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| 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. |
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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. |
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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-) |
