 | The topic of this article may not meet Wikipedia's general notability guideline .(October 2011) |
DCEThreads is an implementation of POSIX Draft 4 threads. DCE Stands for "Distributed Computing Environment" [1] DCEThreads allowed users to create multiple avenues of execution in a single process. [2] It is based on pthreads interface. [3]
DCE/RPC was under development, but the POSIX committee had not finalised POSIX threads at the time. The Open Group had to make a decision about which to use, and the final POSIX threads were different from their selection.
POSIX Draft 4 threads were limited to begin with (the final standard fixed these). Microsoft adopted DCE/RPC wholesale in Windows NT as MSRPC and also in DCOM. Most of the stability and reliability problems that programmers associate with DCOM services - especially memory leaks, exception handling problems and thread cancellation stability issues - can be traced back to the use of POSIX Draft 4 threads.
DCE/RPC is sufficiently complex that the issue of updating it to solve and modernise the POSIX Draft 4 threading problem requires highly skilled and highly specific programming knowledge. Consequently, despite its capacities, the reference implementation of DCE/RPC has been held up due to a lack of information and resources.
The key difference between POSIX Draft 4 threads and the final POSIX threads specification, aside from a number of functions being interruptible where others are not, is thread cancellation. DCE/RPC utilises thread cancellation to propagate signals across the "Remote" of RPC, such that for example a client application terminating a thread results in its corresponding thread on the server also being terminated in the same way. The final POSIX specification does not include such sophisticated cancellation methodology, and, given the difficulties that the Unix vendors had in correctly implementing the POSIX threads specification, it was removed.
Linux, since the introduction of NPTL and the Linux 2.6 kernel, has proper support for thread cancellation.
DCEThreads now only realistically exists as an emulation layer.
The Portable Operating System Interface is a family of standards specified by the IEEE Computer Society for maintaining compatibility between operating systems. POSIX defines both the system and user-level application programming interfaces (APIs), along with command line shells and utility interfaces, for software compatibility (portability) with variants of Unix and other operating systems. POSIX is also a trademark of the IEEE. POSIX is intended to be used by both application and system developers.
Samba is a free software re-implementation of the SMB networking protocol, and was originally developed by Andrew Tridgell. Samba provides file and print services for various Microsoft Windows clients and can integrate with a Microsoft Windows Server domain, either as a Domain Controller (DC) or as a domain member. As of version 4, it supports Active Directory and Microsoft Windows NT domains.
SOAP is a messaging protocol specification for exchanging structured information in the implementation of web services in computer networks. It uses XML Information Set for its message format, and relies on application layer protocols, most often Hypertext Transfer Protocol (HTTP), although some legacy systems communicate over Simple Mail Transfer Protocol (SMTP), for message negotiation and transmission.
The Single UNIX Specification (SUS) is a standard for computer operating systems, compliance with which is required to qualify for using the "UNIX" trademark. The standard specifies programming interfaces for the C language, a command-line shell, and user commands. The core specifications of the SUS known as Base Specifications are developed and maintained by the Austin Group, which is a joint working group of IEEE, ISO/IEC JTC 1/SC 22/WG 15 and The Open Group. If an operating system is submitted to The Open Group for certification, and passes conformance tests, then it is deemed to be compliant with a UNIX standard such as UNIX 98 or UNIX 03.
Network File System (NFS) is a distributed file system protocol originally developed by Sun Microsystems (Sun) in 1984, allowing a user on a client computer to access files over a computer network much like local storage is accessed. NFS, like many other protocols, builds on the Open Network Computing Remote Procedure Call system. NFS is an open IETF standard defined in a Request for Comments (RFC), allowing anyone to implement the protocol.
Distributed Component Object Model (DCOM) is a proprietary Microsoft technology for communication between software components on networked computers. DCOM, which originally was called "Network OLE", extends Microsoft's COM, and provides the communication substrate under Microsoft's COM+ application server infrastructure.
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.
An interface description language or interface definition language (IDL), is a generic term for a language that lets a program or object written in one language communicate with another program written in an unknown language. IDLs describe an interface in a language-independent way, enabling communication between software components that do not share one language, for example, between those written in C++ and those written in Java.
A Universally Unique IDentifier (UUID) is a 128-bit label used for information in computer systems. The term Globally Unique IDentifier (GUID) is also used, mostly in Microsoft systems.
compress is a Unix shell compression program based on the LZW compression algorithm. Compared to gzip's fastest setting, compress is slightly slower at compression, slighty faster at decompression, and has a significantly lower compression ratio. 1.8 MiB of memory is used to compress the Hutter Prize data, slightly more than gzip's slowest setting.
In computing, particularly in the context of the Unix operating system and its workalikes, fork is an operation whereby a process creates a copy of itself. It is an interface which is required for compliance with the POSIX and Single UNIX Specification standards. It is usually implemented as a C standard library wrapper to the fork, clone, or other system calls of the kernel. Fork is the primary method of process creation on Unix-like operating systems.
The Native POSIX Thread Library (NPTL) is an implementation of the POSIX Threads specification for the Linux operating system.
X/Open group was a consortium founded by several European UNIX systems manufacturers in 1984 to identify and promote open standards in the field of information technology. More specifically, the original aim was to define a single specification for operating systems derived from UNIX, to increase the interoperability of applications and reduce the cost of porting software. Its original members were Bull, ICL, Siemens, Olivetti, and Nixdorf—a group sometimes referred to as BISON. Philips and Ericsson joined in 1985, at which point the name X/Open was adopted.
pax is an archiving utility available for various operating systems and defined since 1995. Rather than sort out the incompatible options that have crept up between tar and cpio, along with their implementations across various versions of Unix, the IEEE designed new archive utility pax that could support various archive formats with useful options from both archivers. The pax command is available on Unix and Unix-like operating systems and on IBM i, and Microsoft Windows NT until Windows 2000.
In computing, the Distributed Computing Environment (DCE) software system was developed in the early 1990s from the work of the Open Software Foundation (OSF), a consortium that included Apollo Computer, IBM, Digital Equipment Corporation, and others. The DCE supplies a framework and a toolkit for developing client/server applications. The framework includes:
Signals are standardized messages sent to a running program to trigger specific behavior, such as quitting or error handling. They are a limited form of inter-process communication (IPC), typically used in Unix, Unix-like, and other POSIX-compliant operating systems.
Microsoft RPC is a modified version of DCE/RPC. Additions include partial support for UCS-2 strings, implicit handles, and complex calculations in the variable-length string and structure paradigms already present in DCE/RPC.
In the Linux operating system, LinuxThreads was a partial implementation of POSIX Threads introduced in 1996. The main developer of LinuxThreads was Xavier Leroy. It has been superseded by the Native POSIX Thread Library (NPTL).
Component Object Model (COM) is a binary-interface standard for software components introduced by Microsoft in 1993. It is used to enable inter-process communication object creation in a large range of programming languages. COM is the basis for several other Microsoft technologies and frameworks, including OLE, OLE Automation, Browser Helper Object, ActiveX, COM+, DCOM, the Windows shell, DirectX, UMDF and Windows Runtime. The essence of COM is a language-neutral way of implementing objects that can be used in environments different from the one in which they were created, even across machine boundaries. For well-authored components, COM allows reuse of objects with no knowledge of their internal implementation, as it forces component implementers to provide well-defined interfaces that are separated from the implementation. The different allocation semantics of languages are accommodated by making objects responsible for their own creation and destruction through reference-counting. Type conversion casting between different interfaces of an object is achieved through the QueryInterface method. The preferred method of "inheritance" within COM is the creation of sub-objects to which method "calls" are delegated.
C11 is an informal name for ISO/IEC 9899:2011, a past standard for the C programming language. It replaced C99 and has been superseded by C17. C11 mainly standardizes features already supported by common contemporary compilers, and includes a detailed memory model to better support multiple threads of execution. Due to delayed availability of conforming C99 implementations, C11 makes certain features optional, to make it easier to comply with the core language standard.
 | This computer networking article is a stub. You can help Wikipedia by expanding it. |