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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
parentclang-tidy fixes (diff)
downloadkernel.cpp-b3b1385e7af85ba2cb1f92bc31706099f1b9d562.tar.xz
Move MemoryAllocator to libk
Diffstat (limited to 'src')
-rw-r--r--src/allocator.cc90
-rw-r--r--src/allocator.h39
-rw-r--r--src/kernel.cc3
-rw-r--r--src/makefile1
4 files changed, 1 insertions, 132 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;
-}
diff --git a/src/allocator.h b/src/allocator.h
deleted file mode 100644
index 8a12be8..0000000
--- a/src/allocator.h
+++ /dev/null
@@ -1,39 +0,0 @@
-#pragma once
-
-#include <types.h>
-
-class MemoryAllocator {
-public:
- MemoryAllocator(uint32_t start, size_t size);
-
- void* malloc(size_t size);
- void free(void* ptr);
-
- size_t free_space() const;
- size_t used_space() const;
-
-private:
- struct MemoryChunk {
- MemoryChunk* prev = nullptr;
- MemoryChunk* next = nullptr;
- bool allocated = false;
- size_t size = 0;
- };
- MemoryChunk* begin;
-};
-
-namespace std {
-struct nothrow_t {
- explicit nothrow_t() = default;
-};
-}; // namespace std
-
-void* operator new(unsigned, const std::nothrow_t&) noexcept;
-void* operator new[](unsigned, const std::nothrow_t&) noexcept;
-
-void operator delete(void* ptr);
-void operator delete[](void* ptr);
-
-// placement new
-void* operator new(unsigned, void*);
-void* operator new[](unsigned, void*);
diff --git a/src/kernel.cc b/src/kernel.cc
index 578344c..fc02f5b 100644
--- a/src/kernel.cc
+++ b/src/kernel.cc
@@ -8,9 +8,8 @@
#error "This tutorial needs to be compiled with a ix86-elf compiler"
#endif
+#include <memory.h>
#include <stdlib.h>
-#include <types.h>
-#include "allocator.h"
#include "cga.h"
#include "cpu/cpu.h"
#include "gdt.h"
diff --git a/src/makefile b/src/makefile
index 1d85f4b..d1e2147 100644
--- a/src/makefile
+++ b/src/makefile
@@ -9,7 +9,6 @@ CXX_OBJ = kernel.o \
idt.o \
idt/exception.o idt/interruptgate.o idt/interrupthandler.o \
vmm.o \
- allocator.o \
scheduler.o scheduler/task.o
CXX_OBJ := $(addprefix $(OBJ_DIR)/, $(CXX_OBJ))
CXX_DEP = $(CXX_OBJ:%.o=%.d)