Attempts host name resolution for the given hostname with length namelen. When a result is ready the handler of contp is called with the
TS_EVENT_HOST_LOOKUP event and a
TSHostLookupResultAddrGet() to retrieve the resulting address from the
A call to
TSHostLookup() may be synchronous—in which case the handler for contp will be called with the answer before the call to
TSHostLookup() returns—or the call to
TSHostLookup() may be asynchronous—in which case it returns immediately with a
TSAction, and the handler contp will be called in the future. See Actions for guidance.