… | |
… | |
5 | =head1 SYNOPSIS |
5 | =head1 SYNOPSIS |
6 | |
6 | |
7 | use IO::AIO; |
7 | use IO::AIO; |
8 | |
8 | |
9 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
9 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
10 | my ($fh) = @_; |
10 | my $fh = shift |
|
|
11 | or die "/etc/passwd: $!"; |
11 | ... |
12 | ... |
12 | }; |
13 | }; |
13 | |
14 | |
14 | aio_unlink "/tmp/file", sub { }; |
15 | aio_unlink "/tmp/file", sub { }; |
15 | |
16 | |
… | |
… | |
25 | $req->cancel; # cancel request if still in queue |
26 | $req->cancel; # cancel request if still in queue |
26 | |
27 | |
27 | my $grp = aio_group sub { print "all stats done\n" }; |
28 | my $grp = aio_group sub { print "all stats done\n" }; |
28 | add $grp aio_stat "..." for ...; |
29 | add $grp aio_stat "..." for ...; |
29 | |
30 | |
|
|
31 | # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...) |
|
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32 | use AnyEvent::AIO; |
|
|
33 | |
30 | # AnyEvent integration |
34 | # EV integration |
31 | open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!"; |
35 | my $w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
32 | my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb }); |
|
|
33 | |
36 | |
34 | # Event integration |
37 | # Event integration |
35 | Event->io (fd => IO::AIO::poll_fileno, |
38 | Event->io (fd => IO::AIO::poll_fileno, |
36 | poll => 'r', |
39 | poll => 'r', |
37 | cb => \&IO::AIO::poll_cb); |
40 | cb => \&IO::AIO::poll_cb); |
… | |
… | |
50 | |
53 | |
51 | =head1 DESCRIPTION |
54 | =head1 DESCRIPTION |
52 | |
55 | |
53 | This module implements asynchronous I/O using whatever means your |
56 | This module implements asynchronous I/O using whatever means your |
54 | operating system supports. |
57 | operating system supports. |
|
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58 | |
|
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59 | Asynchronous means that operations that can normally block your program |
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|
60 | (e.g. reading from disk) will be done asynchronously: the operation |
|
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61 | will still block, but you can do something else in the meantime. This |
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62 | is extremely useful for programs that need to stay interactive even |
|
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63 | when doing heavy I/O (GUI programs, high performance network servers |
|
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64 | etc.), but can also be used to easily do operations in parallel that are |
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65 | normally done sequentially, e.g. stat'ing many files, which is much faster |
|
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66 | on a RAID volume or over NFS when you do a number of stat operations |
|
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67 | concurrently. |
|
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68 | |
|
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69 | While most of this works on all types of file descriptors (for |
|
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70 | example sockets), using these functions on file descriptors that |
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71 | support nonblocking operation (again, sockets, pipes etc.) is very |
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72 | inefficient. Use an event loop for that (such as the L<Event|Event> |
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73 | module): IO::AIO will naturally fit into such an event loop itself. |
55 | |
74 | |
56 | In this version, a number of threads are started that execute your |
75 | In this version, a number of threads are started that execute your |
57 | requests and signal their completion. You don't need thread support |
76 | requests and signal their completion. You don't need thread support |
58 | in perl, and the threads created by this module will not be visible |
77 | in perl, and the threads created by this module will not be visible |
59 | to perl. In the future, this module might make use of the native aio |
78 | to perl. In the future, this module might make use of the native aio |
60 | functions available on many operating systems. However, they are often |
79 | functions available on many operating systems. However, they are often |
61 | not well-supported or restricted (Linux doesn't allow them on normal |
80 | not well-supported or restricted (GNU/Linux doesn't allow them on normal |
62 | files currently, for example), and they would only support aio_read and |
81 | files currently, for example), and they would only support aio_read and |
63 | aio_write, so the remaining functionality would have to be implemented |
82 | aio_write, so the remaining functionality would have to be implemented |
64 | using threads anyway. |
83 | using threads anyway. |
65 | |
84 | |
66 | Although the module will work with in the presence of other (Perl-) |
85 | Although the module will work in the presence of other (Perl-) threads, |
67 | threads, it is currently not reentrant in any way, so use appropriate |
86 | it is currently not reentrant in any way, so use appropriate locking |
68 | locking yourself, always call C<poll_cb> from within the same thread, or |
87 | yourself, always call C<poll_cb> from within the same thread, or never |
69 | never call C<poll_cb> (or other C<aio_> functions) recursively. |
88 | call C<poll_cb> (or other C<aio_> functions) recursively. |
|
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89 | |
|
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90 | =head2 EXAMPLE |
|
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91 | |
|
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92 | This is a simple example that uses the Event module and loads |
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93 | F</etc/passwd> asynchronously: |
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94 | |
|
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95 | use Fcntl; |
|
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96 | use Event; |
|
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97 | use IO::AIO; |
|
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98 | |
|
|
99 | # register the IO::AIO callback with Event |
|
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100 | Event->io (fd => IO::AIO::poll_fileno, |
|
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101 | poll => 'r', |
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102 | cb => \&IO::AIO::poll_cb); |
|
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103 | |
|
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104 | # queue the request to open /etc/passwd |
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105 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
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106 | my $fh = shift |
|
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107 | or die "error while opening: $!"; |
|
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108 | |
|
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109 | # stat'ing filehandles is generally non-blocking |
|
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110 | my $size = -s $fh; |
|
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111 | |
|
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112 | # queue a request to read the file |
|
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113 | my $contents; |
|
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114 | aio_read $fh, 0, $size, $contents, 0, sub { |
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115 | $_[0] == $size |
|
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116 | or die "short read: $!"; |
|
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117 | |
|
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118 | close $fh; |
|
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119 | |
|
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120 | # file contents now in $contents |
|
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121 | print $contents; |
|
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122 | |
|
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123 | # exit event loop and program |
|
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124 | Event::unloop; |
|
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125 | }; |
|
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126 | }; |
|
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127 | |
|
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128 | # possibly queue up other requests, or open GUI windows, |
|
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129 | # check for sockets etc. etc. |
|
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130 | |
|
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131 | # process events as long as there are some: |
|
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132 | Event::loop; |
70 | |
133 | |
71 | =head1 REQUEST ANATOMY AND LIFETIME |
134 | =head1 REQUEST ANATOMY AND LIFETIME |
72 | |
135 | |
73 | Every C<aio_*> function creates a request. which is a C data structure not |
136 | Every C<aio_*> function creates a request. which is a C data structure not |
74 | directly visible to Perl. |
137 | directly visible to Perl. |
… | |
… | |
116 | Request has reached the end of its lifetime and holds no resources anymore |
179 | Request has reached the end of its lifetime and holds no resources anymore |
117 | (except possibly for the Perl object, but its connection to the actual |
180 | (except possibly for the Perl object, but its connection to the actual |
118 | aio request is severed and calling its methods will either do nothing or |
181 | aio request is severed and calling its methods will either do nothing or |
119 | result in a runtime error). |
182 | result in a runtime error). |
120 | |
183 | |
|
|
184 | =back |
|
|
185 | |
121 | =cut |
186 | =cut |
122 | |
187 | |
123 | package IO::AIO; |
188 | package IO::AIO; |
|
|
189 | |
|
|
190 | use Carp (); |
124 | |
191 | |
125 | no warnings; |
192 | no warnings; |
126 | use strict 'vars'; |
193 | use strict 'vars'; |
127 | |
194 | |
128 | use base 'Exporter'; |
195 | use base 'Exporter'; |
129 | |
196 | |
130 | BEGIN { |
197 | BEGIN { |
131 | our $VERSION = '2.0'; |
198 | our $VERSION = '3.07'; |
132 | |
199 | |
133 | our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat |
200 | our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close |
134 | aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink |
201 | aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir |
135 | aio_fsync aio_fdatasync aio_readahead aio_rename aio_link aio_move |
202 | aio_scandir aio_symlink aio_readlink aio_sync aio_fsync |
136 | aio_copy aio_group aio_nop aio_mknod); |
203 | aio_fdatasync aio_pathsync aio_readahead |
|
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204 | aio_rename aio_link aio_move aio_copy aio_group |
|
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205 | aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown |
|
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206 | aio_chmod aio_utime aio_truncate); |
|
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207 | |
137 | our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); |
208 | our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); |
138 | our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush |
209 | our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush |
139 | min_parallel max_parallel nreqs nready npending); |
210 | min_parallel max_parallel max_idle |
|
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211 | nreqs nready npending nthreads |
|
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212 | max_poll_time max_poll_reqs); |
140 | |
213 | |
141 | @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; |
214 | @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; |
142 | |
215 | |
143 | require XSLoader; |
216 | require XSLoader; |
144 | XSLoader::load ("IO::AIO", $VERSION); |
217 | XSLoader::load ("IO::AIO", $VERSION); |
145 | } |
218 | } |
146 | |
219 | |
147 | =head1 FUNCTIONS |
220 | =head1 FUNCTIONS |
148 | |
221 | |
149 | =head2 AIO FUNCTIONS |
222 | =head2 AIO REQUEST FUNCTIONS |
150 | |
223 | |
151 | All the C<aio_*> calls are more or less thin wrappers around the syscall |
224 | All the C<aio_*> calls are more or less thin wrappers around the syscall |
152 | with the same name (sans C<aio_>). The arguments are similar or identical, |
225 | with the same name (sans C<aio_>). The arguments are similar or identical, |
153 | and they all accept an additional (and optional) C<$callback> argument |
226 | and they all accept an additional (and optional) C<$callback> argument |
154 | which must be a code reference. This code reference will get called with |
227 | which must be a code reference. This code reference will get called with |
… | |
… | |
157 | syscall has been executed asynchronously. |
230 | syscall has been executed asynchronously. |
158 | |
231 | |
159 | All functions expecting a filehandle keep a copy of the filehandle |
232 | All functions expecting a filehandle keep a copy of the filehandle |
160 | internally until the request has finished. |
233 | internally until the request has finished. |
161 | |
234 | |
162 | All requests return objects of type L<IO::AIO::REQ> that allow further |
235 | All functions return request objects of type L<IO::AIO::REQ> that allow |
163 | manipulation of those requests while they are in-flight. |
236 | further manipulation of those requests while they are in-flight. |
164 | |
237 | |
165 | The pathnames you pass to these routines I<must> be absolute and |
238 | The pathnames you pass to these routines I<must> be absolute and |
166 | encoded in byte form. The reason for the former is that at the time the |
239 | encoded as octets. The reason for the former is that at the time the |
167 | request is being executed, the current working directory could have |
240 | request is being executed, the current working directory could have |
168 | changed. Alternatively, you can make sure that you never change the |
241 | changed. Alternatively, you can make sure that you never change the |
169 | current working directory. |
242 | current working directory anywhere in the program and then use relative |
|
|
243 | paths. |
170 | |
244 | |
171 | To encode pathnames to byte form, either make sure you either: a) |
245 | To encode pathnames as octets, either make sure you either: a) always pass |
172 | always pass in filenames you got from outside (command line, readdir |
246 | in filenames you got from outside (command line, readdir etc.) without |
173 | etc.), b) are ASCII or ISO 8859-1, c) use the Encode module and encode |
247 | tinkering, b) are ASCII or ISO 8859-1, c) use the Encode module and encode |
174 | your pathnames to the locale (or other) encoding in effect in the user |
248 | your pathnames to the locale (or other) encoding in effect in the user |
175 | environment, d) use Glib::filename_from_unicode on unicode filenames or e) |
249 | environment, d) use Glib::filename_from_unicode on unicode filenames or e) |
176 | use something else. |
250 | use something else to ensure your scalar has the correct contents. |
|
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251 | |
|
|
252 | This works, btw. independent of the internal UTF-8 bit, which IO::AIO |
|
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253 | handles correctly wether it is set or not. |
177 | |
254 | |
178 | =over 4 |
255 | =over 4 |
179 | |
256 | |
180 | =item $prev_pri = aioreq_pri [$pri] |
257 | =item $prev_pri = aioreq_pri [$pri] |
181 | |
258 | |
… | |
… | |
201 | aio_read $_[0], ..., sub { |
278 | aio_read $_[0], ..., sub { |
202 | ... |
279 | ... |
203 | }; |
280 | }; |
204 | }; |
281 | }; |
205 | |
282 | |
|
|
283 | |
206 | =item aioreq_nice $pri_adjust |
284 | =item aioreq_nice $pri_adjust |
207 | |
285 | |
208 | Similar to C<aioreq_pri>, but subtracts the given value from the current |
286 | Similar to C<aioreq_pri>, but subtracts the given value from the current |
209 | priority, so effects are cumulative. |
287 | priority, so the effect is cumulative. |
|
|
288 | |
210 | |
289 | |
211 | =item aio_open $pathname, $flags, $mode, $callback->($fh) |
290 | =item aio_open $pathname, $flags, $mode, $callback->($fh) |
212 | |
291 | |
213 | Asynchronously open or create a file and call the callback with a newly |
292 | Asynchronously open or create a file and call the callback with a newly |
214 | created filehandle for the file. |
293 | created filehandle for the file. |
… | |
… | |
220 | list. They are the same as used by C<sysopen>. |
299 | list. They are the same as used by C<sysopen>. |
221 | |
300 | |
222 | Likewise, C<$mode> specifies the mode of the newly created file, if it |
301 | Likewise, C<$mode> specifies the mode of the newly created file, if it |
223 | didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>, |
302 | didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>, |
224 | except that it is mandatory (i.e. use C<0> if you don't create new files, |
303 | except that it is mandatory (i.e. use C<0> if you don't create new files, |
225 | and C<0666> or C<0777> if you do). |
304 | and C<0666> or C<0777> if you do). Note that the C<$mode> will be modified |
|
|
305 | by the umask in effect then the request is being executed, so better never |
|
|
306 | change the umask. |
226 | |
307 | |
227 | Example: |
308 | Example: |
228 | |
309 | |
229 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
310 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
230 | if ($_[0]) { |
311 | if ($_[0]) { |
… | |
… | |
233 | } else { |
314 | } else { |
234 | die "open failed: $!\n"; |
315 | die "open failed: $!\n"; |
235 | } |
316 | } |
236 | }; |
317 | }; |
237 | |
318 | |
|
|
319 | |
238 | =item aio_close $fh, $callback->($status) |
320 | =item aio_close $fh, $callback->($status) |
239 | |
321 | |
240 | Asynchronously close a file and call the callback with the result |
322 | Asynchronously close a file and call the callback with the result |
241 | code. I<WARNING:> although accepted, you should not pass in a perl |
323 | code. |
242 | filehandle here, as perl will likely close the file descriptor another |
|
|
243 | time when the filehandle is destroyed. Normally, you can safely call perls |
|
|
244 | C<close> or just let filehandles go out of scope. |
|
|
245 | |
324 | |
246 | This is supposed to be a bug in the API, so that might change. It's |
325 | Unfortunately, you can't do this to perl. Perl I<insists> very strongly on |
247 | therefore best to avoid this function. |
326 | closing the file descriptor associated with the filehandle itself. |
|
|
327 | |
|
|
328 | Therefore, C<aio_close> will not close the filehandle - instead it will |
|
|
329 | use dup2 to overwrite the file descriptor with the write-end of a pipe |
|
|
330 | (the pipe fd will be created on demand and will be cached). |
|
|
331 | |
|
|
332 | Or in other words: the file descriptor will be closed, but it will not be |
|
|
333 | free for reuse until the perl filehandle is closed. |
|
|
334 | |
|
|
335 | =cut |
248 | |
336 | |
249 | =item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
337 | =item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
250 | |
338 | |
251 | =item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
339 | =item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
252 | |
340 | |
253 | Reads or writes C<length> bytes from the specified C<fh> and C<offset> |
341 | Reads or writes C<$length> bytes from the specified C<$fh> and C<$offset> |
254 | into the scalar given by C<data> and offset C<dataoffset> and calls the |
342 | into the scalar given by C<$data> and offset C<$dataoffset> and calls the |
255 | callback without the actual number of bytes read (or -1 on error, just |
343 | callback without the actual number of bytes read (or -1 on error, just |
256 | like the syscall). |
344 | like the syscall). |
257 | |
345 | |
|
|
346 | If C<$offset> is undefined, then the current file descriptor offset will |
|
|
347 | be used (and updated), otherwise the file descriptor offset will not be |
|
|
348 | changed by these calls. |
|
|
349 | |
|
|
350 | If C<$length> is undefined in C<aio_write>, use the remaining length of C<$data>. |
|
|
351 | |
|
|
352 | If C<$dataoffset> is less than zero, it will be counted from the end of |
|
|
353 | C<$data>. |
|
|
354 | |
258 | The C<$data> scalar I<MUST NOT> be modified in any way while the request |
355 | The C<$data> scalar I<MUST NOT> be modified in any way while the request |
259 | is outstanding. Modifying it can result in segfaults or WW3 (if the |
356 | is outstanding. Modifying it can result in segfaults or World War III (if |
260 | necessary/optional hardware is installed). |
357 | the necessary/optional hardware is installed). |
261 | |
358 | |
262 | Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at |
359 | Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at |
263 | offset C<0> within the scalar: |
360 | offset C<0> within the scalar: |
264 | |
361 | |
265 | aio_read $fh, 7, 15, $buffer, 0, sub { |
362 | aio_read $fh, 7, 15, $buffer, 0, sub { |
266 | $_[0] > 0 or die "read error: $!"; |
363 | $_[0] > 0 or die "read error: $!"; |
267 | print "read $_[0] bytes: <$buffer>\n"; |
364 | print "read $_[0] bytes: <$buffer>\n"; |
268 | }; |
365 | }; |
|
|
366 | |
269 | |
367 | |
270 | =item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
368 | =item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
271 | |
369 | |
272 | Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts |
370 | Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts |
273 | reading at byte offset C<$in_offset>, and starts writing at the current |
371 | reading at byte offset C<$in_offset>, and starts writing at the current |
… | |
… | |
287 | C<$in_fh> than are written, and there is no way to find out how many |
385 | C<$in_fh> than are written, and there is no way to find out how many |
288 | bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only |
386 | bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only |
289 | provides the number of bytes written to C<$out_fh>. Only if the result |
387 | provides the number of bytes written to C<$out_fh>. Only if the result |
290 | value equals C<$length> one can assume that C<$length> bytes have been |
388 | value equals C<$length> one can assume that C<$length> bytes have been |
291 | read. |
389 | read. |
|
|
390 | |
292 | |
391 | |
293 | =item aio_readahead $fh,$offset,$length, $callback->($retval) |
392 | =item aio_readahead $fh,$offset,$length, $callback->($retval) |
294 | |
393 | |
295 | C<aio_readahead> populates the page cache with data from a file so that |
394 | C<aio_readahead> populates the page cache with data from a file so that |
296 | subsequent reads from that file will not block on disk I/O. The C<$offset> |
395 | subsequent reads from that file will not block on disk I/O. The C<$offset> |
… | |
… | |
302 | file. The current file offset of the file is left unchanged. |
401 | file. The current file offset of the file is left unchanged. |
303 | |
402 | |
304 | If that syscall doesn't exist (likely if your OS isn't Linux) it will be |
403 | If that syscall doesn't exist (likely if your OS isn't Linux) it will be |
305 | emulated by simply reading the data, which would have a similar effect. |
404 | emulated by simply reading the data, which would have a similar effect. |
306 | |
405 | |
|
|
406 | |
307 | =item aio_stat $fh_or_path, $callback->($status) |
407 | =item aio_stat $fh_or_path, $callback->($status) |
308 | |
408 | |
309 | =item aio_lstat $fh, $callback->($status) |
409 | =item aio_lstat $fh, $callback->($status) |
310 | |
410 | |
311 | Works like perl's C<stat> or C<lstat> in void context. The callback will |
411 | Works like perl's C<stat> or C<lstat> in void context. The callback will |
… | |
… | |
324 | aio_stat "/etc/passwd", sub { |
424 | aio_stat "/etc/passwd", sub { |
325 | $_[0] and die "stat failed: $!"; |
425 | $_[0] and die "stat failed: $!"; |
326 | print "size is ", -s _, "\n"; |
426 | print "size is ", -s _, "\n"; |
327 | }; |
427 | }; |
328 | |
428 | |
|
|
429 | |
|
|
430 | =item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
|
|
431 | |
|
|
432 | Works like perl's C<utime> function (including the special case of $atime |
|
|
433 | and $mtime being undef). Fractional times are supported if the underlying |
|
|
434 | syscalls support them. |
|
|
435 | |
|
|
436 | When called with a pathname, uses utimes(2) if available, otherwise |
|
|
437 | utime(2). If called on a file descriptor, uses futimes(2) if available, |
|
|
438 | otherwise returns ENOSYS, so this is not portable. |
|
|
439 | |
|
|
440 | Examples: |
|
|
441 | |
|
|
442 | # set atime and mtime to current time (basically touch(1)): |
|
|
443 | aio_utime "path", undef, undef; |
|
|
444 | # set atime to current time and mtime to beginning of the epoch: |
|
|
445 | aio_utime "path", time, undef; # undef==0 |
|
|
446 | |
|
|
447 | |
|
|
448 | =item aio_chown $fh_or_path, $uid, $gid, $callback->($status) |
|
|
449 | |
|
|
450 | Works like perl's C<chown> function, except that C<undef> for either $uid |
|
|
451 | or $gid is being interpreted as "do not change" (but -1 can also be used). |
|
|
452 | |
|
|
453 | Examples: |
|
|
454 | |
|
|
455 | # same as "chown root path" in the shell: |
|
|
456 | aio_chown "path", 0, -1; |
|
|
457 | # same as above: |
|
|
458 | aio_chown "path", 0, undef; |
|
|
459 | |
|
|
460 | |
|
|
461 | =item aio_truncate $fh_or_path, $offset, $callback->($status) |
|
|
462 | |
|
|
463 | Works like truncate(2) or ftruncate(2). |
|
|
464 | |
|
|
465 | |
|
|
466 | =item aio_chmod $fh_or_path, $mode, $callback->($status) |
|
|
467 | |
|
|
468 | Works like perl's C<chmod> function. |
|
|
469 | |
|
|
470 | |
329 | =item aio_unlink $pathname, $callback->($status) |
471 | =item aio_unlink $pathname, $callback->($status) |
330 | |
472 | |
331 | Asynchronously unlink (delete) a file and call the callback with the |
473 | Asynchronously unlink (delete) a file and call the callback with the |
332 | result code. |
474 | result code. |
333 | |
475 | |
|
|
476 | |
334 | =item aio_mknod $path, $mode, $dev, $callback->($status) |
477 | =item aio_mknod $path, $mode, $dev, $callback->($status) |
335 | |
478 | |
|
|
479 | [EXPERIMENTAL] |
|
|
480 | |
336 | Asynchronously create a device node (or fifo). See mknod(2). |
481 | Asynchronously create a device node (or fifo). See mknod(2). |
337 | |
482 | |
338 | The only portable (POSIX) way of calling this function is: |
483 | The only (POSIX-) portable way of calling this function is: |
339 | |
484 | |
340 | aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
485 | aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
|
|
486 | |
341 | |
487 | |
342 | =item aio_link $srcpath, $dstpath, $callback->($status) |
488 | =item aio_link $srcpath, $dstpath, $callback->($status) |
343 | |
489 | |
344 | Asynchronously create a new link to the existing object at C<$srcpath> at |
490 | Asynchronously create a new link to the existing object at C<$srcpath> at |
345 | the path C<$dstpath> and call the callback with the result code. |
491 | the path C<$dstpath> and call the callback with the result code. |
346 | |
492 | |
|
|
493 | |
347 | =item aio_symlink $srcpath, $dstpath, $callback->($status) |
494 | =item aio_symlink $srcpath, $dstpath, $callback->($status) |
348 | |
495 | |
349 | Asynchronously create a new symbolic link to the existing object at C<$srcpath> at |
496 | Asynchronously create a new symbolic link to the existing object at C<$srcpath> at |
350 | the path C<$dstpath> and call the callback with the result code. |
497 | the path C<$dstpath> and call the callback with the result code. |
351 | |
498 | |
|
|
499 | |
|
|
500 | =item aio_readlink $path, $callback->($link) |
|
|
501 | |
|
|
502 | Asynchronously read the symlink specified by C<$path> and pass it to |
|
|
503 | the callback. If an error occurs, nothing or undef gets passed to the |
|
|
504 | callback. |
|
|
505 | |
|
|
506 | |
352 | =item aio_rename $srcpath, $dstpath, $callback->($status) |
507 | =item aio_rename $srcpath, $dstpath, $callback->($status) |
353 | |
508 | |
354 | Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as |
509 | Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as |
355 | rename(2) and call the callback with the result code. |
510 | rename(2) and call the callback with the result code. |
356 | |
511 | |
|
|
512 | |
|
|
513 | =item aio_mkdir $pathname, $mode, $callback->($status) |
|
|
514 | |
|
|
515 | Asynchronously mkdir (create) a directory and call the callback with |
|
|
516 | the result code. C<$mode> will be modified by the umask at the time the |
|
|
517 | request is executed, so do not change your umask. |
|
|
518 | |
|
|
519 | |
357 | =item aio_rmdir $pathname, $callback->($status) |
520 | =item aio_rmdir $pathname, $callback->($status) |
358 | |
521 | |
359 | Asynchronously rmdir (delete) a directory and call the callback with the |
522 | Asynchronously rmdir (delete) a directory and call the callback with the |
360 | result code. |
523 | result code. |
|
|
524 | |
361 | |
525 | |
362 | =item aio_readdir $pathname, $callback->($entries) |
526 | =item aio_readdir $pathname, $callback->($entries) |
363 | |
527 | |
364 | Unlike the POSIX call of the same name, C<aio_readdir> reads an entire |
528 | Unlike the POSIX call of the same name, C<aio_readdir> reads an entire |
365 | directory (i.e. opendir + readdir + closedir). The entries will not be |
529 | directory (i.e. opendir + readdir + closedir). The entries will not be |
366 | sorted, and will B<NOT> include the C<.> and C<..> entries. |
530 | sorted, and will B<NOT> include the C<.> and C<..> entries. |
367 | |
531 | |
368 | The callback a single argument which is either C<undef> or an array-ref |
532 | The callback a single argument which is either C<undef> or an array-ref |
369 | with the filenames. |
533 | with the filenames. |
370 | |
534 | |
|
|
535 | |
|
|
536 | =item aio_load $path, $data, $callback->($status) |
|
|
537 | |
|
|
538 | This is a composite request that tries to fully load the given file into |
|
|
539 | memory. Status is the same as with aio_read. |
|
|
540 | |
|
|
541 | =cut |
|
|
542 | |
|
|
543 | sub aio_load($$;$) { |
|
|
544 | my ($path, undef, $cb) = @_; |
|
|
545 | my $data = \$_[1]; |
|
|
546 | |
|
|
547 | my $pri = aioreq_pri; |
|
|
548 | my $grp = aio_group $cb; |
|
|
549 | |
|
|
550 | aioreq_pri $pri; |
|
|
551 | add $grp aio_open $path, O_RDONLY, 0, sub { |
|
|
552 | my $fh = shift |
|
|
553 | or return $grp->result (-1); |
|
|
554 | |
|
|
555 | aioreq_pri $pri; |
|
|
556 | add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub { |
|
|
557 | $grp->result ($_[0]); |
|
|
558 | }; |
|
|
559 | }; |
|
|
560 | |
|
|
561 | $grp |
|
|
562 | } |
|
|
563 | |
371 | =item aio_copy $srcpath, $dstpath, $callback->($status) |
564 | =item aio_copy $srcpath, $dstpath, $callback->($status) |
372 | |
565 | |
373 | Try to copy the I<file> (directories not supported as either source or |
566 | Try to copy the I<file> (directories not supported as either source or |
374 | destination) from C<$srcpath> to C<$dstpath> and call the callback with |
567 | destination) from C<$srcpath> to C<$dstpath> and call the callback with |
375 | the C<0> (error) or C<-1> ok. |
568 | the C<0> (error) or C<-1> ok. |
376 | |
569 | |
377 | This is a composite request that it creates the destination file with |
570 | This is a composite request that creates the destination file with |
378 | mode 0200 and copies the contents of the source file into it using |
571 | mode 0200 and copies the contents of the source file into it using |
379 | C<aio_sendfile>, followed by restoring atime, mtime, access mode and |
572 | C<aio_sendfile>, followed by restoring atime, mtime, access mode and |
380 | uid/gid, in that order. |
573 | uid/gid, in that order. |
381 | |
574 | |
382 | If an error occurs, the partial destination file will be unlinked, if |
575 | If an error occurs, the partial destination file will be unlinked, if |
… | |
… | |
407 | |
600 | |
408 | # those should not normally block. should. should. |
601 | # those should not normally block. should. should. |
409 | utime $stat[8], $stat[9], $dst; |
602 | utime $stat[8], $stat[9], $dst; |
410 | chmod $stat[2] & 07777, $dst_fh; |
603 | chmod $stat[2] & 07777, $dst_fh; |
411 | chown $stat[4], $stat[5], $dst_fh; |
604 | chown $stat[4], $stat[5], $dst_fh; |
|
|
605 | |
|
|
606 | aioreq_pri $pri; |
412 | close $dst_fh; |
607 | add $grp aio_close $dst_fh; |
413 | } else { |
608 | } else { |
414 | $grp->result (-1); |
609 | $grp->result (-1); |
415 | close $src_fh; |
610 | close $src_fh; |
416 | close $dst_fh; |
611 | close $dst_fh; |
417 | |
612 | |
… | |
… | |
522 | as those tend to return 0 or 1 as link counts, which disables the |
717 | as those tend to return 0 or 1 as link counts, which disables the |
523 | directory counting heuristic. |
718 | directory counting heuristic. |
524 | |
719 | |
525 | =cut |
720 | =cut |
526 | |
721 | |
527 | sub aio_scandir($$$) { |
722 | sub aio_scandir($$;$) { |
528 | my ($path, $maxreq, $cb) = @_; |
723 | my ($path, $maxreq, $cb) = @_; |
529 | |
724 | |
530 | my $pri = aioreq_pri; |
725 | my $pri = aioreq_pri; |
531 | |
726 | |
532 | my $grp = aio_group $cb; |
727 | my $grp = aio_group $cb; |
… | |
… | |
608 | }; |
803 | }; |
609 | |
804 | |
610 | $grp |
805 | $grp |
611 | } |
806 | } |
612 | |
807 | |
|
|
808 | =item aio_rmtree $path, $callback->($status) |
|
|
809 | |
|
|
810 | Delete a directory tree starting (and including) C<$path>, return the |
|
|
811 | status of the final C<rmdir> only. This is a composite request that |
|
|
812 | uses C<aio_scandir> to recurse into and rmdir directories, and unlink |
|
|
813 | everything else. |
|
|
814 | |
|
|
815 | =cut |
|
|
816 | |
|
|
817 | sub aio_rmtree; |
|
|
818 | sub aio_rmtree($;$) { |
|
|
819 | my ($path, $cb) = @_; |
|
|
820 | |
|
|
821 | my $pri = aioreq_pri; |
|
|
822 | my $grp = aio_group $cb; |
|
|
823 | |
|
|
824 | aioreq_pri $pri; |
|
|
825 | add $grp aio_scandir $path, 0, sub { |
|
|
826 | my ($dirs, $nondirs) = @_; |
|
|
827 | |
|
|
828 | my $dirgrp = aio_group sub { |
|
|
829 | add $grp aio_rmdir $path, sub { |
|
|
830 | $grp->result ($_[0]); |
|
|
831 | }; |
|
|
832 | }; |
|
|
833 | |
|
|
834 | (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs; |
|
|
835 | (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs; |
|
|
836 | |
|
|
837 | add $grp $dirgrp; |
|
|
838 | }; |
|
|
839 | |
|
|
840 | $grp |
|
|
841 | } |
|
|
842 | |
|
|
843 | =item aio_sync $callback->($status) |
|
|
844 | |
|
|
845 | Asynchronously call sync and call the callback when finished. |
|
|
846 | |
613 | =item aio_fsync $fh, $callback->($status) |
847 | =item aio_fsync $fh, $callback->($status) |
614 | |
848 | |
615 | Asynchronously call fsync on the given filehandle and call the callback |
849 | Asynchronously call fsync on the given filehandle and call the callback |
616 | with the fsync result code. |
850 | with the fsync result code. |
617 | |
851 | |
… | |
… | |
620 | Asynchronously call fdatasync on the given filehandle and call the |
854 | Asynchronously call fdatasync on the given filehandle and call the |
621 | callback with the fdatasync result code. |
855 | callback with the fdatasync result code. |
622 | |
856 | |
623 | If this call isn't available because your OS lacks it or it couldn't be |
857 | If this call isn't available because your OS lacks it or it couldn't be |
624 | detected, it will be emulated by calling C<fsync> instead. |
858 | detected, it will be emulated by calling C<fsync> instead. |
|
|
859 | |
|
|
860 | =item aio_pathsync $path, $callback->($status) |
|
|
861 | |
|
|
862 | This request tries to open, fsync and close the given path. This is a |
|
|
863 | composite request intended tosync directories after directory operations |
|
|
864 | (E.g. rename). This might not work on all operating systems or have any |
|
|
865 | specific effect, but usually it makes sure that directory changes get |
|
|
866 | written to disc. It works for anything that can be opened for read-only, |
|
|
867 | not just directories. |
|
|
868 | |
|
|
869 | Passes C<0> when everything went ok, and C<-1> on error. |
|
|
870 | |
|
|
871 | =cut |
|
|
872 | |
|
|
873 | sub aio_pathsync($;$) { |
|
|
874 | my ($path, $cb) = @_; |
|
|
875 | |
|
|
876 | my $pri = aioreq_pri; |
|
|
877 | my $grp = aio_group $cb; |
|
|
878 | |
|
|
879 | aioreq_pri $pri; |
|
|
880 | add $grp aio_open $path, O_RDONLY, 0, sub { |
|
|
881 | my ($fh) = @_; |
|
|
882 | if ($fh) { |
|
|
883 | aioreq_pri $pri; |
|
|
884 | add $grp aio_fsync $fh, sub { |
|
|
885 | $grp->result ($_[0]); |
|
|
886 | |
|
|
887 | aioreq_pri $pri; |
|
|
888 | add $grp aio_close $fh; |
|
|
889 | }; |
|
|
890 | } else { |
|
|
891 | $grp->result (-1); |
|
|
892 | } |
|
|
893 | }; |
|
|
894 | |
|
|
895 | $grp |
|
|
896 | } |
625 | |
897 | |
626 | =item aio_group $callback->(...) |
898 | =item aio_group $callback->(...) |
627 | |
899 | |
628 | This is a very special aio request: Instead of doing something, it is a |
900 | This is a very special aio request: Instead of doing something, it is a |
629 | container for other aio requests, which is useful if you want to bundle |
901 | container for other aio requests, which is useful if you want to bundle |
… | |
… | |
741 | Their lifetime, simplified, looks like this: when they are empty, they |
1013 | Their lifetime, simplified, looks like this: when they are empty, they |
742 | will finish very quickly. If they contain only requests that are in the |
1014 | will finish very quickly. If they contain only requests that are in the |
743 | C<done> state, they will also finish. Otherwise they will continue to |
1015 | C<done> state, they will also finish. Otherwise they will continue to |
744 | exist. |
1016 | exist. |
745 | |
1017 | |
746 | That means after creating a group you have some time to add requests. And |
1018 | That means after creating a group you have some time to add requests |
747 | in the callbacks of those requests, you can add further requests to the |
1019 | (precisely before the callback has been invoked, which is only done within |
748 | group. And only when all those requests have finished will the the group |
1020 | the C<poll_cb>). And in the callbacks of those requests, you can add |
749 | itself finish. |
1021 | further requests to the group. And only when all those requests have |
|
|
1022 | finished will the the group itself finish. |
750 | |
1023 | |
751 | =over 4 |
1024 | =over 4 |
752 | |
1025 | |
753 | =item add $grp ... |
1026 | =item add $grp ... |
754 | |
1027 | |
… | |
… | |
766 | itself. Useful when you queued a lot of events but got a result early. |
1039 | itself. Useful when you queued a lot of events but got a result early. |
767 | |
1040 | |
768 | =item $grp->result (...) |
1041 | =item $grp->result (...) |
769 | |
1042 | |
770 | Set the result value(s) that will be passed to the group callback when all |
1043 | Set the result value(s) that will be passed to the group callback when all |
771 | subrequests have finished and set thre groups errno to the current value |
1044 | subrequests have finished and set the groups errno to the current value |
772 | of errno (just like calling C<errno> without an error number). By default, |
1045 | of errno (just like calling C<errno> without an error number). By default, |
773 | no argument will be passed and errno is zero. |
1046 | no argument will be passed and errno is zero. |
774 | |
1047 | |
775 | =item $grp->errno ([$errno]) |
1048 | =item $grp->errno ([$errno]) |
776 | |
1049 | |
… | |
… | |
829 | |
1102 | |
830 | =back |
1103 | =back |
831 | |
1104 | |
832 | =head2 SUPPORT FUNCTIONS |
1105 | =head2 SUPPORT FUNCTIONS |
833 | |
1106 | |
|
|
1107 | =head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION |
|
|
1108 | |
834 | =over 4 |
1109 | =over 4 |
835 | |
1110 | |
836 | =item $fileno = IO::AIO::poll_fileno |
1111 | =item $fileno = IO::AIO::poll_fileno |
837 | |
1112 | |
838 | Return the I<request result pipe file descriptor>. This filehandle must be |
1113 | Return the I<request result pipe file descriptor>. This filehandle must be |
… | |
… | |
842 | |
1117 | |
843 | See C<poll_cb> for an example. |
1118 | See C<poll_cb> for an example. |
844 | |
1119 | |
845 | =item IO::AIO::poll_cb |
1120 | =item IO::AIO::poll_cb |
846 | |
1121 | |
847 | Process all outstanding events on the result pipe. You have to call this |
1122 | Process some outstanding events on the result pipe. You have to call this |
848 | regularly. Returns the number of events processed. Returns immediately |
1123 | regularly. Returns C<0> if all events could be processed, or C<-1> if it |
849 | when no events are outstanding. |
1124 | returned earlier for whatever reason. Returns immediately when no events |
|
|
1125 | are outstanding. The amount of events processed depends on the settings of |
|
|
1126 | C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>. |
850 | |
1127 | |
851 | If not all requests were processed for whatever reason, the filehandle |
1128 | If not all requests were processed for whatever reason, the filehandle |
852 | will still be ready when C<poll_cb> returns. |
1129 | will still be ready when C<poll_cb> returns, so normally you don't have to |
|
|
1130 | do anything special to have it called later. |
853 | |
1131 | |
854 | Example: Install an Event watcher that automatically calls |
1132 | Example: Install an Event watcher that automatically calls |
855 | IO::AIO::poll_cb with high priority: |
1133 | IO::AIO::poll_cb with high priority: |
856 | |
1134 | |
857 | Event->io (fd => IO::AIO::poll_fileno, |
1135 | Event->io (fd => IO::AIO::poll_fileno, |
858 | poll => 'r', async => 1, |
1136 | poll => 'r', async => 1, |
859 | cb => \&IO::AIO::poll_cb); |
1137 | cb => \&IO::AIO::poll_cb); |
860 | |
1138 | |
861 | =item IO::AIO::poll_some $max_requests |
1139 | =item IO::AIO::max_poll_reqs $nreqs |
862 | |
1140 | |
863 | Similar to C<poll_cb>, but only processes up to C<$max_requests> requests |
1141 | =item IO::AIO::max_poll_time $seconds |
864 | at a time. |
|
|
865 | |
1142 | |
866 | Useful if you want to ensure some level of interactiveness when perl is |
1143 | These set the maximum number of requests (default C<0>, meaning infinity) |
867 | not fast enough to process all requests in time. |
1144 | that are being processed by C<IO::AIO::poll_cb> in one call, respectively |
|
|
1145 | the maximum amount of time (default C<0>, meaning infinity) spent in |
|
|
1146 | C<IO::AIO::poll_cb> to process requests (more correctly the mininum amount |
|
|
1147 | of time C<poll_cb> is allowed to use). |
|
|
1148 | |
|
|
1149 | Setting C<max_poll_time> to a non-zero value creates an overhead of one |
|
|
1150 | syscall per request processed, which is not normally a problem unless your |
|
|
1151 | callbacks are really really fast or your OS is really really slow (I am |
|
|
1152 | not mentioning Solaris here). Using C<max_poll_reqs> incurs no overhead. |
|
|
1153 | |
|
|
1154 | Setting these is useful if you want to ensure some level of |
|
|
1155 | interactiveness when perl is not fast enough to process all requests in |
|
|
1156 | time. |
|
|
1157 | |
|
|
1158 | For interactive programs, values such as C<0.01> to C<0.1> should be fine. |
868 | |
1159 | |
869 | Example: Install an Event watcher that automatically calls |
1160 | Example: Install an Event watcher that automatically calls |
870 | IO::AIO::poll_some with low priority, to ensure that other parts of the |
1161 | IO::AIO::poll_cb with low priority, to ensure that other parts of the |
871 | program get the CPU sometimes even under high AIO load. |
1162 | program get the CPU sometimes even under high AIO load. |
872 | |
1163 | |
|
|
1164 | # try not to spend much more than 0.1s in poll_cb |
|
|
1165 | IO::AIO::max_poll_time 0.1; |
|
|
1166 | |
|
|
1167 | # use a low priority so other tasks have priority |
873 | Event->io (fd => IO::AIO::poll_fileno, |
1168 | Event->io (fd => IO::AIO::poll_fileno, |
874 | poll => 'r', nice => 1, |
1169 | poll => 'r', nice => 1, |
875 | cb => sub { IO::AIO::poll_some 256 }); |
1170 | cb => &IO::AIO::poll_cb); |
876 | |
1171 | |
877 | =item IO::AIO::poll_wait |
1172 | =item IO::AIO::poll_wait |
878 | |
1173 | |
|
|
1174 | If there are any outstanding requests and none of them in the result |
879 | Wait till the result filehandle becomes ready for reading (simply does a |
1175 | phase, wait till the result filehandle becomes ready for reading (simply |
880 | C<select> on the filehandle. This is useful if you want to synchronously wait |
1176 | does a C<select> on the filehandle. This is useful if you want to |
881 | for some requests to finish). |
1177 | synchronously wait for some requests to finish). |
882 | |
1178 | |
883 | See C<nreqs> for an example. |
1179 | See C<nreqs> for an example. |
884 | |
1180 | |
|
|
1181 | =item IO::AIO::poll |
|
|
1182 | |
|
|
1183 | Waits until some requests have been handled. |
|
|
1184 | |
|
|
1185 | Returns the number of requests processed, but is otherwise strictly |
|
|
1186 | equivalent to: |
|
|
1187 | |
|
|
1188 | IO::AIO::poll_wait, IO::AIO::poll_cb |
|
|
1189 | |
885 | =item IO::AIO::nreqs |
1190 | =item IO::AIO::flush |
886 | |
1191 | |
887 | Returns the number of requests currently in the ready, execute or pending |
1192 | Wait till all outstanding AIO requests have been handled. |
888 | states (i.e. for which their callback has not been invoked yet). |
|
|
889 | |
1193 | |
890 | Example: wait till there are no outstanding requests anymore: |
1194 | Strictly equivalent to: |
891 | |
1195 | |
892 | IO::AIO::poll_wait, IO::AIO::poll_cb |
1196 | IO::AIO::poll_wait, IO::AIO::poll_cb |
893 | while IO::AIO::nreqs; |
1197 | while IO::AIO::nreqs; |
894 | |
1198 | |
895 | =item IO::AIO::nready |
1199 | =back |
896 | |
1200 | |
897 | Returns the number of requests currently in the ready state (not yet |
1201 | =head3 CONTROLLING THE NUMBER OF THREADS |
898 | executed). |
|
|
899 | |
1202 | |
900 | =item IO::AIO::npending |
1203 | =over |
901 | |
|
|
902 | Returns the number of requests currently in the pending state (executed, |
|
|
903 | but not yet processed by poll_cb). |
|
|
904 | |
|
|
905 | =item IO::AIO::flush |
|
|
906 | |
|
|
907 | Wait till all outstanding AIO requests have been handled. |
|
|
908 | |
|
|
909 | Strictly equivalent to: |
|
|
910 | |
|
|
911 | IO::AIO::poll_wait, IO::AIO::poll_cb |
|
|
912 | while IO::AIO::nreqs; |
|
|
913 | |
|
|
914 | =item IO::AIO::poll |
|
|
915 | |
|
|
916 | Waits until some requests have been handled. |
|
|
917 | |
|
|
918 | Strictly equivalent to: |
|
|
919 | |
|
|
920 | IO::AIO::poll_wait, IO::AIO::poll_cb |
|
|
921 | if IO::AIO::nreqs; |
|
|
922 | |
1204 | |
923 | =item IO::AIO::min_parallel $nthreads |
1205 | =item IO::AIO::min_parallel $nthreads |
924 | |
1206 | |
925 | Set the minimum number of AIO threads to C<$nthreads>. The current |
1207 | Set the minimum number of AIO threads to C<$nthreads>. The current |
926 | default is C<8>, which means eight asynchronous operations can execute |
1208 | default is C<8>, which means eight asynchronous operations can execute |
927 | concurrently at any one time (the number of outstanding requests, |
1209 | concurrently at any one time (the number of outstanding requests, |
928 | however, is unlimited). |
1210 | however, is unlimited). |
929 | |
1211 | |
930 | IO::AIO starts threads only on demand, when an AIO request is queued and |
1212 | IO::AIO starts threads only on demand, when an AIO request is queued and |
931 | no free thread exists. |
1213 | no free thread exists. Please note that queueing up a hundred requests can |
|
|
1214 | create demand for a hundred threads, even if it turns out that everything |
|
|
1215 | is in the cache and could have been processed faster by a single thread. |
932 | |
1216 | |
933 | It is recommended to keep the number of threads relatively low, as some |
1217 | It is recommended to keep the number of threads relatively low, as some |
934 | Linux kernel versions will scale negatively with the number of threads |
1218 | Linux kernel versions will scale negatively with the number of threads |
935 | (higher parallelity => MUCH higher latency). With current Linux 2.6 |
1219 | (higher parallelity => MUCH higher latency). With current Linux 2.6 |
936 | versions, 4-32 threads should be fine. |
1220 | versions, 4-32 threads should be fine. |
… | |
… | |
950 | This module automatically runs C<max_parallel 0> at program end, to ensure |
1234 | This module automatically runs C<max_parallel 0> at program end, to ensure |
951 | that all threads are killed and that there are no outstanding requests. |
1235 | that all threads are killed and that there are no outstanding requests. |
952 | |
1236 | |
953 | Under normal circumstances you don't need to call this function. |
1237 | Under normal circumstances you don't need to call this function. |
954 | |
1238 | |
|
|
1239 | =item IO::AIO::max_idle $nthreads |
|
|
1240 | |
|
|
1241 | Limit the number of threads (default: 4) that are allowed to idle (i.e., |
|
|
1242 | threads that did not get a request to process within 10 seconds). That |
|
|
1243 | means if a thread becomes idle while C<$nthreads> other threads are also |
|
|
1244 | idle, it will free its resources and exit. |
|
|
1245 | |
|
|
1246 | This is useful when you allow a large number of threads (e.g. 100 or 1000) |
|
|
1247 | to allow for extremely high load situations, but want to free resources |
|
|
1248 | under normal circumstances (1000 threads can easily consume 30MB of RAM). |
|
|
1249 | |
|
|
1250 | The default is probably ok in most situations, especially if thread |
|
|
1251 | creation is fast. If thread creation is very slow on your system you might |
|
|
1252 | want to use larger values. |
|
|
1253 | |
955 | =item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs |
1254 | =item IO::AIO::max_outstanding $maxreqs |
956 | |
1255 | |
957 | This is a very bad function to use in interactive programs because it |
1256 | This is a very bad function to use in interactive programs because it |
958 | blocks, and a bad way to reduce concurrency because it is inexact: Better |
1257 | blocks, and a bad way to reduce concurrency because it is inexact: Better |
959 | use an C<aio_group> together with a feed callback. |
1258 | use an C<aio_group> together with a feed callback. |
960 | |
1259 | |
961 | Sets the maximum number of outstanding requests to C<$nreqs>. If you |
1260 | Sets the maximum number of outstanding requests to C<$nreqs>. If you |
962 | to queue up more than this number of requests, the next call to the |
1261 | do queue up more than this number of requests, the next call to the |
963 | C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>) |
1262 | C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>) |
964 | function will block until the limit is no longer exceeded. |
1263 | function will block until the limit is no longer exceeded. |
965 | |
1264 | |
966 | The default value is very large, so there is no practical limit on the |
1265 | The default value is very large, so there is no practical limit on the |
967 | number of outstanding requests. |
1266 | number of outstanding requests. |
968 | |
1267 | |
969 | You can still queue as many requests as you want. Therefore, |
1268 | You can still queue as many requests as you want. Therefore, |
970 | C<max_oustsanding> is mainly useful in simple scripts (with low values) or |
1269 | C<max_outstanding> is mainly useful in simple scripts (with low values) or |
971 | as a stop gap to shield against fatal memory overflow (with large values). |
1270 | as a stop gap to shield against fatal memory overflow (with large values). |
972 | |
1271 | |
973 | =back |
1272 | =back |
974 | |
1273 | |
|
|
1274 | =head3 STATISTICAL INFORMATION |
|
|
1275 | |
|
|
1276 | =over |
|
|
1277 | |
|
|
1278 | =item IO::AIO::nreqs |
|
|
1279 | |
|
|
1280 | Returns the number of requests currently in the ready, execute or pending |
|
|
1281 | states (i.e. for which their callback has not been invoked yet). |
|
|
1282 | |
|
|
1283 | Example: wait till there are no outstanding requests anymore: |
|
|
1284 | |
|
|
1285 | IO::AIO::poll_wait, IO::AIO::poll_cb |
|
|
1286 | while IO::AIO::nreqs; |
|
|
1287 | |
|
|
1288 | =item IO::AIO::nready |
|
|
1289 | |
|
|
1290 | Returns the number of requests currently in the ready state (not yet |
|
|
1291 | executed). |
|
|
1292 | |
|
|
1293 | =item IO::AIO::npending |
|
|
1294 | |
|
|
1295 | Returns the number of requests currently in the pending state (executed, |
|
|
1296 | but not yet processed by poll_cb). |
|
|
1297 | |
|
|
1298 | =back |
|
|
1299 | |
975 | =cut |
1300 | =cut |
976 | |
1301 | |
977 | # support function to convert a fd into a perl filehandle |
|
|
978 | sub _fd2fh { |
|
|
979 | return undef if $_[0] < 0; |
|
|
980 | |
|
|
981 | # try to generate nice filehandles |
|
|
982 | my $sym = "IO::AIO::fd#$_[0]"; |
|
|
983 | local *$sym; |
|
|
984 | |
|
|
985 | open *$sym, "+<&=$_[0]" # usually works under any unix |
|
|
986 | or open *$sym, "<&=$_[0]" # cygwin needs this |
|
|
987 | or open *$sym, ">&=$_[0]" # or this |
|
|
988 | or return undef; |
|
|
989 | |
|
|
990 | *$sym |
|
|
991 | } |
|
|
992 | |
|
|
993 | min_parallel 8; |
1302 | min_parallel 8; |
994 | |
1303 | |
995 | END { |
1304 | END { flush } |
996 | min_parallel 1; |
|
|
997 | flush; |
|
|
998 | }; |
|
|
999 | |
1305 | |
1000 | 1; |
1306 | 1; |
1001 | |
1307 | |
1002 | =head2 FORK BEHAVIOUR |
1308 | =head2 FORK BEHAVIOUR |
1003 | |
1309 | |
… | |
… | |
1023 | bytes of memory. In addition, stat requests need a stat buffer (possibly |
1329 | bytes of memory. In addition, stat requests need a stat buffer (possibly |
1024 | a few hundred bytes), readdir requires a result buffer and so on. Perl |
1330 | a few hundred bytes), readdir requires a result buffer and so on. Perl |
1025 | scalars and other data passed into aio requests will also be locked and |
1331 | scalars and other data passed into aio requests will also be locked and |
1026 | will consume memory till the request has entered the done state. |
1332 | will consume memory till the request has entered the done state. |
1027 | |
1333 | |
1028 | This is now awfully much, so queuing lots of requests is not usually a |
1334 | This is not awfully much, so queuing lots of requests is not usually a |
1029 | problem. |
1335 | problem. |
1030 | |
1336 | |
1031 | Per-thread usage: |
1337 | Per-thread usage: |
1032 | |
1338 | |
1033 | In the execution phase, some aio requests require more memory for |
1339 | In the execution phase, some aio requests require more memory for |
… | |
… | |
1038 | |
1344 | |
1039 | Known bugs will be fixed in the next release. |
1345 | Known bugs will be fixed in the next release. |
1040 | |
1346 | |
1041 | =head1 SEE ALSO |
1347 | =head1 SEE ALSO |
1042 | |
1348 | |
1043 | L<Coro::AIO>. |
1349 | L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a |
|
|
1350 | more natural syntax. |
1044 | |
1351 | |
1045 | =head1 AUTHOR |
1352 | =head1 AUTHOR |
1046 | |
1353 | |
1047 | Marc Lehmann <schmorp@schmorp.de> |
1354 | Marc Lehmann <schmorp@schmorp.de> |
1048 | http://home.schmorp.de/ |
1355 | http://home.schmorp.de/ |