Socket States

Question 1

List the 6 events associated with WSAAsyncSelect( ).

Answer 1

FD_ACCEPT : (Socket State) connection pending: connection request received (stream sockets only)

FD_CLOSE : close pending: connection close received (graceful close or abort) (stream sockets only)

FD_CONNECT : connected : connection now established

FD_OOB : “Out of band” data readability (stream sockets only)

FD_READ : readable : data received by network system is ready for application to read

FD_WRITE : writable : send is possible (network system buffers available for outgoing data)

Question 2

Why do events have re-enabling functions?

Answer 2

So that WinSock DLL can avoid flooding an application with notification messages.

Question 3

What function detects readable socket state?

Answer 3

ioctlsocket() FIONREAD

Question 4

What does the FD_ACCEPT event notify an application of?

Answer 4

the connection pending state (arrival of an incoming connection request)…indicates that a call to accept() should succeed immediately

Question 5

A accept() call on a server signals a ______ on a client.

Answer 5

FD_CONNECT

Question 6

A connect() call on a client signals a ______ on a server.

Answer 6

FD_ACCEPT

Question 7

A send() call reenables a ________.

Answer 7

FD_WRITE

Question 8

A recv() call reenables a __________.

Answer 8

FD_READ

Question 9

closesocket() call signals a __________.

Answer 9

FD_CLOSE

Question 10

Which of the following is/are part of the three basic methods of socket state detection?

a. asynchronous notification
b. function call for success or failure
c. synchronous detection
d. all answers are correct

Answer 10

d. all answers are correct

Question 11

After the closesocket( ) function returns, any function call that references that socket descriptor will fail with a _____________________________ error.

a. None of these
b. WSAELASTERROR 10048
c. WSAENOTSOCK 10038
d. WSAERRLAST 10064

Answer 11

c. WSAENOTSOCK 10038

Question 12

What function is the synchronous counterpart of WSAAsyncSelect( )?

Answer 12

select()

Question 13

What is the name the parameter of the asynchronous notification message, which contains the socket handle.

Answer 13

wParam

Question 14

___________detection means the WinSock DLL detects a socket state at any time after an application calls the asynchronous socket state detection function.

Answer 14

Asynchronous

Question 15

A datagram socket is writable as soon as it is opened, and it is readable as soon as it is _________.

Answer 15

named

Question 16

True or False

Basically the only state most datagram applications need to detect and act upon is the readable state.

Answer 16

True

Question 17

True or False

Data transmission on a datagram socket is reliable.

Answer 17

False