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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.13 by root, Mon Jul 11 01:49:14 2005 UTC vs.
Revision 1.20 by root, Tue Jul 12 11:29:40 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
… …
59use base 'Exporter'; 59use base 'Exporter';
60 60
61use Fcntl (); 61use Fcntl ();
62 62
63BEGIN { 63BEGIN {
64 $VERSION = 0.3; 64 $VERSION = 0.5;
65 65
66 @EXPORT = qw(aio_read aio_write aio_open aio_close aio_stat aio_lstat aio_unlink 66 @EXPORT = qw(aio_read aio_write aio_open aio_close aio_stat aio_lstat aio_unlink
67 aio_fsync aio_fdatasync aio_readahead); 67 aio_fsync aio_fdatasync aio_readahead);
68 @EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel max_outstanding nreqs); 68 @EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel max_outstanding nreqs);
69 69
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75 75
76=head2 AIO FUNCTIONS 76=head2 AIO FUNCTIONS
77 77
78All the C<aio_*> calls are more or less thin wrappers around the syscall 78All the C<aio_*> calls are more or less thin wrappers around the syscall
79with the same name (sans C<aio_>). The arguments are similar or identical, 79with the same name (sans C<aio_>). The arguments are similar or identical,
80and they all accept an additional C<$callback> argument which must be 80and they all accept an additional (and optional) C<$callback> argument
81a code reference. This code reference will get called with the syscall 81which 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 82the 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 83perl, which usually delivers "false") as it's sole argument when the given
84been executed asynchronously. 84syscall has been executed asynchronously.
85 85
86All functions that expect a filehandle will also accept a file descriptor. 86All functions that expect a filehandle will also accept a file descriptor.
87 87
88The filenames you pass to these routines I<must> be absolute. The reason 88The 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 89for this is that at the time the request is being executed, the current
90directory could have changed. Alternatively, you can make sure that you 90working directory could have changed. Alternatively, you can make sure
91never change the current working directory. 91that you never change the current working directory.
92 92
93=over 4 93=over 4
94 94
95=item aio_open $pathname, $flags, $mode, $callback 95=item aio_open $pathname, $flags, $mode, $callback
96 96
… …
98created filehandle for the file. 98created filehandle for the file.
99 99
100The pathname passed to C<aio_open> must be absolute. See API NOTES, above, 100The pathname passed to C<aio_open> must be absolute. See API NOTES, above,
101for an explanation. 101for an explanation.
102 102
103The C<$mode> argument is a bitmask. See the C<Fcntl> module for a 103The C<$flags> argument is a bitmask. See the C<Fcntl> module for a
104list. They are the same as used in C<sysopen>. 104list. They are the same as used by C<sysopen>.
105
106Likewise, C<$mode> specifies the mode of the newly created file, if it
107didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>,
108except that it is mandatory (i.e. use C<0> if you don't create new files,
109and C<0666> or C<0777> if you do).
105 110
106Example: 111Example:
107 112
108 aio_open "/etc/passwd", O_RDONLY, 0, sub { 113 aio_open "/etc/passwd", O_RDONLY, 0, sub {
109 if ($_[0]) { 114 if ($_[0]) {
… …
116 121
117=item aio_close $fh, $callback 122=item aio_close $fh, $callback
118 123
119Asynchronously close a file and call the callback with the result 124Asynchronously close a file and call the callback with the result
120code. I<WARNING:> although accepted, you should not pass in a perl 125code. I<WARNING:> although accepted, you should not pass in a perl
121filehandle here, as perl will likely close the file descriptor itself when 126filehandle here, as perl will likely close the file descriptor another
122the filehandle is destroyed. Normally, you can safely call perls C<close> 127time when the filehandle is destroyed. Normally, you can safely call perls
123or just let filehandles go out of scope. 128C<close> or just let filehandles go out of scope.
129
130This is supposed to be a bug in the API, so that might change. It's
131therefore best to avoid this function.
124 132
125=item aio_read $fh,$offset,$length, $data,$dataoffset,$callback 133=item aio_read $fh,$offset,$length, $data,$dataoffset,$callback
126 134
127=item aio_write $fh,$offset,$length, $data,$dataoffset,$callback 135=item aio_write $fh,$offset,$length, $data,$dataoffset,$callback
128 136
129Reads or writes C<length> bytes from the specified C<fh> and C<offset> 137Reads or writes C<length> bytes from the specified C<fh> and C<offset>
130into the scalar given by C<data> and offset C<dataoffset> and calls the 138into the scalar given by C<data> and offset C<dataoffset> and calls the
131callback without the actual number of bytes read (or -1 on error, just 139callback without the actual number of bytes read (or -1 on error, just
132like the syscall). 140like the syscall).
133 141
134Example: Read 15 bytes at offset 7 into scalar C<$buffer>, strating at 142Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
135offset C<0> within the scalar: 143offset C<0> within the scalar:
136 144
137 aio_read $fh, 7, 15, $buffer, 0, sub { 145 aio_read $fh, 7, 15, $buffer, 0, sub {
138 $_[0] > 0 or die "read error: $!"; 146 $_[0] > 0 or die "read error: $!";
139 print "read $_[0] bytes: <$buffer>\n"; 147 print "read $_[0] bytes: <$buffer>\n";
140 }; 148 };
141 149
142=item aio_readahead $fh,$offset,$length, $callback 150=item aio_readahead $fh,$offset,$length, $callback
143 151
144Asynchronously reads the specified byte range into the page cache, using 152Asynchronously reads the specified byte range into the page cache, using
145the C<readahead> syscall. If that syscall doesn't exist the status will be 153the C<readahead> syscall. If that syscall doesn't exist (likely if your OS
146C<-1> and C<$!> is set to ENOSYS. 154isn't Linux) the status will be C<-1> and C<$!> is set to C<ENOSYS>.
147 155
148readahead() populates the page cache with data from a file so that 156C<aio_readahead> populates the page cache with data from a file so that
149subsequent reads from that file will not block on disk I/O. The C<$offset> 157subsequent reads from that file will not block on disk I/O. The C<$offset>
150argument specifies the starting point from which data is to be read and 158argument specifies the starting point from which data is to be read and
151C<$length> specifies the number of bytes to be read. I/O is performed in 159C<$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 160whole 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 161and 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 162(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. 163file. The current file offset of the file is left unchanged.
156 164
157=item aio_stat $fh_or_path, $callback 165=item aio_stat $fh_or_path, $callback
158 166
159=item aio_lstat $fh, $callback 167=item aio_lstat $fh, $callback
… …
187with the fsync result code. 195with the fsync result code.
188 196
189=item aio_fdatasync $fh, $callback 197=item aio_fdatasync $fh, $callback
190 198
191Asynchronously call fdatasync on the given filehandle and call the 199Asynchronously call fdatasync on the given filehandle and call the
192callback with the fdatasync result code. 200callback with the fdatasync result code. Might set C<$!> to C<ENOSYS> if
201C<fdatasync> is not available.
193 202
194=back 203=back
195 204
196=head2 SUPPORT FUNCTIONS 205=head2 SUPPORT FUNCTIONS
197 206
198=over 4 207=over 4
199 208
200=item $fileno = IO::AIO::poll_fileno 209=item $fileno = IO::AIO::poll_fileno
201 210
202Return the I<request result pipe filehandle>. This filehandle must be 211Return the I<request result pipe file descriptor>. This filehandle must be
203polled for reading by some mechanism outside this module (e.g. Event 212polled 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 213select, see below or the SYNOPSIS). If the pipe becomes readable you have
205C<poll_cb> to check the results. 214to call C<poll_cb> to check the results.
206 215
207See C<poll_cb> for an example. 216See C<poll_cb> for an example.
208 217
209=item IO::AIO::poll_cb 218=item IO::AIO::poll_cb
210 219
211Process all outstanding events on the result pipe. You have to call this 220Process all outstanding events on the result pipe. You have to call this
212regularly. Returns the number of events processed. Returns immediately 221regularly. Returns the number of events processed. Returns immediately
213when no events are outstanding. 222when no events are outstanding.
214 223
215You can use Event to multiplex, e.g.: 224Example: Install an Event watcher that automatically calls
225IO::AIO::poll_cb with high priority:
216 226
217 Event->io (fd => IO::AIO::poll_fileno, 227 Event->io (fd => IO::AIO::poll_fileno,
218 poll => 'r', async => 1, 228 poll => 'r', async => 1,
219 cb => \&IO::AIO::poll_cb); 229 cb => \&IO::AIO::poll_cb);
220 230
221=item IO::AIO::poll_wait 231=item IO::AIO::poll_wait
222 232
223Wait till the result filehandle becomes ready for reading (simply does a 233Wait till the result filehandle becomes ready for reading (simply does a
224select on the filehandle. This is useful if you want to synchronously wait 234C<select> on the filehandle. This is useful if you want to synchronously wait
225for some requests to finish). 235for some requests to finish).
226 236
227See C<nreqs> for an example. 237See C<nreqs> for an example.
228 238
229=item IO::AIO::nreqs 239=item IO::AIO::nreqs
230 240
231Returns the number of requests currently outstanding. 241Returns the number of requests currently outstanding (i.e. for which their
242callback has not been invoked yet).
232 243
233Example: wait till there are no outstanding requests anymore: 244Example: wait till there are no outstanding requests anymore:
234 245
235 IO::AIO::poll_wait, IO::AIO::poll_cb 246 IO::AIO::poll_wait, IO::AIO::poll_cb
236 while IO::AIO::nreqs; 247 while IO::AIO::nreqs;

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