If it is possible, implement with a minimum number of semaphores, a complete serialization (for all variables) between read and write, such that the read operation is always done after the write operation. Specify the number, type and initial values of the necessary semaphores. If a complete serialization is not possible (for all the variables), give the solution for a partial serialization and specify for which variable(s) the serialization is impossible. In your partial serialization consider as more important having: a) b) high concurrency vs. minimum number of semaphores Minimum number of semaphores vs. high concurency Thread A Thread B write z; read x: write y read Z; read y; write X