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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.5 by root, Sun Jul 10 21:04:24 2005 UTC vs.
Revision 1.21 by root, Wed Jul 13 00:13:09 2005 UTC

… …
3IO::AIO - Asynchronous Input/Output 3IO::AIO - Asynchronous Input/Output
4 4
5=head1 SYNOPSIS 5=head1 SYNOPSIS
6 6
7 use IO::AIO; 7 use IO::AIO;
8
9 aio_open "/etc/passwd", O_RDONLY, 0, sub {
10 my ($fh) = @_;
11 ...
12 };
13
14 aio_unlink "/tmp/file", sub { };
15
16 aio_read $fh, 30000, 1024, $buffer, 0, sub {
17 $_[0] > 0 or die "read error: $!";
18 };
19
20 # Event
21 Event->io (fd => IO::AIO::poll_fileno,
22 poll => 'r',
23 cb => \&IO::AIO::poll_cb);
24
25 # Glib/Gtk2
26 add_watch Glib::IO IO::AIO::poll_fileno,
27 in => sub { IO::AIO::poll_cb, 1 };
28
29 # Tk
30 Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
31 readable => \&IO::AIO::poll_cb);
32
33 # Danga::Socket
34 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
35 \&IO::AIO::poll_cb);
36
8 37
9=head1 DESCRIPTION 38=head1 DESCRIPTION
10 39
11This module implements asynchronous I/O using whatever means your 40This module implements asynchronous I/O using whatever means your
12operating system supports. 41operating system supports.
… …
30use base 'Exporter'; 59use base 'Exporter';
31 60
32use Fcntl (); 61use Fcntl ();
33 62
34BEGIN { 63BEGIN {
35 $VERSION = 0.2; 64 $VERSION = 0.9;
36 65
37 @EXPORT = qw(aio_read aio_write aio_open aio_close aio_stat aio_lstat aio_unlink 66 @EXPORT = qw(aio_read aio_write aio_open aio_close aio_stat aio_lstat aio_unlink
38 aio_fsync aio_fdatasync aio_readahead); 67 aio_fsync aio_fdatasync aio_readahead);
39 @EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel max_outstanding nreqs); 68 @EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel max_outstanding nreqs);
40 69
… …
46 75
47=head2 AIO FUNCTIONS 76=head2 AIO FUNCTIONS
48 77
49All the C<aio_*> calls are more or less thin wrappers around the syscall 78All the C<aio_*> calls are more or less thin wrappers around the syscall
50with the same name (sans C<aio_>). The arguments are similar or identical, 79with the same name (sans C<aio_>). The arguments are similar or identical,
51and they all accept an additional C<$callback> argument which must be 80and they all accept an additional (and optional) C<$callback> argument
52a code reference. This code reference will get called with the syscall 81which must be a code reference. This code reference will get called with
53return 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
54usually 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
55been executed asynchronously. 84syscall has been executed asynchronously.
56 85
57All functions that expect a filehandle will also accept a file descriptor. 86All functions that expect a filehandle will also accept a file descriptor.
58 87
59The 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
60is 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
61directory could have changed. Alternatively, you can make sure that you 90working directory could have changed. Alternatively, you can make sure
62never change the current working directory. 91that you never change the current working directory.
63 92
64=over 4 93=over 4
65 94
66=item aio_open $pathname, $flags, $mode, $callback 95=item aio_open $pathname, $flags, $mode, $callback
67 96
… …
69created filehandle for the file. 98created filehandle for the file.
70 99
71The pathname passed to C<aio_open> must be absolute. See API NOTES, above, 100The pathname passed to C<aio_open> must be absolute. See API NOTES, above,
72for an explanation. 101for an explanation.
73 102
74The C<$mode> argument is a bitmask. See the C<Fcntl> module for a 103The C<$flags> argument is a bitmask. See the C<Fcntl> module for a
75list. They are the same as used in C<sysopen>. 104list. They are the same as used by C<sysopen>.
105
106Likewise, C<$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).
76 110
77Example: 111Example:
78 112
79 aio_open "/etc/passwd", O_RDONLY, 0, sub { 113 aio_open "/etc/passwd", O_RDONLY, 0, sub {
80 if ($_[0]) { 114 if ($_[0]) {
… …
87 121
88=item aio_close $fh, $callback 122=item aio_close $fh, $callback
89 123
90Asynchronously close a file and call the callback with the result 124Asynchronously close a file and call the callback with the result
91code. I<WARNING:> although accepted, you should not pass in a perl 125code. I<WARNING:> although accepted, you should not pass in a perl
92filehandle here, as perl will likely close the file descriptor itself when 126filehandle here, as perl will likely close the file descriptor another
93the filehandle is destroyed. Normally, you can safely call perls C<close> 127time when the filehandle is destroyed. Normally, you can safely call perls
94or 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.
95 132
96=item aio_read $fh,$offset,$length, $data,$dataoffset,$callback 133=item aio_read $fh,$offset,$length, $data,$dataoffset,$callback
97 134
98=item aio_write $fh,$offset,$length, $data,$dataoffset,$callback 135=item aio_write $fh,$offset,$length, $data,$dataoffset,$callback
99 136
100Reads or writes C<length> bytes from the specified C<fh> and C<offset> 137Reads or writes C<length> bytes from the specified C<fh> and C<offset>
101into the scalar given by C<data> and offset C<dataoffset> and calls the 138into the scalar given by C<data> and offset C<dataoffset> and calls the
102callback without the actual number of bytes read (or -1 on error, just 139callback without the actual number of bytes read (or -1 on error, just
103like the syscall). 140like the syscall).
104 141
105Example: Read 15 bytes at offset 7 into scalar C<$buffer>, strating at 142Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
106offset C<0> within the scalar: 143offset C<0> within the scalar:
107 144
108 aio_read $fh, 7, 15, $buffer, 0, sub { 145 aio_read $fh, 7, 15, $buffer, 0, sub {
109 $_[0] >= 0 or die "read error: $!"; 146 $_[0] > 0 or die "read error: $!";
110 print "read <$buffer>\n"; 147 print "read $_[0] bytes: <$buffer>\n";
111 }; 148 };
112 149
113=item aio_readahead $fh,$offset,$length, $callback 150=item aio_readahead $fh,$offset,$length, $callback
114 151
115Asynchronously reads the specified byte range into the page cache, using 152Asynchronously reads the specified byte range into the page cache, using
116the C<readahead> syscall. If that syscall doesn't exist the status will be 153the C<readahead> syscall. If that syscall doesn't exist (likely if your OS
117C<-1> and C<$!> is set to ENOSYS. 154isn't Linux) the status will be C<-1> and C<$!> is set to C<ENOSYS>.
118 155
119readahead() populates the page cache with data from a file so that 156C<aio_readahead> populates the page cache with data from a file so that
120subsequent reads from that file will not block on disk I/O. The C<$offset> 157subsequent reads from that file will not block on disk I/O. The C<$offset>
121argument specifies the starting point from which data is to be read and 158argument specifies the starting point from which data is to be read and
122C<$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
123whole 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
124and 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
125(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
126file. The current file offset of the file is left unchanged. 163file. The current file offset of the file is left unchanged.
127 164
128=item aio_stat $fh_or_path, $callback 165=item aio_stat $fh_or_path, $callback
129 166
130=item aio_lstat $fh, $callback 167=item aio_lstat $fh, $callback
… …
158with the fsync result code. 195with the fsync result code.
159 196
160=item aio_fdatasync $fh, $callback 197=item aio_fdatasync $fh, $callback
161 198
162Asynchronously call fdatasync on the given filehandle and call the 199Asynchronously call fdatasync on the given filehandle and call the
163callback with the fdatasync result code. 200callback with the fdatasync result code. Might set C<$!> to C<ENOSYS> if
201C<fdatasync> is not available.
164 202
165=back 203=back
166 204
167=head2 SUPPORT FUNCTIONS 205=head2 SUPPORT FUNCTIONS
168 206
169=over 4 207=over 4
170 208
171=item $fileno = IO::AIO::poll_fileno 209=item $fileno = IO::AIO::poll_fileno
172 210
173Return the I<request result pipe filehandle>. This filehandle must be 211Return the I<request result pipe file descriptor>. This filehandle must be
174polled for reading by some mechanism outside this module (e.g. Event 212polled for reading by some mechanism outside this module (e.g. Event or
175or 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
176C<poll_cb> to check the results. 214to call C<poll_cb> to check the results.
177 215
178See C<poll_cb> for an example. 216See C<poll_cb> for an example.
179 217
180=item IO::AIO::poll_cb 218=item IO::AIO::poll_cb
181 219
182Process 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
183regularly. Returns the number of events processed. Returns immediately 221regularly. Returns the number of events processed. Returns immediately
184when no events are outstanding. 222when no events are outstanding.
185 223
186You can use Event to multiplex, e.g.: 224Example: Install an Event watcher that automatically calls
225IO::AIO::poll_cb with high priority:
187 226
188 Event->io (fd => IO::AIO::poll_fileno, 227 Event->io (fd => IO::AIO::poll_fileno,
189 poll => 'r', async => 1, 228 poll => 'r', async => 1,
190 cb => \&IO::AIO::poll_cb); 229 cb => \&IO::AIO::poll_cb);
191 230
192=item IO::AIO::poll_wait 231=item IO::AIO::poll_wait
193 232
194Wait till the result filehandle becomes ready for reading (simply does a 233Wait till the result filehandle becomes ready for reading (simply does a
195select 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
196for some requests to finish). 235for some requests to finish).
197 236
198See C<nreqs> for an example. 237See C<nreqs> for an example.
199 238
200=item IO::AIO::nreqs 239=item IO::AIO::nreqs
201 240
202Returns the number of requests currently outstanding. 241Returns the number of requests currently outstanding (i.e. for which their
242callback has not been invoked yet).
203 243
204Example: wait till there are no outstanding requests anymore: 244Example: wait till there are no outstanding requests anymore:
205 245
206 IO::AIO::poll_wait, IO::AIO::poll_cb 246 IO::AIO::poll_wait, IO::AIO::poll_cb
207 while IO::AIO::nreqs; 247 while IO::AIO::nreqs;
248
249=item IO::AIO::flush
250
251Wait till all outstanding AIO requests have been handled.
252
253Strictly equivalent to:
254
255 IO::AIO::poll_wait, IO::AIO::poll_cb
256 while IO::AIO::nreqs;
257
258=item IO::AIO::poll
259
260Waits until some requests have been handled.
261
262Strictly equivalent to:
263
264 IO::AIO::poll_wait, IO::AIO::poll_cb
265 if IO::AIO::nreqs;
208 266
209=item IO::AIO::min_parallel $nthreads 267=item IO::AIO::min_parallel $nthreads
210 268
211Set the minimum number of AIO threads to C<$nthreads>. The default is 269Set the minimum number of AIO threads to C<$nthreads>. The default is
212C<1>, which means a single asynchronous operation can be done at one time 270C<1>, which means a single asynchronous operation can be done at one time

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