From 2b901abfb1eb1dbef6cb43edb2d36bd67b98329f Mon Sep 17 00:00:00 2001
From: Bananymous <bananymousosq@gmail.com>
Date: Sat, 3 Jun 2023 02:22:18 +0300
Subject: [PATCH] Kernel: Shell 'memory' now prints heap memory usage

---
 kernel/include/kernel/Memory/Heap.h          |  5 ++++-
 kernel/include/kernel/Memory/PhysicalRange.h |  6 ++++++
 kernel/kernel/Memory/Heap.cpp                | 18 ++++++++++++++++++
 kernel/kernel/Memory/PhysicalRange.cpp       |  9 +++++++++
 kernel/kernel/Shell.cpp                      |  3 +++
 5 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/kernel/include/kernel/Memory/Heap.h b/kernel/include/kernel/Memory/Heap.h
index 92ed0d50..78003d5e 100644
--- a/kernel/include/kernel/Memory/Heap.h
+++ b/kernel/include/kernel/Memory/Heap.h
@@ -21,13 +21,16 @@ namespace Kernel
 		paddr_t take_free_page();
 		void release_page(paddr_t);
 
+		size_t used_pages() const;
+		size_t free_pages() const;
+
 	private:
 		Heap() = default;
 		void initialize_impl();
 
 	private:
 		BAN::Vector<PhysicalRange>	m_physical_ranges;
-		SpinLock					m_lock;
+		mutable SpinLock			m_lock;
 	};
 
 }
diff --git a/kernel/include/kernel/Memory/PhysicalRange.h b/kernel/include/kernel/Memory/PhysicalRange.h
index 39335146..317a052b 100644
--- a/kernel/include/kernel/Memory/PhysicalRange.h
+++ b/kernel/include/kernel/Memory/PhysicalRange.h
@@ -21,6 +21,9 @@ namespace Kernel
 
 		size_t usable_memory() const { return m_reservable_pages * PAGE_SIZE; }
 
+		size_t used_pages() const { return m_used_pages; }
+		size_t free_pages() const { return m_free_pages; }
+
 	private:
 		struct node
 		{
@@ -39,6 +42,9 @@ namespace Kernel
 		uint64_t m_reservable_pages	{ 0 };
 		uint64_t m_list_pages		{ 0 };
 
+		size_t m_used_pages { 0 };
+		size_t m_free_pages { 0 };
+
 		node* m_free_list { nullptr };
 		node* m_used_list { nullptr };
 	};
diff --git a/kernel/kernel/Memory/Heap.cpp b/kernel/kernel/Memory/Heap.cpp
index 5c766180..08e1a7dd 100644
--- a/kernel/kernel/Memory/Heap.cpp
+++ b/kernel/kernel/Memory/Heap.cpp
@@ -74,4 +74,22 @@ namespace Kernel
 		ASSERT_NOT_REACHED();
 	}
 
+	size_t Heap::used_pages() const
+	{
+		LockGuard _(m_lock);
+		size_t result = 0;
+		for (const auto& range : m_physical_ranges)
+			result += range.used_pages();
+		return result;
+	}
+
+	size_t Heap::free_pages() const
+	{
+		LockGuard _(m_lock);
+		size_t result = 0;
+		for (const auto& range : m_physical_ranges)
+			result += range.free_pages();
+		return result;
+	}
+
 }
diff --git a/kernel/kernel/Memory/PhysicalRange.cpp b/kernel/kernel/Memory/PhysicalRange.cpp
index 039db1e2..a0320206 100644
--- a/kernel/kernel/Memory/PhysicalRange.cpp
+++ b/kernel/kernel/Memory/PhysicalRange.cpp
@@ -37,6 +37,9 @@ namespace Kernel
 		m_list_pages		= BAN::Math::div_round_up<uint64_t>(m_total_pages * sizeof(node), PAGE_SIZE);
 		m_reservable_pages	= m_total_pages - m_list_pages;
 
+		m_used_pages = 0;
+		m_free_pages = m_reservable_pages;
+
 		PageTable::kernel().identity_map_range(m_start, m_list_pages * PAGE_SIZE, PageTable::Flags::ReadWrite | PageTable::Flags::Present);
 
 		// Initialize page list so that every page points to the next one
@@ -72,6 +75,9 @@ namespace Kernel
 		page->prev = m_used_list;
 		m_used_list = page;
 
+		m_used_pages++;
+		m_free_pages--;
+
 		return page_address(page);
 	}
 
@@ -95,6 +101,9 @@ namespace Kernel
 		if (m_free_list)
 			m_free_list->next = page;
 		m_free_list = page;
+
+		m_used_pages--;
+		m_free_pages++;
 	}	
 
 	paddr_t PhysicalRange::page_address(const node* page) const
diff --git a/kernel/kernel/Shell.cpp b/kernel/kernel/Shell.cpp
index 3eee4ae4..50753d32 100644
--- a/kernel/kernel/Shell.cpp
+++ b/kernel/kernel/Shell.cpp
@@ -415,6 +415,9 @@ argument_done:
 				return {};
 			}
 			kmalloc_dump_info();
+			TTY_PRINTLN("heap:");
+			TTY_PRINTLN("  used: 0x{8H}", Heap::get().used_pages() * PAGE_SIZE);
+			TTY_PRINTLN("  free: 0x{8H}", Heap::get().free_pages() * PAGE_SIZE);
 		}
 		else if (arguments.front() == "sleep")
 		{