+ docs in xo-alloc2/ + misc improvements

docs/AAllocator-reference.rst

@@ -0,0 +1,39 @@
+.. _AAllocator-reference:
+
+AAllocator Reference
+====================
+
+Abstract interface facet for arena allocator.
+Provides simple arena allocation.
+
+Context
+-------
+
+.. ditaa::
+    :--scale: 0.99
+
+    +--------------------------------+
+    |      IAllocator_DArena         |
+    +--------------------------------+
+    |      IAllocator_Xfer           |
+    +--------------------------------+
+    |      IAllocator_ImplType       |
+    +--------------+-----------------+
+    |cBLU          |    DArena       |
+    |   AAllocator +-----------------+
+    |              | ArenaConfig     |
+    +--------------+-----------------+
+
+.. code-block:: cpp
+
+    #incldue <xo/alloc2/AAllocator.hpp>
+
+Class
+-----
+
+.. doxygenclass:: xo::mm::AAllocator
+
+Methods
+-------
+
+.. doxygengroup:: mm-allocator-methods

docs/ArenaConfig-reference.rst

@@ -0,0 +1,35 @@
+.. _ArenaConfig-reference:
+
+ArenaConfig Reference
+=====================
+
+Configuration for an arena allocator
+
+Context
+-------
+
+.. ditaa::
+    :--scale: 0.99
+
+    +--------------------------------+
+    |      IAllocator_DArena         |
+    +--------------------------------+
+    |      IAllocator_Xfer           |
+    +--------------------------------+
+    |      IAllocator_ImplType       |
+    +--------------+-----------------+
+    |              |    DArena       |
+    |  AAllocator  +-----------------+
+    |              | ArenaConfig cBLU|
+    +--------------+-----------------+
+
+.. code-block:: cpp
+
+    #include <xo/alloc2/DArena.hpp>
+
+Class
+-----
+
+.. doxygenclass:: xo::mm::ArenaConfig
+
+.. doxygenclass:: mm-arenaconfig-instance-vars

docs/CMakeLists.txt

@@ -0,0 +1,17 @@
+# xo-alloc2/docs/CMakeLists.txt
+
+xo_doxygen_collect_deps()
+xo_docdir_doxygen_config()
+xo_docdir_sphinx_config(
+    index.rst
+    glossary.rst
+    implementation.rst
+    ArenaConfig-reference.rst
+    DArena-reference.rst
+    #install.rst
+    #introduction.rst
+    #implementation.rst
+)
+
+# see xo-reader/doc or xo-unit/doc for working examples
+# example.rst install.rst implementation.rst

docs/DArena-reference.rst

@@ -0,0 +1,64 @@
+.. _DArena-reference:
+
+DArena Reference
+================
+
+Native representation for arena allocator
+
+Context
+-------
+
+.. ditaa::
+    :--scale: 0.99
+
+    +--------------------------------+
+    |      IAllocator_DArena         |
+    +--------------------------------+
+    |      IAllocator_Xfer           |
+    +--------------------------------+
+    |      IAllocator_ImplType       |
+    +--------------+-----------------+
+    |              |    DArena   cBLU|
+    |   AAllocator +-----------------+
+    |              | ArenaConfig     |
+    +--------------+-----------------+
+
+.. code-block:: cpp
+
+    #include <xo/alloc2/DArena.hpp>
+
+
+Arena memory layout::
+
+    <----------------------------size-------------------------->
+    <------------committed-----------><-------uncommitted------>
+    <--allocated-->
+
+    XXXXXXXXXXXXXXX___________________..........................
+   ^               ^                  ^                         ^
+   lo              free               limit                     hi
+
+    [X] allocated:   in use
+    [_] committed:   physical memory obtained
+    [.] uncommitted: mapped in virtual memory, not backed by memory
+
+
+Class
+-----
+
+.. doxygenclass:: xo::mm::DArena
+
+Member Variables
+----------------
+
+.. doxygengroup:: mm-arena-instance-vars
+
+Type Traits
+-----------
+
+.. doxygengroup:: mm-arena-traits
+
+Constructors
+------------
+
+.. doxygengroup:: mm-arena-ctors

docs/README

@@ -0,0 +1,70 @@
+build
+
+        +-----------------------------------------------+
+        | cmake                                         |
+        |   CMakeLists.txt                              |
+        |   $PREFIX/share/cmake/xo_macros/xo_cxx.cmake  |
+        +-----------------------------------------------+
+           |
+           |                                                  +----------------------+
+           +------------------------------------------------->| .build/docs/Doxyfile |
+           |                                                  +----------------------+
+           |                                                     |
+           |                                        /------------/
+           |                                        |
+           |                                        v
+           |     +---------------------------------------+    +-----------------+
+           +---->| doxygen                               |--->| .build/docs/dox |
+           |     |   $PREFIX/share/xo-macros/Doxyfile.in |    |   +- html/      |
+           |     +---------------------------------------+    |   +- xml/       |
+           |                                                  +-----------------+
+           |                                                     |
+           |                                        /------------/
+           |                                        |
+           |                                        v
+           |     +---------------------------------------+    +--------------------+
+           \---->| sphinx                                |--->| .build/docs/sphinx |
+                 |   +- conf.py                          |    |   +- html/         |
+                 |   +- _static/                         |    +--------------------+
+                 |   +- *.rst                            |
+                 +---------------------------------------+
+
+files
+
+   README            this file
+   CMakeLists.txt    build entry point
+   conf.py           sphinx config
+   _static           static files for sphinx
+
+map
+
+   index.rst
+   +- install.rst
+   +- examples.rst
+   +- unit-quantities.rst
+   +- classes.rst
+   +- glossary.rst
+   ...
+
+examples
+
+.. doxygenclass:: ${c++ class name}
+   :project:
+   :path:
+   :members:
+   :protected-members:
+   :private-members:
+   :undoc-members:
+   :member-groups:
+   :members-only:
+   :outline:
+   :no-link:
+   :allow-dot-graphs:
+
+.. doxygendefine:: ${c preprocessor define}
+
+.. doxygenconcept:: ${c++ concept definition}
+
+.. doxygenenum:: ${c++ enum definition}
+
+.. doxygenfunction:: ${c++ function name}

docs/_static/README

@@ -0,0 +1 @@
+add any static {.html, .js, ..} files for sphinx to pickup here

docs/conf.py

@@ -0,0 +1,39 @@
+# Configuration file for the Sphinx documentation builder.
+#
+# For the full list of built-in configuration values, see the documentation:
+# https://www.sphinx-doc.org/en/master/usage/configuration.html
+
+# -- Project information -----------------------------------------------------
+# https://www.sphinx-doc.org/en/master/usage/configuration.html#project-information
+
+project = 'xo alloc2 documentation'
+copyright = '2025, Roland Conybeare'
+author = 'Roland Conybeare'
+
+# -- General configuration ---------------------------------------------------
+# https://www.sphinx-doc.org/en/master/usage/configuration.html#general-configuration
+
+#extensions = []
+extensions = [ "breathe",
+               "sphinx.ext.mathjax",     # inline math
+               "sphinx.ext.autodoc",     # generate info from docstrings
+               "sphinxcontrib.ditaa",    # diagrams-through-ascii-art
+               "sphinxcontrib.plantuml"  # text -> uml diagrams
+              ]
+
+# note: breathe requires doxygen xml output -> must have GENERATE_XML = YES in Doxyfile.in
+#       match project name in Doxyfile.in
+breathe_default_project = "xodoxxml"
+
+templates_path = ['_templates']
+exclude_patterns = ['_build', 'Thumbs.db', '.DS_Store']
+
+pygments_style = 'sphinx'
+
+# -- Options for HTML output -------------------------------------------------
+# https://www.sphinx-doc.org/en/master/usage/configuration.html#options-for-html-output
+
+#html_theme = 'alabaster'
+html_theme = 'sphinx_rtd_theme'
+html_static_path = ['_static']
+html_favicon = '_static/img/favicon.ico'

docs/glossary.rst

@@ -0,0 +1,24 @@
+.. _glossary:
+
+Glossary
+--------
+
+.. glossary::
+    FOMO
+     | facet object model
+
+    page
+     | a (4k) page of virtual memory.
+     | O/S manages virtual memory in chunks of this size.
+
+    hugepage
+     | large (2MB) VM page; use to reduce page fault expense and TLB pressure.
+
+    THP
+     | transparent huge pages
+
+    TLB
+     | translation lookaside buffer
+
+    VM
+     | virtual memory

docs/implementation.rst

@@ -0,0 +1,51 @@
+.. _implementation:
+
+Components
+==========
+
+Library dependency tower for *xo-alloc2*
+
+.. ditaa::
+
+    +-----------------+
+    |    xo_alloc2    |
+    +-----------------+
+    |    xo_facet     |
+    +-----------------+
+    |    xo_cmake     |
+    +-----------------+
+
+Abstraction tower for *xo-alloc2* components
+
+.. ditaa::
+    :--scale: 0.99
+
+    +--------------------------------+
+    |      IAllocator_DArena         |
+    +--------------------------------+
+    |      IAllocator_Xfer           |
+    +--------------------------------+
+    |      IAllocator_ImplType       |
+    +--------------+-----------------+
+    |              |    DArena       |
+    |  AAllocator  +-----------------+
+    |              | ArenaConfig     |
+    +--------------+-----------------+
+
+.. list-table:: Descriptions
+    :header-rows: 1
+    :widths: 20 90
+
+    * - Component
+      - Description
+    * - ``AAllocator``
+      - allocator facet (abstract interface)
+    * - ``DArena``
+      - arena representation
+    * - ``IAllocator_ImplType<D>``
+      - lookup implementation for allocator A
+        with representation D.
+    * - ``IAllocator_Xfer<D>``
+      - transfer interface. downcast to native state.
+    * - ``IAllocator_DArena``
+      - allocator implementation for ``DArena``

docs/index.rst

@@ -0,0 +1,28 @@
+# xo-alloc2 documentation master file
+
+xo-alloc2 documentation
+=======================
+
+xo-alloc2 is intended to provide fast vm-aware arena allocation.
+Next-generation version of xo-alloc.
+At present (Dec 2025) xo-alloc is fully functional,
+while xo-alloc2 is aspirational.
+
+Features:
+
+* allocates uncommitted virtual memory, and commits on demand.
+* ses THP (Transparent Huge Pages) when available.
+
+Implemented using FOMO (faceted rust-like object model) from xo-facet
+
+.. toctree::
+    :maxdepth: 2
+    :caption: xo-alloc2 contents
+
+    implementation
+    AAllocator-reference
+    ArenaConfig-reference
+    DArena-reference
+    glossary
+    genindex
+    search