Advanced IPC

1
Advanced IPC

• primarily consist of stream pipes and named
  stream pipes
• essentially full-duplex and named full-duplex
  pipes
• SVR supports some functions directly
• BSD and Linux can use socket functions to emulate
  some SVR functions

2
Stream Pipes

• full-duplex pipe
• native capacity of SVR3.2
• can be emulated using BSD sockets
• socketpair() function
• typically used for networking, but can be used
  for local IPC

3
Passing File Descriptors

• permits server to handle all file operations for
  client
• passed descriptors are actually pointers to a
  file table entry
• processes share entries
• descriptor numbers may vary from sender to
  receiver
• typically, sender will close descriptor after send

4
Client-Server Connection

• full duplex pipes can be used for establishing
  client-server connections on a named pipe
• pipes can be monitored for new clients and
  disconnection of old ones
• services can be provided per-client on new
  pipes
• the pipe monitored for connections is not used to
  establish the conversation between processes, a
  new pipe is created for each new connection