From 148c54a3d470c6019ebebe1387a7d889a2b8808e Mon Sep 17 00:00:00 2001
From: Felix Morgner <felix.morgner@ost.ch>
Date: Tue, 2 Dec 2025 19:17:42 +0100
Subject: x86_64/memory: introduce frame allocation buffer

---
 .../include/x86_64/memory/buffered_allocator.hpp   | 67 ++++++++++++++++++++++
 1 file changed, 67 insertions(+)
 create mode 100644 arch/x86_64/include/x86_64/memory/buffered_allocator.hpp

(limited to 'arch/x86_64/include')

diff --git a/arch/x86_64/include/x86_64/memory/buffered_allocator.hpp b/arch/x86_64/include/x86_64/memory/buffered_allocator.hpp
new file mode 100644
index 0000000..2d05010
--- /dev/null
+++ b/arch/x86_64/include/x86_64/memory/buffered_allocator.hpp
@@ -0,0 +1,67 @@
+#ifndef TEACHOS_X86_64_BUFFERED_ALLOCATOR_HPP
+#define TEACHOS_X86_64_BUFFERED_ALLOCATOR_HPP
+
+#include "kapi/memory.hpp"
+
+#include <algorithm>
+#include <array>
+#include <cstddef>
+
+namespace teachos::memory::x86_64
+{
+
+  template<std::size_t BufferSize>
+  struct buffered_allocator : frame_allocator
+  {
+    explicit buffered_allocator(frame_allocator * underlying)
+        : m_underlying{underlying}
+    {
+      std::ranges::generate(m_pool, [this] { return m_underlying->allocate(); });
+    }
+
+    buffered_allocator(buffered_allocator const &) = delete;
+    buffered_allocator(buffered_allocator &&) = default;
+
+    ~buffered_allocator() override
+    {
+      std::ranges::for_each(m_pool, [this](auto const & maybe_frame) {
+        if (maybe_frame)
+        {
+          m_underlying->release(*maybe_frame);
+        }
+      });
+    }
+
+    auto operator=(buffered_allocator const &) = delete;
+    auto operator=(buffered_allocator &&) = delete;
+
+    auto allocate() -> std::optional<frame> override
+    {
+      auto found = std::ranges::find_if(m_pool, [](auto const & candidate) { return candidate.has_value(); });
+      if (found == std::end(m_pool))
+      {
+        return m_underlying->allocate();
+      }
+      auto frame = found->value();
+      found->reset();
+      return frame;
+    }
+
+    auto release(frame frame) -> void override
+    {
+      auto found = std::ranges::find_if(m_pool, [](auto const & candidate) { return !candidate; });
+      if (found == std::end(m_pool))
+      {
+        return m_underlying->release(frame);
+      }
+      (*found) = frame;
+    }
+
+  private:
+    frame_allocator * m_underlying;
+    std::array<std::optional<frame>, BufferSize> m_pool{};
+  };
+
+}  // namespace teachos::memory::x86_64
+
+#endif
\ No newline at end of file
-- 
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