Inter-process communication

In computer science, inter-process communication or interprocess communication refers specifically to the mechanisms an operating system provides to allow the processes to manage shared data. Typically, applications can use IPC, categorized as clients and servers, where the client requests data and the server responds to client requests. Many applications are both clients and servers, as commonly seen in distributed computing.
IPC is very important to the design process for microkernels and nanokernels, which reduce the number of functionalities provided by the kernel. Those functionalities are then obtained by communicating with servers via IPC, leading to a large increase in communication when compared to a regular monolithic kernel. IPC interfaces generally encompass variable analytic framework structures. These processes ensure compatibility between the multi-vector protocols upon which IPC models rely.
An IPC mechanism is either synchronous or asynchronous. Synchronization primitives may be used to have synchronous behavior with an asynchronous IPC mechanism.


Different approaches to IPC have been tailored to different software requirements, such as performance, modularity, and system circumstances such as network bandwidth and latency.
MethodShort DescriptionProvided by
FileA record stored on disk, or a record synthesized on demand by a file server, which can be accessed by multiple processes.Most operating systems
Communications fileA unique form of IPC in the late-1960s that most closely resembles Plan 9's 9P protocolDartmouth Time-Sharing System
Signal; also Asynchronous System TrapA system message sent from one process to another, not usually used to transfer data but instead used to remotely command the partnered process.Most operating systems
SocketData sent over a network interface, either to a different process on the same computer or to another computer on the network. Stream-oriented or more rarely message-oriented.Most operating systems
Unix domain socketSimilar to an internet socket, but all communication occurs within the kernel. Domain sockets use the file system as their address space. Processes reference a domain socket as an inode, and multiple processes can communicate with one socketAll POSIX operating systems and Windows 10
Message queueA data stream similar to a socket, but which usually preserves message boundaries. Typically implemented by the operating system, they allow multiple processes to read and write to the message queue without being directly connected to each other.Most operating systems
Anonymous pipeA unidirectional data channel using standard input and output. Data written to the write-end of the pipe is buffered by the operating system until it is read from the read-end of the pipe. Two-way communication between processes can be achieved by using two pipes in opposite "directions".All POSIX systems, Windows
Named pipeA pipe that is treated like a file. Instead of using standard input and output as with an anonymous pipe, processes write to and read from a named pipe, as if it were a regular file.All POSIX systems, Windows, AmigaOS 2.0+
Shared memoryMultiple processes are given access to the same block of memory which creates a shared buffer for the processes to communicate with each other.All POSIX systems, Windows
Message passingAllows multiple programs to communicate using message queues and/or non-OS managed channels. Commonly used in concurrency models.Used in RPC, RMI, and MPI paradigms, Java RMI, CORBA, DDS, MSMQ, MailSlots, QNX, others
Memory-mapped fileA file mapped to RAM and can be modified by changing memory addresses directly instead of outputting to a stream. This shares the same benefits as a standard file.All POSIX systems, Windows


Remote procedure call interfaces

The following are messaging and information systems that utilize IPC mechanisms, but don't implement IPC themselves:
The following are platform or programming language-specific APIs:
The following are platform or programming language specific-APIs that use IPC, but do not themselves implement it: