Silberschatz-Operating System Concepts-Processes

Silberschatz-Operating System Concepts-Processes

1. Program in execution

   • New
   • Running
   • Waiting
   • Ready
   • Terminated

2. Process Control Block

   • Process state
   • Program counter
   • CPU registers
   • CPU-scheduling information
   • Memory management information
   • Accounting information
   • I/O status information

3. Threads

4. Process scheduling

   • scheduling queues
     • ready queue
     • job queue
     • device queue
   • schedulers

5. Context

   • save state
   • restore state
   • context switch

6. Multitasking in mobile systems

   • Foreground
   • Background

7. Process creation

   • Process identifier (PID)
   • Possibilities of execution
     • Parent executes concurrently with its child
     • Parent waits untill all children have finished execution

8. Process termination

   • The child has exceeded its usage of some of the resources that it has been allocated
   • Task assigned to child no longer required
   • The parent is exiting, and the operating system does not allow a child to continue if its parent terminates

9. Interprocess communication

   • Reason for this
     • Information sharing
     • computation speedup
     • Modularity
     • Convenience
   • Requires
     • Shared memory
     • message passing