In this model, you design the application to maintain a pool of available Client-Library connection structures. Connections can be shared by multiple threads, but a given connection is used in only one thread at any given time. When a thread needs to perform a Client-Library operation, it takes an available connection and marks it “unavailable,” then performs connection-level operations. When the connection-level operations are complete, the thread marks the connection as “available.” The application design can use the CS_USERDATA connection property to associate state information (such as availability) with a connection structure.This model is similar to the one-thread, one-connection model, except that the binding between connections and threads is dynamic rather than static. The application code and data structures used to manage the connection pool must be thread-safe.
