NachOS implements a simple Unix domain datagram socket to simulate networking. It uses data structures to emulate physical network connections and provides interprocess communication operations. NachOS also provides a Timer that simulates a real-time clock, generating interrupts at regular intervals using the event-driven interrupt mechanism. The Timer supports getting the current time in ticks since NachOS started and setting an interrupt handler to invoke every Stats.TimerTicks ticks.

2. Lockcond.cc

4. Network.cc

5. Data structures to emulate a physical network connection.

6. Sysdep.h

7. Sysdep.cc Interprocess communication operations, for simulating the network Networking infrastructure

9. Post.cc Networking infrastructure

10. Timer in NachOS NachOS provides an instance of a Timer to simulate a real-time clock, generating interrupts at regular intervals. It is implemented using the event driven interrupt mechanism described above, Machine.timer() returns a reference to this time.

12. With this returns the number of ticks since NachOS started.

13. setInterruptHandler()

14. This sets the timer interrupt handler, which is invoked by the simulated timer approximately every Stats.TimerTicks ticks.