Merge pull request #1101 from odin-lang/compiler-allocator-improvements

Compiler Allocator Improvements

src/build_settings.cpp

@@ -500,7 +500,6 @@ String odin_root_dir(void) {
 String internal_odin_root_dir(void) {
 	String path = global_module_path;
 	isize len, i;
-	gbTempArenaMemory tmp;
 	wchar_t *text;
 
 	if (global_module_path_set) {
@@ -525,10 +524,7 @@ String internal_odin_root_dir(void) {
 	mutex_lock(&string_buffer_mutex);
 	defer (mutex_unlock(&string_buffer_mutex));
 
-	tmp = gb_temp_arena_memory_begin(&string_buffer_arena);
-	defer (gb_temp_arena_memory_end(tmp));
-
-	text = gb_alloc_array(string_buffer_allocator, wchar_t, len+1);
+	text = gb_alloc_array(permanent_allocator(), wchar_t, len+1);
 
 	GetModuleFileNameW(nullptr, text, cast(int)len);
 	path = string16_to_string(heap_allocator(), make_string16(text, len));
@@ -559,7 +555,6 @@ String path_to_fullpath(gbAllocator a, String s);
 String internal_odin_root_dir(void) {
 	String path = global_module_path;
 	isize len, i;
-	gbTempArenaMemory tmp;
 	u8 *text;
 
 	if (global_module_path_set) {
@@ -583,10 +578,7 @@ String internal_odin_root_dir(void) {
 	mutex_lock(&string_buffer_mutex);
 	defer (mutex_unlock(&string_buffer_mutex));
 
-	tmp = gb_temp_arena_memory_begin(&string_buffer_arena);
-	defer (gb_temp_arena_memory_end(tmp));
-
-	text = gb_alloc_array(string_buffer_allocator, u8, len + 1);
+	text = gb_alloc_array(permanent_allocator(), u8, len + 1);
 	gb_memmove(text, &path_buf[0], len);
 
 	path = path_to_fullpath(heap_allocator(), make_string(text, len));
@@ -617,7 +609,6 @@ String path_to_fullpath(gbAllocator a, String s);
 String internal_odin_root_dir(void) {
 	String path = global_module_path;
 	isize len, i;
-	gbTempArenaMemory tmp;
 	u8 *text;
 
 	if (global_module_path_set) {
@@ -660,10 +651,7 @@ String internal_odin_root_dir(void) {
 	mutex_lock(&string_buffer_mutex);
 	defer (mutex_unlock(&string_buffer_mutex));
 
-	tmp = gb_temp_arena_memory_begin(&string_buffer_arena);
-	defer (gb_temp_arena_memory_end(tmp));
-
-	text = gb_alloc_array(string_buffer_allocator, u8, len + 1);
+	text = gb_alloc_array(permanent_allocator(), u8, len + 1);
 
 	gb_memmove(text, &path_buf[0], len);
 
@@ -691,13 +679,11 @@ String path_to_fullpath(gbAllocator a, String s) {
 	mutex_lock(&fullpath_mutex);
 	defer (mutex_unlock(&fullpath_mutex));
 
-	gbTempArenaMemory tmp = gb_temp_arena_memory_begin(&string_buffer_arena);
-	defer (gb_temp_arena_memory_end(tmp));
-	String16 string16 = string_to_string16(string_buffer_allocator, s);
+	String16 string16 = string_to_string16(temporary_allocator(), s);
 
 	DWORD len = GetFullPathNameW(&string16[0], 0, nullptr, nullptr);
 	if (len != 0) {
-		wchar_t *text = gb_alloc_array(string_buffer_allocator, wchar_t, len+1);
+		wchar_t *text = gb_alloc_array(permanent_allocator(), wchar_t, len+1);
 		GetFullPathNameW(&string16[0], len, text, nullptr);
 		text[len] = 0;
 		result = string16_to_string(a, make_string16(text, len));

src/common.cpp

@@ -31,179 +31,21 @@
 
 gbAllocator heap_allocator(void);
 
-#include "threading.cpp"
-
-gb_inline void zero_size(void *ptr, isize len) {
-	memset(ptr, 0, len);
-}
-
-#define zero_item(ptr) zero_size((ptr), gb_size_of(ptr))
-
+#define for_array(index_, array_) for (isize index_ = 0; index_ < (array_).count; index_++)
 
 i32 next_pow2(i32 n);
 i64 next_pow2(i64 n);
 isize next_pow2_isize(isize n);
 void debugf(char const *fmt, ...);
 
-template <typename U, typename V>
-gb_inline U bit_cast(V &v) { return reinterpret_cast<U &>(v); }
-
-template <typename U, typename V>
-gb_inline U const &bit_cast(V const &v) { return reinterpret_cast<U const &>(v); }
-
-
-gb_inline i64 align_formula(i64 size, i64 align) {
-	if (align > 0) {
-		i64 result = size + align-1;
-		return result - result%align;
-	}
-	return size;
-}
-gb_inline isize align_formula_isize(isize size, isize align) {
-	if (align > 0) {
-		isize result = size + align-1;
-		return result - result%align;
-	}
-	return size;
-}
-gb_inline void *align_formula_ptr(void *ptr, isize align) {
-	if (align > 0) {
-		uintptr result = (cast(uintptr)ptr) + align-1;
-		return (void *)(result - result%align);
-	}
-	return ptr;
-}
-
-
-GB_ALLOCATOR_PROC(heap_allocator_proc);
-
-gbAllocator heap_allocator(void) {
-	gbAllocator a;
-	a.proc = heap_allocator_proc;
-	a.data = nullptr;
-	return a;
-}
-
-
-GB_ALLOCATOR_PROC(heap_allocator_proc) {
-	void *ptr = nullptr;
-	gb_unused(allocator_data);
-	gb_unused(old_size);
-
-
-
-// TODO(bill): Throughly test!
-	switch (type) {
-#if defined(GB_COMPILER_MSVC)
-	case gbAllocation_Alloc: {
-		isize aligned_size = align_formula_isize(size, alignment);
-		// TODO(bill): Make sure this is aligned correctly
-		ptr = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, aligned_size);
-	} break;
-	case gbAllocation_Free:
-		HeapFree(GetProcessHeap(), 0, old_memory);
-		break;
-	case gbAllocation_Resize: {
-		isize aligned_size = align_formula_isize(size, alignment);
-		ptr = HeapReAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, old_memory, aligned_size);
-	} break;
-#elif defined(GB_SYSTEM_LINUX)
-	// TODO(bill): *nix version that's decent
-	case gbAllocation_Alloc: {
-		ptr = aligned_alloc(alignment, (size + alignment - 1) & ~(alignment - 1));
-		gb_zero_size(ptr, size);
-	} break;
-
-	case gbAllocation_Free: {
-		free(old_memory);
-	} break;
-
-	case gbAllocation_Resize:
-		if (size == 0) {
-			free(old_memory);
-			break;
-		}
-		if (!old_memory) {
-			ptr = aligned_alloc(alignment, (size + alignment - 1) & ~(alignment - 1));
-			gb_zero_size(ptr, size);
-			break;
-		}
-		if (size <= old_size) {
-			ptr = old_memory;
-			break;
-		}
-
-		ptr = aligned_alloc(alignment, (size + alignment - 1) & ~(alignment - 1));
-		gb_memmove(ptr, old_memory, old_size);
-		gb_zero_size(cast(u8 *)ptr + old_size, gb_max(size-old_size, 0));
-		break;
-#else
-	// TODO(bill): *nix version that's decent
-	case gbAllocation_Alloc:
-		posix_memalign(&ptr, alignment, size);
-		gb_zero_size(ptr, size);
-		break;
-
-	case gbAllocation_Free:
-		free(old_memory);
-		break;
-
-	case gbAllocation_Resize:
-		if (size == 0) {
-			free(old_memory);
-			break;
-		}
-		if (!old_memory) {
-			posix_memalign(&ptr, alignment, size);
-			gb_zero_size(ptr, size);
-			break;
-		}
-		if (size <= old_size) {
-			ptr = old_memory;
-			break;
-		}
-
-		posix_memalign(&ptr, alignment, size);
-		gb_memmove(ptr, old_memory, old_size);
-		gb_zero_size(cast(u8 *)ptr + old_size, gb_max(size-old_size, 0));
-		break;
-#endif
-
-	case gbAllocation_FreeAll:
-		break;
-	}
-
-	return ptr;
-}
-
-
-template <typename T>
-void resize_array_raw(T **array, gbAllocator const &a, isize old_count, isize new_count) {
-	GB_ASSERT(new_count >= 0);
-	if (new_count == 0) {
-		gb_free(a, *array);
-		*array = nullptr;
-		return;
-	}
-	if (new_count < old_count) {
-		return;
-	}
-	isize old_size = old_count * gb_size_of(T);
-	isize new_size = new_count * gb_size_of(T);
-	isize alignment = gb_align_of(T);
-	auto new_data = cast(T *)gb_resize_align(a, *array, old_size, new_size, alignment);
-	GB_ASSERT(new_data != nullptr);
-	*array = new_data;
-}
-
-
-
+#include "threading.cpp"
 #include "unicode.cpp"
 #include "array.cpp"
-#include "string.cpp"
 #include "queue.cpp"
+#include "common_memory.cpp"
+#include "string.cpp"
+
 
-#define for_array(index_, array_) for (isize index_ = 0; index_ < (array_).count; index_++)
 
 #include "range_cache.cpp"
 
@@ -401,222 +243,6 @@ void mul_overflow_u64(u64 x, u64 y, u64 *lo, u64 *hi) {
 gb_global String global_module_path = {0};
 gb_global bool global_module_path_set = false;
 
-// Arena from Per Vognsen
-#define ALIGN_DOWN(n, a)     ((n) & ~((a) - 1))
-#define ALIGN_UP(n, a)       ALIGN_DOWN((n) + (a) - 1, (a))
-#define ALIGN_DOWN_PTR(p, a) (cast(void *)ALIGN_DOWN(cast(uintptr)(p), (a)))
-#define ALIGN_UP_PTR(p, a)   (cast(void *)ALIGN_UP(cast(uintptr)(p), (a)))
-
-typedef struct Arena {
-	u8 *                   ptr;
-	u8 *                   end;
-	Array<gbVirtualMemory> blocks;
-	BlockingMutex          mutex;
-	std::atomic<isize>     block_size;
-	std::atomic<isize>     total_used;
-} Arena;
-
-#define ARENA_MIN_ALIGNMENT 16
-#define ARENA_DEFAULT_BLOCK_SIZE (8*1024*1024)
-
-
-gb_global Arena permanent_arena = {};
-
-void arena_init(Arena *arena, gbAllocator block_allocator, isize block_size=ARENA_DEFAULT_BLOCK_SIZE) {
-	mutex_init(&arena->mutex);
-	arena->block_size = block_size;
-	array_init(&arena->blocks, block_allocator, 0, 2);
-}
-
-void arena_internal_grow(Arena *arena, isize min_size) {
-	isize size = gb_max(arena->block_size.load(), min_size);
-	size = ALIGN_UP(size, ARENA_MIN_ALIGNMENT);
-
-	gbVirtualMemory vmem = gb_vm_alloc(nullptr, size);
-	GB_ASSERT(vmem.data != nullptr);
-	GB_ASSERT(vmem.size >= size);
-	arena->ptr = cast(u8 *)vmem.data;
-	GB_ASSERT(arena->ptr == ALIGN_DOWN_PTR(arena->ptr, ARENA_MIN_ALIGNMENT));
-	arena->end = arena->ptr + vmem.size;
-	array_add(&arena->blocks, vmem);
-}
-
-void *arena_alloc(Arena *arena, isize size, isize alignment) {
-	mutex_lock(&arena->mutex);
-
-	if (size > (arena->end - arena->ptr)) {
-		arena_internal_grow(arena, size);
-		GB_ASSERT(size <= (arena->end - arena->ptr));
-	}
-	arena->total_used += size;
-
-	isize align = gb_max(alignment, ARENA_MIN_ALIGNMENT);
-	void *ptr = arena->ptr;
-	arena->ptr = cast(u8 *)ALIGN_UP_PTR(arena->ptr + size, align);
-	GB_ASSERT(arena->ptr <= arena->end);
-	GB_ASSERT(ptr == ALIGN_DOWN_PTR(ptr, align));
-
-	mutex_unlock(&arena->mutex);
-	return ptr;
-}
-
-void arena_free_all(Arena *arena) {
-	mutex_lock(&arena->mutex);
-
-	for_array(i, arena->blocks) {
-		gb_vm_free(arena->blocks[i]);
-	}
-	array_clear(&arena->blocks);
-	arena->ptr = nullptr;
-	arena->end = nullptr;
-
-	mutex_unlock(&arena->mutex);
-}
-
-
-
-GB_ALLOCATOR_PROC(arena_allocator_proc);
-
-gbAllocator arena_allocator(Arena *arena) {
-	gbAllocator a;
-	a.proc = arena_allocator_proc;
-	a.data = arena;
-	return a;
-}
-
-
-GB_ALLOCATOR_PROC(arena_allocator_proc) {
-	void *ptr = nullptr;
-	Arena *arena = cast(Arena *)allocator_data;
-	GB_ASSERT_NOT_NULL(arena);
-
-	switch (type) {
-	case gbAllocation_Alloc:
-		ptr = arena_alloc(arena, size, alignment);
-		break;
-	case gbAllocation_Free:
-		// GB_PANIC("gbAllocation_Free not supported");
-		break;
-	case gbAllocation_Resize:
-		if (size == 0) {
-			ptr = nullptr;
-		} else if (size <= old_size) {
-			ptr = old_memory;
-		} else {
-			ptr = arena_alloc(arena, size, alignment);
-			gb_memmove(ptr, old_memory, old_size);
-		}
-		break;
-	case gbAllocation_FreeAll:
-		arena_free_all(arena);
-		break;
-	}
-
-	return ptr;
-}
-
-
-gbAllocator permanent_allocator() {
-	return arena_allocator(&permanent_arena);
-	// return heap_allocator();
-}
-
-
-
-struct Temp_Allocator {
-	u8 *data;
-	isize len;
-	isize curr_offset;
-	gbAllocator backup_allocator;
-	Array<void *> leaked_allocations;
-	BlockingMutex mutex;
-};
-
-gb_global Temp_Allocator temporary_allocator_data = {};
-
-void temp_allocator_init(Temp_Allocator *s, isize size) {
-	s->backup_allocator = heap_allocator();
-	s->data = cast(u8 *)gb_alloc_align(s->backup_allocator, size, 16);
-	s->len = size;
-	s->curr_offset = 0;
-	s->leaked_allocations.allocator = s->backup_allocator;
-	mutex_init(&s->mutex);
-}
-
-void *temp_allocator_alloc(Temp_Allocator *s, isize size, isize alignment) {
-	size = align_formula_isize(size, alignment);
-	if (s->curr_offset+size <= s->len) {
-		u8 *start = s->data;
-		u8 *ptr = start + s->curr_offset;
-		ptr = cast(u8 *)align_formula_ptr(ptr, alignment);
-		// assume memory is zero
-
-		isize offset = ptr - start;
-		s->curr_offset = offset + size;
-		return ptr;
-	} else if (size <= s->len) {
-		u8 *start = s->data;
-		u8 *ptr = cast(u8 *)align_formula_ptr(start, alignment);
-		// assume memory is zero
-
-		isize offset = ptr - start;
-		s->curr_offset = offset + size;
-		return ptr;
-	}
-
-	void *ptr = gb_alloc_align(s->backup_allocator, size, alignment);
-	array_add(&s->leaked_allocations, ptr);
-	return ptr;
-}
-
-void temp_allocator_free_all(Temp_Allocator *s) {
-	s->curr_offset = 0;
-	for_array(i, s->leaked_allocations) {
-		gb_free(s->backup_allocator, s->leaked_allocations[i]);
-	}
-	array_clear(&s->leaked_allocations);
-	gb_zero_size(s->data, s->len);
-}
-
-GB_ALLOCATOR_PROC(temp_allocator_proc) {
-	void *ptr = nullptr;
-	Temp_Allocator *s = cast(Temp_Allocator *)allocator_data;
-	GB_ASSERT_NOT_NULL(s);
-
-	mutex_lock(&s->mutex);
-	defer (mutex_unlock(&s->mutex));
-
-	switch (type) {
-	case gbAllocation_Alloc:
-		return temp_allocator_alloc(s, size, alignment);
-	case gbAllocation_Free:
-		break;
-	case gbAllocation_Resize:
-		if (size == 0) {
-			ptr = nullptr;
-		} else if (size <= old_size) {
-			ptr = old_memory;
-		} else {
-			ptr = temp_allocator_alloc(s, size, alignment);
-			gb_memmove(ptr, old_memory, old_size);
-		}
-		break;
-	case gbAllocation_FreeAll:
-		temp_allocator_free_all(s);
-		break;
-	}
-
-	return ptr;
-}
-
-
-gbAllocator temporary_allocator() {
-	return permanent_allocator();
-	// return {temp_allocator_proc, &temporary_allocator_data};
-}
-
-
-
 
 #include "string_map.cpp"
 #include "map.cpp"
@@ -633,7 +259,7 @@ struct StringIntern {
 };
 
 Map<StringIntern *> string_intern_map = {}; // Key: u64
-Arena string_intern_arena = {};
+gb_global Arena string_intern_arena = {};
 
 char const *string_intern(char const *text, isize len) {
 	u64 hash = gb_fnv64a(text, len);
@@ -662,7 +288,6 @@ char const *string_intern(String const &string) {
 
 void init_string_interner(void) {
 	map_init(&string_intern_map, heap_allocator());
-	arena_init(&string_intern_arena, heap_allocator());
 }
 
 

src/common_memory.cpp

@@ -0,0 +1,423 @@
+
+gb_inline void zero_size(void *ptr, isize len) {
+	memset(ptr, 0, len);
+}
+
+#define zero_item(ptr) zero_size((ptr), gb_size_of(ptr))
+
+
+template <typename U, typename V>
+gb_inline U bit_cast(V &v) { return reinterpret_cast<U &>(v); }
+
+template <typename U, typename V>
+gb_inline U const &bit_cast(V const &v) { return reinterpret_cast<U const &>(v); }
+
+
+gb_inline i64 align_formula(i64 size, i64 align) {
+	if (align > 0) {
+		i64 result = size + align-1;
+		return result - result%align;
+	}
+	return size;
+}
+gb_inline isize align_formula_isize(isize size, isize align) {
+	if (align > 0) {
+		isize result = size + align-1;
+		return result - result%align;
+	}
+	return size;
+}
+gb_inline void *align_formula_ptr(void *ptr, isize align) {
+	if (align > 0) {
+		uintptr result = (cast(uintptr)ptr) + align-1;
+		return (void *)(result - result%align);
+	}
+	return ptr;
+}
+
+
+gb_global BlockingMutex global_memory_block_mutex;
+gb_global BlockingMutex global_memory_allocator_mutex;
+
+void platform_virtual_memory_init(void);
+
+void virtual_memory_init(void) {
+	mutex_init(&global_memory_block_mutex);
+	mutex_init(&global_memory_allocator_mutex);
+	platform_virtual_memory_init();
+}
+
+
+
+struct MemoryBlock {
+	u8 *         base; 
+	isize        size;
+	isize        used;
+	MemoryBlock *prev;
+};
+
+struct Arena {
+	MemoryBlock * curr_block;
+	isize minimum_block_size;
+};
+
+enum { DEFAULT_MINIMUM_BLOCK_SIZE = 8ll*1024ll*1024ll };
+
+gb_global isize DEFAULT_PAGE_SIZE = 4096;
+
+MemoryBlock *virtual_memory_alloc(isize size);
+void virtual_memory_dealloc(MemoryBlock *block);
+void arena_free_all(Arena *arena);
+
+isize arena_align_forward_offset(Arena *arena, isize alignment) {
+	isize alignment_offset = 0;
+	isize ptr = cast(isize)(arena->curr_block->base + arena->curr_block->used);
+	isize mask = alignment-1;
+	if (ptr & mask) {
+		alignment_offset = alignment - (ptr & mask);
+	}
+	return alignment_offset;
+}
+
+
+void *arena_alloc(Arena *arena, isize min_size, isize alignment) {
+	GB_ASSERT(gb_is_power_of_two(alignment));
+	
+	isize size = 0;
+		
+	// TODO(bill): make it so that this can be done lock free (if possible)
+	mutex_lock(&global_memory_allocator_mutex);
+	
+	if (arena->curr_block != nullptr) {
+		size = min_size + arena_align_forward_offset(arena, alignment);
+	}
+
+	if (arena->curr_block == nullptr || (arena->curr_block->used + size) > arena->curr_block->size) {
+		size = align_formula_isize(min_size, alignment);
+		arena->minimum_block_size = gb_max(DEFAULT_MINIMUM_BLOCK_SIZE, arena->minimum_block_size);
+		
+		isize block_size = gb_max(size, arena->minimum_block_size);
+		
+		MemoryBlock *new_block = virtual_memory_alloc(block_size);
+		new_block->prev = arena->curr_block;
+		arena->curr_block = new_block;
+	}
+	
+	MemoryBlock *curr_block = arena->curr_block;
+	GB_ASSERT((curr_block->used + size) <= curr_block->size);
+	
+	u8 *ptr = curr_block->base + curr_block->used;
+	ptr += arena_align_forward_offset(arena, alignment);
+	
+	curr_block->used += size;
+	GB_ASSERT(curr_block->used <= curr_block->size);
+	
+	mutex_unlock(&global_memory_allocator_mutex);
+	
+	// NOTE(bill): memory will be zeroed by default due to virtual memory 
+	return ptr;	
+}
+
+void arena_free_all(Arena *arena) {
+	while (arena->curr_block != nullptr) {
+		MemoryBlock *free_block = arena->curr_block;
+		arena->curr_block = free_block->prev;
+		virtual_memory_dealloc(free_block);
+	}
+}
+
+
+struct PlatformMemoryBlock {
+	MemoryBlock block; // IMPORTANT NOTE: must be at the start
+	isize total_size;
+	PlatformMemoryBlock *prev, *next;
+};
+
+
+gb_global PlatformMemoryBlock global_platform_memory_block_sentinel;
+
+PlatformMemoryBlock *platform_virtual_memory_alloc(isize total_size);
+void platform_virtual_memory_free(PlatformMemoryBlock *block);
+void platform_virtual_memory_protect(void *memory, isize size);
+
+#if defined(GB_SYSTEM_WINDOWS)
+	void platform_virtual_memory_init(void) {
+		global_platform_memory_block_sentinel.prev = &global_platform_memory_block_sentinel;	
+		global_platform_memory_block_sentinel.next = &global_platform_memory_block_sentinel;
+		
+		SYSTEM_INFO sys_info = {};
+		GetSystemInfo(&sys_info);
+		DEFAULT_PAGE_SIZE = gb_max(DEFAULT_PAGE_SIZE, cast(isize)sys_info.dwPageSize);
+		GB_ASSERT(gb_is_power_of_two(DEFAULT_PAGE_SIZE));
+	}
+
+	PlatformMemoryBlock *platform_virtual_memory_alloc(isize total_size) {
+		PlatformMemoryBlock *pmblock = (PlatformMemoryBlock *)VirtualAlloc(0, total_size, MEM_RESERVE|MEM_COMMIT, PAGE_READWRITE);
+		GB_ASSERT_MSG(pmblock != nullptr, "Out of Virtual Memory, oh no...");
+		return pmblock;
+	}
+	void platform_virtual_memory_free(PlatformMemoryBlock *block) {
+		GB_ASSERT(VirtualFree(block, 0, MEM_RELEASE));
+	}
+	void platform_virtual_memory_protect(void *memory, isize size) {
+		DWORD old_protect = 0;
+		BOOL is_protected = VirtualProtect(memory, size, PAGE_NOACCESS, &old_protect);
+		GB_ASSERT(is_protected);
+	}
+#else
+	void platform_virtual_memory_init(void) {
+		global_platform_memory_block_sentinel.prev = &global_platform_memory_block_sentinel;	
+		global_platform_memory_block_sentinel.next = &global_platform_memory_block_sentinel;
+		
+		DEFAULT_PAGE_SIZE = gb_max(DEFAULT_PAGE_SIZE, cast(isize)sysconf(_SC_PAGE_SIZE));
+		GB_ASSERT(gb_is_power_of_two(DEFAULT_PAGE_SIZE));
+	}
+	
+	PlatformMemoryBlock *platform_virtual_memory_alloc(isize total_size) {
+		PlatformMemoryBlock *pmblock = (PlatformMemoryBlock *)mmap(nullptr, total_size, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+		GB_ASSERT_MSG(pmblock != nullptr, "Out of Virtual Memory, oh no...");
+		return pmblock;
+	}
+	void platform_virtual_memory_free(PlatformMemoryBlock *block) {
+		isize size = block->total_size;
+		munmap(block, size);
+	}
+	void platform_virtual_memory_protect(void *memory, isize size) {
+		int err = mprotect(memory, size, PROT_NONE);
+		GB_ASSERT(err == 0);
+	}
+#endif
+
+MemoryBlock *virtual_memory_alloc(isize size) {
+	isize const page_size = DEFAULT_PAGE_SIZE; 
+	
+	isize total_size     = size + gb_size_of(PlatformMemoryBlock);
+	isize base_offset    = gb_size_of(PlatformMemoryBlock);
+	isize protect_offset = 0;
+	
+	bool do_protection = false;
+	{ // overflow protection
+		isize rounded_size = align_formula_isize(size, page_size);
+		total_size     = rounded_size + 2*page_size;
+		base_offset    = page_size + rounded_size - size;
+		protect_offset = page_size + rounded_size;
+		do_protection  = true;
+	}
+	
+	PlatformMemoryBlock *pmblock = platform_virtual_memory_alloc(total_size);
+	GB_ASSERT_MSG(pmblock != nullptr, "Out of Virtual Memory, oh no...");
+	
+	pmblock->block.base = cast(u8 *)pmblock + base_offset;
+	// Should be zeroed
+	GB_ASSERT(pmblock->block.used == 0);
+	GB_ASSERT(pmblock->block.prev == nullptr);
+	
+	if (do_protection) {
+		platform_virtual_memory_protect(cast(u8 *)pmblock + protect_offset, page_size);
+	}
+	
+	pmblock->block.size = size;
+	pmblock->total_size = total_size;
+
+	PlatformMemoryBlock *sentinel = &global_platform_memory_block_sentinel;
+	mutex_lock(&global_memory_block_mutex);
+	pmblock->next = sentinel;
+	pmblock->prev = sentinel->prev;
+	pmblock->prev->next = pmblock;
+	pmblock->next->prev = pmblock;
+	mutex_unlock(&global_memory_block_mutex);
+	
+	return &pmblock->block;
+}
+
+void virtual_memory_dealloc(MemoryBlock *block_to_free) {
+	PlatformMemoryBlock *block = cast(PlatformMemoryBlock *)block_to_free;
+	if (block != nullptr) {
+		mutex_lock(&global_memory_block_mutex);
+		block->prev->next = block->next;
+		block->next->prev = block->prev;
+		mutex_unlock(&global_memory_block_mutex);
+			
+		platform_virtual_memory_free(block);
+	}
+}
+
+
+
+
+GB_ALLOCATOR_PROC(arena_allocator_proc);
+
+gbAllocator arena_allocator(Arena *arena) {
+	gbAllocator a;
+	a.proc = arena_allocator_proc;
+	a.data = arena;
+	return a;
+}
+
+
+GB_ALLOCATOR_PROC(arena_allocator_proc) {
+	void *ptr = nullptr;
+	Arena *arena = cast(Arena *)allocator_data;
+	GB_ASSERT_NOT_NULL(arena);
+
+	switch (type) {
+	case gbAllocation_Alloc:
+		ptr = arena_alloc(arena, size, alignment);
+		break;
+	case gbAllocation_Free:
+		break;
+	case gbAllocation_Resize:
+		if (size == 0) {
+			ptr = nullptr;
+		} else if (size <= old_size) {
+			ptr = old_memory;
+		} else {
+			ptr = arena_alloc(arena, size, alignment);
+			gb_memmove(ptr, old_memory, old_size);
+		}
+		break;
+	case gbAllocation_FreeAll:
+		arena_free_all(arena);
+		break;
+	}
+
+	return ptr;
+}
+
+
+gb_global Arena permanent_arena = {};
+gbAllocator permanent_allocator() {
+	return arena_allocator(&permanent_arena);
+}
+
+gb_global Arena temporary_arena = {};
+gbAllocator temporary_allocator() {
+	return arena_allocator(&temporary_arena);
+}
+
+
+
+
+
+
+GB_ALLOCATOR_PROC(heap_allocator_proc);
+
+gbAllocator heap_allocator(void) {
+	gbAllocator a;
+	a.proc = heap_allocator_proc;
+	a.data = nullptr;
+	return a;
+}
+
+
+GB_ALLOCATOR_PROC(heap_allocator_proc) {
+	void *ptr = nullptr;
+	gb_unused(allocator_data);
+	gb_unused(old_size);
+
+
+
+// TODO(bill): Throughly test!
+	switch (type) {
+#if defined(GB_COMPILER_MSVC)
+	case gbAllocation_Alloc: {
+		isize aligned_size = align_formula_isize(size, alignment);
+		// TODO(bill): Make sure this is aligned correctly
+		ptr = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, aligned_size);
+	} break;
+	case gbAllocation_Free:
+		HeapFree(GetProcessHeap(), 0, old_memory);
+		break;
+	case gbAllocation_Resize: {
+		isize aligned_size = align_formula_isize(size, alignment);
+		ptr = HeapReAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, old_memory, aligned_size);
+	} break;
+#elif defined(GB_SYSTEM_LINUX)
+	// TODO(bill): *nix version that's decent
+	case gbAllocation_Alloc: {
+		ptr = aligned_alloc(alignment, (size + alignment - 1) & ~(alignment - 1));
+		gb_zero_size(ptr, size);
+	} break;
+
+	case gbAllocation_Free: {
+		free(old_memory);
+	} break;
+
+	case gbAllocation_Resize:
+		if (size == 0) {
+			free(old_memory);
+			break;
+		}
+		if (!old_memory) {
+			ptr = aligned_alloc(alignment, (size + alignment - 1) & ~(alignment - 1));
+			gb_zero_size(ptr, size);
+			break;
+		}
+		if (size <= old_size) {
+			ptr = old_memory;
+			break;
+		}
+
+		ptr = aligned_alloc(alignment, (size + alignment - 1) & ~(alignment - 1));
+		gb_memmove(ptr, old_memory, old_size);
+		gb_zero_size(cast(u8 *)ptr + old_size, gb_max(size-old_size, 0));
+		break;
+#else
+	// TODO(bill): *nix version that's decent
+	case gbAllocation_Alloc:
+		posix_memalign(&ptr, alignment, size);
+		gb_zero_size(ptr, size);
+		break;
+
+	case gbAllocation_Free:
+		free(old_memory);
+		break;
+
+	case gbAllocation_Resize:
+		if (size == 0) {
+			free(old_memory);
+			break;
+		}
+		if (!old_memory) {
+			posix_memalign(&ptr, alignment, size);
+			gb_zero_size(ptr, size);
+			break;
+		}
+		if (size <= old_size) {
+			ptr = old_memory;
+			break;
+		}
+
+		posix_memalign(&ptr, alignment, size);
+		gb_memmove(ptr, old_memory, old_size);
+		gb_zero_size(cast(u8 *)ptr + old_size, gb_max(size-old_size, 0));
+		break;
+#endif
+
+	case gbAllocation_FreeAll:
+		break;
+	}
+
+	return ptr;
+}
+
+
+template <typename T>
+void resize_array_raw(T **array, gbAllocator const &a, isize old_count, isize new_count) {
+	GB_ASSERT(new_count >= 0);
+	if (new_count == 0) {
+		gb_free(a, *array);
+		*array = nullptr;
+		return;
+	}
+	if (new_count < old_count) {
+		return;
+	}
+	isize old_size = old_count * gb_size_of(T);
+	isize new_size = new_count * gb_size_of(T);
+	isize alignment = gb_align_of(T);
+	auto new_data = cast(T *)gb_resize_align(a, *array, old_size, new_size, alignment);
+	GB_ASSERT(new_data != nullptr);
+	*array = new_data;
+}
+

src/gb/gb.h

@@ -893,79 +893,6 @@ GB_DEF GB_ALLOCATOR_PROC(gb_heap_allocator_proc);
 
 
 
-//
-// Arena Allocator
-//
-typedef struct gbArena {
-	gbAllocator backing;
-	void *      physical_start;
-	isize       total_size;
-	isize       total_allocated;
-	isize       temp_count;
-} gbArena;
-
-GB_DEF void gb_arena_init_from_memory   (gbArena *arena, void *start, isize size);
-GB_DEF void gb_arena_init_from_allocator(gbArena *arena, gbAllocator backing, isize size);
-GB_DEF void gb_arena_init_sub           (gbArena *arena, gbArena *parent_arena, isize size);
-GB_DEF void gb_arena_free               (gbArena *arena);
-
-GB_DEF isize gb_arena_alignment_of  (gbArena *arena, isize alignment);
-GB_DEF isize gb_arena_size_remaining(gbArena *arena, isize alignment);
-GB_DEF void  gb_arena_check         (gbArena *arena);
-
-
-// Allocation Types: alloc, free_all, resize
-GB_DEF gbAllocator gb_arena_allocator(gbArena *arena);
-GB_DEF GB_ALLOCATOR_PROC(gb_arena_allocator_proc);
-
-
-
-typedef struct gbTempArenaMemory {
-	gbArena *arena;
-	isize    original_count;
-} gbTempArenaMemory;
-
-GB_DEF gbTempArenaMemory gb_temp_arena_memory_begin(gbArena *arena);
-GB_DEF void              gb_temp_arena_memory_end  (gbTempArenaMemory tmp_mem);
-
-
-
-
-
-
-
-//
-// Pool Allocator
-//
-
-
-typedef struct gbPool {
-	gbAllocator backing;
-	void *      physical_start;
-	void *      free_list;
-	isize       block_size;
-	isize       block_align;
-	isize       total_size;
-} gbPool;
-
-GB_DEF void gb_pool_init      (gbPool *pool, gbAllocator backing, isize num_blocks, isize block_size);
-GB_DEF void gb_pool_init_align(gbPool *pool, gbAllocator backing, isize num_blocks, isize block_size, isize block_align);
-GB_DEF void gb_pool_free      (gbPool *pool);
-
-// Allocation Types: alloc, free
-GB_DEF gbAllocator gb_pool_allocator(gbPool *pool);
-GB_DEF GB_ALLOCATOR_PROC(gb_pool_allocator_proc);
-
-
-
-// NOTE(bill): Used for allocators to keep track of sizes
-typedef struct gbAllocationHeader {
-	isize size;
-} gbAllocationHeader;
-
-GB_DEF gbAllocationHeader *gb_allocation_header     (void *data);
-GB_DEF void                gb_allocation_header_fill(gbAllocationHeader *header, void *data, isize size);
-
 // TODO(bill): Find better way of doing this without #if #elif etc.
 #if defined(GB_ARCH_32_BIT)
 #define GB_ISIZE_HIGH_BIT 0x80000000
@@ -975,64 +902,6 @@ GB_DEF void                gb_allocation_header_fill(gbAllocationHeader *header,
 #error
 #endif
 
-//
-// Free List Allocator
-//
-
-// IMPORTANT TODO(bill): Thoroughly test the free list allocator!
-// NOTE(bill): This is a very shitty free list as it just picks the first free block not the best size
-// as I am just being lazy. Also, I will probably remove it later; it's only here because why not?!
-//
-// NOTE(bill): I may also complete remove this if I completely implement a fixed heap allocator
-
-typedef struct gbFreeListBlock gbFreeListBlock;
-struct gbFreeListBlock {
-	gbFreeListBlock *next;
-	isize            size;
-};
-
-typedef struct gbFreeList {
-	void *           physical_start;
-	isize            total_size;
-
-	gbFreeListBlock *curr_block;
-
-	isize            total_allocated;
-	isize            allocation_count;
-} gbFreeList;
-
-GB_DEF void gb_free_list_init               (gbFreeList *fl, void *start, isize size);
-GB_DEF void gb_free_list_init_from_allocator(gbFreeList *fl, gbAllocator backing, isize size);
-
-// Allocation Types: alloc, free, free_all, resize
-GB_DEF gbAllocator gb_free_list_allocator(gbFreeList *fl);
-GB_DEF GB_ALLOCATOR_PROC(gb_free_list_allocator_proc);
-
-
-
-//
-// Scratch Memory Allocator - Ring Buffer Based Arena
-//
-
-typedef struct gbScratchMemory {
-	void *physical_start;
-	isize total_size;
-	void *alloc_point;
-	void *free_point;
-} gbScratchMemory;
-
-GB_DEF void gb_scratch_memory_init     (gbScratchMemory *s, void *start, isize size);
-GB_DEF b32  gb_scratch_memory_is_in_use(gbScratchMemory *s, void *ptr);
-
-
-// Allocation Types: alloc, free, free_all, resize
-GB_DEF gbAllocator gb_scratch_allocator(gbScratchMemory *s);
-GB_DEF GB_ALLOCATOR_PROC(gb_scratch_allocator_proc);
-
-// TODO(bill): Stack allocator
-// TODO(bill): Fixed heap allocator
-// TODO(bill): General heap allocator. Maybe a TCMalloc like clone?
-
 
 ////////////////////////////////////////////////////////////////
 //
@@ -3948,501 +3817,6 @@ isize gb_virtual_memory_page_size(isize *alignment_out) {
 //
 
 
-//
-// Arena Allocator
-//
-
-gb_inline void gb_arena_init_from_memory(gbArena *arena, void *start, isize size) {
-	arena->backing.proc    = NULL;
-	arena->backing.data    = NULL;
-	arena->physical_start  = start;
-	arena->total_size      = size;
-	arena->total_allocated = 0;
-	arena->temp_count      = 0;
-}
-
-gb_inline void gb_arena_init_from_allocator(gbArena *arena, gbAllocator backing, isize size) {
-	arena->backing         = backing;
-	arena->physical_start  = gb_alloc(backing, size); // NOTE(bill): Uses default alignment
-	arena->total_size      = size;
-	arena->total_allocated = 0;
-	arena->temp_count      = 0;
-}
-
-gb_inline void gb_arena_init_sub(gbArena *arena, gbArena *parent_arena, isize size) { gb_arena_init_from_allocator(arena, gb_arena_allocator(parent_arena), size); }
-
-
-gb_inline void gb_arena_free(gbArena *arena) {
-	if (arena->backing.proc) {
-		gb_free(arena->backing, arena->physical_start);
-		arena->physical_start = NULL;
-	}
-}
-
-
-gb_inline isize gb_arena_alignment_of(gbArena *arena, isize alignment) {
-	isize alignment_offset, result_pointer, mask;
-	GB_ASSERT(gb_is_power_of_two(alignment));
-
-	alignment_offset = 0;
-	result_pointer = cast(isize)arena->physical_start + arena->total_allocated;
-	mask = alignment - 1;
-	if (result_pointer & mask)
-		alignment_offset = alignment - (result_pointer & mask);
-
-	return alignment_offset;
-}
-
-gb_inline isize gb_arena_size_remaining(gbArena *arena, isize alignment) {
-	isize result = arena->total_size - (arena->total_allocated + gb_arena_alignment_of(arena, alignment));
-	return result;
-}
-
-gb_inline void gb_arena_check(gbArena *arena) { GB_ASSERT(arena->temp_count == 0); }
-
-
-
-
-
-
-gb_inline gbAllocator gb_arena_allocator(gbArena *arena) {
-	gbAllocator allocator;
-	allocator.proc = gb_arena_allocator_proc;
-	allocator.data = arena;
-	return allocator;
-}
-
-GB_ALLOCATOR_PROC(gb_arena_allocator_proc) {
-	gbArena *arena = cast(gbArena *)allocator_data;
-	void *ptr = NULL;
-
-	gb_unused(old_size);
-
-	switch (type) {
-	case gbAllocation_Alloc: {
-		void *end = gb_pointer_add(arena->physical_start, arena->total_allocated);
-		isize total_size = size + alignment;
-
-		// NOTE(bill): Out of memory
-		if (arena->total_allocated + total_size > cast(isize)arena->total_size) {
-			gb_printf_err("Arena out of memory\n");
-			return NULL;
-		}
-
-		ptr = gb_align_forward(end, alignment);
-		arena->total_allocated += total_size;
-		if (flags & gbAllocatorFlag_ClearToZero)
-			gb_zero_size(ptr, size);
-	} break;
-
-	case gbAllocation_Free:
-		// NOTE(bill): Free all at once
-		// Use Temp_Arena_Memory if you want to free a block
-		break;
-
-	case gbAllocation_FreeAll:
-		arena->total_allocated = 0;
-		break;
-
-	case gbAllocation_Resize: {
-		// TODO(bill): Check if ptr is on top of stack and just extend
-		gbAllocator a = gb_arena_allocator(arena);
-		ptr = gb_default_resize_align(a, old_memory, old_size, size, alignment);
-	} break;
-	}
-	return ptr;
-}
-
-
-gb_inline gbTempArenaMemory gb_temp_arena_memory_begin(gbArena *arena) {
-	gbTempArenaMemory tmp;
-	tmp.arena = arena;
-	tmp.original_count = arena->total_allocated;
-	arena->temp_count++;
-	return tmp;
-}
-
-gb_inline void gb_temp_arena_memory_end(gbTempArenaMemory tmp) {
-	GB_ASSERT_MSG(tmp.arena->total_allocated >= tmp.original_count,
-	              "%td >= %td", tmp.arena->total_allocated, tmp.original_count);
-	GB_ASSERT(tmp.arena->temp_count > 0);
-	tmp.arena->total_allocated = tmp.original_count;
-	tmp.arena->temp_count--;
-}
-
-
-
-
-//
-// Pool Allocator
-//
-
-
-gb_inline void gb_pool_init(gbPool *pool, gbAllocator backing, isize num_blocks, isize block_size) {
-	gb_pool_init_align(pool, backing, num_blocks, block_size, GB_DEFAULT_MEMORY_ALIGNMENT);
-}
-
-void gb_pool_init_align(gbPool *pool, gbAllocator backing, isize num_blocks, isize block_size, isize block_align) {
-	isize actual_block_size, pool_size, block_index;
-	void *data, *curr;
-	uintptr *end;
-
-	gb_zero_item(pool);
-
-	pool->backing = backing;
-	pool->block_size = block_size;
-	pool->block_align = block_align;
-
-	actual_block_size = block_size + block_align;
-	pool_size = num_blocks * actual_block_size;
-
-	data = gb_alloc_align(backing, pool_size, block_align);
-
-	// NOTE(bill): Init intrusive freelist
-	curr = data;
-	for (block_index = 0; block_index < num_blocks-1; block_index++) {
-		uintptr *next = cast(uintptr *)curr;
-		*next = cast(uintptr)curr + actual_block_size;
-		curr = gb_pointer_add(curr, actual_block_size);
-	}
-
-	end  = cast(uintptr *)curr;
-	*end = cast(uintptr)NULL;
-
-	pool->physical_start = data;
-	pool->free_list      = data;
-}
-
-gb_inline void gb_pool_free(gbPool *pool) {
-	if (pool->backing.proc) {
-		gb_free(pool->backing, pool->physical_start);
-	}
-}
-
-
-gb_inline gbAllocator gb_pool_allocator(gbPool *pool) {
-	gbAllocator allocator;
-	allocator.proc = gb_pool_allocator_proc;
-	allocator.data = pool;
-	return allocator;
-}
-GB_ALLOCATOR_PROC(gb_pool_allocator_proc) {
-	gbPool *pool = cast(gbPool *)allocator_data;
-	void *ptr = NULL;
-
-	gb_unused(old_size);
-
-	switch (type) {
-	case gbAllocation_Alloc: {
-		uintptr next_free;
-		GB_ASSERT(size      == pool->block_size);
-		GB_ASSERT(alignment == pool->block_align);
-		GB_ASSERT(pool->free_list != NULL);
-
-		next_free = *cast(uintptr *)pool->free_list;
-		ptr = pool->free_list;
-		pool->free_list = cast(void *)next_free;
-		pool->total_size += pool->block_size;
-		if (flags & gbAllocatorFlag_ClearToZero)
-			gb_zero_size(ptr, size);
-	} break;
-
-	case gbAllocation_Free: {
-		uintptr *next;
-		if (old_memory == NULL) return NULL;
-
-		next = cast(uintptr *)old_memory;
-		*next = cast(uintptr)pool->free_list;
-		pool->free_list = old_memory;
-		pool->total_size -= pool->block_size;
-	} break;
-
-	case gbAllocation_FreeAll:
-		// TODO(bill):
-		break;
-
-	case gbAllocation_Resize:
-		// NOTE(bill): Cannot resize
-		GB_PANIC("You cannot resize something allocated by with a pool.");
-		break;
-	}
-
-	return ptr;
-}
-
-
-
-
-
-gb_inline gbAllocationHeader *gb_allocation_header(void *data) {
-	isize *p = cast(isize *)data;
-	while (p[-1] == cast(isize)(-1)) {
-		p--;
-	}
-	return cast(gbAllocationHeader *)p - 1;
-}
-
-gb_inline void gb_allocation_header_fill(gbAllocationHeader *header, void *data, isize size) {
-	isize *ptr;
-	header->size = size;
-	ptr = cast(isize *)(header + 1);
-	while (cast(void *)ptr < data) {
-		*ptr++ = cast(isize)(-1);
-	}
-}
-
-
-
-//
-// Free List Allocator
-//
-
-gb_inline void gb_free_list_init(gbFreeList *fl, void *start, isize size) {
-	GB_ASSERT(size > gb_size_of(gbFreeListBlock));
-
-	fl->physical_start   = start;
-	fl->total_size       = size;
-	fl->curr_block       = cast(gbFreeListBlock *)start;
-	fl->curr_block->size = size;
-	fl->curr_block->next = NULL;
-}
-
-
-gb_inline void gb_free_list_init_from_allocator(gbFreeList *fl, gbAllocator backing, isize size) {
-	void *start = gb_alloc(backing, size);
-	gb_free_list_init(fl, start, size);
-}
-
-
-
-gb_inline gbAllocator gb_free_list_allocator(gbFreeList *fl) {
-	gbAllocator a;
-	a.proc = gb_free_list_allocator_proc;
-	a.data = fl;
-	return a;
-}
-
-GB_ALLOCATOR_PROC(gb_free_list_allocator_proc) {
-	gbFreeList *fl = cast(gbFreeList *)allocator_data;
-	void *ptr = NULL;
-
-	GB_ASSERT_NOT_NULL(fl);
-
-	switch (type) {
-	case gbAllocation_Alloc: {
-		gbFreeListBlock *prev_block = NULL;
-		gbFreeListBlock *curr_block = fl->curr_block;
-
-		while (curr_block) {
-			isize total_size;
-			gbAllocationHeader *header;
-
-			total_size = size + alignment + gb_size_of(gbAllocationHeader);
-
-			if (curr_block->size < total_size) {
-				prev_block = curr_block;
-				curr_block = curr_block->next;
-				continue;
-			}
-
-			if (curr_block->size - total_size <= gb_size_of(gbAllocationHeader)) {
-				total_size = curr_block->size;
-
-				if (prev_block)
-					prev_block->next = curr_block->next;
-				else
-					fl->curr_block = curr_block->next;
-			} else {
-				// NOTE(bill): Create a new block for the remaining memory
-				gbFreeListBlock *next_block;
-				next_block = cast(gbFreeListBlock *)gb_pointer_add(curr_block, total_size);
-
-				GB_ASSERT(cast(void *)next_block < gb_pointer_add(fl->physical_start, fl->total_size));
-
-				next_block->size = curr_block->size - total_size;
-				next_block->next = curr_block->next;
-
-				if (prev_block)
-					prev_block->next = next_block;
-				else
-					fl->curr_block = next_block;
-			}
-
-
-			// TODO(bill): Set Header Info
-			header = cast(gbAllocationHeader *)curr_block;
-			ptr = gb_align_forward(header+1, alignment);
-			gb_allocation_header_fill(header, ptr, size);
-
-			fl->total_allocated += total_size;
-			fl->allocation_count++;
-
-
-			if (flags & gbAllocatorFlag_ClearToZero)
-				gb_zero_size(ptr, size);
-			return ptr;
-		}
-		// NOTE(bill): if ptr == NULL, ran out of free list memory! FUCK!
-		return NULL;
-	} break;
-
-	case gbAllocation_Free: {
-		gbAllocationHeader *header = gb_allocation_header(old_memory);
-		isize block_size = header->size;
-		uintptr block_start, block_end;
-		gbFreeListBlock *prev_block = NULL;
-		gbFreeListBlock *curr_block = fl->curr_block;
-
-		block_start = cast(uintptr)header;
-		block_end   = cast(uintptr)block_start + block_size;
-
-		while (curr_block) {
-			if (cast(uintptr)curr_block >= block_end)
-				break;
-			prev_block = curr_block;
-			curr_block = curr_block->next;
-		}
-
-		if (prev_block == NULL) {
-			prev_block = cast(gbFreeListBlock *)block_start;
-			prev_block->size = block_size;
-			prev_block->next = fl->curr_block;
-
-			fl->curr_block = prev_block;
-		} else if ((cast(uintptr)prev_block + prev_block->size) == block_start) {
-			prev_block->size += block_size;
-		} else {
-			gbFreeListBlock *tmp = cast(gbFreeListBlock *)block_start;
-			tmp->size = block_size;
-			tmp->next = prev_block->next;
-			prev_block->next = tmp;
-
-			prev_block = tmp;
-		}
-
-		if (curr_block && (cast(uintptr)curr_block == block_end)) {
-			prev_block->size += curr_block->size;
-			prev_block->next = curr_block->next;
-		}
-
-		fl->allocation_count--;
-		fl->total_allocated -= block_size;
-	} break;
-
-	case gbAllocation_FreeAll:
-		gb_free_list_init(fl, fl->physical_start, fl->total_size);
-		break;
-
-	case gbAllocation_Resize:
-		ptr = gb_default_resize_align(gb_free_list_allocator(fl), old_memory, old_size, size, alignment);
-		break;
-	}
-
-	return ptr;
-}
-
-
-
-void gb_scratch_memory_init(gbScratchMemory *s, void *start, isize size) {
-	s->physical_start = start;
-	s->total_size     = size;
-	s->alloc_point    = start;
-	s->free_point     = start;
-}
-
-
-b32 gb_scratch_memory_is_in_use(gbScratchMemory *s, void *ptr) {
-	if (s->free_point == s->alloc_point) return false;
-	if (s->alloc_point > s->free_point)
-		return ptr >= s->free_point && ptr < s->alloc_point;
-	return ptr >= s->free_point || ptr < s->alloc_point;
-}
-
-
-gbAllocator gb_scratch_allocator(gbScratchMemory *s) {
-	gbAllocator a;
-	a.proc = gb_scratch_allocator_proc;
-	a.data = s;
-	return a;
-}
-
-GB_ALLOCATOR_PROC(gb_scratch_allocator_proc) {
-	gbScratchMemory *s = cast(gbScratchMemory *)allocator_data;
-	void *ptr = NULL;
-	GB_ASSERT_NOT_NULL(s);
-
-	switch (type) {
-	case gbAllocation_Alloc: {
-		void *pt = s->alloc_point;
-		gbAllocationHeader *header = cast(gbAllocationHeader *)pt;
-		void *data = gb_align_forward(header+1, alignment);
-		void *end = gb_pointer_add(s->physical_start, s->total_size);
-
-		GB_ASSERT(alignment % 4 == 0);
-		size = ((size + 3)/4)*4;
-		pt = gb_pointer_add(pt, size);
-
-		// NOTE(bill): Wrap around
-		if (pt > end) {
-			header->size = gb_pointer_diff(header, end) | GB_ISIZE_HIGH_BIT;
-			pt = s->physical_start;
-			header = cast(gbAllocationHeader *)pt;
-			data = gb_align_forward(header+1, alignment);
-			pt = gb_pointer_add(pt, size);
-		}
-
-		if (!gb_scratch_memory_is_in_use(s, pt)) {
-			gb_allocation_header_fill(header, pt, gb_pointer_diff(header, pt));
-			s->alloc_point = cast(u8 *)pt;
-			ptr = data;
-		}
-
-		if (flags & gbAllocatorFlag_ClearToZero)
-			gb_zero_size(ptr, size);
-	} break;
-
-	case gbAllocation_Free: {
-		if (old_memory) {
-			void *end = gb_pointer_add(s->physical_start, s->total_size);
-			if (old_memory < s->physical_start || old_memory >= end) {
-				GB_ASSERT(false);
-			} else {
-				// NOTE(bill): Mark as free
-				gbAllocationHeader *h = gb_allocation_header(old_memory);
-				GB_ASSERT((h->size & GB_ISIZE_HIGH_BIT) == 0);
-				h->size = h->size | GB_ISIZE_HIGH_BIT;
-
-				while (s->free_point != s->alloc_point) {
-					gbAllocationHeader *header = cast(gbAllocationHeader *)s->free_point;
-					if ((header->size & GB_ISIZE_HIGH_BIT) == 0)
-						break;
-
-					s->free_point = gb_pointer_add(s->free_point, h->size & (~GB_ISIZE_HIGH_BIT));
-					if (s->free_point == end)
-						s->free_point = s->physical_start;
-				}
-			}
-		}
-	} break;
-
-	case gbAllocation_FreeAll:
-		s->alloc_point = s->physical_start;
-		s->free_point  = s->physical_start;
-		break;
-
-	case gbAllocation_Resize:
-		ptr = gb_default_resize_align(gb_scratch_allocator(s), old_memory, old_size, size, alignment);
-		break;
-	}
-
-	return ptr;
-}
-
-
-
-
-
-
 ////////////////////////////////////////////////////////////////
 //
 // Sorting

src/main.cpp

@@ -60,7 +60,6 @@ i32 system_exec_command_line_app(char const *name, char const *fmt, ...) {
 	isize const cmd_cap = 4096;
 	char cmd_line[cmd_cap] = {};
 	va_list va;
-	gbTempArenaMemory tmp;
 	String16 cmd;
 	i32 exit_code = 0;
 
@@ -80,10 +79,7 @@ i32 system_exec_command_line_app(char const *name, char const *fmt, ...) {
 		gb_printf_err("%.*s\n\n", cast(int)(cmd_len-1), cmd_line);
 	}
 
-	tmp = gb_temp_arena_memory_begin(&string_buffer_arena);
-	defer (gb_temp_arena_memory_end(tmp));
-
-	cmd = string_to_string16(string_buffer_allocator, make_string(cast(u8 *)cmd_line, cmd_len-1));
+	cmd = string_to_string16(permanent_allocator(), make_string(cast(u8 *)cmd_line, cmd_len-1));
 	if (CreateProcessW(nullptr, cmd.text,
 	                   nullptr, nullptr, true, 0, nullptr, nullptr,
 	                   &start_info, &pi)) {
@@ -2005,10 +2001,8 @@ int main(int arg_count, char const **arg_ptr) {
 	defer (timings_destroy(&global_timings));
 
 	TIME_SECTION("initialization");
-
-	arena_init(&permanent_arena, heap_allocator());
-	temp_allocator_init(&temporary_allocator_data, 16*1024*1024);
-	arena_init(&global_ast_arena, heap_allocator());
+	
+	virtual_memory_init();
 	mutex_init(&fullpath_mutex);
 
 	init_string_buffer_memory();
@@ -2187,7 +2181,7 @@ int main(int arg_count, char const **arg_ptr) {
 		return 1;
 	}
 
-	temp_allocator_free_all(&temporary_allocator_data);
+	arena_free_all(&temporary_arena);
 
 	TIME_SECTION("type check");
 
@@ -2200,7 +2194,7 @@ int main(int arg_count, char const **arg_ptr) {
 		return 1;
 	}
 
-	temp_allocator_free_all(&temporary_allocator_data);
+	arena_free_all(&temporary_arena);
 
 	if (build_context.generate_docs) {
 		if (global_error_collector.count != 0) {
@@ -2237,7 +2231,7 @@ int main(int arg_count, char const **arg_ptr) {
 	}
 	lb_generate_code(gen);
 
-	temp_allocator_free_all(&temporary_allocator_data);
+	arena_free_all(&temporary_arena);
 
 	switch (build_context.build_mode) {
 	case BuildMode_Executable:

src/parser.cpp

@@ -4784,9 +4784,8 @@ ParseFileError init_ast_file(AstFile *f, String fullpath, TokenPos *err_pos) {
 	isize const page_size = 4*1024;
 	isize block_size = 2*f->tokens.count*gb_size_of(Ast);
 	block_size = ((block_size + page_size-1)/page_size) * page_size;
-	block_size = gb_clamp(block_size, page_size, ARENA_DEFAULT_BLOCK_SIZE);
-
-	arena_init(&f->arena, heap_allocator(), block_size);
+	block_size = gb_clamp(block_size, page_size, DEFAULT_MINIMUM_BLOCK_SIZE);
+	f->arena.minimum_block_size = block_size;
 
 
 	array_init(&f->comments, heap_allocator(), 0, 0);

src/parser.hpp

@@ -95,7 +95,7 @@ struct AstFile {
 	AstPackage * pkg;
 	Scope *      scope;
 
-	Arena        arena;
+	Arena  arena;
 
 	Ast *        pkg_decl;
 	String       fullpath;
@@ -741,11 +741,10 @@ gb_inline bool is_ast_when_stmt(Ast *node) {
 	return node->kind == Ast_WhenStmt;
 }
 
-gb_global Arena global_ast_arena = {};
+gb_global gb_thread_local Arena global_ast_arena = {};
 
 gbAllocator ast_allocator(AstFile *f) {
 	Arena *arena = f ? &f->arena : &global_ast_arena;
-	// Arena *arena = &global_ast_arena;
 	return arena_allocator(arena);
 }
 

src/query_data.cpp

@@ -252,10 +252,7 @@ void print_query_data_as_json(QueryValue *value, bool format = true, isize inden
 		char const hex_table[] = "0123456789ABCDEF";
 		isize buf_len = name.len + extra + 2 + 1;
 
-		gbTempArenaMemory tmp = gb_temp_arena_memory_begin(&string_buffer_arena);
-		defer (gb_temp_arena_memory_end(tmp));
-
-		u8 *buf = gb_alloc_array(string_buffer_allocator, u8, buf_len);
+		u8 *buf = gb_alloc_array(temporary_allocator(), u8, buf_len);
 
 		isize j = 0;
 

src/string.cpp

@@ -1,11 +1,6 @@
-gb_global gbArena       string_buffer_arena = {};
-gb_global gbAllocator   string_buffer_allocator = {};
 gb_global BlockingMutex string_buffer_mutex = {};
 
 void init_string_buffer_memory(void) {
-	// NOTE(bill): This should be enough memory for file systems
-	gb_arena_init_from_allocator(&string_buffer_arena, heap_allocator(), gb_megabytes(1));
-	string_buffer_allocator = gb_arena_allocator(&string_buffer_arena);
 	mutex_init(&string_buffer_mutex);
 }