From 49c4ae482ef5843992ec6138faebde8d55ceac15 Mon Sep 17 00:00:00 2001
From: Kearwood Gilbert <kearwood@kearwood.com>
Date: Sun, 27 Sep 2026 22:17:59 -0700
Subject: [PATCH] Implement Heap::reset()

---
 include/heap.h |  3 +++
 src/heap.cpp   | 31 +++++++++++++++++++------------
 2 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/include/heap.h b/include/heap.h
index c7e7f04..891bc2a 100644
--- a/include/heap.h
+++ b/include/heap.h
@@ -60,6 +60,9 @@ public:
   // Free the allocation at `address`
   void free(std::byte* address);
 
+  // Reset the heap, freeing all memory and potentially releasing comitted pages.
+  void reset();
+
   // Get the actual used size.
   // This may differ from the sum of allocations due to alignment requirements.
   size_t getUsed() const;
diff --git a/src/heap.cpp b/src/heap.cpp
index 4019280..a61e273 100644
--- a/src/heap.cpp
+++ b/src/heap.cpp
@@ -118,18 +118,7 @@ bool Heap::init(size_t minSize, size_t maxSize)
   if (!m_region.resize(m_minSize)) {
     return false;
   }
-  TLSFIndex* index = (TLSFIndex*)m_region.getAddress();
-  memset(index, 0, sizeof(TLSFIndex));
-
-  // Start with one free block, filling the entire Region
-  TLSFBlock* block = (TLSFBlock*)(m_region.getAddress() + sizeof(TLSFIndex));
-  block->prevPhys = nullptr;
-  block->nextFree = nullptr;
-  block->prevFree = nullptr;
-  block->size = m_region.getMaxSize();
-  block->size |= 0b10; // T=1: Last Block, F=1: Free Block
-
-  insertFreeBlock(block);
+  reset();
   return true;
 }
 
@@ -330,4 +319,22 @@ void Heap::free(std::byte* address)
 {
 }
 
+// Reset (or initialize) the heap, freeing all memory and potentially releasing comitted pages.
+void Heap::reset()
+{
+  // Clear the index, representing no free blocks
+  TLSFIndex* index = (TLSFIndex*)m_region.getAddress();
+  memset(index, 0, sizeof(TLSFIndex));
+
+  // Start with one free block, filling the entire Region
+  TLSFBlock* block = (TLSFBlock*)(m_region.getAddress() + sizeof(TLSFIndex));
+  block->prevPhys = nullptr;
+  block->nextFree = nullptr;
+  block->prevFree = nullptr;
+  block->size = m_region.getMaxSize();
+  block->size |= 0b10; // T=1: Last Block, F=1: Free Block
+
+  insertFreeBlock(block);
+}
+
 } // namespace mimir