System Model

• System consists of resources

• Resource types R₁, R₂, ..., Rm

• CPU cycles, memory space, I/O devices

• Each resource type R₁ has W; instances.

• Each process utilizes a resource as follows :

  • request

  • use

  • release

Deadlock with Semaphores

• Data :

  • A semaphore S1 initialized to 1

  • A semaphore s2 …