- Industria: Computer
- Number of terms: 4807
- Number of blossaries: 1
- Company Profile:
Sun Microsystems is a multinational vendor of computers, computer software and hardware, and information technology services.
A special-purpose data type introduced by E. W. Dijkstra that coordinates access to a particular resource or set of shared resources. A semaphore has an integer value (that cannot become negative) with two operations allowed on it. The signal (V or up) operation increases the value by one, and in general indicates that a resource has become free. The wait (P or down) operation decreases the value by one, when that can be done without the value going negative, and in general indicates that a free resource is about to start being used. See also semaphore lock.
Industry:Computer
The part of a URL passed by an HTTP request to invoke a servlet. A URL path consists of the context path + servlet path + path info, where
*Context path is the path prefix associated with a servlet context of which the servlet is a part. If this context is the default context rooted at the base of the Web server's URL namespace, the path prefix will be an empty string. Otherwise, the path prefix starts with a / character but does not end with a / character.
*Servlet path is the path section that directly corresponds to the mapping that activated this request. This path starts with a / character.
*Path info is the part of the request path that is not part of the context path or the servlet path.
Industry:Computer
A source file containing a reusable fragment of JSP code that is translated into a tag handler when a JSP page is translated into a servlet.
Industry:Computer
The outermost element in an XML document. The element that contains all other elements.
Industry:Computer
A software unit that consists of one or more J2EE components of the same container type and one deployment descriptor of that type. There are four types of modules: EJB, Web, application client, and resource adapter. Modules can be deployed as stand-alone units or can be assembled into a J2EE application.
Industry:Computer
A software unit that consists of one or more classes and an application client deployment descriptor.
Industry:Computer
The most popular protocol for maintaining cache coherency is called snooping. Cache controllers monitor or snoop on the bus to determine whether or not the cache contains a copy of a shared block.
For reads, multiple copies can reside in the cache of different processors, but because the processors need the most recent copy, all processors must get new values after a write. See also cache, competitive-caching, false sharing, write-invalidate, write-update.
For writes, a processor must have exclusive access to write to cache. Writes to unshared blocks do not cause bus traffic. The consequence of a write to shared data is either to invalidate all other copies or to update the shared copies with the value being written. See also cache, competitive-caching, false sharing, write-invalidate, write-update.
Industry:Computer
A single-threaded context for sending and receiving JMS messages. A JMS session can be nontransacted, locally transacted, or participating in a distributed transaction.
Industry:Computer
The minimum set of security permissions that a J2EE product provider must provide for the execution of each component type.
Industry:Computer
