@CHIP-RTOS C Library - TCP/IP API

select_ms

Await specified events on a selected set of sockets.

int select_ms ( int nfds,
                fd_set far *readfds,
                fd_set far *writefds,
                fd_set far *exceptfds,
                long timeout ) ;

Parameters

nfds

One greater than highest socket descriptor to be monitored in the following set of three fd_set objects.

readfds

Input/Output Parameter:   Pointer to a fd_set bit field that on input specifies the set of sockets to be monitored for receiver activity.   On return those sockets for which receiver data is ready among those specified for monitoring will have their bits in this field set to '1'.   All other bits will be zeroed.

writefds

Input/Output Parameter:   Pointer to a fd_set bit field that on input specifies the set of sockets to be monitored for send ready condition.   On return those sockets ready for send among those specified for monitoring here will have their bits in this field set to '1'.   All other bits will be zeroed.

exceptfds

Input/Output Parameter:   Pointer to a fd_set bit field that on input specifies the set of sockets to be monitored for error conditions.   On return those sockets with errors among those specified for monitoring here will have their bits in this field set to '1'.   All other bits will be zeroed.

timeout

Timeout in milliseconds.   Set to a minus value to block without timeout.   Set to zero for polling.

Return Value

0 if timeout, otherwise number of hits.   This is the number of selected sockets for which a specified event has occurred.

If nfds input parameter was invalid, then the return value will also be zero.

Comments

The alternative to select() API is available when Berkeley sockets compatible source is desired.   The only difference is that this function takes the timeout value as a simple long value in units of milliseconds.

Refer to the select() API description for a more information about these API.

See Also

select        FD_Next        

RTOS API

This library function invokes a RTOS software interrupt. Refer to this RTOS API function's documentation for more details.

Supported since or modified in @CHIP-RTOS version

SC12	SC13	SC11	SC1x3	SC2x
V1.22	V1.22	V1.22	V1.11	V1.00

Supported by @CHIP-RTOS C Library since version

CLIB
V2.08