Note: This function is supported in AIX® 5.1 and earlier only.
Provides the means for receiving data from the token-ring device handler.
#include <sys/device.h> #include <sys/uio.h> #include <sys/comio.h> #include <sys/tokuser.h> int tokread (devno, uiop, chan, arg) dev_t devno; struct uio *uiop; int chan; read_extension *arg;
Item | Description |
---|---|
devno | Specifies major and minor device numbers. |
uiop | Points to a uio structure. For a calling user-mode process, the uio structure specifies the location and length of the caller's data area in which to transfer information. The kernel fills in the uio structure for the user. |
chan | Specifies the channel number assigned by the tokmpx entry point. |
arg | Can be null or points to the read_extension structure. This structure is defined in the /usr/include/sys/comio.h file. |
The tokread entry point provides the means for receiving data from the token-ring device handler. When a user-mode caller issues a read, readx, readv, or readvx subroutine, the kernel calls the tokread entry point.
For this operation, the arg parameter may point to the read_extension structure. This structure is defined in the /usr/include/sys/comio.h file and contains the following fields:
Field | Description |
---|---|
status | Contains additional information about the completion of the tokread entry point. Possible values for this field are: |
netid | Not used |
sessid | Not used |
The tokread entry point functions with a Token-Ring High Performance Network Adapter that has been correctly configured for use on a qualified network. Consult adapter specifications for more information on configuring the adapter and network qualifications.
The tokread entry point can be called from the process environment only.
Item | Description |
---|---|
EACCES | Indicates an illegal call from a kernel-mode user. |
ENXIO | Indicates the specified minor number is not valid. |
EINTR | Indicates a system call was interrupted. |
EMSGSIZE | Indicates the data was too large to fit into the receive buffer and that no arg parameter was supplied to provide an alternate means of reporting this error with a status of CIO_BUF_OVFLW. |
EFAULT | Indicates that the supplied address is not valid. |
ENOCONNECT | Indicates the device has not been started. |