
140 }; 150 };
141 151
142=item aio_readahead $fh,$offset,$length, $callback 152=item aio_readahead $fh,$offset,$length, $callback
143 153
144Asynchronously reads the specified byte range into the page cache, using 154Asynchronously reads the specified byte range into the page cache, using
145the C<readahead> syscall. If that syscall doesn't exist the status will be 155the C<readahead> syscall. If that syscall doesn't exist (likely if your OS
146C<-1> and C<$!> is set to ENOSYS. 156isn't Linux) the status will be C<-1> and C<$!> is set to C<ENOSYS>.
147 157
148readahead() populates the page cache with data from a file so that 158C<aio_readahead> populates the page cache with data from a file so that
149subsequent reads from that file will not block on disk I/O. The C<$offset> 159subsequent reads from that file will not block on disk I/O. The C<$offset>
150argument specifies the starting point from which data is to be read and 160argument specifies the starting point from which data is to be read and
151C<$length> specifies the number of bytes to be read. I/O is performed in 161C<$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 162whole 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 163and 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 164(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. 165file. The current file offset of the file is left unchanged.
156 166
157=item aio_stat $fh_or_path, $callback 167=item aio_stat $fh_or_path, $callback
158 168
159=item aio_lstat $fh, $callback 169=item aio_lstat $fh, $callback
… …
187with the fsync result code. 197with the fsync result code.
188 198
189=item aio_fdatasync $fh, $callback 199=item aio_fdatasync $fh, $callback
190 200
191Asynchronously call fdatasync on the given filehandle and call the 201Asynchronously call fdatasync on the given filehandle and call the
192callback with the fdatasync result code. 202callback with the fdatasync result code. Might set C<$!> to C<ENOSYS> if
203C<fdatasync> is not available.
193 204
194=back 205=back
195 206
196=head2 SUPPORT FUNCTIONS 207=head2 SUPPORT FUNCTIONS
197 208
198=over 4 209=over 4
199 210
200=item $fileno = IO::AIO::poll_fileno 211=item $fileno = IO::AIO::poll_fileno
201 212
202Return the I<request result pipe filehandle>. This filehandle must be 213Return the I<request result pipe file descriptor>. This filehandle must be
203polled for reading by some mechanism outside this module (e.g. Event 214polled 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 215select, see below or the SYNOPSIS). If the pipe becomes readable you have
205C<poll_cb> to check the results. 216to call C<poll_cb> to check the results.
206 217
207See C<poll_cb> for an example. 218See C<poll_cb> for an example.
208 219
209=item IO::AIO::poll_cb 220=item IO::AIO::poll_cb
210 221
211Process all outstanding events on the result pipe. You have to call this 222Process all outstanding events on the result pipe. You have to call this
212regularly. Returns the number of events processed. Returns immediately 223regularly. Returns the number of events processed. Returns immediately
213when no events are outstanding. 224when no events are outstanding.
214 225
215You can use Event to multiplex, e.g.: 226Example: Install an Event watcher that automatically calls
227IO::AIO::poll_cb with high priority:
216 228
217 Event->io (fd => IO::AIO::poll_fileno, 229 Event->io (fd => IO::AIO::poll_fileno,
218 poll => 'r', async => 1, 230 poll => 'r', async => 1,
219 cb => \&IO::AIO::poll_cb); 231 cb => \&IO::AIO::poll_cb);
220 232
221=item IO::AIO::poll_wait 233=item IO::AIO::poll_wait
222 234
223Wait till the result filehandle becomes ready for reading (simply does a 235Wait till the result filehandle becomes ready for reading (simply does a
224select on the filehandle. This is useful if you want to synchronously wait 236C<select> on the filehandle. This is useful if you want to synchronously wait
225for some requests to finish). 237for some requests to finish).
226 238
227See C<nreqs> for an example. 239See C<nreqs> for an example.
228 240
229=item IO::AIO::nreqs 241=item IO::AIO::nreqs
230 242
231Returns the number of requests currently outstanding. 243Returns the number of requests currently outstanding (i.e. for which their
244callback has not been invoked yet).
232 245
233Example: wait till there are no outstanding requests anymore: 246Example: wait till there are no outstanding requests anymore:
234 247
235 IO::AIO::poll_wait, IO::AIO::poll_cb 248 IO::AIO::poll_wait, IO::AIO::poll_cb
236 while IO::AIO::nreqs; 249 while IO::AIO::nreqs;
237 250
238=item IO::AIO::flush 251=item IO::AIO::flush
239 252
240Wait till all outstanding AIO requests have been handled. 253Wait till all outstanding AIO requests have been handled.
254
255Strictly equivalent to:
256
257 IO::AIO::poll_wait, IO::AIO::poll_cb
258 while IO::AIO::nreqs;
259
260=item IO::AIO::poll
261
262Waits until some requests have been handled.
263
264Strictly equivalent to:
265
266 IO::AIO::poll_wait, IO::AIO::poll_cb
267 if IO::AIO::nreqs;
241 268
242=item IO::AIO::min_parallel $nthreads 269=item IO::AIO::min_parallel $nthreads
243 270
244Set the minimum number of AIO threads to C<$nthreads>. The default is 271Set 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 272C<1>, which means a single asynchronous operation can be done at one time

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