IPCCONTROL

Performs special operations on sockets.

IPCCONTROL

IPCCONTROL(descriptor,requestfd,wrtdata,wlen,readdata,rlen, flags,result)

descriptor

32-bit integer, by value in Pascal, by

 

reference in FORTRAN. The descriptor that refers to the

 

socket to be manipulated. May be a call socket descriptor or

 

VC socket descriptor depending on the request code specified

 

in the request parameter.

requests

32-bit integer, by value in Pascal, by

 

reference in FORTRAN. Request code. Defines which

 

operation is to be performed. May be one of the following:

 

D 1 = Place the socket referenced in the descriptor

 

parameter in asynchronous mode. For IPCSend and

 

IPCRecv calls, this is the VC socket described by the VC

 

socket descriptor in the vcdesc parameter. For

 

IPCRecvCn, it is the call socket described by the call

 

socket descriptor in the calldesc parameter.

 

D 2 = Place the socket referenced in the descriptor

 

parameter in synchronous mode. For IPCSend and

 

IPCRecv calls this is the VC socket described by the VC

 

socket descriptor in the vcdesc parameter. For

 

IPCRecvCn, it is the call socket described by the call

 

socket descriptor in the calldesc parameter.

 

D 3 = Change the referenced socket's synchronous timeout.

 

The default timeout value is 60 seconds. For IPCSend

 

and IPCRecv calls, this is the VC socket described by the

 

VC socket descriptor in the vcdesc parameter. For

 

IPCRecvCn, it is the call socket described by the call

 

socket descriptor in the calldesc parameter. The

 

timeout value is given in tenths of seconds. (For example,

 

a value of 1200 would indicate 120 seconds.) The new

 

timeout value must be placed in the wrtdata parameter.

 

The timeout value must be in the range of zero to 32767.

 

Negative values have no meaning and will result in error.

 

A value of zero sets the timeout to infinity. The timeout

 

will not be reset if the referenced socket is switched to

 

asynchronous mode and then back to synchronous mode.

 

D 1000 = Change the read threshold of the VC socket

 

referenced in descriptor parameter. (Read thresholds

 

are one byte by default.) The descriptor parameter

 

must reference a VC socket descriptor. The new read

 

threshold value must be placed in the wrtdata

 

parameter.

 

D 1001 = Change the write threshold of the VC socket

 

referenced by the descriptor parameter. (Write

 

thresholds are one byte by default.) The descriptor

 

parameter must reference a VC socket descriptor. The

 

new write threshold value must be placed in the wrtdata

 

parameter.

Network Interprocess Communication 65