Chapter 3: Processes

Chapter 3: Processes

1. Process Concept

   • jobs
   • user programs
   • Multiple parts
     • text section
     • program counter
     • Stack
     • Data section
     • Heap
   • Program is passive
   • process is active
   • Process State
     • new
     • running
     • waiting
     • ready
     • terminated
   • Process Control Block (PCB)
     • Process state
     • Program counter
     • CPU registers
     • CPU scheduling information-
     • Memory-management information
     • Accounting information
     • I/O status information
   • Threads

2. Process Scheduling

   • Process scheduler
     • Short-term scheduler
     • Long-term scheduler
       • I/O-bound process
       • CPU-bound process
     • Medium-term scheduler
   • scheduling queues
     • Job queue
     • Ready queue
     • Device queues
   • Multitasking in Mobile Systems
     • foreground
     • background
   • Context Switch

3. Operations on Processes

   • process Termination
     • exit()
     • abort()
     • cascading termination
     • zombie
     • orphan
   • process creation
     • Parent
     • children
     • tree
     • process identifier (pid)

4. Interprocess Communication

   • Shared memory
   • Message passing
     • communication link
       • Physical
         • Shared memory
         • Hardware bus
         • Network
       • Logical
         • Direct
           • established automatically Links
           • exactly one pair
           • exists exactly one link
           • unidirectional
         • Synchronous or asynchronous
         • Automatic or explicit buffering
         • Indirect
           • Link established if share a common mailbox
           • associated with many processes
           • several communication links
           • unidirectional or bi-directional
   • Independent process
   • Cooperating process
   • Producer-Consumer Problem
     • unbounded-buffe
     • bounded-buffer

5. Examples of IPC Systems

   • POSIX
   • Mach
   • Windows

6. Communication in Client-Server Systems

   • socket
     • IP address
     • port
     • Connection-oriented (TCP)
     • Connectionless (UDP)
     • MulticastSocket
   • Remote Procedure Calls
     • Stubs
     • marshalls
   • External Data Representation (XDL)
     • Big-endian
     • little-endian
   • Pipes
     • Ordinary Pipes
       • write-end
       • read-end
       • unidirectional
       • Require parent-child relationship between communicating processes
     • Named Pipes
       • bidirectional
       • No parent-child relationship
       • Several processes can use the named pipe for communication

7. Synchronization

   • Blocking
     • Blocking send
     • Blocking receive
   • Non-blocking
     • Non-blocking send
     • Non-blocking receive

8. Buffering

   • Zero capacity
   • Bounded capacity
   • Unbounded capacity