//===--- Mutex.cpp - Mutex Tests ------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//

#include "swift/Threading/Mutex.h"
#include "gtest/gtest.h"
#include <atomic>
#include <chrono>
#include <map>
#include <random>

#include "ThreadingHelpers.h"

using namespace swift;

// -----------------------------------------------------------------------------

template <typename M> void basicLockableThreaded(M &mutex) {
  int count1 = 0;
  int count2 = 0;

  threadedExecute(10, [&](int) {
    for (int j = 0; j < 50; ++j) {
      mutex.lock();
      auto count = count2;
      count1++;
      count2 = count + 1;
      mutex.unlock();
    }
  });

  ASSERT_EQ(count1, 500);
  ASSERT_EQ(count2, 500);
}

TEST(MutexTest, BasicLockableThreaded) {
  Mutex mutex(/* checked = */ true);
  basicLockableThreaded(mutex);
}

TEST(LazyMutexTest, BasicLockableThreaded) {
  static LazyMutex mutex;
  basicLockableThreaded(mutex);
}

TEST(LazyUnsafeMutexTest, BasicLockableThreaded) {
  static LazyUnsafeMutex mutex;
  basicLockableThreaded(mutex);
}

TEST(SmallMutex, BasicLockableThreaded) {
  SmallMutex mutex;
  basicLockableThreaded(mutex);
}

template <typename M> void lockableThreaded(M &mutex) {
  mutex.lock();
  threadedExecute(5, [&](int) { ASSERT_FALSE(mutex.try_lock()); });
  mutex.unlock();
  threadedExecute(1, [&](int) {
    ASSERT_TRUE(mutex.try_lock());
    mutex.unlock();
  });

  int count1 = 0;
  int count2 = 0;
  threadedExecute(10, [&](int) {
    for (int j = 0; j < 50; ++j) {
      if (mutex.try_lock()) {
        auto count = count2;
        count1++;
        count2 = count + 1;
        mutex.unlock();
      } else {
        j--;
      }
    }
  });

  ASSERT_EQ(count1, 500);
  ASSERT_EQ(count2, 500);
}

TEST(MutexTest, LockableThreaded) {
  Mutex mutex(/* checked = */ true);
  lockableThreaded(mutex);
}

TEST(LazyMutexTest, LockableThreaded) {
  static LazyMutex Mutex;
  lockableThreaded(Mutex);
}

TEST(SmallMutexTest, LockableThreaded) {
  SmallMutex Mutex;
  lockableThreaded(Mutex);
}

template <typename SL, typename M> void scopedLockThreaded(M &mutex) {
  int count1 = 0;
  int count2 = 0;

  threadedExecute(10, [&](int) {
    for (int j = 0; j < 50; ++j) {
      SL guard(mutex);
      auto count = count2;
      count1++;
      count2 = count + 1;
    }
  });

  ASSERT_EQ(count1, 500);
  ASSERT_EQ(count2, 500);
}

TEST(MutexTest, ScopedLockThreaded) {
  Mutex mutex(/* checked = */ true);
  scopedLockThreaded<Mutex::ScopedLock>(mutex);
}

TEST(LazyMutexTest, ScopedLockThreaded) {
  static LazyMutex Mutex;
  scopedLockThreaded<LazyMutex::ScopedLock>(Mutex);
}

TEST(SmallMutexTest, ScopedLockThreaded) {
  SmallMutex mutex(/* checked = */ true);
  scopedLockThreaded<ScopedLockT<SmallMutex, false>>(mutex);
}

template <typename SL, typename SU, typename M>
void scopedUnlockUnderScopedLockThreaded(M &mutex) {
  int count1 = 0;
  int count2 = 0;
  int badCount = 0;

  threadedExecute(10, [&](int) {
    for (int j = 0; j < 50; ++j) {
      SL guard(mutex);
      {
        SU unguard(mutex);
        badCount++;
      }
      auto count = count2;
      count1++;
      count2 = count + 1;
    }
  });

  ASSERT_EQ(count1, 500);
  ASSERT_EQ(count2, 500);
}

TEST(MutexTest, ScopedUnlockUnderScopedLockThreaded) {
  Mutex mutex(/* checked = */ true);
  scopedUnlockUnderScopedLockThreaded<Mutex::ScopedLock, Mutex::ScopedUnlock>(
      mutex);
}

TEST(LazyMutexTest, ScopedUnlockUnderScopedLockThreaded) {
  static LazyMutex Mutex;
  scopedUnlockUnderScopedLockThreaded<LazyMutex::ScopedLock,
                                      LazyMutex::ScopedUnlock>(Mutex);
}

TEST(SmallMutexTest, ScopedUnlockUnderScopedLockThreaded) {
  SmallMutex mutex(/* checked = */ true);
  scopedUnlockUnderScopedLockThreaded<SmallMutex::ScopedLock,
                                      SmallMutex::ScopedUnlock>(mutex);
}

template <typename M> void criticalSectionThreaded(M &mutex) {
  int count1 = 0;
  int count2 = 0;

  threadedExecute(10, [&](int) {
    for (int j = 0; j < 50; ++j) {
      mutex.withLock([&] {
        auto count = count2;
        count1++;
        count2 = count + 1;
      });
    }
  });

  ASSERT_EQ(count1, 500);
  ASSERT_EQ(count2, 500);
}

TEST(MutexTest, CriticalSectionThreaded) {
  Mutex mutex(/* checked = */ true);
  criticalSectionThreaded(mutex);
}

TEST(LazyMutexTest, CriticalSectionThreaded) {
  static LazyMutex Mutex;
  criticalSectionThreaded(Mutex);
}

template <typename SRL, bool Locking, typename RW>
void scopedReadThreaded(RW &lock) {
  const int threadCount = 10;

  std::set<int> writerHistory;
  std::vector<std::set<int>> readerHistory;
  readerHistory.assign(threadCount, std::set<int>());

  int protectedValue = 0;
  writerHistory.insert(protectedValue);

  threadedExecute(threadCount,
                  [&](int index) {
                    if (Locking) {
                      for (int i = 0; i < 50; ++i) {
                        {
                          SRL guard(lock);
                          readerHistory[index].insert(protectedValue);
                        }
                        std::this_thread::yield();
                      }
                    } else {
                      lock.readLock();
                      for (int i = 0; i < 50; ++i) {
                        readerHistory[index].insert(protectedValue);

                        {
                          SRL unguard(lock);
                          std::this_thread::yield();
                        }
                      }
                      lock.readUnlock();
                    }
                  },
                  [&] {
                    for (int i = 0; i < 25; ++i) {
                      lock.writeLock();
                      protectedValue += i;
                      writerHistory.insert(protectedValue);
                      lock.writeUnlock();
                    }
                  });

  for (auto &history : readerHistory) {
    for (auto value : history) {
      ASSERT_EQ(writerHistory.count(value), 1U);
    }
  }
}