Final answer:
The TCP Preforked Server model refers to a server architecture where a number of child processes are created at the start to handle incoming connections, improving scalability. Descriptor passing is a technique whereby a file descriptor is shared between processes, allowing both to operate on the same file or socket.
Step-by-step explanation:
TCP Preforked Server Model and Descriptor Passing
The TCP Preforked Server model is a server design pattern used in network programming. In this model, the server starts by pre-forking a certain number of child processes at its initialization. Each of these child processes inherits a copy of the server's listening sockets and can thus independently accept new connections. This approach is primarily used to improve the server's ability to handle multiple simultaneous connection requests, spreading the load across several processes.
Descriptor passing is a technique used between processes where one process sends a file descriptor to another process so that both can perform operations on the same file or socket. In the context of a TCP server, it allows for passing client connections descriptors from a parent process to a preforked child process. By doing so, the server can delegate the handling of a particular client to a child process, which can then read from or write to the client's socket as if it had directly accepted the connection itself.
This server design is commonly used in high-performance network servers where efficiency and scalability are essential. However, managing a preforked server can be complex, as it involves careful handling of resources and potential inter-process communication issues.