Inter-process communication communicat ion From Wikipedia, the free encyclopedia
In computing, inter-process communication (IPC IPC) is a set of methods for the exchange of data among multiple threads in one or more processes. Processes may be running on one or more computers connected by a network. IPC methods are divided into methods for message passing, synchronization, shared memory, and remote procedure procedure call calls (RPC). (RPC). The The meth method od of IPC used used may may vary vary based on the the bandwi bandwidth dth and and laten latency cy of comm communication cation between between the the threads, threads, an and the the type type of data bein being comm communi unicated. There are several reasons for providing an environment that allows process cooperation: Information sharing Com Co mputational putational speedup sp eedup Modularity Convenience Convenience Privilege Privilege separ ation ation IPC may also also be referred to as inter-thread communication and and inter-application inter-application communication. com munication. The combination of IPC with the address space concept is the foundation for address space independence/isolation.[1]
Contents 1 Main IPC methods methods 2 Implementations Implementations 3 See also 4 References 5 External links
Main IPC methods
Method
A record stored on disk that can be accessed by name by any process
File
Signal
Provided by (operating syste ms or other environments)
Short Description
A system message sent from one process to another, not usually used to store information but instead give commands.
Most operating systems Most operating systems; some systems, such as Windows, implement signals in only the C run-time library and provide no support for their use as an IPC method[citation needed ]
Socket
A data stream sent over a network interface, either to a different process on the same computer or to another computer
Message queue
An anonymous data stream similar to the pipe, Most operating systems but stores and retrieves information in packets.
Pipe
A two-way data stream interfaced through standard input and output and is read character by character.
All POSIX systems, Windows
Named pipe
A pipe implemented through a file on the file system instead of standard input and output.
All POSIX systems, Windows
Semaphore
A simple structure that synchronizes threads or All POSIX systems, Windows processes acting on shared resources.
Shared memory
Multiple processes given access to the same memory, allowing all to change it and read changes made by other processes.
All POSIX systems, Windows
Message passing (shared nothing)
Similar to the message queue.
Used in MPI paradigm, Java RMI, CORBA, DDS, MSMQ, MailSlots, QNX, others
Most operating systems
Memory- A file mapped to RAM and can be modified by changing memory addresses directly instead mapped All POSIX systems, Windows of outputting to a stream, shares same benefits file as a standard file.
Implementations There are several APIs which may be used for IPC. A number of platform independent APIs include the following: Anonymous pipes and named pipes Common Object Request Broker Architecture (CORBA) Freedesktop.org's D-Bus Distributed Computing Environment (DCE) Message Bus (Mbus) (specified in RFC 3259)
MCAPI Multicore Communications API Lightweight Communications and Marshalling (http://code.google.com/p/lcm/) (LCM) ONC RPC Unix domain sockets XML XML-RPC or SOAP JSON JSON-RPC Thrift TIPC ZeroC's Internet Communications Engine (ICE) ØMQ The following are platform or programming language specific APIs: Apple Computer's Apple events (previously known as Interapplication Communications (IAC)). Enea's LINX for Linux (open source) and various DSP and general purpose processors under OSE IPC (http://www.cs.cmu.edu/~ipc/) implementation from CMU. Java's Remote Method Invocation (RMI) KDE's Desktop Communications Protocol (DCOP) - Now deprecated. D-Bus is used instead. Libt2n for C++ under Linux only, handles complex objects and exceptions The Mach kernel's Mach Ports Microsoft's ActiveX, Component Object Model (COM), Microsoft Transaction Server (COM+), Distributed Component Object Model (DCOM), Dynamic Data Exchange (DDE), Object Linking and Embedding (OLE), anonymous pipes, named pipes, Local Procedure Call, MailSlots, Message loop, MSRPC, .NET Remoting, and Windows Communication Foundation (WCF) Novell's SPX PHP's sessions POSIX mmap, message queues, semaphores, and Shared memory RISC OS's messages Solaris Doors System V's message queues, semaphores, and shared memory Distributed Ruby DIPC Distributed Inter-Process Communication OpenBinder Open binder IPC Shared Memory Messaging (http://www.solacesystems.com/solutions/messaging-middleware/ipcshared-memory-messaging) from Solace Systems QNX's PPS (Persistant Publish/Subscribe) service SIMPL The Synchronous Interprocess Messaging Project for Linux (SIMPL)
See also Computer network programming Communicating Sequential Processes (CSP paradigm) Data Distribution Service .NET Remoting Microkernel
