See ReadRtFile, WriteRtFile, WaitForRtIo

typedef struct AsyncIo {
    RTHANDLE hFile;             // (set by O/S on initialization)
    RTHANDLE hMailbox;          // [in] handle of reply mailbox
    WORD wOperation;            // (set by O/S on initialization)
    WORD wStatus;               // (set by O/S on completion)
    QWORD qwFilePointer;        // [in] file location for operation 
    LPVOID lpOriginalBuffer;    // (set by O/S on initialization)
    DWORD cbAmountRequested;    // (set by O/S on initialization)
    DWORD cbAmountReturned;     // (set by O/S on completion)
    LPFUNC IoCompletion;        // [in] pointer to completion function
    LPVOID lpContext;           // [in] pointer to user context
} ASYNCIO, *LPASYNCIO;
        
// Operations:
#define ASYNC_OP_READ   1
#define ASYNC_OP_WRITE  2

Fields

hFile

File handle where the operation is to be performed. Updated by O/S.

hMailbox

A handle for a data mailbox supplied by the user. This mailbox will receive the completed ASYNCHIO structure when the operation completes.

wOperation

The I/O operation type. Updated by O/S.

wOperation

The I/O operation type. Updated by O/S.

wStatus

The operation result status. Returned by O/S.

qwFilePointer

The file location for the operation. This field must be set for all asynchronous operations.

lpOriginalBuffer

The original user buffer address. Updated by O/S.

cbAmountRequested

The original size of I/O operation in bytes. Updated by O/S.

cbAmountReturned

The number of bytes actually transferred by the operation. Returned by O/S.

IoCompletion

An optional pointer to a completion function. Supplied by user. If not required must be set to NULL.

lpContext

A pointer to user context information supplied by user.