Inter-Process Communication can be defined as a set of methods which can be used for exchanging data among thread in the same process or between one process to another process. It allows programmers to coordinate activities among various processes that are concurrently running in the system.

Inter-process communication is a mechanism that involves:

• The process to process communication
• The process to process notifications
• The process to process synchronization
• System to process communication or notifications.

It also involves a thread that is:

• Thread to thread communication
• Thread to thread notification
• Thread to thread synchronization
• System to thread communication or notification.

Processes in the system are of two types:

• Independent Processes:
  These are those processes that neither affect nor get affected by other processes running in the system. Any processes that dos do not share data with the other process in an independent process.
  
• Cooperating Processes:
  These kinds of processes can affect and also get affected by other processes running in the system. They share data with other processes running in the system.
  Inter-process communication is useful in creating co-operating processes. For example, ‘ls’ process and ‘grep’ process can cooperate to produce the specific content of a directory.

Significance of Cooperating Process:

• Information sharing among processes
• Increase in computational speed
• It provides modularity
• It provides convenience in accessing data

There are four different types of IPC mechanism:

• Message Queue
• Shared Memory
• Pipe
  • Named Pipe
  • Un-named Pipe
• Signals

Categories: Operating system (OS)