Inter-Process Communication (IPC) is a set of techniques for the exchange of data among two or more threads in one or more processes. Processes may be running on one or more computers connected by a network. IPC techniques are divided into methods for message passing, synchronization, shared memory, and remote procedure calls (RPC). The method of IPC used may vary based on the bandwidth and latency of communication between the threads, and the type of data being communicated.
IPC may also be referred to as inter-thread communication and inter-application communication.
IPC, on a par with the address space concept, is the foundation for address space independence/isolation.
The following are platform or programming language specific APIs:
Table of IPC Methods:
|Method||Provided by (Operating systems or other environments)|
|File||All operating systems.|
|Signal||Most operating systems; some systems, such as Windows, only implement signals in the C run-time library and do not actually provide support for their use as an IPC technique.|
|Socket||Most operating systems.|
|Pipe||All POSIX systems.|
|Named pipe||All POSIX systems.|
|Semaphore||All POSIX systems.|
|Shared memory||All POSIX systems.|
| Message passing |
|Used in MPI paradigm, Java RMI, CORBA and others.|
|memory-mapped file||All POSIX systems; may carry race condition risk if a temporary file is used. Windows also supports this technique but the APIs used are platform specific.|
|Message queue||Most operating systems.|
|Mailbox||Some operating systems.|