Caching a Connection Object

The stack caches connection objects for use by the transaction layer. The stack increments the reference count on the connection object to prevent the connection object from being freed by the system when the connection object is in use by the stack. When the transport protocol is TCP, the stack adds a reference count on the connection object when the stack allocates resources to break the TCP stream at message boundaries. The connection manager registers the sip_hold_conn_object() and sip_rel_conn_object() functions for the purposes of holding and releasing connection objects.