i was asked to write: enter function and exit function for the following case:

there are N processes and M types of processes (N>>M) tere is a critical section in which all processes with the same type can enter. for example: if type A is in cs, type B cannot enter cs. but all processes with type A can enter.

i can use only mutex and "type" which is the type of the process. deadlock is not allowed.

do you think this is ok?

shared: this.type = -1;
mutex m, m1=1;

enter{
    down(m)
    if (this.type == process.type) up(m1)
    down(m1)
    this.type= process.type
    up(m)
}
exit {
    this.type = -1
    up(m1)
}

thanks! (by the way, this is not HW... i have an exam and im solvig tests from previous years)