Node:Configuration of AIO, Previous:Cancel AIO Operations, Up:Asynchronous I/O
The POSIX standard does not specify how the AIO functions are implemented. They could be system calls but it is also possible to emulate them at userlevel. At least the available implementation at the point of this writing is a userlevel implementation which uses threads for handling the enqueued requests. This implementation requires to make some decisions about limitations but hard limitations are something which better should be avoided the GNU C library implementation provides a mean to tune the AIO implementation individually for each use.
struct aioinit | Data Type |
This data type is used to pass the configuration or tunable parameters
to the implementation. The program has to initialize the members of
this struct and pass it to the implementation using the aio_init
function.
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void aio_init (const struct aioinit *init) | Function |
This function must be called before any other AIO function. Calling it
is completely voluntarily since it only is meant to help the AIO
implementation to perform better.
Before calling the aio_init function the members of a variable of
type struct aioinit must be initialized. Then a reference to
this variable is passed as the parameter to aio_init which itself
may or may not pay attention to the hints.
The function has no return value and no error cases are defined. It is
a extension which follows a proposal from the SGI implementation in
Irix 6. It is not covered by POSIX.1b or Unix98.
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