diff options
Diffstat (limited to 'arch/x86_64/include')
4 files changed, 68 insertions, 7 deletions
diff --git a/arch/x86_64/include/arch/memory/heap/global_heap_allocator.hpp b/arch/x86_64/include/arch/memory/heap/global_heap_allocator.hpp index 1b1d964..6719bec 100644 --- a/arch/x86_64/include/arch/memory/heap/global_heap_allocator.hpp +++ b/arch/x86_64/include/arch/memory/heap/global_heap_allocator.hpp @@ -5,24 +5,65 @@ namespace teachos::arch::memory::heap { + /** + * @brief Possible types that should be constructed by the register_heap_allocator factory method. + * Creates the underlying heap allocator instance that is then used by all global allocations using new and delete + */ enum class heap_allocator_type : uint8_t { - NONE, - BUMP, - LINKED_LIST + NONE, ///< Don't use any heap allocation implementation, this will result in all calls of new and delte halting + ///< further execution of the kernel + BUMP, ///< Use the bump allocator as the heap allocation implementation, be aware that using this allocator leaks + ///< memory, because there is no delete implementation + LINKED_LIST ///< Use the linked list allocator as the heap implementation, recommended because it does not leak + ///< memory and }; + /** + * @brief Global instance of a heap allocator implementation created by the factory method pattern @see + * https://refactoring.guru/design-patterns/factory-method for more information. + * + * @note Can only be registered once and only once the kernel and the heap part of the kernel has been remapped + * successfully. If the instance is created before than the device will abort, because it acceses unmapped memory + * areas. + */ struct global_heap_allocator { + /** + * @brief Registers the heap allocation implementation that should be used by the global heap allocator. + * Meaning all future calls to the global new or delete will be forwarded to the allocate and deallocate calls of + * the underlying heap allocation implementation + * + * @param new_type Type of the heap allocation implementation we want to instantiate + */ static auto register_heap_allocator(heap_allocator_type new_type) -> void; + /** + * @brief Allocates the given amount of memory and returns the pointer to the start of the allocatable memory area. + * Simply forwards the call to the allocate method of the registered heap_allocation implementation + * + * @param size Amount of bytes that should be allocated + * @return void* Pointer to the start of the allocatable memory area + */ static auto allocate(std::size_t size) -> void *; + /** + * @brief Deallocated the given amount of memory starting from the given pointer address. + * Simply forwards the call to the deallocate method of the registered heap_allocation implementation + * + * @param pointer Previously allocated memory area, that should now be freed + * @param size Size of the memory area we want to free + */ static auto deallocate(void * pointer, std::size_t size) -> void; private: - static heap_allocator * allocator_instance; + static heap_allocator * allocator_instance; ///< Instance used to actually allocate and deallocate + /** + * @brief Either returns the previously registered heap allocated or halts furthere execution + * + * @return Reference to the registered heap allocation + */ static auto get() -> heap_allocator &; }; } // namespace teachos::arch::memory::heap diff --git a/arch/x86_64/include/arch/memory/heap/heap_allocator.hpp b/arch/x86_64/include/arch/memory/heap/heap_allocator.hpp index 62ba963..1519155 100644 --- a/arch/x86_64/include/arch/memory/heap/heap_allocator.hpp +++ b/arch/x86_64/include/arch/memory/heap/heap_allocator.hpp @@ -8,12 +8,34 @@ namespace teachos::arch::memory::heap std::size_t constexpr HEAP_START = 0x100000000; std::size_t constexpr HEAP_SIZE = 100 * 1024; + /** + * @brief Heap allocator interface containing methods required to allocate and deallocate heap memory areas + */ struct heap_allocator { + /** + * @brief Virtual default destructor, created to ensure that if a pointer to this class is used and deleted, we will + * also call the derived base class destructor. Deleting a base class destructor that does not have a virtual + * destructor is undefined behaviour, because the derived class destructor originally instantiated with new is never + * called. This can cause potential memory leaks, because derived classes can not clean up their internal members as + * expected and instead simply leak them + */ virtual ~heap_allocator() {} + /** + * @brief Allocates the given amount of memory and returns the pointer to the start of the allocatable memory area + * + * @param size Amount of bytes that should be allocated + * @return void* Pointer to the start of the allocatable memory area + */ virtual auto allocate(std::size_t size) -> void * = 0; + /** + * @brief Deallocated the given amount of memory starting from the given pointer address + * + * @param pointer Previously allocated memory area, that should now be freed + * @param size Size of the memory area we want to free + */ virtual auto deallocate(void * pointer, std::size_t size) -> void = 0; }; } // namespace teachos::arch::memory::heap diff --git a/arch/x86_64/include/arch/memory/heap/memory_block.hpp b/arch/x86_64/include/arch/memory/heap/memory_block.hpp index b9a2254..e1cd288 100644 --- a/arch/x86_64/include/arch/memory/heap/memory_block.hpp +++ b/arch/x86_64/include/arch/memory/heap/memory_block.hpp @@ -32,7 +32,6 @@ namespace teachos::arch::memory::heap ///< size variable and the pointer to the next hole. memory_block * next; ///< Optional pointer to the next free memory, holds nullptr if there is none. }; - } // namespace teachos::arch::memory::heap #endif // TEACHOS_ARCH_X86_64_MEMORY_HEAP_MEMORY_BLOCK_HPP diff --git a/arch/x86_64/include/arch/memory/paging/page_entry.hpp b/arch/x86_64/include/arch/memory/paging/page_entry.hpp index 876ea3c..1de31b5 100644 --- a/arch/x86_64/include/arch/memory/paging/page_entry.hpp +++ b/arch/x86_64/include/arch/memory/paging/page_entry.hpp @@ -49,14 +49,13 @@ namespace teachos::arch::memory::paging explicit entry(uint64_t flags); /** - * @brief Converts the given elf section flags into the corresponding correct entry flags. + * @brief Creates a new entry converting the given elf section flags into the corresponding correct entry flags. * * @note Enables us to set the correct flags on a entry depending on which elf section it is contained in. For * example entries of .text sections should be executable and read only or entries of .data sections should be * writable but not executable. * * @param elf_flags Elf section flags we want to convert into entry flags. - * @return Entry that has the corresponding bit flags set. */ explicit entry(multiboot::elf_section_flags elf_flags); |