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56 | |
56 | |
57 | =cut |
57 | =cut |
58 | |
58 | |
59 | package IO::AIO; |
59 | package IO::AIO; |
60 | |
60 | |
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61 | no warnings; |
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62 | |
61 | use base 'Exporter'; |
63 | use base 'Exporter'; |
62 | |
64 | |
63 | use Fcntl (); |
65 | use Fcntl (); |
64 | |
66 | |
65 | BEGIN { |
67 | BEGIN { |
66 | $VERSION = 0.9; |
68 | $VERSION = 1.3; |
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69 | |
67 | |
70 | |
68 | @EXPORT = qw(aio_read aio_write aio_open aio_close aio_stat aio_lstat aio_unlink |
71 | @EXPORT = qw(aio_read aio_write aio_open aio_close aio_stat aio_lstat aio_unlink |
69 | aio_fsync aio_fdatasync aio_readahead); |
72 | aio_rmdir aio_symlink aio_fsync aio_fdatasync aio_readahead); |
70 | @EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel max_outstanding nreqs); |
73 | @EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel max_outstanding nreqs); |
71 | |
74 | |
72 | require XSLoader; |
75 | require XSLoader; |
73 | XSLoader::load IO::AIO, $VERSION; |
76 | XSLoader::load IO::AIO, $VERSION; |
74 | } |
77 | } |
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83 | which must be a code reference. This code reference will get called with |
86 | which must be a code reference. This code reference will get called with |
84 | the syscall return code (e.g. most syscalls return C<-1> on error, unlike |
87 | the syscall return code (e.g. most syscalls return C<-1> on error, unlike |
85 | perl, which usually delivers "false") as it's sole argument when the given |
88 | perl, which usually delivers "false") as it's sole argument when the given |
86 | syscall has been executed asynchronously. |
89 | syscall has been executed asynchronously. |
87 | |
90 | |
88 | All functions that expect a filehandle will also accept a file descriptor. |
91 | All functions expecting a filehandle keep a copy of the filehandle |
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92 | internally until the request has finished. |
89 | |
93 | |
90 | The filenames you pass to these routines I<must> be absolute. The reason |
94 | The pathnames you pass to these routines I<must> be absolute and |
91 | for this is that at the time the request is being executed, the current |
95 | encoded in byte form. The reason for the former is that at the time the |
92 | working directory could have changed. Alternatively, you can make sure |
96 | request is being executed, the current working directory could have |
93 | that you never change the current working directory. |
97 | changed. Alternatively, you can make sure that you never change the |
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98 | current working directory. |
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99 | |
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100 | To encode pathnames to byte form, either make sure you either: a) |
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101 | always pass in filenames you got from outside (command line, readdir |
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102 | etc.), b) are ASCII or ISO 8859-1, c) use the Encode module and encode |
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103 | your pathnames to the locale (or other) encoding in effect in the user |
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104 | environment, d) use Glib::filename_from_unicode on unicode filenames or e) |
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105 | use something else. |
94 | |
106 | |
95 | =over 4 |
107 | =over 4 |
96 | |
108 | |
97 | =item aio_open $pathname, $flags, $mode, $callback |
109 | =item aio_open $pathname, $flags, $mode, $callback |
98 | |
110 | |
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139 | Reads or writes C<length> bytes from the specified C<fh> and C<offset> |
151 | Reads or writes C<length> bytes from the specified C<fh> and C<offset> |
140 | into the scalar given by C<data> and offset C<dataoffset> and calls the |
152 | into the scalar given by C<data> and offset C<dataoffset> and calls the |
141 | callback without the actual number of bytes read (or -1 on error, just |
153 | callback without the actual number of bytes read (or -1 on error, just |
142 | like the syscall). |
154 | like the syscall). |
143 | |
155 | |
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156 | The C<$data> scalar I<MUST NOT> be modified in any way while the request |
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157 | is outstanding. Modifying it can result in segfaults or WW3 (if the |
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158 | necessary/optional hardware is installed). |
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159 | |
144 | Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at |
160 | Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at |
145 | offset C<0> within the scalar: |
161 | offset C<0> within the scalar: |
146 | |
162 | |
147 | aio_read $fh, 7, 15, $buffer, 0, sub { |
163 | aio_read $fh, 7, 15, $buffer, 0, sub { |
148 | $_[0] > 0 or die "read error: $!"; |
164 | $_[0] > 0 or die "read error: $!"; |
149 | print "read $_[0] bytes: <$buffer>\n"; |
165 | print "read $_[0] bytes: <$buffer>\n"; |
150 | }; |
166 | }; |
151 | |
167 | |
152 | =item aio_readahead $fh,$offset,$length, $callback |
168 | =item aio_readahead $fh,$offset,$length, $callback |
153 | |
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154 | Asynchronously reads the specified byte range into the page cache, using |
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155 | the C<readahead> syscall. If that syscall doesn't exist (likely if your OS |
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156 | isn't Linux) the status will be C<-1> and C<$!> is set to C<ENOSYS>. |
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157 | |
169 | |
158 | C<aio_readahead> populates the page cache with data from a file so that |
170 | C<aio_readahead> populates the page cache with data from a file so that |
159 | subsequent reads from that file will not block on disk I/O. The C<$offset> |
171 | subsequent reads from that file will not block on disk I/O. The C<$offset> |
160 | argument specifies the starting point from which data is to be read and |
172 | argument specifies the starting point from which data is to be read and |
161 | C<$length> specifies the number of bytes to be read. I/O is performed in |
173 | C<$length> specifies the number of bytes to be read. I/O is performed in |
162 | whole pages, so that offset is effectively rounded down to a page boundary |
174 | whole pages, so that offset is effectively rounded down to a page boundary |
163 | and bytes are read up to the next page boundary greater than or equal to |
175 | and bytes are read up to the next page boundary greater than or equal to |
164 | (off-set+length). C<aio_readahead> does not read beyond the end of the |
176 | (off-set+length). C<aio_readahead> does not read beyond the end of the |
165 | file. The current file offset of the file is left unchanged. |
177 | file. The current file offset of the file is left unchanged. |
166 | |
178 | |
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179 | If that syscall doesn't exist (likely if your OS isn't Linux) it will be |
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180 | emulated by simply reading the data, which would have a similar effect. |
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181 | |
167 | =item aio_stat $fh_or_path, $callback |
182 | =item aio_stat $fh_or_path, $callback |
168 | |
183 | |
169 | =item aio_lstat $fh, $callback |
184 | =item aio_lstat $fh, $callback |
170 | |
185 | |
171 | Works like perl's C<stat> or C<lstat> in void context. The callback will |
186 | Works like perl's C<stat> or C<lstat> in void context. The callback will |
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189 | =item aio_unlink $pathname, $callback |
204 | =item aio_unlink $pathname, $callback |
190 | |
205 | |
191 | Asynchronously unlink (delete) a file and call the callback with the |
206 | Asynchronously unlink (delete) a file and call the callback with the |
192 | result code. |
207 | result code. |
193 | |
208 | |
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209 | =item aio_rmdir $pathname, $callback |
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210 | |
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211 | Asynchronously rmdir (delete) a directory and call the callback with the |
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212 | result code. |
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213 | |
194 | =item aio_fsync $fh, $callback |
214 | =item aio_fsync $fh, $callback |
195 | |
215 | |
196 | Asynchronously call fsync on the given filehandle and call the callback |
216 | Asynchronously call fsync on the given filehandle and call the callback |
197 | with the fsync result code. |
217 | with the fsync result code. |
198 | |
218 | |
199 | =item aio_fdatasync $fh, $callback |
219 | =item aio_fdatasync $fh, $callback |
200 | |
220 | |
201 | Asynchronously call fdatasync on the given filehandle and call the |
221 | Asynchronously call fdatasync on the given filehandle and call the |
202 | callback with the fdatasync result code. Might set C<$!> to C<ENOSYS> if |
222 | callback with the fdatasync result code. |
203 | C<fdatasync> is not available. |
223 | |
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224 | If this call isn't available because your OS lacks it or it couldn't be |
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225 | detected, it will be emulated by calling C<fsync> instead. |
204 | |
226 | |
205 | =back |
227 | =back |
206 | |
228 | |
207 | =head2 SUPPORT FUNCTIONS |
229 | =head2 SUPPORT FUNCTIONS |
208 | |
230 | |
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310 | |
332 | |
311 | # support function to convert a fd into a perl filehandle |
333 | # support function to convert a fd into a perl filehandle |
312 | sub _fd2fh { |
334 | sub _fd2fh { |
313 | return undef if $_[0] < 0; |
335 | return undef if $_[0] < 0; |
314 | |
336 | |
315 | # try to be perl5.6-compatible |
337 | # try to generate nice filehandles |
316 | local *AIO_FH; |
338 | my $sym = "IO::AIO::fd#$_[0]"; |
317 | open AIO_FH, "+<&=$_[0]" |
339 | local *$sym; |
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340 | |
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341 | open *$sym, "+<&=$_[0]" # usually works under any unix |
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342 | or open *$sym, "<&=$_[0]" # cygwin needs this |
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343 | or open *$sym, ">&=$_[0]" # or this |
318 | or return undef; |
344 | or return undef; |
319 | |
345 | |
320 | *AIO_FH |
346 | *$sym |
321 | } |
347 | } |
322 | |
348 | |
323 | min_parallel 4; |
349 | min_parallel 4; |
324 | |
350 | |
325 | END { |
351 | END { |
326 | max_parallel 0; |
352 | max_parallel 0; |
327 | } |
353 | } |
328 | |
354 | |
329 | 1; |
355 | 1; |
330 | |
356 | |
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357 | =head2 FORK BEHAVIOUR |
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358 | |
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359 | Before the fork IO::AIO enters a quiescent state where no requests can be |
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360 | added in other threads and no results will be processed. After the fork |
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361 | the parent simply leaves the quiescent state and continues request/result |
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362 | processing, while the child clears the request/result queue and starts the |
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363 | same number of threads as were in use by the parent. |
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364 | |
331 | =head1 SEE ALSO |
365 | =head1 SEE ALSO |
332 | |
366 | |
333 | L<Coro>, L<Linux::AIO>. |
367 | L<Coro>, L<Linux::AIO>. |
334 | |
368 | |
335 | =head1 AUTHOR |
369 | =head1 AUTHOR |