As stated earlier, the CORBA policy asserts that method parameters and return results are uniformly caller-owned. This means the method caller has the responsibility for freeing memory after invoking a method, regardless of whether the memory was allocated by the caller or the object.
A class implementor can designate certain method parameters and results as object-owned, however, by using the object_owns_result and object_owns_parameters SOM IDL modifiers. These modifiers signify that the object, rather than the caller, is responsible for freeing the memory associated with the parameter/result. For "in" parameters, the object can free the memory any time after receiving it; for "inout" and "out" parameters, and for return results, the object will free the memory sometime before the object is destroyed. (See the section entitled "Implementation statements" in Chapter 4, "SOM IDL and the SOM Compiler," for more information on these modifiers.)
When a DSOM client program makes a remote method invocation, via a proxy, and the method being invoked has an object-owned parameter or return result, then the client-side memory associated with the parameter/result will be owned by the caller's proxy, and the server-side memory will be owned by the remote object. The memory owned by the caller's proxy will be freed when the proxy is released by the client program. (The time at which the server-side memory will be freed depends on the implementation of the remote object.)
A DSOM client can also instruct a proxy object to free all memory that it owns on behalf of the client without releasing the proxy (assuming that the client program is finished using the object-owned memory), by invoking the somdReleaseResource method on the proxy object. Calling somdReleaseResources can prevent unused memory from accumulating in a proxy.
For example, consider a client program repeatedly invoking a remote method "get_string", which returns a string that is designated (in SOM IDL) as "object-owned". The proxy on which the method is invoked will store the memory associated with all the returned strings, even if the strings are not unique, until the proxy is released. If the client program only uses the last result returned from "get_string", then unused memory accumulates in the proxy. The client program can prevent this by invoking somdReleaseResources on the proxy object periodicall (for example, each time it finishes using the result of the last "get_string" call).