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

120 Chapter3
NetIPC Intrinsics
IPCSHUTDOWN
Description
The IPCSHUTDOWN intrinsic permits the creating process to close a call
socket or a VC socket descriptor or to release a connection. The
descriptor is the only required parameter (option variable).
IPCSHUTDOWN can be called to release a call socket descriptor, a
destination descriptor, or a VC socket descriptor. Since systems
resources are used up as long as call sockets and destination sockets
exist, you should release them whenever they are no longer needed.
The call socket is needed as long as a process expects to receive a
connection request on that socket. A process which receives a
connection request can release the call sockets any time after the
connection request is received via IPCRECVCN, as long as no other
connection requests are expected for that call socket. For more
information on IPCSHUTDOWN, refer to “Shutting Down Sockets and
Connections” at the beginning of this chapter. Condition codes returned
by this intrinsic are:
• CCE — Succeeded.
• CCL — Failed.
• CCG — Not returned by this intrinsic.
This intrinsic cannot be called in split stack mode.
Protocol-Specific Considerations
The following Table 3-11 outlines parameters that are specific to the
particular protocol you are accessing.
X.25 Considerations
Shutting down an X.25 connection causes a clear packet to be sent by
X.25 over an SVC, unless the virtual circuit is already cleared. You can
specify the cause and diagnostic fields in the
opt parameter (code=143)
that will be included in the clear packet over an SVC. Over a public
Table 3-11 IPCSEND Protocol Specific Parameters
Parameters TCP X.25
flags
17 Graceful release of
connection
n/a
opt
2 n/a Clear user data
143 n/a Reason code