//===-- Unittests for a freelist --------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#include <stddef.h>

#include "src/__support/freelist.h"
#include "test/UnitTest/Test.h"

using LIBC_NAMESPACE::Block;
using LIBC_NAMESPACE::FreeList;
using LIBC_NAMESPACE::cpp::byte;
using LIBC_NAMESPACE::cpp::optional;

TEST(LlvmLibcFreeList, FreeList) {
  byte mem[1024];
  optional<Block *> maybeBlock = Block::init(mem);
  ASSERT_TRUE(maybeBlock.has_value());
  Block *block1 = *maybeBlock;

  maybeBlock = block1->split(128);
  ASSERT_TRUE(maybeBlock.has_value());
  Block *block2 = *maybeBlock;

  maybeBlock = block2->split(128);
  ASSERT_TRUE(maybeBlock.has_value());

  FreeList list;
  list.push(block1);
  ASSERT_FALSE(list.empty());
  EXPECT_EQ(list.front(), block1);

  list.push(block2);
  EXPECT_EQ(list.front(), block1);

  list.pop();
  ASSERT_FALSE(list.empty());
  EXPECT_EQ(list.front(), block2);

  list.pop();
  ASSERT_TRUE(list.empty());

  list.push(block1);
  list.push(block2);
  list.remove(reinterpret_cast<FreeList::Node *>(block2->usable_space()));
  EXPECT_EQ(list.front(), block1);
  list.pop();
  ASSERT_TRUE(list.empty());
}