From ae7269e6fd423deb4c18a9cab1a5969a0438fa71 Mon Sep 17 00:00:00 2001
From: Kearwood Gilbert <kearwood@kearwood.com>
Date: Sat, 15 Aug 2026 16:07:00 -0700
Subject: [PATCH] Comments, adding Region to Heap

---
 include/arena.h  | 2 ++
 include/heap.h   | 9 ++++++++-
 include/region.h | 3 +++
 src/heap.cpp     | 9 +++++++--
 4 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/include/arena.h b/include/arena.h
index 9bba7a1..b8252c4 100644
--- a/include/arena.h
+++ b/include/arena.h
@@ -36,6 +36,8 @@
 #include "region.h"
 
 namespace mimir {
+
+// Arena memory allocator, baed by a mimir::Region
 class Arena
 {
 public:
diff --git a/include/heap.h b/include/heap.h
index bd5e0ca..da19c1e 100644
--- a/include/heap.h
+++ b/include/heap.h
@@ -33,14 +33,18 @@
 
 #include <cstddef>
 
+#include "region.h"
+
 namespace mimir {
+
+// Heap implementation based on Two-Level Segregated Fit (TLSF) memory allocation
 class Heap
 {
 public:
   Heap();
   ~Heap();
 
-  bool init(size_t minSize = 1ULL << 24, size_t maxSize = 1ULL << 32);
+  bool init(size_t maxSize = 1ULL << 32);
 
   // Allocate `size` bytes
   std::byte* alloc(size_t size);
@@ -50,6 +54,9 @@ public:
 
   // Allocate `size` bytes, aligned to 64 bytes and padded to next 64-byte offset.
   std::byte* allocA64(size_t size);
+
+private:
+  Region m_region;
 };
 
 } // namespace mimir
diff --git a/include/region.h b/include/region.h
index 8ea5df0..a75d06e 100644
--- a/include/region.h
+++ b/include/region.h
@@ -34,6 +34,9 @@
 #include <cstddef>
 
 namespace mimir {
+
+// Dynamically growable memory region with a contiguous address range.
+// Provides OS and hardware agnostic reservation and committing of memory pages.
 class Region
 {
 public:
diff --git a/src/heap.cpp b/src/heap.cpp
index d8b2550..c666ec3 100644
--- a/src/heap.cpp
+++ b/src/heap.cpp
@@ -38,6 +38,8 @@
 
 namespace mimir {
 
+// Two-Level Segregated Fit (TLSF): http://www.gii.upv.es/tlsf/files/papers/ecrts04_tlsf.pdf
+
 Heap::Heap()
 {
 }
@@ -46,9 +48,12 @@ Heap::~Heap()
 {
 }
 
-bool Heap::init(size_t minSize, size_t maxSize)
+bool Heap::init(size_t maxSize)
 {
-  return false; // not implemented
+  if (!m_region.init(maxSize)) {
+    return false;
+  }
+  return true;
 }
 
 // Allocate `size` bytes