README.TXT

DCOM Impersonation 
 
SUMMARY 
======= 
 
The OLEIMP sample demonstrates a method for emulating auto impersonation 
of clients. Normally, objects created on the server will run in the 
context of the server.  An object method must explicitly impersonate the 
client if the method is to run in the context of the client.  This 
sample demonstrates a way to arrange for methods to "automatically" run 
in the context of the client. 
 
MORE INFORMATION 
================ 
 
This program is based on the oleapt sample.  It uses a set of apartment 
threads that each potentially impersonate a client. All objects created 
for a user run in the same apartment. 
 
The server registers a class-factory on the main application thread and 
also spawns several worker threads. When requests arrive from clients 
to create instances of the class, the server class-factory picks a 
worker thread for the object in the following manner: 
 
  - If there is a thread currently impersonating that user, use that 
    thread. 
  - Otherwise, if there is a free thread, set that thread up to 
    impersonate the client and use that thread. 
  - Otherwise fail the CreateInstance call. 
 
The server and then goes through the process of having the object 
created within the thread and properly marshalled from the worker thread 
back to the class factory where it can be returned to the caller. Note 
that this marshalling to the main thread is fairly transient, it lasts 
for creation only: subsequent calls from the client to the object go 
straight from the client's process into the worker apartment. 
 
This sample may be compiled as either UNICODE or ANSI. 
 
Instructions: 
 
 To use this sample: 
  * build it using the NMAKE command. NMAKE will create OLEIMP.EXE and 
    CLIENT.EXE. 
  * install the OLEIMP.EXE on the current machine or on a remote 
    machine according to the installation instructions found in 
    OLEIMP.CPP. 
  * run CLIENT.EXE. use no command-line arguments to instantiate the 
    object on the current machine. use a single command-line argument of 
    the remote machine-name (UNC or DNS) to instantiate the object on a 
    remote machine. 
  * CLIENT.EXE displays some simple information about the calls it is 
    making on the object. 
  * OLEIMP.EXE displays information about the worker threads.