Interprocess communication (IPC) is a group of techniques used in computer programming that allow different pieces of software to interact. IPC is often facilitated by a computer operating system, although alternate methods do exist. The exact form of this communication between software can vary, ranging from direct messages to a central depository where information is stored and retrieved. Interprocess communication can provide benefits such as greater performance, fewer computer resources consumed, and enhanced security.
In the world of programming, software is talked about in terms of a process, or single piece of code, that can be run or executed on a computer’s Central Processing Unit (CPU). Many applications actually use more than one process, which can increase performance and stability. A web browser with multiple open pages might use a separate process to load each page; this isolates each page from the others and prevents an ill-behaved web page from crashing the entire browser. In this example, each process responsible for rendering a web page communicates with one or more processes that handle other aspects of the browser such as user interface components.
Most computer operating systems provide several different mechanisms for interprocess communication to take place. Some other software technologies also offer support for IPC. Moreover, IPC can be used either on a single computer or across a network. These mechanisms may vary in how they are implemented, but most can be grouped into a few categories based on how the communication takes place.
In some cases, messages are exchanged directly between processes, often in a one-way or asynchronous manner. A few IPC methods that work in this way include signals, pipes, and sockets. Interprocess communication can also take place through the use of a specific location where data can be accessed by more than one process. One example of this is shared memory, a technique in which multiple processes access the same portion of a computer’s memory to exchange information. The method a programmer may choose depends on the rate and volume of data exchange needed as well as other considerations.
There are many reasons a programmer may wish to utilize interprocess communication in their software creations. Splitting a large application into many smaller processes that communicate via IPC can increase performance as well as security. A program can start and end processes as needed instead of all components running at once and consuming hardware resources. If part of a program needs special access to a computer’s hardware or other running software, one or more processes can operate under an administrator or “root” account while the rest of the program runs as a regular user.