preview

Different Types Of Unit Servers

Decent Essays
Open Document

Any thread must be able to call procedures on its own therefore any single thread must each have their own stack. Every stack has one frame for each procedure that was called but not yet returned from. These frames can contain local variables and the return address to use when the procedure call has finished. This concept holds true for both user-level threads and kernel-level threads but there are some slight differences. User level threads are not visible to the kernel meaning there will only be 1 kernel stack for all of the user level threads, but there will non the less be one user stack per user thread. As for kernel level threads there is one kernel stack per kernel threadYes it is possible here is an example lets take a program that …show more content…

The mutex is also decremented to 0 whenever a consumer is about to enter the critical region and changed back to 1 after the consumer takes the needed data, similarly the full is decremented since the consumer takes data and then once the needed data is extracted empty becomes incremented. If only one processor can read or write to shared data at a time then it is theoretically possible for multiple producers and consumers that write (or read) to (from) one shared buffer since the designed helps to guarantee mutual exclusion thanks to the mutex and guarantees synchronization thanks to the full and empty semaphores.1. No two processes may be simultaneously inside their critical regions. 2. No assumptions may be made about speeds or the number of CPUs. 3. No process running outside its critical region may block any process. 4. No process should have to wait forever to enter its critical region. Turn is initialized to 0 so p0 can enter the critical region but p1 cannot and is set in waiting loop meaning no two processes may be simultaneously inside their critical regions. As far as I can tell no assumptions have been made about speeds or the number of CPUs. When P0 enters the critical region and leaves the turn is set to 0 and P0 is in the non critical region. Because of this p1 can never enter enter its critical region since turn is always 0 and never changed to 1 at any point whether P0 is entering or leaving the critical

Get Access
Related
Get Access