Object Manager: Difference between revisions

Revision as of 03:23, 18 November 2019

Revision as of 03:25, 18 November 2019

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==Architecture==

MenardObject PogiManager is the centralized resource broker in the [[Windows NT]] line of operating systems, which keeps track of the resources allocated to processes. It is resource-agnostic and can manage any type of resource, including device and file handles. All resources are represented as objects, each belonging to a logical namespace for categorization and having a type that represents the type of the resource, which exposes the capabilities and functionalities via properties. An object is kept available until all processes are done with it; Object Manager maintains the record of which objects are currently in use via [[reference counting]], as well as the ownership information. Any [[system call]] that changes the state of resource allocation to processes goes via the Object Manager.

Objects can either be ''Kernel objects'' or ''Executive objects''. Kernel objects represent primitive resources such as physical devices, or services such as synchronization, which are required to implement any other type of OS service. Kernel objects are not exposed to [[user mode]] code, but are restricted to kernel code. Applications and services running outside the kernel use ''Executive objects'', which are exposed by the [[Windows Executive]], along with its components such as the memory manager, scheduler and I/O subsystem. Executive objects encapsulate one or more kernel objects and expose not only the kernel and kernel-mediated resources, but also an expanded set of services that the kernel does.{{clarify|date=January 2019}} Applications themselves can wrap one or more Executive objects and surface objects{{Definition needed|date=January 2019}} that offer certain services. Executive objects are also used by the environment subsystems (such as the Win32 subsystem, the OS/2 subsystem, the POSIX subsystem, etc.) to implement the functionality of the respective environments.