In a multi-thread environment, if the dc_rpc_call_s function and the dc_clt_cltin_s function are issued in different threads, they might operate incorrectly.

The following figures show examples of executing functions not suited to a multi-thread environment.

Figure 2-35 Execution of functions not suited to a multi-thread environment (example 1)

Figure 2-36 Execution of functions not suited to a multi-thread environment (example 2)

To ensure suitability when executing functions in a multi-thread environment, keep the following points in mind:

• In each thread, always issue the dc_clt_cltin_s function to receive a descriptor called a client ID. For all functions issued in all threads, specify the received client ID.
  A client ID that a process or thread has acquired through user authentication cannot be used in another process or thread.
  
• To execute RPCs concurrently in a multi-thread environment, an RPC must be executed from the dc_clt_cltin_s function for each thread.
  For the client ID argument of a function provided by TP1/Client, specify a client ID returned by the dc_clt_cltin_s function in the same thread. A client ID cannot be used across threads.