User guide

Ethernet Developers Guide
840 USE 115 00 Version 1.0
69
B.7 The CSample_View Class
The CSample_View class mana
g
es the TCP/IP connection, sends re
q
uests to
remote nodes, and displa
y
s either connection state, or the results of a transaction.
In addition it sets the states of the tool bar buttons and menu items.
B.7.1 Accessing TCP/IP
The CSample_View interfaces with window sockets via its application
pro
g
rammin
g
interface, and via messa
g
es sent b
y
the window sockets DLL to the
CSample_View window. The reference for the window socket API is
g
iven above.
The first call made to the window sockets DLL must be WSAStartup. This call is
made b
y
InitInstance member function of the CSample_app class. The last call to
the window socket DLL must be WSACleanup. This call is made b
y
the
ExitInstance member function of the Csample_app class.
The CSample_View allocates and sets the socket attributes. The attributes it sets
are
g
iven in the followin
g
table.
Set Lin
g
er to cause a hard close
Receive out of band data in the normal data stream
Disable Na
g
el al
g
orithm for send coalescin
g
When Na
g
el al
g
orithm is disabled, if the stack receives an application messa
g
e, it
will immediatel
y
pass the messa
g
e to the application and will send a TCP/IP
acknowled
g
ment messa
g
e. Althou
g
h this can
g
enerate more traffic, the application
receives the messa
g
e sooner then if Na
g
el al
g
orithm is enabled. The member
function tcpip_setsocket_options sets the socket attributes.
The window socket interface provides the WSAAs
y
ncSelect function which notifies
the window of network events. The member function tcpip_setsocket_options calls
WSAAs
y
ncSelect function. The different events are
g
iven b
y
the followin
g
table.
Event Description
FD_READ A socket can read data
FD_WRITE A socket can write data
FD_OOB A socket can read out of band data
FD_CONNECT A connect response has been received
FD_CLOSE The connection has been closed