HackMD
tags: UCX
UCX Api Overview
UCX Example(1) - Init
What is context?
UCP application context (or just a context) is an opaque handle that holds a UCP communication instance’s global information. It represents a single UCP communication instance. The communication instance could be an OS process (an application) that uses UCP library. This global information includes communication resources, endpoints, memory, temporary file storage, and other communication information directly associated with a specific UCP instance. The context also acts as an isolation mechanism, allowing resources associated with the context to manage multiple concurrent communication instances. For example, users using both MPI and OpenSHMEM sessions simultaneously can isolate their communication by allocating and using separate contexts for each of them. Alternatively, users can share the communication resources (memory, network resource context, etc.) between them by using the same application context. A message sent or a RMA operation performed in one application context cannot be received in any other application context.
(轉自UCX Docs)
What is worker?
UCP worker is an opaque object representing the communication context. The worker represents an instance of a local communication resource and the progress engine associated with it. The progress engine is a construct that is responsible for asynchronous and independent progress of communication directives. The progress engine could be implemented in hardware or software. The worker object abstracts an instance of network resources such as a host channel adapter port, network interface, or multiple resources such as multiple network interfaces or communication ports. It could also represent virtual communication resources that are defined across multiple devices. Although the worker can represent multiple network resources, it is associated with a single UCX application context. All communication functions require a context to perform the operation on the dedicated hardware resource(s) and an endpoint to address the destination.
ucp_worker_create prototype
Example(2) - Connect
Endpoint?
An endpoint is the ‘connection point’ of a service, tool, or application accessed over a network. In the world of software, any software application that is running and “listening” for connections uses an endpoint as the “front door.” When you want to connect to the application/service/tool to exchange data you connect to its endpoint.
轉自程式前沿
