Operating systems - synchronization/Concurrency control

Assume you are given a graph that represents the relationship between four threads (T T2, T3, T4). An arrow from one thread (Tx) to another (Ty) means that thread Tx must finish its computation before Ty starts. Assume that the threads can arrive in any order. Use semaphores to enforce this relationship specified by the graph. Be sure to show the initial values and the locations of the semaphore operations T2 T3 T4 // Semaphores definitions and their initial values void T1(void) void T2(void) void T3(void) void T4(void) //T1 computation I T2 computation /I T3 computation // T4 computation