Class Semaphore
Placement in the overall structure
- Module
- meeting
- Base classes
- Waitingroom
- Derived classes
- Guarded_Semaphore
-
- Time of creation
- Task 6
- Files
semaphore.h and semaphore.cc
Description
The class Semaphore implements the synchronization concept of the counting semaphore.
It inherits the required waiting list from its base class Waitingroom.
Public methods
Semaphore (int c)- The constructor initializes the semaphore counter with the
specified value c.
void p ()- Wait operation: If the semaphore counter is greater than zero,
it is decremented by one only. Otherwise, the currently running
process (a Customer object) is added
to the waiting list and is blocked.
void v ()- Release operation: If there is at least one customer on the
waiting list, the first of them will be woken up. Otherwise,
the semaphore counter is incremented by one.
void wait ()- This method is just another name for the method
p().
void signal ()- This method is just another name for the method
v().
Notes
To ensure that the call to wait() and signal()
does not cost more than to p() and v(),
these two methods should be defined as inline.