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authorAqua-sama <aqua@iserlohn-fortress.net>2021-03-28 12:41:57 +0300
committerAqua-sama <aqua@iserlohn-fortress.net>2021-03-28 12:41:57 +0300
commitb3b1385e7af85ba2cb1f92bc31706099f1b9d562 (patch)
tree2086f7333e33970f17898049d7392e7dece705ff /src/allocator.cc
parentclang-tidy fixes (diff)
downloadkernel.cpp-b3b1385e7af85ba2cb1f92bc31706099f1b9d562.tar.xz
Move MemoryAllocator to libk
Diffstat (limited to 'src/allocator.cc')
-rw-r--r--src/allocator.cc90
1 files changed, 0 insertions, 90 deletions
diff --git a/src/allocator.cc b/src/allocator.cc
deleted file mode 100644
index 77736cc..0000000
--- a/src/allocator.cc
+++ /dev/null
@@ -1,90 +0,0 @@
-#include "allocator.h"
-
-static MemoryAllocator* mem_alloc = nullptr;
-
-MemoryAllocator::MemoryAllocator(uint32_t start, size_t size) {
- if (size < sizeof(MemoryChunk)) {
- begin = nullptr;
- return;
- }
- begin = new (reinterpret_cast<void*>(start)) MemoryChunk{.size = static_cast<size_t>(size - sizeof(MemoryChunk))};
- if (mem_alloc == nullptr) mem_alloc = this;
-}
-
-void* MemoryAllocator::malloc(size_t size) {
- // TODO spinlock
- // TODO memset 0 over allocated memory
- MemoryChunk* result = nullptr;
-
- // find the first chunk that is at least size and not allocated
- for (auto* iter = begin; iter != nullptr; iter = iter->next) {
- if (iter->size >= size && !iter->allocated) {
- result = iter;
-
- // split chunk if there is at least one byte left over
- if (result->size >= size + sizeof(MemoryChunk) + 1) {
- auto* _new = new (result + sizeof(MemoryChunk) + size) MemoryChunk{
- .prev = result, .next = result->next, .size = static_cast<size_t>(result->size - sizeof(MemoryChunk))};
- result->next = _new;
- }
-
- break;
- }
- }
-
- return result + sizeof(MemoryChunk);
-}
-void MemoryAllocator::free(void* ptr) {
- auto* chunk = reinterpret_cast<MemoryChunk*>(reinterpret_cast<uint32_t>(ptr) - sizeof(MemoryChunk));
- chunk->allocated = false;
-
- // merge in next chunk
- if (chunk->next != nullptr && !chunk->next->allocated) {
- chunk->size += chunk->next->size + sizeof(MemoryChunk);
- chunk->next = chunk->next->next;
- if (chunk->next != nullptr) chunk->next->prev = chunk;
- }
-
- // merge into previous chunk
- if (chunk->prev != nullptr && !chunk->prev->allocated) {
- chunk->prev->size += chunk->size + sizeof(MemoryChunk);
- chunk->prev->next = chunk->next;
- if (chunk->next != nullptr) chunk->next->prev = chunk->prev;
- }
-};
-
-size_t MemoryAllocator::free_space() const {
- size_t r = 0;
- for (auto* iter = begin; iter != nullptr; iter = iter->next)
- if (!iter->allocated) r += iter->size;
- return r;
-}
-size_t MemoryAllocator::used_space() const {
- size_t r = 0;
- for (auto* iter = begin; iter != nullptr; iter = iter->next)
- if (iter->allocated) r += iter->size;
- return r;
-}
-
-void* operator new(unsigned sz, const std::nothrow_t&) noexcept {
- if (mem_alloc == nullptr) return nullptr;
- return mem_alloc->malloc(sz);
-}
-void* operator new[](unsigned sz, const std::nothrow_t&) noexcept {
- if (mem_alloc == nullptr) return nullptr;
- return mem_alloc->malloc(sz);
-}
-
-void operator delete(void* ptr) {
- if (mem_alloc != nullptr) mem_alloc->free(ptr);
-}
-void operator delete[](void* ptr) {
- if (mem_alloc != nullptr) mem_alloc->free(ptr);
-}
-
-void* operator new(unsigned /* size_bytes */, void* ptr) {
- return ptr;
-}
-void* operator new[](unsigned /* size_bytes */, void* ptr) {
- return ptr;
-}