IPC in BSD UNIX

1
IPC in BSD UNIX

• Pipes
• a pipe is an IPC mechanism for transmitting data
  from one process to another within a single
  machine
• e.g., between a parent and child processes
• a pipe is a uni-directional IPC channel with two
  ends, or sockets
• Data that is written into one end can be read
  from the other

2

• Sockets
• a socket is an IPC mechanism for transmitting
  data from one process to another both within a
  single machine and between machines
• a socket is a bi-directional IPC channel
• Domains for sockets - a domain is the space from
  which an address is drawn for a socket
• UNIX domain(AF_UNIX)
• uses the UNIX file system name space
• used for local IPC
• Internet domain(AF_INET)
• uses Internet address plus a port number
• used for local and remote IPC

3

• Stream Sockets
• connection-oriented - communication takes place
  after a connection between two sockets is made
• reliable, error-free, no message boundaries
• Datagram Sockets
• no connections
• each message is addressed individually
• message boundaries exist
• delivery not guaranteed
• error checking not provided

4
Client-Server Communication using Sockets
5
More on Sockets

• More details on UNIX IPC can be found in Chapter
  5 of the Bloomers book, Power Programming with
  RPC.
• Tutorials and sample programs can be found in
  the
• /afs/p/class/cse/cs600/ipc directory