MailSlot

Last updated

A Mailslot is a one-way interprocess communication mechanism, available on the Microsoft Windows operating system, that allows communication between processes both locally and over a network. The use of Mailslots is generally simpler than named pipes or sockets when a relatively small number of relatively short messages are expected to be transmitted, such as for example infrequent state-change messages, or as part of a peer-discovery protocol. The Mailslot mechanism allows for short message broadcasts ("datagrams") to all listening computers across a given network domain.

Contents

Features

Mailslots function as a server-client interface. A server can create a Mailslot, and a client can write to it by name. Only the server can read the mailslot, as such mailslots represent a one-way communication mechanism. A server-client interface could consist of two processes communicating locally or across a network. Mailslots operate over the RPC protocol and work across all computers in the same network domain. Mailslots offer no confirmation that a message has been received. Mailslots are generally a good choice when one client process must broadcast a message to multiple server processes.

Uses

The most widely known use of the Mailslot IPC mechanism is the Windows Messenger service that is part of the Windows NT-line of products, including Windows XP. The Messenger Service, not to be confused with the MSN Messenger internet chat service, is essentially a Mailslot server that waits for a message to arrive. When a message arrives it is displayed in a popup onscreen. The NET SEND command is therefore a type of Mailslot client, because it writes to specified mailslots on a network.

A number of programs also use Mailslots to communicate. Generally these are amateur chat clients and other such programs[ citation needed ]. Commercial programs usually prefer pipes or sockets.

Mailslots are implemented as files in a mailslot file system (MSFS). Examples of Mailslots include:


Related Research Articles

In distributed computing, a remote procedure call (RPC) is when a computer program causes a procedure (subroutine) to execute in a different address space, which is written as if it were a normal (local) procedure call, without the programmer explicitly writing the details for the remote interaction. That is, the programmer writes essentially the same code whether the subroutine is local to the executing program, or remote. This is a form of client–server interaction, typically implemented via a request–response message-passing system. In the object-oriented programming paradigm, RPCs are represented by remote method invocation (RMI). The RPC model implies a level of location transparency, namely that calling procedures are largely the same whether they are local or remote, but usually, they are not identical, so local calls can be distinguished from remote calls. Remote calls are usually orders of magnitude slower and less reliable than local calls, so distinguishing them is important.

<span class="mw-page-title-main">Instant messaging</span> Form of communication over the internet

Instant messaging (IM) technology is a type of online chat allowing real-time text transmission over the Internet or another computer network. Messages are typically transmitted between two or more parties, when each user inputs text and triggers a transmission to the recipient(s), who are all connected on a common network. It differs from email in that conversations over instant messaging happen in real-time. Most modern IM applications use push technology and also add other features such as emojis, file transfer, chatbots, voice over IP, or video chat capabilities.

Berkeley sockets is an application programming interface (API) for Internet sockets and Unix domain sockets, used for inter-process communication (IPC). It is commonly implemented as a library of linkable modules. It originated with the 4.2BSD Unix operating system, which was released in 1983.

<span class="mw-page-title-main">Inter-process communication</span> How computer operating systems enable data sharing

In computer science, inter-process communication (IPC), also spelled interprocess communication, are the mechanisms provided by an operating system for 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.

Messenger was an instant messaging and presence system developed by Microsoft in 1999 for use with its MSN Messenger software. It was used by instant messaging clients including Windows 8, Windows Live Messenger, Microsoft Messenger for Mac, Outlook.com and Xbox Live. Third-party clients also connected to the service. It communicated using the Microsoft Notification Protocol, a proprietary instant messaging protocol. The service allowed anyone with a Microsoft account to sign in and communicate in real time with other people who were signed in as well.

<span class="mw-page-title-main">XMPP</span> Communications protocol for message-oriented middleware

Extensible Messaging and Presence Protocol is an open communication protocol designed for instant messaging (IM), presence information, and contact list maintenance. Based on XML, it enables the near-real-time exchange of structured data between two or more network entities. Designed to be extensible, the protocol offers a multitude of applications beyond traditional IM in the broader realm of message-oriented middleware, including signalling for VoIP, video, file transfer, gaming and other uses.

<span class="mw-page-title-main">Client (computing)</span> Piece of software accessing a server service

In computing, a client is a piece of computer hardware or software that accesses a service made available by a server as part of the client–server model of computer networks. The server is often on another computer system, in which case the client accesses the service by way of a network.

In computing, a named pipe is an extension to the traditional pipe concept on Unix and Unix-like systems, and is one of the methods of inter-process communication (IPC). The concept is also found in OS/2 and Microsoft Windows, although the semantics differ substantially. A traditional pipe is "unnamed" and lasts only as long as the process. A named pipe, however, can last as long as the system is up, beyond the life of the process. It can be deleted if no longer used. Usually a named pipe appears as a file, and generally processes attach to it for IPC.

HCL Sametime Premium is a client–server application and middleware platform that provides real-time, unified communications and collaboration for enterprises. Those capabilities include presence information, enterprise instant messaging, web conferencing, community collaboration, and telephony capabilities and integration. Currently it is developed and sold by HCL Software, a division of Indian company HCL Technologies, until 2019 by the Lotus Software division of IBM.

In computer science and networking in particular, a session is a time-delimited two-way link, a practical layer in the TCP/IP protocol enabling interactive expression and information exchange between two or more communication devices or ends – be they computers, automated systems, or live active users. A session is established at a certain point in time, and then ‘torn down’ - brought to an end - at some later point. An established communication session may involve more than one message in each direction. A session is typically stateful, meaning that at least one of the communicating parties needs to hold current state information and save information about the session history to be able to communicate, as opposed to stateless communication, where the communication consists of independent requests with responses.

<span class="mw-page-title-main">Google Talk</span> Instant messaging service

Google Talk was an instant messaging service that provided both text and voice communication. The instant messaging service was variously referred to colloquially as Gchat, Gtalk, or Gmessage among its users.

In computing, Dynamic Data Exchange (DDE) is a technology for interprocess communication used in early versions of Microsoft Windows and OS/2. DDE allows programs to manipulate objects provided by other programs, and respond to user actions affecting those objects. DDE was partially superseded by Object Linking and Embedding (OLE), and is currently maintained in Windows systems only for the sake of backward compatibility.

<span class="mw-page-title-main">Skype for Business Server</span> Real-time communications server software

Skype for Business Server is real-time communications server software that provides the infrastructure for enterprise instant messaging, presence, VoIP, ad hoc and structured conferences and PSTN connectivity through a third-party gateway or SIP trunk. These features are available within an organization, between organizations and with external users on the public internet or standard phones.

Push technology or server push is a style of Internet-based communication where the request for a given transaction is initiated by the publisher or central server. It is contrasted with pull, or get, where the request for the transmission of information is initiated by the receiver or client.

<span class="mw-page-title-main">Skype for Business</span> Enterprise instant messaging and video conferencing software by Microsoft

Skype for Business is an enterprise software application for instant messaging and videotelephony developed by Microsoft as part of the Microsoft 365 suite. It is designed for use with the on-premises Skype for Business Server software, and a software as a service version offered as part of 365. It supports text, audio, and video chat, and integrates with Microsoft 365 components such as Exchange and SharePoint.

The Local Inter-Process Communication is an internal, undocumented inter-process communication facility provided by the Microsoft Windows NT kernel for lightweight IPC between processes on the same computer. As of Windows Vista, LPC has been rewritten as Asynchronous Local Inter-Process Communication in order to provide a high-speed scalable communication mechanism required to efficiently implement User-Mode Driver Framework (UMDF), whose user-mode parts require an efficient communication channel with UMDF's components in the executive.

A network socket is a software structure within a network node of a computer network that serves as an endpoint for sending and receiving data across the network. The structure and properties of a socket are defined by an application programming interface (API) for the networking architecture. Sockets are created only during the lifetime of a process of an application running in the node.

A Unix domain socket aka UDS or IPC socket is a data communications endpoint for exchanging data between processes executing on the same host operating system. It is also referred to by its address family AF_UNIX. Valid socket types in the UNIX domain are:

.NET Remoting is a Microsoft application programming interface (API) for interprocess communication released in 2002 with the 1.0 version of .NET Framework. It is one in a series of Microsoft technologies that began in 1990 with the first version of Object Linking and Embedding (OLE) for 16-bit Windows. Intermediate steps in the development of these technologies were Component Object Model (COM) released in 1993 and updated in 1995 as COM-95, Distributed Component Object Model (DCOM), released in 1997, and COM+ with its Microsoft Transaction Server (MTS), released in 2000. It is now superseded by Windows Communication Foundation (WCF), which is part of the .NET Framework 3.0.

<span class="mw-page-title-main">Shared memory</span> Computer memory that can be accessed by multiple processes

In computer science, shared memory is memory that may be simultaneously accessed by multiple programs with an intent to provide communication among them or avoid redundant copies. Shared memory is an efficient means of passing data between programs. Depending on context, programs may run on a single processor or on multiple separate processors.