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An asynchronous procedure call (APC) is a unit of work in a computer.
Procedure calls can be synchronous or asynchronous. Synchronous procedure calls are made on one thread in a series, with each call waiting for the prior call to complete. on some thread. APCs instead are made without waiting for prior calls to complete.
For example, if some data are not ready (for example, a program waits for a user to reply), then stopping other activity on the thread is expensive, the thread has consumes memory and potentially other resources.
Structureedit
An APC is typically formed as an object with a small amount of memory and this object is passed to a service which handles the wait interval, activating it when the appropriate event (e.g., user input) occurs.
The life cycle of an APC consists of 2 stages: the passive stage, when it passively waits for input data, and active state, when that data is calculated in the same way as at the usual procedure call.
A reusable asynchronous procedure is termed Actor. In the Actor model two ports are used: one to receive input, and another (hidden) port to handle the input. In Dataflow programming many ports are used, passing to an execution service when all inputs are present.
Implementationsedit
In Windows, APC is a function that executes asynchronously in the context of a specific thread.[1] APCs can be generated by the system (kernel-mode APCs) or by an application (user mode APCs).[1]
asynchronous, procedure, call, this, article, relies, largely, entirely, single, source, relevant, discussion, found, talk, page, please, help, improve, this, article, introducing, citations, additional, sources, find, sources, news, newspapers, books, scholar. This article relies largely or entirely on a single source Relevant discussion may be found on the talk page Please help improve this article by introducing citations to additional sources Find sources Asynchronous procedure call news newspapers books scholar JSTOR March 2017 An asynchronous procedure call APC is a unit of work in a computer Contents 1 Definition 2 Structure 3 Implementations 4 See also 5 ReferencesDefinition editProcedure calls can be synchronous or asynchronous Synchronous procedure calls are made on one thread in a series with each call waiting for the prior call to complete on some thread APCs instead are made without waiting for prior calls to complete For example if some data are not ready for example a program waits for a user to reply then stopping other activity on the thread is expensive the thread has consumes memory and potentially other resources Structure editAn APC is typically formed as an object with a small amount of memory and this object is passed to a service which handles the wait interval activating it when the appropriate event e g user input occurs The life cycle of an APC consists of 2 stages the passive stage when it passively waits for input data and active state when that data is calculated in the same way as at the usual procedure call A reusable asynchronous procedure is termed Actor In the Actor model two ports are used one to receive input and another hidden port to handle the input In Dataflow programming many ports are used passing to an execution service when all inputs are present Implementations editIn Windows APC is a function that executes asynchronously in the context of a specific thread 1 APCs can be generated by the system kernel mode APCs or by an application user mode APCs 1 See also editSignalReferences edit a b Asynchronous Procedure Calls Windows Retrieved 1 March 2017 nbsp This Microsoft Windows article is a stub You can help Wikipedia by expanding it vte nbsp This computer programming related article is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title Asynchronous procedure call amp oldid 1184489414, wikipedia, wiki, book, books, library,
