/*
 * @project      The CERN Tape Archive (CTA)
 * @copyright    Copyright © 2021-2022 CERN
 * @license      This program is free software, distributed under the terms of the GNU General Public
 *               Licence version 3 (GPL Version 3), copied verbatim in the file "COPYING". You can
 *               redistribute it and/or modify it under the terms of the GPL Version 3, or (at your
 *               option) any later version.
 *
 *               This program 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 for more details.
 *
 *               In applying this licence, CERN does not waive the privileges and immunities
 *               granted to it by virtue of its status as an Intergovernmental Organization or
 *               submit itself to any jurisdiction.
 */

#include <gtest/gtest.h>
#include <iostream>

#include "common/threading/RWLock.hpp"
#include "common/threading/RWLockRdLocker.hpp"
#include "common/threading/RWLockWrLocker.hpp"
#include "common/threading/Thread.hpp"

namespace unitTests {

class cta_threading_RWLockTest : public ::testing::Test {
protected:

  virtual void SetUp() {
  }

  virtual void TearDown() {
  }

  class RdLockerThread: public ::cta::threading::Thread {
  public:

    RdLockerThread(cta::threading::RWLock &lock, uint32_t &counter): m_lock(lock), m_counter(counter) {
    }

    void run() {
      cta::threading::RWLockRdLocker rdLocker(m_lock);

      // Just read the counter - do not write to it
      uint32_t copyOfCounter = m_counter;
      copyOfCounter++;
    }

  private:

    cta::threading::RWLock &m_lock;

    uint32_t &m_counter;
  };

  class WrLockerThread: public ::cta::threading::Thread {
  public:

    WrLockerThread(cta::threading::RWLock &lock, uint32_t &counter): m_lock(lock), m_counter(counter) {
    }

    void run() {
      cta::threading::RWLockWrLocker wrLocker(m_lock);
      m_counter++;
    }

  private:

    cta::threading::RWLock &m_lock;

    uint32_t &m_counter;
  };
};

TEST_F(cta_threading_RWLockTest, rdlock) {
  using namespace cta::threading;

  RWLock lock;

  lock.rdlock();
  lock.unlock();
}

TEST_F(cta_threading_RWLockTest, wrlock) {
  using namespace cta::threading;

  RWLock lock;

  lock.wrlock();
  lock.unlock();
}

TEST_F(cta_threading_RWLockTest, RWLockRdLocker) {
  using namespace cta::threading;

  RWLock lock;

  RWLockRdLocker rdLocker(lock);
}

TEST_F(cta_threading_RWLockTest, RWLockWrLocker) {
  using namespace cta::threading;

  RWLock lock;

  RWLockWrLocker wrLocker(lock);
}

TEST_F(cta_threading_RWLockTest, multiple_threads) {
  using namespace cta::threading;

  RWLock lock;
  uint32_t counter = 0;

  RdLockerThread rdLockerThreads[4] = {{lock, counter}, {lock, counter}, {lock, counter}, {lock, counter}};
  WrLockerThread wrLockerThreads[4] = {{lock, counter}, {lock, counter}, {lock, counter}, {lock, counter}};

  for(uint32_t i = 0; i <4; i++) {
    rdLockerThreads[i].start();
    wrLockerThreads[i].start();
  }
  for(uint32_t i = 0; i <4; i++) {
    rdLockerThreads[i].wait();
    wrLockerThreads[i].wait();
  }

  ASSERT_EQ(4, counter);
}

} // namespace unitTests