aio_read

Syntax

Description

The aio_read() function requests an asynchronous read operation, calling the function,

"ReadFile(hFile, lpBuffer, nNumberOfBytesToRead, lpNumberOfBytesRead, NULL);" 

where,

• hFile is given by aiocbp->aio_fildes
• lpBuffer is given by aiocbp->aio_buf
• nNumberOfBytesToRead is given by aiocbp->aio_nbytes

Use the function aio_return() to retrieve the actual bytes read in lpNumberOfBytesRead.

Use the extension aiocb->aio_offset == (intptr_t)-1 to start the read operation after the last read record. This extension avoids extra file positioning and enhances performance.

Returns

0: On success

-1: On error

To get the correct error code, use errno. To get the error that occurred during asynchronous read operation, use aio_error() function.