Semaphores/Creating a Critical Section

Question

How can you use a semaphore to create a special critical section that allows two threads to be executing inside instead of the usual one thread?

http://stackoverflow.com/questions/10898022/differnce-between-counting-and-binary-semaphores. — Pradheep, Sep 02 '13 at 19:36

score 0 · Answer 1 · answered Sep 04 '13 at 15:46

In pseudocode it looks like so:

s = Semaphore(2)    # max 2 possible threads accessing the critical section

Each thread then uses the semaphore to serialize access:

s.decrement()    # may block 
    # enter critical section
s.increment()

1 Answers1