add new filesHEADmaster

1 files changed, 38 insertions, 0 deletions

diff --git a/arena.c b/arena.c
new file mode 100644
index 0000000..03a1c1c
--- /dev/null
+++ b/arena.c
@@ -0,0 +1,38 @@
+#include "arena.h"
+#include "macros.h"
+#include "sys.h"
+
+struct arena alloc_arena(u64 capacity)
+{
+	/* TODO(pryazha): Find reasonable maximum capacity through testing */
+	assert(capacity <= (u64)gigabytes(16));
+	if (!capacity)
+		capacity = kilobytes(4);
+	void *memory = sys_alloc(capacity);
+	assert(memory);
+	return (struct arena){memory, capacity, 0};
+}
+
+void release_arena(struct arena *arena)
+{
+	assert(arena);
+	sys_free(arena->memory, arena->capacity);
+	arena->memory = 0;
+	arena->capacity = 0;
+	arena->used = 0;
+}
+
+void *push_arena(struct arena *arena, u64 size)
+{
+	assert(arena);
+	assert(arena->used + size <= arena->capacity);
+	void *memory = arena->memory + arena->used;
+	arena->used += size;
+	return memory;
+}
+
+void pop_arena(struct arena *arena, u64 size)
+{
+	assert(arena);
+	arena->used -= min(size, arena->used);
+}