… | |
… | |
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 | |
… | |
… | |
50 | |
51 | |
51 | =head1 DESCRIPTION |
52 | =head1 DESCRIPTION |
52 | |
53 | |
53 | This module implements asynchronous I/O using whatever means your |
54 | This module implements asynchronous I/O using whatever means your |
54 | operating system supports. |
55 | operating system supports. |
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56 | |
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57 | Asynchronous means that operations that can normally block your program |
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58 | (e.g. reading from disk) will be done asynchronously: the operation |
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59 | will still block, but you can do something else in the meantime. This |
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60 | is extremely useful for programs that need to stay interactive even |
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61 | when doing heavy I/O (GUI programs, high performance network servers |
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62 | etc.), but can also be used to easily do operations in parallel that are |
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63 | normally done sequentially, e.g. stat'ing many files, which is much faster |
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64 | on a RAID volume or over NFS when you do a number of stat operations |
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65 | concurrently. |
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66 | |
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67 | While most of this works on all types of file descriptors (for |
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68 | example sockets), using these functions on file descriptors that |
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69 | support nonblocking operation (again, sockets, pipes etc.) is very |
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70 | inefficient. Use an event loop for that (such as the L<Event|Event> |
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71 | module): IO::AIO will naturally fit into such an event loop itself. |
55 | |
72 | |
56 | In this version, a number of threads are started that execute your |
73 | In this version, a number of threads are started that execute your |
57 | requests and signal their completion. You don't need thread support |
74 | 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 |
75 | 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 |
76 | 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 |
77 | functions available on many operating systems. However, they are often |
61 | not well-supported or restricted (Linux doesn't allow them on normal |
78 | 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 |
79 | files currently, for example), and they would only support aio_read and |
63 | aio_write, so the remaining functionality would have to be implemented |
80 | aio_write, so the remaining functionality would have to be implemented |
64 | using threads anyway. |
81 | using threads anyway. |
65 | |
82 | |
66 | Although the module will work with in the presence of other (Perl-) |
83 | 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 |
84 | 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 |
85 | 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. |
86 | call C<poll_cb> (or other C<aio_> functions) recursively. |
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87 | |
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88 | =head2 EXAMPLE |
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89 | |
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90 | This is a simple example that uses the Event module and loads |
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91 | F</etc/passwd> asynchronously: |
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92 | |
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93 | use Fcntl; |
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94 | use Event; |
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95 | use IO::AIO; |
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96 | |
|
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97 | # register the IO::AIO callback with Event |
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98 | Event->io (fd => IO::AIO::poll_fileno, |
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99 | poll => 'r', |
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100 | cb => \&IO::AIO::poll_cb); |
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101 | |
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102 | # queue the request to open /etc/passwd |
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103 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
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104 | my $fh = shift |
|
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105 | or die "error while opening: $!"; |
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106 | |
|
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107 | # stat'ing filehandles is generally non-blocking |
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108 | my $size = -s $fh; |
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109 | |
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110 | # queue a request to read the file |
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111 | my $contents; |
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112 | aio_read $fh, 0, $size, $contents, 0, sub { |
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113 | $_[0] == $size |
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114 | or die "short read: $!"; |
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115 | |
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116 | close $fh; |
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117 | |
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118 | # file contents now in $contents |
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119 | print $contents; |
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120 | |
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121 | # exit event loop and program |
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122 | Event::unloop; |
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123 | }; |
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124 | }; |
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125 | |
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126 | # possibly queue up other requests, or open GUI windows, |
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127 | # check for sockets etc. etc. |
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128 | |
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129 | # process events as long as there are some: |
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130 | Event::loop; |
70 | |
131 | |
71 | =head1 REQUEST ANATOMY AND LIFETIME |
132 | =head1 REQUEST ANATOMY AND LIFETIME |
72 | |
133 | |
73 | Every C<aio_*> function creates a request. which is a C data structure not |
134 | Every C<aio_*> function creates a request. which is a C data structure not |
74 | directly visible to Perl. |
135 | directly visible to Perl. |
… | |
… | |
116 | Request has reached the end of its lifetime and holds no resources anymore |
177 | 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 |
178 | (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 |
179 | aio request is severed and calling its methods will either do nothing or |
119 | result in a runtime error). |
180 | result in a runtime error). |
120 | |
181 | |
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182 | =back |
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183 | |
121 | =cut |
184 | =cut |
122 | |
185 | |
123 | package IO::AIO; |
186 | package IO::AIO; |
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187 | |
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188 | use Carp (); |
124 | |
189 | |
125 | no warnings; |
190 | no warnings; |
126 | use strict 'vars'; |
191 | use strict 'vars'; |
127 | |
192 | |
128 | use base 'Exporter'; |
193 | use base 'Exporter'; |
129 | |
194 | |
130 | BEGIN { |
195 | BEGIN { |
131 | our $VERSION = '2.0'; |
196 | our $VERSION = '2.51'; |
132 | |
197 | |
133 | our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat |
198 | our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat |
134 | aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink |
199 | aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink |
135 | aio_fsync aio_fdatasync aio_readahead aio_rename aio_link aio_move |
200 | aio_readlink aio_fsync aio_fdatasync aio_readahead aio_rename aio_link |
136 | aio_group aio_nop); |
201 | aio_move aio_copy aio_group aio_nop aio_mknod aio_load aio_rmtree aio_mkdir |
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202 | aio_chown aio_chmod aio_utime aio_truncate); |
137 | our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); |
203 | our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block)); |
138 | our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush |
204 | our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush |
139 | min_parallel max_parallel nreqs); |
205 | min_parallel max_parallel max_idle |
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206 | nreqs nready npending nthreads |
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207 | max_poll_time max_poll_reqs); |
140 | |
208 | |
141 | @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; |
209 | @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; |
142 | |
210 | |
143 | require XSLoader; |
211 | require XSLoader; |
144 | XSLoader::load ("IO::AIO", $VERSION); |
212 | XSLoader::load ("IO::AIO", $VERSION); |
145 | } |
213 | } |
146 | |
214 | |
147 | =head1 FUNCTIONS |
215 | =head1 FUNCTIONS |
148 | |
216 | |
149 | =head2 AIO FUNCTIONS |
217 | =head2 AIO REQUEST FUNCTIONS |
150 | |
218 | |
151 | All the C<aio_*> calls are more or less thin wrappers around the syscall |
219 | All the C<aio_*> calls are more or less thin wrappers around the syscall |
152 | with the same name (sans C<aio_>). The arguments are similar or identical, |
220 | with the same name (sans C<aio_>). The arguments are similar or identical, |
153 | and they all accept an additional (and optional) C<$callback> argument |
221 | 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 |
222 | which must be a code reference. This code reference will get called with |
… | |
… | |
157 | syscall has been executed asynchronously. |
225 | syscall has been executed asynchronously. |
158 | |
226 | |
159 | All functions expecting a filehandle keep a copy of the filehandle |
227 | All functions expecting a filehandle keep a copy of the filehandle |
160 | internally until the request has finished. |
228 | internally until the request has finished. |
161 | |
229 | |
162 | All requests return objects of type L<IO::AIO::REQ> that allow further |
230 | All functions return request objects of type L<IO::AIO::REQ> that allow |
163 | manipulation of those requests while they are in-flight. |
231 | further manipulation of those requests while they are in-flight. |
164 | |
232 | |
165 | The pathnames you pass to these routines I<must> be absolute and |
233 | 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 |
234 | 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 |
235 | request is being executed, the current working directory could have |
168 | changed. Alternatively, you can make sure that you never change the |
236 | changed. Alternatively, you can make sure that you never change the |
169 | current working directory. |
237 | current working directory anywhere in the program and then use relative |
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238 | paths. |
170 | |
239 | |
171 | To encode pathnames to byte form, either make sure you either: a) |
240 | 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 |
241 | 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 |
242 | 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 |
243 | 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) |
244 | environment, d) use Glib::filename_from_unicode on unicode filenames or e) |
176 | use something else. |
245 | use something else to ensure your scalar has the correct contents. |
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246 | |
|
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247 | This works, btw. independent of the internal UTF-8 bit, which IO::AIO |
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248 | handles correctly wether it is set or not. |
177 | |
249 | |
178 | =over 4 |
250 | =over 4 |
179 | |
251 | |
180 | =item aioreq_pri $pri |
252 | =item $prev_pri = aioreq_pri [$pri] |
181 | |
253 | |
182 | Sets the priority for the next aio request. The default priority |
254 | Returns the priority value that would be used for the next request and, if |
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255 | C<$pri> is given, sets the priority for the next aio request. |
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256 | |
183 | is C<0>, the minimum and maximum priorities are C<-4> and C<4>, |
257 | The default priority is C<0>, the minimum and maximum priorities are C<-4> |
184 | respectively. Requests with higher priority will be serviced first. |
258 | and C<4>, respectively. Requests with higher priority will be serviced |
|
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259 | first. |
185 | |
260 | |
186 | The priority will be reset to C<0> after each call to one of the C<aio_> |
261 | The priority will be reset to C<0> after each call to one of the C<aio_*> |
187 | functions. |
262 | functions. |
188 | |
263 | |
189 | Example: open a file with low priority, then read something from it with |
264 | Example: open a file with low priority, then read something from it with |
190 | higher priority so the read request is serviced before other low priority |
265 | higher priority so the read request is serviced before other low priority |
191 | open requests (potentially spamming the cache): |
266 | open requests (potentially spamming the cache): |
… | |
… | |
198 | aio_read $_[0], ..., sub { |
273 | aio_read $_[0], ..., sub { |
199 | ... |
274 | ... |
200 | }; |
275 | }; |
201 | }; |
276 | }; |
202 | |
277 | |
|
|
278 | |
203 | =item aioreq_nice $pri_adjust |
279 | =item aioreq_nice $pri_adjust |
204 | |
280 | |
205 | Similar to C<aioreq_pri>, but subtracts the given value from the current |
281 | Similar to C<aioreq_pri>, but subtracts the given value from the current |
206 | priority, so effects are cumulative. |
282 | priority, so the effect is cumulative. |
|
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283 | |
207 | |
284 | |
208 | =item aio_open $pathname, $flags, $mode, $callback->($fh) |
285 | =item aio_open $pathname, $flags, $mode, $callback->($fh) |
209 | |
286 | |
210 | Asynchronously open or create a file and call the callback with a newly |
287 | Asynchronously open or create a file and call the callback with a newly |
211 | created filehandle for the file. |
288 | created filehandle for the file. |
… | |
… | |
217 | list. They are the same as used by C<sysopen>. |
294 | list. They are the same as used by C<sysopen>. |
218 | |
295 | |
219 | Likewise, C<$mode> specifies the mode of the newly created file, if it |
296 | Likewise, C<$mode> specifies the mode of the newly created file, if it |
220 | didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>, |
297 | didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>, |
221 | except that it is mandatory (i.e. use C<0> if you don't create new files, |
298 | except that it is mandatory (i.e. use C<0> if you don't create new files, |
222 | and C<0666> or C<0777> if you do). |
299 | and C<0666> or C<0777> if you do). Note that the C<$mode> will be modified |
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300 | by the umask in effect then the request is being executed, so better never |
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301 | change the umask. |
223 | |
302 | |
224 | Example: |
303 | Example: |
225 | |
304 | |
226 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
305 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
227 | if ($_[0]) { |
306 | if ($_[0]) { |
… | |
… | |
230 | } else { |
309 | } else { |
231 | die "open failed: $!\n"; |
310 | die "open failed: $!\n"; |
232 | } |
311 | } |
233 | }; |
312 | }; |
234 | |
313 | |
|
|
314 | |
235 | =item aio_close $fh, $callback->($status) |
315 | =item aio_close $fh, $callback->($status) |
236 | |
316 | |
237 | Asynchronously close a file and call the callback with the result |
317 | Asynchronously close a file and call the callback with the result |
238 | code. I<WARNING:> although accepted, you should not pass in a perl |
318 | code. |
239 | filehandle here, as perl will likely close the file descriptor another |
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240 | time when the filehandle is destroyed. Normally, you can safely call perls |
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241 | C<close> or just let filehandles go out of scope. |
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242 | |
319 | |
243 | This is supposed to be a bug in the API, so that might change. It's |
320 | Unfortunately, you can't do this to perl. Perl I<insists> very strongly on |
244 | therefore best to avoid this function. |
321 | closing the file descriptor associated with the filehandle itself. Here is |
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322 | what aio_close will try: |
|
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323 | |
|
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324 | 1. dup()licate the fd |
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325 | 2. asynchronously close() the duplicated fd |
|
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326 | 3. dup()licate the fd once more |
|
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327 | 4. let perl close() the filehandle |
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328 | 5. asynchronously close the duplicated fd |
|
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329 | |
|
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330 | The idea is that the first close() flushes stuff to disk that closing an |
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331 | fd will flush, so when perl closes the fd, nothing much will need to be |
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332 | flushed. The second async. close() will then flush stuff to disk that |
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333 | closing the last fd to the file will flush. |
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334 | |
|
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335 | Just FYI, SuSv3 has this to say on close: |
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336 | |
|
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337 | All outstanding record locks owned by the process on the file |
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338 | associated with the file descriptor shall be removed. |
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339 | |
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340 | If fildes refers to a socket, close() shall cause the socket to be |
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341 | destroyed. ... close() shall block for up to the current linger |
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342 | interval until all data is transmitted. |
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343 | [this actually sounds like a specification bug, but who knows] |
|
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344 | |
|
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345 | And at least Linux additionally actually flushes stuff on every close, |
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346 | even when the file itself is still open. |
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347 | |
|
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348 | Sounds enourmously inefficient and complicated? Yes... please show me how |
|
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349 | to nuke perl's fd out of existence... |
|
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350 | |
|
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351 | =cut |
|
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352 | |
|
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353 | sub aio_close($;$) { |
|
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354 | aio_block { |
|
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355 | my ($fh, $cb) = @_; |
|
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356 | |
|
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357 | my $pri = aioreq_pri; |
|
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358 | my $grp = aio_group $cb; |
|
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359 | |
|
|
360 | my $fd = fileno $fh; |
|
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361 | |
|
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362 | defined $fd or Carp::croak "aio_close called with fd-less filehandle"; |
|
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363 | |
|
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364 | # if the dups fail we will simply get EBADF |
|
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365 | my $fd2 = _dup $fd; |
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366 | aioreq_pri $pri; |
|
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367 | add $grp _aio_close $fd2, sub { |
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368 | my $fd2 = _dup $fd; |
|
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369 | close $fh; |
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370 | aioreq_pri $pri; |
|
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371 | add $grp _aio_close $fd2, sub { |
|
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372 | $grp->result ($_[0]); |
|
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373 | }; |
|
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374 | }; |
|
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375 | |
|
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376 | $grp |
|
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377 | } |
|
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378 | } |
|
|
379 | |
245 | |
380 | |
246 | =item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
381 | =item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
247 | |
382 | |
248 | =item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
383 | =item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
249 | |
384 | |
250 | Reads or writes C<length> bytes from the specified C<fh> and C<offset> |
385 | Reads or writes C<$length> bytes from the specified C<$fh> and C<$offset> |
251 | into the scalar given by C<data> and offset C<dataoffset> and calls the |
386 | into the scalar given by C<$data> and offset C<$dataoffset> and calls the |
252 | callback without the actual number of bytes read (or -1 on error, just |
387 | callback without the actual number of bytes read (or -1 on error, just |
253 | like the syscall). |
388 | like the syscall). |
254 | |
389 | |
|
|
390 | If C<$offset> is undefined, then the current file descriptor offset will |
|
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391 | be used (and updated), otherwise the file descriptor offset will not be |
|
|
392 | changed by these calls. |
|
|
393 | |
|
|
394 | If C<$length> is undefined in C<aio_write>, use the remaining length of C<$data>. |
|
|
395 | |
|
|
396 | If C<$dataoffset> is less than zero, it will be counted from the end of |
|
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397 | C<$data>. |
|
|
398 | |
255 | The C<$data> scalar I<MUST NOT> be modified in any way while the request |
399 | The C<$data> scalar I<MUST NOT> be modified in any way while the request |
256 | is outstanding. Modifying it can result in segfaults or WW3 (if the |
400 | is outstanding. Modifying it can result in segfaults or World War III (if |
257 | necessary/optional hardware is installed). |
401 | the necessary/optional hardware is installed). |
258 | |
402 | |
259 | Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at |
403 | Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at |
260 | offset C<0> within the scalar: |
404 | offset C<0> within the scalar: |
261 | |
405 | |
262 | aio_read $fh, 7, 15, $buffer, 0, sub { |
406 | aio_read $fh, 7, 15, $buffer, 0, sub { |
263 | $_[0] > 0 or die "read error: $!"; |
407 | $_[0] > 0 or die "read error: $!"; |
264 | print "read $_[0] bytes: <$buffer>\n"; |
408 | print "read $_[0] bytes: <$buffer>\n"; |
265 | }; |
409 | }; |
266 | |
410 | |
267 | =item aio_move $srcpath, $dstpath, $callback->($status) |
|
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268 | |
|
|
269 | Try to move the I<file> (directories not supported as either source or |
|
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270 | destination) from C<$srcpath> to C<$dstpath> and call the callback with |
|
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271 | the C<0> (error) or C<-1> ok. |
|
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272 | |
|
|
273 | This is a composite request that tries to rename(2) the file first. If |
|
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274 | rename files with C<EXDEV>, it creates the destination file with mode 0200 |
|
|
275 | and copies the contents of the source file into it using C<aio_sendfile>, |
|
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276 | followed by restoring atime, mtime, access mode and uid/gid, in that |
|
|
277 | order, and unlinking the C<$srcpath>. |
|
|
278 | |
|
|
279 | If an error occurs, the partial destination file will be unlinked, if |
|
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280 | possible, except when setting atime, mtime, access mode and uid/gid, where |
|
|
281 | errors are being ignored. |
|
|
282 | |
|
|
283 | =cut |
|
|
284 | |
|
|
285 | sub aio_move($$$) { |
|
|
286 | my ($src, $dst, $cb) = @_; |
|
|
287 | |
|
|
288 | my $grp = aio_group $cb; |
|
|
289 | |
|
|
290 | add $grp aio_rename $src, $dst, sub { |
|
|
291 | if ($_[0] && $! == EXDEV) { |
|
|
292 | add $grp aio_open $src, O_RDONLY, 0, sub { |
|
|
293 | if (my $src_fh = $_[0]) { |
|
|
294 | my @stat = stat $src_fh; |
|
|
295 | |
|
|
296 | add $grp aio_open $dst, O_WRONLY, 0200, sub { |
|
|
297 | if (my $dst_fh = $_[0]) { |
|
|
298 | add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { |
|
|
299 | close $src_fh; |
|
|
300 | |
|
|
301 | if ($_[0] == $stat[7]) { |
|
|
302 | utime $stat[8], $stat[9], $dst; |
|
|
303 | chmod $stat[2] & 07777, $dst_fh; |
|
|
304 | chown $stat[4], $stat[5], $dst_fh; |
|
|
305 | close $dst_fh; |
|
|
306 | |
|
|
307 | add $grp aio_unlink $src, sub { |
|
|
308 | $grp->result ($_[0]); |
|
|
309 | }; |
|
|
310 | } else { |
|
|
311 | my $errno = $!; |
|
|
312 | add $grp aio_unlink $dst, sub { |
|
|
313 | $! = $errno; |
|
|
314 | $grp->result (-1); |
|
|
315 | }; |
|
|
316 | } |
|
|
317 | }; |
|
|
318 | } else { |
|
|
319 | $grp->result (-1); |
|
|
320 | } |
|
|
321 | }, |
|
|
322 | |
|
|
323 | } else { |
|
|
324 | $grp->result (-1); |
|
|
325 | } |
|
|
326 | }; |
|
|
327 | } else { |
|
|
328 | $grp->result ($_[0]); |
|
|
329 | } |
|
|
330 | }; |
|
|
331 | |
|
|
332 | $grp |
|
|
333 | } |
|
|
334 | |
411 | |
335 | =item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
412 | =item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
336 | |
413 | |
337 | Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts |
414 | Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts |
338 | reading at byte offset C<$in_offset>, and starts writing at the current |
415 | reading at byte offset C<$in_offset>, and starts writing at the current |
… | |
… | |
352 | C<$in_fh> than are written, and there is no way to find out how many |
429 | C<$in_fh> than are written, and there is no way to find out how many |
353 | bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only |
430 | bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only |
354 | provides the number of bytes written to C<$out_fh>. Only if the result |
431 | provides the number of bytes written to C<$out_fh>. Only if the result |
355 | value equals C<$length> one can assume that C<$length> bytes have been |
432 | value equals C<$length> one can assume that C<$length> bytes have been |
356 | read. |
433 | read. |
|
|
434 | |
357 | |
435 | |
358 | =item aio_readahead $fh,$offset,$length, $callback->($retval) |
436 | =item aio_readahead $fh,$offset,$length, $callback->($retval) |
359 | |
437 | |
360 | C<aio_readahead> populates the page cache with data from a file so that |
438 | C<aio_readahead> populates the page cache with data from a file so that |
361 | subsequent reads from that file will not block on disk I/O. The C<$offset> |
439 | subsequent reads from that file will not block on disk I/O. The C<$offset> |
… | |
… | |
367 | file. The current file offset of the file is left unchanged. |
445 | file. The current file offset of the file is left unchanged. |
368 | |
446 | |
369 | If that syscall doesn't exist (likely if your OS isn't Linux) it will be |
447 | If that syscall doesn't exist (likely if your OS isn't Linux) it will be |
370 | emulated by simply reading the data, which would have a similar effect. |
448 | emulated by simply reading the data, which would have a similar effect. |
371 | |
449 | |
|
|
450 | |
372 | =item aio_stat $fh_or_path, $callback->($status) |
451 | =item aio_stat $fh_or_path, $callback->($status) |
373 | |
452 | |
374 | =item aio_lstat $fh, $callback->($status) |
453 | =item aio_lstat $fh, $callback->($status) |
375 | |
454 | |
376 | Works like perl's C<stat> or C<lstat> in void context. The callback will |
455 | Works like perl's C<stat> or C<lstat> in void context. The callback will |
… | |
… | |
389 | aio_stat "/etc/passwd", sub { |
468 | aio_stat "/etc/passwd", sub { |
390 | $_[0] and die "stat failed: $!"; |
469 | $_[0] and die "stat failed: $!"; |
391 | print "size is ", -s _, "\n"; |
470 | print "size is ", -s _, "\n"; |
392 | }; |
471 | }; |
393 | |
472 | |
|
|
473 | |
|
|
474 | =item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
|
|
475 | |
|
|
476 | Works like perl's C<utime> function (including the special case of $atime |
|
|
477 | and $mtime being undef). Fractional times are supported if the underlying |
|
|
478 | syscalls support them. |
|
|
479 | |
|
|
480 | When called with a pathname, uses utimes(2) if available, otherwise |
|
|
481 | utime(2). If called on a file descriptor, uses futimes(2) if available, |
|
|
482 | otherwise returns ENOSYS, so this is not portable. |
|
|
483 | |
|
|
484 | Examples: |
|
|
485 | |
|
|
486 | # set atime and mtime to current time (basically touch(1)): |
|
|
487 | aio_utime "path", undef, undef; |
|
|
488 | # set atime to current time and mtime to beginning of the epoch: |
|
|
489 | aio_utime "path", time, undef; # undef==0 |
|
|
490 | |
|
|
491 | |
|
|
492 | =item aio_chown $fh_or_path, $uid, $gid, $callback->($status) |
|
|
493 | |
|
|
494 | Works like perl's C<chown> function, except that C<undef> for either $uid |
|
|
495 | or $gid is being interpreted as "do not change" (but -1 can also be used). |
|
|
496 | |
|
|
497 | Examples: |
|
|
498 | |
|
|
499 | # same as "chown root path" in the shell: |
|
|
500 | aio_chown "path", 0, -1; |
|
|
501 | # same as above: |
|
|
502 | aio_chown "path", 0, undef; |
|
|
503 | |
|
|
504 | |
|
|
505 | =item aio_truncate $fh_or_path, $offset, $callback->($status) |
|
|
506 | |
|
|
507 | Works like truncate(2) or ftruncate(2). |
|
|
508 | |
|
|
509 | |
|
|
510 | =item aio_chmod $fh_or_path, $mode, $callback->($status) |
|
|
511 | |
|
|
512 | Works like perl's C<chmod> function. |
|
|
513 | |
|
|
514 | |
394 | =item aio_unlink $pathname, $callback->($status) |
515 | =item aio_unlink $pathname, $callback->($status) |
395 | |
516 | |
396 | Asynchronously unlink (delete) a file and call the callback with the |
517 | Asynchronously unlink (delete) a file and call the callback with the |
397 | result code. |
518 | result code. |
398 | |
519 | |
|
|
520 | |
|
|
521 | =item aio_mknod $path, $mode, $dev, $callback->($status) |
|
|
522 | |
|
|
523 | [EXPERIMENTAL] |
|
|
524 | |
|
|
525 | Asynchronously create a device node (or fifo). See mknod(2). |
|
|
526 | |
|
|
527 | The only (POSIX-) portable way of calling this function is: |
|
|
528 | |
|
|
529 | aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
|
|
530 | |
|
|
531 | |
399 | =item aio_link $srcpath, $dstpath, $callback->($status) |
532 | =item aio_link $srcpath, $dstpath, $callback->($status) |
400 | |
533 | |
401 | Asynchronously create a new link to the existing object at C<$srcpath> at |
534 | Asynchronously create a new link to the existing object at C<$srcpath> at |
402 | the path C<$dstpath> and call the callback with the result code. |
535 | the path C<$dstpath> and call the callback with the result code. |
403 | |
536 | |
|
|
537 | |
404 | =item aio_symlink $srcpath, $dstpath, $callback->($status) |
538 | =item aio_symlink $srcpath, $dstpath, $callback->($status) |
405 | |
539 | |
406 | Asynchronously create a new symbolic link to the existing object at C<$srcpath> at |
540 | Asynchronously create a new symbolic link to the existing object at C<$srcpath> at |
407 | the path C<$dstpath> and call the callback with the result code. |
541 | the path C<$dstpath> and call the callback with the result code. |
408 | |
542 | |
|
|
543 | |
|
|
544 | =item aio_readlink $path, $callback->($link) |
|
|
545 | |
|
|
546 | Asynchronously read the symlink specified by C<$path> and pass it to |
|
|
547 | the callback. If an error occurs, nothing or undef gets passed to the |
|
|
548 | callback. |
|
|
549 | |
|
|
550 | |
409 | =item aio_rename $srcpath, $dstpath, $callback->($status) |
551 | =item aio_rename $srcpath, $dstpath, $callback->($status) |
410 | |
552 | |
411 | Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as |
553 | Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as |
412 | rename(2) and call the callback with the result code. |
554 | rename(2) and call the callback with the result code. |
413 | |
555 | |
|
|
556 | |
|
|
557 | =item aio_mkdir $pathname, $mode, $callback->($status) |
|
|
558 | |
|
|
559 | Asynchronously mkdir (create) a directory and call the callback with |
|
|
560 | the result code. C<$mode> will be modified by the umask at the time the |
|
|
561 | request is executed, so do not change your umask. |
|
|
562 | |
|
|
563 | |
414 | =item aio_rmdir $pathname, $callback->($status) |
564 | =item aio_rmdir $pathname, $callback->($status) |
415 | |
565 | |
416 | Asynchronously rmdir (delete) a directory and call the callback with the |
566 | Asynchronously rmdir (delete) a directory and call the callback with the |
417 | result code. |
567 | result code. |
|
|
568 | |
418 | |
569 | |
419 | =item aio_readdir $pathname, $callback->($entries) |
570 | =item aio_readdir $pathname, $callback->($entries) |
420 | |
571 | |
421 | Unlike the POSIX call of the same name, C<aio_readdir> reads an entire |
572 | Unlike the POSIX call of the same name, C<aio_readdir> reads an entire |
422 | directory (i.e. opendir + readdir + closedir). The entries will not be |
573 | directory (i.e. opendir + readdir + closedir). The entries will not be |
423 | sorted, and will B<NOT> include the C<.> and C<..> entries. |
574 | sorted, and will B<NOT> include the C<.> and C<..> entries. |
424 | |
575 | |
425 | The callback a single argument which is either C<undef> or an array-ref |
576 | The callback a single argument which is either C<undef> or an array-ref |
426 | with the filenames. |
577 | with the filenames. |
|
|
578 | |
|
|
579 | |
|
|
580 | =item aio_load $path, $data, $callback->($status) |
|
|
581 | |
|
|
582 | This is a composite request that tries to fully load the given file into |
|
|
583 | memory. Status is the same as with aio_read. |
|
|
584 | |
|
|
585 | =cut |
|
|
586 | |
|
|
587 | sub aio_load($$;$) { |
|
|
588 | aio_block { |
|
|
589 | my ($path, undef, $cb) = @_; |
|
|
590 | my $data = \$_[1]; |
|
|
591 | |
|
|
592 | my $pri = aioreq_pri; |
|
|
593 | my $grp = aio_group $cb; |
|
|
594 | |
|
|
595 | aioreq_pri $pri; |
|
|
596 | add $grp aio_open $path, O_RDONLY, 0, sub { |
|
|
597 | my $fh = shift |
|
|
598 | or return $grp->result (-1); |
|
|
599 | |
|
|
600 | aioreq_pri $pri; |
|
|
601 | add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub { |
|
|
602 | $grp->result ($_[0]); |
|
|
603 | }; |
|
|
604 | }; |
|
|
605 | |
|
|
606 | $grp |
|
|
607 | } |
|
|
608 | } |
|
|
609 | |
|
|
610 | =item aio_copy $srcpath, $dstpath, $callback->($status) |
|
|
611 | |
|
|
612 | Try to copy the I<file> (directories not supported as either source or |
|
|
613 | destination) from C<$srcpath> to C<$dstpath> and call the callback with |
|
|
614 | the C<0> (error) or C<-1> ok. |
|
|
615 | |
|
|
616 | This is a composite request that it creates the destination file with |
|
|
617 | mode 0200 and copies the contents of the source file into it using |
|
|
618 | C<aio_sendfile>, followed by restoring atime, mtime, access mode and |
|
|
619 | uid/gid, in that order. |
|
|
620 | |
|
|
621 | If an error occurs, the partial destination file will be unlinked, if |
|
|
622 | possible, except when setting atime, mtime, access mode and uid/gid, where |
|
|
623 | errors are being ignored. |
|
|
624 | |
|
|
625 | =cut |
|
|
626 | |
|
|
627 | sub aio_copy($$;$) { |
|
|
628 | aio_block { |
|
|
629 | my ($src, $dst, $cb) = @_; |
|
|
630 | |
|
|
631 | my $pri = aioreq_pri; |
|
|
632 | my $grp = aio_group $cb; |
|
|
633 | |
|
|
634 | aioreq_pri $pri; |
|
|
635 | add $grp aio_open $src, O_RDONLY, 0, sub { |
|
|
636 | if (my $src_fh = $_[0]) { |
|
|
637 | my @stat = stat $src_fh; |
|
|
638 | |
|
|
639 | aioreq_pri $pri; |
|
|
640 | add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub { |
|
|
641 | if (my $dst_fh = $_[0]) { |
|
|
642 | aioreq_pri $pri; |
|
|
643 | add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { |
|
|
644 | if ($_[0] == $stat[7]) { |
|
|
645 | $grp->result (0); |
|
|
646 | close $src_fh; |
|
|
647 | |
|
|
648 | # those should not normally block. should. should. |
|
|
649 | utime $stat[8], $stat[9], $dst; |
|
|
650 | chmod $stat[2] & 07777, $dst_fh; |
|
|
651 | chown $stat[4], $stat[5], $dst_fh; |
|
|
652 | close $dst_fh; |
|
|
653 | } else { |
|
|
654 | $grp->result (-1); |
|
|
655 | close $src_fh; |
|
|
656 | close $dst_fh; |
|
|
657 | |
|
|
658 | aioreq $pri; |
|
|
659 | add $grp aio_unlink $dst; |
|
|
660 | } |
|
|
661 | }; |
|
|
662 | } else { |
|
|
663 | $grp->result (-1); |
|
|
664 | } |
|
|
665 | }, |
|
|
666 | |
|
|
667 | } else { |
|
|
668 | $grp->result (-1); |
|
|
669 | } |
|
|
670 | }; |
|
|
671 | |
|
|
672 | $grp |
|
|
673 | } |
|
|
674 | } |
|
|
675 | |
|
|
676 | =item aio_move $srcpath, $dstpath, $callback->($status) |
|
|
677 | |
|
|
678 | Try to move the I<file> (directories not supported as either source or |
|
|
679 | destination) from C<$srcpath> to C<$dstpath> and call the callback with |
|
|
680 | the C<0> (error) or C<-1> ok. |
|
|
681 | |
|
|
682 | This is a composite request that tries to rename(2) the file first. If |
|
|
683 | rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if |
|
|
684 | that is successful, unlinking the C<$srcpath>. |
|
|
685 | |
|
|
686 | =cut |
|
|
687 | |
|
|
688 | sub aio_move($$;$) { |
|
|
689 | aio_block { |
|
|
690 | my ($src, $dst, $cb) = @_; |
|
|
691 | |
|
|
692 | my $pri = aioreq_pri; |
|
|
693 | my $grp = aio_group $cb; |
|
|
694 | |
|
|
695 | aioreq_pri $pri; |
|
|
696 | add $grp aio_rename $src, $dst, sub { |
|
|
697 | if ($_[0] && $! == EXDEV) { |
|
|
698 | aioreq_pri $pri; |
|
|
699 | add $grp aio_copy $src, $dst, sub { |
|
|
700 | $grp->result ($_[0]); |
|
|
701 | |
|
|
702 | if (!$_[0]) { |
|
|
703 | aioreq_pri $pri; |
|
|
704 | add $grp aio_unlink $src; |
|
|
705 | } |
|
|
706 | }; |
|
|
707 | } else { |
|
|
708 | $grp->result ($_[0]); |
|
|
709 | } |
|
|
710 | }; |
|
|
711 | |
|
|
712 | $grp |
|
|
713 | } |
|
|
714 | } |
427 | |
715 | |
428 | =item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
716 | =item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
429 | |
717 | |
430 | Scans a directory (similar to C<aio_readdir>) but additionally tries to |
718 | Scans a directory (similar to C<aio_readdir>) but additionally tries to |
431 | efficiently separate the entries of directory C<$path> into two sets of |
719 | efficiently separate the entries of directory C<$path> into two sets of |
… | |
… | |
433 | recurse into (everything else, including symlinks to directories). |
721 | recurse into (everything else, including symlinks to directories). |
434 | |
722 | |
435 | C<aio_scandir> is a composite request that creates of many sub requests_ |
723 | C<aio_scandir> is a composite request that creates of many sub requests_ |
436 | C<$maxreq> specifies the maximum number of outstanding aio requests that |
724 | C<$maxreq> specifies the maximum number of outstanding aio requests that |
437 | this function generates. If it is C<< <= 0 >>, then a suitable default |
725 | this function generates. If it is C<< <= 0 >>, then a suitable default |
438 | will be chosen (currently 6). |
726 | will be chosen (currently 4). |
439 | |
727 | |
440 | On error, the callback is called without arguments, otherwise it receives |
728 | On error, the callback is called without arguments, otherwise it receives |
441 | two array-refs with path-relative entry names. |
729 | two array-refs with path-relative entry names. |
442 | |
730 | |
443 | Example: |
731 | Example: |
… | |
… | |
477 | as those tend to return 0 or 1 as link counts, which disables the |
765 | as those tend to return 0 or 1 as link counts, which disables the |
478 | directory counting heuristic. |
766 | directory counting heuristic. |
479 | |
767 | |
480 | =cut |
768 | =cut |
481 | |
769 | |
482 | sub aio_scandir($$$) { |
770 | sub aio_scandir($$;$) { |
|
|
771 | aio_block { |
483 | my ($path, $maxreq, $cb) = @_; |
772 | my ($path, $maxreq, $cb) = @_; |
484 | |
773 | |
|
|
774 | my $pri = aioreq_pri; |
|
|
775 | |
485 | my $grp = aio_group $cb; |
776 | my $grp = aio_group $cb; |
486 | |
777 | |
487 | $maxreq = 6 if $maxreq <= 0; |
778 | $maxreq = 4 if $maxreq <= 0; |
488 | |
779 | |
489 | # stat once |
780 | # stat once |
|
|
781 | aioreq_pri $pri; |
490 | add $grp aio_stat $path, sub { |
782 | add $grp aio_stat $path, sub { |
491 | return $grp->result () if $_[0]; |
783 | return $grp->result () if $_[0]; |
492 | my $now = time; |
784 | my $now = time; |
493 | my $hash1 = join ":", (stat _)[0,1,3,7,9]; |
785 | my $hash1 = join ":", (stat _)[0,1,3,7,9]; |
494 | |
786 | |
495 | # read the directory entries |
787 | # read the directory entries |
|
|
788 | aioreq_pri $pri; |
496 | add $grp aio_readdir $path, sub { |
789 | add $grp aio_readdir $path, sub { |
497 | my $entries = shift |
790 | my $entries = shift |
498 | or return $grp->result (); |
791 | or return $grp->result (); |
499 | |
792 | |
500 | # stat the dir another time |
793 | # stat the dir another time |
|
|
794 | aioreq_pri $pri; |
501 | add $grp aio_stat $path, sub { |
795 | add $grp aio_stat $path, sub { |
502 | my $hash2 = join ":", (stat _)[0,1,3,7,9]; |
796 | my $hash2 = join ":", (stat _)[0,1,3,7,9]; |
503 | |
797 | |
504 | my $ndirs; |
798 | my $ndirs; |
505 | |
799 | |
506 | # take the slow route if anything looks fishy |
800 | # take the slow route if anything looks fishy |
507 | if ($hash1 ne $hash2 or (stat _)[9] == $now) { |
801 | if ($hash1 ne $hash2 or (stat _)[9] == $now) { |
508 | $ndirs = -1; |
802 | $ndirs = -1; |
509 | } else { |
803 | } else { |
510 | # if nlink == 2, we are finished |
804 | # if nlink == 2, we are finished |
511 | # on non-posix-fs's, we rely on nlink < 2 |
805 | # on non-posix-fs's, we rely on nlink < 2 |
512 | $ndirs = (stat _)[3] - 2 |
806 | $ndirs = (stat _)[3] - 2 |
513 | or return $grp->result ([], $entries); |
807 | or return $grp->result ([], $entries); |
514 | } |
808 | } |
515 | |
809 | |
516 | # sort into likely dirs and likely nondirs |
810 | # sort into likely dirs and likely nondirs |
517 | # dirs == files without ".", short entries first |
811 | # dirs == files without ".", short entries first |
518 | $entries = [map $_->[0], |
812 | $entries = [map $_->[0], |
519 | sort { $b->[1] cmp $a->[1] } |
813 | sort { $b->[1] cmp $a->[1] } |
520 | map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length], |
814 | map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length], |
521 | @$entries]; |
815 | @$entries]; |
522 | |
816 | |
523 | my (@dirs, @nondirs); |
817 | my (@dirs, @nondirs); |
524 | |
818 | |
525 | my $statgrp = add $grp aio_group sub { |
819 | my $statgrp = add $grp aio_group sub { |
526 | $grp->result (\@dirs, \@nondirs); |
820 | $grp->result (\@dirs, \@nondirs); |
527 | }; |
821 | }; |
528 | |
822 | |
529 | limit $statgrp $maxreq; |
823 | limit $statgrp $maxreq; |
530 | feed $statgrp sub { |
824 | feed $statgrp sub { |
531 | return unless @$entries; |
825 | return unless @$entries; |
532 | my $entry = pop @$entries; |
826 | my $entry = pop @$entries; |
533 | |
827 | |
|
|
828 | aioreq_pri $pri; |
534 | add $statgrp aio_stat "$path/$entry/.", sub { |
829 | add $statgrp aio_stat "$path/$entry/.", sub { |
535 | if ($_[0] < 0) { |
830 | if ($_[0] < 0) { |
536 | push @nondirs, $entry; |
831 | push @nondirs, $entry; |
537 | } else { |
832 | } else { |
538 | # need to check for real directory |
833 | # need to check for real directory |
|
|
834 | aioreq_pri $pri; |
539 | add $statgrp aio_lstat "$path/$entry", sub { |
835 | add $statgrp aio_lstat "$path/$entry", sub { |
540 | if (-d _) { |
836 | if (-d _) { |
541 | push @dirs, $entry; |
837 | push @dirs, $entry; |
542 | |
838 | |
543 | unless (--$ndirs) { |
839 | unless (--$ndirs) { |
544 | push @nondirs, @$entries; |
840 | push @nondirs, @$entries; |
545 | feed $statgrp; |
841 | feed $statgrp; |
|
|
842 | } |
|
|
843 | } else { |
|
|
844 | push @nondirs, $entry; |
546 | } |
845 | } |
547 | } else { |
|
|
548 | push @nondirs, $entry; |
|
|
549 | } |
846 | } |
550 | } |
847 | } |
551 | } |
848 | }; |
552 | }; |
849 | }; |
553 | }; |
850 | }; |
554 | }; |
851 | }; |
555 | }; |
852 | }; |
|
|
853 | |
|
|
854 | $grp |
556 | }; |
855 | } |
|
|
856 | } |
557 | |
857 | |
|
|
858 | =item aio_rmtree $path, $callback->($status) |
|
|
859 | |
|
|
860 | Delete a directory tree starting (and including) C<$path>, return the |
|
|
861 | status of the final C<rmdir> only. This is a composite request that |
|
|
862 | uses C<aio_scandir> to recurse into and rmdir directories, and unlink |
|
|
863 | everything else. |
|
|
864 | |
|
|
865 | =cut |
|
|
866 | |
|
|
867 | sub aio_rmtree; |
|
|
868 | sub aio_rmtree($;$) { |
|
|
869 | aio_block { |
|
|
870 | my ($path, $cb) = @_; |
|
|
871 | |
|
|
872 | my $pri = aioreq_pri; |
|
|
873 | my $grp = aio_group $cb; |
|
|
874 | |
|
|
875 | aioreq_pri $pri; |
|
|
876 | add $grp aio_scandir $path, 0, sub { |
|
|
877 | my ($dirs, $nondirs) = @_; |
|
|
878 | |
|
|
879 | my $dirgrp = aio_group sub { |
|
|
880 | add $grp aio_rmdir $path, sub { |
|
|
881 | $grp->result ($_[0]); |
|
|
882 | }; |
|
|
883 | }; |
|
|
884 | |
|
|
885 | (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs; |
|
|
886 | (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs; |
|
|
887 | |
|
|
888 | add $grp $dirgrp; |
|
|
889 | }; |
|
|
890 | |
558 | $grp |
891 | $grp |
|
|
892 | } |
559 | } |
893 | } |
560 | |
894 | |
561 | =item aio_fsync $fh, $callback->($status) |
895 | =item aio_fsync $fh, $callback->($status) |
562 | |
896 | |
563 | Asynchronously call fsync on the given filehandle and call the callback |
897 | Asynchronously call fsync on the given filehandle and call the callback |
… | |
… | |
714 | itself. Useful when you queued a lot of events but got a result early. |
1048 | itself. Useful when you queued a lot of events but got a result early. |
715 | |
1049 | |
716 | =item $grp->result (...) |
1050 | =item $grp->result (...) |
717 | |
1051 | |
718 | Set the result value(s) that will be passed to the group callback when all |
1052 | Set the result value(s) that will be passed to the group callback when all |
719 | subrequests have finished. By default, no argument will be passed. |
1053 | subrequests have finished and set thre groups errno to the current value |
|
|
1054 | of errno (just like calling C<errno> without an error number). By default, |
|
|
1055 | no argument will be passed and errno is zero. |
|
|
1056 | |
|
|
1057 | =item $grp->errno ([$errno]) |
|
|
1058 | |
|
|
1059 | Sets the group errno value to C<$errno>, or the current value of errno |
|
|
1060 | when the argument is missing. |
|
|
1061 | |
|
|
1062 | Every aio request has an associated errno value that is restored when |
|
|
1063 | the callback is invoked. This method lets you change this value from its |
|
|
1064 | default (0). |
|
|
1065 | |
|
|
1066 | Calling C<result> will also set errno, so make sure you either set C<$!> |
|
|
1067 | before the call to C<result>, or call c<errno> after it. |
720 | |
1068 | |
721 | =item feed $grp $callback->($grp) |
1069 | =item feed $grp $callback->($grp) |
722 | |
1070 | |
723 | Sets a feeder/generator on this group: every group can have an attached |
1071 | Sets a feeder/generator on this group: every group can have an attached |
724 | generator that generates requests if idle. The idea behind this is that, |
1072 | generator that generates requests if idle. The idea behind this is that, |
… | |
… | |
763 | |
1111 | |
764 | =back |
1112 | =back |
765 | |
1113 | |
766 | =head2 SUPPORT FUNCTIONS |
1114 | =head2 SUPPORT FUNCTIONS |
767 | |
1115 | |
|
|
1116 | =head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION |
|
|
1117 | |
768 | =over 4 |
1118 | =over 4 |
769 | |
1119 | |
770 | =item $fileno = IO::AIO::poll_fileno |
1120 | =item $fileno = IO::AIO::poll_fileno |
771 | |
1121 | |
772 | Return the I<request result pipe file descriptor>. This filehandle must be |
1122 | Return the I<request result pipe file descriptor>. This filehandle must be |
… | |
… | |
776 | |
1126 | |
777 | See C<poll_cb> for an example. |
1127 | See C<poll_cb> for an example. |
778 | |
1128 | |
779 | =item IO::AIO::poll_cb |
1129 | =item IO::AIO::poll_cb |
780 | |
1130 | |
781 | Process all outstanding events on the result pipe. You have to call this |
1131 | Process some outstanding events on the result pipe. You have to call this |
782 | regularly. Returns the number of events processed. Returns immediately |
1132 | regularly. Returns the number of events processed. Returns immediately |
783 | when no events are outstanding. |
1133 | when no events are outstanding. The amount of events processed depends on |
|
|
1134 | the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>. |
784 | |
1135 | |
785 | If not all requests were processed for whatever reason, the filehandle |
1136 | If not all requests were processed for whatever reason, the filehandle |
786 | will still be ready when C<poll_cb> returns. |
1137 | will still be ready when C<poll_cb> returns. |
787 | |
1138 | |
788 | Example: Install an Event watcher that automatically calls |
1139 | Example: Install an Event watcher that automatically calls |
… | |
… | |
790 | |
1141 | |
791 | Event->io (fd => IO::AIO::poll_fileno, |
1142 | Event->io (fd => IO::AIO::poll_fileno, |
792 | poll => 'r', async => 1, |
1143 | poll => 'r', async => 1, |
793 | cb => \&IO::AIO::poll_cb); |
1144 | cb => \&IO::AIO::poll_cb); |
794 | |
1145 | |
795 | =item IO::AIO::poll_some $max_requests |
1146 | =item IO::AIO::max_poll_reqs $nreqs |
796 | |
1147 | |
797 | Similar to C<poll_cb>, but only processes up to C<$max_requests> requests |
1148 | =item IO::AIO::max_poll_time $seconds |
798 | at a time. |
|
|
799 | |
1149 | |
800 | Useful if you want to ensure some level of interactiveness when perl is |
1150 | These set the maximum number of requests (default C<0>, meaning infinity) |
801 | not fast enough to process all requests in time. |
1151 | that are being processed by C<IO::AIO::poll_cb> in one call, respectively |
|
|
1152 | the maximum amount of time (default C<0>, meaning infinity) spent in |
|
|
1153 | C<IO::AIO::poll_cb> to process requests (more correctly the mininum amount |
|
|
1154 | of time C<poll_cb> is allowed to use). |
|
|
1155 | |
|
|
1156 | Setting C<max_poll_time> to a non-zero value creates an overhead of one |
|
|
1157 | syscall per request processed, which is not normally a problem unless your |
|
|
1158 | callbacks are really really fast or your OS is really really slow (I am |
|
|
1159 | not mentioning Solaris here). Using C<max_poll_reqs> incurs no overhead. |
|
|
1160 | |
|
|
1161 | Setting these is useful if you want to ensure some level of |
|
|
1162 | interactiveness when perl is not fast enough to process all requests in |
|
|
1163 | time. |
|
|
1164 | |
|
|
1165 | For interactive programs, values such as C<0.01> to C<0.1> should be fine. |
802 | |
1166 | |
803 | Example: Install an Event watcher that automatically calls |
1167 | Example: Install an Event watcher that automatically calls |
804 | IO::AIO::poll_some with low priority, to ensure that other parts of the |
1168 | IO::AIO::poll_cb with low priority, to ensure that other parts of the |
805 | program get the CPU sometimes even under high AIO load. |
1169 | program get the CPU sometimes even under high AIO load. |
806 | |
1170 | |
|
|
1171 | # try not to spend much more than 0.1s in poll_cb |
|
|
1172 | IO::AIO::max_poll_time 0.1; |
|
|
1173 | |
|
|
1174 | # use a low priority so other tasks have priority |
807 | Event->io (fd => IO::AIO::poll_fileno, |
1175 | Event->io (fd => IO::AIO::poll_fileno, |
808 | poll => 'r', nice => 1, |
1176 | poll => 'r', nice => 1, |
809 | cb => sub { IO::AIO::poll_some 256 }); |
1177 | cb => &IO::AIO::poll_cb); |
810 | |
1178 | |
811 | =item IO::AIO::poll_wait |
1179 | =item IO::AIO::poll_wait |
812 | |
1180 | |
|
|
1181 | If there are any outstanding requests and none of them in the result |
813 | Wait till the result filehandle becomes ready for reading (simply does a |
1182 | phase, wait till the result filehandle becomes ready for reading (simply |
814 | C<select> on the filehandle. This is useful if you want to synchronously wait |
1183 | does a C<select> on the filehandle. This is useful if you want to |
815 | for some requests to finish). |
1184 | synchronously wait for some requests to finish). |
816 | |
1185 | |
817 | See C<nreqs> for an example. |
1186 | See C<nreqs> for an example. |
818 | |
1187 | |
|
|
1188 | =item IO::AIO::poll |
|
|
1189 | |
|
|
1190 | Waits until some requests have been handled. |
|
|
1191 | |
|
|
1192 | Returns the number of requests processed, but is otherwise strictly |
|
|
1193 | equivalent to: |
|
|
1194 | |
|
|
1195 | IO::AIO::poll_wait, IO::AIO::poll_cb |
|
|
1196 | |
819 | =item IO::AIO::nreqs |
1197 | =item IO::AIO::flush |
820 | |
1198 | |
821 | Returns the number of requests currently outstanding (i.e. for which their |
1199 | Wait till all outstanding AIO requests have been handled. |
822 | callback has not been invoked yet). |
|
|
823 | |
1200 | |
824 | Example: wait till there are no outstanding requests anymore: |
1201 | Strictly equivalent to: |
825 | |
1202 | |
826 | IO::AIO::poll_wait, IO::AIO::poll_cb |
1203 | IO::AIO::poll_wait, IO::AIO::poll_cb |
827 | while IO::AIO::nreqs; |
1204 | while IO::AIO::nreqs; |
828 | |
1205 | |
829 | =item IO::AIO::flush |
1206 | =back |
830 | |
1207 | |
831 | Wait till all outstanding AIO requests have been handled. |
1208 | =head3 CONTROLLING THE NUMBER OF THREADS |
832 | |
1209 | |
833 | Strictly equivalent to: |
1210 | =over |
834 | |
|
|
835 | IO::AIO::poll_wait, IO::AIO::poll_cb |
|
|
836 | while IO::AIO::nreqs; |
|
|
837 | |
|
|
838 | =item IO::AIO::poll |
|
|
839 | |
|
|
840 | Waits until some requests have been handled. |
|
|
841 | |
|
|
842 | Strictly equivalent to: |
|
|
843 | |
|
|
844 | IO::AIO::poll_wait, IO::AIO::poll_cb |
|
|
845 | if IO::AIO::nreqs; |
|
|
846 | |
1211 | |
847 | =item IO::AIO::min_parallel $nthreads |
1212 | =item IO::AIO::min_parallel $nthreads |
848 | |
1213 | |
849 | Set the minimum number of AIO threads to C<$nthreads>. The current |
1214 | Set the minimum number of AIO threads to C<$nthreads>. The current |
850 | default is C<8>, which means eight asynchronous operations can execute |
1215 | default is C<8>, which means eight asynchronous operations can execute |
851 | concurrently at any one time (the number of outstanding requests, |
1216 | concurrently at any one time (the number of outstanding requests, |
852 | however, is unlimited). |
1217 | however, is unlimited). |
853 | |
1218 | |
854 | IO::AIO starts threads only on demand, when an AIO request is queued and |
1219 | IO::AIO starts threads only on demand, when an AIO request is queued and |
855 | no free thread exists. |
1220 | no free thread exists. Please note that queueing up a hundred requests can |
|
|
1221 | create demand for a hundred threads, even if it turns out that everything |
|
|
1222 | is in the cache and could have been processed faster by a single thread. |
856 | |
1223 | |
857 | It is recommended to keep the number of threads relatively low, as some |
1224 | It is recommended to keep the number of threads relatively low, as some |
858 | Linux kernel versions will scale negatively with the number of threads |
1225 | Linux kernel versions will scale negatively with the number of threads |
859 | (higher parallelity => MUCH higher latency). With current Linux 2.6 |
1226 | (higher parallelity => MUCH higher latency). With current Linux 2.6 |
860 | versions, 4-32 threads should be fine. |
1227 | versions, 4-32 threads should be fine. |
… | |
… | |
874 | This module automatically runs C<max_parallel 0> at program end, to ensure |
1241 | This module automatically runs C<max_parallel 0> at program end, to ensure |
875 | that all threads are killed and that there are no outstanding requests. |
1242 | that all threads are killed and that there are no outstanding requests. |
876 | |
1243 | |
877 | Under normal circumstances you don't need to call this function. |
1244 | Under normal circumstances you don't need to call this function. |
878 | |
1245 | |
|
|
1246 | =item IO::AIO::max_idle $nthreads |
|
|
1247 | |
|
|
1248 | Limit the number of threads (default: 4) that are allowed to idle (i.e., |
|
|
1249 | threads that did not get a request to process within 10 seconds). That |
|
|
1250 | means if a thread becomes idle while C<$nthreads> other threads are also |
|
|
1251 | idle, it will free its resources and exit. |
|
|
1252 | |
|
|
1253 | This is useful when you allow a large number of threads (e.g. 100 or 1000) |
|
|
1254 | to allow for extremely high load situations, but want to free resources |
|
|
1255 | under normal circumstances (1000 threads can easily consume 30MB of RAM). |
|
|
1256 | |
|
|
1257 | The default is probably ok in most situations, especially if thread |
|
|
1258 | creation is fast. If thread creation is very slow on your system you might |
|
|
1259 | want to use larger values. |
|
|
1260 | |
879 | =item $oldnreqs = IO::AIO::max_outstanding $nreqs |
1261 | =item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs |
880 | |
1262 | |
881 | [REMOVED] |
1263 | This is a very bad function to use in interactive programs because it |
|
|
1264 | blocks, and a bad way to reduce concurrency because it is inexact: Better |
|
|
1265 | use an C<aio_group> together with a feed callback. |
882 | |
1266 | |
883 | Pre-2.x versions used max_outstanding for a crude request queue length limit. |
|
|
884 | |
|
|
885 | In 2.x+ you are advised to use a group and a feeder to limit |
|
|
886 | concurrency. The max_outstanding feature ran very unstable (endless |
|
|
887 | recursions causing segfaults, bad interaction with groups etc.) and was |
|
|
888 | removed. |
|
|
889 | |
|
|
890 | I am deeply sorry, but I am still on the hunt for a good limiting interface. |
|
|
891 | |
|
|
892 | Original description was as follows: |
|
|
893 | |
|
|
894 | Sets the maximum number of outstanding requests to C<$nreqs>. If you try |
1267 | Sets the maximum number of outstanding requests to C<$nreqs>. If you |
895 | to queue up more than this number of requests, the caller will block until |
1268 | do queue up more than this number of requests, the next call to the |
896 | some requests have been handled. |
1269 | C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>) |
|
|
1270 | function will block until the limit is no longer exceeded. |
|
|
1271 | |
|
|
1272 | The default value is very large, so there is no practical limit on the |
|
|
1273 | number of outstanding requests. |
|
|
1274 | |
|
|
1275 | You can still queue as many requests as you want. Therefore, |
|
|
1276 | C<max_oustsanding> is mainly useful in simple scripts (with low values) or |
|
|
1277 | as a stop gap to shield against fatal memory overflow (with large values). |
897 | |
1278 | |
898 | =back |
1279 | =back |
899 | |
1280 | |
|
|
1281 | =head3 STATISTICAL INFORMATION |
|
|
1282 | |
|
|
1283 | =over |
|
|
1284 | |
|
|
1285 | =item IO::AIO::nreqs |
|
|
1286 | |
|
|
1287 | Returns the number of requests currently in the ready, execute or pending |
|
|
1288 | states (i.e. for which their callback has not been invoked yet). |
|
|
1289 | |
|
|
1290 | Example: wait till there are no outstanding requests anymore: |
|
|
1291 | |
|
|
1292 | IO::AIO::poll_wait, IO::AIO::poll_cb |
|
|
1293 | while IO::AIO::nreqs; |
|
|
1294 | |
|
|
1295 | =item IO::AIO::nready |
|
|
1296 | |
|
|
1297 | Returns the number of requests currently in the ready state (not yet |
|
|
1298 | executed). |
|
|
1299 | |
|
|
1300 | =item IO::AIO::npending |
|
|
1301 | |
|
|
1302 | Returns the number of requests currently in the pending state (executed, |
|
|
1303 | but not yet processed by poll_cb). |
|
|
1304 | |
|
|
1305 | =back |
|
|
1306 | |
900 | =cut |
1307 | =cut |
901 | |
1308 | |
902 | # support function to convert a fd into a perl filehandle |
|
|
903 | sub _fd2fh { |
|
|
904 | return undef if $_[0] < 0; |
|
|
905 | |
|
|
906 | # try to generate nice filehandles |
|
|
907 | my $sym = "IO::AIO::fd#$_[0]"; |
|
|
908 | local *$sym; |
|
|
909 | |
|
|
910 | open *$sym, "+<&=$_[0]" # usually works under any unix |
|
|
911 | or open *$sym, "<&=$_[0]" # cygwin needs this |
|
|
912 | or open *$sym, ">&=$_[0]" # or this |
|
|
913 | or return undef; |
|
|
914 | |
|
|
915 | *$sym |
|
|
916 | } |
|
|
917 | |
|
|
918 | min_parallel 8; |
1309 | min_parallel 8; |
919 | |
1310 | |
920 | END { |
1311 | END { flush } |
921 | max_parallel 0; |
|
|
922 | } |
|
|
923 | |
1312 | |
924 | 1; |
1313 | 1; |
925 | |
1314 | |
926 | =head2 FORK BEHAVIOUR |
1315 | =head2 FORK BEHAVIOUR |
927 | |
1316 | |
… | |
… | |
947 | bytes of memory. In addition, stat requests need a stat buffer (possibly |
1336 | bytes of memory. In addition, stat requests need a stat buffer (possibly |
948 | a few hundred bytes), readdir requires a result buffer and so on. Perl |
1337 | a few hundred bytes), readdir requires a result buffer and so on. Perl |
949 | scalars and other data passed into aio requests will also be locked and |
1338 | scalars and other data passed into aio requests will also be locked and |
950 | will consume memory till the request has entered the done state. |
1339 | will consume memory till the request has entered the done state. |
951 | |
1340 | |
952 | This is now awfully much, so queuing lots of requests is not usually a |
1341 | This is not awfully much, so queuing lots of requests is not usually a |
953 | problem. |
1342 | problem. |
954 | |
1343 | |
955 | Per-thread usage: |
1344 | Per-thread usage: |
956 | |
1345 | |
957 | In the execution phase, some aio requests require more memory for |
1346 | In the execution phase, some aio requests require more memory for |