Contexts

The Solace Messaging APIs use processing contexts for organizing communication between an application and a Solace event broker. Contexts act as containers in which sessions are created and session-related events can be handled.

A context encapsulates threads that drive network I/O and message delivery notification for the sessions and session components associated with that context. For the Solace Java RTO API, Solace C API, and Solace .NET API, a single thread is used for both I/O and for notification. The life cycle of a context‑owned thread is bound to the life cycle of the context. The Solace JavaScript API and Solace Node.js API APIs are single threaded and have a single global context that is not exposed.

Typically, a context initializes and manages its own threads and file descriptors. However, the Solace C API also allows client applications to drive the context’s main loop with their own application-thread. For more information, see Solace C API Best Practices.

Context APIs

Solace Messaging API	Call or Property
Solace Java RTO API	com.solacesystems.solclientj.core.handle.ContextHandle
Solace C API	solClient_context_create(...) solClient_opaqueContext_pt
Solace .NET API	SolaceSystems.Solclient.Messaging.ContextFactory SolaceSystems.Solclient.Messaging.IContext
Solace JavaScript API and Solace Node.js API	Not applicable

The figure below shows the basic relationship between a context and its dependent processing components.

Overview of Core Concepts