Browse Definitions :
Definition

lightweight, middleweight, and heavyweight threads

In computer programming, a thread is an instance of a sequence of code that is operating as a unit, typically on behalf of a single user, transaction, or message. Threads are sometimes described in terms of their weight, meaning how much contextual information must be saved for a given thread so that it can be referred to by the system during the life of the thread.

For example, the context of a UNIX process includes the hardware register , the kernel stack , user-level stack, and so on. The time required to switch that much context, in thousands of microseconds, is considered large, so a UNIX process is said to be a heavyweight thread.

In some modern operating system kernels, such as Mach , multiple threads can exist in a single address space , which decreases the amount of context that must be saved with each one, and reduces the switching time to hundreds of microseconds. These kernel-level threads are considered to be middleweight threads.

When all context and thread operations are exposed at the user level, each application needs only the minimal amount of context saved with it, so that context switching can be reduced to tens of microseconds. Therefore, user-level threads are considered lightweight threads.

This was last updated in September 2005

SearchCompliance

  • information governance

    Information governance is a holistic approach to managing corporate information by implementing processes, roles, controls and ...

  • enterprise document management (EDM)

    Enterprise document management (EDM) is a strategy for overseeing an organization's paper and electronic documents so they can be...

  • risk assessment

    Risk assessment is the identification of hazards that could negatively impact an organization's ability to conduct business.

SearchSecurity

  • spam trap

    A spam trap is an email address that is used to identify and monitor spam email.

  • honeypot (computing)

    A honeypot is a network-attached system set up as a decoy to lure cyber attackers and detect, deflect and study hacking attempts ...

  • cracker

    A cracker is someone who breaks into someone else's computer system, often on a network; bypasses passwords or licenses in ...

SearchHealthIT

SearchDisasterRecovery

  • risk mitigation

    Risk mitigation is a strategy to prepare for and lessen the effects of threats faced by a business.

  • call tree

    A call tree is a layered hierarchical communication model that is used to notify specific individuals of an event and coordinate ...

  • Disaster Recovery as a Service (DRaaS)

    Disaster recovery as a service (DRaaS) is the replication and hosting of physical or virtual servers by a third party to provide ...

SearchStorage

  • cloud storage

    Cloud storage is a service model in which data is transmitted and stored on remote storage systems, where it is maintained, ...

  • cloud testing

    Cloud testing is the process of using the cloud computing resources of a third-party service provider to test software ...

  • storage virtualization

    Storage virtualization is the pooling of physical storage from multiple storage devices into what appears to be a single storage ...

Close