… | |
… | |
20 | poll => 'r', |
20 | poll => 'r', |
21 | cb => \&IO::AIO::poll_cb); |
21 | cb => \&IO::AIO::poll_cb); |
22 | |
22 | |
23 | # Glib/Gtk2 |
23 | # Glib/Gtk2 |
24 | add_watch Glib::IO IO::AIO::poll_fileno, |
24 | add_watch Glib::IO IO::AIO::poll_fileno, |
25 | in => sub { IO::AIO::poll_cb, 1 }; |
25 | in => sub { IO::AIO::poll_cb; 1 }; |
26 | |
26 | |
27 | # Tk |
27 | # Tk |
28 | Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "", |
28 | Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "", |
29 | readable => \&IO::AIO::poll_cb); |
29 | readable => \&IO::AIO::poll_cb); |
30 | |
30 | |
… | |
… | |
45 | currently, for example), and they would only support aio_read and |
45 | currently, for example), and they would only support aio_read and |
46 | aio_write, so the remaining functionality would have to be implemented |
46 | aio_write, so the remaining functionality would have to be implemented |
47 | using threads anyway. |
47 | using threads anyway. |
48 | |
48 | |
49 | Although the module will work with in the presence of other threads, it |
49 | Although the module will work with in the presence of other threads, it |
50 | is currently not reentrant, so use appropriate locking yourself. |
50 | is currently not reentrant, so use appropriate locking yourself, always |
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51 | call "poll_cb" from within the same thread, or never call "poll_cb" (or |
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52 | other "aio_" functions) recursively. |
51 | |
53 | |
52 | FUNCTIONS |
54 | FUNCTIONS |
53 | AIO FUNCTIONS |
55 | AIO FUNCTIONS |
54 | All the "aio_*" calls are more or less thin wrappers around the syscall |
56 | All the "aio_*" calls are more or less thin wrappers around the syscall |
55 | with the same name (sans "aio_"). The arguments are similar or |
57 | with the same name (sans "aio_"). The arguments are similar or |
… | |
… | |
57 | argument which must be a code reference. This code reference will get |
59 | argument which must be a code reference. This code reference will get |
58 | called with the syscall return code (e.g. most syscalls return -1 on |
60 | called with the syscall return code (e.g. most syscalls return -1 on |
59 | error, unlike perl, which usually delivers "false") as it's sole |
61 | error, unlike perl, which usually delivers "false") as it's sole |
60 | argument when the given syscall has been executed asynchronously. |
62 | argument when the given syscall has been executed asynchronously. |
61 | |
63 | |
62 | All functions that expect a filehandle will also accept a file |
64 | All functions expecting a filehandle keep a copy of the filehandle |
63 | descriptor. |
65 | internally until the request has finished. |
64 | |
66 | |
65 | The filenames you pass to these routines *must* be absolute. The reason |
67 | The pathnames you pass to these routines *must* be absolute and encoded |
66 | is that at the time the request is being executed, the current working |
68 | in byte form. The reason for the former is that at the time the request |
67 | directory could have changed. Alternatively, you can make sure that you |
69 | is being executed, the current working directory could have changed. |
68 | never change the current working directory. |
70 | Alternatively, you can make sure that you never change the current |
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71 | working directory. |
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72 | |
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73 | To encode pathnames to byte form, either make sure you either: a) always |
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74 | pass in filenames you got from outside (command line, readdir etc.), b) |
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75 | are ASCII or ISO 8859-1, c) use the Encode module and encode your |
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76 | pathnames to the locale (or other) encoding in effect in the user |
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77 | environment, d) use Glib::filename_from_unicode on unicode filenames or |
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78 | e) use something else. |
69 | |
79 | |
70 | aio_open $pathname, $flags, $mode, $callback |
80 | aio_open $pathname, $flags, $mode, $callback |
71 | Asynchronously open or create a file and call the callback with a |
81 | Asynchronously open or create a file and call the callback with a |
72 | newly created filehandle for the file. |
82 | newly created filehandle for the file. |
73 | |
83 | |
74 | The pathname passed to "aio_open" must be absolute. See API NOTES, |
84 | The pathname passed to "aio_open" must be absolute. See API NOTES, |
75 | above, for an explanation. |
85 | above, for an explanation. |
76 | |
86 | |
77 | The $mode argument is a bitmask. See the "Fcntl" module for a list. |
87 | The $flags argument is a bitmask. See the "Fcntl" module for a list. |
78 | They are the same as used in "sysopen". |
88 | They are the same as used by "sysopen". |
|
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89 | |
|
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90 | Likewise, $mode specifies the mode of the newly created file, if it |
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91 | didn't exist and "O_CREAT" has been given, just like perl's |
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92 | "sysopen", except that it is mandatory (i.e. use 0 if you don't |
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93 | create new files, and 0666 or 0777 if you do). |
79 | |
94 | |
80 | Example: |
95 | Example: |
81 | |
96 | |
82 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
97 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
83 | if ($_[0]) { |
98 | if ($_[0]) { |
… | |
… | |
90 | |
105 | |
91 | aio_close $fh, $callback |
106 | aio_close $fh, $callback |
92 | Asynchronously close a file and call the callback with the result |
107 | Asynchronously close a file and call the callback with the result |
93 | code. *WARNING:* although accepted, you should not pass in a perl |
108 | code. *WARNING:* although accepted, you should not pass in a perl |
94 | filehandle here, as perl will likely close the file descriptor |
109 | filehandle here, as perl will likely close the file descriptor |
95 | itself when the filehandle is destroyed. Normally, you can safely |
110 | another time when the filehandle is destroyed. Normally, you can |
96 | call perls "close" or just let filehandles go out of scope. |
111 | safely call perls "close" or just let filehandles go out of scope. |
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112 | |
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113 | This is supposed to be a bug in the API, so that might change. It's |
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114 | therefore best to avoid this function. |
97 | |
115 | |
98 | aio_read $fh,$offset,$length, $data,$dataoffset,$callback |
116 | aio_read $fh,$offset,$length, $data,$dataoffset,$callback |
99 | aio_write $fh,$offset,$length, $data,$dataoffset,$callback |
117 | aio_write $fh,$offset,$length, $data,$dataoffset,$callback |
100 | Reads or writes "length" bytes from the specified "fh" and "offset" |
118 | Reads or writes "length" bytes from the specified "fh" and "offset" |
101 | into the scalar given by "data" and offset "dataoffset" and calls |
119 | into the scalar given by "data" and offset "dataoffset" and calls |
102 | the callback without the actual number of bytes read (or -1 on |
120 | the callback without the actual number of bytes read (or -1 on |
103 | error, just like the syscall). |
121 | error, just like the syscall). |
104 | |
122 | |
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123 | The $data scalar *MUST NOT* be modified in any way while the request |
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124 | is outstanding. Modifying it can result in segfaults or WW3 (if the |
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125 | necessary/optional hardware is installed). |
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126 | |
105 | Example: Read 15 bytes at offset 7 into scalar $buffer, starting at |
127 | Example: Read 15 bytes at offset 7 into scalar $buffer, starting at |
106 | offset 0 within the scalar: |
128 | offset 0 within the scalar: |
107 | |
129 | |
108 | aio_read $fh, 7, 15, $buffer, 0, sub { |
130 | aio_read $fh, 7, 15, $buffer, 0, sub { |
109 | $_[0] > 0 or die "read error: $!"; |
131 | $_[0] > 0 or die "read error: $!"; |
110 | print "read $_[0] bytes: <$buffer>\n"; |
132 | print "read $_[0] bytes: <$buffer>\n"; |
111 | }; |
133 | }; |
112 | |
134 | |
113 | aio_readahead $fh,$offset,$length, $callback |
135 | aio_readahead $fh,$offset,$length, $callback |
114 | Asynchronously reads the specified byte range into the page cache, |
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115 | using the "readahead" syscall. If that syscall doesn't exist (likely |
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116 | if your OS isn't Linux) the status will be -1 and $! is set to |
|
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117 | ENOSYS. |
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118 | |
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119 | readahead() populates the page cache with data from a file so that |
136 | "aio_readahead" populates the page cache with data from a file so |
120 | subsequent reads from that file will not block on disk I/O. The |
137 | that subsequent reads from that file will not block on disk I/O. The |
121 | $offset argument specifies the starting point from which data is to |
138 | $offset argument specifies the starting point from which data is to |
122 | be read and $length specifies the number of bytes to be read. I/O is |
139 | be read and $length specifies the number of bytes to be read. I/O is |
123 | performed in whole pages, so that offset is effectively rounded down |
140 | performed in whole pages, so that offset is effectively rounded down |
124 | to a page boundary and bytes are read up to the next page boundary |
141 | to a page boundary and bytes are read up to the next page boundary |
125 | greater than or equal to (off-set+length). aio_readahead() does not |
142 | greater than or equal to (off-set+length). "aio_readahead" does not |
126 | read beyond the end of the file. The current file offset of the file |
143 | read beyond the end of the file. The current file offset of the file |
127 | is left unchanged. |
144 | is left unchanged. |
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145 | |
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146 | If that syscall doesn't exist (likely if your OS isn't Linux) it |
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147 | will be emulated by simply reading the data, which would have a |
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148 | similar effect. |
128 | |
149 | |
129 | aio_stat $fh_or_path, $callback |
150 | aio_stat $fh_or_path, $callback |
130 | aio_lstat $fh, $callback |
151 | aio_lstat $fh, $callback |
131 | Works like perl's "stat" or "lstat" in void context. The callback |
152 | Works like perl's "stat" or "lstat" in void context. The callback |
132 | will be called after the stat and the results will be available |
153 | will be called after the stat and the results will be available |
… | |
… | |
149 | |
170 | |
150 | aio_unlink $pathname, $callback |
171 | aio_unlink $pathname, $callback |
151 | Asynchronously unlink (delete) a file and call the callback with the |
172 | Asynchronously unlink (delete) a file and call the callback with the |
152 | result code. |
173 | result code. |
153 | |
174 | |
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175 | aio_rmdir $pathname, $callback |
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176 | Asynchronously rmdir (delete) a directory and call the callback with |
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177 | the result code. |
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178 | |
154 | aio_fsync $fh, $callback |
179 | aio_fsync $fh, $callback |
155 | Asynchronously call fsync on the given filehandle and call the |
180 | Asynchronously call fsync on the given filehandle and call the |
156 | callback with the fsync result code. |
181 | callback with the fsync result code. |
157 | |
182 | |
158 | aio_fdatasync $fh, $callback |
183 | aio_fdatasync $fh, $callback |
159 | Asynchronously call fdatasync on the given filehandle and call the |
184 | Asynchronously call fdatasync on the given filehandle and call the |
160 | callback with the fdatasync result code. |
185 | callback with the fdatasync result code. |
161 | |
186 | |
|
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187 | If this call isn't available because your OS lacks it or it couldn't |
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188 | be detected, it will be emulated by calling "fsync" instead. |
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189 | |
162 | SUPPORT FUNCTIONS |
190 | SUPPORT FUNCTIONS |
163 | $fileno = IO::AIO::poll_fileno |
191 | $fileno = IO::AIO::poll_fileno |
164 | Return the *request result pipe filehandle*. This filehandle must be |
192 | Return the *request result pipe file descriptor*. This filehandle |
165 | polled for reading by some mechanism outside this module (e.g. Event |
193 | must be polled for reading by some mechanism outside this module |
166 | or select, see below). If the pipe becomes readable you have to call |
194 | (e.g. Event or select, see below or the SYNOPSIS). If the pipe |
167 | "poll_cb" to check the results. |
195 | becomes readable you have to call "poll_cb" to check the results. |
168 | |
196 | |
169 | See "poll_cb" for an example. |
197 | See "poll_cb" for an example. |
170 | |
198 | |
171 | IO::AIO::poll_cb |
199 | IO::AIO::poll_cb |
172 | Process all outstanding events on the result pipe. You have to call |
200 | Process all outstanding events on the result pipe. You have to call |
173 | this regularly. Returns the number of events processed. Returns |
201 | this regularly. Returns the number of events processed. Returns |
174 | immediately when no events are outstanding. |
202 | immediately when no events are outstanding. |
175 | |
203 | |
176 | You can use Event to multiplex, e.g.: |
204 | Example: Install an Event watcher that automatically calls |
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|
205 | IO::AIO::poll_cb with high priority: |
177 | |
206 | |
178 | Event->io (fd => IO::AIO::poll_fileno, |
207 | Event->io (fd => IO::AIO::poll_fileno, |
179 | poll => 'r', async => 1, |
208 | poll => 'r', async => 1, |
180 | cb => \&IO::AIO::poll_cb); |
209 | cb => \&IO::AIO::poll_cb); |
181 | |
210 | |
182 | IO::AIO::poll_wait |
211 | IO::AIO::poll_wait |
183 | Wait till the result filehandle becomes ready for reading (simply |
212 | Wait till the result filehandle becomes ready for reading (simply |
184 | does a select on the filehandle. This is useful if you want to |
213 | does a "select" on the filehandle. This is useful if you want to |
185 | synchronously wait for some requests to finish). |
214 | synchronously wait for some requests to finish). |
186 | |
215 | |
187 | See "nreqs" for an example. |
216 | See "nreqs" for an example. |
188 | |
217 | |
189 | IO::AIO::nreqs |
218 | IO::AIO::nreqs |
190 | Returns the number of requests currently outstanding. |
219 | Returns the number of requests currently outstanding (i.e. for which |
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220 | their callback has not been invoked yet). |
191 | |
221 | |
192 | Example: wait till there are no outstanding requests anymore: |
222 | Example: wait till there are no outstanding requests anymore: |
193 | |
223 | |
194 | IO::AIO::poll_wait, IO::AIO::poll_cb |
224 | IO::AIO::poll_wait, IO::AIO::poll_cb |
195 | while IO::AIO::nreqs; |
225 | while IO::AIO::nreqs; |
… | |
… | |
244 | If you queue up many requests in a loop it it often improves speed |
274 | If you queue up many requests in a loop it it often improves speed |
245 | if you set this to a relatively low number, such as 100. |
275 | if you set this to a relatively low number, such as 100. |
246 | |
276 | |
247 | Under normal circumstances you don't need to call this function. |
277 | Under normal circumstances you don't need to call this function. |
248 | |
278 | |
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279 | FORK BEHAVIOUR |
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280 | Before the fork IO::AIO enters a quiescent state where no requests can |
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281 | be added in other threads and no results will be processed. After the |
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282 | fork the parent simply leaves the quiescent state and continues |
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283 | request/result processing, while the child clears the request/result |
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284 | queue and starts the same number of threads as were in use by the |
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285 | parent. |
|
|
286 | |
249 | SEE ALSO |
287 | SEE ALSO |
250 | Coro, Linux::AIO. |
288 | Coro, Linux::AIO. |
251 | |
289 | |
252 | AUTHOR |
290 | AUTHOR |
253 | Marc Lehmann <schmorp@schmorp.de> |
291 | Marc Lehmann <schmorp@schmorp.de> |