Decrements a semaphore by the specified amount. If any processes are waiting for the semaphore they will be allowed to proceed.

Once a semaphore has reached its limit, any subsequent attempts to increment the semaphore will wait until the semaphore is decremented. If several pages attempt to increment the semaphore simultaneously, any that go over the semaphore limit will have to wait until one of the other pages has decremented the semaphore.

Note: The use of thread tools is entirely voluntary. There is nothing in Lasso that prevents access to the same shared resource, but the diligent use of the thread tools will ensure predictable results.