/*

 * Copyright (c) 2015, 2017, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

#include "precompiled.hpp"

#include "runtime/semaphore.hpp"

#include "unittest.hpp"

static void test_semaphore_single_separate(uint count) {

  Semaphore sem(0);

  for (uint i = 0; i < count; i++) {

    sem.signal();

  }

  for (uint i = 0; i < count; i++) {

    sem.wait();

  }

}

static void test_semaphore_single_combined(uint count) {

  Semaphore sem(0);

  for (uint i = 0; i < count; i++) {

    sem.signal();

    sem.wait();

  }

}

static void test_semaphore_many(uint value, uint max, uint increments) {

  Semaphore sem(value);

  uint total = value;

  for (uint i = value; i + increments <= max; i += increments) {

    sem.signal(increments);

    total += increments;

  }

  for (uint i = 0; i < total; i++) {

    sem.wait();

  }

}

static void test_semaphore_trywait(uint value, uint max) {

  Semaphore sem(value);

  for (uint i = 0; i < max; ++i) {

    if (i < value) {

      ASSERT_EQ(sem.trywait(), true);

    } else {

      ASSERT_EQ(sem.trywait(), false);

    }

  }

}

TEST(Semaphore, single_separate) {

  for (uint i = 1; i < 10; i++) {

    test_semaphore_single_separate(i);

  }

}

TEST(Semaphore, single_combined) {

  for (uint i = 1; i < 10; i++) {

    test_semaphore_single_combined(i);

  }

}

TEST(Semaphore, many) {

  for (uint max = 0; max < 10; max++) {

    for (uint value = 0; value < max; value++) {

      for (uint inc = 1; inc <= max - value; inc++) {

        test_semaphore_many(value, max, inc);

      }

    }

  }

}

TEST(Semaphore, trywait) {

  for (uint max = 0; max < 10; max++) {

    for (uint value = 0; value < max; value++) {

      test_semaphore_trywait(value, max);

    }

  }

}