psblas3/docs/internals/README.md

PSBLAS Developer Guide (Internals)

This directory documents the internal architecture of PSBLAS: how the classes relate to each other and how the library is implemented. It is aimed at developers who modify or extend PSBLAS, not at end users.

The split is deliberate and two-layered:

• User manual (docs/src/*.tex, built into psblas-3.9.pdf) describes the public API: what each routine does, its arguments, and the semantics a user must know to call it correctly. For example, it documents that psb_halo accepts a mode flag and what synchronous vs. split-phase exchange means for the caller.
• Developer guide (this directory) describes how those features are implemented: the dispatch path, the communication-handle class hierarchy, the MPI mechanisms behind each scheme, and the extension points. A user never needs to read this to use psb_halo.

When you add a feature, update the layer that matches its audience. A new public flag goes in the user manual; a new internal communication scheme goes here.

Contents

• communication.md — the communication subsystem: the psb_halo/psb_ovrl → psi_swapdata → communication-handle dispatch path, the available MPI schemes, and the swap-status state machine.