Process Mutual Exclusion

Process mutual exclusion means that when multiple processes need to use the same shared resource, only one process is allowed to access the resource at any time, and the rest of the processes must wait until the resource is released. This mutual exclusion ensures the safe use of shared resources by processes and avoids resource conflicts and data inconsistency problems.

Core points of process mutual exclusion:

  1. Mutual exclusion access to shared resources: Access to shared resources requires exclusivity, and only one process can enter the critical section of the resource at the same time.

  2. Critical section management: Mutual exclusion between processes is achieved through the management of entry into the critical section. Related processes must meet the mutual exclusion conditions when entering the critical section to ensure safe access.

  3. Main methods for achieving mutual exclusion:

    • Flag method: Use flag variables to control whether the process can enter the critical section.

    • Lock/unlock method: Use a lock mechanism to control access rights to resources.

    • PV operation: Mutual exclusion and synchronization are achieved through the P and V operations of semaphores.

    • Monitor method: Use the monitor structure provided by high-level languages ​​to encapsulate mutual exclusion access to shared resources.