API Reference

• Dragon Native
  • Reference by Language
  • Specification by Language
  • Architecture
• Dragon GS Client
  • Python Reference
  • Architecture
• Dragon Infrastructure
  • Reference
  • Architecture
• Dragon Core
  • Managed Memory
  • Channels
  • File Like Interface
  • C Reference
  • Python Reference
• MPBridge
  • Python Reference
  • Architecture
• Workflows
  • Python Reference
• Data
  • Distributed Dictionary

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The Dragon API is broken up into a few services with different usability characteristics. The core API includes several lower-level synchronization and communication objects. The managed API, built on top of the core API provides several services in addition to the core API, including discoverability and reference counting. The multiprocessing API, part of the Python distribution, is re-implemented using managed core objects from the Dragon run-time services.

The core services, provide bindings for several different languages including Python, C++, C, and Fortran. Synchronization and communication objects include shared memory pools, shared memory allocations, channels, queues, barriers. These services can be used on-node with or without running the Dragon run-time services. When using them while running the Dragon run-time services the objects transparently work in a distributed fashion across all nodes in the Dragon run-time instance.

The managed services provide additional discoverability of pools, memory allocations, and channels. In addition, the programmer may choose to have memory allocations and channels be [reference counted](term:refcounted <Refcounted Object>) by the Dragon run-time services when they are created. These services are available from Python and rely on the Dragon run-time services.

The Dragon implementation of multiprocessing provides a distributed run-time environment for multiprocessing, where the original implementation of multiprocessing was confined to one node. These objects are always managed and refcounted. The Dragon implementation runs across all nodes in the Dragon run-time services instance.

The following table provides an overview over the Dragon API stack. For a description of the Dragon APIs, see the Programming Guide

Table 2 API capability overview

API Name	Languages	Requires Run-time Services	Use Case
Multiprocessing	Python	Yes	Distributed multiprocessing
Managed Dragon	Python	Yes	Extend the Core API
Core Dragon	C and Python	No, but multinode with it.	Custom implementations