@CHIP-RTOS C Library - TCP/IP API

recv_bsd

Receive data from TCP socket.

int far recv_bsd ( int sd,
                   char far * bufptr,
                   int buflen,
                   int flags,
                   unsigned long timeout ) ;

Parameters

sd

Socket descriptor

bufptr

Output Parameter:   Received data will be put here.

buflen

Maximum bytes to write to the buffer at bufptr .

flags

Control flags:   Either MSG_BLOCKING or MSG_DONTWAIT.

timeout

Maximum wait time in milliseconds.   Set to zero to wait forever.

Return Value

> 0:   Number of data bytes placed at bufptr .
-1:   Failure, error code is available using get_socketerror().

Comments

This API function applies only to TCP sockets.   It receives a message from another socket.   This API function may be used only if the socket is in a connected state.

If flags parameter is set to MSG_DONTWAIT, this API call returns immediately.  If no data is available -1 is returned and get_socketerror() will report error code 235 in this case.

If flags parameter is set to MSG_BLOCKING, the recv call waits for either a message to arrive or a socket error condition to occur (such as connection lost or socket closed).   By default the blocking mode is set for all sockets at the opensocket() call.   If however the socket was subsequently set to non-blocking mode with the Set_Blocking_Mode() API, the MSG_BLOCKING flag will then not work here.

If the compilation switch

     #define BSD44_SOCKET_API_STYLE

is set as a global define in the user application prior to including the Beck C-library header files, the recv() call can be used in BSD 4.4 compatible style with the parameters specified above.   Using this switch the CLIB TCPIP_Socket.H redefines recv() to recv_bsd() .

See Also

send_bsd        recvfrom_bsd        opensocket
Set_Blocking_Mode        select        select_ms
recv        get_socketerror        

RTOS API

On the first call, this library function invokes a software interrupt which modifies the code at the calling site inside your application program.   A direct FAR JMP into the @CHIP-RTOS-x86 implementation for this function is installed so that on return and on any subsequent calls to this API this dynamic link reaches the function's implementation directly.

Supported since or modified in @CHIP-RTOS version

SC12	SC13	SC11	SC1x3	SC2x
n/a	n/a	n/a	V1.36	V1.36

Supported by @CHIP-RTOS C Library since version

CLIB
V2.20