NetSock_Sel() / select() (TCP/UDP)

Check if any sockets are ready for available read or write operations or error conditions.

Files

net_sock.h/net_sock.c
net_bsd.h/net_bsd.c

Prototypes

Arguments

sock_nbr_max

Specifies the maximum number of socket file descriptors in the file descriptor sets.

psock_desc_rd

Pointer to a set of socket file descriptors to:

• • Check for available read operations.
  • Returns the actual socket file descriptors ready for available read operations, if no errors;
  • Returns the initial, non-modified set of socket file descriptors, on any errors;
  • Returns a null-valued (i.e., zero-cleared) descriptor set, if any timeout expires.

psock_desc_wr

Pointer to a set of socket file descriptors to:

• • Check for available read operations.
  • Returns the actual socket file descriptors ready for available write operations, if no errors;
  • Returns the initial, non-modified set of socket file descriptors, on any errors;
  • Returns a null-valued (i.e., zero-cleared) descriptor set, if any timeout expires.

psock_desc_err

Pointer to a set of socket file descriptors to:

• • Check for any available socket errors.
  • Returns the actual socket file descriptors ready with any pending errors;
  • Returns the initial, non-modified set of socket file descriptors, on any errors;
  • Returns a null-valued (i.e., zero-cleared) descriptor set, if any timeout expires.

ptimeout

Pointer to a timeout argument.

perr

Pointer to variable that will receive the error code from this function:

NET_SOCK_ERR_NONE
NET_SOCK_ERR_TIMEOUT
NET_ERR_INIT_INCOMPLETE
NET_SOCK_ERR_INVALID_DESC
NET_SOCK_ERR_INVALID_TIMEOUT
NET_SOCK_ERR_INVALID_SOCK
NET_SOCK_ERR_INVALID_TYPE
NET_SOCK_ERR_NOT_USED
NET_SOCK_ERR_EVENTS_NBR_MAX
NET_OS_ERR_LOCK

Returned Value

Returns the number of sockets ready with available operations, if successful;

NET_SOCK_BSD_RTN_CODE_TIMEOUT/0, upon timeout;

NET_SOCK_BSD_ERR_SEL/-1, otherwise.

Required Configuration

NetSock_Sel() is available only if either NET_CFG_TRANSPORT_LAYER_SEL is configured for TCP (see section D-12-1) and/or NET_UDP_CFG_APP_API_SEL is configured for sockets (see section D-13-1) and if NET_SOCK_CFG_SEL_EN is enabled (see section D-15-4).

In addition, select() is available only if NET_BSD_CFG_API_EN is enabled (see section D-17-1).

Notes / Warnings

Supports socket file descriptors only (i.e., socket ID numbers).

The descriptor macro’s is used to prepare and decode socket file descriptor sets (see section C-13-33 through section C-13-37).

See “net_sock.c NetSock_Sel() Note #3” for more details.