Repository: google/googletest
File: googletest/include/gtest/internal/gtest-port.h (C/C++)

Code before:
// These classes are only for testing Google Test's own constructs. Do
// not use them in user tests, either directly or indirectly.
template <typename T>
class ThreadWithParam : public ThreadWithParamBase {
 public:
  typedef void UserThreadFunc(T);

  ThreadWithParam(UserThreadFunc* func, T param, Notification* thread_can_start)
      : func_(func),
        param_(param),
        thread_can_start_(thread_can_start),
        finished_(false) {
    ThreadWithParamBase* const base = this;
    // The thread can be created only after all fields except thread_
    // have been initialized.
    GTEST_CHECK_POSIX_SUCCESS_(
        pthread_create(&thread_, nullptr, &ThreadFuncWithCLinkage, base));
  }
  ~ThreadWithParam() override { Join(); }

  void Join() {
    if (!finished_) {
      GTEST_CHECK_POSIX_SUCCESS_(pthread_join(thread_, nullptr));
      // Yield to the joining thread to ensure its destructors are run
      // before marking the thread as finished.
      sched_yield();
      finished_ = true;
    }
  }

  void Run() override {
    if (thread_can_start_ != nullptr) thread_can_start_->WaitForNotification();
    func_(param_);
  }

 private:
  UserThreadFunc* const func_;  // User-supplied thread function.
  const T param_;  // User-supplied parameter to the thread function.
  // When non-NULL, used to block execution until the controller thread
  // notifies.
  Notification* const thread_can_start_;
  bool finished_;  // true if and only if we know that the thread function has
                   // finished.
  pthread_t thread_;  // The native thread object.

  GTEST_DISALLOW_COPY_AND_ASSIGN_(ThreadWithParam);
};
# endif  // !GTEST_OS_WINDOWS && GTEST_HAS_PTHREAD ||
         // GTEST_HAS_MUTEX_AND_THREAD_LOCAL_

# if GTEST_HAS_MUTEX_AND_THREAD_LOCAL_

Review comment (suggestion):
Relying on sched_yield to get interleaving is almost never correct.  The joined thread should have its dtors run before join returns regardless.  I have serious concerns about this

Code after:
// not use them in user tests, either directly or indirectly.
template <typename T>
class ThreadWithParam : public ThreadWithParamBase {
 public:
  typedef void UserThreadFunc(T);

  ThreadWithParam(UserThreadFunc* func, T param, Notification* thread_can_start)
      : func_(func),
        param_(param),
        thread_can_start_(thread_can_start),
        finished_(false) {
    ThreadWithParamBase* const base = this;
    // The thread can be created only after all fields except thread_
    // have been initialized.
    GTEST_CHECK_POSIX_SUCCESS_(
        pthread_create(&thread_, nullptr, &ThreadFuncWithCLinkage, base));
  }
  ~ThreadWithParam() override { Join(); }

  void Join() {
    if (!finished_) {
      GTEST_CHECK_POSIX_SUCCESS_(pthread_join(thread_, nullptr));
      finished_ = true;
    }
  }

  void Run() override {
    if (thread_can_start_ != nullptr) thread_can_start_->WaitForNotification();
    func_(param_);
  }

 private:
  UserThreadFunc* const func_;  // User-supplied thread function.
  const T param_;  // User-supplied parameter to the thread function.
  // When non-NULL, used to block execution until the controller thread
  // notifies.
  Notification* const thread_can_start_;
  bool finished_;  // true if and only if we know that the thread function has
                   // finished.
  pthread_t thread_;  // The native thread object.

  GTEST_DISALLOW_COPY_AND_ASSIGN_(ThreadWithParam);
};
# endif  // !GTEST_OS_WINDOWS && GTEST_HAS_PTHREAD ||
         // GTEST_HAS_MUTEX_AND_THREAD_LOCAL_

# if GTEST_HAS_MUTEX_AND_THREAD_LOCAL_
// Mutex and ThreadLocal have already been imported into the namespace.
// Nothing to do here.

# elif GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_PHONE && !GTEST_OS_WINDOWS_RT