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Server Context Run-down Routine

If communication breaks down while the server is maintaining context on behalf of the client, a cleanup routine may be needed to clean up the state maintained by the server on behalf of a given client. This cleanup routine is called a context run-down routine. When a connection breaks, the server stub and the run-time library will call this routine on every context handle opened by the client.

The context run-down routine is required, and is implicitly declared and named, when you apply the [context_handle] attribute to a type definition. The server will not call the context run-down routine if the [context_handle] attribute was applied directly to a parameter.

The context run-down routine syntax is:


void __RPC_USER type-id_rundown (type-id);

Note that the type name determines the name of the context run-down routine.

The code fragment that follows presents a sample context run-down routine. that calls the RemoteClose procedure used in the example in Interface Development Using Context Handles, Server Development Using Context Handles, and Client Development Using Context Handles. This procedure closes the file handle, frees the memory associated with the file, and assigns NULL to the context handle. Assigning NULL is a result of calling the RemoteClose function, and is not necessary in a run-down scenario. The RPC run time cleans up its state regardless of whether the context handle is set to NULL.

//file: cxhndp.c (fragment of file containing remote procedures)
//The rundown routine is associated with the context handle type.  
void __RPC_USER PCONTEXT_HANDLE_TYPE_rundown(
    PCONTEXT_HANDLE_TYPE phContext)
{
    printf("Client died with an open file, closing it..\n");
    RemoteClose(&phContext);
    assert(phContext == 0);
}

 

 

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