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50 | |
| 51 | =head1 DESCRIPTION |
51 | =head1 DESCRIPTION |
| 52 | |
52 | |
| 53 | This module implements asynchronous I/O using whatever means your |
53 | This module implements asynchronous I/O using whatever means your |
| 54 | operating system supports. |
54 | operating system supports. |
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55 | |
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56 | Asynchronous means that operations that can normally block your program |
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57 | (e.g. reading from disk) will be done asynchronously: the operation |
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58 | will still block, but you can do something else in the meantime. This |
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59 | is extremely useful for programs that need to stay interactive even |
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60 | when doing heavy I/O (GUI programs, high performance network servers |
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61 | etc.), but can also be used to easily do operations in parallel that are |
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62 | normally done sequentially, e.g. stat'ing many files, which is much faster |
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63 | on a RAID volume or over NFS when you do a number of stat operations |
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64 | concurrently. |
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65 | |
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66 | While this works on all types of file descriptors (for example sockets), |
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67 | using these functions on file descriptors that support nonblocking |
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68 | operation (again, sockets, pipes etc.) is very inefficient. Use an event |
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69 | loop for that (such as the L<Event|Event> module): IO::AIO will naturally |
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70 | fit into such an event loop itself. |
| 55 | |
71 | |
| 56 | In this version, a number of threads are started that execute your |
72 | In this version, a number of threads are started that execute your |
| 57 | requests and signal their completion. You don't need thread support |
73 | 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 |
74 | 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 |
75 | 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 |
76 | functions available on many operating systems. However, they are often |
| 61 | not well-supported or restricted (Linux doesn't allow them on normal |
77 | 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 |
78 | files currently, for example), and they would only support aio_read and |
| 63 | aio_write, so the remaining functionality would have to be implemented |
79 | aio_write, so the remaining functionality would have to be implemented |
| 64 | using threads anyway. |
80 | using threads anyway. |
| 65 | |
81 | |
| 66 | Although the module will work with in the presence of other (Perl-) |
82 | Although the module will work with in the presence of other (Perl-) |
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| 331 | Asynchronously unlink (delete) a file and call the callback with the |
347 | Asynchronously unlink (delete) a file and call the callback with the |
| 332 | result code. |
348 | result code. |
| 333 | |
349 | |
| 334 | =item aio_mknod $path, $mode, $dev, $callback->($status) |
350 | =item aio_mknod $path, $mode, $dev, $callback->($status) |
| 335 | |
351 | |
| 336 | Asynchronously create a device node (or fifo). See mknod(2): the only |
352 | Asynchronously create a device node (or fifo). See mknod(2). |
| 337 | portable value for C<$mode> is C<S_IFIFO> ored with permissions, and C<0> |
353 | |
| 338 | for C<$dev>. |
354 | The only portable (POSIX) way of calling this function is: |
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355 | |
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356 | aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
| 339 | |
357 | |
| 340 | =item aio_link $srcpath, $dstpath, $callback->($status) |
358 | =item aio_link $srcpath, $dstpath, $callback->($status) |
| 341 | |
359 | |
| 342 | Asynchronously create a new link to the existing object at C<$srcpath> at |
360 | Asynchronously create a new link to the existing object at C<$srcpath> at |
| 343 | the path C<$dstpath> and call the callback with the result code. |
361 | the path C<$dstpath> and call the callback with the result code. |
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| 989 | } |
1007 | } |
| 990 | |
1008 | |
| 991 | min_parallel 8; |
1009 | min_parallel 8; |
| 992 | |
1010 | |
| 993 | END { |
1011 | END { |
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1012 | min_parallel 1; |
| 994 | flush; |
1013 | flush; |
| 995 | }; |
1014 | }; |
| 996 | |
1015 | |
| 997 | 1; |
1016 | 1; |
| 998 | |
1017 | |
