What is the current scheduling strategy used by Pintos? Where in the code is this strategy implemented?

As defined in the structure thread (in thread.h line 83), each thread has a priority. How this priority used by the current scheduling strategy?

How many priority levels are there? Which one is the lowest priority and which one is the higher?

Considering 3 threads: H (high Priority), M (medium priority) and L (low priority), can you explain a situation where the thread H would starve (meaning not get the CPU) despite its high priority?

What is the technique to solve this problem?

(Simple donation) What should line priority_donate_one.c:35 print out and why?

(Simple donation) After we release the lock in priority_donate_one.c:40, which thread should get the lock and what the priority of the main thread should be lowered to?

(Multiple donations) What should line priority_donate_multiple.c:39 and line 42 print out and why?

(Multiple donations) What should line priority_donate_multiple.c:48 print out and why?