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62 | argument when the given syscall has been executed asynchronously. |
62 | argument when the given syscall has been executed asynchronously. |
63 | |
63 | |
64 | All functions expecting a filehandle keep a copy of the filehandle |
64 | All functions expecting a filehandle keep a copy of the filehandle |
65 | internally until the request has finished. |
65 | internally until the request has finished. |
66 | |
66 | |
67 | 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 |
68 | for this is that at the time the request is being executed, the current |
68 | in byte form. The reason for the former is that at the time the request |
69 | working directory could have changed. Alternatively, you can make sure |
69 | is being executed, the current working directory could have changed. |
70 | that you 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. |
71 | |
79 | |
72 | aio_open $pathname, $flags, $mode, $callback |
80 | aio_open $pathname, $flags, $mode, $callback |
73 | 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 |
74 | newly created filehandle for the file. |
82 | newly created filehandle for the file. |
75 | |
83 | |
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119 | $_[0] > 0 or die "read error: $!"; |
127 | $_[0] > 0 or die "read error: $!"; |
120 | print "read $_[0] bytes: <$buffer>\n"; |
128 | print "read $_[0] bytes: <$buffer>\n"; |
121 | }; |
129 | }; |
122 | |
130 | |
123 | aio_readahead $fh,$offset,$length, $callback |
131 | aio_readahead $fh,$offset,$length, $callback |
124 | Asynchronously reads the specified byte range into the page cache, |
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125 | using the "readahead" syscall. If that syscall doesn't exist (likely |
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126 | if your OS isn't Linux) the status will be -1 and $! is set to |
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127 | "ENOSYS". |
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128 | |
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129 | "aio_readahead" populates the page cache with data from a file so |
132 | "aio_readahead" populates the page cache with data from a file so |
130 | that subsequent reads from that file will not block on disk I/O. The |
133 | that subsequent reads from that file will not block on disk I/O. The |
131 | $offset argument specifies the starting point from which data is to |
134 | $offset argument specifies the starting point from which data is to |
132 | be read and $length specifies the number of bytes to be read. I/O is |
135 | be read and $length specifies the number of bytes to be read. I/O is |
133 | performed in whole pages, so that offset is effectively rounded down |
136 | performed in whole pages, so that offset is effectively rounded down |
134 | to a page boundary and bytes are read up to the next page boundary |
137 | to a page boundary and bytes are read up to the next page boundary |
135 | greater than or equal to (off-set+length). "aio_readahead" does not |
138 | greater than or equal to (off-set+length). "aio_readahead" does not |
136 | read beyond the end of the file. The current file offset of the file |
139 | read beyond the end of the file. The current file offset of the file |
137 | is left unchanged. |
140 | is left unchanged. |
138 | |
141 | |
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142 | If that syscall doesn't exist (likely if your OS isn't Linux) it |
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143 | will be emulated by simply reading the data, which would have a |
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144 | similar effect. |
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145 | |
139 | aio_stat $fh_or_path, $callback |
146 | aio_stat $fh_or_path, $callback |
140 | aio_lstat $fh, $callback |
147 | aio_lstat $fh, $callback |
141 | Works like perl's "stat" or "lstat" in void context. The callback |
148 | Works like perl's "stat" or "lstat" in void context. The callback |
142 | will be called after the stat and the results will be available |
149 | will be called after the stat and the results will be available |
143 | using "stat _" or "-s _" etc... |
150 | using "stat _" or "-s _" etc... |
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159 | |
166 | |
160 | aio_unlink $pathname, $callback |
167 | aio_unlink $pathname, $callback |
161 | Asynchronously unlink (delete) a file and call the callback with the |
168 | Asynchronously unlink (delete) a file and call the callback with the |
162 | result code. |
169 | result code. |
163 | |
170 | |
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171 | aio_rmdir $pathname, $callback |
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172 | Asynchronously rmdir (delete) a directory and call the callback with |
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173 | the result code. |
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174 | |
164 | aio_fsync $fh, $callback |
175 | aio_fsync $fh, $callback |
165 | Asynchronously call fsync on the given filehandle and call the |
176 | Asynchronously call fsync on the given filehandle and call the |
166 | callback with the fsync result code. |
177 | callback with the fsync result code. |
167 | |
178 | |
168 | aio_fdatasync $fh, $callback |
179 | aio_fdatasync $fh, $callback |
169 | Asynchronously call fdatasync on the given filehandle and call the |
180 | Asynchronously call fdatasync on the given filehandle and call the |
170 | callback with the fdatasync result code. Might set $! to "ENOSYS" if |
181 | callback with the fdatasync result code. |
171 | "fdatasync" is not available. |
182 | |
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183 | If this call isn't available because your OS lacks it or it couldn't |
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184 | be detected, it will be emulated by calling "fsync" instead. |
172 | |
185 | |
173 | SUPPORT FUNCTIONS |
186 | SUPPORT FUNCTIONS |
174 | $fileno = IO::AIO::poll_fileno |
187 | $fileno = IO::AIO::poll_fileno |
175 | Return the *request result pipe file descriptor*. This filehandle |
188 | Return the *request result pipe file descriptor*. This filehandle |
176 | must be polled for reading by some mechanism outside this module |
189 | must be polled for reading by some mechanism outside this module |
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257 | If you queue up many requests in a loop it it often improves speed |
270 | If you queue up many requests in a loop it it often improves speed |
258 | if you set this to a relatively low number, such as 100. |
271 | if you set this to a relatively low number, such as 100. |
259 | |
272 | |
260 | Under normal circumstances you don't need to call this function. |
273 | Under normal circumstances you don't need to call this function. |
261 | |
274 | |
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275 | FORK BEHAVIOUR |
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276 | IO::AIO handles all outstanding AIO requests before the fork, destroys |
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277 | all AIO threads, and recreates them in both the parent and the child |
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278 | after the fork. |
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279 | |
262 | SEE ALSO |
280 | SEE ALSO |
263 | Coro, Linux::AIO. |
281 | Coro, Linux::AIO. |
264 | |
282 | |
265 | AUTHOR |
283 | AUTHOR |
266 | Marc Lehmann <schmorp@schmorp.de> |
284 | Marc Lehmann <schmorp@schmorp.de> |