Example 1 Solution

A preferred method for solving the problem in the example above is to avoid the dependency between the data and flag values. You can do this by using a more robust thread synchronization scheme. Although you can employ many of the thread synchronization techniques, one that lends itself well to this problem is a semaphore.

In order for the following logic to be appropriate, you must assume the following:

The program created the semaphore before starting the cooperating threads.
The program initialized the semaphore to a count of 1.

    Initializing Thread                     All Other Threads
    -------------------                 ---------------------------
        DATA = 10                     Wait for semaphore count to reach 0
        Decrement semaphore           use DATA