NetIPC 3000/XL Programmer's Reference Manual (5958-8600)

24 Chapter1
NetIPC Fundamentals
Using NetIPC for Interprocess Communication
3. Looking Up a Call Socket Name
Process A must reference the call socket of Process B by its name in the
call to IPCLOOKUP to “look up” the name of the call socket in the socket
registry at the node where Process B resides. IPCLOOKUP returns a
destination descriptor in its
destdesc parameter (see Figure 1-4). The
destination descriptor indicates the location of the destination call
socket which is owned by Process B. IPCLOOKUP is similar to a telephone
company’s directory assistance service: Process A calls the “operator”
(IPCLOOKUP), and gives him/her a “city” (
location parameter) and a
“name” (
socketname parameter). Using the “city,” that is, the node
name or environment ID, the operator looks for the name in the proper
“telephone directory” (socket registry). Once the name is found, the
operator returns a “telephone number” (
destdesc parameter) to the
caller.
Figure 1-4 IPCLOOKUP (Process A)
4. Requesting a Connection
Process A specifies the destination descriptor returned by IPCLOOKUP
and the call socket descriptor returned by IPCCREATE in its call. With
these two parameters, IPCCONNECT requests a virtual circuit connection
between Process A and Process B (see Figure 1-5). This could be
compared to dialing a phone number. IPCCONNECT then returns a VC
socket descriptor in its
vcdesc parameter that describes the VC socket
endpoint of the connection at Process A.
Call
Socket
Descriptor
Call
Socket
Descriptor
PROCESS A PROCESS B
SOCKET REGISTRY
“NAME”
Destination
Descriptor