// vim: ft=c
#include <ttest.h>

#include <memory.h>
#undef P2V
#define P2V(addr) ((void *)((uintptr_t)(addr)+1))
#undef V2P
#define V2P(addr) ((uintptr_t)(addr)-1)
#include "pmm.c"

struct {
  uint8_t data[PAGE_SIZE];
}__attribute__((packed)) mem[2];

TEST(alloc_returns_freed_page)
{
  pmm_free(V2P(&mem[0]));
  uintptr_t a = pmm_alloc();
  ASSERT_EQ_PTR(a, V2P(&mem[0]));
}
TEST(alloc_returns_0_if_no_free_pages)
{
  uintptr_t a = pmm_alloc();
  ASSERT_EQ_PTR(a, 0);
}
TEST(alloc_zero_after_all_free_pages)
{
  pmm_free(V2P(&mem[0]));
  pmm_alloc();
  uintptr_t a = pmm_alloc();
  ASSERT_EQ_PTR(a, 0);
}

TEST(alloc_two_pages___first_page_is_not_zero)
{
  pmm_free(V2P(&mem[0]));
  pmm_free(V2P(&mem[1]));
  uintptr_t a = pmm_alloc();
  pmm_alloc();
  ASSERT_NEQ_PTR(a, 0);
}
TEST(alloc_two_pages___second_page_is_not_zero)
{
  pmm_free(V2P(&mem[0]));
  pmm_free(V2P(&mem[1]));
  pmm_alloc();
  uintptr_t a = pmm_alloc();
  ASSERT_NEQ_PTR(a, 0);
}
TEST(alloc_two_pages___doesnt_return_same_page_twice)
{
  pmm_free(V2P(&mem[0]));
  pmm_free(V2P(&mem[1]));
  uintptr_t a = pmm_alloc();
  uintptr_t b = pmm_alloc();
  ASSERT_NEQ_PTR(a, b);
}